WorldWideScience

Sample records for hydrocarbon-like hoa cooking-related

  1. Characterization of Cooking-Related Aerosols

    Science.gov (United States)

    Niedziela, R. F.; Blanc, L. E.

    2010-12-01

    The temperatures at which food is cooked are usually high enough to drive oils and other organic compounds out of materials which are being prepared for consumption. As these compounds move away from the hot cooking surface and into the atmosphere, they can participate in chemical reactions or condense to form particles. Given the high concentration of cooking in urban areas, cooking-related aerosols likely contribute to the overall amount of particulate matter on a local scale. Reported here are results for the mid-infrared optical characterization of aerosols formed during the cooking of several meat and vegetable samples in an inert atmosphere. The samples were heated in a novel aerosol generator that is designed to collect particles formed immediately above the cooking surface and inject them into a laminar aerosol flow cell. Preliminary results for the chemical processing of cooking-related aerosols in synthetic air will also be presented.

  2. 78 FR 51208 - Request for Nominations for the Na Hoa Pili O Kaloko-Honokohau Advisory Commission

    Science.gov (United States)

    2013-08-20

    ... National Park Service Request for Nominations for the Na Hoa Pili O Kaloko-Honokohau Advisory Commission AGENCY: National Park Service, Interior. ACTION: Notice of Request for Nominations for the Na Hoa Pili O... Interior, proposes to appoint new members to the Na Hoa Pili O Kaloko-Honokohau (The Friends of...

  3. 76 FR 64103 - Request for Nominations for the Na Hoa Pili O Kaloko-Honokohau Advisory Commission

    Science.gov (United States)

    2011-10-17

    ... National Park Service Request for Nominations for the Na Hoa Pili O Kaloko-Honokohau Advisory Commission AGENCY: National Park Service, Interior. ACTION: Notice of request for nominations for the Na Hoa Pili O... Interior, proposes to appoint new members to the Na Hoa Pili O Kaloko-Honokohau (The Friends of...

  4. Generating Bijections between HOAS and the Natural Numbers

    CERN Document Server

    Boyland, John Tang

    2010-01-01

    A provably correct bijection between higher-order abstract syntax (HOAS) and the natural numbers enables one to define a "not equals" relationship between terms and also to have an adequate encoding of sets of terms, and maps from one term family to another. Sets and maps are useful in many situations and are preferably provided in a library of some sort. I have released a map and set library for use with Twelf which can be used with any type for which a bijection to the natural numbers exists. Since creating such bijections is tedious and error-prone, I have created a "bijection generator" that generates such bijections automatically together with proofs of correctness, all in the context of Twelf.

  5. Sarcophaga (Hoa)flexuosa Ho (Diptera: Sarcophagidae): association of sexes using morphological and molecular approaches, and a redefinition of Hoa Rohdendorf.

    Science.gov (United States)

    Zhang, Dong; Zhang, Ming; Pape, Thomas; Gu, Cai-Wei; Wu, Wei

    2013-01-01

    Sarcophaga flexuosa Ho, 1934 is the type species of the currently monotypic genus-group taxon Hoa Rohdendorf, 1937, which here is considered a subgenus of Sarcophaga Meigen, 1826. Using DNA sequences of mitochondrial genes (cytochrome oxidase I and cytochrome b), we positively identify, for the first time, the female of S. (H.)flexuosa. The female is described, the male is redescribed, and both sexes are illustrated using a combination of line drawings, photographs and scanning electron microscopy images. It is argued from the morphology of the male terminalia that Sarcophagaflexuosa is the sister taxon of Sarcophaga basiseta Baranov, 1931, and the subgenus Hoa is redefined to include both of these species.

  6. Impact of Homeowner Association (HOA) landscaping guidelines on residential water use

    Science.gov (United States)

    Wentz, Elizabeth A.; Rode, Sandra; Li, Xiaoxiao; Tellman, Elizabeth M.; Turner, B. L., II

    2016-05-01

    The association between increasing water intensive land-cover, such as the use of turf grass and trees, and increasing water use is a growing concern for water-stressed arid cities. Appropriate regulatory measures addressing residential landscaping, such as those applied by Homeowner Associations (HOAs), may serve to reduce municipal water use, joining other water-use reducing measures under consideration by arid cities. This research assesses quantitatively the role that Covenants, Conditions, and Restrictions (CCRs) applied to landscaping by HOAs play on water consumption. Statistical comparisons and models of n=1973 parcels in Goodyear, Arizona, USA, reveal that: HOA yards have less vegetation cover and those households use less peak-season water (July) than those households in non-HOA neighborhoods. This hold true even though the HOA CCRs regulate only the minimum required front-yard vegetation and most residents maintain more than the minimum vegetation level. Furthermore, front-yard landscaping tends to be mimicked in the backyard such that total yard landscaping tracks best with total household water use. Results of the study suggest that HOA landscaping regulations have the potential to reduce peak-season water use by up to 24% if CCRs were to set maximum vegetation regulations rather than minimum and if compliance were enforced. Lowering residential water consumption in this way potentially involves tradeoffs with the cooling effects of vegetation and its consequences on the urban heat island effect, on energy use, and on home values.

  7. Capture Efficiency of Cooking-Related Fine and Ultrafine Particles by Residential Exhaust Hoods

    Energy Technology Data Exchange (ETDEWEB)

    Lunden, Melissa M.; Delp, William W.

    2014-06-05

    Effective exhaust hoods can mitigate the indoor air quality impacts of pollutant emissions from residential cooking. This study reports capture efficiencies (CE) measured for cooking generated particles for scripted cooking procedures in a 121-m3 chamber with kitchenette. CEs also were measured for burner produced CO2 during cooking and separately for pots and pans containing water. The study used four exhaust hoods previously tested by Delp and Singer (Environ. Sci. Technol., 2012, 46, 6167-6173). For pan-frying a hamburger over medium heat on the back burner, CEs for particles were similar to those for burner produced CO2 and mostly above 80percent. For stir-frying green beans in a wok (high heat, front burner), CEs for burner CO2 during cooking varied by hood and airflow: CEs were 34-38percent for low (51?68 L s-1) and 54?72percent for high (109?138 L s-1) settings. CEs for 0.3?2.0 ?m particles during front burner stir-frying were 3?11percent on low and 16?70percent on high settings. Results indicate that CEs measured for burner CO2 are not predictive of CEs of cooking-generated particles under all conditions, but they may be suitable to identify devices with CEs above 80percent both for burner combustion products and for cooking-related particles.

  8. hoa Near Miss: Serendipity? Or Science?

    Science.gov (United States)

    Trusdell, F.; Orr, T. R.; Lee, R. L.

    2015-12-01

    The "June 27th" flow, named for the date on which it started, threatened communities on the lower East Rift Zone (ERZ) of Kīlauea Volcano, Hawaii, for several months during 2014-2015. The flow encroached on Pāhoa, threatening to cross the main street and sever Highway 130, which serves the rural communities on Kīlauea's south and east flanks. The rate of flow advance was influenced greatly by magma supply from the summit. Increases in ERZ discharge, presaged by inflationary summit tilt, resulted in flow advance of up to several hundred meters per day. When summit tilt switched to deflation, discharge waned and the flow slowed and often stalled, repeatedly stopping short of destroying critical infrastructure. When activity resumed, it typically did so as many small breakouts as far as a few km behind the flow front, which then had to resurface previously covered ground to extend the overall length of the flow. At the same time, lava near the flow front had a very spiny texture and was noticeably less fluid than lava closer to the vent, leading to speculation that physiochemical changes along the flow were limiting its length. In December 2014, we collected a suite of lava samples along the flow from near Pu`u `Ō`ō to its distal end (3 km to 18 km) to better understand the physiochemical changes along its length. The magma flux on that day was calculated at 90,000- 100,000 m3/day (~1 m3/s). Preliminary analyses of the samples reveal a down-flow decrease in lava vesicularity and temperature and a corresponding increase in density and microcrystallinity. We propose that the lava flow could only attain a length of ~21 km because of the changes in its apparent viscosity, for the calculated magma flux. The flows could not overcome the increasing downstream yield strength, and breakouts from the flow margins farther upslope were easier to achieve than forcing the front forward. These upslope breakouts were themselves limited in length by the same factors.

  9. Hair-inspired crystal growth of HOA in cavities of cellulose matrix via hydrophobic-hydrophilic interface interaction.

    Science.gov (United States)

    He, Meng; Kwok, Ryan T K; Wang, Zhenggang; Duan, Bo; Tang, Ben Zhong; Zhang, Lina

    2014-06-25

    As one of the most ordinary phenomena in nature, numerous pores on animal skins induce the growth of abundant hairs. In this study, cavities of a cellulose matrix were used as hard templates to lead the hair-inspired crystal growth of 12-hydroxyoctadecanoic acid (HOA) through hydrophobic-hydrophilic interface interaction, and short hair-like HOA crystals with a smooth surface were formed on cellulose films. In our findings, by using solvent evaporation induced crystallization, hydrophobic HOA grew along the hydrophilic cellulose pore wall to form regular vertical worm-like and pillar-like crystals with an average diameter of about 200 nm, depending on the experimental conditions and HOA concentration. The formation mechanism of the short hair-like HOA crystals as well as the structure and properties of the cellulose/HOA submicrometer composite films were studied. The pores of the cellulose matrix supplied not only cavities for the HOA crystals fixation but also hydrophilic shells to favor the vertical growth of the relatively hydrophobic HOA crystals. The cellulose/HOA submicrometer composite films exhibited high hydrophobicity, as a result of the formation of the solid/air composite surface. Furthermore, 4-(1,2,2-triphenylethenyl) benzoic acid, an aggregation-induced emission luminogen, was used to aggregate on the cellulose surface with HOA to emit and monitor the HOA crystal growth, showing bifunctional photoluminscence and self-cleaning properties. This work opens up a novel one-step pathway to design bio-inspired submicrometer materials by utilizing natural products, showing potential applications in self-cleaning optical devices.

  10. Simulation and optimisation modelling approach for operation of the Hoa Binh Reservoir, Vietnam

    DEFF Research Database (Denmark)

    Ngo, Long le; Madsen, Henrik; Rosbjerg, Dan

    2007-01-01

    Hoa Binh, the largest reservoir in Vietnam, plays an important role in flood control for the Red River delta and hydropower generation. Due to its multi-purpose character, conflicts and disputes in operating the reservoir have been ongoing since its construction, particularly in the flood season......, the hydro-meteorological conditions, and the time of the year. A heuristic global optimisation tool, the shuffled complex evolution (SCE) algorithm, is adopted for optimising the reservoir operation. The optimisation puts focus on the trade-off between flood control and hydropower generation for the Hoa....... This paper proposes to optimise the control strategies for the Hoa Binh reservoir operation by applying a combination of simulation and optimisation models. The control strategies are set up in the MIKE 11 simulation model to guide the releases of the reservoir system according to the current storage level...

  11. 77 FR 66864 - Notice of November 15, 2012, Meeting for Na Hoa Pili O Kaloko-Honokohau National Historical Park...

    Science.gov (United States)

    2012-11-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR National Park Service Notice of November 15, 2012, Meeting for Na Hoa Pili O Kaloko- Honokohau National.... SUMMARY: This notice sets forth the date of the November 15, 2012, meeting of the Na Hoa Pili O...

  12. Industrial application of HOA -03 type additive for producing more propylene%HOA-03增产丙烯助剂的工业应用

    Institute of Scientific and Technical Information of China (English)

    王巍慈

    2007-01-01

    在中国石油抚顺石化分公司120万t/a催化裂化装置中,以直馏蜡油、常压渣油和焦化蜡油为原料,采用LBO-16降烯烃催化剂,在加入HOA-03增产丙烯助剂后,可以提高丙烯收率.工业试验表明,当HOA-03增产丙烯助剂加入量占系统藏量5%时,与未添加者相比,前者液态烃中丙烯平均质量分数由39.3%升至44.5%,丙烯平均收率由4.55%升至5.83%;HOA-03增产丙烯助剂对主催化剂及产物性质无不良影响.

  13. Public health assessment of dioxin-contaminated fish at former US airbase, Bien Hoa, Vietnam.

    Science.gov (United States)

    Durant, James T; Boivin, Thomas G; Pohl, Hana R; Sinks, Thomas H

    2015-01-01

    Ponds at the former US airbase at Ben Hoa, Vietnam are contaminated with Agent Orange. The ponds had been used for aquaculture, and in all likelihood, fish from those ponds have been sold to the public. We assessed human exposure to 2,3,7,8-tetrachloro-dibenzo-dioxin (2,3,7,8-TCDD) in fish samples from the ponds. For on-base tilapia, muscle concentrations 2,3,7,8-TCDD ranged from 1.4 to 32.7 pg/g. Fat concentrations ranged from 73.3 to 3990 pg/g. Estimated human exposure doses exceed international guidelines and exceed 2,3,7,8-TCDD's lowest adverse effect levels. The Bien Hoa fishponds are a completed human pathway for TCDD exposure.

  14. Potential flood hazard assessment by integration of ALOS PALSAR and ASTER GDEM: a case study for the Hoa Chau commune, Hoa Vang district, in central Vietnam

    Science.gov (United States)

    Huong, Do Thi Viet; Nagasawa, Ryota

    2014-01-01

    The potential flood hazard was assessed for the Hoa Chau commune in central Vietnam in order to identify the high flood hazard zones for the decision makers who will execute future rural planning. A new approach for deriving the potential flood hazard based on integration of inundation and flow direction maps is described. Areas inundated in the historical flood event of 2007 were extracted from Advanced Land Observing Satellite (ALOS) phased array L-band synthetic aperture data radar (PALSAR) images, while flow direction characteristics were derived from the ASTER GDEM to extract the depressed surfaces. Past flood experience and the flow direction were then integrated to analyze and rank the potential flood hazard zones. The land use/cover map extracted from LANDSAT TM and flood depth point records from field surveys were utilized to check the possibility of susceptible inundated areas, extracting data from ALOS PALSAR and ranking the potential flood hazard. The estimation of potential flood hazard areas revealed that 17.43% and 17.36% of Hoa Chau had high and medium potential flood hazards, respectively. The flow direction and ALOS PALSAR data were effectively integrated for determining the potential flood hazard when hydrological and meteorological data were inadequate and remote sensing images taken during flood times were not available or were insufficient.

  15. 浅谈医院现代管理“利器”——HOA

    Institute of Scientific and Technical Information of China (English)

    陈腾云

    2012-01-01

    文章通过医院通过一种新型的办公系统——HOA,使得医院现代管理中各类信息在HOA平台进行快速有效的传递,提高办公效率,降低了医疗成本,并有效防范医疗纠纷,促进医患和谐.现就我院使用HOA平台的经验,对其在医院现代管理中所发挥的主要作用进行简要探讨.

  16. Probing magnetostructural correlations in multiferroic HoA l3(BO3) 4

    Science.gov (United States)

    Zhang, H.; Yu, T.; Chen, Z.; Nelson, C. S.; Bezmaternykh, L. N.; Abeykoon, A. M. M.; Tyson, T. A.

    2015-09-01

    The system HoA l3(BO3) 4 has recently been found to exhibit a large magnetoelectric effect. To understand the mechanism, macroscopic and atomic level properties of HoA l3(BO3) 4 were explored by temperature and magnetic field dependent heat capacity measurements, pressure and temperature dependent x-ray diffraction measurements, as well as temperature and magnetic field dependent x-ray absorption fine structure measurements. The experimental work was complemented by density functional theory calculations. An anomalous change in the structure is found in the temperature range where large magnetoelectric effects occur. No significant structural change or distortion of the Ho O6 polyhedra is seen to occur with magnetic field. However, the magnetic field dependent structural measurements reveal enhanced correlation between neighboring Ho O6 polyhedra. This observed response is seen to saturate near 3 T. A qualitative atomic level description of the mechanism behind the large electric polarization induced by magnetic fields in the general class of RA l3(BO3) 4 systems (R = rare earth) is developed.

  17. Food as a source of dioxin exposure in the residents of Bien Hoa City, Vietnam.

    Science.gov (United States)

    Schecter, Arnold; Quynh, Hoang Trong; Pavuk, Marian; Päpke, Olaf; Malisch, Rainer; Constable, John D

    2003-08-01

    Recently, elevated dioxin levels, over 5 parts per trillion (ppt) 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), from Agent Orange was reported in 95% of 43 selected residents of Bien Hoa City, a city in southern Vietnam near a former air base used for Agent Orange-spraying missions. Agent Orange herbicide, contaminated with TCDD, was sprayed in Vietnam between 1962 and 1971 primarily for use as a defoliant. Typical blood TCCD levels are 2 ppt in Vietnamese, but levels are as high as 413 ppt in Bien Hoa City. Elevated TCDD was found in children born many years after Agent Orange spraying ended and in immigrants from non-Agent Orange-sprayed parts of Vietnam, which documented new exposures. Extremely elevated soil TCDD samples, over 1 million ppt, and elevated TCDD in sediment were found in some nearby areas such as Bien Hung Lake. The primary route of intake of almost all dioxins in humans is food. However, in our prior studies in Bien Hoa, food was unavailable for dioxin analysis so the route of intake was not confirmed. In the 1970s, while Agent Orange was still being sprayed, elevated human milk TCDD levels as high as 1850 were detected in milk from Vietnamese people living in Agent Orange-sprayed areas where consumption of fish was high. Furthermore, also in the 1970s, elevated TCDD levels (up to 810 ppt) were found in fish and shrimp from the same area as the milk donors. In the 1980s, we found elevated TCDD and also other organohalogen levels in human tissue, pork, fish, a turtle, and a snake in Southern Vietnam. For these reasons, we recently collected food from Bien Hoa and analyzed it for dioxins, polychlorinated biphenyls (PCBs), DDT and its metabolites, and other organochlorines. We found marked elevation of TCDD, the dioxin characteristic of Agent Orange, in some of the food products, including ducks with 276 ppt and 331 ppt wet weight, chickens from 0.031-15 ppt wet weight, fish from 0.063-65 ppt wet weight, and a toad with 56 ppt wet weight. Usual TCDD

  18. 77 FR 77091 - Notice of February 22; May 17; August 23; and November 8, 2013, Meetings for Na Hoa Pili O Kaloko...

    Science.gov (United States)

    2012-12-31

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR National Park Service Notice of February 22; May 17; August 23; and November 8, 2013, Meetings for Na Hoa...; August 23; and November 8, 2013, meetings of the Na Hoa Pili O Kaloko- Honokohau National Historical...

  19. Infant growth disparity in the Khanh Hoa province in Vietnam: a follow-up study

    Directory of Open Access Journals (Sweden)

    Vaktskjold Arild

    2010-08-01

    Full Text Available Abstract Background Surveys in Vietnam have indicated that wasting and stunting have been prevalent among children, but the country is undergoing rapid socio-economic changes and little has been known about the relative situation in the different areas of the country. In 2006, the WHO introduced new growth standards applicable to all infant and child populations, which facilitates for improved assessments of the prevalence of growth impairment, independent of time, place and ethnicity. The aim of our study was to assess the growth of singleton infants delivered at term in three main birth clinics in the Khanh Hoa province in Vietnam by using the new WHO standards as reference, and the association between growth and some maternal, birth and health factors. Methods A cohort of 237 singleton infants born in the period May-July 2005 in three main delivery clinics in the Khanh Hoa province were observed prospectively. Their anthropometrical measures a year later were compared to the WHO sex-specific growth standards for weight-for-age, length-for-age, weight-for-length, and BMI-for-age. These measures were analysed as dependent outcomes using multiple linear regression models including the following independent factors: urban vs. rural birth, 1-minute Apgar score, weight and length at birth, duration of lactation, ever had diarrhoea, dengue fever, pneumonia or dysentery, and maternal age, height, gestational duration and parity. Results Compared to the standard distributions, 79% were below the median for weight-for-length; 18.0% were within the 5th percentile for length-for-age, 9.6% for weight-for-age, 20.3% for weight-for-length, and 19.8% for BMI. A lower length- and weight-for-age were statistically associated with being born rurally. Conclusions In this delivery-clinic based sample of children in the Khanh Hoa province in Vietnam, the proportions within the WHO-standard 5th percentiles for length-for-age, weight-for-length and BMI in late

  20. A new Cyrtodactylus (Squamata: Gekkonidae) from Khanh Hoa Province, southern Vietnam.

    Science.gov (United States)

    Schneider, Nicole; Phung, Trung My; Le, Minh Duc; Nguyen, Truong Quang; Ziegler, Thomas

    2014-04-07

    We describe a new species of the genus Cyrtodactylus from southern Vietnam, based on morphological and molecular datasets. Cyrtodactylus cucdongensis sp. nov. is described on the basis of seven specimens collected from Cuc Dong Cape, Khanh Hoa Province. The new species can be distinguished from the remaining bent-toed geckos by a combination of the following characters: maximum SVL 65.9 mm; 16-19 dorsal tubercle rows; 41-44 ventral scales at midbody; 5 or 6 precloacal pores in males, 4-6 pitted precloacal scales in females; no femoral pores; 6-13 enlarged precloacal scales; 5-9 enlarged femoral scales; no transversally enlarged subcaudals; dorsal pattern consisting of irregular dark bands. This is the 33rd species of Cyrtodactylus known from Vietnam.

  1. Two new species of Cyrtodactylus (Squamata: Gekkonidae) from the karst forest of Hoa Binh Province, Vietnam.

    Science.gov (United States)

    Nguyen, Truong Quang; Le, Minh Duc; Pham, Anh Van; Ngo, Hai Ngoc; Hoang, Chung Van; Ziegler, Thomas

    2015-07-13

    We describe two new species of the genus Cyrtodactylus on the basis of a new reptile collection from the limestone karst forest of Hoa Binh Province, northwestern Vietnam. Cyrtodactylus otai sp. nov. from Hang Kia-Pa Co Nature Reserve and Cyrtodactylus bobrovi sp. nov. from Ngoc Son-Ngo Luong Nature Reserve can be distinguished from each other and from their congeners by their genetic distinction and morphological differences in number of precloacal pores, femoral scales, ventral scales, lamellae, subcaudals and dorsal tubercle arrangement, as well as in size and color pattern. In phylogenetic analyses, both new species are nested in a clade containing taxa from northwestern and northcentral Vietnam and northern Laos, i.e., C. bichnganae and C. cf. martini from northwestern Vietnam, C. puhuensis from northcentral Vietnam, and C. spelaeus, C. vilaphongi, and C. wayakonei from northern Laos.

  2. Environmental Health Risk Assessment of Dioxin Exposure through Foods in a Dioxin Hot Spot—Bien Hoa City, Vietnam

    OpenAIRE

    Tran Thi Tuyet-Hanh; Le Vu-Anh; Nguyen Ngoc-Bich; Thomas Tenkate

    2010-01-01

    This study used the Australian Environmental Health Risk Assessment Framework to assess the human health risk of dioxin exposure through foods for local residents in two wards of Bien Hoa City, Vietnam. These wards are known hot-spots for dioxin and a range of stakeholders from central government to local levels were involved in this process. Publications on dioxin characteristics and toxicity were reviewed and dioxin concentrations in local soil, mud, foods, milk and blood samples were used ...

  3. Impact of the Hoa Binh dam (Vietnam) on water and sediment budgets in the Red River basin and delta

    Science.gov (United States)

    Vinh, V. D.; Ouillon, S.; Thanh, T. D.; Chu, L. V.

    2014-10-01

    The Hoa Binh dam (HBD), located on a tributary of the Red River in Vietnam, has a capacity of 9.45 × 109 m3 and was commissioned in December 1988. Although it is important for flood prevention, electricity production and irrigation in northern Vietnam, the Hoa Binh dam has also highly influenced the suspended sediment distribution in the lower Red River basin, in the delta and in the coastal zone. Its impact was analysed from a 50-year data set of water discharge and suspended sediment concentration (1960-2010), and the distribution of water and sediment across the nine mouths of the delta was simulated using the MIKE11 numerical model before and after the dam settlement. Although water discharge at the delta inlet decreased by only 9%, the yearly suspended sediment flux dropped, on average, by 61% at Son Tay near Hanoi (from 119 to 46 × 106 t yr-1). Along the coast, reduced sedimentation rates are coincident with the lower sediment delivery observed since the impoundment of the Hoa Binh dam. Water regulation has led to decreased water discharge in the wet season (-14% in the Red River at Son Tay) and increased water discharge in the dry season (+12% at the same station). The ratios of water and suspended sediment flows, as compared to the total flows in the nine mouths, increased in the northern and southern estuaries and decreased in the central, main Ba Lat mouth. The increasing volume of dredged sediments in the Haiphong harbour is evidence of the silting up of the northern estuary of Cam-Bach Dang. The effect of tidal pumping on enhanced flow occurring in the dry season and resulting from changed water regulation is discussed as a possible cause of the enhanced siltation of the estuary after Hoa Binh dam impoundment.

  4. Predictors for dioxin accumulation in residents living in Da Nang and Bien Hoa, Vietnam, many years after Agent Orange use.

    Science.gov (United States)

    Pham, Diem T; Nguyen, Hang M; Boivin, Thomas G; Zajacova, Anna; Huzurbazar, Snehalata V; Bergman, Harold L

    2015-01-01

    Agent Orange (AO) was the main defoliant used by the US in Vietnam from 1961 to 1971; AO was contaminated with dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD). Three major dioxin “hot spots” remain from previous AO storage and use at former US bases at Bien Hoa, Da Nang, and Phu Cat, posing potential health risks for Vietnamese living on or near these hot spots. We evaluated potential risk factors contributing to serum TCDD levels in Vietnamese residents at and near contaminated sites in Da Nang and Bien Hoa, Vietnam. We used multiple linear regression to analyze possible associations of blood dioxin concentrations with demographic, socioeconomic, lifestyle, and dietary risk factors for residents living on or near these hot spots. For the Da Nang study, fish farming on the site, living on property flooded from monsoon rains, and age were among the factors showing significant positive associations with serum TCDD concentrations. For the Bien Hoa study, fish farmers working at this site and their immediate family members had significantly higher serum TCDD concentrations. Our results suggest that water-related activities, especially fish-farming, at the hot spots increased the risk of exposure to dioxin.

  5. Strengthening emergency obstetric care in Thanh Hoa and Quang Tri provinces in Vietnam.

    Science.gov (United States)

    Otchere, S A; Binh, H T

    2007-11-01

    Save the Children/USA and the Ministry of Health of Vietnam undertook a project between 2001 and 2004 to improve the availability of, access to, quality and utilization of emergency obstetric care (EmOC) services at district and provincial hospitals in two provinces in Vietnam. The project improved the functional capacity of 3 provincial and 1 district hospitals providing comprehensive EmOC services, and upgraded 1 district hospital providing basic EmOC into a comprehensive EmOC facility through training, infrastructure and quality improvement. Data presented in this paper focus on only the 2 district hospitals even though the UN process indicators showed increases in utilization of EmOC in all 5 hospitals. In the case of Hai Lang, the proportion of births increased from 13% at baseline to 31% at the end of 2004, and met need increased significantly from 16% to 87% largely due to increased capacity of the hospital and staff. Met need in Hoang Hoa hospital more than doubled (17% at baseline versus 54% in 2004) and the proportion of births increased slightly from 19% in 2001 to 22% in 2004. Case fatality rates for the two hospitals remarkably remained at zero. Lessons from this project have been incorporated into national policy and guidelines. Improvements in the capacity of existing health facilities to treat complications in pregnancy and childbirth can be realized in a relatively short period of time and is an essential element in reducing maternal mortality.

  6. Evaluation of three adolescent sexual health programs in ha noi and khanh hoa province, Vietnam.

    Science.gov (United States)

    Pham, Van; Nguyen, Hoang; Tho, Le Huu; Minh, Truong Tan; Lerdboon, Porntip; Riel, Rosemary; Green, Mackenzie S; Kaljee, Linda M

    2012-01-01

    With an increase in sexual activity among young adults in Vietnam and associated risks, there is a need for evidence-based sexual health interventions. This evaluation of three sexual health programs based on the Protection Motivation Theory (PMT) was conducted in 12 communes in Ha Noi, Nha Trang City, and Ninh Hoa District. Inclusion criteria included unmarried youth 15-20 years residing in selected communes. Communes were randomly allocated to an intervention, and participants were randomly selected within each commune. The intervention programs included Vietnamese Focus on Kids (VFOK), the gender-based program Exploring the World of Adolescents (EWA), and EWA plus parental and health provider education (EWA+). Programs were delivered over a ten-week period in the communities by locally trained facilitators. The gender-based EWA program with parental involvement (EWA+) compared to VFOK showed significantly greater increase in knowledge. EWA+ in comparison to VFOK also showed significant decrease at immediate postintervention for intention to have sex. Sustained changes are observed in all three interventions for self-efficacy condom use, self-efficacy abstinence, response efficacy for condoms, extrinsic rewards, and perceived vulnerability for HIV. These findings suggest that theory-based community programs contribute to sustained changes in knowledge and attitudes regarding sexual risk among Vietnamese adolescents.

  7. Vertical distribution of dioxins in soil of Bien Hoa airbase, Vietnam.

    Science.gov (United States)

    Huyen, Dang Thuong; Igarashi, Toshifumi; Shiraiwa, Takuya

    2015-01-01

    Bien Hoa airbase is a known dioxin-contaminated hotspot in Vietnam. The contamination occurred during the Vietnam War at the site where dioxins were transported, stored, sprayed, and spilled in the area. Dioxins, which are cancer inducing substances, may transfer from the soil to food crops and finally to human beings living around the area. Many surveys of dioxins in soil, water, organisms, and human have been carried out in this study area since 2002. In this paper vertical distribution of dioxins in undisturbed soil cores were examined. Twelve soil samples from three drilled cores were collected to analyze dioxin levels according to the standard Japanese analytical method. The results showed that the toxicity equivalency quantity (TEQ) in one soil sample at a depth of 2.6 m reached 3,300 pg-TEQ/g-dw. High TEQs were also observed in the clay layer. This anomaly of dioxin concentrations could be attributed to the affinity of dioxins for the clay layer. The isomer patterns in the soils were different from those in the soil of Hokkaido in that 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) was the most dominant in the soil sample. This indicates that the dioxins originate from a defoliant Agent Orange disposed at the site after the Vietnam War.

  8. Evaluation of Three Adolescent Sexual Health Programs in Ha Noi and Khanh Hoa Province, Vietnam

    Directory of Open Access Journals (Sweden)

    Van Pham

    2012-01-01

    Full Text Available With an increase in sexual activity among young adults in Vietnam and associated risks, there is a need for evidence-based sexual health interventions. This evaluation of three sexual health programs based on the Protection Motivation Theory (PMT was conducted in 12 communes in Ha Noi, Nha Trang City, and Ninh Hoa District. Inclusion criteria included unmarried youth 15–20 years residing in selected communes. Communes were randomly allocated to an intervention, and participants were randomly selected within each commune. The intervention programs included Vietnamese Focus on Kids (VFOK, the gender-based program Exploring the World of Adolescents (EWA, and EWA plus parental and health provider education (EWA+. Programs were delivered over a ten-week period in the communities by locally trained facilitators. The gender-based EWA program with parental involvement (EWA+ compared to VFOK showed significantly greater increase in knowledge. EWA+ in comparison to VFOK also showed significant decrease at immediate postintervention for intention to have sex. Sustained changes are observed in all three interventions for self-efficacy condom use, self-efficacy abstinence, response efficacy for condoms, extrinsic rewards, and perceived vulnerability for HIV. These findings suggest that theory-based community programs contribute to sustained changes in knowledge and attitudes regarding sexual risk among Vietnamese adolescents.

  9. Impact of the Hoa Binh Dam (Vietnam on water and sediment budgets in the Red River basin and delta

    Directory of Open Access Journals (Sweden)

    D. V. Vu

    2014-01-01

    Full Text Available The Hoa Binh Dam, located on a tributary of the Red River in Vietnam, has a capacity of 9.45 × 109 m3 and was commissioned in December 1988. Although being important for flood prevention, electricity production, and irrigation in northern Vietnam, the Hoa Binh Dam has also highly influenced the suspended sediment distribution in the lower Red River basin, in the delta and in the coastal zone. Its impact was analysed from 50 yr dataset of water discharge and suspended sediment concentration (1960–2010 and the distribution of water and sediment across the nine mouths of the delta was calculated using the MIKE 11 numerical model before and after the dam settlement. Although water discharge at the delta inlet decreased by only 8.8%, the yearly suspended sediment flux dropped, on average from 119 to 43 × 106 t yr−1 at Son Tay near Hanoi, and from 85 to 35 × 106 t yr−1 in the river mouths. Water regulation has led to decreased water discharge in the wet season and increased water discharge in the dry season. Suspended sediment discharge proportionally increased in northern and southern estuaries and decreased through the main and central Ba Lat mouth. Tidal pumping, which causes a net sediment flux from the coast to the estuary at low discharge, is high in the northern delta, as a consequence of the high tidal range (up to 4.5 m in spring tide; diurnal tide. The shifts in the dynamic and characteristics of the turbidity maximum zone in the Cam-Bach Dang estuary are probably the cause of the enhanced sediment deposition in the Haiphong harbor. Along the coast, the reduced sedimentation rates are coincident with the lower sediment delivery that has been observed since the impoundment of the Hoa Binh Dam.

  10. 周围型肺癌脑转移伴HOA 1例临床分析

    Institute of Scientific and Technical Information of China (English)

    孙道进

    2011-01-01

    1.介绍肥大性骨关节病的背景知识,提出文献很少提到我们应该怎样重视HOA,以及意义何在.2.患者男,62岁."双下肢肿伴膝关节痛3月余"被临床诊断为周围性肺癌脑转移伴HOA.行化放疗治疗,杵状指存在,膝关节疼痛消失,压痛(-),双踝区肥大性表现未好转.对于中老年人患有双下肢肿大或肥大,压无凹陷性,相关检查无果的情况下建议查胸CT以排除肺癌可能,即使无肺部体征,以免延误患者病情,要向患者说明检查的必要性.

  11. Prevalence of metabolic syndrome in adults in Khanh Hoa, Viet Nam

    Institute of Scientific and Technical Information of China (English)

    Huy Van Tran; M.T. Truong; Thach Nguyen

    2004-01-01

    Background The metabolic syndrome (MS) is characterized by a specific clustering of risk factors, including dyslipidemia, central adiposity, systemic hypertension, insulin resistance, and dysglycemia. It is associated with an increased risk of developing cardiovascular disease (CVD). Accurate data on prevalence and characteristics of MS will facilitate the development of preventive strategies for CVD. Objective To estimate accurately the prevalence of MS among Vietnamese adults with the usual criteria or with the criteria modified for Asian populations. Design and methods We studied a representative, cross-sectional, population-based sample of 856 subjects (mean age 52.82 ± 16.36) classified in three age groups from 15-34 years, 35-54 years and > 54 years of age, living in Khanh Hoa Province, Viet Nam. MS was diagnosed according to the criteria defined by the Third Report of the National Cholesterol Education Program Expect Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel Ⅲ) (NCEP-ATP Ⅲ) and by the modified criteria for some Asian populations in which the waist circumference (WC) is considered abnormal if it is > 90 cm for males and > 80 cm for females.Results Using the NCEP-ATP Ⅲ criteria, the prevalence of MS in the studied population was 10.0% (CI 95 %:8.1-12.3). It was 2.4 % in the 15-34 age group (men 4.5% and women 1.2%),5.2% (men 6.3%,women 4.5% ) in 35-54 age group and 15.8% (men 9.7%, women 21.7%) in over 54 age group, respectively. And it was more common in women than in men (11.7% vs 8.0%, P <0.001). Using 2001 population census data of the whole province over 15 years (695 218 habitants) we estimated that about 35 193 people suffered from the MS.The WC was the least common feature of MS (2.1% for men and in 6.1% for women).Overall,45.2 % of the studied population had one feature of MS, 23.1% had two features, 8.2% had three features, 1.6% had four

  12. HOA-03丙烯助剂在催化裂化装置的应用%Application of the HOA-03 Propylene Accessory Ingredient in Catalytic Cracking Unit

    Institute of Scientific and Technical Information of China (English)

    高飞; 王强; 潘若非; 张杨; 李晓光; 沈健

    2007-01-01

    丙烯是重要的有机化工原料之一,可以生产多种高附加值的产品,而且市场对丙烯的需求也逐年增长.利用现有的FCC装置,采用HOA-03丙烯助剂,在保证装置总液收、各产品质量指标、催化剂流化性能和操作平稳性等操作参数基本不变的情况下,多产丙烯,提高炼化企业的经济效益.

  13. Transport and bioaccumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans at the Bien Hoa Agent Orange hotspot in Vietnam.

    Science.gov (United States)

    Van Thuong, Nguyen; Hung, Nguyen Xuan; Mo, Nguyen Thi; Thang, Nguyen Manh; Huy, Pham Quang; Van Binh, Hoang; Nam, Vu Duc; Van Thuy, Nguyen; Son, Le Ke; Minh, Nguyen Hung

    2015-10-01

    The Bien Hoa airbase (south of Vietnam) is known as one of the Agent Orange hotspots which have been seriously contaminated by Agent Orange/dioxin during the Vietnam War. Hundreds of samples including soil, sediment and fish were collected at the Bien Hoa Agent Orange hotspot for assessment of the environmental contamination caused by dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). The toxicity equivalency quotient (TEQ) concentration of PCDD/Fs in soil and sediment varied from 7.6 to 962,000 and 17 to 4860 pg/g dry wt, respectively, implying very high contamination of PCDD/Fs in several areas. PCDD/F levels in fish ranged between 1.8 and 288 pg/g TEQ wet wt and was generally higher than advisory guidelines for food consumption. 2,3,7,8-Tetrachlorinated dibenzo-p-dioxins (2,3,7,8-TCDD) contributed 66-99 % of TEQ for most of the samples, suggesting 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) from Agent Orange as the major source of the contamination. The vertical transport of PCDD/Fs was observed in soil column with high TEQ levels above 1000 pg/g dry wt (Vietnamese limit for necessary remediation activities- TCVN 8183:2009 (2009)) even at a depth of 1.8 m. The vertical transport of PCDD/Fs has probably mainly taken place during the "Ranch Hand" defoliant spray activities due to the leaks and spills of phenoxy herbicides and solvents. The congener patterns suggest that transports of PCDD/Fs by weathering processes have led to their redistribution in the low-land areas. Also, an estimate for the total volume of contaminated soil requiring remediation to meet Vietnamese regulatory limits is provided.

  14. Environmental Health Risk Assessment of Dioxin Exposure through Foods in a Dioxin Hot Spot—Bien Hoa City, Vietnam

    Science.gov (United States)

    Tuyet-Hanh, Tran Thi; Vu-Anh, Le; Ngoc-Bich, Nguyen; Tenkate, Thomas

    2010-01-01

    This study used the Australian Environmental Health Risk Assessment Framework to assess the human health risk of dioxin exposure through foods for local residents in two wards of Bien Hoa City, Vietnam. These wards are known hot-spots for dioxin and a range of stakeholders from central government to local levels were involved in this process. Publications on dioxin characteristics and toxicity were reviewed and dioxin concentrations in local soil, mud, foods, milk and blood samples were used as data for this risk assessment. A food frequency survey of 400 randomly selected households in these wards was conducted to provide data for exposure assessment. Results showed that local residents who had consumed locally cultivated foods, especially fresh water fish and bottom-feeding fish, free-ranging chicken, duck, and beef were at a very high risk, with their daily dioxin intake far exceeding the tolerable daily intake recommended by the WHO. Based on the results of this assessment, a multifaceted risk management program was developed and has been recognized as the first public health program ever to have been implemented in Vietnam to reduce the risks of dioxin exposure at dioxin hot-spots. PMID:20623031

  15. Household opportunity costs of protecting and developing forest lands in Son La and Hoa Binh Provinces, Vietnam

    Directory of Open Access Journals (Sweden)

    Le Ngoc Lan

    2016-09-01

    Full Text Available Vietnam has pilot-tested a payment for forest environmental services (PFES program in an effort to restore and protect forest areas, some of which have been severely degraded by the excessive cutting of trees by small-scale farmers planting annual crops on steep, sloping lands. The pilot program implemented in southern Vietnam seems to be successful, yet the program in northern Vietnam has not produced the desired rates of planting and maintaining forest areas. The reasons for these mixed results include differences in socio-economic characteristics and also the production and marketing opportunities available to rural households in the project areas. To gain insight regarding program participation, we examine the household-level opportunity costs of planting and ­maintaining small plots of forest trees in northern Vietnam. We find that small-scale farmers in Hoa Binh Province, with limited financial resources, prefer the annual revenue stream provided by crops such as maize and cassava, rather than waiting for 7 years to obtain revenue from a forest planting. Farmers in Son La Province, with limited access to markets, prefer annual crops because they are not able to sell bamboo shoots and other forest products harvested from their small plots. In both provinces, the payments offered for planting and maintaining forest trees are smaller than the opportunity costs of planting and harvesting annual crops. Thus, most households likely would choose not to participate in the PFES program, at current payment rates, if given the opportunity to decline.

  16. Environmental health risk assessment of dioxin exposure through foods in a dioxin hot spot-Bien Hoa City, Vietnam.

    Science.gov (United States)

    Tuyet-Hanh, Tran Thi; Vu-Anh, Le; Ngoc-Bich, Nguyen; Tenkate, Thomas

    2010-05-01

    This study used the Australian Environmental Health Risk Assessment Framework to assess the human health risk of dioxin exposure through foods for local residents in two wards of Bien Hoa City, Vietnam. These wards are known hot-spots for dioxin and a range of stakeholders from central government to local levels were involved in this process. Publications on dioxin characteristics and toxicity were reviewed and dioxin concentrations in local soil, mud, foods, milk and blood samples were used as data for this risk assessment. A food frequency survey of 400 randomly selected households in these wards was conducted to provide data for exposure assessment. Results showed that local residents who had consumed locally cultivated foods, especially fresh water fish and bottom-feeding fish, free-ranging chicken, duck, and beef were at a very high risk, with their daily dioxin intake far exceeding the tolerable daily intake recommended by the WHO. Based on the results of this assessment, a multifaceted risk management program was developed and has been recognized as the first public health program ever to have been implemented in Vietnam to reduce the risks of dioxin exposure at dioxin hot-spots.

  17. Environmental Health Risk Assessment of Dioxin Exposure through Foods in a Dioxin Hot Spot—Bien Hoa City, Vietnam

    Directory of Open Access Journals (Sweden)

    Tran Thi Tuyet-Hanh

    2010-05-01

    Full Text Available This study used the Australian Environmental Health Risk Assessment Framework to assess the human health risk of dioxin exposure through foods for local residents in two wards of Bien Hoa City, Vietnam. These wards are known hot-spots for dioxin and a range of stakeholders from central government to local levels were involved in this process. Publications on dioxin characteristics and toxicity were reviewed and dioxin concentrations in local soil, mud, foods, milk and blood samples were used as data for this risk assessment. A food frequency survey of 400 randomly selected households in these wards was conducted to provide data for exposure assessment. Results showed that local residents who had consumed locally cultivated foods, especially fresh water fish and bottom-feeding fish, free-ranging chicken, duck, and beef were at a very high risk, with their daily dioxin intake far exceeding the tolerable daily intake recommended by the WHO. Based on the results of this assessment, a multifaceted risk management program was developed and has been recognized as the first public health program ever to have been implemented in Vietnam to reduce the risks of dioxin exposure at dioxin hot-spots.

  18. Screening of inorganic and organic contaminants in floodwater in paddy fields of Hue and Thanh Hoa in Vietnam

    DEFF Research Database (Denmark)

    Trinh Thu, Ha; Marcussen, Helle; Hansen, Hans Chr. Bruun

    2017-01-01

    was investigated in Thanh Hoa and Hue. Water samples were taken at 16 locations in canals, paddy fields and rivers before and during the flood. In total, 940 organic micro-pollutants in the water samples were determined simultaneously by GC-MS method with automatic identification and quantification system (AIQS......In the rainy season, rice growing areas in Vietnam often become flooded by up to 1.5 m water. The floodwater brings contaminants from cultivated areas, farms and villages to the rice fields resulting in widespread contamination. In 2012 and 2013, the inorganic and organic contaminants in floodwater......), while ICP-MS was used for determination of ten trace elements in the samples. The concentrations of 277 organic micro-pollutants and ten elements (As, Cu, Cd, Cr, Co, Pb, Zn, Fe, Mn, Al) ranged from 0.01 to 7.6 μg L−1 and 0.1 to 3170 μg L−1, respectively, in the floodwater. Contaminants originated from...

  19. Correlation analysis between forest carbon stock and spectral vegetation indices in Xuan Lien Nature Reserve, Thanh Hoa, Viet Nam

    Science.gov (United States)

    Dung Nguyen, The; Kappas, Martin

    2017-04-01

    In the last several years, the interest in forest biomass and carbon stock estimation has increased due to its importance for forest management, modelling carbon cycle, and other ecosystem services. However, no estimates of biomass and carbon stocks of deferent forest cover types exist throughout in the Xuan Lien Nature Reserve, Thanh Hoa, Viet Nam. This study investigates the relationship between above ground carbon stock and different vegetation indices and to identify the most likely vegetation index that best correlate with forest carbon stock. The terrestrial inventory data come from 380 sample plots that were randomly sampled. Individual tree parameters such as DBH and tree height were collected to calculate the above ground volume, biomass and carbon for different forest types. The SPOT6 2013 satellite data was used in the study to obtain five vegetation indices NDVI, RDVI, MSR, RVI, and EVI. The relationships between the forest carbon stock and vegetation indices were investigated using a multiple linear regression analysis. R-square, RMSE values and cross-validation were used to measure the strength and validate the performance of the models. The methodology presented here demonstrates the possibility of estimating forest volume, biomass and carbon stock. It can also be further improved by addressing more spectral bands data and/or elevation.

  20. Isolation and characteristics of protocatechuic acid from Paenibacillus elgii HOA73 against Botrytis cinerea on strawberry fruits.

    Science.gov (United States)

    Nguyen, Xuan Hoa; Naing, Kyaw Wai; Lee, Young Seong; Moon, Jae Hak; Lee, Jeong Hyun; Kim, Kil Yong

    2015-05-01

    This study was undertaken to describe purification, identification, and characteristics of protocatechuic acid (PCA) isolated for the first time from Paenibacillus elgii HOA73 against Botrytis cinerea (the cause of gray mold disease on strawberry fruit). PCA was purified by different chromatographic techniques and identified as PCA (3,4-dihydroxybenzoic acid) by nuclear magnetic resonance and liquid chromatography-mass spectrometry analyses. PCA displayed potent antifungal activity against B. cinerea and Rhizoctonia solani. However, the antifungal activities were not sufficient to inhibit mycelial growth of Phytophthora capsici and Fusarium oxysporum. The minimum inhibitory concentration of PCA to inhibit any visible mycelial growth of both B. cinerea and R. solani was 64 µg ml(-1) . Most B. cinerea conidia displayed altered shape and absence of germination, or were degraded after treatment with 50 and 100 µg ml(-1) PCA, respectively. Moreover, gray mold formation on strawberry fruit was almost or completely inhibited by these PCA concentrations 7 days following infection with B. cinerea conidia, respectively. PCA may be a promising alternative to chemical fungicides as a potential biofungicide to prevent growth of B. cinerea in strawberry fruit disease management.

  1. High latrine coverage is not reducing the prevalence of soil-transmitted helminthiasis in Hoa Binh province, Vietnam.

    Science.gov (United States)

    Yajima, Aya; Jouquet, Pascal; Do, Trung Dung; Dang, Thi Cam Thach; Tran, Cong Dai; Orange, Didier; Montresor, Antonio

    2009-03-01

    A baseline epidemiological survey for parasite infections was conducted between December 2007 and January 2008 in 155 villagers in a rural commune in Hoa Binh province, Vietnam. The prevalence of Ascaris lumbricoides, Trichuris trichiura and hookworm infection was 13.5%, 45.2% and 58.1%, respectively. At least one of the parasites was detected in 72.3% of the samples. We found no association between infection with A. lumbricoides or T. trichiura and engagement in agriculture, while hookworm infection was more prevalent in populations having frequent contact with soil. Agricultural use of human faeces was not correlated with any of the infections. We suggest that the consumption of vegetables that are commonly fertilized with human faeces in the community has led to the high infection rates with A. lumbricoides and T. trichiura, rather than the manipulation of faeces in farming activity. This also explains the high infection prevalence, despite high latrine coverage (98.1%) in the study population. The presence of latrines alone is not sufficient to reduce the prevalence of helminthiasis in a rural agricultural community if fresh faeces are used as fertilizer.

  2. Hoa Phat钢新建第2条达涅利棒材生产线

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    经越南Hoa Phat钢公司与达涅利摩根沙玛通力合作和密切配合,第一套30万t棒线材轧机于2002年中期顺利建成投产。几年后,作为友好合作关系的继续和发展,达涅利于2007年9月又得到第二套棒材轧机订单。新建18机架棒材轧机全部由SHS元牌坊机架组成,每年将生产φ10-55mm螺纹钢35万t,最大小时生产能力将达到60t。双线切分轧制技术将用于生产小规格螺纹钢;QTB工艺将用于生产最大直径为40mm、经过在线水淬火和自回火的螺纹钢棒材。达涅利自动化公司将提供电气设备、基础自动化和过程控制系统。新建设备计划在2009年第3季度试车投产。

  3. New biogeographical and morphological information on Physaloptera ngoci Le-Van-Hoa, 1961 (Nematoda: Physalopteridae) in South-east Asian rodents.

    Science.gov (United States)

    Veciana, Marina; Chaisiri, Kittiponk; Morand, Serge; Miquel, Jordi; Ribas, Alexis

    2013-01-01

    During a study of the helminth fauna of 1,643 rodents trapped along the Mekong River (Thailand, Lao People's Democratic Republic and Cambodia) in 2008-2011, the spirurid nematode Physaloptera ngoci Le-Van-Hoa, 1961 was recovered with an overall prevalence of 2.8%. Based on the original description, it was identified in nine of 23 different Murinae host species and is here reported for the first time from these three countries. A scanning electron microscopy study provides additional morphological data.

  4. 业主委员会制度绩效影响因素分析%Analysis on the Factors Influencing the Performance of HOAs System

    Institute of Scientific and Technical Information of China (English)

    雷岁江; 孙荣

    2012-01-01

    Homeowners self - govern and organize the reason for the different governing performances of homeowners committee is an important research topic. The explosive research of this topic applies to enter multivari- ate and regression model to analyze the investigation data. It turns out that the six independent variables can explain 78.30% variation amount of the dependent variables. "The scale of community" is weakly and negatively related with the performance of HOAs system. This is to say, the larger the community scale is, the lower the performance of HOAs system will be. But this impact is not that obvious. The general social capital can not well explain the variable amount of the performance of HOAs system. "Special social capital" affects the performance of HOAs system most, and the contribution coefficient is 0. 678.%业主自主治理组织——业主委员会(HOAs)治理绩效出现差异的原因是一个重要的研究问题。对此采用强迫进入多元回归模型对同一地方的调查数据进行分析。结果发现:6个自变量共可以解释因变量78.30%的变异量;“小区规模”与业主委员会制度绩效成弱负相关关系,即小区规模越大,业主委员会制度绩效则越低,这种影响并不明显;一般社会资本对业主委员会制度绩效变异量的解释并不明显;“特殊社会资本”对业主委员会制度绩效的影响最大,其贡献系数0.678。

  5. Heavy metals in the farming environment and in some selected aquaculture species in the Van Phong Bay and Nha Trang Bay of the Khanh Hoa Province in Vietnam.

    Science.gov (United States)

    Nghia, Ngo Dang; Lunestad, Bjørn Tore; Trung, Trang Si; Son, Nguyen Thanh; Maage, Amund

    2009-01-01

    Aquaculture is currently one of the most rapidly growing production sectors in Vietnam. This publication describes the concentrations of heavy metals in the farming environment and some aquaculture species in the Khanh Hoa Province in Vietnam. The concentration of total As in the sediments ranged from 0.07 to 0.64 mg/kg, whereas the concentration of Hg varied from <0.0005 to 0.56 mg/kg. The corresponding concentration span for Cd and Pb, were 0.001-0.069 and 0.016-0.078 mg/kg, respectively. The concentrations of As in the aquaculture organisms spanned from 0.14 to 1.03 mg/kg. For Hg the concentrations varied from 0.1 to 0.45 mg/kg, for Cd from 0.02 to 0.10 mg/kg and for Pb from 0.07 to 0.37 mg/kg.

  6. The 2014-2015 Pāhoa lava flow crisis at Kīlauea Volcano, Hawai‘i: Disaster avoided and lessons learned

    Science.gov (United States)

    Poland, Michael; Orr, Tim; Kauahikaua, James P.; Brantley, Steven R.; Babb, Janet; Patrick, Matthew R.; Neal, Christina; Anderson, Kyle R.; Antolik, Loren; Burgess, Matthew K.; Elias, Tamar; Fuke, Steven; Fukunaga, Pauline; Johanson, Ingrid; Kagimoto, Marian; Kamibayashi, Kevan P.; Lee, Lopaka; Miklius, Asta; Million, William; Moniz, Cyril J.; Okubo, Paul G.; Sutton, Andrew; Takahashi, T. Jane; Thelen, Weston A.; Tollett, Willam; Trusdell, Frank A.

    2016-01-01

    Lava flow crises are nothing new on the Island of Hawai‘i, where their destructive force has been demonstrated repeatedly over the past several hundred years. The 2014–2015 Pāhoa lava flow crisis, however, was unique in terms of its societal impact and volcanological characteristics. Despite low effusion rates, a long-lived lava flow whose extent reached 20 km (the longest at Kīlauea Volcano in the past several hundred years) was poised for months to impact thousands of people, although direct impacts were ultimately minor (thus far). Careful observation of the flow reaffirmed and expanded knowledge of the processes associated with pāhoehoe emplacement, including the direct correlation between summit pressurization and flow advance, the influence of existing geologic structures on flow pathways, and the possible relationship between effusion rate and flow length. Communicating uncertainty associated with lava flow hazards was a challenge throughout the crisis, but online distribution of information and direct contact with residents proved to be effective strategies for keeping the public informed and educated about flow progress and how lava flows work (including forecasting limitations). Volcanological and sociological lessons will be important for inevitable future lava flow crises in Hawai‘i and, potentially, elsewhere in the world.

  7. Parent-youth communication and concordance between parents and adolescents on reported engagement in social relationships and sexually intimate behaviors in Hanoi and Khanh Hoa Province, Vietnam.

    Science.gov (United States)

    Kaljee, Linda M; Green, Mackenzie; Lerdboon, Porntip; Riel, Rosemary; Pham, Van; Tho, Le Huu; Ha, Nguyen T; Minh, Truong Tan; Li, Xiaoming; Chen, Xinguang; Stanton, Bonita

    2011-03-01

    Parent-child communication is associated with positive outcomes for youths' engagement in sexual behaviors. Limited data are available regarding parent-child communication in transitional countries. We present data from Vietnamese parent-youth dyads on parent reproductive health (RH) knowledge, comfort of communication, frequency of talk, and discordancy between youths' reported and parents' perceptions for engagement in relationships and sexually intimate behaviors. The cohort included 185 randomly selected parent-youth dyads in four communes in Hanoi and Khanh Hoa Province. Descriptive and comparative analysis included chi-squared tests, independent samples t-tests, and ANOVA. Linear regression analysis was used to assess relationships between parental knowledge, level of comfort, frequency of talk, and discordancy. Seventy-six percent of parents and 44% of youth were female. The mean age of youth was 17.2 years. The mean score for parental "RH knowledge" was 24.74 (SD, 3.84; range, 15-34). Lower parental RH knowledge was positively associated with lower levels of education (F = 2.983; df, 184; p = .014). Data indicate a linear model in which knowledge is related to "comfort" (β = .17; p = .048), and "comfort" to frequency of "talk" (β = .6; p communication about RH. There is a need for more data to assess the effect of these communication patterns on youths' engagement in sexual behaviors and for development of family-centered interventions to increase parental knowledge and skills for positive communication. Copyright © 2011 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  8. Analysis of higher-order aberrations (HOAs) and related factors after small incision lenticule extraction (SMILE) surgery%SMILE术后全眼高阶像差变化及相关因素分析

    Institute of Scientific and Technical Information of China (English)

    梁刚; 查旭; 张丰菊

    2015-01-01

    目的 通过观察飞秒激光小切口基质透镜取出术(SMILE)治疗近视及近视散光眼术后全眼高阶像差的改变,探讨SMILE术后全眼高阶像差的变化特点及其相关因素.方法 回顾性研究.选择行SMILE手术治疗近视及近视散光患者共81例(162眼),随访时间3个月.术中眼球定位采用术前kappa角结合术中注视水印居中中心定位法.术前、术后3个月采用WASCA波前像差分析仪测量6 mm瞳孔直径下术眼的总高阶像差(HOA)及各单项HOA,同时采用Oculyzer眼前节分析系统测量kappa角及角膜Q值.手术前后数据比较应用配对t检验,运用Spearman秩相关分析法和Pearson相关分析总HOA及各项HOA的变化与术前等效球镜度(SE)、散光度及轴向、kappa角等参数的相关性.结果 手术前后总HOA(t=-12.24,P<0.01)、球差(C40)(t=16.60,P<0.01)、水平彗差(C31)(t=-11.06,P<0.01)、垂直彗差(C3-1)(t=-3.14,P<0.01)、垂直三叶草(C3-3)(t=-6.30,P<0.01)、四阶水平散光(C42)(t=5.84,P<0.01)的均方根(RMS)值差异均有统计学意义.手术前后Q值分别为-0.24±0.13和0.69±0.52,差异有统计学意义(t=-22.55,P<0.01).术后3个月总HOA与SE相关(r=-0.23,P<0.01),△总HOA主要与△C40、△C31相关(r=-0.40、0.26,P<0.01),与术前Q值、Kappa角、散光度均无相关性;术后C40、△C40与术前SE相关(r=0.35、0.29,P<0.01);C31与术前散光度和Q值相关(r=-0.24、-0.22,P<0.05),△C31与术前散光度相关(r=-0.29,P<0.01);术后C3-1和△C3-1与术前的SE、Q值、Kappa角、散光度均不相关.结论 近视及近视散光眼SMILE手术后总HOA增加,主要与术前SE有关,与散光度无关;手术前后C40变化量与术前SE有关,C31增加量与术前散光度有关.%Objective To investigate the changes in higher-order aberrations (HOAs) after small incision lenticule extraction (SMILE) surgery for myopia and myopic astigmatism, and to evaluate the association between the postoperative

  9. 满意度测评系统在HOA中的快速构建及应用%The Quick Construction and Application of Satisfaction Evaluation System in HOA

    Institute of Scientific and Technical Information of China (English)

    张瑜; 王爱东; 周杰红

    2014-01-01

    主要阐述垂杨柳医院HOA系统所配套的快速开发平台,以及利用该平台快速构建满意度测评系统的背景、系统的需求、系统的快速构建以及在医院应用的效果。HOA配套平台中强大的快速构建工具为实现该项紧急任务提供了有力的支持。%This paper mainly discusses about the supporting rapid development platform of HOA system in Chuiyangliu Hospital, the background of rapidly building the satisfaction evaluation system with the platform, the demands of the system, the fast building of the system and the effect of application in our hospital. The powerful quick building tool in the supporting platform of HOA provides the strong support for realizing the urgent task.

  10. Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    X.-F. Huang

    2010-09-01

    Full Text Available As part of Campaigns of Air Quality Research in Beijing and Surrounding Region-2008 (CAREBeijing-2008, an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed in urban Beijing to characterize submicron aerosol particles during the time of 2008 Beijing Olympic Games and Paralympic Games (24 July to 20 September 2008. The campaign mean PM1 mass concentration was 63.1 ± 39.8 μg m−3; the mean composition consisted of organics (37.9%, sulfate (26.7%, ammonium (15.9%, nitrate (15.8%, black carbon (3.1%, and chloride (0.87%. The average size distributions of the species (except BC were all dominated by an accumulation mode peaking at about 600 nm in vacuum aerodynamic diameter, and organics was characterized by an additional smaller mode extending below 100 nm. Positive Matrix Factorization (PMF analysis of the high resolution organic mass spectral dataset differentiated the organic aerosol into four components, i.e., hydrocarbon-like (HOA, cooking-related (COA, and two oxygenated organic aerosols (OOA-1 and OOA-2, which on average accounted for 18.1, 24.4, 33.7 and 23.7% of the total organic mass, respectively. The HOA was identified to be closely associated with primary combustion sources, while the COA mass spectrum and diurnal pattern showed similar characteristics to that measured for cooking emissions. The OOA components correspond to aged secondary organic aerosol. Although the two OOA components have similar elemental (O/C, H/C compositions, they display differences in mass spectra and time series which appear to correlate with the different source regions sampled during the campaign. Back trajectory clustering analysis indicated that the southerly air flows were associated with the highest PM1 pollution during the campaign. Aerosol particles in southern airmasses were especially rich in inorganic and oxidized organic species. Aerosol particles in northern airmasses

  11. Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    X.-F. Huang

    2010-05-01

    Full Text Available As part of Campaigns of Air Quality Research in Beijing and Surrounding Region–2008 (CAREBeijing-2008, an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed in urban Beijing to characterize submicron aerosol particles during the time of 2008 Beijing Olympic Games and Paralytic Games (24 July to 20 September 2008. The campaign mean PM1 mass concentration was 63.1±39.8 μg m−3; the mean composition consisted of organics (37.9%, sulfate (26.7%, ammonium (15.9%, nitrate (15.8%, black carbon (3.1%, and chloride (0.87%. The average size distributions of the species (except BC were all dominated by an accumulation mode peaking at about 600 nm in vacuum aerodynamic diameter, and organics was characterized by an additional smaller mode extending below 100 nm. Positive Matrix Factorization (PMF analysis of the high resolution organic mass spectral dataset differentiated the organic aerosol into four components, i.e., hydrocarbon-like (HOA, cooking-related (COA, and two oxygenated organic aerosols (OOA-1 and OOA-2, which on average accounted for 18.1, 24.4, 33.7 and 23.7% of the total organic mass, respectively. The HOA was identified to be closely associated with primary combustion sources, while the COA mass spectrum showed high similarity to that measured from cooking aerosol emissions. The OOA components correspond to aged secondary organic aerosol. Although the two OOA components have similar elemental (O/C, H/C compositions, they display differences in mass spectra and time series which appear to correlate with the different source regions sampled during the campaign. Back trajectory clustering analysis indicated that the southerly air flows were associated with the highest PM1 pollution during the campaign. This result is similar to observations made in the summer of 2006, although the average PM1 concentration level for the southerly air flows is 31% lower than

  12. 越南和平水电站库区不同农林复合模式的环境效益比较%Environmental benefits evaluation of different agroforestry systems in Hoa Binh Hydropower Station Reservoir Area of Vietnam

    Institute of Scientific and Technical Information of China (English)

    Vu Thi Thuong; Nguyen The Ky; 王来; 张硕新

    2015-01-01

    Nowadays, agroforestry farming is a major issue in Vietnamat midland and mountainous region as it has to satisfy the demand of forest production and ecosystem protection. Compared to some other types of forest, agroforest has demonstrated outstanding strength as it provides landowners with early and fast income generation. Therefore, developing agroforest becomes a trend when the research on land use gets much attention. However, environmental efficiency of agroforest is quite varied and closely reliable on the structure of the forest system. Taking into consideration of both environmental condition and the efficiency at the same time is significant not only in evaluating the current situation of the forest but also in improving its structure, thereby reaching environmental goals. Nevertheless, there is a shortage of research on above problem in Hoa Binh hydropower reservoir environment. Due to this restriction many agroforests were in failure to enhance their economic and protective functions and the forest also showed low stability. In order to have a part in solving the aforesaid inadequacies, this paper has been conducted. The environmental protection and soil conservation of vegetation have high requirements in hydropower station reservoir area. Finding a kind of land use pattern that can meet the interests of all parties is particularly important in the context that moving local residents out of the reservoir area is impossible. In the present study, the four main agroforestry system patterns (Acacia mangium-Zea mays;Acacia mangium-Manihot esculenta crantz;Eucalyptus camandulensis-Oryza sativa;Acacia mangium-Manihot esculenta crantz-Zea mays) were employed as the research subjects in two different areas (Thung Nai Commune, Cao Phong District and Vay Nua Commune, Da Bac District) of Hoa Binh hydropower station reservoir area in Vietnam. Multiple structural indicators such as plant species composition, morphemic structures, density and canopy of the plantation

  13. Organic Aerosol Composition and Sources in Pasadena, California during the 2010 CalNex Campaign

    Science.gov (United States)

    Organic aerosols (OA) in Pasadena are characterized using multiple measurements from the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign. Five OA components are identified using positive matrix factorization including hydrocarbon-like OA (HOA) ...

  14. Application of (economic) water valuation for devising a multiple uses operational strategy for Hoa Binh Dam. Hoa Binh hydropower dam and command area (Hoa Binh Province).

    NARCIS (Netherlands)

    Wageningen International,

    2008-01-01

    Vietnam is located in typical monsoon climate region and therefore river are very abundant water. However, about 2/3 of water resources is originated from neighboring countries. Moreover, uneven spatial distribution and huge seasonal change are additional reasons that make Vietnam ranked low

  15. Application of (economic) water valuation for devising a multiple uses operational strategy for Hoa Binh Dam. Hoa Binh hydropower dam and command area (Hoa Binh Province).

    NARCIS (Netherlands)

    Wageningen International,

    2008-01-01

    Vietnam is located in typical monsoon climate region and therefore river are very abundant water. However, about 2/3 of water resources is originated from neighboring countries. Moreover, uneven spatial distribution and huge seasonal change are additional reasons that make Vietnam ranked low compare

  16. Formation of secondary organic aerosols from gas-phase emissions of heated cooking oils

    Science.gov (United States)

    Liu, Tengyu; Li, Zijun; Chan, ManNin; Chan, Chak K.

    2017-06-01

    Cooking emissions can potentially contribute to secondary organic aerosol (SOA) but remain poorly understood. In this study, formation of SOA from gas-phase emissions of five heated vegetable oils (i.e., corn, canola, sunflower, peanut and olive oils) was investigated in a potential aerosol mass (PAM) chamber. Experiments were conducted at 19-20 °C and 65-70 % relative humidity (RH). The characterization instruments included a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS). The efficiency of SOA production, in ascending order, was peanut oil, olive oil, canola oil, corn oil and sunflower oil. The major SOA precursors from heated cooking oils were related to the content of monounsaturated fat and omega-6 fatty acids in cooking oils. The average production rate of SOA, after aging at an OH exposure of 1. 7 × 1011 molecules cm-3 s, was 1. 35 ± 0. 30 µg min-1, 3 orders of magnitude lower compared with emission rates of fine particulate matter (PM2. 5) from heated cooking oils in previous studies. The mass spectra of cooking SOA highly resemble field-derived COA (cooking-related organic aerosol) in ambient air, with R2 ranging from 0.74 to 0.88. The average carbon oxidation state (OSc) of SOA was -1.51 to -0.81, falling in the range between ambient hydrocarbon-like organic aerosol (HOA) and semi-volatile oxygenated organic aerosol (SV-OOA), indicating that SOA in these experiments was lightly oxidized.

  17. ACTRIS ACSM intercomparison – Part 2: Intercomparison of ME-2 organic source apportionment results from 15 individual, co-located aerosol mass spectrometers

    Directory of Open Access Journals (Sweden)

    R. Fröhlich

    2015-02-01

    Full Text Available Chemically resolved atmospheric aerosol data sets from the largest intercomparison of the Aerodyne aerosol chemical speciation monitors (ACSM performed to date were collected at the French atmospheric supersite SIRTA. In total 13 quadrupole ACSMs (Q-ACSM from the European ACTRIS ACSM network, one time-of-flight ACSM (ToF-ACSM, and one high-resolution ToF aerosol mass spectrometer (AMS were operated in parallel for about three weeks in November and December 2013. Part 1 of this study reports on the accuracy and precision of the instruments for all the measured species. In this work we report on the intercomparison of organic components and the results from factor analysis source apportionment by positive matrix factorisation (PMF utilising the multilinear engine 2 (ME-2. Except for the organic contribution of m/z 44 to the total organics (f44, which varied by factors between 0.6 and 1.3 compared to the mean, the peaks in the organic mass spectra were similar among instruments. The m/z 44 differences in the spectra resulted in a variable f44 in the source profiles extracted by ME-2, but had only a minor influence on the extracted mass contributions of the sources. The presented source apportionment yielded four factors for all 15 instruments: hydrocarbon-like organic aerosol (HOA, cooking-related organic aerosol (COA, biomass burning-related organic aerosol (BBOA and secondary oxygenated organic aerosol (OOA. Individual application and optimisation of the ME-2 boundary conditions (profile constraints are discussed together with the investigation of the influence of alternative anchors (reference profiles. A comparison of the ME-2 source apportionment output of all 15 instruments resulted in relative SD from the mean between 13.7 and 22.7% of the source's average mass contribution depending on the factors (HOA: 14.3 ± 2.2%, COA: 15.0 ± 3.4%, OOA: 41.5 ± 5.7%, BBOA: 29.3 ± 5.0%. Factors which tend to be subject to minor factor mixing (in this

  18. Real-time optimisation of the Hoa Binh reservoir, Vietnam

    DEFF Research Database (Denmark)

    Richaud, Bertrand; Madsen, Henrik; Rosbjerg, Dan

    2011-01-01

    -time optimisation. First, the simulation-optimisation framework is applied for optimising reservoir operating rules. Secondly, real-time and forecast information is used for on-line optimisation that focuses on short-term goals, such as flood control or hydropower generation, without compromising the deviation......Multi-purpose reservoirs often have to be managed according to conflicting objectives, which requires efficient tools for trading-off the objectives. This paper proposes a multi-objective simulation-optimisation approach that couples off-line rule curve optimisation with on-line real...... of the forecast is addressed. The results illustrate the importance of a sufficient forecast lead time to start pre-releasing water in flood situations....

  19. Circulating antibodies directed against "polycyclic aromatic hydrocarbon-like" structures in the sera of cancer patients.

    Science.gov (United States)

    Pouns, Olivier; Mangas, Arturo; Coveñas, Rafael; Geffard, Michel

    2009-07-01

    An increase in immunoglobulin (Ig) A isotype directed against benzo(a)pyrene (BP) structure has previously been described in sera of cancer patients. In this study, new polycyclic aromatic hydrocarbon (PAH) conjugates were synthesized in order to more closely mimic the endogenous ligands of the cytosolic aryl hydrocarbon receptor (AhR). PAH [benzo(a)pyrene; 1,2-benzanthracene; dibenz[a,c]anthracene; 7,12-dimethylbenza[a]anthracene; benzo(ghi)perylene] were bound to protein carriers such as bovine serum albumin (BSA) via N-acetyl-cysteine (NAC). The levels of circulating antibodies (Abs) directed against PAH-NAC conjugates in the sera of cancer patients were evaluated using an Enzyme-Linked Immunosorbent Assay (ELISA) with these new conjugates. The avidity (IC(50)) and specificity of these circulating Abs were assessed via competition experiments. An increase in Ig directed against these PAH-NAC conjugates was found in the sera of cancer patients, irrespective of the state and stage of the tumors. These Ig were principally of the A isotype. Sera from cancer patients had significantly higher optical density (OD) ranges than the controls, p<0.0001. The ELISA test for breast cancer (n=155) and ovarian cancer (n=62) identified 82% and 92% of positive patients, respectively. The percentage positive in the control group (n=60) was around 5%. Moreover, competition experiments with the different PAH-NAC conjugates and NAC-BSA revealed an estimated avidity of 10(-6)M for the circulating IgA antibodies. The Abs discriminated between the different PAH-NAC conjugates and NAC-BSA. Therefore, these Abs recognize a carcinogenic PAH-NAC structure and not only a BP structure. These markers may be useful in the future for monitoring cancer evolution and recurrence.

  20. Characterization of the sources and processes of organic and inorganic aerosols in New York City with a high-resolution time-of-flight aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    Y.-L. Sun

    2010-10-01

    Full Text Available Submicron aerosol particles (PM1 were measured in-situ using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS during the summer 2009 Field Intensive Study at Queens College in New York City. Organic aerosol (OA and sulfate are the two dominant species, accounting for 54% and 24%, respectively, of total PM1 mass on average. The average mass size distribution of OA presents a small mode peaking at ~150 nm (Dva in addition to an accumulation mode (~550 nm that is internally mixed with sulfate, nitrate, and ammonium. The diurnal cycles of sulfate and OA both show pronounced peaks between 01:00–02:00 p.m. EST due to photochemical production. The average (±1σ oxygen-to-carbon (O/C, hydrogen-to-carbon (H/C, and nitrogen-to-carbon (N/C ratios of OA in NYC are 0.36 (±0.09, 1.49 (±0.08, and 0.012(±0.005, respectively, corresponding to an average organic mass-to-carbon (OM/OC ratio of 1.62(±0.11. Positive matrix factorization (PMF of the high resolution mass spectra identified five OA components: a hydrocarbon-like OA (HOA, two types of oxygenated OA (OOA including a low-volatility OOA (LV-OOA and a semi-volatile OOA (SV-OOA, a cooking-emission related OA (COA, and a unique nitrogen-enriched OA (NOA. HOA appears to represent primary OA (POA from urban traffic emissions. It comprises primarily of reduced species (H/C=1.83; O/C=0.06 and shows a mass spectral pattern very similar to those of POA from fossil fuel combustion, and correlates tightly with traffic emission tracers including elemental carbon and NOx. LV-OOA, which is highly oxidized (O/C=0.63 and correlates well with sulfate, appears to be representative for regional, aged secondary OA (SOA. SV-OOA, which is less oxidized (O/C=0.38 and correlates well with non-refractory chloride, likely represents less photo-chemically aged, semi-volatile SOA. COA shows a similar spectral pattern to the reference spectra of POA from

  1. Characterization of submicron aerosols during a serious pollution month in Beijing (2013 using an aerodyne high-resolution aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    J. K. Zhang

    2013-07-01

    Full Text Available In January 2013, Beijing experienced several serious haze events. To achieve a better understanding of the characteristics, sources and processes of aerosols during this month, an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed at an urban site between 1 January and 1 February 2013 to obtain the size-resolved chemical composition of non-refractory submicron particles (NR-PM1. During this period, the mean measured NR-PM1 mass concentration was 87.4 μg m-3 and was composed of organics (49.8%, sulfate (21.4%, nitrate (14.6%, ammonium (10.4%, and chloride (3.8%. Moreover, inorganic matter, such as sulfate and nitrate comprised an increasing fraction of the NR-PM1 load as NR-PM1 loading increased, denoting their key roles in particulate pollution during this month. The average size distributions of the species were all dominated by an accumulation mode peaking at approximately 600 nm in vacuum aerodynamic diameter and organics characterized by an additional smaller size (∼200 nm. Elemental analyses showed that the average O/C, H/C, and N/C (molar ratio of organic matter were 0.34, 1.44 and 0.015, respectively, corresponding to an OM/OC ratio (mass ratio of organic matter to organic carbon of 1.60. Positive matrix factorization (PMF analyses of the high-resolution organic mass spectral dataset differentiated the organic aerosol into four components, i.e., oxygenated organic aerosols (OOA, cooking-related (COA, nitrogen-containing (NOA and hydrocarbon-like (HOA, which on average accounted for 40.0, 23.4, 18.1 and 18.5% of the total organic mass, respectively. Back trajectory clustering analyses indicated that the WNW air masses were associated with the highest NR-PM1 pollution during the campaign. Aerosol particles in southern air masses were especially rich in inorganic and oxidized organic species, whereas northern air masses contained a large fraction of primary species.

  2. Cooking-related PM2.5 and acrolein measured in grocery stores and comparison with other retail types.

    Science.gov (United States)

    Chan, W R; Sidheswaran, M; Sullivan, D P; Cohn, S; Fisk, W J

    2016-06-01

    We measured particulate matter (PM), acrolein, and other indoor air contaminants in eight visits to grocery stores in California. Retail stores of other types (hardware, furniture, and apparel) were also sampled on additional visits. Based on tracer gas decay data, most stores had adequate ventilation according to minimum ventilation rate standards. Grocery stores had significantly higher concentrations of acrolein, fine and ultrafine PM, compared to other retail stores, likely attributable to cooking. Indoor concentrations of PM2.5 and acrolein exceeded health guidelines in all tested grocery stores. Acrolein emission rates to indoors in grocery stores had a mean estimate about 30 times higher than in other retail store types. About 80% of the indoor PM2.5 measured in grocery stores was emitted indoors, compared to only 20% for the other retail store types. Calculations suggest a substantial increase in outdoor air ventilation rate by a factor of three from current level is needed to reduce indoor acrolein concentrations. Alternatively, acrolein emission to indoors needs to be reduced 70% by better capturing of cooking exhaust. To maintain indoor PM2.5 below the California annual ambient standard of 12 μg/m(3) , grocery stores need to use air filters with an efficiency rating higher than the MERV 8 air filters commonly used today.

  3. Cheсklist of gastropod molluscs in mangroves of Khanh Hoa province, Vietnam.

    Science.gov (United States)

    Zvonareva, Sofya; Kantor, Yuri

    2016-09-12

    Gastropod molluscs are one of the most important components of mangrove ecosystem. Mangroves in Central Vietnam have a rather limited distribution due to peculiarities of the coastline morphology and presently their fauna remains understudied. Extensive surveys were conducted in both natural vegetation and artificial mangrove plantations in several localities in Nha Trang Bay from 2005 to 2015. In total 65 species of gastropod molluscs were found alive, 17 of which can be considered as predominantly mangrove-associated. An illustrated guide is provided, with short synonymies and data on ecology and distribution. The recorded molluscan diversity is compared with published data on mangrove gastropods in different regions of the Indo-Pacific. Total species number and the proportion of mangrove-associated species are similar to studied faunas in Hong Kong, Malaysia and Thailand, but the diversity is much lower than that of the mangal fauna of the Philippines.

  4. Analyzing Drought Adaptation Practices of Sugarcane Growers in Thanh Cong, Thach Thanh District, Thanh Hoa, Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen, GTH.

    2016-01-01

    Full Text Available Embedded in a package of climate change adaptation, researchers and farmers tested the melon hybrid variety, Kim Hoang Hau (KHH, for yield and disease resistance during the spring-summer season from March to June 2015 in Giao Thuy district, Nam Dinh province. The results were analysed and subsequently discussed with local farmers in focused groups. Analysis showed that the KHH was suitable to local soil conditions. The farmers preferred this new variety over the local melon, because not only did KHH give higher yield and pest resistance, it also showed less vulnerability to climatic stressors. Farmers decided to grow KHH based on the prevailing good market price at that time. However, farmers only shifted away from the old melon when they could anticipate the possibility of selling the new product. Those who did not continue with the KHH had difficulty in actively accessing the market for this new product. This study suggests that the market information does not solely drive the process of the adaptation itself, but it also provides relevant stimuli to farmers enabling them to successfully shift to new crop varieties. This study also implies that such process-based understanding is crucial in formulating strategies that increase the farmer's capacity to adapt to climate change.

  5. Alcohol Use and HIV Risk Behaviors among Rural Adolescents in Khanh Hoa Province Viet Nam

    Science.gov (United States)

    Kaljee, L. M.; Genberg, B. L.; Minh, T. T.; Tho, L. H.; Thoa, L. T. K.; Stanton, B.

    2005-01-01

    Research suggests that youth are consuming more alcohol and at younger ages than in the past. Data also indicate that alcohol consumption is associated with participation in other risk behaviors including aggression and sexual behaviors. As part of a randomized control effectiveness trial for an HIV prevention program, 480 Vietnamese youth (15-20…

  6. The United States History = Lich Su Hoa Ky. [34 Self-Learning Packets for Vietnamese Students.

    Science.gov (United States)

    Nhi, Do Dien; And Others

    Designed primarily for Indochinese students in grades 9-12, 34 United States history self-learning packets are presented in eight sections. The publication could be used by mainstream teachers who have a number of limited English proficient (LEP) Vietnamese students in their classes or by parents to tutor their children. The packets were adapted…

  7. Quantification of black carbon mixing state from traffic: implications for aerosol optical properties

    Science.gov (United States)

    Willis, Megan D.; Healy, Robert M.; Riemer, Nicole; West, Matthew; Wang, Jon M.; Jeong, Cheol-Heon; Wenger, John C.; Evans, Greg J.; Abbatt, Jonathan P. D.; Lee, Alex K. Y.

    2016-04-01

    The climatic impacts of black carbon (BC) aerosol, an important absorber of solar radiation in the atmosphere, remain poorly constrained and are intimately related to its particle-scale physical and chemical properties. Using particle-resolved modelling informed by quantitative measurements from a soot-particle aerosol mass spectrometer, we confirm that the mixing state (the distribution of co-emitted aerosol amongst fresh BC-containing particles) at the time of emission significantly affects BC-aerosol optical properties even after a day of atmospheric processing. Both single particle and ensemble aerosol mass spectrometry observations indicate that BC near the point of emission co-exists with hydrocarbon-like organic aerosol (HOA) in two distinct particle types: HOA-rich and BC-rich particles. The average mass fraction of black carbon in HOA-rich and BC-rich particle classes was < 0.1 and 0.8, respectively. Notably, approximately 90 % of BC mass resides in BC-rich particles. This new measurement capability provides quantitative insight into the physical and chemical nature of BC-containing particles and is used to drive a particle-resolved aerosol box model. Significant differences in calculated single scattering albedo (an increase of 0.1) arise from accurate treatment of initial particle mixing state as compared to the assumption of uniform aerosol composition at the point of BC injection into the atmosphere.

  8. Knowledge and provision practices regarding medical abortion among public providers in Hanoi, Khanh Hoa, and Ho Chi Minh City, Vietnam.

    Science.gov (United States)

    Ngo, Thoai D; Free, Caroline; Le, Hoan T; Edwards, Phil; Pham, Kiet H T; Nguyen, Yen B T; Nguyen, Thang H

    2014-03-01

    To assess public service providers' knowledge of medical abortion (MA) and practices, and perspectives on expanding the use of MA to primary and secondary health facilities in Vietnam. A cross-sectional study was conducted via an interviewer-administered questionnaire among abortion providers (n=905) from public health facilities between August 2011 and January 2012. Overall, 31.1% of providers performed both surgical and medical abortions; 68.9% offered only surgical abortion. Providers were knowledgeable about the regimen/dosage of mifepristone plus misoprostol regimen; however, knowledge scores were low for gestational age limits for MA, adverse effects of the combined drug regimen, and safety and effectiveness of MA compared with surgical abortion. Knowledge scores were significantly lower among providers in rural areas than among those in urban settings. A large proportion of providers (82.9%) thought that MA should be expanded to primary and secondary health facilities. Perceived barriers to MA expansion included lack of knowledge and training, qualified staff, adequate drug supplies, equipment, or facilities, guidelines and protocols on MA, and patient awareness. Provision of MA in Vietnam was found to be disproportionate to surgical abortion provision and to vary by region. Knowledge of MA was moderate, but poorer among providers in rural settings. Copyright © 2013 International Federation of Gynecology and Obstetrics. All rights reserved.

  9. Vai Tro Cua Phu Huynh Viet Nam Tai Hoc Duong Hoa Ky. The Role of Vietnamese Parents in American Schools.

    Science.gov (United States)

    Thuy, Vuong G.

    This document, written in Vietnamese and containing a bilingual (English/Vietnamese) forward, examines the differences between the American and Vietnamese educational systems with respect to basic educational philosophy, content, learning style and organization. Also discussed are specific learning problems which affect the education of Vietnamese…

  10. Vai Tro Cua Phu Huynh Viet Nam Tai Hoc Duong Hoa Ky. The Role of Vietnamese Parents in American Schools.

    Science.gov (United States)

    Thuy, Vuong G.

    This document, written in Vietnamese and containing a bilingual (English/Vietnamese) forward, examines the differences between the American and Vietnamese educational systems with respect to basic educational philosophy, content, learning style and organization. Also discussed are specific learning problems which affect the education of Vietnamese…

  11. Sach Huong Dan Nguoiti Nan O Hoa Ky (Your New Life in the United States). [Vietnamese Edition.

    Science.gov (United States)

    Center for Applied Linguistics, Washington, DC. Language and Orientation Resource Center.

    An illustrated guide to aspects of life in the United States is presented in Vietnamese for recent Vietnamese arrivals. The guidelines address such topics as resettlement agencies, community relations and national customs, the U.S. government, local and long distance transport, mail and telephone communication systems, employment practices, the…

  12. Optical and crystal-chemical changes in aquamarines and yellow beryls from Thanh Hoa province, Vietnam induced by heat treatment

    Science.gov (United States)

    Fridrichová, Jana; Bačík, Peter; Rusinová, Petra; Antal, Peter; Škoda, Radek; Bizovská, Valéria; Miglierini, Marcel

    2015-04-01

    Optical and crystal-chemical changes in two beryl varieties after the heat treatment were determined using a wide spectrum of analytical methods. Studied aquamarines are generally more enriched in Fe (up to 0.25 apfu) and alkali (up to 0.08 apfu) than yellow beryls (up to 0.07 apfu Fe, up to 0.04 apfu alkali). The determined c/ a ratio of 0.997-0.998 classified all our studied beryls as "normal" beryls. While no crystal structure changes were observed in samples heated to 700 °C, those heated to 900 and 1,100 °C exhibited cracks and fissures. Reduced Fe occurred in samples heated between 300 and 700 °C, and subsequent oxidation from 900 to 1,100 °C induced changes in their colour and clarity. The Fe-bearing beryl colour is controlled by the position of the absorption edge and the presence of a broad band attributed to Fe2+ in the NIR region. Blue colour results from the absorption edge located deeper in the UV region and the presence of broad band in the NIR region. Shift of absorption edge to the visible region at the presence of the broad band gives a yellow colour. Although our studied beryls are enriched in H2O I molecule due to their low alkali content, the H2O II molecule is also present. The following two dehydration processes were observed: (1) release of one double-coordinating H2O II molecule at 300-500 °C and (2) total dehydration at 900-1,100 °C. The observed cracks and fissures likely resulted from channel water release in large beryl crystals.

  13. Aerosol Composition in the Los Angeles Basin Studied by High Resolution Aerosol Mass Spectrometry

    Science.gov (United States)

    Hayes, P. L.; Ortega, A. M.; Cubison, M.; Hu, W.; Toohey, D. W.; Flynn, J. H.; Grossberg, N.; Lefer, B. L.; Alvarez, S. L.; Rappenglueck, B.; Allan, J. D.; Taylor, J.; Holloway, J. S.; Gilman, J. B.; Kuster, W. C.; De Gouw, J. A.; Massoli, P.; Zhang, X.; Weber, R.; Zhao, Y.; Cliff, S. S.; Wexler, A. S.; Isaacman, G. A.; Worton, D. R.; Kreisberg, N. M.; Hering, S. V.; Goldstein, A. H.; Jimenez, J. L.

    2011-12-01

    Atmospheric aerosols impact climate and health, but their sources and composition are poorly understood. To address this knowledge gap, a high-resolution aerosol mass spectrometer (AMS) and complementary instrumentation were deployed during the 2010 CalNex campaign to characterize aerosol composition in the Los Angeles (LA) area. Total mass concentrations as well as the species concentrations measured by the AMS compare well with most other instruments. Nitrate dominates in the mornings, but its concentration is reduced in the afternoon when organic aerosols (OA) increase and dominate. The diurnal variations in concentrations are strongly influenced by emission transport from the source-rich western basin. The average OA to enhanced CO ratio increases with photochemical age from 25 to 80 μg m-3 ppm-1, which indicates significant secondary OA (SOA) production and that a large majority of OA is secondary in aged air. The ratio values are similar to those from Mexico City as well as New England and the Mid-Atlantic States. Positive matrix factorization (PMF) is used to assess the concentrations of different OA components. The major OA classes are oxygenated OA (OOA, a surrogate for total SOA), and hydrocarbon-like OA (HOA, a surrogate for primary combustion OA). Several subclasses of OA are identified as well including diesel-influenced HOA (DI-HOA) and non-diesel HOA. DI-HOA exhibits low concentrations on Sundays consistent with the well-known weekday/weekend effect in LA. PMF analysis finds that OOA is 67% of the total OA concentration. A strong correlation between OOA and Ox (O3 + NO2) concentrations is observed with a slope of 0.15 that suggests the production of fresh SOA in Pasadena. Plotting the OA elemental ratios in a Van Krevelen diagram (H:C vs. O:C) yields a slope of -0.6, which is less steep than that observed in Riverside during the SOAR-2005 campaign. The difference in slopes may be attributed to the highly oxidized HOA present in Pasadena that is

  14. Submicron aerosol source apportionment of wintertime pollution in Paris, France by Double Positive Matrix Factorization (PMF2 using Aerosol Chemical Speciation Monitor (ACSM and multi-wavelength Aethalometer

    Directory of Open Access Journals (Sweden)

    J.-E. Petit

    2014-06-01

    Full Text Available Online non-refractory submicron Aerosol Mass Spectrometer (AMS measurements in urban areas have successfully allowed the apportionment of specific sources and/or physical and chemical properties of the organic fraction. However, in order to be fully representative of PM pollution, a comprehensive source apportionment analysis is needed by taking into account all major components of submicron aerosols, creating strengthened bonds between the organic components and pollution sources. We present here a novel two-step methodology to perform such an analysis, by taking advantage of high time resolution of monitoring instruments: the Aerosol Chemical Speciation Monitor (ACSM and the multi-wavelength absorption measurements (Aethalometer AE31 in Paris, France. As a first step, organic aerosols (OA were deconvoluted to hydrocarbon-like OA (HOA, Biomass Burning OA (BBOA and Oxygenated OA (OOA with Positive Matrix Factorization, and black carbon was deconvolved into its wood burning and fossil fuel combustion fractions. A second PMF analysis was then carried out with organic factors, BC fractions and inorganic species (nitrate, sulfate, ammonium, chloride, leading to a~four-factor solution allowing real-time characterization of the major sources of PM1. Outputs of this PMF2 include two dominant combustion sources (wood burning and traffic as well as semi-volatile and low-volatile secondary aerosols. While HOA is found to be emitted by both wood burning and traffic, the latter sources occurred to significantly contribute also to OOA.

  15. Chemically-resolved aerosol eddy covariance flux measurements in urban Mexico City during MILAGRO 2006

    Science.gov (United States)

    Zalakeviciute, R.; Alexander, M. L.; Allwine, E.; Jimenez, J. L.; Jobson, B. T.; Molina, L. T.; Nemitz, E.; Pressley, S. N.; VanReken, T. M.; Ulbrich, I. M.; Velasco, E.; Lamb, B. K.

    2012-08-01

    As part of the MILAGRO 2006 field campaign, the exchange of atmospheric aerosols with the urban landscape was measured from a tall tower erected in a heavily populated neighborhood of Mexico City. Urban submicron aerosol fluxes were measured using an eddy covariance method with a quadrupole aerosol mass spectrometer during a two week period in March, 2006. Nitrate and ammonium aerosol concentrations were elevated at this location near the city center compared to measurements at other urban sites. Significant downward fluxes of nitrate aerosol, averaging -0.2 μg m-2 s-1, were measured during daytime. The urban surface was not a significant source of sulfate aerosols. The measurements also showed that primary organic aerosol fluxes, approximated by hydrocarbon-like organic aerosols (HOA), displayed diurnal patterns similar to CO2 fluxes and anthropogenic urban activities. Overall, 47% of submicron organic aerosol emissions were HOA, 35% were oxygenated (OOA) and 18% were associated with biomass burning (BBOA). Organic aerosol fluxes were bi-directional, but on average HOA fluxes were 0.1 μg m-2 s-1, OOA fluxes were -0.03 μg m-2 s-1, and BBOA fluxes were -0.03 μg m-2 s-1. After accounting for size differences (PM1 vs PM2.5) and using an estimate of the black carbon component, comparison of the flux measurements with the 2006 gridded emissions inventory of Mexico City, showed that the daily-averaged total PM emission rates were essentially identical for the emission inventory and the flux measurements. However, the emission inventory included dust and metal particulate contributions, which were not included in the flux measurements. As a result, it appears that the inventory underestimates overall PM emissions for this location.

  16. Evaluation of chemical transport model predictions of primary organic aerosol for air masses classified by particle component-based factor analysis

    Directory of Open Access Journals (Sweden)

    C. A. Stroud

    2012-09-01

    Full Text Available Observations from the 2007 Border Air Quality and Meteorology Study (BAQS-Met 2007 in Southern Ontario, Canada, were used to evaluate predictions of primary organic aerosol (POA and two other carbonaceous species, black carbon (BC and carbon monoxide (CO, made for this summertime period by Environment Canada's AURAMS regional chemical transport model. Particle component-based factor analysis was applied to aerosol mass spectrometer measurements made at one urban site (Windsor, ON and two rural sites (Harrow and Bear Creek, ON to derive hydrocarbon-like organic aerosol (HOA factors. A novel diagnostic model evaluation was performed by investigating model POA bias as a function of HOA mass concentration and indicator ratios (e.g. BC/HOA. Eight case studies were selected based on factor analysis and back trajectories to help classify model bias for certain POA source types. By considering model POA bias in relation to co-located BC and CO biases, a plausible story is developed that explains the model biases for all three species.

    At the rural sites, daytime mean PM1 POA mass concentrations were under-predicted compared to observed HOA concentrations. POA under-predictions were accentuated when the transport arriving at the rural sites was from the Detroit/Windsor urban complex and for short-term periods of biomass burning influence. Interestingly, the daytime CO concentrations were only slightly under-predicted at both rural sites, whereas CO was over-predicted at the urban Windsor site with a normalized mean bias of 134%, while good agreement was observed at Windsor for the comparison of daytime PM1 POA and HOA mean values, 1.1 μg m−3 and 1.2 μg m−3, respectively. Biases in model POA predictions also trended from positive to negative with increasing HOA values. Periods of POA over-prediction were most evident at the urban site on calm nights due to an overly-stable model surface layer

  17. Optical properties of a tropical estuary during wet and dry conditions in the Nha Phu estuary, Khanh Hoa Province, south-east Vietnam

    DEFF Research Database (Denmark)

    Lund-Hansen, Lars Chresten; Hai, Doan Nhu; Lam, Nguyen Ngoc

    2010-01-01

    There has been a strong research focus on optical properties in temperate estuaries but very much less in tropical estuaries. These properties comprise light and beam attenuation dominated by suspended particulate matter, Chl a, and CDOM. Spatially and temporally distributed data on optical prope...... estuaries, was the episodic character with days of strong rainfall followed by longer periods of dry weather. All sampling, both wet and dry, was carried out in the dry season which implies a less definitive perception of wet and dry seasons....

  18. Living With an American Family: A Guide for Vietnamese Youth. (Song Trong Mot Gia Dinh Hoa Ky: Cam nang cho thieu nien Viet Nam.)

    Science.gov (United States)

    Dye, Dale; And Others

    This booklet was written for Vietnamese adolescents who are living with American families. The booklet describes, in both Vietnamese and English, the structure and mores of American family and social life. Concerns common to teenagers are also discussed. Among the topics addressed are: school; typical weekdays and weekends; forms of address;…

  19. Han Hoan Chao Ban Den Hoa Ky. Sach Chi Dan Danh Cho Nguoi Ti Nan. (Welcome to the United States. A Guidebook for Refugees).

    Science.gov (United States)

    Center for Applied Linguistics, Washington, DC. Refugee Service Center.

    This guidebook provides Vietnamese-speaking refugees being resettled in the United States with general information about what they will encounter and the services they can receive in their first months in the country. The book is distributed to overseas processing agencies, refugees overseas who have been approved for U.S. admission, and service…

  20. Tai Lieu Huong Dan Ve Van De Dinh Cu Tai Hoa Ky (Resettlement Guide: Vietnamese. A Guide for Refugees Resettling in the United States).

    Science.gov (United States)

    Center for Applied Linguistics, Washington, DC.

    This resettlement guide, entirely in Vietnamese, describes the initial stage of resettlement and the processes that refugees undergo as new arrivals. The information is intended to prepare refugees for the first few weeks in an American community and to explain fundamental aspects of American life. An initial chapter outlines issues in pre-arrival…

  1. Organic aerosol source apportionment by offline-AMS over a full year in Marseille

    Science.gov (United States)

    Bozzetti, Carlo; El Haddad, Imad; Salameh, Dalia; Daellenbach, Kaspar Rudolf; Fermo, Paola; Gonzalez, Raquel; Cruz Minguillón, María; Iinuma, Yoshiteru; Poulain, Laurent; Elser, Miriam; Müller, Emanuel; Gates Slowik, Jay; Jaffrezo, Jean-Luc; Baltensperger, Urs; Marchand, Nicolas; Prévôt, André Stephan Henry

    2017-07-01

    We investigated the seasonal trends of OA sources affecting the air quality of Marseille (France), which is the largest harbor of the Mediterranean Sea. This was achieved by measurements of nebulized filter extracts using an aerosol mass spectrometer (offline-AMS). In total 216 PM2. 5 (particulate matter with an aerodynamic diameter hydrocarbons (PAHs), lignin and cellulose pyrolysis products, and nitrocatechols. The application of positive matrix factorization (PMF) to the water-soluble AMS spectra enabled the extraction of five factors, related to hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), oxygenated OA (OOA), and an industry-related OA (INDOA). Seasonal trends and relative contributions of OA sources were compared with the source apportionment of OA spectra collected from the AMS field deployment at the same station but in different years and for shorter monitoring periods (February 2011 and July 2008). Online- and offline-AMS source apportionment revealed comparable seasonal contribution of the different OA sources. Results revealed that BBOA was the dominant source during winter, representing on average 48 % of the OA, while during summer the main OA component was OOA (63 % of OA mass on average). HOA related to traffic emissions contributed on a yearly average 17 % to the OA mass, while COA was a minor source contributing 4 %. The contribution of INDOA was enhanced during winter (17 % during winter and 11 % during summer), consistent with an increased contribution from light alkanes, light PAHs (fluoranthene, pyrene, phenanthrene), and selenium, which is commonly considered as a unique coal combustion and coke production marker. Online- and offline-AMS source apportionments revealed evolving levoglucosan : BBOA ratios, which were higher during late autumn and March. A similar seasonality was observed in the ratios of cellulose combustion markers to lignin combustion markers, highlighting the contribution from cellulose

  2. Real time measurements of submicrometer aerosols in Seoul, Korea: Sources, characteristics, and processing of organic aerosols during winter time.

    Science.gov (United States)

    Kim, H.; Zhang, Q.

    2016-12-01

    Highly time-resolved chemical characterization of non-refractory submicrometer particulate matter (NR-PM1) was conducted in Seoul, the capital of Korea, using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The measurements were performed during winter when persistent air quality problems associated with elevated PM concentrations were observed. The average NR-PM1 concentration was 27.5 µg m-3 and the average mass was dominated by organics (44%), followed by nitrate (24%) and sulfate (10%). Five distinct sources of organic aerosol (OA) were identified from positive matrix factorization (PMF) analysis of the AMS data: vehicle emissions represented by a hydrocarbon-like OA factor (HOA), cooking represented by a cooking OA factor (COA), wood combustion represented by a biomass burning OA factor (BBOA), and secondary aerosol formation in the atmosphere that is represented by a semi-volatile oxygenated OA factor (SVOOA) and a low volatile oxygenated OA factor (LVOOA). These factors, on average, contributed 16, 20, 23, 15 and 26% to the total OA mass, respectively, with primary organic aerosol (POA = HOA + COA + BBOA) accounting for 59% of the OA mass. On average, both primary emissions and secondary aerosol formation are important factors affecting air quality in Seoul during winter, contributing approximately equal. However, differences in the fraction of PM source and properties were observed between high and low loading PM period. For example, during stagnant period with low wind speed (WS) (0.99 ± 0.7 m/s) and high RH (71%), high PM loadings (43.6 ± 12.4 µg m-3) with enhanced fractions of nitrate (27%) and SVOOA (8%) were observed, indicating a strong influence from locally generated secondary aerosol. On the other hand, when low PM loadings (12.6 ± 7.1 µg m-3), which were commonly associated with high WS (1.8 ± 1.1 m/s) and low RH (50 %), were observed, the fraction of regional sources, such as sulfate (12%) and LVOOA (21

  3. Direct measurements of near-highway emissions in a high diesel environment

    Science.gov (United States)

    DeWitt, H. L.; Hellebust, S.; Temime-Roussel, B.; Ravier, S.; Polo, L.; Jacob, V.; Buisson, C.; Charron, A.; André, M.; Pasquier, A.; Besombes, J. L.; Jaffrezo, J. L.; Wortham, H.; Marchand, N.

    2014-10-01

    Diesel-powered passenger cars currently outnumber gasoline-powered cars in many countries, particularly in Europe. In France, diesel cars represented 61% of Light Duty Vehicles in 2011 and this percentage is still increasing (French Environment and Energy Management Agency, ADEME). As part of the September~2011 joint PM-DRIVE (Particulate Matter- DiRect and Indirect on-road Vehicular Emissions) and MOCOPO (Measuring and mOdeling traffic COngestion and POllution) field campaign, the concentration and high-resolution chemical composition of aerosols and volatile organic carbon (VOC) species were measured adjacent to a major urban highway south of Grenoble, France. Alongside these atmospheric measurements, detailed traffic data were collected from nearby traffic cameras and loop detectors, which allowed the identification of vehicle type and characteristics, traffic concentration, and traffic speed to be quantified and compared to measured aerosol and VOCs. Six aerosol age and source profiles were resolved using the positive matrix factorization (PMF) model on real-time high-resolution aerosol mass spectra. These six aerosol source/age categories included a hydrocarbon-like organic aerosol (HOA) commonly associated with primary vehicular emissions, a nitrogen containing aerosol (NOA) with a diurnal pattern similar to that of HOA, oxidized organic aerosol (OOA), and biomass burning aerosol (BBOA). While quantitatively separating the influence of diesel vs. gasoline proved impossible, a low HOA : black carbon ratio, similar to that measured in other high-diesel environments, and high levels of NOx, also indicative of diesel emissions, were observed. A comparison between these high-diesel environment measurements and measurements taken in low-diesel (North American) environments was examined and the potential feedback between vehicular emissions and SOA formation was probed. Although the measurement site was located next to a large source of primary emissions, which are

  4. Direct measurements of near-highway emissions in a high diesel environment

    Directory of Open Access Journals (Sweden)

    H. L. DeWitt

    2014-10-01

    Full Text Available Diesel-powered passenger cars currently outnumber gasoline-powered cars in many countries, particularly in Europe. In France, diesel cars represented 61% of Light Duty Vehicles in 2011 and this percentage is still increasing (French Environment and Energy Management Agency, ADEME. As part of the September~2011 joint PM-DRIVE (Particulate Matter- DiRect and Indirect on-road Vehicular Emissions and MOCOPO (Measuring and mOdeling traffic COngestion and POllution field campaign, the concentration and high-resolution chemical composition of aerosols and volatile organic carbon (VOC species were measured adjacent to a major urban highway south of Grenoble, France. Alongside these atmospheric measurements, detailed traffic data were collected from nearby traffic cameras and loop detectors, which allowed the identification of vehicle type and characteristics, traffic concentration, and traffic speed to be quantified and compared to measured aerosol and VOCs. Six aerosol age and source profiles were resolved using the positive matrix factorization (PMF model on real-time high-resolution aerosol mass spectra. These six aerosol source/age categories included a hydrocarbon-like organic aerosol (HOA commonly associated with primary vehicular emissions, a nitrogen containing aerosol (NOA with a diurnal pattern similar to that of HOA, oxidized organic aerosol (OOA, and biomass burning aerosol (BBOA. While quantitatively separating the influence of diesel vs. gasoline proved impossible, a low HOA : black carbon ratio, similar to that measured in other high-diesel environments, and high levels of NOx, also indicative of diesel emissions, were observed. A comparison between these high-diesel environment measurements and measurements taken in low-diesel (North American environments was examined and the potential feedback between vehicular emissions and SOA formation was probed. Although the measurement site was located next to a large source of primary emissions

  5. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the UK

    Science.gov (United States)

    McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

    2011-05-01

    Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the UK. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA observed in

  6. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

    Science.gov (United States)

    McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

    2011-09-01

    Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA

  7. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

    Directory of Open Access Journals (Sweden)

    G. R. McMeeking

    2011-09-01

    Full Text Available Black carbon (BC aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2 measurements of refractory BC (rBC mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA operated by the Facility for Airborne Atmospheric Measurements (FAAM. We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS and used positive matrix factorization to separate hydrocarbon-like (HOA and oxygenated organic aerosols (OOA. We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA did change for

  8. Chemically-resolved aerosol eddy covariance flux measurements in urban Mexico City during MILAGRO 2006

    Directory of Open Access Journals (Sweden)

    R. Zalakeviciute

    2012-08-01

    Full Text Available As part of the MILAGRO 2006 field campaign, the exchange of atmospheric aerosols with the urban landscape was measured from a tall tower erected in a heavily populated neighborhood of Mexico City. Urban submicron aerosol fluxes were measured using an eddy covariance method with a quadrupole aerosol mass spectrometer during a two week period in March, 2006. Nitrate and ammonium aerosol concentrations were elevated at this location near the city center compared to measurements at other urban sites. Significant downward fluxes of nitrate aerosol, averaging −0.2 μg m−2 s−1, were measured during daytime. The urban surface was not a significant source of sulfate aerosols. The measurements also showed that primary organic aerosol fluxes, approximated by hydrocarbon-like organic aerosols (HOA, displayed diurnal patterns similar to CO2 fluxes and anthropogenic urban activities. Overall, 47% of submicron organic aerosol emissions were HOA, 35% were oxygenated (OOA and 18% were associated with biomass burning (BBOA. Organic aerosol fluxes were bi-directional, but on average HOA fluxes were 0.1 μg m−2 s−1, OOA fluxes were −0.03 μg m−2 s−1, and BBOA fluxes were −0.03 μg m−2 s−1. After accounting for size differences (PM1 vs PM2.5 and using an estimate of the black carbon component, comparison of the flux measurements with the 2006 gridded emissions inventory of Mexico City, showed that the daily-averaged total PM emission rates were essentially identical for the emission inventory and the flux measurements. However, the emission inventory included dust and metal particulate contributions, which were not included in the flux measurements. As a result, it appears that the inventory underestimates overall PM emissions for this location.

  9. Receptor modeling of near-roadway aerosol mass spectrometer data in Las Vegas, Nevada, with EPA PMF

    Directory of Open Access Journals (Sweden)

    S. G. Brown

    2012-01-01

    Full Text Available Ambient non-refractory PM1 aerosol particles were measured with an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS at an elementary school 18 m from the US 95 freeway soundwall in Las Vegas, Nevada, during January 2008. Additional collocated continuous measurements of black carbon (BC, carbon monoxide (CO, nitrogen oxides (NOx, and meteorological data were collected. The US~Environmental Protection Agency's (EPA positive matrix factorization (PMF data analysis tool was used to apportion organic matter (OM as measured by HR-AMS, and rotational tools in EPA PMF were used to better characterize the solution space and pull resolved factors toward known source profiles. Three- to six-factor solutions were resolved. The four-factor solution was the most interpretable, with the typical AMS PMF factors of hydrocarbon-like organic aerosol (HOA, low-volatility oxygenated organic aerosol (LV-OOA, biomass burning organic aerosol (BBOA, and semi-volatile oxygenated organic aerosol (SV-OOA. When the measurement site was downwind of the freeway, HOA composed about half the OM, with SV-OOA and LV-OOA accounting for the rest. Attempts to pull the PMF factor profiles toward source profiles were successful but did not qualitatively change the results, indicating that these factors are very stable. Oblique edges were present in G-space plots, suggesting that the obtained rotation may not be the most plausible one. Since solutions found by pulling the profiles or using Fpeak retained these oblique edges, there appears to be little rotational freedom in the base solution. On average, HOA made up 26% of the OM, while LV-OOA was highest in the afternoon and accounted for 26% of the OM. BBOA occurred in the evening hours, was predominantly from the residential area to the north, and on average constituted 12% of the OM; SV-OOA accounted for the remaining third of the OM. Use of the pulling techniques

  10. Receptor modeling of near-roadway aerosol mass spectrometer data in Las Vegas, Nevada, with EPA PMF

    Directory of Open Access Journals (Sweden)

    S. G. Brown

    2011-08-01

    Full Text Available Ambient non-refractory PM1 aerosol particles were measured with an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS at an elementary school 20 m from the US 95 freeway in Las Vegas, Nevada, during January 2008. Additional collocated continuous measurements of black carbon (BC, carbon monoxide (CO, nitrogen oxides (NOx, and meteorological data were collected. The US Environmental Protection Agency's (EPA positive matrix factorization (PMF data analysis tool was used to apportion organic matter (OM as measured by HR-AMS, and rotational tools in EPA PMF were used to better characterize the solution space and pull resolved factors toward known source profiles. Three- to six-factor solutions were resolved. The four-factor solution was the most interpretable, with the typical AMS PMF factors of hydrocarbon-like organic aerosol (HOA, low-volatility oxygenated organic aerosol (LV-OOA, biomass burning organic aerosol (BBOA, and semi-volatile oxygenated organic aerosol (SV-OOA. When the measurement site was downwind of the freeway, HOA composed about half the OM, with SV-OOA and LV-OOA accounting for the rest. Attempts to pull the PMF factor profiles toward source profiles were successful but did not qualitatively change the results, indicating that these factors are very stable. Oblique edges were present in G-space plots, suggesting that the obtained rotation may not be the most plausible one. Since solutions found by pulling the profiles or using Fpeak retained these oblique edges, there appears to be little rotational freedom in the base solution. On average, HOA made up 26 % of the OM, and it made up nearly half of the OM when the monitoring site was downwind of US 95 during morning rush hour. LV-OOA was highest in the afternoon and accounted for 26 % of the OM. BBOA occurred in the evening hours, was predominantly from the residential area to the north, and on average constituted 12

  11. Chemically-resolved aerosol volatility measurements from two megacity field studies

    Directory of Open Access Journals (Sweden)

    J. A. Huffman

    2009-09-01

    Full Text Available The volatilities of different chemical species in ambient aerosols are important but remain poorly characterized. The coupling of a recently developed rapid temperature-stepping thermodenuder (TD, operated in the range 54–230°C with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS during field studies in two polluted megacities has enabled the first direct characterization of chemically-resolved urban particle volatility. Measurements in Riverside, CA and Mexico City are generally consistent and show ambient nitrate as having the highest volatility of any AMS standard aerosol species while sulfate showed the lowest volatility. Total organic aerosol (OA showed volatility intermediate between nitrate and sulfate, with an evaporation rate of 0.6%·K−1 near ambient temperature, although OA dominates the residual species at the highest temperatures. Different types of OA were characterized with marker ions, diurnal cycles, and positive matrix factorization (PMF and show significant differences in volatility. Reduced hydrocarbon-like OA (HOA, a surrogate for primary OA, POA, oxygenated OA (OOA, a surrogate for secondary OA, SOA, and biomass-burning OA (BBOA separated with PMF were all determined to be semi-volatile. The most aged OOA-1 and its dominant ion, CO2+, consistently exhibited the lowest volatility, with HOA, BBOA, and associated ions for each among the highest. The similar or higher volatility of HOA/POA compared to OOA/SOA contradicts the current representations of OA volatility in most atmospheric models and has important implications for aerosol growth and lifetime. A new technique using the AMS background signal was demonstrated to quantify the fraction of species up to four orders-of-magnitude less volatile than those detectable in the MS mode, which for OA represent ~5% of the non-refractory (NR OA signal. Our results strongly imply that all OA types should be considered

  12. 西安大气细颗粒(P M1)化学组成及其对能见度的影响%Chemical Composition of Atmospheric Fine Particle (PM1)and Its Effect on Visibility in Xi’an

    Institute of Scientific and Technical Information of China (English)

    王浥尘; 曹军骥; 张宁宁; 肖舜; 王启元; 陈阳

    2014-01-01

    organic is about 58% of PM1 ,other components (including SO2-4 ,NO-3 ,NH+4 and Cl-)is about 42%;higher relative humidity increases the mass fraction of primary component,and rainfall significantly improves the wet deposition of primary component;hydrocarbon-like organic aerosol (HOA ) and oxygenated organic aerosol (OOA)are resolved from organics by the means of PMF;mass concentration of OOA is about 54% of organics,and that of HOA is about 46%;HOA volatilizes and translates to OOA after a photochemical reaction in the afternoon;nitrate contributes most to light scattering coefficient.

  13. Evaluation of chemical transport model predictions of primary organic aerosol for air masses classified by particle-component-based factor analysis

    Directory of Open Access Journals (Sweden)

    C. A. Stroud

    2012-02-01

    Full Text Available Observations from the 2007 Border Air Quality and Meteorology Study (BAQS-Met 2007 in southern Ontario (ON, Canada, were used to evaluate Environment Canada's regional chemical transport model predictions of primary organic aerosol (POA. Environment Canada's operational numerical weather prediction model and the 2006 Canadian and 2005 US national emissions inventories were used as input to the chemical transport model (named AURAMS. Particle-component-based factor analysis was applied to aerosol mass spectrometer measurements made at one urban site (Windsor, ON and two rural sites (Harrow and Bear Creek, ON to derive hydrocarbon-like organic aerosol (HOA factors. Co-located carbon monoxide (CO, PM2.5 black carbon (BC, and PM1 SO4 measurements were also used for evaluation and interpretation, permitting a detailed diagnostic model evaluation.

    At the urban site, good agreement was observed for the comparison of daytime campaign PM1 POA and HOA mean values: 1.1 μg m−3 vs. 1.2 μg m−3, respectively. However, a POA overprediction was evident on calm nights due to an overly-stable model surface layer. Biases in model POA predictions trended from positive to negative with increasing HOA values. This trend has several possible explanations, including (1 underweighting of urban locations in particulate matter (PM spatial surrogate fields, (2 overly-coarse model grid spacing for resolving urban-scale sources, and (3 lack of a model particle POA evaporation process during dilution of vehicular POA tail-pipe emissions to urban scales. Furthermore, a trend in POA bias was observed at the urban site as a function of the BC/HOA ratio, suggesting a possible association of POA underprediction for diesel combustion sources. For several time periods, POA overprediction was also observed for sulphate-rich plumes, suggesting that our model POA fractions for the PM2.5 chemical

  14. Higher order aberrations of the eye: Part one

    Directory of Open Access Journals (Sweden)

    Marsha Oberholzer

    2016-03-01

    Full Text Available This article is the first in a series of two articles that provide a comprehensive literature review of higher order aberrations (HOAs of the eye. The present article mainly explains the general principles of such HOAs as well as HOAs of importance, and the measuring apparatus used to measure HOAs of the eye. The second article in the series discusses factors contributing to variable results in measurements of HOAs of the eye.Keywords: Higher order aberrations; wavefront aberrations; aberrometer

  15. Sources and atmospheric processing of organic aerosol in the Mediterranean: insights from aerosol mass spectrometer factor analysis

    Directory of Open Access Journals (Sweden)

    L. Hildebrandt

    2011-12-01

    Full Text Available Atmospheric particles were measured in the late winter (25 February–26 March 2009 at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiment-2009. A quadrupole aerosol mass spectrometer (Q-AMS was employed to quantify the size-resolved chemical composition of non-refractory submicron aerosol, and a thermodenuder was used to analyze the organic aerosol (OA volatility. Complementary measurements included particle size distributions from a scanning mobility particle sizer, inorganic and organic particle composition from filter analysis, air ion concentrations, O3, NOx and NOy concentrations, and meteorological measurements. Factor analysis was performed on the OA mass spectra, and the variability in OA composition could best be explained with three OA components. The oxygenated organic aerosol (OOA was similar in composition and volatility to the summertime OA previously measured at this site and may represent an effective endpoint in particle-phase oxidation of organics. The two other OA components, one associated with amines (Amine-OA and the other probably associated with the burning of olive branches (OB-OA, had very low volatility but were less oxygenated. Hydrocarbon-like organic aerosol (HOA was not detected. The absence of OB-OA and Amine-OA in the summer data may be due to lower emissions and/or photochemical conversion of these components to OOA.

  16. Sources and atmospheric processing of organic aerosol in the Mediterranean: insights from aerosol mass spectrometer factor analysis

    Directory of Open Access Journals (Sweden)

    L. Hildebrandt

    2011-07-01

    Full Text Available Atmospheric particles were measured in the winter at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiment-2009. A Quadrupole aerosol mass spectrometer (Q-AMS was employed to quantify the size-resolved chemical composition of non-refractory submicron aerosol, and a thermodenuder was used to analyze the organic aerosol (OA volatility. Complementary measurements included particle size distributions from a scanning mobility particle sizer, inorganic and organic particle composition from filter analysis, concentrations of O3, NOx and NOy, and meteorological measurements. Factor analysis was performed on the OA mass spectra, and the variability in OA composition could best be explained with three OA components. The oxygenated organic aerosol (OOA was similar in composition and volatility to the summertime OA previously measured at this site and appears to represent an effective endpoint in particle-phase oxidation of organics. The two other OA components, one associated with amines (Amine-OA and the other probably associated with the burning of olive branches (OB-OA, had lower volatility but were less oxygenated. Hydrocarbon-like organic aerosol (HOA was not detected. The absence of OB-OA and Amine-OA in the summer data may be due to lower emissions and/or photochemical conversion of these components to OOA.

  17. SoFi, an Igor based interface for the efficient use of the generalized multilinear engine (ME-2 for source apportionment: application to aerosol mass spectrometer data

    Directory of Open Access Journals (Sweden)

    F. Canonaco

    2013-07-01

    Full Text Available Source apportionment using the bilinear model through the multilinear engine (ME-2 was successfully applied to non-refractory organic aerosol (OA mass spectra collected during winter 2011 and 2012 in Zurich, Switzerland using the aerosol chemical speciation monitor ACSM. Five factors were identified: low-volatility oxygenated OA (LV-OOA, semivolatile oxygenated OA (SV-OOA, hydrocarbon-like OA (HOA, cooking OA (COA and biomass burning OA (BBOA. A graphical user interface SoFi (Source Finder was developed at PSI in order to facilitate the testing of different rotational techniques available within the ME-2 engine by providing a priori factor profiles for some or all of the expected factors. ME-2 was used to test the positive matrix factorization (PMF model, the fully constrained chemical mass balance (CMB model, and partially constrained models utilizing a values and pulling equations. Within the set of model solutions determined to be environmentally reasonable, BBOA and SV-OOA factor mass spectra and time series showed the greatest variability. This variability represents uncertainty in the model solution and indicates that analysis of model rotations provides a useful approach for assessing the uncertainty of bilinear source apportionment models.

  18. Chemical composition, sources and secondary processes of aerosols in Baoji city of northwest China

    Science.gov (United States)

    Wang, Y. C.; Huang, R.-J.; Ni, H. Y.; Chen, Y.; Wang, Q. Y.; Li, G. H.; Tie, X. X.; Shen, Z. X.; Huang, Y.; Liu, S. X.; Dong, W. M.; Xue, P.; Fröhlich, R.; Canonaco, F.; Elser, M.; Daellenbach, K. R.; Bozzetti, C.; El Haddad, I.; Prévôt, A. S. H.; Canagaratna, M. R.; Worsnop, D. R.; Cao, J. J.

    2017-06-01

    Particulate air pollution is a severe environmental problem in China, affecting visibility, air quality, climate and human health. However, previous studies focus mainly on large cities such as Beijing, Shanghai, and Guangzhou. In this study, an Aerodyne Aerosol Chemical Speciation Monitor was deployed in Baoji, a middle size inland city in northwest China from 26 February to 27 March 2014. The non-refractory submicron aerosol (NR-PM1) was dominated by organics (55%), followed by sulfate (16%), nitrate (15%), ammonium (11%) and chloride (3%). A source apportionment of the organic aerosol (OA) was performed with the Sofi (Source Finder) interface of ME-2 (Multilinear Engine), and six main sources/factors were identified and classified as hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), coal combustion OA (CCOA), less oxidized oxygenated OA (LO-OOA) and more oxidized oxygenated OA (MO-OOA), which contributed 20%, 14%, 13%, 9%, 23% and 21% of total OA, respectively. The contribution of secondary components shows increasing trends from clean days to polluted days, indicating the importance of secondary aerosol formation processes in driving particulate air pollution. The formation of LO-OOA and MO-OOA is mainly driven by photochemical reactions, but significantly influenced by aqueous-phase chemistry during periods of low atmospheric oxidative capacity.

  19. Modeling SOA formation from the oxidation of intermediate volatility n-alkanes

    Directory of Open Access Journals (Sweden)

    J. Lee-Taylor

    2012-06-01

    Full Text Available The chemical mechanism leading to SOA formation and ageing is expected to be a multigenerational process, i.e. a successive formation of organic compounds with higher oxidation degree and lower vapor pressure. This process is here investigated with the explicit oxidation model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere. Gas phase oxidation schemes are generated for the C8–C24 series of n-alkanes. Simulations are conducted to explore the time evolution of organic compounds and the behavior of secondary organic aerosol (SOA formation for various preexisting organic aerosol concentration (COA. As expected, simulation results show that (i SOA yield increases with the carbon chain length of the parent hydrocarbon, (ii SOA yield decreases with decreasing COA, (iii SOA production rates increase with increasing COA and (iv the number of oxidation steps (i.e. generations needed to describe SOA formation and evolution grows when COA decreases. The simulated oxidative trajectories are examined in a two dimensional space defined by the mean carbon oxidation state and the volatility. Most SOA contributors are not oxidized enough to be categorized as highly oxygenated organic aerosols (OOA but reduced enough to be categorized as hydrocarbon like organic aerosols (HOA, suggesting that OOA may underestimate SOA. Results show that the model is unable to produce highly oxygenated aerosols (OOA with large yields. The limitations of the model are discussed.

  20. Modeling SOA formation from the oxidation of intermediate volatility n-alkanes

    Directory of Open Access Journals (Sweden)

    J. Lee-Taylor

    2012-08-01

    Full Text Available The chemical mechanism leading to SOA formation and ageing is expected to be a multigenerational process, i.e. a successive formation of organic compounds with higher oxidation degree and lower vapor pressure. This process is here investigated with the explicit oxidation model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere. Gas phase oxidation schemes are generated for the C8–C24 series of n-alkanes. Simulations are conducted to explore the time evolution of organic compounds and the behavior of secondary organic aerosol (SOA formation for various preexisting organic aerosol concentration (COA. As expected, simulation results show that (i SOA yield increases with the carbon chain length of the parent hydrocarbon, (ii SOA yield decreases with decreasing COA, (iii SOA production rates increase with increasing COA and (iv the number of oxidation steps (i.e. generations needed to describe SOA formation and evolution grows when COA decreases. The simulated oxidative trajectories are examined in a two dimensional space defined by the mean carbon oxidation state and the volatility. Most SOA contributors are not oxidized enough to be categorized as highly oxygenated organic aerosols (OOA but reduced enough to be categorized as hydrocarbon like organic aerosols (HOA, suggesting that OOA may underestimate SOA. Results show that the model is unable to produce highly oxygenated aerosols (OOA with large yields. The limitations of the model are discussed.

  1. Seasonal Variations of High Time-Resolved Chemical Compositions, Sources and Evolution for Atmospheric Submicron Aerosols in the Megacity of Beijing

    Science.gov (United States)

    Hu, Min; Hu, Wei; Hu, Weiwei; Zheng, Jing; Guo, Song; Wu, Yusheng; Lu, Sihua; Zeng, Limin

    2016-04-01

    This study aims to investigate aerosol secondary formation and aging process in the megacity of Beijing. Seasonal intensive campaigns were conducted from March 2012 to March 2013 at an urban site located at the campus of Peking University (116.31° E, 37.99° N). An Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) and other relevant instrumentations for gaseous and particulate pollutants were deployed. The average submicron aerosol (PM1) mass concentrations were 45.1 ± 45.8, 37.5 ± 31.0, 41.3 ± 42.7 and 81.7 ± 72.4 μg m-3 in spring, summer, autumn and winter, respectively. Organic matter was the most abundant component, accounting for 31%, 33%, 44% and 36% in PM1 correspondingly, followed by sulfate and nitrate. Distinct seasonal and diurnal patterns of the components of PM1 tracking primary sources (e.g., BC and HOA) and secondary formation (e.g., sulfate, nitrate, ammonium, LV-OOA and SV-OOA) were significantly influenced by primary emissions and mesoscale meteorology. Combining positive matrix factorization (PMF) analysis with the mass spectrometry of organics measured by AMS, the contributions of primary and secondary sources to submicron organic aerosols (OA) were apportioned. In spring and summer, the primary sources were hydrocarbon-like OA (HOA) and cooking OA (COA), and the secondary components were low volatility (LV-OOA) and semi-volatile oxygenated OA (SV-OOA). In winter biomass burning OA (BBOA) was also resolved. In autumn, four factors were resolved, that is, OOA, HOA, COA and BBOA. In general, OOA (sum of LV-OOA and SV-OOA) was important in OA in four seasons, accounting for about 63%, 70%, 47% and 50%, respectively. SV-OOA dominated OA in summer (44%) due to the fresh secondary formation from strong photochemical oxidations; whereas, LV-OOA was dominant in OA in winter (33%), maybe because the transported air masses were more aged in heavily polluted days. The POA (sum of HOA, COA and BBOA) in OA was dominant in

  2. Young Adults in America. A Booklet for [Vietnamese] Refugees in Their Late Teens = Doi Song Thanh Thieu Nien O Hoa Ky. Tap Huong Dan Thanh Thieu Nien Viet-Nam.

    Science.gov (United States)

    Center for Applied Linguistics, Washington, DC. Language and Orientation Resource Center.

    Young persons in their late teens have problems and concerns that are different from those of persons who are younger or older. This booklet recognizes this fact and discusses some aspects of American life that might be of particular interest to young people of Vietnamese origin. It gives information that will be helpful in making knowledgeable…

  3. Orientation to Employment in the U.S. for Refugees--Vietnamese = Cong an viec lam o Hoa Ky: Tap Huong Dan danh cho Nguoi Ti Nan moi toi.

    Science.gov (United States)

    Center for Applied Linguistics, Washington, DC. Language and Orientation Resource Center.

    One of a series of refugee orientation materials, this guide to employment is intended to assist Vietnamese refugees in their understanding of the employment situation in the United States and to give them necessary information for obtaining work. The text is in Vietnamese followed by an English-language version, which is not an exact translation…

  4. English-Vietnamese Scientific Terminology for High School and Junior College Students. Book 4: Chemistry = Danh Tu Khoa Hoc Anh-Viet Danh Cho Hoc Sinh Trung Hoc Va Sinh Vien Nam Thu Nhat Dai Hoc. Quyen 4: Hoa Hoc.

    Science.gov (United States)

    Khanh-Van, Tran Thi

    Vietnamese students now enrolled in American high schools incur an extremely special need in English. After being taught subject matter disciplines in Vietnamese for many years, and while English is still a foreign language for them, these students are bound to go through two linguistic processes. First, while reading or sitting through lectures…

  5. The relationship between osteoarthritis of the hands, bone mineral ...

    African Journals Online (AJOL)

    Abir Naguib

    2011-08-09

    Aug 9, 2011 ... b Department of Clinical Pathology, Alexandria University, Egypt ... HOA were recruited along with 10 age-matched post-menopausal women with no signs of HOA ... and activities of daily living causing disability and lifestyle.

  6. Hypertrophe pulmonale Osteoarthropathie (Pierre-Marie-Bamberger-Syndrom) Fallbericht

    OpenAIRE

    2016-01-01

    Die Ätiologie der hypertrophen pulmonalen Osteoarthropathie (HOA) ist nicht bekannt. Die hypertrophen Veränderungen an den Knochen, Gelenken und Nägeln postulieren einen gemeinsamen pathophysiologischen Mechanismus der HOA. HOA ist üblicherweise assoziiert mit bösartigen Lungenerkrankungen wie dem nichtkleinzelligen Lungenkarzinom. Die Diagnose der hypertrophen pulmonalen Osteoarthropathie ist einfach zu stellen, soweit das Vollbild der HOA ausgeprägt ist. Wir berichten von einem Fall mit ei...

  7. Highly time-resolved chemical characterization of atmospheric fine particles during 2010 Shanghai World Expo

    Directory of Open Access Journals (Sweden)

    X.-F. Huang

    2012-06-01

    Full Text Available Shanghai, with a population of over 20 million, is the largest mega-city in China. Rapidly increasing industrial and metropolitan emissions have deteriorated its air quality in the past decades, with fine particle pollution as one of the major issues. However, systematic characterization of atmospheric fine particles with advanced measurement techniques has been very scarce in Shanghai. During 2010 Shanghai World Expo, we deployed a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS and a single particle soot photometer (SP2 in urban Shanghai between 15 May and 10 June 2010 to measure fine particles with a high time resolution. The 4-min resolution PM1 mass concentration ranged from 5.5 to 155 μg m−3, with an average of 29.2 μg m−3. On average, sulfate and organic matter (OM were the most abundant PM1 components, accounting for 33.3 and 28.7% of the total mass, respectively, while the fraction of nitrate showed an increasing trend with the increasing PM1 loading, indicating the photochemical nature of high fine particle pollution in Shanghai. Taking advantage of HR-ToF-AMS and SP2, OM was found to have an average OM/OC ratio (organic matter mass/organic carbon mass of 1.55 and black carbon (BC had an average number fraction of internally mixed BC of 41.2%. Positive matrix factorization (PMF analysis on the high resolution organic mass spectral dataset identified a hydrocarbon-like (HOA, a semi-volatile oxygenated (SV-OOA, and a low-volatility oxygenated (LV-OOA organic aerosol component, which on average accounted for 24.0, 46.8, and 29.2% of the total organic mass, respectively. The diurnal patterns of them with interesting time delay possibly implied a photochemical oxidizing process from HOA (and/or its concurrently emitted gaseous organic pollutants to SV-OOA to LV-OOA. Back trajectory analysis indicated that the northwesterly continental air mass represented the

  8. Chemical characterization of springtime submicrometer aerosol in Po Valley, Italy

    Directory of Open Access Journals (Sweden)

    S. Saarikoski

    2012-03-01

    Full Text Available The chemistry of submicron particles was investigated at San Pietro Capofiume (SPC measurement station in the Po Valley, Italy, in spring 2008. The measurements were performed by using both off-line and on-line instruments. Organic carbon (OC and elemental carbon, organic acids and biomass burning tracers were measured off-line by using a 24-h PM1 filter sampling. More detailed particle chemistry was achieved by using an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS and analyzing the data by positive matrix factorization (PMF. Oxalic acid had the highest concentrations of organic acids (campaign-average 97.4 ng m−3 followed by methane sulfonic, formic, malonic, and malic acids. Samples were also analyzed for glyoxylic, succinic, azelaic and maleic acids. In total, the nine acids composed 1.9 and 3.8% of OC and water-soluble OC, respectively (average, in terms of carbon atoms. Levoglucosan concentration varied from 17.7 to 495 ng m−3 with the concentration decreasing in the course of the campaign most likely due to the reduced use of domestic heating with wood. Six factors were found for organic aerosol (OA at SPC by PMF: hydrocarbon-like OA (HOA, biomass burning OA (BBOA, nitrogen-containing OA (N-OA and three different oxygenated OAs (OOA-a, OOA-b and OOA-c. Most of the OA mass was composed of OOA-a, HOA and OOA-c (26, 24 and 22%, respectively followed by OOA-b (13%, BBOA (8% and N-OA (7%. As expected, OOAs were the most oxygenated factors with organic matter:organic carbon (OM:OC ratios ranging from 1.9 to 2.2. The diurnal variability of the aerosol chemical composition was greatly affected by the boundary layer meteorology. Specifically, the effect of the nocturnal layer break-up in morning hours was most evident for nitrate and N-OA indicating that these compounds originated mainly from the local sources in the Po Valley. For sulfate and OOA-a the concentration did not

  9. Characterization of aerosol composition, concentrations, and sources at Baengnyeong Island, Korea using an aerosol mass spectrometer

    Science.gov (United States)

    Lee, Taehyoung; Choi, Jinsoo; Lee, Gangwoong; Ahn, Junyoung; Park, Jin Soo; Atwood, Samuel A.; Schurman, Misha; Choi, Yongjoo; Chung, Yoomi; Collett, Jeffrey L.

    2015-11-01

    To improve understanding of the sources and chemical properties of particulate pollutants on the western side of the Korean Peninsula, an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) measured non-refractory fine (PM1) particles from May to November, 2011 at Baengnyeong Island, South Korea. Organic matter and sulfate were generally the most abundant species and exhibited maximum concentrations of 36 μg/m3 and 39 μg/m3, respectively. Nitrate concentrations peaked at 32 μg/m3 but were typically much lower than sulfate and organic matter concentrations. May, September, October, and November featured the highest monthly average concentrations, with lower concentrations typically observed from June through August. Potential source contribution function (PSCF) analysis and individual case studies revealed that transport from eastern China, an area with high SO2 emissions, was associated with high particulate sulfate concentrations at the measurement site. Observed sulfate aerosol sometimes was fully neutralized by ammonium but often was acidic; the average ammonium to sulfate molar ratio was 1.49. Measured species size distributions revealed a range of sulfate particle size distributions with modes between 100 and 600 nm. Organic aerosol source regions were widespread, including contributions from eastern China and South Korea. Positive matrix factorization (PMF) analysis indicated three "factors," or types of organic aerosol, comprising one primary, hydrocarbon-like organic aerosol (HOA) and two oxidized organic aerosol (OOA) components, including a more oxidized (MO-OOA) and a less oxidized (LO-OOA) oxidized organic aerosol. On average, HOA and OOA contributed 21% and 79% of the organic mass (OM), respectively, with the MO-OOA fraction nearly three times as abundant as the LO-OOA fraction. Biomass burning contributions to observed OM were low during the late spring/early summer agricultural burning season in eastern China, since

  10. Diurnal variations of ambient particulate wood burning emissions and their contribution to the concentration of Polycyclic Aromatic Hydrocarbons (PAHs in Seiffen, Germany

    Directory of Open Access Journals (Sweden)

    L. Poulain

    2011-12-01

    Full Text Available Residential wood burning is becoming an increasingly important cause of air quality problems since it has become a popular source of alternative energy to fossil fuel. In order to characterize the contribution of residential wood burning to local particle pollution, a field campaign was organized at the village of Seiffen (Saxony, Germany. During this campaign, an Aerosol Mass Spectrometer (AMS was deployed in parallel to a PM1 high volume filter sampler. The AMS mass spectra were analyzed using Positive Matrix Factorization (PMF to obtain detailed information about the organic aerosol (OA. Biomass-burning organic aerosol (BBOA, Hydrocarbon-like organic aerosol (HOA, and Oxygenated Organic Aerosol (OOA were identified and represented 20%, 17% and 62% of total OA, respectively. Additionally, Polycyclic Aromatic Hydrocarbons (PAH were measured by the AMS with an average concentration of 10 ng m−3 and short term events of extremely high PAH concentration (up to 500 ng m−3 compared to the mean PAH value were observed during the whole measurement period. A comparison with the results from PM1 filter samples showed that the BBOA factor and the AMS PAH are good indicators of the total concentration of the different monosaccharide anhydrides and PAH measured on the filter samples. Based on its low correlation with CO and the low car traffic, the HOA factor was considered to be related to residential heating using liquid fuel. An influence of the time of the week (week vs. weekend on the diurnal profiles of the different OA components was observed. The weekdays were characterized by two maxima; a first one early in the morning and a stronger one in the evening. During the weekend days, the different OA components principally reached only one maximum in the afternoon. Finally, the PAH emitted directly from residential wood combustion was estimated to represent 1.5% of the total mass of the BBOA factor and

  11. Chemical characterization of springtime submicrometer aerosol in Po Valley, Italy

    Directory of Open Access Journals (Sweden)

    S. Saarikoski

    2012-09-01

    Full Text Available The chemistry of submicron particles was investigated at San Pietro Capofiume (SPC measurement station in the Po Valley, Italy, in spring 2008. The measurements were performed by using both off-line and on-line instruments. Organic carbon (OC and elemental carbon, organic acids and biomass burning tracers were measured off-line by using a 24-h PM1 filter sampling. More detailed particle chemistry was achieved by using a Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS and analyzing the data by positive matrix factorization (PMF. Oxalic acid had the highest concentrations of organic acids (campaign-average 97.4 ng m−3 followed by methane sulfonic, formic, malonic, and malic acids. Samples were also analyzed for glyoxylic, succinic, azelaic and maleic acids. In total, the nine acids composed 1.9 and 3.8% of OC and water-soluble OC, respectively (average, in terms of carbon atoms. Levoglucosan concentration varied from 17.7 to 495 ng m−3 with the concentration decreasing in the course of the campaign most likely due to the reduced use of domestic heating with wood. Six factors were found for organic aerosol (OA at SPC by PMF: hydrocarbon-like OA (HOA, biomass burning OA (BBOA, nitrogen-containing OA (N-OA and three different oxygenated OAs (OOA-a, OOA-b and OOA-c. Most of the OA mass was composed of OOA-a, HOA and OOA-c (26, 24 and 22%, respectively followed by OOA-b (13%, BBOA (8% and N-OA (7%. As expected, OOAs were the most oxygenated factors with organic matter:organic carbon (OM : OC ratios ranging from 1.9 to 2.2. The diurnal variability of the aerosol chemical composition was greatly affected by the boundary layer meteorology. Specifically, the effect of the nocturnal layer break-up in morning hours was most evident for nitrate and N-OA indicating that these compounds originated mainly from the local sources in the Po Valley. For sulfate and OOA-a the concentration did not

  12. Physical and chemical characterization of urban winter-time aerosols by mobile measurements in Helsinki, Finland

    Science.gov (United States)

    Pirjola, Liisa; Niemi, Jarkko V.; Saarikoski, Sanna; Aurela, Minna; Enroth, Joonas; Carbone, Samara; Saarnio, Karri; Kuuluvainen, Heino; Kousa, Anu; Rönkkö, Topi; Hillamo, Risto

    2017-06-01

    A two-week measurement campaign by a mobile laboratory van was performed in urban environments in the Helsinki metropolitan area, Finland, in winter 2012, to obtain a comprehensive view on aerosol properties and sources. The abundances and physico-chemical properties of particles varied strongly in time and space, depending on the main sources of aerosols. Four major types of winter aerosol were recognized: 1) clean background aerosol with low particle number (Ntot) and lung deposited surface area (LDSA) concentrations due to marine air flows from the Atlantic Ocean; 2) long-range transported (LRT) pollution aerosol due to air flows from eastern Europe where the particles were characterized by the high contribution of oxygenated organic aerosol (OOA) and inorganic species, particularly sulphate, but low BC contribution, and their size distribution possessed an additional accumulation mode; 3) fresh smoke plumes from residential wood combustion in suburban small houses, these particles were characterized by high biomass burning organic aerosol (BBOA) and black carbon (BC) concentrations; and 4) fresh emissions from traffic while driving on busy streets in the city centre and on the highways during morning rush hours. This aerosol was characterized by high concentration of Ntot, LDSA, small particles in the nucleation mode, as well as high hydrocarbon-like organic aerosol (HOA) and BC concentrations. In general, secondary components (OOA, NO3, NH4, and SO4) dominated the PM1 chemical composition during the LRT episode accounting for 70-80% of the PM1 mass, whereas fresh primary emissions (BC, HOA and BBOA) dominated the local traffic and wood burning emissions. The major individual particle types observed with electron microscopy analysis (TEM/EDX) were mainly related to residential wood combustion (K/S/C-rich, soot, other C-rich particles), traffic (soot, Si/Al-rich, Fe-rich), heavy fuel oil combustion in heat plants or ships (S with V-Ni-Fe), LRT pollutants (S

  13. Aerosol composition, sources and processes during wintertime in Beijing, China

    Directory of Open Access Journals (Sweden)

    Y. L. Sun

    2013-01-01

    Full Text Available Air pollution is a major environmental concern among all seasons in megacity Beijing, China. Here we present the results from a winter study that was conducted from 21 November 2011 to 20 January 2012 with an Aerodyne Aerosol Chemical Speciation Monitor (ACSM and various collocated instruments. The non-refractory submicron aerosol (NR-PM1 species vary dramatically with clean periods and pollution episodes alternating frequently. Compared to summer, wintertime submicron aerosols show much enhanced organics and chloride, which on average account for 52% and 5%, respectively of the total NR-PM1 mass. All NR-PM1 species show quite different diurnal behaviors between summer and winter. For example, the wintertime nitrate presents a gradual increase during daytime and correlates well with secondary organic aerosol (OA, indicating a dominant role of photochemical production over gas-particle partitioning. Positive matrix factorization was performed on ACSM OA mass spectra, and identified three primary OA (POA factors, i.e. hydrocarbon-like OA (HOA, cooking OA (COA, and coal combustion OA (CCOA, and one secondary factor, i.e. oxygenated OA (OOA. The POA dominates OA during wintertime, contributing 69% with the rest of 31% being SOA. Further, all POA components show pronounced diurnal cycles with the highest concentrations occurring at nighttime. CCOA is the largest primary source during the heating season, on average accounting for 33% of OA and 17% of NR-PM1. CCOA also plays a significant role in chemically-resolved particulate matter (PM pollution as its mass contribution increases linearly as a function of NR-PM1 mass loadings. The SOA however presents a reversed trend, which might indicate the limited SOA formation during high PM pollution episodes in winter. The effects of meteorology on PM pollution and aerosol processing were also explored. In particular, the sulfate mass is largely enhanced

  14. A case study of aerosol processing and evolution in summer in New York City

    Directory of Open Access Journals (Sweden)

    Y. L. Sun

    2011-09-01

    Full Text Available We have investigated an aerosol processing and evolution event from 21–22 July during the summer 2009 Field Intensive Study at Queens College in New York City (NYC. The evolution processes are characterized by three consecutive stages: (1 aerosol wet scavenging, (2 nighttime nitrate formation, and (3 photochemical production and evolution of secondary aerosol species. Our results suggest that wet scavenging of aerosol species tends to be strongly related to their hygroscopicities and also mixing states. The scavenging leads to a significant change in bulk aerosol composition and average carbon oxidation state because of scavenging efficiencies in the following order: sulfate > low-volatility oxygenated organic aerosol (LV-OOA > semi-volatile OOA (SV-OOA > hydrocarbon-like OA (HOA. The second stage involves a quick formation of nitrate from heterogeneous reactions at nighttime. During the third stage, simultaneous increases of sulfate and SV-OOA were observed shortly after sunrise, indicating secondary aerosol formation. Organic aerosol particles become highly oxidized in ~half day as the result of photochemical processing, consistent with previously reported results from the CO-tracer method (OA/ΔCO. The photochemical reactions appear to progress gradually associated with a transformation of semi-volatile OOA to low-volatility species based on the evolution trends of oxygen-to-carbon (O/C ratio, relationship between f44 (fraction of m/z 44 in OA and f43 (fraction of m/z 43 in OA, and size evolution of OOA and HOA. Aerosols appear to become more internally mixed during the processing. Our results suggest that functionalization by incorporation of both C and O plays a major role in the early period of OA oxidation (O/C <0.5. Our results also show that photochemical production of LV-OOA during this event is approximately a few hours behind of sulfate production, which might explain the sometimes lack of correlations between LV

  15. Seasonal characterization of submicron aerosol chemical composition and organic aerosol sources in the southeastern United States: Atlanta, Georgia,and Look Rock, Tennessee

    Science.gov (United States)

    Hapsari Budisulistiorini, Sri; Baumann, Karsten; Edgerton, Eric S.; Bairai, Solomon T.; Mueller, Stephen; Shaw, Stephanie L.; Knipping, Eladio M.; Gold, Avram; Surratt, Jason D.

    2016-04-01

    A year-long near-real-time characterization of non-refractory submicron aerosol (NR-PM1) was conducted at an urban (Atlanta, Georgia, in 2012) and rural (Look Rock, Tennessee, in 2013) site in the southeastern US using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) collocated with established air-monitoring network measurements. Seasonal variations in organic aerosol (OA) and inorganic aerosol species are attributed to meteorological conditions as well as anthropogenic and biogenic emissions in this region. The highest concentrations of NR-PM1 were observed during winter and fall seasons at the urban site and during spring and summer at the rural site. Across all seasons and at both sites, NR-PM1 was composed largely of OA (up to 76 %) and sulfate (up to 31 %). Six distinct OA sources were resolved by positive matrix factorization applied to the ACSM organic mass spectral data collected from the two sites over the 1 year of near-continuous measurements at each site: hydrocarbon-like OA (HOA), biomass burning OA (BBOA), semi-volatile oxygenated OA (SV-OOA), low-volatility oxygenated OA (LV-OOA), isoprene-derived epoxydiols (IEPOX) OA (IEPOX-OA) and 91Fac (a factor dominated by a distinct ion at m/z 91 fragment ion previously observed in biogenic influenced areas). LV-OOA was observed throughout the year at both sites and contributed up to 66 % of total OA mass. HOA was observed during the entire year only at the urban site (on average 21 % of OA mass). BBOA (15-33 % of OA mass) was observed during winter and fall, likely dominated by local residential wood burning emission. Although SV-OOA contributes quite significantly ( ˜ 27 %), it was observed only at the urban site during colder seasons. IEPOX-OA was a major component (27-41 %) of OA at both sites, particularly in spring and summer. An ion fragment at m/z 75 is well correlated with the m/z 82 ion associated with the aerosol mass spectrum of IEPOX-derived secondary organic aerosol (SOA). The

  16. Spatial variation of chemical composition and sources of submicron aerosol in Zurich: factor analysis of mobile aerosol mass spectrometer data

    Directory of Open Access Journals (Sweden)

    C. Mohr

    2011-04-01

    Full Text Available Mobile measurements of PM1 (PM with an aerodynamic diameter D<1 μm chemical composition using a quadrupole aerosol mass spectrometer and a multi-angle absorption photometer were performed using the PSI mobile laboratory during winter 2007/2008 and December 2008 in the metropolitan area of Zurich, Switzerland. Positive matrix factorization (PMF applied to the organic fraction of PM1 yielded 3 factors: Hydrocarbon-like organic aerosol (HOA related to traffic emissions; organic aerosol from wood burning for domestic heating purposes (WBOA; and oxygenated organic aerosol (OOA, assigned to secondary organic aerosol formed by oxidation of volatile precursors. The spatial variation of the chemical composition of PM1 shows a uniform distribution throughout the city: for primary emissions, road traffic is important along major roads (varying between 7 and 14% of PM1 for different sites within the city, but overall, domestic wood burning is more important for the organic aerosol concentrations in Zurich during winter time (varying between 8–15% of PM1 for different sites within the city. OOA makes up the largest fraction of organic aerosol (44% on average. A new method, based on simultaneous on-road mobile and stationary background measurements and using the ratio of on-road sulfate to stationary sulfate to correct for small-scale dynamic effects, allows for the separation of PM1 emitted or produced locally and the PM1 from the regional background. It could be shown that especially during thermal inversions over the Swiss plateau, regional background concentrations contribute substantially to particulate number concentrations (60% on average as well as to the concentrations of PM1 components (on average 60% for black carbon and HOA, over 97% for WBOA and OOA, and more than 94% for the measured inorganic components in downtown Zurich. The results emphasize, on

  17. Highly time-resolved chemical characterization of atmospheric fine particles during 2010 Shanghai World Expo

    Directory of Open Access Journals (Sweden)

    X.-F. Huang

    2012-01-01

    Full Text Available Shanghai, with a population of over 20 million, is the largest mega-city in China. Rapidly increasing industrial and metropolitan emissions have deteriorated its air quality in the past decades, with fine particle pollution as one of the major issues. However, systematic characterization of atmospheric fine particles with advanced measurement techniques has been very scarce in Shanghai. During 2010 Shanghai World Expo, we deployed a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS and a single particle soot photometer (SP2 in urban Shanghai between 15 May and 10 June 2010 to measure fine particles with a high time resolution. The 4-min resolution PM1 mass concentration ranged from 5.5 to 155 μg m−3, with an average of 29.2 μg m−3. On average, sulfate and organic matter (OM were the most abundant PM1 components, accounting for 33.3 and 28.7% of the total mass, respectively, while the fraction of nitrate showed an increasing trend with the increasing PM1 loading, indicating the photochemical nature of high fine particle pollution in Shanghai. Taking advantage of HR-ToF-AMS and SP2, OM was found to have an average OM/OC ratio (organic matter mass/organic carbon mass of 1.55 and black carbon (BC had an average number fraction of internally mixed BC of 41.2%. Positive matrix factorization (PMF analysis on the high resolution organic mass spectral dataset identified a hydrocarbon-like (HOA, a semi-volatile oxygenated (SV-OOA, and a low-volatility oxygenated (LV-OOA organic aerosol component, which on average accounted for 24.0, 46.8, and 29.2% of the total organic mass, respectively. The diurnal patterns of them with interesting time delay possibly implied a photochemical oxidizing process from HOA (and/or its concurrently emitted gaseous organic pollutants to SV-OOA to LV-OOA. Back trajectory analysis indicated that the northwesterly continental air mass represented the

  18. Organic aerosol source apportionment by offline-AMS over a full year in Marseille

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    C. Bozzetti

    2017-07-01

    Full Text Available We investigated the seasonal trends of OA sources affecting the air quality of Marseille (France, which is the largest harbor of the Mediterranean Sea. This was achieved by measurements of nebulized filter extracts using an aerosol mass spectrometer (offline-AMS. In total 216 PM2. 5 (particulate matter with an aerodynamic diameter  <  2.5 µm filter samples were collected over 1 year from August 2011 to July 2012. These filters were used to create 54 composite samples which were analyzed by offline-AMS. The same samples were also analyzed for major water-soluble ions, metals, elemental and organic carbon (EC ∕ OC, and organic markers, including n-alkanes, hopanes, polycyclic aromatic hydrocarbons (PAHs, lignin and cellulose pyrolysis products, and nitrocatechols. The application of positive matrix factorization (PMF to the water-soluble AMS spectra enabled the extraction of five factors, related to hydrocarbon-like OA (HOA, cooking OA (COA, biomass burning OA (BBOA, oxygenated OA (OOA, and an industry-related OA (INDOA. Seasonal trends and relative contributions of OA sources were compared with the source apportionment of OA spectra collected from the AMS field deployment at the same station but in different years and for shorter monitoring periods (February 2011 and July 2008. Online- and offline-AMS source apportionment revealed comparable seasonal contribution of the different OA sources. Results revealed that BBOA was the dominant source during winter, representing on average 48 % of the OA, while during summer the main OA component was OOA (63 % of OA mass on average. HOA related to traffic emissions contributed on a yearly average 17 % to the OA mass, while COA was a minor source contributing 4 %. The contribution of INDOA was enhanced during winter (17 % during winter and 11 % during summer, consistent with an increased contribution from light alkanes, light PAHs (fluoranthene, pyrene, phenanthrene, and

  19. Genome-wide association and functional studies identify a role for IGFBP3 in hip osteoarthritis

    NARCIS (Netherlands)

    D.S. Evans (Daniel); F. Cailotto (Frederic); N. Parimi (Neeta); A.M. Valdes (Ana Maria); M.C. Castaño Betancourt (Martha); Y. Liu (Youfang); R.C. Kaplan (Robert); M. Bidlingmaier (Martin); R.S. Vasan (Ramachandran Srini); A. Teumer (Alexander); G.J. Tranah (Gregory); M.C. Nevitt (Michael); S. Cummings; E.S. Orwoll (Eric); E. Barrett-Connor (Elizabeth); J.B. Renner (Jordan); J.M. Jordan (Joanne); M. Doherty (Michael); S. Doherty (Sally); A.G. Uitterlinden (André); J.B.J. van Meurs (Joyce); T.D. Spector (Timothy); R.J. Lories (Rik); N.E. Lane

    2014-01-01

    textabstractObjectives To identify genetic associations with hip osteoarthritis (HOA), we performed a meta-analysis of genome-wide association studies (GWAS) of HOA. Methods The GWAS meta-analysis included approximately 2.5 million imputed HapMap single nucleotide polymorphisms (SNPs). HOA cases and

  20. Comparison of higher order aberrations after wavefront-guided LASIK and PRK: One year follow-up results

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    Seyed Hamid Reza Jahadi Hosseini

    2016-01-01

    Conclusion: For the 6mm pupil size, the total HOA increased following both personalized PRK and LASIK with no significant difference between the two groups. Change of the total HOA RMS was influenced by the preoperative values. The known influencing factors could predict nearly 50% of the changes in total HOA.

  1. Higher order antibunching and subpossonian photon statistics in five wave mixing process

    CERN Document Server

    Verma, Amit

    2009-01-01

    We have investigated the possibility of observing higher order antibunching (HOA) and higher order subpossonian photon statistics (HOSPS) in five wave mixing and third harmonic generation process. It had been shown that both processes satisfy the criteria of HOA and HOSPS. Further, some observations on the nature of interaction which produces HOA and HOSPS are reported.

  2. Organic aerosol source apportionment in London 2013 with ME-2: exploring the solution space with annual and seasonal analysis

    Science.gov (United States)

    Reyes-Villegas, Ernesto; Green, David C.; Priestman, Max; Canonaco, Francesco; Coe, Hugh; Prévôt, André S. H.; Allan, James D.

    2016-12-01

    The multilinear engine (ME-2) factorization tool is being widely used following the recent development of the Source Finder (SoFi) interface at the Paul Scherrer Institute. However, the success of this tool, when using the a value approach, largely depends on the inputs (i.e. target profiles) applied as well as the experience of the user. A strategy to explore the solution space is proposed, in which the solution that best describes the organic aerosol (OA) sources is determined according to the systematic application of predefined statistical tests. This includes trilinear regression, which proves to be a useful tool for comparing different ME-2 solutions. Aerosol Chemical Speciation Monitor (ACSM) measurements were carried out at the urban background site of North Kensington, London from March to December 2013, where for the first time the behaviour of OA sources and their possible environmental implications were studied using an ACSM. Five OA sources were identified: biomass burning OA (BBOA), hydrocarbon-like OA (HOA), cooking OA (COA), semivolatile oxygenated OA (SVOOA) and low-volatility oxygenated OA (LVOOA). ME-2 analysis of the seasonal data sets (spring, summer and autumn) showed a higher variability in the OA sources that was not detected in the combined March-December data set; this variability was explored with the triangle plots f44 : f43 f44 : f60, in which a high variation of SVOOA relative to LVOOA was observed in the f44 : f43 analysis. Hence, it was possible to conclude that, when performing source apportionment to long-term measurements, important information may be lost and this analysis should be done to short periods of time, such as seasonally. Further analysis on the atmospheric implications of these OA sources was carried out, identifying evidence of the possible contribution of heavy-duty diesel vehicles to air pollution during weekdays compared to those fuelled by petrol.

  3. Modeling regional secondary organic aerosol using the Master Chemical Mechanism

    Science.gov (United States)

    Li, Jingyi; Cleveland, Meredith; Ziemba, Luke D.; Griffin, Robert J.; Barsanti, Kelley C.; Pankow, James F.; Ying, Qi

    2015-02-01

    A modified near-explicit Master Chemical Mechanism (MCM, version 3.2) with 5727 species and 16,930 reactions and an equilibrium partitioning module was incorporated into the Community Air Quality Model (CMAQ) to predict the regional concentrations of secondary organic aerosol (SOA) from volatile organic compounds (VOCs) in the eastern United States (US). In addition to the semi-volatile SOA from equilibrium partitioning, reactive surface uptake processes were used to simulate SOA formation due to isoprene epoxydiol, glyoxal and methylglyoxal. The CMAQ-MCM-SOA model was applied to simulate SOA formation during a two-week episode from August 28 to September 7, 2006. The southeastern US has the highest SOA, with a maximum episode-averaged concentration of ∼12 μg m-3. Primary organic aerosol (POA) and SOA concentrations predicted by CMAQ-MCM-SOA agree well with AMS-derived hydrocarbon-like organic aerosol (HOA) and oxygenated organic aerosol (OOA) urban concentrations at the Moody Tower at the University of Houston. Predicted molecular properties of SOA (O/C, H/C, N/C and OM/OC ratios) at the site are similar to those reported in other urban areas, and O/C values agree with measured O/C at the same site. Isoprene epoxydiol is predicted to be the largest contributor to total SOA concentration in the southeast US, followed by methylglyoxal and glyoxal. The semi-volatile SOA components are dominated by products from β-caryophyllene oxidation, but the major species and their concentrations are sensitive to errors in saturation vapor pressure estimation. A uniform decrease of saturation vapor pressure by a factor of 100 for all condensable compounds can lead to a 150% increase in total SOA. A sensitivity simulation with UNIFAC-calculated activity coefficients (ignoring phase separation and water molecule partitioning into the organic phase) led to a 10% change in the predicted semi-volatile SOA concentrations.

  4. Aerosol Simulation in the Mexico City Metropolitan Area during MCMA2003 using CMAQ/Models3

    Science.gov (United States)

    Bei, N.; Zavala, M.; Lei, W.; de Foy, B.; Molina, L.

    2007-12-01

    CMAQ/Models3 has been employed to simulate the aerosol distribution and variation during the period from 13 to 16 April 2003 over the Mexico City Metropolitan Area as part of MCMA-2003 campaign. The meteorological fields are simulated using MM5, with three one-way nested grids with horizontal resolutions of 36, 12 and 3 km and 23 sigma levels in the vertical. MM5 3DVAR system has also been incorporated into the meteorological simulations. Chemical initial and boundary conditions are interpolated from the MOZART output. The SAPRC emission inventory is developed based on the official emission inventory for MCMA in 2004. The simulated mass concentrations of different aerosol compositions, such as elemental carbon (EC), primary organic aerosol (POA), secondary organic aerosol (SOA), nitrate, ammonium, and sulfate have been compared to the measurements taken at the National Center for Environmental Research and Training (Centro Nacional de Investigacion y Capacitacion Ambiental, CENICA) super-site. Hydrocarbon-like organic aerosol (HOA) and oxygenated organic aerosol (OOA) are used as observations of POA and SOA, respectively in this study. The preliminary model results show that the temporal evolutions of EC and POA are reasonable compared with measurements. The peak time of EC and POA are basically reproduced, thus validating the emission inventory and its processing through CMAQ/Models3. But the magnitude of EC and POA are underestimated over the entire episode. The modeled nitrate and ammonium concentrations are overestimated on most of the days. There is 1-2 hour difference between the simulated peak time of nitrate and ammonium aerosols compared to observations at CENICA. The simulated mass concentrations of SOA and sulfate are significantly underestimated. The reasons of the discrepancy between simulations and measurements are due to the uncertainties existing in the emission inventory, meteorological fields, and as well as aerosol formation mechanism in the case

  5. Source apportionment of size and time resolved trace elements and organic aerosols from an urban courtyard site in Switzerland

    Directory of Open Access Journals (Sweden)

    A. Richard

    2011-02-01

    Full Text Available Time and size resolved data of trace elements were obtained from measurements with a rotating drum impactor (RDI and subsequent X-ray fluorescence spectrometry. Trace elements can act as indicators for the identification of sources of particulate matter <10 μm (PM10 in ambient air. Receptor modeling was performed with positive matrix factorization (PMF for trace element data from an urban background site in Zürich, Switzerland. Eight different sources were identified for the three examined size ranges (PM1−0.1, PM2.5−1 and PM10−2.5: secondary sulfate, wood combustion, fire works, road traffic, mineral dust, de-icing salt, industrial and local anthropogenic activities. The major component was secondary sulfate for the smallest size range; the road traffic factor was found in all three size ranges. This trace element analysis is complemented with data from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (AMS, assessing the PM1 fraction of organic aerosols. A separate PMF analysis revealed three factors related to three of the sources found with the RDI: oxygenated organic aerosol (OOA, related to inorganic secondary sulfate, hydrocarbon like organic aerosol (HOA, related to road traffic and biomass burning organic aerosol (BBOA, explaining 60%, 22% and 17% of total measured organics, respectively. Since different compounds are used for the source classification, a higher percentage of the ambient PM10 mass concentration can be apportioned to sources by the combination of both methods.

  6. Aged organic aerosol in the Eastern Mediterranean: the Finokalia Aerosol Measurement Experiment – 2008

    Directory of Open Access Journals (Sweden)

    L. Hildebrandt

    2010-05-01

    Full Text Available Aged organic aerosol (OA was measured at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiment-2008 (FAME-2008, which was part of the EUCAARI intensive campaign of May 2008. The site at Finokalia is influenced by air masses from different source regions, including long-range transport of pollution from continental Europe. A quadrupole aerosol mass spectrometer (Q-AMS was employed to measure the size-resolved chemical composition of non-refractory submicron aerosol (NR-PM1, and to estimate the extent of oxidation of the organic aerosol. Factor analysis was used to gain insights into the processes and sources affecting the OA composition. The particles were internally mixed and liquid. The largest fraction of the dry NR-PM1 sampled was ammonium sulfate and ammonium bisulfate, followed by organics and a small amount of nitrate. The variability in OA composition could be explained with two factors of oxygenated organic aerosol (OOA with differing extents of oxidation but similar volatility. Hydrocarbon-like organic aerosol (HOA was not detected. There was no statistically significant diurnal variation in the bulk composition of NR-PM1 such as total sulfate or total organic aerosol concentrations. However, the OA composition exhibited statistically significant diurnal variation with more oxidized OA in the afternoon. The organic aerosol was highly oxidized, regardless of the source region. Total OA concentrations also varied little with source region, suggesting that local sources had only a small effect on OA concentrations measured at Finokalia. The aerosol was transported for about one day before arriving at the site, corresponding to an OH exposure of approximately 4×1011 molecules cm−3 s. The constant extent of oxidation suggests that atmospheric aging results in a highly oxidized OA at these OH exposures, regardless of the aerosol source.

  7. Measurement of nonvolatile particle number size distribution

    Science.gov (United States)

    Gkatzelis, G. I.; Papanastasiou, D. K.; Florou, K.; Kaltsonoudis, C.; Louvaris, E.; Pandis, S. N.

    2016-01-01

    An experimental methodology was developed to measure the nonvolatile particle number concentration using a thermodenuder (TD). The TD was coupled with a high-resolution time-of-flight aerosol mass spectrometer, measuring the chemical composition and mass size distribution of the submicrometer aerosol and a scanning mobility particle sizer (SMPS) that provided the number size distribution of the aerosol in the range from 10 to 500 nm. The method was evaluated with a set of smog chamber experiments and achieved almost complete evaporation (> 98 %) of secondary organic as well as freshly nucleated particles, using a TD temperature of 400 °C and a centerline residence time of 15 s. This experimental approach was applied in a winter field campaign in Athens and provided a direct measurement of number concentration and size distribution for particles emitted from major pollution sources. During periods in which the contribution of biomass burning sources was dominant, more than 80 % of particle number concentration remained after passing through the thermodenuder, suggesting that nearly all biomass burning particles had a nonvolatile core. These remaining particles consisted mostly of black carbon (60 % mass contribution) and organic aerosol (OA; 40 %). Organics that had not evaporated through the TD were mostly biomass burning OA (BBOA) and oxygenated OA (OOA) as determined from AMS source apportionment analysis. For periods during which traffic contribution was dominant 50-60 % of the particles had a nonvolatile core while the rest evaporated at 400 °C. The remaining particle mass consisted mostly of black carbon with an 80 % contribution, while OA was responsible for another 15-20 %. Organics were mostly hydrocarbon-like OA (HOA) and OOA. These results suggest that even at 400 °C some fraction of the OA does not evaporate from particles emitted from common combustion processes, such as biomass burning and car engines, indicating that a fraction of this type of OA

  8. Measurement of non-volatile particle number size distribution

    Science.gov (United States)

    Gkatzelis, G. I.; Papanastasiou, D. K.; Florou, K.; Kaltsonoudis, C.; Louvaris, E.; Pandis, S. N.

    2015-06-01

    An experimental methodology was developed to measure the non-volatile particle number concentration using a thermodenuder (TD). The TD was coupled with a high-resolution time-of-flight aerosol mass spectrometer, measuring the chemical composition and mass size distribution of the submicrometer aerosol and a scanning mobility particle sizer (SMPS) that provided the number size distribution of the aerosol in the range from 10 to 500 nm. The method was evaluated with a set of smog chamber experiments and achieved almost complete evaporation (> 98 %) of secondary organic as well as freshly nucleated particles, using a TD temperature of 400 °C and a centerline residence time of 15 s. This experimental approach was applied in a winter field campaign in Athens and provided a direct measurement of number concentration and size distribution for particles emitted from major pollution sources. During periods in which the contribution of biomass burning sources was dominant, more than 80 % of particle number concentration remained after passing through the thermodenuder, suggesting that nearly all biomass burning particles had a non-volatile core. These remaining particles consisted mostly of black carbon (60 % mass contribution) and organic aerosol, OA (40 %). Organics that had not evaporated through the TD were mostly biomass burning OA (BBOA) and oxygenated OA (OOA) as determined from AMS source apportionment analysis. For periods during which traffic contribution was dominant 50-60 % of the particles had a non-volatile core while the rest evaporated at 400 °C. The remaining particle mass consisted mostly of black carbon (BC) with an 80 % contribution, while OA was responsible for another 15-20 %. Organics were mostly hydrocarbon-like OA (HOA) and OOA. These results suggest that even at 400 °C some fraction of the OA does not evaporate from particles emitted from common combustion processes, such as biomass burning and car engines, indicating that a fraction of this type

  9. Source apportionment of size and time resolved trace elements and organic aerosols from an urban courtyard site in Switzerland

    Directory of Open Access Journals (Sweden)

    A. Richard

    2011-09-01

    Full Text Available Time and size resolved data of trace elements were obtained from measurements with a rotating drum impactor (RDI and subsequent X-ray fluorescence spectrometry. Trace elements can act as indicators for the identification of sources of particulate matter <10 μm (PM10 in ambient air. Receptor modeling was performed with positive matrix factorization (PMF for trace element data from an urban background site in Zürich, Switzerland. Eight different sources were identified for the three examined size ranges (PM1−0.1, PM2.5−1 and PM10−2.5: secondary sulfate, wood combustion, fire works, road traffic, mineral dust, de-icing salt, industrial and local anthropogenic activities. The major component was secondary sulfate for the smallest size range; the road traffic factor was found in all three size ranges. This trace element analysis is complemented with data from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (AMS, assessing the PM1 fraction of organic aerosols. A separate PMF analysis revealed three factors related to three of the sources found with the RDI: oxygenated organic aerosol (OOA, related to inorganic secondary sulfate, hydrocarbon-like organic aerosol (HOA, related to road traffic and biomass burning organic aerosol (BBOA, explaining 60 %, 22 % and 17 % of total measured organics, respectively. Since different compounds are used for the source classification, a higher percentage of the ambient PM10 mass concentration can be apportioned to sources by the combination of both methods.

  10. Emission and chemistry of organic carbon in the gas and aerosol phase at a sub-urban site near Mexico City in March 2006 during the MILAGRO study

    Directory of Open Access Journals (Sweden)

    J. A. de Gouw

    2008-12-01

    Full Text Available Volatile organic compounds (VOCs and carbonaceous aerosol were measured at a sub-urban site near Mexico City in March of 2006 during the MILAGRO study (Megacity Initiative: Local and Global Research Objectives. Diurnal variations of hydrocarbons, elemental carbon (EC and hydrocarbon-like organic aerosol (HOA were dominated by a high peak in the early morning when local emissions accumulated in a shallow boundary layer, and a minimum in the afternoon when the emissions were diluted in a significantly expanded boundary layer and, in case of the reactive gases, removed by OH. In comparison, diurnal variations of species with secondary sources such as the aldehydes, ketones, oxygenated organic aerosol (OOA and water-soluble organic carbon (WSOC stayed relatively high in the afternoon indicating strong photochemical formation. Emission ratios of many hydrocarbon species relative to CO were higher in Mexico City than in the US, but we found similar emission ratios for most oxygenated VOCs and organic aerosol. Secondary formation of acetone may be more efficient in Mexico City than in the US, due to higher emissions of alkane precursors from the use of liquefied petroleum gas. Secondary formation of organic aerosol was similar between Mexico City and the US. Combining the data for all measured gas and aerosol species, we describe the budget of total observed organic carbon (TOOC, and find that the enhancement ratio of TOOC relative to CO is conserved between the early morning and mid afternoon despite large compositional changes. Finally, the influence of biomass burning is investigated using the measurements of acetonitrile, which was found to correlate with levoglucosan in the particle phase. Diurnal variations of acetonitrile indicate a contribution from local burning sources. Scatter plots of acetonitrile versus CO suggest that the contribution of biomass burning to the enhancement of most gas and aerosol species was not dominant and perhaps not

  11. Emission and Chemistry of Organic Carbon in the Gas and Aerosol Phase at a Sub-Urban Site Near Mexico City in March 2006 During the MILAGRO Study

    Energy Technology Data Exchange (ETDEWEB)

    de Gouw, Joost A.; Welsh-Bon, Daniel; Warneke, Carsten; Kuster, W. C.; Alexander, M. L.; Baker, Angela K.; Beyersdorf, Andreas J.; Blake, D. R.; Canagaratna, Manjula R.; Celada, A. T.; Huey, L. G.; Junkermann, W.; Onasch, Timothy B.; Salcido, A.; Sjostedt, S. J.; Sullivan, Amy; Tanner, David J.; Vargas-Ortiz, Leroy; Weber, R. J.; Worsnop, Douglas R.; Yu, Xiao-Ying; Zaveri, Rahul A.

    2009-05-28

    Volatile organic compounds (VOCs) and carbonaceous aerosol were measured at a sub-urban site near Mexico City in March of 2006 during the MILAGRO study (Megacity Initiative: Local and Global Research Objectives). Diurnal variations of hydrocarbons, elemental carbon (EC) and hydrocarbon-like organic aerosol (HOA) were dominated by a high peak in the early morning when local emissions accumulated in a shallow boundary layer, and a minimum in the afternoon when the emissions were diluted in a significantly expanded boundary layer and, in case of the reactive gases, removed by OH. In comparison, diurnal variations of species with secondary sources such as the aldehydes, ketones, oxygenated organic aerosol (OOA) and water-soluble organic carbon (WSOC) stayed relatively high in the afternoon indicating strong photochemical formation. Emission ratios of many hydrocarbon species relative to CO were higher in Mexico City than in the U.S., but we found similar emission ratios for most oxygenated VOCs and organic aerosol. Secondary formation of acetone may be more efficient in Mexico City than in the U.S., due to higher emissions of alkane precursors from the use of liquefied petroleum gas. Secondary formation of organic aerosol was similar between Mexico City and the U.S. Combining the data for all measured gas and aerosol species, we describe the budget of total observed organic carbon (TOOC), and find that the enhancement ratio of TOOC relative to CO is conserved between the early morning and mid afternoon despite large compositional changes. Finally, the influence of biomass burning is investigated using the measurements of acetonitrile, which was found to correlate with levoglucosan in the particle phase. Diurnal variations of acetonitrile indicate a contribution from local burning sources. Scatter plots of acetonitrile versus CO suggest that the contribution of biomass burning to the enhancement of most gas and aerosol species was not dominant and perhaps not dissimilar

  12. Aged organic aerosol in the Eastern Mediterranean: the Finokalia aerosol measurement experiment-2008

    Directory of Open Access Journals (Sweden)

    L. Hildebrandt

    2010-01-01

    Full Text Available Aged organic aerosol (OA was measured at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiment-2008 (FAME-2008, which was part of the EUCAARI intensive campaign of May 2008. The site at Finokalia is influenced by air masses from different source regions, including long-range transport of pollution from continental Europe. A quadrupole aerosol mass spectrometer (Q-AMS was employed to measure the size-resolved chemical composition of non-refractory submicron aerosol (NR-PM1, and to estimate the extent of oxidation of the organic aerosol. Factor analysis was used to gain insights into the processes and sources affecting the OA composition. The particles were internally mixed and liquid. The largest fraction of the dry NR-PM1 sampled was ammonium sulfate and ammonium bisulfate, followed by organics and a small amount of nitrate. The variability in OA composition could be explained with two factors of oxygenated organic aerosol (OOA with differing extents of oxidation but similar volatility. Hydrocarbon-like organic aerosol (HOA was not detected. There was no statistically significant diurnal variation in the bulk composition of NR-PM1 such as total sulfate or total organic aerosol concentrations. However, the OA composition exhibited statistically significant diurnal variation with more oxidized OA in the afternoon. The organic aerosol was highly oxidized, regardless of the source region. Total OA concentrations also varied little with time of day, suggesting that local sources had only a small effect on OA concentrations measured at Finokalia. The aerosol was transported for about one day before arriving at the site, corresponding to an OH exposure of approximately 4×1011 molecules cm−3 s. The constant extent of oxidation suggests that atmospheric aging results in a highly oxidized OA at these OH exposures, regardless of the aerosol source.

  13. Submicron particle mass concentrations and sources in the Amazonian wet season (AMAZE-08)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q.; Farmer, D. K.; Rizzo, L. V.; Pauliqueivis, T.; Kuwata, Mikinori; Karl, Thomas G.; Guenther, Alex B.; Allan, James D.; Coe, H.; Andreae, M. O.; Poeschl, U.; Jiminez, J. L.; Artaxo, Paulo; Martin, Scot T.

    2015-01-01

    Real-time mass spectra of non-refractory component of submicron aerosol particles were recorded in a tropical rainforest in the central Amazon basin during the wet season of 2008, as a part of the Amazonian Aerosol Characterization Experiment (AMAZE-08). Organic components accounted on average for more than 80% of the non-refractory submicron particle mass concentrations during the period of measurements. Ammonium was present in sufficient quantities to halfway neutralize sulfate. In this acidic, isoprene-dominated, low-NOx environment the high-resolution mass spectra as well as mass closures with ion chromatography measurements did not provide evidence for significant contributions of organosulfate species, at least at concentrations above uncertainty levels. Positive-matrix factorization of the time series of particle mass spectra identified four statistical factors to account for the variance of the signal intensities of the organic constituents: a factor HOA having a hydrocarbon-like signature and identified as regional emissions of primary organic material, a factor OOA-1 associated with fresh production of secondary organic material by a mechanism of BVOC oxidation followed by gas-to-particle conversion, a factor OOA-2 consistent with reactive uptake of isoprene oxidation products, especially epoxydiols by acidic particles, and a factor OOA-3 associated with long range transport and atmospheric aging. The OOA-1, -2, and -3 factors had progressively more oxidized signatures. Diameter-resolved mass spectral markers also suggested enhanced reactive uptake of isoprene oxidation products to the accumulation mode for the OOA-2 factor, and such size partitioning can be indicative of in-cloud process. The campaign-average factor loadings were in a ratio of 1.1:1.0 for the OOA-1 compared to the OOA-2 pathway, suggesting the comparable importance of gas-phase compared to particle-phase (including cloud waters) production pathways of secondary organic material during

  14. Characterization of urban aerosol in Cork City (Ireland using aerosol mass spectrometry

    Directory of Open Access Journals (Sweden)

    M. Dall'Osto

    2012-11-01

    Full Text Available Ambient wintertime background urban aerosol in Cork City, Ireland, was characterized using aerosol mass spectrometry. During the three-week measurement study in 2009, 93% of the 1 200 000 single particles characterized by an Aerosol Time-Of-Flight Mass Spectrometer (TSI ATOFMS were classified into five organic-rich particle types, internally-mixed to different proportions with Elemental Carbon (EC, sulphate and nitrate while the remaining 7% was predominantly inorganic in nature. Non-refractory PM1 aerosol was also characterized using a High Resolution Time-Of-Flight Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS and was also found to comprise organic matter as the most abundant species (62%, followed by nitrate (15%, sulphate (9% and ammonium (9%, and then chloride (5%.

    Positive matrix factorization (PMF was applied to the HR-ToF-AMS organic matrix and a five-factor solution was found to describe the variance in the data well. Specifically, "Hydrocarbon-like" Organic Aerosol (HOA comprised 19% of the mass, "Oxygenated low volatility" Organic Aerosols (LV-OOA comprised 19%, "Biomass wood Burning" Organic Aerosol (BBOA comprised 23%, non-wood solid-fuel combustion "Peat and Coal" Organic Aerosol (PCOA comprised 21%, and finally, a species type characterized by primary m/z peaks at 41 and 55, similar to previously-reported "Cooking" Organic Aerosol (COA but possessing different diurnal variations to what would be expected for cooking activities, contributed 18%. Despite wood, cool and peat being minor fuel types used for domestic space heating in urban areas, their relatively low combustion efficiencies result in a significant contribution to PM1 aerosol mass (44% and 28% of the total organic aerosols mass and non refractory PM1, respectively.

  15. Characterization of urban aerosol in Cork city (Ireland using aerosol mass spectrometry

    Directory of Open Access Journals (Sweden)

    M. Dall'Osto

    2013-05-01

    Full Text Available Ambient wintertime background urban aerosol in Cork city, Ireland, was characterized using aerosol mass spectrometry. During the three-week measurement study in 2009, 93% of the ca. 1 350 000 single particles characterized by an Aerosol Time-of-Flight Mass Spectrometer (TSI ATOFMS were classified into five organic-rich particle types, internally mixed to different proportions with elemental carbon (EC, sulphate and nitrate, while the remaining 7% was predominantly inorganic in nature. Non-refractory PM1 aerosol was characterized using a High Resolution Time-of-Flight Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS and was also found to comprise organic aerosol as the most abundant species (62%, followed by nitrate (15%, sulphate (9% and ammonium (9%, and chloride (5%. Positive matrix factorization (PMF was applied to the HR-ToF-AMS organic matrix, and a five-factor solution was found to describe the variance in the data well. Specifically, "hydrocarbon-like" organic aerosol (HOA comprised 20% of the mass, "low-volatility" oxygenated organic aerosol (LV-OOA comprised 18%, "biomass burning" organic aerosol (BBOA comprised 23%, non-wood solid-fuel combustion "peat and coal" organic aerosol (PCOA comprised 21%, and finally a species type characterized by primary extit{m/z}~peaks at 41 and 55, similar to previously reported "cooking" organic aerosol (COA, but possessing different diurnal variations to what would be expected for cooking activities, contributed 18%. Correlations between the different particle types obtained by the two aerosol mass spectrometers are also discussed. Despite wood, coal and peat being minor fuel types used for domestic space heating in urban areas, their relatively low combustion efficiencies result in a significant contribution to PM1 aerosol mass (44% and 28% of the total organic aerosol mass and non-refractory total PM1, respectively.

  16. Characterization of submicron aerosols at a suburban site in central China

    Science.gov (United States)

    Wang, Qingqing; Zhao, Jian; Du, Wei; Ana, Godson; Wang, Zhenzhu; Sun, Lu; Wang, Yuying; Zhang, Fang; Li, Zhanqing; Ye, Xingnan; Sun, Yele

    2016-04-01

    We have characterized the chemical composition and sources of submicron aerosol (PM1) at a suburban site in Xinzhou in central China using an Aerosol Chemical Speciation Monitor from July 17 to September 5, 2014. The average (±1σ) PM1 concentration was 35.4 (±20.8) μg/m3 for the entire study period, indicating that Xinzhou was less polluted compared to the megacities in the North China Plain (NCP). The PM1 was mainly composed of organic aerosol and sulfate, on average accounting for 33.1% and 32.4%, respectively, followed by nitrate (14.4%) and ammonium (11.8%). Higher sulfate and lower nitrate contributions than those in megacities in the NCP elucidated an important emission source of coal combustion in central China. Three organic aerosol (OA) factors, i.e., hydrocarbon-like OA (HOA), semi-volatile oxygenated OA (SV-OOA) and low-volatility OOA (LV-OOA), were identified using positive matrix factorization. Secondary OA (=SV-OOA + LV-OOA) dominated OA, on average accounting for 82%, indicating that OA at the Xinzhou site was overall oxidized. We also observed relatively similar aerosol bulk composition and OA composition at low and high mass loading periods, and also from the different source areas, indicating that aerosol species were homogeneously distributed over a regional scale near the site for most of the time during this study. Slightly higher mass concentrations and sulfate contributions from the southern air masses were likely due to the transport from the polluted cities, such as Taiyuan to the south. In addition, the daily variation of PM1 in Xinzhou resembled that observed in Beijing, indicating that the wide-scale regional haze pollution often influences both the NCP and the central China.

  17. Emission and chemistry of organic carbon in the gas and aerosol phase at a sub-urban site near Mexico City in March 2006 during the MILAGRO study

    Directory of Open Access Journals (Sweden)

    J. A. de Gouw

    2009-05-01

    Full Text Available Volatile organic compounds (VOCs and carbonaceous aerosol were measured at a sub-urban site near Mexico City in March of 2006 during the MILAGRO study (Megacity Initiative: Local and Global Research Objectives. Diurnal variations of hydrocarbons, elemental carbon (EC and hydrocarbon-like organic aerosol (HOA were dominated by a high peak in the early morning when local emissions accumulated in a shallow boundary layer, and a minimum in the afternoon when the emissions were diluted in a significantly expanded boundary layer and, in case of the reactive gases, removed by OH. In comparison, diurnal variations of species with secondary sources such as the aldehydes, ketones, oxygenated organic aerosol (OOA and water-soluble organic carbon (WSOC stayed relatively high in the afternoon indicating strong photochemical formation. Emission ratios of many hydrocarbon species relative to CO were higher in Mexico City than in the U.S., but we found similar emission ratios for most oxygenated VOCs and organic aerosol. Secondary formation of acetone may be more efficient in Mexico City than in the U.S., due to higher emissions of alkane precursors from the use of liquefied petroleum gas. Secondary formation of organic aerosol was similar between Mexico City and the U.S. Combining the data for all measured gas and aerosol species, we describe the budget of total observed organic carbon (TOOC, and find that the enhancement ratio of TOOC relative to CO is conserved between the early morning and mid afternoon despite large compositional changes. Finally, the influence of biomass burning is investigated using the measurements of acetonitrile, which was found to correlate with levoglucosan in the particle phase. Diurnal variations of acetonitrile indicate a contribution from local burning sources. Scatter plots of acetonitrile versus CO suggest that the contribution of biomass burning to the enhancement of most gas and aerosol species was not dominant and perhaps

  18. Urban increments of gaseous and aerosol pollutants and their sources using mobile aerosol mass spectrometry measurements

    Science.gov (United States)

    Elser, Miriam; Bozzetti, Carlo; El-Haddad, Imad; Maasikmets, Marek; Teinemaa, Erik; Richter, Rene; Wolf, Robert; Slowik, Jay G.; Baltensperger, Urs; Prévôt, André S. H.

    2016-06-01

    Air pollution is one of the main environmental concerns in urban areas, where anthropogenic emissions strongly affect air quality. This work presents the first spatially resolved detailed characterization of PM2.5 (particulate matter with aerodynamic equivalent diameter daero ≤ 2.5 µm) in two major Estonian cities, Tallinn and Tartu. The measurements were performed in March 2014 using a mobile platform. In both cities, the non-refractory (NR)-PM2.5 was characterized by a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) using a recently developed lens which increases the transmission of super-micron particles. Equivalent black carbon (eBC) and several trace gases including carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4) were also measured. The chemical composition of PM2.5 was found to be very similar in the two cities. Organic aerosol (OA) constituted the largest fraction, explaining on average about 52 to 60 % of the PM2.5 mass. Four sources of OA were identified using positive matrix factorization (PMF): hydrocarbon-like OA (HOA, from traffic emissions), biomass burning OA (BBOA, from biomass combustion), residential influenced OA (RIOA, probably mostly from cooking processes with possible contributions from waste and coal burning), and oxygenated OA (OOA, related to secondary aerosol formation). OOA was the major OA source during nighttime, explaining on average half of the OA mass, while during daytime mobile measurements the OA was affected by point sources and dominated by the primary fraction. A strong increase in the secondary organic and inorganic components was observed during periods with transport of air masses from northern Germany, while the primary local emissions accumulated during periods with temperature inversions. Mobile measurements offered the identification of different source regions within the urban areas and the assessment of the extent to which pollutants concentrations exceeded regional background

  19. Three-dimensional factorization of size-resolved organic aerosol mass spectra from Mexico City

    Directory of Open Access Journals (Sweden)

    I. M. Ulbrich

    2012-01-01

    Full Text Available A size-resolved submicron organic aerosol composition dataset from a high-resolution time-of-flight mass spectrometer (HR-ToF-AMS collected in Mexico City during the MILAGRO campaign in March 2006 is analyzed using 3-dimensional (3-D factorization models. A method for estimating the precision of the size-resolved composition data for use with the factorization models is presented here for the first time. Two 3-D models are applied to the dataset. One model is a 3-vector decomposition (PARAFAC model, which assumes that each chemical component has a constant size distribution over all time steps. The second model is a vector-matrix decomposition (Tucker 1 model that allows a chemical component to have a size distribution that varies in time. To our knowledge, this is the first report of an application of 3-D factorization models to data from fast aerosol instrumentation, and the first application of this vector-matrix model to any ambient aerosol dataset. A larger number of degrees of freedom in the vector-matrix model enable fitting real variations in factor size distributions, but also make the model susceptible to fitting noise in the dataset, giving some unphysical results. For this dataset and model, more physically meaningful results were obtained by partially constraining the factor mass spectra using a priori information and a new regularization method. We find four factors with each model: hydrocarbon-like organic aerosol (HOA, biomass-burning organic aerosol (BBOA, oxidized organic aerosol (OOA, and a locally occurring organic aerosol (LOA. These four factors have previously been reported from 2-dimensional factor analysis of the high-resolution mass spectral dataset from this study. The size distributions of these four factors are consistent with previous reports for these particle types. Both 3-D models produce useful results, but the vector-matrix model captures real variability in the size distributions that cannot be captured by the

  20. Three-dimensional factorization of size-resolved organic aerosol mass spectra from Mexico City

    Directory of Open Access Journals (Sweden)

    I. M. Ulbrich

    2011-07-01

    Full Text Available A size-resolved submicron organic aerosol composition dataset from a high-resolution time-of-flight mass spectrometer (HR-ToF-AMS collected in Mexico City during the MILAGRO campaign in March 2006 is analyzed using 3-dimensional (3-D factorization models. A method for estimating the precision of the size-resolved composition data for use with the factorization models is presented here for the first time. Two 3-D models are applied to the dataset. One model is a 3-vector decomposition (PARAFAC model, which assumes that each chemical component has a constant size distribution over all time steps. The second model is a vector-matrix decomposition (Tucker 1 model that allows a chemical component to have a size distribution that varies in time. To our knowledge, this is the first report of an application of 3-D factorization models to data from fast aerosol instrumentation; it is also the first application of this vector-matrix model to any ambient aerosol dataset. A larger number of degrees of freedom in the vector-matrix model enable fitting real variations in factor size distributions, but also make the model susceptible to fitting noise in the dataset, giving some unphysical results. For this dataset and model, more physical results were obtained by partially constraining the factor mass spectra using a priori information and a new regularization method. We find four factors with each model: hydrocarbon-like organic aerosol (HOA, biomass-burning organic aerosol (BBOA, oxidized organic aerosol (OOA, and a locally occurring organic aerosol (LOA. These four factors have previously been reported from 2-dimensional factor analysis of the high-resolution mass spectral dataset from this study. The size distributions of these four factors are consistent with previous reports for these particle types. Both 3-D models produce useful results, but the vector-matrix model captures real variability in the size distributions that cannot be captured by the 3

  1. Source characterization of ambient fine aerosol in Singapore during a haze episode in 2015

    Science.gov (United States)

    Hapsari Budisulistiorini, Sri; Riva, Matthieu; Williams, Michael; Miyakawa, Takuma; Komazaki, Yuichi; Chen, Jing; Surratt, Jason; Kuwata, Mikinori

    2017-04-01

    Recurring transboundary haze from Indonesia peatland fires in the previous decades has significantly elevated particulate matter (PM) concentration in Southeast Asia, particularly during the 2015 El Niño event. Previous studies have investigated chemical composition of particles emitted during haze episodes; however, they were limited to time-integrated samples and the number of identified compounds. Low time-resolution measurement results in co-variance of PM sources; therefore, higher time-resolution measurement is important in PM source apportionment. Between October 10-31, 2015, Aerodyne Time-of-Flight Aerosol Chemical Speciation Monitor (ToF-ACSM) was deployed for real-time chemical characterization of ambient submicron PM (NR-PM1) in Singapore. Simultaneously, PM2.5 filter samples were collected for molecular-level organic aerosol (OA) constituents, organic carbon (OC), elemental carbon (EC) and water-soluble OC (WSOC) analyses. OA constituents were quantified by gas chromatography interfaced to electron ionization mass spectrometry (GC/EI-MS) and ultra-performance liquid chromatography interfaced to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometer operated in the negative ion mode (UPLC/(-)ESI-HR-Q-TOFMS). OA and SO42- are dominant components of the haze particles, accounting for ˜77% and ˜12% of the total NR-PM1 mass, respectively. OC/EC ratio of 4.8 might indicate formation of secondary OA (SOA) and aerosols from biomass burning, including those from peat burning. OA fraction from ToF-ACSM measurements was analyzed for source apportionment using a bilinear model through multi-linear engine algorithm (ME-2) in graphical user interface SoFi (Source Finder). Five OA factors were identified: hydrocarbon-like OA (HOA), biomass burning OA (BBOA), peat burning OA (PBOA), low-volatility oxygenated OA (LV-OOA), and semi-volatile oxygenated OA (SV-OOA). The HOA factor shows a distinct diurnal profile peaking in the morning and

  2. Wintertime organic and inorganic aerosols in Lanzhou, China: sources, processes, and comparison with the results during summer

    Science.gov (United States)

    Xu, Jianzhong; Shi, Jinsen; Zhang, Qi; Ge, Xinlei; Canonaco, Francesco; Prévôt, André S. H.; Vonwiller, Matthias; Szidat, Sönke; Ge, Jinming; Ma, Jianmin; An, Yanqing; Kang, Shichang; Qin, Dahe

    2016-12-01

    during winter. Positive matrix factorization (PMF) with the multi-linear engine (ME-2) solver identified six OA sources, i.e., a hydrocarbon-like OA (HOA), a biomass burning OA (BBOA), a cooking-emitted OA (COA), a coal combustion OA (CCOA), and two oxygenated OA (OOA) factors. One of the OOAs was less oxidized (LO-OOA), and the other one more oxidized (MO-OOA). LO-OOA was the most abundant OA component (22.3 % of OA mass), followed by CCOA (22.0 %), COA (20.2 %), MO-OOA (14.9 %), BBOA (10.8 %), and HOA (9.8 %). The mass fraction of primary OA ( = HOA + BBOA + COA + CCOA) increased during high PM pollution periods, indicating that local primary emissions were a main reason for the formation of air pollution events in Lanzhou during winter. Radiocarbon (14C) measurement was conducted on four PM2.5 filter samples from this study, which allowed for a quantitative source apportionment of organic carbon (OC). The non-fossil sources on average accounted for 55 ± 3 % of OC, which could be mainly from biomass burning and cooking activities, suggesting the importance of non-fossil sources for the PM pollution in Lanzhou. Together with the PMF results, we also found that a large fraction (66 ± 10 %) of the secondary OC was from non-fossil OC.

  3. Effect of higher-order aberrations and intraocular scatter on contrast sensitivity measured with a single instrument

    Science.gov (United States)

    Zhao, Junlei; Xiao, Fei; Zhao, Haoxin; Dai, Yun; Zhang, Yudong

    2017-01-01

    Higher-order aberrations (HOAs) and intraocular scatter lead to the degradation of image quality on the retina, and consequently deteriorate subjective visual performance. In this article, we modified an adaptive optics double-pass system to combine objective and subjective visual testing capabilities. Employing the modified DP system, we investigated the effects of HOAs and intraocular scatter on contrast sensitivity. Contrast sensitivity measurements were performed with HOAs either retained or corrected by adaptive optics, and with scatter either remaining at the natural eye-induced level or further enhanced by a set of three different scatter filters. Contrast sensitivity was found to be worse when HOAs were uncorrected or scatter increased. Quantitative analysis indicated that the joint effect of HOAs and scatter on contrast sensitivity was not a simple summation of each contributing factor, suggesting a potential compensatory mechanism between HOAs and intraocular scatter on contrast sensitivity. PMID:28736660

  4. Increased internal higher-order aberrations as a useful parameter for indication of vitrectomy in three asteroid hyalosis cases.

    Science.gov (United States)

    Yokoyama, Sho; Kojima, Takashi; Kaga, Tatsushi; Ichikawa, Kazuo

    2015-12-23

    We report three asteroid hyalosis cases in which internal higher-order aberrations (HOAs) were improved concomitant with improved visual symptoms after vitrectomy. Cases 1 and 2 reported severe floaters and glare disability, although their visual acuities were fairly good. Case 3 showed poor visual acuity since this patient also suffered from mild macular degeneration. For these three asteroid hyalosis cases, we were unsure if treatment with vitrectomy could improve visual symptoms. Therefore, we measured internal HOAs with an aberrometer, and found that the internal HOA values in these cases were high. We suspected that internal high HOAs values were associated with visual disturbance, and performed vitrectomy. After the vitrectomy, the internal HOA values in these three asteroid hyalosis cases markedly decreased, and visual symptoms improved. These observations suggested that measurement of internal HOAs may be useful to determine the indication for vitrectomy. 2015 BMJ Publishing Group Ltd.

  5. Which optical processes are suitable to make probabilistic single photon sources for quantum cryptography?

    CERN Document Server

    Verma, Amit

    2009-01-01

    Single photon sources to be used in quantum cryptography must show higher order antibunching (HOA). HOA is reported by us in several many wave mixing processes. In the present work we have investigated the possibility of observing HOA in multiwave mixing processes in general. The generalized Hamiltonian is solved for several particular cases in Heisenberg picture and possibility of observing HOA is investigated with the help of criterion of Pathak and Garcia. Several particular cases of the generalized Hamiltonian are solved with the help of short time approximation technique and HOA is reported for pump modes of different multiwave mixing processes. It is also found that HOA can not be observed for the signal and stokes modes in of the cases studied here.

  6. A Call for National Security System Transformation

    Science.gov (United States)

    2012-06-01

    Vaccinates Animals, Trains Veterinarians in Ethiopia,” United States Central Command, http://www.hoa.africom.mil/getArticleFresh.asp?art=2092&lang=0... Vaccinates Animals, Trains Veterinarians in Ethiopia,” United States Central Command, http://www.hoa.africom.mil/getArticleFresh.asp?art=2092&lang=0...Department, CJTF-HOA has resorted to “flanking and enveloping with the combat power of veterinarians , host nation military partnerships, and new

  7. Higher Order Aberration and Astigmatism in Children with Hyperopic Amblyopia.

    Science.gov (United States)

    Choi, Seung Kwon; Chang, Ji Woong

    2016-02-01

    To investigate the changes in corneal higher-order aberration (HOA) during amblyopia treatment and the correlation between HOA and astigmatism in hyperopic amblyopia children. In this retrospective study, a total of 72 eyes from 72 patients ranging in age from 38 to 161 months were included. Patients were divided into two groups based on the degree of astigmatism. Corneal HOA was measured using a KR-1W aberrometer at the initial visit and at 3-, 6-, and 12-month follow-ups. Correlation analysis was performed to assess the association between HOA and astigmatism. A total of 72 patients were enrolled in this study, 37 of which were classified as belonging to the higher astigmatism group, while 35 were assigned to the lower astigmatism group. There was a statistically significant difference in success rate between the higher and lower astigmatism groups. In both groups, all corneal HOAs were significantly reduced during amblyopia treatment. When comparing the two groups, a significant difference in coma HOA at the 12-month follow-up was detected (p = 0.043). In the Pearson correlation test, coma HOA at the 12-month follow-up demonstrated a statistically significant correlation with astigmatism and a stronger correlation with astigmatism in the higher astigmatism group than in the lower astigmatism group (coefficient values, 0.383 and 0.284 as well as p = 0.021 and p = 0.038, respectively). HOA, particularly coma HOA, correlated with astigmatism and could exert effects in cases involving hyperopic amblyopia.

  8. Dicty_cDB: SLK673 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available DNA clone PC_0013_A1_E04_MR 5', mRNA sequence. 58 2e-07 3 BG897685 |BG897685.1 HOA16-1-D7 HOA (Human Osteoarthritic Cartilage...osome 2 map 4624505-4657775 strain AX4, complete sequence. 959 0.0 4 BG899581 |BG899581.1 HOA24-1-H11 HOA (Human Osteoarthritic Carti...lage) Homo sapiens cDNA, mRNA sequence. 76 1e-09 1 BG781718 |BG781718.1 SEAUMC00167

  9. Modelling winter organic aerosol at the European scale with CAMx: evaluation and source apportionment with a VBS parameterization based on novel wood burning smog chamber experiments

    Directory of Open Access Journals (Sweden)

    G. Ciarelli

    2017-06-01

    Full Text Available We evaluated a modified VBS (volatility basis set scheme to treat biomass-burning-like organic aerosol (BBOA implemented in CAMx (Comprehensive Air Quality Model with extensions. The updated scheme was parameterized with novel wood combustion smog chamber experiments using a hybrid VBS framework which accounts for a mixture of wood burning organic aerosol precursors and their further functionalization and fragmentation in the atmosphere. The new scheme was evaluated for one of the winter EMEP intensive campaigns (February–March 2009 against aerosol mass spectrometer (AMS measurements performed at 11 sites in Europe. We found a considerable improvement for the modelled organic aerosol (OA mass compared to our previous model application with the mean fractional bias (MFB reduced from −61 to −29 %. We performed model-based source apportionment studies and compared results against positive matrix factorization (PMF analysis performed on OA AMS data. Both model and observations suggest that OA was mainly of secondary origin at almost all sites. Modelled secondary organic aerosol (SOA contributions to total OA varied from 32 to 88 % (with an average contribution of 62 % and absolute concentrations were generally under-predicted. Modelled primary hydrocarbon-like organic aerosol (HOA and primary biomass-burning-like aerosol (BBPOA fractions contributed to a lesser extent (HOA from 3 to 30 %, and BBPOA from 1 to 39 % with average contributions of 13 and 25 %, respectively. Modelled BBPOA fractions were found to represent 12 to 64 % of the total residential-heating-related OA, with increasing contributions at stations located in the northern part of the domain. Source apportionment studies were performed to assess the contribution of residential and non-residential combustion precursors to the total SOA. Non-residential combustion and road transportation sector contributed about 30–40 % to SOA formation (with increasing

  10. Sources and atmospheric processing of winter aerosols in Seoul, Korea: insights from real-time measurements using a high-resolution aerosol mass spectrometer

    Science.gov (United States)

    Kim, Hwajin; Zhang, Qi; Bae, Gwi-Nam; Kim, Jin Young; Bok Lee, Seung

    2017-02-01

    Highly time-resolved chemical characterization of nonrefractory submicrometer particulate matter (NR-PM1) was conducted in Seoul, the capital and largest metropolis of Korea, using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The measurements were performed during winter, when elevated particulate matter (PM) pollution events are often observed. This is the first time that detailed real-time aerosol measurement results have been reported from Seoul, Korea, and they reveal valuable insights into the sources and atmospheric processes that contribute to PM pollution in this region. The average concentration of submicron aerosol (PM1 = NR-PM1+ black carbon (BC)) was 27.5 µg m-3, and the total mass was dominated by organics (44 %), followed by nitrate (24 %) and sulfate (10 %). The average atomic ratios of oxygen to carbon (O / C), hydrogen to carbon (H / C), and nitrogen to carbon (N / C) of organic aerosols (OA) were 0.37, 1.79, and 0.018, respectively, which result in an average organic mass-to-carbon (OM / OC) ratio of 1.67. The concentrations (2.6-90.7 µg m-3) and composition of PM1 varied dynamically during the measurement period due to the influences of different meteorological conditions, emission sources, and air mass origins. Five distinct sources of OA were identified via positive matrix factorization (PMF) analysis of the HR-ToF-AMS data: vehicle emissions represented by a hydrocarbon-like OA factor (HOA, O / C = 0.06), cooking activities represented by a cooking OA factor (COA, O / C = 0.14), wood combustion represented by a biomass burning OA factor (BBOA, O / C = 0.34), and secondary organic aerosol (SOA) represented by a semivolatile oxygenated OA factor (SV-OOA, O / C = 0.56) and a low-volatility oxygenated OA factor (LV-OOA, O / C = 0.68). On average, primary OA (POA = HOA + COA + BBOA) accounted for 59 % the OA mass, whereas SV-OOA and LV-OOA contributed 15 and 26 %, respectively. Our results indicate that air

  11. Enhancing non-refractory aerosol apportionment from an urban industrial site through receptor modelling of complete high time-resolution aerosol mass spectra

    Directory of Open Access Journals (Sweden)

    M. L. McGuire

    2014-02-01

    Full Text Available Receptor modelling was performed on quadrupole unit mass resolution aerosol mass spectrometer (Q-AMS sub-micron particulate matter (PM chemical speciation measurements from Windsor, Ontario, an industrial city situated across the Detroit River from Detroit, Michigan. Aerosol and trace gas measurements were collected on board Environment Canada's CRUISER mobile laboratory. Positive matrix factorization (PMF was performed on the AMS full particle-phase mass spectrum (PMFFull MS encompassing both organic and inorganic components. This approach was compared to the more common method of analysing only the organic mass spectra (PMFOrg MS. PMF of the full mass spectrum revealed that variability in the non-refractory sub-micron aerosol concentration and composition was best explained by six factors: an amine-containing factor (Amine; an ammonium sulphate and oxygenated organic aerosol containing factor (Sulphate-OA; an ammonium nitrate and oxygenated organic aerosol containing factor (Nitrate-OA; an ammonium chloride containing factor (Chloride; a hydrocarbon-like organic aerosol (HOA factor; and a moderately oxygenated organic aerosol factor (OOA. PMF of the organic mass spectrum revealed three factors of similar composition to some of those revealed through PMFFull MS: Amine, HOA and OOA. Including both the inorganic and organic mass proved to be a beneficial approach to analysing the unit mass resolution AMS data for several reasons. First, it provided a method for potentially calculating more accurate sub-micron PM mass concentrations, particularly when unusual factors are present, in this case, an Amine factor. As this method does not rely on a priori knowledge of chemical species, it circumvents the need for any adjustments to the traditional AMS species fragmentation patterns to account for atypical species, and can thus lead to more complete factor profiles. It is expected that this method would be even more useful for HR-ToF-AMS data, due to

  12. Source apportionment of submicron organic aerosol collected from Atlanta, Georgia, during 2014-2015 using the aerosol chemical speciation monitor (ACSM)

    Science.gov (United States)

    Rattanavaraha, Weruka; Canagaratna, Manjula R.; Budisulistiorini, Sri Hapsari; Croteau, Philip L.; Baumann, Karsten; Canonaco, Francesco; Prevot, Andre S. H.; Edgerton, Eric S.; Zhang, Zhenfa; Jayne, John T.; Worsnop, Douglas R.; Gold, Avram; Shaw, Stephanie L.; Surratt, Jason D.

    2017-10-01

    The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) was redeployed at the Jefferson Street (JST) site in downtown Atlanta, Georgia (GA) for 1 year (March 20, 2014-February 08, 2015) to chemically characterize non-refractory submicron particulate matter (NR-PM1) in near real-time and to assess whether organic aerosol (OA) types and amounts change from year-to-year. Submicron organic aerosol (OA) mass spectra were analyzed by season using multilinear engine (ME-2) to apportion OA subtypes to potential sources and chemical processes. A suite of real-time collocated measurements from the Southeastern Aerosol Research and Characterization (SEARCH) network was compared with ME-2 factor solutions to aid in the interpretation of OA subtypes during each season. OA tracers measured from high-volume filter samples using gas chromatography interfaced with electron ionization-mass spectrometry (GC/EI-MS) also aided in identifying OA sources. The initial application of ME-2 to the yearlong ACSM dataset revealed that OA source apportionment by season was required to better resolve sporadic OA types. Spring and fall OA mass spectral datasets were separated into finer periods to capture potential OA sources resulting from non-homogeneous emissions during transitioning periods. NR-PM1 was highest in summer (16.7 ± 8.4 μg m-3) and lowest in winter (8.0 ± 5.7 μg m-3), consistent with prior studies. OA dominated NR-PM1 mass (56-74% on average) in all seasons. Hydrocarbon-like OA (HOA) from primary emissions was observed in all seasons, averaging 5-22% of total OA mass. Strong correlations of HOA with carbon monoxide (CO) (R = 0.71-0.88) and oxides of nitrogen (NOx) (R = 0.55-0.79) indicated that vehicular traffic was the likely source. Biomass burning OA (BBOA) was observed in all seasons, with lower contributions (2%) in summer and higher in colder seasons (averaging 8-20% of total OA mass). BBOA correlated strongly with levoglucosan (R = 0.78-0.95) during colder seasons

  13. Seasonal characterization of submicron aerosol chemical composition and organic aerosol sources in the southeastern United States: Atlanta, Georgia and Look Rock, Tennessee

    Directory of Open Access Journals (Sweden)

    S. H. Budisulistiorini

    2015-08-01

    Full Text Available A yearlong near-real-time characterization of non-refractory submicron aerosol (NR-PM1 was conducted at an urban (Atlanta, Georgia and rural (Look Rock, Tennessee site in the southeastern US using the Aerodyne aerosol chemical speciation monitor (ACSM collocated with established air-monitoring network measurements. Seasonal variations in organic aerosol (OA and inorganic aerosol species are attributed to meteorological conditions as well as anthropogenic and biogenic emissions in this region. The highest concentrations of NR-PM1 were observed during winter and fall seasons at the urban site and during spring and summer at the rural site. Across all seasons and at both sites, NR-PM1 was composed largely of OA (50–76 % and inorganic sulfate (12–31 %. Six distinct OA sources were resolved by positive matrix factorization applied to the ACSM organic mass spectral data collected from the two sites over the one year of near-continuous measurements at each site: hydrocarbon-like OA (HOA, biomass burning OA (BBOA, semi-volatile oxygenated OA (SV-OOA, low-volatility oxygenated OA (OOA, isoprene-derived epoxydiol (IEPOX OA (IEPOX-OA, and 91Fac OA (a factor dominated by a distinct ion at m/z 91 fragment ion previously observed in biogenic influenced areas. LV-OOA was observed throughout the year at both sites and contributed 30–66 % of total OA mass. HOA was also observed during the entire year only at the urban site (15–24 % of OA mass. BBOA (15–33 % of OA mass was observed during winter and fall, likely dominated by local residential wood burning emission. Although SV-OOA contributes quite significantly (∼ 27 %, it was observed only at the urban site during colder seasons. IEPOX-OA was a major component (27–41 % of OA at both sites, particularly in spring and summer. An ion fragment at m/z 75 is proposed as an additional marker for IEPOX-OA, as it is shown to correlate well with the m/z 82 ion shown to be associated with the aerosol mass

  14. Characterization of aerosol chemical composition with aerosol mass spectrometry in Central Europe: an overview

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    V. A. Lanz

    2010-11-01

    Full Text Available Real-time measurements of non-refractory submicron aerosols (NR-PM1 were conducted within the greater Alpine region (Switzerland, Germany, Austria, France and Liechtenstein during several week-long field campaigns in 2002–2009. This region represents one of the most important economic and recreational spaces in Europe. A large variety of sites was covered including urban backgrounds, motorways, rural, remote, and high-alpine stations, and also mobile on-road measurements were performed. Inorganic and organic aerosol (OA fractions were determined by means of aerosol mass spectrometry (AMS. The data originating from 13 different field campaigns and the combined data have been utilized for providing an improved temporal and spatial data coverage.

    The average mass concentration of NR-PM1 for the different campaigns typically ranged between 10 and 30 μg m−3. Overall, the organic portion was most abundant, ranging from 36% to 81% of NR-PM1. Other main constituents comprised ammonium (5–15%, nitrate (8–36%, sulfate (3–26%, and chloride (0–5%. These latter anions were, on average, fully neutralized by ammonium. As a major result, time of the year (winter vs. summer and location of the site (Alpine valleys vs. Plateau could largely explain the variability in aerosol chemical composition for the different campaigns and were found to be better descriptors for aerosol composition than the type of site (urban, rural etc.. Thus, a reassessment of classifications of measurements sites might be considered in the future, possibly also for other regions of the world.

    The OA data was further analyzed using positive matrix factorization (PMF and the multi-linear engine ME (factor analysis separating the total OA into its underlying components, such as oxygenated (mostly secondary organic aerosol (OOA, hydrocarbon-like and freshly emitted organic aerosol (HOA, as well as OA from biomass

  15. Understanding sources of organic aerosol during CalNex-2010 using the CMAQ-VBS

    Directory of Open Access Journals (Sweden)

    M. C. Woody

    2015-10-01

    efficiency for that model is estimated to be too low by about 7×. For CMAQ-VBS, 90 % of the anthropogenic SOA mass formed was attributed to aged secondary semivolatile vapors (70 % originating from volatile organic compounds (VOCs and 20 % from intermediate volatility compounds (IVOCs. From source-apportioned model results, we found most of the CMAQ-VBS modeled POA at the Pasadena CalNex site was attributable to meat cooking emissions (48 %, and consistent with a substantial fraction of cooking OA in the observations, compared to 18 % from gasoline vehicle emissions, 13 % from biomass burning (in the form of residential wood combustion, and 8 % from diesel vehicle emissions. All "other" inventoried emission sources (e.g. industrial/point sources comprised the final 13 %. The CMAQ-VBS semivolatile POA treatment underpredicted AMS hydrocarbon-like OA (HOA + cooking-influenced OA (CIOA at Pasadena by a factor of 1.8 (1.16 μg m−3 modeled vs. 2.05 μg m−3 observed compared to a factor of 1.4 overprediction of POA in CMAQ-AE6, but did well to capture the AMS diurnal profile of HOA and CIOA, with the exception of the midday peak. We estimated that using the National Emission Inventory (NEI POA emissions without scaling to represent SVOCs underestimates SVOCs by ~1.7×.

  16. Submicron aerosol analysis and organic source apportionment in an urban atmosphere in Pearl River Delta of China using high-resolution aerosol mass spectrometry

    Science.gov (United States)

    He, Ling-Yan; Huang, Xiao-Feng; Xue, Lian; Hu, Min; Lin, Yun; Zheng, Jun; Zhang, Renyi; Zhang, Yuan-Hang

    2011-06-01

    The Pearl River Delta (PRD) region in South China is one of the most economically developed regions in China while also noted for its severe air pollution, especially in the urban environments. In order to understand in depth the aerosol chemistry and the emission sources in PRD, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed at an urban site in the Hong Kong-Shenzhen metropolitan area between 25 October and 2 December 2009. Ten minute-resolved measurement data were analyzed, and an average mass concentration of 44.5 ± 34.0 μg m-3 was calculated for the entire campaign. On average, organic matter was the most abundant PM1 component accounting for 39.7% of the total mass, followed by sulfate (24.5%), black carbon (measured by aethalometer, 14.0%), ammonium (10.2%), nitrate (10.0%), and chloride (1.6%). Moreover, organic matter comprised an increasing fraction of the PM1 loading as the PM1 loading increased, denoting its key role in particulate pollution in this region. Calculations of organic elemental composition based on the high-resolution organic mass spectra obtained indicated that C, H, O, and N on average contributed 33.8%, 55.1%, 10.2%, and 0.9%, respectively, to the total atomic numbers of organic aerosol (OA), which corresponded to an OM/OC ratio (the ratio of organic matter mass/organic carbon mass) of 1.57 ± 0.08. Positive matrix factorization analysis was then conducted on the high-resolution organic mass spectral data set. Four OA components were identified, including a hydrocarbon-like (HOA), a biomass burning (BBOA), and two oxygenated (LV-OOA and SV-OOA) components, which on average accounted for 29.5%, 24.1%, 18.8%, and 27.6%, respectively, of the total organic mass. The HOA was found to have contributions from both fossil fuel combustion and cooking emissions, while the BBOA was well correlated with acetonitrile, a known biomass burning marker. The LV-OOA and SV-OOA corresponded to more aged and

  17. Understanding sources of organic aerosol during CalNex-2010 using the CMAQ-VBS

    Science.gov (United States)

    Woody, Matthew C.; Baker, Kirk R.; Hayes, Patrick L.; Jimenez, Jose L.; Koo, Bonyoung; Pye, Havala O. T.

    2016-03-01

    estimated to be too low by about 7 × . From source-apportioned model results, we found most of the CMAQ-VBS modeled POA at the Pasadena CalNex site was attributable to meat cooking emissions (48 %, consistent with a substantial fraction of cooking OA in the observations). This is compared to 18 % from gasoline vehicle emissions, 13 % from biomass burning (in the form of residential wood combustion), and 8 % from diesel vehicle emissions. All "other" inventoried emission sources (e.g., industrial, point, and area sources) comprised the final 13 %. The CMAQ-VBS semivolatile POA treatment underpredicted AMS hydrocarbon-like OA (HOA) + cooking-influenced OA (CIOA) at Pasadena by a factor of 1.8 compared to a factor of 1.4 overprediction of POA in CMAQ-AE6, but it did capture the AMS diurnal profile of HOA and CIOA well, with the exception of the midday peak. Overall, the CMAQ-VBS with its semivolatile treatment of POA, SOA from intermediate volatility organic compounds (IVOCs), and aging of SOA improves SOA model performance (though SOA formation efficiency is still 1.6-2 × too low). However, continued efforts are needed to better understand assumptions in the parameterization (e.g., SOA aging) and provide additional certainty to how best to apply existing emission inventories in a framework that treats POA as semivolatile, which currently degrades existing model performance at routine monitoring networks. The VBS and other approaches (e.g., AE6) require additional work to appropriately incorporate IVOC emissions and subsequent SOA formation.

  18. Synthesis of hydroximic acid functionalized PMMA/AM/HOA resin and its adsorbability for Hg2+ and Cd2+%羟肟酸功能化PMMA/AM/HOA的合成及对Hg2+和Cd2+的吸附性能

    Institute of Scientific and Technical Information of China (English)

    孙林; 刘春萍; 马松梅; 孙豪展; 陈秋

    2016-01-01

    用悬浮聚合法合成了甲基丙烯酸甲酯(MMA)与丙烯酰胺(AM)的共聚物PMMA/AM,再经羟胺改性制备了含羟肟酸功能基的改性PMMA/AM/HOA树脂.通过红外光谱(FTIR)和热重分析(TG)对PMMA/AM/HOA树脂的结构和稳定性进行了表征.以PMMA/AM/HOA为吸附剂,考察了温度、吸附时间、pH值和金属离子浓度等条件对Hg2+、Cd2+两种金属离子吸附性能的影响.结果表明,改性树脂对Hg2+、Cd2+具有良好的吸附能力,其实验吸附量分别为0.822和0.384 mmol·g-1.改性树脂对Hg2+和Cd2+的吸附过程符合拟二级动力学方程,25℃时其二级动力学吸附速率常数分别为5.301×10-2和3.582×10-2g·(mmol·min)-1;改性树脂对Hg2+和Cd2+的吸附量随温度的升高有所增大,吸附过程符合Langmuir和Freundlich吸附等温式.

  19. Atmospheric aerosol compositions and sources at two national background sites in northern and southern China

    Science.gov (United States)

    Zhu, Qiao; He, Ling-Yan; Huang, Xiao-Feng; Cao, Li-Ming; Gong, Zhao-Heng; Wang, Chuan; Zhuang, Xin; Hu, Min

    2016-08-01

    Although China's severe air pollution has become a focus in the field of atmospheric chemistry and the mechanisms of urban air pollution there have been researched extensively, few field sampling campaigns have been conducted at remote background sites in China, where air pollution characteristics on a larger scale are highlighted. In this study, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), together with an Aethalometer, was deployed at two of China's national background sites in northern (Lake Hongze site; 33.23° N, 118.33° E; altitude 21 m) and southern (Mount Wuzhi site; 18.84° N, 109.49° E; altitude 958 m) China in the spring seasons in 2011 and 2015, respectively, in order to characterize submicron aerosol composition and sources. The campaign-average PM1 concentration was 36.8 ± 19.8 µg m-3 at the northern China background (NCB) site, which was far higher than that at the southern China background (SCB) site (10.9 ± 7.8 µg m-3). Organic aerosol (OA) (27.2 %), nitrate (26.7 %), and sulfate (22.0 %) contributed the most to the PM1 mass at NCB, while OA (43.5 %) and sulfate (30.5 %) were the most abundant components of the PM1 mass at SCB, where nitrate only constituted a small fraction (4.7 %) and might have contained a significant amount of organic nitrates (5-11 %). The aerosol size distributions and organic aerosol elemental compositions all indicated very aged aerosol particles at both sites. The OA at SCB was more oxidized with a higher average oxygen to carbon (O / C) ratio (0.98) than that at NCB (0.67). Positive matrix factorization (PMF) analysis was used to classify OA into three components, including a hydrocarbon-like component (HOA, attributed to fossil fuel combustion) and two oxygenated components (OOA1 and OOA2, attributed to secondary organic aerosols from different source areas) at NCB. PMF analysis at SCB identified a semi-volatile oxygenated component (SV-OOA) and a low-volatility oxygenated

  20. Investigating the annual behaviour of submicron secondary inorganic and organic aerosols in London

    Directory of Open Access Journals (Sweden)

    D. E. Young

    2014-07-01

    Full Text Available For the first time, the behaviour of non-refractory inorganic and organic submicron particulate through an entire annual cycle is investigated using measurements from an Aerodyne compact time-of-flight aerosol mass spectrometer (cToF-AMS located at a UK urban background site in North Kensington, London. We show secondary aerosols account for a significant fraction of the submicron aerosol burden and that high concentration events are governed by different factors depending on season. Furthermore, we demonstrate that on an annual basis there is no variability in the extent of secondary organic aerosol (SOA oxidation, as defined by the oxygen content, irrespective of amount. This result is surprising given the changes in precursor emissions and contributions as well as photochemical activity throughout the year; however it may make the characterisation of SOA in urban environments more straightforward than previously supposed. Organic species, nitrate, sulphate, ammonium, and chloride were measured during 2012 with average concentrations (±one standard deviation of 4.32 (±4.42, 2.74 (±5.00, 1.39 (±1.34, 1.30 (±1.52 and 0.15 (±0.24 μg m–3, contributing 43, 28, 14, 13 and 2% to the total submicron mass, respectively. Components of the organic aerosol fraction are determined using positive matrix factorisation (PMF where five factors are identified and attributed as hydrocarbon-like OA (HOA, cooking OA (COA, solid fuel OA (SFOA, type 1 oxygenated OA (OOA1, and type 2 oxygenated OA (OOA2. OOA1 and OOA2 represent more and less oxygenated OA with average concentrations of 1.27 (±1.49 and 0.14 (±0.29 μg m–3, respectively, where OOA1 dominates the SOA fraction (90%. Diurnal, monthly, and seasonal trends are observed in all organic and inorganic species, due to meteorological conditions, specific nature of the aerosols, and availability of precursors. Regional and transboundary pollution as well as other individual pollution events influence

  1. Organic and inorganic decomposition products from the thermal desorption of atmospheric particles

    Science.gov (United States)

    Williams, Brent J.; Zhang, Yaping; Zuo, Xiaochen; Martinez, Raul E.; Walker, Michael J.; Kreisberg, Nathan M.; Goldstein, Allen H.; Docherty, Kenneth S.; Jimenez, Jose L.

    2016-04-01

    ) component. TAG signal found in the traditional compound elution time period reveals higher correlations with AMS hydrocarbon-like OA (HOA) combined with the fraction of OOA that is less oxygenated. Potential to quantify nitrate and sulfate aerosol mass concentrations using the TAG system is explored through analysis of ammonium sulfate and ammonium nitrate standards. While chemical standards display a linear response in the TAG system, redesorptions of the CTD cell following ambient sample analysis show some signal carryover on sulfate and organics, and new desorption methods should be developed to improve throughput. Future standards should be composed of complex organic/inorganic mixtures, similar to what is found in the atmosphere, and perhaps will more accurately account for any aerosol mixture effects on compositional quantification.

  2. Factor analysis of combined organic and inorganic aerosol mass spectra from high resolution aerosol mass spectrometer measurements

    Directory of Open Access Journals (Sweden)

    Y. L. Sun

    2012-05-01

    Full Text Available The high resolution mass spectra of organic and inorganic aerosols from aerosol mass spectrometer (AMS measurements were first combined into positive matrix factorization (PMF analysis to investigate the sources and evolution processes of atmospheric aerosols. The new approach is able to study the mixing of organic aerosols (OA and inorganic species, the acidity of OA factors, and the fragment ion patterns related to photochemical processing. In this study, PMF analysis of the unified AMS spectral matrices resolved 8 factors for the submicron aerosols measured at Queens College in New York City in summer 2009. The hydrocarbon-like OA (HOA and cooking OA (COA contain very minor inorganic species, indicating the different sources and mixing characteristics between primary OA and secondary species. The two factors that are primarily ammonium sulfate (SO4-OA and ammonium nitrate (NO3-OA, respectively, are overall neutralized, of which the OA in SO4-OA shows the highest oxidation state (O/C = 0.69 among OA factors. The semi-volatile oxygenated OA comprises two components, i.e., a less oxidized (LO-OOA and a more oxidized (MO-OOA. The MO-OOA represents a local photochemical product with the diurnal profile exhibiting a pronounced noon peak, consistent with those of formaldehyde (HCHO and Ox (= O3+NO2. The much higher NO+/NO2+ fragment ion ratio in MO-OOA than that from ammonium nitrate alone provides evidence for the formation of organic nitrates. The amine-related nitrogen-enriched OA (NOA contains ~25% of acidic inorganic salts, elucidating the formation of secondary OA from amines in acidic environments. The size distributions derived from 3-dimensional size-resolved mass spectra show distinct diurnal evolving behaviors for different OA factors, but overall a progressing evolution from smaller to larger particle mode as a function of oxidation states

  3. Sub-Antarctic marine aerosol: significant contributions from biogenic sources

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    J. Schmale

    2013-03-01

    Full Text Available Biogenic influences on the composition and characteristics of aerosol were investigated on Bird Island (54°00' S, 38°03' W in the South Atlantic during November and December 2010. This remote marine environment is characterised by large seabird and seal colonies. The chemical composition of the submicron particles, measured by an aerosol mass spectrometer (AMS, was 21% non-sea salt sulfate 2% nitrate, 7% ammonium, 22% organics and 47% sea salt including sea salt sulfate. A new method to isolate the sea salt signature from the high-resolution AMS data was applied. Generally, the aerosol was found to be less acidic than in other marine environments due to the high availability of ammonia, from local fauna emissions. By positive matrix factorisation five different organic aerosol (OA profiles could be isolated: an amino acids/amine factor (AA-OA, 18% of OA mass, a methanesulfonic acid OA factor (MSA-OA, 25%, a marine oxygenated OA factor (M-OOA, 40%, a sea salt OA fraction (SS-OA, 7% and locally produced hydrocarbon-like OA (HOA, 9%. The AA-OA was dominant during the first two weeks of November and found to be related with the hatching of penguins in a nearby colony. This factor, rich in nitrogen (C : N ratio = 0.13, has implications for the biogeochemical cycling of nitrogen in the area as particulate matter is often transported over longer distances than gaseous N-rich compounds. The MSA-OA was mainly transported from more southerly latitudes where phytoplankton bloomed. The bloom was identified as one of three sources for particulate sulfate on Bird Island, next to sea salt sulfate and sulfate transported from South America. M-OOA was the dominant organic factor and found to be similar to marine OA observed at Mace Head, Ireland. An additional OA factor highly correlated with sea salt aerosol was identified (SS-OA. However, based on the available data the type of mixture, internal or external, could not be determined. Potassium was not

  4. Insights on organic aerosol aging and the influence of coal combustion at a regional receptor site of central eastern China

    Directory of Open Access Journals (Sweden)

    W. W. Hu

    2013-10-01

    Full Text Available In order to understand the aging and processing of organic aerosols (OA, an intensive field campaign (Campaign of Air Pollution at Typical Coastal Areas IN Eastern China, CAPTAIN was conducted March–April at a receptor site (a Changdao island in central eastern China. Multiple fast aerosol and gas measurement instruments were used during the campaign, including a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS that was applied to measure mass concentrations and non-refractory chemical components of submicron particles (PM1nr. The average mass concentration of PM1(PM1nr+black carbon was 47 ± 36 μg m−3 during the campaign and showed distinct variation, depending on back trajectories and their overlap with source regions. Organic aerosol (OA is the largest component of PM1 (30%, followed by nitrate (28%, sulfate (19%, ammonium (15%, black carbon (6%, and chloride (3%. Four OA components were resolved by positive matrix factorization (PMF of the high-resolution spectra, including low-volatility oxygenated organic aerosol (LV-OOA, semi-volatile oxygenated OA (SV-OOA, hydrocarbon-like OA (HOA and a coal combustion OA (CCOA. The mass spectrum of CCOA had high abundance of fragments from polycyclic aromatic hydrocarbons (PAHs (m/z 128, 152, 178, etc.. The average atomic ratio of oxygen to carbon in OA (O / C at Changdao was 0.59, which is comparable to other field studies reported at locations downwind of large pollution sources, indicating the oxidized nature of most OA during the campaign. The evolution of OA elemental composition in the van Krevelen diagram (H / C vs. O / C showed a slope of −0.63; however, the OA influenced by coal combustion exhibits a completely different evolution that appears dominated by physical mixing. The aging of organic aerosols vs. photochemical age was investigated. It was shown that OA / ΔCO, as well as LV-OOA / ΔCO and SV-OOA / ΔCO, positively correlated with photochemical age. LV

  5. Evaluation of the volatility basis-set approach for the simulation of organic aerosol formation in the Mexico City metropolitan area

    Directory of Open Access Journals (Sweden)

    A. P. Tsimpidi

    2010-01-01

    Full Text Available New primary and secondary organic aerosol modules have been added to PMCAMx, a three dimensional chemical transport model (CTM, for use with the SAPRC99 chemistry mechanism based on recent smog chamber studies. The new modelling framework is based on the volatility basis-set approach: both primary and secondary organic components are assumed to be semivolatile and photochemically reactive and are distributed in logarithmically spaced volatility bins. This new framework with the use of the new volatility basis parameters for low-NOx and high-NOx conditions tends to predict 4–6 times higher anthropogenic SOA concentrations than those predicted with the older generation of models. The resulting PMCAMx-2008 was applied in Mexico City Metropolitan Area (MCMA for approximately a week during April 2003 during a period of very low regional biomass burning impact. The emission inventory, which uses as a starting point the MCMA 2004 official inventory, is modified and the primary organic aerosol (POA emissions are distributed by volatility based on dilution experiments. The predicted organic aerosol (OA concentrations peak in the center of Mexico City, reaching values above 40 μg m−3. The model predictions are compared with the results of the Positive Matrix Factorization (PMF analysis of the Aerosol Mass Spectrometry (AMS observations. The model reproduces both Hydrocarbon-like Organic Aerosol (HOA and Oxygenated Organic Aerosol (OOA concentrations and diurnal profiles. The small OA underprediction during the rush-hour periods and overprediction in the afternoon suggest potential improvements to the description of fresh primary organic emissions and the formation of the oxygenated organic aerosols, respectively, although they may also be due to errors in the simulation of dispersion and vertical mixing. However, the AMS OOA data are not specific enough to prove that the model reproduces the organic aerosol

  6. Water and organic nitrate detection in an AMS. Laboratory characterization and application to ambient measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mensah, Amewu A.

    2011-08-12

    Atmospheric aerosols were studied by three different means. Laboratory experiments determined the relative ionization efficiency of water (RIE{sub H2O}) in an Aerodyne Aerosol Mass Spectrometers (AMS), simulation chamber experiments gave insight to the reaction products of biogenic volatile organic compounds (BVOC) oxidation products, and the findings were applied to two field campaign measurements at Cabauw, NL, in May 2008 and February 2009. Knowing the liquid water content of aerosol particles is vital for the assessment of their climate forcing potential. A value of 2 for RIE{sub H2O} was determined by studying oxalate salts with different amounts of crystal water. BVOCs contribute much more to the global budget of VOCs than anthropogenic ones but oxidation products in terms of secondary organic aerosol often correlate to anthropogenic tracers such as NO{sub x} from fossil fuel burning. In atmospheric simulation chamber experiments, organic nitrates from BVOC-NO{sub 3} oxidation showed higher vapor pressures than pure organic compounds produced in the same reactions. Organic nitrates comprised up to approx. 41 % of the particulate phase. A specific fragmentation ratio of nitrate (NO{sub 2}{sup +}/NO{sup +}) of 0.1 was found by high resolution AMS analysis differing strongly from the value of 0.4 known for the most abundant ambient NO{sub 3} specie (NH{sub 4}NO{sub 3}). Ambient average particulate mass loadings were 9.72 {mu}g/m{sup 3} dominated by organics (40 %) in 2008 and 5.62 {mu}g/m{sup 3} dominated by nitrate (42 %) in 2009. Data comparison to collocated instruments showed good agreement. Positive Matrix Factorization analysis of the particulate organic fraction distinguished semi and low volatile oxygenated organic aerosol (OOA) as well as hydrocarbon like organic aerosol (HOA) in both campaigns. An additional highly oxygenated OA with a mass spectrum very similar to fulvic acid was found in 2008. The average contribution of organic nitrate to the

  7. Characterization of submicron aerosols influenced by biomass burning at a site in the Sichuan Basin, southwestern China

    Science.gov (United States)

    Hu, Wei; Hu, Min; Hu, Wei-Wei; Niu, Hongya; Zheng, Jing; Wu, Yusheng; Chen, Wentai; Chen, Chen; Li, Lingyu; Shao, Min; Xie, Shaodong; Zhang, Yuanhang

    2016-10-01

    Severe air pollution in Asia is often the consequence of a combination of large anthropogenic emissions and adverse synoptic conditions. However, limited studies on aerosols have been conducted under high emission intensity and under unique geographical and meteorological conditions. In this study, an Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) and other state-of-the-art instruments were utilized at a suburban site, Ziyang, in the Sichuan Basin during December 2012 to January 2013. The chemical compositions of atmospheric submicron aerosols (PM1) were determined, the sources of organic aerosols (OA) were apportioned, and the aerosol secondary formation and aging process were explored as well. Due to high humidity and static air, PM1 maintained a relatively stable level during the whole campaign, with the mean concentration of 59.7 ± 24.1 µg m-3. OA was the most abundant component (36 %) in PM1, characterized by a relatively high oxidation state. Positive matrix factorization analysis was applied to the high-resolution organic mass spectral matrix, which deconvolved OA mass spectra into four factors: low-volatility (LV-OOA) and semivolatile oxygenated OA (SV-OOA), biomass burning (BBOA) and hydrocarbon-like OA (HOA). OOA (sum of LV-OOA and SV-OOA) dominated OA as high as 71 %. In total, secondary inorganic and organic formation contributed 76 % of PM1. Secondary inorganic species correlated well (Pearson r = 0.415-0.555, p < 0.01) with relative humidity (RH), suggesting the humid air can favor the formation of secondary inorganic aerosols. As the photochemical age of OA increased with higher oxidation state, secondary organic aerosol formation contributed more to OA. The slope of OOA against Ox( = O3+NO2) steepened with the increase of RH, implying that, besides the photochemical transformation, the aqueous-phase oxidation was also an important pathway of the OOA formation. Primary emissions, especially biomass burning, resulted

  8. Composition and sources of particulate matter in an industrialised Alpine valley

    Directory of Open Access Journals (Sweden)

    N. Perron

    2010-04-01

    Full Text Available A three-week long field campaign was carried out under autumnal meteorological conditions at four valley floor sites in the industrialised Swiss Rhone Valley. For one week of stable meteorological conditions, particulate matter with an aerodynamic diameter below 10 μm (PM10 was analysed from daily filters using ion chromatography, X-ray fluorescence, anhydrosugars and radiocarbon analysis of the organic and elemental matter (OM and EM, respectively. Furthermore, PM1 composition along the whole campaign was monitored in Massongex (a site near industries by a seven-wavelength aethalometer and a quadrupole aerosol mass spectrometer (Q-AMS. At all sites, PM10 secondary inorganics and non-fossil EM and OM exhibited relatively stable concentrations over the selected days. On the contrary, PM10 fossil carbonaceous fractions, mineral dust components and several trace elements showed a significant decrease on Sunday, compared to the analysed working days. Their concentrations were also highly correlated. This evidenced the role of exhaust and resuspension emissions by heavy-duty vehicle traffic to the PM10 concentrations along the valley.

    In Massongex, organic matter and black carbon (BC were the main contributors to PM1 over the campaign (accounting for 45% and 18% of PM1, respectively. An optical discrimination of BC highlighted the prevalence of fossil over wood-burning sources. Three types of PM1 organics could be identified by factor analysis: primary wood-burning organic aerosol (P-WBOA dominated the PM1 carbonaceous fraction, followed by oxygenated organics (OOA mostly representing secondary organics, and by traffic or possibly industry-related hydrocarbon-like organics (HOA as the smallest carbonaceous contribution.

    Furthermore, unusually high contributions of fine chloride were detected at all sites. They were attributed to

  9. The characteristics and origins of carbonaceous aerosol at a rural site of PRD in summer of 2006

    Directory of Open Access Journals (Sweden)

    W. W. Hu

    2012-02-01

    estimated POC versus hydrocarbon-like organic aerosol (HOA.

  10. Burning of olive tree branches: a major organic aerosol source in the Mediterranean

    Directory of Open Access Journals (Sweden)

    E. Kostenidou

    2013-09-01

    Full Text Available Aerosol produced during the burning of olive tree branches was characterized with both direct source sampling (using a mobile smog chamber and with ambient measurements during the burning season. The fresh particles were composed of 80% organic matter, 8–10% black carbon (BC, 5% potassium, 3–4% sulfate, 2–3% nitrate and 0.8% chloride. Almost half of the fresh olive tree branches burning organic aerosol (otBB-OA consisted of alkane groups. Their mode diameter was close to 70 nm. The oxygen to carbon (O : C ratio of the fresh otBB-OA was 0.29 ± 0.04. The mass fraction of levoglucosan in PM1 was 0.034–0.043, relatively low in comparison with most fuel types. This may lead to an underestimation of the otBB-OA contribution if levoglucosan is being used as a wood burning tracer. Chemical aging was observed during smog chamber experiments, as f44 and O : C ratio increased, due to reactions with OH radicals and O3. The otBB-OA AMS mass spectrum differs from the other published biomass burning spectra, with a main difference at m/z 60, used as levoglucosan tracer. In addition to particles, volatile organic compounds (VOCs such as methanol, acetonitrile, acrolein, benzene, toluene and xylenes are also emitted. Positive matrix factorization (PMF was applied to the ambient organic aerosol data and 3 factors could be identified: OOA (oxygenated organic aerosol, 55%, HOA (hydrocarbon-like organic aerosol, 11.3% and otBB-OA 33.7%. The fresh chamber otBB-OA AMS spectrum is close to the PMF otBB-OA spectrum and resembles the ambient mass spectrum during olive tree branches burning periods. We estimated an otBB-OA emission factor of 3.5 ± 0.9 g kg−1. Assuming that half of the olive tree branches pruned is burned in Greece, 2300 ± 600 tons of otBB-OA are emitted every year. This activity is one of the most important fine aerosol sources during the winter months in Mediterranean countries.

  11. Burning of olive tree branches: a major organic aerosol source in the Mediterranean

    Directory of Open Access Journals (Sweden)

    E. Kostenidou

    2013-03-01

    Full Text Available Aerosol produced during the burning of olive tree branches was characterized with both direct source-sampling (using a mobile smog chamber and with ambient measurements during the burning season. The fresh particles were composed of 80% organic matter, 8–10% black carbon (BC, 5% potassium, 3–4% sulfate, 2–3% nitrate and 0.8% chloride. Almost half of the fresh olive tree branches burning organic aerosol (otBB-OA consisted of alkane groups. Their mode diameter was close to 70 nm. The oxygen to carbon (O:C ratio of the fresh otBB-OA was 0.29 ± 0.04. The mass fraction of levoglucosan in PM1 was 0.034–0.043, relatively low in comparison with most fuel types. This may lead to an underestimation of the otBB-OA contribution if levoglucosan is being used as a wood burning tracer. Chemical aging was observed during smog chamber experiments, as f44 and O:C ratio increased, due to reactions with OH radicals and O3. The otBB-OA AMS mass spectrum differs from the other published biomass burning spectra, with a main difference at m/z 60, used as levoglucosan tracer. In addition to particles, volatile organic compounds (VOCs such as methanol, acetonitrile, acrolein, benzene, toluene and xylenes are also emitted. Positive matrix factorization (PMF was applied to the ambient organic aerosol data and 3 factors could be identified: OOA (oxygenated organic aerosol, 55%, HOA (hydrocarbon-like organic aerosol, 11.3% and otBB-OA 33.7%. The fresh chamber otBB-OA AMS spectrum is close to the PMF otBB-OA spectrum and resembles the ambient mass spectrum during olive tree branches burning periods. We estimated an otBB-OA emission factor of 3.5 ± 0.2 g kg−1. Assuming that half of the olive tree branches pruned is burned in Greece 2280 ± 140 tons of otBB-OA are emitted every year. This activity is one of the most important fine aerosol sources during the winter months in the Mediterranean countries.

  12. Seasonal variations in high time-resolved chemical compositions, sources, and evolution of atmospheric submicron aerosols in the megacity Beijing

    Science.gov (United States)

    Hu, Wei; Hu, Min; Hu, Wei-Wei; Zheng, Jing; Chen, Chen; Wu, Yusheng; Guo, Song

    2017-08-01

    A severe regional haze problem in the megacity Beijing and surrounding areas, caused by fast formation and growth of fine particles, has attracted much attention in recent years. In order to investigate the secondary formation and aging process of urban aerosols, four intensive campaigns were conducted in four seasons between March 2012 and March 2013 at an urban site in Beijing (116.31° E, 37.99° N). An Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) was deployed to measure non-refractory chemical components of submicron particulate matter (NR-PM1). The average mass concentrations of PM1 (NR-PM1+black carbon) were 45.1 ± 45.8, 37.5 ± 31.0, 41.3 ± 42.7, and 81.7 ± 72.4 µg m-3 in spring, summer, autumn, and winter, respectively. Organic aerosol (OA) was the most abundant component in PM1, accounting for 31, 33, 44, and 36 % seasonally, and secondary inorganic aerosol (SNA, sum of sulfate, nitrate, and ammonium) accounted for 59, 57, 43, and 55 % of PM1 correspondingly. Based on the application of positive matrix factorization (PMF), the sources of OA were obtained, including the primary ones of hydrocarbon-like (HOA), cooking (COA), biomass burning OA (BBOA) and coal combustion OA (CCOA), and secondary component oxygenated OA (OOA). OOA, which can be split into more-oxidized (MO-OOA) and less-oxidized OOA (LO-OOA), accounted for 49, 69, 47, and 50 % in four seasons, respectively. Totally, the fraction of secondary components (OOA+SNA) contributed about 60-80 % to PM1, suggesting that secondary formation played an important role in the PM pollution in Beijing, and primary sources were also non-negligible. The evolution process of OA in different seasons was investigated with multiple metrics and tools. The average carbon oxidation states and other metrics show that the oxidation state of OA was the highest in summer, probably due to both strong photochemical and aqueous-phase oxidations. It was indicated by the good correlations

  13. Assessing the factors related with winter haze events in Europe and Asia

    Science.gov (United States)

    Dällenbach, Kaspar Rudolf; El Haddad, Imad; Bozzetti, Carlo; Gates Slowik, Jay; Huang, Ru-Jin; Ho, Kin Fai; Cao, Jun Ji; Krepelova, Adela; Zotter, Peter; Canonaco, Francesco; Zhang, Yanlin; Ciobanu, Viorela Gabriela; Vlachou, Athanasia; Piazzalunga, Andrea; Fermo, Paola; Baltensperger, Urs; Szidat, Sönke; Prévôt, André Stéphane Henry

    2014-05-01

    Organic aerosol (OA) is a large fraction of total particulate matter, either directly emitted into the atmosphere (primary) or formed in air by oxidation processes (secondary) of gas precoursors (Jimenez et al., 2009). The aerosol's climate and health effects are strongly influenced by the chemical composition of OA and hence by the contributing emission sources and formation processes (Cassée et al., 2009). Thus examining sources and their contribution in different regions during severe pollution episodes is important for designing effective mitigation strategies. Such analyses require measurements capable of quantitatively distinguishing OA sources, distributed over a broad spatial scale with sufficient spatial density to capture regional differences. Aerosol mass spectrometer (AMS, Aerodyne) measurements of OA and subsequent application of positive matrix factorization (PMF) quantify the contribution of different primaries as biomass burning (BBOA), traffic emissions (hydrocarbon-like OA, HOA), and cooking (COA) and also secondary oxygenated OA separated by their volatility (semi-volatile: SV-OOA and low-volatile: LV-OOA) (e.g. Lanz et al. 2007). However, the systematic deployment on a dense network to determine regional differences is hindered by the instrument cost and intensive maintenance. To overcome these limitations, we have developed a method for the analysis of conventional aerosol filter samples using high-resolution AMS measurements. Such samples are relatively easy and inexpensive to collect and store, and are already routinely collected worldwide. The analysis method consists of water extraction of the particulate material from quartz filters and subsequent atomization of the resulting solutions into the AMS. The recovery of organics is estimated as ~70% and the mass spectra obtained by this methodology are comparable to the corresponding online measurements for different seasons. We present the application of this technique to filter samples

  14. Sampling strategies and post-processing methods for increasing the time resolution of organic aerosol measurements requiring long sample-collection times

    Science.gov (United States)

    Modini, Rob L.; Takahama, Satoshi

    2016-07-01

    The composition and properties of atmospheric organic aerosols (OAs) change on timescales of minutes to hours. However, some important OA characterization techniques typically require greater than a few hours of sample-collection time (e.g., Fourier transform infrared (FTIR) spectroscopy). In this study we have performed numerical modeling to investigate and compare sample-collection strategies and post-processing methods for increasing the time resolution of OA measurements requiring long sample-collection times. Specifically, we modeled the measurement of hydrocarbon-like OA (HOA) and oxygenated OA (OOA) concentrations at a polluted urban site in Mexico City, and investigated how to construct hourly resolved time series from samples collected for 4, 6, and 8 h. We modeled two sampling strategies - sequential and staggered sampling - and a range of post-processing methods including interpolation and deconvolution. The results indicated that relative to the more sophisticated and costly staggered sampling methods, linear interpolation between sequential measurements is a surprisingly effective method for increasing time resolution. Additional error can be added to a time series constructed in this manner if a suboptimal sequential sampling schedule is chosen. Staggering measurements is one way to avoid this effect. There is little to be gained from deconvolving staggered measurements, except at very low values of random measurement error (< 5 %). Assuming 20 % random measurement error, one can expect average recovery errors of 1.33-2.81 µg m-3 when using 4-8 h-long sequential and staggered samples to measure time series of concentration values ranging from 0.13-29.16 µg m-3. For 4 h samples, 19-47 % of this total error can be attributed to the process of increasing time resolution alone, depending on the method used, meaning that measurement precision would only be improved by 0.30-0.75 µg m-3 if samples could be collected over 1 h instead of 4 h. Devising a

  15. Volatility of organic aerosol and its components in the megacity of Paris

    Science.gov (United States)

    Paciga, Andrea; Karnezi, Eleni; Kostenidou, Evangelia; Hildebrandt, Lea; Psichoudaki, Magda; Engelhart, Gabriella J.; Lee, Byong-Hyoek; Crippa, Monica; Prévôt, André S. H.; Baltensperger, Urs; Pandis, Spyros N.

    2016-02-01

    Using a mass transfer model and the volatility basis set, we estimate the volatility distribution for the organic aerosol (OA) components during summer and winter in Paris, France as part of the collaborative project MEGAPOLI. The concentrations of the OA components as a function of temperature were measured combining data from a thermodenuder and an aerosol mass spectrometer (AMS) with Positive Matrix Factorization (PMF) analysis. The hydrocarbon-like organic aerosol (HOA) had similar volatility distributions for the summer and winter campaigns with half of the material in the saturation concentration bin of 10 µg m-3 and another 35-40 % consisting of low and extremely low volatility organic compounds (LVOCs with effective saturation concentrations C* of 10-3-0.1 µg m-3 and ELVOCs C* less or equal than 10-4 µg m-3, respectively). The winter cooking OA (COA) was more than an order of magnitude less volatile than the summer COA. The low-volatility oxygenated OA (LV-OOA) factor detected in the summer had the lowest volatility of all the derived factors and consisted almost exclusively of ELVOCs. The volatility for the semi-volatile oxygenated OA (SV-OOA) was significantly higher than that of the LV-OOA, containing both semi-volatile organic components (SVOCs with C* in the 1-100 µg m-3 range) and LVOCs. The oxygenated OA (OOA) factor in winter consisted of SVOCs (45 %), LVOCs (25 %) and ELVOCs (30 %). The volatility of marine OA (MOA) was higher than that of the other factors containing around 60 % SVOCs. The biomass burning OA (BBOA) factor contained components with a wide range of volatilities with significant contributions from both SVOCs (50 %) and LVOCs (30 %). Finally, combining the bulk average O : C ratios and volatility distributions of the various factors, our results are placed into the two-dimensional volatility basis set (2D-VBS) framework. The OA factors cover a broad spectrum of volatilities with no direct link between the average volatility and

  16. Characterization of high-resolution aerosol mass spectra of primary organic aerosol emissions from Chinese cooking and biomass burning

    Directory of Open Access Journals (Sweden)

    L.-Y. He

    2010-09-01

    Full Text Available Aerosol Mass Spectrometer (AMS has proved to be a powerful tool to measure submicron particulate composition with high time resolution. Factor analysis of mass spectra (MS collected worldwide by AMS demonstrates that submicron organic aerosol (OA is usually composed of several major components, such as oxygenated (OOA, hydrocarbon-like (HOA, biomass burning (BBOA, and other primary OA. In order to help interpretation of component MS from factor analysis of ambient OA datasets, AMS measurement of different primary sources is required for comparison. Such work, however, has been very scarce in the literature, especially for high resolution MS (HR-MS measurement, which performs improved characterization by separating the ions of different elemental compositions at each m/z in comparison with unit mass resolution MS (UMR-MS measurement. In this study, primary emissions from four types of Chinese cooking (CC and six types of biomass burning (BB were simulated systemically and measured using an Aerodyne High-Resolution Time-of-Flight AMS (HR-ToF-AMS. The MS of the CC emissions show high similarity with m/z 41 and m/z 55 being the highest signals; the MS of the BB emissions also show high similarity with m/z 29 and m/z 43 being the highest signals. The MS difference between the CC and BB emissions is much bigger than that between different CC (or BB types, especially for the HR-MS. The O/C ratio of OA ranges from 0.08 to 0.13 for the CC emissions while from 0.18 to 0.26 for the BB emissions. The ions of m/z 43, m/z 44, m/z 57, and m/z 60, usually used as tracer ions in AMS measurement, were examined for their HR-MS characteristics in the CC and BB emissions. Moreover, the MS of the CC and BB emissions are also used to compare with component MS from factor analysis of ambient OA datasets observed in China, as well as with other AMS measurements of primary sources in the literature. The MS

  17. Sub-Antarctic marine aerosol: dominant contributions from biogenic sources

    Directory of Open Access Journals (Sweden)

    J. Schmale

    2013-09-01

    Full Text Available Biogenic influences on the composition and characteristics of aerosol were investigated on Bird Island (54°00' S, 38°03' W in the South Atlantic during November and December 2010. This remote marine environment is characterised by large seabird and seal colonies. The chemical composition of the submicron particles, measured by an aerosol mass spectrometer (AMS, was 21% non-sea-salt sulfate, 2% nitrate, 8% ammonium, 22% organics and 47% sea salt including sea salt sulfate. A new method to isolate the sea spray signature from the high-resolution AMS data was applied. Generally, the aerosol was found to be less acidic than in other marine environments due to the high availability of ammonia, from local fauna emissions. By positive matrix factorisation five different organic aerosol (OA profiles could be isolated: an amino acid/amine factor (AA-OA, 18% of OA mass, a methanesulfonic acid OA factor (MSA-OA, 25%, a marine oxygenated OA factor (M-OOA, 41%, a sea spray OA fraction (SS-OA, 7% and locally produced hydrocarbon-like OA (HOA, 9%. The AA-OA was dominant during the first two weeks of November and found to be related with the hatching of penguins in a nearby colony. This factor, rich in nitrogen (N : C ratio = 0.13, has implications for the biogeochemical cycling of nitrogen in the area as particulate matter is often transported over longer distances than gaseous N-rich compounds. The MSA-OA was mainly transported from more southerly latitudes where phytoplankton bloomed. The bloom was identified as one of three sources for particulate sulfate on Bird Island, next to sea salt sulfate and sulfate transported from South America. M-OOA was the dominant organic factor and found to be similar to marine OA observed at Mace Head, Ireland. An additional OA factor highly correlated with sea spray aerosol was identified (SS-OA. However, based on the available data the type of mixture, internal or external, could not be determined. Potassium was not

  18. Chemical composition, sources, and processes of urban aerosols during summertime in northwest China: insights from high-resolution aerosol mass spectrometry

    Science.gov (United States)

    Xu, J.; Zhang, Q.; Chen, M.; Ge, X.; Ren, J.; Qin, D.

    2014-12-01

    An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed along with a scanning mobility particle sizer (SMPS) and a multi-angle absorption photometer (MAAP) to measure the temporal variations of the mass loading, chemical composition, and size distribution of submicron particulate matter (PM1) in Lanzhou, northwest China, during 11 July-7 August 2012. The average (PM1 mass concentration including non-refractory (PM1 (NR-(PM1) measured by HR-ToF-AMS and black carbon (BC) measured by MAAP during this study was 24.5 μg m-3 (ranging from 0.86 to 105 μg m-3), with a mean composition consisting of 47% organics, 16% sulfate, 12% BC, 11% ammonium, 10% nitrate, and 4% chloride. Organic aerosol (OA) on average consisted of 70% carbon, 21% oxygen, 8% hydrogen, and 1% nitrogen, with the average oxygen-to-carbon ratio (O / C) of 0.33 and organic mass-to-carbon ratio (OM / OC) of 1.58. Positive matrix factorization (PMF) of the high-resolution organic mass spectra identified four distinct factors which represent, respectively, two primary OA (POA) emission sources (traffic and food cooking) and two secondary OA (SOA) types - a fresher, semi-volatile oxygenated OA (SV-OOA) and a more aged, low-volatility oxygenated OA (LV-OOA). Traffic-related hydrocarbon-like OA (HOA) and BC displayed distinct diurnal patterns, both with peak at ~ 07:00-11:00 (BJT: UTC +8), corresponding to the morning rush hours, while cooking-emission related OA (COA) peaked during three meal periods. The diurnal profiles of sulfate and LV-OOA displayed a broad peak between ~ 07:00 and 15:00, while those of nitrate, ammonium, and SV-OOA showed a narrower peak between ~ 08:00-13:00. The later morning and early afternoon maximum in the diurnal profiles of secondary aerosol species was likely caused by downward mixing of pollutants aloft, which were likely produced in the residual layer decoupled from the boundary layer during nighttime. The mass spectrum of SV-OOA was

  19. Source apportionment of ambient aerosol applying PMF on AMS mobile and stationary data

    Science.gov (United States)

    Mohr, C.; Weimer, S.; Richter, R.; Decarlo, P. F.; Chirico, R.; Heringa, M. F.; Prévôt, A. S. H.; Baltensperger, U.

    2009-04-01

    Ambient aerosols are divided into the categories "primary" and "secondary", referring to particles directly emitted into the air, or formed out of precursor species such as volatile organic compounds, respectively. Main sources for primary urban aerosol and precursor species are traffic emissions, but also wood burning for domestic heating purposes especially in winter time (Alfarra et al., 2007). The quantification of various types of aerosol components is important for source identification which in turn is the basis of all mitigation activities. Positive Matrix Factorization (PMF) is a statistical based source apportionment tool that uses constrained, weighted least squares estimation to determine source profiles and strengths. PMF has been applied recently for the first time on highly time resolved organic mass spectra (Lanz et al., 2007) measured by an Aerodyne aerosol mass spectrometer (AMS) (Canagaratna et al., 2007). For the data presented here, two AMS were deployed together with additional instrumentation in the metropolitan area of Zurich in winter 2007/2008. The high-resolution time-of-flight AMS was stationed at an urban background site in the center, 30 meters from and shielded against direct traffic emissions. The quadrupole-based AMS was deployed in a mobile van allowing for on-road submicron aerosol composition measurements, and investigations into the spatial variability of aerosol concentration and composition. Results indicate that traffic emissions are the main contributor to submicron aerosol concentrations measured on-road. Hydrocarbon-like organic aerosol (HOA), a marker for traffic emissions (Lanz et al. 2007), dominates the primary aerosol mass, together with black carbon (BC). BC was monitored with the MAAP (multi angle absorption photometer). Another significant contributor to primary organic aerosol mass in downtown Zurich is domestic wood burning for heating purposes. Traffic and wood burning emissions make up roughly 50% of the total

  20. Chemical composition, sources, and processes of urban aerosols during summertime in Northwest China: insights from High Resolution Aerosol Mass Spectrometry

    Science.gov (United States)

    Xu, J.; Zhang, Q.; Chen, M.; Ge, X.; Ren, J.; Qin, D.

    2014-06-01

    An aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed along with a Scanning Mobility Particle Sizer (SMPS) and a Multi Angle Absorption Photometers (MAAP) to measure the temporal variations of the mass loading, chemical composition, and size distribution of sub-micrometer particulate matter (PM1) in Lanzhou, northwest China, during 12 July-7 August 2012. The average PM1 mass concentration including non-refractory PM1 (NR-PM1) measured by HR-ToF-AMS and black carbon (BC) measured by MAAP during this study was 24.5 μg m-3 (ranging from 0.86 to 105μg m-3), with a mean composition consisting of 47% organics, 16% sulfate, 12% BC, 11% ammonium, 10% nitrate, and 4% chloride. The organics was consisted of 70% carbon, 21% oxygen, 8% hydrogen, and 1% nitrogen, with the average oxygen-to-carbon ratio (O / C) of 0.33 and organic mass-to-carbon ratio (OM / OC) of 1.58. Positive matrix factorization (PMF) of the high-resolution mass spectra of organic aerosols (OA) identified four distinct factors which represent, respectively, two primary OA (POA) emission sources (traffic and food cooking) and two secondary OA (SOA) types - a fresher, semi-volatile oxygenated OA (SV-OOA) and a more aged, low-volatility oxygenated OA (LV-OOA). Traffic-related hydrocarbon-like OA (HOA) and BC displayed distinct diurnal patterns both with peak at ~07:00-11:00 (BJT: UTC +8) corresponding to the morning rush hours, while cooking OA (COA) peaked during three meal periods. The diurnal profiles of sulfate and LV-OOA displayed a broad peak between ∼07:00-15:00, while those of nitrate, ammonium, and SV-OOA showed a narrower peak at ~08:00-13:00. The later morning and early afternoon peak in the diurnal profiles of secondary aerosol species was likely caused by mixing down of pollutants aloft, which were likely produced in the residual layer decoupled from the boundary layer during night time. The mass spectrum of SV-OOA also showed similarity with that of

  1. Laryngeal Aerodynamics in Healthy Older Adults and Adults with Parkinson's Disease

    Science.gov (United States)

    Matheron, Deborah; Stathopoulos, Elaine T.; Huber, Jessica E.; Sussman, Joan E.

    2017-01-01

    Purpose: The present study compared laryngeal aerodynamic function of healthy older adults (HOA) to adults with Parkinson's disease (PD) while speaking at a comfortable and increased vocal intensity. Method: Laryngeal aerodynamic measures (subglottal pressure, peak-to-peak flow, minimum flow, and open quotient [OQ]) were compared between HOAs and…

  2. A Concept for Directing Combat Air Operations

    Science.gov (United States)

    2014-08-01

    within its inventory to meet this new requirement. However, by borrowing from the U.S. Army, a force of O-1 aircraft was assembled at Bien Hoa in July...1967, when an off-the-shelf commercial aircraft, the O-2, began service. Five years after the activation of the Bien Hoa O-1 squadron, and roughly a

  3. 76 FR 19516 - Public Meeting/Notice of Availability, Review, and Comment on Preliminary Alternatives for the...

    Science.gov (United States)

    2011-04-07

    ...., Hawai`i Volcanoes National Park, K lauea Visitor Center, 1 Crater Rim Drive. P hoa, Hawaii, Tuesday, April 19, 2011, 5-7 p.m., P hoa Community Center, 15-2910 Puna Rd. N ` lehu, Hawaii, Wednesday, April...

  4. Relationship between corneal and ocular higher order wavefront aberrations and age in children

    Science.gov (United States)

    Saito, Aya; Ito, Misae; Kawamorita, Takushi; Shimizu, Kimiya

    2017-05-01

    Abstract Purpose To evaluate the relationship between corneal and ocular higher order wavefront aberrations (HOAs) and age in young subjects aged 20 years or less. Methods Corneal and ocular HOAs of the right eyes of 87 normal subjects were measured using videokeratography and the Hartmann-Shack wavefront aberrometer (KR-9000PW; Topcon Corp., Tokyo, Japan). The HOAs were calculated using Zernike polynomials up to the sixth order. From the Zernike coefficients, the root mean squares (RMS) of coma and spherical aberration were calculated. Results Corneal spherical-like aberrations significantly correlated with age (r = 0.420, p Conclusion In children, the corneal and ocular total HOAs did not vary with age. Compared to the previous reports in adults, we found fewer corneal and ocular HOAs in children.

  5. Rural continental aerosol properties and processes observed during the Hohenpeissenberg Aerosol Characterization Experiment (HAZE2002

    Directory of Open Access Journals (Sweden)

    N. Hock

    2007-06-01

    of optical and other sizing techniques (OPC, AMS, SMPS, an average refractive index of 1.40–1.45 was inferred for the measured rural aerosol particles.

    The average ratio of OM1 to OC2.5 was 2, indicating a high proportion of heteroelements in the organic fraction of the sampled rural aerosol. This is consistent with the high ratio of oxygenated organic aerosol (OOA over hydrocarbon-like organic aerosol (HOA inferred from the AMS results (4:1, and also with the high abundance of proteins (~3% indicating a high proportion of primary biological material (~30% in PM2.5. Moreover, the low abundance of PAHs (<1 ng m−3 and EC (<1 μg m−3 in PM2.5 confirm a low contribution of combustion emissions, which are usually also major sources for HOA. Slightly enhanced HOA concentrations indicating fresh anthropogenic emissions were observed during a period when air masses were advected from the densely populated Po Valley, Italy.

    Detection of several secondary organic aerosol compounds (dicarboxylic acids and their precursors (monoterpenes confirmed the finding that secondary aerosol from natural sources was an important aerosol constituent. A sharp decrease of the short lived monoterpenes indicated that during night-time the measurement station was isolated from ground emission sources by a stable inversion layer. Nighttime values can therefore be regarded to represent regional or long range transport.

    New particle formation was observed almost every day with particle number concentrations exceeding 104 cm−3 (nighttime background level 1000–2000 cm−3. Closer inspection of two major events indicated that ternary H2SO4/H2O/NH3 nucleation triggered particle formation and that condensation of both organic and inorganic species contributed to particle growth.

  6. Early back-to-Africa migration into the Horn of Africa.

    Directory of Open Access Journals (Sweden)

    Jason A Hodgson

    2014-06-01

    Full Text Available Genetic studies have identified substantial non-African admixture in the Horn of Africa (HOA. In the most recent genomic studies, this non-African ancestry has been attributed to admixture with Middle Eastern populations during the last few thousand years. However, mitochondrial and Y chromosome data are suggestive of earlier episodes of admixture. To investigate this further, we generated new genome-wide SNP data for a Yemeni population sample and merged these new data with published genome-wide genetic data from the HOA and a broad selection of surrounding populations. We used multidimensional scaling and ADMIXTURE methods in an exploratory data analysis to develop hypotheses on admixture and population structure in HOA populations. These analyses suggested that there might be distinct, differentiated African and non-African ancestries in the HOA. After partitioning the SNP data into African and non-African origin chromosome segments, we found support for a distinct African (Ethiopic ancestry and a distinct non-African (Ethio-Somali ancestry in HOA populations. The African Ethiopic ancestry is tightly restricted to HOA populations and likely represents an autochthonous HOA population. The non-African ancestry in the HOA, which is primarily attributed to a novel Ethio-Somali inferred ancestry component, is significantly differentiated from all neighboring non-African ancestries in North Africa, the Levant, and Arabia. The Ethio-Somali ancestry is found in all admixed HOA ethnic groups, shows little inter-individual variance within these ethnic groups, is estimated to have diverged from all other non-African ancestries by at least 23 ka, and does not carry the unique Arabian lactase persistence allele that arose about 4 ka. Taking into account published mitochondrial, Y chromosome, paleoclimate, and archaeological data, we find that the time of the Ethio-Somali back-to-Africa migration is most likely pre-agricultural.

  7. Lung carcinoma with hypertrophic osteoarthropathy in a teenager

    Directory of Open Access Journals (Sweden)

    Jeremy Whelan

    2011-03-01

    Full Text Available Hypertrophic osteoarthropathy (HOA characterised by arthralgia, clubbing and periosteal proliferation of long bones, is rarely encountered in children and adolescents. Whereas in adults over 80% of cases are associated with malignancy, in children the majority of cases are due to non-neoplastic causes such as cystic fibrosis, bilary atresia and congenital heart disease. Up to 5% of adults with lung cancer demonstrate signs of HOA. However, lung cancer is extremely uncommon in children and young people. Here we report a case of lung adenocarcinoma in an 18 year old male associated with HOA present both at diagnosis and at subsequent disease progression.

  8. Hypertrophic osteoarthropathy of one leg - a sign of aortic graft infection

    Energy Technology Data Exchange (ETDEWEB)

    Spruijt, S.; Krijgsman, A.A. [Department of Orthopaedic and Trauma Surgery, Elkerliek Hospital, Helmond (Netherlands); Broek, J.A.C. van den [Department of Radiology, Elkerliek Hospital, Helmond (Netherlands); Tutein Nolthenius-Puylaert, M.C.B.J.E. [Department of Pathology, Elkerliek Hospital, Helmond (Netherlands)

    1999-04-01

    We report a rare case of hypertrophic osteoarthropathy (HOA) confined to the right leg secondary to aortic graft infection. The development of HOA exclusively localized to areas distal to a vascular prosthesis may be the presenting manifestation of graft infection and a crucial diagnostic clue in the early detection of vascular graft infection. HOA is diagnosed by its characteristic radiographic and scintigraphic pattern. Most prosthetic, especially aortic, graft infections are uniformly fatal if not treated by aggressive surgical and antibiotic therapy. Recognition of this uncommon association may facilitate an early diagnosis, which usually requires immediate surgical therapy. (orig.) With 6 figs., 28 refs.

  9. A new TDOA algorithm based on Taylor series expansion in cellular networks

    Institute of Scientific and Technical Information of China (English)

    Lingwen ZHANG; Zhenhui TAN

    2008-01-01

    Time difference of arrival (TDOA) is the positioning technique with the most potential in cellular mobile telecommunication systems. The Taylor series expansion method has been widely used in solving nonlinear equations for its high accuracy and good robustness. However, the performance of the Taylor's method depends highly on the initial estimation. Therefore, one new algorithm, hybrid optimizing algo-rithm (HOA) was proposed, which combines the Taylor series expansion method with the steepest decent method. The steepest decent method features fast convergence at the initial iteration and small computation complexity. HOA takes great advantage of both methods. Simulation results show that HOA achieves better performance on positioning accuracy and efficiency.

  10. High Optical Access Trap 2.0.

    Energy Technology Data Exchange (ETDEWEB)

    Maunz, Peter Lukas Wilhelm [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-26

    The High Optical Access (HOA) trap was designed in collaboration with the Modular Universal Scalable Ion-trap Quantum Computer (MUSIQC) team, funded along with Sandia National Laboratories through IARPA's Multi Qubit Coherent Operations (MQCO) program. The design of version 1 of the HOA trap was completed in September 2012 and initial devices were completed and packaged in February 2013. The second version of the High Optical Access Trap (HOA-2) was completed in September 2014 and is available at IARPA's disposal.

  11. Hea ahi on pool toitu / Kirsti Herttua ja Ingrid Maasik

    Index Scriptorium Estoniae

    Herttua, Kirsti

    2013-01-01

    Võrdluses integreeritavad õhuringlusega küpsetusahjud: Bosch HBG34150S, Gorenje BO9950AX, Hoover HOA03VX, Ikea Framtid OV9 pitsaküpstuse funktsiooniga, Miele H4402B Komfort, UPO O9850DS, Whirlpool AKZM837

  12. Photorefractive keratectomy results in myopic patients with thin cornea eyes

    Directory of Open Access Journals (Sweden)

    Hassan Hashemi

    2015-01-01

    Conclusion: PRK is a safe, effective, and predictable procedure with desirable effects on mesopic CS in patients with corneal thickness <500 μm, which increases HOAs and decreases corneal integrity proportionate to its value before the procedure.

  13. Distance Perception in a loudspeaker-based room auralization system

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2009-01-01

    A loudspeaker-based room auralization (LoRA) system has been recently proposed that efficiently combines modern room acoustic modeling techniques with high-order Ambisonics (HOA) auralization to generate virtual auditory environments (VAEs). The reproduction of the distance of sound events...... in such VAE is very important for its fidelity. A direct-scaling distance perception experiment was conducted to evaluate the LoRA system including the use of near-field control (NFC) for HOA. Experimental results showed that (i) loudspeaker-based auralization in the LoRA system provides similar distance...... perception to that of the corresponding real environment and that (ii) NFC-HOA provides a significant increase in the range of perceived distances for near sound sources as compared to standard HOA....

  14. Association of Metabolic Factors with Symptomatic Hand Osteoarthritis in the Chinese Han Population Aged 40 Years and above

    Institute of Scientific and Technical Information of China (English)

    Fei Wang; Lei Shi; Qing-Yun Xue

    2016-01-01

    Background:The relationship between hand osteoarthritis (HOA) and systemic metabolic factors is unclear.The aim of this study was to investigate the prevalence of systemic metabolic factors including obesity,hypertension,diabetes mellitus,and atherosclerosis in symptomatic patients with HOA and the association between these systemic metabolic factors and symptomatic HOA in the Chinese Hann population aged 40 years and above.Methods:A cross-sectional survey was conducted on Chinese Han population aged 40 years and above in six centers in China.The sociodemographic features,lifestyle of the participants,and medical history of hypertension,diabetes mellitus,and atherosclerosis were collected.The cases with hand symptoms underwent anteroposterior radiographic examination of both hands to obtain a diagnosis.The correlations between systemic metabolic factors and symptomatic HOA were analyzed using Logistic regression analysis.Results:Overweight (39.3% vs.30.5%,P < 0.001),hypertension (34.7% vs.18.6%,P < 0.001),diabetes mellitus (11.2% vs.3.3%,P < 0.001),and atherosclerosis (19.8% vs.8.3%,P < 0.001) were more prevalent in symptomatic patients with HOA than those in the population without HOA.Overweight (odds ratio [OR] =1.35,95% confidence interval [CI]:1.10-1.65,P =0.005),hypertension (OR =1.47,95% CI:1.18-1.83,P < 0.001),and diabetes mellitus (OR =2.45,95% CI:1.74-3.45,P < 0.001) were associated with a higher prevalence of symptomatic HOA and the OR of symptomatic HOA significantly increased with the accumulated number of the three metabolic factors.Symptomatic HOA was associated with a higher prevalence of atherosclerosis (OR =1.39,95% CI:1.05-1.85,P =0.023).Conclusions:Overweight,hypertension,and diabetes mellitus were associated with a higher prevalence of HOA,showing cumulative effects.Atherosclerosis risk should be assessed in patients with HOA.

  15. Human Factors Considerations of Undergrounds in Insurgencies

    Science.gov (United States)

    1966-09-01

    agencies have diplomatic immunity and, if arrested for espionage activities, are not jailed but de- clared persona non grata and forced to leave the...Tactics Used Earlier a t Bien Hoa," The Washington Post, February 8 , 1965, p. A-10; Fred H. Barton, Salient Operational Aspects of Paramilitary...American-made ammunition and six 81-mm mortars, the Viet Cong attacked the Bien Hoa air base for 20 minutes. Targets were the control tower, the

  16. Homeowner Associations as a Vehicle for Promoting Native Urban Biodiversity

    Directory of Open Access Journals (Sweden)

    Susannah B. Lerman

    2012-12-01

    Full Text Available The loss of habitat due to suburban and urban development represents one of the greatest threats to biodiversity. Conservation developments have emerged as a key player for reconciling new ex-urban residential development with ecosystem services. However, as more than half of the world population lives in urban and suburban developments, identifying conservation partners to facilitate retrofitting existing residential neighborhoods becomes paramount. Homeowner associations (HOA manage a significant proportion of residential developments in the United States, which includes the landscape design for yards and gardens. These areas have the potential to mitigate the loss of urban biodiversity when they provide habitat for native wildlife. Therefore, the conditions and restrictions imposed upon the homeowner by the HOA could have profound effects on the local wildlife habitat. We explored the potential of HOAs to promote conservation by synthesizing research from three monitoring programs from Phoenix, Arizona. We compared native bird diversity, arthropod diversity, and plant diversity between neighborhoods with and without a HOA. Neighborhoods belonging to HOAs had significantly greater bird and plant diversity, although insect diversity did not differ. The institutional framework structuring HOAs, including sanctions for enforcement coupled with a predictable maintenance regime that introduces regular disturbance, might explain why neighborhoods with a HOA had greater bird diversity. For neighborhoods with a HOA, we analyzed landscape form and management practices. We linked these features with ecological function and suggested how to modify management practices by adopting strategies from the Sustainable Sites Initiative, an international sustainable landscaping program, to help support biodiversity in current and future residential landscapes.

  17. Corneal Higher Order Aberrations in Granular, Lattice and Macular Corneal Dystrophies

    Science.gov (United States)

    Yagi-Yaguchi, Yukari; Yamaguchi, Takefumi; Okuyama, Yumi; Satake, Yoshiyuki; Tsubota, Kazuo; Shimazaki, Jun

    2016-01-01

    Purpose To evaluate the corneal higher-order aberrations (HOAs) in granular, lattice and macular corneal dystrophies. Methods This retrospective study includes consecutive patients who were diagnosed as granular corneal dystrophy type2 (GCD2; 121 eyes), lattice corneal dystrophies type 1, type 3A (LCDI; 20 eyes, LCDIIIA; 32 eyes) and macular corneal dystrophies (MCD; 13 eyes), and 18 healthy control eyes. Corneal HOAs were calculated using anterior segment optical coherence tomography, and the correlations between HOAs and visual acuity were analyzed. Results HOAs of the total cornea within 4 mm diameter were significantly larger in GCD2 (0.17 ± 0.35 μm), in LCDI (0.33 ± 0.27), LCDIIIA (0.61 ± 1.56) and in MCD (0.23 ± 0.18), compared with healthy controls (0.09 ± 0.02μm, all P GCD2 (0.32 ± 0.48), in LCDI (0.60 ± 0.46), LCDIIIA (0.83 ± 2.29) and in MCD (0.44 ± 0.24), compared with healthy controls (0.19 ± 0.06, all P GCD2, there was no significant correlation between logMAR and HOAs (r = 0.113, P = 0.227). In MCD, LCDI and LCDIIIA, logMAR was positively significantly correlated with HOAs (r = 0.620 and P = 0.028, r = 0.587 and P = 0.007, r = 0.614 and P < 0.001, respectively). Conclusions Increased HOAs occur in eyes with corneal dystrophies, especially in eye with LCD and MCD. Larger amount corneal HOAs are associated with poorer visual acuity in patients with LCD and MCD. PMID:27536778

  18. Alternate methods to teach history of anesthesia.

    Science.gov (United States)

    Desai, Manisha S; Desai, Sukumar P

    2014-02-01

    Residency programs in anesthesiology in the United States struggle to balance the conflicting needs of formal didactic sessions, clinical teaching, and clinical service obligations. As a consequence of the explosion in knowledge about basic and applied sciences related to our specialty, residents and fellows are expected to make substantial efforts to supplement formal lectures with self-study. There is strong evidence to suggest that members of the younger generation use nontraditional methods to acquire information. Although training programs are not required to include topics related to history of anesthesia (HOA) in the didactic curriculum, and despite the fact that such knowledge does not directly impact clinical care, many programs include such lectures and discussions. We describe and discuss our experience with 3 alternate modalities of teaching HOA.First, we provide brief descriptions of HOA-related historical narratives and novels within the domain of popular literature, rather than those that might be considered textbooks. Second, we analyze content in movies and videodiscs dealing with HOA and determine their utility as educational resources. Third, we describe HOA tours to sites in close proximity to our institutions, as well as those in locations elsewhere in the United States and abroad.We suggest that informal HOA teaching can be implemented by every residency program without much effort and without taking away from the traditional curriculum. Participating in this unique and enriching experience may be a means of academic advancement. It is our hope and expectation that graduates from programs that incorporate such exposure to HOA become advocates of history and may choose to devote a part of their academic career toward exploration of HOA.

  19. Effects of 3% diquafosol sodium ophthalmic solution on higher-order aberrations in patients diagnosed with dry eye after cataract surgery

    Science.gov (United States)

    Inoue, Yasushi; Ochi, Shintarou

    2017-01-01

    Purpose To evaluate the effects of diquafosol sodium ophthalmic solution 3% (DQS) and artificial tears (AT) on higher-order aberrations (HOAs) in patients with dry eye after cataract surgery. Design This was a post hoc analysis of a previously conducted randomized clinical study. Methods Fifty-nine eyes from 42 patients (17 males and 25 females, aged 72.6±8.0 years) with verified or suspected dry eye at 4 weeks after cataract surgery were evaluated. The dry eye patients were randomly assigned to receive DQS or AT for 4 weeks. Tear breakup time (BUT), corneal and conjunctival fluorescein staining scores, and HOAs were analyzed before and after instillation. HOAs were measured consecutively for 10 seconds with a wavefront analyzer. Average HOAs, HOA fluctuations (fluctuation index [FI]) and changes in HOAs (stability index [SI]) were compared within and between the two groups. Results After 4 weeks of instillation, BUT significantly increased (P=0.001) compared with preinstillation values in the DQS group, but not in the AT group. This increase in BUT in the DQS group was significantly greater than in the AT group (P=0.014). Corneal and conjunctival fluorescein staining scores after instillation significantly improved compared with preinstillation values in the DQS group (P=0.018). In HOAs, the cornea aberration changed from an upward curve (a sawtooth pattern) to an almost constant value (a stable pattern) in the DQS group, but not in the AT group. In FI and SI, there were no significant changes in either group; however, FI and SI were significantly lower in the DQS group than in the AT group (both, P=0.004). Conclusion The dry eye patients after cataract surgery had a visual dysfunction in HOAs. DQS is effective to treat dry eye disease after cataract surgery with improvement of visual function. PMID:28096651

  20. Development of Carbon Nanotube-Based Sensor to Monitor Crack Growth in Cracked Aluminum Structures Underneath Composite Patching

    Science.gov (United States)

    2014-06-01

    carbon nanotube/epoxy composites,” Carbon, vol. 44, no. 14, pp. 3022–3029, Nov. 2006. [15] I. D. Rosca and S. V. Hoa , “Highly conductive...nanotube- based sensor- A review,” IEEE Sensors Journal, vol. 7, no. 1-2, pp. 266–284, Jan.–Feb., 2007. [23] M. Nofar, S. V. Hoa and M. D. Pugh

  1. CT findings of intrathoricic neoplasm associated with hypertrophic osteoarthropathy

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Hee Sung; Choe, Kyu Ok; Chung, Jin Il; Oh, Sei Chung [College of Medicine Yonsei University, Seoul (Korea, Republic of)

    1994-02-15

    Hypertrophic osteoarthropathy(HOA) is a clinical syndrome consisting of clubbing, periostitis and synovitis. Most frequent causes of hypertrophic osteoarthropathy are intrathoracic neoplasms, among which the bronchogenic carcinoma ranks the highest. But computed tomographic evaluation of intrathoracic neoplasm associated with HOA has been seldom reported. The purpose of this study is to evaluate CT findings of intrathoracic neoplasm associated with HOA, and to infer possible mechanism. Seven cases of intrathoracic neoplasm associated with HOA were included in our study. Diagnoses of HOA were made by Tc99m bone scintigraphy or plain radiography. The findings of chest CT scans were reviewed retrospectively, with main interests on their size, location and internal characteristics, ect. Seven cases of intrathoracic neoplasm consisted of five bronchogenic carcinomas and two thymic tumors. The size of intrathoracic tumors were relatively large ranging from 6cm to 13cm(average 8.0cm). All thoracic neoplasms showed wide pleural contact, and one of them invaded thoracic wall. The range of length of pleural contact was 5-18cm(average 9.9cm). All of seven patients had internal necrosis, and one of them showed cavitation in thoracic mass. Intrathoracic neoplasms associated with HOA had a tendency to be large, to contain internal necrosis, and to widely abut the thoracic pleura.

  2. Wintertime aerosol chemistry and haze evolution in an extremely polluted city of the North China Plain: significant contribution from coal and biomass combustion

    Science.gov (United States)

    Li, Haiyan; Zhang, Qi; Zhang, Qiang; Chen, Chunrong; Wang, Litao; Wei, Zhe; Zhou, Shan; Parworth, Caroline; Zheng, Bo; Canonaco, Francesco; Prévôt, André S. H.; Chen, Ping; Zhang, Hongliang; Wallington, Timothy J.; He, Kebin

    2017-04-01

    The North China Plain (NCP) frequently experiences heavy haze pollution, particularly during wintertime. In winter 2015-2016, the NCP region suffered several extremely severe haze episodes with air pollution red alerts issued in many cities. We have investigated the sources and aerosol evolution processes of the severe pollution episodes in Handan, a typical industrialized city in the NCP region, using real-time measurements from an intensive field campaign during the winter of 2015-2016. The average (±1σ) concentration of submicron aerosol (PM1) during 3 December 2015-5 February 2016 was 187.6 (±137.5) µg m-3, with the hourly maximum reaching 700.8 µg m-3. Organic was the most abundant component, on average accounting for 45 % of total PM1 mass, followed by sulfate (15 %), nitrate (14 %), ammonium (12 %), chloride (9 %) and black carbon (BC, 5 %). Positive matrix factorization (PMF) with the multilinear engine (ME-2) algorithm identified four major organic aerosol (OA) sources, including traffic emissions represented by a hydrocarbon-like OA (HOA, 7 % of total OA), industrial and residential burning of coal represented by a coal combustion OA (CCOA, 29 % of total OA), open and domestic combustion of wood and crop residuals represented by a biomass burning OA (BBOA, 25 % of total OA), and formation of secondary OA (SOA) in the atmosphere represented by an oxygenated OA (OOA, 39 % of total OA). Emissions of primary OA (POA), which together accounted for 61 % of total OA and 27 % of PM1, are a major cause of air pollution during the winter. Our analysis further uncovered that primary emissions from coal combustion and biomass burning together with secondary formation of sulfate (mainly from SO2 emitted by coal combustion) are important driving factors for haze evolution. However, the bulk composition of PM1 showed comparatively small variations between less polluted periods (daily PM2. 5 ≤ 75 µg m-3) and severely polluted periods (daily PM2. 5 > 75 µg m-3

  3. Wintertime aerosol chemistry and haze evolution in an extremely polluted city of North China Plain: significant contribution from coal and biomass combustions

    Science.gov (United States)

    Li, Haiyan; Zhang, Qi; Zhang, Qiang; Chen, Chunrong; Wang, Litao; Wei, Zhe; Zhou, Shan; Parworth, Caroline; Zheng, Bo; Canonaco, Francesco; Prévôt, André; Chen, Ping; Zhang, Hongliang; He, Kebin

    2017-04-01

    The North China Plain (NCP) frequently encountered heavy haze pollution in recent years, particularly during wintertime. In 2015-2016 winter, the NCP region suffered several extremely severe haze episodes with air pollution red alerts issued in many cities. In this work, we investigated the sources and aerosol evolution processes of the severe pollution episodes in Handan, a typical industrialized city in the NCP region, using real-time measurements from an intensive field campaign during the winter of 2015-2016. The average (± 1σ) concentration of submicron aerosol (PM1) during December 3, 2015 - February 5, 2016 was 187.6 (± 137.5) μg m-3, with the hourly maximum reaching 700.8 μg m-3. Organic was the most abundant component, on average accounting for 45% of total PM1 mass, followed by sulfate (15%), nitrate (14%), ammonium (12%), chloride (9%) and BC (5%). Positive matrix factorization (PMF) with multi-linear engine (ME-2) identified four major organic aerosol (OA) sources, including traffic emissions represented by a hydrocarbon-like OA (HOA, 7% of total OA), industrial and residential burning of coal represented by a coal combustion OA (CCOA, 29% of total OA), open and domestic combustion of wood and crop residuals represented by a biomass burning OA (BBOA, 25% of total OA), and formation of secondary OA (SOA) in the atmosphere represented by an oxygenated OA (OOA, 39% of total OA). Emissions of primary OA (POA), which together accounted for 61% of total OA and 27% of PM1, are a major cause of air pollution in this region during the winter. Our analysis further uncovered that, primary emissions from coal combustion and biomass burning together with secondary formation of sulfate (mainly from SO2 emitted by coal combustion) are important driving factors for haze evolution. However, the bulk composition of PM1 showed comparatively small variations between less polluted periods (daily PM2.5 ≤ 75 μg m-3) and severely polluted periods (daily PM2.5 > 75

  4. Organic aerosol components observed in Northern Hemispheric datasets from Aerosol Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    N. L. Ng

    2010-05-01

    Full Text Available In this study we compile and present results from the factor analysis of 43 Aerosol Mass Spectrometer (AMS datasets (27 of the datasets are reanalyzed in this work. The components from all sites, when taken together, provide a holistic overview of Northern Hemisphere organic aerosol (OA and its evolution in the atmosphere. At most sites, the OA can be separated into oxygenated OA (OOA, hydrocarbon-like OA (HOA, and sometimes other components such as biomass burning OA (BBOA. We focus on the OOA components in this work. In many analyses, the OOA can be further deconvolved into low-volatility OOA (LV-OOA and semi-volatile OOA (SV-OOA. Differences in the mass spectra of these components are characterized in terms of the two main ions m/z 44 (CO2+ and m/z 43 (mostly C2H3O+, which are used to develop a new mass spectral diagnostic for following the aging of OA components in the atmosphere. The LV-OOA component spectra have higher f44 (ratio of m/z 44 to total signal in the component mass spectrum and lower f43 (ratio of m/z 43 to total signal in the component mass spectrum than SV-OOA. A wide range of f44 and O:C ratios are observed for both LV-OOA (0.17±0.04, 0.73±0.14 and SV-OOA (0.07±0.04, 0.35±0.14 components, reflecting the fact that there is a continuum of OOA properties in ambient aerosol. The OOA components (OOA, LV-OOA, and SV-OOA from all sites cluster within a well-defined triangular region in the f44 vs. f43 space, which can be used as a standardized means for comparing and characterizing any OOA components (laboratory or ambient observed with the AMS. Examination of the OOA components in this triangular space indicates that OOA component spectra become increasingly similar to each other and to fulvic acid and HULIS sample spectra as f44 (a

  5. Two year-long continuous monitoring of PM1 aerosol chemical composition at the Cyprus Atmospheric Observatory. Source apportionment of the Organic content and geographic origins.

    Science.gov (United States)

    Stavroulas, Iasonas; Pikridas, Michael; Oikonomou, Kostantina; Vasiliadou, Emily; Savvides, Chrysanthos; Vrekoussis, Mihalis; Mihalopoulos, Nikolaos; Gros, Valerie; Sciare, Jean

    2017-04-01

    Lagrangian dispersion model FLEXPART in backward mode. Analysis of the PMF on the organic mass spectra, based on good agreement with external standard mass spectra, led to the selection of a solution with three factors, an HOA (Hydrocarbon-like Organic Aerosol) factor with relatively low overall contribution (9{%}), a typical Low Volatility (LV-OOA) factor contributing 54{%}, and a factor attributed to Semi-Volatile organics (SV-OOA), contributing 37{%}. The FLEXPART model analysis, led to eight main regions of influence, namely Europe, West Turkey, Anatolia, Middle East, North Africa, Marine, Local and Mixed. Organic content exhibits maximum values when air masses originate from the wider northern sector (West Turkey and Anatolia) and the Middle East. Less aged organic content was identified for air masses originating from the immediate neighboring regions (West Turkey, Anatolia, Middle East and North Africa) while fresh organics peaked when air masses originated from the Middle East, coinciding with elevated BC concentrations, suggesting strong anthropogenic sources for this sector. This project received funding from the ChArMEx (Chemistry Aerosol Mediterranean Experiment) program, the ENVI-MED CyAr project, the European Union's Seventh Framework Programme (FP7) project BACCHUS under grant agreement no. 603445, and the European Union's Horizon 2020 research and innovation programme ACTRIS-2 under grant agreement No 654109.

  6. Detection of Saharan dust and biomass burning events using near-real-time intensive aerosol optical properties in the north-western Mediterranean

    Science.gov (United States)

    Ealo, Marina; Alastuey, Andrés; Ripoll, Anna; Pérez, Noemí; Cruz Minguillón, María; Querol, Xavier; Pandolfi, Marco

    2016-10-01

    % at MSY and MSA respectively. Linear relationships were found between AAE and %BCbb, with AAE values reaching around 1.5 when %BCbb was higher than 50 %. BB contribution to organic matter (OM) at MSY was around 30 %. Thus fossil fuel (FF) combustion sources showed important contributions to both BC and OM in the region under study. Results for OM source apportionment showed good agreement with simultaneous biomass burning organic aerosol (BBOA) and hydrocarbon-like organic aerosol (HOA) obtained by applying a positive matrix factorization model (PMF) to simultaneous Aerosol Chemical Speciation Monitor (ACSM) measurements. A wildfire episode was identified at MSY, showing AAE values up to 2 when daily BB contributions to BC and OM were 73 and 78 % respectively.

  7. Chemical composition, sources, and processes of urban aerosols during summertime in Northwest China: insights from High Resolution Aerosol Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    J. Xu

    2014-06-01

    Full Text Available An aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed along with a Scanning Mobility Particle Sizer (SMPS and a Multi Angle Absorption Photometers (MAAP to measure the temporal variations of the mass loading, chemical composition, and size distribution of sub-micrometer particulate matter (PM1 in Lanzhou, northwest China, during 12 July–7 August 2012. The average PM1 mass concentration including non-refractory PM1 (NR-PM1 measured by HR-ToF-AMS and black carbon (BC measured by MAAP during this study was 24.5 μg m−3 (ranging from 0.86 to 105μg m−3, with a mean composition consisting of 47% organics, 16% sulfate, 12% BC, 11% ammonium, 10% nitrate, and 4% chloride. The organics was consisted of 70% carbon, 21% oxygen, 8% hydrogen, and 1% nitrogen, with the average oxygen-to-carbon ratio (O / C of 0.33 and organic mass-to-carbon ratio (OM / OC of 1.58. Positive matrix factorization (PMF of the high-resolution mass spectra of organic aerosols (OA identified four distinct factors which represent, respectively, two primary OA (POA emission sources (traffic and food cooking and two secondary OA (SOA types – a fresher, semi-volatile oxygenated OA (SV-OOA and a more aged, low-volatility oxygenated OA (LV-OOA. Traffic-related hydrocarbon-like OA (HOA and BC displayed distinct diurnal patterns both with peak at ~07:00–11:00 (BJT: UTC +8 corresponding to the morning rush hours, while cooking OA (COA peaked during three meal periods. The diurnal profiles of sulfate and LV-OOA displayed a broad peak between ∼07:00–15:00, while those of nitrate, ammonium, and SV-OOA showed a narrower peak at ~08:00–13:00. The later morning and early afternoon peak in the diurnal profiles of secondary aerosol species was likely caused by mixing down of pollutants aloft, which were likely produced in the residual layer decoupled from the boundary layer during night time. The mass spectrum of SV-OOA also showed similarity

  8. Hygroscopic and chemical characterisation of Po Valley aerosol

    Science.gov (United States)

    Bialek, J.; Dall Osto, M.; Vaattovaara, P.; Decesari, S.; Ovadnevaite, J.; Laaksonen, A.; O'Dowd, C.

    2014-02-01

    Continental summer-time aerosol in the Italian Po Valley was characterised in terms of hygroscopic properties and the influence of chemical composition therein. Additionally, the ethanol affinity of particles was analysed. The campaign-average minima in hygroscopic growth factors (HGFs, at 90% relative humidity) occurred just before and during sunrise from 03:00 to 06:00 LT (all data are reported in the local time), but, more generally, the hygroscopicity during the whole night is very low, particularly in the smaller particle sizes. The average HGFs recorded during the low HGF period were in a range from 1.18 (for the smallest, 35nm particles) to 1.38 (for the largest, 165 nm particles). During the day, the HGF gradually increased to achieve maximum values in the early afternoon hours 12:00-15:00, reaching 1.32 for 35 nm particles and 1.46 for 165 nm particles. Two contrasting case scenarios were encountered during the measurement period: Case 1 was associated with westerly air flow moving at a moderate pace and Case 2 was associated with more stagnant, slower moving air from the north-easterly sector. Case 1 exhibited weak diurnal temporal patterns, with no distinct maximum or minimum in HGF or chemical composition, and was associated with moderate non-refractory aerosol mass concentrations (for 50% size cut at 1 μ) of the order of 4.5 μg m-3. For Case 1, organics contributed typically 50% of the mass. Case 2 was characterised by >9.5 μg m-3 total non-refractory mass (organic mass concentrations. Specifically, the concentrations of nitrate peaked at night-time, along with the concentrations of hydrocarbon-like organic aerosol (HOA) and of semi-volatile oxygenated organic aerosol (SV-OOA). In general, organic growth factors (OGFs) followed a trend which was opposed to HGF and also to the total organic mass as measured by the aerosol mass spectrometer. The analysis of the HGF probability distribution function (PDF) reveals an existence of a predominant "more

  9. Investigation of the sources and processing of organic aerosol over the Central Mexican Plateau from aircraft measurements during MILAGRO

    Directory of Open Access Journals (Sweden)

    P. F. DeCarlo

    2010-02-01

    Full Text Available Organic aerosol (OA represents approximately half of the submicron aerosol in Mexico City and the Central Mexican Plateau. This study uses the high time resolution measurements performed onboard the NCAR/NSF C-130 aircraft during the MILAGRO/MIRAGE-Mex field campaign in March 2006 to investigate the sources and chemical processing of the OA in this region. An examination of the OA/ΔCO ratio evolution as a function of photochemical age shows distinct behavior in the presence or absence of substantial open biomass burning (BB influence, with the latter being consistent with other studies in polluted areas. In addition, we present results from Positive Matrix Factorization (PMF analysis of 12-s High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS OA spectra. Four components were resolved. Three of the components contain substantial organic oxygen and are termed semivolatile oxygenated OA (SV-OOA, low-volatility OOA (LV-OOA, and biomass burning OA (BBOA. A reduced "hydrocarbon-like OA" (HOA component is also resolved. LV-OOA is highly oxygenated (atomic O/C~1 and is aged organic aerosol linked to regional airmasses, with likely contributions from pollution, biomass burning, and other sources. SV-OOA is strongly correlated with ammonium nitrate, Ox, and the Mexico City Basin. We interpret SV-OOA as secondary OA which is nearly all (>90% anthropogenic in origin. In the absence of biomass burning it represents the largest fraction of OA over the Mexico City basin, consistent with other studies in this region. BBOA is identified as arising from biomass burning sources due to a strong correlation with HCN, and the elevated contribution of the ion C2H4O2+ (m/z 60, a marker for levoglucosan and other primary BB species. WRF-FLEXPART calculated fire impact factors (FIF show good correlation with BBOA mass concentrations within the basin, but show location offsets in the far field

  10. Characterization of submicron particles influenced by mixed biogenic and anthropogenic emissions using high-resolution aerosol mass spectrometry: results from CARES

    Directory of Open Access Journals (Sweden)

    A. Setyan

    2012-09-01

    Full Text Available An Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS was deployed during the Carbonaceous Aerosols and Radiative Effects Study (CARES that took place in northern California in June 2010. We present results obtained at Cool (denoted as the T1 site of the project in the foothills of the Sierra Nevada Mountains, where intense biogenic emissions are periodically mixed with urban outflow transported by daytime southwesterly winds from the Sacramento metropolitan area. During this study, the average mass loading of submicrometer particles (PM1 was 3.0 μg m−3, dominated by organics (80% and sulfate (9.9%. The organic aerosol (OA had a nominal formula of C1H1.38N0.004OM0.44, thus an average organic mass-to-carbon (OM/OC ratio of 1.70. Two distinct oxygenated OA factors were identified via Positive matrix factorization (PMF of the high-resolution mass spectra of organics. The more oxidized MO-OOA (O/C = 0.54 was interpreted as a surrogate for secondary OA (SOA influenced by biogenic emissions whereas the less oxidized LO-OOA (O/C = 0.42 was found to represent SOA formed in photochemically processed urban emissions. LO-OOA correlated strongly with ozone and MO-OOA correlated well with two 1st generation isoprene oxidation products (methacrolein and methyl vinyl ketone, indicating that both SOAs were relatively fresh. A hydrocarbon like OA (HOA factor was also identified, representing primary emissions mainly due to local traffic. On average, SOA (= MO-OOA + LO-OOA accounted for 91% of the total OA mass and 72% of the PM1 mass observed at Cool. Twenty three periods of urban plumes from T0 (Sacramento to T1 (Cool were identified using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem. The average PM1 mass loading was considerably higher in urban plumes than in air masses dominated by biogenic SOA. The change in OA

  11. Investigation of the sources and processing of organic aerosol over the Central Mexican Plateau from aircraft measurements during MILAGRO

    Directory of Open Access Journals (Sweden)

    P. F. DeCarlo

    2010-06-01

    Full Text Available Organic aerosol (OA represents approximately half of the submicron aerosol in Mexico City and the Central Mexican Plateau. This study uses the high time resolution measurements performed onboard the NCAR/NSF C-130 aircraft during the MILAGRO/MIRAGE-Mex field campaign in March 2006 to investigate the sources and chemical processing of the OA in this region. An examination of the OA/ΔCO ratio evolution as a function of photochemical age shows distinct behavior in the presence or absence of substantial open biomass burning (BB influence, with the latter being consistent with other studies in polluted areas. In addition, we present results from Positive Matrix Factorization (PMF analysis of 12-s High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS OA spectra. Four components were resolved. Three of the components contain substantial organic oxygen and are termed semivolatile oxygenated OA (SV-OOA, low-volatility OOA (LV-OOA, and biomass burning OA (BBOA. A reduced "hydrocarbon-like OA" (HOA component is also resolved. LV-OOA is highly oxygenated (atomic O/C~1 and is aged organic aerosol linked to regional airmasses, with likely contributions from pollution, biomass burning, and other sources. SV-OOA is strongly correlated with ammonium nitrate, Ox, and the Mexico City Basin. We interpret SV-OOA as secondary OA which is nearly all (>90% anthropogenic in origin. In the absence of biomass burning it represents the largest fraction of OA over the Mexico City basin, consistent with other studies in this region. BBOA is identified as arising from biomass burning sources due to a strong correlation with HCN, and the elevated contribution of the ion C2H4O2+ (m/z 60, a marker for levoglucosan and other primary BB species. WRF-FLEXPART calculated fire impact factors (FIF show good correlation with BBOA mass concentrations within the basin, but show location offsets in the far field

  12. Influences of emission sources and meteorology on aerosol chemistry in a polluted urban environment: results from DISCOVER-AQ California

    Science.gov (United States)

    Young, Dominique E.; Kim, Hwajin; Parworth, Caroline; Zhou, Shan; Zhang, Xiaolu; Cappa, Christopher D.; Seco, Roger; Kim, Saewung; Zhang, Qi

    2016-05-01

    The San Joaquin Valley (SJV) in California experiences persistent air-quality problems associated with elevated particulate matter (PM) concentrations due to anthropogenic emissions, topography, and meteorological conditions. Thus it is important to unravel the various sources and processes that affect the physicochemical properties of PM in order to better inform pollution abatement strategies and improve parameterizations in air-quality models. During January and February 2013, a ground supersite was installed at the Fresno-Garland California Air Resources Board (CARB) monitoring station, where comprehensive, real-time measurements of PM and trace gases were performed using instruments including an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and an Ionicon proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) as part of the NASA Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) campaign. The average submicron aerosol (PM1) concentration was 31.0 µg m-3 and the total mass was dominated by organic aerosols (OA, 55 %), followed by ammonium nitrate (35 %). High PM pollution events were commonly associated with elevated OA concentrations, mostly from primary sources. Organic aerosols had average atomic oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), and nitrogen-to-carbon (N / C) ratios of 0.42, 1.70, and 0.017, respectively. Six distinct sources of organic aerosol were identified from positive matrix factorization (PMF) analysis of the AMS data: hydrocarbon-like OA (HOA; 9 % of total OA, O / C = 0.09) associated with local traffic, cooking OA (COA; 18 % of total OA, O / C = 0.19) associated with food cooking activities, two biomass burning OA (BBOA1: 13 % of total OA, O / C = 0.33; BBOA2: 20 % of total OA, O / C = 0.60) most likely associated with residential space heating from wood combustion, and semivolatile oxygenated OA (SV

  13. Olive Tree Branches Burning: A major pollution source in the Mediterranean

    Science.gov (United States)

    Kostenidou, Evangelia; Kaltsonoudis, Christos; Tsiflikiotou, Maria; Louvaris, Evangelos; Russell, Lynn; Pandis, Spyros

    2013-04-01

    ambient organic data 3 factors could be identified: OOA (oxygenated organic aerosol), HOA (hydrocarbon-like organic aerosol) and otBB-OA. The chamber organic AMS spectrum resembles the ambient mass spectrum during olive tree branches burning events. We estimated an otBB-OA emission factor of 3.45±0.2 g kg-1. Assuming that half of the olive trees branches are burned 2,300 tons of otBB-OA are emitted in Greece each winter. This is one of the most important fine aerosol emission sources during the winter months in the Mediterranean countries in which this activity is prevalent.

  14. Studying organic aerosols during bonfire night in Manchester: ME-2 source apportionment

    Science.gov (United States)

    Reyes Villegas, Ernesto; Allan, James

    2016-04-01

    Over the past decade, there has been an increasing interest in short-term events that negatively affect air quality (Zhao et al. 2014) such as bonfires and fireworks. In general, during these episodes, high particulate matter concentrations drop within 24 hrs; however, it is the fine fraction that dominates the emissions, known to have a potentially negative impact on air quality, thus the impact of bonfires/fireworks on air quality must be considered. Aerosols and gases were measured using a variety of instruments at The University of Manchester, sampling atmospheric emissions on Bonfire night, 5 November, one week before and one week later, in 2013 and 2014. The Multilinear Engine (ME-2) factorization tool was used through the recently developed source finder interface (SoFi, Canonaco et al. 2013) to identify sources of organic aerosols (OA) sampled with an Aerosol Mass Spectrometer (AMS). ME-2 identified five sources: solid fuel OA (SFOA), hydrocarbon like OA (HOA), cooking OA (COA), semi-volatile (SVOOA) and low volatility (LVOOA) during both years. In 2014, air pollutant concentrations were particularly high, with the highest SFOA concentrations being 20 μgm-3 at 20:30 hrs. when fireworks from different parks in Manchester were launched. Black carbon (BC) concentrations started increasing before the fireworks, around 18:00 hrs; these concentrations are representative of bonfire emissions. However, traffic emissions may be contributing to BC here; further work will be done to differentiate traffic emissions from solid fuel emissions. By analysing daily aerosol concentrations according to DEFRA's Daily Air Quality Index, it is possible to observe that in 2014, PM2.5 concentrations were considered to be high (65 μgm-3) while in 2013, PM2.5 concentrations were considered low (12 μgm-3); in the case of BBOA, concentrations ranged from 2.9 μgm-3 in 2014 to 0.65 μgm-3 in 2013. The discrepancy between these studies is mainly a result of different meteorological

  15. The Pasadena Aerosol Characterization Observatory (PACO: chemical and physical analysis of the Western Los Angeles Basin aerosol

    Directory of Open Access Journals (Sweden)

    S. P. Hersey

    2011-02-01

    appearance of a distinct fine mode dominated by organics. Particulate NH4NO3 and (NH42SO4 appear to be NH3-limited in regimes I and II, but a significant excess of particulate NH4+ in the hot, dry regime III suggests less marine SO42− and the presence of organic amines.

    Positive Matrix Factorization (PMF analysis of C-ToF-AMS data resolved three factors, corresponding to a hydrocarbon-like OA (HOA, semivolatile OOA (SV-OOA, and low-volatility OOA (LV-OOA. HOA appears to be a periodic plume source, while SV-OOA exhibits a strong diurnal pattern correlating with ozone. Peaks in SV-OOA concentration correspond to peaks in DMA number concentration and the appearance of a fine organic mode. LV-OOA appears to be an aged accumulation mode constituent that may be associated with aqueous-phase processing, correlating strongly with sulfate and representing the dominant background organic component.

    Filter analysis revealed a complex mixture of species during periods dominated by SV-OOA and LV-OOA, with LV-OOA periods characterized by shorter-chain dicarboxylic acids (higher O:C ratio, as well as appreciable amounts of nitrate- and sulfate-substituted organics. Phthalic acid was ubiquitous in filter samples, suggesting that PAH photochemistry may be an important SOA pathway in Los Angeles.

    Water uptake characteristics indicate that hygroscopicity is largely controlled by organic mass fraction (OMF. The hygroscopicity parameter κ averaged 0.31 ± 0.08, approaching 0.5 at low OMF and 0.1 at high OMF, with increasing OMF suppressing hygroscopic growth and increasing critical dry diameter for CCN activation (Dd.

    Finally, PACO will provide context for results forthcoming from the CalNex field campaign, which involved ground sampling in Pasadena during the spring and summer of 2010.

  16. The Pasadena Aerosol Characterization Observatory (PACO): chemical and physical analysis of the Western Los Angeles basin aerosol

    Science.gov (United States)

    Hersey, S. P.; Craven, J. S.; Schilling, K. A.; Metcalf, A. R.; Sorooshian, A.; Chan, M. N.; Flagan, R. C.; Seinfeld, J. H.

    2011-08-01

    mode aerosol, while afternoon SOA production coincides with the appearance of a distinct fine mode dominated by organics. Particulate NH4NO3 and (NH4)2SO4 appear to be NH3-limited in regimes I and II, but a significant excess of particulate NH4+ in the hot, dry regime III suggests less SO42- and the presence of either organic amines or NH4+-associated organic acids. C-ToF-AMS data were analyzed by Positive Matrix Factorization (PMF), which resolved three factors, corresponding to a hydrocarbon-like OA (HOA), semivolatile OOA (SV-OOA), and low-volatility OOA (LV-OOA). HOA appears to be a periodic plume source, while SV-OOA exhibits a strong diurnal pattern correlating with ozone. Peaks in SV-OOA concentration correspond to peaks in DMA number concentration and the appearance of a fine organic mode. LV-OOA appears to be an aged accumulation mode constituent that may be associated with aqueous-phase processing, correlating strongly with sulfate and representing the dominant background organic component. Periods characterized by high SV-OOA and LV-OOA were analyzed by filter analysis, revealing a complex mixture of species during periods dominated by SV-OOA and LV-OOA, with LV-OOA periods characterized by shorter-chain dicarboxylic acids (higher O:C ratio), as well as appreciable amounts of nitrate- and sulfate-substituted organics. Phthalic acid was ubiquitous in filter samples, suggesting that PAH photochemistry may be an important SOA pathway in Los Angeles. Aerosol composition was related to water uptake characteristics, and it is concluded that hygroscopicity is largely controlled by organic mass fraction (OMF). The hygroscopicity parameter κ averaged 0.31 ± 0.08, approaching 0.5 at low OMF and 0.1 at high OMF, with increasing OMF suppressing hygroscopic growth and increasing critical dry diameter for CCN activation (Dd). An experiment-averaged κorg of 0.14 was calculated, indicating that the highly-oxidized organic fraction of aerosol in Los Angeles is appreciably

  17. The Pasadena Aerosol Characterization Observatory (PACO: chemical and physical analysis of the Western Los Angeles basin aerosol

    Directory of Open Access Journals (Sweden)

    S. P. Hersey

    2011-08-01

    in accumulation mode aerosol, while afternoon SOA production coincides with the appearance of a distinct fine mode dominated by organics. Particulate NH4NO3 and (NH42SO4 appear to be NH3-limited in regimes I and II, but a significant excess of particulate NH4+ in the hot, dry regime III suggests less SO42− and the presence of either organic amines or NH4+-associated organic acids. C-ToF-AMS data were analyzed by Positive Matrix Factorization (PMF, which resolved three factors, corresponding to a hydrocarbon-like OA (HOA, semivolatile OOA (SV-OOA, and low-volatility OOA (LV-OOA. HOA appears to be a periodic plume source, while SV-OOA exhibits a strong diurnal pattern correlating with ozone. Peaks in SV-OOA concentration correspond to peaks in DMA number concentration and the appearance of a fine organic mode. LV-OOA appears to be an aged accumulation mode constituent that may be associated with aqueous-phase processing, correlating strongly with sulfate and representing the dominant background organic component. Periods characterized by high SV-OOA and LV-OOA were analyzed by filter analysis, revealing a complex mixture of species during periods dominated by SV-OOA and LV-OOA, with LV-OOA periods characterized by shorter-chain dicarboxylic acids (higher O:C ratio, as well as appreciable amounts of nitrate- and sulfate-substituted organics. Phthalic acid was ubiquitous in filter samples, suggesting that PAH photochemistry may be an important SOA pathway in Los Angeles. Aerosol composition was related to water uptake characteristics, and it is concluded that hygroscopicity is largely controlled by organic mass fraction (OMF. The hygroscopicity parameter κ averaged 0.31 ± 0.08, approaching 0.5 at low OMF and 0.1 at high OMF, with increasing OMF suppressing hygroscopic growth and increasing critical dry diameter for CCN activation

  18. A prospective, randomized, fellow eye comparison of WaveLight® Allegretto Wave ® Eye-Q versus VISX CustomVue™ STAR S4 IR™ in laser in situ keratomileusis (LASIK): analysis of visual outcomes and higher order aberrations.

    Science.gov (United States)

    Moshirfar, Majid; Betts, Brent S; Churgin, Daniel S; Hsu, Maylon; Neuffer, Marcus; Sikder, Shameema; Church, Dane; Mifflin, Mark D

    2011-01-01

    To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs), contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK) using wavefront (WF) guided VISX CustomVue and WF optimized WaveLight Allegretto platforms. In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients), with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, root-mean-square (RMS) value of total and grouped HOAs, contrast sensitivity, and Schirmers testing. Mean values for UDVA (logMAR) were -0.067 ± 0.087 and -0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909). UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000). In the WF optimized group, total HOA increased 4% (P = 0.012), coma increased 11% (P = 0.065), and spherical aberration increased 19% (P = 0.214), while trefoil decreased 5% (P = 0.490). In the WF guided group, total HOA RMS decreased 9% (P = 0.126), coma decreased 18% (P = 0.144), spherical aberration decreased 27% (P = 0.713) and trefoil decreased 19% (P = 0.660). One patient lost one line of CDVA secondary to residual irregular astigmatism. Both the WaveLight Allegretto and the VISX CustomVue platforms had equal visual and safety outcomes. Most wavefront optimized HOA values trended upward, with a statistically significant increase in total HOA RMS. Eyes treated with the WF guided platform showed a decreasing trend in HOA values.

  19. Correlation between Corneal Topographic Indices and Higher-Order Aberrations in Keratoconus

    Directory of Open Access Journals (Sweden)

    Sepehr Feizi

    2013-01-01

    Full Text Available Purpose: To compare corneal higher-order aberrations (HOAs between normal and keratoconic eyes, and to investigate the association between elevation-based corneal topographic indices and corneal wavefront data in the latter group. Methods: In this cross-sectional comparative study, 77 normal right eyes of 77 control subjects and 66 eyes of 36 keratoconic patients were included. In each eye, elevationbased corneal topographic indices including mean keratometry readings, best-fit sphere, maximum elevation, and 3-mm and 5-mm zone irregularity indices were measured using Orbscan II. The Galilei Scheimpflug analyzer was used to measure HOAs of the corneal surface. The independent student t-test was used to compare HOAs between the study groups. Spearman correlation was used to investigate possible associations between Orbscan and Galilei data in the keratoconus group. Results: All Zernike coefficients up to the 4th order except for horizontal trefoil, and vertical and horizontal tetrafoil were significantly greater in the keratoconus group than normal eyes (P<0.05. Root mean square (RMS of HOAs up to the 6th order and total HOAs were significantly higher in the keratoconus group (P<0.05. In the keratoconus group, the strongest association was observed between vertical coma (r=-0.71, P<0.01 and total RMS of HOAs (r=0.94, P<0.01 with irregularity in the 3-mm zone. Spherical and vertical coma aberrations were significantly correlated with mean keratometry (P<0.05 for both comparisons. Conclusion: Centrally located corneal HOAs are significantly greater in keratoconic eyes than normal controls. Anterior and inferior displacement of the cornea causes the majority of higher-order aberrations observed in keratoconus.

  20. Characteristics of sagittal spine-pelvis-leg alignment in patients with severe hip osteoarthritis.

    Science.gov (United States)

    Weng, Wen-Jie; Wang, Wei-Jun; Wu, Ming-Da; Xu, Zhi-Hong; Xu, Lei-Lei; Qiu, Yong

    2015-06-01

    The interaction between the sagittal alignment of the spine and pelvis and the compensatory mechanism in patients suffering from spinal disorders has been well documented. However, in patients with hip osteoarthritis (HOA), few studies have explored how the hip joint pathology could affect the sagittal alignment of the hip, pelvis and spine, and no reports have investigated whether these changes are involved in the pathogenesis of low back pain in these patients. The aims of this case-control study were to investigate the sagittal spine-pelvis-leg alignment in patients suffering from severe HOA and to understand whether the alignment was related to the occurrence of low back pain and the health-related quality of life in these patients. Fifty-eight patients with severe HOA and 64 asymptomatic controls were studied. Digital lateral X-rays of the spine, pelvis and proximal femur were obtained with the patients placed in upright positions. The following radiographic parameters were measured to examine the sagittal alignment of the pelvis, hip and spine: pelvic incidence (PI), pelvic tilting (PT), sacral slope (SS), pelvic femoral angle (PFA), femoral inclination (FI), lumbar lordosis (LL), spino-sacral angle (SSA), C7 tilt (C7T) and T1 spinal-pelvic inclination (T1-SPI). The global balance patterns of spinal-pelvic alignment were classified as normal balance, slight unbalance and severe unbalance according to the relative position of the C7 plumb line to the sacrum and femoral heads. Short Form-36 questionnaire was carried out in the patients. Comparisons were carried out between the patients with HOA and the controls and between the HOA patients with or without low back pain. Correlation analysis was used to measure relationships between the HOA patients' parameters. There were no significant differences in the age and gender distribution between the HOA patients and control. Compared with the controls, the patients with HOA showed significantly higher SS and lower

  1. Long-Term Trend of Climate Change and Drought Assessment in the Horn of Africa

    Directory of Open Access Journals (Sweden)

    Mihretab G. Ghebrezgabher

    2016-01-01

    Full Text Available Climate change due to global warming is a world concern, particularly in Africa. In this study, precipitation and temperature variables are taken as a proxy to assess and quantify the long-term climate change and drought in the Horn of Africa (HOA (1930–2014. We adapted a simple linear regression and interpolation to analyze, respectively, the trend and spatial distribution of the mean annual precipitation and temperature. In addition, standardized precipitation evapotranspiration index (SPEI was applied to evaluate the drought condition of the HOA. The results revealed that statistically the trend of precipitation decreased insignificantly; the trend of temperature was observed to drop very significantly between 1930 and 1969, but it was dramatically elevated very significantly from 1970 to 2014. The SPEI showed that the HOA experienced from mild to moderate drought throughout the study period with severe to extreme drought in some regions, particularly in 1943, 1984, 1991, and 2009. The drought was a very serious environmental problem in the HOA in the last 85 years. Thus, an immediate action is required to tackle drought and hence poverty and famine in the HOA.

  2. Hypertrophic osteoarthropathy manifested with isolated calcaneal periostitis in bone scintigraphy.

    Science.gov (United States)

    Moralidis, Efstratios; Gerasimou, Georgios; Theodoridou, Athina; Hilidis, Ilias; Mylonaki, Efrosyni; Gotzamani-Psarrakou, Anna

    2010-05-01

    Hypertrophic osteoarthropathy (HOA) is an incompletely understood syndrome characterized by digital clubbing and periosteal proliferation of long bones and it is commonly associated with primary lung tumors. Bone scintigraphy is a sensitive method in detecting HOA and characteristic findings have been reported. We present the case of a man with newly diagnosed non-small cell lung cancer, unremarkable clinical examination and blood tests and no digital clubbing. During disease staging, however, bone scintigraphy showed intense calcaneal cortical proliferation bilaterally without involvement of other parts of the skeleton. Cortical reaction of both calcanei resolved significantly after chemotherapy. This case indicates that HOA may manifest with isolated calcaneal periostitis bilaterally, which is a new addition to the literature.

  3. Performance optimization of EDFA-Raman hybrid optical amplifier using genetic algorithm

    Science.gov (United States)

    Singh, Simranjit; Kaler, R. S.

    2015-05-01

    For the first time, a novel net gain analytical model of EDFA-Raman hybrid optical amplifier (HOA) is designed and optimized the various parameters using genetic algorithm. Our method has shown to be robust in the simultaneous analysis of multiple parameters, such as Raman length, EDFA length and its pump powers, to obtained highest possible gain. The optimized HOA is further investigated and characterized on system level in the scenario of 100×10 Gbps dense wavelength division multiplexed (DWDM) system with 25 GHz interval. With an optimized HOA, a flat gain of >18 dB is obtained from frequency region 187 to 189.5 THz with a gain variation of less than 1.35 dB without using any gain flattened technique. The obtained noise figure is also the lowest value (<2 dB/channel) ever reported for proposed hybrid optical amplifier at reduced channel spacing with acceptable bit error rate.

  4. Validation of a loudspeaker-based room auralization system using speech intelligibility measures

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2009-01-01

    A novel loudspeaker-based room auralization (LoRA) system has been proposed to generate versatile and realistic virtual auditory environments (VAEs) for investigating human auditory perception. This system efficiently combines modern room acoustic models with loudspeaker auralization using either...... single loudspeaker or high-order Ambisonics (HOA) auralization. The LoRA signal processing of the direct sound and the early reflections was investigated by measuring the speech intelligibility enhancement by early reflections in diffuse background noise. Danish sentences were simulated in a classroom...... and the direct sound and each early reflection were either auralized with a single loudspeaker, HOA or first-order Ambisonics. Results indicated that (i) absolute intelligibility scores are significantly dependent on the reproduced technique and that (ii) early reflections reproduced with HOA provide a similar...

  5. Wavefront aberration and contrast sensitivity after implantation of foldable and rigid iris claw phakic intraocular lenses: Artiflex versus artisan

    Directory of Open Access Journals (Sweden)

    Faroogh Parsipour

    2016-01-01

    Full Text Available Aim of study: The aim of this study is to assess wavefront aberration and contrast sensitivity (CS after implantation of foldable iris claw - artiflex- and rigid iris claw - artisan- phakic intraocular lenses (pIOLs. Materials and Methods: A nonrandomized prospective comparative case study was performed on 57 eyes; of which, 54 were myopia and 3 were hyperopia. Twenty-four patients had artisan pIOL implantation and 33 had artiflex pIOL implantation. Higher-order aberration (HOA and CS were obtained 1 year after surgery. Results: Total HOA in artisan group was greater than artiflex group (P = 0.044 with a mean HOA of 0.44 ± 0.15 root mean square (RMS for artisan and 0.35 ± 0.15 RMS for artiflex. Although, there were no significant differences in the vertical trefoil, vertical coma, horizontal trefoil, horizontal coma, secondary astigmatism, quatrefoil, and fourth order spherical aberration in two groups. CS in mesopic conditions was better in artiflex-treated eyes at three spatial frequencies of 6, 12, and 18 cycles per degree (cpd (P = 0.003, P = 0.007, and P = 0.00, respectively, and no significant difference was seen between two lenses at 3 cpd. Conclusion: Although the components of HOA were not significantly different between two groups, total HOA was higher in artisan group, which may be due to the slight differences in each component, increasing the HOA as a total. CS was significantly better in artiflex group.

  6. Improved Fractal Space Filling Curves Hybrid Optimization Algorithm for Vehicle Routing Problem.

    Science.gov (United States)

    Yue, Yi-xiang; Zhang, Tong; Yue, Qun-xing

    2015-01-01

    Vehicle Routing Problem (VRP) is one of the key issues in optimization of modern logistics system. In this paper, a modified VRP model with hard time window is established and a Hybrid Optimization Algorithm (HOA) based on Fractal Space Filling Curves (SFC) method and Genetic Algorithm (GA) is introduced. By incorporating the proposed algorithm, SFC method can find an initial and feasible solution very fast; GA is used to improve the initial solution. Thereafter, experimental software was developed and a large number of experimental computations from Solomon's benchmark have been studied. The experimental results demonstrate the feasibility and effectiveness of the HOA.

  7. Piracy in the Horn of Africa the role of Somalia's fishermen

    OpenAIRE

    Sone, Emmanuel N.

    2010-01-01

    Approved for public release; distribution is unlimited Despite a strong naval presence, piracy off the Horn of Africa (HOA) has been rising at the impressive annual rate of about 100 percent since 2006. Repression at sea does not seem to be working, and it is critical to identify the root cause(s) of piracy before additional counter-measures can be applied with any measurable success. The rise in piracy off the HOA is blamed by some on the disenfranchisement of Somali fishermen. This paper...

  8. Effect of acidity of drugs on the prediction of human oral absorption by biopartitioning micellar chromatography

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Biopartitioning micellar chromatography(BMC)is a potentially high throughput and low cost alternative for in vitro prediction of drug absorption,which can mimic the drug partitioning process in biological systems.In this paper,a data set of 56 compounds representing acidic,basic,neutral and amphoteric drugs from various structure classes with human oral absorption(HOA)data available were employed to show the effect of acidity of drugs in oral absorption prediction.HOA was reciprocally correlated to the nega...

  9. Carbonate platform growth and demise offshore Central Vietnam

    DEFF Research Database (Denmark)

    Fyhn, Michael B.W.; Boldreel, Lars Ole; Nielsen, Lars H.;

    2013-01-01

    Fault Zone, the Tuy Hoa Carbonate Platform fringes the continental margin between Da Nang and Nha Trang. Here, platform growth initiated during the Early Miocene and continued until Middle Miocene time when regional uplift led to subaerial exposure, termination of platform growth and karstification...... is interpreted as a consequence of regional uplift and denudation of central and south Indochina starting during Middle Miocene time when the Tuy Hoa Carbonate Platform became subaerially exposed. Stressed carbonate growth conditions on the Triton Carbonate Platform probably resulted from increased inorganic...

  10. Capturing and reproducing realistic acoustic scenes for hearing research

    DEFF Research Database (Denmark)

    Marschall, Marton; Buchholz, Jörg

    -order ambisonics (HOA) with additional, horizontally oriented spherical harmonic functions of higher orders. Simulations of a MOA array, with a higher density of microphones near the equator, and an array with a nearly uniform distribution of microphones were compared in terms of spatial resolution and robustness....... A MOA array was constructed, and some of the simulation results were validated with measurements. Results showed that for MOA, the spatial resolution was improved for horizontal sources at mid to high frequencies and the robustness to noise and measurement errors was similar to that of HOA...

  11. Evaluation of a mixed-order planar and periphonic Ambisonics playback implementation

    DEFF Research Database (Denmark)

    Käsbach, Johannes; Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2011-01-01

    Planar (2D) and periphonic (3D) higher-order Ambisonics (HOA) playback systems are widely used in multi-channel audio applications. For a given Ambisonics order, 2D systems require far less loudspeakers and provide a larger spatial resolution but cannot naturally reproduce elevated sound sources...... can be significantly increased by adding 2D components and thereby approaching 2D system’s performance. Simultaneously, frequency spectrum properties of horizontal sound sources were restored and did not show a low pass filtering effect as it is present in 3D HOA systems....

  12. Metrics for performance assessment of mixed-order Ambisonics spherical microphone arrays

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Marschall, Marton

    2012-01-01

    Mixed-order Ambisonics (MOA) combines planar (2D) higher order Ambisonics (HOA) with lower order periphonic (3D) Ambisonics. MOA encoding from spherical microphone arrays has the potential to provide versatile recordings that can be played back using 2D, 3D or mixed systems. A procedure to generate...... suitable layouts for a given MOA combination order is introduced consisting of rings of microphones at several elevation angles for any given MOA combination order. Robustness and directivity measures were evaluated for four MOA layouts. Results showed that MOA vertical directivity was similar to 3D HOA...

  13. Assessment of genetic diversity and population structure of Vietnamese indigenous cattle populations by microsatellites

    DEFF Research Database (Denmark)

    Pham, Lan Doan; Do, Duy Ngoc; Binh, Nguyen Trong;

    2013-01-01

    geographic distances. Structure analysis indicated five homogeneous clusters. The Brahman, Lang Son, Ha Giang and U Dau Riu cattle were assigned to independent clusters while Nghe An, Thanh Hoa and Phu Yen cattle were grouped in a single cluster. We conclude that Vietnamese indigenous cattle have high levels...... of genetic diversity and distinct genetic structures. Based on these results, we recommend that for conservation homogenous populations (Nghe An, Thanh Hoa and Phu Yen) can be grouped to reduce costs and U Dau Riu, Lang Son and Ha Giang populations should be conserved separately to avoid loss of genetic...

  14. Effects of 3% diquafosol sodium ophthalmic solution on higher-order aberrations in patients diagnosed with dry eye after cataract surgery

    Directory of Open Access Journals (Sweden)

    Inoue Y

    2016-12-01

    Full Text Available Yasushi Inoue, Shintarou Ochi Inoue Eye Clinic, Tamano, Okayama, Japan Purpose: To evaluate the effects of diquafosol sodium ophthalmic solution 3% (DQS and artificial tears (AT on higher-order aberrations (HOAs in patients with dry eye after cataract surgery. Design: This was a post hoc analysis of a previously conducted randomized clinical study. Methods: Fifty-nine eyes from 42 patients (17 males and 25 females, aged 72.6±8.0 years with verified or suspected dry eye at 4 weeks after cataract surgery were evaluated. The dry eye patients were randomly assigned to receive DQS or AT for 4 weeks. Tear breakup time (BUT, corneal and conjunctival fluorescein staining scores, and HOAs were analyzed before and after instillation. HOAs were measured consecutively for 10 seconds with a wavefront analyzer. Average HOAs, HOA fluctuations (fluctuation index [FI] and changes in HOAs (stability index [SI] were compared within and between the two groups. Results: After 4 weeks of instillation, BUT significantly increased (P=0.001 compared with preinstillation values in the DQS group, but not in the AT group. This increase in BUT in the DQS group was significantly greater than in the AT group (P=0.014. Corneal and conjunctival fluorescein staining scores after instillation significantly improved compared with preinstillation values in the DQS group (P=0.018. In HOAs, the cornea aberration changed from an upward curve (a sawtooth pattern to an almost constant value (a stable pattern in the DQS group, but not in the AT group. In FI and SI, there were no significant changes in either group; however, FI and SI were significantly lower in the DQS group than in the AT group (both, P=0.004. Conclusion: The dry eye patients after cataract surgery had a visual dysfunction in HOAs. DQS is effective to treat dry eye disease after cataract surgery with improvement of visual function. Keywords: cataract surgery, dry eye, tear film breakup time, higher-order aberrations

  15. Improved Fractal Space Filling Curves Hybrid Optimization Algorithm for Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Yi-xiang Yue

    2015-01-01

    Full Text Available Vehicle Routing Problem (VRP is one of the key issues in optimization of modern logistics system. In this paper, a modified VRP model with hard time window is established and a Hybrid Optimization Algorithm (HOA based on Fractal Space Filling Curves (SFC method and Genetic Algorithm (GA is introduced. By incorporating the proposed algorithm, SFC method can find an initial and feasible solution very fast; GA is used to improve the initial solution. Thereafter, experimental software was developed and a large number of experimental computations from Solomon’s benchmark have been studied. The experimental results demonstrate the feasibility and effectiveness of the HOA.

  16. Improved Fractal Space Filling Curves Hybrid Optimization Algorithm for Vehicle Routing Problem

    Science.gov (United States)

    Yue, Yi-xiang; Zhang, Tong; Yue, Qun-xing

    2015-01-01

    Vehicle Routing Problem (VRP) is one of the key issues in optimization of modern logistics system. In this paper, a modified VRP model with hard time window is established and a Hybrid Optimization Algorithm (HOA) based on Fractal Space Filling Curves (SFC) method and Genetic Algorithm (GA) is introduced. By incorporating the proposed algorithm, SFC method can find an initial and feasible solution very fast; GA is used to improve the initial solution. Thereafter, experimental software was developed and a large number of experimental computations from Solomon's benchmark have been studied. The experimental results demonstrate the feasibility and effectiveness of the HOA. PMID:26167171

  17. The Rok protein of Bacillus subtilis represses genes for cell surface and extracellular functions

    NARCIS (Netherlands)

    Albano, M; Smits, WK; Ho, LTY; Kraigher, B; Mandic-Mulec, [No Value; Kuipers, OP; Dubnau, D; Smits, Wiep Klaas; Ho, Linh T.Y.; Mandic-Mulec, Ines

    2005-01-01

    Rok is a repressor of the transcriptional activator ComK and is therefore an important regulator of competence in Bacillus subtilis (T. T. Hoa, P. Tortosa, M. Albano, and D. Dubnau, Mol. Microbiol. 43:15-26, 2002). To address the wider role of Rok in the physiology of B. subtilis, we have used a com

  18. Executive function subcomponents and their relations to everyday functioning in healthy older adults.

    Science.gov (United States)

    McAlister, Courtney; Schmitter-Edgecombe, Maureen

    2016-10-01

    Everyday functioning and its executive functioning cognitive correlates (i.e., switching, inhibition, and updating) were investigated in healthy older adults (HOAs) using multiple methods of functional status. In addition to whether computerized experimental tasks would better dissociate these subcomponents than neuropsychological measures of executive functioning, we were also interested in the contributions of both experimental and neuropsychological measures of executive function subcomponents to functional abilities. Seventy HOAs (45 young-old and 25 old-old) and 70 younger adults completed executive function and neuropsychological tests. In addition to self- and informant questionnaires of functional abilities, HOAs completed two performance-based measures. An aging effect was found on all executive function measures. Old-old older adults and their informants did not report more functional difficulties but demonstrated more difficulties on performance-based measures than did young-old participants. For the HOAs, after controlling for age and education, the neuropsychological measures of executive functioning, but not experimental measures, explained a significant amount of variance in the informant-report and both performance-based measures. Updating measures differentially predicted performance-based measures, while switching was important for questionnaire and performance-based measures. The contribution of executive functioning to functional status when measured with experimental measures specifically designed to isolate the executive subcomponent was not as strong as hypothesized. Further research examining the value of isolating executive function subcomponents in neuropsychological assessment and the prediction of functional abilities in older adults is warranted.

  19. Assessment of genetic diversity and population structure of Vietnamese indigenous cattle populations by microsatellites

    DEFF Research Database (Denmark)

    Pham, Lan Doan; Do, Duy Ngoc; Binh, Nguyen Trong

    2013-01-01

    geographic distances. Structure analysis indicated five homogeneous clusters. The Brahman, Lang Son, Ha Giang and U Dau Riu cattle were assigned to independent clusters while Nghe An, Thanh Hoa and Phu Yen cattle were grouped in a single cluster. We conclude that Vietnamese indigenous cattle have high levels...

  20. Names and numberplates: quasi-everyday associative memory tasks for distinguishing amnestic mild cognitive impairment from healthy aging.

    Science.gov (United States)

    Pike, Kerryn E; Kinsella, Glynda J; Ong, Ben; Mullaly, Elizabeth; Rand, Elizabeth; Storey, Elsdon; Ames, David; Saling, Michael; Clare, Linda; Parsons, Samuel

    2012-01-01

    Amnestic mild cognitive impairment (aMCI) delineates a population at high risk for subsequently developing Alzheimer's disease (AD)--that is, people with preclinical AD. Associative episodic memory tasks are particularly sensitive to preclinical AD; however, they often lack ecological validity, which is important when evaluating performance in daily activities. We describe the development of two quasi-everyday associative memory tasks--the La Trobe Face-Name test and the La Trobe Numberplate task--and their utility in profiling and separating 70 aMCI participants from 101 healthy older adults (HOA) compared with standard episodic memory tasks. aMCI participants performed significantly worse overall and demonstrated a greater forgetting rate than HOA on both tasks. The everyday tasks separated aMCI from HOA participants as effectively as standard episodic memory tasks and were well tolerated. These tasks provide a valuable addition to neuropsychologists' toolkits with enhanced ecological (verisimilitude) and face validity for assisting in counseling clients, measuring the effect of interventions, and profiling everyday memory performance in HOA and aMCI.

  1. Practical Programming with Higher-Order Encodings and Dependent Types

    DEFF Research Database (Denmark)

    Poswolsky, Adam; Schürmann, Carsten

    2008-01-01

    utilizing HOAS free the programmer from concerns of handling explicit contexts and substitutions, our system permits programming over such encodings without making these constructs explicit, leading to concise and elegant programs. To this end our system distinguishes bindings of variables intended...

  2. AFRICOM: Can America’s Newest Combatant Command Stabilize Africa Using a Strategy of "Sunshine and Love"?

    Science.gov (United States)

    2009-04-01

    Lemonier in Djibouti. CJTF-HOA was stood-up at Camp Lejeune, North 12 Carolina in October 2002.61 As Operation ENDURING FREEDOM was ongoing in...to Camp Lemonier , Djibouti, in May 2003. Its mission adapted from a capture and kill focus to a mission of security cooperation and training

  3. Developing a Joint Engineer Headquarters for the JTF Commander

    Science.gov (United States)

    2007-04-05

    projects.5 The JTF- Horn of Africa (HOA) engineer identified their most important mission supporting the JTF Commander as humanitaria efforts. Since...Commander. The academics can provide organizational insights to the headquarters, Engineer Planning during Crisis Action Planning, Execution of Operations

  4. Reproduction of nearby sound sources using higher-order ambisonics with practical loudspeaker arrays

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2012-01-01

    In order to reproduce nearby sound sources with distant loudspeakers to a single listener, the near field compensated (NFC) method for higher-order Ambisonics (HOA) has been previously proposed. In practical realization, this method requires the use of regularization functions. This study analyze...

  5. Aircrew Compliance with Standard Operating Procedures as a Component of Airline Safety.

    Science.gov (United States)

    1980-01-01

    Pilot A-37B, Bien Hoa Air Base, Republic of Viet Nam 1970-1972 ........... .. Pilot, C-141A, McGuire Air Force Base, New Jersey 1973-1974...experlmentum personae were not uniform for all eighteen simulator runs, it has become necessary to eliminate some trials from the current investigation. Ten

  6. U. S. Naval Forces, Vietnam Monthly Historical Supplement for November 1967

    Science.gov (United States)

    1968-03-23

    detention of 45 craft and 488 persona . On 22 Noveaber MARKET TIME airborne patrol tracks were re- Tised in an effort to improve star Teillance and...channel from the see to the Port of Saigon and the Dong Ngai River from Saigon to Bien Hoa, and the underwater deaolition teas (LDNN) detachasnts

  7. Impact of regularization of near field coding filters for 2D and 3D higher-order Ambisonics on auditory distance cues

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2010-01-01

    A known challenge in sound field reproduction techniques such as high-order Ambisonics (HOA) is the reproduction of nearby sound sources. In order to reproduce such nearby sound sources, the near-field compensated (NFC) method with angular weighting windows (AWWs) has been previously roposed...

  8. The market for vegetables in North Vietnam

    NARCIS (Netherlands)

    Wijk, S.; Everaarts, A.P.

    2007-01-01

    The purpose of this project is first to develop the technical oppertunities for vegetable cultivation in the Hoa Binh highlands, and later to establish the ways and means for marketing of the product. To get some first insights in the marketing possibilities, a desk study was carried out of the

  9. Comparison of ocular monochromatic Higher-order aberrations in normal refractive surgery candidates of Arab and South Asian Origin

    Directory of Open Access Journals (Sweden)

    Gaurav Prakash

    2016-01-01

    Conclusions: Preoperative whole eye HOA were similar for refractive surgery candidates of Arab and South.Asian origin. The values were comparable to historical data for Caucasian eyes and were lower than Asian. (Chinese eyes. These findings may aid in refining refractive nomograms for wavefront ablations.

  10. Visual performance with changes in eccentricity in PROSE device: a case report.

    Science.gov (United States)

    Jagadeesh, Divya; Mahadevan, Rajeswari

    2014-01-01

    This case report describes the variations in visual performance of a subject with moderate keratoconus with changes in front surface eccentricities (FSEs) of PROSE (Prosthetic Replacement of Ocular Surface Ecosystem). PROSE device of 0.6 FSE provided maximum visual improvement and reduction in Higher Order Aberrations (HOAs) compared to 0, 0.3 and 0.8 FSEs in this clinical condition.

  11. MRI diagnosis of hypertrophic osteoarthropathy from a remote childhood malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Sainani, Nisha I.; Lawande, Malini A.; Pungavkar, Sona A.; Patkar, Deepak P.; Sase, Kirti S. [Dr. Balabhai Nanavati Hospital and Research Centre, Department of MRI, Mammography and BMD, Mumbai (India); Parikh, Vipul P. [Dr. Balabhai Nanavati Hospital and Research Centre, Department of CT and USG, Mumbai (India)

    2007-06-15

    Hypertrophic osteoarthropathy (HOA) is a clinico-radiological syndrome characterized by digital clubbing, periosteal proliferation, bone pain, synovitis and arthralgia, all of these being commonly symmetrical. It is occasionally associated with nasopharyngeal lymphoepitheliomas and may develop before or after development of lung metastases in these patients. We report a case of a healthy 22-year-old female who presented to our institution with pain and swelling in the thighs and legs. She had a history of childhood nasopharyngeal lymphoepithelioma. Radiographs of the knees were negative. Magnetic resonance imaging (MRI) showed features suggestive of bilateral periostitis. Because of the propensity of the rare childhood nasopharyngeal lymphoepithelioma to present with HOA, this entity was included in the differential diagnosis. A subsequent chest radiograph and CT demonstrated a lung and mediastinal mass that were histologically confirmed to be metastatic. To the best of our knowledge, HOA and metastases from nasopharyngeal lymphoepithelioma occurring after such a long time interval have not been previously reported. Early demonstration and consideration of HOA on the basis of MRI, lead to expeditious and appropriate subsequent investigation. (orig.)

  12. The market for vegetables in North Vietnam

    NARCIS (Netherlands)

    Wijk, S.; Everaarts, A.P.

    2007-01-01

    The purpose of this project is first to develop the technical oppertunities for vegetable cultivation in the Hoa Binh highlands, and later to establish the ways and means for marketing of the product. To get some first insights in the marketing possibilities, a desk study was carried out of the avai

  13. Binding of pyrene to dissolved organic matters:fractionation and characterization

    Institute of Scientific and Technical Information of China (English)

    DAI Jing-yu; ZHOU Jiang-min; QIN Shu-ping

    2004-01-01

    Based on a modified Leenheer DOM fractionation scheme, fractionation of DOM from the paddy soil was conducted by using XAD-8 resin into hydrophobic bases(HOB), hydrophobic acids(HOA), acid-insoluble matter(AIM), hydrophobic neutrals(HON) and hydrophilic matter(HIM). In total carbon content of DOM, 35.32% were the HIM and only 0.73% the HOB. However, HOA and AIM altogether occupied 53.45%, while the HON fraction represented 10%. The sorption experiments were conducted to determine the sorption capcity of pyrene on unfractionated DOM and its fractions. Elemental analysis, 1H-NMR and FTIR spectra were carried out on unfractionated DOM and its fractions to examine the relationship between the structure of DOM and partition coefficients(Koc). The results showed that HON had a greater affinity for binding pyrene than other fractions. While HON was characterized by large long-chain alkylate (aliphatic structure). AIM exhibited relative higher Koc values than HOA and HIM, due to much aromatic structure in AIM, while the high content of carboxylic groups of HOA and HIM depressed their binding capacity. This study demonstrates HON is a key subcomponents of DOM in binding of pyrene, in other words, aliphalic structure in DOM play a important role in binding of pyrene.

  14. Effect of Light Scattering and Higher-order Aberrations on Visual Performance in Eyes with Granular Corneal Dystrophy.

    Science.gov (United States)

    Kamiya, Kazutaka; Kobashi, Hidenaga; Igarashi, Akihito; Shoji, Nobuyuki; Shimizu, Kimiya

    2016-04-18

    This study was aimed to assess the relationship of intraocular forward scattering, corneal backward scattering, and corneal higher-order aberrations (HOAs) with corrected distance visual acuity (CDVA) in eyes with granular corneal dystrophy (GCD). We retrospectively examined forty two eyes of 42 consecutive patients who diagnosed GCD, and age-matched 20 eyes of 20 healthy subjects. We assessed objective scattering index (OSI) using the double-pass instrument (OQAS II, Visiometrics), corneal densitometry (CD) using the Scheimpflug rotating camera (Pentacam HR, Oculus), and corneal HOAs using the Hartmann-Shack aberrometry (KR-9000, Topcon). The OSI, CD, and corneal HOAs were significantly larger in the GCD group than those in the control group (Mann-Whitney U test, p GCD were higher than that in normal eyes. The CDVA was significantly correlated with intraocular forward scattering, but not with corneal HOAs in eyes with GCD, suggesting that light scattering, especially forward scattering, plays a more vital role in visual performance than corneal aberrations in eyes with GCD.

  15. Radioactive holmium acetylacetonate microspheres for interstitial microbrachytherapy : an in vitro and in vivo stability study

    NARCIS (Netherlands)

    Bult, Wouter; de Leeuw, Hendrik; Steinebach, Olav M; van der Bom, Martijn J; Wolterbeek, Hubert Th; Heeren, Ron M A; Bakker, Chris J G; van Het Schip, Alfred D; Hennink, Wim E; Nijsen, J Frank W

    2012-01-01

    PURPOSE: The clinical application of holmium acetylacetonate microspheres (HoAcAcMS) for the intratumoral radionuclide treatment of solid malignancies requires a thorough understanding of their stability. Therefore, an in vitro and an in vivo stability study with HoAcAcMS was conducted. METHODS: HoA

  16. Two new species of the genus Pararrhynchium de Saussure (Hymenoptera: Vespidae: Eumeninae) from northern Vietnam.

    Science.gov (United States)

    Nguyen, Lien Thi Phuong

    2015-06-22

    Two new species of the genus Pararrhynchium are described and figured: P. striatum sp. nov. (northern Vietnam: Hoa Binh, Ha Tinh and Thai Nguyen) and P. concavum sp. nov. (northern Vietnam: Cao Bang). A key to all known species of the genus is provided.

  17. Application of a circular 2D hard-sphere microphone array for higher-order Ambisonics auralization

    DEFF Research Database (Denmark)

    Weller, Tobias; Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2011-01-01

    A circular microphone array mounted on a rigid sphere was realized and its application to higherorder Ambisonics (HOA) auralization was analysed. Besides the 2D Ambisonics application this array design provides a promising basis for the development of a mixed-order Ambisonics recording system...

  18. Mixed-order Ambisonics recording and playback for improving horizontal directionality

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Marschall, Marton; Käsbach, Johannes;

    2011-01-01

    Planar (2D) and periphonic (3D) higher-order Ambisonics (HOA) systems are widely used to reproduce spatial properties of acoustic scenarios. Mixed-order Ambisonics (MOA) systems combine the benet of higher order 2D systems, i.e. a high spatial resolution over a larger usable frequency bandwidth...

  19. Do metabolic factors add to the effect of overweight on hand osteoarthritis? The Rotterdam Study

    NARCIS (Netherlands)

    S. Dahaghin; S.M. Bierma-Zeinstra (Sita); B.W. Koes (Bart); J.M.W. Hazes (Mieke); H.A.P. Pols (Huib)

    2007-01-01

    textabstractBackground: As hand joints are non-weight bearing, the association between overweight and hand osteoarthritis (HOA) is critical to understanding how overweight may associate with osteoarthritis (OA) apart from axial load. Overweight might be associated with the occurrence of OA through o

  20. IRAN SANCTIONS: Impact in Furthering U.S. Objectives is Unclear and Should be Reviewed

    Science.gov (United States)

    2007-12-01

    2007 Nonbinding Heads of Agreement (HOA) Austria, OMV OMV has 20% share in the development of South Pars Phase 12 and holds 10% share in...Iran LNG Project. OMV also agreed to buy 2.2 mt LNG from Iran LNG Project. (Natural Gas) Early planning stages, no details Under negotiations May

  1. Genetic diversity of an endangered species, Fokienia hodginsii ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-14

    Nov 14, 2011 ... Nguyen Minh Tam1,2*, Nguyen T. Phuong Trang1 and Nguyen Thi Hoa1,2. 1Laboratory of .... related to the conservation of this conifer in Vietnam. MATERIALS ..... Harper KT, Clair LL St, Thome KH, Hess WW, Univ. Colorado ...

  2. A prospective, randomized, fellow eye comparison of WaveLight® Allegretto Wave® Eye-Q versus VISX CustomVue™ STAR S4 IR™ in laser in situ keratomileusis (LASIK: analysis of visual outcomes and higher order aberrations

    Directory of Open Access Journals (Sweden)

    Moshirfar M

    2011-09-01

    Full Text Available Majid Moshirfar1, Brent S Betts2, Daniel S Churgin3, Maylon Hsu1, Marcus Neuffer1, Shameema Sikder4, Dane Church5, Mark D Mifflin11John A Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USA; 2Temple University School of Medicine, Philadelphia, PA, USA; 3University of Arizona College of Medicine – Phoenix, Phoenix, AZ, USA; 4Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 5Virginia Commonwealth University School of Medicine, Richmond, VA, USAPurpose: To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs, contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK using wavefront (WF guided VISX CustomVue and WF optimized WaveLight Allegretto platforms.Methods: In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients, with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, refractive error, root-mean-square (RMS value of total and grouped HOAs, contrast sensitivity, and Schirmers testing.Results: Mean values for UDVA (logMAR were -0.067 ± 0.087 and -0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909. UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000. In the WF optimized group, total HOA increased 4% (P = 0.012, coma increased 11% (P = 0.065, and spherical aberration increased 19% (P = 0.214, while trefoil decreased 5% (P = 0.490. In the WF guided group, total HOA RMS decreased 9% (P = 0.126, coma decreased 18% (P = 0.144, spherical aberration decreased 27% (P = 0.713 and trefoil

  3. The relationship between higher-order aberrations and amblyopia treatment in hyperopic anisometropic amblyopia.

    Science.gov (United States)

    Lee, Soo Han; Chang, Ji Woong

    2014-02-01

    To investigate the relationship between higher-order aberrations (HOAs) and amblyopia treatment in children with hyperopic anisometropic amblyopia. The medical records of hyperopic amblyopia patients with both spherical anisometropia of 1.00 diopter (D) or more and astigmatic anisometropia of less than 1.00 D were reviewed retrospectively. Based on the results of the amblyopia treatment, patients were divided into two groups: treatment successes and failures. Using the degree of spherical anisometropia, subjects were categorized into mild, moderate, or severe groups. Ocular, corneal, and internal HOAs were measured using a KR-1W aberrometer at the initial visit, and at 3-month, 6-month, and 12-month follow-ups. The results of the 45 (21 males and 24 females) hyperopic anisometropic amblyopia patients who completed the 12-month follow-up examinations were analyzed. The mean patient age at the initial visit was 70.3 months. In total, 28 patients (62.2%) had successful amblyopia treatments and 17 patients (37.8%) failed treatment after 12 months. Among the patient population, 24 (53.3%) had mild hyperopic anisometropia and 21 (46.7%) had moderate hyperopic anisometropia. When comparing the two groups (i.e., the success and failure groups), ocular spherical aberrations and internal spherical aberrations in the amblyopic eyes were significantly higher in the failure group at every follow-up point. There were no significant differences in any of the HOAs between mild and moderate cases of hyperopic anisometropia at any follow-up. When the amblyopic and fellow eyes were compared between the groups there were no significant differences in any of the HOAs. HOAs, particularly ocular spherical aberrations and internal spherical aberrations, should be considered as reasons for failed amblyopia treatment.

  4. Characterization and biotoxicity assessment of dissolved organic matter in RO concentrate from a municipal wastewater reclamation reverse osmosis system.

    Science.gov (United States)

    Sun, Ying-Xue; Gao, Yue; Hu, Hong-Ying; Tang, Fang; Yang, Zhe

    2014-12-01

    Reverse osmosis (RO) concentrate from municipal wastewater reclamation reverse osmosis (mWRRO) system containing organic compounds may associate with toxic risk, and its discharge might pose an environmental risk. To identify a basis for the selection of feasible technology in treating RO concentrates, the characteristics and biotoxicity of different fractions of dissolved organic matter (DOM) in RO concentrates from an mWRRO system were investigated. The results indicated that the hydrophilic neutrals (HIN), hydrophobic acids (HOA) and hydrophobic bases (HOB) accounted for 96% of the dissolved organic carbon (DOC) of the total DOM in the RO concentrate. According to the SEC chromatograph detected at 254 nm wavelength of UV, the DOM with molecular weight (MW) 1-3 kDa accounted for the majority of the basic and neutral fractions. The fluorescence spectra of the excitation emission matrix (EEM) indicated that most aromatic proteins, humic/fulvic acid-like and soluble microbial by-product-like substances existed in the fractions HOA and hydrophobic neutrals (HON). The genotoxicity and anti-estrogenic activity of the RO concentrate were 1795.6 ± 57.2 μg 4-NQOL(-1) and 2.19 ± 0.05 mg TAM L(-1), respectively. The HIN, HOA, and HOB contributed to the genotoxicity of the RO concentrate, and the HIN was with the highest genotoxic level of 1007.9 ± 94.8 μg 4-NQOL(-1). The HOA, HON, and HIN lead to the total anti-estrogenic activity of the RO concentrate, and HOA occupied approximately 60% of the total, which was 1.3 ± 0.17 mg TAM L(-1).

  5. Higher-Order Aberrations in Myopic Eyes

    Directory of Open Access Journals (Sweden)

    Farid Karimian

    2010-01-01

    Full Text Available Purpose: To evaluate the correlation between refractive error and higher-order aberrations (HOAs in patients with myopic astigmatism. Methods: HOAs were measured using the Zywave II aberrometer over a 6 mm pupil. Correlations between HOAs and myopia, astigmatism, and age were analyzed. Results: One hundred and twenty-six eyes of 63 subjects with mean age of 26.4±5.9 years were studied. Mean spherical equivalent refractive error and refractive astigmatism were -4.94±1.63 D and 0.96±1.06 D, respectively. The most common higher-order aberration was primary horizontal trefoil with mean value of 0.069±0.152 μm followed by spherical aberration (-0.064±0.130 μm and primary vertical coma (-0.038±0.148 μm. As the order of aberration increased from third to fifth, its contribution to total HOA decreased: 53.9% for third order, 31.9% for fourth order, and 14.2% for fifth order aberrations. Significant correlations were observed between spherical equivalent refractive error and primary horizontal coma (R=0.231, P=0.022, and root mean square (RMS of spherical aberration (R=0.213, P=0.031; between astigmatism and RMS of total HOA (R=0.251, P=0.032, RMS of fourth order aberration (R=0.35, P<0.001, and primary horizontal coma (R=0.314, P=0.004. Spherical aberration (R=0.214, P=0.034 and secondary vertical coma (R=0.203, P=0.031 significantly increased with age. Conclusion: Primary horizontal trefoil, spherical aberration and primary vertical coma are the predominant higher-order aberrations in eyes with myopic astigmatism.

  6. EFFECTS OF PREOPERATIVE SOFT CONTACT LENS WEAR ON HIGHER-ORDER ABERRATIONS AFTER LASER IN SITU KERATOMILEUSIS

    Institute of Scientific and Technical Information of China (English)

    YU Jing; CHEN Hui; CHENG Xin-liang; WANG Fang

    2008-01-01

    Objective To evaluate the effects of preoperative soft contact lens (SCL) wear on higher-order aberrations(HOAs)correction after wavefront-guided and conventional laser in situ keratomileusis (LASIK).Methods A prospective randomized double-masked comparative study was conducted in 180 eyes of 90 patients scheduled for LASIK, including 92 eyes of 46 patients with previous SCL wear. The patients were divided into four groups: no SCL-conventional group, SCL-conventional group, no SCL-wavefront group and SCL-wavefront group. Preoperative and postoperative examinations included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), contrast sensitivity and HOAs.Results The UCVA and BSCVA were 20/20 in all patients at 6 months postoperatively. And 36.3%, 22.7%, 18.1% and 35.4% gained one line or more of BSCVA in no SCL-wavefront group, SCL-wavefront group, no SCL-conventional group and SCL-conventional group, respectively. Both the safety index and efficacy index surpassed one in 4 groups and were highest in no SCL-wavefront group. The increase in root-mean-square (RMS) values of HOAs was significantly lower in no SCL-wavefront group and higher in SCL-wavefront group. At 6 months postoperatively, the increase in RMS of HOAs (RMSh) were 0.67, 1.58, 1.17 and 1.28 in no SCL-wavefront group, SCL-wavefront group, no SCL-conventional group and SCL-conventional group, respectively.Conclusion Preoperative contact lens wear has significant influence on the efficacy of HOAs correction in wavefront-guided LASIK. Patients with contact lens wear preoperatively should be cautious when scheduled for wavefront-guided LASIK.

  7. Effect of tilt and decentration of intraocular lens asphericity on visual quality%不同人工晶状体植入术后倾斜和偏心及视觉质量的临床研究

    Institute of Scientific and Technical Information of China (English)

    王莹; 马忠旭; 刘汝瑜; 张伟

    2011-01-01

    Objective: To analyze the effect of tilt and decentration of intraocular lenses (IOLs) asphericity on visual quality after pha-coemulsification surgery and IOLs implantation. Methods: It was a prospective clinical study. A total of 85 eyes of 69 patients with IOLs implantation and 3 to 4 months after surgery were analyzed in this study, including 30 eyes with spherical IOL of Sensar AR40e, 25 eyes with aspherically neutral IOL of Softec HD and 30 eyes aspheric IOL of Tecnis ZA9003 with negative spherical aberration. At postoperat ive follow-up visits, higher-order aberrations (HOAs) and modulation transfer function(MTF) at six spatial frequencies (5,10,15,20,25,30cpd) were measured in 5.0 mm pupil size. Tilt and decentration of the IOLs were measured using Scheimpflug photography(Pentacam ,0culus). The tilt and decentration, HOAs and subtracted lower order aberration MTF( MTF(HOA) )were compared. The effect of tilt and decentration on HOAs and MTF(HOA)was assessed using multiple regression analysis. Results: No significant differences in IOL tilt or decentration were found(F=0.001, F=0.050;P=0.999, ,P=0.952).The spherical aberration in AR40e group was largest and the differences were statistically significant(F= 65.68, P=0.000). In 5.0 mm pupil size,MTF(HOA)at all spatial frequencies in AR40e group were lowest and the differ ences were statistically significant(P<0.05). Tilt and decentration did not significantly affect HOAs and MTF(HOA)- Conclusion: The amounts of tilt and decentration of both IOLs are not large enough to affect the correction of spherical aberration and cause deterioration of visual quality.%目的:研究白内障超声乳化吸除术植入不同球差人工晶状体(IOL)的倾斜和偏心对高阶像差(HOAs)和调制传递函数(MTF)的影响.方法:前瞻性研究.选取老年性白内障患者69例(85只眼),随机分成3组,25例(30只眼)植入球面IOL Sensar AR40e,19例(25只眼)植入零球差IOL Softec HD,30

  8. Comparison of the effects among three different corneal refractive surgeries for low and moderate myopia%三种角膜屈光手术矫正低中度近视效果的比较

    Institute of Scientific and Technical Information of China (English)

    周继红; 刘龙; 高妍; 郭秀花

    2016-01-01

    Objective To compare postoperative uncorrected visual acuity (UCVA) and residual diopters among three different corneal refractive surgeries for low and moderate myopia.Methods This is a retrospective study on non-randomized clinical trial without control group.The following three groups were involved in this trial:LASEK group,261 patients (521 eyes);microkeratome-assisted flap creation LASIK (MM-LASIK) group,1513 patients (3024 eyes) and the femtosecond laser-assisted flap creation LASIK (FS-LASIK) group,1082 patients (2164 eyes).Single factor analysis of variance was used to compare the postoperative UCVA,residual spherical equivalent (S E),root mean aquare of high aberration for pupil diameter of 3mm and 5mm (HOA RMS3 and HOA RMS5) groups.Results After the follow-up of 12 months,the difference in UCVA between MM-LASIK and LASEK group was not statistically significant (P =0.705).The UCVA in MM-LASIK and LASEK group were better than that in FS-LASIK group and the differences were statistically significant (F =17.08,P =0.00).The differences in postoperative residual S E among the three groups were statistically significant (F =4.36,P =0.01).The residual SE in MMLASIK and FS-LASIK group were lower than that in LASEK group.The descending order of HOA RMS3 was FS-LASIK group,MM-LASIK and LASEK group.There was no statistically significant difference in HOA RMS5 among three groups.Conclusion Three corneal refractive surgeries for correcting low to moderate myopia brought good results.Smaller postoperative residual SE and lower HOA RMS3 are beneficial to the recovery of postoperative UCVA.LASEK and MM-LASIK produced better visual acuity and less corneal aberrations compared to FS-LASIK.The value of HOA RMS3 in LASEK group was the smallest and the postoperative residual SE in LASEK group was the biggest.%目的 比较3种角膜屈光手术矫正低中度近视术后裸眼视力、及残留屈光度等.方法 回顾性研究,非随机临床对照设计.纳入研究的3个

  9. Hyaline cartilage calcification of the first metatarsophalangeal joint is associated with osteoarthritis but independent of age and BMI.

    Science.gov (United States)

    Hubert, Jan; Hawellek, Thelonius; Hischke, Sandra; Bertrand, Jessica; Krause, Matthias; Püschel, Klaus; Rüther, Wolfgang; Niemeier, Andreas

    2016-11-15

    Hyaline cartilage calcification (CC) is associated with osteoarthritis (OA) in hip and knee joints. The first metatarsophalangeal joint (1(st)MTPJ) is frequently affected by OA, but it is unclear if CC occurs in the 1(st)MTPJ. The aim of the present study was to analyze the prevalence of CC of the 1(st)MTPJ in the general population by high-resolution digital contact radiography (DCR) and to determine its association with histological OA severity, age and body mass index (BMI). 168 metatarsal heads of 84 donors (n = 47 male, n = 37 female; mean age 62.73 years, SD ±18.8, range 20-93) were analyzed by DCR for the presence of CC. Histological OA grade (hOA) by OARSI was analyzed in the central load-bearing zone of the first metatarsal head (1(st) MH). Structural equation modeling (SEM) was performed to analyze the interrelationship between CC, hOA, age and BMI. The prevalence of CC of 1(st)MH was 48.8 % (41/84) (95 %-CI [37.7 %, 60.0 %]), independent of the affected side (p = 0.42), gender (p = 0.41) and BMI (p = 0.51). The mean amount of CC of one MH correlated significantly with that of the contralateral side (rs = 0.4, 95 %-CI [0.26, 0.52], p cartilage area) of the MH correlated significantly with the severity of hOA (rs = 0.51, 95 %-CI [0.32, 0.65], p < 0.001). SEM revealed significant associations between CC and hOA (r = 0.74, p < 0.001) and between hOA and age (β = 0.62, p = 0.001), but not between CC and age (p = 0.15). There was no significant influence of BMI on either CC (p = 0.37) or hOA (p = 0.16). The observation that CC of the 1(st)MH is significantly associated with the severity of OA but independent of age and BMI, suggests an intimate relationship between CC and the pathogenesis of OA, the exact nature of which will have to be explored by future studies.

  10. Process for the continuous biological production of lipids, hydrocarbons or mixtures thereof

    NARCIS (Netherlands)

    Van der Wielen, L.A.M.; Heijnen, J.J.

    2010-01-01

    The present invention is directed to a process for the continuous biological production of lipids, hydrocarbons, hydrocarbon like material or mixtures thereof by conversion of a suitable substrate using micro-organisms, in which process the said substrate is continuously, anaerobically fermented to

  11. Catalytic Hydrotreatment of Fast Pyrolysis Oil : Model Studies on Reaction Pathways for the Carbohydrate Fraction

    NARCIS (Netherlands)

    Wildschut, J.; Arentz, J.; Rasrendra, C. B.; Venderbosch, R. H.; Heeres, H. J.

    2009-01-01

    Fast pyrolysis oil can be upgraded by a catalytic hydrotreatment (250-400 degrees C, 100-200 bar) using heterogeneous catalysts such as Ru/C to hydrocarbon-like products that can serve as liquid transportation fuels. Insight into the complex reaction pathways of the various component fractions durin

  12. Study on Laboratory Method for Refining of SR Diesel Fuel

    Institute of Scientific and Technical Information of China (English)

    Li Junling; Zheng Tinglu; Han Zhaping

    2006-01-01

    The method for refining the straight-run diesel fuel was studied in laboratory scale in order to make the acid number of diesel fraction comply with the standard while removing the naphthenic acids contained in diesel without causing environmental pollution. After comparing the effect of refining using three solvents, the isopropyl alcohol-HOA was specified as the best solvent. Meanwhile, the relationship between the acid number of diesel fraction and the amount of solvent used and the relationship between the concentration of solvent and temperature and the stability of diesel in terms of its acid number were also investigated. Experimental results had shown that when the mass fraction of the HOA-IPA solvent was 20% at a dosage of 17 mL of the solvent and a temperature of 30℃, the acid number of the refined diesel fraction was 0.015 mg KOH/g with a good stability of acidity in the diesel traction.

  13. Periostitis secondary to prolonged voriconazole therapy in lung transplant recipients.

    Science.gov (United States)

    Wang, T F; Wang, T; Altman, R; Eshaghian, P; Lynch, J P; Ross, D J; Belperio, J A; Weigt, S S; Saggar, R; Gregson, A; Kubak, B; Saggar, R

    2009-12-01

    We report five cases of possible drug-induced periostitis associated with long-term use of voriconazole therapy after lung transplantation (LT). The diagnosis of periostitis was made by the documentation of bone pain, elevation of serum alkaline phosphatase and characteristic findings on radionuclide bone imaging in the absence of any identifiable rheumatologic disease. This periostitis appears similar to hypertrophic osteoarthopathy (HOA) but does not meet all criteria for HOA. In all patients, the symptoms resolved rapidly after discontinuation of voriconazole therapy. Awareness of this potential syndrome, which manifests as bone pain, elevated serum alkaline phosphatase and a bone scan suggestive of periostitis, is necessary in LT recipients on long-term voriconazole.

  14. Kinetics of 12-Hydroxyoctadecanoic Acid SAFiN Crystallization Rationalized Using Hansen Solubility Parameters.

    Science.gov (United States)

    Rogers, Michael A; Marangoni, Alejandro G

    2016-12-06

    Changes in solvent chemistry influenced kinetics of both nucleation and crystallization of 12-hydroxyoctadecenoic, as determined using differential scanning calorimetry and applying a modified Avrami model to the calorimetric data. Altering solvent properties influenced solvent-gelator compatibility, which in turn altered the chemical potential of the system at the onset of crystallization, the kinetics of gelation, and the resulting 12HOA crystal fiber length. The chemical potential at the onset of crystallization was linearly correlated to both the hydrogen-bonding Hansen solubility parameter and the solvent-gelator vectorial distance in Hansen space, Ra. Our work suggests that solvent properties can be modulated to affect the solubility of 12HOA, which in turn influences the kinetics of crystallization and the self-assembly of this organogelator into supramolecular crystalline structures. Therefore, modulation of solvent properties during organogelation can be used to control fiber length and thus engineer the physical properties of the gel.

  15. Dicty_cDB: SLK146 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available core E Sequences producing significant alignments: (bits) Value N BG926995 |BG926995.1 HNC25-1-D2.R HNC (Human Normal Cartilage...) Homo sapiens cDNA, mRNA sequence. 88 5e-17 2 BG929206 |BG929206.1 HNC59-1-F10.R HNC (Human Normal Cartilage...379 |BG929379.1 HNC49-1-H4.R HNC (Human Normal Cartilage) Homo sapiens cDNA, mRNA sequence. 88 3e-16 2 BG899...246 |BG899246.1 HOA45-1-H9.R HOA (Human Osteoarthritic Cartilage) Homo sapiens cDNA , mRNA sequence. 88 8e-1...6 2 BG924943 |BG924943.1 HNC70-1-B2.R HNC (Human Normal Cartilage) Homo sapiens c

  16. Dioxins and Nonortho PCBs in Breast Milk of Vietnamese Mothers Living in the Largest Hot Spot of Dioxin Contamination.

    Science.gov (United States)

    Nghi, Tran Ngoc; Nishijo, Muneko; Manh, Ho Dung; Tai, Pham The; Van Luong, Hoang; Anh, Tran Hai; Thao, Pham Ngoc; Trung, Nguyen Viet; Waseda, Tomoo; Nakagawa, Hideaki; Kido, Teruhiko; Nishijo, Hisao

    2015-05-05

    Bien Hoa Air Base is the largest dioxin contamination hot spot in Vietnam. In 2012, we recruited 216 mothers who were living in 10 communities around Bien Hoa Air Base and had delivered newborns at a prefecture hospital, and we investigated recent exposure levels of dioxins and nonortho PCBs in their breast milk. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-tetraCDD) was present at 2.6 pg/g lipid in primiparae and 2.2 pg/g lipid in multiparae. Among multiparae and total subjects, significant high prevalence of 2,3,7,8-tetraCDD≥5 pg/g lipid and 2,3,7,8-tetraCDD contribution≥40% were observed in mothers living in the five communities closest to Bien Hoa Air Base. The TEQ for nonortho PCBs was 1.6 pg-TEQ/g lipid for primiparae, and this was even lower than that in the unsprayed area. The length of residency was a strong factor to increase dioxins, including 2,3,7,8-tetraCDD. Residency in the five communities with the highest exposure was a specific risk factor for increased 2,3,7,8-tetraCDD in breast milk. Food intake might contribute partly to the increased levels of dioxin congeners other than 2,3,7,8-tetraCDD in breast milk. These results suggest that Bien Hoa Air Base has led to elevated 2,3,7,8-tetraCDD levels in breast milk of mothers in nearby areas even in the recent years.

  17. Africa Command: U.S. Strategic Interests and the Role of the U.S. Military in Africa

    Science.gov (United States)

    2009-07-28

    Horn of Africa (CJTF-HOA) has a semi- permanent troop presence at Camp Lemonier in Djibouti with more than 1,500 U.S. military and civilian personnel...in residence. The U.S. military has a five year lease with the Djiboutian government for Lemonier , with the option to extend the lease for two more...Department’s military construction request includes $41.8 million for Camp Lemonier in Djibouti.41 CJTF

  18. Energy to the Edge (E2E) Equipment Assessment U.S. Army Rapid Equipping Force

    Science.gov (United States)

    2015-05-01

    USCENTCOM 12 TOC UPS, REAP, TALS USPACOM 1 11 Power Surety for NetZero Camp (Lite Camps) TS & HOA USSOUTHCOM 3 Power Surety for NetZero Camp (Lite Camps...Deployment AOR LOCATION APPLICATIONS SUPPORTED CAPABILITIES Lite Camp USCENTCOM 10* Mobile Kitchen, Dining Building , Mortar Fire Control USSOUTHCOM Power...Surety for NetZero Camp (Lite Camps) * six awaiting installation Appendixes U.S. Army Rapid Equipping Force | 35 Demonstrated Capabilities Equipment

  19. Vietnamese Victims of Agent Orange and U.S.-Vietnam Relations

    Science.gov (United States)

    2008-11-21

    assistance — including U.S. assistance — provided to people with medical conditions associated with dioxin exposure , and the implications for bilateral...it difficult to firmly establish the connection between dioxin exposure and a variety of health problems purportedly occurring among the Vietnamese...Constable, “Food as a Source of Dioxin Exposure in the Residents of Bien Hoa City, Vietnam,” Journal of Occupational and Environmental Medicine, Vol

  20. New strategy toward dioxin risk reduction for local residents surrounding severe dioxin hotspots in Vietnam

    OpenAIRE

    Thi Tran, Tuyet-Hanh; Nguyen, Ngoc-Bich; Le, Vu-Anh

    2013-01-01

    Background: A public health intervention program with active involvement of local related stakeholders was piloted in the Bien Hoa dioxin hotspot (2007-2009), and then expanded to the Da Nang dioxin hotspot in Vietnam (2009-2011). It aimed to reduce the risk of dioxin exposure through foods for local residents. This article presents the results of the intervention in Da Nang.Methodology: To assess the results of this intervention program, pre- and post-intervention knowledge, attitude, and pr...

  1. Entomology with the U.S. Marines in Vietnam - Some Lessons Learned

    Science.gov (United States)

    2008-11-16

    Danang area and for part of the viruses . The vectors Culex year in the Phu Bai and An Hoa areas. tritaeniorhynchus, C. gelidus and C. Populations were...prevalent in the and had to dispose of their own. Sanitary port cities. During the year, 757 rodents landfills were the basic recommendation were trapped...39% were Norway Rats, 42% commands to designate personnel to be were Roof Rats, 8% were Polynesian responsible for the landfills , few units Rats

  2. Ethnic Minorities in Northern Mountains of Vietnam: Poverty, Income and Assets

    OpenAIRE

    Nguyen Viet, Cuong

    2012-01-01

    This study examines the asset and income pattern of poor ethnic minorities in Northern Mountains of Vietnam using data from a 2010 Northern Mountain Baseline Survey (NMBS) of the Second Northern Mountains Poverty Reduction Project and Vietnam Household Living Standard Survey (VHLSS) 2010. The poor ethnic minorities in Northern Mountains have lower assets and income than ethnic minorities in other regions. Their income is mainly from crops and livestock. Compared with Kinh/Hoa and ethnic minor...

  3. Relationships between the structure of natural organic matter and its reactivity towards molecular ozone and hydroxyl radicals

    Science.gov (United States)

    Westerhoff, P.; Aiken, G.; Amy, G.; Debroux, J.

    1999-01-01

    Oxidation reaction rate parameters for molecular ozone (O3) and hydroxyl (HO) radicals with a variety of hydrophobic organic acids (HOAs) isolated from different geographic locations were determined from batch ozonation studies. Rate parameter values, obtained under equivalent dissolved organic carbon concentrations in both the presence and absence of non-NOM HO radical scavengers, varied as a function of NOM structure. First-order rate constants for O3 consumption (k(O3)) averaged 8.8 x 10-3 s-1, ranging from 3.9 x 10-3 s-1 for a groundwater HOA to > 16 x 10-3 s-1 for river HOAs with large terrestrial carbon inputs. The average second-order rate constant (k(HO,DOC) between HO radicals and NOM was 3.6 x 108 l (mol C)-1 s-1; a mass of 12 g C per mole C was used in all calculations. Specific ultraviolet absorbance (SUVA) at 254 or 280 nm of the HOAs correlated well (r > 0.9) with O3 consumption rate parameters, implying that organic ??-electrons strongly and selectively influence oxidative reactivity. HO radical reactions with NOM were less selective, although correlation between k(HO,DOC) and SUVA existed. Other physical-chemical properties of NOM, such as aromatic and aliphatic carbon content from 13C-NMR spectroscopy, proved less sensitive for predicting oxidation reactivity than SUVA. The implication of this study is that the structural nature of NOM varies temporally and spatially in a water source, and both the nature and amount of NOM will influence oxidation rates.

  4. Assessment of refractive astigmatism and simulated therapeutic refractive surgery strategies in coma-like-aberrations-dominant corneal optics

    OpenAIRE

    ZHOU Wen; Stojanovic, Aleksandar; Utheim, Tor Paaske

    2016-01-01

    Background The aim of the study is to raise the awareness of the influence of coma-like higher-order aberrations (HOAs) on power and orientation of refractive astigmatism (RA) and to explore how to account for that influence in the planning of topography-guided refractive surgery in eyes with coma-like-aberrations-dominant corneal optics. Methods Eleven eyes with coma-like-aberrations-dominant corneal optics and with low lenticular astigmatism (LA) were selected for astigmatism analysis and f...

  5. Evaluation of possible factors affecting contrast sensitivity function in patients with primary Sjögren’s syndrome

    Directory of Open Access Journals (Sweden)

    Sedat Arikan

    2015-06-01

    Full Text Available ABSTRACT Purpose: The contrast sensitivity (CS function in patients with primary Sjögren’s syndrome (pSS may be impaired either frequently as a result of dry eye diseases or rarely as a result of optic neuropathy. In this study, we aimed to evaluate the CS function in pSS patients as well as to assess corneal aberrations and thickness of the peripapillary retinal nerve fiber layer (pRNFL. Methods: Fourteen eyes of 14 pSS patients (pSS group and 14 eyes of 14 healthy participants (control group were subjected to assessment of CS at the spatial frequencies of 1.5, 3.0, 6.0, 12, and 18 cycles/degree (cpd using a functional visual acuity contrast test (FACT; measurement of corneal high-order aberrations (HOAs in terms of coma-like, spherical-like, and total HOAs using Scheimpflug corneal topography; and measurement of the thickness of both the macular ganglion cell-inner plexiform layer (mGCIPL and pRNFL in all quadrants using optical coherence tomography. None of the participants were under treatment with artificial tears. Results: The results of the CS test did not differ between the 2 groups at all spatial frequencies (p>0.05. In addition, there were no statistically significant differences between the 2 groups in terms of corneal HOAs (p>0.05 and thickness of mGCIPL (p>0.05. However, among all quadrants, only the inferior quadrant of pRNFL in pSS patients was statistically significantly thinner than that in the healthy participants (p=0.04. Conclusions: The CS function in pSS patients can be maintained with normal thickness of both pRNFL and mGCIPL and with lack of increased corneal HOAs, which may be present even in the absence of artificial tear usage.

  6. The effect of tinted soft contact lens wear on functional visual acuity and higher-order aberrations.

    Science.gov (United States)

    Watanabe, Kazuhiro; Kaido, Minako; Ishida, Reiko; Dogru, Murat; Negishi, Kazuno; Tsubota, Kazuo

    2014-06-01

    To investigate the differences of functional visual acuity (FVA) and high order aberrations (HOAs) in relation to tinted and clear hydrogel soft contact lens (SCL) wear. A prospective comparative study was performed in 16 eyes of 16 healthy volunteers. Dynamic visual acuity (using a FVA measurement system) and higher-order aberrations (using a wavefront sensor) were compared in subjects wearing two types of soft contact lenses: 1-day Acuvue(®) (Vistakon, Jacksonville, FL) clear and the 1-day Acuvue(®) Define(TM) (Vistakon, Jacksonville, FL) tinted lens. The blink rates were recorded during FVA testing. The correlation between the difference of HOAs and differences in FVA values was analyzed. The mean LogMAR FVA scores with clear and tinted SCLs were 0.07 ± 0.13 and 0.14 ± 0.17 (P<0.05). The mean blink frequencies with clear and tinted SCL wear were 18.4 ± 8.3 and 25.3 ± 4.7 blinks/min (P<0.05). Both 3rd-order aberrations and total HOAs showed statistically significant differences between the two types of soft contact lenses for 6mm pupil measurements (P<0.05). A significant positive linear correlation was observed between ΔHOAs and ΔLogMAR FVA for 6mm pupil measurements (R=0.53, P=0.04). Tinted contact lens wear appears to induce a reduction in optical quality. Functional visual acuity measurement is a useful procedure to study the changes of visual performance and quality in tinted contact lens wear. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  7. Goniothalamusflagellistylus Tagane & V. S. Dang (Annonaceae), a new species from Mt. Hon Ba, Vietnam.

    Science.gov (United States)

    Tagane, Shuichiro; Dang, Van Son; Yahara, Tetsukazu; Toyama, Hironori; Tran, Hop

    2015-01-01

    A new species, Goniothalamusflagellistylus Tagane & V. S. Dang, sp. nov. from Hon Ba Nature Reserve in Khanh Hoa Province, South Vietnam is described and illustrated. This species is most similar to Goniothalamustortilipetalus M.R.Hend., but distinct in having 308-336 stamens (vs. ca. 170-260) and ca.120 carpels (vs. ca. 50-100) per flower, and Stigma and pseudostyles ca.8.5 mm (vs. 4-4.5 mm) long.

  8. Goniothalamus flagellistylus Tagane & V. S. Dang (Annonaceae, a new species from Mt. Hon Ba, Vietnam

    Directory of Open Access Journals (Sweden)

    Shuichiro Tagane

    2015-05-01

    Full Text Available A new species, Goniothalamus flagellistylus Tagane & V. S. Dang, sp. nov. from Hon Ba Nature Reserve in Khanh Hoa Province, South Vietnam is described and illustrated. This species is most similar to Goniothalamus tortilipetalus M.R.Hend., but distinct in having 308–336 stamens (vs. ca. 170–260 and ca.120 carpels (vs. ca. 50–100 per flower, and Stigma and pseudostyles ca.8.5 mm (vs. 4–4.5 mm long.

  9. Associated Factors Contributing to Child Stunting in Yemen

    OpenAIRE

    Laetícia Rodrigues de Souza

    2015-01-01

    "Malnutrition is part of a vicious cycle involving associated underlying factors, which means that undernourishment is related not only to biological but also social aspects. As the causes of child malnutrition are complex, there are several models explaining its determinants. We have adapted the conceptual framework developed by Hien and Hoa (2009), which provides a way of understanding how different factors affecting child malnutrition may be connected. This framework allows us to verify ho...

  10. Optimising reservoir operation

    DEFF Research Database (Denmark)

    Ngo, Long le

    , den såkaldte Pareto-front. Disse løsninger er karakteriseret ved, at det ikke er muligt at opnå bedre værdier af en af målfunktionerne uden samtidig at forringe en eller flere af de øvrige målfunktioner. Metodikken er afprøvet på Hoa Binh reservoiret beliggende i Den Røde Flods opland i Vietnam under...

  11. Robustness of a Mixed-Order Ambisonics Microphone Array for Sound Field Reproduction

    DEFF Research Database (Denmark)

    Marschall, Marton; Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2012-01-01

    Spherical microphone arrays can be used to capture and reproduce the spatial characteristics of acoustic scenes. A mixed-order Ambisonics (MOA) approach was recently proposed to improve the horizontal spatial resolution of microphone arrays with a given number of transducers. In this paper, the p...... errors was similar to that of HOA arrays with both strategies. The approach based on minimizing the error of the reproduced spherical harmonic functions showed better performance at high frequencies for the MOA layout....

  12. 亲水性非球面与球面人工晶状体植入术后高阶像差的研究%Higher order aberrations in eyes implanted with aspheric vs spherical hydrophilic intraocular lenses

    Institute of Scientific and Technical Information of China (English)

    Ibrahim Kocak; Faruk Kaya; Hakan Baybora

    2012-01-01

    AIM: To compare the effect of spherical and aspheric hydrophilic intraocular lenses (IOL) on postoperative higher order aberrations (HOA). METHODS: Uneventful phacoemulsification was performed in 78 eyes of 66 patients with implanting either spherical Softec or aspheric Ocuva lenses. Preoperative and postoperative 3rd month aberrometry was performed with Visx Wavescan aberrometer to be compared. RESULTS: There was no statistically significant difference between two groups. Postoperative root-mean-square (RMS) value of HOA: 0.27±0.11 in Softec and 0.28±0.13 in Ocuva group, spherical aberration (SA): 0.11±0.07 in Softec and 0.11±0.08 in Ocuva group. CONCLUSION: Aspheric Ocuva IOL seems not to have an advantage of decreasing postoperative HOA compared to spherical Softec IOL.%目的:比较亲水性球面和非球面人工晶状体(intraocular lenses,IOL)对术后高阶像差(higher order aberrations,HOA)的影响.方法:66例78眼行白内障超声乳化术并顺利植入球面Softec或者非球面Ocuva人工晶状体.术前和术后第3mo使用VISX Wavescan像差计进行像差测量与比较.结果:两组间统计学无显著性差异.术后的高阶像差均方根值(root-mean-square,RMS):Softec组0.27±0.11,Ocuva组0.28±0.13,球面像差(spherical aberration,SA):Softec组0.11±0.07,Ocuva组0.11±0.08.结论:与球面Softec人工晶状体比较,Ocuva非球面人工晶状体似乎没有减少术后高阶像差的优势.

  13. 沙特基础工业公司与埃克森美孚化工签订框架协议将在沙特建设新的塑胶弹性体项目

    Institute of Scientific and Technical Information of China (English)

    杨扬; 姚冀方

    2008-01-01

    @@ [本刊讯](记者 杨扬 通讯员 姚冀方)11月18日,沙特基础工业公司与埃克森美孚化工的附属公司就在双方合资的石化公司Kemya和Yanpet投建新的塑胶弹性体项目签署了框架协议(HOA).

  14. 越南Dak Lak公司新建橡胶厂

    Institute of Scientific and Technical Information of China (English)

    黄元昌

    2012-01-01

    越南多乐(Dak Lak)橡胶丝公司在越南中部地区的和富(Hoa Phu)工业园新建的橡胶丝线厂开工运营,投资总额约为1700亿越南盾C约合860万美元),年产能达4000t。

  15. Southeast Asia Report.

    Science.gov (United States)

    2007-11-02

    December Planning Journal (TAP CHI KE HOACH HOA, No 12, Dec 86) ........... 77 National Assembly Delegate Speaks on Economic Management (Tran...its own religious school in Kuala Sungai Baharu, Melaka . Its adherents totally reject the Prophet’s Hadits [traditional account of the Prophet’s...activities and sayings] because they believe it was written by their political enemies (the Prophet’s disciples). Also, Haji Ahmad Yunus, the Melaka

  16. Discovery of Paragonimus skrjabini in Vietnam and its phylogenetic status in the Paragonimus skrjabini complex.

    Science.gov (United States)

    Doanh, P N; Hien, H V; Nonaka, N; Horii, Y; Nawa, Y

    2013-12-01

    Two members of the Paragonimus skrjabini complex, P. skrjabini and P. miyazakii, are now considered as two sub-species, P. skrjabini skrjabini and P. skrjabini miyazakii. They are well known as important pathogens for human paragonimiasis in China and Japan. Recently, members of this species complex have been reported from India. Here we report the first discovery of P. skrjabini from freshwater crab hosts in Thanh Hoa province, Vietnam. For morphological and molecular phylogenetic studies, adult worms were obtained by experimental infection in cats and dogs. Molecular analyses of metacercariae and adults revealed that the P. skrjabini population from Thanh Hoa, Vietnam was almost completely identical with that from Yunnan province, China. Those populations from Thanh Hoa, Vietnam and Yunnan, China and those from Manipur, India were significantly different from P. skrjabini populations reported from other localities of China in cytochrome oxidase subunit 1 (CO1) gene sequences, indicating considerable genetic variation within the P. skrjabini complex. Moreover, low bootstrap values in the CO1 tree suggested that more variant genotypes belonging to P. skrjabini complex may be found in other Asian countries in between Vietnam and India, such as Myanmar, Laos and Thailand. Since P. skrjabini is known as a pathogen for humans, paragonimiasis cases caused by P. skrjabini might be found in Vietnam and other Asian countries.

  17. Role of high-order aberrations in senescent changes in spatial vision

    Energy Technology Data Exchange (ETDEWEB)

    Elliot, S; Choi, S S; Doble, N; Hardy, J L; Evans, J W; Werner, J S

    2009-01-06

    The contributions of optical and neural factors to age-related losses in spatial vision are not fully understood. We used closed-loop adaptive optics to test the visual benefit of correcting monochromatic high-order aberrations (HOAs) on spatial vision for observers ranging in age from 18-81 years. Contrast sensitivity was measured monocularly using a two-alternative forced choice (2AFC) procedure for sinusoidal gratings over 6 mm and 3 mm pupil diameters. Visual acuity was measured using a spatial 4AFC procedure. Over a 6 mm pupil, young observers showed a large benefit of AO at high spatial frequencies, whereas older observers exhibited the greatest benefit at middle spatial frequencies, plus a significantly larger increase in visual acuity. When age-related miosis is controlled, young and old observers exhibited a similar benefit of AO for spatial vision. An increase in HOAs cannot account for the complete senescent decline in spatial vision. These results may indicate a larger role of additional optical factors when the impact of HOAs is removed, but also lend support for the importance of neural factors in age-related changes in spatial vision.

  18. An Improved Implementation and Abstract Interface for Hybrid

    CERN Document Server

    Martin, Alan J; 10.4204/EPTCS.71.6

    2011-01-01

    Hybrid is a formal theory implemented in Isabelle/HOL that provides an interface for representing and reasoning about object languages using higher-order abstract syntax (HOAS). This interface is built around an HOAS variable-binding operator that is constructed definitionally from a de Bruijn index representation. In this paper we make a variety of improvements to Hybrid, culminating in an abstract interface that on one hand makes Hybrid a more mathematically satisfactory theory, and on the other hand has important practical benefits. We start with a modification of Hybrid's type of terms that better hides its implementation in terms of de Bruijn indices, by excluding at the type level terms with dangling indices. We present an improved set of definitions, and a series of new lemmas that provide a complete characterization of Hybrid's primitives in terms of properties stated at the HOAS level. Benefits of this new package include a new proof of adequacy and improvements to reasoning about object logics. Such...

  19. Strategic Variations in Fitts’ Task: Comparison of Healthy Older Adults and Cognitively Impaired Patients

    Science.gov (United States)

    Poletti, Céline; Sleimen-Malkoun, Rita; Decker, Leslie Marion; Retornaz, Frédérique; Lemaire, Patrick; Temprado, Jean-Jacques

    2017-01-01

    The present study aimed at investigating how healthy older adults (HOA) and cognitively impaired patients (CIP) differ in a discrete Fitts’ aiming task. Four levels of task difficulty were used, resulting from the simultaneous manipulation of the size of the target and its distance from home position. We found that movement times (MTs) followed Fitts’ law in both HOA and CIP, with the latter being significantly slower and more affected by increased task difficulty. Moreover, correlation analyses suggest that lower information processing speed (IPS) and deficits in executive functions (EFs) are associated with decline of sensorimotor performance in Fitts’ task. Analyses of strategic variations showed that HOA and CIP differed in strategy repertoire (which strategies they used), strategy distribution (i.e., how often they used each available strategy), and strategy execution (i.e., how quick they were with each available strategy). These findings further our understanding of how strategic variations used in a sensorimotor task are affected by cognitive impairment in older adults. PMID:28163682

  20. Patient education, disease activity and physical function: can we be more targeted? A cross sectional study among people with rheumatoid arthritis, psoriatic arthritis and hand osteoarthritis.

    Science.gov (United States)

    Drăgoi, Răzvan G; Ndosi, Mwidimi; Sadlonova, Martina; Hill, Jackie; Duer, Mona; Graninger, Winfried; Smolen, Josef; Stamm, Tanja A

    2013-10-20

    In order to target educational needs of patients more effectively, an Austrian-German educational needs assessment tool (OENAT) was developed, the educational needs of patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and hand osteoarthritis (HOA) were described and the relationships between educational needs, gender, disease activity and function were explored. The English ENAT was adapted into Austrian-German using Beaton's cross-cultural adaptation process. Internal construct validity was assessed by Rasch analysis. Educational needs across diagnostic groups and subgroups of patients were summarized descriptively and their relationship with disease activity and physical functioning explored. The sample comprised 130 RA, 125 PsA and 48 HOA patients. Their mean ages ± SD were 56 ± 14, 51 ± 11 and 64 ± 7 years for RA, PsA and HOA; disease duration was 11 ± 9, 11 ± 11 and 14 ± 9 years, respectively. More than 70% in each patient group expressed interest in receiving education about their disease. This study showed that educational needs vary with personal characteristics. Patient education may be more targeted and effective, if gender, age, educational background and disease duration are taken into account. Correlations with disease activity and function suggest that the OENAT could enable identification of 'intervention points', which can be ideal opportunities for effective patient education.

  1. Influence of aspheric intraocular lens on frequency doubling technology and contrast sensitivity: a fellow eye study

    Directory of Open Access Journals (Sweden)

    Rodrigo França de Espíndola

    2014-12-01

    Full Text Available Purpose: To evaluate whether implantation of an aspheric intraocular lens (IOL results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery and, therefore, changes on frequency-doubling technology (FDT testing. Methods: The present prospective clinical study enrolled 25 patients with bilateral cataract (50 eyes, who randomly received either an aspheric (Akreos AO or a spherical (Akreos Fit IOL in one eye and the other IOL in the second eye. Assessment 12 months postoperatively included photopic and mesopic contrast sensitivity testing. Higher-order aberrations (HOAs were computed. FDT testing was divided into four areas to evaluate the variation of the values at different points. The median values of the local pattern thresholds (median area contrast sensitivity [MACS] obtained with that division were calculated. Results: The Akreos AO group obtained statistically significantly lower values of HOAs and spherical aberration compared with the Akreos Fit group. There was a statistically significant between-group difference in contrast sensitivity under mesopic conditions at all spatial frequencies. No statistically significant differences were observed in mean deviation and pattern standard deviation. The aspheric IOL exhibited higher MACS in all areas, although a statistically significant difference was reached only in the 20-degree field area (P=0.043. Conclusion: Aspheric IOLs significantly reduced spherical aberration and HOAs, improving mesopic contrast sensitivity. Although there was a trend toward slightly improved FDT in the aspheric IOL group, it was not statistically significant.

  2. Fouling characteristics of reverse osmosis membranes at different positions of a full-scale plant for municipal wastewater reclamation.

    Science.gov (United States)

    Tang, Fang; Hu, Hong-Ying; Sun, Li-Juan; Sun, Ying-Xue; Shi, Na; Crittenden, John C

    2016-03-01

    Membrane fouling is an important shortcoming limiting the efficiency and wide application of reverse osmosis (RO) technology. In this paper, RO membranes in a full-scale municipal wastewater reclamation plant were autopsied. From the lead to tail position RO membranes in RO system, both of organic and inorganic matters on membranes reduced gradually. The higher ion products in RO concentrate didn't result in more serious inorganic scaling on the last position RO membranes, which was contrast with some other researches. Fe, Ca and Mg were major inorganic elements. Fe had a relatively low concentration in RO influent but the highest content on membranes. However, there was no specific pretreatment in terms of Fe removal. Ca and Mg scaling was controlled by the antiscalants injected. Organic fouling (75.0-84.5% of dry weights) was major problem on RO membranes due to the large amount of dissolved organic matters in secondary effluent as raw water. Hydrophilic acid (HIA, 48.0% of total DOC), hydrophobic acid (HOA, 23.6%) and hydrophobic neutral (HON, 19.0%) fraction was largest among the six fractions in RO influent, while HON (38.2-51.1%) and HOA (22.1-26.1%) tended to accumulate on membranes in higher quantities. Monitoring HON and HOA might help to forecast organic fouling.

  3. Functional MRI demonstrates pain perception in hand osteoarthritis has features of central pain processing.

    Science.gov (United States)

    Sofat, Nidhi; Smee, Cori; Hermansson, Monika; Howard, Matthew; Baker, Emma H; Howe, Franklyn A; Barrick, Thomas R

    2013-11-01

    Hand osteoarthritis (HOA) is typified by pain and reduced function. We hypothesised that people with HOA have enhanced sensitivity and activation of peripheral nociceptors in the hand, thereby potentiating chronic pain. In our study we aimed to assess if central sensitisation mediates pain perception in osteoarthritis of the hand. Participants with proximal and distal interphalangeal joint (PIP/DIP) HOA and non-OA controls were recruited. Clinical pain scores using the visual analogue scale (VAS) were recorded before and after performing a painful hand task. Central pain processing was evaluated with functional brain neuroimaging (fMRI) using a finger flexion-extension (FFE) task performed over 3 minutes. Data was analysed with FMRIB software (www.fmrib.ox.ac.uk/fsl). Group mean activation of functional MRI signal between hand osteoarthritis and control non-arthritic participants was compared. Our group of hand OA participants reported high pain levels compared with non-arthritic controls as demonstrated by the mean VAS in hand OA participants of 59.31± 8.19 mm compared to 4.00 ± 1.89 mm in controls (p central sensitisation. People with hand osteoarthritis demonstrated features of central sensitisation that was evident after a finger flexion-extension task using functional MRI. Functional MRI is a useful biomarker in detecting pain in hand osteoarthritis and could be used in future hand osteoarthritis pain studies to evaluate pain modulation strategies.

  4. Properties of sediment NOM collected from a drinking water reservoir in South China, and its association with THMs and HAAs formation

    Science.gov (United States)

    Hong, H. C.; Huang, F. Q.; Wang, F. Y.; Ding, L. X.; Lin, H. J.; Liang, Y.

    2013-01-01

    SummaryThe natural organic matter (NOM) from the sediment elutriate, which was obtained from a drinking water reservoir in South China, was fractionated into four fractions by using XAD-8 and XAD-4 resin. Dissolved organic carbon (DOC) as well as UV absorbance at 254 nm (UV254) and specific UV254 (SUV254) were used to quantify and characterize the NOM of raw sediment elutriate and the fractions. Formation of disinfection by-products (DBPs), i.e. trihalomethanes (THMs) and haloacetic acids (HAAs) were also investigated. Results showed that lots of organic matter can be liberated from the sediment during suspension. Hydrophilic organic matter (HiM) accounted for 50.7% of the DOC, followed by hydrophobic acid (HoA) (21.3%), transphilic organic matter (TPH) (15.2%) and other hydrophobic substances (HoS) (12.9%). Different from DOC distribution, the highest UV254 and SUV254 were detected in HoA, while the least were observed in HiM. All the organic fractions were good DBPs precursors. The hydrophobic fractions (HoS and HoA) were more important precursors of CHCl3 and TCAA as compared to other fractions, and UV254 was a good indicator for trichloroacetic acid (TCAA) formation. While for the hydrophilic fraction, relative higher dichloroacetic acid (DCAA) yields were observed, and DOC were good index for its formation.

  5. Wave field synthesis of a sound field described by spherical harmonics expansion coefficients.

    Science.gov (United States)

    Ahrens, Jens; Spors, Sascha

    2012-03-01

    Near-field compensated higher order Ambisonics (NFC-HOA) and wave field synthesis (WFS) constitute the two best-known analytic sound field synthesis methods. While WFS is typically used for the synthesis of virtual sound scenes, NFC-HOA is typically employed in order to synthesize sound fields that have been captured with appropriate microphone arrays. Such recorded sound fields are essentially represented by the coefficients of the underlying surface spherical harmonics expansion. A sound field described by such coefficients cannot be straightforwardly synthesized in WFS. This is a consequence of the fact that, unlike in NFC-HOA, it is critical in WFS to carefully select those loudspeakers that contribute to the synthesis of a given sound source in a sound field under consideration. In order to enable such a secondary source selection, it is proposed to employ the well-known concept of decomposing the sound field under consideration into a continuum of plane waves, for which the secondary source selection is straightforward. The plane wave representation is projected onto the horizontal plane and a closed form expression of the secondary source driving signals for horizontal WFS systems of arbitrary convex shape is derived.

  6. Effect of Single Administration of Coffee on Pupil Size and Ocular Wavefront Aberration Measurements in Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Handan Bardak

    2016-01-01

    Full Text Available No study has so far evaluated the impact of coffee drinking on ocular wavefront aberration (OWA measurements. This study presents novel findings regarding the OWA of the eye following coffee intake. We aimed to evaluate the acute changes in pupil size and OWA of the eye after single administration of coffee. A total of 30 otherwise healthy participants were included in this prospective study. All subjects drank a cup of coffee containing 57 mg caffeine. Measurements of pupil size, total coma (TC, total trefoil (TF, total spherical aberration (TSA, and total higher order aberration (HOA were performed before and at 5 minutes, at 30 minutes, and at 4 hours after coffee drinking using a wavefront aberrometer device (Irx3, Imagine Eyes, Orsay, France. The mean age of the study population was 20.30 ± 2.74 years. Pupil size did not show a significant change during the measurements (p>0.05. A significant increase was observed in TF and HOA measurements following coffee intake (p=0.029 and p=0.009, resp.. Single administration of coffee results in significant increase in TF and total HOAs in healthy subjects without any effect on pupil diameter. Ultrastructural changes in the cornea following coffee intake might be of relevance to the alterations in ocular aberrations in healthy subjects.

  7. Effect of tilt and decentration of spherical and aspheric intraocular lens on visual quality%球面和非球面人工晶状体倾斜和偏心对视觉质量的影响

    Institute of Scientific and Technical Information of China (English)

    张伟; 马忠旭; 刘汝瑜; 张玲

    2010-01-01

    目的 研究超声乳化白内障吸除术后球面和非球面人工晶状体(intraocularlens,IOL)的倾斜和偏心及其对高阶像差(higher-order aberrations,HOAs)和视觉质量的影响.方法 前瞻性研究.取50例单纯性老年性白内障患者60只眼,30只眼随机植入AMO公司的球面IOLSensar AR40e,30只眼植入非球面IOLTecnisZA9003.术后3到4个月,检测患者在5.0mm瞳孔下的HOAs以及5、10、15、20、25、30周每度(cycles per degree,cpd)空间频率下的调制传递函数(modulation transfer function,MTF).通过Scheimpflug像,测量IOL的倾斜与偏心.比较两组间倾斜度和偏心值、HOAs及各空间频率下去除低阶像差的MTF(MTF(HOA))值.使用多元回归分析来确定倾斜和偏心对HOAs和视觉质量的影响.结果 光学部倾斜AR40e组(2.99±0.94)°,ZA9003组(2.98±1.15)°.光学部偏心AR40e组(0.30±0.13)mm,ZA9003组(0.31±0.14)mm.组间倾斜和偏心差异无统计学意义(Z=-0.044,-0.525,P=0.965,0.600,Mann-WhitneyU检验).总4阶球差,AR40e组(0.366±0.163)μm大于ZA9003组(0.027±0.072)μm,差异有统计学意义(t=-10.386,P=0.000).ZA9003组在5.0mm瞳孔直径下各频段的MTF(HOA)值均高于AR40e组,有统计学意义(P<0.05).两组IOL倾斜和偏心对各自的HOAs及各频段的MTF(HOA)值均无明显影响.结论 当IOL的倾斜和偏心在正常限度内时,不会危害非球面IOL对球差的补偿作用,不足以导致视觉质量的下降.%Objective To study tilt and decentration of spherical and aspheric IOL implantation after phacoemulsification surgery and effect on higher-order aberrations (HOAs) and visual quality. Methods It was a prospective clinical study. A total of 60 eyes (50 patients) were divided into 2 groups randomly, of 30 eyes in each group, one group with Sensar AR40e (AMO), one group with Tecnis ZA9003 (AMO). Three to four months after surgery, higher-order aberrations (HOAs) and modulation transfer function (MTF) at six spatial frequencies (5, 10, 15, 20

  8. Context dependent reference states of solvent accessibility derived from native protein structures and assessed by predictability analysis

    Directory of Open Access Journals (Sweden)

    Ahmad Shandar

    2009-04-01

    Full Text Available Abstract Background Solvent accessibility (ASA of amino acid residues is often transformed from absolute values of exposed surface area to their normalized relative values. This normalization is typically attained by assuming a highest exposure conformation based on extended state of that residue when it is surrounded by Ala or Gly on both sides i.e. Ala-X-Ala or Gly-X-Gly solvent exposed area. Exact sequence context, the folding state of the residues, and the actual environment of a folded protein, which do impose additional constraints on the highest possible (or highest observed values of ASA, are currently ignored. Here, we analyze the statistics of these constraints and examine how the normalization of absolute ASA values using context-dependent Highest Observed ASA (HOA instead of context-free extended state ASA (ESA of residues can influence the performance of sequence-based prediction of solvent accessibility. Characterization of burial and exposed states of residues based on this normalization has also been shown to provide better enrichment of DNA-binding sites in exposed residues. Results We compiled the statistics of highest observed ASA (HOA of residues in their different contexts and analyzed their distribution in all 400 possible combinations for each residue type. We observe that many trippetides are more exposed than ESA and that HOA residues are often found in turn, coil and bend conformations. On the other hand several residues are never observed in an exposure state close to ESA values. A neural networks trained with HOA-normalized data outperforms the one trained with ESA-normalized values. However, the improvements are subtle in some residues, while they are more significant in others. Conclusion HOA based normalization of solvent accessibility from native structures is proposed and it shows improvement in sequence-based predictability, as well as enrichment in interface residues on surface. There may still be some

  9. 紫外-可见光谱研究堆肥水溶性有机物不同组分演化特征%Evolution based on the spectra of different hydrophilic and hydrophobic components separated from dissolved organic matter (DOM) during compost

    Institute of Scientific and Technical Information of China (English)

    李丹; 何小松; 高如泰; 席北斗; 檀文炳; 张慧; 黄彩红; 许鹏达

    2016-01-01

    The dissolved organic matter (DOM) extracted from chicken manure composting samples during different stages were divided into hydrophobic acid (HOA), hydrophobic base (HOB), hydrophilic matter (HIM) and acid insoluble matter (AIM) according hydrophobic and polarity. The composition and transformation of different components were analyzed by ultraviolet-visible spectra, and 14 characteristic parameters were selected. The humification level of AIM was highest, followed by HOA, HOB and HIM. The molecular aggregation of HOB and HIM increased obviously, the molecular weight of HOA, HOB and AIM increased appearently, and the aromatic substance content of AIM and HOA increased significantly. The correlation analysis showed that the different band area integral could reach significant level, the correlation between S275-295 and many other characteristic parameters were significant or highly significant, so S275-295, A226-400, Am/As, Al/As and Al/Am were more precise than other ultraviolet-visible parameters to characterize humification level of organic matter.%按亲疏水-极性不同将鸡粪不同堆肥阶段样品提取出的水溶性有机物(DOM)分成疏水酸性(HOA)、疏水碱性(HOB)、亲水性(HIM)及酸不溶性(AIM)4个组分,通过紫外-可见光谱,选取了14个特征参数,研究了不同组分的组成与演化特征。结果显示:4个组分中AIM腐殖化水平最高,HOA次之,HOB第三,HIM最低;随着堆肥的进行,4个组分中HOB和HIM分子内团聚化程度提高显著, HOA、HOB及AIM的分子量显著增大, AIM及HOA的芳香类物质含量显著增加。相关性分析表明,不同波段面积积分相关性可达极显著水平,S275-295与多个特征参数相关性达显著或极显著水平,因此,特征S275-295、A226-400、Am/As、Al/As及Al/Am比其他紫外-可见参数表征有机质腐殖化水平更为精确。

  10. The Estimation of Higher Order Aberrations in Children with Anisometropic Amblyopic%高阶像差在远视儿童屈光参差性弱视中的评价

    Institute of Scientific and Technical Information of China (English)

    邱煦; 谭琦; 廖孟; 刘陇黔

    2011-01-01

    使用美国ZYWAVEⅡ像差分析仪对54例屈光参差性远视弱视儿童共108只眼进行像差检查,就像差均方根(RMS)分布情况进行统计分析研究,观察各类高阶像差(HOAs)分布、屈光参差性弱视程度与HOAs的关系.所有患儿弱视眼的总HOAs、总彗差(TC)、总球差(TSA)、总5阶像差(RMS5)的均方根逐阶递减.弱视眼各阶像差均方根值均大于对测眼,但无统计学差异.弱视眼随弱视程度增大,TC、TSA和RMA5呈递增趋势.弱视眼TSA与屈光参差度正相关.HOAs可能在屈光参差性弱视的发展中起了一定作用,但不是主要影响因素.%Higher order aberrations (HOAs) were measured in 54 anisometropic amblyopic children using the ZY-WAVE II aberrometer. The results were compared in normal fellow and amblyoic eyes which were determined by the corrected visual acuity. Between the normal eyes and anisometropic amblyopic eyes, no statistically significant difference were found in mean root square of total HOAs, total coma (TO ? Total spherical aberration (TSA), and the 5th root mean square (RMS5). There was no correlation among best corrected visual acuity (BCVA)t HOAst TC. TSA, and RMS5, There was some positively correlation between the degree of anisometropia and TC. HOAs increase with the increasing of the degree of anisometropic amblyopia. Lower order aberrations are the main refractive factors leading to amblyopia. And HOAs is related to anisometropia amblyopia. The study helps us understand the mechanism of amblyopia and make the further study.

  11. Clinical analysis of hypertrophic osteoarthropathy%肥大性骨关节病病例分析并文献复习

    Institute of Scientific and Technical Information of China (English)

    满斯亮; 宋慧; 伍沪生

    2009-01-01

    Objective To help clinicians understanding and better diagnosing of hypertrophic osteoarthropathy(HOA).Methods Clinical data of five HOA patients in Jishuitan Hospital were analyzed and the literature were reviewed.Results In 18 patients with primary HOA(PHOA),their age ranged from 14 to 24 years.Seventeen patients were male.Most PHOA occurred in age 1 to 42.Two of them had positive family history.Clubbing fingers,hypertrophic skin changes and radiographic evidence of periostitis were found in all patients.Nine of them had cutis vertices gyrate,14 patients had hyperhydrosis and 10 patients had symmetrical joints swelling.Three secondary HOA (SHOA)patients of our hospital,predominantly manifested as symmetrical joints swelling with mild joint tender and clubbing fingers.There were no skin changes in these 3 patients.Conclusion PHOA predominantly manifests as clubbing fingers.hypertrophic skin changes and periostitis.%目的 提高对肥大性骨关节病(HOA)的认识、诊断和鉴别.方法 报告我院2例原发性HOA(PHOA)及3例继发性HOA(SHOA)确诊病例,并分析既往国内报道16例文献.结果 国内PHOA发病年龄多数在14~24岁,多为男性,最小者1岁起病,最大者为42岁.18例PHOA患者中2例有家族史,2例有近亲结婚史,所有患者均有杵状指(趾)、皮肤增厚粗糙、骨膜增生的临床表现,多汗14例,回状颅皮9例,关节痛和(或)关节积液10例,指(趾)端骨质溶解4例,类风湿因子阳性2例,1例弱阳性.我院报告3例SHOA均继发于肺部肿瘤,中年后起病,病程较短.以关节症状及杵状指(趾)为主要表现,面部及皮肤症状少,全身伴随症状多见.结论 PHOA青少年起病多见.男性多,主要表现为杵状指(趾)、皮肤增厚及骨膜反应.与SHOA需从起病年龄、病程及全身伴随症状等方面鉴别.

  12. Changes in high order aberrations of anterior and posterior surfaces of cornea before and after phacoemulsification%超声乳化白内障吸除术后角膜前后表面高阶像差的变化

    Institute of Scientific and Technical Information of China (English)

    王娟; 汤欣; 张帅; 李丽华

    2008-01-01

    目的 探讨利用Pentacam观察超声乳化白内障吸除术前后角膜前后表面高阶像差的变化.方法 前瞻性系列病例研究.对45例(51只眼)年龄相关性白内障患者行3.2 mm透明角膜切口的超声乳化白内障吸除联合折叠型人工晶状体植入术,分别于术前1 d,术后7 d、1个月及3个月利用Pentacam测量角膜前后表面的高阶像差(包括总的高阶像差、球差、彗差、三叶草以及3~6阶像差),将角膜前、后表面高阶像差按直径范围不同(3 mm直径和6 mm直径)分为两组,用具有一个重复测量的两因素设计定量资料方差分析方法对两组数据分别进行统计学分析.结果 角膜前表面总的高阶像差术前1 d为(0.289±0.171)μm,至术后3个月时轻度增加为(0.312±0.158)μm(3 mm直径);术前1 d为(0.980 ±0.215)μm,至术后3个月时轻度增加为(1.054±0.308)μm(6mm直径),但手术前后变化无统计学差异(F=1.55,P=0.22),且两组总的高阶像差随时间的变化趋势相同(F=0.95,P=0.42);其余各项高阶像差手术前后的变化与总的高阶像差的变化相似.角膜后表面总的高阶像差术前1 d为(0.548±0.220)μm,至术后3个月时明显增加为(0.661±0.275)μm(3 mm直径);术前1 d为(1.780±0.453)μm,至术后3个月时明显增加为(1.945±0.532)μm(6mm直径),手术前后变化差异有统计学意义(F=15.83,P=0.00),且两组总的高阶像差随时间的变化趋势不同(F=12.46,P=0.00);其余各项高阶像差手术前后的变化与总的高阶像差的变化相似.结论 超声乳化白内障吸除术后角膜前表面高阶像差的变化不影响术后患者的视觉质量.但是,手术前后角膜后表面高阶像差发生了显著的变化,可能影响术后患者的视觉质量.%Objective To study the effects of phacoemulsification surgery on the optical high order aberrations(HOA)of the cornea measured with Pentacarm.Methods It was a prospective case series study.HOAs of the anterior and

  13. Hydrogen generation from biogenic and fossil fuels by autothermal reforming

    Science.gov (United States)

    Rampe, Thomas; Heinzel, Angelika; Vogel, Bernhard

    Hydrogen generation for fuel cell systems by reforming technologies from various fuels is one of the main fields of investigation of the Fraunhofer ISE. Suitable fuels are, on the one hand, gaseous hydrocarbons like methane, propane but also, on the other hand, liquid hydrocarbons like gasoline and alcohols, e.g., ethanol as biogenic fuel. The goal is to develop compact systems for generation of hydrogen from fuel being suitable for small-scale membrane fuel cells. The most recent work is related to reforming according to the autothermal principle — fuel, air and steam is supplied to the reactor. Possible applications of such small-scale autothermal reformers are mobile systems and also miniature fuel cell as co-generation plant for decentralised electricity and heat generation. For small stand-alone systems without a connection to the natural gas grid liquid gas, a mixture of propane and butane is an appropriate fuel.

  14. Methane-the Promising Career of a Humble Molecule

    Institute of Scientific and Technical Information of China (English)

    Serge Kioes; Waldemar Liebner

    2004-01-01

    Methane, CH4, here represents natural gas (NG) of which it is the main constituent. Routes of chemical utilisation of NG - as opposed to energy usage - are discussed. A main step is the conversion of NG to synthesis gas, a mixture of CO and H2. Simple molecules derived from synthesis gas, like methanol,can be further reacted to longer-chained hydrocarbons like propylene and other olefins and even to gasoline and diesel.

  15. Environmental Assessment of the Trinity River Discharge on Productivity in Trinity Bay.

    Science.gov (United States)

    1972-09-15

    salinities in this semiarid zone, thus occasional floods wreak greater havoc on the populations. The Laguna Madre , a coastal lagoon with little or no...values have been recorded, for a similar habitat, from the Laguna Madre in Texas (Thomas and Simmons, 1960: Parker, 1959), but the waters are much...hydrocarbon like materials. Z. Allg. Mikrobiol. 5:284-307. 1969. Geomicrobial effects on estuarine environments. un Simposio. Men. Simp. Intern. Lagunas

  16. Evaluation of anterior segment parameters and possible influencing factors in normal subjects using a dual Scheimpflug analyzer.

    Directory of Open Access Journals (Sweden)

    Xiaogang Wang

    Full Text Available PURPOSE: To investigate normal anterior segment parameters and analyze the possible influencing factors using a dual Scheimpflug system. SETTING: Department of Ophthalmology, Affiliated Sixth People's Hospital Shanghai Jiao Tong University, Shanghai, China. DESIGN: A prospective observational case series. METHODS: A total of 153 normal subjects (153 eyes were studied. The anterior segment parameters, including the central corneal thickness (CCT, anterior chamber depth (ACD, pupil diameter (PD, keratoconus prediction index (KPI, simulated keratometry (SimK values, anterior instantaneous curvature (AIC, posterior axial curvature (PAC, corneal eccentricity, total corneal power (TCP, axial curvature (AC, total corneal wavefront (TCW, high order aberration (HOA, and spherical aberration (SA, were determined using a dual Scheimpflug analyzer. RESULTS: The CCT and ACD were both negatively correlated with age (r = -0.203, p = 0.012; r = -0.589, p<0.001. There was no significant difference in the refractive indices of AIC and SimK. Compared with the negative correlation of HOA and SA (r = -0.358, p<0.001, a positive correlation was found between TCW and HOA (r = 0.561, p<0.001. Unlike the decreased tendency of AC, the TCP increased gradually from the center to the periphery in the central 8 mm diameter. TCP showed a significant correlation with AC in the analyzed area. CONCLUSIONS: AIC and SimK provide different information in clinic, but the refractive indices of them showed no difference in this healthy study population, and age should be considered when using CCT and ACD values.

  17. The knowledge of the history of astronomy and a proposal to improve it

    Science.gov (United States)

    Saucedo Morales, Julio Cesar; Loera Gonzalez, Pablo

    In this work we present the results of a survey conducted in Hermosillo, Sonora, México, among several different samples to assess the knowledge of the History of Astronomy (HoA), and at the same time, to evaluate the degree of success of the Astronomy Basic Course (ABC) in teaching this particular subject. We claim that astronomy has always been an important player in the history of civilization; however, as the results of this study indicate, this is not widely known. An example of this is that the work of great astronomers such as Aristarchus and Hipparchus are known to only a small fraction of the population. But people find astronomy attractive, which gives us an opportunity to fill gaps in astronomical knowledge. We present our experience of 25 years (the first half of these in the classroom, and the second half both in classroom and virtual mode through the Internet) teaching astronomy to the public with the ABC. In about 60 hours of class spread over a 3-month period, the ABC covers some of the most relevant topics of astronomy, one of which is a 3-hour session on the HoA, which it is taught trying to captivate the attention of wide audiences while discussing the contributions of astronomy to humankind. Although the level of knowledge of the HoA is somewhat disappointing, meaning that much work needs to be done, we have also found that it really pays off to offer opportunities like the ABC to the public. This success encourages us to present a proposal to extend the ABC, to teach it not just in Spanish as we have been done so far, but also in English and perhaps other languages, collaborations to improve it and to spread its use as an outreach and STEM educational device are most welcome.

  18. Sustainability of Public Health Interventions to Reduce the Risk of Dioxin Exposure at Severe Dioxin Hot Spots in Vietnam.

    Science.gov (United States)

    Tuyet-Hanh, Tran Thi; Vu-Anh, Le; Dunne, Michael; Toms, Leisa-Maree; Tenkate, Thomas; Harden, Fiona

    2015-08-01

    Severe dioxin contamination at Bien Hoa and Da Nang airbases, Vietnam is of international concern. Public Health risk reduction programs were implemented in Bien Hoa in 2007-2009 and in Da Nang in 2009-2011. In 2009 and 2011 we reported the encouraging results of these interventions in improving the knowledge, attitude and practices (KAP) of local residents in reducing the dioxin exposure risk through foods. In 2013 we revisited these dioxin hot spots, aimed to evaluate whether the results of the intervention were maintained and to identify factors affecting the sustainability of the programs. To assess this, 16 in-depth interviews, six focus group discussions, and pre and post intervention KAP surveys were undertaken. 800 respondents from six intervention wards and 200 respondents from Buu Long Ward (the control site) were randomly selected to participate in the surveys. The results showed that as of 2013, the programs were rated as "moderately sustained" with a score of 3.3 out of 5.0 (cut off points 2.5 to <3.5) for Bien Hoa, and "well sustained" with a score of 3.8 out of 5.0 (cut off points 3.5 to <4.5) for Da Nang. Most formal intervention program activities had ceased and dioxin risk communication activities were no longer integrated into local routine health education programs. However, the main outcomes were maintained and were better than that in the control ward. Migration, lack of official guidance from City People's Committees and local authorities as well as the politically sensitive nature of dioxin issues were the main challenges for the sustainability of the programs.

  19. Refractive, Topographic, and Aberrometric Results at 2-Year Follow-Up for Accelerated Corneal Cross-Link for Progressive Keratoconus

    Science.gov (United States)

    Bozkurt, Ercüment; Akcay, Betul Ilkay Sezgin; Kurt, Tugba; Yildirim, Yusuf; Günaydin, Zehra Karaagaç; Demirok, Ahmet

    2017-01-01

    Purpose. To report the visual, refractive, and corneal topography and wavefront aberration results of accelerated corneal cross-linking (CXL) during a 24-month follow-up. Methods. Forty-seven eyes underwent riboflavin-ultraviolet A-induced accelerated CXL treatment (30 mW/cm2 with a total dose of 7.2 joules/cm2). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical and cylindrical values, keratometry (K) measurements (Ksteep, Kflat, Kavg, and Kapex), central corneal thickness, and anterior corneal aberrometric analyses including total wavefront error (WFE), total high order aberration (HOA), astigmatism, trefoil, coma, quadrafoil, secondary astigmatism, and spherical aberration were evaluated. Results. The mean UDVA and CDVA were significantly improved at 1 (p = 0.003 and p = 0.004, resp.) and 2 years after treatment (p = 0.001 and p = 0.001, resp.). The mean Ksteep, Kflat, Kaverage, and Kapex values were significantly lower than baseline at 12 months (p = 0.008, p = 0.024, p = 0.001, and p = 0.014, resp.) and 24 months (p = 0.014, p = 0.017, p = 0.001, and p = 0.012, resp.). Corneal thickness showed a significant decrease at 1 month. Total HOA and coma decreased significantly at the 12-month (p = 0.001 and p = 0.009, resp.) and 24-month visits (p = 0.001 and p = 0.007, resp.). Conclusion. Accelerated CXL (30 mW/cm2) was found to be effective in improving UDVA, CDVA, corneal topography readings, total HOA, and coma aberrations during the 24-month follow-up. PMID:28197339

  20. Mirror symmetry of higher order aberrations between right and left eyes

    Directory of Open Access Journals (Sweden)

    M. Oberholzer

    2014-08-01

    Full Text Available Introduction: There is evidence that certain measures of visual function show some type of relationship between right and left eyes in the same individual.  Similarly, particular ocular maladies may be related, or be symmetric, in the right and left eyes of the same person. There is also evidence to suggest that certain relationships do not exist between eyes in an individual. For example, diseases such as glaucoma are often asymmetric in their progression in the two eyes of an afflicted individual. Inter-ocular mirror symmetry between right and left eyes, when considering ocular wave-front aberrations (WAs, has been shown to exist by some authors. This study investigates whether mirror symmetry of high order aberrations (HOAs exists between the right and left eyes in a cohort of South African subjects. Method: Third to 5th order Zernike coefficients (HOAs were measured on both eyes of 66 subjects (132 eyes using a Zywave aberrometer. A total of 15 Zernike coefficients for each eye were obtained. Mirror symmetry was investigated using correlation coefficients between the various measurements obtained from each eye. Results: Pearson product-moment correlation coefficients provide evidence that the majority of the 15 Zernike coefficients suggest the presence of mirror symmetry between right and left eyes of the 66 subjects. Examples of individual scatter plots comparing right and left eyes are presented.  Conclusion: The results of this study suggest that mirror symmetry exists in the HOAs obtained from the 132 eyes measured and thus care should be exercised when combining eyes of individuals for analysis. (S Afr Optom 2013 73(1 39-44

  1. Effectiveness of Technolas torsional eye tracking system on visual outcomes after photorefractive keratectomy.

    Science.gov (United States)

    Gharaee, Hamid; Ghanavati, Siamak Zaree; Rad, Saeed Shokoohi; Omidtabrizi, Arash; Naseri, Hashem

    2015-01-01

    To investigate the efficacy of Technolas 217Z eye tracking system (torsional component) in corneal surface irregularity and high order aberrations (HOAs) after photorefractive keratectomy. Patients with compound myopic astigmatism among persons demanding refractive surgery in Khatam-al-Anbia Eye Hospital with the mean age of 29 years were enrolled in this double-blind randomized interventional study. The mean spherical equivalent (SE) of refractive error was -4.75 diopters(D) (range: -1.5 to -7.0), and the mean astigmatism was 3 D (range:1.0-4). Many studies were performed for each patient including: A complete eye examination, visual acuity and Monocular contrast sensitivity evaluation, and refraction. Corneal topography, Orbscan II, and wavefront aberrometry were conducted. One eye was randomly assigned for aspheric treatment and applying eye tracking system. The other eye was treated without torsional eye tracking system. The outcome measures were uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), contrast sensitivity, corneal irregularity index in 3 mm and 5 mm optical zones in Orbscan II, and mean total HOAs at the 6-monthvisit. Fifty eyes of 25 patients were enrolled. Mean UCVA was improved significantly in both the study and control groups in the 6-month post-operative follow-up. There was no significant difference between the 2 groups in UCVA and BCVA (P = 0.185 and P = 0.176, respectively). Total HOAs increased in both groups after PRK. However, they were lower in eyes treated with the eye tracking system (P eye tracker system (Bausch and Lomb Advanced) results in a more regular anterior surface of cornea. Therefore, we recommend it for surface laser refractive surgery.

  2. Hands-On Astrophysics: Variable Stars in Math, Science, and Computer Education

    Science.gov (United States)

    Mattei, J. A.; Percy, J. R.

    1999-12-01

    Hands-On Astrophysics (HOA): Variable Stars in Math, Science, and Computer Education, is a project recently developed by the American Association of Variable Star Observers (AAVSO) with funds from the National Science Foundation. HOA uses the unique methods and the international database of the AAVSO to develop and integrate students' math and science skills through variable star observation and analysis. It can provide an understanding of basic astronomy concepts, as well as interdisciplinary connections. Most of all, it motivates the user by exposing them to the excitement of doing real science with real data. Project materials include: a database of 600,000 variable star observations; VSTAR (a data plotting and analysis program), and other user friendly software; 31 slides and 14 prints of five constellations; 45 variable star finder charts; an instructional videotape in three 15-minute segments; and a 560-page student's and teacher's manual. These materials support the National Standards for Science and Math education by directly involving the students in the scientific process. Hands-On Astrophysics is designed to be flexible. It is organized so that it can be used at many levels, in many contexts: for classroom use from high school to college level, or for individual projects. In addition, communication and support can be found through the AAVSO home page on the World Wide Web: http://www.aavso.org. The HOA materials can be ordered through this web site or from the AAVSO, 25 Birch Street Cambridge, MA 02138, USA. We gratefully acknowledge the education grant ESI-9154091 from the National Science Foundation which funded the development of this project.

  3. Changes of Ocular Higher-order Aberration with Age and Symmetry Between Right and Left Eyes%人眼高阶像差与年龄的关系及左右眼对称性研究

    Institute of Scientific and Technical Information of China (English)

    肖巴伊; 张振平; 王铮; 杨斌; 邱平; 郑丹莹; 陈伟蓉

    2005-01-01

    [目的]研究人眼高阶像差(higher-order aberration,HOA)随年龄增长的变化规律以及HOA在左右眼的对称性.[方法]用一基于Hartmann-Shack原理的Zywave波前像差仪测量了35例正常人69眼的HOA,评估时所取的瞳孔直径为6 mm.根据测试对象年龄的不同分为3组:青年组(<35岁),中年组(35岁~54岁),老年组(>54岁),计算各组高阶像差的均方根(root mean square,RMS)值,并对3组进行单因素方差分析,对HOA与年龄作相关分析,研究高阶像差随年龄的变化规律;同时对左右眼各Zernike系数作相关分析,以研究高阶像差在左右眼的对称性.[结果]总体高阶像差(HOA)、球差、三阶与四阶像差与年龄均有相关关系(P<0.05),彗差与五阶像差与年龄的关联性不大(P>0.05);左右眼的15项Zernike系数中有8项存在关联性(P<0.05).[结论]高阶像差随年龄的增长而增加,左右眼的高阶像差存在一定程度的对称性.

  4. Comparison of the femtosecond laser and mechanical microkeratome for flap cutting in LASIK.

    Science.gov (United States)

    Xia, Li-Kun; Yu, Jie; Chai, Guang-Rui; Wang, Dang; Li, Yang

    2015-01-01

    To compare refractive results, higher-order aberrations (HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis (LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism. In this prospective, non-randomized study, 120 eyes with myopia received a LASIK surgery with the VisuMax femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function (CSF) curves, HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery. At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was 113.05±5.89 µm (attempted thickness 110 µm), and 148.36±21.24 µm (attempted thickness 140 µm) in mechanical microkeratome procedure. An uncorrected distance visual acuity (UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in logMAR lines of corrected distance visual acuity (CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant (P>0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery (Plaser and the mechanical microkeratome for LASIK flap cutting are safe and effective to correct myopia, with no statistically significant difference in the UDVA, CDVA during 6mo follow-up. Refractive results remained stable after 1mo post-operation for both groups. The femtosecond laser may have advantages over the microkeratome in the flap thickness predictability, fewer induced HOAs, better CSF, and longer

  5. Difficulties in Forecasting Flow Paths During the 2014-2015 Lava Flow Crisis at Kīlauea Volcano (Hawaíi)

    Science.gov (United States)

    Patrick, M. R.; Orr, T. R.; Trusdell, F.; Llewellin, E. W.; Kauahikaua, J. P.

    2015-12-01

    Kīlauea's East Rift Zone (ERZ) eruptive activity at Púu ´Ō´ō shifted to a new vent in June 2014, sparking a lava flow crisis that threatened critical infrastructure near the town of Pāhoa in east Hawaíi. The lava flow proved to be challenging to forecast because of the influence of ground cracks on flow direction, frequent fluctuations in lava supply, and the subtle interplay between ground slope and confining topography that prevented the flow from spreading laterally. After its onset, the "June 27th" flow, named informally for its start date, advanced northeast at up to several hundred m/day. The flow's path through heavy forest was forecast using steepest-descent paths derived from a digital elevation model (DEM). Flow path uncertainties were minimized using a multiple-run technique and built-in random DEM errors (modified from Favalli et al., 2005). In mid-August, the flow encountered and entered one of many deep, discontinuous ground cracks along Kīlauea's middle ERZ. The flow continued to advance out of sight in the crack, as inferred from a forward-progressing line of steam. A week later, lava spilled from the crack 1.3 km downslope, advancing along a different flow path than was forecast. By early September, the flow had entered and exited three more cracks sequentially, carrying the flow across slope, thus making flow path forecasts unreliable. Moreover, lava-occupied cracks dilated by up to 3 m. The lava accumulating in the ground cracks forced immense, but apparently mobile, blocks to shift. Thus, while an open crack was required to capture the lava, the lava was able to force its way beyond where the crack closed. In this way, the lava flow acted as an intruding dike. The flow eventually advanced beyond the area of cracks and onto a steepest-descent path that guided the flow toward the town of Pāhoa, where it destroyed one house, reached to within ~155 m of the main street in Pāhoa, and threatened the main highway and shopping center serving

  6. Threat to Cedar, Cedrela odorata, Plantations in Vietnam by the Weevil, Aclees sp.

    OpenAIRE

    Thu, Pham Quang; Quang, Dao Ngoc; Dell, Bernard

    2010-01-01

    The recent decline and death of young cedar, Cedrela odorata L. (Sapindales: Meliaceae), plantations in Vietnam is caused by Aclees sp. (Coleoptera: Curculionidae), a wood-boring brown weevil. A field study was undertaken in three-year-old plantations in two districts in Thanh Hoa province in August 2008. Trees were heavily impacted by the weevil, Aclees; the infestation level (P) ranged from 80 to 100% and the average damage index (R) ranged from 1.8 to 2.8. Observations over one year enable...

  7. 皮肤骨膜增厚症1例报告

    Institute of Scientific and Technical Information of China (English)

    刘丽艳; 赵立峰

    2011-01-01

    @@ 肥大性骨关节病(hypertrophic osteoarthropathy,HOA)是一种以杵状指、骨膜增生和关节炎为特征的综合征.可分为原发和继发两种类型,原发性HOA通常称之为皮肤骨膜增厚症(pachydermoperiostosis,PDP)或Touraine-Solente-Gol è综合征[1].继发性HOA多为在心脏或(和)肺脏疾病(偶尔为肿瘤)基础

  8. Comparative Analysis of High-Order Aberration After Different Corneal Refractive Surgeries%不同角膜屈光手术后高阶像差情况对比分析

    Institute of Scientific and Technical Information of China (English)

    聂新钢; 黄琰霞

    2016-01-01

    Objective To investigate the characteristic changes of high-order aberration (HOA) after different corneal refractive surgeries.Methods120 cases of patients with 236-eyes myopia and myopic astigmatism admitted into our hospital from June 2015 to December 2015, including 37 cases of 73-eyes received LASIK (A group), 40 cases of 78-eyes received FS-LASIK (B group), 43 cases of 85-eyes received FLEx (C group), compared 1 mo of cornea of HOA before and after surgeries of three groups.Results Comparing HOA of three groups before and after surgeries, there was statistical signiifcance (P<0.05), The vertical coma aberration of A and B groups, compared with that of C group, there was statistical significance (P<0.05).Conclusion HOA is increased signiifcantly after different corneal refractive surgeries, but FLEx surgery does not show obvious advantage because of the inlfuence of incision.%目的:探究不同角膜屈光手术后高阶像差(HOA)的特征性变化。方法选取我院2015年6~12月收治的120例236眼近视及近视散光患者,其中行LASIK(准分子激光原位角膜磨镶术)37例73眼(A组),行FS-LASIK(飞秒激光制瓣的LASIK)40例78眼(B组)B组,行FLEx(全飞秒激光FLEx)43例85眼(C组),对比三组手术前后1mo的角膜HOA。结果手术前后三组HOA相比,差异有统计学意义(P<0.05);A、B两组与C组相比,差异有统计意义(P<0.05)。结论不同角膜屈光手术后HOA均明显增加,而FLEx术因切口影响,未表现出明显优势。

  9. Characterizing and Exploring the Implications of Maritime Irregular Warfare

    Science.gov (United States)

    2012-01-01

    gunfire support Sri Lanka vs. Sea Tigers Solomon Islands—regional Assistance Mission to Solomon Islands Israel vs. hezbollah OEF hoA tomahawk missile...phases I and II) Iraq—OIF (phases I and II) Vietnam—Operation Sealords persian Gulf—Operation Earnest Will OEF-P Israel vs. hezbollah Mumbai—LeT...at the time of the operation’s inception in 2001–2002, then- President Gloria Macapagal- Arroyo “insisted the U.S. military role should be advisory

  10. Comparison of the femtosecond Laser and mechanical microkeratome for flap cutting in LASIK

    Institute of Scientific and Technical Information of China (English)

    Li-Kun; Xia; Jie; Yu; Guang-Rui; Chai; Dang; Wang; Yang; Li

    2015-01-01

    · AIM: To compare refractive results, higher-order aberrations(HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis(LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism.·METHODS: In this prospective, non-randomized study,120 eyes with myopia received a LASIK surgery with the Visu Max femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function(CSF) curves,HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery.·RESULTS: At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was113.05 ±5.89 μm(attempted thickness 110 μm), and148.36 ±21.24 μm(attempted thickness 140 μm) in mechanical microkeratome procedure. An uncorrected distance visual acuity(UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in log MAR lines of corrected distance visual acuity(CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant(P >0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery(P <0.01). The CSF values of the femtosecond treated eyes were also higherthan those of the microkeratome treated eyes at all space frequency(P <0.01). The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time(TBUT) of the femtosecond treated eyes were markedly longer than those of

  11. United States Army Combat Units of the War in the Republic of Vietnam: 1966-73. A Preliminary List

    Science.gov (United States)

    1979-04-01

    34-, Engr Co Qui Nhon USA Spt Cmd QN 9)6230 578 Ord Co Snigon Saigon xog urea 963)7 570 Sig Co CO m, h Tay 2 Sig Gp 96312 579 2n,-r eDot Tan Son Nhut 1L...96308 bEJ 133 MED DOT TM DA DISP 68TH MED OP BIEN HOA 96227 C2U 136 CS CO LT MAIZ ’ oS USASUPCOM-CRB CAN RANH BAY 96312 bLIA 138 AVN CO RADIO RESEARCH

  12. Preliminary study of spinal-pelvic sagittal alignment and its relationship with lumbar pain in patients with end-stage primary hip osteoarthritis%终末期原发髋关节骨关节炎患者脊柱-骨盆矢状面形态异常及其与腰痛关系的初步研究

    Institute of Scientific and Technical Information of China (English)

    吴明达; 王渭君; 徐志宏; 刘飞; 邱勇; 翁文杰

    2014-01-01

    Objective To discuss the correlation between the spinal-pelvic sagittal alignment and the lower back pain ( LBP) in the patients with end-stage primary hip osteoarthritis ( HOA) .Methods The up-right standing lateral X-ray films of the spine and pelvis were taken from 46 patients with primary HOA and 55 normal controls.The lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), spinal sacral angle (SSA), and spinal tilt (ST) were measured.The patients with HOA were divided into two subgroups based on LBP ( 23 cases in each subgroup ) , and the LBP was assessed by visual analogue score ( VAS) .The comparison between HOA patients and normal controls were performed by independent-samples t test while the subgroups and the normal-control group were compared by non-parametric t test .The correlations between VAS and the measured parameters were analysed in the patients with HOA.The statistical significance was defined as P <0.05.Results There was no significant difference in neither age or gender distribution between the HOA patients and the normal controls .The HOA patients showed significant lower LL (45.2°±17.3°vs 51.1°±8.5°, t=-4.260, P<0.05) and ST (87.8°±8.3°vs 94.5°±3.0°, P<0.01) but no difference in SS, PI, PI and SSA when compared to the normal controls.The patients with LBP showed significantly smaller LL (39.4°±19.7°, t=-4.260, P<0.05), SSA (121.5°±13.5°, t=-3.287, P<0.05) and ST (87.6°±8.0°, t=-6.478, P<0.05) compared to the normal controls , while the patients without LBP showed significant larger SS ( 42.1°± 11.1°, t=3.496, P<0.05) but smaller PT (10.3°±8.8°, t=-2.466, P<0.05) and ST (88.1°± 8.8°, t=-5.678, P<0.05).In addition, the significant correlations were retrieved between the VAS scores and LL, SS and PT in the patients with HOA (P<0.05).Conclusions Abnormal spinal-pelvic sagittal alignment was found in the patients with HOA , presenting with decreased lumbar lordosis but increased forward

  13. Higher-order awareness, misrepresentation and function.

    Science.gov (United States)

    Rosenthal, David

    2012-05-19

    Conscious mental states are states we are in some way aware of. I compare higher-order theories of consciousness, which explain consciousness by appeal to such higher-order awareness (HOA), and first-order theories, which do not, and I argue that higher-order theories have substantial explanatory advantages. The higher-order nature of our awareness of our conscious states suggests an analogy with the metacognition that figures in the regulation of psychological processes and behaviour. I argue that, although both consciousness and metacognition involve higher-order psychological states, they have little more in common. One thing they do share is the possibility of misrepresentation; just as metacognitive processing can misrepresent one's cognitive states and abilities, so the HOA in virtue of which one's mental states are conscious can, and sometimes does, misdescribe those states. A striking difference between the two, however, has to do with utility for psychological processing. Metacognition has considerable benefit for psychological processing; in contrast, it is unlikely that there is much, if any, utility to mental states' being conscious over and above the utility those states have when they are not conscious.

  14. Comparison of corneal topographic measurements and high order aberrations in keratoconus and normal eyes.

    Science.gov (United States)

    Colak, Hatice Nur; Kantarci, Feride Aylin; Yildirim, Aydin; Tatar, Mehmet Gurkan; Goker, Hasan; Uslu, Hasim; Gurler, Bulent

    2016-10-01

    The aim of this report was to compare corneal topographic measurements and anterior high order corneal aberrations in eyes with keratoconus and normal eyes by using Scheimpflug-Placido topography. Eighty cases diagnosed with mild (group 1), moderate (group 2), and advanced (group 3) stage keratoconus (KC) according to Amsler-Krumeich Classification and 81 healthy (control group) cases were retrospectively examined. The mean keratometric measurements (as both diopters (Kavg) and mm values (mmavg)), central corneal thickness values (CCT), high order aberration (HOA), total wavefront aberration (TWA), coma, trefoil, and spherical aberration measurements were performed using Sirius topography equipment. The topographic values were compared between the groups. There were 25 cases in group 1 KC (15.5%), 34 cases in group 2 KC (21.1%), 21 cases in group 3 KC (13.1%), and 81 cases (50.3%) in the control group. In terms of mean age and gender distributions, there was no statistically significant difference between the groups (p>0.05). However, there was significant difference between the groups in terms of Kavg, CCT, HOA, TWA, coma, trefoil, and spherical aberration values (pkeratoconus. Anterior high order corneal aberration measurements are a useful tool to guide the physician in diagnosis and classification of keratoconus. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  15. Visual Performance and Optical Quality of Standardized Asymmetric Soft Contact Lenses in Patients With Keratoconus.

    Science.gov (United States)

    Suzaki, Asaki; Maeda, Naoyuki; Fuchihata, Mutsumi; Koh, Shizuka; Nishida, Kohji; Fujikado, Takashi

    2017-06-01

    To evaluate the visual performance and optical quality of a standardized asymmetric soft contact lens (SCL) used for correction of higher-order aberrations (HOAs) in eyes with keratoconus. We included 30 eyes (26 patients) with keratoconus (average K: 45.7 ± 2.3 diopters [D]). The patients were subjected to corneal tomography, aberrometry, measurements of manifest refraction and visual acuity (VA), and visual analog scale (VAS) assessments. The study lenses were made using a molding method and consisted of six standardized types, in which an asymmetric power distribution of approximately 2 to 12 D (2-D step) was used to correct HOAs. The lens type suitable for each eye was selected based on the corneal tomography and aberrometry data. The on-eye performance of the lens was evaluated using aberrometry (4-mm pupil), over refraction, VA, and VAS. The standardized asymmetric SCL improved the best spectacle-corrected VA from -0.07 ± 0.09 to -0.11 ± 0.08 logMAR (P keratoconus who wear rigid gas-permeable lenses.

  16. 全眼球差对人工晶状体眼视觉质量的作用%Effect of ocular spherical aberration on vision quality in pseudophakic eyes

    Institute of Scientific and Technical Information of China (English)

    甄小妹; 马忠旭; 刘汝瑜; 张娜; 张伟; 薛庆

    2012-01-01

    Objective To compare the difference of spherical aberration, modulation transfer function! MTF) and depth of focus( DOF) in eyes implanted with aspher-ical and spherical intraocular lens( IOL) ,and then analyze the relationship between ocular spherical aberration, MTF and DOF to subjectively evaluate the ocular spherical aberration on vision quality. Methods A total of 72 patients (77 eyes) with age-related cataract were divided into 3 groups randomly. Group I (25 cases, 26 eyes) implanted with Tecnis ZA9O03 IOL,Group II (23 cases,26 eyes) implanted with Acrysof IQ IOL, Group ID (24 cases,25 eyes) implanted with Acrysof SN60AT IOL. The iTrace was used to measure the ocular spherical aberration, MTF under each spatial frequency (5c-d-1,10c ? D-1,15 c- d-1,20c ? D-1 ,25 c ? D-1,30 c ? D-1) and defocus MTF curve at 6 mm pupil diameter. One-way AVONA and Spearson correlation analysis were used to assess the date. Results At 6 mm pupil diameter, there was statistical difference in the ocular spherical aberration among three groups (P < 0. 05), which in group I was less than group H , and group II was less than group IH , there were statistical differences ( both P < 0. 05). There were statistical differences in MTF( tHOA) value among three groups under each spatial frequency (both P < 0.05), which in group I and H were all higher than group IE , there were statistical differences ( both P < 0. 05). There was statistical difference in DOF value among three groups (P < 0.05), which in group I and H were all less than group IE , there were statistical differences (both P < 0. 05 ). The MTF (tHOA) value under each spatial frequency was negative correlated with ocular spherical aberration( all P < 0. 05 ), positive correlated with DOF value ( r = 0. 388, P =0.003). Conclusion The eyes implanted with aspherical IOL with negative spherical aberration have a high value of MTF (tHOA), while eyes implanted with spherical IOL have a high value of DOF. The ocular spherical

  17. Differences of Longitudinal Chromatic Aberration (LCA) between Eyes with Intraocular Lenses from Different Manufacturers.

    Science.gov (United States)

    Nakajima, Masashi; Hiraoka, Takahiro; Yamamoto, Toshiya; Takagi, Seiu; Hirohara, Yoko; Oshika, Tetsuro; Mihashi, Toshifumi

    2016-01-01

    Several researchers have studied the longitudinal chromatic aberration (LCA) of eyes implanted with an intraocular lens (IOL). We investigated the LCA of eyes implanted with yellow-colored IOLs from three different manufacturers: Alcon Inc., HOYA Corp., and AMO Inc. The number of subjects was 11, 16, and 16, respectively. The LCA of eyes implanted with SN60WF and SN60AT (Alcon Inc.), and with XY-1 (HOYA Corp.), was the same as that of phakic eyes. The LCA of eyes with ZCB00V (AMO Inc.) was smaller than that of phakic eyes. The LCA of eyes implanted with Alcon's and HOYA's IOLs, but not the LCA of eyes implanted with AMO's IOLs, was positively correlated with the powers of the IOLs. We also performed simulations to verify the impacts of LCA on visual performance for 4-mm pupil diameter; the simulations were a polychromatic modulation transfer function (MTF) and a visual Strehl ratio computed on the basis of an optical transfer function (VSOTF). We concluded that the differences between the LCA of different manufacturers do not affect visual performances when some extent of higher-order aberration (HOA) exists. The smaller HOA of AMO IOLs may enhance visual performance.

  18. Effectiveness and Optical Quality of Topical 3.0% Diquafosol versus 0.05% Cyclosporine A in Dry Eye Patients following Cataract Surgery

    Directory of Open Access Journals (Sweden)

    Jang Hoon Lee

    2016-01-01

    Full Text Available Purpose. To evaluate the effectiveness and optical quality of 3.0% topical diquafosol versus 0.05% cyclosporine A in dry eye patients following cataract surgery. Methods. In total, 40 eyes of 40 patients newly diagnosed with dry eye syndrome 1 week after cataract surgery were randomized to receive either 3.0% diquafosol ophthalmic solution six times daily or 0.05% cyclosporine A twice daily for 3 months. Outcome measures were tear film break-up time (TBUT, results on Schirmer 1 test, ocular surface staining score, the ocular surface disease index (OSDI score, and higher-order aberrations (HOAs. Measurements were taken at baseline and at 1, 2, and 3 months. Results. In the diquafosol group, TBUT showed higher outcomes than the cyclosporine A group at 1 and 3 months. Both groups showed increased scores on Schirmer 1 test. The ocular surface staining score decreased in all periods in both groups. Vertical coma and total HOAs decreased more in the cyclosporine A group than in the diquafosol group at 3 months. Conclusion. Both 3.0% diquafosol and 0.05% cyclosporine A were effective in treating dry eye after cataract surgery. Diquafosol was more effective in increasing the tear secretion, but cyclosporine A was more effective in improving optical aberrations.

  19. Is the WMS-IV verbal paired associates as effective as other memory tasks in discriminating amnestic mild cognitive impairment from normal aging?

    Science.gov (United States)

    Pike, Kerryn E; Kinsella, Glynda J; Ong, Ben; Mullaly, Elizabeth; Rand, Elizabeth; Storey, Elsdon; Ames, David; Saling, Michael; Clare, Linda; Parsons, Samuel

    2013-01-01

    Paired associate learning tasks are reportedly particularly sensitive to preclinical Alzheimer's disease. We aimed to determine the effectiveness of the recently updated Wechsler Memory Scale verbal paired associates (VPA) in distinguishing the earliest stages of memory impairment (amnestic mild cognitive impairment, aMCI), and the clinical application at the case level, compared with other episodic memory tasks. Participants were 77 people with aMCI and 77 matched healthy older adults (HOA). VPA performance distinguished aMCI from HOA at the group level with large effect sizes, of similar size to the other tasks at immediate recall, but smaller than the CVLT-II list-learning task at delayed recall. Similarly, receiver operating characteristic (ROC) analysis demonstrated good discrimination, similar to other tasks, but again with CVLT-II more accurate at delayed recall. Although group differences remained for normative data, on a case basis using existing normative data the VPA failed to identify 70% of aMCI as impaired. The findings suggest further examination of the normative data is required before the VPA is useful in clinical practice, and highlight the importance of comprehensive neuropsychological assessment in detecting mild memory changes in older adults.

  20. EFFECT OF SHORT-TERM SOFT CONTACT LENS WEAR ON HUMAN OCULAR ABERRATIONS

    Institute of Scientific and Technical Information of China (English)

    YU Jing; CHEN Yi-hui; CHEN Hui; SHENG Min-jie

    2009-01-01

    Objective To evaluate the effect of short-term soft contact lens (SCLs) wearing on human ocular aberrations (HOA).Methods This prospective study included 50 eyes of 50 young volunteers wearing SCLs for 1month. The ocular aberrations were measured by Allegretto Wavefront Analyzer. The root-mean-square (RMS) values of the general (RMSG), higher-order (RMSH), first to sixth order (RMS1 to RMS6) and aberration coefficients were analyzed.Results There were no significant differences in the mean values of RMSG, RMSH, RMS1 to RMS6 (P>0.05) and changes of absolute values of aberration coefficients between baseline and various visits after SCLs discontinuation. However, at d1 after the discontinuation of SCLs, changes in coefficient values of the third-order aberrations (C6 to C9) were slightly higher than others, and C7 was the highest. The increase factors of RMS values were higher at 1 week and lower at the 2 week visit after SCLs discontinuation. The uniformity of dominating type in HOA and the corneal topography form was both about 60% after discontinuation of SCLs. The corneal thickness increased after SCLs wear and gradually decreased to baseline until 1month discontinuation of SCLs.Conclusion The effect of short-term SCLs wear on human ocular aberrations is slight but profound. A month or more wait should be allowed before the short-term SCLs wearers are scheduled for wavefronted-guided LASIK.

  1. Developments in Accommodating Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Zeki Tunç

    2012-07-01

    Full Text Available Technical progress in cataract surgery has decreased the incidence of severe complications in this type of surgery. The introduction of micro incision cataract surgery (MICS (sub- 2.0 mm incision allow the surgeon to achieve better postoperative control of astigmatism and higherorder aberration (HOAs with minimum induction of both. It is believed that multifocal lenses provide very successful results, however, there are limitations to these. Implantation of accommodating intraocular lenses (IOLs is an option to treat presbyopia. The IOLs work by using the continued functionality of the ciliary muscle after cataract removal. Accommodating IOLs were designed to avoid the optical side effects of multifocal IOLs. Two main design concepts exist. First, axial shift concepts rely on anterior axial movement of one or two optics creating accommodative ability. Second, curvature change designs are designed to provide significant amplitudes of accommodation with little physical displacement. Accommodative IOLs to correct astigmatism and HOAs in the future are needed. (Turk J Ophthalmol 2012; 42: 288-93

  2. Making the most of data: An information selection and assessment framework to improve water systems operations

    Science.gov (United States)

    Giuliani, M.; Pianosi, F.; Castelletti, A.

    2015-11-01

    Advances in Environmental monitoring systems are making a wide range of data available at increasingly higher temporal and spatial resolution. This creates an opportunity to enhance real-time understanding of water systems conditions and to improve prediction of their future evolution, ultimately increasing our ability to make better decisions. Yet, many water systems are still operated using very simple information systems, typically based on simple statistical analysis and the operator's experience. In this work, we propose a framework to automatically select the most valuable information to inform water systems operations supported by quantitative metrics to operationally and economically assess the value of this information. The Hoa Binh reservoir in Vietnam is used to demonstrate the proposed framework in a multiobjective context, accounting for hydropower production and flood control. First, we quantify the expected value of perfect information, meaning the potential space for improvement under the assumption of exact knowledge of the future system conditions. Second, we automatically select the most valuable information that could be actually used to improve the Hoa Binh operations. Finally, we assess the economic value of sample information on the basis of the resulting policy performance. Results show that our framework successfully select information to enhance the performance of the operating policies with respect to both the competing objectives, attaining a 40% improvement close to the target trade-off selected as potentially good compromise between hydropower production and flood control.

  3. The effect of aberrations on objectively assessed image quality and depth of focus.

    Science.gov (United States)

    Águila-Carrasco, Antonio J Del; Read, Scott A; Montés-Micó, Robert; Iskander, D Robert

    2017-02-01

    The effects of aberrations on image quality and the objectively assessed depth of focus (DoF) were studied. Aberrometry data from 80 young subjects with a range of refractive errors was used for computing the visual Strehl ratio based on the optical transfer function (VSOTF), and then, through-focus simulations were performed in order to calculate the objective DoF (using two different relative thresholds of 50% and 80%; and two different pupil diameters) and the image quality (the peak VSOTF). Both lower order astigmatism and higher order aberration (HOA) terms up to the fifth radial order were considered. The results revealed that, of the HOAs, the comatic terms (third and fifth order) explained most of the variations of the DoF and the image quality in this population of subjects. Furthermore, computer simulations demonstrated that the removal of these terms also had a significant impact on both DoF and the peak VSOTF. Knowledge about the relationship between aberrations, DoF, image quality, and their interactions is essential in optical designs aiming to produce large values of DoF while maintaining an acceptable level of image quality. Comatic aberration terms appear to contribute strongly towards the configuration of both of these visually important parameters.

  4. Sex-specific differences in adrenocortical attunement in mothers with a history of childhood abuse and their 5-month-old boys and girls.

    Science.gov (United States)

    Fuchs, Anna; Möhler, E; Resch, F; Kaess, M

    2016-09-01

    Recent evidence points to the existence of a neurobiological attunement between mother and child, e.g., associations between maternal and child hypothalamic-pituitary-adrenal (HPA) axis functioning. As maternal history of abuse (HoA) has been shown to negatively affect mother-child interaction and HPA-axis functioning, we theorized those experiences to exert an influence on cortisol attunement, and we examined the role of infant gender in this context. Shortly after birth of their first child, a community sample of women was screened using the Childhood Trauma Questionnaire. Mothers reporting moderate or severe sexual and/or physical abuse were included in the maltreatment group (n = 41; MG) and compared with a non-maltreated comparison group (n = 47; CG). At the child's age of 5 months, mother and infant baseline salivary cortisol was collected on two consecutive days between 11 and 1 o'clock. Correlation analyses confirmed an association between maternal and infant salivary cortisol levels for the complete sample. However, hierarchical regression models revealed a moderating role of maternal HoA and infant gender: in the CG, cortisol attunement was only significant in mother-daughter dyads, whereas in the MG, we found cortisol levels to be associated only in mother-son dyads. Consequently, alterations of neurobiological attunement between mother and child might compose a mechanism for the transgenerational transmission of adverse childhood experiences.

  5. High order aberration and straylight evaluation after cataract surgery with implantation of an aspheric,aberration correcting monofocal intraocular lens

    Institute of Scientific and Technical Information of China (English)

    Florian; T; A; Kretz; Tamer; Tandogan; Ramin; Khoramnia; Gerd; U; Auffarth

    2015-01-01

    ·AIM: To evaluate the quality of vision in respect to high order aberrations and straylight perception after implantation of an aspheric, aberration correcting,monofocal intraocular lens(IOL).·METHODS: Twenty-one patients(34 eyes) aged 50 to83 y underwent cataract surgery with implantation of an aspheric, aberration correcting IOL(Tecnis ZCB00,Abbott Medical Optics). Three months after surgery they were examined for uncorrected(UDVA) and corrected distance visual acuity(CDVA), contrast sensitivity(CS)under photopic and mesopic conditions with and without glare source, ocular high order aberrations(HOA, Zywave II) and retinal straylight(C-Quant).· RESULTS: Postoperatively, patients achieved a postoperative CDVA of 0.0 log MAR or better in 97.1% of eyes. Mean values of high order abberations were +0.02±0.27(primary coma components) and-0.04 ±0.16(spherical aberration term). Straylight values of the C-Quant were 1.35±0.44 log which is within normal range of age matched phakic patients. The CS measurements under mesopic and photopic conditions in combination with and without glare did not show any statistical significance in the patient group observed(P ≥0.28).· CONCLUSION: The implantation of an aspherical aberration correcting monofocal IOL after cataractsurgery resulted in very low residual higher order aberration(HOA) and normal straylight.

  6. Application of Network Mode in Standardized Management of Head Nurse%网络模式在护士长规范化管理中的应用

    Institute of Scientific and Technical Information of China (English)

    张德凤; 郭丽

    2008-01-01

    医院办公自动化管理(hospital office automated system,HOA)系统包括护理办公系统管理、护理科研管理、护理质量管理及护理质量监测记录,各模块相互关联,涵盖了各项护理管理工作内容及质量管理的信息及功能.HOA的应用优势包括:护士长工作的实时记录,护理部通过信息系统实施质量控制,护士长日常工作的快捷性,提高护士长的工作效率,护士长质量管理的随时性、规范性等.利用HOA,规范了护理工作中办公管理程序的流程,拓展了护理管理的模式,是实现医院信息化的管理改革,提高工作效率与管理水平的快捷途径.

  7. 糖尿病合并高血压与高血脂、血尿酸的关系分析

    Institute of Scientific and Technical Information of China (English)

    曼地娜木·卡马尔丁

    2011-01-01

    目的 探讨糖尿病血脂、血尿酸(HOA)与高血压的关系.方法 测定34 例,糖尿病合并高血压,胰岛素敏感性脂数(LS1)、胰岛素抵抗指数(HOMA、LR)及胰岛β细胞分泌功能脂数(HOMA-b)并与非糖尿病高血压(NDACI)患者对照组(NC)比较.结果 HOA 组FPCT、FINS、HOMA、TR 及血脂、血尿酸(SOA)水平明显高于NC 组、ISI 明显低于NC 组,差异均有统计学意义(P 均<0.01)排除年龄及入选病例时已除外的,高血压等相关因素,HVA 与IR 密切相关.结论 糖尿病合并高血压(DACI)血脂、血尿酸关系是代谢综合征的危险因素之一.

  8. 角膜和全眼高阶波前像差的特点及年龄相关性变化的研究%Distribution and age-related changes in corneal and ocular higher-order aberrations in Chinese

    Institute of Scientific and Technical Information of China (English)

    吴文捷; 钱益勇; 张振平; 李秀梅; 柏凌; 林浩添; 晏丕松; 余秋蓉

    2009-01-01

    目的 研究人眼角膜和全眼单色高阶波前像差特点及年龄相关性变化.方法 使用Tracey-iTrace视觉功能分析仪测量113只正常国人眼计59人,年龄5~73岁,平均(33.81±20.50)岁,角膜和全眼的球差(Z40)、总高阶像差(HOAs)、总彗差(TC)、总球差(TS)、总三叶草像差(TT).并对角膜和全眼高阶波前像差进行年龄相关性分析.结果 角膜Z40的均方根系数值平均为(0.27±0.07)μm(0.130~0.451)μm,虽然角膜Z40随年龄略呈增加趋势,但无统计学意义(r=0.172,p=0.069).全眼的Z40随年龄增加而增加(r=0.545,p=0.000).角膜的HOAs(r=0.499,p=0.000)、TC(r=0.149,p=0.021)、TT(J=0.344,p=0.000)和全眼的HOAs(r=0.427,p=0.000)、TC(r=0.253,p=0.007)、TT(r=0.185,p=0.050)均随年龄的增加而增加.角膜HOAs、TC、,TT.与全眼相对应像差呈正相关(r=0.327,p=0.000;r=0.233,p=0.013;r=0.481,p=0.000).角膜TS不随年龄而变化(r=0.180,p=0.057),但全眼的TS随年龄的增加而增加(r=0.560,p=0.000).结论 国人角膜的HOAs、Tc、1Tr随年龄的增加而增加,并导致了全眼的上述波前像差随年龄的增加而增高.角膜的TS和Z40不随年龄发生明显变化,全眼的TS和Z40随年龄增加是由于晶状体总球差和球差随年龄增加的结果.国人角膜球差具有较大个体差异性,手术前角膜球差的测量是非球面IOL选择的必要步骤.%Objective To investigate age-related changes in corneal and ocular monochromatic high-er-order aberrations and elucidate the distribution of corneal primary spherical in Chinese. Methods Using Traeey-iTrace visual function analyzer (EyeSys corneal topography combined with a ray-tracing aberrometer),113 normal eyes of 59 Chinese,mean age of 33.81+20.50 years (range,5-73 years),were evaluated for corneal and ocular monochromatic total higher-order aberrations (HOAs), primary spherical aberration (Z40),total spherical (TS),total coma (TC),and total trefoil aberration (TT) in the central 6mm diameter

  9. Study on the compensation effect of internal higher -order aberrations on corneal higher - order aberrations in myopia%近视眼患者眼内高阶像差对角膜高阶像差补偿作用的研究

    Institute of Scientific and Technical Information of China (English)

    马代金; 朱睿玲; 蔡望

    2014-01-01

    目的:探讨青年中、低度近视眼患者眼内高阶像差对角膜高阶像差的补偿作用。  方法:收集2012-04/05在我院准分子激光中心接受角膜屈光手术的近视眼患者76例152眼,用OPD Scan ARK-10000测量瞳孔直径6 mm时角膜前表面和全眼球3~6阶总高阶像差( total higher-order aberrations ,HOAs)、总彗差( total coma aberration , TC )、总三叶草( total trefoil aberration,TT)、总球差( total spherical aberration ,TS)均方根值( root mean square ,RMS)及三阶彗差( Z3-1,Z31)、三叶草( Z3-3,Z33)、四阶球差( Z40)的Zernike系数,计算补偿因子( compensation factor ,CF)。  结果:角膜球差均为正值,33眼(21.7%)全眼球差为负值;角膜TC均方根值及Z3-1,Z31小于全眼像差,补偿因子为负值;角膜HOAs,TT,TS均方根值及Z3-3,Z33,Z40均高于全眼像差,补偿因子为正值。  结论:眼内高阶像差对角膜高阶像差主要表现为补偿作用;眼内球差对角膜球差有补偿作用,可降低全眼球差;眼内彗差、三叶草对角膜高阶像差的作用个体差异较大,可表现为部分补偿、过度补偿和叠加,其中彗差以叠加作用为主,三叶草以补偿作用为主。%AIM:To investigate the compensation effects of internal higher-order aberrations ( HOAs) on the corneal HOAs in youth with low and moderate myopia. METHODS: Seventy-six myopic patients ( 152 eyes ) who received corneal refractive surgery from April to May in 2012 were included in this study. The HOAs of the anterior corneal surface and the total ocular HOAs ( 3-6 stage) ocular were measured using OPD Scan ARK-10000.The root mean square values ( RMS ) of total HOAs, total coma ( TC ) , total trefoil ( TT ) and total spherical aberration ( TS) and Zernike terms of Z3-1 , Z3 1 , Z3-3 , Z3 3 , Z4 0 of a pupil with a diameter of 6mm were recorded to calculate the

  10. Odor Identification Screening Improves Diagnostic Classification in Incipient Alzheimer’s Disease

    Science.gov (United States)

    Quarmley, Megan; Moberg, Paul J.; Mechanic-Hamilton, Dawn; Kabadi, Sushila; Arnold, Steven E.; Wolk, David A.; Roalf, David R.

    2017-01-01

    Background Measurements of olfaction may serve as useful biomarkers of incipient dementia. Here we examine the improvement in diagnostic accuracy of Alzheimer’s disease (AD) and mild cognitive impairment (MCI) when assessing both cognitive functioning and odor identification. Objective To determine the utility of odor identification as a supplementary screening test in incipient AD. Methods Sniffin’ Sticks Odor Identification Test (SS-OIT) and the Montreal Cognitive Assessment (MoCA) were administered in 262 AD, 174 MCI [150 amnestic (aMCI), and 24 non-amnestic (naMCI)], and 292 healthy older adults (HOA). Results Odor identification scores were higher in HOA relative to MCI or AD groups, and MCI outperformed AD. Odor identification scores were higher in aMCI single domain than aMCI multiple domain. Complementing MoCA scores with the SS-OIT significantly improved diagnostic accuracy of individuals with AD and MCI, including within MCI subgroups. Discussion Odor identification is a useful supplementary screening tool that provides additional information relevant for clinical categorization of AD and MCI, including those who are at highest risk to convert to AD. PMID:27886011

  11. Drought Prediction for Socio-Cultural Stability Project

    Science.gov (United States)

    Peters-Lidard, Christa; Eylander, John B.; Koster, Randall; Narapusetty, Balachandrudu; Kumar, Sujay; Rodell, Matt; Bolten, John; Mocko, David; Walker, Gregory; Arsenault, Kristi; Rheingrover, Scott

    2014-01-01

    The primary objective of this project is to answer the question: "Can existing, linked infrastructures be used to predict the onset of drought months in advance?" Based on our work, the answer to this question is "yes" with the qualifiers that skill depends on both lead-time and location, and especially with the associated teleconnections (e.g., ENSO, Indian Ocean Dipole) active in a given region season. As part of this work, we successfully developed a prototype drought early warning system based on existing/mature NASA Earth science components including the Goddard Earth Observing System Data Assimilation System Version 5 (GEOS-5) forecasting model, the Land Information System (LIS) land data assimilation software framework, the Catchment Land Surface Model (CLSM), remotely sensed terrestrial water storage from the Gravity Recovery and Climate Experiment (GRACE) and remotely sensed soil moisture products from the Aqua/Advanced Microwave Scanning Radiometer - EOS (AMSR-E). We focused on a single drought year - 2011 - during which major agricultural droughts occurred with devastating impacts in the Texas-Mexico region of North America (TEXMEX) and the Horn of Africa (HOA). Our results demonstrate that GEOS-5 precipitation forecasts show skill globally at 1-month lead, and can show up to 3 months skill regionally in the TEXMEX and HOA areas. Our results also demonstrate that the CLSM soil moisture percentiles are a goof indicator of drought, as compared to the North American Drought Monitor of TEXMEX and a combination of Famine Early Warning Systems Network (FEWS NET) data and Moderate Resolution Imaging Spectrometer (MODIS)'s Normalizing Difference Vegetation Index (NDVI) anomalies over HOA. The data assimilation experiments produced mixed results. GRACE terrestrial water storage (TWS) assimilation was found to significantly improve soil moisture and evapotransportation, as well as drought monitoring via soil moisture percentiles, while AMSR-E soil moisture

  12. Evaluation of repeatability of higher-order aberrations measurement, in pseudophakic eyes by I-Trace wavefront analyzer%i-Trace像差分析仪在人工晶体眼高阶像差测量的可重复性研究

    Institute of Scientific and Technical Information of China (English)

    徐力; 刘奕志; 何明光; 柳夏玲; 曾明兵

    2008-01-01

    Objective To assess the repeatability in measuring higher-order aberrations (HOAs) in intraocular lens (IOL)eyes by a ray trace wavefront analyzer. Methods HOAs were consecutively examined 3 times across a 5.0 ram aperture diameter in 47 intraoeular lens (IOL) eyes using a ray trace wavefront analyzer. Root-mean-square (RMS) values of total higher-order aberrations (THOA), total coma-like aberrations (TC), total spherical-like aberrations (TSA) and total trefoil-like aberrations (TT) were recorded. The repeatability of measurements was assessed by Pearson correlation analysis between each pair of measures and the intra-class correlation coefficient (ICC) among the 3 measurements. The mirror symmetry of HOAs between each pair of the eyes was studied using Pearson correlation analysis. Results In IOL eyes HOAs measurements, all ICC>.73 (P .57 (P 0.05). But the mean RMS values of THOA,TT had low correlation between right and left eyes. Conclusions The repeatability of i-Trace wavefi'ont analyzer in measuring HOAs in IOL eyes is better. There have good symmetry in the TSA mean RMS values between fight and left eyes, while the mean RMS values of THOA, TC and TT have bad symmetry between right and left eyes.%目的 评价i-Trace波前像差分析仪测量人工晶体眼高阶像差的可重复性.方法 随机选取47只人工晶体眼,连续3次测量5.0mm扫描直径下高阶像差,包括总高阶像差(THOA),总慧差(TC),总球差(TSA),总三叶草(TT),以均方根(RMS)表示.3次测量的可重复性用组间相关系数(ICC)评价,两次测量间的重复性以Pearson相关系数评价.用Pearson相关系数分析左右眼高阶像差的对称性.结果 高阶像差测量3次测量ICC均大于0.73(P<0.01),两次测量间Pearson相关系数r均大于0.57(P<0.01).双眼RMS值对称性分析,左右眼TSA有相关性,而THOA、TC、TT无相关性.结论 i-Trace像差分析仪在人工晶体眼高阶像差测量的可重复性较强.TSA的RMS值双眼对称性显著,而THOA、TC、TT双眼对称性较差.

  13. Assessing the impact of landuse change, climate change and reservoirs on suspended sediment load in Da river (China-Vietnam)

    Science.gov (United States)

    Van Thinh, Le; Soncini, Andrea; Bocchiola, Daniele; Ranzi, Roberto; Rulli, Maria Cristina

    2016-04-01

    Sediment issues have critical implications for aquatic ecology, agriculture, water supply and river navigation. Recently, with the construction and operation of several reservoirs in Da river basin (China-Vietnam), such as Hoa Binh, Lai Chau, Son La and so on, this issue has risen high interest and concern. Reservoirs have been built to meet several important needs, including increasing energy, irrigation, and drinking water demand. However, the decision maker should pay attention to the effects on sediment load, namely trapping of sediments, reduction of sediment concentration downstream reservoirs, increasing riverbank erosion, and localized erosion nearby hydraulic structures. In addition, land use changes, and climate changes are also to be considered as causing effect on sediment erosion and transport. The aim of this work is to evaluate the effects of separate factors (reservoirs, land use change, and climate change) on sediment load in the Da river basin. To this purpose, an updated and enhanced version of the soil erosion and transport model at the catchment scale, namely DIMOSHONG_RUSLE is applied to the Da river basin. More than 50 years of monthly precipitation, runoff and suspended sediment load data are processed. Two historical (1983, 2000) land use maps were generated based on statistic data of the government. The effect of land use change, and reservoirs is assessed on the basis of trends observed in the last decades. To develop the DIMOSHONG_RUSLE model in the period 1961-1985 with land use 1983 (before Hoa Binh reservoir was constructed completely) an updated version of the parameters of the RUSLE equation is determined according to the space variability on the soil types base on experimental data. Then, using chosen optimized parameter of RUSLE, suspended sediment load for the period 1986-2005 (with the Hoa Binh reservoir built and in operation) corresponding with land use in 2000 are calculated. The results are in good agreement with observed

  14. SMILE术后角膜前表面非球面性与角膜高阶像差的关系%The correlation between corneal asphericity and higher order aberrations after SMILE surgery

    Institute of Scientific and Technical Information of China (English)

    苏小连; 王雁

    2014-01-01

    Objective To evaluate the characteristics of anterior corneal asphericity and higher order aberrations after SMILE surgery,and to analyze the correlation between them.Methods In this prospective study,41 subjects who underwent SMILE surgery were enrolled with right eyes selected for the study.The asphericity coefficient Q-value at diameters of 6,7,8 and 9 mm and total higher order aberrations (HOA),spherical aberrations (Z40),secondary spherical aberrations (Z60),vertical coma (Z3-1),horizontal coma (Z31),y-trefoil (Z3-3) and x-trefoil (Z33) of the cornea were measured before surgery and 3 months following the surgery.A paired-samples t test and Pearson correlation were used for analysis.Results All Q-values increased from negative to positive after SMILE surgery and the differences were statistically significant (t=-23.558,-26.661,-28.366,-28.788,P<0.01).Corneal HOA,Z40,Z60,Z3-1 and Z31 increased and the differences were statistically significant as well (t=-11.815,-11.813,-16.209,6.470,4.835,P<0.01).However,the change in Z3-3 or Z33 was not significant (t=0.278,-1.064,P>0.05).Among corneal higher order aberrations,a linear correlation was found between the Q-value and corneal HOA,Z40 and Z3-t before surgery (P<0.05).The change in corneal HOA and Z40 had a positive linear correlation with the Q-value at each diameter (HOA:r=0.554,0.480,0.416,0.352,P<0.05; Z40:r=0.671,0.577,0.495,0.395,P<0.05).The difference in Z3-1 had a positive linear correlation with the Q-values at diameters 6 and 7 mm (r=0.377,0.342,P<0.05).The difference in Z31 had a positive linear correlation with the Q-values at diameters 6,7 and 8 mm (r=0.436,0.385,0.316,P<0.05).No linear correlation was found between the changes in the Q-values at each diameter and those of Z3 3,Z33 or Z60 (P>0.05).There was not a linear correlation between the change in the Q-values and lens diameter (P>0.05).Lens diameter had a negative linear correlation with the changes in HOA and Z40 (r=-0

  15. Chilean Euphorbiaceae species as sources of fuels and raw chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Gnecco, S.; Bartulin, J.; Marticorena, C.; Ramirez, A.

    1988-01-01

    The potential of some species of Chilean Euphorbiaceae as sources of hydrocarbon-like materials was evaluated. Samples of plants excluding roots, were analyzed for CH/sub 2/Cl/sub 2/ extractives, resins and hydrocarbons. The presence of waxes and natural rubber (cis-1,4-polyisoprene) was confirmed using spectroscopic and chromatographic methods. C/H values for representative fractions were calculated and extracted samples from selected species analyzed for apparent protein contents. Results suggested that at least two species, Euphorbia lactiflua and Euphorbia copiapina might have an industrial potential.

  16. Arctic Aerosols and Sources

    DEFF Research Database (Denmark)

    Nielsen, Ingeborg Elbæk

    2017-01-01

    winter and spring explained by expansion of the polar dome enabling long-range transport of aerosols from source regions outside the Arctic. This phenomenon is better known as the Arctic haze. Contrary, the summer and fall concentrations were lower due to the retreat of the polar dome. These seasonal...... species. The aerosol concentration decreased during spring as the Arctic haze leveled off. A source apportionment analysis showed that three factors were contributing to organic aerosols. A hydrocarbon-like organic aerosol factor was assigned to fossil fuel combustion and a second factor, less oxygenated...

  17. Characterization of indoor aerosol temporal variations for the real-time management of indoor air quality

    Science.gov (United States)

    Ciuzas, Darius; Prasauskas, Tadas; Krugly, Edvinas; Sidaraviciute, Ruta; Jurelionis, Andrius; Seduikyte, Lina; Kauneliene, Violeta; Wierzbicka, Aneta; Martuzevicius, Dainius

    2015-10-01

    The study presents the characterization of dynamic patterns of indoor particulate matter (PM) during various pollution episodes for real-time IAQ management. The variation of PM concentrations was assessed for 20 indoor activities, including cooking related sources, other thermal sources, personal care and household products. The pollution episodes were modelled in full-scale test chamber representing a standard usual living room with the forced ventilation of 0.5 h-1. In most of the pollution episodes, the maximum concentration of particles in exhaust air was reached within a few minutes. The most rapid increase in particle concentration was during thermal source episodes such as candle, cigarette, incense stick burning and cooking related sources, while the slowest decay of concentrations was associated with sources, emitting ultrafine particle precursors, such as furniture polisher spraying, floor wet mopping with detergent etc. Placement of the particle sensors in the ventilation exhaust vs. in the centre of the ceiling yielded comparable results for both measured maximum concentrations and temporal variations, indicating that both locations were suitable for the placement of sensors for the management of IAQ. The obtained data provides information that may be utilized considering measurements of aerosol particles as indicators for the real-time management of IAQ.

  18. Comparison of higher order aberrations and modulation transfer function with different intraocular lens to normal young phakic eyes%人工晶状体眼与正常年轻人眼高阶像差及调制传递函数对比分析

    Institute of Scientific and Technical Information of China (English)

    姜丽丽; 马忠旭; 王新; 高原; 孙龙格

    2014-01-01

    Objective To compare higher order aberrations (HOAs) and modulation transfer function (MTF) with postoperative cataract phacoemulsification and intraocular lens implantation with different IOLs to normal younger phakic eyes.Methods Base on spherical aberration of IOLs,the 80 cases (98 eyes) were divided into three groups:group Ⅰ spherical IOLs HQ201HEP,group Ⅱ aspheric IOL with zero aberration Akreos AO and group Ⅲ aspheric IOLs with negative aberration Tecnis ZA9003.Normal young phakic eyes were group ⅣV.Compute higher order aberrations and modulation transfer function of the patients of 3-month follow-up after cataract surgery and normal younger phakic eyes.Results Spherical aberration of four groups had statistically significant differences (P <0.05),except group Ⅲ and group ⅣV.The difference of coma between intraocular lens and normal young phakic eyes was statistically significant (P <0.05) while the differences between the different intraocular lens were no statistically significant (P >0.05).Total HOAs of four groups had statistically significant differences (P <0.05),except group Ⅰ and group Ⅱ.MTF(HOA) of eyes with intraocular lens was lower than normal young phakic eyes and the difference was statistically significant (P< 0.0083).MTF(HOA) of the three groups with different intraocular lens also had statistically significant differences (P <0.0083).Conclusions Aspheric IOLs can significantly reduce the spherical aberration and improve postoperative visual quality of the patients,especially the aspheric IOLs with negative sPherical aberration.However,there are differences between aspheric IOLs and normal young phakic eyes.%目的 比较白内障超声乳化吸除术后植入不同人工晶状体(IOL)眼与正常年轻人晶状体眼的高阶像差(HOAs)和调制传递函数(MTF).方法 回顾性病例系列研究.对于2012年4月至2013年1月在天津市眼科医院白内障中心行白内障超声乳化联合IOL植入术的80

  19. 高阶像差对人工晶状体眼调制传递函数的作用分析%Effect of higher-order aberration on modulation transfer function in eyes implanted with intraocular lens

    Institute of Scientific and Technical Information of China (English)

    甄小妹; 马忠旭; 刘汝瑜; 张娜

    2012-01-01

    Objective To analyze higher-order aberration,modulation transfer function (MTF)and the changes of MTF value with or without different mode higher-order aberration in eyes implanted with two different types of intraocular lens (IOL) at 6mm pupil diameter. Methods A total of 80 eyes (74 patients) were divided into two groups randomly.Group I implanted with Akreos AO IOL,Group Ⅱ implanted with Tecnis ZA9003 IOL.The iTrace was used to measure higher-order aberrations,MTF value of total higher-order aberration (tHOA),MTF value without different Zernike mode (C3-3~C3+3,C40) and different mode of higher-order aberration (S3,S4,S5).The independent samples t test and paired-t test was used to assess the data. Results ①The spherical aberration C40of total eyes was significantly different between the two groups,while the tHOA was not.The MTF value without C40 was not significantly different while the MTF (tHOA) and the MTF value without C3-3~C3+3 respectively was significantly different between the two groups at 6mm pupil diameter.②In group,the MTF value improved at (5~30) cycle per degree (c/d) without C3-3~C3+3,C40 respectively and the MTF value got the most improvement without C40; while in group Ⅱ,the MTF value improved at (5~30) c/d without C3-3~C3+3 respectively and there was no significantly improvement of MTF value without C40 at (5~30) c/d,the MTF value got the most improvement without C3-3.③In group Ⅰ,the MTF value improved at (5~30) c/d without S3,S4 respectively and improved at (5~10) c/d without S5.The MTF value without S3,S4 respectively increased more than without S5;while in group Ⅱ,the MTF value got the most improvement at (5~30) c/d without S3. Conclusions The MTF (tHOA) is different between the two groups,and the spherical aberration C40 is responsible for the difference.C40 and S4,S3 show a more significant effect in the eyes implanted with Akreos AO IOL,vertical trefoil C3-3 and S3 show a more significant effect in the

  20. Photorefractive keratectomy combined with corneal wavefront-guided and hyperaspheric ablation profiles to correct myopia.

    Science.gov (United States)

    Lee, Hun; Park, Si Yoon; Yong Kang, David Sung; Ha, Byoung Jin; Choi, Jin Young; Kim, Eung Kweon; Seo, Kyoung Yul; Kim, Tae-Im

    2016-06-01

    To evaluate the effects of photorefractive keratectomy (PRK) combined with corneal wavefront-guided ablation profiles and hyperaspheric ablation profiles on changes in higher-order aberrations (HOAs). Yonsei University College of Medicine and Eyereum Clinic, Seoul, South Korea. Comparative observational case series. Medical records of patients who had corneal wavefront-guided hyperaspheric PRK, corneal wavefront-guided mild-aspheric PRK, or non-corneal wavefront-guided mild-aspheric PRK were analyzed. The logMAR uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent (MRSE), and changes in corneal aberrations (root-mean-square [RMS] HOAs, spherical aberration, coma) were evaluated 1, 3, and 6 months postoperatively. The records of 61 patients (96 eyes) were reviewed. There was no statistically significant difference in logMAR UDVA or MRSE between the 3 groups at any timepoint. Corneal RMS HOAs were significantly smaller in the corneal wavefront-guided hyperaspheric group and the corneal wavefront-guided mild-aspheric group than in the noncorneal wavefront-guided mild-aspheric group at each timepoint. Corneal spherical aberration was significantly smaller for corneal wavefront-guided hyperaspheric PRK than for noncorneal wavefront-guided mild-aspheric PRK 6 months postoperatively. Changes in corneal spherical aberration (preoperatively and 6 months postoperatively) in corneal wavefront-guided hyperaspheric PRK were significantly smaller than in corneal wavefront-guided mild-aspheric PRK (P = .046). Corneal coma was significantly smaller with corneal wavefront-guided hyperaspheric PRK and corneal wavefront-guided mild-aspheric PRK than with noncorneal wavefront-guided mild-aspheric PRK 3 months and 6 months postoperatively. Corneal wavefront-guided hyperaspheric PRK induced less corneal spherical aberration 6 months postoperatively than corneal wavefront-guided mild-aspheric PRK and noncorneal wavefront-guided mild-aspheric PRK

  1. Long-term outcomes of limbal relaxing incisions during cataract surgery: aberrometric analysis

    Directory of Open Access Journals (Sweden)

    Monaco G

    2015-08-01

    Full Text Available Gaspare Monaco, Antonio ScialdoneDepartment of Ophthalmology, Ospedale Fatebenefratelli e Oftalmico, Milan, ItalyPurpose: To compare the final changes in corneal wavefront aberration by limbal relaxing incisions (LRIs after cataract surgery.Methods: This prospective cumulative interventional nonrandomized case study included cataract and astigmatic patients undergoing LRIs and phaco with intraocular lens implantation. LRIs were planned using Donnenfeld nomogram. The root mean square of corneal wave aberration for total Z(n,i(1≤n≤8, astigmatism Z(2,±1, coma Z(3–5–7,±1, trefoil Z(3–5–7,±2, spherical Z(4–6–8,0, and higher-order aberration (HOA Z(3≤n≤8 was examined before and 3 years after surgery (optical path difference-Scan II [OPD-Scan II]. Uncorrected distance visual acuity and best-corrected distance visual acuity (CDVA for distance, keratometric cylinder, and variations in average corneal power were also analyzed.Results: Sixty-four eyes of 48 patients were included in the study. Age ranged from 42 to 92 years (70.6±8.4 years. After LRIs, uncorrected distance visual acuity and best-corrected distance visual acuity improved statistically (P<0.01. The keratometric cylinder value decreased by 40.1%, but analysis of KP90 and KP135 polar values did not show any decrease that could be statistically confirmed (P=0.22 and P=0.24. No significant changes were detected in root mean square of total (P=0.61 and HOAs (P=0.13 aberrations. LRIs did not induce alteration in central corneal power confirming a 1:1 coupling ratio.Conclusion: LRIs determined a nonsignificant alteration of corneal HOA. Therefore, LRIs can be still considered a qualitatively viable mean in those cases where toric intraocular lenses are contraindicated or not available. Yet, the authors raise the question of nonpersonalized nomograms, as in the present study, LRIs did not reach the preset target cylinder. Keywords: astigmatism, ocular wavefront, intraocular

  2. Basical characteristics of fluid geologic process of interlayer oxidation zone sandstone-typeuranium deposit

    Institute of Scientific and Technical Information of China (English)

    WU; BoLin; LIU; ChiYang; WANG; JianQiang

    2007-01-01

    This paper reveals the physicochemical properties such as component, formulation, genesis, tem- perature, pH, Eh, salinity and pressure of all main alteration fluid of interlayer oxidation zone sand- stone-type uranium deposits after studying the geologic process and geochemistry of internal typical sandstone-type uranium deposits such as Shihongtan deposit in the Turpan-Hami basin, 512 deposit in the Yili basin, Dongsheng deposit in the Ordos basin. The composition of fluid can be divided into two parts based on the analysis of inclusion: one can be affirmed as atmospheric water with ordinary temperature epigenesist according to the character of hydrogen and oxygen isotope of inclusion, the other is natural gas containing gaseous hydrocarbon like CH4, and CO2 as well as a little H2S, CO, H2, N2 and so on, it always contains a small quantity of hydrocarbon liquid in petroliferous basins. The fluid property of oxidation alteration zone is always oxidation alkaline, and neutrality or weak acid-weak alkaline and reducibility during the metallizing process, but at secondary reduction or deoxidization zone it becomes strong reduction alkaline. Oxygenic groundwater in the fluid is the activate and mig- ratory medium of uranium element, but the gaseous hydrocarbon like CH4 as well as H2, H2S, CO from natural gas is the important sedimentary reducer of uranium mineral; the transformation of pH,Eh in fluid environment is the main reason for the formation of uranium metallization.

  3. Catalytic production of aromatics and olefins from plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Haag, W.O.; Rodewald, P.G.; Weisz, P.B.

    1980-08-01

    Hydrocarbons and hydrocarbon-like plant materials offer the possibility of relatively simple and energy-efficient processing to liquid fuels or petrochemicals. The use of such highly reduced photosynthesis products as potential fuels has been advocated by Calvin and coworkers, and Buchanan and coworkers have evaluated several hundred plant species for the presence of hydrocarbons. The yield of extracted oils may exceed 10 wt % of the plant dry weight. Some field growth studies of the most promising of these plants are underway, e.g., by Calvin in California, by Native Plants, Inc., and by the Diamond Shamrock Co., in conjunction with the University of Arizona, mostly with Euphorbia and related genera. Exploratory studies were performed to determine if direct catalytic upgrading of the hydrocarbon-like plant constituents could be carried out. A preliminary report has been published recently. A variety of plant materials were shown to be upgraded to liquid premium fuels by relatively simple catalytic processing over Mobil's shape selective zeolite, ZSM-5. The present paper contains additional information on the conversion of a variety of plant materials with special emphasis on the production of petrochemicals, and discusses key mechanistic aspects of the reactions. Feedstocks were chosen to represent different types of plant materials: corn oil, castor oil and jojoba seed oil; plant extracts from Euphorbia lathyrus and Grindelia squarrosa; and hydrocarbons obtained by tapping of trees such as copaiba oil and natural rubber latex.

  4. Single particle characterization using a light scattering module coupled to a time-of-flight aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    E. S. Cross

    2008-12-01

    Full Text Available We present the first single particle results obtained using an Aerodyne time-of-flight aerosol mass spectrometer coupled with a light scattering module (LS-ToF-AMS. The instrument was deployed at the T1 ground site approximately 40 km northeast of the Mexico City Metropolitan Area (MCMA as part of the MILAGRO field study in March of 2006. The instrument was operated as a standard AMS from 12–30 March, acquiring average chemical composition and size distributions for the ambient aerosol, and in single particle mode from 27–30 March. Over a 75-h sampling period, 12 853 single particle mass spectra were optically triggered, saved, and analyzed. The correlated optical and chemical detection allowed detailed examination of single particle collection and quantification within the LS-ToF-AMS. The single particle data enabled the mixing states of the ambient aerosol to be characterized within the context of the size-resolved ensemble chemical information.

    The particulate mixing states were examined as a function of sampling time and most of the particles were found to be internal mixtures containing many of the organic and inorganic species identified in the ensemble analysis. The single particle mass spectra were deconvolved, using techniques developed for ensemble AMS data analysis, into HOA, OOA, NH4NO3, (NH42SO4, and NH4Cl fractions. Average single particle mass and chemistry measurements are shown to be in agreement with ensemble MS and PTOF measurements. While a significant fraction of ambient particles were internal mixtures of varying degrees, single particle measurements of chemical composition allowed the identification of time periods during which the ambient ensemble was externally mixed. In some cases the chemical composition of the particles suggested a likely source. Throughout the full sampling period, the ambient ensemble was an external mixture of combustion

  5. Volk FLD. Camp Douglas, Wisconsin. Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F

    Science.gov (United States)

    1970-08-03

    TI~ HOa 9L.L 3, 6r NW Q 󈧞t s 95 1 .ON11 70 TOA NUBE Of OBSERVATIONS NNE 4 ~. - _ __ _ __ __ 4307 NE ~ j ~ -~~ __ ___1.8 ENAF ETA jv .±L 0-- - --1...34:.-++,,,. i Zt I 3M 240 0 07, 004 4. 4+ TOA NUBE OF OBERATON ,FORM USAF < TA -~ ,4 0-. (OW P +~ umc"s ,o +;.THIS ++ J:AAR & . t...34~~~- " , " -" 4 CAVA, -. , , .. 5,64 12 to, , + fi _ k JO NUBE Of OBSERVATIONS" • + . + *..,.+. ?. ,, ; ,.2 0 • ’-m A USAF~:,.’, ,ET.A+ 0--5OL1 "yt" mm o

  6. Effects of Fatty Acid Inclusion in a DMPC Bilayer Membrane

    DEFF Research Database (Denmark)

    Peters, Günther H.J.; Hansen, Flemming Yssing; Møller, Martin S.

    2009-01-01

    Free fatty acids in biomembranes have been proposed to be a central component in several cellular control and regulatory mechanisms. To elucidate some fundamental elements underlying this, we have applied molecular dynamics simulations and experimental density measurements to study the molecular...... packing and structure of oleic acid (HOA) and stearic acid (HSA) in fluid bilayers of dimyristoylphosphatidylcholine (DMPC). The experimental data show a small but consistent positive excess volume for fatty acid concentrations below 10 mol %. At higher concentrations the fatty acids mix ideally...... with fluid DMPC. The simulations, which were benchmarked against the densitometric data, revealed interesting differences in the structure and location of the fatty acids depending on their protonation status. Thus, the protonated (uncharged) acid is located rather deeply in the membrane with an average...

  7. Rheumatic manifestations of primary and metastatic bone tumors and paraneoplastic bone disease.

    Science.gov (United States)

    Waimann, Christian A; Lu, Huifang; Suarez Almazor, Maria E

    2011-11-01

    Bone tumors can show a wide range of nonspecific rheumatic manifestations. The presence of unexplained or atypical chronic bone pain, an enlarging bone mass, neurovascular compression syndromes, or pathologic fractures should alert us to the possibility of a bone tumor causing these symptoms. These patients must undergo a complete physical examination; adequate imaging; and, if needed, a biopsy to confirm their diagnosis and offer them an opportune treatment. In addition, bone tumors and other malignancies can present remote clinical manifestations and unusual laboratory findings (eg, HOA, hypophosphatemia, hyperphosphaturia, and hypercalcemia) that may be the first and early manifestation of an occult cancer. These findings should motivate a cancer screening according to age, sex, and personal history. Cancer therapies also have a big impact on bone health, increasing the risk of osteoporosis, osteomalacia, and/or osteonecrosis. Rheumatologists should be aware of possible long-term adverse events of cancer treatment to avoid future complications.

  8. Cosmological Attractor Models and Higher Curvature Supergravity

    CERN Document Server

    Cecotti, Sergio

    2014-01-01

    We study cosmological $\\alpha$-attractors in superconformal/supergravity models, where $\\alpha$ is related to the geometry of the moduli space. For $\\alpha=1$ attractors \\cite{Kallosh:2013hoa} we present a generalization of the previously known manifestly superconformal higher curvature supergravity model \\cite{Cecotti:1987sa}. The relevant standard 2-derivative supergravity with a minimum of two chiral multiplets is shown to be dual to a 4-derivative higher curvature supergravity, where in general one of the chiral superfields is traded for a curvature superfield. There is a degenerate case when both matter superfields become non-dynamical and there is only a chiral curvature superfield, pure higher derivative supergravity. Generic $\\alpha$-models \\cite{Kallosh:2013yoa} interpolate between the attractor point at $\\alpha=0$ and generic chaotic inflation models at large $\\alpha$, in the limit when the inflaton moduli space becomes flat. They have higher derivative duals with the same number of matter fields as...

  9. Analysis of corneal high order aberrations in eyes with subclinical keratoconus%亚临床期圆锥角膜眼角膜高阶像差分析

    Institute of Scientific and Technical Information of China (English)

    马代金; 罗丽佳; 蔡望; 朱睿玲

    2013-01-01

    目的:分析亚临床期圆锥角膜的角膜高阶像差特点,为圆锥角膜的诊断提供理论依据.方法:亚临床期圆锥角膜患者26例43眼作为可疑圆锥角膜(keratoconus suspect,KCS)组,平均年龄25.32±4.18岁;选取同时期检查的近视眼30例60眼作为对照组,平均年龄24.63±4.82岁,用OPD Scan ARK-10000分别测量两组患者中央直径3mm和6mm角膜前表面的3~6阶总高阶像差(HOAs)、总彗差(TC)、总三叶草(TT)、总球差(TS)均方根值,用t检验进行统计分析.结果:直径3 mm时KCS组角膜的HOAs,TC,TT,TS分别为0.424±0.175μm,0.113±0.068μm,0.262±0.132μm,0.016±0.010μm;对照组为0.310±0.093μm,0.070±0.038μm,0.244±0.106μm,0.019±0.016μm;KCS组的HOAs和TC明显增加,差异有统计学意义(t=3.896,3.748;P=0.000,0.ooo),两组的TT和TS差异无统计学意义(t=0.740,1.169;P=0.231,0.124);6mm直径时KCS组角膜的HOAs,TC,TF,TS分别为0.987±0.292μm,0.642±0.260μm,0.487±0.208μm,0.292±0.145μm;对照组为0.587±0.146μm,0.252±0.113μm,0.337±0.182μm,0.271 ±0.065 μm;KCS组的HOAs,TC和TT显著增加,差异有统计学意义(t=8.273,9.231,3.800;P=0.000,0.000,0.000),两组的TS差异无统计学意义(t=0.888,P=0.191).结论:亚临床期圆锥角膜的角膜高阶像差明显增加,以彗差增加为主,角膜高阶像差的检查有助于亚临床期圆锥角膜的诊断.

  10. Study on energy up-conversion in Yb, Ho:YAG crystal

    Institute of Scientific and Technical Information of China (English)

    Lilei Huang(黄莉蕾); Liangneng Wu(邬良能); Yanbin Fu(付晏彬)

    2003-01-01

    Optic parameters, such as the probabilities of radiative and non-radiative transition and the cross-relaxation probability between Yb3+ and Hoa+ ions in Yb,Ho:YAG crystal, are calculated on the basis ofJudd-Ofelt and Dexter theories. The energy up-conversion process is analyzed by solving the transitionrate-equations. The results show that (1) the intensity of the green fluorescence relates to the square ofthe concentration of the active ions; (2) the intensity increases with the concentration of sensitive ions aswell, but the increasing rate goes rather too slow; (3) the efficiency of the energy up-conversion relateswith the speed of the energy up-conversion and the quantum efficiency of the transiting from upper levelto lower level.

  11. Opto-mechanical artificial eye with accommodative ability.

    Science.gov (United States)

    Esteve-Taboada, José J; Del Águila-Carrasco, Antonio J; Marín-Franch, Iván; Bernal-Molina, Paula; Montés-Micó, Robert; López-Gil, Norberto

    2015-07-27

    The purpose of this study was to describe the design and characterization of a new opto-mechanical artificial eye (OMAE) with accommodative ability. The OMAE design is based on a second-pass configuration where a small source of light is used at the artificial retina plane. A lens whose focal length can be changed electronically was used to add the accommodation capability. The changes in the OMAE's aberrations with the lens focal length, which effectively changes the accommodative state of the OMAE, were measured with a commercial aberrometer. Changes in power and aberrations with room temperature were also measured. The OMAE's higher-order aberrations (HOAs) were similar to the ones of the human eye, including the rate at which fourth-order spherical aberration decreased with accommodation. The OMAE design proposed here is simple, and it can be implemented in an optical system to mimic the optics of the human eye.

  12. Prevalence and first genotyping of Giardia duodenalis in beef calves in Vietnam.

    Science.gov (United States)

    Nguyen, Sam Thi; Fukuda, Yasuhiro; Nguyen, Duc Tan; Tada, Chika; Nakai, Yutaka

    2016-04-01

    Little information is available on the epidemiology of Giardia duodenalis in beef cattle from Vietnam. This study was performed to determine the prevalence and genotypes/assemblages of G. duodenalis in native beef calves younger than 6 months in the region. A total of 412 calf fecal samples, randomly selected from 99 small-scale farms located in DacLac and KhanhHoa provinces, central Vietnam, were screened for the presence of G. duodenalis cysts using the zinc-sulfate flotation method followed by iodine staining. The overall prevalence on the sample and herd levels were 13.8% (57/412) and 42.4% (42/99), respectively. Molecular analysis in the β-giardin and triosephosphate isomerase genes demonstrated the presence of only G. duodenalis assemblage E in the animals. Since assemblage E has been rarely reported in humans, the zoonotic risk in beef calves in the region appears to be minimal.

  13. Molecular identification of Fasciola spp. (Digenea: Platyhelminthes in cattle from Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen S.

    2012-02-01

    Full Text Available Fasciola spp. were collected from naturally infected cattle at a local abattoir of Khanh Hoa province, Vietnam, for morphological and genetic investigations. Microscopic examination detected no sperm cells in the seminal vesicles, suggesting a parthenogenetic reproduction of the flukes. Analyses of sequences from the first and second internal transcribed spacers (ITS1 and ITS2 of the ribosomal RNA revealed that 13 out of 16 isolates were of Fasciola gigantica type, whereas three isolates presented a hybrid sequence from F. gigantica and Fasciola hepatica. Interestingly, all the mitochondrial sequences (partial COI and NDI were of F. gigantica type, suggesting that the maternal lineage of the hybrid form is from F. gigantica. No intra-sequence variation was detected.

  14. 越南Dak Lak公司新建橡胶丝工厂

    Institute of Scientific and Technical Information of China (English)

    缘耶

    2011-01-01

    越南多乐(Dak Lak)橡胶丝公司在越南中部地区的和富(Hoa Phu)工业园新建的橡胶丝线厂开工运营,投资总额约为1700亿越南盾(约合860万美元),年产能达4000吨。该工厂的产品将用来织造松紧带,供应海外和国内服装业市场,这将最大限度地减少对泰国和马来西亚的进口依赖。

  15. Flexible and adaptive water systems operations through more informed and dynamic decisions

    Science.gov (United States)

    Castelletti, A.; Giuliani, M.

    2016-12-01

    Timely adapting the operations of water systems to be resilient against rapid changes in both hydroclimatic and socioeconomic forcing is generally recommended as a part of planning and managing water resources under uncertain futures. A great opportunity to make the operations more flexible and adaptive is offered by the unprecedented amount of information that is becoming available to water system operators, providing a wide range of data at increasingly higher temporal and spatial resolution. Yet, many water systems are still operated using very simple information systems, typically based on basic statistical analysis and the operator's experience. In this work, we discuss the potential offered by incorporating improved information to enhance water systems operation and increase their ability of adapting to different external conditions and resolving potential conflicts across sectors. In particular, we focus on the use of different variables associated to different dynamics of the system (slow and fast) diversely impacting the operating objectives on the short-, medium- and long-term. The multi-purpose operations of the Hoa Binh reservoir in the Red River Basin (Vietnam) is used to demonstrate our approach. Numerical results show that our procedure is able to automatically select the most valuable information for improving the Hoa Binh operations and mitigating the conflict between short-term objectives, i.e. hydropower production and flood control. Moreover, we also successfully identify low-frequency climate information associated to El-Nino Southern Oscillation for improving the performance in terms of long-term objectives, i.e. water supply. Finally, we assess the value of better informing operational decisions for adapting the system operations to changing conditions by considering different climate change projections.

  16. Forward light scatter and visual acuity before and after intrastromal corneal ring segment implantation at different stages of keratoconus.

    Science.gov (United States)

    Puell, María Cinta; Carballo-Álvarez, Jesús

    2016-12-01

    To assess forward light scatter (stray light) before and after intrastromal corneal ring segment (ICRS) implantation at different stages of keratoconus and to examine correlation between postoperative stray light and visual acuity (VA). In 27 eyes of 27 subjects with keratoconus, stray light was determined using the compensation comparison technique before and 6 months after ICRS implantation. Monocular corrected distance VA (CDVA) was measured using a high-contrast logMAR letter chart. Corneal higher-order aberrations (HOAs), contrast sensitivity (CS) and minimum corneal thickness (CT) were also measured. Mean CDVA was 0.42 ± 0.28 preoperatively and 0.24 ± 0.15 logMAR postoperatively (p  0.05) for stage I, 0.13 ± 0.14 (p = 0.013) for stage II and 0.18 ± 0.21 (p = 0.023) for stage III. Significant positive correlation (r = 0.47, p = 0.01) was detected between postoperative stray light and postoperative CDVA such that as stray light increased, CDVA worsened (higher logMAR values). Postoperative stray light was neither associated with HOAs, CS nor minimum CT. Stray light values in these patients with keratoconus were higher than normal preoperatively. In eyes with stage II and III keratoconus, stray light increased 6 months after ICRS placement. Higher postoperative stray light was correlated with a worse visual acuity outcome. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  17. Lipidomic evidence that lowering the typical dietary palmitate to oleate ratio in humans decreases the leukocyte production of proinflammatory cytokines and muscle expression of redox-sensitive genes.

    Science.gov (United States)

    Kien, C Lawrence; Bunn, Janice Y; Fukagawa, Naomi K; Anathy, Vikas; Matthews, Dwight E; Crain, Karen I; Ebenstein, David B; Tarleton, Emily K; Pratley, Richard E; Poynter, Matthew E

    2015-12-01

    We recently reported that lowering the high, habitual palmitic acid (PA) intake in ovulating women improved insulin sensitivity and both inflammatory and oxidative stress. In vitro studies indicate that PA can activate both cell membrane toll-like receptor-4 and the intracellular nucleotide oligomerization domain-like receptor protein (NLRP3). To gain further insight into the relevance to human metabolic disease of dietary PA, we studied healthy, lean and obese adults enrolled in a randomized, crossover trial comparing 3-week, high-PA (HPA) and low-PA/high-oleic-acid (HOA) diets. After each diet, both hepatic and peripheral insulin sensitivities were measured, and we assessed cytokine concentrations in plasma and in supernatants derived from lipopolysaccharide-stimulated peripheral blood mononuclear cells (PBMCs) as well as proinflammatory gene expression in skeletal muscle. Insulin sensitivity was unaffected by diet. Plasma concentration of tumor necrosis factor-α was higher during the HPA diet. Lowering the habitually high PA intake by feeding the HOA diet resulted in lower secretion of interleukin (IL)-1β, IL-18, IL-10, and tumor necrosis factor-α by PBMCs, as well as lower relative mRNA expression of cJun and NLRP3 in muscle. Principal components analysis of 156 total variables coupled to analysis of covariance indicated that the mechanistic pathway for the differential dietary effects on PBMCs involved changes in the PA/OA ratio of tissue lipids. Our results indicate that lowering the dietary and tissue lipid PA/OA ratio resulted in lower leukocyte production of proinflammatory cytokines and muscle expression of redox-sensitive genes, but the relevance to diabetes risk is uncertain.

  18. A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function.

    Science.gov (United States)

    Hatch, Bryndon B; Moshirfar, Majid; Ollerton, Andrew J; Sikder, Shameema; Mifflin, Mark D

    2011-01-01

    To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. At 6 months, mean values for UDVA (logMAR) were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.

  19. Effects of different cutting centers on LASIK surgery in myopic patients

    Directory of Open Access Journals (Sweden)

    Yan-Wei Liu

    2017-07-01

    Full Text Available AIM:To investigate the effect of different cutting centers on the visual acuity, refractive diopter and visual quality of patients undergoing laser assisted in situ keratomileusis(LASIK. METHODS: A total of 80 patients(160 eyeswith myopia treated by elective LASIK were divided into two groups. Thirty-six cases(72 eyeswith visual axis corneal reflection point(VACRPas the cutting center were included into the VACRP group while 44 cases(88 eyeswith pupil center(PCas the cutting center were included into the PC group. The uncorrected visual acuity(UCVA, the best corrected visual acuity(BCVA, refractive diopter, corneal aberration \\〖total corneal and anterior corneal surface higher-order aberrations(HOA, spherical aberration(Z40, vertical coma(Z3-1, horizontal coma(totZ31and offset of cutting centers were determined before surgery and 1mo after surgery. RESULTS: There was no difference in the probability of UCVA ≥ 0.1, BCVA and refractive diopter between the two groups at 1mo after surgery(P>0.05. The astigmatism and cutting center deviation of VACRP group were lower than those of PC group(P40, totZ3-1, totZ31, froHOA, froZ3-1、froZ31 and froZ40 were lower in VACRP group than PC group at 1mo after surgery(PCONCLUSION: The UCVA of patients treated with both cutting centers for LASIK is good but VACRP has more advantages in reducing the offset of cutting center and improving postoperative visual quality.

  20. Transfer method of conducting in the symphony orchestra of the Hanoi National Conservatory of Music, Vietnam

    Directory of Open Access Journals (Sweden)

    Parichat Wiang-in

    2015-11-01

    Full Text Available This is a qualitative designed and conducted with two primary research aims, which were: 1 To study the life and experiences of symphonic orchestra conductors in Hanoi, Vietnam; 2 To study the inheritance process for conductors of the symphonic orchestra in Hanoi, Vietnam. The research area for this investigation was purposively selected as the Vietnam National Academy of Music in Hanoi. The investigation began in October 2012 and was concluded in January 2014. The two key informants for this investigation were expert conductors and teachers at the academy, Dr. Nguyễn Phúc Linh and Dr. Nguyễn Thiếu Hoa. Data was collected from a combination of document analysis and field research. Tools used for data collection included interviews, participant and non-participant observation and focus group discussions. Results show that both of the key informants for this investigation were born into families of artists and had a particularly close relationship with traditional folk art. Scholarships to study abroad at the Tchaikovsky University, Russia enabled them to learn from Russian conductors and they developed the skills that have now led them to be recognized as being among the most accomplished conductors in Vietnam. The process of instruction preferred by these two academics is taught in three steps: the preparation stage, the teaching stage and the assessment and evaluation stage. The benefits of studying with Dr. Nguyễn Phúc Linh and Dr. Nguyễn Thiếu Hoa are the cumulative experiences of international conducting practices and the high standards that the two academics possess and demand.

  1. Effect of end-stage hip, knee, and ankle osteoarthritis on walking mechanics.

    Science.gov (United States)

    Schmitt, Daniel; Vap, Alexander; Queen, Robin M

    2015-09-01

    This study tested the hypothesis that the presence of isolated ankle (A-OA; N=30), knee (K-OA; N=20), or hip (H-OA; N=30) osteoarthritis (OA) compared to asymptomatic controls (N=15) would lead to mechanical changes in the affected joint but also in all other lower limb joints and gait overall. Stride length, stance and swing times, as well as joint angles and moments at the hip, knee, and ankle were derived from 3-D kinematic and kinetic data collected from seven self-selected speed walking trial. Values were compared across groups using a 1×4 ANCOVA, covarying for walking speed. With walking speed controlled, the results indicated a reduction in hip and knee extension and ankle plantar flexion in accordance with the joint affected. In addition, OA in one joint had strong effects on other joints. In both H-OA and K-OA groups the hip never passed into extension, and A-OA subjects significantly changed hip kinematics to compensate for lack of plantar flexion. Finally, OA in any joint led to lower peak vertical forces as well as extension and plantar flexion moments compared to controls. The presence of end-stage OA at various lower extremity joints results in compensatory gait mechanics that cause movement alterations throughout the lower extremity. This work reinforces our understanding of the complex interaction of joints of the lower limb and the importance of focusing on the mechanics of the entire lower limb when considering gait disability and potential interventions in patients with isolated OA.

  2. Corneal tomography and biomechanics in primary pterygium.

    Science.gov (United States)

    Vanathi, M; Goel, Sahil; Ganger, Anita; Agarwal, Tushar; Dada, T; Khokhar, Sudarshan

    2017-05-13

    To study the Scheimpflug's imaging and corneal biomechanics in primary pterygium. A prospective observational study of 55 patients with unilateral primary nasal pterygium was done. The normal fellow eyes of patients with pterygium were taken as controls. Clinical parameters noted included visual acuity, values of corneal curvature by doing Scheimpflug imaging, wavefront aberrations in terms of higher and lower-order aberrations and corneal hysteresis (CH) as well as corneal resistance factor (CRF) values by using ocular response analyzer. Of the total 55 patients, mean age was 43.0 + 11.4 years (range: 20-72 years). Mean LogMar uncorrected visual acuity in pterygium eyes and control eyes was 0.21 + 0.20 and 0.12 + 0.15, respectively (p = 0.016). On Scheimpflug imaging the mean anterior corneal curvature values (Ka1/Ka2 D) were 41.09 + 3.38/44.33 + 2.29 in pterygium eyes, 43.13 + 1.79/43.98 + 2.17 in control eyes (p  0.05). Analysis of corneal aberrations showed significantly higher corneal wavefront aberrations in pterygium eyes. Highest correlation of corneal astigmatism was noted with corneal area encroached by pterygium (ρ = 0.540 for LOA and 0.553 for HOA) and distance from pupillary center (ρ = 0.531 for LOA and 0.564 for HOA). Corneal biomechanical parameters including CH and CRF were found to be lower in the pterygium eyes, though not statistically significant (p value 0.60 and 0.59, respectively). Pterygium leads to deterioration of visual performance not only by causing refractive and topographic changes but also by causing a significant increase in corneal wavefront aberrations.

  3. Assessing water reservoir management and development in Northern Vietnam

    Science.gov (United States)

    Pianosi, F.; Quach, X.; Castelletti, A.; Soncini-Sessa, R.

    2012-04-01

    In many developing countries water is a key renewable resource to complement carbon-emitting energy production and support food security in the face of demand pressure from fast-growing industrial production and urbanization. To cope with undergoing changes, water resources development and management have to be reconsidered by enlarging their scope across sectors and adopting effective tools to analyze current and projected infrastructure potential and operation strategies. In this work we use multi-objective deterministic and stochastic optimization to assess the current reservoir operation and planned capacity expansion in the Red River Basin (Northern Vietnam), focusing on the major controllable infrastructure in the basin, the HoaBinh reservoir on the Da River. We first provide a general and mathematical description of the socio economic and physical system of the Red River Basin, including the three main objectives of hydropower production, flood control, and water supply, and using conceptual and data-driven modeling tools. Then, we analyze the historical operation of the HoaBinh reservoir and explore re-operation options corresponding to different tradeoffs among the three main objectives, using Multi-Objective Genetic Algorithm. Results show that there exist several operating policies that prove Pareto-dominant over the historical one, that is, they can improve all three management objectives simultaneously. However, while the improvement is rather significant with respect to hydropower production and water supply, it is much more limited in terms of flood control. To understand whether this is due to structural constraints (insufficient storing capacity) or to the imperfect information system (uncertainty in forecasting future flows and thus anticipate floods), we assessed the infrastructural system potential by application of Deterministic Dynamic Programming. Results show that the current operation can only be relatively improved by advanced optimization

  4. Mini-scleral Contact Lens for Management of Poor Visual Outcomes after Intrastromal Corneal Ring Segments Implantation in Keratoconus

    Science.gov (United States)

    Alipour, Fatemeh; Rahimi, Firoozeh; Hashemian, Mohammad Naser; Ajdarkosh, Zahra; Roohipoor, Ramak; Mohebi, Masoumeh

    2016-01-01

    Purpose: To evaluate the feasibility and efficacy of mini-scleral design (MSD) contact lenses to treat keratoconus patients who were unsatisfied with the results of corneal inlay. Methods: In this prospective interventional case series, 9 eyes of 6 keratoconus patients who were unsatisfied with the results of corneal inlay were fitted with MSD contact lenses. Demographic data, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and higher order aberrations (HOAs) were evaluated before contact lens fitting. Corrected visual acuity by placing the MSD contact lens with or without over-refraction, and HOAs were measured one hour after contact lens fitting. One month after contact lens wearing, corrected visual acuity by placing the MSD contact lens with over-refraction and possible contact lens related problems were assessed. Ocular comfort and contact lens handling problems were asked in follow-up visits. The data was analyzed using descriptive statistical tests. Results: Nine eyes of 6 patients were successfully fitted with the mini-scleral lens. Fitting was ideal in 7 eyes and acceptable in 2 eyes. Mean corrected visual acuity by placing the MSD lens without over-refraction was 0.09 (range, 0.00-0.15) LogMAR which was significantly better than the mean BSCVA of 0.38 (range, 0.2-0.6) LogMAR (P = 0.007). The mean root mean square (RMS) of third-order coma and trefoil significantly decreased after MSD contact lens fitting (P = 0.012 and P = 0.015, respectively); however, changes in the fourth-order spherical aberration were not statistically significant (P = 0.336). Conclusion: Mini-scleral contact lenses may be helpful in the management of visually unsatisfied patients after corneal inlay. PMID:27621780

  5. Ocean-lagoon water and plankton exchanges in a semi-closed pearl farming atoll lagoon (Ahe, Tuamotu archipelago, French Polynesia)

    Science.gov (United States)

    Pagano, M.; Rodier, M.; Guillaumot, C.; Thomas, Y.; Henry, K.; Andréfouët, S.

    2017-05-01

    In atoll lagoons, plankton richness is highly dependent on water exchange with the ocean through the atoll rim. However, the dynamics of the physical and biological fluxes at the lagoon-ocean interface remain poorly characterized. Here, we studied the combined effects of lagoon-ocean water exchanges and local environmental conditions on the phyto- and zooplankton abundance and community structure across the atoll lagoon rim of Ahe (Tuamotu Archipelago, French Polynesia). Plankton and environmental variables were monitored in May 2013 (i) at several stations inside and outside the lagoon and (ii) during time-series corresponding to ebb-flood tidal cycles in the two types of channels connecting the lagoon to the ocean: at the passage (300 m long and about 11 m deep) and in hoa (i.e reef-flat less than 50 cm depth). Our results highlight tidally-driven selective plankton exchanges between the lagoon and external ocean. Phytoplankton (chlorophyll-a) and zooplankton biomass were respectively 4 times and 7 times higher in the lagoon than at stations outside the atoll lagoon. Copepoda was the dominant zooplankton group at the oceanic station (>75% abundance) whereas meroplankton (with bivalve larvae most common) was dominant at the lagoon stations (54%), in the passage (55-82%) and in hoa (>80%). These differences between sites suggest a loss of bivalve larvae through export to the ocean and retention and/or increased production of copepods in the lagoon. The daily export of bivalve larvae represents a low percentage of the lagoon stock, in agreement with previously published larval dispersal numerical models. The retention of copepods could constitute a significant input of nutrients and organic matter (through excretion, feces release, decomposition, and remineralization) into the lagoon.

  6. ENSO detection and use to inform the operation of large scale water systems

    Science.gov (United States)

    Pham, Vuong; Giuliani, Matteo; Castelletti, Andrea

    2016-04-01

    El Nino Southern Oscillation (ENSO) is a large-scale, coupled ocean-atmosphere phenomenon occurring in the tropical Pacific Ocean, and is considered one of the most significant factors causing hydro-climatic anomalies throughout the world. Water systems operations could benefit from a better understanding of this global phenomenon, which has the potential for enhancing the accuracy and lead-time of long-range streamflow predictions. In turn, these are key to design interannual water transfers in large scale water systems to contrast increasingly frequent extremes induced by changing climate. Despite the ENSO teleconnection is well defined in some locations such as Western USA and Australia, there is no consensus on how it can be detected and used in other river basins, particularly in Europe, Africa, and Asia. In this work, we contribute a general framework relying on Input Variable Selection techniques for detecting ENSO teleconnection and using this information for improving water reservoir operations. Core of our procedure is the Iterative Input variable Selection (IIS) algorithm, which is employed to find the most relevant determinants of streamflow variability for deriving predictive models based on the selected inputs as well as to find the most valuable information for conditioning operating decisions. Our framework is applied to the multipurpose operations of the Hoa Binh reservoir in the Red River basin (Vietnam), taking into account hydropower production, water supply for irrigation, and flood mitigation during the monsoon season. Numerical results show that our framework is able to quantify the relationship between the ENSO fluctuations and the Red River basin hydrology. Moreover, we demonstrate that such ENSO teleconnection represents valuable information for improving the operations of Hoa Binh reservoir.

  7. 屈光手术前个体眼高阶像差与中间视觉状态下瞳孔大小%Ocular higher-order aberrations and mesopic pupil size in individuals screened for refractive surgery

    Institute of Scientific and Technical Information of China (English)

    Seyed Javad Hashemian; Mohammad Soleimani; Alireza Foroutan; Mahmood Joshaghani; Mohammad Jafar Ghaempanah; Mohammad Ebrahim Jafari; Mehdi Yaseri

    2012-01-01

    目的:研究眼高阶像差的分布(HOAs)和mesopic瞳孔的大小在个体中筛选的屈光手术.方法:我们采用Zywave像差分析仪(博士伦)分别对患有近视、近视散光和复性近视散光患者1 240例2 458眼和患有远视、远视散光和复性远视散光患者110例215眼的高阶像差和瞳孔大小进行检测.所有患者屈光不正均可矫正,无屈光手术史或潜在疾病.HOAs的均方根值、总球面像差、总斜射球面像差和中间视觉状态下瞳孔的大小进行了分析,眼高阶像差测量均在瞳孔≥6.0mm,且瞳孔大小的测量均为在中间视觉状态下进行.结果:HOAs均方根值、总球面像差和总斜射球面像差在近视眼组与远视眼组分别为0.369±0.233μm、0.133±0.112μm、0.330±0.188μm;0.418±0.214μm、0.202±0.209μm、0.343±0.201μm.与近视患者相比,远视患者的总HOAs和总球面像差更大(P均<0.01).年龄匹配分析显示在远视眼组只有总球面像差较高(P=0.05).近视眼组的中间视觉状态下瞳孔大小较大(P≤0.05).结论:实验结果表明两组的HOAs的水平有显著差异,这对于将行屈光手术的伊朗人很重要.远视眼组的总球面像差显著高于近视眼组,中间视觉状态下瞳孔大小在近视眼组较大.%AIM: To study the distribution of ocular higher-order aberrations(HOAs) and mesopic pupil size in individuals screened for refractive surgery.patients with myopia, myopic astigmatism and compound myopic astigmatism and 215 eyes of 110 patients with hyperopia, hyperopic astigmatism and compound hyperopic astigmatism using the Zywave aberrometer (Busch& Lomb). All patients had correctable refractive errors without a history of refractive surgery or underlying diseases. Root-mean-square values of HOAs, total spherical aberration, total coma and mesopic pupil size were analyzed. Ocular HOAs were measured across a ≥6.0mm pupil, and pupil size measurements were performed under the mesopic condition. the

  8. Isoflavone content and profile comparisons of cooked soybean-rice mixtures: electric rice cooker versus electric pressure rice cooker.

    Science.gov (United States)

    Chung, Ill-Min; Yu, Bo-Ra; Park, Inmyoung; Kim, Seung-Hyun

    2014-12-10

    This study examined the effects of heat and pressure on the isoflavone content and profiles of soybeans and rice cooked together using an electric rice cooker (ERC) and an electric pressure rice cooker (EPRC). The total isoflavone content of the soybean-rice mixture after ERC and EPRC cooking relative to that before cooking was ∼90% in soybeans and 14-15% in rice. Malonylglucosides decreased by an additional ∼20% in EPRC-cooked soybeans compared to those cooked using the ERC, whereas glucosides increased by an additional ∼15% in EPRC-cooked soybeans compared to those in ERC-cooked soybeans. In particular, malonylgenistin was highly susceptible to isoflavone conversion during soybean-rice cooking. Total genistein and total glycitein contents decreased in soybeans after ERC and EPRC cooking, whereas total daidzein content increased in EPRC-cooked soybeans (p soybeans.

  9. Proton irradiation of simple gas mixtures: Influence of irradiation parameters

    Science.gov (United States)

    Sack, Norbert J.; Schuster, R.; Hofmann, A.

    1990-01-01

    In order to get information about the influence of irradiation parameters on radiolysis processes of astrophysical interest, methane gas targets were irradiated with 6.5 MeV protons at a pressure of 1 bar and room temperature. Yields of higher hydrocarbons like ethane or propane were found by analysis of irradiated gas samples using gas chromatography. The handling of the proton beam was of great experimental importance for determining the irradiation parameters. In a series of experiments current density of the proton beam and total absorbed energy were shown to have a large influence on the yields of produced hydrocarbons. Mechanistic interpretations of the results are given and conclusions are drawn with regard to the chemistry and the simulation of various astrophysical systems.

  10. Cytochrome P450 1B1, a novel chemopreventive target for benzo[a]pyrene-initiated human esophageal cancer.

    Science.gov (United States)

    Wen, Xia; Walle, Thomas

    2007-02-08

    Esophageal cancer is common worldwide, with poor prognosis. Smoking, including exposure to polyaromatic hydrocarbons like benzo[a]pyrene (BaP), is a major risk factor. In human esophageal HET-1A cells, we found that time-dependent BaP-DNA binding was associated with upregulation of CYP1B1, but not CYP1A1, mRNA and protein. The dietary flavonoid 5,7-dimethoxyflavone significantly inhibited BaP-DNA binding and down-regulated BaP-induced CYP1B1 mRNA and protein. 3',4'-Dimethoxyflavone was an even more potent inhibitor of CYP1B1 expression, while resveratrol had no effect. Thus, dietary methoxylated flavones inhibited BaP-induced CYP1B1 transcription in a cell-specific manner and hold promise as chemopreventive agents in esophageal carcinogenesis.

  11. Comparison of corneal aberrations after femtosecond laser LASIK and SBK%飞秒LASIK与SBK术后角膜像差的对比分析

    Institute of Scientific and Technical Information of China (English)

    张静; 张士胜; 吴江秀; 于青; 董世奇; 廉井财

    2014-01-01

    Objective To compare changes in wavefront aberrations on the cornea after femtosecond laser LASIK (FS-LASIK) and sub-Bowman's keratomileusis (SBK),especially for total higher order aberrations (HOA),corneal spherical aberrations (C40),corneal horizontal coma (C31),corneal vertical coma (C3-1),corneal horizontal trefoil (C33) and corneal oblique trefoil (C3-3).Methods A prospective study was designed for 2 groups based on the procedure used.The groups were composed of 68 eyes of 34 patients who had undergone FS-LASIK and 90 eyes of 45 patients who had been treated with SBK.A Pentacam was used under dark room conditions to measure corneal aberrations before surgery and 1 and 3 months after surgery.Data were analyzed using ANOVA,an independent samples t test and Pearson correlation.Results The preoperative and postoperative differences for the total corneal HOA,corneal C40,and corneal C31in the FS-LASIK group were significant (F=8.511,12.356,11.843,P<0.01).The corresponding differences and in addition corneal C31 were also significant for the SBK group (F=46.601,38.627,10.874,11.727,P<0.01).One month after surgery,HOAs were higher in the SBK group than in the FS group (t=-3.063,P<0.05),and the same tendency was found 3 months after surgery (t=2.998,P<0.05).The differences for C40 at 1 month were not significant between the two groups (t=-1.990,P>0.05) but the differences were statistically significant at 3 months (t=-2.666,P<0.05).One and 3 months after surgery,the trefoil aberrations (C33,C3-3) of the cornea in the two groups were higher than before surgery; only the difference for C3-3 was significant.However,the difference in the trefoil aberrations of the cornea between the two groups was not statistically significant.Conclusion Both FS-LASIK and SBK can increase corneal HOA,corneal spherical aberrations and vertical coma,but the degree of increase after FS-LASIK is smaller than that after SBK.FS-LASIK improves visual quality more than SBK.%目的

  12. 焦化废水中溶解性有机物组分的特征分析%Composition characterization of dissolved organic matters in coking wastewater

    Institute of Scientific and Technical Information of China (English)

    张万辉; 韦朝海; 晏波; 任曼; 彭平安

    2012-01-01

    Coking wastewater is the representative wastewater containing various organic pollutants.In order to ascertain the composition,XAD-8 resin was applied to concentrate and isolate the organic compounds in coking wastewater.Dissolved organic matter in coking wastewater was fractionated into four different fractions: hydrophobic acids(HOA),hydrophobic bases(HOB),hydrophobic neutrals(HON) and hydrophilic substances(HIS).Thereafter,the dissolved organic carbon(DOC),ultraviolet-visible(UV) absorption spectroscopy,chroma and the organic component were determined.The DOC values of HIS and HOA showed these two were the main fractions of DOM,comprising 44.3% and 32.4% of the total sample.The characteristic absorption wavelength of coking wastewaater ranged from 200 nm to 250 nm and 300 nm to 400 nm,and the intension order was HISHOAHONHOB.The chroma of coking wastewater was composed of HOA and HON,and their absorbance at 525 nm and 436 nm contributed 42.9%,42.1% and 21.4%,15.8% of the total.The dominant compounds were aniline,phenol,quinoline and isoquinoline for HIS,various alkyl phenols for HOA,aniline bases and polycyclic nitrogen-containing aromatics for HOB and indole with its ramifications for HON.%焦化废水是典型的具有复杂有机质的工业废水,其复杂的有机构成制约了水处理的水质达标,且可能对排入水体构成危害.为了探明其溶解性有机物的组成,采用XAD-8大孔树脂将焦化废水中的溶解性有机物分为亲水性组分(HIS)、疏水酸性组分(HOA)、疏水碱性组分(HOB)和疏水中性组分(HON),分析了各组分的溶解性有机物(DOC)、紫外-可见光谱、色度,并采用GC/MS对各组分中有机物进行定性分析.结果表明,焦化废水中的有机物主要为HIS和HOA组分,其DOC含量分别占总DOC的44.3%和32.4%;焦化废水在200—250 nm和300—400 nm范围内有特征吸收峰,且吸收光强度顺序为HIS〉HOA〉HON〉HOB;焦化废水

  13. 污水厂出水DOM各组分的荧光特性及其THMFP%Fluorescence Characteristic and THMFP of DOM Fractions in Secondary Effluent

    Institute of Scientific and Technical Information of China (English)

    韩芸; 周学瑾; 彭党聪; 王晓昌

    2011-01-01

    According to different chemical composition, dissolved organic matter ( DOM) in secondary effluent from a conventional wastewater treatment plant was isolated using XAD resin adsorbents into six classes; hydrophobic acids ( HoA) , hydrophobic bases ( HoB) , hydrophobic neutrals ( HoN ) , hydrophilic acids (HiA), hydrophilic bases (HiB) and hydrophilic neutrals (HiN). The objective of this study was to investigate the relationship between source and components of each DOM fraction and THMFP. The results show that HoA and HiA are the dominant fractions in the secondary effluent DOM, being 29% and 36% of total DOC respectively, and THMFPs of these two fractions are the maximum, being 301.9 μg/L and 92.9 μg/L respectively. The analysis results of 3DEEM show that HiA and HoA contain a large amount of aromatic proteins, SMP and humic matters, which lead to high THMFP, andHoB also contains aromatic proteins and SMP. Thus, aromatic amino acid, humic acid, fulvic acid and SMP are important THMs precursors. It is also found that SUVA exhibits a positive correlation with THM-FP, which indicates that SUVA is one of main factors influencing THMs formation.%对城市污水处理厂二级出水中的DOM进行树脂分离得到6种组分:疏水性有机酸(HoA)、疏水性有机碱(HoB)、疏水中性有机物(HoN)、亲水性有机酸(HiA)、亲水性有机碱(HiB)、亲水中性有机物(HiN),探寻各组分中有机物的种类、来源及其与消毒副产物生成潜能(THMFP)的关系.结果表明,HoA和HiA的含量最多,分别占原水DOC的29%和36%,二者的THMFP也最大,分别为301.9 μg/L和92.9 μg/L.通过对三维荧光光谱的分析得出,HoA和HiA含有大量的芳香族蛋白质、溶解性微生物代谢产物(SMP)、腐殖质类物质,HoB中含有明显的芳香族蛋白质和SMP荧光峰,三者均导致较高的THMFP.因此,芳香族氨基酸、腐殖酸、富里酸和SMP是重要的消毒副产物前体物.研究还发现各组分的SUVA与THMFP具

  14. 三片式与一片式人工晶状体囊袋旋转稳定性比较及对高阶像差影响%Comparison of rotational stability between three-piece and one-piece intraocular lenses:effect on high-order aberration

    Institute of Scientific and Technical Information of China (English)

    陈雪红; 汤欣; 宋慧

    2012-01-01

    目的 比较三片式与一片式人工晶状体(intraocular lenses,IOL)不同时间段的囊袋旋转稳定性及研究不同旋转角度下内眼及全眼各高阶像差成分的变化,为散光型IOL的最佳设计提供新思路.方法 临床病例对照研究.对2010年11月至2011年7月在天津眼科医院白内障超声乳化植入IOL 60例患者随机分为两组,A组30例(30只眼),植入三片式疏水性丙烯酸酯IOL AR40e;B组30例(30只眼),植入一片式疏水性丙烯酸酯IOL ZCBOO.术中手术显微镜照相,术后1天、7天及1月裂隙灯后照法采集照片,用图像分析软件联合MB-ruler软件计算IOL襻的旋转度.用iTrace视觉功能分析仪测量术后7天及1月6 mm瞳孔直径内眼及全眼高阶像差成分,再将7天及1月两组IOL眼根据旋转度<3°和3°分组比较内眼及全眼高阶像差成分.结果 术后1月两组UCVA≥0.6、BCVA≥0.8.术后1天与术中夹角比较,A组(t =-0.435,P=0.667),B组(t=-0.336,P=0.739),差异均无统计学意义(P>0.05),体位对旋转度无影响.以术后1天为参考值,7天及1月IOL旋转度A组分别为(2.21±1.45)°和(2.43±1.59)°,B组分别为(1.98±1.20)°和(2.14±1.37)°,两组间不同时间段比较,差异均无统计学意义(P>0.05).术后7天和1月两组IOL内眼球差及全眼总高阶像差、球差差异均有统计学意义(P<0.05),而内眼总高阶像差、彗差和三叶草及全眼彗差、三叶草差异均无统计学意义(P>0.05).在不同旋转角度下,7天和1月两组内眼和全眼高阶像差成分各自比较,差异均无统计学意义(P>0.05).结论 三片式与一片式IOL均有良好囊袋旋转稳定性,一片式更为稳定,更适合设计散光型IOL;两种IOL的旋转度对内眼及全眼高阶像差无影响.%Objective To compare rotational stability in the capsular bag between three-piece and one-piece intraocular lenses (IOL) and study the influence of rotation angle (RA) on the high-order aberrations (HOAs) of

  15. Comparison of ocular modulation transfer function determined by a ray-tracing aberrometer and a double-pass system in early cataract patients

    Institute of Scientific and Technical Information of China (English)

    Qiao Liya; Wan Xiuhua; Cai Xiaogu; Balamurali Vasudevan; Xiong Ying; Tan Jiaxuan; Guan Zheng

    2014-01-01

    Background The evaluation of retinal image quality in cataract eyes has gained importance and the clinical modulation transfer functions (MTF) can obtained by aberrometer and double pass (DP) system.This study aimed to compare MTF derived from a ray tracing aberrometer and a DP system in eady cataractous and normal eyes.Methods There were 128 subjects with 61 control eyes and 67 eyes with early cataract defined according to the Lens Opacities Classification System Ⅲ.A laser ray-tracing wavefront aberrometer (iTrace) and a double pass (DP) system (OQAS) assessed ocular MTF for 6.0 mm pupil diameters following dilation.Areas under the MTF (AUMTF) and their correlations were analyzed.Stepwise multiple regression analysis assessed factors affecting the differences between iTrace-and OQAS-derived AUMTF for the early cataract group.Results For both early cataract and control groups,iTrace-derived MTFs were higher than OQAS-derived MTFs across a range of spatial frequencies (P <0.01).No significant difference between the two groups occurred for iTrace-derived AUMTF,but the early cataract group had significantly smaller OQAS-derived AUMTF than did the control group (P <0.01).AUMTF determined from both the techniques demonstrated significant correlations with nuclear opacities,higher-order aberrations (HOAs),visual acuity,and contrast sensitivity functions,while the OQAS-derived AUMTF also demonstrated significant correlations with age and cortical opacity grade.The factors significantly affecting the difference between iTrace and OQAS AUMTF were root-mean-squared HOAs (standardized beta coefficient=-0.63,P <0.01) and age (standardized beta coefficient=0.26,P <0.01).Conclusions MTFs determined from a iTrace and a DP system (OQAS) differ significantly in early cataractous and normal subjects.Correlations with visual performance were higher for the DP system.OQAS-derived MTF may be useful as an indicator of visual performance in early cataract eyes.

  16. A prospective, contralateral comparison of photorefractive keratectomy (PRK versus thin-flap LASIK: assessment of visual function

    Directory of Open Access Journals (Sweden)

    Hatch BB

    2011-04-01

    Full Text Available Bryndon B Hatch1, Majid Moshirfar1, Andrew J Ollerton1, Shameema Sikder2, Mark D Mifflin11John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USAPurpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs in eyes with stable myopia undergoing either photorefractive keratectomy (PRK or thin-flap laser in situ keratomileusis (LASIK (intended flap thickness of 90 µm using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively.Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, contrast sensitivity, and complications.Results: At 6 months, mean values for UDVA (logMAR were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466. UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600. Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156 or CDVA (P = 0.800 at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears.Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.Keywords: photorefractive keratectomy, thin-flap LASIK, visual

  17. Attributes and perspectives of public providers related to provision of medical abortion at public health facilities in Vietnam: a cross-sectional study in three provinces

    Directory of Open Access Journals (Sweden)

    Ngo TD

    2014-08-01

    Full Text Available Thoai D Ngo,1,2 Caroline Free,1 Hoan T Le,3 Phil Edwards,1 Kiet HT Pham,4 Yen BT Nguyen,4 Thang H Nguyen5 1Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK; 2Research, Monitoring and Evaluation Team, Health System Department, Marie Stopes International, London, UK; 3Department of Environmental Health, 4Department of Health Economics, Hanoi Medical University, 5Research and Metrics Team, Marie Stopes International Vietnam, Hanoi, Vietnam Background: The purpose of this study was to investigate attributes of public service providers associated with the provision of medical abortion in Vietnam. Methods: We conducted a cross-sectional study via interviewer-administered questionnaire among abortion providers from public health facilities in Hanoi, Khanh Hoa, and Ho Chi Minh City in Vietnam between August 2011 and January 2012. We recruited abortion providers at all levels of Vietnam's public health service delivery system. Participants were questioned about their medical abortion provision practices and perspectives regarding abortion methods. Results: A total of 905 providers from 62 health facilities were included, comprising 525 (58.0% from Hanoi, 122 (13.5% from Khanh Hoa, and 258 (28.5% from Ho Chi Minh City. The majority of providers were female (96.7%, aged ≥25 years (94%, married (84.4%, and had at least one child (89%; 68.9% of providers offered only manual vacuum aspiration and 31.1% performed both medical abortion and manual vacuum aspiration. Those performing both methods included physicians (74.5%, midwives (21.7%, and nurses (3.9%. Unadjusted analyses showed that female providers (odds ratio 0.1; 95% confidence interval 0.01–0.30 and providers in rural settings (odds ratio 0.3; 95% confidence interval 0.08–0.79 were less likely to provide medical abortion than their counterparts. Obstetricians and gynecologists were more likely to provide medical abortion than providers with

  18. Wavefront-Guided Laser in Situ Keratomileusis (Lasik) versus Wavefront-Guided Photorefractive Keratectomy (Prk): A Prospective Randomized Eye-to-Eye Comparison (An American Ophthalmological Society Thesis)

    Science.gov (United States)

    Manche, Edward E.; Haw, Weldon W.

    2011-01-01

    Purpose To compare the safety and efficacy of wavefront-guided laser in situ keratomileusis (LASIK) vs photorefractive keratectomy (PRK) in a prospective randomized clinical trial. Methods A cohort of 68 eyes of 34 patients with −0.75 to −8.13 diopters (D) of myopia (spherical equivalent) were randomized to receive either wavefront-guided PRK or LASIK in the fellow eye using the VISX CustomVue laser. Patients were evaluated at 1 day, 1 week, and months 1, 3, 6, and 12. Results At 1 month, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), 5% and 25% contrast sensitivity, induction of higher-order aberrations (HOAs), and subjective symptoms of vision clarity, vision fluctuation, ghosting, and overall self-assessment of vision were worse (P0.05). At 1 year, mean spherical equivalent was reduced 94% to −0.27 ± 0.31 D in the LASIK group and reduced 96% to −0.17 ± 0.41 D in the PRK group. At 1 year, 91% of eyes were within ±0.50 D and 97 % were within ±1.0 D in the PRK group. At 1 year, 88% of eyes were within ±0.50 D and 97% were within ±1.0 D in the LASIK group. At 1 year, 97% of eyes in the PRK group and 94% of eyes in the LASIK group achieved an UCVA of 20/20 or better (P=0.72). Refractive stability was achieved in both PRK and LASIK groups after 1 month. There were no intraoperative or postoperative flap complications in the LASIK group. There were no instances of corneal haze in the PRK group. Conclusions Wavefront-guided LASIK and PRK are safe and effective at reducing myopia. At 1 month postoperatively, LASIK demonstrates an advantage over PRK in UCVA, BSCVA, low-contrast acuity, induction of total HOAs, and several subjective symptoms. At postoperative month 3, these differences between PRK and LASIK results had resolved. PMID:22253488

  19. Paragonimus and paragonimiasis in Vietnam: an update.

    Science.gov (United States)

    Doanh, Pham Ngoc; Horii, Yoichiro; Nawa, Yukifumi

    2013-12-01

    Paragonimiasis is a food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Vietnam, research on Paragonimus and paragonimiasis has been conducted in northern and central regions of the country. Using a combination of morphological and molecular methods, 7 Paragonimus species, namely P. heterotremus, P. westermani, P. skrjabini, P. vietnamensis, P. proliferus, P. bangkokenis and P. harinasutai, have been identified in Vietnam. Of these, the first 3, P. heterotremus, P. westermani and P. skrjabini, are known to infect humans in other countries. However, in Vietnam, only P. heterotremus, found in some northern provinces, has been shown to infect humans. Even nowadays, local people in some northern provinces, such as Lai Chau and Yen Bai, are still suffering from P. heterotremus infection. In some provinces of central Vietnam, the prevalence and infection intensity of P. westermani metacercariae in freshwater crabs (the second intermediate hosts) are extremely high, but human cases have not been reported. Likewise, although P. skrjabini was found in Thanh Hoa Province, its pathogenicity to humans in Vietnam still remains uncertain. The results of molecular phylogenetic analyses of Vietnamese Paragonimus species provides new insights on the phylogeny and taxonomy of the genus Paragonimus. Comprehensive molecular epidemiological and geobiological studies on the genus in Vietnam and adjacent countries are needed to clarify the biodiversity and public health significance of the lung flukes.

  20. Effects of selected food phytochemicals in reducing the toxic actions of TCDD and p,p'-DDT in U937 macrophages.

    Science.gov (United States)

    Sciullo, Eric M; Vogel, Christoph F; Wu, Dalei; Murakami, Akira; Ohigashi, Hajime; Matsumura, Fumio

    2010-12-01

    To assess the effectiveness of selected food phytochemicals in reducing the toxic effects of the environmental toxicants, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and p,p'-DDT (DDT), we tested the potencies of auraptene, nobiletin, zerumbone, and (±)-13-hydroxy-10-oxo-trans-11-octadecenoic acid (13-HOA) in reversing the inflammatory action of these toxicants in U937 human macrophages. Using quantitative RT-PCR as the initial screening assay, we identified antagonistic actions of zerumbone and auraptene against the action of TCDD and DDT in up-regulating the mRNA expressions of COX-2 and VEGF. The functional significance of the inhibitory action of zerumbone on COX-2 expression was confirmed by demonstrating its suppression of TCDD-induced activation of COX-2 gene expression in mouse MMDD1 cells. We tested auraptene on DDT-induced reactive oxygen species (ROS) formation in U937 macrophages and found that auraptene is a powerful agent antagonizing this action of DDT. To confirm the significance of these actions of zerumbone and auraptene at the cellular level, we assessed their influence on TCDD-induced apoptosis resistance in intact U937 macrophages and found that they are capable of reversing this action of TCDD. In conclusion, zerumbone and auraptene were identified to be the most effective agents in protecting U937 macrophages from developing these cell toxic effects of TCDD and DDT.

  1. Learning from the Neighbors: Economic and Environmental Impacts from Intensive Shrimp Farming in the Mekong Delta of Vietnam

    Directory of Open Access Journals (Sweden)

    Thuy T.H. Nguyen

    2010-07-01

    Full Text Available Intensive shrimp farming is a lucrative and highly risky business. Before entering this industry, most farmers spend time observing the operation of pilot farms. This stage is important to master essential techniques and judge the profitability and risk associated with shrimp farming. Learning is a complex process that leads to misconceptions about the nature of short-term and long-term risks. This paper uses computer simulation to illuminate the dynamic nature of the learning processes, land conversion, shrimp production and environmental contamination. The model is based on conditions of the Dai Hoa Loc Commune in the Mekong Delta of Vietnam. Initial simulations match statistical data by revealing the high risk: high initial profits from the pilot farms followed by conversion from rice land to shrimp farms. When rapid conversion occurs, the region is vulnerable to excessive accumulation of nutrients, a decline in shrimp yields and financial failure. In contrast, low stock densities deliver a lower profit which is insufficient to stimulate mass land conversion. The paper concludes with testing recovery strategies for farmers who have suffered the longer term impacts of high stocking density. Results show that yield recovery is possible by improving the channel and imposing regulatory control over stocking density.

  2. A Scalable Microfabricated Ion Trap for Quantum Information Processing

    Science.gov (United States)

    Maunz, Peter; Haltli, Raymond; Hollowell, Andrew; Lobser, Daniel; Mizrahi, Jonathan; Rembetski, John; Resnick, Paul; Sterk, Jonathan D.; Stick, Daniel L.; Blain, Matthew G.

    2016-05-01

    Trapped Ion Quantum Information Processing (QIP) relies on complex microfabricated trap structures to enable scaling of the number of quantum bits. Building on previous demonstrations of surface-electrode ion traps, we have designed and characterized the Sandia high-optical-access (HOA-2) microfabricated ion trap. This trap features high optical access, high trap frequencies, low heating rates, and negligible charging of dielectric trap components. We have observed trap lifetimes of more than 100h, measured trap heating rates for ytterbium of less than 40quanta/s, and demonstrated shuttling of ions from a slotted to an above surface region and through a Y-junction. Furthermore, we summarize demonstrations of high-fidelity single and two-qubit gates realized in this trap. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. This work was supported by the Intelligence Advanced Research Projects Activity (IARPA).

  3. New strategy toward dioxin risk reduction for local residents surrounding severe dioxin hotspots in Vietnam

    Science.gov (United States)

    Thi Tran, Tuyet-Hanh; Nguyen, Ngoc-Bich; Le, Vu-Anh

    2013-01-01

    Background A public health intervention program with active involvement of local related stakeholders was piloted in the Bien Hoa dioxin hotspot (2007–2009), and then expanded to the Da Nang dioxin hotspot in Vietnam (2009–2011). It aimed to reduce the risk of dioxin exposure of local residents through foods. This article presents the results of the intervention in Da Nang. Methodology To assess the results of this intervention program, pre- and post-intervention knowledge, attitude, and practice (KAP) surveys were implemented in 400 households, randomly selected from four wards surrounding the Da Nang Airbase in 2009 and 2011, respectively. Results After the intervention, the knowledge on the existence of dioxin in food, dioxin exposure pathways, potential high-risk foods, and preventive measures significantly increased (Pdioxin exposure. Practices to reduce the risk of dioxin exposure also significantly improved (Pdioxin at dioxin hotspots. While greater efforts are needed for remediating dioxin-polluted areas inside airbases, there is also evidence to suggest that, during the past four decades, pollution has expanded to the surrounding areas. For this reason, this model should be quickly expanded to the remaining dioxin hotspots in Vietnam to further reduce the exposure risks in other areas. PMID:23791241

  4. Myosin-cross-reactive antigen (MCRA) protein from Bifidobacterium breve is a FAD-dependent fatty acid hydratase which has a function in stress protection

    LENUS (Irish Health Repository)

    Rosberg-Cody, Eva

    2011-02-17

    Abstract Background The aim of this study was to determine the catalytic activity and physiological role of myosin-cross-reactive antigen (MCRA) from Bifidobacterium breve NCIMB 702258. MCRA from B. breve NCIMB 702258 was cloned, sequenced and expressed in heterologous hosts (Lactococcus and Corynebacterium) and the recombinant proteins assessed for enzymatic activity against fatty acid substrates. Results MCRA catalysed the conversion of palmitoleic, oleic and linoleic acids to the corresponding 10-hydroxy fatty acids, but shorter chain fatty acids were not used as substrates, while the presence of trans-double bonds and double bonds beyond the position C12 abolished hydratase activity. The hydroxy fatty acids produced were not metabolised further. We also found that heterologous Lactococcus and Corynebacterium expressing MCRA accumulated increasing amounts of 10-HOA and 10-HOE in the culture medium. Furthermore, the heterologous cultures exhibited less sensitivity to heat and solvent stresses compared to corresponding controls. Conclusions MCRA protein in B. breve can be classified as a FAD-containing double bond hydratase, within the carbon-oxygen lyase family, which may be catalysing the first step in conjugated linoleic acid (CLA) production, and this protein has an additional function in bacterial stress protection.

  5. Liberal education and the connection with Vygotsky’s theory of the zone of proximal development

    Directory of Open Access Journals (Sweden)

    Nguyen M.A.,

    2017-08-01

    Full Text Available Liberal education came into recognition in Roman Empire, spread throughout Europe during the sixteenth century and has become a revolution in the United States in the last centuries. The term “liberal education” has roots in the Latin word for a free person (liber and the artes liberales emerged historically as the education appropriate for free people. In the modern world, and especially in the United States after the American Revolution, liberal education drew on these roots to position itself as the best preparation for self-governance in a free democratic society. At Hoa Sen University, liberal education has been chosen as a way to develop students, alongside their professional preparation. In the search for best application options of liberal education, the author realized the connection between liberal education philosophy and Vygotsky’s educational approach, as known as the zone of proximal development. This article analyzes the perspectives of liberal education and its logical connection with Vygotsky’s theory of the zone of proximal development.

  6. Assessing water reservoirs management and development in Northern Vietnam

    Directory of Open Access Journals (Sweden)

    A. Castelletti

    2012-01-01

    Full Text Available In many developing countries water is a key renewable resource to complement carbon-emitting energy production and support food security in the face of demand pressure from fast-growing industrial production and urbanization. To cope with undergoing changes, water resources development and management have to be reconsidered by enlarging their scope across sectors and adopting effective tools to analyze current and projected infrastructure potential and operation strategies. In this paper we use multi-objective deterministic and stochastic optimization to assess the current reservoir operation and planned capacity expansion in the Red River Basin (Northern Vietnam, and to evaluate the potential improvement by the adoption of a more sophisticated information system. To reach this goal we analyze the historical operation of the major controllable infrastructure in the basin, the HoaBinh reservoir on the Da River, explore re-operation options corresponding to different tradeoffs among the three main objectives (hydropower production, flood control and water supply, using multi-objective optimization techniques, namely Multi-Objective Genetic Algorithm. Finally, we assess the structural system potential and the need for capacity expansion by application of Deterministic Dynamic Programming. Results show that the current operation can only be relatively improved by advanced optimization techniques, while investment should be put into enlarging the system storage capacity and exploiting additional information to inform the operation.

  7. Removal of natural organic matter in a typical south-China source water during enhanced coagulation with IPF-PACl

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-long; WANG Dong-sheng; XIA Zhong-huan; TANG Hong-xiao; ZHANG Jin-song

    2005-01-01

    Systematic investigation on enhancing removal of natural organic matter (NOM) using inorganic polymer flocculant (IPF),polyaluminum chloride(PACI) and polyacrylamide (PAM) was performed in a typical south-China source water. Enhanced coagulation and applying polymer flocculant-aid were compared through jar tests and pilot tests. Raw water and settled water were characterized and fractionated by resin adsorption. The results show that DOC composes major part of TOC. The DOC distribution keeps relatively stable all around the year with typical high amounts of the hydrophilic matter around 50%. The distribution between HoB, HoA and HoN varies and undergoes fluctuation with the year round. During the summer season, the HoN becomes gradually the major part in hydrophobic parts.PACl with the species being tailor-made shows little pH effect during coagulation. The enhanced coagulation dosage for PACl could be 4.5mg/L for the typical source water. The highest TOC removal achieved 31%. To be economically, 3 mg/L dose is the optimum dosage.Although hydrophilic fractions of NOM of both treatment strategies are removed about 30%, NOM causing UV254 absorbance were well removed(about 90% ). Hydrophobic bases and acids fractions are much more removed under enhanced conditions. The hydrophilic fraction could be better removed using PAM, the polymer coagulant aid.

  8. Promoting accountability in obstetric care: use of criteria-based audit in Viet Nam.

    Science.gov (United States)

    Bailey, P E; Binh, H T; Bang, H T

    2010-01-01

    Audits can improve clinical and managerial practices, enhance the rational use of limited resources, and improve staff morale and motivation. Staff at five hospitals in Thanh Hoa and Quang Tri provinces (Viet Nam) used criteria-based audit (CBA) as a tool to improve the quality of emergency obstetric and newborn care. CBA compares current practice with standards based on the best available evidence and the local context. The audit cycle begins with a known problem, proceeds with an initial assessment and data collection, analysis of those data, formulation and implementation of an action plan, and a re-evaluation of the topic initially assessed. Teams found that clinical protocols for treating major obstetric complications were not followed, although, national guidelines had been issued in 2002. In an audit of facility organisation, staff addressed obstacles to the timely treatment of obstetric emergencies during off hours. In each audit, teams devised mechanisms to correct problems that resulted in significant improvements when the audit cycle was repeated. CBA improved adherence to national guidelines, improved record-keeping, heightened teamwork, and showed staff that they could identify and solve many of their own problems.

  9. Comparing the Effectiveness Between Payment for Environmental Services (PES and a Local Compensation System on Conservation of Special-Use Forests, Son La Province, Vietnam

    Directory of Open Access Journals (Sweden)

    Phan, TT.

    2016-01-01

    Full Text Available To understand drought adaptation practices, we compared two groups of sugarcane growers in Thanh Cong commune, Thach Thanh district, Thanh Hoa province in Vietnam. Results of this study point out that farmers, depending on their preferred type of market channels, reacted differently to the impacts of drought. Contractual farmers paid more attention to the impact on sugarcane tillering and sugar content, while market-oriented farmers paid more attention to sugarcane colour, as this trait directly determined the market price on the cane that is either consumed as cane or as juice. In responding to water stress in the growing season, the open market-oriented farmers showed more flexibility in changing their cropping calendar. They were also more willing to invest in enhancing the water management system and in providing organic fertilizer than the contractual farmers. On the other hand, the low cane price and the harvesting date set in contract by the processing company lessened the contractual farmers' flexibility in investing in water management technologies; thus, hampering their adaptation to drought.

  10. Review of Hua Lanhong's Architectural and Planning Thought And about Research on Chinese Modern Architectural History after 1949%华揽洪的建筑与规划思想探析——兼论中国现代建筑史研究

    Institute of Scientific and Technical Information of China (English)

    刘亦师

    2013-01-01

    第一部分回顾华揽洪先生的主要著作和实践,总结其建筑与规划思想;积极探索中国特色的城市建设道路、倡导现代建筑设计原则、提倡“环境观念”及在城乡统筹和区域规划等方面的远见卓识;第二部分略论中国现代建筑史研究的几个待进行的课题和研究中需要注意的问题.%The first part of the paper reviews primary works and practice of Hua Lanhong (Leon Hoa) and summarizes his architectural and planning thought as four aspects: enduring exploration of urban construction with Chinese characteristics; enthusiastically promoting the principles of modernism design; advocating "environment idea" and integration of rural and urban planning, etc The second part extends from Hua Lanhong to the historical research on Chinese architecture and city planning after 1949, highlighting several subjects to be studied.

  11. Primary Idiopathic Osteoarthropathy: Could It Be Related to Alcoholism?

    Science.gov (United States)

    Subedi, Suresh; Dawood, Thair

    2017-01-01

    Background. Hypertrophic osteoarthropathy (HOA) is a syndrome characterized by abnormal proliferation of the skin and bony structures at the distal extremities resulting in digital clubbing, periosteal bony reaction, and joint effusion. It can be primary (idiopathic) without any clear identifiable etiology as well as secondary to variety of systemic diseases most notably lung pathology. Case Presentation. We describe a rare case of primary idiopathic osteoarthropathy in a male patient who presented with severe pain and tenderness in his legs. His history was significant for long standing alcoholism. Physical examination showed severe fingers and toes clubbing. He reported similar changes in his mother. Clinical and radiological findings were remarkable for distal leg tenderness and diffuse periosteal bony reactions, respectively. Computerized tomography scan failed to show any pathology apart from fatty liver infiltration. In the absence of obesity or diabetes, this was consistent with alcoholic steatosis. He was started on nonsteroidal anti-inflammatory drug which dramatically improved his symptoms. Conclusion. Primary hypertrophic osteoarthropathy should be considered in a previously healthy person presenting with bony pain and finger clubbing especially after ruling out the common secondary causes. Moreover, alteration of prostaglandin metabolism secondary to alcoholic consumption might be a contributing factor. PMID:28116207

  12. Early childhood development interventions and cognitive development of young children in rural Vietnam.

    Science.gov (United States)

    Watanabe, Koichiro; Flores, Rafael; Fujiwara, Junko; Tran, Lien Thi Huong

    2005-08-01

    Little is known about the long-term benefits of interventions that aim to promote early childhood development programs. The goal of this research was to determine whether an early childhood development intervention added to a nutrition intervention during preschool ages had lasting effects on the cognitive development of school-age children in communes of Thanh Hoa province in rural Vietnam. The study focused on a total of 313 children aged 6.5-8.5 y (grades 1 and 2 in primary school) in 2 communes that were exposed to nutrition intervention or nutrition and early childhood development (ECD) intervention from 1999 to 2003. Measurements of height and cognitive test scores (Raven's Progressive Matrices Test) were collected from the children; household characteristics were determined by interviews with mothers. Longitudinal analysis was performed by integrating the data with that collected from the same children in past surveys. Significant effects of the ECD intervention compared with the nutrition intervention were detected. The beneficial effect of ECD intervention on the cognitive test scores was large for the most nutritionally challenged children whose height-for-age Z-scores declined or remained in the stunted range. The findings help provide useful insights into the development of an effective integrated model of ECD and nutrition intervention for children in rural Vietnam.

  13. Seasonal variations of chemical and physical characteristics of dissolved organic matter and trihalomethane precursors in a reservoir: a case study.

    Science.gov (United States)

    Wei, Qun-shan; Feng, Cheng-hong; Wang, Dong-sheng; Shi, Bao-you; Zhang, Li-tian; Wei, Qia; Tang, Hong-xiao

    2008-01-31

    Dissolved organic matter (DOM) and its potential to form disinfection by-products (DBPs) during water treatment are of great public health concern. Understanding the seasonal changes in DOM composition and their reactivity in DBP formation could lead to a better treatment of drinking water and a more consistent water quality. DOM from the East-Lake, a reservoir in the south-China, was fractionated and characterized by XAD resin adsorption (RA) and ultrafiltration (UF) techniques during different seasons within a year. The properties of chemical fractions (isolated by RA) appeared more stable than those of physical fractions (separated by UF) throughout the sampling period. The relative contribution of each chemical fraction to the total dissolved organic carbon (DOC), UV(254) absorbance and trihalomethane formation potential (THMFP) remained relatively constant across the sampling period. However, the physical (molecular weight) fractions of the DOM exhibited large seasonal changes in UV(254) and THMFP. Compared to the parameter of DOC, the THMFP and specific THMFP (STHMFP) of either chemical or physical fractions were more variable. In terms of DOC concentration, the hydrophobic acids (HoA) and hydrophilic matter (HiM) dominated in the DOM in most of the seasons; while the components with molecular weight of 10-30 kDa and less than 1 kDa were the predominant physical fractions.

  14. Threat to cedar, Cedrela odorata, plantations in Vietnam by the weevil, Aclees sp.

    Science.gov (United States)

    Thu, Pham Quang; Quang, Dao Ngoc; Dell, Bernard

    2010-01-01

    The recent decline and death of young cedar, Cedrela odorata L. (Sapindales: Meliaceae), plantations in Vietnam is caused by Aclees sp. (Coleoptera: Curculionidae), a wood-boring brown weevil. A field study was undertaken in three-year-old plantations in two districts in Thanh Hoa province in August 2008. Trees were heavily impacted by the weevil, Aclees; the infestation level (P) ranged from 80 to 100% and the average damage index (R) ranged from 1.8 to 2.8. Observations over one year enabled the life history to be determined. Eggs were laid (February to March, September to November) inside the bark from the base of the trunk up to 60 cm in height. Larvae formed extensive feeding tunnels in the inner bark and sap wood. Pupation occurred in feeding tunnels or pupal chambers in the sapwood. Adults emerged twice a year, February to March and August to October. It is concluded that Aclees is a threat to C. odorata plantations in tropical regions of the world, and quarantine measures should be implemented to reduce the risk of spread.

  15. Comparative study of visual acuity and aberrations after intralase femtosecond LASIK: small corneal flap versus big corneal flap

    Institute of Scientific and Technical Information of China (English)

    Ya-Li; Zhang; Lei; Liu; Chang-Xia; Cui; Ming; Hu; Zhao-Na; Li; Li-Jun; Cao; Xiu-Hua; Jing; Guo-Ying; Mu

    2014-01-01

    AIM:To study the effects of different flap sizes on visual acuity, refractive outcomes, and aberrations after femtosecond laser for laser keratomileusis (LASIK). ·METHODS: In each of the forty patients enrolled, 1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap, defined as the small flap, while the other eye was treated with a 8.6mm diameter corneal flap, defined as the big flap. Refractive errors, visual acuity, and higher -order aberrations were compared between the two groups at week 1, month 1 and 3 postoperatively. · RESULTS: The postoperative refractive errors and visual acuity all conformed to the intended goal. Postoperative higher -order aberrations were increased, especially in spherical aberration (Z12) and vertical coma (Z7). There were no statistically significant differences between the two groups in terms of postoperative refractive errors, visual acuity, root mean square of total HOAs (HO -RMS), trefoil 30° (Z6), vertical coma (Z7), horizontal coma (Z8), trefoil 0° (Z9), and spherical aberration (Z12) at any point during the postoperative follow-up. ·CONCLUSION: Both the small and big flaps are safe and effective procedures to correct myopia, provided the exposure stroma meets the excimer laser ablations. The personalized size corneal flap is feasible, as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.

  16. Trihalomethanes (THMs) precursor fractions removal by coagulation and adsorption for bio-treated municipal wastewater: Molecular weight, hydrophobicity/hydrophily and fluorescence.

    Science.gov (United States)

    Han, Qi; Yan, Han; Zhang, Feng; Xue, Nan; Wang, Yan; Chu, Yongbao; Gao, Baoyu

    2015-10-30

    Due to concerns over health risk of disinfection byproducts (DBPs), removal of trihalomethanes (THMs) precursor from bio-treated wastewater by coagulation and adsorption was investigated in this study. Ultrafiltration (UF) membranes and nonionic resins were applied to fractionate THMs precursor into various molecular weight (MW) fractions and hydrophobic/hydrophilic fractions. Characteristics of coagulated water and adsorbed water were evaluated by the three-dimensional excitation and emission matrix (3DEEM) fluorescence spectroscopy. Results showed that coagulation and adsorption were suitable for removing different hydrophobic/hydrophilic and fluorescent fractions. Coagulation decreased THMs concentration in hydrophobic acids (HoA) fraction from 59 μg/L to 39 μg/L, while the lowest THMs concentration (9 μg/L) in hydrophilic substances (HiS) fraction was obtained in adsorbed water. However, both coagulation and adsorption were ineffective for removing fractions with MWadsorption processes could reduce THMs formation, some specific THMs formation potential (STHMFP) in residual dissolved organic matter (DOM) fractions increased in this study. Hydrophobic acid and hydrophilic fractions increased after coagulation treatment, and low MW and hydrophobic fractions increased after adsorption treatment. In addition, active carbon adsorbed more organic matter than coagulant, but brominated disinfection byproducts (Br-DBPs) in adsorbed water turned to the major THMs species after chlorination. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Integration of coagulation and adsorption for removal of N-nitrosodimethylamine (NDMA) precursors from biologically treated municipal wastewater.

    Science.gov (United States)

    Wang, Miaomiao; Meng, Yingjie; Ma, Defang; Wang, Yan; Li, Fengli; Xu, Xing; Xia, Chufan; Gao, Baoyu

    2017-05-01

    This study investigated the N-nitrosodimethylamine (NDMA) formation potential of various dissolved organic matter (DOM) fractions in biologically treated municipal wastewater by UF fractionation, XAD-8 resin adsorption isolation, and excitation and emission matrix (EEM) fluorescence spectroscopy. Removal of various NDMA precursor fractions was also analyzed to evaluate the efficiency of traditional water treatment processes (coagulation, adsorption, and coagulation-adsorption). Results showed that NDMA were mainly formed by low molecular weight (MW) fractions (wastewater. Integrated coagulation-adsorption treatments showed the highest reduction capacity for NDMA formation potential (57%), followed by isolated adsorption treatment (50%) and isolated coagulation treatment (28%). The powdered activated carbon (PAC) adsorption process could reduce the high MW precursors (>30 kDa) by 48%, which was higher than other treatments. In contrast, the highest uptake (66%) of low MW precursors (adsorption process. All treatments preferentially removed the hydrophobic acids (HoA) fraction compared to other fractions. Coagulation could remove more fulvic acid-like substances and adsorption could remove more microbial by-products and aromatic proteins.

  18. Primary Idiopathic Osteoarthropathy: Could It Be Related to Alcoholism?

    Directory of Open Access Journals (Sweden)

    Yanal Alnimer

    2017-01-01

    Full Text Available Background. Hypertrophic osteoarthropathy (HOA is a syndrome characterized by abnormal proliferation of the skin and bony structures at the distal extremities resulting in digital clubbing, periosteal bony reaction, and joint effusion. It can be primary (idiopathic without any clear identifiable etiology as well as secondary to variety of systemic diseases most notably lung pathology. Case Presentation. We describe a rare case of primary idiopathic osteoarthropathy in a male patient who presented with severe pain and tenderness in his legs. His history was significant for long standing alcoholism. Physical examination showed severe fingers and toes clubbing. He reported similar changes in his mother. Clinical and radiological findings were remarkable for distal leg tenderness and diffuse periosteal bony reactions, respectively. Computerized tomography scan failed to show any pathology apart from fatty liver infiltration. In the absence of obesity or diabetes, this was consistent with alcoholic steatosis. He was started on nonsteroidal anti-inflammatory drug which dramatically improved his symptoms. Conclusion. Primary hypertrophic osteoarthropathy should be considered in a previously healthy person presenting with bony pain and finger clubbing especially after ruling out the common secondary causes. Moreover, alteration of prostaglandin metabolism secondary to alcoholic consumption might be a contributing factor.

  19. Prevalence of Fasciola in cattle and of its intermediate host Lymnaea snails in central Vietnam.

    Science.gov (United States)

    Nguyen, Sam Thi; Nguyen, Duc Tan; Van Nguyen, Thoai; Huynh, Vu Vy; Le, Duc Quyet; Fukuda, Yasuhiro; Nakai, Yutaka

    2012-12-01

    The aims of this study were to investigate the prevalence of natural Fasciola infections in both the definitive hosts (cattle) and the intermediate hosts (Lymnaea snails) in central Vietnam. A total of 1,075 fecal samples, randomly collected from cattle in Binh Dinh, Khanh Hoa, and Phu Yen provinces, were examined for Fasciola eggs by a sedimentation method. The overall prevalence of Fasciola was 45.3 %. A subset of the animals (235) was also screened for antibodies against Fasciola by an enzyme-linked immunosorbent assay. Overall, 46.3 % of these animals were shedding Fasciola eggs while 87.2 % were Fasciola seropositive. A lower prevalence of Fasciola was observed in calves ≤ 2 years of age (37.6 %) compared to that in cattle >2 years of age (53.7 %) (p Lymnaea viridis and 1.128 Lymnaea swinhoei examined, 31 (0.95 %) and seven (0.62 %), respectively, were found to be infected with Fasciola. This appears to be the first epidemiological survey of the prevalence of Fasciola in cattle and snails in these three provinces in central Vietnam.

  20. Groin pain and iliopsoas bursitis: always a cause-effect relationship?

    Science.gov (United States)

    Di Sante, Luca; Paoloni, Marco; De Benedittis, Stefano; Tognolo, Lucrezia; Santilli, Valter

    2014-01-01

    Iliopsoas bursitis (IB) is characterized by inflammation and enlargement of the iliopsoas bursa. Although this condition is often associated with degenerative or inflammatory arthritis, infections, trauma, overuse and impingement syndromes, osteonecrosis and hip replacement, the pathogenesis of IB remains uncertain. We present a case report of IB associated with moderate hip osteoarthritis (HOA). We present a case report of a 73-year-old man with chronic left hip pain that did not respond to conservative treatments. An ultrasonography examination of the left hip revealed fluid-induced distension of the iliopsoas bursa, which was treated with aspiration followed by a corticosteroid-anesthetic injection. At the 30-day follow-up, despite an initial improvement in the patient's symptoms, both the pain and functional limitation returned, though not in association with bursa distension. The patient therefore underwent a total hip arthroplasty, which fully relieved the symptoms. We hypothesize that iliopsoas bursitis may, when associated with other pathological conditions, not be the only source of pain. It should, nevertheless, be considered for differential diagnosis purposes.

  1. Daily variation of organic aerosol concentration and composition in Seoul, Korea during KORUS pre-campaign

    Science.gov (United States)

    Shin, H. J.; Lee, J.; Choi, A. Y.; Park, S. M.; Park, J. S.; Song, I. H.; Hong, Y. D.

    2015-12-01

    Daily variation of Organic Aerosol (OA) as well as organic tracer compounds have been observed in aerosol samples collected during KORUS-AQ (Korea-US Air Quality Study) pre-campaign (From May 18 to June 12) in Seoul, Korea. NR-PM1 bounded OA was measured by HR-TOF-AMS (Aerodyne) and the temporal variation, composition of OA by family group characterization, and oxidation state of OA was studied. And to distinguish the source characteristics (such as HOA, COA, NOA, SV-OOA, LV-OOA, etc…) of the organic, AMS-PMF model will be used.For the observation of organic tracer compounds, solvent extractable fractions were analyzed by GC-MS. More than 80 organic compounds were detected in the aerosol samples and grouped by source characterized classes, including vehicular emission tracers, biomass burning tracers, coal emission tracers, secondary organic aerosol (SOA) tracers. The main objective of this study is evaluation of the validity of OA fractionation based on the AMS measurement. So, we will compare daily variation of OA composition measured by AMS with daily variation of organic tracer compounds. Further, we will specify source characteristics estimated using AMS-PMF model by comparing the results of source apportionment of OA using PMF of organic tracer compounds.

  2. Assessing water reservoirs management and development in Northern Vietnam

    Science.gov (United States)

    Castelletti, A.; Pianosi, F.; Quach, X.; Soncini-Sessa, R.

    2012-01-01

    In many developing countries water is a key renewable resource to complement carbon-emitting energy production and support food security in the face of demand pressure from fast-growing industrial production and urbanization. To cope with undergoing changes, water resources development and management have to be reconsidered by enlarging their scope across sectors and adopting effective tools to analyze current and projected infrastructure potential and operation strategies. In this paper we use multi-objective deterministic and stochastic optimization to assess the current reservoir operation and planned capacity expansion in the Red River Basin (Northern Vietnam), and to evaluate the potential improvement by the adoption of a more sophisticated information system. To reach this goal we analyze the historical operation of the major controllable infrastructure in the basin, the HoaBinh reservoir on the Da River, explore re-operation options corresponding to different tradeoffs among the three main objectives (hydropower production, flood control and water supply), using multi-objective optimization techniques, namely Multi-Objective Genetic Algorithm. Finally, we assess the structural system potential and the need for capacity expansion by application of Deterministic Dynamic Programming. Results show that the current operation can only be relatively improved by advanced optimization techniques, while investment should be put into enlarging the system storage capacity and exploiting additional information to inform the operation.

  3. Enzyme Architecture: The Activating Oxydianion Binding Domain for Orotidine 5′-Monophophate Decarboxylase

    Science.gov (United States)

    Spong, Krisztina; Amyes, Tina L.; Richard, John P.

    2014-01-01

    Orotidine 5′-monophosphate decarboxylase catalyzes the decarboxylation of truncated substrate (1-β-D-erythrofuranosyl)orotic acid (EO) to form (1-β-D-erythrofuranosyl)uracil (EU). This enzymecatalyzed reaction is activated by tetrahedral oxydianions, which bind weakly to unliganded OMPDC and tightly to the enzyme-transition state complex, with the following intrinsic oxydianion binding energies (kcal/mole): SO32−, −8.3; HPO32−, −7.7; S2O32−, −4.6; SO42−, −4.5; HOPO32−, −3.0; HOAsO32−, no activation detected. We propose that oxydianion and orotate binding domains perform complementary functions in catalysis of decarboxylation reactions. (1) The orotate binding domain carries out decarboxylation of the orotate ring. (2) The activating oxydianion binding domain has the cryptic function of utilizing binding interactions with tetrahedral inorganic oxydianions to drive an enzyme conformational change that results in the stabilization of transition states at the distant orotate domain. PMID:24274746

  4. Enzyme architecture: the activating oxydianion binding domain for orotidine 5'-monophophate decarboxylase.

    Science.gov (United States)

    Spong, Krisztina; Amyes, Tina L; Richard, John P

    2013-12-11

    Orotidine 5'-monophosphate decarboxylase catalyzes the decarboxylation of truncated substrate (1-β-D-erythrofuranosyl)orotic acid to form (1-β-D-erythrofuranosyl)uracil. This enzyme-catalyzed reaction is activated by tetrahedral oxydianions, which bind weakly to unliganded OMPDC and tightly to the enzyme-transition state complex, with the following intrinsic oxydianion binding energies (kcal/mol): SO3(2-), -8.3; HPO3(2-), -7.7; S2O3(2-), -4.6; SO4(2-), -4.5; HOPO3(2-), -3.0; HOAsO3(2-), no activation detected. We propose that the oxydianion and orotate binding domains of OMPDC perform complementary functions in catalysis of decarboxylation reactions: (1) The orotate binding domain carries out decarboxylation of the orotate ring. (2) The activating oxydianion binding domain has the cryptic function of utilizing binding interactions with tetrahedral inorganic oxydianions to drive an enzyme conformational change that results in the stabilization of transition states at the distant orotate domain.

  5. PEMBELAJARAN FISIKA BERBASIS HANDS ON ACTIVITIES UNTUK MENUMBUHKAN KEMAMPUAN BERPIKIR KRITIS DAN MENINGKATKAN HASIL BELAJAR SISWA SMP

    Directory of Open Access Journals (Sweden)

    D. I. Yuliati

    2012-05-01

    Full Text Available Penelitian tindakan kelas ini bertujuan untuk mendeskripsikan model pembelajaran berbasis Hands on Activities, menumbuhkankemampuan berpikir kritis serta meningkatkan hasil belajar siswa SMP kelas VIII. Penelitian ini dilaksanakan dalam tiga siklus.Setiap siklus terdiri dari empat tahap yaitu perencanaan, pelaksanaan tindakan, pengamatan dan refleksi. Data kemampuanberpikir kritis, hasil belajar afektif dan psikomotorik diperoleh dari lembar observasi, hasil belajar kognitif diperoleh melalui tes.Hasil penelitian menunjukkan bahwa nilai kemampuan berpikir kritis meningkat secara signifikan disertai dengan peningkatanjumlah siswa yang termasuk kategori kritis maupun sangat kritis. Selain itu nilai rata-rata hasil belajar juga mengalami peningkatansecara signifikan sehingga dapat disimpulkan bahwa penerapan pembelajaran fisika berbasis Hands on Activities dapatmenumbuhkan kemampuan berpikir kritis serta meningkatkan hasil belajar siswa. The goals of this three-cycles classroom action research are to describe Hands on Activities based learning model, grow criticalthinking ability and increase learning achievement of JHS student-grade VIII. The data of critical thinking ability, affective andpsychomotor learning achievement are derived from observation sheet, while those of cognitive learning achievement was takenfrom test. The result shows that there is a significant increase of critical thinking ability and average of learning achievement leadingto the conclusion that Hands on Activities based learning model, grow critical thinking ability and increase learning achievement ofJHS.Keywords: critical thinking; Hands on activities (HOA; classroom action research

  6. 基于泰勒级数展开的蜂窝TDOA定位新算法%New TDOA algorithm based on Taylor series expansion in cellular networks

    Institute of Scientific and Technical Information of China (English)

    张令文; 谈振辉

    2007-01-01

    在蜂窝移动通信系统中,TDOA(到达时间差)是目前最有发展潜力的无线定位技术.其中的泰勒级数展开算法因为具有精度高和顽健性强等特点在求解非线性定位方程组中得到了广泛的应用,但它对初始值有很强的依赖性.在此基础上,提出一种混合优化算法(HOA,hybrid optimizing algorithm)将泰勒级数展开算法和最速下降法有机结合,扬长避短,既继承了泰勒级数展开算法的精确性和顽健性,又具备最速下降法迭代前期收敛速率快,计算量小的优点.仿真结果表明HOA算法能显著提高传统的泰勒级数展开算法的定位精度和定位效率.

  7. Sequential anaerobic-aerobic biodegradation of 2,3,7,8-TCDD contaminated soil in the presence of CMC-coated nZVI and surfactant.

    Science.gov (United States)

    Binh, Nguyen Duy; Imsapsangworn, Chaiyaporn; Kim Oanh, Nguyen Thi; Parkpian, Preeda; Karstensen, Kare; Giao, Pham Huy; DeLaune, Ronald D

    2016-01-01

    Enriched microorganisms in sediment collected from a dioxin-contaminated site in Vietnam (Bien Hoa airbase) were used for examining the effectiveness in biological treatment of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in soil. Four bio-treatments were investigated using a sequential anaerobic (17 weeks) followed by an aerobic (6 weeks) incubation. The maximum removal efficiency was approximately 60% even at an extremely low pH (approx. 3.6) condition. Surfactant Tween-80 was added to enhance the bioavailability of dioxin in two treatments, but it appeared to biostimulate methanogens rather than dechlorinators. As a result, methane production was the highest while the dioxin removal efficiency was the lowest, as compared with the other bio-treatments. Carboxymethylcellulose (CMC) coated on nanoscale zero valent iron (nZVI) surface used in two treatments could prevent the direct contact between bacterial cell surface and nZVI which prevented cell death and lysis, hence enhancing dioxin removal. The presence of CMC--_nZVI in bio-treatments gradually released H2 required for microbiological processes, but the amount used in the experiments were likely too high to maintain optimum H2 levels for biostimulating dechlorinators rather than methanogens.

  8. The Hidden Burden of Trichinellosis in Vietnam: A Postoutbreak Epidemiological Study

    Directory of Open Access Journals (Sweden)

    Nga Vu Thi

    2013-01-01

    Full Text Available A cross-sectional study was conducted in Muong Lat town (Thanh Hoa province, North Vietnam, following the confirmed diagnosis of trichinellosis in six patients from that town who had eaten hunted wild boar meat during the Vietnamese lunar year celebration. All inhabitants who declared to have eaten undercooked or raw wild boar meat at the celebration and showed at least one clinical symptom compatible with trichinellosis were included in the study and blood sampled. Anti-Trichinella IgG were determined by ELISA and Western Blot. Seropositive persons were given appropriate albendazole treatment and were followed up. A total of 100 inhabitants met the inclusion criteria. Among these, 30 (30% had antibodies to Trichinella. Serologically confirmed cases had fever (90.0%, myalgia (86.7%, facial oedema (63.3%, diarrhoea (53.3%, and pain of the masseter muscles (43.3%. Eosinophilia was detected in 83.3% of these individuals. Clinical symptoms resolved in all patients during albendazole treatment. The results suggest that only a proportion of the trichinellosis cases had sought health care during the outbreak. There is a need to implement surveillance and better diagnosis for trichinellosis and to set up educational programs to prevent infection in North Vietnam.

  9. Regional water quality management for the Dong Nai River Basin, Vietnam.

    Science.gov (United States)

    Grayman, W M; Day, H J; Luken, R

    2003-01-01

    A three-year study that started solely as an industrial pollution reduction effort in Dong Nai Province of Vietnam expanded into an ongoing regional river basin water quality management effort. The project was a cooperative effort between the United Nations (UNDP and UNIDO) and the Federal and Provincial governments in Vietnam. A comprehensive approach was used to assess the impacts and strategies for reducing industrial, municipal and agricultural pollution to the water, air and land. The strategy was based upon use of knowledge in four subject areas, economics, ecology, technology and institutions, integrated within a framework for regional environmental quality management, sometimes called Areawide Environmental Quality Management (AEQM). Dong Nal Province encompasses a major developing area immediately north of Ho Chi Minh City. The land area chosen for the AEQM study is the 1,400 square kilometre region in and around Bien Hoa that drains into the Dong Nai River. The Dong Nai River serves many purposes including navigation, fisheries and a water supply for both the Province and Ho Chi Minh City. Extensive industrial and residential development was underway and was projected to increase in the coming decade. A strategy for the control of pollution from liquid, gaseous and solid wastes for the period 1998 to 2010 in Dong Nai Province was developed.

  10. Hypocretin/Orexin Peptides Excite Rat Neuroendocrine Dopamine Neurons through Orexin 2 Receptor-Mediated Activation of a Mixed Cation Current

    Science.gov (United States)

    Lyons, David J.; Hellysaz, Arash; Ammari, Rachida; Broberger, Christian

    2017-01-01

    Hypocretin/Orexin (H/O) neurons of the lateral hypothalamus are compelling modulator candidates for the chronobiology of neuroendocrine output and, as a consequence, hormone release from the anterior pituitary. Here we investigate the effects of H/O peptides upon tuberoinfundibular dopamine (TIDA) neurons – cells which control, via inhibition, the pituitary secretion of prolactin. In whole cell recordings performed in male rat hypothalamic slices, application of H/O-A, as well as H/O-B, excited oscillating TIDA neurons, inducing a reversible depolarising switch from phasic to tonic discharge. The H/O-induced inward current underpinning this effect was post-synaptic (as it endured in the presence of tetrodotoxin), appeared to be carried by a Na+-dependent transient receptor potential-like channel (as it was blocked by 2-APB and was diminished by removal of extracellular Na+), and was a consequence of OX2R receptor activation (as it was blocked by the OX2R receptor antagonist TCS OX2 29, but not the OX1R receptor antagonist SB 334867). Application of the hormone, melatonin, failed to alter TIDA membrane potential or oscillatory activity. This first description of the electrophysiological effects of H/Os upon the TIDA network identifies cellular mechanisms that may contribute to the circadian rhythmicity of prolactin secretion. PMID:28145492

  11. Composition and Temperature Dependence of Excess Volume of Heavy Oil-Stocks Mixtures + (Gas oil or Toluene or Reformate

    Directory of Open Access Journals (Sweden)

    Shahad Z. Atta

    2011-01-01

    Full Text Available Binary mixtures of three, heavy oil-stocks was subjected to density measurements at temperatures of 30, 35 and 40 °C. and precise data was acquired on the volumetric behavior of these systems. The results are reported in terms of equations for excess specific volumes of mixtures. The heavy oil-stocks used were of good varity, namely 40 stock, 60 stock, and 150 stock. The lightest one is 40 stock with API gravity 33.69 while 60 stock is a middle type and 150 stock is a heavy one, with API gravity 27.74 and 23.79 respectively. Temperatures in the range of 30-40 °C have a minor effect on excess volume of heavy oil-stock binary mixture thus, insignificant expansion or shrinkage is observed by increasing the temperature this effect becomes more significant although the heavy oil-stocks is spiked with hydrocarbons like (gas oil, toluene and reformate. Blending of Heavy oil-stocks with hydrocarbons spikes (gas oil, toluene and reformate form non-ideal mixtures, for which excess volume can be positive or negative depending on nature species. Spiking of Heavy oil-stocks with either gas oil or reformate resulted in negative excess volume. This shrinkage is greater for the lowest boiling point spike as in the case of reformate, While, the presence of methyl groups in aromatic rings results in a positive excess volume, as shown in toluene when blended with 40 stock but a negative excess volume was found when blended with 60 stock and 150 stock. The API gravity of heavy oil-stocks has an effect on excess volume when the oil-stocks spiked with hydrocarbons like (gas oil, toluene and reformate. This 40 stocks as a typical light types resulted in minimum negative excess volume of -0.47 at 30 °C, when it was spiked with the gas oil; while the spiked heavy oil-stock with kerosene shows a maximum excess volume of -15.56 at 40 °C.

  12. Addressing Kitchen Contaminants for Healthy, Low-Energy Homes

    Energy Technology Data Exchange (ETDEWEB)

    Stratton, J. Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Cooking and cooking burners emit pollutants that can adversely affect indoor air quality in residences and significantly impact occupant health. Effective kitchen exhaust ventilation can reduce exposure to cooking-related air pollutants as an enabling step to healthier, low-energy homes. This report by Lawrence Berkeley National Laboratory identifies barriers to the widespread adoption of kitchen exhaust ventilation technologies and practice and proposes a suite of strategies to overcome these barriers. The recommendations have been vetted by a group of industry, regulatory, health, and research experts and stakeholders who convened for two meetings and provided input and feedback to early drafts of this document. The most fundamental barriers are (1) the common misconception, based on a sensory perception of risk, that kitchen exhaust when cooking is unnecessary and (2) the lack of a code requirement for kitchen ventilation in most U.S. locations. Highest priority objectives include the following: (1) Raise awareness among the public and the building industry of the need to install and routinely use kitchen ventilation; (2) Incorporate kitchen exhaust ventilation as a requirement of building codes and improve the mechanisms for code enforcement; (3) Provide best practice product and use-behavior guidance to ventilation equipment purchasers and installers, and; (4) Develop test methods and performance targets to advance development of high performance products. A specific, urgent need is the development of an over-the-range microwave that meets the airflow and sound requirements of ASHRAE Standard 62.2.

  13. Addressing Kitchen Contaminants for Healthy, Low-Energy Homes

    Energy Technology Data Exchange (ETDEWEB)

    Stratton, J. Chris; Singer, Brett C.

    2014-01-01

    Cooking and cooking burners emit pollutants that can adversely affect indoor air quality in residences and significantly impact occupant health. Effective kitchen exhaust ventilation can reduce exposure to cooking-related air pollutants as an enabling step to healthier, low-energy homes. This report identifies barriers to the widespread adoption of kitchen exhaust ventilation technologies and practice and proposes a suite of strategies to overcome these barriers. The recommendations have been vetted by a group of industry, regulatory, health, and research experts and stakeholders who convened for two web-based meetings and provided input and feedback to early drafts of this document. The most fundamental barriers are (1) the common misconception, based on a sensory perception of risk, that kitchen exhaust when cooking is unnecessary and (2) the lack of a code requirement for kitchen ventilation in most US locations. Highest priority objectives include the following: (1) Raise awareness among the public and the building industry of the need to install and routinely use kitchen ventilation; (2) Incorporate kitchen exhaust ventilation as a requirement of building codes and improve the mechanisms for code enforcement; (3) Provide best practice product and use-behavior guidance to ventilation equipment purchasers and installers, and; (4) Develop test methods and performance targets to advance development of high performance products. A specific, urgent need is the development of an over-the-range microwave that meets the airflow and sound requirements of ASHRAE Standard 62.2.

  14. SPUTUM CYTOLOGY CULTURE HAEMATOLOGICAL CHANGES AND AIR QUALITY IN CHRONIC EXPOSURE TO SMOKE FROM BIOMASS FUEL IN RURAL AREA OF SOUTH INDIA

    Directory of Open Access Journals (Sweden)

    Razia Sultana

    2016-08-01

    Full Text Available BACKGROUND Air pollution is generally perceived as an urban problem associated with automobiles and industries. However, half of the world’s population in rural areas of the developing countries is exposed to some of the highest levels of air pollution due to burning of traditional biomass fuels. In view of this, the health impact of biomass fuel use in rural India has been evaluated in this study. OBJECTIVES To analyse the mass concentration in biomass fuel user and LPG user household and to investigate the effects of biomass smoke exposure in a group of rural women who cook regularly with biomass fuels and compare the results obtained from control group women who cook relatively cleaner fuel, liquefied petroleum gas (LPG. METHODS Respiratory health was evaluated from Questionnaire survey, Clinical examination, haematology, sputum cytology culture and serum C-reactive protein (CRP levels are investigated in biomass and control users. RESULTS A total of 150 women were approached, of which only 70 non-smoking women without any history of any major chronic illness in the past were selected for this study. CRP levels differ significantly in biomass exposure than control users. CONCLUSION From our study it is clear that with increasing duration of exposure to biomass fuel combustion. Women who used to cook with traditional biomass fuels had low haemoglobin & Red Blood Cells values, increased neutrophil and allergic manifestations. Sputum cytology of majority biomass users revealed bacterial infections & chronic inflammation.

  15. Biogas cook stoves for healthy and sustainable diets? A case study in Southern India

    Directory of Open Access Journals (Sweden)

    Tal Lee Anderman

    2015-09-01

    Full Text Available Alternative cook stoves that replace solid fuels with cleaner energy sources, such as biogas, are gaining popularity in low-income settings across Asia, Africa and South America. Published research on these technologies focuses on their potential to reduce indoor air pollution and improve respiratory health. Effects on other cooking related aspects, such as diets and women’s time management, are less understood. In this study in southern India, we investigate if using biogas cook stoves alters household diets and women’s time management. We compare treatment households who are supplied with a biogas cook stove with comparison households who do not have access to these stoves, while controlling for several socio-economic factors. We find that diets of treatment households are more diverse than diets of comparison households. In addition, women from treatment households spend on average 40 minutes less cooking and 70 minutes less collecting firewood per day than women in comparison households. This study illustrates that alongside known benefits for respiratory health, using alternative cook stoves may benefit household diets and free up women’s time. To inform development investments and ensure these co-benefits, we argue that multiple dimensions of sustainability should be considered in evaluating the impact of alternative cook stoves.

  16. Characterization of organic aerosol in fine particles in a mega-city of South China: Molecular composition, seasonal variation, and size distribution

    Science.gov (United States)

    Huang, Xiao-Feng; Chen, Dong-Lei; Lan, Zi-Juan; Feng, Ning; He, Ling-Yan; Yu, Guang-He; Luan, Sheng-Ji

    2012-10-01

    A one-year-long observation on major organic compounds in PM2.5 was performed in a coastal mega-city in South China, Shenzhen, in order to gain information of their ambient concentration levels and the implications for sources. The compounds identified included alkanes, PAHs, hopanes, fatty acids and dicarboxylic acids, whose annual average concentrations during the year were 56.0, 14.8, 2.51, 253, and 25.2 ng m- 3, respectively. The seasonal molecular distributions of these organic compounds were discussed to explore their contributing sources in Shenzhen. Conclusively, alkanes and PAHs had the dominant source of fossil fuel combustion, although alkanes also had significant contribution from plant wax (~ 16%). The hopane series distributions further indicated that vehicle emissions were the dominant fossil fuel combustion source for PM2.5 in Shenzhen. Cooking emissions were inferred to be the most possible main source for fatty acids, while both primary and secondary origins were implied for azelaic acid, the dominant one in the dicarboxylic acids identified. Most of the organic compounds analyzed showed a size distribution pattern peaking at 0.32-0.56 or 0.56-1 μm in the accumulation mode, except that the cooking-related organic acids showed implication of a coarse mode-dominated pattern.

  17. 配戴透气性硬性角膜接触镜后圆锥角膜眼高阶像差的变化%Changes of ocular higher order aberration in keratoconus eyes wearing rigid gas-permeable contact lens

    Institute of Scientific and Technical Information of China (English)

    石迎辉; 王丽娅; 吕天斌; 覃建

    2011-01-01

    Objective To compare the wavefront characteristics of normal and keratoconus eyes with and without rigid gas-permeable contact lens(RGPCL) ,and to evaluate the visual quality in keratoconus eyes corrected by RGPCL Methods Retrospective study. Higher order aberrations (HOAs) of 90 eyes in 56 keratoconus patients and 30 eyes of 17 subjects with refractive errors were quantified with a Bausch&Lomb Zywave Wavefront Analyzer. The keratoconus eyes were divided into mild (28 eyes) , moderate (33 eyes)and severe (29 eyes) groups. Zernike's polynomial was used to describe the wavefront measurements. Root mean square (RMS) values of the total HOAs, S3, S4, S5, total coma (T. Coma) and total spherical aberrations (T. Sph) were obtained in the same eye with and without contact lenses. We used paired sample t-test and independent-samples t-test to analyze the data. Results Mean RMS values for High(F=72. 12,P1 =0.00)、S3(F = 68.15,P = 0.00)、S4(F = 24.95,P=0.00)、T. Coma(F =44.67,P =0.00) 、T. Sph (F = 28. 90,P =0. 01) increased significantly from mild to sever keratoconus eyes RMS values of the total HOAs (t = 4. 83 ) , S3 (t = 4. 39 ) 、 total coma (t = 3. 71) of refractive error eyes decreased significantly after fitting with RGPCL(P<0. 05). RMS values of the total HOAs(t = 8. 27) ,S3(t = 8. 14) ,S4(t =2. 29)、total coma( t = 4. 38 ) of mild keratoconus eyes decreased significantly after fitting with RGPCL( P < 0. 05 )RMS values of the total HOAs(t =8. 03) ,S3(t=7. 22) ,s4(t=4. 38) ,S5(t=4. 53) 、total coma(t =5. 26)and total spherical (t =2. 77) of moderate keratoconus eyes decreased significantly after fitting with RGPCL ( P < 0. 05 ). Every high front-wave aberration of mild keratoconus eyes decreased to refractive error eyes'level after RGPCL fitting. Moderate (tHOAs = 0. 63, ts3 = 0. 31,t s4 = 1. 70, ts5 = 0. 95, tcoma = 0. 06,tspherical=1.99) and sever keratoconus eyes'higher order aberrations decreased significantly after RGPCL fitting (thoas=7. 50,ts3 =5

  18. Change of higher order aberration after 2 mm micro-incision SMILE in myopia%2mm微切口SMILE术后近视矫治眼高阶像差的变化

    Institute of Scientific and Technical Information of China (English)

    李晓晶; 王雁; 张琳

    2015-01-01

    背景 飞秒激光小切口基质内透镜取出术(SMILE)已逐渐应用于临床,但术中切口大小不统一,2 mm微切口SMILE对术眼术后屈光度及像差的影响尚不清楚. 目的 研究2 mm微切口SMILE术后术眼屈光度和高阶像差(HOA)的变化,探讨术眼术前屈光度对术后HOA可能的影响.方法 采用系列病例观察的研究方法,选取2013年1-4月在天津市眼科医院行2 mm微切口SMILE的近视及近视散光患者31例55眼,测量患者术前及术后1周、1个月、6个月的裸眼视力(UCVA)、最佳矫正视力(BCVA)和球镜及柱镜度,评价SMILE的有效性、安全性、稳定性及可预测性,应用WaveScan波阵面像差仪测量术前及术后各时间点的HOA.采用重复测量单因素方差分析比较术前和术后各时间点的各HOA,不同时间点间两两比较采用LSD-t检验,采用Spearman秩相关分析评价术前球镜及柱镜度与术后各阶像差及总像差间的相关关系.结果 术后1周、1个月和6个月的有效性指数均为1.2,安全性指数分别为1.2、1.2和1.5.术后3个时间点的等效球镜度(SE)均为0.00D.术后1个月和6个月,分别有96.4%和97.8%的术眼达到预计矫治SE的±0.5 D以内,所有术眼均达到±1.0D以内.术后各时间点术眼垂直彗差(Z7)和球差(Z12)较术前均明显增大,差异均有统计学意义(Z7:t=9.668、10.607、9.772,均P<0.001;Z12:t=-6.227、-6.923、-7.441,均P<0.001),但术后3个时间点之间Z7和Z12的差异均无统计学意义(均P>0.05).术眼术后各时间点3~6阶像差和总HOA较术前均明显增大,差异均有统计学意义(均P<0.05),而术后3个时间点间各阶像差的差异均无统计学意义(均P>0.05).术眼术后各时间点S3、S4、HOA与术前球镜度均呈正相关(均P<0.05),与术前柱镜度均呈负相关(均P<0.05).术后各时间点术眼Z7与术前球镜度呈负相关,与术前柱镜度呈正相关;Z12与术前球镜度呈正相关,而与术

  19. A study of photochemical againg of ambient air using Potential Aerosol Mass (PAM) chamber under the different sources and types of emissions

    Science.gov (United States)

    Lee, T.; Son, J.; Kim, J.; Kim, S.; Sung, K.; Park, G.; Link, M.; Park, T.; Kim, K.; Kang, S.; Ban, J.; Kim, D. S.

    2016-12-01

    Recent research proposed that Secondary Aerosol (SA) is important class of predicting future climate change scenarios, health effect, and a general air quality. However, there has been lack of studies to investigate SA formation all over the world. This study tried to focus on understanding potential secondary aerosol formation and its local impact by the photochemical aging of inorganic and organic aerosols in the ambient air using the Potential Aerosol Mass (PAM) chamber under the different sources and types of emissions. PAM chamber manufactured by Aerodyne make an oxidizing environment that simulates oxidation processes on timescales of 12-15 hrs in the atmosphere. Chemical compositions of ambient aerosol and aerosol that was aged in the PAM chamber were alternately measured every 2-minutes using the High Resolution-Time of Flight-Aerosol Mass Spectrometer (HR-ToF-AMS). HR-ToF-AMS provides non-refractory aerosol mass concentrations including nitrate, sulfate, hydrocarbon-like and oxygenated organic aerosol in real time. This study includes a residence area of mixture of sources, a forest site of dominant source of biogenic VOCs, an underground parking lot of dominant vehicle emission, and laboratory experiment of vehicle emissions under different fuels and speeds using the chassis dynamometer. As a result, it was revealed that gasoline and LPG vehicle relatively made more potential SA than diesel vehicle.

  20. Airborne molecular contamination: quality criterion for laser and optical components

    Science.gov (United States)

    Otto, Michael

    2015-02-01

    Airborne molecular contaminations (AMCs) have been recognized as a major problem in semiconductor fabrication. Enormous technical and financial efforts are made to remove or at least reduce these contaminations in production environments to increase yield and process stability. It can be shown that AMCs from various sources in laser devices have a negative impact on quality and lifetime of lasers and optical systems. Outgassing of organic compounds, especially condensable compounds were identified as the main source for deterioration of optics. These compounds can lead to hazing on surfaces of optics, degradation of coating, reducing the signal transmission or the laser signal itself and can enhance the probability of laser failure and damage. Sources of organic outgassing can be molding materials, resins, seals, circuit boards, cable insulation, coatings, paints and others. Critical compounds are siloxanes, aromatic amines and high boiling aromatic hydrocarbons like phthalates which are used as softeners in plastic materials. Nowadays all sensitive assembly steps are performed in controlled cleanroom environments to reduce risks of contamination. We will demonstrate a high efficient air filter concept to remove AMCs for production environments with special AMC filters and methods for the qualification and monitoring of these environments. Additionally, we show modern techniques and examples for the pre-qualification of materials. For assembled components, we provide sampling concepts for a routine measurement for process, component and product qualification. A careful selection of previously tested and certified materials and components is essential to guarantee the quality of lasers and optical devices.

  1. Naphthalene and acenaphthene decomposition by electron beam generated plasma application

    Energy Technology Data Exchange (ETDEWEB)

    Ostapczuk, A.; Hakoda, T.; Shimada, A.; Kojima, T. [Institute for Nuclear Chemistry and Technology, Warsaw (Poland)

    2008-08-15

    The application of non-thermal plasma generated by electron beam (EB) was investigated in laboratory scale to study decomposition of polycyclic aromatic hydrocarbons like naphthalene and acenaphthene in flue gas. PAH compounds were treated by EB with the dose up to 8 kGy in dry and humid base gas mixtures. Experimentally established G-values gained 1.66 and 3.72 mol/100 eV for NL and AC at the dose of 1 kGy. NL and AC removal was observed in dry base gas mixtures showing that the reaction with OH radical is not exclusive pathway to initialize PAH decomposition; however in the presence of water remarkably higher decomposition efficiency was observed. As by-products of NL decomposition were identified compounds containing one aromatic ring and oxygen atoms besides CO and CO{sub 2}. It led to the conclusion that PAH decomposition process in humid flue gas can be regarded as multi-step oxidative de-aromatization analogical to its atmospheric chemistry.

  2. Fuel processors for fuel cell APU applications

    Science.gov (United States)

    Aicher, T.; Lenz, B.; Gschnell, F.; Groos, U.; Federici, F.; Caprile, L.; Parodi, L.

    The conversion of liquid hydrocarbons to a hydrogen rich product gas is a central process step in fuel processors for auxiliary power units (APUs) for vehicles of all kinds. The selection of the reforming process depends on the fuel and the type of the fuel cell. For vehicle power trains, liquid hydrocarbons like gasoline, kerosene, and diesel are utilized and, therefore, they will also be the fuel for the respective APU systems. The fuel cells commonly envisioned for mobile APU applications are molten carbonate fuel cells (MCFC), solid oxide fuel cells (SOFC), and proton exchange membrane fuel cells (PEMFC). Since high-temperature fuel cells, e.g. MCFCs or SOFCs, can be supplied with a feed gas that contains carbon monoxide (CO) their fuel processor does not require reactors for CO reduction and removal. For PEMFCs on the other hand, CO concentrations in the feed gas must not exceed 50 ppm, better 20 ppm, which requires additional reactors downstream of the reforming reactor. This paper gives an overview of the current state of the fuel processor development for APU applications and APU system developments. Furthermore, it will present the latest developments at Fraunhofer ISE regarding fuel processors for high-temperature fuel cell APU systems on board of ships and aircrafts.

  3. Monitoring the alkane monooxygenase gene alkB in different soil interfaces during plant litter degradation of C3 and C4 plants

    Science.gov (United States)

    Schulz, S.; Munch, J. C.; Schloter, M.

    2009-04-01

    Hydrocarbons like n-alkanes are ubiquitous in the environment as a result of anthropogenic contamination (e.g. oil spills) as well as a part of an ecosystem's biomass. For example n-alkanes become released during plant litter degradation; consequently they become a high abundant carbon source for microorganism. One possibility for the prokaryotic hydrocarbon metabolisation is an aerobic degradation pathway where the initial step is catalysed by the membrane bound alkane monooxygenase alkB. We analysed the influence of alkanes on the abundance of the alkB gene in different interfaces of the litter-soil system during the degradation of maize and pea litter. Therefore soil samples of a sandy and a loamy soil have been incubated with straw of maize and pea plants up to 30 weeks with constant soil moisture and temperature. Using quantitative real-time PCR we were able to monitor the changes of the abundance and the expression rates of alkB. In our experiments we focused on the straw layer, the litter/soil interface and the soil 1 cm below this interface (bulk soil). Our results clearly demonstrate time and space dependent abundance patterns of alkB genes and transcripts in the different layers studied, which are additionally shaped by the soil type used.

  4. Synthesis and characterization of carbon fibers obtained through plasma techniques; Sintesis y caracterizacion de fibras de carbono obtenidas mediante tecnicas de plasma

    Energy Technology Data Exchange (ETDEWEB)

    Valdivia B, M

    2005-07-01

    The study of carbon, particularly the nano technology is a recent field, the one which has important implications in the science of new materials. It investigation is of great interest for industries producers of ceramic, metallurgy, electronic, energy storage, biomedicine, among others. The diverse application fields are a reason at national as international level, so that many works are focused in the production of nano fibers of carbon. The Thermal plasma applications laboratory (LAPT) of the National Institute of Nuclear Research (ININ), it is carrying out works about carbon nano technology. The present work has as purpose to carry out the synthesis and characterization of the carbon nano fibers which are obtained by electric arch of alternating current (CA) to high frequencies and by a plasma gun of non transferred arch, where are used hydrocarbons like benzene, methane, acetylene like carbon source and ferrocene, nickel, yttrium and cerium oxide like catalysts. For both techniques its were thought about a relationship among hydrocarbon-catalyst that it favored to the nano fibers production. The obtained product of each experiment outlined it was analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD), analysis with those were obtained pictures and diffraction graphs, which were observed to arrive to one conclusion on the operation conditions, same analysis with those were characterized the tests carried out according to the nano structures formation of carbon. (Author)

  5. Pathway to fuel additives or designer fuels from bio-based alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Breitkreuz, Klaas; Menne, Andreas [Fraunhofer-Institut fuer Umwelt-, Sicherheits- und Energietechnik UMSICHT, Oberhausen (Germany); Kraft, Axel

    2013-06-01

    A continuous heterogeneous-catalytic gas-phase process developed by Fraunhofer UMSICHT makes it possible to condense small alcohols and ketones to larger hydrocarbon molecules containing only one atom of oxygen per molecule. After an optional oxygen-removing step such as hydrotreatment, fuel-identical hydrocarbons are yielded. The overall conversion of feedstock to fuel additives or fuels is depicted below: Alcohol - Conversion to higher alcohols - Condensation with acetone - Hydrotreatment (Schematic process flow for the production of fuel-identical hydrocarbons and additives). Depending on raw materials and process conditions, a tailor-made product distribution is possible. The products can be used as fuel additives or as drop-in fuel, matching either diesel or kerosene specifications. The intermediates - secondary alcohols - are valuable as raw materials for several chemical applications, i.e. plasticizer, surfactants, solvents or lubricants. This process offers an attractive alternative to other competing processes producing long-chain hydrocarbons, like Fischer-Tropsch or hydrotreatment of fats and oils. Being based on economical, stable and commercially available catalysts as well as on a wide range of possible raw materials, this method 1s ready for scale up and related process development. (orig.)

  6. Development of a Thermoplastic Magnesia Carbon Brick——"A Cold Process Flexible System"

    Institute of Scientific and Technical Information of China (English)

    R.Mishra; S.Mukhopadhyay

    2006-01-01

    Conventional resin bonded MgO-C bricks, which are manufactured via cold mixing process, harden and attain brittleness during carbonization of resin due to the formation of isotropic glassy carbon. They do not exhibit thermo-plasticity, which can facilitate the release of huge amount of stresses generated during preheating or in operation. On the contrary, pitch bonded MgO-C bricks, show better pyro-plasticity due to formation of an anisotropic and graphitized coke structure during carbonization of pitch. Hence, pitch bonded bricks show a superior structural spalling resistance in comparison to resin-bonded bricks. One of the drawbacks of pitch-bonded bricks is that the manufacturing requires a hot mixing process and hot pressing facility. This paper describes how a combination of above two processes was optimized to make a MgO-C brick via cold process. These bricks exhibit a low Modulus of Elasticity and thereby facilitate release of stresses during operation. Normal coal tar pitch is considered as an environmental hazard due to the presence of polyaromatic hydrocarbons like benzopyrene B [ a ] P. So, a special binder with a low B [ a ] P was selected, which is eco-friendly in nature. Such bricks were made in our plant in China and supplied to an integrated steel plant in Europe for their ladle. The bricks supplied have given encouraging life.

  7. Bio diesel from vegetable oils; Biodiesel a partir de oleos vegetais

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, W.A.; Nunes, P.P.; Ferreira, M.S.; Martins, E.P.; Reguera, F.M.; Pastura, N.M.R. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Quimica. Grupo de Catalise

    2000-07-01

    Obtention alternative fuel from vegetable oils using catalytic transformation is a very interesting possibility, that begin to be research from petroleum crisis in 1973 and 1978, and has an advantage from others ways of energy because it do not vanish the soil nor harmful the ambient. M E catalysis group development research in combustible renewable source since 1979, with several publications. At first, various vegetable oils were researched and became evident that oils must be pre-hydrogenated in order to improve the quantity of hydrocarbons like diesel oil. So far, when the acidity of solids catalysts were studied, Broensted and Lewis acidity from supported catalysts with different acidity were compared, using soybean oil not hydrogenated, babassu and 'pinhao manso and wild', and others fatty acids as models compounds. So, carboxylic acid were studies as models compounds and the vegetable oil reforming on acids catalysts with niobium, modifying zeolites or not by rare earth, in order to get more quantity in bio diesel. This paper objective is notice the research that since 1970 decade is done by this group improving vegetable oils as renewable energy source. (author)

  8. Bacterial biosurfactant in enhancing solubility and metabolism of petroleum hydrocarbons.

    Science.gov (United States)

    Bordoloi, N K; Konwar, B K

    2009-10-15

    Biosurfactant can make hydrocarbon complexes more mobile with the potential use in oil recovery, pumping of crude oil and in bioremediation of crude oil contaminant. In the investigation, bacterial isolates capable of utilizing poly-cyclic aromatic hydrocarbons like phenanthrene, pyrene and fluorene were used. A gradual decrease of the supplemented hydrocarbons in the culture medium was observed with corresponding increase in bacterial biomass and protein. The medium having the combined application of fluorine and phenanthrene caused better biosurfactant production (0.45 g l(-1)) and (0.38 g l(-1)) by Pseudomonas aeruginosa strains MTCC7815 and MTCC7814. The biosurfactant from MTCC7815 (41.0 microg ml(-1)) and MTCC7812 (26 microg ml(-1)) exhibited higher solubilization of pyrene; whereas, MTCC8165 caused higher solubilization of phenanthrene; and that of MTCC7812 (24.45 microg ml(-1)) and MTCC8163 (24.49 microg ml(-1)) caused more solubilzation of fluorene. Higher solubilization of pyrene and fluorene by the biosurfactant of MTCC7815 and MTCC7812, respectively enhanced their metabolism causing sustained growth. Biosurfactants were found to be lipopeptide and protein-starch-lipid complex in nature and they could reduce the surface tension of pure water (72 m Nm(-1)) to 35 m Nm(-1). The critical micelle concentration (CMC) was also lower than the chemical surfactant sodium dodecyl sulphate (SDS). They differed in quantity and structure. The predominant rhamnolipids present in biosurfactants were Rha-C(8)-C(10) and Rha-C(10)-C(8).

  9. New oilseed crops on the horizon

    Energy Technology Data Exchange (ETDEWEB)

    Princen, L.H.

    Fats and oils for food uses are now plentiful on a worldwide basis. Tallow, lard and fish oils, as well as vegetable oils, such as those derived from soybean, sunflower, palm, rapeseed, peanut and cottonseed, are often overproduced. Although many of these products are also used for industrial chemicals, they often are not of the most favorable composition for nonfood applications. A search for new oilseed crops with more advantageous oil composition has led to the development of excellent candidates that are now close to commercial acceptance. Among them are Crambe, Limnanthes, Vernonia, Sapium and Simmondsia. Other crops are at a much lower stage of development but also have excellent potential. They include Cuphea, Foeniculum, Stokesia, Lesquerella and Lunaria. One new oilseed crop which is being considered for hydrocarbon-like fuel is the Chinese tallow tree (Sapium Sebiferum). Recent research estimates predict that seed yield could amount to 10,000 lbs. per acre. At 40% seed lipid levels, this can translate to 4000 lbs. per acre of fuel, more than any other plant species now growing in the US. 24 references, 6 figures, 5 tables.

  10. A magnonic gas sensor based on magnetic nanoparticles.

    Science.gov (United States)

    Matatagui, D; Kolokoltsev, O V; Qureshi, N; Mejía-Uriarte, E V; Saniger, J M

    2015-06-07

    In this paper, we propose an innovative, simple and inexpensive gas sensor based on the variation in the magnetic properties of nanoparticles due to their interaction with gases. To measure the nanoparticle response a magnetostatic spin wave (MSW) tunable oscillator has been developed using an yttrium iron garnet (YIG) epitaxial thin film as a delay line (DL). The sensor has been prepared by coating a uniform layer of CuFe2O4 nanoparticles on the YIG film. The unperturbed frequency of the oscillator is determined by a bias magnetic field, which is applied parallel to the YIG film and perpendicularly to the wave propagation direction. In this device, the total bias magnetic field is the superposition of the field of a permanent magnet and the field associated with the layer of magnetic nanoparticles. The perturbation produced in the magnetic properties of the nanoparticle layer due to its interaction with gases induces a frequency shift in the oscillator, allowing the detection of low concentrations of gases. In order to demonstrate the ability of the sensor to detect gases, it has been tested with organic volatile compounds (VOCs) which have harmful effects on human health, such as dimethylformamide, isopropanol and ethanol, or the aromatic hydrocarbons like benzene, toluene and xylene more commonly known by its abbreviation (BTX). All of these were detected with high sensitivity, short response time, and good reproducibility.

  11. Valorization of biogas into liquid hydrocarbons in plasma-catalyst reactor

    Science.gov (United States)

    Nikravech, Mehrdad; Rahmani, Abdelkader; Labidi, Sana; Saintini, Noiric

    2016-09-01

    Biogas represents an important source of renewable energy issued from biological degradation of biomass. It is planned to produce in Europe the amount of biogas equivalent to 6400 kWh electricity and 4500 kteo (kilo tons equivalent oil) in 2020. Currently the biogas is used in cogeneration engines to produce heat and electricity directly in farms or it is injected in gas networks after purification and odorisation. The aim of this work is to propose a third option that consists of valorization of biogas by transformation into liquid hydrocarbons like acetone, methanol, ethanol, acetic acid etc. These chemicals, among the most important feed materials for chemical industries, retain CO2 molecules participating to reduce the greenhouse gas emissions and have high storage energy capacity. We developed a low temperature atmospheric plasma-catalyst reactor (surface dielectric barrier discharge) to transform biogas into chemicals. The conversion rates of CH4 and CO2 are respectively about 50% and 30% depending on operational conditions. The energetic cost is 25 eV/molecule. The yields of liquid hydrocarbon reaches currently 10% wt. More the 11 liquid chemicals are observed in the liquid fraction. Acknowledgements are due to SPC Programme Energie de demain.

  12. Assessment of soil pollution based on total petroleum hydrocarbons and individual oil substances.

    Science.gov (United States)

    Pinedo, J; Ibáñez, R; Lijzen, J P A; Irabien, Á

    2013-11-30

    Different oil products like gasoline, diesel or heavy oils can cause soil contamination. The assessment of soils exposed to oil products can be conducted through the comparison between a measured concentration and an intervention value (IV). Several national policies include the IV based on the so called total petroleum hydrocarbons (TPH) measure. However, the TPH assessment does not indicate the individual substances that may produce contamination. The soil quality assessment can be improved by including common hazardous compounds as polycyclic aromatic hydrocarbons (PAHs) and aromatic volatile hydrocarbons like benzene, toluene, ethylbenzene and xylenes (BTEX). This study, focused on 62 samples collected from different sites throughout The Netherlands, evaluates TPH, PAH and BTEX concentrations in soils. Several indices of pollution are defined for the assessment of individual variables (TPH, PAH, B, T, E, and X) and multivariables (MV, BTEX), allowing us to group the pollutants and simplify the methodology. TPH and PAH concentrations above the IV are mainly found in medium and heavy oil products such as diesel and heavy oil. On the other hand, unacceptable BTEX concentrations are reached in soils contaminated with gasoline and kerosene. The TPH assessment suggests the need for further action to include lighter products. The application of multivariable indices allows us to include these products in the soil quality assessment without changing the IV for TPH. This work provides useful information about the soil quality assessment methodology of oil products in soils, focussing the analysis into the substances that mainly cause the risk.

  13. Chemical reaction and dust formation studies in laboratory hydrocarbon plasmas.

    Science.gov (United States)

    Hippler, Rainer; Majumdar, Abhijit; Thejaswini, H. C.

    Plasma chemical reaction studies with relevance to, e.g., Titan's atmosphere have been per-formed in various laboratory plasmas [1,2]. Chemical reactions in a dielectric barrier discharge at medium pressure of 250-300 mbar have been studied in CH4 /N2 and CH4 /Ar gas mixtures by means of mass spectrometry. The main reaction scheme is production of H2 by fragmenta-tion of CH4 , but also production of larger hydrocarbons like Cn Hm with n up to 10 including formation of different functional CN groups is observed. [1] A. Majumdar and R. Hippler, Development of dielectric barrier discharge plasma processing apparatus for mass spectrometry and thin film deposition, Rev. Sci. Instrum. 78, 075103 (2007) [2] H.T. Do, G. Thieme, M. Frühlich, H. Kersten, and R. Hippler, Ion Molecule and Dust Particle Formation in Ar/CH4 , Ar/C2 H2 and Ar/C3 H6 Radio-frequency Plasmas, Contrib. Plasma Phys. 45, No. 5-6, 378-384 (2005)

  14. Considerations to the nuclear safety in Mexico; Consideraciones a la seguridad nuclear en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Salas M, B. [UNAM, Facultad de Ciencias, Departamento de Fisica, Laboratorio de Analisis Radiologicos de Muestras Ambientales, Ciudad Universitaria, 04510 Mexico D.F. (Mexico)]. e-mail: salasmarb@yahoo.com.mx

    2006-07-01

    The uncertain future of the hydrocarbons like main source of energy, force us to think on the nuclear energy as the suitable substitute that we can inherit to those future generations. Mexico therefore should multiply the number of nuclear power centrals and to be in this way prepared for the new challenges, however, it is necessary and advisable, to restate the mexican nuclear plan that includes mainly the transparency. The 'WANO Report' (World Association of Nuclear Operators - for their initials in English), result of a technical audit to the Nuclear Power station of Laguna Verde (CNLV), it is a polemic topic, because in accordance with David Lochbaum of 'The Union of Concerned Scientists' of the United States of America and of John Large of 'Large and Associates' of the Great Britain, the security in the CNLV is questionable. The pronouncements of concern of Abel J. Gonzalez and Ken E. Brockman, high officials of the International Atomic Energy Agency who took knowledge of diverse irregularities in the CNLV, should be analysis reason for to take actions in pro of the future of the nuclear energy in Mexico. (Author)

  15. Molecular characterisation of organic material in air fine particles (PM10) using conventional and reactive pyrolysis-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Fabbri, Daniele; Prati, Silvia; Vassura, Ivano

    2002-04-01

    Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) was applied to study the composition of organic constituents in air particulate matter (PM10) collected inside an industrial area. A few milligrams of sampling filters containing air particles were pyrolysed at 700 degrees C directly (conventional) or after the addition of a derivatising reagent (tetramethylammonium hydroxide, TMAH, for pyrolysis-methylation; hexamethyldisilazane, HMDS, for pyrolysis-silylation). Py-GC-MS was also applied to synthetic polymers (poly(styrene-co-isoprene), polylimonene and polypinene) and vegetation samples (coniferous pollen, bark and resin) to identify markers indicative of possible precursors. Pyrolysates of PM10 showed the same suite of compounds in all the four seasons, dominated by hydrocarbons like styrene, limonene and clusters of isomeric alkenes with 14, 15 and 16 carbon atoms. Pyrolysis products of natural origin, including furaldehyde, benzeneacetonitrile, dehydroabietin and other diterpenoids were found, while no specific markers of synthetic rubbers were detected. The principal products released from reactive pyrolysis of PM10 were methyl or trimethylsilyl (TMS) derivatives of 1,6-anhydroglucose (levoglucosan), fatty acids, dehydroabietic acid and other resin acids along with hydroxy (di)carboxylic acids. Possible sources of the detected products (e.g. pine forest, biomass combustion) are discussed.

  16. Demonstration of the economic feasibility of plant tissue culture for jojoba (Simmondsia chinensis) and Euphorbia spp

    Energy Technology Data Exchange (ETDEWEB)

    Sluis, C.

    1980-09-01

    The economic feasibility of plant tissue culture was demonstrated as applied to two plants: jojoba (Simmondsia chinensis) and Euphorbia spp. The gopher weed (Euphorbia lathyris) was selected as the species of Euphorbia to research due to the interest in this plant as a potential source of hydrocarbon-like compounds. High yield female selections of jojoba were chosen from native stands and were researched to determine the economic feasibility of mass producing these plants via a tissue culture micropropagation program. The female jojoba selection was successfully mass produced through tissue culture. Modifications in initiation techniques, as well as in multiplication media and rooting parameters, were necessary to apply the tissue culture system, which had been developed for juvenile seedling tissue, to mature jojobas. Since prior attempts at transfer of tissue cultured plantlets were unsuccessful, transfer research was a major part of the project and has resulted in a system for transfer of rooted jojoba plantlets to soil. Euphorbia lathyris was successfully cultured using shoot tip cultures. Media and procedures were established for culture initiation, multiplication of shoots, callus induction and growth, and root initiation. Well-developed root systems were not attained and root initiation percentages should be increased if the system is to become commercially feasible.

  17. Potential contribution of semi-volatile and intermediate volatility primary organic compounds to secondary organic aerosol in the Mexico City region

    Directory of Open Access Journals (Sweden)

    A. Hodzic

    2010-01-01

    Full Text Available It has been established that observed local and regional levels of secondary organic aerosols (SOA in polluted areas cannot be explained by the oxidation and partitioning of anthropogenic and biogenic VOC precursors, at least using current mechanisms and parameterizations. In this study, the 3-D regional air quality model CHIMERE is applied to quantify the contribution to SOA formation of recently identified semi-volatile and intermediate volatility organic vapors (S/IVOC in and around Mexico City for the MILAGRO field experiment during March 2006. The model has been updated to include explicitly the volatility distribution of primary organic aerosols (POA, their gas-particle partitioning and the gas-phase oxidation of the vapors. Two recently proposed parameterizations, those of Robinson et al. (2007 ("ROB" and Grieshop et al. (2009 ("GRI" are compared and evaluated against surface and aircraft measurements. The 3-D model results are assessed by comparing with the concentrations of OA components from Positive Matrix Factorization of Aerosol Mass Spectrometer (AMS data, and for the first time also with oxygen-to-carbon ratios derived from high-resolution AMS measurements.

    The results show a substantial enhancement in predicted SOA concentrations (3–6 times with respect to the previously published base case without S/IVOCs (Hodzic et al., 2009, both within and downwind of the city leading to much reduced discrepancies with the total OA measurements. The predicted anthropogenic POA levels are found to agree within 20% with the observed HOA concentrations for both the ROB and GRI simulations, consistent with the interpretation of the emissions inventory by previous studies. The impact of biomass burning POA within the city is underestimated in comparison to the AMS BBOA, presumably due to insufficient nighttime smoldering emissions. Model improvements in OA predictions are associated with the better-captured SOA magnitude and diurnal

  18. 南京夏季大气有机气溶胶老化过程在线观测研究

    Institute of Scientific and Technical Information of China (English)

    张运江; 汤莉莉; 王壮; 于红霞; 张祥志; 周宏仓; 陈杨; 江蓉馨

    2014-01-01

    大气有机气溶胶(OA)老化过程的在线观测是气溶胶化学研究领域的难点之一.本研究应用颗粒物化学组分监测仪(ACSM)对南京夏季城区大气非难熔性亚微米细颗粒物(NR-PM1)组分进行在线连续观测,并利用ACSM观测出的特征碎片离子,即f44(m/z 44与总OA的质谱信号之比)与f57(m/z 57与总OA的质谱信号之比)间的函数关系(f44 vs f57)及变化规律来动态估计大气中烃类有机气溶胶(HOA)的老化过程.结果表明:观测期间NR-PM1平均质量浓度为19.87±8.46μg m-3,其中OA占比最大(51.8%),且OA中氧化态有机气溶胶(OOA)的贡献较大(72%±0.14%).OOA,Ox(Ox=O3+NO2)的质量浓度与OOA/ΔCO(ΔCO是去除CO背景值后的质量浓度)呈相似的日变化规律,表明OOA的生成过程主要受大气光化学活性的影响.在f44 vs f57中,OOA/ΔCO和Ox质量浓度随f44的增大而逐渐增大,而HOA/ΔCO和HOA/OA的大小随f44的增大逐渐减小.这些特征反映出HOA通过光化学反应作用逐渐向OOA转化的过程.此外,利用f57的变化规律估算大气中HOA所需的老化时间约为5~10 h.本文为外场观测中动态长期地研究大气气溶胶的老化进程及其寿命提供一种新思路和方法.

  19. Is hexamerin receptor a GPI-anchored protein in Achaea janata (Lepidoptera: Noctuidae)?

    Science.gov (United States)

    Budatha, Madhusudhan; Ningshen, Thuirei Jacob; Dutta-Gupta, Aparna

    2011-08-01

    The process of uptake of hexamerins during metamorphosis from insect haemolymph by fat body cells is reminiscent of receptor-mediated endocytosis. Previously, we had identified a hexamerin-binding protein (HBP) and reported for the first time that uptake of hexamerins is dependent on the phosphorylation of HBP partly by a tyrosine kinase, which is, in turn, activated by 20-hydroxyecdysone (20E). However, the exact nature of HBP and the mechanism of interaction are still unknown. Here we report the possibility of HBP being a GPI-anchored protein in the fat body of Achaea janata and its role in the tyrosine-kinase-mediated phosphorylation signalling. Digestion of fat body membrane preparation with bacterial phosphatidylinositol-specific phospholipase C (PI-PLC), and the subsequent recognition by antibodies specific for the cross-reacting determinant (CRD), revealed that HBP is glycosylphosphatidylinositol (GPI)-anchored protein and, further, that the hexamerin binding to HBP was inhibited after digestion. Hexamerin overlay assay (HOA) of co-immunoprecipitated in vitro phosphorylated HBP showed exclusive binding to ~120 kDa protein. Lectin-binding analysis of hexamerins revealed the presence of N-acetylgalactosamine (GalNAc) and N-acetylglucosamine (GluNAc), whereas HBP showed the presence of GalNac alone. Mild chemical deglycosylation studies and binding interaction in the presence of sugars revealed that glycan moieties are possibly not involved in the interaction between HBP and hexamerins. Taken together, these results suggest that HBP may be a GPI-anchored protein, and interaction and activation of HBP is through lipid-linked non-receptor src tyrosine kinases. However, additional studies are needed to prove that HBP is a GPI-anchored protein.

  20. Prediction of acute stroke progression by the National Institutes of Health Stroke Scale

    Institute of Scientific and Technical Information of China (English)

    Vinh Phuong; Tran Van Huy

    2007-01-01

    Objective To determine the occurrence of neurological changes during the first 48 hours after acute stroke as it relates to the initial stroke severity assessment. Methods The assessment with the National Institutes of Health Stroke Scale (NIHSS) was performed serially for the first 48 hours on 68 consecutive ischemic stroke patients admitted to the Department of Geriatric Cardiology at the Khanh Hoa Hospital, Nha Trang, Vietnam. Incidence of stroke progression (a ≥ 3-point increase on the NIHSS) was recorded and analysis performed to determine its association with initial stroke severity and other demographic and physiological variables. Deficit resolution by 48 hours, defined as an NIHSS score of 0 or 1, measured the frequency of functional recovery predicted by the initial deficit.Results Overall progression was noted in 28% of events (19/68). Applying Bayes' solution to the observed frequency of worsening, the greatest likelihood of predicting future patient progression occurred with NIHSS score of =7 and >7. Patients with an initial NIHSS score of =7 experienced a 13% (6/47) worsening rate versus those of an initial score of>7 with a 62% (13/21) worsening rate (P<0.01). 42.5%(20/47) of those with an initial score of =7 were functionally normal at 48 hours, whereas only 4.7% (1/21) of those with scores of >7 retnrned to a normal examination within this period (x2, P<0.05). Conclusions This study suggests that the early clinical course of neurological deficit after acute stroke be dependent on the initial stroke severity and that a dichotomy in early outcome exist surrounding an initial NIHSS score of 7. These findings may have significant implications for the design and patient stratification in treatment protocols with respect to primary clinical outcome.

  1. Risk factors of regression and undercorrection in photorefractive keratectomy:a case-control study

    Directory of Open Access Journals (Sweden)

    Seyed-Farzad Mohammadi

    2015-10-01

    Full Text Available AIM:To determine risk factors of regression and undercorrection following photorefractive keratectomy (PRK in myopia or myopic astigmatism.METHODS: A case-control study was designed in which eyes with an indication for re-treatment (RT were defined as cases; primary criteria for RT indication, as assessed at least 9mo postoperatively, included an uncorrected distance visual acuity (UDVA of 20/30 or worse and a stable refraction for more than 3mo. Additional considerations included optical quality symptoms and significant higher order aberrations (HOAs. Controls were chosen from the same cohort of operated eyes which had complete post-operative follow up data beyond 9mo and did not need RT. The cohort included patients who had undergone PRK by the Tissue-Saving (TS ablation profile of Technolas 217z100 excimer laser (Bausch & Lomb, Rochester, NY, USA. Mitomycin C had been used in all of the primary procedures.RESULTS:We had 70 case eyes and 158 control eyes, and they were comparable in terms of age, sex and follow-up time (P values:0.58, 1.00 and 0.89, respectively. Pre-operative spherical equivalent of more than -5.00 diopter (D, intended optical zone (OZ diameter of less than 6.00 mm and ocular fixation instability during laser ablation were associated with RT indications (all P values <0.001. These factors maintained their significance in the multiple logistic regression model with odd ratios of 6.12, 6.71 and 7.89, respectively.CONCLUSION:Higher refractive correction (>-5.00 D, smaller OZ (<6.00 mm and unstable fixation during laser ablation of PRK for myopia and myopic astigmatism were found to be strong predictors of undercorrection and regression.

  2. New strategy toward dioxin risk reduction for local residents surrounding severe dioxin hotspots in Vietnam

    Directory of Open Access Journals (Sweden)

    Vu-Anh Le

    2013-06-01

    Full Text Available Background: A public health intervention program with active involvement of local related stakeholders was piloted in the Bien Hoa dioxin hotspot (2007–2009, and then expanded to the Da Nang dioxin hotspot in Vietnam (2009–2011. It aimed to reduce the risk of dioxin exposure of local residents through foods. This article presents the results of the intervention in Da Nang. Methodology: To assess the results of this intervention program, pre- and post-intervention knowledge, attitude, and practice (KAP surveys were implemented in 400 households, randomly selected from four wards surrounding the Da Nang Airbase in 2009 and 2011, respectively. Results: After the intervention, the knowledge on the existence of dioxin in food, dioxin exposure pathways, potential high-risk foods, and preventive measures significantly increased (P<0.05. Ninety-eight percent were willing to follow advice on preventing dioxin exposure. Practices to reduce the risk of dioxin exposure also significantly improved (P<0.05. After intervention, 60.4% of households undertook exposure preventive measures, significantly higher than that of the pre-intervention survey (39.6%; χ2=40.15, P<0.001. High-risk foods had quite low rates of daily consumption (from 0 to 2.5% and were significantly reduced (P<0.05. Conclusions: This is seen as an effective intervention strategy toward reducing the risk of human exposure to dioxin at dioxin hotspots. While greater efforts are needed for remediating dioxin-polluted areas inside airbases, there is also evidence to suggest that, during the past four decades, pollution has expanded to the surrounding areas. For this reason, this model should be quickly expanded to the remaining dioxin hotspots in Vietnam to further reduce the exposure risks in other areas.

  3. Diagnóstico e tratamento do lenticone anterior

    Directory of Open Access Journals (Sweden)

    Ana Luiza Biancardi

    2011-08-01

    Full Text Available Relato de caso de um paciente de 18 anos com sindrome de Alport apresentando perda visual progressiva. A biomicroscopia revelou lenticone anterior bilateral. O paciente realizou tomografia de córnea e segmento anterior com o sistema Scheimpflug (Pentacam e aberrometria e topografia corneana (i-Trace. O paciente foi submetido à facoemulsificação com implante de lente intraocular peça única hidrofóbica (Acrysof® SN60AT. As imagens de Scheimpflug documentaram o lenticone anterior. A aberrometria total mostrou acentuado astigmatismo miópico com acentuada aberração esférica negativa, havendo grande impacto das aberrações de alta ordem (HOA na conversão da letra E de Snellen. O mapa de integração da aberrometria do olho todo com a topografia corneana mostrou maior semelhança das aberrrações totais com as aberrações intraoculares do que com as aberrações da superfície anterior da córnea. Após a cirurgia, o paciente apresentou acuidade visual corrigida igual a 20/20 em ambos os olhos, as imagens de Scheimpflug revelaram lentes intraoculares tópicas e os mapas diferenciais revelaram resolução da miopia e redução das aberrações da alta ordem (total e interna. Os exames de imagem foram úteis para demonstrar o impacto do lenticone anterior na qualidade visual e a resolução das aberrações ópticas após a cirurgia.

  4. 婴儿湿疹辨治心得%The experience of syndrome differentiation in infantile eczema

    Institute of Scientific and Technical Information of China (English)

    李淑霞

    2014-01-01

    从病因病机、诊断要点、治疗方法等方面总结治疗婴儿湿疹的临证心得。认为婴儿湿疹多因母食五辛炙煿,遗热与胎儿,生后复感风热,或饮食不节,脾失健运,内蕴湿热所致,主要与心肺和脾胃等脏腑功能失调有关。因小儿的生理特点为“脾常不足”,婴儿湿疹多因脾虚湿阻,治疗应健脾与清化湿热相结合,兼以散肺经风热。内服自拟方“清热利湿止痒汤”,外用自拟方“湿疹洗剂”外涂。%We summarize the clinical experience in the treatment of infantile eczema from the aspects of etiology and pathogenesis,diagnosed main points and treatment methods.We consider that infantile eczema because of mother eat Wuxinzhibo, left heat with fetal,postnatal reply the feeling the heat,or improper diet,dysfunction of the spleen in transport,intrinsic hot and humid,and mainly related to the dysfunction of heart-lung,spleen-stomach and other organs.Because the physiological features of children is “the spleen is often insufficient”,infantile eczema more due to spleen deficiency and damp obstruction,so the treatment should combine tonifying spleen with thanh hoa hot and humid,and scattered in the lung by wind heat.To be taken orally self “Qingre Lishi Zhiyang decoction”,external using self "eczema lotion besmear" exterior coating.

  5. Mapping seagrass beds and coral reefs in the coastal region of Vietnam using VNREDSAT-1 data

    Science.gov (United States)

    Lau, K. V.; Chen, C. F.; Nguyen, S. T.; Chen, C. R.; Tong Phuoc, H. S.; Nguyen, H. H.

    2015-12-01

    Seagrass beds and coral reefs are two important ecosystems in the coastal zone. They play an important role to protect and shelter various marine organisms. Both seagrass beds and coral reefs could prevent the coastline from erosion. While seagrass stabilizes sediments and acts as a biofilter, coral reefs can control carbon dioxide in the ocean water. Besides, seagrass also provides direct food for many fish and marine animals. Therefore, mapping seagrass beds and coral reefs is very important for coastal management and conservation. In May 2013, Vietnam launched the first satellite for earth observations, called Vietnam Natural Resources, Environment and Disaster Monitoring Satellite (VNREDSAT-1). It is a great opportunity for environmental monitoring in the country using the data from this satellite. The objective of this study is to use the VNREDSAT-1 data to map seagrass beds and coral reefs in the coastal region of Ninh Hai district, Ninh Thuan province, Vietnam, where the seagrass still remains in good a condition. We processed the VNREDSAT-1 image through four steps: (1) Atmospheric correction using Second Simulation of the Satellite Signal in the Solar Spectrum radiative transfer model (6S), (2) Sun glint removal by using Hedley method, (3) Water column correction using the depth-variant index (DII) proposed by Lyzenga, and (4) Image classification using the maximum likelihood algorithm. The mapping results verified with the ground reference data showed a good overall accuracy of 75% and Kappa coefficient of 0.7. The total area of seagrass beds was approximately 323.09 ha, which mainly distributed in My Hoa and Thai An villages. The total area of coral reefs was approximately 564.42 ha, located along the coast and on outer area to seagrass and shoreline reefs. This study demonstrates the applicability of VNREDSAT-1 for underwater habitat monitoring. The results could be useful for natural resources managers to devise strategies for management and

  6. Using measured octanol-air partition coefficients to explain environmental partitioning of organochlorine pesticides.

    Science.gov (United States)

    Shoeib, Mahiba; Harner, Tom

    2002-05-01

    Octanol-air partition coefficients (Koa) were measured directly for 19 organochlorine (OC) pesticides over the temperature range of 5 to 35 degrees C. Values of log Koa at 25 degrees C ranged over three orders of magnitude, from 7.4 for hexachlorobenzene to 10.1 for 1,1-dichloro-2,2-bis(p-chlorophenyl) ethane. Measured values were compared to values calculated as KowRT/H (where R is the ideal gas constant [8.314 J mol(-1) K(-1)], T is absolute temperature, and H is Henry's law constant) were, in general, larger. Discrepancies of up to three orders of magnitude were observed, highlighting the need for direct measurements of Koa. Plots of Koa versus inverse absolute temperature exhibited a log-linear correlation. Enthalpies of phase transition between octanol and air (deltaHoa) were determined from the temperature slopes and were in the range of 56 to 105 kJ mol(-1) K(-1). Activity coefficients in octanol (gamma(o)) were determined from Koa and reported supercooled liquid vapor pressures (pL(o)), and these were in the range of 0.3 to 12, indicating near-ideal solution behavior. Differences in Koa values for structural isomers of hexachlorocyclohexane were also explored. A Koa-based model was described for predicting the partitioning of OC pesticides to aerosols and used to calculate particulate fractions at 25 and -10 degrees C. The model also agreed well with experimental results for several OC pesticides that were equilibrated with urban aerosols in the laboratory. A log-log regression of the particle-gas partition coefficient versus Koa had a slope near unity, indicating that octanol is a good surrogate for the aerosol organic matter.

  7. One year online chemical speciation of submicron particulate matter (PM1) sampled at a French industrial and coastal site

    Science.gov (United States)

    Zhang, Shouwen; Riffault, Véronique; Dusanter, Sébastien; Augustin, Patrick; Fourmentin, Marc; Delbarre, Hervé

    2015-04-01

    The harbor of Dunkirk (Northern France) is surrounded by different industrial plants (metallurgy, petrochemistry, food processing, power plant, etc.), which emit gaseous and particulate pollutants such as Volatile Organic Compounds (VOCs), oxides of nitrogen (NOx) and sulfur (SO2), and submicron particles (PM1). These emissions are poorly characterized and their impact on neighboring urban areas has yet to be assessed. Studies are particularly needed in this type of complex environments to get a better understanding of PM1sources, especially from the industrial sector, their temporal variability, and their transformation. Several instruments, capable of real-time measurements (temporal resolution ≤ 30 min), were deployed at a site located downwind from the industrial area of Dunkirk for a one-year duration (July 2013-September 2014). An Aerosol Chemical Speciation Monitor (ACSM) and an Aethalometer monitored the main chemical species in the non-refractory submicron particles and black carbon, respectively. Concomitant measurements of trace gases and wind speed and direction were also performed. This dataset was analyzed considering four wind sectors, characteristics of marine, industrial, industrial-urban, and urban influences, and the different seasons. We will present a descriptive analysis of PM1, showing strong variations of ambient concentrations, as well as evidences of SO2 to SO4 gas-particle conversion when industrial plumes reached the monitoring site. The organic fraction measured by ACSM (37% of the total mass on average) was analyzed using a source-receptor model based on Positive Matrix Factorization (PMF) to identify chemical signatures of main emission sources and to quantify the contribution of each source to the PM1 budget given the wind sector. Four main factors were identified: hydrocarbon organic aerosol (HOA), oxygenated organic aerosol (OOA), biomass burning organic aerosol (BBOA) and cooking-like organic aerosol (COA). Overall, the total PM

  8. Is hexamerin receptor a GPI-anchored protein in Achaea janata (Lepidoptera: Noctuidae)?

    Indian Academy of Sciences (India)

    Madhusudhan Budatha; Thuirei Jacob Ningshen; Aparna Dutta-Gupta

    2011-08-01

    The process of uptake of hexamerins during metamorphosis from insect haemolymph by fat body cells is reminiscent of receptor-mediated endocytosis. Previously, we had identified a hexamerin-binding protein (HBP) and reported for the first time that uptake of hexamerins is dependent on the phosphorylation of HBP partly by a tyrosine kinase, which is, in turn, activated by 20-hydroxyecdysone (20E). However, the exact nature of HBP and the mechanism of interaction are still unknown. Here we report the possibility of HBP being a GPI-anchored protein in the fat body of Achaea janata and its role in the tyrosine-kinase-mediated phosphorylation signalling. Digestion of fat body membrane preparation with bacterial phosphatidylinositol-specific phospholipase C (PI-PLC), and the subsequent recognition by antibodies specific for the cross-reacting determinant (CRD), revealed that HBP is glycosylphosphatidylinositol (GPI)-anchored protein and, further, that the hexamerin binding to HBP was inhibited after digestion. Hexamerin overlay assay (HOA) of co-immunoprecipitated in vitro phosphorylated HBP showed exclusive binding to ∼120 kDa protein. Lectin-binding analysis of hexamerins revealed the presence of -acetylgalactosamine (GalNAc) and -acetylglucosamine (GluNAc), whereas HBP showed the presence of GalNac alone. Mild chemical deglycosylation studies and binding interaction in the presence of sugars revealed that glycan moieties are possibly not involved in the interaction between HBP and hexamerins. Taken together, these results suggest that HBP may be a GPI-anchored protein, and interaction and activation of HBP is through lipid-linked non-receptor src tyrosine kinases. However, additional studies are needed to prove that HBP is a GPI-anchored protein.

  9. PERANCANGAN FLOATING DOCK UNTUK DAERAH PERAIRAN PELABUHAN KOTA TEGAL

    Directory of Open Access Journals (Sweden)

    Kiryanto Kiryanto

    2013-06-01

    Full Text Available Floating dock merupakan bangunan air sebagai tempat reparasi kapal yang dinilai cukup efisien dalam pembangunannya karena tidak membutuhkan dana yang terlalu mahal. Di sektor indusrti perkapalan kota tegal sudah memiliki galangan dan dock reparasi kapal yang cukup berkembang.  Ide perancangan floating dock ini dirancang sebagai alternatif baru pelayanan reparasi kapal. Perancangan floating dock ini juga memperhatikan dengan detail kapasitas kapal – kapal yang pernah melakukan repararasi di sekitar galangan di Kota Tegal agar ditemukan ukuran utama floating dock yang tepat. Dari Kapasitas kapal yang ada dan berdasarkan metode perbandingan ukuran beberapa floating dock, maka ditemukan ukuran utama yang tepat untuk menampung kebutuhan pelayanan reparasi kapal yaitu LOA = 136,37 m, Lpt = 114.80 m, Bmax = 36,40 m, Bmd: 30,80 m, Tmin = 0,86 m, Tmax = 1,58 m, Hpt = 2,10 m, HOA = 9,60 m. Berdasarkan perhitungan ditemukan juga Ton Lifting Capacity (TLC sebesar 3000 ton. Perancangan menggunakan software perkapalan yaitu dengan menggunakan AutoCad, Delftship, Maxsurf dan Hidromax. Dengan analisa stabilitas menggunakan software Hidromax diketahui bahwa floating dock ini mampu memiliki stabilitas yang baik dengan 4 kondisi yang semua memenuhi criteria  International Maritime Organisation (IMO. Perancangan floating dock ini juga menghitung analisa ekonomis dan investasi. Dari rekapitulasi dana investasi pembangunan floating dock yaitu sebesar Rp.136.622.888.000,00 dengan nilai kembali atau break even point selama 10 tahun dengan modal sendiri, 14 tahun dengan 50% modal sendiri dan 50 % pinjaman bank, dan break event point 18 tahun untuk dana pembangunan floating dock yang berasal dari 100 % pinjaman bank

  10. Respiratory virus laboratory pandemic planning an surveillance in central Viet Nam, 2008-2010

    Directory of Open Access Journals (Sweden)

    Trinh Xuan Mai

    2012-07-01

    Full Text Available Introduction: Laboratory capacity is needed in central Viet Nam to provide early warning to public health authorities of respiratory outbreaks of importance to human health, for example the outbreak of influenza A(H1N1 pandemic in 2009. Polymerase chain reaction (PCR procedures established as part of a capacity-building process were used to conduct prospective respiratory surveillance in a region where few previous studies have been undertaken.Methods: Between October 2008 and September 2010, nose and throat swabs from adults and children (approximately 20 per week presenting with an acute respiratory illness to the Ninh Hoa General Hospital were collected. Same-day PCR testing and result reporting for 13 respiratory viruses were carried out by locally trained scientists.Results: Of 2144 surveillance samples tested, 1235 (57.6% were positive for at least one virus. The most common were influenza A strains (17.9%, with pandemic influenza A(H1N1 2009 and seasonal H3N2 strain accounting for 52% and 43% of these, respectively. Other virus detections included: rhinovirus (12.4%, enterovirus (8.9%, influenza B (8.3%, adenovirus (5.3%, parainfluenza (4.7%, respiratory syncytial virus (RSV (3.9%, human coronavirus (3.0% and human metapneumovirus (0.3%. The detection rate was greatest in the 0–5 year age group. Viral co-infections were identified in 148 (6.9% cases.Discussion: The outbreak in 2009 of the influenza A(H1N1 pandemic strain provided a practical test of the laboratory’s pandemic plan. This study shows that the availability of appropriate equipment and molecular-based testing can contribute to important individual and public health outcomes in geographical locations susceptible to emerging infections.

  11. Youth Evaluations of CVE/PVE Programming in Kenya in Context

    Directory of Open Access Journals (Sweden)

    Melissa Finn

    2016-06-01

    Full Text Available Despite the military efforts of the Kenyan, Ethiopian, and Somali Federal governments, the collaboration of the African Union Mission in Somalia (AMISOM forces with US and coalition forces, and despite the enormous tactical and strategic set-backs that al-Shabaab has faced over the last five years, its insurgency in Horn of Africa (HoA remains resilient. The Kenyan government’s approach to stemming domestic recruitment to al-Shabaab remains fixated on law enforcement control and surveillance. As a result, many Somali communities are subject to daily crackdowns, interrogations, and discriminatory profiling practices whose negative effects are only heightened by current tribal and clan-based tensions in the country. Current scholarly evaluations of Kenya’s countering violent extremism (CVE policies tend to adhere to three major approaches: top-down evaluations by elites repeatedly locating the protection of national security in inter-agency cooperation; bottom-up CVE evaluations placing primacy on the voices of Muslim community elders, such as imams, social workers, parents, and community leaders for interventions with at-risk youth; and social scientific evaluations of CVE policy through empirical exploration of the push and pull factors of youth recruitment into militancy. To date, there is a dearth of studies asking what Kenyan youth leaders think about CVE policies especially in light of the fact that they are often the main targets of al-Shabaab attacks. This study has one key objective: to use input from Kenyan youth to evaluate the effectiveness, suitability, and appropriateness of Kenya’s current CVE policies in order to dissect their utility, inefficiencies, and possible harms, and contribute to the academic and policy discussions on the best CVE policy mix.

  12. Biểu Đạt Căn Tính Di Dân trên Quê Hương Việt-Mỹ và tại Hải Ngoại 1975-2015:Từ Những Tự Phát Sắc Tộc đến Thể Hiện Toàn Cầu

    OpenAIRE

    Glassey-Tranguyen, Trangdai

    2016-01-01

    Từ khi cuộc chiến Việt Nam kết thúc ngày 30 tháng Tư, 1975, nhiều đợt người Việt di tản, tỵ nạn, và di dân đã đến Hoa Kỳ và xây dựng một mái ấm mới trên toàn quốc. Quận Cam, California, là nơi tập trung người Mỹ gốc Việt nhiều nhất từ năm 1975, và được mệnh danh là “thủ đô tỵ nạn của người Việt” tại hải ngoại. Tôi cho rằng có một nền văn học và truyền thông tiếng Việt tự phát, sung mãn – tuy chưa được nghiên cứu thoả đáng – tại Quận Cam và quê hương Việt-Mỹ (VietnAmerica) từ năm 1975. Nền văn...

  13. Changes of wavefront aberrations in keratoconus corrected with rigid gas permeable contact lens%圆锥角膜患者配戴硬性透氧性角膜接触镜后波前像差的改变

    Institute of Scientific and Technical Information of China (English)

    张立华; 王兵; 贾丁; 冯恬风; 董慧

    2012-01-01

    Objective To investigate the changes of wavefront aberrations in keratoconus corrected with rigid gas permeable contact lens (RGPCL).Methods It was a prospective case-control study.Twenty-five patients (43 eyes) confirmed by corneal topography as keratoconus were corrected with RGPCL.Their corrected visual acuity (VA) and wavefront aberrations were detected by iTrace dynamic laserefraction before and after wearing RGPCL for 2 weeks.Lower-order abberations LOAs,higher-order abberation HOAs,coma,spherical and trefoil were measured.The results measured were compared using paired samples t test.Results There were statistic differences in total ocular wavefront aberrations,LOAs,HOAs,coma and trefoil.Total ocular wavefront aberrations were reduced from 9.12±4.20 μm to 1.67±0.92 μm after wearing RGPCL (t=9.062,P<0.01); LOAs were reduced from 8.88-±3.90 μm to 1.37±0.75 μm after wearing RGPCL (t=9.507,P<0.01); HOAs were reduced from 1.90±0.14 μm to 0.79±0.21 μm after wearing RGPCL (t=2.473,P<0.05); coma were reduced from 0.99±0.15 μm to 0.30±0.18 μm after wearing RGPCL (t=2.364,P<0.05); trefoil were reduced from 0.92±0.19 μm to 0.22±0.14 μm after wearing RGPCL (t=2.757,P<0.05).There were no statistics differences in spherical abberation.Spherical abberation were reduced from 0.54±0.25 μm to 0.32±0.27 μm after wearing RGPCL (t=1.239,P>0.05).Conclusion Keratoconus patients with RGPCL can reach satisfying corrected visual acuity and visual quantity.Total ocular wavefront aberrations were significant reduced after wearing RGPCL.%目的 研究圆锥角膜患者配戴硬性透氧性角膜接触镜(RGPCL)后波前像差及视觉质量的改变.方法 前瞻性病例对照研究.收集在山西省眼科医院就诊的圆锥角膜患者25例(43眼),选配合适的RGPCL配戴2周后,分别于配戴前及配戴后测定其矫正视力,采用iTrace波前像差仪进行戴镜前后的全眼波前像差测量,并测量戴镜前后高阶、低阶像差

  14. Clinical effect observation of wavefront-guided femtosecond laser in situ keratomileusis for correcting high myopia%波前像差引导的飞秒激光LASIK手术矫正高度近视的效果

    Institute of Scientific and Technical Information of China (English)

    崔敏; 周奇志

    2013-01-01

    were chosen as control group.These patients were followed up for 6 months. Uncorrected visual acuity ( UCVA ) , refraction, total high order aberrations ( HOA) , spherical values and coma values between two groups were compared. RESULTS:Six months after the operation, UCVA of all eyes were higher than 0.8.UCVA achieved 1.0 or better, which account for 91.4%of eyes in wavefront group and 87.5% in control group, the difference was not statistically significant (P=0.360).UCVA achieved 1.2 or better in 60.3%of eyes in wavefront group and 57.1%in control group, the difference was not statistically significant (P=0.729).UCVA achieved 1.5 or better in 17.2%of eyes in wavefront group and 12.5% in control group, the difference was not statistically significant ( P=0.477).The coma values were lower in wavefront group than that in control group, the difference was statistically significant ( P =0.021 ) . There was no statistically significant difference in postoperative UCVA, refractions, total HOA and spherical values between two groups ( P>0.05). CONCLUSION: Compared with conventional LASIK with femtosecond laser, although wavefront -guided LASIK with femtosecond laser canreduce the coma values of patients with high myopia, wavefront-guided LASIK with femtosecond laser has no adventage in improving UCVA, correcting refractions, reducing the total HOA, and.spherica values.

  15. A critical comparative study of indoor air pollution from household cooking fuels and its effect on health

    Directory of Open Access Journals (Sweden)

    Basant Shubhankar

    2016-03-01

    Full Text Available This paper throws light on household cooking related exposures and level of indoor air pollutants (particulate matter and gaseous pollutants CO, CO2, SO2, NO, NO2 in different exposure area from the different types of cooking fuels used. Still the prevalence of biomass fuels exists in Indian households, combustion of which releases higher levels of solid and gaseous pollutants during the cooking hours. The indoor air pollutants (SPM, CO, CO2, SO2, NO, NO2 were measured with handy samplers with different types of cooking fuels (biomass and LPG. For this purpose 50 randomly selected sampled of the indoor air quality were monitored. The results suggests that average concentration of PM10 (394.07 μg/m3 and gaseous pollutants (CO-3.15 ppm, CO2- 492.63 ppm, SO2-0.56 ppm, NO-0.58 ppm, NO2-0.52 ppm were highest during cooking hours with biofuels cooking places. Thus, not only the women who are involved in cooking suffer from the various ill effects, but also other family members who are inside the house during cooking hours also face exposures. The recorded SPM (114.73 μg/m3 for PM10 and gaseous pollutants (CO-1.34 ppm, CO2-379.83 ppm, SO2-0.52 ppm, NO-0.54 ppm, NO2-0.52 ppm in LPG using households were lower as compared to biomass fuel using households. Due to the LPG efficiency the time involved in cooking is also low leading to less exposure to the pollutants released.

  16. Development of Disease-specific, Context-specific Surveillance Models: Avian Influenza (H5N1)-Related Risks and Behaviours in African Countries.

    Science.gov (United States)

    Fasina, F O; Njage, P M K; Ali, A M M; Yilma, J M; Bwala, D G; Rivas, A L; Stegeman, A J

    2016-02-01

    Avian influenza virus (H5N1) is a rapidly disseminating infection that affects poultry and, potentially, humans. Because the avian virus has already adapted to several mammalian species, decreasing the rate of avian-mammalian contacts is critical to diminish the chances of a total adaptation of H5N1 to humans. To prevent the pandemic such adaptation could facilitate, a biology-specific disease surveillance model is needed, which should also consider geographical and socio-cultural factors. Here, we conceptualized a surveillance model meant to capture H5N1-related biological and cultural aspects, which included food processing, trade and cooking-related practices, as well as incentives (or disincentives) for desirable behaviours. This proof of concept was tested with data collected from 378 Egyptian and Nigerian sites (local [backyard] producers/live bird markets/village abattoirs/commercial abattoirs and veterinary agencies). Findings revealed numerous opportunities for pathogens to disseminate, as well as lack of incentives to adopt preventive measures, and factors that promoted epidemic dissemination. Supporting such observations, the estimated risk for H5N1-related human mortality was higher than previously reported. The need for multidimensional disease surveillance models, which may detect risks at higher levels than models that only measure one factor or outcome, was supported. To develop efficient surveillance systems, interactions should be captured, which include but exceed biological factors. This low-cost and easily implementable model, if conducted over time, may identify focal instances where tailored policies may diminish both endemicity and the total adaptation of H5N1 to the human species.

  17. Lifestyle constraints, not inadequate nutrition education, cause gap between breakfast ideals and realities among Japanese in Tokyo.

    Science.gov (United States)

    Melby, Melissa K; Takeda, Wakako

    2014-01-01

    Japanese public health nutrition often promotes 'traditional' cuisine. In-depth interviews with 107 Japanese adults were conducted in Tokyo from 2009 to 2011, using free-listing methods to examine dietary ideals and realities to assess the extent to which realities reflect inadequate nutrition education or lifestyle constraints. Ideal-reality gaps were widest for breakfast. Most people reported Japanese ideals: rice and miso soup were prototypical foods. However, breakfast realities were predominantly western (bread-based). While those aged 40-59 were more likely to hold Japanese ideals (P=0.063), they were less likely to achieve them (P=0.007). All those reporting western ideals achieved them on weekdays, while only 64% of those with Japanese ideals achieved them (PJapanese ideals were positively correlated with proportion of cooking-related housework, and negatively correlated with living standard and income. Ideal menu content was in line with current Japanese nutrition advice, suggesting that more nutrition education may not change dietary ideals or behavior. Participant-reported reasons for ideal-reality discordance demonstrate that work-life balance issues, especially lack of time and family structure/life rhythm, are the largest obstacles to the attainment of dietary ideals. People reporting 'no time' as a primary reason for ideal-reality gaps were less likely to achieve their Japanese ideals (odds ratio=0.212). Time realities of people's lives may undermine educational efforts promoting Japanese breakfasts. When dietary reality/behavior departs from guidelines, it is often assumed that people lack knowledge. If ideals are in line with dietary guidelines, then lack of knowledge is not the likely cause and nutrition education is not the optimal solution. By asking people about the reasons for gaps between their ideals and realities, we can identify barriers and design more effective policies and programs to achieve dietary ideals.

  18. COOKING APPLIANCE USE IN CALIFORNIA HOMES DATA COLLECTED FROM A WEB-BASED SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Klug, Victoria; Lobscheid, Agnes; Singer, Brett

    2011-08-01

    Cooking of food and use of natural gas cooking burners generate pollutants that can have substantial impacts on residential indoor air quality. The extent of these impacts depends on cooking frequency, duration and specific food preparation activities in addition to the extent to which exhaust fans or other ventilation measures (e.g. windows) are used during cooking. With the intent of improving our understanding of indoor air quality impacts of cooking-related pollutants, we created, posted and advertised a web-based survey about cooking activities in residences. The survey included questions similar to those in California's Residential Appliance Saturation Survey (RASS), relating to home, household and cooking appliance characteristics and weekly patterns of meals cooked. Other questions targeted the following information not captured in the RASS: (1) oven vs. cooktop use, the number of cooktop burners used and the duration of burner use when cooking occurs, (2) specific cooking activities, (3) the use of range hood or window to increase ventilation during cooking, and (4) occupancy during cooking. Specific cooking activity questions were asked about the prior 24 hours with the assumption that most people are able to recollect activities over this time period. We examined inter-relationships among cooking activities and patterns and relationships of cooking activities to household demographics. We did not seek to obtain a sample of respondents that is demographically representative of the California population but rather to inexpensively gather information from homes spanning ranges of relevant characteristics including the number of residents and presence or absence of children. This report presents the survey, the responses obtained, and limited analysis of the results.

  19. Temperature-induced volatility of molecular markers in ambient airborne particulate matter

    Directory of Open Access Journals (Sweden)

    C. R. Ruehl

    2010-08-01

    Full Text Available Molecular markers are organic compounds used to represent known sources of particulate matter (PM in statistical source apportionment studies. The utility of molecular markers depends on, among other things, their ability to represent PM volatility under realistic atmospheric conditions. We measured the particle-phase concentrations and temperature-induced volatility of commonly-used molecular markers in California's heavily polluted San Joaqin Valley. Concentrations of elemental carbon, organic carbon, levoglucosan, and polycyclic aromatic hydrocarbons were not reduced by mild (~10 K heating. In contrast, both hopane/sterane and n-alkane concentrations were reduced, especially during the summer sampling events at the urban site. These results suggest that hopanes and steranes have effective saturation concentrations ~1 μg m−3, and therefore can be considered semi-volatile in realistic ambient conditions. The volatility behavior of n-alkanes during the urban summer is consistent with that predicted for absorption by suberic acid (a C8 diacid using a group contribution modelling method. Observations can also be matched by an absorbent whose composition is based on recently-obtained high-resolution aerosol mass spectrometer factors (approximately 33% "hydrocarbon-like" and 67% oxygenated organic aerosol. The diminished volatility of the n-alkanes, hopanes, and steranes during rural and/or winter experiments could be explained by a more oxygenated absorbing phase along with a non-absorptive partitioning mechanism, such as adsorption to soot. This suggests that the temperature-induced volatility of large hydrocarbons in PM is most important if a relatively non-polar absorbing organic phase exists. While the activity coefficients of most organic aerosol compounds may be close to unity, the assumption of ideality for large hydrocarbons (e.g., hopanes may result in large errors in partitioning calculations.

  20. Nucleotide Excision Repair and Transcription-coupled DNA Repair Abrogate the Impact of DNA Damage on Transcription.

    Science.gov (United States)

    Nadkarni, Aditi; Burns, John A; Gandolfi, Alberto; Chowdhury, Moinuddin A; Cartularo, Laura; Berens, Christian; Geacintov, Nicholas E; Scicchitano, David A

    2016-01-01

    DNA adducts derived from carcinogenic polycyclic aromatic hydrocarbons like benzo[a]pyrene (B[a]P) and benzo[c]phenanthrene (B[c]Ph) impede replication and transcription, resulting in aberrant cell division and gene expression. Global nucleotide excision repair (NER) and transcription-coupled DNA repair (TCR) are among the DNA repair pathways that evolved to maintain genome integrity by removing DNA damage. The interplay between global NER and TCR in repairing the polycyclic aromatic hydrocarbon-derived DNA adducts (+)-trans-anti-B[a]P-N(6)-dA, which is subject to NER and blocks transcription in vitro, and (+)-trans-anti-B[c]Ph-N(6)-dA, which is a poor substrate for NER but also blocks transcription in vitro, was tested. The results show that both adducts inhibit transcription in human cells that lack both NER and TCR. The (+)-trans-anti-B[a]P-N(6)-dA lesion exhibited no detectable effect on transcription in cells proficient in NER but lacking TCR, indicating that NER can remove the lesion in the absence of TCR, which is consistent with in vitro data. In primary human cells lacking NER, (+)-trans-anti-B[a]P-N(6)-dA exhibited a deleterious effect on transcription that was less severe than in cells lacking both pathways, suggesting that TCR can repair the adduct but not as effectively as global NER. In contrast, (+)-trans-anti-B[c]Ph-N(6)-dA dramatically reduces transcript production in cells proficient in global NER but lacking TCR, indicating that TCR is necessary for the removal of this adduct, which is consistent with in vitro data showing that it is a poor substrate for NER. Hence, both global NER and TCR enhance the recovery of gene expression following DNA damage, and TCR plays an important role in removing DNA damage that is refractory to NER.

  1. The Paleobiosphere: a novel device for the in vivo testing of hydrocarbon producing-utilizing microorganisms.

    Science.gov (United States)

    Strobel, Gary; Booth, Eric; Schaible, George; Mends, Morgan Tess; Sears, Joe; Geary, Brad

    2013-04-01

    The construction and testing of a unique instrument, the Paleobiosphere, which mimics some of the conditions of the ancient earth, is described. The instrument provides an experimental testing system for determining if certain microbes, when provided an adequate environment, can degrade biological materials to produce fuel-like hydrocarbons in a relatively short time frame that become trapped by the shale. The conditions selected for testing included a particulate Montana shale (serving as the "Trap Shale"), plant materials (leaves and stems of three extant species whose origins are in the late Cretaceous), a water-circulating system, sterile air, and a specially designed Carbotrap through which all air was passed as exhaust and volatile were hydrocarbons trapped. The fungus for initial testing was Annulohypoxylon sp., isolated as an endophyte of Citrus aurantifolia. It produces, in solid and liquid media, a series of hydrocarbon-like molecules. Some of these including 1,8-cineole, 2-butanone, propanoic acid, 2-methyl-, methyl ester, benzene (1-methylethyl)-, phenylethyl alcohol, benzophenone and azulene, 1,2,3,5,6,7,8,8a-octahydro-1,4-dimethyl-7-(1-methylethenyl), [1S-(1α,7α,8aβ)]. These were the key signature compounds used in an initial Paleobiosphere test. After 3 weeks, incubation, the volatiles associated with the harvested "Trap Shale" included each of the signature substances as well as other fungal-associated products: some indanes, benzene derivatives, some cyclohexanes, 3-octanone, naphthalenes and others. The fungus thus produced a series of "Trap Shale" products that were representative of each of the major classes of hydrocarbons in diesel fuel (Mycodiesel). Initial tests with the Paleobiosphere offer some evidence for a possible origin of hydrocarbons trapped in bentonite shale. Thus, with modifications, numerous other tests can also be designed for utilization in