Miniaturized Antimicrobial Susceptibility Test by Combining Concentration Gradient Generation and Rapid Cell Culturing

Directory of Open Access Journals (Sweden)

Samuel C. Kim

2015-10-01

Full Text Available Effective treatment of bacterial infection relies on timely diagnosis and proper prescription of antibiotic drugs. The antimicrobial susceptibility test (AST is one of the most crucial experimental procedures, providing the baseline information for choosing effective antibiotic agents and their dosages. Conventional methods, however, require long incubation times or significant instrumentation costs to obtain test results. We propose a lab-on-a-chip approach to perform AST in a simple, economic, and rapid manner. Our assay platform miniaturizes the standard broth microdilution method on a microfluidic device (20 × 20 mm that generates an antibiotic concentration gradient and delivers antibiotic-containing culture media to eight 30-nL chambers for cell culture. When tested with 20 μL samples of a model bacterial strain (E. coli ATCC 25922 treated with ampicillin or streptomycin, our method allows for the determination of minimum inhibitory concentrations consistent with the microdilution test in three hours, which is almost a factor of ten more rapid than the standard method.

Variation in bacterial ATP concentration during rapid changes in extracellular pH and implications for the activity of attached bacteria.

Science.gov (United States)

Albert, Lynal S; Brown, Derick G

2015-08-01

In this study we investigated the relationship between a rapid change in extracellular pH and the alteration of bacterial ATP concentration. This relationship is a key component of a hypothesis indicating that bacterial bioenergetics - the creation of ATP from ADP via a proton gradient across the cytoplasmic membrane - can be altered by the physiochemical charge-regulation effect, which results in a pH shift at the bacteria's surface upon adhesion to another surface. The bacterial ATP concentration was measured during a rapid change in extracellular pH from a baseline pH of 7.2 to pH values between 3.5 and 10.5. Experiments were conducted with four neutrophilic bacterial strains, including the Gram-negative Escherichia coli and Pseudomonas putida and the Gram-positive Bacillus subtilis and Staphylococcus epidermidis. A change in bulk pH produced an immediate response in bacterial ATP, demonstrating a direct link between changes in extracellular pH and cellular bioenergetics. In general, the shifts in ATP were similar across the four bacterial strains, with results following an exponential relationship between the extracellular pH and cellular ATP concentration. One exception occurred with S. epidermidis, where there was no variation in cellular ATP at acidic pH values, and this finding is consistent with this species' ability to thrive under acidic conditions. These results provide insight into obtaining a desired bioenergetic response in bacteria through (i) the application of chemical treatments to vary the local pH and (ii) the selection and design of surfaces resulting in local pH modification of attached bacteria via the charge-regulation effect. Copyright © 2015 Elsevier B.V. All rights reserved.

Stratification of living organisms in ballast tanks: how do organism concentrations vary as ballast water is discharged?

Science.gov (United States)

First, Matthew R; Robbins-Wamsley, Stephanie H; Riley, Scott C; Moser, Cameron S; Smith, George E; Tamburri, Mario N; Drake, Lisa A

2013-05-07

Vertical migrations of living organisms and settling of particle-attached organisms lead to uneven distributions of biota at different depths in the water column. In ballast tanks, heterogeneity could lead to different population estimates depending on the portion of the discharge sampled. For example, concentrations of organisms exceeding a discharge standard may not be detected if sampling occurs during periods of the discharge when concentrations are low. To determine the degree of stratification, water from ballast tanks was sampled at two experimental facilities as the tanks were drained after water was held for 1 or 5 days. Living organisms ≥50 μm were counted in discrete segments of the drain (e.g., the first 20 min of the drain operation, the second 20 min interval, etc.), thus representing different strata in the tank. In 1 and 5 day trials at both facilities, concentrations of organisms varied among drain segments, and the patterns of stratification varied among replicate trials. From numerical simulations, the optimal sampling strategy for stratified tanks is to collect multiple time-integrated samples spaced relatively evenly throughout the discharge event.

Collaborative validation of a rapid method for efficient virus concentration in bottled water

DEFF Research Database (Denmark)

Schultz, Anna Charlotte; Perelle, Sylvie; Di Pasquale, Simona

2011-01-01

. Three newly developed methods, A, B and C, for virus concentration in bottled water were compared against the reference method D: (A) Convective Interaction Media (CIM) monolithic chromatography; filtration of viruses followed by (B) direct lysis of viruses on membrane; (C) concentration of viruses......Enteric viruses, including norovirus (NoV) and hepatitis A virus (HAV), have emerged as a major cause of waterborne outbreaks worldwide. Due to their low infectious doses and low concentrations in water samples, an efficient and rapid virus concentration method is required for routine control...... by ultracentrifugation; and (D) concentration of viruses by ultrafiltration, for each methods' (A, B and C) efficacy to recover 10-fold dilutions of HAV and feline calicivirus (FCV) spiked in bottles of 1.5L of mineral water. Within the tested characteristics, all the new methods showed better performance than method D...

Kinetics of ethanol production by immobilized Kluyveromyces marxianus cells at varying sugar concentrations of Jerusalem artichoke juice

Energy Technology Data Exchange (ETDEWEB)

Bajpai, P.; Margaritis, A.

1987-08-01

Kinetics of ethanol fermentation at varying sugar concentrations of Jerusalem artichoke tuber extract has been studied using Kluyveromyces marxianus cells immobilized in calcium alginate gel beads. A maximum ethanol concentration of 111 g/l was achieved at an initial sugar concentration of 260 g/l in 20 hours, when the immobilized cell concentration in the calcium alginate beads was 53.3 g dry wt./l bead volume. Ethanol yield remained almost unaffected by initial sugar concentration up to 250 g/l and was found to be about 88% of the theoretical. Maximum rate of ethanol production decreased from 22.5 g ethanol/l/h to 10.5 g ethanol/l/h while the maximum rate of total sugars utilization decreased from 74.9 g sugars/l/h to 28.5 g sugars/l/h as the initial substrate concentration was increased from 100 to 300 g/l. The concentration of free cells in the fermentation broth was low.

Rapid and sensitive determination of deuterium concentration by gas chromatography

International Nuclear Information System (INIS)

Takahashi, Tomiki; Ohokoshi, Sumio; Shinriki, Nariko; Sato, Toshio

1984-01-01

Gas chromatographic determination of hydrogen isotopes D 2 and HD has hitherto been carried out with a molecular sieve column kept at -195 0 C under the H 2 carrier gas. However, the amount of D 2 in hydrogen gas containing low HD concentration of less than 5 % can be practically neglected judging from the equilibrium constant of H 2 -D 2 exchange reaction. Therefore, there is no need to separate HD from D 2 . As an improvement, in this paper, the gas chromatographic determination of HD in low concentration ( 2 as a carrier gas enabled us to enhance the cell current of TCD drastically, hence gave rise to high sensitivity of HD detection. The limit of determination of the concentration of HD was 0.01%. In the case of the higher concentration (>5%) of HD in hydrogen gas, D 2 and HD have been separated and determined by the method described above, but this method takes more than ten minutes. Therefore, we designed a new gas chromatographic analysis of the HD-D 2 mixture with an activated alumina column at -195 0 C under the H 2 carrier gas (330 ml/min). The advantages of this method are in (1) rapid analysis (in 1 min), (2) no need of the rigid activation temperature ((110--250) 0 C), (3) no change of the relative molar sensitivity of HD to D 2 at the various flow rates of H 2 carrier gas ((100--300)ml/min). (author)

Glutamate/glutamine concentrations in the dorsal anterior cingulate vary with Post-Traumatic Stress Disorder symptoms.

Science.gov (United States)

Harnett, Nathaniel G; Wood, Kimberly H; Ference, Edward W; Reid, Meredith A; Lahti, Adrienne C; Knight, Amy J; Knight, David C

2017-08-01

Trauma and stress-related disorders (e.g., Acute Stress Disorder; ASD and Post-Traumatic Stress Disorder; PTSD) that develop following a traumatic event are characterized by cognitive-affective dysfunction. The cognitive and affective functions disrupted by stress disorder are mediated, in part, by glutamatergic neural systems. However, it remains unclear whether neural glutamate concentrations, measured acutely following trauma, vary with ASD symptoms and/or future PTSD symptom expression. Therefore, the current study utilized proton magnetic resonance spectroscopy ( 1 H-MRS) to investigate glutamate/glutamine (Glx) concentrations within the dorsal anterior cingulate cortex (ACC) of recently (i.e., within one month) traumatized individuals and non-traumatized controls. Although Glx concentrations within dorsal ACC did not differ between recently traumatized and non-traumatized control groups, a positive linear relationship was observed between Glx concentrations and current stress disorder symptoms in traumatized individuals. Further, Glx concentrations showed a positive linear relationship with future stress disorder symptoms (i.e., assessed 3 months post-trauma). The present results suggest glutamate concentrations may play a role in both acute and future post-traumatic stress symptoms following a traumatic experience. The current results expand our understanding of the neurobiology of stress disorder and suggest glutamate within the dorsal ACC plays an important role in cognitive-affective dysfunction following a traumatic experience. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rapid, portable and cost-effective yeast cell viability and concentration analysis using lensfree on-chip microscopy and machine learning

KAUST Repository

Feizi, Alborz; Zhang, Yibo; Greenbaum, Alon; Guziak, Alex; Luong, Michelle; Chan, Raymond Yan Lok; Berg, Brandon; Ozkan, Haydar; Luo, Wei; Wu, Michael; Wu, Yichen; Ozcan, Aydogan

2016-01-01

and cost-effective automatic yeast analysis platform (AYAP), which can rapidly measure cell concentration and viability. AYAP is based on digital in-line holography and on-chip microscopy and rapidly images a large field-of-view of 22.5 mm2. This lens

Electrochemical corrosion behavior of A 516 steel using corrosive environments with varying concentrations of sodium thiosulphate

International Nuclear Information System (INIS)

Karim, F.; Arif, M.; Reza, I.; Akram, M.; Hussain, N.; Ali, L.

2012-01-01

The corrosion behavior of A 516 steel was studied by potentiodynamic polarization technique. Environment used for these tests was sodium chloride (5%), acetic acid (0.5%) and sodium thiosulphate with varying concentration from 0.001 M to 1 M. Surface study was also carried out using optical microscope. The potentiodynamic polarization results revealed the formation of large number of pits in the sample, which was tested in the solution containing NaCl. Pitting corrosion study of alloy A516 G-70 was also conducted to see the effect of different concentrations of thiosulfate with or without addition of NaCl and acetic acid at room temperature. It was observed that different thiosulfate concentrations did not produce any difference in the polarization behavior of the alloys, when added in 5% NaCl and 0.5% acetic acid solution. However, in the absence of NaCl and acetic acid, thiosulfate concentration 0.001 mol/l or higher did produce general corrosion and pitting in the alloy at room temperature is shown.(Orig./A.B.)

Mercury Concentrations of Bluegill (Lepomis macrochirus Vary by Sex

Directory of Open Access Journals (Sweden)

Charles P. Madenjian

2015-11-01

Full Text Available Patterns in relative differences in contaminant concentrations between the sexes across many species of fish may reveal clues for important behavioral and physiological differences between the sexes, and may also be useful in developing fish consumption advisories and efficient designs for programs meant to monitor contaminant levels in fish. We determined skin-off fillet and whole-fish total mercury (Hg concentrations of 28 adult female and 26 adult male bluegills (Lepomis macrochirus from Squaw Lake, Oakland County, Michigan (MI, USA. Bioenergetics modeling was used to quantify the effect of growth dilution on the difference in Hg concentrations between the sexes. On average, skin-off fillet and whole-fish Hg concentrations were 25.4% higher and 26.6% higher, respectively, in females compared with males. Thus, the relative difference in Hg concentrations between the sexes for skin-off fillets was nearly identical to that for whole fish. However, mean skin-off fillet Hg concentration (363 ng/g was 2.3 times greater than mean whole-fish Hg concentration (155 ng/g. Males grew substantially faster than females, and bioenergetics modeling results indicated that the growth dilution effect could account for females having 14.4% higher Hg concentrations than males. Our findings should be useful in revising fish consumption advisories.

Evolution in an Afternoon: Rapid Natural Selection and Adaptation of Bacterial Populations

Science.gov (United States)

Delpech, Roger

2009-01-01

This paper describes a simple, rapid and low-cost technique for growing bacteria (or other microbes) in an environmental gradient, in order to determine the tolerance of the microbial population to varying concentrations of sodium chloride ions, and suggests how the evolutionary response of a microbial population to the selection pressure of the…

Rapid determination of radionuclide activity concentrations in contaminated drinking water

International Nuclear Information System (INIS)

Medley, P.; Ryan, B.; Bollhofer, A.; Martin, P.; International Atomic Energy Agency, Vienna

2007-01-01

As a result of an incident at the Ranger Uranium mine in which drinking water was contaminated with process water, it was necessary to perform quick analysis for naturally occurring uranium and thorium series radionuclide activity concentrations, including 226Ra, 210Pb, 210Po, U and Th isotopes. The methods which were subsequently used are presented here. The techniques used were high-resolution gamma spectrometry, Inductively Coupled Plasma Mass Spectrometry (ICPMS) and high-resolution alpha spectrometry. Routine methods were modified to allow for rapid analyses on priority samples in 1-2 days, with some results for highest priority samples available in less than 1 day. Comparison of initial results obtained through standard procedures, is discussed. An emphasis is placed on high-resolution alpha spectrometry of major alpha-emitting nuclides, specifically 226Ra, 230Th and 238U. The range of uranium concentrations in the samples investigated was from background levels to 6.6ppm. Implications for radiological dose assessment in contamination incidents involving process water are presented. The worst-case scenario for the incident at Ranger Uranium Mine indicates that the maximum committed effective dose to workers was well below the ICRP limit for worker-related dose and below the dose limit for a member of the public, with 230Th being the highest contributor

The concentration of plasma metabolites varies throughout reproduction and affects offspring number in wild brown trout (Salmo trutta).

Science.gov (United States)

Gauthey, Zoé; Freychet, Marine; Manicki, Aurélie; Herman, Alexandre; Lepais, Olivier; Panserat, Stéphane; Elosegi, Arturo; Tentelier, Cédric; Labonne, Jacques

2015-06-01

In wild populations, measuring energy invested in the reproduction and disentangling investment in gametes versus investment in reproductive behavior (such as intrasexual competition or intersexual preference) remain challenging. In this study, we investigated the energy expenditure in brown trout reproductive behavior by using two proxies: variation in weight and variation of plasma metabolites involved in energy production, over the course of reproductive season in a semi natural experimental river. We estimated overall reproductive success using genetic assignment at the end of the reproductive season. Results show that triglycerides and free fatty acid concentrations vary negatively during reproduction, while amino-acids and glucose concentrations remain stable. Decrease in triglyceride and free fatty acid concentrations during reproduction is not related to initial concentration levels or to weight variation. Both metabolite concentration variations and weight variations are correlated to the number of offspring produced, which could indicate that gametic and behavioral reproductive investments substantially contribute to reproductive success in wild brown trout. This study opens a path to further investigate variations in reproductive investment in wild populations. Copyright © 2015 Elsevier Inc. All rights reserved.

Rapid determination of radon daughter concentrations

International Nuclear Information System (INIS)

Bigu, J.

1990-08-01

A technical evaluation of four radon 222 progeny measuring instruments has been conducted. The evaluation has been carried out under laboratory controlled conditions and at several locations in an underground uranium mine. The laboratory evaluation consisted of a thorough study of the behaviour and performance of the instruments under a wide variety of environmental conditions such as radon 222 gas concentration, radon 222 progeny concentration, temperature, relative humidity, aerosol concentration, and gamma-field exposure. The four instruments tested were: the Pylon WL-1000C, the MDA IWLM-811, the MIMIL IIM, and the EDA WLM-30. The readings of the instruments were compared with a widely accepted radon 222 progeny concentration measuring method, namely, the Thomas-Tsivoglou method. Two variables affected two instruments significantly, namely, under high aerosol concentration conditions, one of the instruments (EDA WLM-30) ceased to operate because of filter loading. The other variable was gamma-field exposure which affected another instrument (MDA-811) adversely. The instruments were rated according to several criteria. The overall best performer was the MIMIL IIM, although other instruments also fared quite well under a variety of experimental conditions

Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis

Science.gov (United States)

Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

2017-08-01

In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4+ strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS.

Simultaneous and rapid determination of multiple component concentrations in a Kraft liquor process stream

Science.gov (United States)

Li, Jian [Marietta, GA; Chai, Xin Sheng [Atlanta, GA; Zhu, Junyoung [Marietta, GA

2008-06-24

The present invention is a rapid method of determining the concentration of the major components in a chemical stream. The present invention is also a simple, low cost, device of determining the in-situ concentration of the major components in a chemical stream. In particular, the present invention provides a useful method for simultaneously determining the concentrations of sodium hydroxide, sodium sulfide and sodium carbonate in aqueous kraft pulping liquors through use of an attenuated total reflectance (ATR) tunnel flow cell or optical probe capable of producing a ultraviolet absorbency spectrum over a wavelength of 190 to 300 nm. In addition, the present invention eliminates the need for manual sampling and dilution previously required to generate analyzable samples. The inventive method can be used in Kraft pulping operations to control white liquor causticizing efficiency, sulfate reduction efficiency in green liquor, oxidation efficiency for oxidized white liquor and the active and effective alkali charge to kraft pulping operations.

PCB concentrations of lake whitefish (Coregonus clupeaformis) vary by sex

Science.gov (United States)

Madenjian, Charles P.; Ebener, Mark P.; Sepulveda, Maria S.

2015-01-01

We determined whole-fish polychlorinated biphenyl (PCB) concentrations in 26 female lake whitefish (Coregonus clupeaformis) and 34 male lake whitefish from northern Lake Huron. In 5 of the 26 female lake whitefish, we also determined PCB concentrations in the somatic tissue and ovaries. In addition, bioenergetics modeling was used to determine the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 60 ng/g and 80 ng/g, respectively; thus males were 34% higher in PCB concentration compared with females. Based on the PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 2.5%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain, to any degree, the higher PCB concentrations observed in males compared with females. Bioenergetics modeling results indicated that the growth dilution effect could account for males being only 0.7% higher in PCB concentration compared with females. Thus, the growth dilution effect contributed very little to the observed difference in PCB concentrations between the sexes. We conclude that males were higher than females in PCB concentration most likely due to a higher rate of energy expenditure, stemming from greater activity and a greater resting metabolic rate. A higher rate of energy expenditure leads to a higher rate of food consumption, which, in turn, leads to a higher PCB accumulation rate.

Rapid detection of chlorpyrifos pesticide residue concentration in agro-product using Raman spectroscopy

Science.gov (United States)

Dhakal, Sagar; Peng, Yankun; Li, Yongyu; Chao, Kuanglin; Qin, Jianwei; Zhang, Leilei; Xu, Tianfeng

2014-05-01

Different chemicals are sprayed in fruits and vegetables before and after harvest for better yield and longer shelf-life of crops. Cases of pesticide poisoning to human health are regularly reported due to excessive application of such chemicals for greater economic benefit. Different analytical technologies exist to detect trace amount of pesticides in fruits and vegetables, but are expensive, sample destructive, and require longer processing time. This study explores the application of Raman spectroscopy for rapid and non-destructive detection of pesticide residue in agricultural products. Raman spectroscopy with laser module of 785 nm was used to collect Raman spectral information from the surface of Gala apples contaminated with different concentrations of commercially available organophosphorous (48% chlorpyrifos) pesticide. Apples within 15 days of harvest from same orchard were used in this study. The Raman spectral signal was processed by Savitzky-Golay (SG) filter for noise removal, Multiplicative Scatter Correction (MSC) for drift removal and finally polynomial fitting was used to eliminate the fluorescence background. The Raman spectral peak at 677 cm-1 was recognized as Raman fingerprint of chlorpyrifos. Presence of Raman peak at 677 cm-1 after fluorescence background removal was used to develop classification model (presence and absence of pesticide). The peak intensity was correlated with actual pesticide concentration obtained using Gas Chromatography and MLR prediction model was developed with correlation coefficient of calibration and validation of 0.86 and 0.81 respectively. Result shows that Raman spectroscopy is a promising tool for rapid, real-time and non-destructive detection of pesticide residue in agro-products.

Effects of dynamic operating conditions on nitrification in biological rapid sand filters for drinking water treatment

DEFF Research Database (Denmark)

Lee, Carson Odell; Boe-Hansen, Rasmus; Musovic, Sanin

2014-01-01

Biological rapid sand filters are often used to remove ammonium from groundwater for drinking water supply. They often operate under dynamic substrate and hydraulic loading conditions, which can lead to increased levels of ammonium and nitrite in the effluent. To determine the maximum nitrification...... operating conditions. The ammonium removal rate of the filter was determined by the ammonium loading rate, but was independent of both the flow and influent ammonium concentration individually. Ammonia-oxidizing bacteria and archaea were almost equally abundant in the filter. Both ammonium removal...... rates and safe operating windows of rapid sand filters, a pilot scale rapid sand filter was used to test short-term increased ammonium loads, set by varying either influent ammonium concentrations or hydraulic loading rates. Ammonium and iron (flock) removal were consistent between the pilot...

Evaluation of the Impact of Varied Carvacrol Concentrations on Salmonella Recovery in Oregano and How Corn Oil Can Minimize the Effect of Carvacrol during Preenrichment.

Science.gov (United States)

Beaubrun, Junia Jean-Gilles; Addy, Nicole; Keltner, Zachary; Farris, Samantha; Ewing, Laura; Gopinath, Gopal; Hanes, Darcy E

2018-06-01

Phenolic compounds, like carvacrol, in oregano interfere with the detection of foodborne pathogens such as Salmonella enterica. Carvacrol concentration varies based on plant cultivars and growth region. Six oregano cultivars were used to compare the impact of carvacrol concentration on Salmonella and to evaluate the effectiveness of corn oil to help increase Salmonella survival for detection. The results of Agilent 1200 series high-performance liquid chromatography analysis showed that carvacrol concentration in the six oregano cultivars ranged from 64 to 11,200 ppm. Oregano samples were artificially contaminated with S. enterica and were preenriched in Trypticase soy broth with or without 2% (v/v) corn oil. After 18 to 24 h at 37°C, aliquots were transferred to selective enrichment broths. Salmonella was recovered onto xylose lysine Tergitol 4 agar. Six Salmonella serovars were compared, and recovery varied based on carvacrol concentration and serovar. Samples with higher concentrations of carvacrol showed Salmonella recovery only when they were preenriched with corn oil. Based on metagenomic analysis, the microflora associated with the oregano also varied per cultivar. The results show that, as carvacrol levels increased, Salmonella survival decreased. However, the addition of corn oil to the preenrichment broth can minimize the antimicrobial effects of the phenolic compounds, thus allowing for increased detection of Salmonella from oregano cultivars.

A new method for rapid determination of carbohydrate and total carbon concentrations using UV spectrophotometry.

Science.gov (United States)

Albalasmeh, Ammar A; Berhe, Asmeret Asefaw; Ghezzehei, Teamrat A

2013-09-12

A new UV spectrophotometry based method for determining the concentration and carbon content of carbohydrate solution was developed. This method depends on the inherent UV absorption potential of hydrolysis byproducts of carbohydrates formed by reaction with concentrated sulfuric acid (furfural derivatives). The proposed method is a major improvement over the widely used Phenol-Sulfuric Acid method developed by DuBois, Gilles, Hamilton, Rebers, and Smith (1956). In the old method, furfural is allowed to develop color by reaction with phenol and its concentration is detected by visible light absorption. Here we present a method that eliminates the coloration step and avoids the health and environmental hazards associated with phenol use. In addition, avoidance of this step was shown to improve measurement accuracy while significantly reducing waiting time prior to light absorption reading. The carbohydrates for which concentrations and carbon content can be reliably estimated with this new rapid Sulfuric Acid-UV technique include: monosaccharides, disaccharides and polysaccharides with very high molecular weight. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of varying concentrations of Dioscorea bulbifera (Fam ...

African Journals Online (AJOL)

Tablets of paracetamol BP prepared with purified starch obtained from the bulbs of locally cultivated Dioscorea bulbifera in comparison with corn starch BP, both at concentrations, 3-10 %w/w were evaluated for their disintegration time, mechanical properties and dissolution profiles. All the batches of tablets prepared with ...

Prenatal bisphenol a urine concentrations and early rapid growth and overweight risk in the offspring.

Science.gov (United States)

Valvi, Damaskini; Casas, Maribel; Mendez, Michelle A; Ballesteros-Gómez, Ana; Luque, Noelia; Rubio, Soledad; Sunyer, Jordi; Vrijheid, Martine

2013-11-01

Increasing experimental evidence suggests that prenatal bisphenol A (BPA) exposure induces offspring weight gain, but these effects remain largely unexplored in humans. We examined the effects of prenatal BPA exposure on postnatal growth and obesity. BPA concentrations were measured in two spot-urine samples collected in the 1st and 3rd trimesters of pregnancy from mothers in a Spanish birth cohort study (n = 402). We used the average of the two creatinine-adjusted BPA concentrations as the exposure variable. Rapid child growth was defined as a weight gain Z score >0.67 in the first 6 months of life. Age- and sex-specific Z scores for body mass index (BMI) were calculated at age 14 months and 4 years, based on the World Health Organization referent; overweight was defined as a BMI Z score greater than or equal to the 85th percentile. Age- and sex-specific waist circumference Z scores were calculated at age 14 months and 4 years using the analysis population mean. Twenty-six percent of children were rapid growers; 25% were overweight at 14 months and 21% at 4 years. Geometric mean BPA concentrations were 2.6 μg/g creatinine (standard deviation = 2.3) in 1st trimester and 2.0 (2.3) in 3rd trimester samples (Pearson r = 0.13). At 4 years, BPA exposure was associated with increased waist circumference (β per log10 μg/g = 0.28 [95% confidence interval = 0.01 to 0.57]) and BMI (β = 0.28 [-0.06 to 0.63]). BPA was not associated with obesity-related outcomes at earlier ages. This study provides some evidence for an association between prenatal BPA exposure and obesity-related outcomes in childhood, although not in infancy. The large uncertainties in BPA exposure assessment require that findings be interpreted with caution.

Coordinated Control of Multi-Agent Systems in Rapidly Varying Environments, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The main objective of this Phase II STTR project is to develop advanced control algorithms that enable multiple autonomous agents to perform complex tasks in rapidly...

Distribution and time course of corticosterone excretion in faeces and urine of female mice with varying systemic concentrations

DEFF Research Database (Denmark)

Kalliokoski, Otto; Hau, Jann; Jacobsen, Kirsten R

2010-01-01

distribution and time course of corticosterone excretion, after intravenous injection of varying corticosterone concentrations, was investigated in female mice. Female BALB/c mice excreted 60% of all corticosterone in the urine with an approximate delay of 5h from tail vein administration. The remaining 40......% were excreted in faeces, with an approximate delay of 9h from administration. The faecal/urinary excretion ratio, as well as time course of excretion, remained unaltered by administration of various doses of corticosterone covering the entire physiological range of serum corticosterone. Although...

Rapid measurement of plasma free fatty acid concentration and isotopic enrichment using LC/MS

Science.gov (United States)

Persson, Xuan-Mai T.; Błachnio-Zabielska, Agnieszka Urszula; Jensen, Michael D.

2010-01-01

Measurements of plasma free fatty acids (FFA) concentration and isotopic enrichment are commonly used to evaluate FFA metabolism. Until now, gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS) was the best method to measure isotopic enrichment in the methyl derivatives of 13C-labeled fatty acids. Although IRMS is excellent for analyzing enrichment, it requires time-consuming derivatization steps and is not optimal for measuring FFA concentrations. We developed a new, rapid, and reliable method for simultaneous quantification of 13C-labeled fatty acids in plasma using high-performance liquid chromatography-mass spectrometry (HPLC/MS). This method involves a very quick Dole extraction procedure and direct injection of the samples on the HPLC system. After chromatographic separation, the samples are directed to the mass spectrometer for electrospray ionization (ESI) and analysis in the negative mode using single ion monitoring. By employing equipment with two columns connected parallel to a mass spectrometer, we can double the throughput to the mass spectrometer, reducing the analysis time per sample to 5 min. Palmitate flux measured using this approach agreed well with the GC/C/IRMS method. This HPLC/MS method provides accurate and precise measures of FFA concentration and enrichment. PMID:20526002

Accuracy limits on rapid assessment of gently varying bathymetry

Science.gov (United States)

McDonald, B. Edward; Holland, Charles

2002-05-01

Accuracy limits for rapidly probing shallow water bathymetry are investigated as a function of bottom slope and other relevant parameters. The probe scheme [B. E. McDonald and Charles Holland, J. Acoust. Soc. Am. 110, 2767 (2001)] uses a time reversed mirror (TRM) to ensonify a thin annulus on the ocean bottom at ranges of a few km from a vertical send/ receive array. The annulus is shifted in range by variable bathymetry (perturbation theory shows that the focal annulus experiences a radial shift proportional to the integrated bathymetry along a given azimuth). The range shift implies an azimuth-dependent time of maximum reverberation. Thus the reverberant return contains information that might be inverted to give bathymetric parameters. The parameter range over which the perturbation result is accurate is explored using the RAM code for propagation in arbitrarily range-dependent environments. [Work supported by NRL.

Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis.

Science.gov (United States)

Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

2017-08-05

In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH 4 + strategy for ethylene and SO 2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO 2 from fruits. It was satisfied that trace ethylene and SO 2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO 2 during the entire LVCC sampling process were proved to be gas targets from real samples by SERS. Copyright © 2017 Elsevier B.V. All rights reserved.

Analytical sensitivity of rapid isotopic analysis of water by refractometry for monitoring D2O concentration in nuclear reactor

International Nuclear Information System (INIS)

Dhole, K.; Tripathy, M.K.; Ghadigaonkar, R.D.; Datta, A.; Bose, H.; Roy, M.

2011-01-01

The feasibility of refractometry for rapid measurement of D 2 O (heavy water) concentration has been studied. Refractometry has been utilised to be an excellent analytical technique to quickly and non-invasively determine D 2 O concentration in water samples without using any chemical reagents. The measurement of refractive index property of water samples with use of temperature control has been utilized for the purpose of their quantitative analysis. The calibration performance provided a reasonable analytical sensitivity of this technique in the 1-100% D 2 O range. (author)

FINITE ELEMENT ANALYSIS OF THE BEHAVIOUR OF REINFORCED CONCRETE COLUMNS CONFINED BY OVERLAPPING HOOPS SUBJECTED TO RAPID CONCENTRIC LOADING

Directory of Open Access Journals (Sweden)

Xiang Zeng

2017-12-01

Full Text Available The strain rate sensitivity of concrete material was discovered approximately one hundred years ago, and it has a marked effect on the behaviour of concrete members subjected to dynamic loadings such as strong earthquake and impact loading. Because of the great importance of the confined reinforced concrete (RC columns in RC structures, the dynamic behaviour of the columns induced by the strain rate effect has been studied, but only few experiments and analyses have been conducted. To investigate the behaviour of overlapping hoop-confined square reinforced normal-strength concrete columns, considering the strain rate effect at a strain rate of 10-5/sec to 10-1/sec induced by earthquake excitation, an explicit dynamic finite element analysis (FEA model was developed in ABAQUS to predict the behaviour of confined RC columns subjected to the rapid concentric loading. A locally modified stress-strain relation of confined concrete with the strain rate sensitivity of the concrete material and the confining effect of overlapping hoops were proposed to complete the simulation of the dynamic behaviour of concrete with the concrete plastic-constitutive model in ABAQUS. The finite element predictions are consistent with the existing test results. Based on the FEA model, a parametric investigation was conducted to capture more information about the behaviour of confined RC columns under varying loading rates.

Selectivity improvement of positive photoionization ion mobility spectrometry for rapid detection of organophosphorus pesticides by switching dopant concentration.

Science.gov (United States)

Zhou, Qinghua; Li, Jia; Wang, Bin; Wang, Shuang; Li, Haiyang; Chen, Jinyuan

2018-01-01

Ion mobility spectrometry (IMS) opened a potential avenue for the rapid detection of organophosphorus pesticides (OPPs), though an improved selectivity of stand-alone IMS was still in high demand. In this study, a stand-alone positive photoionization ion mobility spectrometry (PP-IMS) apparatus was constructed for the rapid detection of OPPs with acetone as dopant. The photoionization of acetone molecules was induced by the ultraviolet irradiation to produce the reactant ions (Ac) 2 H + , which were employed to ionize the OPPs including fenthion, imidan, phosphamidon, dursban, dimethoate and isocarbophos via the proton transfer reaction. Due to the difference in proton affinity, the tested OPPs exhibited the different dopant-dependent manners. Based on this observation, the switching of dopant concentration was implemented to improve the selectivity of PP-IMS for OPPs detection. For instance, a mixture of fenthion, dursban and dimethoate was tested. By switching the concentration of doped acetone from 0.07 to 2.33 to 19.94mgL -1 , the ion peaks of fenthion and dursban were inhibited in succession, achieving the selective detection of dimethoate at last. In addition, another mixture of imidan and phosphamidon was initially detected by PP-IMS with a dose of 0.07mgL -1 acetone, indicating that their ion peaks were severely overlapped; when the concentration of doped acetone was switched to 19.94mgL -1 , the inhibition of imidan signals promised the accurate identification of phosphamidon in mixture. Finally, the PP-IMS in combination of switching dopant concentration was applied to detect the mixed fenthion, dursban and dimethoate in Chinese cabbage, demonstrating the applicability of proposed method to real samples. Copyright © 2017. Published by Elsevier B.V.

Adaptation of the concept of varying time of concentration within flood modelling: Theoretical and empirical investigations across the Mediterranean

Science.gov (United States)

Michailidi, Eleni Maria; Antoniadi, Sylvia; Koukouvinos, Antonis; Bacchi, Baldassare; Efstratiadis, Andreas

2017-04-01

The time of concentration, tc, is a key hydrological concept and often is an essential parameter of rainfall-runoff modelling, which has been traditionally tackled as a characteristic property of the river basin. However, both theoretical proof and empirical evidence imply that tc is a hydraulic quantity that depends on flow, and thus it should be considered as variable and not as constant parameter. Using a kinematic method approach, easily implemented in GIS environment, we first illustrate that the relationship between tc and the effective rainfall produced over the catchment is well-approximated by a power-type law, the exponent of which is associated with the slope of the longest flow path of the river basin. Next, we take advantage of this relationship to adapt the concept of varying time of concentration within flood modelling, and particularly the well-known SCS-CN approach. In this context, the initial abstraction ratio is also considered varying, while the propagation of the effective rainfall is employed through a parametric unit hydrograph, the shape of which is dynamically adjusted according to the runoff produced during the flood event. The above framework is tested in a number of Mediterranean river basins in Greece, Italy and Cyprus, ensuring faithful representation of most of the observed flood events. Based on the outcomes of this extended analysis, we provide guidance for employing this methodology for flood design studies in ungauged basins.

Influence of supplemental vitamin C on postmortem protein degradation and fatty acid profiles of the longissimus thoracis of steers fed varying concentrations of dietary sulfur.

Science.gov (United States)

Pogge, Danielle J; Lonergan, Steven M; Hansen, Stephanie L

2014-02-01

The objective was to examine the effects of supplemental vitamin C (VC) on postmortem protein degradation and fatty acid profiles of cattle receiving varying concentrations of dietary sulfur (S). A longissimus muscle was collected from 120 Angus-cross steers assigned to a 3 × 2 factorial, evaluating three concentrations of dietary S (0.22, 0.34, and 0.55%) and two concentrations of supplemental VC (0 or 10 g h(-1)d(-1)). Increasing dietary S and VC supplementation (Pdegradation (P = 0.07) and protein carbonylation (Pdegradation. © 2013.

Normal Morning Melanin-Concentrating Hormone Levels and No Association with Rapid Eye Movement or Non-Rapid Eye Movement Sleep Parameters in Narcolepsy Type 1 and Type 2

DEFF Research Database (Denmark)

Schrölkamp, Maren; Jennum, Poul J; Gammeltoft, Steen

2017-01-01

in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep regulation. Hypocretin neurons reciprocally interact with MCH neurons. We hypothesized that altered MCH secretion contributes to the symptoms and sleep abnormalities of narcolepsy and that this is reflected in morning cerebrospinal fluid...... MCH levels. CONCLUSIONS: Our study shows that MCH levels in CSF collected in the morning are normal in narcolepsy and not associated with the clinical symptoms, REM sleep abnormalities, nor number of muscle movements during REM or NREM sleep of the patients. We conclude that morning lumbar CSF MCH......STUDY OBJECTIVES: Other than hypocretin-1 (HCRT-1) deficiency in narcolepsy type 1 (NT1), the neurochemical imbalance of NT1 and narcolepsy type 2 (NT2) with normal HCRT-1 levels is largely unknown. The neuropeptide melanin-concentrating hormone (MCH) is mainly secreted during sleep and is involved...

A Rapid Method for Determining the Concentration of Recombinant Protein Secreted from Pichia pastoris

International Nuclear Information System (INIS)

Sun, L W; Zhao, Y; Jiang, R; Song, Y; Feng, H; Feng, K; Niu, L P; Qi, C

2011-01-01

Pichia secretive expression system is one of powerful eukaryotic expression systems in genetic engineering, which is especially suitable for industrial utilization. Because of the low concentration of the target protein in initial experiment, the methods and conditions for expression of the target protein should be optimized according to the protein yield repetitively. It is necessary to set up a rapid, simple and convenient analysis method for protein expression levels instead of the generally used method such as ultrafiltration, purification, dialysis, lyophilization and so on. In this paper, acetone precipitation method was chosen to concentrate the recombinant protein firstly after comparing with four different protein precipitation methods systematically, and then the protein was analyzed by SDS-Polyacrylamide Gel Electrophoresis. The recombinant protein was determined with the feature of protein band by the Automated Image Capture and 1-D Analysis Software directly. With this method, the optimized expression conditions of basic fibroblast growth factor secreted from pichia were obtained, which is as the same as using traditional methods. Hence, a convenient tool to determine the optimized conditions for the expression of recombinant proteins in Pichia was established.

Assessing toxicity of varying major ion concentrations to marine organisms

International Nuclear Information System (INIS)

Mount, D.R.; Quast, W.

1993-01-01

Recent regulatory developments have required that produced waters discharged in the Gulf of Mexico be monitored for toxicity to marine organisms. While produced water may contain a variety of indigenous and introduced chemicals, virtually all have moderate to high concentrations of major ions. Although seawater is also rich in these ions, excessive salinity can cause toxicity to marine organisms. Perhaps more importantly, toxicity to marine organisms can be caused by deviations from normal ion ratios even if the total salinity is within organism tolerances. To provide a better understanding of marine organism responses to variations in major ion concentrations, the authors conducted a series of laboratory experiments to quantify the responses of mysid shrimp (Mysidopsis bahia) and sheepshead minnows (Cyprinodon variegatus) to modifications of normal seawater chemistry. Acute testing included both increasing and decreasing the concentrations of individual ions relative to seawater, as well as altering total salinity. Results show these organisms can be adversely affected by this altered chemistry and their sensitivity is dependent upon the individual ions that are manipulated. Results from these studies are being incorporated into an overall strategy for evaluating the influence of major ion chemistry on produced water toxicity tests

Rapid changes in small fish mercury concentrations in estuarine wetlands: Implications for wildlife risk and monitoring programs

Science.gov (United States)

Eagles-Smith, Collin A.; Ackerman, Joshua T.

2009-01-01

Small fish are commonly used to assess mercury (Hg) risk to wildlife and monitor Hg in wetlands. However, limited research has evaluated short-term Hg variability in small fish, which can have important implications for monitoring programs and risk assessment. We conducted a time-series study of Hg concentrations in two small fish species representing benthic (longjaw mudsuckers [Gillichthys mirabilis]) and pelagic (threespine sticklebacks [Gasterosteus aculeatus]) food-webs within three wetland habitats in San Francisco Bay Estuary. We simultaneously monitored prey deliveries, nest initiation, and chick hatching dates of breeding Forster's terns (Sterna forsteri), the most abundant nesting piscivore in the region. Mudsuckers and sticklebacks were the predominant prey fish, comprising 36% and 25% of tern diet, and Hg concentrations averaged (geometric mean ?? SE, ??g/g dw) 0.44 ?? 0.01 and 0.68 ?? 0.03, respectively. Fish Hg concentrations varied substantially over time following a quadratic form in both species, increasing 40% between March and May then decreasing 40% between May and July. Importantly, Forster's terns initiated 68% of nests and 31% of chicks hatched during the period of peak Hg concentrations in prey fish. These results illustrate the importance of short-term temporal variation in small fish Hg concentrations for both Hg monitoring programs and assessing wildlife risk.

Thermodynamic balance of photosynthesis and transpiration at increasing CO2 concentrations and rapid light fluctuations.

Science.gov (United States)

Marín, Dolores; Martín, Mercedes; Serrot, Patricia H; Sabater, Bartolomé

2014-02-01

Experimental and theoretical flux models have been developed to reveal the influence of sun flecks and increasing CO2 concentrations on the energy and entropy balances of the leaf. The rapid and wide range of fluctuations in light intensity under field conditions were simulated in a climatic gas exchange chamber and we determined the energy and entropy balance of the leaf based on radiation and gas exchange measurements. It was estimated that the energy of photosynthetic active radiation (PAR) accounts for half of transpiration, which is the main factor responsible for the exportation of the entropy generated in photosynthesis (Sg) out of the leaf in order to maintain functional the photosynthetic machinery. Although the response of net photosynthetic production to increasing concentrations of CO2 under fluctuating light is similar to that under continuous light, rates of transpiration respond slowly to changes of light intensity and are barely affected by the concentration of CO2 in the range of 260-495 ppm, in which net photosynthesis increases by more than 100%. The analysis of the results confirms that future increases of CO2 will improve the efficiency of the conversion of radiant energy into biomass, but will not reduce the contribution of plant transpiration to the leaf thermal balance. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Effect of diet of Varying Protein concentrations on the Activity of ...

African Journals Online (AJOL)

Alterations in protein diet have been reported to result in alterations in calcium homeostasis in the body. Ca2+Mg2+ATPase is an ubiquitous enzyme important in calcium homeostasis in the body. The effect of varying protein diet on the activities of Ca2+ pump across cell membranes is however yet to be fully elucidated.

Determinants of spikes in ultrafine particle concentration whilst commuting by bus

Science.gov (United States)

Lim, Shanon; Dirks, Kim N.; Salmond, Jennifer A.; Xie, Shanju

2015-07-01

This paper examines concentration of ultrafine particles (UFPs) based on data collected using high-resolution UFP monitors whilst travelling by bus during rush hour along three different urban routes in Auckland, New Zealand. The factors influencing in-bus UFP concentration were assessed using a combination of spatial, statistical and GIS analysis techniques to determine both spatial and temporal variability. Results from 68 bus trips showed that concentrations varied more within a route than between on a given day, despite differences in urban morphology, land use and traffic densities between routes. A number of trips were characterised by periods of very rapid increases in UFPs (concentration 'spikes'), followed by slow declines. Trips which recorded at least one spike (an increase of greater than 10,000 pt/cm3) resulted in significantly higher mean concentrations. Spikes in UFPs were significantly more likely to occur when travelling at low speeds and when passengers were alighting and boarding at bus stops close to traffic light intersections.

Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry

International Nuclear Information System (INIS)

Hoetzl, H.; Winkler, R.

1993-01-01

For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of only contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meteorological conditions, the measured air concentrations of 214 Pb, the first gamma-ray-emitting member of the 222 Rn decay series, varied from about 1 to 50 Bq m -3 . For the artifical radionuclides 60 Co, 131 I and 137 Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m -3 , respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2. (orig.)

Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Hoetzl, H.; Winkler, R. (GSF-Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg (Germany). Inst. fuer Strahlenschutz)

1993-04-01

For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of only contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meteorological conditions, the measured air concentrations of [sup 214]Pb, the first gamma-ray-emitting member of the [sup 222]Rn decay series, varied from about 1 to 50 Bq m[sup -3]. For the artifical radionuclides [sup 60]Co, [sup 131]I and [sup 137]Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m[sup -3], respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2. (orig.).

The effect of Cu (II) on the electro-olfactogram (EOG) of the Atlantic salmon (Salmo salar L) in artificial freshwater of varying inorganic carbon concentrations

DEFF Research Database (Denmark)

Winberg, S; Bjerselius, R; Baatrup, E

1993-01-01

The effect of inorganic copper species was studied by recording the receptor potential, electro-olfactogram (EOG), from the olfactory epithelium of Atlantic salmon (Salmo salar L). In a series of experiments, the olfactory organ was irrigated with aqueous copper solutions with concentrations...... of the free cupric ion (Cu2+) ranging from 0.2 to 9.7 microM. The diverse copper species were created by varying the amount of bicarbonate (NaHCO3) in artificial freshwater solutions of equal total copper concentrations. In general, these copper solutions induced a slow depolarization of the baseline followed...

PCB concentrations and activity of sea lamprey Petromyzon marinus vary by sex

Science.gov (United States)

Madenjian, Charles P.; Johnson, Nicholas S.; Binder, Thomas R.; Rediske, Richard R.; O'Keefe, James P.

2013-01-01

We determined the polychlorinated biphenyl (PCB) concentrations of 40 male and 40 female adult sea lampreys Petromyzon marinus captured in the Cheboygan River, a tributary to Lake Huron, during May 2011. In addition, we performed a laboratory experiment using passive integrated transponder tags to determine whether male adult sea lampreys were more active than female adult sea lampreys. Sex had a significant effect on PCB concentration, and PCB concentration at a given level of sea lamprey condition was approximately 25 % greater in males than in females. Adjusting for the difference in condition between the sexes, males averaged a 17 % greater PCB concentration compared with females. Results from the laboratory experiment indicated that males were significantly more active than females. The observed sex difference in PCB concentrations was not due to female sea lampreys releasing eggs at spawning because the sea lamprey is semelparous, and we caught the sea lampreys before spawning. Rather, we attributed the sex difference in PCB concentrations to a greater rate of energy expenditure in males compared with females. We proposed that this greater rate of energy expenditure was likely due to greater activity. Our laboratory experiment results supported this hypothesis. A greater resting metabolic rate may also have contributed to a greater rate of energy expenditure. Our findings should eventually be applicable toward improving control of sea lamprey, a pest responsible for considerable damage to fisheries in lakes where it is not native.

Solute concentration at a well in non-Gaussian aquifers under constant and time-varying pumping schedule

Science.gov (United States)

Libera, Arianna; de Barros, Felipe P. J.; Riva, Monica; Guadagnini, Alberto

2017-10-01

Our study is keyed to the analysis of the interplay between engineering factors (i.e., transient pumping rates versus less realistic but commonly analyzed uniform extraction rates) and the heterogeneous structure of the aquifer (as expressed by the probability distribution characterizing transmissivity) on contaminant transport. We explore the joint influence of diverse (a) groundwater pumping schedules (constant and variable in time) and (b) representations of the stochastic heterogeneous transmissivity (T) field on temporal histories of solute concentrations observed at an extraction well. The stochastic nature of T is rendered by modeling its natural logarithm, Y = ln T, through a typical Gaussian representation and the recently introduced Generalized sub-Gaussian (GSG) model. The latter has the unique property to embed scale-dependent non-Gaussian features of the main statistics of Y and its (spatial) increments, which have been documented in a variety of studies. We rely on numerical Monte Carlo simulations and compute the temporal evolution at the well of low order moments of the solute concentration (C), as well as statistics of the peak concentration (Cp), identified as the environmental performance metric of interest in this study. We show that the pumping schedule strongly affects the pattern of the temporal evolution of the first two statistical moments of C, regardless the nature (Gaussian or non-Gaussian) of the underlying Y field, whereas the latter quantitatively influences their magnitude. Our results show that uncertainty associated with C and Cp estimates is larger when operating under a transient extraction scheme than under the action of a uniform withdrawal schedule. The probability density function (PDF) of Cp displays a long positive tail in the presence of time-varying pumping schedule. All these aspects are magnified in the presence of non-Gaussian Y fields. Additionally, the PDF of Cp displays a bimodal shape for all types of pumping

Fate of low arsenic concentrations during full-scale aeration and rapid filtration.

Science.gov (United States)

Gude, J C J; Rietveld, L C; van Halem, D

2016-01-01

In the Netherlands, groundwater treatment commonly consists of aeration, with subsequent sand filtration without using chemical oxidants like chlorine. With arsenic (As) concentrations well below the actual guidelines of 10 μg As/L, groundwater treatment plants have been exclusively designed for the removal of iron (Fe), manganese and ammonium. The aim of this study was to investigate the As removal capacity at three of these groundwater treatment plants (10-26 μg As/L) in order to identify operational parameters that can contribute to lowering the filtrate As concentration to removal. Results showed that after aeration, As largely remained mobile in the supernatant water; even during extended residence times only 20-48% removal was achieved (with 1.4-4.2 mg/L precipitated Fe(II)). Speciation showed that the mobile As was in the reduced As(III) form, whereas, As(V) was readily adsorbed to the formed HFO flocs. In the filter bed, the remaining As(III) completely oxidized within 2 min of residence time and As removal efficiencies increased to 48-90%. Filter grain coating analysis showed the presence of manganese at all three treatment plants. It is hypothesized that these manganese oxides are responsible for the accelerated As(III) oxidation in the filter bed, leading to an increased removal capacity. In addition, pH adjustment from 7.8 to 7.0 has been found to improve the capacity for As(V) uptake by the HFO flocs in the filter bed. The overall conclusion is, that during groundwater treatment, the filter bed is crucial for rapid As(III) removal, indicating the importance to control the oxidation sequence of Fe and As for improved As removal efficiencies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Numerical modeling of rapidly varying flows using HEC-RAS and WSPG models.

Science.gov (United States)

Rao, Prasada; Hromadka, Theodore V

2016-01-01

The performance of two popular hydraulic models (HEC-RAS and WSPG) for modeling hydraulic jump in an open channel is investigated. The numerical solutions are compared with a new experimental data set obtained for varying channel bottom slopes and flow rates. Both the models satisfactorily predict the flow depths and location of the jump. The end results indicate that the numerical models output is sensitive to the value of chosen roughness coefficient. For this application, WSPG model is easier to implement with few input variables.

Rapid and efficient treatment of wastewater with high-concentration heavy metals using a new type of hydrogel-based adsorption process.

Science.gov (United States)

Zhou, Guiyin; Liu, Chengbin; Chu, Lin; Tang, Yanhong; Luo, Shenglian

2016-11-01

In this study, a new type of double-network hydrogel sorbent was developed to remove heavy metals in wastewater. The amino-functionalized Starch/PAA hydrogel (NH2-Starch/PAA) could be conducted in a wide pH and the adsorption process could rapidly achieve the equilibrium. The adsorption capacity got to 256.4mg/g for Cd(II). Resultantly, even though Cd(II) concentration was as high as 180mg/L, the Cd(II) could be entirely removed using 1g/L sorbent. Furthermore, the desirable mechanical durability of the adsorbent allowed easy separation and reusability. In the fixed-bed column experiments, the treatment volume of the effluent with a high Cd(II) concentration of 200mg/L reached 2400BV (27.1L) after eight times cycle. The NH2-Starch/PAA overcame the deficiency of conventional sorbents that could not effectively treat the wastewater with relatively high metal concentrations. This work provides a new insight into omnidirectional enhancement of sorbents for removing high-concentration heavy metals in wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distribution of indoor radon concentrations and elements of a strategy for control

International Nuclear Information System (INIS)

Nero, A.V. Jr.

1986-05-01

Indoor radon concentrations vary widely in the US housing stock, with normal concentrations estimated to cause a significant risk of lung cancer by comparison with environmental exposures normally considered, and high concentrations causing risks that exceed even those from cigarette smoking. The probability distribution, i.e., the number of houses at various concentrations, can be estimated from an analysis of the US indoor radon data accumulated to date. Such an analysis suggests that in about a million houses, occupants are receiving exposures greater than those experienced by uranium miners. The form of the frequency distribution, including not only the average concentration, but also the number of houses with high levels, has substantial influence on strategies for control of indoor radon. Such strategies require three major elements: formulation of control objectives in terms of guidelines for remedial action and for new houses; selection of means for identifying homes with high concentrations; and a framework for deciding what types of control measures are appropriate to particular circumstances and how rapidly they should be employed

A simple method for point-of-need extraction, concentration and rapid multi-mycotoxin immunodetection in feeds using aqueous two-phase systems.

Science.gov (United States)

Soares, Ruben R G; Azevedo, Ana M; Fernandes, Pedro; Chu, Virginia; Conde, João P; Aires-Barros, M Raquel

2017-08-18

The rapid detection of mycotoxins in feed samples is becoming an increasingly relevant challenge for the food production sector, in order to effectively enforce current regulations and assure food and feed safety. To achieve rapid mycotoxin detection, several biosensing strategies have been published, many reaching assay times of the order of a few minutes. However, the vast majority of these rely on sample preparation based on volatile organic solvents, often comprising complex multi-step procedures and devoid of clean-up and/or concentration effects. Here, a novel sample preparation methodology based on a green, non-toxic and inexpensive polyethylene glycol-sodium citrate aqueous two-phase system is reported, providing single-step extraction and concentration of three target mycotoxins within 20min: aflatoxin B1 (AFB1), ochratoxin A (OTA) and deoxynivalenol (DON). With point-of-need applications in mind, the extraction procedure was optimized and validated using a rapid multi-toxin microfluidic competitive immunoassay. The assay was successfully tested with spiked complex solid matrices including corn, soy, chickpea and sunflower-based feeds and limits of detection of 4.6ngg -1 ±15.8%, 24.1ngg -1 ±8.1% and 129.7ngg -1 ±53.1% (±CV) were obtained in corn for AFB1, OTA and DON, respectively. These sensitivities are fit-for-purpose at the required regulatory and recommended limits for animal feed, providing an effective and safe semi-quantitative mycotoxin analysis that can be performed in the field. Copyright © 2017 Elsevier B.V. All rights reserved.

Ion mobility spectrometry as a simple and rapid method to measure the plasma propofol concentrations for intravenous anaesthesia monitoring

Science.gov (United States)

Wang, Xin; Zhou, Qinghua; Jiang, Dandan; Gong, Yulei; Li, Enyou; Li, Haiyang

2016-11-01

The plasma propofol concentration is important information for anaesthetists to monitor and adjust the anaesthesia depth for patients during a surgery operation. In this paper, a stand-alone ion mobility spectrometer (IMS) was constructed for the rapid measurement of the plasma propofol concentrations. Without any sample pre-treatment, the plasma samples were dropped on a piece of glass microfiber paper and then introduced into the IMS cell by the thermal desorption directly. Each individual measurement could be accomplished within 1 min. For the plasma propofol concentrations from 1 to 12 μg mL-1, the IMS response was linear with a correlation coefficient R2 of 0.998, while the limit of detection was evaluated to be 0.1 μg mL-1. These measurement results did meet the clinical application requirements. Furthermore, other clinically-often-used drugs, including remifentanil, flurbiprofen and atracurium, were found no significant interference with the qualitative and quantitative analysis of the plasma propofol. The plasma propofol concentrations measured by IMS were correlated well with those measured by the high performance liquid chromatography (HPLC). The results confirmed an excellent agreement between these two methods. Finally, this method was applied to monitor the plasma propofol concentrations for a patient undergoing surgery, demonstrating its capability of anaesthesia monitoring in real clinical environments.

Parameterization using Fourier series expansion of the diffuse reflectance of human skin to vary the concentration of the melanocytes

Science.gov (United States)

Narea, J. Freddy; Muñoz, Aarón A.; Castro, Jorge; Muñoz, Rafael A.; Villalba, Caroleny E.; Martinez, María. F.; Bravo, Kelly D.

2013-11-01

Human skin has been studied in numerous investigations, given the interest in knowing information about physiology, morphology and chemical composition. These parameters can be determined using non invasively optical techniques in vivo, such as the diffuse reflectance spectroscopy. The human skin color is determined by many factors, but primarily by the amount and distribution of the pigment melanin. The melanin is produced by the melanocytes in the basal layer of the epidermis. This research characterize the spectral response of the human skin using the coefficients of Fourier series expansion. Simulating the radiative transfer equation for the Monte Carlo method to vary the concentration of the melanocytes (fme) in a simplified model of human skin. It fits relating the Fourier series coefficient a0 with fme. Therefore it is possible to recover the skin biophysical parameter.

Use of passive sampling devices to determine soil contaminant concentrations

Energy Technology Data Exchange (ETDEWEB)

Johnson, K.A. [Clemson Univ., Pendleton, SC (United States)]|[Washington State Univ., Richland, WA (United States); Hooper, M.J. [Clemson Univ., Pendleton, SC (United States); Weisskopf, C.P. [Washington State Univ., Richland, WA (United States)

1996-12-31

The effective remediation of contaminated sites requires accurate identification of chemical distributions. A rapid sampling method using passive sampling devices (PSDs) can provide a thorough site assessment. We have been pursuing their application in terrestrial systems and have found that they increase the ease and speed of analysis, decrease solvent usage and overall cost, and minimize the transport of contaminated soils. Time and cost savings allow a higher sampling frequency than is generally the case using traditional methods. PSDs have been used in the field in soils of varying physical properties and have been successful in estimating soil concentrations ranging from 1 {mu}g/kg (parts per billion) to greater than 200 mg/kg (parts per million). They were also helpful in identifying hot spots within the sites. Passive sampling devices show extreme promise as an analytical tool to rapidly characterize contaminant distributions in soil. There are substantial time and cost savings in laboratory personnel and supplies. By selectively excluding common interferences that require sample cleanup, PSDs can be retrieved from the field and processed rapidly (one technician can process approximately 90 PSDs in an 8-h work day). The results of our studies indicate that PSDs can be used to accurately estimate soil contaminant concentrations and provide lower detection limits. Further, time and cost savings will allow a more thorough and detailed characterization of contaminant distributions. 13 refs., 4 figs., 2 tabs.

Evaluation of the iodine concentration in serum and urine of hypothyroid males an inexpensive and rapid method

International Nuclear Information System (INIS)

Kandhro, G.A.; Kazi, T.G.; Sirajuddin; Afridi, H.I.; Baig, J.A.; Shah, A.Q.; Arain, M.B.

2009-01-01

The aim of present study was to evaluate the iodine/iodide status in biological samples (serum and urine) of 172 male hypothyroid patients (HPs) and their supplemental effects on thyroid hormones. For comparison purpose, non-goitrous subjects (n= 220) of same age group and socioeconomic status were also studied. A simple and rapid iodide-ion selective electrode (ISE) was used to measure the concentration of iodine in microwave assisted acid digested serum and urine samples. Quality control for the methodology was established with certified samples and with those obtained by conventional wet acid digestion method on the same certified reference materials (CRMs) and real samples. A linear calibration curve was obtained for a reasonable concentration range of the potassium iodide solutions. The mean concentration of iodine in the serum and urine samples of the HPs was significantly reduced as compared to control male subjects (p< 0.01). The low levels of free triiodothyronine and thyroxin were found in HPs than age matched healthy control (p< 0.005 and 0.002) respectively while high levels of thyroid stimulating hormone were observed in HPs (p< 0.008). The proposed method was relatively efficient as well as cost effective by using inexpensive equipment. It was observed that iodine in biological samples of HPs can play an important role in determining the severity of the hypothyroidism. (author)

Paired assessment of volatile anesthetic concentrations with synaptic actions recorded in vitro.

Directory of Open Access Journals (Sweden)

Stuart J McDougall

Full Text Available The volatile anesthetic isoflurane poses a number of experimental challenges in the laboratory. Due to its rapid evaporation, the open conditions of most in vitro electrophysiological recording systems make the determination of actual isoflurane concentrations a challenge. Since the absolute anesthetic concentration in solution is directly related to efficacy, concentration measurements are important to allow comparisons between laboratory and clinical studies. In this study we quantify the sources of isoflurane loss during experimentation and describe a method for the measurement of isoflurane concentrations using gas chromatography and mass spectrometry simultaneous to in vitro electrophysiological measurements. Serial samples of perfused bath solution allowed correlation of isoflurane concentrations with ongoing biological effects. Saturated physiological solutions contained 13.4 +/- 0.2 mM isoflurane and were diluted to desired "nominal" concentrations for experiments. The perfusion system established stable isoflurane concentrations within the bath by 2 minutes. However, bath isoflurane concentrations varied substantially and unpredictably between experiments. The magnitudes of such discrepancies in isoflurane concentrations spanned clinically important levels. Our studies suggest that, despite countermeasures, solution handling significantly impacted the isoflurane content in the tissue bath. The magnitude of these discrepancies appears to necessitate systematic direct measurement of bath isoflurane concentrations during most in vitro conditions.

Development of a nonlocal convective mixing scheme with varying upward mixing rates for use in air quality and chemical transport models.

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Mihailović, Dragutin T; Alapaty, Kiran; Sakradzija, Mirjana

2008-06-01

Asymmetrical convective non-local scheme (CON) with varying upward mixing rates is developed for simulation of vertical turbulent mixing in the convective boundary layer in air quality and chemical transport models. The upward mixing rate form the surface layer is parameterized using the sensible heat flux and the friction and convective velocities. Upward mixing rates varying with height are scaled with an amount of turbulent kinetic energy in layer, while the downward mixing rates are derived from mass conservation. This scheme provides a less rapid mass transport out of surface layer into other layers than other asymmetrical convective mixing schemes. In this paper, we studied the performance of a nonlocal convective mixing scheme with varying upward mixing in the atmospheric boundary layer and its impact on the concentration of pollutants calculated with chemical and air-quality models. This scheme was additionally compared versus a local eddy-diffusivity scheme (KSC). Simulated concentrations of NO(2) and the nitrate wet deposition by the CON scheme are closer to the observations when compared to those obtained from using the KSC scheme. Concentrations calculated with the CON scheme are in general higher and closer to the observations than those obtained by the KSC scheme (of the order of 15-20%). Nitrate wet deposition calculated with the CON scheme are in general higher and closer to the observations than those obtained by the KSC scheme. To examine the performance of the scheme, simulated and measured concentrations of a pollutant (NO(2)) and nitrate wet deposition was compared for the year 2002. The comparison was made for the whole domain used in simulations performed by the chemical European Monitoring and Evaluation Programme Unified model (version UNI-ACID, rv2.0) where schemes were incorporated.

Rapid Modulation of Aromatase Activity in the Vertebrate Brain

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Thierry D. Charlier

2013-01-01

Full Text Available Numerous steroid hormones, including 17β-estradiol (E2, activate rapid and transient cellular, physiological, and behavioral changes in addition to their well-described genomic effects. Aromatase is the key-limiting enzyme in the production of estrogens, and the rapid modulation of this enzymatic activity could produce rapid changes in local E2 concentrations. The mechanisms that might mediate such rapid enzymatic changes are not fully understood but are currently under intense scrutiny. Recent studies in our laboratory indicate that brain aromatase activity is rapidly inhibited by an increase in intracellular calcium concentration resulting from potassium-induced depolarization or from the activation of glutamatergic receptors. Phosphorylating conditions also reduce aromatase activity within minutes, and this inhibition is blocked by the addition of multiple protein kinase inhibitors. This rapid modulation of aromatase activity by phosphorylating conditions is a general mechanism observed in different cell types and tissues derived from a variety of species, including human aromatase expressed in various cell lines. Phosphorylation processes affect aromatase itself and do not involve changes in aromatase protein concentration. The control of aromatase activity by multiple kinases suggests that several amino acids must be concomitantly phosphorylated to modify enzymatic activity but site-directed mutagenesis of several amino acids alone or in combination has not to date revealed the identity of the targeted residue(s. Altogether, the phosphorylation processes affecting aromatase activity provide a new general mechanism by which the concentration of estrogens can be rapidly altered in the brain.

Correlates of rapid neuroleptic response in male patients with schizophrenia.

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Petrie, E C; Faustman, W O; Moses, J A; Lombrozo, L; Csernansky, J G

1990-08-01

Correlates of neuroleptic response latency were assessed in 16 male schizophrenic inpatients during 4 weeks of fixed dose (20 mg/day) haloperidol treatment. Rapid responders showed a mean 40% reduction in Brief Psychiatric Rating Scale (BPRS) positive symptom scores by day 10 of treatment. Rapid responders had significantly lower plasma homovanillic acid (pHVA) concentrations compared to non-rapid responders during week 4 of haloperidol treatment. However, rapid versus non-rapid responders did not differ with respect to demographics, baseline positive or negative BPRS symptom scores, performance on tests of neuropsychological function, or mean plasma haloperidol concentrations.

Rapid sensing of melamine in milk by interference green synthesis of silver nanoparticles

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Varun, S.; Kiruba Daniel, S.C.G.; Gorthi, Sai Siva, E-mail: saisiva.gorthi@iap.iisc.ernet.in

2017-05-01

A highly sensitive, selective, and rapid interference green synthesis based determination of potential milk adulterant melamine has been reported here. Melamine is a nitrogenous compound added to milk for mimicking proteins, consumption of which leads to kidney stones and renal failures. Melamine interacts with ascorbic acid (AA) through strong hydrogen-bonding interactions, thus resulting in an interference/interruption in the formation of silver (Ag) nanoparticles which was confirmed by UV–Vis spectroscopy and Transmission Electron Microscopy (TEM). The corresponding benchmark validations for melamine spiked milk samples were performed using High Performance Liquid Chromatography (HPLC). This interference in the formation of Ag nanoparticles resulted in color change that varies with concentration of melamine, thereby enabling in-situ rapid sensing of melamine from milk to a lower limit of 0.1 ppm with a linear correlation coefficient of 0.9908. - Highlights: • Rapid detection of milk adulterant melamine based on interference green synthesis. • Green chemical ascorbic acid used as the reducing agent for interference sensing. • Enabling in-situ sensing of melamine from milk with a limit of detection of 0.1 ppm. • Presence of analyte inhibits the nanoparticle formation.

Characterizing the Frequency and Elevation of Rapid Drainage Events in West Greenland

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Cooley, S.; Christoffersen, P.

2016-12-01

Rapid drainage of supraglacial lakes on the Greenland Ice Sheet is critical for the establishment of surface-to-bed hydrologic connections and the subsequent transfer of water from surface to bed. Yet, estimates of the number and spatial distribution of rapidly draining lakes vary widely due to limitations in the temporal frequency of image collection and obscureness by cloud. So far, no study has assessed the impact of these observation biases. In this study, we examine the frequency and elevation of rapidly draining lakes in central West Greenland, from 68°N to 72.6°N, and we make a robust statistical analysis to estimate more accurately the likelihood of lakes draining rapidly. Using MODIS imagery and a fully automated lake detection method, we map more than 500 supraglacial lakes per year over a 63000 km2 study area from 2000-2015. Through testing four different definitions of rapidly draining lakes from previously published studies, we find that the number of rapidly draining lakes varies from 3% to 38%. Logistic regression between rapid drainage events and image sampling frequency demonstrates that the number of rapid drainage events is strongly dependent on cloud-free observation percentage. We then develop three new drainage criteria and apply an observation bias correction that suggests a true rapid drainage probability between 36% and 45%, considerably higher than previous studies without bias assessment have reported. We find rapid-draining lakes are on average larger and disappear earlier than slow-draining lakes, and we also observe no elevation differences for the lakes detected as rapidly draining. We conclude a) that methodological problems in rapid drainage research caused by observation bias and varying detection methods have obscured large-scale rapid drainage characteristics and b) that the lack of evidence for an elevation limit on rapid drainage suggests surface-to-bed hydrologic connections may continue to propagate inland as climate warms.

Effect of Photochemical Transformation on Dissolved Organic Carbon Concentration and Bioavailability from Watersheds with Varying Landcover

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Vermilyea, A.; Sanders, A.; Vazquez, E.

2017-12-01

The transformation of freshwater dissolved organic carbon (DOC) can have important implications for water quality, aquatic ecosystem health, and our climate. DOC is an important nutrient for heterotrophic microorganisms near the base of the aquatic food chain and the extent of conversion of DOC to CO2 is a critical piece of the global carbon cycle. Photochemical pathways have the potential to transform recalcitrant DOC into more labile forms that can then be converted to smaller DOC molecules and eventually be completely mineralized to CO2. This may lead to a DOC pool with different bioavailability depending on the structural composition of the original DOC pool and the mechanistic pathways undergone during transformation. This study aimed to measure the changes in DOC concentration and bioavailability due solely to photochemical processes in three watersheds of northern Vermont, USA that have varied land cover, land use (LCLU) attributes. Our hypothesis was that photochemical transformations will lead to (1) an overall loss of DOC due to mineralization to CO2 and (2) a relative increase in the bioavailable fraction of DOC. Additionally, the influence of LCLU and base flow versus storm flow on both mineralization rates and changes in DOC bioavailability was investigated. Irradiation of filtered samples in quartz vessels under sunlight led to small changes in DOC concentration over time, but significant changes in DOC bioavailability. In general, fluorescence excitation-emission matrices (EEMs) showed a shift from an initially more humic-like DOC pool, to a more protein-like (bioavailable) DOC pool. Specific UV index (SUVA) along with bioavailable DOC (BDOC) incubations were also used to characterize DOC and its bioavailability. There were only small differences in the DOC transformation that took place among sites, possibly due to only small differences in the initial bioavailability and fluorescent properties between water samples. Photochemical transformation

What’s normal? Oligosaccharide concentrations and profiles in milk produced by healthy women vary geographically12

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Meehan, Courtney L; McGuire, Mark A; Foster, James; Sellen, Daniel W; Kamau-Mbuthia, Elizabeth W; Kamundia, Egidioh W; Mbugua, Samwel; Moore, Sophie E; Prentice, Andrew M; Kvist, Linda J; Otoo, Gloria E; Brooker, Sarah L; Price, William J; Shafii, Bahman; Placek, Caitlyn; Lackey, Kimberly A; Robertson, Bianca; Ruíz, Lorena; Pareja, Rossina G; Bode, Lars

2017-01-01

Background: Human milk is a complex fluid comprised of myriad substances, with one of the most abundant substances being a group of complex carbohydrates referred to as human milk oligosaccharides (HMOs). There has been some evidence that HMO profiles differ in populations, but few studies have rigorously explored this variability. Objectives: We tested the hypothesis that HMO profiles differ in diverse populations of healthy women. Next, we examined relations between HMO and maternal anthropometric and reproductive indexes and indirectly examined whether differences were likely related to genetic or environmental variations. Design: In this cross-sectional, observational study, milk was collected from a total of 410 healthy, breastfeeding women in 11 international cohorts and analyzed for HMOs by using high-performance liquid chromatography. Results: There was an effect of the cohort (P 4 times higher in milk collected in Sweden than in milk collected in rural Gambia (mean ± SEM: 473 ± 55 compared with 103 ± 16 nmol/mL, respectively; P < 0.05), and disialyllacto-N-tetraose (DSLNT) concentrations ranged from 216 ± 14 nmol/mL (in Sweden) to 870 ± 68 nmol/mL (in rural Gambia) (P < 0.05). Maternal age, time postpartum, weight, and body mass index were all correlated with several HMOs, and multiple differences in HMOs [e.g., lacto-N-neotetrose and DSLNT] were shown between ethnically similar (and likely genetically similar) populations who were living in different locations, which suggests that the environment may play a role in regulating the synthesis of HMOs. Conclusions: The results of this study support our hypothesis that normal HMO concentrations and profiles vary geographically, even in healthy women. Targeted genomic analyses are required to determine whether these differences are due at least in part to genetic variation. A careful examination of sociocultural, behavioral, and environmental factors is needed to determine their roles in this regard. This

Compartmental analysis of roots in intact rapidly-growing Spergularia marina and Lactuca sativa: partial characterization of the symplasms functional in the radial transport of Na+ and K+

International Nuclear Information System (INIS)

Lazof, D.B.

1987-01-01

Techniques of compartmental analysis were adapted to the study of intact roots of rapidly-growing Spergularia marine and Lactuca sativa. Using large numbers of plants short time-courses of uptake and chase, 42 K + and 22 Na + transport could be resolved, even during a chase following a brief 10 minute labeling period. The use of intact plant systems allowed distinction of that portion of the isotope flux into the root, associated with the ion-conducting symplasms. A small compartment, which rapidly (t/sub .5/ + , accounting for the observed obtention of linear translocation rates within minutes of transferring to labeled solution. The ion contents of this compartment varied in proportion to the external ion concentration. When K + was at a high external concentration, labeled K + exchanged into this same symplasm, but chasing a short pulse indicated that K + transport to the xylem was not through a rapidly-exchanging compartment. At physiological concentrations of K + the evidence indicated that transport of K + across the root proceeded through a compartment which was not exchanging rapidly with the external medium. The rise to a linear rate of isotope translocation was gradual and translocation during a chase, following a brief pulse,was prolonged, indicating that this compartment retained its specific activity for a considerable period

Evaluation of the Iodine Concentration in Serum and Urine of Hypothyroid Males Using an Inexpensive and Rapid Method

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Ghulam Abbas Kandhro

2009-12-01

Full Text Available The aim of present study was to evaluate the iodine/iodide status in biological samples (serum and urine of 172 male hypothyroid patients (HPs and their supplemental effects on thyroid hormones. For comparison purpose, non-goitrous subjects (n= 220 of same age group and socioeconomic status were also studied. A simple and rapid iodide-ion selective electrode (ISE was used to measure the concentration of iodine in microwave assisted acid digested serum and urine samples. Quality control for the methodology was established with certified samples and with those obtained by conventional wet acid digestion method on the same certified reference materials (CRMs and real samples. A linear calibration curve was obtained for a reasonable concentration range of the potassium iodide solutions. The mean concentration of iodine in the serum and urine samples of the HPs was significantly reduced as compared to control male subjects (p< 0.01. The low levels of free triiodothyronine and thyroxin were found in HPs than age matched healthy control (p< 0.005 and 0.002 respectively while high levels of thyroid stimulating hormone were observed in HPs (p< 0.008. The proposed method was relatively efficient as well as cost effective by using inexpensive equipment. It was observed that iodine in biological samples of HPs can play an important role in determining the severity of the hypothyroidism.

Factors affecting ANKOM™ fiber analysis of forage and browse varying in condensed tannin concentration.

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Terrill, Thomas H; Wolfe, Richard M; Muir, James P

2010-12-01

Browse species containing condensed tannins (CTs) are an important source of nutrition for grazing/browsing livestock and wildlife in many parts of the world, but information on fiber concentration and CT-fiber interactions for these plants is lacking. Ten forage or browse species with a range of CT concentrations were oven dried and freeze dried and then analyzed for ash-corrected neutral detergent fiber (NDFom) and corrected acid detergent fiber (ADFom) using separate samples (ADFSEP) and sequential NDF-ADF analysis (ADFSEQ) with the ANKOM™ fiber analysis system. The ADFSEP and ADFSEQ residues were then analyzed for nitrogen (N) concentration. Oven drying increased (P < 0.05) fiber concentrations with some species, but not with others. For high-CT forage and browse species, ADFSEP concentrations were greater (P < 0.05) than NDFom values and approximately double the ADFSEQ values. Nitrogen concentration was greater (P < 0.05) in ADFSEP than ADFSEQ residues, likely due to precipitation with CTs. Sequential NDF-ADF analysis gave more realistic values and appeared to remove most of the fiber residue contaminants in CT forage samples. Freeze drying samples with sequential NDF-ADF analysis is recommended in the ANKOM™ fiber analysis system with CT-containing forage and browse species. Copyright © 2010 Society of Chemical Industry.

Free surface profiles in river flows: Can standard energy-based gradually-varied flow computations be pursued?

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Cantero, Francisco; Castro-Orgaz, Oscar; Garcia-Marín, Amanda; Ayuso, José Luis; Dey, Subhasish

2015-10-01

Is the energy equation for gradually-varied flow the best approximation for the free surface profile computations in river flows? Determination of flood inundation in rivers and natural waterways is based on the hydraulic computation of flow profiles. This is usually done using energy-based gradually-varied flow models, like HEC-RAS, that adopts a vertical division method for discharge prediction in compound channel sections. However, this discharge prediction method is not so accurate in the context of advancements over the last three decades. This paper firstly presents a study of the impact of discharge prediction on the gradually-varied flow computations by comparing thirteen different methods for compound channels, where both energy and momentum equations are applied. The discharge, velocity distribution coefficients, specific energy, momentum and flow profiles are determined. After the study of gradually-varied flow predictions, a new theory is developed to produce higher-order energy and momentum equations for rapidly-varied flow in compound channels. These generalized equations enable to describe the flow profiles with more generality than the gradually-varied flow computations. As an outcome, results of gradually-varied flow provide realistic conclusions for computations of flow in compound channels, showing that momentum-based models are in general more accurate; whereas the new theory developed for rapidly-varied flow opens a new research direction, so far not investigated in flows through compound channels.

Extremely high concentration of folates in premature newborns.

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Zikavska, T; Brucknerova, I

2014-01-01

Extremely high concentration of folates in premature newborns: case reports. Folates are a group of water soluble compounds, which are important for metabolic processes in human body. These are important during periods of rapid cell growth. The most accurate indicator of long-term folate level status in the body is the determination of red blood cell (RBC) folate concentrations. The optimal level of RBC folate is not known in neonatal period. Authors discuss the reasons for extremely high level of RBC folate concentrations. In our work we present the cases of two premature newborns with extremely high level of RBC folate concentrations, which were analyzed immunochemically on the first day of life and after six weeks of life. In both cases we measured RBC folate concentrations on the 1st day of life. After 6 weeks we found extremely high RBC folate concentration level (5516.67 ng/ml) in the first case after RBC transfusions. In second case after two months of life the RBC folate concentration level was doubled (2335.1 ng/ml) until 24 hours after RBC transfusion compared to levels after birth. The normal range of RBC folate values vary in newborns. The upper limit of daily dose of folic acid in pregnancy and neonatal period is not known. On the other hand it is an easily excreted water-soluble vitamin but in premature newborn it can lead to the disruption of metabolic balance and slow its degradation. Some factors can have an impact on RBC folate concentration. Blood transfusion can be one of the main influences on RBC folate concentration. To clarify these mechanisms further studies are required (Ref. 29).

The effect of emulsifying salts on the turbidity of a diluted milk system with varying pH and protein concentration.

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Culler, M D; Saricay, Y; Harte, F M

2017-06-01

Solutions of 10 commonly used emulsifying salts (ES) listed in the Code of Federal Regulations (21CFR133.179) for pasteurized process cheese were tested for their effect on the turbidity of a diluted milk system at different pH and protein concentrations to characterize the conditions that affect micellar structure. Emulsifying salt solutions were made by mixing the ES in a 1-in-20 dilution of water in skim milk ultrafiltrate (3 kDa molecular weight cut-off) to obtain ES concentrations from 0 to 248 mM. Skim milk was added to solutions containing nanopure water, skim milk ultrafiltrate, and a specific ES ranging in concentration from 0 to 248 mM and pH 5, 5.8, 6.8, 7.8, and 8.8. The turbidity of the samples was measured as the optical density at 400 nm immediately after mixing (time, t = 0), after 30 s (t = 30s), and after 30 min (t = 30min). Emulsifying salts were found to cause a decrease in the turbidity of the system, which was modeled using an exponential decay model, where C* represents a threshold salt concentration at which rapid dissociation occurs. At pH values 5.8 and 6.8, the ES caused the greatest decrease in turbidity of the diluted milk system. At pH 5, the ES had the least effect on the turbidity of the system. Sodium hexametaphosphate was found to have the strongest dissociative effect, with a C* value of 0.33 mM for t = 0 at pH 6.8. In contrast, the largest C* value calculated at pH 6.8 was monosodium phosphate at 278.22 mM. Increased time resulted in lower C* values. The model established for this study can be used to predict the dissociation of casein micelles in the presence of various types of ES. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Marangoni-buoyancy convection in binary fluids under varying noncondensable concentrations

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Li, Yaofa; Yoda, Minami

2014-11-01

Marangoni-buoyancy convection in binary fluids in the presence of phase change is a complex and poorly understood problem. Nevertheless, this flow is of interest in evaporative cooling because solutocapillary stresses could reduce film dryout. Convection was therefore studied in methanol-water (MeOH-H2O) layers of depth h ~ 1 - 3 mm confined in a sealed rectangular cell driven by horizontal temperature differences of ~6° C applied over ~ 5 cm. Particle-image velocimetry (PIV) was used to study how varying the fraction of noncondensables (i.e., air) ca from ~ 7 mol% to ambient conditions in the vapor space affects soluto- and thermocapillary stresses in this flow. Although solutocapillary stresses can be used to drive the flow towards hot regions, solutocapillarity appears to have the greatest effect on the flow at small ca, because noncondensables suppress phase change and hence the gradient in the liquid-phase composition at the interface. Surprisingly, convection at ca ~ 50 % leads to a very weak flow and significant condensation in the central portion of the layer i.e., away from the heated and cooled walls). Supported by ONR.

Assessment of life quality in patients with bronchial asthma residing in Krakow in the areas of varying concentrations of particulate matter (PM10

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Monika Ścibor

2015-03-01

Full Text Available Introduction. Asthma is a chronic disease, from which more and more people in the world suffer. It is connected with many bothersome symptoms and limitations, which result in decreased quality of life for the patient. Environmental and individual aspects do not necessarily affect individuals in the same way, so it is necessary to determine which factors have predominantly impacted on an individual, in order to minimize their impact and to take better control over treatment of asthma. The aim of this research was to compare the quality of life among patients with bronchial asthma living in Krakow in the areas where they get exposed to varying concentrations of particulate matter (PM10. Material and methods. The study included 98 adults diagnosed with bronchial asthma. The research was conducted using the AQLQ poll. PM10 concentration was measured in several Malopolska Air Pollution Monitoring Stations located throughout the city. Results. Analyzing the quality of life in the view of symptoms, activity limitations and emotional well being, there was a substantial statistical difference observed in people occupying the areas with different PM10 concentrations. No significant statistical difference was observed in the frequency of asthma symptoms caused by the environmental stimuli between the 2 discussed groups. One group of patients who came to the allergy clinic for control of asthma symptoms and the second group who live in the vicinity of the monitoring stations measuring PM10 concentrations. Conclusions. For many of the cases, the quality of life was not worse for patients with asthma living in an area with slightly elevated concentrations of PM10, and sometimes paradoxically the quality of life was improved. These results show that PM10 concentrations do not correlate with quality of life of asthma patients.

Semi-solid dosage form of clonazepam for rapid oral mucosal absorption.

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Sakata, Osamu; Machida, Yoshiharu; Onishi, Hiraku

2011-07-01

In order to obtain an alternative to the intravenous (i.v.) dosage form of clonazepam (CZ), an oral droplet formulation of CZ was developed previously; however, the droplet was physically unstable. Therefore, in the present study, it was attempted to develop an easily-handled dosage form, which was more physically stable and allowed rapid drug absorption from oral mucosa. A semi-solid dosage form, composed of polyethylene glycol 1500 (PEG), CZ, and oleic acid (OA) at 37/1/2 (w/w) and named PEG/CZ/OA, and a semi-solid dosage form containing PEG and CZ at 39/1 (w/w), called PEG/CZ, were prepared. Their physical stability in air at room temperature and oral mucosal absorption in rats were investigated. The semi-solid dosage forms were much more stable physically than the droplet, that is, no recrystallization of CZ was observed for at least 8 days. The effective concentration for humans and rats (20 ng/mL or more) was achieved within 30 min after buccal administration for both PEG/CZ/OA and PEG/CZ. The plasma concentration increased gradually and less varied at each time point for PEG/CZ/OA. PEG/CZ/OA was found to show more rapid and higher absorption of CZ in buccal administration than in sublingual administration. Buccal administration with the semi-solid dosage PEG/CZ with or without OA was suggested to be a possibly useful novel dosage form as an alternative to i.v. injection.

Rapid concentration and dialysis of proteins with single hollow fibers: possible applications in analysis of protein secretion by isolated cells and steroid radioimmunoassays

International Nuclear Information System (INIS)

Rommerts, F.F.G.; Clotscher, W.F.; Van der Molen, H.J.

1977-01-01

Single hollow fibers were used in specially made cells for fast concentration and dialysis of solutions containing macromolecules. Volumes on the order of 5 ml of diluted protein solutions could be concentrated to 50--100 μl or less within 7 min with a protein recovery of 60--80%. More than 99% of the molecules with a molecular weight less than 500 could be removed in less than 1 hr. A possible application of the rapid dialysis method for the mechanization of radioimmunoassays is indicated. It was shown that in the radioimmunoassay of steriods the unbound steroids could be removed after incubation with antiserum, within 10 min and without a change in volume

Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement.

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Mahler, Barbara J; Van Metre, Peter C; Foreman, William T

2014-05-01

Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement. Published by Elsevier Ltd.

Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement

Science.gov (United States)

Mahler, Barbara J.; Van Metre, Peter C.; Foreman, William T.

2014-01-01

Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement.

Rapid Aminoglycoside NP Test for Rapid Detection of Multiple Aminoglycoside Resistance in Enterobacteriaceae.

Science.gov (United States)

Nordmann, Patrice; Jayol, Aurélie; Dobias, Jan; Poirel, Laurent

2017-04-01

The rapid aminoglycoside NP (Nordmann/Poirel) test was developed to rapidly identify multiple aminoglycoside (AG) resistance in Enterobacteriaceae It is based on the detection of the glucose metabolism related to enterobacterial growth in the presence of a defined concentration of amikacin plus gentamicin. Formation of acid metabolites was evidenced by a color change (orange to yellow) of the red phenol pH indicator. The rapid aminoglycoside NP test was evaluated by using bacterial colonies of 18 AG-resistant isolates producing 16S rRNA methylases, 20 AG-resistant isolates expressing AG-modifying enzymes (acetyl-, adenyl-, and phosphotransferases), and 10 isolates susceptible to AG. Its sensitivity and specificity were 100% and 97%, respectively, compared to the broth dilution method, which was taken as the gold standard for determining aminoglycoside resistance. The test is inexpensive, rapid (<2 h), and implementable worldwide. Copyright © 2017 American Society for Microbiology.

Rapid MR measurements of contrast medium dilution kinetics (gadolinium-DTPA) in a flow phantom

International Nuclear Information System (INIS)

Boeck, J.C.; Sander, B.; Frank, J.; Schoerner, W.

1991-01-01

We studied first-pass MRI-contrast dilution to compute flow and volume of distribution in a realistic flow phantom. Pulsatile flow was provided by a one-chamber artificial heart. Physiological stroke volume, rate, pressure, and flow were adjustable. An elastic tube with dimensions similar to that of the human aorta was imaged at a rate of 2.4 Hz. After contrast injection, an initial increase in signal intensity was followed by a decrease. Signal-intensity-time plots demonstrated slightly skewed curves as expected from dispersion theory. After calibration at different gadolinium-DTPA concentrations, signal intensities were converted into true gadolinium concentrations, and flow was calculated from the concentration-time curves. Flow was varied between 2.5 and 10.0 l/min and a significant correlation was found between the MRI-estimate and true flow. Volume of distribution between injection and detection site was reliably estimated. This study demonstrates rapid 2-D imaging of a paramagnetic contrast bolus in a realistic flow phantom. Reliable estimates of flow and volume are obtained. (orig.) [de

Steady shear viscosity of stirred yoghurts with varying ropiness

NARCIS (Netherlands)

van Marle, M.E.; van Marle, M.E.; van den Ende, Henricus T.M.; de Kruif, C.G.; de Kruif, C.G.; Mellema, J.

1999-01-01

Stirred yogurt was viewed as a concentrated dispersion of aggregates consisting of protein particles. The steady-shear behavior of three types of stirred yogurt with varying ropiness was investigated experimentally. To describe the shear-dependent viscosity, a microrheological model was used which

Growth performance and carcass characteristics of growing ram lambs fed sweet sorghum bagasse-based complete rations varying in roughage-to-concentrate ratios.

Science.gov (United States)

Kumari, Nagireddy Nalini; Reddy, Yerradoddi Ramana; Blummel, Michel; Nagalakshmi, Devanaboyina; Monika, Thamatam; Reddy, Belum Venkata Subba; Reddy, Chintalapani Ravinder

2013-02-01

Different roughage-to-concentrate ratios of sweet sorghum bagasse (SSB) (a by-product of the biofuel industry)-based complete diets were assessed. Twenty four growing Nellore × Deccani ram lambs aged about 3 months (average body wt., 10.62 ± 0.25 kg) were randomly allotted to four complete rations (CR) varying in roughage-to-concentrate ratios viz. 60:40 (CR-I), 50:50 (CR-II), 40:60 (CR-III) and 30:70(CR-IV) for a period of 180 days. The feed intake was comparable among the lambs fed different experimental complete diets. Average daily weight gain (in grams) was 77.31 ± 4.90, 81.76 ± 5.16, 85.83 ± 2.83 and 86.30 ± 3.25, and feed conversion ratio (in kilograms of feed per kilogram gain) averaged 11.42 ± 0.68, 10.57 ± 0.64, 10.17 ± 0.37 and 9.96 ± 0.38 in ram lambs fed CR-I, CR-II, CR-III and CR-IV rations, respectively. Statistically, differences in daily weight gain and feed conversion ratio among the lambs fed four experimental rations were not significant (P > 0.05). The cost per kilogram gain was significantly (P carcass weights, dressing percentage, wholesale cuts and edible and non-edible portions of experimental animals. Similarly, no significant variation could be seen in bone and meat yield (in per cent) and their ratios in various wholesale cuts among the dietary treatments. The roughage-to-concentrate ratio did not affect the chemical composition of meat; however, the fat content of meat was linearly increased with increase in the proportion of concentrate in the diets. The results of the experiment indicated that SSB can be included at 60 % level in the complete diet for economical mutton production from growing Nellore × Deccani ram lambs.

Effects of fumaric acid supplementation on methane production and rumen fermentation in goats fed diets varying in forage and concentrate particle size.

Science.gov (United States)

Li, Zongjun; Liu, Nannan; Cao, Yangchun; Jin, Chunjia; Li, Fei; Cai, Chuanjiang; Yao, Junhu

2018-01-01

In rumen fermentation, fumaric acid (FA) could competitively utilize hydrogen with methanogenesis to enhance propionate production and suppress methane emission, but both effects were diet-dependent. This study aimed to explore the effects of FA supplementation on methanogenesis and rumen fermentation in goats fed diets varying in forage and concentrate particle size. Four rumen-cannulated goats were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments: low or high ratio of forage particle size: concentrate particle size (Fps:Cps), without or with FA supplementation (24 g/d). Fps:Cps was higher in the diet with chopped alfalfa hay plus ground corn than in that with ground alfalfa hay plus crushed corn. Both increasing dietary Fps:Cps and FA supplementation shifted ruminal volatile fatty acid (VFA) patterns toward more propionate and less acetate in goats. An interaction between dietary Fps:Cps and FA supplementation was observed for the ratio of acetate to propionate (A:P), which was more predominant when FA was supplemented in the low-Fps:Cps diet. Methane production was reduced by FA, and the reduction was larger in the low-Fps:Cps diet (31.72%) than in the high-Fps:Cps diet (17.91%). Fumaric acid decreased ruminal total VFA concentration and increased ruminal pH. No difference was found in ruminal DM degradation of concentrate or alfalfa hay by dietary Fps:Cps or FA. Goats presented a lower ruminal methanogen abundance with FA supplementation and a higher B. fibrisolvens abundance with high dietary Fps:Cps. Adjusting dietary Fps:Cps is an alternative dietary model for studying diet-dependent effects without changing dietary chemical composition. Fumaric acid supplementation in the low-Fps:Cps diet showed greater responses in methane mitigation and propionate increase.

Optimum Er concentration for in situ doped GaN visible and infrared luminescence

International Nuclear Information System (INIS)

Lee, D. S.; Heikenfeld, J.; Steckl, A. J.; Hommerich, U.; Seo, J. T.; Braud, A.; Zavada, J.

2001-01-01

GaN thin films have been doped with varying Er concentrations (0.01--10 at.%) during molecular-beam-epitaxy growth. As expected, the visible and infrared (IR) emissions, from photoluminescence (PL) and electroluminescence (EL), are a strong function of Er concentration. We report on the determination of an optimum Er doping level for PL and EL intensity. Secondary ion mass spectroscopy and Rutherford backscattering measurements showed that the Er concentration in GaN increased exponentially with Er cell temperature. PL and EL intensity of green emission at 537 and 558 nm, due to Er 4f--4f inner shell transitions, exhibited a maximum at ∼1 at.% Er. IR PL intensity at 1.54 μm, due to another Er transition, revealed the same maximum for ∼1 at.% Er concentration. PL lifetime measurements at 537 nm showed that samples with Er concentration <1 at.% had a lifetime of ∼5 μs. For Er concentration ≥1 at.%, the lifetime decreased rapidly to values below 1 μs. This concentration quenching is believed to be due to a combination of Er cross relaxation and energy transfer to GaN defects, eventually followed by precipitation. This conclusion is supported by x-ray diffraction measurements. As a result, we have determined that the optimum Er doping concentration into GaN is ∼1 at.%. Copyright 2001 American Institute of Physics

[Development of a portable mid-infrared rapid analyzer for oil concentration in water based on MEMS linear sensor array].

Science.gov (United States)

Gao, Zhi-fan; Zeng, Li-bo; Shi, Lei; Li, Kai; Yang, Yuan-zhou; Wu, Qiong-shui

2014-06-01

Aiming at the existing problems such as weak environmental adaptability, low analytic efficiency and poor measuring repeatability in the traditional spectral oil analyzers, the present paper designed a portable mid-infrared rapid analyzer for oil concentration in water. To reduce the volume of the instrument, the non-symmetrical folding M-type Czerny-Turner optical structure was adopted in the core optical path. With a periodically rotating chopper, controlled by digital PID algorithm, applied for infrared light modulation, the modulating accuracy reached ±0.5%. Different from traditional grating-scanning spectrophotometers, this instrument used a fixed grating for light dispersion and avoided rotating error in the course of the measuring procedures. A new-type MEMS infrared linear sensor array was applied for modulated spectral signals detection, which improved the measuring efficiency remarkably. Optical simulation and experimental results indicate that the spectral range is 2 800 - 3 200 cm(-1), the spectral resolution is 6 cm(-1) (@3 130 cm(-1)), and the signal to noise ratio is up to 5 200 : 1. The acquisition time is 13 milliseconds per spectrogram, and the standard deviation of absorbance is less than 3 x 10(-3). These performances meet the standards of oil concentration measurements perfectly. Compared with traditional infrared spectral analyzers for oil concentration, the instrument demonstrated in this paper has many advantages such as smaller size, more efficiency, higher precision, and stronger vibration & moisture isolation. In addition, the proposed instrument is especially suitable for the environmental monitoring departments to implement real-time measurements in the field for oil concentration in water, hence it has broad prospects of application in the field of water quality monitoring.

Antimicrobial Efficacy of Various Essential Oils at Varying Concentrations against Periopathogen Porphyromonas gingivalis

Science.gov (United States)

Grover, Harpreet Singh; Deswal, Himanshu; Agarwal, Preeti

2016-01-01

Introduction Porphyromonas gingivalis (P.gingivalis) is a notorious perio-pathogen with the ability to evade host defense mechanism and invade into the periodontal tissues. Many antimicrobial agents have been tested that curb its growth, although these agents tend to produce side effects such as antibiotic resistance and opportunistic infections. Therefore search for naturally occurring anti-microbials with lesser side effects is the need of the hour. Aim The aim of this study was to substantiate the antimicrobial activity of various essential oils; eucalyptus oil, chamomile oil, tea tree oil and turmeric oil against P. gingivalis. Materials and Methods Pure cultures of P. gingivalis were grown on selective blood agar. Antimicrobial efficacy of various concentrations of essential oils (0%, 25%, 50% and 100%) was assessed via disc diffusion test. Zone of inhibition were measured around disc after 48 hours in millimeters. Results Zones of inhibition were directly proportional to the concentration of essential oils tested. At 100% concentration all the tested oils possess antimicrobial activity against P.gingivalis with eucalyptus oil being most effective followed by tea tree oil, chamomile oil and turmeric oil. Conclusion All essential oils tested were effective against P.gingivalis. After testing for their clinical safety they could be developed into local agents to prevent and treat periodontitis. PMID:27790572

Screening for transfusion transmissible infections using rapid diagnostic tests in Africa: a potential hazard to blood safety?

Science.gov (United States)

Prugger, C.; Laperche, S.; Murphy, E. L.; Bloch, E. M.; Kaidarova, Z.; Tafflet, M.; Lefrère, J.-J.; Jouven, X.

2016-01-01

Rapid diagnostic tests (RDTs) are routinely used in African blood centres. We analysed data from two cross-sectional studies representing 95 blood centres in 29 African countries. Standardized panels of sera containing varying concentrations of anti-human immunodeficiency virus (HIV) antibodies (Ab), hepatitis B virus antigen (HBsAg) and antihepatitis C virus (HCV) Ab were screened using routine operational testing procedures at the centres. Sensitivity of detection using RDTs was high for HIV Ab-positive samples, but low for intermediately HBsAg (51·5%) and HCV Ab (40·6%)-positive samples. These findings suggest that current RDT use in Africa could pose a hazard to blood safety. PMID:26646317

Rearing Chrysomya megacephala on artificial diets composed of varying concentrations of albumin

Directory of Open Access Journals (Sweden)

Paloma Martins Mendonça

2009-04-01

Full Text Available Larvae of the blowfly Chrysomya megacephala were reared on an artificial diet composed of five different concentrations of albumin (2, 4, 6, 8 and 10% and the control group was fed on putrid bovine meat. No larvae developed in the 2 and 10% albumin concentrations. The period from newly hatched larvae to adults reared on 4, 6 and 8% albumin was 13.1, 13.1 and 13.6 days, respectively, whereas for the control group, it was 11.2 days. Concentrations of 4, 6 and 8% albumin proved viabile for larval periods of 29.3, 44.0 and 57.3%, respectively, whereas for the control group, it was 77.3%. Pupal viability was 77.3, 36.4 and 83.7%, while for the control group, it was 84.5%; the newly hatched larvae to adult viability was 21.3, 16.0 and 48.0%, respectively, and for the control group, it was 65.3%.O presente trabalho teve como objetivo avaliar o desenvolvimento pós-embrionário de Chrysomya megacephala (Fabricius, 1794 (Diptera: Calliphoridae em dietas artificiais à base de albumina nas concentrações de 2%, 4%, 6%, 8% e 10% de albumina e como controle foi utilizada a carne bovina moída putrefata. Não houve desenvolvimento nas dietas de concentração 2% e 10% de albumina. A duração do período de larva a adulto foi 13,1; 13,1 e 13,6 dias, respectivamente, e a do controle foi de 11,2 dias. As dietas artificiais nas concentrações 4, 6 e 8% de albumina apresentaram viabilidades larvais de 29,3; 44,0 e 57,3%, respectivamente e o controle 77,3%; as viabilidades de pupa foram 77,3; 36,4 e 83,7% e o controle 84,5%, respectivamente; as viabilidades de larva a adulto foram 21,3; 16,0 e 48,0% e o controle foi de 65,3%, respectivamente.

Rapid serial visual presentation design for cognition

CERN Document Server

Spence, Robert

2013-01-01

A powerful new image presentation technique has evolved over the last twenty years, and its value demonstrated through its support of many and varied common tasks. Conceptually, Rapid Serial Visual Presentation (RSVP) is basically simple, exemplified in the physical world by the rapid riffling of the pages of a book in order to locate a known image. Advances in computation and graphics processing allow RSVP to be applied flexibly and effectively to a huge variety of common tasks such as window shopping, video fast-forward and rewind, TV channel selection and product browsing. At its heart is a

Are serum adiponectin concentrations in a population sample of 64-year-old Caucasian women with varying glucose tolerance associated with ultrasound-assessed atherosclerosis?

Science.gov (United States)

Behre, C J; Brohall, G; Hulthe, J; Wikstrand, J; Fagerberg, B

2006-09-01

To examine whether serum adiponectin concentrations were associated with subclinical atherosclerosis assessed as intima media thickness (IMT) in the carotid arteries in Caucasian women with varying degrees of glucose tolerance. From a population-based cohort of 64-year-old Swedish women, 533 subjects with type 2 diabetes (DM2, n=177), impaired glucose tolerance (IGT; n=178) or normal glucose tolerance (NGT, n=178) were recruited. Anthropometrics, usual cardiovascular risk factors were examined and ultrasound examination of the carotid arteries was performed. Women with low adiponectin concentrations were characterized by thick IMT, higher prevalence of DM2, history of previous myocardial infarction, angina pectoris, anti-hypertensive treatment and high body mass index (BMI), waist circumference, plasma insulin, serum triglycerides, fasting glucose, HbA1c, and low serum HDL cholesterol levels. Carotid IMT correlated with HbA1c (r=0.24, PDM2 (r=0.16, P<0.001), systolic blood pressure (r=0.16, P<0.001), blood glucose (r=0.16, P<0.001), triglycerides (r=0.15, P<0.001), and reversely to adiponectin (r=-0.11, P=0.01), HDL cholesterol (r=-0.13, P=0.004), and alcohol intake (r=-0.087, P<0.05). A more detailed analysis of underlying associations was difficult due to a high co-linearity between these variable. Low serum adiponectin concentrations were associated with increased carotid artery IMT, and several risk factors for cardiovascular diseases, mainly those constituting the metabolic syndrome.

Continuous measurement of the radon concentration in water using electret ion chamber method

International Nuclear Information System (INIS)

Dua, S.K.; Hopke, P.K.

1992-10-01

A radon concentration of 300 pCi/L has been proposed by the US Environmental Protection Agency as a limit for radon dissolved in municipal drinking water supplies. There is therefore a need for a continuous monitor to insure that the daily average concentration does not exceed this limit. In order to calibrate the system, varying concentrations of radon in water have been generated by bubbling radon laden air through a dynamic flowthrough water system. The value of steady state concentration of radon in water from this system depends on the concentration of radon in air, the air bubbling rate, and the water flow rate. The measurement system has been designed and tested using a 1 L volume electret ion chamber to determine the radon in water. In this dynamic method, water flows directly through the electret ion chamber. Radon is released to the air and measured with the electret. A flow of air is maintained through the chamber to prevent the build-up of high radon concentrations and too rapid discharge of the electret. It was found that the system worked well when the air flow was induced by the application of suction. The concentration in the water was calculated from the measured concentration in air and water and air flow rates. Preliminary results suggest that the method has sufficient sensitivity to measure concentrations of radon in water with acceptable accuracy and precision

Use of rapid sampling microdialysis for intraoperative monitoring of bowel ischemia.

Science.gov (United States)

Deeba, S; Corcoles, E P; Hanna, G B; Hanna, B G; Pareskevas, P; Aziz, O; Boutelle, M G; Darzi, A

2008-09-01

Intestinal ischemia is a major cause of anastomotic leak and death and remains a clinical challenge as the physician relies on several nonspecific signs, biologic markers, and radiologic studies to make the diagnosis. This study used rapid sampling online microdialysis to evaluate the biochemical changes occurring in a segment of human bowel during and after resection, and assessed for the feasibility and reproducibility of this technique in monitoring intestinal ischemia. A custom made, rapid sampling online microdialysis analyzer was used to monitor the changes in the bowel wall of specimens being resected intraoperatively. Two patients were recruited for the pilot study to optimize the analyzer and seven patients undergoing colonic resections were recruited for the data collection and analysis. The concentration of glucose in the extracellular bowel wall fluid decreased transiently after division of individual feeding arteries followed by a rebound increase in the concentration back to baseline concentrations. After completion of resection, glucose concentrations continued to decrease while lactate concentrations increased constantly. Rapid sampling microdialysis was feasible in the clinical environment. These results suggest that tissue responds to ischemic insult by mobilizing glucose stores which later decrease again, whereas lactate concentrations constantly increased.

The Effect of Elevated Ozone Concentrations with Varying Shading on Dry Matter Loss in a Winter Wheat-Producing Region in China.

Science.gov (United States)

Xu, Jingxin; Zheng, Youfei; He, Yuhong; Wu, Rongjun; Mai, Boru; Kang, Hanqing

2016-01-01

Surface-level ozone pollution causes crop production loss by directly reducing healthy green leaf area available for carbon fixation. Ozone and its precursors also affect crop photosynthesis indirectly by decreasing solar irradiance. Pollutants are reported to have become even more severe in Eastern China over the last ten years. In this study, we investigated the effect of a combination of elevated ozone concentrations and reduced solar irradiance on a popular winter wheat Yangmai13 (Triticum aestivum L.) at field and regional levels in China. Winter wheat was grown in artificial shading and open-top-chamber environments. Treatment 1 (T1, i.e., 60% shading with an enhanced ozone of 100±9 ppb), Treatment 2 (T2, i.e., 20% shading with an enhanced ozone of 100±9 ppb), and Control Check Treatment (CK, i.e., no shading with an enhanced ozone of 100±9 ppb), with two plots under each, were established to investigate the response of winter wheat under elevated ozone concentrations and varying solar irradiance. At the field level, linear temporal relationships between dry matter loss and cumulative stomatal ozone uptake were first established through a parameterized stomatal-flux model. At the regional level, ozone concentrations and meteorological variables, including solar irradiance, were simulated using the WRF-CMAQ model (i.e., a meteorology and air quality modeling system). These variables were then used to estimate cumulative stomatal ozone uptake for the four major winter wheat-growing provinces. The regional-level cumulative ozone uptake was then used as the independent variable in field data-based regression models to predict dry matter loss over space and time. Field-level results showed that over 85% (T1: R(2) = 0.85 & T2: R(2) = 0.89) of variation in dry matter loss was explained by cumulative ozone uptake. Dry matter was reduced by 3.8% in T1 and 2.2% in T2 for each mmol O3·m(-2) of cumulative ozone uptake. At the regional level, dry matter loss in winter

The Effect of Elevated Ozone Concentrations with Varying Shading on Dry Matter Loss in a Winter Wheat-Producing Region in China.

Directory of Open Access Journals (Sweden)

Jingxin Xu

Full Text Available Surface-level ozone pollution causes crop production loss by directly reducing healthy green leaf area available for carbon fixation. Ozone and its precursors also affect crop photosynthesis indirectly by decreasing solar irradiance. Pollutants are reported to have become even more severe in Eastern China over the last ten years. In this study, we investigated the effect of a combination of elevated ozone concentrations and reduced solar irradiance on a popular winter wheat Yangmai13 (Triticum aestivum L. at field and regional levels in China. Winter wheat was grown in artificial shading and open-top-chamber environments. Treatment 1 (T1, i.e., 60% shading with an enhanced ozone of 100±9 ppb, Treatment 2 (T2, i.e., 20% shading with an enhanced ozone of 100±9 ppb, and Control Check Treatment (CK, i.e., no shading with an enhanced ozone of 100±9 ppb, with two plots under each, were established to investigate the response of winter wheat under elevated ozone concentrations and varying solar irradiance. At the field level, linear temporal relationships between dry matter loss and cumulative stomatal ozone uptake were first established through a parameterized stomatal-flux model. At the regional level, ozone concentrations and meteorological variables, including solar irradiance, were simulated using the WRF-CMAQ model (i.e., a meteorology and air quality modeling system. These variables were then used to estimate cumulative stomatal ozone uptake for the four major winter wheat-growing provinces. The regional-level cumulative ozone uptake was then used as the independent variable in field data-based regression models to predict dry matter loss over space and time. Field-level results showed that over 85% (T1: R(2 = 0.85 & T2: R(2 = 0.89 of variation in dry matter loss was explained by cumulative ozone uptake. Dry matter was reduced by 3.8% in T1 and 2.2% in T2 for each mmol O3·m(-2 of cumulative ozone uptake. At the regional level, dry matter

Investigation of Structural and Electronic Properties of CH3NH3PbI3 Stabilized by Varying Concentrations of Poly(Methyl Methacrylate (PMMA

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Celline Awino

2017-08-01

Full Text Available Studies have shown that perovskites have a high potential of outdoing silicon based solar cells in terms of solar energy conversion, but their rate of degradation is also high. This study reports on improvement on the stability of CH3NH3PbI3 by passivating it with polymethylmethacrylate (PMMA. Structural and electronic properties of CH3NH3PbI3 stabilized by polymethylmethacrylate (PMMA were investigated by varying concentrations of PMMA in the polymer solutions. Stability tests were performed over a period of time using modulated surface photovoltage (SPV spectroscopy, X-ray diffraction (XRD, and photoluminescence (PL measurements. The XRD patterns confirm the tetragonal structure of the deposited CH3NH3PbI3 for every concentration of PMMA. Furthermore, CH3NH3PbI3 coated with 40 mg/mL of PMMA did not show any impurity phase even after storage in air for 43 days. The Tauc gap (ETauc determined on the basis of the in-phase SPV spectra was found in the range from 1.585 to 1.62 eV for the samples stored during initial days, but shifted towards lower energies as the storage time increased. This can be proposed to be due to different chemical reactions between CH3NH3PbI3/PMMA interfaces and air. PL intensity increased with increasing concentration of PMMA except for the perovskite coated with 40 mg/mL of PMMA. PL quenching in the perovskite coated with 40 mg/mL of PMMA can be interpreted as fast electron transfer towards the substrate in the sample. This study shows that, with an optimum concentration of PMMA coating on CH3NH3PbI3, the lifetime and hence stability on electrical and structural behavior of CH3NH3PbI3 is improved.

Effects of concentrated sunlight on organic photovoltaics

DEFF Research Database (Denmark)

Tromholt, Thomas; Katz, Eugene A.; Hirsch, Baruch

2010-01-01

We report the effects of concentrated sunlight on key photovoltaic parameters and stability of organic photovoltaics (OPV). Sunlight collected and concentrated outdoors was focused into an optical fiber and delivered onto a 1 cm2 bulk-heterojunction cell. Sunlight concentration C was varied gradu...

Effect of Crosslinking Agent Concentration on the Properties of Unmedicated Hydrogels

Directory of Open Access Journals (Sweden)

Rachel Shet Hui Wong

2015-09-01

Full Text Available Novel polyethylene oxide (PEO hydrogel films were synthesized via UV crosslinking with varying concentrations of pentaerythritol tetra-acrylate (PETRA as crosslinking agent. The aim was to study the effects of the crosslinking agent on the material properties of hydrogel films intended for dermatological applications. Fabricated film samples were characterized using swelling studies, scanning electron microscopy, tensile testing and rheometry. Films showed rapid swelling and high elasticity. The increase of PETRA concentration resulted in significant increase in the gel fraction and crosslinking density (ρc, while causing a significant decrease in the equilibrium water content (EWC, average molecular weight between crosslinks (\\({\\overline{M}}_{c}\\, and mesh size (ζ of films. From the scanning electron microscopy, cross-linked PEO hydrogel network appeared as cross-linked mesh-like structure with interconnected micropores. Rheological studies showed PEO films required a minimum of 2.5% w/w PETRA to form stable viscoelastic solid gels. Preliminary studies concluded that a minimum of 2.5% w/w PETRA is required to yield films with desirable properties for skin application.

Pulse pile-up in nuclear particle detection systems with rapidly varying counting rates

International Nuclear Information System (INIS)

Datlowe, D.W.

1977-01-01

Pulse pile-up in nuclear particle detection systems is the distortion of the measured pulse height distribution which occurs when there is a significant probability that more than one particle will arrive within the detector resolving time. This paper treats the problem in cases where the probability of pile-up varies on a time scale comparable to the rise time of the detector system electronics. These variations introduce structure into the pulse height distributions which cannot occur for a time-independent pile-up probability. Three classes of problems which exemplify these effects are as follows: 1) Pile-up rejection circuits. 2) Cascaded nuclear decays, in which the lifetime for emission of a second X-ray is comparable to the detector rise time. 3) Bursts of particles where the intensity is modulated on a time scale comparable to the detector rise time. These problems are solved computationally by an extension of a numerical technique previously developed. (Auth.)

Simultaneous denitrification and phosphorus removal by Agrobacterium sp. LAD9 under varying oxygen concentration.

Science.gov (United States)

Ma, Tao; Chen, Qian; Gui, Mengyao; Li, Can; Ni, Jinren

2016-04-01

Although efficient aerobic denitrification has received increasing attention, few studies have been made on simultaneous denitrification and phosphorus removal (SDPR) under aerobic condition. In this study, SDPR by an efficient aerobic denitrifier, Agrobacterium sp. LAD9, was firstly demonstrated. High nitrate and phosphorus removal rates of 7.50 and 1.02 mg L(-1) h(-1) were achieved in wide range of O2 concentration from 5.92 to 20.02 mg L(-1). The N2O production would be inhibited as O2 concentration exceeded 11.06 mg L(-1), while the phosphorus removal efficiency would be generally improved with increasing O2 concentration. (15)N mass spectrometry revealed that nitrogen removal accorded with the typical aerobic denitrification pathway, while (31)P nuclear magnetic resonance spectroscopy ((31)P NMR) indicated the fate of phosphorus to cells, extracellular polymeric substances (EPS), and polyphosphate (poly-P) of the denitrifier. EPS acted as a reservoir of phosphorus and the transformation of poly-P was dynamic and depended on initial orthophosphate (ortho-P) content. The aerobic SDPR would greatly simplify the conventional wastewater treatment processes which required separated considerations of nitrogen and phosphorus removal.

Behavior of varying-alpha cosmologies

International Nuclear Information System (INIS)

Barrow, John D.; Sandvik, Haavard Bunes; Magueijo, Joao

2002-01-01

We determine the behavior of a time-varying fine structure 'constant' α(t) during the early and late phases of universes dominated by the kinetic energy of changing α(t), radiation, dust, curvature, and lambda, respectively. We show that after leaving an initial vacuum-dominated phase during which α increases, α remains constant in universes such as our own during the radiation era, and then increases slowly, proportional to a logarithm of cosmic time, during the dust era. If the universe becomes dominated by a negative curvature or a positive cosmological constant then α tends rapidly to a constant value. The effect of an early period of de Sitter or power-law inflation is to drive α to a constant value. Various cosmological consequences of these results are discussed with reference to recent observational studies of the value of α from quasar absorption spectra and to the existence of life in expanding universes

Development of rapid mixing fuel nozzle for premixed combustion

International Nuclear Information System (INIS)

Katsuki, Masashi; Chung, Jin Do; Kim, Jang Woo; Hwang, Seung Min; Kim, Seung Mo; Ahn, Chul Ju

2009-01-01

Combustion in high-preheat and low oxygen concentration atmosphere is one of the attractive measures to reduce nitric oxide emission as well as greenhouse gases from combustion devices, and it is expected to be a key technology for the industrial applications in heating devices and furnaces. Before proceeding to the practical applications, we need to elucidate combustion characteristics of non-premixed and premixed flames in high-preheat and low oxygen concentration conditions from scientific point of view. For the purpose, we have developed a special mixing nozzle to create a homogeneous mixture of fuel and air by rapid mixing, and applied this rapidmixing nozzle to a Bunsen-type burner to observe combustion characteristics of the rapid-mixture. As a result, the combustion of rapid-mixture exhibited the same flame structure and combustion characteristics as the perfectly prepared premixed flame, even though the mixing time of the rapid-mixing nozzle was extremely short as a few milliseconds. Therefore, the rapid-mixing nozzle in this paper can be used to create preheated premixed flames as far as the mixing time is shorter than the ignition delay time of the fuel

Plasma concentrations of inflammatory cytokines rise rapidly during ECMO-related SIRS due to the release of preformed stores in the intestine.

Science.gov (United States)

McILwain, R Britt; Timpa, Joseph G; Kurundkar, Ashish R; Holt, David W; Kelly, David R; Hartman, Yolanda E; Neel, Mary Lauren; Karnatak, Rajendra K; Schelonka, Robert L; Anantharamaiah, G M; Killingsworth, Cheryl R; Maheshwari, Akhil

2010-01-01

Extracorporeal membrane oxygenation (ECMO) is a life-saving support system used in neonates and young children with severe cardiorespiratory failure. Although ECMO has reduced mortality in these critically ill patients, almost all patients treated with ECMO develop a systemic inflammatory response syndrome (SIRS) characterized by a 'cytokine storm', leukocyte activation, and multisystem organ dysfunction. We used a neonatal porcine model of ECMO to investigate whether rising plasma concentrations of inflammatory cytokines during ECMO reflect de novo synthesis of these mediators in inflamed tissues, and therefore, can be used to assess the severity of ECMO-related SIRS. Previously healthy piglets (3-week-old) were subjected to venoarterial ECMO for up to 8 h. SIRS was assessed by histopathological analysis, measurement of neutrophil activation (flow cytometry), plasma cytokine concentrations (enzyme immunoassays), and tissue expression of inflammatory genes (PCR/western blots). Mast cell degranulation was investigated by measurement of plasma tryptase activity. Porcine neonatal ECMO was associated with systemic inflammatory changes similar to those seen in human neonates. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) concentrations rose rapidly during the first 2 h of ECMO, faster than the tissue expression of these cytokines. ECMO was associated with increased plasma mast cell tryptase activity, indicating that increased plasma concentrations of inflammatory cytokines during ECMO may result from mast cell degranulation and associated release of preformed cytokines stored in mast cells. TNF-alpha and IL-8 concentrations rose faster in plasma than in the peripheral tissues during ECMO, indicating that rising plasma levels of these cytokines immediately after the initiation of ECMO may not reflect increasing tissue synthesis of these cytokines. Mobilization of preformed cellular stores of inflammatory cytokines such as in mucosal mast cells may have

Occupation of the cytochrome P450 substrate pocket by diverse compounds at general anesthesia concentrations.

Science.gov (United States)

LaBella, F S; Stein, D; Queen, G

1998-10-02

Each of a diverse array of compounds, at concentrations reported to effect general anesthesia, when added to liver microsomes, forms a complex with cytochromes P450 to generate, with reference to a cuvette containing microsomes only, a characteristic absorbance-difference spectrum. This spectrum results from a change in the electron-spin state of the heme iron atom induced upon entry by the anesthetic molecule into the enzyme catalytic pocket. The difference spectrum, representing the anesthetic-P450 complex, is characteristic of substances that are substrates for the enzyme. For the group of compounds as a whole, the magnitudes of the absorbance-difference spectra vary only about twofold, although the anesthetic potencies vary by several orders of magnitude. The dissociation constants (Ks), calculated from absorbance data and representing affinities of the anesthetics for P450, agree closely with the respective EC50 (concentration that effects anesthesia in 50% of individuals) values, and with the respective Ki (concentration that inhibits P450 catalytic activities half-maximally) values reported by us previously. The absorbance complex resulting from the occupation of the catalytic pocket by endogenous substrates, androstenedione and arachidonic acid, is inhibited, competitively, by anesthetics. Occupation of and perturbation of the heme catalytic pocket by anesthetic, as monitored by the absorbance-difference spectrum, is rapidly reversible. The presumed in vivo consequences of perturbation by general anesthetics of heme proteins is suppression of the generation of chemical signals that determine cell sensitivity and response.

Vaginal oxytetracycline concentrations.

Science.gov (United States)

Thin, R N; Al Rawi, Z H; Simmons, P D; Treharne, J; Tabaqchali, S

1979-01-01

Although tetracycline preparations are widely used in departments of genitourinary medicine, or sexually transmitted diseases clinics, little is known of the concentrations of these preparations in genital secretions. For this reason a microbiological method was used for estimating oxytetracycline concentrations in vaginal secretions. These concentrations varied from 0.6 to 6.5 microgram/ml in 19 women who had had sexual contact with a man with non-specific urethritis and who were taking oxytetracycline dihydrate 250 mg four times daily. They were well in excess of the minimum inhibitory concentration of oxytetracycline (0.2 microgram/ml) for the strains of Chlamydia trachomatis isolated from the patients with positive culture results. Thus, oxytetracycline 250 mg four times daily appears to be a satisfactory regimen for the treatment of chlamydial genital infection in women. PMID:509190

Soil erosion under multiple time-varying rainfall events

Science.gov (United States)

Heng, B. C. Peter; Barry, D. Andrew; Jomaa, Seifeddine; Sander, Graham C.

2010-05-01

Soil erosion is a function of many factors and process interactions. An erosion event produces changes in surface soil properties such as texture and hydraulic conductivity. These changes in turn alter the erosion response to subsequent events. Laboratory-scale soil erosion studies have typically focused on single independent rainfall events with constant rainfall intensities. This study investigates the effect of multiple time-varying rainfall events on soil erosion using the EPFL erosion flume. The rainfall simulator comprises ten Veejet nozzles mounted on oscillating bars 3 m above a 6 m × 2 m flume. Spray from the nozzles is applied onto the soil surface in sweeps; rainfall intensity is thus controlled by varying the sweeping frequency. Freshly-prepared soil with a uniform slope was subjected to five rainfall events at daily intervals. In each 3-h event, rainfall intensity was ramped up linearly to a maximum of 60 mm/h and then stepped down to zero. Runoff samples were collected and analysed for particle size distribution (PSD) as well as total sediment concentration. We investigate whether there is a hysteretic relationship between sediment concentration and discharge within each event and how this relationship changes from event to event. Trends in the PSD of the eroded sediment are discussed and correlated with changes in sediment concentration. Close-up imagery of the soil surface following each event highlight changes in surface soil structure with time. This study enhances our understanding of erosion processes in the field, with corresponding implications for soil erosion modelling.

Iodide Residues in Milk Vary between Iodine-Based Teat Disinfectants

NARCIS (Netherlands)

French, Elizabeth A; Mukai, Motoko; Zurakowski, Michael; Rauch, Bradley; Gioia, Gloria; Hillebrandt, Joseph R; Henderson, Mark; Schukken, Ynte H; Hemling, Thomas C

Majority of iodine found in dairy milk comes from the diet and teat disinfection products used during milking process. The objective of this study was to evaluate the effects of 4 iodine-based teat dips on milk iodide concentrations varying in iodine level (0.25% vs. 0.5%, w/w), normal low viscosity

Lithium treatment of manio-depressive disorder. Two examples of treatment regimes with varying serum lithium concentration curves

International Nuclear Information System (INIS)

Veimer Jensen, H.

1998-07-01

The importance of serum lithium profile in lithium maintenance treatment of manic-depressive disorder was studied by comparing pro-phylactic efficacy, side-effects and brain lithium level in patients on daily or alternate-day lithium dosing schedules. The aim of the study was to determine firstly, whether it is only necessary for the serum lithium concentration to periodically reach a certain level in order to ensure good prophylactic efficacy, and secondly, whether periodical lowering of the serum lithium level diminishes lithium-related side-effects. This was examined by extending the interval between lithium doses from 1 to 2 days, while maintaining the 12-h serum lithium concentration unchanged so as to achieve an unchanged serum lithium profile during the first 24-h period after lithium intake. The 12-h brain lithium concentration measured by 7 Li-magnetic resonance spectroscopy seemed to be independent of lithium dosing schedule, but correlated significantly with the 12-h serum lithium concentration, suggesting that at identical 12-h serum lithium concentrations, the 12-h brain lithium concentration is similar with both treatment regimens. (EG)

Rapidly dissociated autologous meniscus tissue enhances meniscus healing: An in vitro study.

Science.gov (United States)

Numpaisal, Piya-On; Rothrauff, Benjamin B; Gottardi, Riccardo; Chien, Chung-Liang; Tuan, Rocky S

Treatment of meniscus tears is a persistent challenge in orthopedics. Although cell therapies have shown promise in promoting fibrocartilage formation in in vitro and preclinical studies, clinical application has been limited by the paucity of autologous tissue and the need for ex vivo cell expansion. Rapid dissociation of the free edges of the anterior and posterior meniscus with subsequent implantation in a meniscus lesion may overcome these limitations. The purpose of this study was to explore the effect of rapidly dissociated meniscus tissue in enhancing neotissue formation in a radial meniscus tear, as simulated in an in vitro explant model. All experiments in this study, performed at minimum with biological triplicates, utilized meniscal tissues from hind limbs of young cows. The effect of varying collagenase concentration (0.1%, 0.2% and 0.5% w/v) and treatment duration (overnight and 30 minutes) on meniscus cell viability, organization of the extracellular matrix (ECM), and gene expression was assessed through a cell metabolism assay, microscopic examination, and quantitative real-time reverse transcription polymerase chain reaction analysis, respectively. Thereafter, an explant model of a radial meniscus tear was used to evaluate the effect of a fibrin gel seeded with one of the following: (1) fibrin alone, (2) isolated and passaged (P2) meniscus cells, (3) overnight digested tissue, and (4) rapidly dissociated tissue. The quality of in vitro healing was determined through histological analysis and derivation of an adhesion index. Rapid dissociation in 0.2% collagenase yielded cells with higher levels of metabolism than either 0.1% or 0.5% collagenase. When seeded in a three-dimensional fibrin hydrogel, both overnight digested and rapidly dissociated cells expressed greater levels of collagens type I and II than P2 meniscal cells at 1 week. At 4 and 8 weeks, collagen type II expression remained elevated only in the rapid dissociation group. Histological

Phase behaviour of oat β-glucan/sodium caseinate mixtures varying in molecular weight.

Science.gov (United States)

Agbenorhevi, Jacob K; Kontogiorgos, Vassilis; Kasapis, Stefan

2013-05-01

The isothermal phase behaviour at 5 °C of mixtures of sodium caseinate and oat β-glucan isolates varying in molecular weight (MW) was investigated by means of phase diagram construction, rheometry, fluorescence microscopy and electrophoresis. Phase diagrams indicated that the compatibility of the β-glucan/sodium caseinate system increases as β-glucan MW decreases. Images of mixtures taken at various biopolymer concentrations revealed phase separated domains. Results also revealed that at the state of thermodynamic equilibrium, lower MW samples yielded considerable viscosity in the mixture. At equivalent hydrodynamic volume of β-glucan in the mixtures, samples varying in molecular weight exhibited similar flow behaviour. A deviation dependent on the protein concentration was observed for the high MW sample in the concentrated regime due to the size of β-glucan aggregates formed. Results demonstrate that by controlling the structural features of β-glucan in mixtures with sodium caseinate, informed manipulation of rheological properties in these systems can be achieved. Copyright © 2012 Elsevier Ltd. All rights reserved.

Determination of anionic concentrations in ground water samples using ion chromatography

International Nuclear Information System (INIS)

Prathibha, P.; Saradhi, I.V.; Pandit, G.G.; Puranik, V.D.

2011-01-01

Ion chromatography is a powerful separation technique for the quantitative measurement of anions in aqueous samples as well as in soil, sediment and air particulate samples leached in aqueous solutions. Ion chromatographic technique is developed by making use of suppressed ion conductivity detection (Small et.al.,1975) and it is a rapid multi ion analysis technique. The time, processing and effort required for the analysis of anions is much less compared to other techniques available such as ion selective electrode technique. In the present paper ground water samples collected around New BARC campus, Visakhapatnam are analyzed for anions using Ion chromatograph. The data generated will establish the current baseline status of the ionic contaminants in the study area. Groundwater samples are collected at 13 locations around BARC Vizag campus covering 30 km radius in September, 2009, April and July, 2010. The water samples include samples from hand pump and open wells in villages. The water samples are analyzed for fluoride, chloride, nitrate and sulphate using Metrohm make Ion chromatograph. The fluoride concentration in samples varied from 0.22 to 1.26 ppm, chloride from 18.7 to 810.9, nitrate from 1.34 to 378.5 ppm and sulphate from 13.29 to 250.69 ppm. No significant seasonal variations are observed in the samples collected from various locations except chloride at two locations. Ions Chromatograph is found to be a useful tool for simultaneous analysis of environmental samples with good accuracy where the concentrations of anions vary within an order of magnitude among them themselves. (author)

Multiscale response of ionic systems to a spatially varying electric field

DEFF Research Database (Denmark)

Hansen, Jesper Schmidt

2017-01-01

In this paper the response of ionic systems subjected to a spatially varying electric field is studied. Following the Nernst-Planck equation, two forces driving the mass flux are present, namely, the concentration gradient and the electric potential gradient. The mass flux due to the concentratio...

Dynamics of soluble and inert pollutant concentrations in linear and deterministic systems with time varying parameters

International Nuclear Information System (INIS)

Meltzer, M.

1977-04-01

The tracer theory in steady and non-steady systems is presented. The unsteady system was applied in the study of the concentration dynamics of the National Water Carrier in Israel. A method that uses Bromine 82 for the investigation of the transfer time distribution and of the dynamics of inert matter concentration in the system is desribed. (B.G.)

Ecological and Landscape Drivers of Neonicotinoid Insecticide Detections and Concentrations in Canada's Prairie Wetlands.

Science.gov (United States)

Main, Anson R; Michel, Nicole L; Headley, John V; Peru, Kerry M; Morrissey, Christy A

2015-07-21

Neonicotinoids are commonly used seed treatments on Canada's major prairie crops. Transported via surface and subsurface runoff into wetlands, their ultimate aquatic fate remains largely unknown. Biotic and abiotic wetland characteristics likely affect neonicotinoid presence and environmental persistence, but concentrations vary widely between wetlands that appear ecologically (e.g., plant composition) and physically (e.g., depth) similar for reasons that remain unclear. We conducted intensive surveys of 238 wetlands, and documented 59 wetland (e.g., dominant plant species) and landscape (e.g., surrounding crop) characteristics as part of a novel rapid wetland assessment system. We used boosted regression tree (BRT) analysis to predict both probability of neonicotinoid analytical detection and concentration. BRT models effectively predicted the deviance in neonicotinoid detection (62.4%) and concentration (74.7%) from 21 and 23 variables, respectively. Detection was best explained by shallow marsh plant species identity (34.8%) and surrounding crop (13.9%). Neonicotinoid concentration was best explained by shallow marsh plant species identity (14.9%) and wetland depth (14.2%). Our research revealed that plant composition is a key indicator and/or driver of neonicotinoid presence and concentration in Prairie wetlands. We recommend wetland buffers consisting of diverse native vegetation be retained or restored to minimize neonicotinoid transport and retention in wetlands, thereby limiting their potential effects on wetland-dependent organisms.

Microwave-assisted routes for rapid and efficient modification of layered perovskites.

Science.gov (United States)

Akbarian-Tefaghi, S; Wiley, J B

2018-02-27

Recent advances in exploiting microwave radiation in the topochemical modification of layered oxide perovskites are presented. Such methods work well for rapid bulk synthetic steps used in the production of novel inorganic-organic hybrids (protonation, grafting, intercalation, and in situ click reactions), exfoliation to produce dispersed nanosheets, and post-exfoliation processing to rapidly vary nanosheet surface groups. Compared to traditional methods that often take days, microwave methods can produce quality products in as little as 1-2 h.

Evaluation of the potassium adsorption capacity of a potassium adsorption filter during rapid blood transfusion.

Science.gov (United States)

Matsuura, H; Akatsuka, Y; Muramatsu, C; Isogai, S; Sugiura, Y; Arakawa, S; Murayama, M; Kurahashi, M; Takasuga, H; Oshige, T; Yuba, T; Mizuta, S; Emi, N

2015-05-01

The concentration of extracellular potassium in red blood cell concentrates (RCCs) increases during storage, leading to risk of hyperkalemia. A potassium adsorption filter (PAF) can eliminate the potassium at normal blood transfusion. This study aimed to investigate the potassium adsorption capacity of a PAF during rapid blood transfusion. We tested several different potassium concentrations under a rapid transfusion condition using a pressure bag. The adsorption rates of the 70-mEq/l model were 76·8%. The PAF showed good potassium adsorption capacity, suggesting that this filter may provide a convenient method to prevent hyperkalemia during rapid blood transfusion. © 2015 International Society of Blood Transfusion.

Fourier transform infrared spectroscopy, a new method for rapid determination of total organic and inorganic carbon and biogenic silica concentration in lake sediments

DEFF Research Database (Denmark)

Rosén, Peter; Vogel, Hendrik; Cunningham, Laura

2010-01-01

We demonstrate the use of Fourier transform infrared spectroscopy (FTIRS) to make quantitative measures of total organic carbon (TOC), total inorganic carbon (TIC) and biogenic silica (BSi) concentrations in sediment. FTIRS is a fast and cost-effective technique and only small sediment samples...... varied between r = 0.84-0.99 for TOC, r = 0.85-0.99 for TIC, and r = 0.68-0.94 for BSi. Because FTIR spectra contain information on a large number of both inorganic and organic components, there is great potential for FTIRS to become an important tool in paleolimnology....

Process model for ammonia volatilization from anaerobic swine lagoons incorporating varying wind speeds and biogas bubbling

Science.gov (United States)

Ammonia volatilization from treatment lagoons varies widely with the total ammonia concentration, pH, temperature, suspended solids, atmospheric ammonia concentration above the water surface, and wind speed. Ammonia emissions were estimated with a process-based mechanistic model integrating ammonia ...

A mesocosm study using four native Hawaiian plants to assess nitrogen accumulation under varying surface water nitrogen concentrations.

Science.gov (United States)

Unser, C U; Bruland, G L; Hood, A; Duin, K

2010-01-01

Accumulation of nitrogen (N) by native Hawaiian riparian plants from surface water was measured under a controlled experimental mesocosm setting. Four species, Cladium jamaicense, Cyperus javanicus, Cyperus laevigatus, and Cyperus polystachyos were tested for their ability to survive in coconut fiber coir log media with exposure to differing N concentrations. It was hypothesized that the selected species would have significantly different tissue total nitrogen (TN) concentrations, aboveground biomass, and TN accumulation rates because of habitat preference and physiological growth differences. A general linear model (GLM) analysis of variance (ANOVA) determined that species differences accounted for the greatest proportion of variance in tissue TN concentration, aboveground biomass growth, and accumulation rates, when compared with the other main effects (i.e. N concentration, time) and their interactions. A post hoc test of means demonstrated that C. jamaicense had significantly higher tissue TN concentration, aboveground biomass growth, and accumulation rates than the other species under all N concentrations. It was also hypothesized that tissue TN concentrations and biomass growth would increase in plants exposed to elevated N concentrations, however data did not support this hypothesis. Nitrogen accumulation rates by species were controlled by differences in plant biomass growth.

Bioaerosol collection and concentration for microseparations-based detectors.

Energy Technology Data Exchange (ETDEWEB)

Cummings, Eric B. (Sandia National Laboratories, Livermore, CA); Ellis, C. R. Bowe (Sandia National Laboratories, Livermore, CA); Kanouff, Michael P. (Sandia National Laboratories, Livermore, CA); Rader, Daniel John; Wally, Karl (Sandia National Laboratories, Livermore, CA)

2005-03-01

The ability to detect Weapons of Mass Destruction biological agents rapidly and sensitively is vital to homeland security, spurring development of compact detection systems at Sandia and elsewhere. One such system is Sandia's microseparations-based pChemLab. Many bio-agents are serious health threats even at extremely low concentrations. Therefore, a universal challenge for detection systems is the efficient collection and selective transport of highly diffuse bio-agents against the enormous background of benign particles and species ever present in the ambient environment. We have investigated development of a ''front end'' system for the collection, preconcentration, and selective transport of aerosolized biological agents from dilute (1-10 active particles per liter of air) atmospheric samples, to ultimate concentrations of {approx}20 active particles per microliter of liquid, for interface with microfluidic-based analyses and detection systems. Our approach employs a Sandia-developed aerosol particle-focusing microseparator array to focus size-selected particles into a mating microimpinger array of open microfluidic transport channels. Upon collection (i.e., impingement, submergence, and liquid suspension), microfluidic dielectrophoretic particle concentrators and sorters can be employed to further concentrate and selectively transport bio-agent particles to the sample preparation stages of microfluidic analyses and detection systems. This report documents results in experimental testing, modeling and analysis, component design, and materials fabrication critical to establishing proof-of-principle for this collection ''front end''. Outstanding results have been achieved for the aerodynamic microseparator, and for the post-collection dielectrophoretic concentrator and sorter. Results have been obtained for the microimpinger, too, but issues of particle-trapping by surface tension in liquid surfaces have proven

Algal and water-quality data for Rapid Creek and Canyon Lake near Rapid City, South Dakota, 2007

Science.gov (United States)

Hoogestraat, Galen K.; Putnam, Larry D.; Graham, Jennifer L.

2008-01-01

and retention ponds during May and September also contained cyanobacteria. Geosmin and 2-methylisoborneol concentrations were less than detection limits (0.005 ug/L) in all five of the Rapid Creek samples collected in May. Actinomycetes bacteria were present at the water treatment plant intake in May 2007, at a concentration of 6 colonies per milliliter. During this study, no taste-and-odor problems with the drinking water within the study area were reported. However, the presence of cyanobacterial taxa known to contain taste-and-odor producing strains (such as Leptolyngbya, Phormidium, and Anabaena) indicates the potential for taste-and-odor problems under certain physical and chemical conditions.

Modeling uranium(VI) adsorption onto montmorillonite under varying carbonate concentrations: A surface complexation model accounting for the spillover effect on surface potential

Science.gov (United States)

Tournassat, C.; Tinnacher, R. M.; Grangeon, S.; Davis, J. A.

2018-01-01

The prediction of U(VI) adsorption onto montmorillonite clay is confounded by the complexities of: (1) the montmorillonite structure in terms of adsorption sites on basal and edge surfaces, and the complex interactions between the electrical double layers at these surfaces, and (2) U(VI) solution speciation, which can include cationic, anionic and neutral species. Previous U(VI)-montmorillonite adsorption and modeling studies have typically expanded classical surface complexation modeling approaches, initially developed for simple oxides, to include both cation exchange and surface complexation reactions. However, previous models have not taken into account the unique characteristics of electrostatic surface potentials that occur at montmorillonite edge sites, where the electrostatic surface potential of basal plane cation exchange sites influences the surface potential of neighboring edge sites ('spillover' effect). A series of U(VI) - Na-montmorillonite batch adsorption experiments was conducted as a function of pH, with variable U(VI), Ca, and dissolved carbonate concentrations. Based on the experimental data, a new type of surface complexation model (SCM) was developed for montmorillonite, that specifically accounts for the spillover effect using the edge surface speciation model by Tournassat et al. (2016a). The SCM allows for a prediction of U(VI) adsorption under varying chemical conditions with a minimum number of fitting parameters, not only for our own experimental results, but also for a number of published data sets. The model agreed well with many of these datasets without introducing a second site type or including the formation of ternary U(VI)-carbonato surface complexes. The model predictions were greatly impacted by utilizing analytical measurements of dissolved inorganic carbon (DIC) concentrations in individual sample solutions rather than assuming solution equilibration with a specific partial pressure of CO2, even when the gas phase was

Plasma acceleration in a wave with varying frequency

International Nuclear Information System (INIS)

Petrzilka, V.A.

1978-01-01

The averaged velocity of a test particle and the averaged velocity of a plasma in an electromagnetic wave packet with varying frequency (e.g., a radiation pulse from pulsar) is derived. The total momentum left by the wave packet in regions of plasma inhomogeneity is found. In case the plasma concentration is changing due to ionization the plasma may be accelerated parallelly or antiparallelly to the direction of the wave packet propagation which is relevant for a laser induced breakdown in gas. (author)

Variations of Growth and Toxin Yield in Cylindrospermopsis raciborskii under Different Phosphorus Concentrations

Directory of Open Access Journals (Sweden)

Yiming Yang

2016-12-01

Full Text Available The bloom-forming cyanobacteria, Cylindrospermopsis raciborskii, is a producer of the cytotoxic cylindrospermopsin (CYN. In this study, the growth, toxin yield, and expression of CYN biosynthesis genes of C. raciborskii were examined under varying phosphorus (P concentrations. The results show the cell number at 0.00 and 0.01 mg·L−1 P was significantly lower than that at higher P concentrations (≥0.5 mg·L−1. The chlorophyll a content, filament length, heterocyst, and akinete numbers at P ≤ 0.05 mg·L−1 were also significantly reduced. The intracellular and extracellular CYN concentrations and the extracellular proportions increased during the culture period, and larger values were observed at higher P concentrations. Total CYN content reached 45.34–63.83 fg·cell−1 and extracellular CYN proportion reached 11.49%–20.44% at the stationary growth phase. A significantly positive correlation was observed between CYN production and cell growth rate. Three cyr genes were expressed constantly even at P-deficient conditions. The transcription of cyr genes at P-replete conditions or after P supplementation increased from 1.18-fold to 8.33-fold. In conclusion, C. raciborskii may rapidly reorganize metabolic processes as an adaptive response to environmental P fluctuations. CYN production and cyr gene expression were constitutive metabolic processes in toxic C. raciborskii.

Lock-in thermography as a rapid and reproducible thermal characterization method for magnetic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Lemal, Philipp; Geers, Christoph; Monnier, Christophe A.; Crippa, Federica; Daum, Leopold; Urban, Dominic A.; Rothen-Rutishauser, Barbara [Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg (Switzerland); Bonmarin, Mathias, E-mail: mathias.bonmarin@zhaw.ch [Institute of Computational Physics, Zurich University of Applied Sciences, Technikumstrasse 9, 8400 Winterthur (Switzerland); Petri-Fink, Alke, E-mail: alke.fink@unifr.ch [Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg (Switzerland); Chemistry Department, University of Fribourg, Chemin du Museé 9, CH-1700 Fribourg (Switzerland); Moore, Thomas L., E-mail: thomaslee.moore@unifr.ch [Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg (Switzerland)

2017-04-01

Lock-in thermography (LIT) is a sensitive imaging technique generally used in engineering and materials science (e.g. detecting defects in composite materials). However, it has recently been expanded for investigating the heating power of nanomaterials, such as superparamagnetic iron oxide nanoparticles (SPIONs). Here we implement LIT as a rapid and reproducible method that can evaluate the heating potential of various sizes of SPIONs under an alternating magnetic field (AMF), as well as the limits of detection for each particle size. SPIONs were synthesized via thermal decomposition and stabilized in water via a ligand transfer process. Thermographic measurements of SPIONs were made by stimulating particles of varying sizes and increasing concentrations under an AMF. Furthermore, a commercially available SPION sample was included as an external reference. While the size dependent heating efficiency of SPIONs has been previously described, our objective was to probe the sensitivity limits of LIT. For certain size regimes it was possible to detect signals at concentrations as low as 0.1 mg Fe/mL. Measuring at different concentrations enabled a linear regression analysis and extrapolation of the limit of detection for different size nanoparticles. - Highlights: • A multi-sample screening assessment of magnetic nanoparticle thermal characteristics is shown via lock-in thermography. • Lower concentration limit of nanoparticle detection based on particle size is proposed. • A commercially available reference sample indicates the stability and reproducibility of LIT.

Effects of varying doses of β-nerve growth factor on the timing of ovulation, plasma progesterone concentration and corpus luteum size in female alpacas (Vicugna pacos).

Science.gov (United States)

Stuart, C C; Vaughan, J L; Kershaw-Young, C M; Wilkinson, J; Bathgate, R; de Graaf, S P

2015-11-01

Ovulation in camelids is induced by the seminal plasma protein ovulation-inducing factor (OIF), recently identified as β-nerve growth factor (β-NGF). The present study measured the total protein concentration in alpaca seminal plasma using a bicinchoninic acid (BCA) protein quantification assay and found it to be 22.2±2.0mgmL(-1). To measure the effects of varying doses of β-NGF on the incidence and timing of ovulation, corpus luteum (CL) size and plasma progesterone concentration, 24 female alpacas were synchronised and treated with either: (1) 1mL 0.9% saline (n=5); (2) 4µg buserelin (n=5); (3) 1mg β-NGF protein (n=5); (4) 0.1mg β-NGF (n=5); or (5) 0.01mg β-NGF (n=4). Females were examined by transrectal ultrasonography at 1-2-h intervals between 20 and 45h after treatment or until ovulation occurred, as well as on Day 8 to observe the size of the CL, at which time blood was collected to measure plasma progesterone concentrations. Ovulation was detected in 0/5, 5/5, 5/5, 3/5 and 0/4 female alpacas treated with saline, buserelin, 1, 0.1 and 0.01mg β-NGF, respectively. Mean ovulation interval (P=0.76), CL diameter (P=0.96) and plasma progesterone concentration (P=0.96) did not differ between treatments. Mean ovulation interval overall was 26.2±1.0h. In conclusion, buserelin and 1mg β-NGF are equally effective at inducing ovulation in female alpacas, but at doses ≤0.1mg, β-NGF is not a reliable method for the induction of ovulation.

Structural, optical, Induced ferromagnetism and anti-ferromagnetism in SnO2 nanoparticles by varying cobalt concentration

International Nuclear Information System (INIS)

Ali, Atif; Sarfraz, A.K.; Ali, Kashif; Mumtaz, A.

2015-01-01

The SnO 2 nanoparticles were prepared with different cobalt concentrations (0.0%, 0.5%, 1%, 3% and 4%) by chemical co-precipitation method. The NH 4 OH was used as precipitating agent; the pH value, reaction time and reaction temperature were optimized during synthesis. The x-ray diffraction (XRD) pattern reveals the formation of single phase tetragonal structure of undoped and cobalt doped SnO 2 nanoparticles which lies in the range of 19–22 nm calculated by De-Bye Scherrer's formula. The optical properties were studied by measuring the reflectance spectroscopy which shows that band gap energy decreases with increase in cobalt concentration. The magnetic characterization was performed by Quantum Design Physical property measurement system (PPMS). Interestingly magnetic measurements show that ferromagnetism in a Co doped SnO 2 becomes visible for x=0.5% and diminishes with further increasing of cobalt concentration. - Highlights: • SnO 2 nanoparticles were prepared with different cobalt concentrations (0.0 % 0.5%, 1%, 3% and 4%) by the chemical co-precipitation method. • Structure was confirmed through x-ray diffraction (XRD) analysis. • The optical properties were studied by measuring the reflectance spectroscopy. • The magnetic characterization was performed

Physical modelling of a rapid boron dilution transient

Energy Technology Data Exchange (ETDEWEB)

Anderson, N.G.; Hemstroem, B.; Karlsson, R. [Vattenfall Utveckling AB, Aelvkarleby (Sweden); Jacobson, S. [Vattenfall AB, Ringhals, Vaeroebacka (Sweden)

1995-09-01

The analysis of boron dilution accidents in pressurised water reactors has traditionally assumed that mixing is instantaneous and complete everywhere, eliminating in this way the possibility of concentration inhomogeneities. Situations can nevertheless arise where a volume of coolant with a low boron concentration may eventually enter the core and generate a severe reactivity transient. The work presented in this paper deals with a category of Rapid Boron Dilution Events characterised by a rapid start of a Reactor Coolant Pump (RCP) with a plug of relatively unborated water present in the RCS pipe. Model tests have been made at Vattenfall Utveckling AB in a simplified 1:5 scale model of a Westinghouse PWR. Conductivity measurements are used to determine dimensionless boron concentration. The main purpose of this experimental work is to define an experimental benchmark against which a mathematical model can be tested. The final goal is to be able to numerically predict Boron Dilution Transients. This work has been performed as a part of a Co-operative Agreement with Electricite` de France (EDF).

Rapid MR imaging

International Nuclear Information System (INIS)

Edelman, R.R.; Buxton, R.B.; Brady, T.J.

1988-01-01

Conventional magnetic resonance (MR) imaging methods typically require several minutes to produce an image, but the periods of respiration, cardiac motion and peristalsis are on the order of seconds or less. The need to reduce motion artifact, as well as the need to reduce imaging time for patient comfort and efficiency, have provided a strong impetus for the development of rapid imaging methods. For abdominal imaging, motion artifacts due to respiration can be significantly reduced by collecting the entire image during one breath hold. For other applications, such as following the kinetics of administered contrast agents, rapid imaging is essential to achieve adequate time resolution. A shorter imaging time entails a cost in image signal/noise (S/N), but improvements in recent years in magnet homogeneity, gradient and radiofrequency coil design have led to steady improvements in S/N and consequently in image quality. For many chemical applications the available S/N is greater than needed, and a trade-off of lower S/N for a shorter imaging time is acceptable. In this chapter, the authors consider the underlying principles of rapid imaging as well as clinical applications of these methods. The bulk of this review concentrates on short TR imaging, but methods that provide for a more modest decrease in imaging time as well as or those that dramatically shorten the imaging time to tens of milliseconds are also discussed

The effects of forage proportion and rapidly degradable dry matter from concentrate on ruminal digestion in dairy cows fed corn silage-based diets with fixed neutral detergent fiber and starch contents.

Science.gov (United States)

Lechartier, C; Peyraud, J-L

2010-02-01

This study investigated the effects of the forage-to-concentrate (F:C) ratio and the rate of ruminal degradation of carbohydrates from the concentrate on digestion in dairy cows fed corn silage-based diets. Six cows with ruminal cannulas were assigned to 6 treatments in a 6x6 Latin square. Treatments were arranged in a 3x2 factorial design. Three proportions of neutral detergent fiber from forage [FNDF; 7.6, 13.2, and 18.9% of dry matter (DM)] were obtained by modifying F:C (20:80, 35:65, and 50:50). These F:C were combined with concentrates with either high or low content of rapidly degradable carbohydrates. The dietary content of rapidly degradable carbohydrates from the concentrate was estimated from the DM disappearance of concentrate after 4h of in sacco incubation (CRDM). Thus, 2 proportions of CRDM were tested (20 and 30% of DM). Wheat and corn grain were used as rapidly and slowly degradable starch sources, respectively. Soybean hulls and citrus pulp were used as slowly and rapidly degradable fiber sources, respectively. Concentrate composition was adjusted to maintain dietary starch and neutral detergent fiber contents at 35.9 and 28.9% of DM, respectively. There was no effect of the interaction between F:C and CRDM on DM intake (DMI), ruminal fermentation, chewing activity, and fibrolytic activity. When F:C decreased, DMI increased, the mean ruminal pH linearly decreased, and the pH range linearly increased from 0.95 to 1.27 pH unit. At the same time, the acetate-to-propionate ratio decreased linearly. Decreasing F:C linearly decreased the average time spent chewing per kilogram of DMI from 35.2 to 19.5min/kg of DMI and decreased ruminal liquid outflow from 11.6 to 9.2L/kg of DMI, suggesting a decrease in the salivary flow. Increasing CRDM decreased DMI and increased the time during which pH was below 6.0 (3.1 vs. 4.8h), the pH range (0.90 vs. 1.33), and the initial rate of pH drop. It also increased the volatile fatty acid range (35 vs. 59mM), thus

An estimation of U.S. gasoline demand. A smooth time-varying cointegration approach

International Nuclear Information System (INIS)

Park, Sung Y.; Zhao, Guochang

2010-01-01

In this paper the U.S. gasoline demand from 1976 to 2008 is estimated using a time-varying cointegrating regression. We find that price elasticity increased rapidly during the late 1970s and then decreased until 1987. After a relatively small-scaled 'increase-decrease' cycle from 1987 to 2000, the price elasticity rose again after 2000. The time-varying change of the elasticities may be explained by the proportion of gasoline consumption to income and fluctuation of the degree of necessity. The result of the error correction model shows that a deviation from a long-run equilibrium is corrected quickly, and the welfare analysis illustrates there may be a gain by shifting the tax scheme from income tax to gasoline tax. (author)

An estimation of U.S. gasoline demand. A smooth time-varying cointegration approach

Energy Technology Data Exchange (ETDEWEB)

Park, Sung Y. [Department of Economics, University of Illinois, Urbana, IL 61801 (United States); The Wang Yanan Institute for Studies in Economics, Xiamen University, Xiamen, Fujian 361005 (China); Zhao, Guochang [Research School of Economics, College of Business and Economics, The Australian National University, Canberra, ACT 2601 (Australia)

2010-01-15

In this paper the U.S. gasoline demand from 1976 to 2008 is estimated using a time-varying cointegrating regression. We find that price elasticity increased rapidly during the late 1970s and then decreased until 1987. After a relatively small-scaled 'increase-decrease' cycle from 1987 to 2000, the price elasticity rose again after 2000. The time-varying change of the elasticities may be explained by the proportion of gasoline consumption to income and fluctuation of the degree of necessity. The result of the error correction model shows that a deviation from a long-run equilibrium is corrected quickly, and the welfare analysis illustrates there may be a gain by shifting the tax scheme from income tax to gasoline tax. (author)

Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement

International Nuclear Information System (INIS)

Mahler, Barbara J.; Van Metre, Peter C.; Foreman, William T.

2014-01-01

Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement. - Highlights: • We compare PAH and azaarene concentrations in runoff from coal-tar- and asphalt-sealed pavement. • Concentrations in coal-tar-sealcoat runoff greatly exceeded those in asphalt-sealcoat runoff. • Decreases in azaarenes and LMW PAHs were offset by increases in HMW PAHs. • PAH concentrations in coal-tar-sealcoat runoff remained high for months after application. - Concentrations of PAHs in runoff from pavement with coal-tar-based sealcoat continue to be elevated for at least 3 months following sealcoat application

Carbon dioxide concentrations are very high in developing oilseeds.

Science.gov (United States)

Goffman, Fernando D; Ruckle, Mike; Ohlrogge, John; Shachar-Hill, Yair

2004-09-01

A new method has been developed to rapidly determine the total inorganic carbon concentration (gaseous [CO2] + aqueous [CO(2)] + [HCO3-] + [CO3(2)-]) in developing seeds. Seeds are rapidly dissected and homogenized in 1 N HCl in gas-tight vials. The headspace gas is then analyzed by infrared gas analysis. Developing rapeseed (Brassica napus L.) and soybean [Glycine max (L.) Merr.] seeds were analyzed and found to have up to 40 and 12 mM total inorganic carbon, respectively. These concentrations are ca. 600-2000-fold higher than in ambient air or values reported for leaves. Carbon dioxide concentrations in rapeseed peaked during the stage of maximum oil synthesis and declined as seeds matured. The consequences for seed metabolism, physiology and carbon economy are discussed.

Volatile flavor analysis and sensory evaluation of custard desserts varying in type and concentration of carboxymethyl cellulose.

Science.gov (United States)

van Ruth, Saskia M; de Witte, Leontien; Uriarte, Amaya Rey

2004-12-29

The influence of type and concentration of carboxymethyl cellulose (CMC) on flavor and textural properties of custard desserts was examined. A synthetic strawberry flavor mixture was used to flavor the custards; it comprised 15 volatile flavor compounds. The viscosity of the custards was determined using rheometric measurements. Static headspace gas chromatography and in-nose proton transfer reaction-mass spectrometry analyses were conducted to determine the custards' volatile flavor properties. Perceived odor, flavor, and textural properties were assessed in sensory analysis experiments using magnitude estimation against a fixed modulus. Both type and concentration of CMC altered the viscosity of the custards. Softer custards had higher static headspace flavor concentrations. On the contrary, firmer custards demonstrated higher in-nose flavor concentrations. In sensory analysis, firmer custards showed higher thickness and lower sweetness intensities than their low-viscosity counterparts. The thickness perception corresponded to the viscosity of the custards. Removal of sucrose from the custards affected sweetness intensity only and not the intensity of other attributes. Therefore, the influence of the viscosity of the custards on the release of sweet-tasting components is held responsible for the effect on perceived sweetness intensity. Odor intensities were generally higher for the low-viscosity custard, whereas fruity flavor intensities were higher for the firmer custards. Odor intensities correlated with static headspace concentrations and flavor intensities related reasonably well with in-nose concentrations. Opening and closing of the nasal cavity is regarded as an important factor determining the discrepancy between static and in-nose measurements.

Audiovisual Simultaneity Judgment and Rapid Recalibration throughout the Lifespan.

Science.gov (United States)

Noel, Jean-Paul; De Niear, Matthew; Van der Burg, Erik; Wallace, Mark T

2016-01-01

Multisensory interactions are well established to convey an array of perceptual and behavioral benefits. One of the key features of multisensory interactions is the temporal structure of the stimuli combined. In an effort to better characterize how temporal factors influence multisensory interactions across the lifespan, we examined audiovisual simultaneity judgment and the degree of rapid recalibration to paired audiovisual stimuli (Flash-Beep and Speech) in a sample of 220 participants ranging from 7 to 86 years of age. Results demonstrate a surprisingly protracted developmental time-course for both audiovisual simultaneity judgment and rapid recalibration, with neither reaching maturity until well into adolescence. Interestingly, correlational analyses revealed that audiovisual simultaneity judgments (i.e., the size of the audiovisual temporal window of simultaneity) and rapid recalibration significantly co-varied as a function of age. Together, our results represent the most complete description of age-related changes in audiovisual simultaneity judgments to date, as well as being the first to describe changes in the degree of rapid recalibration as a function of age. We propose that the developmental time-course of rapid recalibration scaffolds the maturation of more durable audiovisual temporal representations.

Bed Evolution under Rapidly Varying Flows by a New Method for Wave Speed Estimation

Directory of Open Access Journals (Sweden)

Khawar Rehman

2016-05-01

Full Text Available This paper proposes a sediment-transport model based on coupled Saint-Venant and Exner equations. A finite volume method of Godunov type with predictor-corrector steps is used to solve a set of coupled equations. An efficient combination of approximate Riemann solvers is proposed to compute fluxes associated with sediment-laden flow. In addition, a new method is proposed for computing the water depth and velocity values along the shear wave. This method ensures smooth solutions, even for flows with high discontinuities, and on domains with highly distorted grids. The numerical model is tested for channel aggradation on a sloping bottom, dam-break cases at flume-scale and reach-scale with flat bottom configurations and varying downstream water depths. The proposed model is tested for predicting the position of hydraulic jump, wave front propagation, and for predicting magnitude of bed erosion. The comparison between results based on the proposed scheme and analytical, experimental, and published numerical results shows good agreement. Sensitivity analysis shows that the model is computationally efficient and virtually independent of mesh refinement.

One versus five-days of exposure to varying concentrations of B100 soya biodiesel exhaust reveals a threshold concentration for increased sensitivity to aconitine-induced arrhythmia

Science.gov (United States)

Although biodiesel (BD) is rapidly being considered as an alternative to diesel fuel, its health effects have not been thoroughly characterized. We previously used the aconitine challenge test to demonstrate that a single exposure to petroleum diesel exhaust (DE) increases the ri...

Rapid suppression of growth hormone concentration by overeating: potential mediation by hyperinsulinemia.

Science.gov (United States)

Cornford, Andrea S; Barkan, Ariel L; Horowitz, Jeffrey F

2011-03-01

The very low GH concentration in obesity is commonly attributed to high body fat mass; however, the influence of overeating on GH secretion is not clear. The aim of the study was to examine the effects of 2 wk of overeating on changes in GH secretion. Subjects were admitted to the hospital and stayed within the Michigan Clinical Research Unit throughout the entire 2-wk overeating period. We studied seven healthy, nonobese men (body mass index, 24 ± 1 kg/m(2); age, 25 ± 1 yr). Subjects ate standardized meals containing 70 kcal/kg fat free mass/d (∼4000 kcal/d) for 2 wk. Twenty-four-hour plasma concentrations of GH (every 20 min) and insulin (every 2 h) were measured before overeating (baseline), on d 3, and after 2 wk of overeating. Compared with baseline, average 24-h plasma GH concentration declined nearly 80% by d 3 of overeating (1.30 ± 0.18 vs. 0.36 ± 0.09 ng/ml; P = 0.01). This marked suppression of GH secretion occurred in the absence of an increase in body weight (77.0 ± 2.2 vs. 76.4 ± 2.4 kg). At the same time, average 24-h insulin concentration doubled (16.6 ± 2.1 vs. 31.7 ± 5.8 μU/ml; P = 0.009). After 2 wk, body weight significantly increased (79.0 ± 2.1 kg; P overeating markedly suppressed GH secretion before any measurable weight gain and was accompanied by chronic hyperinsulinemia. Increased body weight and body fat by 2 wk of overeating did not further suppress GH secretion.

Lead concentration in roadside soils and vegetation in Damascus city

International Nuclear Information System (INIS)

Othman, I.; Al-Oudat, M.; Al-Masri, M.S.

1998-01-01

Seasonal variations of lead concentration in roadside soils and plants in 12 sites in Damascus city have been investigated. Lead concentrations in soil were found to be varied from 78.4 ppm to 832 ppm; lower levels in the wet period than in the dry period were observed. While lead levels in roadside plants varied between 3.39 ppm to 13.28 ppm. The results have also shown that most of the vegetables grown on the roadside of Damascus city have high concentrations of lead and the normal washing does not decrease it to unacceptable level. (author)

Rapid colorimetric assay for gentamicin injection.

Science.gov (United States)

Tarbutton, P

1987-01-01

A rapid colorimetric method for determining gentamicin concentration in commercial preparations of gentamicin sulfate injection was developed. Methods currently available for measuring gentamicin concentration via its colored complex with cupric ions in alkaline solution were modified to reduce the time required for a single analysis. The alkaline copper tartrate (ACT) reagent solution was prepared such that each milliliter contained 100 mumol cupric sulfate, 210 mumol potassium sodium tartrate, and 1.25 mmol sodium hydroxide. The assay involves mixing 0.3 mL gentamicin sulfate injection 40 mg/mL (of gentamicin), 1.0 mL ACT reagent, and 0.7 mL water; the absorbance of the resulting solution at 560 nm was used to calculate the gentamicin concentration in the sample. For injections containing 10 mg/mL of gentamicin, the amount of the injection was increased to 0.5 mL and water decreased to 0.5 mL. The concentration of gentamicin in samples representing 11 lots of gentamicin sulfate injection 40 mg/mL and 8 lots of gentamicin sulfate injection 10 mg/mL was determined. The specificity, reproducibility, and accuracy of the assay were assessed. The colored complex was stable for at least two hours. Gentamicin concentration ranged from 93.7 to 108% and from 95 to 109% of the stated label value of the 40 mg/mL and the 10 mg/mL injections, respectively. No components of the preservative system present in the injections interfered with the assay. Since other aminoglycosides produced a colored complex, the assay is not specific for gentamicin. The assay was accurate and reproducible over the range of 4-20 mg of gentamicin. This rapid and accurate assay can be easily applied in the hospital pharmacy setting.

An analytically solvable model for rapid evolution of modular structure.

Directory of Open Access Journals (Sweden)

Nadav Kashtan

2009-04-01

Full Text Available Biological systems often display modularity, in the sense that they can be decomposed into nearly independent subsystems. Recent studies have suggested that modular structure can spontaneously emerge if goals (environments change over time, such that each new goal shares the same set of sub-problems with previous goals. Such modularly varying goals can also dramatically speed up evolution, relative to evolution under a constant goal. These studies were based on simulations of model systems, such as logic circuits and RNA structure, which are generally not easy to treat analytically. We present, here, a simple model for evolution under modularly varying goals that can be solved analytically. This model helps to understand some of the fundamental mechanisms that lead to rapid emergence of modular structure under modularly varying goals. In particular, the model suggests a mechanism for the dramatic speedup in evolution observed under such temporally varying goals.

Timed arrays wideband and time varying antenna arrays

CERN Document Server

Haupt, Randy L

2015-01-01

Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

Supplemental effect of varying L-cysteine concentrations on the quality of cryopreserved boar semen

Science.gov (United States)

Kaeoket, Kampon; Chanapiwat, Panida; Tummaruk, Padet; Techakumphu, Mongkol

2010-01-01

Cryopreservation is associated with the production of reactive oxygen species, which leads to lipid peroxidation of the sperm membrane and consequently a reduction in sperm motility and decreased fertility potential. The aim of this study was to determine the optimal concentration of L-cysteine needed for cryopreservation of boar semen. Twelve boars provided semen of proven motility and morphology for this study. The semen was divided into four portions in which the lactose-egg yolk (LEY) extender used to resuspend the centrifuged sperm pellet was supplemented with various concentrations of L-cysteine to reach 0 mmol L−1 (group I, control), 5 mmol L−1 (group II), 10 mmol L−1 (group III) and 15 mmol L−1 (group IV). Semen suspensions were loaded in straws (0.5 mL) and placed in a controlled-rate freezer. After cryopreservation, frozen semen samples were thawed and investigated for progressive motility, viability using SYBR-14/EthD-1 staining and acrosome integrity using FITC-PNA/EthD-1 staining. There was a significantly higher (P extender for improving the quality of frozen–thawed boar semen. PMID:20601963

A metastable Mg11Sm phase obtained by rapid solidification

International Nuclear Information System (INIS)

Budurov, S.

1993-01-01

Molten Mg-Sm alloys with a Sm concentration of 4.93, 6.86, and 8.35 at.% were rapidly soldified with the aid of a shock wave gun device. Investigations of the obtained splats were performed with the aid of DSC, X-ray analysis, and metallography. Rapid soldification of the eutectic MgSm 8.35 alloy forms a new Im3m-type phase. (orig.)

Computational algorithm for molybdenite concentrate annealing

International Nuclear Information System (INIS)

Alkatseva, V.M.

1995-01-01

Computational algorithm is presented for annealing of molybdenite concentrate with granulated return dust and that of granulated molybdenite concentrate. The algorithm differs from the known analogies for sulphide raw material annealing by including the calculation of return dust mass in stationary annealing; the latter quantity varies form the return dust mass value obtained in the first iteration step. Masses of solid products are determined by distribution of concentrate annealing products, including return dust and benthonite. The algorithm is applied to computations for annealing of other sulphide materials. 3 refs

Variation of boron concentration in metallic glass ribbons

International Nuclear Information System (INIS)

Nagy, A.Z.; Vasvari, B.; Bakos, L.; Duwez, P.; Bogancs, J.; Nazarov, V.M.

1980-01-01

The boron concentration of Fe 40 Ni 40 P 14 B 6 , Fe 32 Ni 36 Cr 14 P 12 B 6 and Fe 40 Ni 40 B 20 metallic glasses is measured by neutron activation analysis on both surfaces of the ribbon samples. It is found that the boron concentration is always higher on the bright side of the ribbon than that on the dull side which is in contact with the cold surface of the wheel during the rapid quenching from the melt. A possible explanation is given in terms of the solid-liquid interface moving rapidly from the cooled surface to the free surface when preparing the samples. (author)

Evidence of co-metabolic bentazone transformation by methanotrophic enrichment from a groundwater-fed rapid sand filter

DEFF Research Database (Denmark)

Hedegaard, Mathilde Jørgensen; Deliniere, Hélène; Prasse, Carsten

2018-01-01

from 58 to 158, well within the range for methanotrophic co-metabolic degradation of trace contaminants calculated from the literature, with normalized substrate preferences varying from 3 to 400. High-resolution mass spectrometry revealed formation of the transformation products (TPs) 6-OH, 8-OH......The herbicide bentazone is recalcitrant in aquifers and is therefore frequently detected in wells used for drinking water production. However, bentazone degradation has been observed in filter sand from a rapid sand filter at a waterworks with methane-rich groundwater. Here, the association between...... and bentazone at concentrations below 2 mg/L showed methanotrophic co-metabolic bentazone transformation: The culture removed 53% of the bentazone in 21 days in presence of 5 mg/L of methane, while only 31% was removed in absence of methane. Addition of acetylene inhibited methane oxidation and stopped...

A rapid approach for measuring silver nanoparticle concentration and dissolution in seawater by UV-Vis.

Science.gov (United States)

Sikder, Mithun; Lead, Jamie R; Chandler, G Thomas; Baalousha, Mohammed

2018-03-15

Detection and quantification of engineered nanoparticles (NPs) in environmental systems is challenging and requires sophisticated analytical equipment. Furthermore, dissolution is an important environmental transformation process for silver nanoparticles (AgNPs) which affects the size, speciation and concentration of AgNPs in natural water systems. Herein, we present a simple approach for the detection, quantification and measurement of dissolution of PVP-coated AgNPs (PVP-AgNPs) based on monitoring their optical properties (extinction spectra) using UV-vis spectroscopy. The dependence of PVP-AgNPs extinction coefficient (ɛ) and maximum absorbance wavelength (λ max ) on NP size was experimentally determined. The concentration, size, and extinction spectra of PVP-AgNPs were characterized during dissolution in 30ppt synthetic seawater. AgNPs concentration was determined as the difference between the total and dissolved Ag concentrations measured by inductively coupled plasma-mass spectroscopy (ICP-MS); extinction spectra of PVP-AgNPs were monitored by UV-vis; and size evolution was monitored by atomic force microscopy (AFM) over a period of 96h. Empirical equations for the dependence of maximum absorbance wavelength (λ max ) and extinction coefficient (ɛ) on NP size were derived. These empirical formulas were then used to calculate the size and concentration of PVP-AgNPs, and dissolved Ag concentration released from PVP-AgNPs in synthetic seawater at variable particle concentrations (i.e. 25-1500μgL -1 ) and in natural seawater at particle concentration of 100μgL -1 . These results suggest that UV-vis can be used as an easy and quick approach for detection and quantification (size and concentration) of sterically stabilized PVP-AgNPs from their extinction spectra. This approach can also be used to monitor the release of Ag from PVP-AgNPs and the concurrent NP size change. Finally, in seawater, AgNPs dissolve faster and to a higher extent with the decrease in NP

Rapid decreases in preoptic aromatase activity and brain monoamine concentrations after engaging in male sexual behavior.

Science.gov (United States)

Cornil, C A; Dalla, C; Papadopoulou-Daifoti, Z; Baillien, M; Dejace, C; Ball, G F; Balthazart, J

2005-09-01

In Japanese quail, as in rats, the expression of male sexual behavior over relatively long time periods (days to weeks) is dependent on the local production of estradiol in the preoptic area via the aromatization of testosterone. On a short-term basis (minutes to hours), central actions of dopamine as well as locally produced estrogens modulate behavioral expression. In rats, a view of and sexual interaction with a female increase dopamine release in the preoptic area. In quail, in vitro brain aromatase activity (AA) is rapidly modulated by calcium-dependent phosphorylations that are likely to occur in vivo as a result of changes in neurotransmitter activity. Furthermore, an acute estradiol injection rapidly stimulates copulation in quail, whereas a single injection of the aromatase inhibitor vorozole rapidly inhibits this behavior. We hypothesized that brain aromatase and dopaminergic activities are regulated in quail in association with the expression of male sexual behavior. Visual access as well as sexual interactions with a female produced a significant decrease in brain AA, which was maximal after 5 min. This expression of sexual behavior also resulted in a significant decrease in dopaminergic as well as serotonergic activity after 1 min, which returned to basal levels after 5 min. These results demonstrate for the first time that AA is rapidly modulated in vivo in parallel with changes in dopamine activity. Sexual interactions with the female decreased aromatase and dopamine activities. These data challenge established views about the causal relationships among dopamine, estrogen action, and male sexual behavior.

Microbial degradation of pesticides in rapid sand filters for treatment of drinking water

DEFF Research Database (Denmark)

Hedegaard, Mathilde Jørgensen; Albrechtsen, Hans-Jørgen

2014-01-01

In Denmark drinking water supply is based on groundwater which is treated by aeration followed by filtration in rapid sand filters. Unfortunately pesticide contamination of the groundwater poses a threat to the water supply, since the simple treatment process at the waterworks is not considered...... to remove pesticides from the water phase and pesticides are detected in 24% of the active Danish waterworks wells. This study aimed at investigating the potential of microbial pesticide removal in rapid sand filters for drinking water treatment. Removal of the pesticides MCPP, bentazone, glyphosate...... and the degradation compound p-nitrophenol was investigated in the rapid sand filters at Islevbro and Sjælsø waterworks plant I and II. Microcosms were set up with sand from rapid sand filters, water and an initial pesticide concentration of 0.03-0.38 μg/L. In all the investigated waterworks the concentration...

Spin-Label CW Microwave Power Saturation and Rapid Passage with Triangular Non-Adiabatic Rapid Sweep (NARS) and Adiabatic Rapid Passage (ARP) EPR Spectroscopy

Science.gov (United States)

Kittell, Aaron W.; Hyde, James S.

2015-01-01

Non-adiabatic rapid passage (NARS) electron paramagnetic resonance (EPR) spectroscopy was introduced by Kittell, A.W., Camenisch, T.G., Ratke, J.J. Sidabras, J.W., Hyde, J.S., 2011 as a general purpose technique to collect the pure absorption response. The technique has been used to improve sensitivity relative to sinusoidal magnetic field modulation, increase the range of inter-spin distances that can be measured under near physiological conditions, and enhance spectral resolution in copper (II) spectra. In the present work, the method is extended to CW microwave power saturation of spin-labeled T4 Lysozyme (T4L). As in the cited papers, rapid triangular sweep of the polarizing magnetic field was superimposed on slow sweep across the spectrum. Adiabatic rapid passage (ARP) effects were encountered in samples undergoing very slow rotational diffusion as the triangular magnetic field sweep rate was increased. The paper reports results of variation of experimental parameters at the interface of adiabatic and non-adiabatic rapid sweep conditions. Comparison of the forward (up) and reverse (down) triangular sweeps is shown to be a good indicator of the presence of rapid passage effects. Spectral turning points can be distinguished from spectral regions between turning points in two ways: differential microwave power saturation and differential passage effects. Oxygen accessibility data are shown under NARS conditions that appear similar to conventional field modulation data. However, the sensitivity is much higher, permitting, in principle, experiments at substantially lower protein concentrations. Spectral displays were obtained that appear sensitive to rotational diffusion in the range of rotational correlation times of 10−3 to 10−7 s in a manner that is analogous to saturation transfer spectroscopy. PMID:25917132

Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion

KAUST Repository

Zhang, Ji; Jing, Wei; Roberts, William L.; Fang, Tiegang

2015-01-01

during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color

Engineered, Spatially Varying Isothermal Holds: Enabling Combinatorial Studies of Temperature Effects, as Applied to Metastable Titanium Alloy β-21S

International Nuclear Information System (INIS)

Martin, Brian; Colorado School of Mines, Golden, CO; Samimi, Peyman; Colorado School of Mines, Golden, CO; Collins, Peter

2017-01-01

A novel method to systematically vary temperature and thus study the resulting microstructure of a material is presented. This new method has the potential to be used in a combinatorial fashion, allowing the rapid study of thermal holds on microstructures to be conducted. This is demonstrated on a beta titanium alloy, where the thermal history has a strong effect on microstructure. It is informed by simulation and executed using the resistive heating capabilities of a Gleeble 3800 thermomechanical simulator. Spatially varying isothermal holds of 4 h were affected, where the temperature range of the multiple isothermal holds varied by ~175 °C.

Enhanced separation efficiency of photoinduced charges for antimony-doped tin oxide (Sb-SnO{sub 2})/TiO{sub 2} heterojunction semiconductors with varied Sb doping concentration

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhen-Long [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Ma, Wen-Hai [School of Physical Education, Henan University, Kaifeng 475004 (China); Mao, Yan-Li, E-mail: ylmao1@163.com [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute for Computational Materials Science, Henan University, Kaifeng 475004 (China)

2014-09-07

In this paper, antimony-doped tin oxide (Sb-SnO{sub 2}) nanoparticles were synthesized with varied Sb doping concentration, and the Sb-SnO{sub 2}/TiO{sub 2} heterojunction semiconductors were prepared with Sb-SnO{sub 2} and TiO{sub 2}. The separation efficiency of photoinduced charges was characterized with surface photovoltage (SPV) technique. Compared with Sb-SnO{sub 2} and TiO{sub 2}, Sb-SnO{sub 2}/TiO{sub 2} presents an enhanced separation efficiency of photoinduced charges, and the SPV enhancements were estimated to be 1.40, 1.43, and 1.99 for Sb-SnO{sub 2}/TiO{sub 2} composed of Sb-SnO{sub 2} with the Sb doping concentration of 5%, 10%, and 15%, respectively. To understand the enhancement, the band structure of Sb-SnO{sub 2} and TiO{sub 2} in the heterojunction semiconductor was determined, and the conduction band offsets (CBO) between Sb-SnO{sub 2} and TiO{sub 2} were estimated to be 0.56, 0.64, and 0.98 eV for Sb-SnO{sub 2}/TiO{sub 2} composed of Sb-SnO{sub 2} with the Sb doping concentration of 5%, 10%, and 15%, respectively. These results indicate that the separation efficiency enhancement is resulting from the energy level matching, and the increase of enhancement is due to the rising of CBO.

Estimating time-varying RSA to examine psychophysiological linkage of marital dyads.

Science.gov (United States)

Gates, Kathleen M; Gatzke-Kopp, Lisa M; Sandsten, Maria; Blandon, Alysia Y

2015-08-01

One of the primary tenets of polyvagal theory dictates that parasympathetic influence on heart rate, often estimated by respiratory sinus arrhythmia (RSA), shifts rapidly in response to changing environmental demands. The current standard analytic approach of aggregating RSA estimates across time to arrive at one value fails to capture this dynamic property within individuals. By utilizing recent methodological developments that enable precise RSA estimates at smaller time intervals, we demonstrate the utility of computing time-varying RSA for assessing psychophysiological linkage (or synchrony) in husband-wife dyads using time-locked data collected in a naturalistic setting. © 2015 Society for Psychophysiological Research.

Rapid and simultaneous determination of Strontium-89 and Strontium-90 in seawater.

Science.gov (United States)

Tayeb, Michelle; Dai, Xiongxin; Sdraulig, Sandra

2016-03-01

A rapid method has been developed for the direct determination of radiostrontium ((89)Sr and (90)Sr) released in seawater in the early phase of an accident. The method employs a fast and effective pre-concentration of radiostrontium by Sr-Ca co-precipitation followed by separation of radiostrontium using extraction chromatography technique. Radiostrontium is effectively separated in the presence of excessive dominant salts of seawater. Čerenkov and liquid scintillation assay (LSA) techniques are used to determine (89)Sr and (90)Sr. Sample preparation time is approximately 4 h for a set of 10 samples. The method was validated using spiked seawater samples at various activity ratios of (89)Sr:(90)Sr ranging from 1:10 to 9:1. The mean chemical recovery of Sr was 85 ± 3%. (90)Sr showed variable relative bias which enhanced with increasing ratio of (89)Sr:(90)Sr and was in the range ± 21%. The highest biases of (90)Sr determination were due to lower activity concentrations of (90)Sr and are regarded as acceptable in emergency situations with elevated levels of radiostrontium in the sample. The minimum detectable concentration (MDC) of (90)Sr and (89)Sr varied at different (89)Sr:(90)Sr ratios. For 0.1 L seawater and 15 min counting time on a low background Hidex liquid scintillation counter (LSC), the MDC of (90)Sr was in the range of 1.7-3.5 Bq L(-1) and MDC of (89)Sr was in the range 0.5-2.4 Bq L(-1). Copyright © 2016 Elsevier Ltd. All rights reserved.

JINR rapid communications

International Nuclear Information System (INIS)

1995-01-01

The present collection of rapid communications from JINR, Dubna, contains eight separate reports on the measurement of charge radii for Ti nuclei, spectroscopy of 13 Be, concentrations of hadrons and quark-gluon plasma in mixed phase, experimental results on one-spin pion asymmetry in the d↑ + A → π±(90 0 ) + X process, new results on cumulative pion and proton production in p-D collisions, investigation of charge exchange reactions, the study of the tensor analyzing power in cumulative particle production on a deuteron beam and an evidence for the excited states of the S = -2 stable light dibaryon. 32 figs., 6 tabs

Heavy metal concentrations in soils and vegetation in urban areas of Quezon City, Philippines.

Science.gov (United States)

Navarrete, Ian A; Gabiana, Christella C; Dumo, Joan Ruby E; Salmo, Severino G; Guzman, Maria Aileen Leah G; Valera, Nestor S; Espiritu, Emilyn Q

2017-04-01

Limited data have been published on the chemistry of urban soils and vegetation in the Philippines. The aim of this study is to quantify the concentrations of heavy metals (i.e., Cr, Ni, Cu, Zn, and Pb) in soils and vegetation in the urban landscape of Quezon City, Philippines, and to elucidate the relationships between soil properties and the concentration of heavy metals pertaining to different land uses [i.e., protected forest (LM), park and wildlife area (PA), landfill (PL), urban poor residential and industrial areas (RA), and commercial areas (CA)]. Soil (0-15 cm) and senescent plant leaves were collected and were analyzed for soil properties and heavy metal concentrations. Results revealed that the concentrations of heavy metals (i.e., Cr, Ni, Cu, Zn, and Pb) in urban soils were higher in areas where anthropogenic activities or disturbance (PL, RA, and CA) were dominant as compared to the less disturbed areas (LM and PA). Organic matter and available phosphorous were strongly correlated with heavy metal concentrations, suggesting that heavy metal concentrations were primarily controlled by these soil properties. The average foliar heavy metal concentrations varied, ranging from 0 to 0.4 mg/kg for Cd, 0-10 mg/kg for Cr, 2-22 mg/kg for Cu, 0-5 mg/kg for Pb, and 11-250 mg/kg for Zn. The concentrations of Cd and Cr exceeded the critical threshold concentrations in some plants. Leaves of plants growing in PL (i.e., landfill) showed the highest levels of heavy metal contamination. Our results revealed that anthropogenic activities and disturbance caused by the rapid urbanization of the city are major contributors to the heavy metal accumulation and persistence in the soils in these areas.

Race, ethnicity, concentrated poverty, and low birth weight disparities.

Science.gov (United States)

Sims, Mario; Sims, Tammy L; Bruce, Marino A

2008-07-01

This study examines the extent to which the relationship between area socioeconomic position (SEP) and low birth weight (LBW) varies by race and ethnicity. A cross-sectional, secondary data analysis was performed with 1992-1994 Vital Statistics and 1990 U.S. Census data for selected metropolitan areas. Low birth weight (rates were calculated for non-Hispanic Black, Latino, and non-Hispanic White live singleton births. Concentrated poverty was defined as poor persons living in neighborhoods with 40% or more poverty in metropolitan areas. The results showed that the relationship between concentrated poverty and LBW varied by race and ethnicity. Concentrated poverty was significant for Latinos, even when controlling for maternal health and MSA-level factors. By contrast, maternal health characteristics, such as pre-term birth, teen birth and tobacco use, explained much of the variance in African-American and White LBW These findings extend the discussion about race, class, and health disparities to include Latinos and shows how the relationship between SEP and LBW can vary within an ethnic group.

Assessing concentrations and health impacts of air quality management strategies: Framework for Rapid Emissions Scenario and Health impact ESTimation (FRESH-EST).

Science.gov (United States)

Milando, Chad W; Martenies, Sheena E; Batterman, Stuart A

2016-09-01

In air quality management, reducing emissions from pollutant sources often forms the primary response to attaining air quality standards and guidelines. Despite the broad success of air quality management in the US, challenges remain. As examples: allocating emissions reductions among multiple sources is complex and can require many rounds of negotiation; health impacts associated with emissions, the ultimate driver for the standards, are not explicitly assessed; and long dispersion model run-times, which result from the increasing size and complexity of model inputs, limit the number of scenarios that can be evaluated, thus increasing the likelihood of missing an optimal strategy. A new modeling framework, called the "Framework for Rapid Emissions Scenario and Health impact ESTimation" (FRESH-EST), is presented to respond to these challenges. FRESH-EST estimates concentrations and health impacts of alternative emissions scenarios at the urban scale, providing efficient computations from emissions to health impacts at the Census block or other desired spatial scale. In addition, FRESH-EST can optimize emission reductions to meet specified environmental and health constraints, and a convenient user interface and graphical displays are provided to facilitate scenario evaluation. The new framework is demonstrated in an SO2 non-attainment area in southeast Michigan with two optimization strategies: the first minimizes emission reductions needed to achieve a target concentration; the second minimizes concentrations while holding constant the cumulative emissions across local sources (e.g., an emissions floor). The optimized strategies match outcomes in the proposed SO2 State Implementation Plan without the proposed stack parameter modifications or shutdowns. In addition, the lower health impacts estimated for these strategies suggest that FRESH-EST could be used to identify potentially more desirable pollution control alternatives in air quality management planning

Histogram analysis for smartphone-based rapid hematocrit determination

Science.gov (United States)

Jalal, Uddin M.; Kim, Sang C.; Shim, Joon S.

2017-01-01

A novel and rapid analysis technique using histogram has been proposed for the colorimetric quantification of blood hematocrits. A smartphone-based “Histogram” app for the detection of hematocrits has been developed integrating the smartphone embedded camera with a microfluidic chip via a custom-made optical platform. The developed histogram analysis shows its effectiveness in the automatic detection of sample channel including auto-calibration and can analyze the single-channel as well as multi-channel images. Furthermore, the analyzing method is advantageous to the quantification of blood-hematocrit both in the equal and varying optical conditions. The rapid determination of blood hematocrits carries enormous information regarding physiological disorders, and the use of such reproducible, cost-effective, and standard techniques may effectively help with the diagnosis and prevention of a number of human diseases. PMID:28717569

Individual and household characteristics of persons with Plasmodium falciparum malaria in sites with varying endemicities in Kinshasa Province, Democratic Republic of the Congo.

Science.gov (United States)

Mwandagalirwa, Melchior Kashamuka; Levitz, Lauren; Thwai, Kyaw L; Parr, Jonathan B; Goel, Varun; Janko, Mark; Tshefu, Antoinette; Emch, Michael; Meshnick, Steven R; Carrel, Margaret

2017-11-09

The Democratic Republic of the Congo (DRC) bears a large share of global malaria burden despite efforts to control and eliminate the disease. More detailed understanding of individual and household level characteristics associated with malaria are needed, as is an understanding of how these characteristics vary spatiotemporally and across different community-level malaria endemicities. An ongoing study in Kinshasa Province is designed to address gaps in prior malaria surveillance in the DRC by monitoring malaria across seasons, age groups and in high and low malaria sites. Across seven sites, 242 households and 1591 individuals are participating in the study. Results of the enrollment questionnaire, rapid diagnostic tests and PCR testing of dried blood spots are presented. Overall malaria prevalence in the study cohort is high, 27% by rapid diagnostic test and 31% by polymerase chain reaction, and malaria prevalence is highly varied across very small geographic distances. Malaria prevalence is highest in children aged 6-15. While the majority of households own bed nets, bed net usage is less than 50%. The study cohort will provide an understanding of how malaria persists in populations that have varying environmental exposures, varying community-level malaria, and varying access to malaria control efforts.

A rapid method of predicting radiocaesium concentrations in sheep from activity levels in faeces

International Nuclear Information System (INIS)

McGee, E.J.; Synnott, H.J.; Colgan, P.A.; Keatinge, M.J.

1994-01-01

The use of faecal samples taken from sheep flocks as a means of predicting radiocaesium concentrations in live animals was studied. Radiocaesium levels in 1726 sheep from 29 flocks were measured using in vivo techniques and a single faecal sample taken from each flock was also analysed. A highly significant relationship was found to exist between mean flock activity and activity in the corresponding faecal samples. Least-square regression yielded a simple model for predicting mean flock radiocaesium concentrations based on activity levels in faecal samples. A similar analysis of flock maxima and activity levels in faeces provides an alternative model for predicting the expected within-flock maximum radiocaesium concentration. (Author)

Characterization and concentration of manganese ore waste

International Nuclear Information System (INIS)

Lima, Rosa Malena Fernandes; Pereira, Eder Esper; Reis, Erica Linhares; Silva, Glaucia Regina da

2010-01-01

In this work is presented the tests results of characterization and concentration by gravity and flotation methods carried out with a manganese sample waste. By optical microscopy, SEM/EDS and X-ray diffractometry were identified the Mn minerals spessartite (20%), tephroite (15%), rhodonite (5%), rhodochrosite and carbonates minerals (29%), opaque minerals and others (16%), micaceus minerals (6%) and quartz (4%). It was obtained Mn metallurgical recovery of 58% with Mn concentrate contents varying from 30 to 32.5%. The concentrates SiO_2 contents of flotation were until 1.5% smaller than those contents of gravity method concentrates. (author)

Concentration quenching in Nd-doped glasses

International Nuclear Information System (INIS)

Stokowski, S.E.; Cook, L.; Mueller, H.; Weber, M.J.

1984-01-01

Fluorescence from trivalent Nd in solids is unfortunately quenched by interactions between Nd ions. Thus, laser materials with high Nd concentrations have reduced efficiencies because of this self-quenching, also known as concentration quenching. Nd self-quenching in different crystals and glasses varies considerably. We are therefore investigating this effect in a large number of materials in an effort to: (1) find those materials with long Nd fluorescent lifetimes at high Nd concentrations; and (2) elucidate the basic mechanisms of quenching and how the material structure controls its magnitude. We have concentrated on Nd-doped glasses because they provide a rich variety of structures, albeit complicated by Nd site inhomogeneities, and are easily and quickly made

Acute phase response to surgery of varying intensity in horses

DEFF Research Database (Denmark)

Jacobsen, Stine; Nielsen, Jon Vedding; Kjelgaard-Hansen, Mads

2009-01-01

OBJECTIVE: To evaluate the postoperative inflammatory response of horses to elective surgery of varying intensity. STUDY DESIGN: Prospective longitudinal study. ANIMALS: Horses referred to 2 hospitals for either arthroscopic removal of a unilateral osteochondritic lesion in the tibiotarsal joint...... (minimal surgical trauma, n=11), correction of recurrent laryngeal neuropathy by laryngoplasty and ventriculectomy (intermediate surgical trauma, n=10) or removal of an ovarian tumor by laparotomy (major surgical trauma, n=5). METHODS: Horses had a thorough clinical examination every day. White blood cell....... RESULTS: Postoperative concentrations of SAA and fibrinogen were significantly higher in horses that had laparotomy and ovariectomy than in horses that had laryngoplasty and ventriculectomy, or arthroscopy. Iron concentrations decreased to lower levels after intermediate and major surgical trauma than...

Tracking time-varying cerebral autoregulation in response to changes in respiratory PaCO2

International Nuclear Information System (INIS)

Liu, Jia; Simpson, M David; Allen, Robert; Yan, Jingyu

2010-01-01

Cerebral autoregulation has been studied by linear filter systems, with arterial blood pressure (ABP) as the input and cerebral blood flow velocity (CBFV—from transcranial Doppler Ultrasound) as the output. The current work extends this by using adaptive filters to investigate the dynamics of time-varying cerebral autoregulation during step-wise changes in arterial PaCO 2 . Cerebral autoregulation was transiently impaired in 11 normal adult volunteers, by switching inspiratory air to a CO 2 /air mixture (5% CO 2 , 30% O 2 and 65% N 2 ) for approximately 2 min and then back to the ambient air, causing step-wise changes in end-tidal CO 2 (EtCO 2 ). Simultaneously, ABP and CBFV were recorded continuously. Simulated data corresponding to the same protocol were also generated using an established physiological model, in order to refine the signal analysis methods. Autoregulation was quantified by the time-varying phase lead, estimated from the adaptive filter model. The adaptive filter was able to follow rapid changes in autoregulation, as was confirmed in the simulated data. In the recorded signals, there was a slow decrease in autoregulatory function following the step-wise increase in PaCO 2 (but this did not reach a steady state within approximately 2 min of recording), with a more rapid change in autoregulation on return to normocapnia. Adaptive filter modelling was thus able to demonstrate time-varying autoregulation. It was further noted that impairment and recovery of autoregulation during transient increases in EtCO 2 occur in an asymmetric manner, which should be taken into account when designing experimental protocols for the study of autoregulation

[Accuracy of three methods for the rapid diagnosis of oral candidiasis].

Science.gov (United States)

Lyu, X; Zhao, C; Yan, Z M; Hua, H

2016-10-09

Objective: To explore a simple, rapid and efficient method for the diagnosis of oral candidiasis in clinical practice. Methods: Totally 124 consecutive patients with suspected oral candidiasis were enrolled from Department of Oral Medicine, Peking University School and Hospital of Stomatology, Beijing, China. Exfoliated cells of oral mucosa and saliva or concentrated oral rinse) obtained from all participants were tested by three rapid smear methods(10% KOH smear, gram-stained smear, Congo red stained smear). The diagnostic efficacy(sensitivity, specificity, Youden's index, likelihood ratio, consistency, predictive value and area under curve(AUC) of each of the above mentioned three methods was assessed by comparing the results with the gold standard(combination of clinical diagnosis, laboratory diagnosis and expert opinion). Results: Gram-stained smear of saliva(or concentrated oral rinse) demonstrated highest sensitivity(82.3%). Test of 10%KOH smear of exfoliated cells showed highest specificity(93.5%). Congo red stained smear of saliva(or concentrated oral rinse) displayed highest diagnostic efficacy(79.0% sensitivity, 80.6% specificity, 0.60 Youden's index, 4.08 positive likelihood ratio, 0.26 negative likelihood ratio, 80% consistency, 80.3% positive predictive value, 79.4% negative predictive value and 0.80 AUC). Conclusions: Test of Congo red stained smear of saliva(or concentrated oral rinse) could be used as a point-of-care tool for the rapid diagnosis of oral candidiasis in clinical practice. Trial registration: Chinese Clinical Trial Registry, ChiCTR-DDD-16008118.

[Factors of the rapid startup for nitrosation in sequencing batch reactor].

Science.gov (United States)

Li, Dong; Tao, Xiao-Xiao; Li, Zhan; Wang, Jun-An; Zhang, Jie

2011-08-01

The approach and factors for realizing the rapid startup of nitrosation were researched at the low level of dissolved oxygen (DO) in sequencing batch reactor (SBR). The main parameters of the reactor were controlled as follows: DO were 0.15-0.40 mg/L, pH values kept from 7.52 to 8.30, temperature maintained at 22.3-27.1 degrees C, and time of aeration was 8 hours. The purpose of rapid startup for nitrosation was achieved after 57 cycles (36 d) with the alternative influent of high and low ammonium wastewater (the mean values were 245.28 mg/L and 58.08 mg/L respectively) in a SBR, and the nitrosation rate was even 100%. Factors of accumulation of nitrite were investigated and the effects of DO and pH were analyzed during the startup for nitrosation. The results showed that it could improve the efficiency of nitrosation when DO concentration was increased appropriately. The activity of nitrite oxidizing bacteria (NOB) was recovered gradually when DO was higher than 0.72 mg/L. The key factor of controlling nitrosation reaction was the concentration of free ammonia (FA), while the final factor was the concentration of DO. pH was a desired controlling parameter to show the end of nitrification in a SBR cycle, while DO concentration did not indicate the finishing of SBR nitrification accurately because it increased rapidly before ammonia nitrogen was oxidized absolutely.

Characteristics of centrifugal rapid contactor, (3)

International Nuclear Information System (INIS)

Nakanishi, Mitsuo; Hirayama, Hiroshi; Takasu, Nobuyuki; Takeda, Hiroshi; Hoshino, Tadaya

1979-01-01

Organic solvent yields the degradation product as a result of irradiation, in the extraction process of spent fuel reprocessing. The development of a centrifugal rapid contactor is required for the reduction of the solvent degradation by shortening the contact time. The effects of fine solid particles were investigated with a SGN-Robatel LX-208N contactor, following the uranium extraction and re-extraction performance tests. It was found as the experimental result that the considerable quantity of solids accumulated in the rotor of the centrifugal contactor. As for this experimental apparatus, the flow diagram for the centrifugal rapid contactor and auxiliary apparatuses is shown, which are the same system used for the uranium extraction and re-extraction tests. The schematic diagram, the typical stage construction and fluid transfer path of the LX-208 contactor are illustrated. The main specifications of the LX-208 contactor are as follows: the internal diameter of a rotating bowl 200 mm, the material SUS 316, the number of stages 8, and the total hold-up volume of the contactor 1.8 l. Most tests were carried out with aqueous feed only, because white Alundum is easily deposited in the rotor, and the particle concentration in effluent stream becomes undetectable when organic and aqueous feeds are supplied simultaneously. As the experimental results, the correlation of Alundum concentration in effluent and running time, the effect of rotor speed on effluent stream concentration, the particle size distribution curves for No. 6000 and No. 8000 white Alundum, the effect of flow rate on effluent stream concentration and the effect of flow rate on particle size distribution for both No. 6000 and No. 8000 white Alundum are presented. (Nakai, Y.)

Characterization of acetate-utilizing methanogenic bacteria, depending on varying acetate concentrations, in a biogas plant. Phase 1

International Nuclear Information System (INIS)

Ahring, B.K.

1994-12-01

The present report contains the results of a project concerning behaviour of acetate-utilizing methanogenic bacteria in mesophilic and thermophilic biogas plants, collected in 1992 - 1994 period. Labelled acetates (2-C 14 -CH 3 COOH) have been used to characterize the types of methane bacteria populations in the Danish biogas plants, the optimum acetate concentration for these bacteria and acetate metabolism in mesophilic and thermophilic biogas reactors with low acetate concentrations. 2 publications are included. (EG)

Rapid Airfield Damage Recovery: Deployable Saw Technology Evaluation

Science.gov (United States)

2017-12-29

portland cement concrete for Rapid Airfield Damage Recovery (RADR). However, the next generation of RADR is focusing on lighter and leaner efforts...best tools for cutting portland cement concrete (PCC) in ADR scenarios (Bell et al. 2015 and Edwards et al. 2015). The saws are easily attached to...Various teeth are available for varying needs and jobs. Most teeth are made of steel with carbide tips. The carbide may be produced as a seat tip or

Time-varying value of electric energy efficiency

Energy Technology Data Exchange (ETDEWEB)

Mims, Natalie A.; Eckman, Tom; Goldman, Charles

2017-06-30

in value of all the components of avoided costs across the locations studied. -Of the five energy efficiency measures studied, those targeting residential air conditioning in summer-peaking electric systems have the most significant added value when the total time-varying value is considered. -The increased use of rooftop solar systems, storage, and demand response, and the addition of electric vehicles and other major new electricity-consuming end uses are anticipated to significantly alter the load shape of many utility systems in the future. Data used to estimate the impact of energy efficiency measures on electric system peak demands will need to be updated periodically to accurately reflect the value of savings as system load shapes change. -Publicly available components of electric system costs avoided through energy efficiency are not uniform across states and utilities. Inclusion or exclusion of these components and differences in their value affect estimates of the time-varying value of energy efficiency. -Publicly available data on end-use load and energy savings shapes are limited, are concentrated regionally, and should be expanded.

Nanotip analysis for dielectrophoretic concentration of nanosized viral particles.

Science.gov (United States)

Yeo, Woon-Hong; Lee, Hyun-Boo; Kim, Jong-Hoon; Lee, Kyong-Hoon; Chung, Jae-Hyun

2013-05-10

Rapid and sensitive detection of low-abundance viral particles is strongly demanded in health care, environmental control, military defense, and homeland security. Current detection methods, however, lack either assay speed or sensitivity, mainly due to the nanosized viral particles. In this paper, we compare a dendritic, multi-terminal nanotip ('dendritic nanotip') with a single terminal nanotip ('single nanotip') for dielectrophoretic (DEP) concentration of viral particles. The numerical computation studies the concentration efficiency of viral particles ranging from 25 to 100 nm in radius for both nanotips. With DEP and Brownian motion considered, when the particle radius decreases by two times, the concentration time for both nanotips increases by 4-5 times. In the computational study, a dendritic nanotip shows about 1.5 times faster concentration than a single nanotip for the viral particles because the dendritic structure increases the DEP-effective area to overcome the Brownian motion. For the qualitative support of the numerical results, the comparison experiment of a dendritic nanotip and a single nanotip is conducted. Under 1 min of concentration time, a dendritic nanotip shows a higher sensitivity than a single nanotip. When the concentration time is 5 min, the sensitivity of a dendritic nanotip for T7 phage is 10(4) particles ml(-1). The dendritic nanotip-based concentrator has the potential for rapid identification of viral particles.

Nanotip analysis for dielectrophoretic concentration of nanosized viral particles

International Nuclear Information System (INIS)

Yeo, Woon-Hong; Lee, Hyun-Boo; Kim, Jong-Hoon; Chung, Jae-Hyun; Lee, Kyong-Hoon

2013-01-01

Rapid and sensitive detection of low-abundance viral particles is strongly demanded in health care, environmental control, military defense, and homeland security. Current detection methods, however, lack either assay speed or sensitivity, mainly due to the nanosized viral particles. In this paper, we compare a dendritic, multi-terminal nanotip (‘dendritic nanotip’) with a single terminal nanotip (‘single nanotip’) for dielectrophoretic (DEP) concentration of viral particles. The numerical computation studies the concentration efficiency of viral particles ranging from 25 to 100 nm in radius for both nanotips. With DEP and Brownian motion considered, when the particle radius decreases by two times, the concentration time for both nanotips increases by 4–5 times. In the computational study, a dendritic nanotip shows about 1.5 times faster concentration than a single nanotip for the viral particles because the dendritic structure increases the DEP-effective area to overcome the Brownian motion. For the qualitative support of the numerical results, the comparison experiment of a dendritic nanotip and a single nanotip is conducted. Under 1 min of concentration time, a dendritic nanotip shows a higher sensitivity than a single nanotip. When the concentration time is 5 min, the sensitivity of a dendritic nanotip for T7 phage is 10 4 particles ml −1 . The dendritic nanotip-based concentrator has the potential for rapid identification of viral particles. (paper)

Exploring the Early Structure of a Rapidly Decompressed Particle Bed

Science.gov (United States)

Zunino, Heather; Adrian, R. J.; Clarke, Amanda; Johnson, Blair; Arizona State University Collaboration

2017-11-01

Rapid expansion of dense, pressurized beds of fine particles subjected to rapid reduction of the external pressure is studied in a vertical shock tube. A near-sonic expansion wave impinges on the particle bed-gas interface and rapidly unloads the particle bed. A high-speed video camera captures events occurring during bed expansion. The particle bed does not expand homogeneously, but breaks down into horizontal slabs and then transforms into a cellular-type structure. There are several key parameters that affect the particle bed evolution, including particle size and initial bed height. Analyses of this bed structure evolution from experiments with varying particle sizes and initial bed heights is presented. This work is supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science and Academic Alliance Program, under Contract No. DE-NA0002378.

The cost of implementing rapid HIV testing in sexually transmitted disease clinics in the United States.

Science.gov (United States)

Eggman, Ashley A; Feaster, Daniel J; Leff, Jared A; Golden, Matthew R; Castellon, Pedro C; Gooden, Lauren; Matheson, Tim; Colfax, Grant N; Metsch, Lisa R; Schackman, Bruce R

2014-09-01

Rapid HIV testing in high-risk populations can increase the number of persons who learn their HIV status and avoid spending clinic resources to locate persons identified as HIV infected. We determined the cost to sexually transmitted disease (STD) clinics of point-of-care rapid HIV testing using data from 7 public clinics that participated in a randomized trial of rapid testing with and without brief patient-centered risk reduction counseling in 2010. Costs included counselor and trainer time, supplies, and clinic overhead. We applied national labor rates and test costs. We calculated median clinic start-up costs and mean cost per patient tested, and projected incremental annual costs of implementing universal rapid HIV testing compared with current testing practices. Criteria for offering rapid HIV testing and methods for delivering nonrapid test results varied among clinics before the trial. Rapid HIV testing cost an average of US $22/patient without brief risk reduction counseling and US $46/patient with counseling in these 7 clinics. Median start-up costs per clinic were US $1100 and US $16,100 without and with counseling, respectively. Estimated incremental annual costs per clinic of implementing universal rapid HIV testing varied by whether or not brief counseling is conducted and by current clinic testing practices, ranging from a savings of US $19,500 to a cost of US $40,700 without counseling and a cost of US $98,000 to US $153,900 with counseling. Universal rapid HIV testing in STD clinics with same-day results can be implemented at relatively low cost to STD clinics, if brief risk reduction counseling is not offered.

Tuning the electrocaloric effect by varying Sr concentration in ferroelectric Ba1 -xSrxTiO3

Science.gov (United States)

Lisenkov, S.; Ponomareva, I.

2018-05-01

The electrocaloric effect is investigated systematically in Ba1 -xSrxTiO3 ferroelectrics using a semiclassical direct computational approach. The data are reported for the technologically important range of Sr concentrations of 0.0-0.6, electric fields up to 1000 kV/cm, and temperatures ranging from 5 to 600 K. A detailed comparison of computational data with experimental data from the literature reveals semiquantitative agreement and suggests the origin of discrepancies. The electrocaloric change in temperature Δ T shows strong dependence on Sr concentration which offers a way to tune electrocaloric response. In particular, the maximum electrocaloric Δ T is found to decrease with the increase in Sr concentration, whereas the location of the maximum shifts towards lower temperatures following the Curie point of the ferroelectric. Surprisingly, the width of the peak in the dependence of Δ T on the initial temperature is independent of the Sr concentration but shows a strong dependence on the applied electric field. Computational data are used to propose a compositionally graded ferroelectric Ba0.70Sr0.30TiO3/Ba0.55Sr0.45TiO3/Ba0.50Sr0.50TiO3/Ba0.45Sr0.55TiO3 whose Δ T shows almost no temperature dependence in the technologically important range of temperatures and electric fields. Such a desirable feature could potentially lead to the enhancement of relative cooling power.

Rapid neural discrimination of communicative gestures.

Science.gov (United States)

Redcay, Elizabeth; Carlson, Thomas A

2015-04-01

Humans are biased toward social interaction. Behaviorally, this bias is evident in the rapid effects that self-relevant communicative signals have on attention and perceptual systems. The processing of communicative cues recruits a wide network of brain regions, including mentalizing systems. Relatively less work, however, has examined the timing of the processing of self-relevant communicative cues. In the present study, we used multivariate pattern analysis (decoding) approach to the analysis of magnetoencephalography (MEG) to study the processing dynamics of social-communicative actions. Twenty-four participants viewed images of a woman performing actions that varied on a continuum of communicative factors including self-relevance (to the participant) and emotional valence, while their brain activity was recorded using MEG. Controlling for low-level visual factors, we found early discrimination of emotional valence (70 ms) and self-relevant communicative signals (100 ms). These data offer neural support for the robust and rapid effects of self-relevant communicative cues on behavior. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Multispectral Imaging for Determination of Astaxanthin Concentration in Salmonids

DEFF Research Database (Denmark)

Dissing, Bjørn Skovlund; Nielsen, Michael Engelbrecht; Ersbøll, Bjarne Kjær

2011-01-01

Multispectral imaging has been evaluated for characterization of the concentration of a specific cartenoid pigment; astaxanthin. 59 fillets of rainbow trout, Oncorhynchus mykiss, were filleted and imaged using a rapid multispectral imaging device for quantitative analysis. The multispectral imaging...... device captures reflection properties in 19 distinct wavelength bands, prior to determination of the true concentration of astaxanthin. The samples ranged from 0.20 to 4.34 mu g per g fish. A PLSR model was calibrated to predict astaxanthin concentration from novel images, and showed good results...... concentration in rainbow trout fillets....

Changes in power and force generation during coupled eccentric-concentric versus concentric muscle contraction with training and aging

DEFF Research Database (Denmark)

Caserotti, Paolo; Aagaard, Per; Puggaard, Lis

2008-01-01

Age-related decline in maximal concentric muscle power is associated with frailty and functional impairments in the elderly. Compared to concentric contraction, mechanical muscle output is generally enhanced when muscles are rapidly pre-stretched (eccentric contraction), albeit less pronounced...... with increasing age. Exercise has been recommended to prevent loss of muscle power and function and recent guidelines indicate training program for increasing muscle power highly relevant for elderly subjects. This study examined the differences in muscle power, force and movement pattern during concentric......) and JH increased in training group (P age-related decline in muscle power and functional performance observed in the control subjects, while substantial gains...

FRAMES User Defined Body Burden Concentration File Module Documentation

International Nuclear Information System (INIS)

Pelton, Mitchell A.; Rutz, Frederick C.; Eslinger, Melany A.; Gelston, Gariann M.

2001-01-01

The Framework for Risk Analysis in Multimedia Environmental Systems (FRAMES) Body Burden Concentration File (BBF) contains time-varying, instantaneous, constituent concentrations for body burden by contaminant. This report contains the requirements for this file and will be used by software engineers and testers to ensure that the file inputs properly.

Rapid pretreatment and detection of trace aflatoxin B1 in traditional soybean sauce.

Science.gov (United States)

Xie, Fang; Lai, WeiHua; Saini, Jasdeep; Shan, Shan; Cui, Xi; Liu, DaoFeng

2014-05-01

Soybean sauce, a traditional fermented food in China, has different levels of aflatoxin B1 pollution. Two kinds of direct and indirect immunomagnetic bead methods for the pretreatment of aflatoxin B1 were evaluated in this work. A method was established to detect aflatoxin B1 in soybean sauce using an immunomagnetic bead system for pretreatment and ELISA for quantification. The pretreatment method of immunomagnetic beads performed better compared with the conventional extraction and immunoaffinity column method. ELISA exhibited a good linear relationship at an aflatoxin B1 concentration of 0.05-0.3μg/kg (r(2)=0.9842). The average recoveries across spike levels varied from 0.5 to 7μg/kg were 83.6-104% with a relative standard deviation between 4.2% and 11.7%. With the advantages of rapid detection, easy operation, simple equipment, sensitivity, accuracy, and high recovery; this method can be well applied in the trace determination of aflatoxin B1 in soybean sauce samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

7746 CONCENTRATIONS OF FORMALDEHYDE IN RAIN WATERS ...

African Journals Online (AJOL)

Win7Ent

2013-06-03

Jun 3, 2013 ... The chromotropic acid method described by the. National Institute for ... concentration range of the formaldehyde in the rain waters varied from month to month throughout the six ... vicinity of vegetation [3]. Formaldehyde is the ...

Performance of a rapidly-refuelable aluminum-air battery

Science.gov (United States)

Levy, D. J.; Hollandsworth, R. P.; Gonzales, E. M.; Littauer, E. L.

The Al-air battery is being developed to provide an electric vehicle with conventional automobile performance. A rapidly-refuelable, 6-cell battery (200-sq cm electrodes) was evaluated. RX-808 aluminum anodes and air cathodes were used with a flowing alkaline electrolyte. Peak power was found to increase with temperature, decrease with aluminate concentration and be unaffected by electrolyte flow. The best performance was 5.28 kW/sq m peak power density, 2.08 kWh/kg Al energy density and 80 percent coulombic efficiency. Anode refueling is rapid and 100 percent utilization is achieved. Additional evaluation included cathode catalysts, a thermal balance and monitoring electrolyte composition.

The Handling of Constant Volumes of Various Concentrations of ...

African Journals Online (AJOL)

The Handling of Constant Volumes of Various Concentrations of Seawater by the Jackass Penguin Spheniscus Demersus. T Erasmus. Abstract. This paper reports on the effects of varying the concentration of sea water dosed at a rate of 10% of body mass on the handling of fluid and solutes by jackass penguins ...

Topsoil and Deep Soil Organic Carbon Concentration and Stability Vary with Aggregate Size and Vegetation Type in Subtropical China

Science.gov (United States)

Fang, Xiang-Min; Chen, Fu-Sheng; Wan, Song-Ze; Yang, Qing-Pei; Shi, Jian-Min

2015-01-01

The impact of reforestation on soil organic carbon (OC), especially in deep layer, is poorly understood and deep soil OC stabilization in relation with aggregation and vegetation type in afforested area is unknown. Here, we collected topsoil (0–15 cm) and deep soil (30–45 cm) from six paired coniferous forests (CF) and broad-leaved forests (BF) reforested in the early 1990s in subtropical China. Soil aggregates were separated by size by dry sieving and OC stability was measured by closed-jar alkali-absorption in 71 incubation days. Soil OC concentration and mean weight diameter were higher in BF than CF. The cumulative carbon mineralization (Cmin, mg CO2-C kg-1 soil) varied with aggregate size in BF and CF topsoils, and in deep soil, it was higher in larger aggregates than in smaller aggregates in BF, but not CF. The percentage of soil OC mineralized (SOCmin, % SOC) was in general higher in larger aggregates than in smaller aggregates. Meanwhile, SOCmin was greater in CF than in BF at topsoil and deep soil aggregates. In comparison to topsoil, deep soil aggregates generally exhibited a lower Cmin, and higher SOCmin. Total nitrogen (N) and the ratio of carbon to phosphorus (C/P) were generally higher in BF than in CF in topsoil and deep soil aggregates, while the same trend of N/P was only found in deep soil aggregates. Moreover, the SOCmin negatively correlated with OC, total N, C/P and N/P. This work suggests that reforested vegetation type might play an important role in soil OC storage through internal nutrient cycling. Soil depth and aggregate size influenced OC stability, and deep soil OC stability could be altered by vegetation reforested about 20 years. PMID:26418563

Vitamin concentrations in human milk vary with time within feed, circadian rhythm, and single-dose supplementation

Science.gov (United States)

Importance: Human milk is the subject of many nutrition studies but methods for representative sample collection are not established. Our recently improved, validated methods for analyzing micronutrients in human milk now enable systematic study of factors affecting their concentration. Objective...

The scope of application of incremental rapid prototyping methods in foundry engineering

Directory of Open Access Journals (Sweden)

M. Stankiewicz

2010-01-01

Full Text Available The article presents the scope of application of selected incremental Rapid Prototyping methods in the process of manufacturing casting models, casting moulds and casts. The Rapid Prototyping methods (SL, SLA, FDM, 3DP, JS are predominantly used for the production of models and model sets for casting moulds. The Rapid Tooling methods, such as: ZCast-3DP, ProMetalRCT and VoxelJet, enable the fabrication of casting moulds in the incremental process. The application of the RP methods in cast production makes it possible to speed up the prototype preparation process. This is particularly vital to elements of complex shapes. The time required for the manufacture of the model, the mould and the cast proper may vary from a few to several dozen hours.

A novel, rapid and automated conductometric method to evaluate surfactant-cells interactions by means of critical micellar concentration analysis.

Science.gov (United States)

Tiecco, Matteo; Corte, Laura; Roscini, Luca; Colabella, Claudia; Germani, Raimondo; Cardinali, Gianluigi

2014-07-25

Conductometry is widely used to determine critical micellar concentration and micellar aggregates surface properties of amphiphiles. Current conductivity experiments of surfactant solutions are typically carried out by manual pipetting, yielding some tens reading points within a couple of hours. In order to study the properties of surfactant-cells interactions, each amphiphile must be tested in different conditions against several types of cells. This calls for complex experimental designs making the application of current methods seriously time consuming, especially because long experiments risk to determine alterations of cells, independently of the surfactant action. In this paper we present a novel, accurate and rapid automated procedure to obtain conductometric curves with several hundreds reading points within tens of minutes. The method was validated with surfactant solutions alone and in combination with Saccharomyces cerevisiae cells. An easy-to use R script, calculates conductometric parameters and their statistical significance with a graphic interface to visualize data and results. The validations showed that indeed the procedure works in the same manner with surfactant alone or in combination with cells, yielding around 1000 reading points within 20 min and with high accuracy, as determined by the regression analysis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Histopathological effects of lethal and sub-lethal concentrations of ...

African Journals Online (AJOL)

The histopathological effects of lethal and sub-lethal concentrations of glyphosate on African catfish Clarias gariepinus were investigated. C. gariepinus juveniles were assessed in a static renewal bioassay for 96 hours (acute toxicity) and 28 days (chronic toxicity) using varying concentrations (0.0 mg/l 20.0 mg/l, 30.0 mg/l, ...

Effects of Barium Concentration on Oropharyngeal Swallow Timing Measures

OpenAIRE

Stokely, Shauna L.; Molfenter, Sonja M.; Steele, Catriona M.

2013-01-01

Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between “thin” (40 % w/v concentration) and “ultrathin” (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; ...

Rapid increases in tropospheric ozone production and export from China

NARCIS (Netherlands)

Verstraeten, W.W.; Neu, J.L.; Williams, J.E.; Bowman, K.W.; Worden, J.R.; Boersma, K.F.

2015-01-01

Rapid population growth and industrialization have driven substantial increases in Asian ozone precursor emissions over the past decade1, with highly uncertain impacts on regional and global tropospheric ozone levels. According to ozonesonde measurements2, 3, tropospheric ozone concentrations at two

Coupling age-structured stock assessment and fish bioenergetics models: a system of time-varying models for quantifying piscivory patterns during the rapid trophic shift in the main basin of Lake Huron

Science.gov (United States)

He, Ji X.; Bence, James R.; Madenjian, Charles P.; Pothoven, Steven A.; Dobiesz, Norine E.; Fielder, David G.; Johnson, James E.; Ebener, Mark P.; Cottrill, Adam R.; Mohr, Lloyd C.; Koproski, Scott R.

2015-01-01

We quantified piscivory patterns in the main basin of Lake Huron during 1984–2010 and found that the biomass transfer from prey fish to piscivores remained consistently high despite the rapid major trophic shift in the food webs. We coupled age-structured stock assessment models and fish bioenergetics models for lake trout (Salvelinus namaycush), Chinook salmon (Oncorhynchus tshawytscha), walleye (Sander vitreus), and lake whitefish (Coregonus clupeaformis). The model system also included time-varying parameters or variables of growth, length–mass relations, maturity schedules, energy density, and diets. These time-varying models reflected the dynamic connections that a fish cohort responded to year-to-year ecosystem changes at different ages and body sizes. We found that the ratio of annual predation by lake trout, Chinook salmon, and walleye combined with the biomass indices of age-1 and older alewives (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) increased more than tenfold during 1987–2010, and such increases in predation pressure were structured by relatively stable biomass of the three piscivores and stepwise declines in the biomass of alewives and rainbow smelt. The piscivore stability was supported by the use of alternative energy pathways and changes in relative composition of the three piscivores. In addition, lake whitefish became a new piscivore by feeding on round goby (Neogobius melanostomus). Their total fish consumption rivaled that of the other piscivores combined, although fish were still a modest proportion of their diet. Overall, the use of alternative energy pathways by piscivores allowed the increases in predation pressure on dominant diet species.

Land-use regression panel models of NO2 concentrations in Seoul, Korea

Science.gov (United States)

Kim, Youngkook; Guldmann, Jean-Michel

2015-04-01

Transportation and land-use activities are major air pollution contributors. Since their shares of emissions vary across space and time, so do air pollution concentrations. Despite these variations, panel data have rarely been used in land-use regression (LUR) modeling of air pollution. In addition, the complex interactions between traffic flows, land uses, and meteorological variables, have not been satisfactorily investigated in LUR models. The purpose of this research is to develop and estimate nitrogen dioxide (NO2) panel models based on the LUR framework with data for Seoul, Korea, accounting for the impacts of these variables, and their interactions with spatial and temporal dummy variables. The panel data vary over several scales: daily (24 h), seasonally (4), and spatially (34 intra-urban measurement locations). To enhance model explanatory power, wind direction and distance decay effects are accounted for. The results show that vehicle-kilometers-traveled (VKT) and solar radiation have statistically strong positive and negative impacts on NO2 concentrations across the four seasonal models. In addition, there are significant interactions with the dummy variables, pointing to VKT and solar radiation effects on NO2 concentrations that vary with time and intra-urban location. The results also show that residential, commercial, and industrial land uses, and wind speed, temperature, and humidity, all impact NO2 concentrations. The R2 vary between 0.95 and 0.98.

Concentration Sensing by the Moving Nucleus in Cell Fate Determination: A Computational Analysis.

Directory of Open Access Journals (Sweden)

Varun Aggarwal

Full Text Available During development of the vertebrate neuroepithelium, the nucleus in neural progenitor cells (NPCs moves from the apex toward the base and returns to the apex (called interkinetic nuclear migration at which point the cell divides. The fate of the resulting daughter cells is thought to depend on the sampling by the moving nucleus of a spatial concentration profile of the cytoplasmic Notch intracellular domain (NICD. However, the nucleus executes complex stochastic motions including random waiting and back and forth motions, which can expose the nucleus to randomly varying levels of cytoplasmic NICD. How nuclear position can determine daughter cell fate despite the stochastic nature of nuclear migration is not clear. Here we derived a mathematical model for reaction, diffusion, and nuclear accumulation of NICD in NPCs during interkinetic nuclear migration (INM. Using experimentally measured trajectory-dependent probabilities of nuclear turning, nuclear waiting times and average nuclear speeds in NPCs in the developing zebrafish retina, we performed stochastic simulations to compute the nuclear trajectory-dependent probabilities of NPC differentiation. Comparison with experimentally measured nuclear NICD concentrations and trajectory-dependent probabilities of differentiation allowed estimation of the NICD cytoplasmic gradient. Spatially polarized production of NICD, rapid NICD cytoplasmic consumption and the time-averaging effect of nuclear import/export kinetics are sufficient to explain the experimentally observed differentiation probabilities. Our computational studies lend quantitative support to the feasibility of the nuclear concentration-sensing mechanism for NPC fate determination in zebrafish retina.

Progress on MEVVA source VARIS at GSI

Science.gov (United States)

Adonin, A.; Hollinger, R.

2018-05-01

For the last few years, the development of the VARIS (vacuum arc ion source) was concentrated on several aspects. One of them was the production of high current ion beams of heavy metals such as Au, Pb, and Bi. The requested ion charge state for these ion species is 4+. This is quite challenging to produce in vacuum arc driven sources for reasonable beam pulse length (>120 µs) due to the physical properties of these elements. However, the situation can be dramatically improved by using the composite materials or alloys with enhanced physical properties of the cathodes. Another aspect is an increase of the beam brilliance for intense U4+ beams by the optimization of the geometry of the extraction system. A new 7-hole triode extraction system allows an increase of the extraction voltage from 30 kV to 40 kV and also reduces the outer aperture of the extracted ion beam. Thus, a record beam brilliance for the U4+ beam in front of the RFQ (Radio-Frequency Quadrupole) has been achieved, exceeding the RFQ space charge limit for an ion current of 15 mA. Several new projectiles in the middle-heavy region have been successfully developed from VARIS to fulfill the requirements of the future FAIR (Facility for Antiproton and Ion Research) programs. An influence of an auxiliary gas on the production performance of certain ion charge states as well as on operation stability has been investigated. The optimization of the ion source parameters for a maximum production efficiency and highest particle current in front of the RFQ has been performed. The next important aspect of the development will be the increase of the operation repetition rate of VARIS for all elements especially for uranium to 2.7 Hz in order to provide the maximum availability of high current ion beams for future FAIR experiments.

Induced sputum MMP-1, -3 & -8 concentrations during treatment of tuberculosis.

Directory of Open Access Journals (Sweden)

Cesar A Ugarte-Gil

Full Text Available Tuberculosis (TB destroys lung tissues and this immunopathology is mediated in part by Matrix Metalloproteinases (MMPs. There are no data on the relationship between local tissue MMPs concentrations, anti-tuberculosis therapy and sputum conversion.Induced sputum was collected from 68 TB patients and 69 controls in a cross-sectional study. MMPs concentrations were measured by Luminex array, TIMP concentrations by ELISA and were correlated with a disease severity score (TBscore. 46 TB patients were then studied longitudinally at the 2nd, 8th week and end of treatment.Sputum MMP-1,-2,-3,-8,-9 and TIMP-1 and -2 concentrations are increased in TB. Elevated MMP-1 and -3 concentrations are independently associated with higher TB severity scores (p<0.05. MMP-1, -3 and -8 concentrations decreased rapidly during treatment (p<0.05 whilst there was a transient increase in TIMP-1/2 concentrations at week 2. MMP-2, -8 and -9 and TIMP-2 concentrations were higher at TB diagnosis in patients who remain sputum culture positive at 2 weeks and MMP-3, -8 and TIMP-1 concentrations were higher in these patients at 2nd week of TB treatment.MMPs are elevated in TB patients and associate with disease severity. This matrix-degrading phenotype resolves rapidly with treatment. The MMP profile at presentation correlates with a delayed treatment response.

Monthly variation in faeces:blood concentration ratio of persistent organic pollutants over the first year of life: a case study of one infant

International Nuclear Information System (INIS)

Chen, Yiqin; McLachlan, Michael S.; Kaserzon, Sarit; Wang, Xianyu; Weijs, Liesbeth; Gallen, Michael; Toms, Leisa-Maree L.; Li, Yan; Aylward, Lesa L.; Sly, Peter D.; Mueller, Jochen F.

2016-01-01

Previous studies have found that the concentrations of a range of persistent organic pollutants (POPs) in faeces is linearly proportional to the POP concentrations in blood of human adults irrespective of age and gender. In order to investigate the correlation between POP concentrations in faeces and blood in infants, the monthly variation of POP concentrations in faeces over the first year of life of one infant was investigated in this study and compared to modelled blood concentrations. Faecal samples were collected from one male infant daily. The samples were pooled by month and analysed for three selected POPs (2,2 ′ ,4,4 ′ ,5,5 ′ -Hexachlorobiphenyl (PCB153), p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and 2,2 ′ ,4,4′-tetrabromodiphenyl ether (BDE47)). The POP concentrations in faecal samples increased for the first four months by a factor of 2.9, 4.9 and 1.4 for PCB153, BDE47, and p,p′-DDE, respectively. The faecal concentrations of all POPs decreased rapidly following the introduction of formula and solid food to the diet and subsequent weaning of the infant. Further, a one-compartment model was developed to estimate the daily POP concentrations in the blood of the infant. The POP concentrations in blood were predicted to vary much less over the first year than those observed in faeces. The faeces:blood concentration ratio of selected POPs (K fb ) differed significantly (P<0.0001) between the period before and after weaning, and observed changes in K fb are far greater than the uncertainty in the estimated K fb . A more stable K fb after weaning indicates the possibility of applying the stable K fb values for non-invasive assessment of internal exposure in infants after weaning. The intra-individual variation in K fb in infants is worthy of further investigation. - Highlights: • Measured POPs concentrations in faecal samples decreased rapidly following weaning. • Ratio of faecal:blood concentrations (K fb ) changed over the first

Serum concentrations of apelin-17 isoform vary in accordance to blood pressure categories in individuals with obesity class 3.

Science.gov (United States)

Cano Martínez, Luis Javier; Coral Vázquez, Ramón Mauricio; Méndez, Juan Pablo; Trejo, Silvia; Pérez Razo, Juan Carlos; Canto, Patricia

2018-04-13

The aim of this study was to investigate if serum concentrations of apelin-36, apelin-17, apelin-13 or apelin-12 were different in obesity class 3 individuals with hypertension, when compared to those without hypertension (normal or high-normal). Twenty six individuals with obesity class 3-related hypertension and thirty three individuals without hypertension, who were divided in individuals with normal (n = 23) or with high-normal (n = 10) blood pressure (BP) were analyzed. All individuals presented obesity class 3, without diabetes mellitus. Measurements of all apelin isoforms were performed using enzyme-linked immunosorbent assay kits. Analysis of differences between groups of Apelin isoform concentrations was performed by a One-way ANOVA, with a Tukey test post hoc. The individuals of the hypertensive group presented a slightly lower serum concentration of all apelin isoforms, but these differences were not statistically significant. These results were more evident when the group of patients without hypertension were divided based in normal and high-normal BP, observing that apelin-17 isoform were higher in individuals with high-normal BP in comparison to subjects with normal BP (P = 0.018); concentrations were also higher when compared to subjects with hypertension (P = 0.004). To our knowledge, this is the first study regarding the differences of apelin-17 isoform concentrations in individuals pertaining to different categories of BP, who presented obesity class 3. The group of patients that presented hypertension showed a lower concentration of all isoforms. This observation could be due to the fact that these patients were taking antihypertensive medication.

Intra-pulse Cavity Enhanced Measurements of Carbon Monoxide in a Rapid Compression Machine

KAUST Repository

Nasir, Ehson Fawad

2018-05-07

A laser absorption sensor for carbon monoxide concentration was developed for combustion studies in a rapid compression machine using a pulsed quantum cascade laser near 4.89 μm. Cavity enhancement reduced minimum detection limit down to 2.4 ppm at combustion relevant conditions. Off-axis alignment and rapid intra-pulse down-chirp resulted in effective suppression of cavity noise.

Continuous measurement of uranium concentrations with the laser spark

International Nuclear Information System (INIS)

Gutmacher, R.G.; Cremers, D.A.; Wachter, J.R.

1987-01-01

Laser-induced breakdown spectroscopy has been applied to the continuous determination of uranium concentrations between 0.1 and 300 g/L in flowing solutions. The technique is rapid, noninvasive, and unaffected by radioactivity. A concentration of 10 g/L was measured with 0.8% precision in 3 min. Substances that absorb at the laser wavelength, suspended materials, and variations in the acidity of the solution have little or no effect on the results. High concentrations of zirconium, cadmium, aluminum, or stainless steel in solution do not interfere

Rapid determination of total phenols in seawater by 4-aminoantipyrine colorimetry

Digital Repository Service at National Institute of Oceanography (India)

Kadam, A.N.; Bhangale, V.P.

A rapid and efficient 4-aminoantipyrine (4-AAP) colorimetric method without any cleanup step to determine total phenols in seawater is described. Efficiency of the method for seawater using external addition of phenol concentrations with working...

A multilayer concentric filter device to diminish clogging for separation of particles and microalgae based on size.

Science.gov (United States)

Chen, Chih-Chung; Chen, Yu-An; Liu, Yi-Ju; Yao, Da-Jeng

2014-04-21

Microalgae species have great economic importance; they are a source of medicines, health foods, animal feeds, industrial pigments, cosmetic additives and biodiesel. Specific microalgae species collected from the environment must be isolated for examination and further application, but their varied size and culture conditions make their isolation using conventional methods, such as filtration, streaking plate and flow cytometric sorting, labour-intensive and costly. A separation device based on size is one of the most rapid, simple and inexpensive methods to separate microalgae, but this approach encounters major disadvantages of clogging and multiple filtration steps when the size of microalgae varies over a wide range. In this work, we propose a multilayer concentric filter device with varied pore size and is driven by a centrifugation force. The device, which includes multiple filter layers, was employed to separate a heterogeneous population of microparticles into several subpopulations by filtration in one step. A cross-flow to attenuate prospective clogging was generated by altering the rate of rotation instantly through the relative motion between the fluid and the filter according to the structural design of the device. Mixed microparticles of varied size were tested to demonstrate that clogging was significantly suppressed due to a highly efficient separation. Microalgae in a heterogeneous population collected from an environmental soil collection were separated and enriched into four subpopulations according to size in a one step filtration process. A microalgae sample contaminated with bacteria and insect eggs was also tested to prove the decontamination capability of the device.

Rapid ion-exchange separations of actinides

International Nuclear Information System (INIS)

Usuda, Shigekazu

1988-01-01

For the purpose of studying short-lived actinide nuclides, three methods for rapid ion exchange separation of actinide elements with mineral acid-alcohol mixed media were developed: anion exchange with nitric acid-methyl alcohol mixed media to separate the transplutonium and rare earth elements from target material, U or Pu and Al catcher foils; anion exchange with hydrochloric acid-methyl alcohol media to separate Am+Cm, Bk and Cf+Fm from the target, catcher foils and major fission products; and cation exchange with hydrochloric acid-methyl alcohol media and with concentrated hydrochloric acid to separate the transplutonium elements as a group from the rare earths after eliminating the large amounts of U, Al, Cu, Fe etc. The methods enable one to perform rapid and effective separation at elevated temperature (90 deg C) and immediate source preparation for alpha-ray spectrometry. (author) 47 refs.; 10 figs

Relationships among developmental stage, metamorphic timing, and concentrations of elements in bullfrogs (Rana catesbeiana)

Energy Technology Data Exchange (ETDEWEB)

Snodgrass, J.W.; Hopkins, W.A.; Roe, J.H. [Towson University, Towson, MD (United States). Dept. for Biological Science

2003-07-01

We collected bullfrog (Rana catesbeiana) larvae from a coal combustion waste settling basin to investigate the effects of developmental stage and timing of metamorphosis on concentrations of a series of trace elements in bullfrog tissues. Bullfrogs at four stages of development (from no hind limbs to recently metamorphosed juveniles) and bullfrogs that metamorphosed in the fall or overwintered in the contaminated basin and metamorphosed in the spring were analyzed for whole-body concentrations of Al, V, Cr, Ni, Cu, As, Pb, Cd, Zn, Ag, Sr, and Se. After the effects of dry mass were removed, tissue concentrations of six elements (Al, V, Cr, Ni, Cu, As, and Pb) decreased from the late larval stage through metamorphosis. Decreases in concentrations through metamorphosis ranged from 40% for Cu to 97% for Al. Tissue concentrations of these elements were also similar or higher in spring; Al and Cr concentrations were 34 and 90% higher in the spring, respectively, whereas As, Ni, Cu, and Pb concentrations were {lt} 10% higher. Concentrations of Cd, Se, and Ag varied among seasons but not among stages; Cd and Ag concentrations were 40 and 62% lower, respectively, and Se concentrations were 21% higher in spring. Concentrations of Zn varied only among stages; concentrations decreased gradually through late larval stage and then increased through metamorphosis. Concentrations of Sr varied among stages, but this variation was dependent on the season. Concentrations of Sr were higher in larval stages during the spring, but because concentrations of Sr increased 122% through metamorphosis in the fall and only 22% in the spring, concentrations were higher in fall metamorphs when compared with spring metamorphs. Our results indicate that metamorphosis and season of metamorphosis affects trace element concentrations in bullfrogs and may have important implications for the health of juveniles and the transfer of pollutants from the aquatic to the terrestrial environment.

Relevance of new multispectral imagery for assessing tropical forest disturbance: RapidEye and WorldView-2

CSIR Research Space (South Africa)

Cho, Moses A

2012-11-01

Full Text Available The aims of this study were to assess utility of RapidEye imagery for predicting leaf nitrogen concentration and evaluate the effects of forest fragmentation on leaf nitrogen distribution in the Dukuduku forest, KwaZulu Natal, South Africa. RapidEye...

Revealing source signatures in ambient BTEX concentrations

International Nuclear Information System (INIS)

Zalel, Amir; Yuval; Broday, David M.

2008-01-01

Management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-induced VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations to their pertinent sources. This study presents an approach that can aid in identifying sources that contribute to observed BTEX concentrations in areas characterized by low BTEX concentrations, where traditional source apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to allocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations. - BTEX sources are identified from temporal variations of ambient concentration

Monitoring of radon concentration in dwellings

International Nuclear Information System (INIS)

Kurosawa, Ryuhei

1991-01-01

Radon problems in dwellings have recently received much attention. Radon concentration in dwellings, as well as in the general environment, varies with various factors such as meteorological conditions and soil components. Therefore, a long term monitoring of radon concentration is required to obtain an average concentration. This paper reviews a passive type radon monitor that is handy and allows a long term radon monitoring. It provides the structure and principle of the radon monitor, covering the type, filter function, sensitivity of diffusion collecting type (cup type), electrostatic collecting type, adsorption collecting type, and detector of radon monitor. Actual examples of the radon monitor are also given. Radon daughter nuclides will have become major foci of exposure countermeasures. In the future, the development of a passive type monitor for determining potential alpha energy concentration is required. (N.K.)

Variation of boron concentration in metallic glass ribbons

International Nuclear Information System (INIS)

Nagy, A.Z.; Vasvari, B.; Duwez, P.; Bakos, L.; Seres, Z.; Bogancs, J.; Nazarov, V.M.

1979-12-01

The surface boron concentration of Fe 40 Ni 40 P 14 B 6 , Fe 32 Ni 36 Cr 14 P 12 B 6 and Fe 40 Ni 40 B 20 metallic glasses was measured by neutron activation analysis on both sides of the ribbon samples. It was found that the boron concentration is always higher at the bright side of the ribbon than that at the dull side which is in contact with the cold surface of the wheel during the rapid quenching from the melt. A possible explanation is given in terms of the solid-liquid interface moving rapidly from the cooled surface to the free surface when preparing the samples. Range values of alpha-particles for some characteristic compositions of metallic glasses are tabulated. A mathematical technique for the deconvolution of experimental data is described and the listing of the Fortran program is enclosed. (author)

Telehealth Delivery of Rapid Syllable Transitions (ReST) Treatment for Childhood Apraxia of Speech

Science.gov (United States)

Thomas, Donna C.; McCabe, Patricia; Ballard, Kirrie J.; Lincoln, Michelle

2016-01-01

Background: Rapid Syllable Transitions (ReST) treatment uses pseudo-word targets with varying lexical stress to target simultaneously articulation, prosodic accuracy and coarticulatory transitions in childhood apraxia of speech (CAS). The treatment is efficacious for the acquisition of imitated pseudo-words, and generalization of skill to…

Unraveling the rapid radiation of crested newts, Triturus cristatus superspecies, using complete mitogenomic sequences

NARCIS (Netherlands)

Wielstra, B.M.; Arntzen, J.W.

2011-01-01

Background - The rapid radiation of crested newts (Triturus cristatus superspecies) comprises four morphotypes: 1) the T. karelinii group, 2) T. carnifex - T. macedonicus, 3) T. cristatus and 4) T. dobrogicus. These vary in body build and the number of rib-bearing pre-sacral vertebrae (NRBV). The

Connection of automatic integral multichannel monitor of aerosol concentration

International Nuclear Information System (INIS)

Krejci, M.; Stulik, P.

1985-01-01

The instrument consists of the actual aerosol concentration monitor with two equivalent inputs, of an electropneumatic sampling selector, an aerosol pump, an electropneumatic valve, and of an exhaust device. For integral operating mode the instrument allows rapid checking and indication of exceedance of the permissible aerosol concentration limit at any sampling point. Upon exceedance of the permissible concentration limit, the device automatically switches into the multichannel cyclic measurement mode while the sampling point is identified where the aerosol concentration was increased. An emergency is displayed if the permissible limit has been exceeded. Following removal of the source of dangerous aerosol concentration, the control unit automatically switches the device into the integral measurement mode. (J.B.)

Projectile rapidity dependence in target fragmentation

International Nuclear Information System (INIS)

Haustein, P.E.; Cumming, J.B.; Hseuh, H.C.

1979-01-01

The thick-target, thick-catcher technique was used to determine mean kinetic properties of selected products of the fragmentation of Cu by 1 H, 4 He, and 12 C ions (180 to 28,000 MeV/amu). Momentum transfer, as inferred from F/B ratios, is ovserved to occur most efficiently for the lower velocity projectiles. Recoil properties of target fragments vary strongly with product mass, but show only a weak dependence on projectile type. The projectile's rapidity is shown to be a useful variable for quantitative intercomparison of different reactions. These results indicate that E/sub proj//A/sub proj/ is the dominant parameter which governs the mean recoil behavior of target fragments. 20 references

Ignition properties of n-butane and iso-butane in a rapid compression machine

NARCIS (Netherlands)

Gersen, S.; Mokhov, A. V.; Darmeveil, J. H.; Levinsky, H. B.

Autoignition delay times of n-butane and iso-butane have been measured in a Rapid Compression Machine in the temperature range 660-1010 K, at pressures varying from 14 to 36 bar and at equivalence ratios phi = 1.0 and phi = 0.5. Both butane isomers exhibit a negative-temperature-coefficient (NTC)

Progress In Fresnel-Köhler Concentrators

Science.gov (United States)

Mohedano, Rubén; Cvetković, Aleksandra; Benítez, Pablo; Chaves, Julio; Miñano, Juan C.; Zamora, Pablo; Hernandez, Maikel; Vilaplana, Juan

2011-12-01

The Fresnel Köhler (FK) concentrator was first presented in 2008. Since then, various CPV companies have adopted this technology as base for their future commercial product. The key for this rapid penetration is a mixture of simplicity (the FK is essentially a Fresnel lens concentrator, a technology that dominates the market) and excellent performance: high concentration without giving up large manufacturing/aiming tolerances, enabling high efficiency even at the array level. All these features together have a great potential to lower energy costs. This work shows recent results and progress regarding this device, covering new design features, measurements and tests along with first performance achievements at the array level (pilot 6.5 Kwp plant). The work also discusses the potential impact of the FK enhanced performance on the Levelized Cost Of Electricity (LCOE).

Countermeasures for electrolytic corrosion - Part II: Implementation of a rapid potential-controlled rectifier

Energy Technology Data Exchange (ETDEWEB)

Ha, Tae-Hyun; Kim, Dae-Kyeong; Lee, Hyun-Goo; Ha, Yoon-Cheol; Bae, Jeong-Hyo [Underground Systems Group, Korea Electrotechnology Research Institute, 28-1 Sungju-dong, Changwon, 641-120 (Korea)

2004-07-01

In electrolytic interference circumstances such as underground pipelines in the vicinity of DC electrified railroads, drainage method or impressed current cathodic protection method has been widely used as a countermeasure for the electrolytic corrosion. In the former method, forced or polarized drainage is commonly adopted and in the latter, the phase-controlled rectifier with thyristor is in common use. Both methods, however, does not show as the optimal measure for the integrity of the pipeline, since the pipe-to-soil potential fluctuates highly positive to the cathodic protection criterion. In particular, as the potential of the pipeline near the railroad varies rapidly, a new rapidly responding countermeasure is necessary. In this paper, we introduce a new rapid potential controlled rectifier and report the result in field tests. Comparison with the existing forced drainage method is also made. The pipe-to-soil potential data show the effectiveness of the rapid potential-controlled rectifier. (authors)

Serum testosterone concentrations in men with alcoholic cirrhosis

DEFF Research Database (Denmark)

Gluud, C

1987-01-01

Median serum testosterone concentration of men with alcoholic cirrhosis (n = 216) did not differ significantly from normal controls (n = 51), but serum testosterone concentrations varied by a factor 43.9 in patients compared to 3.2 in controls (P less than .001). Nineteen percent of the patients...... had serum testosterone concentrations above 30 nmol/L. Serum concentrations of sex-hormone-binding globulin (SHBG) were significantly (P less than .001) raised, and serum concentrations of calculated nonprotein-bound and non-SHBG-bound testosterone were significantly (P less than .001) decreased...... in patients compared to normal control values. A number of background variables were analyzed with reference to serum testosterone concentrations by means of multiple regression techniques after having divided the patients into groups (A, B, C) with decreasing liver function by a modification of the Child...

Determination of some heavy metals concentration in the tissues of ...

African Journals Online (AJOL)

Lead (Pb), Cobalt (Co), and Copper (Cu) concentrations were determined in bone, muscle and gill of two fish species (tilapia fish and cat-fish) collected from Tiga dam Kano, Nigeria during October, 2010. The mean concentrations of the heavy metals varied depending on the type of the tissue and fish species. Generally ...

Rapid Hip Osteoarthritis Development in a Patient with Anterior Acetabular Cyst with Sagittal Alignment Change

Directory of Open Access Journals (Sweden)

Yasuhiro Homma

2014-01-01

Full Text Available Rapidly destructive coxarthrosis (RDC is rare and develops unusual clinical course. Recent studies suggest multiple possible mechanisms of the development of RDC. However the exact mechanism of RDC is still not clear. The difficulty of the study on RDC is attributed to its rareness and the fact that the data before the onset of RDC is normally unavailable. In this report, we presented the patient having the radiographic data before the onset who had rapid osteoarthritis (OA development after contralateral THA, which meets the current criteria of RDC. We thought that the increased posterior tilt of the pelvis after THA reinforced the stress concentration at pre-existed anterior acetabular cyst, thereby the destruction of the cyst was occurred. As a result the rapid OA was developed. We think that there is the case of rapid osteoarthritis developing due to alternating load concentration by posterior pelvic tilt on preexisting anterior acetabular cyst such as our patient among the cases diagnosed as RDC without any identifiable etiology. The recognition of sagittal alignment changes and anterior acetabular cyst may play important role in prediction and prevention of the rapid hip osteoarthritis development similar to RDC.

Trace metal concentration in some marine algae of the Maharashtra coast (India)

Digital Repository Service at National Institute of Oceanography (India)

Agadi, V.V.; Bhosle, N.B.; Untawale, A.G.

74 marine algal species representing Chlorophyta, Phaeophyta and Rhodophyta from ten different stations along the Maharashtra Coast were analysed for the concentration of Mn, Fe, Co, Ni, Cu, Zn and Pb Concentration varies with species and also from...

Calculation of rectal dose surface histograms in the presence of time varying deformations

International Nuclear Information System (INIS)

Roeske, John C.; Spelbring, Danny R.; Vijayakumar, S.; Forman, Jeffrey D.; Chen, George T.Y.

1996-01-01

arrangement and weights used for each field. Two dose gradients exist, a slowly varying gradient (e.g. within the high dose volume) and rapidly varying gradient (e.g. dose gradient from the field edges). Superimposed on this variation are the sampling points from a deformable hollow organ, which can translate and deform in both slow and rapidly varying regions of dose. The individual scan nDSHs and average nDSH summarize the effects of these variations. Conclusion: The initial DSH for the rectum in a given plan can vary by 8% for moderate to high dose in comparison to the time averaged nDSH. The effect on NTCP is expected to be relatively small, but it is important to note that at any given instant of time, uncertainty in the absolute surface area of a structure at a given dose can vary by as much as 20% due to distortion and movement

Altitude distribution of electron concentration in ionospheric D-region in presence of time-varying solar radiation flux

International Nuclear Information System (INIS)

Nina, A.; Čadež, V.; Srećković, V.; Šulić, D.

2012-01-01

In this paper, we study the influence of solar flares on electron concentration in the terrestrial ionospheric D-region by analyzing the amplitude and phase time variations of very low frequency (VLF) radio waves emitted by DHO transmitter (Germany) and recorded by the AWESOME receiver in Belgrade (Serbia) in real time. The rise of photo-ionization rate in the ionospheric D-region is a typical consequence of solar flare activity as recorded by GOES-15 satellite for the event on March 24, 2011 between 12:01 UT and 12:11 UT. At altitudes around 70 km, the photo-ionization and recombination are the dominant electron gain and electron loss processes, respectively. We analyze the relative contribution of each of these two processes in the resulting electron concentration variation in perturbed ionosphere.

Altitude distribution of electron concentration in ionospheric D-region in presence of time-varying solar radiation flux

Energy Technology Data Exchange (ETDEWEB)

Nina, A., E-mail: sandrast@ipb.ac.rs [Institute of Physics, University of Belgrade, P.O. Box 57, Belgrade (Serbia); Cadez, V. [Astronomical Observatory, Volgina 7, 11060 Belgrade (Serbia); Sreckovic, V. [Institute of Physics, University of Belgrade, P.O. Box 57, Belgrade (Serbia); Sulic, D. [Faculty of Ecology and Environmental Protection, Union - Nikola Tesla University, Cara Dusana 62, 11000 Belgrade (Serbia)

2012-05-15

In this paper, we study the influence of solar flares on electron concentration in the terrestrial ionospheric D-region by analyzing the amplitude and phase time variations of very low frequency (VLF) radio waves emitted by DHO transmitter (Germany) and recorded by the AWESOME receiver in Belgrade (Serbia) in real time. The rise of photo-ionization rate in the ionospheric D-region is a typical consequence of solar flare activity as recorded by GOES-15 satellite for the event on March 24, 2011 between 12:01 UT and 12:11 UT. At altitudes around 70 km, the photo-ionization and recombination are the dominant electron gain and electron loss processes, respectively. We analyze the relative contribution of each of these two processes in the resulting electron concentration variation in perturbed ionosphere.

Human response to varying concentrations of toluene

DEFF Research Database (Denmark)

Bælum, Jesper; Lundqvist, G R; Mølhave, Lars

1990-01-01

less than 0.1) towards irritation in the throat, headache and dizziness. In the four performance tests there was a tendency towards a lower score in a vigilance test while no effect of toluene exposure was seen in a peg board test, a five choice serial reaction test, or a colour test, indicating only...

Effect of Pumping Strategies on Pesticide Concentrations in Water Abstraction Wells

DEFF Research Database (Denmark)

Aisopou, Angeliki; Bjerg, Poul Løgstrup; Albrechtsen, Hans-Jørgen

Pesticide use in agriculture is one of the main sources of groundwater contamination and poses an important threat to groundwater abstraction. Pesticides have been detected in 37% of Danish monitoring wells sampled, with 12 % exceeding drinking water guidelines. Field data captured in monitoring...... and pumping wells show that pesticide concentrations vary greatly in both time and space. This study aimed to use models to determine how pumping affects pesticide concentrations in drinking water wells placed in two hypothetical aquifer systems; a homogeneous layered aquifer and a layered aquifer...... in a pumping well capture zone were constructed using COMSOL Multiphysics. A series of simulations were conducted to examine the effect of pumping strategies (constant versus varying pumping rate), pesticide properties and aquifer hydrogeology on the concentration in drinking water wells. The results...

ERP evidence for rapid hedonic evaluation of logos.

Science.gov (United States)

Handy, Todd C; Smilek, Daniel; Geiger, Lena; Liu, Cindy; Schooler, Jonathan W

2010-01-01

We know that human neurocognitive systems rapidly and implicitly evaluate emotionally charged stimuli. But what about more everyday, frequently encountered kinds of objects, such as computer desktop icons and business logos? Do we rapidly and implicitly evaluate these more prosaic visual images, attitude objects that might only engender a mild sense of liking or disliking, if at all? To address this question, we asked participants to view a set of unfamiliar commercial logos in the context of a target identification task as brain electrical responses to these objects were recorded via event-related potentials (ERPs). Following this task, participants individually identified those logos that were most liked or disliked, allowing us to then compare how ERP responses to logos varied as a function of hedonic evaluation-a procedure decoupling evaluative responses from any normative classification of the logos themselves. In Experiment 1, we found that visuocortical processing manifest a specific bias for disliked logos that emerged within the first 200 msec of stimulus onset. In Experiment 2, we replicated this effect while dissociating normative- and novelty-related influences. Taken together, our results provide direct electrophysiological evidence suggesting that we rapidly and implicitly evaluate commercial branding images at a hedonic level.

Uranium, Thorium and Potassium concentrations and volumetric heat production rates at the eastern border of the Parana basin

International Nuclear Information System (INIS)

Andrade, Telma C.Q.; Ribeiro, Fernando B.

1997-01-01

Uranium, thorium and potassium concentrations were measured and volumetric heat production rates were calculated for rocks from the exposed basement at the eastern-southeastern border of the Parana Basin between 23 deg S and 32 deg S. Heat generating element concentration data available in the literature were also used when possible, for volumetric heat production calculations. The uranium concentrations vary from below determination limit (0.51 ppm) and 16 ppm whereas the thorium concentrations vary from below the determination limit (1.26 ppm) and 68 ppm, and K concentrations vary between 0.08% and 5.6%. Volumetric heat production rates vary between 0.07 μW/m 3 to 6.2 μW/m 3 , and the obtained results show a variable heat generation rate with high heat producing bodies scattered along this Parana Basin border. The higher observed values concentrate in the Ribeira fold belt at about 23 deg S and between 30 deg S and 32 deg S in the Down Feliciano fold belt. Isolated high heat production rates can also be observed between 26 deg S and 28 deg S. (author). 11 refs., 3 tabs

[Efficient and rapid non-test tube cloning of Jatropha curcas].

Science.gov (United States)

Wang, Zhao-Yu; Lin, Jing-Ming; Xu, Zeng-Fu

2007-08-01

To develop a new technique for efficient and rapid non-test tube cloning of the medicinal and energy- producing plant Jatropha curcas. Using the mini-stem fragment (2-3 cm) of Jatropha curcas with merely one axillary bud as the explant, the effect of an auxin IBA concentration on the plantlet regeneration was studied. When treated with 1 mg/LIBA for 1h, the explants showed the most rapid propagation. The mini-stem fragments high root regeneration ratio (96.7%), short root regeneration period (18.2-/+2.0 d), large number of new roots per explant (6.3-/+1.8), and long total root length (6.8-/+3.5 cm), demonstrating that this technique can be a simple and efficient method for rapid non-test tube cloning of Jatropha curcas of potential industrial value.

Research on the Features of Chlorophyll-a Derived from RapidEye and EOS/MODIS Data in Chaohu Lake

International Nuclear Information System (INIS)

Wen, X; Chen, B; Li, Z; Zhou, Z; Tang, X

2014-01-01

Chaohu Lake is one of the largest freshwater lakes in China, however, with the rapid expansion of Hefei, the water environment of Chaohu Lake shows significantly deterioration. In this paper, RapidEye and MODIS imagery were used to monitor the chlorophyll alpha (Chla) distribution in Chaohu Lake. After analyzing the correlation between in-situ measured Chla concentrations and each channel of RapidEye and MODIS imagery, the optimal band combination for the establishment of Chla concentration was determined. For RapidEye imagery, the red edge channel and near infrared channel are relatively more sensitive than other channels. The inversion model using the feature of (B5+B4)/(B2+B1) worked the best with the square value of correlation coefficient reaching up to 0.745. A similar procedure was applied to MODIS imagery. The experiments show that RapidEye with its red edge channel is an effective data source for water environment monitoring, it could provide high spatial resolution of Chla distribution thematic map, MODIS with its higher temporal resolution is also an effective data source in dynamically monitoring water environment. The Chla concentration in the western half of Chao Lake is higher than that in the eastern half

Distribution and source analysis of heavy metal pollutants in sediments of a rapid developing urban river system.

Science.gov (United States)

Xia, Fang; Qu, Liyin; Wang, Ting; Luo, Lili; Chen, Han; Dahlgren, Randy A; Zhang, Minghua; Mei, Kun; Huang, Hong

2018-09-01

Heavy metal pollution of aquatic environments in rapidly developing industrial regions is of considerable global concern due to its potential to cause serious harm to aquatic ecosystems and human health. This study assessed heavy metal contamination of sediments in a highly industrialized urban watershed of eastern China containing several historically unregulated manufacturing enterprises. Total concentrations and solid-phase fractionation of Cu, Zn, Pb, Cr and Cd were investigated for 39 river sediments using multivariate statistical analysis and geographically weighted regression (GWR) methods to quantitatively examine the relationship between land use and heavy metal pollution at the watershed scale. Results showed distinct spatial patterns of heavy metal contamination within the watershed, such as higher concentrations of Zn, Pb and Cd in the southwest and higher Cu concentration in the east, indicating links to specific pollution sources within the watershed. Correlation and PCA analyses revealed that Zn, Pb and Cd were dominantly contributed by anthropogenic activities; Cu originated from both industrial and agricultural sources; and Cr has been altered by recent pollution control strategies. The GWR model indicated that several heavy metal fractions were strongly correlated with industrial land proportion and this correlation varied with the level of industrialization as demonstrated by variations in local GWR R 2 values. This study provides important information for assessing heavy metal contaminated areas, identifying heavy metal pollutant sources, and developing regional-scale remediation strategies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluate of head loss, sediment value and copper removal in sand media (rapid sand filter

Directory of Open Access Journals (Sweden)

Daneshi Navab

2014-06-01

Full Text Available Along with the technology development and increasing consumption of water resources, we are experiencing low qualities in the mentioned resources. Copper brings about serious environment al pollution, threatening human health and ecosystem. This metal found variously in water resources and industrial activities. Therefore, it needs to treat the water resources from these excessive amounts. Different methods have used for this reason but the most used method during recent years has been the absorption by economic absorbers such as sand. Rapid sand filters usually used in water and wastewater treatment plants for water clarification. In this research, a single layer gravity rapid sand filter has used to reduce different concentrations of copper. sediment value and head loss arising in filter media is simulated by using combination of Carman-Kozeny, Rose and Gregory models in different discharges of rapid sand filter. Results have shown that with increasing in discharge and decreasing in input copper concentration, arriving time to given head loss, is increasing. In addition, results demonstrated that with increasing in copper concentration in influent, removal efficiency is decreasing somewhat. Results of this research can applied in an appropriate design of rapid sand filter to copper removal, a prediction of rapid sand filter ability to copper removal and an estimation of arising head loss during filter work thus evaluating of time interval backwash. DOI: http://dx.doi.org/10.3126/ije.v3i2.10641 International Journal of the Environment Vol.3(2 2014: 276-286

Optimal control methods for rapidly time-varying Hamiltonians

International Nuclear Information System (INIS)

Motzoi, F.; Merkel, S. T.; Wilhelm, F. K.; Gambetta, J. M.

2011-01-01

In this article, we develop a numerical method to find optimal control pulses that accounts for the separation of timescales between the variation of the input control fields and the applied Hamiltonian. In traditional numerical optimization methods, these timescales are treated as being the same. While this approximation has had much success, in applications where the input controls are filtered substantially or mixed with a fast carrier, the resulting optimized pulses have little relation to the applied physical fields. Our technique remains numerically efficient in that the dimension of our search space is only dependent on the variation of the input control fields, while our simulation of the quantum evolution is accurate on the timescale of the fast variation in the applied Hamiltonian.

Reduced trace element concentrations in fast-growing juvenile Atlantic salmon in natural streams.

Science.gov (United States)

Ward, Darren M; Nislow, Keith H; Chen, Celia Y; Folt, Carol L

2010-05-01

To assess the effect of rapid individual growth on trace element concentrations in fish, we measured concentrations of seven trace elements (As, Cd, Cs, Hg, Pb, Se, Zn) in stream-dwelling Atlantic salmon (Salmo salar) from 15 sites encompassing a 10-fold range in salmon growth. All salmon were hatched under uniform conditions, released into streams, and sampled approximately 120 days later for trace element analysis. For most elements, element concentrations in salmon tracked those in their prey. Fast-growing salmon had lower concentrations of all elements than slow growers, after accounting for prey concentrations. This pattern held for essential and nonessential elements, as well as elements that accumulate from food and those that can accumulate from water. At the sites with the fastest salmon growth, trace element concentrations in salmon were 37% (Cs) to 86% (Pb) lower than at sites where growth was suppressed. Given that concentrations were generally below levels harmful to salmon and that the pattern was consistent across all elements, we suggest that dilution of elements in larger biomass led to lower concentrations in fast-growing fish. Streams that foster rapid, efficient fish growth may produce fish with lower concentrations of elements potentially toxic for human and wildlife consumers.

Study of Uranium Concentrations in Water and Organic Material from Streams in Sweden

International Nuclear Information System (INIS)

Ek, J.

1981-12-01

The purpose of the investigation has been to study how uranium concentrations in stream water and organic material are related to various geological parameters such as rock types, average uranium content and radioactivity, fracturing, leachability of uranium from the bedrock, occurrence of uranium mineralisations and thickness and type of Quarternary deposits. The investigation has also taken account of the effects of environmental factors such as climate , precipitation, height above sea level and topography. The background concentration of uranium in organic stream sediment varies from 1 ppm to 45 ppm, with a background value of 10 ppm for all 14 areas considered together. The threshold value for organic stream material varies from 3 ppm U to 303 ppm U with a threshold value of 133 ppm U for all 14 areas considered together. For water, the background concentration varies between the 5 areas from 0.2 ppb U to 0.7 ppb U with a background value of 0.4 ppb U for all 5 areas together. The threshold value varies from 0.3 ppb U to 5.2 ppb U with a threshold value of 2.9 ppb U for all 5 areas together. An investigation of the correlation between uranium concentrations in water and organic stream material from one and the same sampling point shows a positive correlation for high concentrations, but the correlation becomes successively less significant with lower concentrations. Uranium concentrations in organic stream material and water are positively correlated with the following geological parameters:1) Background concentrations of uranium in the bedrock. 2) Abundance of fractures in the bedrock. 3) Leachability of uranium from the bedrock. 4) Presence of uranium mineralisations. For organic stream material, this positive correlation is obtained for both high and low uranium concentrations whereas for water it occurs only with high concentrations. In areas of broken topography and high relief, there is a more clearly defined correlation to the bedrock than in areas of

Informing climate models with rapid chamber measurements of forest carbon uptake.

Science.gov (United States)

Metcalfe, Daniel B; Ricciuto, Daniel; Palmroth, Sari; Campbell, Catherine; Hurry, Vaughan; Mao, Jiafu; Keel, Sonja G; Linder, Sune; Shi, Xiaoying; Näsholm, Torgny; Ohlsson, Klas E A; Blackburn, M; Thornton, Peter E; Oren, Ram

2017-05-01

Models predicting ecosystem carbon dioxide (CO 2 ) exchange under future climate change rely on relatively few real-world tests of their assumptions and outputs. Here, we demonstrate a rapid and cost-effective method to estimate CO 2 exchange from intact vegetation patches under varying atmospheric CO 2 concentrations . We find that net ecosystem CO 2 uptake (NEE) in a boreal forest rose linearly by 4.7 ± 0.2% of the current ambient rate for every 10 ppm CO 2 increase, with no detectable influence of foliar biomass, season, or nitrogen (N) fertilization. The lack of any clear short-term NEE response to fertilization in such an N-limited system is inconsistent with the instantaneous downregulation of photosynthesis formalized in many global models. Incorporating an alternative mechanism with considerable empirical support - diversion of excess carbon to storage compounds - into an existing earth system model brings the model output into closer agreement with our field measurements. A global simulation incorporating this modified model reduces a long-standing mismatch between the modeled and observed seasonal amplitude of atmospheric CO 2 . Wider application of this chamber approach would provide critical data needed to further improve modeled projections of biosphere-atmosphere CO 2 exchange in a changing climate. © 2016 John Wiley & Sons Ltd.

Estimation of suspended sediment concentration by acoustic ...

African Journals Online (AJOL)

concentration of sediments such as glass spheres or sand. However, the acoustic properties of natural sediments vary and depend on many parameters such as particle size, shape, mineralogy and distribution of those parameters in sample. Therefore, this study was conducted to determine the possibility of soil sediment ...

High permeation rates in liposome systems explain rapid glyphosate biodegradation associated with strong isotope fractionation.

Science.gov (United States)

Ehrl, Benno; Mogusu, Emmanuel O; Kim, Kyoungtea; Hofstetter, Heike; Pedersen, Joel A; Elsner, Martin

2018-05-23

Bacterial uptake of charged organic pollutants such as the widely used herbicide glyphosate is typically attributed to active transporters, whereas passive membrane permeation as an uptake pathway is usually neglected. For 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes, pH-dependent membrane permeation coefficients (Papp) of glyphosate, determined by nuclear magnetic resonance (NMR) spectroscopy, varied from Papp(pH 7.0) = 3.7 (+/-0.3) × 10-7 m∙s-1 to Papp(pH 4.1) = 4.2 (+/-0.1) × 10-6 m∙s-1. This surprisingly rapid membrane permeation depended on glyphosate speciation and was, at physiological pH, in the range of polar, non-charged molecules suggesting that passive membrane permeation is a potential uptake pathway during glyphosate biodegradation. To test this hypothesis, a Gram-negative glyphosate degrader, Ochrobactrum sp. FrEM, was isolated from glyphosate-treated soil and glyphosate permeation rates inferred from the liposome model were compared to bacterial degradation rates. Estimated maximum permeation rates were, indeed, two orders of magnitudes higher than glyphosate degradation rates. Moreover, biodegradation of millimolar glyphosate concentrations gave rise to pronounced carbon isotope fractionation with an apparent kinetic isotope effect of AKIEcarbon= 1.014 ± 0.003. This value is consistent with unmasked enzymatic isotope fractionation demonstrating that glyphosate biodegradation was little mass transfer-limited and glyphosate exchange across the cell membrane was rapid relative to enzymatic turnover.

Effects of Zn doping concentration on resistive switching ...

Indian Academy of Sciences (India)

conduction mechanism at low resistance state varies with Zn doping concentration. The dominant .... shows the evolution of RHRS and RLRS in 1000 cycles under a reading voltage of 2 V ... 0.5 exhibited poor fatigue properties. As shown in ...

Calcium Concentration in Culture Medium as a Nondestructive and Rapid Marker of Osteogenesis.

Science.gov (United States)

Tanikake, Yohei; Akahane, Manabu; Furukawa, Akira; Tohma, Yasuaki; Inagaki, Yusuke; Kira, Tsutomu; Tanaka, Yasuhito

2017-06-09

Artificial bones made of β-tricalcium phosphate (β-TCP) combined with bone marrow-derived mesenchymal stromal cells (BM-MSCs) are used for effective reconstruction of bone defects caused by genetic defects, traumatic injury, or surgical resection of bone tumors. However, the selection of constructs with high osteogenic potential before implantation is challenging. The purpose of this study was to determine whether the calcium concentration in BM-MSC culture medium can be used as a nondestructive and simple osteogenic marker for selecting tissue-engineered grafts constructed using β-TCP and BM-MSCs. We prepared three cell passages of BM-MSCs derived from three 7-week-old, male Fischer 344 rats; the cells were cultured in osteoinductive medium in the presence of β-TCP for 15 days. The medium was replaced with fresh medium on day 1 in culture and subsequently changed every 48 h; it was collected for measurement of osteocalcin secretion and calcium concentration by enzyme-linked immunosorbent assay and X-ray fluorescence spectrometry, respectively. After cultivation, the constructs were implanted subcutaneously into the backs of recipient rats. Four weeks after implantation, the alkaline phosphatase (ALP) activity and osteocalcin content of the constructs were measured. A strong inverse correlation was observed between the calcium concentration in the medium and the ALP activity and osteocalcin content of the constructs, with Pearson's correlation coefficients of 0.92 and 0.90, respectively. These results indicate that tissue-engineered bone with high osteogenic ability can be selected before implantation based on low calcium content of the culture medium, resulting in successful bone formation after implantation. This nondestructive, simple method shows great promise for assessing the osteogenic ability of tissue-engineered bone.

Evaluation of cetacean exposure to organotin compounds in Brazilian waters through hepatic total tin concentrations

International Nuclear Information System (INIS)

Dorneles, Paulo R.; Lailson-Brito, Jose; Fernandez, Marcos A.S.; Vidal, Lara G.; Barbosa, Lupercio A.; Azevedo, Alexandre F.; Fragoso, Ana B.L.; Torres, Joao P.M.; Malm, Olaf

2008-01-01

In Brazil, there is no restriction to the use of organotins (OTs). Previous investigations have shown that hepatic ΣSn in cetaceans is predominantly organic. Hepatic ΣSn concentrations were determined by GFAAS in 67 cetaceans (13 species) that stranded on Rio de Janeiro (RJ) and Espirito Santo (ES) states. Concentrations (in ng/g wet wt.) of marine tucuxis (n = 20) from the highly contaminated Guanabara Bay (in RJ) varied from 1703 to 9638. Concentrations of three marine tucuxi foetuses and one newborn calf (all from Guanabara Bay) varied between 431 and 2107. Contrastingly, the maximum level among 19 oceanic dolphins was 346, and 15 out of these 19 specimens presented concentrations below detection limit. The levels of Sn in six marine tucuxis from a less contaminated area (ES) varied from below detection limit to 744. Comparing to the literature, coastal cetaceans from Brazil appear to be highly exposed to OTs. - Cetaceans from Brazil are highly exposed to organotin compounds

Evaluation of cetacean exposure to organotin compounds in Brazilian waters through hepatic total tin concentrations

Energy Technology Data Exchange (ETDEWEB)

Dorneles, Paulo R. [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro (Brazil); Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: dornelespr@gmail.com; Lailson-Brito, Jose [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro (Brazil); Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: lailson@uerj.br; Fernandez, Marcos A.S. [Laboratorio de Oceanografia Quimica, Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: hallfz@uerj.br; Vidal, Lara G. [Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: vidallara@yahoo.com.br; Barbosa, Lupercio A. [Instituto ORCA, Vila Velha, ES (Brazil)], E-mail: lupercio@orca.org.br; Azevedo, Alexandre F. [Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: alexandre.maqua@gmail.com; Fragoso, Ana B.L. [Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: abfragoso@gmail.com; Torres, Joao P.M. [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro (Brazil)], E-mail: jptorres@biof.ufrj.br; Malm, Olaf [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro (Brazil)], E-mail: olaf@biof.ufrj.br

2008-12-15

In Brazil, there is no restriction to the use of organotins (OTs). Previous investigations have shown that hepatic {sigma}Sn in cetaceans is predominantly organic. Hepatic {sigma}Sn concentrations were determined by GFAAS in 67 cetaceans (13 species) that stranded on Rio de Janeiro (RJ) and Espirito Santo (ES) states. Concentrations (in ng/g wet wt.) of marine tucuxis (n = 20) from the highly contaminated Guanabara Bay (in RJ) varied from 1703 to 9638. Concentrations of three marine tucuxi foetuses and one newborn calf (all from Guanabara Bay) varied between 431 and 2107. Contrastingly, the maximum level among 19 oceanic dolphins was 346, and 15 out of these 19 specimens presented concentrations below detection limit. The levels of Sn in six marine tucuxis from a less contaminated area (ES) varied from below detection limit to 744. Comparing to the literature, coastal cetaceans from Brazil appear to be highly exposed to OTs. - Cetaceans from Brazil are highly exposed to organotin compounds.

Comparison of marine dispersion model predictions with environmental radionuclide concentrations

International Nuclear Information System (INIS)

Johnson, C.E.; McKay, W.A.

1988-01-01

The comparison of marine dispersion model results with measurements is an essential part of model development and testing. The results from two residual flow models are compared with seawater concentrations, and in one case with concentrations measured in marine molluscs. For areas with short turnover times, seawater concentrations respond rapidly to variations in discharge rate and marine currents. These variations are difficult to model, and comparison with concentrations in marine animals provides an alternative and complementary technique for model validation with the advantages that the measurements reflect the mean conditions and frequently form a useful time series. (author)

On the dark side of therapies with immunoglobulin concentrates: the adverse events

NARCIS (Netherlands)

Späth, Peter J.; Granata, Guido; La Marra, Fabiola; Kuijpers, Taco W.; Quinti, Isabella

2015-01-01

Therapy by human immunoglobulin G (lgG) concentrates is a success story ongoing for decades with an ever increasing demand for this plasma product. The success of IgG concentrates on a clinical level is documented by the slowly increasing number of registered indication and the more rapid increase

Environmental effects of the Big Rapids dam remnant removal, Big Rapids, Michigan, 2000-02

Science.gov (United States)

Healy, Denis F.; Rheaume, Stephen J.; Simpson, J. Alan

2003-01-01

The U.S. Geological Survey (USGS), in cooperation with the city of Big Rapids, investigated the environmental effects of removal of a dam-foundation remnant and downstream cofferdam from the Muskegon River in Big Rapids, Mich. The USGS applied a multidiscipline approach, which determined the water quality, sediment character, and stream habitat before and after dam removal. Continuous water-quality data and discrete water-quality samples were collected, the movement of suspended and bed sediment were measured, changes in stream habitat were assessed, and streambed elevations were surveyed. Analyses of water upstream and downstream from the dam showed that the dam-foundation remnant did not affect water quality. Dissolved-oxygen concentrations downstream from the dam remnant were depressed for a short period (days) during the beginning of the dam removal, in part because of that removal effort. Sediment transport from July 2000 through March 2002 was 13,800 cubic yards more at the downstream site than the upstream site. This increase in sediment represents the remobilized sediment upstream from the dam, bank erosion when the impoundment was lowered, and contributions from small tributaries between the sites. Five habitat reaches were monitored before and after dam-remnant removal. The reaches consisted of a reference reach (A), upstream from the effects of the impoundment; the impoundment (B); and three sites below the impoundment where habitat changes were expected (C, D, and E, in downstream order). Stream-habitat assessment reaches varied in their responses to the dam-remnant removal. Reference reach A was not affected. In impoundment reach B, Great Lakes and Environmental Assessment Section (GLEAS) Procedure 51 ratings went from fair to excellent. For the three downstream reaches, reach C underwent slight habitat degradation, but ratings remained good; reach D underwent slight habitat degradation with ratings changing from excellent to good; and, in an area

Rapid sensing of l-leucine by human and murine hypothalamic neurons: Neurochemical and mechanistic insights.

Science.gov (United States)

Heeley, Nicholas; Kirwan, Peter; Darwish, Tamana; Arnaud, Marion; Evans, Mark L; Merkle, Florian T; Reimann, Frank; Gribble, Fiona M; Blouet, Clemence

2018-04-01

Dietary proteins are sensed by hypothalamic neurons and strongly influence multiple aspects of metabolic health, including appetite, weight gain, and adiposity. However, little is known about the mechanisms by which hypothalamic neural circuits controlling behavior and metabolism sense protein availability. The aim of this study is to characterize how neurons from the mediobasal hypothalamus respond to a signal of protein availability: the amino acid l-leucine. We used primary cultures of post-weaning murine mediobasal hypothalamic neurons, hypothalamic neurons derived from human induced pluripotent stem cells, and calcium imaging to characterize rapid neuronal responses to physiological changes in extracellular l-Leucine concentration. A neurochemically diverse subset of both mouse and human hypothalamic neurons responded rapidly to l-leucine. Consistent with l-leucine's anorexigenic role, we found that 25% of mouse MBH POMC neurons were activated by l-leucine. 10% of MBH NPY neurons were inhibited by l-leucine, and leucine rapidly reduced AGRP secretion, providing a mechanism for the rapid leucine-induced inhibition of foraging behavior in rodents. Surprisingly, none of the candidate mechanisms previously implicated in hypothalamic leucine sensing (K ATP channels, mTORC1 signaling, amino-acid decarboxylation) were involved in the acute activity changes produced by l-leucine. Instead, our data indicate that leucine-induced neuronal activation involves a plasma membrane Ca 2+ channel, whereas leucine-induced neuronal inhibition is mediated by inhibition of a store-operated Ca 2+ current. A subset of neurons in the mediobasal hypothalamus rapidly respond to physiological changes in extracellular leucine concentration. Leucine can produce both increases and decreases in neuronal Ca 2+ concentrations in a neurochemically-diverse group of neurons, including some POMC and NPY/AGRP neurons. Our data reveal that leucine can signal through novel mechanisms to rapidly

Measurement of gross alpha and gross beta activity concentrations in human tooth

International Nuclear Information System (INIS)

Soeguet, Omer; Aydin, Mehmet Fatih; Kuecuekoender, Erdal; Zorer, Ozlem Selcuk; Dogru, Mahmut

2010-01-01

The gross alpha and gross beta activity concentrations were measured in human tooth taken from 3 to 6 age-groups to 40 and over ones. Accumulated teeth samples are investigated in two groups as under and above 18 years. The gross alpha and beta radioactivity of human tooth samples was measured by using a gas-flow proportional counter (PIC-MPC 9604-α/β counter). In tooth samples, for female age-groups, the obtained results show that the mean gross alpha and gross beta activity concentrations varied between 0.534-0.203 and 0.010-0.453 Bq g -1 and the same concentrations for male age-groups varied between 0.009-1.168 and 0.071-0.204 Bq g -1 , respectively.

Advanced powder metallurgy aluminum alloys via rapid solidification technology

Science.gov (United States)

Ray, R.

1984-01-01

Aluminum alloys containing 10 to 11.5 wt. pct. of iron and 1.5 to 3 wt. pct. of chromium using the technique of rapid solidification powder metallurgy were studied. Alloys were prepared as thin ribbons (.002 inch thick) rapidly solidified at uniform rate of 10(6) C/second by the melt spinning process. The melt spun ribbons were pulverized into powders (-60 to 400 mesh) by a rotating hammer mill. The powders were consolidated by hot extrusion at a high reduction ratio of 50:1. The powder extrusion temperature was varied to determine the range of desirable processing conditions necessary to yield useful properties. Powders and consolidated alloys were characterized by SEM and optical metallography. The consolidated alloys were evaluated for (1) thermal stability, (2) tensile properties in the range, room temperature to 450 F, and (3) notch toughness in the range, room temperature to 450 F.

The Effect of Source Suspended Sediment Concentration on the Sediment Dynamics of a Macrotidal Creek and Salt Marsh

Science.gov (United States)

Poirier, E.; van Proosdij, D.; Milligan, T. G.

2017-12-01

Seasonal variability in the sediment dynamics of a Bay of Fundy tidal creek and salt marsh system was analyzed to better understand the ecomorphodynamics of a high suspended sediment concentration intertidal habitat. Data were collected over 62 tides for velocity, suspended sediment concentration, deposition, and grain size at four stations from the creek thalweg to the marsh surface. Five topographic surveys were also conducted throughout the 14-month study. Deposition rates per tide varied spatially from 56.4 g·m-2 at the creek thalweg to 15.3 g·m-2 at the marsh surface. Seasonal variations in deposition in the creek and marsh surface were from 38.0 g·m-2 to 97.7 g·m-2 and from 12.2 g·m-2 to 19.6 g·m-2 respectively. Deposition and erosion were greatest in late fall and winter. This seasonal change, led by higher suspended sediment concentrations, was observed in the creek and at the marsh bank but notably absent from the marsh edge and marsh surface. Sediments were predominantly deposited in floc form (76-83%). Because of high floc content, higher suspended sediment concentrations led to more rapid loss of sediment from suspension. With increasing sediment concentration, deposition increased in the tidal creek and at the marsh bank but not at the marsh edge or marsh surface. This suggests that in highly flocculated environments the water column clears fast enough that very little sediment remains in suspension when the water reaches the marsh and that the sediment concentration during marsh inundation is independent of the initial concentration in the creek.

A rapid situation assessment of the market for surrogate and illegal alcohols in Tallinn, Estonia.

Science.gov (United States)

Pärna, Kersti; Lang, Katrin; Raju, Kadi; Väli, Marika; McKee, Martin

2007-01-01

To understand the phenomenon of consumption of surrogate and illegal alcohols in Tallinn, capital of Estonia. This study, conducted in Tallinn in May 2006, used rapid situation assessment. Interviews with key informants in relevant settings such as emergency departments of hospitals, accommodation for the homeless, police etc. (n = 22), with alcohol abusers (n = 33), natural observations of surrogate sale and consumption venues (n = 46), and tracking of trade data were carried out. Key informants confirmed that consumption of illegal and surrogate alcohols are widely used by alcohol abusers, a finding confirmed by the alcohol abusers. Availability of surrogates varied by area of the city, mainly sold from street kiosks. Illegally produced spirits were also easily available. Sales of surrogates appear to have increased in recent years. A range of alcohol-containing substances that appear to be easily available at low cost, and that have high concentration of ethanol or contaminants known to be toxic, were identified in Tallinn. Alcohol policies in Estonia should address the consumption and availability of these substances.

Rapid and label-free separation of Burkitt's lymphoma cells from red blood cells by optically-induced electrokinetics.

Directory of Open Access Journals (Sweden)

Wenfeng Liang

Full Text Available Early stage detection of lymphoma cells is invaluable for providing reliable prognosis to patients. However, the purity of lymphoma cells in extracted samples from human patients' marrow is typically low. To address this issue, we report here our work on using optically-induced dielectrophoresis (ODEP force to rapidly purify Raji cells' (a type of Burkitt's lymphoma cell sample from red blood cells (RBCs with a label-free process. This method utilizes dynamically moving virtual electrodes to induce negative ODEP force of varying magnitudes on the Raji cells and RBCs in an optically-induced electrokinetics (OEK chip. Polarization models for the two types of cells that reflect their discriminate electrical properties were established. Then, the cells' differential velocities caused by a specific ODEP force field were obtained by a finite element simulation model, thereby established the theoretical basis that the two types of cells could be separated using an ODEP force field. To ensure that the ODEP force dominated the separation process, a comparison of the ODEP force with other significant electrokinetics forces was conducted using numerical results. Furthermore, the performance of the ODEP-based approach for separating Raji cells from RBCs was experimentally investigated. The results showed that these two types of cells, with different concentration ratios, could be separated rapidly using externally-applied electrical field at a driven frequency of 50 kHz at 20 Vpp. In addition, we have found that in order to facilitate ODEP-based cell separation, Raji cells' adhesion to the OEK chip's substrate should be minimized. This paper also presents our experimental results of finding the appropriate bovine serum albumin concentration in an isotonic solution to reduce cell adhesion, while maintaining suitable medium conductivity for electrokinetics-based cell separation. In short, we have demonstrated that OEK technology could be a promising tool for

Rapid green synthesis of silver nanoparticles and nanorods using Piper nigrum extract

International Nuclear Information System (INIS)

Mohapatra, Bandita; Kuriakose, Sini; Mohapatra, Satyabrata

2015-01-01

Highlights: • Silver nanorods were synthesized by photoreduction using Piper nigrum extract. • The morphological and structural properties were studied by XRD and AFM. • Silver nanoparticles were formed at lower AgNO 3 concentration. • Increase in AgNO 3 concentration resulted in formation of silver nanorods. - Abstract: We report sun light driven rapid green synthesis of stable aqueous dispersions of silver nanoparticles and nanorods at room temperature using photoreduction of silver ions with Piper nigrum extract. Silver nanoparticles were formed within 3 min of sun light irradiation following addition of Piper nigrum extract to the AgNO 3 solution. The effects of AgNO 3 concentration and irradiation time on the formation and plasmonic properties of biosynthesized silver nanoparticles were studied using UV–visible absorption spectroscopy. The morphology and structure of silver nanoparticles were well characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). The size of Ag nanoparticles increased with increase in irradiation time, leading to the formation of anisotropic nanostructures. Increasing the AgNO 3 concentration resulted in the formation of Ag nanorods. UV–visible absorption studies revealed the presence of surface plasmon resonance (SPR) peaks which red shift and broaden with increasing AgNO 3 concentration. We have demonstrated a facile, energy efficient and rapid green synthetic route to synthesize stable aqueous dispersions of silver nanoparticles and nanorods

Rapid green synthesis of silver nanoparticles and nanorods using Piper nigrum extract

Energy Technology Data Exchange (ETDEWEB)

Mohapatra, Bandita [Multifunctional Nanomaterials Laboratory, School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, New Delhi 110078 (India); Kuriakose, Sini [Multifunctional Nanomaterials Laboratory, School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, New Delhi 110078 (India); School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, New Delhi 110078 (India); Mohapatra, Satyabrata, E-mail: smiuac@gmail.com [Multifunctional Nanomaterials Laboratory, School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, New Delhi 110078 (India); School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, New Delhi 110078 (India)

2015-07-15

Highlights: • Silver nanorods were synthesized by photoreduction using Piper nigrum extract. • The morphological and structural properties were studied by XRD and AFM. • Silver nanoparticles were formed at lower AgNO{sub 3} concentration. • Increase in AgNO{sub 3} concentration resulted in formation of silver nanorods. - Abstract: We report sun light driven rapid green synthesis of stable aqueous dispersions of silver nanoparticles and nanorods at room temperature using photoreduction of silver ions with Piper nigrum extract. Silver nanoparticles were formed within 3 min of sun light irradiation following addition of Piper nigrum extract to the AgNO{sub 3} solution. The effects of AgNO{sub 3} concentration and irradiation time on the formation and plasmonic properties of biosynthesized silver nanoparticles were studied using UV–visible absorption spectroscopy. The morphology and structure of silver nanoparticles were well characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). The size of Ag nanoparticles increased with increase in irradiation time, leading to the formation of anisotropic nanostructures. Increasing the AgNO{sub 3} concentration resulted in the formation of Ag nanorods. UV–visible absorption studies revealed the presence of surface plasmon resonance (SPR) peaks which red shift and broaden with increasing AgNO{sub 3} concentration. We have demonstrated a facile, energy efficient and rapid green synthetic route to synthesize stable aqueous dispersions of silver nanoparticles and nanorods.

Degadation of semiconducting polymers by concentrated sunlight

DEFF Research Database (Denmark)

Tromholt, Thomas; Manceau, Matthieu; Petersen, Martin Helgesen

2011-01-01

infra-red spectra of MEH-PPV degraded at 1 sun intensity and at high solar concentration only showed minor deviations in degradation mechanisms. The acceleration factor was found to vary linearly with the solar concentration. Finally, a comparison of the degradation rates at 1 sun and 100 suns...... was carried out in a materials study employing five different conjugated polymers relevant to polymer solar cells for which acceleration factors in the range 19–55 were obtained.......A lens based sunlight concentration setup was used to accelerate the degradation of semiconducting polymers. Sunlight was collected outdoor and focused into an optical fiber bundle allowing for indoor experimental work. Photo-degradation of several polymers was studied by UV–vis absorbance...

Concentration of radiocesium in cultivated mushrooms and substrates

International Nuclear Information System (INIS)

Miyake, Sadaaki; Higasa, Mamoru; Urabe, Ken-ichi; Haraguchi, Masato; Omura, Toshitaka

2008-01-01

Concentrations of 134 Cs, 137 Cs and 40 K in mushrooms cultivated in Saitama prefecture and those substrates were measured by gamma-ray spectrometry. In all mushrooms and substrates, 134 Cs was not detected. Concentrations of 137 Cs in mushrooms were in the range of 0.012 - 2.1 Bq/kg·fresh, and those in substrates were in the range of 0.080 - 1.8 Bq/kg·dry. Concentrations of 137 Cs in mushrooms varied widely with mushroom species, and the average concentration of 137 Cs in Lentinus edodes (Shiitake) was over 30 times higher than that in Pleurotus ostreatus (Hiratake). Mushroom-to-substrate concentration ratios of 137 Cs (fresh/dry) were 0.11-0.53. They were higher than the reported transfer factors for common agricultural plants. (author)

Rapid determination of oxygen saturation and vascularity for cancer detection.

Directory of Open Access Journals (Sweden)

Fangyao Hu

Full Text Available A rapid heuristic ratiometric analysis for estimating tissue hemoglobin concentration and oxygen saturation from measured tissue diffuse reflectance spectra is presented. The analysis was validated in tissue-mimicking phantoms and applied to clinical measurements in head and neck, cervical and breast tissues. The analysis works in two steps. First, a linear equation that translates the ratio of the diffuse reflectance at 584 nm and 545 nm to estimate the tissue hemoglobin concentration using a Monte Carlo-based lookup table was developed. This equation is independent of tissue scattering and oxygen saturation. Second, the oxygen saturation was estimated using non-linear logistic equations that translate the ratio of the diffuse reflectance spectra at 539 nm to 545 nm into the tissue oxygen saturation. Correlations coefficients of 0.89 (0.86, 0.77 (0.71 and 0.69 (0.43 were obtained for the tissue hemoglobin concentration (oxygen saturation values extracted using the full spectral Monte Carlo and the ratiometric analysis, for clinical measurements in head and neck, breast and cervical tissues, respectively. The ratiometric analysis was more than 4000 times faster than the inverse Monte Carlo analysis for estimating tissue hemoglobin concentration and oxygen saturation in simulated phantom experiments. In addition, the discriminatory power of the two analyses was similar. These results show the potential of such empirical tools to rapidly estimate tissue hemoglobin in real-time spectral imaging applications.

Facile Synthesis of Magnetic Mesoporous Hollow Carbon Microspheres for Rapid Capture of Low-Concentration Peptides

OpenAIRE

Cheng, Gong; Zhou, Ming-Da; Zheng, Si-Yang

2014-01-01

Mesoporous and hollow carbon microspheres embedded with magnetic nanoparticles (denoted as MHM) were prepared via a facile self-sacrificial method for rapid capture of low-abundant peptides from complex biological samples. The morphology, structure, surface property, and magnetism were well-characterized. The hollow magnetic carbon microspheres have a saturation magnetization value of 130.2 emu g?1 at room temperature and a Brunauer?Emmett?Teller specific surface area of 48.8 m2 g?1 with an a...

Mecoprop (MCPP) removal in full-scale rapid sand filters at a groundwater-based waterworks

DEFF Research Database (Denmark)

Hedegaard, Mathilde Jørgensen; Arvin, Erik; Corfitzen, Charlotte B.

2014-01-01

and secondary rapid sand filters. Water quality parameters were measured throughout the waterworks, and they behaved as designed for. MCPP was removed in secondary rapid sand filters — removal was the greatest in the sand filters in the filter line with the highest contact time (63min). In these secondary sand...... in the full-scale system. Therefore, microcosms were set up with filter sand, water and 14C-labelled MCPP at an initial concentration of 0.2μg/L. After 24h, 79–86% of the initial concentration of MCPP was removed. Sorption removed 11–15%, while the remaining part was removed by microbial processes, leading...... to a complete mineralisation of 13–18%. Microbial removal in the filter sand was similar at different depths of the rapid sand filter, while the amount of MCPP which adsorbed to the filter sand after 48h decreased with depth from 21% of the initial MCPP in the top layer to 7% in the bottom layer...

Wave scattering by an axisymmetric ice floe of varying thickness

Science.gov (United States)

Bennetts, Luke G.; Biggs, Nicholas R. T.; Porter, David

2009-04-01

The problem of water wave scattering by a circular ice floe, floating in fluid of finite depth, is formulated and solved numerically. Unlike previous investigations of such situations, here we allow the thickness of the floe (and the fluid depth) to vary axisymmetrically and also incorporate a realistic non-zero draught. A numerical approximation to the solution of this problem is obtained to an arbitrary degree of accuracy by combining a Rayleigh-Ritz approximation of the vertical motion with an appropriate variational principle. This numerical solution procedure builds upon the work of Bennets et al. (2007, J. Fluid Mech., 579, 413-443). As part of the numerical formulation, we utilize a Fourier cosine expansion of the azimuthal motion, resulting in a system of ordinary differential equations to solve in the radial coordinate for each azimuthal mode. The displayed results concentrate on the response of the floe rather than the scattered wave field and show that the effects of introducing the new features of varying floe thickness and a realistic draught are significant.

Augmented brain function by coordinated reset stimulation with slowly varying sequences

Directory of Open Access Journals (Sweden)

Magteld eZeitler

2015-03-01

Full Text Available Several brain disorders are characterized by abnormally strong neuronal synchrony. Coordinated Reset (CR stimulation was developed to selectively counteract abnormal neuronal synchrony by desynchronization. For this, phase resetting stimuli are delivered to different subpopulations in a timely coordinated way. In neural networks with spike timing-dependent plasticity CR stimulation may eventually lead to an anti-kindling, i.e. an unlearning of abnormal synaptic connectivity and abnormal synchrony. The spatiotemporal sequence by which all stimulation sites are stimulated exactly once is called the stimulation site sequence, or briefly sequence. So far, in simulations, pre-clinical and clinical applications CR was applied either with fixed sequences or rapidly varying sequences (RVS. In this computational study we show that appropriate repetition of the sequence with occasional random switching to the next sequence may significantly improve the anti-kindling effect of CR. To this end, a sequence is applied many times before randomly switching to the next sequence. This new method is called SVS CR stimulation, i.e. CR with slowly varying sequences. In a neuronal network with strong short-range excitatory and weak long-range inhibitory dynamic couplings SVS CR stimulation turns out to be superior to CR stimulation with fixed sequences or RVS.

Augmented brain function by coordinated reset stimulation with slowly varying sequences.

Science.gov (United States)

Zeitler, Magteld; Tass, Peter A

2015-01-01

Several brain disorders are characterized by abnormally strong neuronal synchrony. Coordinated Reset (CR) stimulation was developed to selectively counteract abnormal neuronal synchrony by desynchronization. For this, phase resetting stimuli are delivered to different subpopulations in a timely coordinated way. In neural networks with spike timing-dependent plasticity CR stimulation may eventually lead to an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and abnormal synchrony. The spatiotemporal sequence by which all stimulation sites are stimulated exactly once is called the stimulation site sequence, or briefly sequence. So far, in simulations, pre-clinical and clinical applications CR was applied either with fixed sequences or rapidly varying sequences (RVS). In this computational study we show that appropriate repetition of the sequence with occasional random switching to the next sequence may significantly improve the anti-kindling effect of CR. To this end, a sequence is applied many times before randomly switching to the next sequence. This new method is called SVS CR stimulation, i.e., CR with slowly varying sequences. In a neuronal network with strong short-range excitatory and weak long-range inhibitory dynamic couplings SVS CR stimulation turns out to be superior to CR stimulation with fixed sequences or RVS.

Time-varying parameter models for catchments with land use change: the importance of model structure

Science.gov (United States)

Pathiraja, Sahani; Anghileri, Daniela; Burlando, Paolo; Sharma, Ashish; Marshall, Lucy; Moradkhani, Hamid

2018-05-01

Rapid population and economic growth in Southeast Asia has been accompanied by extensive land use change with consequent impacts on catchment hydrology. Modeling methodologies capable of handling changing land use conditions are therefore becoming ever more important and are receiving increasing attention from hydrologists. A recently developed data-assimilation-based framework that allows model parameters to vary through time in response to signals of change in observations is considered for a medium-sized catchment (2880 km2) in northern Vietnam experiencing substantial but gradual land cover change. We investigate the efficacy of the method as well as the importance of the chosen model structure in ensuring the success of a time-varying parameter method. The method was used with two lumped daily conceptual models (HBV and HyMOD) that gave good-quality streamflow predictions during pre-change conditions. Although both time-varying parameter models gave improved streamflow predictions under changed conditions compared to the time-invariant parameter model, persistent biases for low flows were apparent in the HyMOD case. It was found that HyMOD was not suited to representing the modified baseflow conditions, resulting in extreme and unrealistic time-varying parameter estimates. This work shows that the chosen model can be critical for ensuring the time-varying parameter framework successfully models streamflow under changing land cover conditions. It can also be used to determine whether land cover changes (and not just meteorological factors) contribute to the observed hydrologic changes in retrospective studies where the lack of a paired control catchment precludes such an assessment.

Time-varying parameter models for catchments with land use change: the importance of model structure

Directory of Open Access Journals (Sweden)

S. Pathiraja

2018-05-01

Full Text Available Rapid population and economic growth in Southeast Asia has been accompanied by extensive land use change with consequent impacts on catchment hydrology. Modeling methodologies capable of handling changing land use conditions are therefore becoming ever more important and are receiving increasing attention from hydrologists. A recently developed data-assimilation-based framework that allows model parameters to vary through time in response to signals of change in observations is considered for a medium-sized catchment (2880 km2 in northern Vietnam experiencing substantial but gradual land cover change. We investigate the efficacy of the method as well as the importance of the chosen model structure in ensuring the success of a time-varying parameter method. The method was used with two lumped daily conceptual models (HBV and HyMOD that gave good-quality streamflow predictions during pre-change conditions. Although both time-varying parameter models gave improved streamflow predictions under changed conditions compared to the time-invariant parameter model, persistent biases for low flows were apparent in the HyMOD case. It was found that HyMOD was not suited to representing the modified baseflow conditions, resulting in extreme and unrealistic time-varying parameter estimates. This work shows that the chosen model can be critical for ensuring the time-varying parameter framework successfully models streamflow under changing land cover conditions. It can also be used to determine whether land cover changes (and not just meteorological factors contribute to the observed hydrologic changes in retrospective studies where the lack of a paired control catchment precludes such an assessment.

An in situ study of growth of Lemongrass Cymbopogon flexuosus (Nees ex Steud.) W. Watson on varying concentration of Chromium (Cr+6) on soil and its bioaccumulation: Perspectives on phytoremediation potential and phytostabilisation of chromium toxicity.

Science.gov (United States)

Patra, Deepak Kumar; Pradhan, Chinmay; Patra, Hemanta Kumar

2018-02-01

Chromium (Cr) contamination in soil is a growing concern in sustainable agricultural production and food safety. Remediation of Cr from contaminated soils is a challenging task which may not only help in sustaining agriculture but also in minimizing adverse environmental impacts. Pot culture experiments were performed with the application of varied concentration of Cr +6 to assess the Chromium accumulation potential of Lemongrass and to study the impact of toxic concentration of Cr +6 on morphological, physiological and biochemical parameters of the plant. The results showed an increasing accumulation trend of Chromium with increasing Chromium concentrations in both root and shoot of 60 days old Lemongrass plants, while the protein and chlorophyll contents decreased. Similarly, accumulation of Cr increased the levels of proline and antioxidant enzymes indicating the enhanced damage control activity. The potentiality of the plant with the capacity to accumulate and stabilize Cr compound in Cr contaminated soil by phytoremediation process has been explored in the present investigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Holographic cinematography of time-varying reflecting and time-varying phase objects using a Nd:YAG laser

Science.gov (United States)

Decker, A. J.

1982-01-01

The use of a Nd:YAG laser to record holographic motion pictures of time-varying reflecting objects and time-varying phase objects is discussed. Sample frames from both types of holographic motion pictures are presented. The holographic system discussed is intended for three-dimensional flow visualization of the time-varying flows that occur in jet-engine components.

Radiometers for radon concentration in air

International Nuclear Information System (INIS)

Bartak, J.; Machaj, B.; Pienkos, J.P.

2002-01-01

Constant grow of science and technology stimulates development of new improved measuring tools. New measuring demand arise also in radon concentration measurements. Varying rock stress and rock cracks influencing radon emanation encouraged research aimed at use of this phenomenon to predict crumps of mine formation among others based on variation of radon emanation. A measuring set was developed in the Institute of Nuclear Chemistry and Technology enabling long term monitoring of radon concentration in mine bore-hole. The set consists probe and probe controller. Detection threshold of the probe is 230 Bq/m 3 . The set can operate in the environment with methane explosion hazard. A radiometer employing Lucas cell as radiation detector for radon concentration in air was also developed its detection threshold is approx. 10 Bq/m 3 . Replaceable Lucas cell of the radiometer allows for measurement of high as well as low radon concentration in short time interval. (author)

The effects of varying concentrations of growth regulators benzyladenine and naphthalene acetic acid and gamma irradiation on the gross plantlet morphology of Garcinia mangostana L

International Nuclear Information System (INIS)

Bonsol, Ma. Fatima Nona M.; Lasiste, Jade Marie Edenvirg F.; Quinio, Ma. Franchesca S.

2004-02-01

Mangosteen (Garcinia mangostana L.) is regarded as one of the best flavored fruits in the world. Though this fruit yields high income and has great potential as an export, productivity in the Philippines is still limited due to its slow and difficult conventional propagation. To increase the plants' productivity, growth regulators can be added, the seeds can be exposed to irradiation to cause genetic mutations, and micropropagation techniques can be used. This study seeks to determine the effects of these three variables on the general morphological characteristics of the plantlets grown both in vitro and in vivo. The first set of mangosteen seeds was inoculated and grown in Murashige and Skoog (MS) basal culture medium with different treatment combinations of growth regulators, naphthalene acetic acid (NAA) and benzyladenine (BA). Treatment concentrations ranged from 0 parts per million (ppm) to 6 ppm. The treatment that best induced stem, leaf and root formation, and produced plantlets with long stems and roots was MS with 6 ppm NAA combined with 6 ppm BA. A second set of seeds was then exposed to varying levels of gamma radiation and propagated in vivo and in vitro. For in vivo, it was observed that the length of stem of the plantlet decreases with increasing radiation dose; length of leaves of the mangosteen plantlets was best noted in seeds exposed to 10 Gy gamma rays. In in vitro, the two treatment concentrations that best helped seeds to develop callus, which were 0 ppm BA with 4 pmm NAA and 4 ppm BA with 6 ppm NAA, were added to MS basal medium. Seeds exposed to 5 Gy and grown in basal medium with 0 ppm BA and 4 ppm NAA were observed to have developed the most callus. (Author)

Time-varying BRDFs.

Science.gov (United States)

Sun, Bo; Sunkavalli, Kalyan; Ramamoorthi, Ravi; Belhumeur, Peter N; Nayar, Shree K

2007-01-01

The properties of virtually all real-world materials change with time, causing their bidirectional reflectance distribution functions (BRDFs) to be time varying. However, none of the existing BRDF models and databases take time variation into consideration; they represent the appearance of a material at a single time instance. In this paper, we address the acquisition, analysis, modeling, and rendering of a wide range of time-varying BRDFs (TVBRDFs). We have developed an acquisition system that is capable of sampling a material's BRDF at multiple time instances, with each time sample acquired within 36 sec. We have used this acquisition system to measure the BRDFs of a wide range of time-varying phenomena, which include the drying of various types of paints (watercolor, spray, and oil), the drying of wet rough surfaces (cement, plaster, and fabrics), the accumulation of dusts (household and joint compound) on surfaces, and the melting of materials (chocolate). Analytic BRDF functions are fit to these measurements and the model parameters' variations with time are analyzed. Each category exhibits interesting and sometimes nonintuitive parameter trends. These parameter trends are then used to develop analytic TVBRDF models. The analytic TVBRDF models enable us to apply effects such as paint drying and dust accumulation to arbitrary surfaces and novel materials.

Monthly variation in faeces:blood concentration ratio of persistent organic pollutants over the first year of life: a case study of one infant

Energy Technology Data Exchange (ETDEWEB)

Chen, Yiqin, E-mail: y.chen16@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Australia); McLachlan, Michael S. [Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University (Sweden); Kaserzon, Sarit; Wang, Xianyu; Weijs, Liesbeth; Gallen, Michael [The University of Queensland, National Research Centre for Environmental Toxicology (Australia); Toms, Leisa-Maree L. [School of Public Health and Social Work and Institute of Health and Biomedical Innovation, Faculty of Health, Queensland University of Technology (Australia); Li, Yan [The University of Queensland, National Research Centre for Environmental Toxicology (Australia); Aylward, Lesa L. [The University of Queensland, National Research Centre for Environmental Toxicology (Australia); Summit Toxicology, LLP, Falls Church, VA (United States); Sly, Peter D. [Children’s Health and Environment Program, Queensland Children’s Medical Research Institute, Brisbane (Australia); Child Health Research Centre, The University of Queensland (Australia); Mueller, Jochen F. [The University of Queensland, National Research Centre for Environmental Toxicology (Australia)

2016-05-15

Previous studies have found that the concentrations of a range of persistent organic pollutants (POPs) in faeces is linearly proportional to the POP concentrations in blood of human adults irrespective of age and gender. In order to investigate the correlation between POP concentrations in faeces and blood in infants, the monthly variation of POP concentrations in faeces over the first year of life of one infant was investigated in this study and compared to modelled blood concentrations. Faecal samples were collected from one male infant daily. The samples were pooled by month and analysed for three selected POPs (2,2{sup ′},4,4{sup ′},5,5{sup ′}-Hexachlorobiphenyl (PCB153), p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and 2,2{sup ′},4,4′-tetrabromodiphenyl ether (BDE47)). The POP concentrations in faecal samples increased for the first four months by a factor of 2.9, 4.9 and 1.4 for PCB153, BDE47, and p,p′-DDE, respectively. The faecal concentrations of all POPs decreased rapidly following the introduction of formula and solid food to the diet and subsequent weaning of the infant. Further, a one-compartment model was developed to estimate the daily POP concentrations in the blood of the infant. The POP concentrations in blood were predicted to vary much less over the first year than those observed in faeces. The faeces:blood concentration ratio of selected POPs (K{sub fb}) differed significantly (P<0.0001) between the period before and after weaning, and observed changes in K{sub fb} are far greater than the uncertainty in the estimated K{sub fb}. A more stable K{sub fb} after weaning indicates the possibility of applying the stable K{sub fb} values for non-invasive assessment of internal exposure in infants after weaning. The intra-individual variation in K{sub fb} in infants is worthy of further investigation. - Highlights: • Measured POPs concentrations in faecal samples decreased rapidly following weaning. • Ratio of faecal

Rapid characterization of superconducting wires and tapes in strong pulsed magnetic fields

International Nuclear Information System (INIS)

Bockstal, L. van; Keyser, A. de; Deschagt, J.; Hopkins, S.C.; Glowacki, B.A.

2007-01-01

A new measurement system for rapid characterization of superconducting wires and tapes is developed. The CryoPulse-BI is a system to provide a direct measurement of critical material parameters for superconducting materials when high long pulsed magnetic fields and strong currents are applied. In the experiments, synchronized magnetic fields up to 30 T and current pulses up to 5 kA are generated with adjustable timing. Varying the magnetic field strength, the current through the sample and the BI timing allows for a thorough characterization of the sample and the determination of critical currents. The rapid cycle time of the experiments yields a rapid and thorough determination of the critical parameters. The method has been tested on low T c as well as high T c materials with the field parallel or perpendicular to the current. The discussion covers the current state of the art including a comparison of our results to classical DC characterization measurements

Varying coefficients model with measurement error.

Science.gov (United States)

Li, Liang; Greene, Tom

2008-06-01

We propose a semiparametric partially varying coefficient model to study the relationship between serum creatinine concentration and the glomerular filtration rate (GFR) among kidney donors and patients with chronic kidney disease. A regression model is used to relate serum creatinine to GFR and demographic factors in which coefficient of GFR is expressed as a function of age to allow its effect to be age dependent. GFR measurements obtained from the clearance of a radioactively labeled isotope are assumed to be a surrogate for the true GFR, with the relationship between measured and true GFR expressed using an additive error model. We use locally corrected score equations to estimate parameters and coefficient functions, and propose an expected generalized cross-validation (EGCV) method to select the kernel bandwidth. The performance of the proposed methods, which avoid distributional assumptions on the true GFR and residuals, is investigated by simulation. Accounting for measurement error using the proposed model reduced apparent inconsistencies in the relationship between serum creatinine and GFR among different clinical data sets derived from kidney donor and chronic kidney disease source populations.

Effects of different NaCl Concentrations on germination and ...

African Journals Online (AJOL)

USER

Salinity refers to the salt content of any given system. By nature, arid .... Effect of varying concentrations of NaCl on seed germination of Amaranthus hybridus in percentages. .... Osmotic differences could explain this phenomenon where by ...

Stress concentration effects in high pressure components

International Nuclear Information System (INIS)

Aller, J.E.

1990-01-01

This paper examines the stress concentration effects of sideholes in thick walled, high pressure cylinders. It has been shown that the theoretical stress concentration factor at the intersection of a small crossbore in a closed end, thick walled cylinder varies between 3.0 and 4.0. Tests have shown that this effect can be greatly reduced in practice by carefully radiusing the bore intersection and autofrettaging the cylinder. It has also been shown that the minimum stress concentration factor occurs when the main bore and sidehole or crossbore have the same diameter, and the radius of the intersection is approximately equal to the sidehole radius. When the bore and sidehole intersection angle decreases from 90 degrees, the stress concentration factor increases significantly. Knowledge of these fundamental relationships can be used in maintaining, as well ad designing, high pressure equipment

Rapid, Sensitive and Validated Ultra-Performance Liquid Chromatography/Mass Spectrometric Method for the Determination of Fenofibric Acid and its Application to Human Pharmacokinetic Study

Directory of Open Access Journals (Sweden)

Sunil K. Dubey

2010-01-01

Full Text Available The first, rapid and sensitive ultra performance liquid chromatography mass spectrometric method for the determination of fenofibric acid, the active metabolite of fenofibrate, a lipid regulating agent, in human EDTA plasma has been developed and validated using fenofibric d6 acid as internal standard and Waters LC-MS/MS. Negative ions of fenofibric acid and fenofibric d6 acid were detected in multiple reaction-monitoring (MRM mode. The method was validated over a concentration range of 0.176 μg/mL to 19.837 μg/mL (r ≥ 0.99. It took only 1.5 minute to analyse a sample. Intra- and inter-run precision of fenofibric acid assay at four concentrations ranged from 0.5% to 4.3% with accuracy varied from 93.1 to 108.1% indicating good precision and accuracy. Analytical recoveries of fenofibric acid and internal standard in plasma were less than 90%. This method was successfully applied for evaluation of pharmacokinetics of fenofibric acid after a single oral dose of 145 mg fenofibrate to 10 Indian healthy volunteers

Hydroxyisohexyl 3-cyclohexene carboxaldehyde (lyral) in patch test preparations under varied storage conditions.

Science.gov (United States)

Hamann, Dathan; Hamann, Carsten R; Zimerson, Erik; Bruze, Magnus

2013-01-01

The common practice of preparing patch tests in advance has recently been called into question by researchers. It has been established that fragrance compounds are volatile and their testing efficacy may be affected by storage conditions and preparation. Allergens in fragrance mix I rapidly decrease in concentration after preapplication to test chambers. This study aimed to investigate the volatility of hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) in petrolatum when stored in test chambers and to explore the correlation between vapor pressure and allergen loss in petrolatum during preparation and storage. Standardized HICC in petrolatum was prepared and stored in IQ Chambers and Finn Chambers with covers at 5°C, 25°C, and 35°C, and concentration was analyzed at intervals for up to 9 days using gel permeation chromatography. Changes in HICC concentrations were not statistically significant at 8 hours at 5°C, 25°C, and 35°C. After 9 days, HICC concentrations were found to fall approximately 30% when stored at 35°C, 10% at 25°C, and less than 5% at 5°C. There was no significant difference between IQ and Finn chambers. Hydroxyisohexyl 3-cyclohexene carboxaldehyde concentrations are more stable in petrolatum than many other studied fragrance allergens, but HICC is still at risk for decreasing concentration when exposed to ambient air or heat for prolonged periods.

Dislocation behavior of surface-oxygen-concentration controlled Si wafers

International Nuclear Information System (INIS)

Asazu, Hirotada; Takeuchi, Shotaro; Sannai, Hiroya; Sudo, Haruo; Araki, Koji; Nakamura, Yoshiaki; Izunome, Koji; Sakai, Akira

2014-01-01

We have investigated dislocation behavior in the surface area of surface-oxygen-concentration controlled Si wafers treated by a high temperature rapid thermal oxidation (HT-RTO). The HT-RTO process allows us to precisely control the interstitial oxygen concentration ([O i ]) in the surface area of the Si wafers. Sizes of rosette patterns, generated by nano-indentation and subsequent thermal annealing at 900 °C for 1 h, were measured for the Si wafers with various [O i ]. It was found that the rosette size decreases in proportion to the − 0.25 power of [O i ] in the surface area of the Si wafers, which were higher than [O i ] of 1 × 10 17 atoms/cm 3 . On the other hand, [O i ] of lower than 1 × 10 17 atoms/cm 3 did not affect the rosette size very much. These experimental results demonstrate the ability of the HT-RTO process to suppress the dislocation movements in the surface area of the Si wafer. - Highlights: • Surface-oxygen-concentration controlled Si wafers have been made. • The oxygen concentration was controlled by high temperature rapid thermal oxidation. • Dislocation behavior in the surface area of the Si wafers has been investigated. • Rosette size decreased with increasing of interstitial oxygen atoms. • The interstitial oxygen atoms have a pinning effect of dislocations at the surface

Gas Exchange Characteristics in Tectona grandis L. Clones under Varying Concentrations of CO2 Levels

Directory of Open Access Journals (Sweden)

S. Saravanan

2014-08-01

Full Text Available The Institute of Forest Genetics and Tree Breeding, Coimbatore, India functioning under the Indian Council of Forestry Research and Education, Dehara Dun, has a long term systematic tree improvement program for Tectona grandis aimed to enhancing productivity and screening of clones for site specific. In the process, twenty clones of T. grandis L. were studied for the physiological parameters and water use efficiency with reference to the elevated CO2 levels. CO2 enrichment studies in special chambers help in understanding the changes at individual level, and also at physiological, biochemical and genetic level. It also provides valuable information for establishing plantations at different geographic locations. Considerable variations were observed when the selected 20 clones of T. grandis were subjected to physiological studies under elevated CO2 conditions (600 and 900 mol mol-1. Eight clones exhibited superior growth coupled with favorable physiological characteristics including high photosynthetic rate, carboxylation and water use efficiency under elevated CO2 levels. Clones with minimal variation in physiological characteristics under elevated levels of CO2 suggest their ability to overcome physiological stresses and adapt to varying climatic conditions.

Rapid measurement of meat spoilage using fluorescence spectroscopy

Science.gov (United States)

Wu, Binlin; Dahlberg, Kevin; Gao, Xin; Smith, Jason; Bailin, Jacob

2017-02-01

Food spoilage is mainly caused by microorganisms, such as bacteria. In this study, we measure the autofluorescence in meat samples longitudinally over a week in an attempt to develop a method to rapidly detect meat spoilage using fluorescence spectroscopy. Meat food is a biological tissue, which contains intrinsic fluorophores, such as tryptophan, collagen, nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) etc. As meat spoils, it undergoes various morphological and chemical changes. The concentrations of the native fluorophores present in a sample may change. In particular, the changes in NADH and FAD are associated with microbial metabolism, which is the most important process of the bacteria in food spoilage. Such changes may be revealed by fluorescence spectroscopy and used to indicate the status of meat spoilage. Therefore, such native fluorophores may be unique, reliable and nonsubjective indicators for detection of spoiled meat. The results of the study show that the relative concentrations of all above fluorophores change as the meat samples kept in room temperature ( 19° C) spoil. The changes become more rapidly after about two days. For the meat samples kept in a freezer ( -12° C), the changes are much less or even unnoticeable over a-week-long storage.

Ownership Concentration and Market Value of European Banks

DEFF Research Database (Denmark)

Busta, Ildura; Sinani, Evis; Thomsen, Steen

2014-01-01

This paper investigates the relationship between ownership concentration and market value of European banks, and the role of the institutional environment in shaping this relationship. Using GMM dynamic estimator on a sample of European banks over a 13-year period (1993–2005) we find on average...... concentration is positive in Scandinavia. We propose that, besides the legal protection of small investors, the differences in the impact of ownership concentration across the countries could be due to the identity of the predominant owners, i.e. financial institutions in Germany and trusts and foundations...... a negative effect of ownership concentration on bank value, measured by Tobin's Q. However, this effect varies across different institutional settings; while higher ownership concentration results in a lower bank value particularly in the countries belonging to German legal family, the impact of ownership...

Rapid Analysis of Eukaryotic Bioluminescence to Assess Potential Groundwater Contamination Events

Directory of Open Access Journals (Sweden)

Zacariah L. Hildenbrand

2015-01-01

Full Text Available Here we present data using a bioluminescent dinoflagellate, Pyrocystis lunula, in a toxicological bioassay to rapidly assess potential instances of groundwater contamination associated with natural gas extraction. P. lunula bioluminescence can be quantified using spectrophotometry as a measurement of organismal viability, with normal bioluminescent output declining with increasing concentration(s of aqueous toxicants. Glutaraldehyde and hydrochloric acid (HCl, components used in hydraulic fracturing and shale acidization, triggered significant toxicological responses in as little as 4 h. Conversely, P. lunula was not affected by the presence of arsenic, selenium, barium, and strontium, naturally occurring heavy metal ions potentially associated with unconventional drilling activities. If exogenous compounds, such as glutaraldehyde and HCl, are thought to have been introduced into groundwater, quantification of P. lunula bioluminescence after exposure to water samples can serve as a cost-effective detection and risk assessment tool to rapidly assess the impact of putative contamination events attributed to unconventional drilling activity.

Self-assembly of concentric quantum double rings.

Science.gov (United States)

Mano, Takaaki; Kuroda, Takashi; Sanguinetti, Stefano; Ochiai, Tetsuyuki; Tateno, Takahiro; Kim, Jongsu; Noda, Takeshi; Kawabe, Mitsuo; Sakoda, Kazuaki; Kido, Giyuu; Koguchi, Nobuyuki

2005-03-01

We demonstrate the self-assembled formation of concentric quantum double rings with high uniformity and excellent rotational symmetry using the droplet epitaxy technique. Varying the growth process conditions can control each ring's size. Photoluminescence spectra emitted from an individual quantum ring complex show peculiar quantized levels that are specified by the carriers' orbital trajectories.

Energy Flow and Rapidity Gaps Between Jets in Photoproduction at HERA

CERN Document Server

Adloff, C.; Andrieu, B.; Anthonis, T.; Arkadov, V.; Astvatsatourov, A.; Babaev, A.; Bahr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bate, P.; Becker, J.; Beglarian, A.; Behnke, O.; Beier, C.; Belousov, A.; Benisch, T.; Berger, C.; Berndt, T.; Bizot, J.C.; Boehme, J.; Boudry, V.; Braunschweig, W.; Brisson, V.; Broker, H.B.; Brown, D.P.; Bruckner, W.; Bruncko, D.; Burger, J.; Busser, F.W.; Bunyatyan, A.; Burrage, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cao, Jun; Caron, S.; Cassol-Brunner, F.; Clarke, D.; Collard, C.; Contreras, J.G.; Coppens, Y.R.; Coughlan, J.A.; Cousinou, M.C.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; Davidsson, M.; Delcourt, B.; Delerue, N.; Demirchyan, R.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dingfelder, J.; Dixon, P.; Dodonov, V.; Dowell, J.D.; Droutskoi, A.; Dubak, A.; Duprel, C.; Eckerlin, Guenter; Eckstein, D.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Ferron, S.; Fleischer, M.; Fleming, Y.H.; Flugge, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Franke, G.; Gabathuler, E.; Gabathuler, K.; Garvey, J.; Gassner, J.; Gayler, Joerg; Gerhards, R.; Gerlich, C.; Ghazaryan, Samvel; Goerlich, L.; Gogitidze, N.; Grab, C.; Grassler, H.; Greenshaw, T.; Grindhammer, Guenter; Hadig, T.; Haidt, D.; Hajduk, L.; Haller, J.; Haynes, W.J.; Heinemann, B.; Heinzelmann, G.; Henderson, R.C.W.; Hengstmann, S.; Henschel, H.; Heremans, R.; Herrera, G.; Herynek, I.; Hildebrandt, M.; Hilgers, M.; Hiller, K.H.; Hladky, J.; Hoting, P.; Hoffmann, D.; Horisberger, R.; Hurling, S.; Ibbotson, M.; Issever, C .; Jacquet, M.; Jaffre, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, C.; Johnson, D.P.; Jones, M.A.S.; Jung, H.; Kant, D.; Kapichine, M.; Karlsson, M.; Karschnick, O.; Keil, F.; Keller, N.; Kennedy, J.; Kenyon, I.R.; Kermiche, S.; Kiesling, Christian M.; Kjellberg, P.; Klein, M.; Kleinwort, C.; Kluge, T.; Knies, G.; Koblitz, B.; Kolya, S.D.; Korbel, V.; Kostka, P.; Kotelnikov, S.K.; Koutouev, R.; Koutov, A.; Krehbiel, H.; Kroseberg, J.; Kruger, K.; Kupper, A.; Kuhr, T.; Kurca, T.; Lamb, D.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Laycock, P.; Lebailly, E.; Lebedev, A.; Leissner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; Lindstroem, M.; List, B.; Lobodzinska, E.; Lobodzinski, B.; Loginov, A.; Loktionova, N.; Lubimov, V.; Luders, S.; Luke, D.; Lytkin, L.; Mahlke-Kruger, H.; Malden, N.; Malinovski, E.; Malinovski, I.; Maracek, R.; Marage, P.; Marks, J.; Marshall, R.; Martyn, H.U.; Martyniak, J.; Maxfield, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Meyer, P.O.; Mikocki, S.; Milstead, D.; Mkrtchyan, T.; Mohr, R.; Mohrdieck, S.; Mondragon, M.N.; Moreau, F.; Morozov, A.; Morris, J.V.; Muller, K.; Murin, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, T.; Nellen, G.; Newman, Paul R.; Nicholls, T.C.; Niebergall, F.; Niebuhr, C.; Nix, O.; Nowak, G.; Olsson, J.E.; Ozerov, D.; Panassik, V.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Phillips, J.P.; Pitzl, D.; Poschl, R.; Potachnikova, I.; Povh, B.; Radel, G.; Rauschenberger, J.; Reimer, P.; Reisert, B.; Reyna, D.; Risler, C.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rusakov, S.; Rybicki, K.; Sankey, D.P.C.; Schatzel, S.; Scheins, J.; Schilling, F.P.; Schleper, P.; Schmidt, D.; Schmidt, S.; Schmitt, S.; Schneider, M.; Schoeffel, L.; Schoning, A.; Schorner, T.; Schroder, V.; Schultz-Coulon, H.C.; Schwanenberger, C.; Sedlak, K.; Sefkow, F.; Chekelian, V.; Sheviakov, I.; Shtarkov, L.N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Spitzer, H.; Stamen, R.; Stella, B.; Stiewe, J.; Straumann, U.; Swart, M.; Tasevsky, M.; Tchetchelnitski, S.; Thompson, Graham; Thompson, P.D.; Tobien, N.; Traynor, D.; Truoel, Peter; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Turney, J.E.; Tzamariudaki, E.; Udluft, S.; Urban, Marcel; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vassiliev, S.; Vazdik, Y.; Vichnevski, A.; Wacker, K.; Wagner, J.; Wallny, R.; Waugh, B.; Weber, G.; Weber, M.; Wegener, D.; Werner, C.; Werner, M.; Werner, N.; Wessels, M.; White, G.; Wiesand, S.; Wilksen, T.; Winde, M.; Winter, G.G.; Wissing, C.; Wobisch, M.; Woehrling, E.E.; Wunsch, E.; Wyatt, A.C.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zomer, F.; zur Nedden, M.

2002-01-01

Dijet events in photon-proton collisions in which there is a large pseudorapidity separation Delta eta > 2.5 between the two highest E_T jets are studied with the H1 detector at HERA. The inclusive dijet cross sections are measured as functions of the longitudinal momentum fractions of the proton and photon which participate in the production of the jets, x_pjet and x_gjet respectively, Delta eta, the pseudorapidity separation between the two highest E_T jets, and E_T^gap, the total summed transverse energy between the jets. Rapidity gap events are defined as events in which E_T^gap is less than E_T^cut, for E_T^cut varied between 0.5 and 2.0 GeV. The fraction of dijet events with a rapidity gap is measured differentially in Delta eta, x_pjet and x_gjet. An excess of events with rapidity gaps at low values of E_T^cut is observed above the expectation from standard photoproduction processes. This excess can be explained by the exchange of a strongly interacting colour singlet object between the jets.

Microbial degradation of pesticides in rapid sand filters used for drinking water treatment

DEFF Research Database (Denmark)

Hedegaard, Mathilde Jørgensen

significantly with the maximum methane concentration in the raw water and did not correlate with other water quality parameters, such as the ammonium concentration. Furthermore, the connection between bentazone degradation and methane oxidation in filter sand was demonstrated by inhibition experiments, in which...... sustainable methods to remove pesticides from polluted water sources. Aeration of anaerobic groundwater, followed by biological rapid sand filtration is a widespread technology in drinking water treatment. Even though these systems are not designed for removal of trace contaminants, they have shown potential...... for microbial degradation of pesticides and their degradation products. If pesticides can be removed in rapid sand filters, it is of large commercial interest due to the importance in maintaining a simple, sustainable water treatment. To take advantage of the microbial pesticide degradation and identify...

Nutritive evaluation of Telfairia occidentalis leaf protein concentrate ...

African Journals Online (AJOL)

Leaf meal (LM), leaf proteins concentrate (LPC) and LPC residues from Telfairia occidentalis were produced, chemically characterized and the protein quality of the LPC evaluated using rats. Five infant weaning foods were formulated using varying combinations of T. occidentalis LPC and soybean meal. These foods were ...

Selection of antibiotic resistance at very low antibiotic concentrations

OpenAIRE

Sandegren, Linus

2014-01-01

Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic varies in different body compartments during treatment, and low concentrations of antibiotics are fou...

Assessing Methods for Mapping 2D Field Concentrations of CO2 Over Large Spatial Areas for Monitoring Time Varying Fluctuations

Science.gov (United States)

Zaccheo, T. S.; Pernini, T.; Botos, C.; Dobler, J. T.; Blume, N.; Braun, M.; Levine, Z. H.; Pintar, A. L.

2014-12-01

This work presents a methodology for constructing 2D estimates of CO2 field concentrations from integrated open path measurements of CO2 concentrations. It provides a description of the methodology, an assessment based on simulated data and results from preliminary field trials. The Greenhouse gas Laser Imaging Tomography Experiment (GreenLITE) system, currently under development by Exelis and AER, consists of a set of laser-based transceivers and a number of retro-reflectors coupled with a cloud-based compute environment to enable real-time monitoring of integrated CO2 path concentrations, and provides 2D maps of estimated concentrations over an extended area of interest. The GreenLITE transceiver-reflector pairs provide laser absorption spectroscopy (LAS) measurements of differential absorption due to CO2 along intersecting chords within the field of interest. These differential absorption values for the intersecting chords of horizontal path are not only used to construct estimated values of integrated concentration, but also employed in an optimal estimation technique to derive 2D maps of underlying concentration fields. This optimal estimation technique combines these sparse data with in situ measurements of wind speed/direction and an analytic plume model to provide tomographic-like reconstruction of the field of interest. This work provides an assessment of this reconstruction method and preliminary results from the Fall 2014 testing at the Zero Emissions Research and Technology (ZERT) site in Bozeman, Montana. This work is funded in part under the GreenLITE program developed under a cooperative agreement between Exelis and the National Energy and Technology Laboratory (NETL) under the Department of Energy (DOE), contract # DE-FE0012574. Atmospheric and Environmental Research, Inc. is a major partner in this development.

Temporal variations of Escherichia coli concentrations in a large Midwestern river

Science.gov (United States)

Schilling, K.E.; Zhang, Y.-K.; Hill, D.R.; Jones, C.S.; Wolter, C.F.

2009-01-01

The Raccoon River used by the Des Moines Water Works to serve more than 400,000 people in central Iowa is threatened by contamination from Escherichia coli bacteria from point and nonpoint sources. The 9389 km2 watershed is highly agricultural, with 73% of the land in row crop production and widespread animal production. Results from 2155 grab samples from 1997 to 2005 for E. coli analysis were examined for temporal variations. E. coli concentrations were found to vary across years, seasons, and flow conditions, with a 9-year mean value of 1156 most probable number (MPN)/100 ml. Monthly concentrations exhibited clear seasonality with highest values in May through July. Although E. coli concentrations were higher during periods of greater discharge, the relation of log E. coli to log discharge was not particularly strong (r2 = 0.35). The variogram of E. coli concentrations showed temporal correlation within a span of 4 days suggesting that concentrations measured on 1 day may be related in time to concentrations measured up to 3 days later and beyond 4 days the concentrations vary randomly. The spectral analysis of the time series of E. coli was also carried out and was fitted well with the spectrum of an exponential covariance function. Deciphering temporal patterns and correlation of E. coli bacteria in streams may be useful for developing future monitoring strategies to track concentration patterns and loads. ?? 2008 Elsevier B.V. All rights reserved.

Dissociation of rapid response learning and facilitation in perceptual and conceptual networks of person recognition.

Science.gov (United States)

Valt, Christian; Klein, Christoph; Boehm, Stephan G

2015-08-01

Repetition priming is a prominent example of non-declarative memory, and it increases the accuracy and speed of responses to repeatedly processed stimuli. Major long-hold memory theories posit that repetition priming results from facilitation within perceptual and conceptual networks for stimulus recognition and categorization. Stimuli can also be bound to particular responses, and it has recently been suggested that this rapid response learning, not network facilitation, provides a sound theory of priming of object recognition. Here, we addressed the relevance of network facilitation and rapid response learning for priming of person recognition with a view to advance general theories of priming. In four experiments, participants performed conceptual decisions like occupation or nationality judgments for famous faces. The magnitude of rapid response learning varied across experiments, and rapid response learning co-occurred and interacted with facilitation in perceptual and conceptual networks. These findings indicate that rapid response learning and facilitation in perceptual and conceptual networks are complementary rather than competing theories of priming. Thus, future memory theories need to incorporate both rapid response learning and network facilitation as individual facets of priming. © 2014 The British Psychological Society.

A dynamic growth model of vegetative soya bean plants: model structure and behaviour under varying root temperature and nitrogen concentration

Science.gov (United States)

Lim, J. T.; Wilkerson, G. G.; Raper, C. D. Jr; Gold, H. J.

1990-01-01

A differential equation model of vegetative growth of the soya bean plant (Glycine max (L.) Merrill cv. Ransom') was developed to account for plant growth in a phytotron system under variation of root temperature and nitrogen concentration in nutrient solution. The model was tested by comparing model outputs with data from four different experiments. Model predictions agreed fairly well with measured plant performance over a wide range of root temperatures and over a range of nitrogen concentrations in nutrient solution between 0.5 and 10.0 mmol NO3- in the phytotron environment. Sensitivity analyses revealed that the model was most sensitive to changes in parameters relating to carbohydrate concentration in the plant and nitrogen uptake rate.

Effect of Alkaline Solution with Varying Mix Proportion on Geopolymer Mortar

Science.gov (United States)

Karuppuchamy, K.; Ananthkumar, M.; Raghavapriya, S. M.

2018-02-01

Cement production is attributed by emission of carbon dioxide which causes severe environmental impacts. This has led to the invention of special construction materials which can replace cement. On the other hand, these construction materials (like Fly ash, Metakaolin) also need to be inexpensive and should possess all the characteristics of cementitious materials. In this project, the effect of geopolymerization on the properties of the end product were studied with varying distillation of NaOH solution (10M, 12M and 15M) for different mix proportion (1:1, 1:2 and 1:3). Curing was done for 1 day at a temperature of 60°C and 80°C respectively. The densities, compressive strength, alkalinity, co-efficient of absorption were determined. As a result, the experiments showed the effect of factors such as mix proportion, curing temperature and curing day on the physical and mechanical properties such as mix proportion of the geopolymer concrete. Results of NaOH concentration of 12M concentration cured for 24 hours at 80°C and 60°C showed better mechanical performance than the rest of the concentrations.

Water-soluble carbohydrates and in vitro digestibility of annual ryegrass (Lolium ridigum Gaudin) sown at varying densities

NARCIS (Netherlands)

Smouter, H.; Simpson, R.J.; Pear, G.R.

1995-01-01

An experiment is described in which the tiller density of microswards of Lolium rigidum was varied by altering planting density. The treatments were expected to alter the interplant competition for light and thus affect the concentration of water-soluble carbohydrates (WSC) of the grass swards.

Preparation of counterion stabilized concentrated silver sols.

Science.gov (United States)

LaPlante, Sylas; Halaciuga, Ionel; Goia, Dan V

2011-07-01

A strategy for obtaining stable concentrated silver dispersions without dedicated stabilizing agents is presented. This approach consists of rapidly mixing aqueous solutions of silver salicylate and ascorbic acid. By using salicylate as Ag(+) counterion, it is possible to prepare stable sols with metal concentrations up to two orders of magnitude higher than with silver nitrate. The stabilizing effect of the counterion is the result of a decreased ionic strength due to salicylate protonation and its adsorption on the surface of silver. Both effects increase the range of the electrostatic repulsive forces by expanding the electrical double layer. Copyright © 2011 Elsevier Inc. All rights reserved.

Uranium concentrations and 234U/238U activity ratios in fault-associated groundwater as possible earthquake precursors

International Nuclear Information System (INIS)

Finkel, R.C.

1981-01-01

In order to assess the utility of uranium isotopes as fluid phase earthquake precursors, uranium concentrations and 234 U/ 238 U activity ratios have been monitored on a monthly or bimonthly basis in water from 24 wells and springs associated with Southern California fault zones. Uranium concentrations vary from 0.002 ppb at Indian Canyon Springs on the San Jacinto fault to 8.3 ppb at Lake Hughes well on the San Andreas fault in the Palmdale area. 234 U/ 238 U activity ratios vary from 0.88 at Agua Caliente Springs on the Elsinore fault to 5.4 at Niland Slab well on the San Andreas fault in the Imperial Valley. There was one large earthquake in the study area during 1979, the 15 October 1979 M = 6.6 Imperial Valley earthquake. Correlated with this event, uranium concentrations varied by a factor of more than 60 and activity ratios by a factor of 3 at the Niland Slab site, about 70 km from the epicenter. At the other sites monitored, uranium concentrations varied in time, but with no apparent pattern, while uranium activity ratios remained essentially constant throughout the monitoring period

Radon concentration levels in Fatima Jinnah women university Pakistan

International Nuclear Information System (INIS)

Khan, S.A.; Ali, S.; Tufail, A.; Qureshi, A.A.

2005-01-01

Public exposure to radioactive gas radon and its progeny present in the air results in the largest contribution to total effective dose received by human beings. It is therefore of great concern to monitor radon concentration in energy conserved air tight buildings. Measurements of radon in the Fatima Jinnah Women University (FJWU) have been carried out for investigation and comparison of radon concentration in the new and old buildings of the campus at Rawalpindi, Pakistan. The study was done because according to the international guidelines concerning environmental problems, it is necessary to evaluate and know the radon levels, especially since most of the natural radiation dose to human beings comes from radon gas and its progeny. Solid State Nuclear Track Detectors (SSNTDs) being efficient, therefore, the measurements were carried out by passive, time integrated method, using CR-39 detector in polythene bags. The detectors were exposed for more than six month in various locations indoors and outdoors. The detectors were etched using NaOH, the tracks were counted manually, and the track density was converted to radon concentration. Radon concentration varied from 31 to 213 Bq.m -3 in old building and from 27 to 143 Bq.m -3 in new buildings, showing slight elevated values in the old buildings. Radon concentration values were found to be less than the values quoted by radiation protection agencies. Radiation dose due to radon varied in the university campus depending on occupancy factor. (author)

Two-step rapid sulfur capture. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-04-01

The primary goal of this program was to test the technical and economic feasibility of a novel dry sorbent injection process called the Two-Step Rapid Sulfur Capture process for several advanced coal utilization systems. The Two-Step Rapid Sulfur Capture process consists of limestone activation in a high temperature auxiliary burner for short times followed by sorbent quenching in a lower temperature sulfur containing coal combustion gas. The Two-Step Rapid Sulfur Capture process is based on the Non-Equilibrium Sulfur Capture process developed by the Energy Technology Office of Textron Defense Systems (ETO/TDS). Based on the Non-Equilibrium Sulfur Capture studies the range of conditions for optimum sorbent activation were thought to be: activation temperature > 2,200 K for activation times in the range of 10--30 ms. Therefore, the aim of the Two-Step process is to create a very active sorbent (under conditions similar to the bomb reactor) and complete the sulfur reaction under thermodynamically favorable conditions. A flow facility was designed and assembled to simulate the temperature, time, stoichiometry, and sulfur gas concentration prevalent in the advanced coal utilization systems such as gasifiers, fluidized bed combustors, mixed-metal oxide desulfurization systems, diesel engines, and gas turbines.

Rapid radioimmunoassay of human apolipoproteins C-II and C-III

Energy Technology Data Exchange (ETDEWEB)

Gustafson, S; Oestlund-Lindqvist, A M; Vessby, B [Uppsala Univ. (Sweden)

1984-06-01

Apolipoprotein (apo) C-II is an activator of lipoprotein lipase, while apo C-III has the ability to inhibit apo C-II activated lipolysis. In order to study further the relationship between lipoprotein lipase mediated hydrolysis and the serum concentrations of apo C-II and apo C-III radioimmunoassays for these apolipoproteins have been developed. Formalin-treated Staphylococcus aureus Cowan I was used for immunoprecipitation and were shown to give rapid uptake of immune complexes that could easily be harvested by centrifugation. The assays were shown to be sensitive (10 ..mu..g/1), specific, precise (inter- and intra-assay coefficients of variation below 10%), rapid (completed in less than 6 h) and simple to perform. Delipidation of serum and lipoproteins had no effect on the results, indicating that the immunologically active sites of apo C-II and apo C-III are exposed to the aqueous environment under assay conditions. Serum apo C-II and apo C-III levels of normolipidaemic subjects were approximately 25 mg/1 and 110 mg/1, respectively. Highly significant positive correlations were found between VLDL apo C-II and VLDL apo C-III, respectively, and VLDL triglycerides, VLDL cholesterol and total serum TG. There was also a highly significant correlation between the HDL cholesterol concentration and the HDL apo C-III concentration.

Chemically synthesized PbS Nano particulate thin films for a rapid NO2 gas sensor

Directory of Open Access Journals (Sweden)

Burungale Vishal V.

2016-03-01

Full Text Available Rapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 °C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 °C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 °C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.

Nonlinear systems time-varying parameter estimation: Application to induction motors

Energy Technology Data Exchange (ETDEWEB)

Kenne, Godpromesse [Laboratoire d' Automatique et d' Informatique Appliquee (LAIA), Departement de Genie Electrique, IUT FOTSO Victor, Universite de Dschang, B.P. 134 Bandjoun (Cameroon); Ahmed-Ali, Tarek [Ecole Nationale Superieure des Ingenieurs des Etudes et Techniques d' Armement (ENSIETA), 2 Rue Francois Verny, 29806 Brest Cedex 9 (France); Lamnabhi-Lagarrigue, F. [Laboratoire des Signaux et Systemes (L2S), C.N.R.S-SUPELEC, Universite Paris XI, 3 Rue Joliot Curie, 91192 Gif-sur-Yvette (France); Arzande, Amir [Departement Energie, Ecole Superieure d' Electricite-SUPELEC, 3 Rue Joliot Curie, 91192 Gif-sur-Yvette (France)

2008-11-15

In this paper, an algorithm for time-varying parameter estimation for a large class of nonlinear systems is presented. The proof of the convergence of the estimates to their true values is achieved using Lyapunov theories and does not require that the classical persistent excitation condition be satisfied by the input signal. Since the induction motor (IM) is widely used in several industrial sectors, the algorithm developed is potentially useful for adjusting the controller parameters of variable speed drives. The method proposed is simple and easily implementable in real-time. The application of this approach to on-line estimation of the rotor resistance of IM shows a rapidly converging estimate in spite of measurement noise, discretization effects, parameter uncertainties (e.g. inaccuracies on motor inductance values) and modeling inaccuracies. The robustness analysis for this IM application also revealed that the proposed scheme is insensitive to the stator resistance variations within a wide range. The merits of the proposed algorithm in the case of on-line time-varying rotor resistance estimation are demonstrated via experimental results in various operating conditions of the induction motor. The experimental results obtained demonstrate that the application of the proposed algorithm to update on-line the parameters of an adaptive controller (e.g. IM and synchronous machines adaptive control) can improve the efficiency of the industrial process. The other interesting features of the proposed method include fault detection/estimation and adaptive control of IM and synchronous machines. (author)

Study of selected phenotype switching strategies in time varying environment

Energy Technology Data Exchange (ETDEWEB)

Horvath, Denis, E-mail: horvath.denis@gmail.com [Centre of Interdisciplinary Biosciences, Institute of Physics, Faculty of Science, P.J. Šafárik University in Košice, Jesenná 5, 040 01 Košice (Slovakia); Brutovsky, Branislav, E-mail: branislav.brutovsky@upjs.sk [Department of Biophysics, Institute of Physics, P.J. Šafárik University in Košice, Jesenná 5, 040 01 Košice (Slovakia)

2016-03-22

Population heterogeneity plays an important role across many research, as well as the real-world, problems. The population heterogeneity relates to the ability of a population to cope with an environment change (or uncertainty) preventing its extinction. However, this ability is not always desirable as can be exemplified by an intratumor heterogeneity which positively correlates with the development of resistance to therapy. Causation of population heterogeneity is therefore in biology and medicine an intensively studied topic. In this paper the evolution of a specific strategy of population diversification, the phenotype switching, is studied at a conceptual level. The presented simulation model studies evolution of a large population of asexual organisms in a time-varying environment represented by a stochastic Markov process. Each organism disposes with a stochastic or nonlinear deterministic switching strategy realized by discrete-time models with evolvable parameters. We demonstrate that under rapidly varying exogenous conditions organisms operate in the vicinity of the bet-hedging strategy, while the deterministic patterns become relevant as the environmental variations are less frequent. Statistical characterization of the steady state regimes of the populations is done using the Hellinger and Kullback–Leibler functional distances and the Hamming distance. - Highlights: • Relation between phenotype switching and environment is studied. • The Markov chain Monte Carlo based model is developed. • Stochastic and deterministic strategies of phenotype switching are utilized. • Statistical measures of the dynamic heterogeneity reveal universal properties. • The results extend to higher lattice dimensions.

Study of selected phenotype switching strategies in time varying environment

International Nuclear Information System (INIS)

Horvath, Denis; Brutovsky, Branislav

2016-01-01

Population heterogeneity plays an important role across many research, as well as the real-world, problems. The population heterogeneity relates to the ability of a population to cope with an environment change (or uncertainty) preventing its extinction. However, this ability is not always desirable as can be exemplified by an intratumor heterogeneity which positively correlates with the development of resistance to therapy. Causation of population heterogeneity is therefore in biology and medicine an intensively studied topic. In this paper the evolution of a specific strategy of population diversification, the phenotype switching, is studied at a conceptual level. The presented simulation model studies evolution of a large population of asexual organisms in a time-varying environment represented by a stochastic Markov process. Each organism disposes with a stochastic or nonlinear deterministic switching strategy realized by discrete-time models with evolvable parameters. We demonstrate that under rapidly varying exogenous conditions organisms operate in the vicinity of the bet-hedging strategy, while the deterministic patterns become relevant as the environmental variations are less frequent. Statistical characterization of the steady state regimes of the populations is done using the Hellinger and Kullback–Leibler functional distances and the Hamming distance. - Highlights: • Relation between phenotype switching and environment is studied. • The Markov chain Monte Carlo based model is developed. • Stochastic and deterministic strategies of phenotype switching are utilized. • Statistical measures of the dynamic heterogeneity reveal universal properties. • The results extend to higher lattice dimensions.

Modeling sediment concentration of rill flow

Science.gov (United States)

Yang, Daming; Gao, Peiling; Zhao, Yadong; Zhang, Yuhang; Liu, Xiaoyuan; Zhang, Qingwen

2018-06-01

Accurate estimation of sediment concentration is essential to establish physically-based erosion models. The objectives of this study were to evaluate the effects of flow discharge (Q), slope gradient (S), flow velocity (V), shear stress (τ), stream power (ω) and unit stream power (U) on sediment concentration. Laboratory experiments were conducted using a 10 × 0.1 m rill flume under four flow discharges (2, 4, 8 and 16 L min-1), and five slope gradients (5°, 10°, 15°, 20° and 25°). The results showed that the measured sediment concentration varied from 87.08 to 620.80 kg m-3 with a mean value of 343.13 kg m-3. Sediment concentration increased as a power function with flow discharge and slope gradient, with R2 = 0.975 and NSE = 0.945. The sediment concentration was more sensitive to slope gradient than to flow discharge. The sediment concentration was well predicted by unit stream power (R2 = 0.937, NSE = 0.865), whereas less satisfactorily by flow velocity (R2 = 0.470, NSE = 0.539) and stream power (R2 = 0.773, NSE = 0.732). In addition, using the equations to simulate the measured sediment concentration of other studies, the result further indicated that slope gradient, flow discharge and unit stream power were good predictors of sediment concentration. In general, slope gradient, flow discharge and unit stream power seem to be the preferred predictors for estimating sediment concentration.

A varying-α brane world cosmology

International Nuclear Information System (INIS)

Youm, Donam

2001-08-01

We study the brane world cosmology in the RS2 model where the electric charge varies with time in the manner described by the varying fine-structure constant theory of Bekenstein. We map such varying electric charge cosmology to the dual variable-speed-of-light cosmology by changing system of units. We comment on cosmological implications for such cosmological models. (author)

Concentration and Viability of Airborne Bacteria Over the Kuroshio Extension Region in the Northwestern Pacific Ocean: Data From Three Cruises

Science.gov (United States)

Hu, Wei; Murata, Kotaro; Fukuyama, Shinichiro; Kawai, Yoshimi; Oka, Eitarou; Uematsu, Mitsuo; Zhang, Daizhou

2017-12-01

Airborne bacteria have been shown to act as condensation and ice nuclei in mixed-phase clouds and are consequently hypothesized to have significant effects on atmospheric processes and even the global climate. However, few data are available regarding their concentration and variation in the air over the open ocean. Aerosol samples were collected during three cruises in the early summers of 2013, 2014, and 2016 over the Kuroshio Extension region of the northwest Pacific Ocean. The concentrations of viable and nonviable bacterial cells in the marine surface air were quantified using epifluorescence enumeration with the LIVE/DEAD BacLight stain. The concentrations of total bacteria varied between 1.0 × 104 and 2.5 × 105 cells m-3 and averaged 5.2 × 104, 1.0 × 105, and 7.5 × 104 cells m-3 in the three respective cruises. The viabilities, i.e., the ratios of the concentration of viable bacterial cells to that of total bacterial cells, ranged from 80% to 100% (average 93%), and the respective means were 93%, 89%, and 96% in the cruises. The total bacterial concentration had a close correlation with the wind speed near the sea surface, and the bacterial viability correlated negatively with the air temperature, sea surface temperature, and concentration of coarse particles (size > 1 μm). The deposition and sea spray fluxes of bacteria were roughly estimated as hundreds of cells m-2 s-1 on average. The limited data on bacterial concentration and viability from the three cruises indicate the rapid air-sea exchange of bacteria over the Kuroshio Extension region of the northwest Pacific Ocean.

Activity concentration and AACED due to 40K in some selected medicinal plants

International Nuclear Information System (INIS)

Chandrashekara, K.; Radhakrishna, A.P.; Somashekarappa, H.M.

2017-01-01

The activity concentrations in soil and medicinal plants, soil to plant transfer factors (TF), and Average Annual Committed Effective Dose (AACED) of 40 K in prominent medicinal plants of Malnad Kerala were estimated. The range of activity concentrations were 144.15 - 558.99 and 405.87 - 2990.75 Bq kg -1 in soil and medicinal plants respectively. The TF was found to vary from 2.34 to 14.84, whereas AACED varied in the range 2.51 - 18.54 mSv y -1 . The study may help to form the database and safety regulations connected with 40 K activity in medicinal plants. (author)

Rapid evolution and spread of carbapenemases among Enterobacteriaceae in Europe.

Science.gov (United States)

Cantón, R; Akóva, M; Carmeli, Y; Giske, C G; Glupczynski, Y; Gniadkowski, M; Livermore, D M; Miriagou, V; Naas, T; Rossolini, G M; Samuelsen, Ø; Seifert, H; Woodford, N; Nordmann, P

2012-05-01

Plasmid-acquired carbapenemases in Enterobacteriaceae, which were first discovered in Europe in the 1990s, are now increasingly being identified at an alarming rate. Although their hydrolysis spectrum may vary, they hydrolyse most β-lactams, including carbapenems. They are mostly of the KPC, VIM, NDM and OXA-48 types. Their prevalence in Europe as reported in 2011 varies significantly from high (Greece and Italy) to low (Nordic countries). The types of carbapenemase vary among countries, partially depending on the cultural/population exchange relationship between the European countries and the possible reservoirs of each carbapenemase. Carbapenemase producers are mainly identified among Klebsiella pneumoniae and Escherichia coli, and still mostly in hospital settings and rarely in the community. Although important nosocomial outbreaks with carbapenemase-producing Enterobacteriaceae have been extensively reported, many new cases are still related to importation from a foreign country. Rapid identification of colonized or infected patients and screening of carriers is possible, and will probably be effective for prevention of a scenario of endemicity, as now reported for extended-spectrum β-lactamase (mainly CTX-M) producers in all European countries. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

Point-of-care estimation of haemoglobin concentration in neonates ...

African Journals Online (AJOL)

Objective. The HemoCue is a point-of-care analytical system for haemoglobin concentration (Hb) measurement. Point-of-care testing has been validated in hospitals and outpatient departments to assist with urgent patient management by providing rapid laboratory test results. Method. In this prospective study we compared ...

Quantification of protein concentration using UV absorbance and Coomassie dyes.

Science.gov (United States)

Noble, James E

2014-01-01

The measurement of a solubilized protein concentration in solution is an important assay in biochemistry research and development labs for applications ranging from enzymatic studies to providing data for biopharmaceutical lot release. Spectrophotometric protein quantification assays are methods that use UV and visible spectroscopy to rapidly determine the concentration of protein, relative to a standard, or using an assigned extinction coefficient. Where multiple samples need measurement, and/or the sample volume and concentration is limited, preparations of the Coomassie dye commonly known as the Bradford assay can be used. © 2014 Elsevier Inc. All rights reserved.

Rate of solidification of aluminium casting in varying wall thickness of cylindrical metallic moulds

Directory of Open Access Journals (Sweden)

Katsina Christopher BALA

2014-02-01

Full Text Available The quality of final casting mainly depends on the rate of solidification as rapid solidification produces fine grains structures with better mechanical properties. The analysis of heat transfer during the casting and solidification of aluminium alloy as well as the experimental investigation of the rate of solidification in varying thicknesses of cylindrical metallic mould was carried out. The temperature variation with time of the casting was recorded from which cooling curves were obtained for the determination of solidification time of the cast. The results showed that as the cylindrical mould thickness increases the solidification time decreases due to the chilling effect of the mould.

Continuous-Flow Detector for Rapid Pathogen Identification

Energy Technology Data Exchange (ETDEWEB)

Barrett, Louise M. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Microfluidics; Skulan, Andrew J. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Microfluidics; Singh, Anup K. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Microfluidics; Cummings, Eric B. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Microfluidics; Fiechtner, Gregory J. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Microfluidics

2006-09-01

This report describes the continued development of a low-power, portable detector for the rapid identification of pathogens such as B. anthracis and smallpox. Based on our successful demonstration of the continuous filter/concentrator inlet, we believe strongly that the inlet section will enable differentiation between viable and non-viable populations, between types of cells, and between pathogens and background contamination. Selective, continuous focusing of particles in a microstream enables highly selective and sensitive identification using fluorescently labeled antibodies and other receptors such as peptides, aptamers, or small ligands to minimize false positives. Processes such as mixing and lysing will also benefit from the highly localized particle streams. The concentrator is based on faceted prisms to contract microfluidic flows while maintaining uniform flowfields. The resulting interfaces, capable of high throughput, serve as high-, low-, and band-pass filters to direct selected bioparticles to a rapid, affinity-based detection system. The proposed device is superior to existing array-based detectors as antibody-pathogen binding can be accomplished in seconds rather than tens of minutes or even hours. The system is being designed to interface with aerosol collectors under development by the National Laboratories or commercial systems. The focused stream is designed to be interrogated using diode lasers to differentiate pathogens by light scattering. Identification of particles is done using fluorescently labeled antibodies to tag the particles, followed by multiplexed laser-induced fluorescence (LIF) detection (achieved by labeling each antibody with a different dye).

Radionuclide concentration in fuels and ash products from biofuel heating plants

International Nuclear Information System (INIS)

Erlandsson, B.; Hedvall, R.; Mattsson, S.

1995-01-01

The activity concentration of the radionuclides K-40, Ac-228, Pa-234, Mn-54, Co-60, Zr-95, Ru-106, Ag-110m, Sb-125, Cs-134, Cs-137 and Ce-144 have been investigated in peat wood chips and ash products from 13 Swedish district heating plants during the winter seasons of 1986/1987, 1988/89, 1989/90 and 1990/91. There is a significant decrease in the activity concentration of Cs-137 in the fuel which is especially pronounced between the first two seasons, 86/87 and 88/89 after the Chernobyl accident. In spite of the varying deposition of Cs-137 over the country it has been possible to give a relation between the activity concentration in the peat and wood chips as a function of the deposition. The Swedish biofuel heating plants of which 35-40 are burning peat and 70-75 chips have been divided in three groups according to the activity concentration in the ash products. The mean Cs-137 concentration in ash and the total activity 'produced' per year in Sweden have been calculated. The maximum concentration in air at ground level and the corresponding effective dose rate of inhaled Cs-137 as a function of the emission rates of flue gases from stacks with varying heights and during different weather conditions has been calculated. 16 refs, 18 tabs, 4 figs

Chemical and physical characteristics of phosphate rock materials of varying reactivity

International Nuclear Information System (INIS)

Syers, J.K.; Currie, L.D.

1986-01-01

Several chemical and physical properties of 10 phosphate rock (PR) materials of varying reactivity were evaluated. The highest concentrations of As and Cd were noted. Because Cd and U can accumulate in biological systems, it may be necessary to direct more attention towards the likely implications of Cd and U concentrations when evaluating a PR for direct application. Three sequential extractions with 2% citric acid may be more useful for comparing the chemical solubility of PR materials, particularly for those containing appreciable CaC0 3 . The poor relationship obtained between surface area and the solubility of the PR materials suggests that surface area plays a secondary role to chemical reactivity in controlling the solubility of a PR in a chemical extractant. A Promesh plot provided an effective method for describing the particle-size characteristics of those PR materials which occurred as sands. Fundamental characteristics, such as mean particle size and uniformity, can readily be determined from a Promesh plot. (author)

Denitrification of fertilizer wastewater at high chloride concentration

DEFF Research Database (Denmark)

Ucisik, Ahmed Süheyl; Henze, Mogens

Wastewater from fertilizer industry is characterized by high contents of chloride concentration, which normally vary between 60 and 76 g/l. Experiments with bilogical denitrification were performed in lab-scale "fill and draw" reactors with synthetic wastewater with chloride concentrations up to 77.......4 g/l. The results of the experiments showed that biological denitrification was feasible at the extreme environmental conditions prevailing in fertilizer wastewater. Stable continuous biological denitrfication of the synthetic high chloride wastewater was performed up to 77.4 g Cl/l at 37 degree C...

Generation of tunable and pulsatile concentration gradients via microfluidic network

KAUST Repository

Zhou, Bingpu

2014-06-04

We demonstrate a compact Polydimethylsiloxane microfluidic chip which can quickly generate ten different chemical concentrations simultaneously. The concentration magnitude of each branch can be flexibly regulated based on the flow rate ratios of the two injecting streams. The temporal/pulsatile concentration gradients are achieved by integrating on-chip pneumatic actuated valves controlled by the external signals. The temporal concentration gradients can also be tuned precisely by varying applied frequency and duty cycle of the trigger signal. It is believed that such microdevice will be potentially used for some application areas of producing stable chemical gradients as well as allowing fast, pulsatile gradient transformation in seconds.

Monitoring variation in greenhouse gases concentration in urban environment of Delhi.

Science.gov (United States)

Sahay, Samraj; Ghosh, Chirashree

2013-01-01

Cities across the globe are considered as major anthropogenic sources of greenhouse gases (GHG), yet very few efforts has been made to monitor ambient concentration of GHG in cities, especially in a developing country like India. Here, variations in the ambient concentrations of carbon dioxide (CO(2)) and methane (CH(4)) in residential, commercial, and industrial areas of Delhi are determined from fortnightly daytime observations from July, 2008 to March, 2009. Results indicate that the average daytime ambient concentration of CO(2) varied from 495 to 554 ppm in authorized residential areas, 503 to 621 ppm in the slums or jhuggies in the unauthorized residential areas, 489 to 582 ppm in commercial areas, and 512 to 568 ppm in industrial areas with an average of 541 ± 27 ppm. CH(4) concentration varied from 652 to 5,356 ppbv in authorized residential areas, 500 to 15,220 ppbv in the unauthorized residential areas, 921 to 11,000 ppbv in the commercial areas, and 250 to 2,550 ppbv in the industrial areas with an average of 3,226 ± 1,090 ppbv. A low mid-afternoon CO(2) concentration was observed at most of the sites, primarily due to strong biospheric photosynthesis coupled with strong vertical mixing.

Plasma protein concentration and control of coronary vascular resistance in isolated rat heart

NARCIS (Netherlands)

Avolio, A. P.; Spaan, J. A.; Laird, J. D.

1980-01-01

Isolated externally paced (300 beats/min) rat hearts were perfused at constant pressure (70 mmHg) using a modified Krebs-Henseleit solution with (n = 52) and without (n = 15) washed bovine red cells. Albumin concentration varied from 1 to 10 g/dl. With increasing albumin concentration in

Adaptive observer-based control for an IPMC actuator under varying humidity conditions

Science.gov (United States)

Bernat, Jakub; Kolota, Jakub

2018-05-01

As ionic polymer metal composites (IPMC) are increasingly applied to mechatronic systems, many new IPMC modeling efforts have been reported in the literature. The demands of rapidly growing technology has generated interest in advancing the intrinsic actuation and sensing capabilities of IPMC. Classical IPMC applications need constant hydration to operate. On the other hand, for IPMCs operating in air, the water content of the polymer varies with the humidity level of the ambient environment, which leads to its strong humidity-dependent behavior. Furthermore, decreasing water content over time plays a crucial role in the effectiveness of IPMC. Therefore, the primary challenge of this work is to accurately model this phenomenon. The principal contribution of the paper is a new IPMC model, which considers the change of moisture content. A novel nonlinear adaptive observer is designed to determine the unknown electric potential and humidity level in the polymer membrane. This approach effectively determines the moisture content of the IPMC during long-term continuous operation in air. This subsequently allows us to develop an effective back-stepping control algorithm that considers varying moisture content. Data from experiments are presented to support the effectiveness of the observation process, which is shown in illustrative examples.

Variation in plasmonic (electronic) spectral parameters of Pr (III) and Nd (III) with varied concentration of moderators

Energy Technology Data Exchange (ETDEWEB)

Mishra, Shubha, E-mail: shubhamishra03@gmail.com [School of Studies in Physics, Vikram University, Ujjain (M. P.) (India); Limaye, S. N., E-mail: snl222@yahoo.co.in [Department of Chemistry, Dr. H.S. Gour University, A Central University, Sagar (M.P.) (India)

2015-07-31

It is said that the -4f shells behave as core and are least perturbed by changes around metal ion surrounding. However, there are evidences that-4f shells partially involved in direct moderator interaction. A systematic investigation on the plasmonic (electronic) spectral studies of some Rare Earths[RE(III).Mod] where, RE(III) = Pr(III),Nd(III) and Mod(moderator) = Y(III),La(III),Gd(III) and Lu(III), increased moderator concentration from 0.01 mol dm{sup −3} to 0.025 mol dm{sup −3} keeping the metal ion concentration at 0.01mol dm{sup −3} have been carried out. Variations in oscillator strengths (f), Judd-Ofelt parameters (T{sub λ}),inter-electronic repulsion Racah parameters (δE{sup k}),nephelauxetic ratio (β), radiative parameters (S{sub ED},A{sub T},β{sub R},T{sub R}). The values of oscillator strengths and Judd-Ofelt parameters have been discussed in the light of coordination number of RE(III) metal ions, denticity and basicity of the moderators. The [RE(III).Mod] bonding pattern has been studies in the light of the change in Racah parameters and nephelauxetic ratio.

Rapid shallow breathing

Science.gov (United States)

Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the ...

[Introduction and some problems of the rapid time series laboratory reporting system].

Science.gov (United States)

Kanao, M; Yamashita, K; Kuwajima, M

1999-09-01

We introduced an on-line system of biochemical, hematological, serological, urinary, bacteriological, and emergency examinations and associated office work using a client server system NEC PC-LACS based on a system consisting of concentration of outpatient blood collection, concentration of outpatient reception, and outpatient examination by reservation. Using this on-line system, results of 71 items in chemical serological, hematological, and urinary examinations are rapidly reported within 1 hour. Since the ordering system at our hospital has not been completed yet, we constructed a rapid time series reporting system in which time series data obtained on 5 serial occasions are printed on 2 sheets of A4 paper at the time of the final report. In each consultation room of the medical outpatient clinic, at the neuromedical outpatient clinic, and at the kidney center where examinations are frequently performed, terminal equipment and a printer for inquiry were established for real-time output of time series reports. Results are reported by FAX to the other outpatient clinics and wards, and subsequently, time series reports are output at the clinical laboratory department. This system allowed rapid examination, especially preconsultation examination. This system was also useful for reducing office work and effectively utilize examination data.

Biotunable Nanoplasmonic Filter on Few-Layer MoS2 for Rapid and Highly Sensitive Cytokine Optoelectronic Immunosensing.

Science.gov (United States)

Park, Younggeun; Ryu, Byunghoon; Oh, Bo-Ram; Song, Yujing; Liang, Xiaogan; Kurabayashi, Katsuo

2017-06-27

Monitoring of the time-varying immune status of a diseased host often requires rapid and sensitive detection of cytokines. Metallic nanoparticle-based localized surface plasmon resonance (LSPR) biosensors hold promise to meet this clinical need by permitting label-free detection of target biomolecules. These biosensors, however, continue to suffer from relatively low sensitivity as compared to conventional immunoassay methods that involve labeling processes. Their response speeds also need to be further improved to enable rapid cytokine quantification for critical care in a timely manner. In this paper, we report an immunobiosensing device integrating a biotunable nanoplasmonic optical filter and a highly sensitive few-layer molybdenum disulfide (MoS 2 ) photoconductive component, which can serve as a generic device platform to meet the need of rapid cytokine detection with high sensitivity. The nanoplasmonic filter consists of anticytokine antibody-conjugated gold nanoparticles on a SiO 2 thin layer that is placed 170 μm above a few-layer MoS 2 photoconductive flake device. The principle of the biosensor operation is based on tuning the delivery of incident light to the few-layer MoS 2 photoconductive flake thorough the nanoplasmonic filter by means of biomolecular surface binding-induced LSPR shifts. The tuning is dependent on cytokine concentration on the nanoplasmonic filter and optoelectronically detected by the few-layer MoS 2 device. Using the developed optoelectronic biosensor, we have demonstrated label-free detection of IL-1β, a pro-inflammatory cytokine, with a detection limit as low as 250 fg/mL (14 fM), a large dynamic range of 10 6 , and a short assay time of 10 min. The presented biosensing approach could be further developed and generalized for point-of-care diagnosis, wearable bio/chemical sensing, and environmental monitoring.

Rapid growth, maturity, current problems, future prospects of NAA

International Nuclear Information System (INIS)

Guinn, V.P.

2000-01-01

The early rapid growth, the attainment of maturity, current problems, and future prospects of NAA (neutron activation analysis) are discussed, each in reasonable detail. In particular, the nature and causes of its current problems are examined, and suggestions are presented for the solution of these problems. The author believes that vigorous action in suggested areas of concentration can reinvigorate the status of NAA as an important method of elemental analysis. (author)

On the Dark Side of Therapies with Immunoglobulin Concentrates: The Adverse Events

OpenAIRE

Sp?th, Peter J.; Granata, Guido; La Marra, Fabiola; Kuijpers, Taco W.; Quinti, Isabella

2015-01-01

Abstract to the dark side of therapies with human immunoglobulin G concentratesTherapy by human immunoglobulin G (IgG) concentrates is a success story ongoing for decades with an ever increasing demand for this plasma product. The success of IgG concentrates on a clinical level is documented by the slowly increasing number of registered indication and the more rapid increase of the off-label uses, a topic dealt with in another contribution to this special issue of Frontiers in Immunology. A p...

Rapid improvement teams.

Science.gov (United States)

Alemi, F; Moore, S; Headrick, L; Neuhauser, D; Hekelman, F; Kizys, N

1998-03-01

Suggestions, most of which are supported by empirical studies, are provided on how total quality management (TQM) teams can be used to bring about faster organizationwide improvements. Ideas are offered on how to identify the right problem, have rapid meetings, plan rapidly, collect data rapidly, and make rapid whole-system changes. Suggestions for identifying the right problem include (1) postpone benchmarking when problems are obvious, (2) define the problem in terms of customer experience so as not to blame employees nor embed a solution in the problem statement, (3) communicate with the rest of the organization from the start, (4) state the problem from different perspectives, and (5) break large problems into smaller units. Suggestions for having rapid meetings include (1) choose a nonparticipating facilitator to expedite meetings, (2) meet with each team member before the team meeting, (3) postpone evaluation of ideas, and (4) rethink conclusions of a meeting before acting on them. Suggestions for rapid planning include reducing time spent on flowcharting by focusing on the future, not the present. Suggestions for rapid data collection include (1) sample patients for surveys, (2) rely on numerical estimates by process owners, and (3) plan for rapid data collection. Suggestions for rapid organizationwide implementation include (1) change membership on cross-functional teams, (2) get outside perspectives, (3) use unfolding storyboards, and (4) go beyond self-interest to motivate lasting change in the organization. Additional empirical investigations of time saved as a consequence of the strategies provided are needed. If organizations solve their problems rapidly, fewer unresolved problems may remain.

Micro solar concentrators: Design and fabrication for microcells arrays

Science.gov (United States)

Jutteau, Sébastien; Paire, Myriam; Proise, Florian; Lombez, Laurent; Guillemoles, Jean-François

2015-09-01

In this work we look at a micro-concentrating system adapted to a new type of concentrator photovoltaic material, well known for flate-plate applications, Cu(In,Ga)Se2. Cu(In,Ga)Se2 solar cells are polycrystalline thin film devices that can be deposited by a variety of techniques. We proposed to use a microcell architecture [1], [2], with lateral dimensions varying from a few μm to hundreds of μm, to adapt the film cell to concentration conditions. A 5% absolute efficiency increase on Cu(In,Ga)Se2 microcells at 475 suns has been observed for a final efficiency of 21.3%[3]. We study micro-concentrating systems adapted to the low and middle concentration range, where thin film concentrator cells will lean to substrate fabrication simplification and cost savings. Our study includes optical design, fabrication and experimental tests of prototypes.

Intra-pulse Cavity Enhanced Measurements of Carbon Monoxide in a Rapid Compression Machine

KAUST Repository

Nasir, Ehson Fawad; Farooq, Aamir

2018-01-01

A laser absorption sensor for carbon monoxide concentration was developed for combustion studies in a rapid compression machine using a pulsed quantum cascade laser near 4.89 μm. Cavity enhancement reduced minimum detection limit down to 2.4 ppm

Studies on osmotic concentration of radioactive effluents

International Nuclear Information System (INIS)

Thomas, K.C.; Ramachandhran, V.; Misra, B.M.

1986-01-01

The potential of direct osmosis for concentrating radioactive effluents is examined on the laboratory scale. Studies were carried out using asymmetric cellulose acetate membranes of a range of porosities under varying salinity gradients. A suitable bench scale osmotic concentrator employing tubular membrane systems has been fabricated and tested. An attempt to understand the mechanism of water permeation under osmotic and hydrostatic gradients has been made based on the irreversible thermodynamic approach. The solute separation of sodium chloride and radionuclides under osmosis is in the range of 85 to 95% for various osmotic sink solutions. The osmotic water flux is observed to be lower than the hydraulic water flux under reverse osmosis conditions. While the solute separation increases with an increase in annealing temperature, water flux decreases for both osmosis and reverse osmosis systems for various feed salinities. The effect of concentration polarization is analysed, and the effect of feed and osmotic sink velocity on the performance of the osmotic concentrator has also been studied. (orig.)

Spatiotemporal Characterization of Ambient PM2.5 Concentrations in Shandong Province (China).

Science.gov (United States)

Yang, Yong; Christakos, George

2015-11-17

China experiences severe particulate matter (PM) pollution problems closely linked to its rapid economic growth. Advancing the understanding and characterization of spatiotemporal air pollution distribution is an area where improved quantitative methods are of great benefit to risk assessment and environmental policy. This work uses the Bayesian maximum entropy (BME) method to assess the space-time variability of PM2.5 concentrations and predict their distribution in the Shandong province, China. Daily PM2.5 concentrations obtained at air quality monitoring sites during 2014 were used. On the basis of the space-time PM2.5 distributions generated by BME, we performed three kinds of querying analysis to reveal the main distribution features. The results showed that the entire region of interest is seriously polluted (BME maps identified heavy pollution clusters during 2014). Quantitative characterization of pollution severity included both pollution level and duration. The number of days during which regional PM2.5 exceeded 75, 115, 150, and 250 μg m(-3) varied: 43-253, 13-128, 4-66, and 0-15 days, respectively. The PM2.5 pattern exhibited an increasing trend from east to west, with the western part of Shandong being a heavily polluted area (PM2.5 exceeded 150 μg m(-3) during long time periods). Pollution was much more serious during winter than during other seasons. Site indicators of PM2.5 pollution intensity and space-time variation were used to assess regional uncertainties and risks with their interpretation depending on the pollutant threshold. The observed PM2.5 concentrations exceeding a specified threshold increased almost linearly with increasing threshold value, whereas the relative probability of excess pollution decreased sharply with increasing threshold.

Integrated database for rapid mass movements in Norway

Directory of Open Access Journals (Sweden)

C. Jaedicke

2009-03-01

terrain of the Norwegian west coast, but major events are recorded all over the country. Snow avalanches account for most fatalities, while large rock slides causing flood waves and huge quick clay slides are the most damaging individual events in terms of damage to infrastructure and property and for causing multiple fatalities. The quality of the data is strongly influenced by the personal engagement of local observers and varying observation routines. This database is a unique source for statistical analysis including, risk analysis and the relation between rapid mass movements and climate. The database of rapid mass movement events will also facilitate validation of national hazard and risk maps.

Effect of ventilation rate on concentrations of indoor radon and its progenies

International Nuclear Information System (INIS)

Wang Chunhong; Liu Yanyang; Liu Fudong; Liu Senlin; Chen Ling

2012-01-01

To study concentrations of indoor radon and its progenies, ventilation rates and their corresponding concentrations of indoor radon and its progenies were measured using tracer-gas dilution method. Results show that both ventilation rates and concentrations of indoor radon varied insignificantly and radon concentration were higher than the outdoor environment while doors and windows were all closed with air-conditioner on and off respectively; the concentrations declined and close to the outdoor level when doors and windows were all open with ventilators in operation. Accordingly, in modern life, especially in summer, people's preference for air-conditioners but natural ventilation would result in an increase of indoor radon concentration. (authors)

Concentration of Melton Valley Storage Tank surrogates with a wiped film evaporator

International Nuclear Information System (INIS)

Boring, M.D.; Farr, L.L.; Fowler, V.L.; Hewitt, J.D.

1994-08-01

This report describes experiments to determine whether a wiped film evaporator (WFE) might be used to concentrate low-level liquid radioactive waste (LLLW). Solutions used in these studies were surrogates that contain no radionuclides. The compositions of the surrogates were based on one of Oak Ridge National Laboratory's (ORNL's) Melton Valley Storage Tanks (MVSTs). It was found that a WFE could be used to concentrate LLLW to varying degrees by manipulating various parameters. The parameters studied were rotor speed, process fluid feed temperature and feed rate, and evaporator temperature. Product consistency varied from an unsaturated liquid to a dry powder. Volume reductions up to 68% were achieved. System decontamination factors were consistently in the range of 10 4

Lead and cadmium in human teeth from Jordan by atomic absorption spectrometry: Some factors influencing their concentrations

Energy Technology Data Exchange (ETDEWEB)

Alomary, A. [Department of Chemistry, Yarmouk University, Irbid (Jordan)]. E-mail: ahmedalomary1000@hotmail.com; Al-Momani, I.F. [Department of Chemistry, Yarmouk University, Irbid (Jordan); Massadeh, A.M. [Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid (Jordan)

2006-10-01

The aim of this study was to measure the concentrations of lead (Pb) and cadmium (Cd) in human teeth and to investigate the affecting factors. Teeth samples (n = 268) were collected from people living in different cities in Jordan including Amman, Zarqa, Al-Mafraq and Irbid and analyzed for Pb and Cd using atomic absorption spectrometry (AAS). A questionnaire was used to gather information on each person, such as age, sex, place where the patient lives, smoking, presence of amalgam fillings inside the mouth, and whether the patient uses toothpaste or not. The mean concentrations of Pb and Cd were 28.91 {mu}g/g and 0.44 {mu}g/g, respectively. The results indicate that there is a clear relation between Pb and Cd concentrations and the presence of amalgam fillings, smoking, and place of living. Pb was sex-dependent, whereas Cd was not. Our results show that Pb and Cd concentrations in samples obtained from Al-Mafraq and Irbid are higher than those obtained from Amman and Zarqa. Pb was highest in Mafraq, whereas Cd was highest in Irbid. The Pb and Cd concentrations in teeth from smokers (means: Pb = 31.89 {mu}g/g, Cd = 0.49 {mu}g/g) were significantly higher than those from nonsmokers (means: Pb = 24.07 {mu}g/g, Cd = 0.37 {mu}g/g). Pb and Cd concentrations in teeth of patients with amalgam fillings (means: Pb = 31.02 {mu}g/g and Cd = 0.52 {mu}g/g) were significantly higher than those from patients without amalgam fillings (means: Pb = 26.87 {mu}g/g and Cd = 0.41 {mu}g/g). Our results show that brushing the teeth daily with toothpaste does not significantly decrease the concentration of both Pb and Cd. The mean concentrations of Pb and Cd do not vary significantly between the ages 20-30, 31-40, and 41-50, but both increased rapidly at age 51-60.

Lead and cadmium in human teeth from Jordan by atomic absorption spectrometry: Some factors influencing their concentrations

International Nuclear Information System (INIS)

Alomary, A.; Al-Momani, I.F.; Massadeh, A.M.

2006-01-01

The aim of this study was to measure the concentrations of lead (Pb) and cadmium (Cd) in human teeth and to investigate the affecting factors. Teeth samples (n = 268) were collected from people living in different cities in Jordan including Amman, Zarqa, Al-Mafraq and Irbid and analyzed for Pb and Cd using atomic absorption spectrometry (AAS). A questionnaire was used to gather information on each person, such as age, sex, place where the patient lives, smoking, presence of amalgam fillings inside the mouth, and whether the patient uses toothpaste or not. The mean concentrations of Pb and Cd were 28.91 μg/g and 0.44 μg/g, respectively. The results indicate that there is a clear relation between Pb and Cd concentrations and the presence of amalgam fillings, smoking, and place of living. Pb was sex-dependent, whereas Cd was not. Our results show that Pb and Cd concentrations in samples obtained from Al-Mafraq and Irbid are higher than those obtained from Amman and Zarqa. Pb was highest in Mafraq, whereas Cd was highest in Irbid. The Pb and Cd concentrations in teeth from smokers (means: Pb = 31.89 μg/g, Cd = 0.49 μg/g) were significantly higher than those from nonsmokers (means: Pb = 24.07 μg/g, Cd = 0.37 μg/g). Pb and Cd concentrations in teeth of patients with amalgam fillings (means: Pb = 31.02 μg/g and Cd = 0.52 μg/g) were significantly higher than those from patients without amalgam fillings (means: Pb = 26.87 μg/g and Cd = 0.41 μg/g). Our results show that brushing the teeth daily with toothpaste does not significantly decrease the concentration of both Pb and Cd. The mean concentrations of Pb and Cd do not vary significantly between the ages 20-30, 31-40, and 41-50, but both increased rapidly at age 51-60

Local thermodynamic equilibrium in rapidly heated high energy density plasmas

International Nuclear Information System (INIS)

Aslanyan, V.; Tallents, G. J.

2014-01-01

Emission spectra and the dynamics of high energy density plasmas created by optical and Free Electron Lasers (FELs) depend on the populations of atomic levels. Calculations of plasma emission and ionization may be simplified by assuming Local Thermodynamic Equilibrium (LTE), where populations are given by the Saha-Boltzmann equation. LTE can be achieved at high densities when collisional processes are much more significant than radiative processes, but may not be valid if plasma conditions change rapidly. A collisional-radiative model has been used to calculate the times taken by carbon and iron plasmas to reach LTE at varying densities and heating rates. The effect of different energy deposition methods, as well as Ionization Potential Depression are explored. This work shows regimes in rapidly changing plasmas, such as those created by optical lasers and FELs, where the use of LTE is justified, because timescales for plasma changes are significantly longer than the times needed to achieve an LTE ionization balance

Effect of soil moisture on trace elements concentrations using ...

African Journals Online (AJOL)

Portable X-ray fluorescence (PXRF) technology can offer rapid and cost-effective determination of the trace elements concentrations in soils. The aim of this study was to assess the influence of soil moisture content under different condition on PXRF measurement quality. For this purpose, PXRF was used to evaluate the soil ...

Rapid quantification of biomarkers during kerogen microscale pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Stott, A.W.; Abbott, G.D. [Fossil Fuels and Environmental Geochemistry NRG, The University, Newcastle-upon-Tyne (United Kingdom)

1995-02-01

A rapid, reproducible method incorporating closed system microscale pyrolysis and thermal desorption-gas chromatography/mass spectrometry has been developed and applied to the quantification of sterane biomarkers released during pyrolysis of the Messel oil shale kerogen under confined conditions. This method allows a substantial experimental concentration-time data set to be collected at accurately controlled temperatures, due to the low thermal inertia of the microscale borosilicate glass reaction vessels, which facilitates kinetic studies of biomarker reactions during kerogen microscale pyrolysis

"Rapid Revisit" Measurements of Sea Surface Winds Using CYGNSS

Science.gov (United States)

Park, J.; Johnson, J. T.

2017-12-01

The Cyclone Global Navigation Satellite System (CYGNSS) is a space-borne GNSS-R (GNSS-Reflectometry) mission that launched December 15, 2016 for ocean surface wind speed measurements. CYGNSS includes 8 small satellites in the same LEO orbit, so that the mission provides wind speed products having unprecedented coverage both in time and space to study multi-temporal behaviors of oceanic winds. The nature of CYGNSS coverage results in some locations on Earth experiencing multiple wind speed measurements within a short period of time (a "clump" of observations in time resulting in a "rapid revisit" series of measurements). Such observations could seemingly provide indications of regions experiencing rapid changes in wind speeds, and therefore be of scientific utility. Temporally "clumped" properties of CYGNSS measurements are investigated using early CYGNSS L1/L2 measurements, and the results show that clump durations and spacing vary with latitude. For example, the duration of a clump can extend as long as a few hours at higher latitudes, with gaps between clumps ranging from 6 to as high as 12 hours depending on latitude. Examples are provided to indicate the potential of changes within a clump to produce a "rapid revisit" product for detecting convective activity. Also, we investigate detector design for identifying convective activities. Results from analyses using recent CYGNSS L2 winds will be provided in the presentation.

Spatiotemporal variation of radon and carbon dioxide concentrations in an underground quarry: coupled processes of natural ventilation, barometric pumping and internal mixing

International Nuclear Information System (INIS)

Perrier, Frederic; Richon, Patrick

2010-01-01

Radon-222 and carbon dioxide concentrations have been measured during several years at several points in the atmosphere of an underground limestone quarry located at a depth of 18 m in Vincennes, near Paris, France. Both concentrations showed a seasonal cycle. Radon concentration varied from 1200 to 2000 Bq m -3 in summer to about 800-1400 Bq m -3 in winter, indicating winter ventilation rates varying from 0.6 to 2.5 x 10 -6 s -1 . Carbon dioxide concentration varied from 0.9 to 1.0% in summer, to about 0.1-0.3% in winter. Radon concentration can be corrected for natural ventilation using temperature measurements. The obtained model also accounts for the measured seasonal variation of carbon dioxide. After correction, radon concentrations still exhibit significant temporal variation, mostly associated with the variation of atmospheric pressure, with coupling coefficients varying from -7 to -26 Bq m -3 hPa -1 . This variation can be accounted for using a barometric pumping model, coupled with natural ventilation in winter, and including internal mixing as well. After correction, radon concentrations exhibit residual temporal variation, poorly correlated between different points, with standard deviations varying from 3 to 6%. This study shows that temporal variation of radon concentrations in underground cavities can be understood to a satisfactory level of detail using non-linear and time-dependent modelling. It is important to understand the temporal variation of radon concentrations and the limitations in their modelling to monitor the properties of natural or artificial underground settings, and to be able to assess the existence of new processes, for example associated with the preparatory phases of volcanic eruptions or earthquakes.

Fluctuating interaction network and time-varying stability of a natural fish community

Science.gov (United States)

Ushio, Masayuki; Hsieh, Chih-Hao; Masuda, Reiji; Deyle, Ethan R.; Ye, Hao; Chang, Chun-Wei; Sugihara, George; Kondoh, Michio

2018-02-01

Ecological theory suggests that large-scale patterns such as community stability can be influenced by changes in interspecific interactions that arise from the behavioural and/or physiological responses of individual species varying over time. Although this theory has experimental support, evidence from natural ecosystems is lacking owing to the challenges of tracking rapid changes in interspecific interactions (known to occur on timescales much shorter than a generation time) and then identifying the effect of such changes on large-scale community dynamics. Here, using tools for analysing nonlinear time series and a 12-year-long dataset of fortnightly collected observations on a natural marine fish community in Maizuru Bay, Japan, we show that short-term changes in interaction networks influence overall community dynamics. Among the 15 dominant species, we identify 14 interspecific interactions to construct a dynamic interaction network. We show that the strengths, and even types, of interactions change with time; we also develop a time-varying stability measure based on local Lyapunov stability for attractor dynamics in non-equilibrium nonlinear systems. We use this dynamic stability measure to examine the link between the time-varying interaction network and community stability. We find seasonal patterns in dynamic stability for this fish community that broadly support expectations of current ecological theory. Specifically, the dominance of weak interactions and higher species diversity during summer months are associated with higher dynamic stability and smaller population fluctuations. We suggest that interspecific interactions, community network structure and community stability are dynamic properties, and that linking fluctuating interaction networks to community-level dynamic properties is key to understanding the maintenance of ecological communities in nature.

Hybrid Perovskites: Prospects for Concentrator Solar Cells.

Science.gov (United States)

Lin, Qianqian; Wang, Zhiping; Snaith, Henry J; Johnston, Michael B; Herz, Laura M

2018-04-01

Perovskite solar cells have shown a meteoric rise of power conversion efficiency and a steady pace of improvements in their stability of operation. Such rapid progress has triggered research into approaches that can boost efficiencies beyond the Shockley-Queisser limit stipulated for a single-junction cell under normal solar illumination conditions. The tandem solar cell architecture is one concept here that has recently been successfully implemented. However, the approach of solar concentration has not been sufficiently explored so far for perovskite photovoltaics, despite its frequent use in the area of inorganic semiconductor solar cells. Here, the prospects of hybrid perovskites are assessed for use in concentrator solar cells. Solar cell performance parameters are theoretically predicted as a function of solar concentration levels, based on representative assumptions of charge-carrier recombination and extraction rates in the device. It is demonstrated that perovskite solar cells can fundamentally exhibit appreciably higher energy-conversion efficiencies under solar concentration, where they are able to exceed the Shockley-Queisser limit and exhibit strongly elevated open-circuit voltages. It is therefore concluded that sufficient material and device stability under increased illumination levels will be the only significant challenge to perovskite concentrator solar cell applications.

X-ray fluorescence analysis of metal concentration in an alloy electroplating bath

International Nuclear Information System (INIS)

Hines, R.A.

1980-06-01

An energy-dispersive x-ray fluorescence analysis system has been developed for rapid, simultaneous analysis of gold and copper concentrations in an aqueous electroplating bath. The speed and repeatability of the system make it well suited for in-process control. Data collection and reduction are automatic. The analysis requires less than 10 minutes from taking the sample to printing the gold and copper concentrations

Particle interactions in concentrated suspensions

International Nuclear Information System (INIS)

Mondy, L.A.; Graham, A.L.; Abbott, J.R.; Brenner, H.

1993-01-01

An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small. The authors describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with such a flow-induced, spatially varying concentration, one must know how the viscosity of a homogeneous suspension depends on such variables as solids concentration and particle orientation. The authors suggest the technique of falling ball viscometry, using small balls, as a method to determine the effective viscosity of a suspension without affecting the original microstructure significantly. They also describe data from experiments in which the detailed fluctuations of a falling ball's velocity indicate the noncontinuum nature of the suspension and may lead to more insights into the effects of suspension microstructure on macroscopic properties. Finally, they briefly describe other experiments that can be performed in quiescent suspensions (in contrast to the use of conventional shear rotational viscometers) in order to learn more about boundary effects in concentrated suspensions

Influence of rapid changes in cytosolic pH on oxidative phosphorylation in skeletal muscle: theoretical studies.

Science.gov (United States)

Korzeniewski, Bernard; Zoladz, Jerzy A

2002-07-01

Cytosolic pH in skeletal muscle may vary significantly because of proton production/consumption by creatine kinase and/or proton production by anaerobic glycolysis. A computer model of oxidative phosphorylation in intact skeletal muscle developed previously was used to study the kinetic effect of these variations on the oxidative phosphorylation system. Two kinds of influence were analysed: (i) via the change in pH across the inner mitochondrial membrane and (ii) via the shift in the equilibrium of the creatine kinase-catalysed reaction. Our simulations suggest that cytosolic pH has essentially no impact on the steady-state fluxes and most metabolite concentrations. On the other hand, rapid acidification/alkalization of cytosol causes a transient decrease/increase in the respiration rate. Furthermore, changes in pH seem to affect significantly the kinetic properties of transition between resting state and active state. An increase in pH brought about by proton consumption by creatine kinase at the onset of exercise lengthens the transition time. At intensive exercise levels this pH increase could lead to loss of the stability of the system, if not compensated by glycolytic H+ production. Thus our theoretical results stress the importance of processes/mechanisms that buffer/compensate for changes in cytosolic proton concentration. In particular, we suggest that the second main role of anaerobic glycolysis, apart from additional ATP supply, may be maintaining the stability of the system at intensive exercise.

Heterogeneous Nitrification in a Full Scale Rapid Sand Filter Treating Groundwater

DEFF Research Database (Denmark)

Lopato, Laure; Röttgers, Nina; Binning, Philip John

2013-01-01

Experiments were conducted to determine ammonium removal kinetics in an operating biologically active sand filter at a waterworks treating anaerobic groundwater. The ammonium load varied between 0.7 and 3 g N/h/m2 (concentration ranged from 0.23 to 0.78 mg N/l) and the inlet water flux varied...... nitrification rate constant was closely related to the water pore velocity which implies that the rate is strongly determined by the resistance to mass transport in the diffusion boundary layer around the sand grains. Read More: http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EE.1943-7870.0000653...

Automated rapid particle investigation using scanning electron microscopy

Science.gov (United States)

Wilkins, Jerod Laurence

The chemical composition of fly ash particles has been known to vary significantly depending on a number of factors. Current bulk methods of investigation including X-Ray Fluorescence and X-Ray Diffraction are thought to be inadequate in determining the performance of fly ash in concrete. It is the goal of this research to develop a method of Automated Rapid Particle Investigation that will not look at fly ash as a bulk material but as individual particles. By examining each particle individually scientists and engineers will have the ability to study the variation in chemical composition by comparing the chemistry present in each particle. The method of investigation developed by this research provides a practical technique that will allow the automated chemical analysis of hundreds, or even thousands, of fly ash particles in a matter of minutes upon completion of sample preparation and automated scanning electron microscope (ASEM) scanning. This research does not examine the significance of the chemical compounds discovered; rather, only the investigation methodology is discussed. Further research will be done to examine the importance of the chemistry discovered with this automated rapid particle investigation technique.

Rapid determination of actinides in seawater samples

International Nuclear Information System (INIS)

Maxwell, S.L.; Culligan, B.K.; Hutchison, J.B.; Utsey, R.C.; McAlister, D.R.

2014-01-01

A new rapid method for the determination of actinides in seawater samples has been developed at the Savannah River National Laboratory. The actinides can be measured by alpha spectrometry or inductively-coupled plasma mass spectrometry. The new method employs novel pre-concentration steps to collect the actinide isotopes quickly from 80 L or more of seawater. Actinides are co-precipitated using an iron hydroxide co-precipitation step enhanced with Ti +3 reductant, followed by lanthanum fluoride co-precipitation. Stacked TEVA Resin and TRU Resin cartridges are used to rapidly separate Pu, U, and Np isotopes from seawater samples. TEVA Resin and DGA Resin were used to separate and measure Pu, Am and Cm isotopes in seawater volumes up to 80 L. This robust method is ideal for emergency seawater samples following a radiological incident. It can also be used, however, for the routine analysis of seawater samples for oceanographic studies to enhance efficiency and productivity. In contrast, many current methods to determine actinides in seawater can take 1-2 weeks and provide chemical yields of ∼30-60 %. This new sample preparation method can be performed in 4-8 h with tracer yields of ∼85-95 %. By employing a rapid, robust sample preparation method with high chemical yields, less seawater is needed to achieve lower or comparable detection limits for actinide isotopes with less time and effort. (author)

Concentrations of Se, Ba, Zn and Mn in Brazil nuts

Energy Technology Data Exchange (ETDEWEB)

Armelin, Maria José A.; Maihara, Vera A.; Cardoso, Paulo S.; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Cozollino, Silvia M.F., E-mail: marmelin@ipen.br, E-mail: vmaihara@ipen.br, E-mail: msaiki@ipen.br, E-mail: pscsilva@ipen.br, E-mail: smfcozzo@usp.br [Universidade de São Paulo (USP), SP (Brazil). Faculdade de Ciências Farmacêuticas

2017-07-01

The concentrations of Se, Ba, Zn and Mn were determined in samples of Brazil nuts collected in two ways: a) in a production farm predominantly for export and, b) in various points of sale from different regions of Brazil. Instrumental neutron activation analysis was the analytical technique used in this study. Results indicate that the concentrations of Se and Ba varied greatly among the Brazil nut samples analyzed. This large variability may be related to the soil characteristics from which the nuts were produced. An inverse correlation was observed between the concentrations of Se and Ba. On the other hand, the concentrations of Zn and Mn did not show significant differences among these samples. (author)

Concentrations of Se, Ba, Zn and Mn in Brazil nuts

International Nuclear Information System (INIS)

Armelin, Maria José A.; Maihara, Vera A.; Cardoso, Paulo S.; Saiki, Mitiko; Cozollino, Silvia M.F.

2017-01-01

The concentrations of Se, Ba, Zn and Mn were determined in samples of Brazil nuts collected in two ways: a) in a production farm predominantly for export and, b) in various points of sale from different regions of Brazil. Instrumental neutron activation analysis was the analytical technique used in this study. Results indicate that the concentrations of Se and Ba varied greatly among the Brazil nut samples analyzed. This large variability may be related to the soil characteristics from which the nuts were produced. An inverse correlation was observed between the concentrations of Se and Ba. On the other hand, the concentrations of Zn and Mn did not show significant differences among these samples. (author)

A Comparison of Evolutionary Algorithms for Tracking Time-Varying Recursive Systems

Directory of Open Access Journals (Sweden)

White Michael S

2003-01-01

Full Text Available A comparison is made of the behaviour of some evolutionary algorithms in time-varying adaptive recursive filter systems. Simulations show that an algorithm including random immigrants outperforms a more conventional algorithm using the breeder genetic algorithm as the mutation operator when the time variation is discontinuous, but neither algorithm performs well when the time variation is rapid but smooth. To meet this deficit, a new hybrid algorithm which uses a hill climber as an additional genetic operator, applied for several steps at each generation, is introduced. A comparison is made of the effect of applying the hill climbing operator a few times to all members of the population or a larger number of times solely to the best individual; it is found that applying to the whole population yields the better results, substantially improved compared with those obtained using earlier methods.

Zhang neural network for online solution of time-varying convex quadratic program subject to time-varying linear-equality constraints

International Nuclear Information System (INIS)

Zhang Yunong; Li Zhan

2009-01-01

In this Letter, by following Zhang et al.'s method, a recurrent neural network (termed as Zhang neural network, ZNN) is developed and analyzed for solving online the time-varying convex quadratic-programming problem subject to time-varying linear-equality constraints. Different from conventional gradient-based neural networks (GNN), such a ZNN model makes full use of the time-derivative information of time-varying coefficient. The resultant ZNN model is theoretically proved to have global exponential convergence to the time-varying theoretical optimal solution of the investigated time-varying convex quadratic program. Computer-simulation results further substantiate the effectiveness, efficiency and novelty of such ZNN model and method.

The dynamics of Orimulsion in water with varying energy, salinity and temperature

International Nuclear Information System (INIS)

Fingas, M.F.; Fieldhouse, B.; Wang, Z.; Environment Canada, Ottawa, ON

2004-01-01

Orimulsion is a surfactant-stabilized oil-in-water emulsion composed of 70 per cent bitumen and 30 per cent water. Its unique composition causes it to behave differently from conventional fuel oils when spilled at sea. Earlier studies have shown that Orimulsion is driven by buoyancy to rise in salt water and sink in fresh water. This study conducted 11 experiments at lower temperature and salinity values to obtain new information on the behaviour of Orimulsion in salt, fresh and brackish water. The applied rotational field was adjusted to vary the energy. A time-series of samples of Orimulsion in a 300 litre tank of water were taken to determine depletion rates and characteristics. Oil on the surface was quantified and the concentration of bitumen and particle size distribution was determined. The study also measured changes in bitumen concentration and particle size distribution as a function of time. The data was used to develop simple equations that predict concentrations of bitumen resurfacing and remaining in the water column as a function of time. It was concluded that there is a complex interaction between salinity, time, energy and temperature. 9 refs., 5 tabs., 8 figs

Rapid method to determine actinides and 89/90Sr in limestone and marble samples

International Nuclear Information System (INIS)

Maxwell, S.L.; Culligan, Brian; Hutchison, J.B.; Utsey, R.C.; Sudowe, Ralf; McAlister, D.R.

2016-01-01

A new method for the determination of actinides and radiostrontium in limestone and marble samples has been developed that utilizes a rapid sodium hydroxide fusion to digest the sample. Following rapid pre-concentration steps to remove sample matrix interferences, the actinides and 89 / 90 Sr are separated using extraction chromatographic resins and measured radiometrically. The advantages of sodium hydroxide fusion versus other fusion techniques will be discussed. This approach has a sample preparation time for limestone and marble samples of <4 h. (author)

New method and installation for rapid determination of radon diffusion coefficient in various materials.

Science.gov (United States)

Tsapalov, Andrey; Gulabyants, Loren; Livshits, Mihail; Kovler, Konstantin

2014-04-01

The mathematical apparatus and the experimental installation for the rapid determination of radon diffusion coefficient in various materials are developed. The single test lasts not longer than 18 h and allows testing numerous materials, such as gaseous and liquid media, as well as soil, concrete and radon-proof membranes, in which diffusion coefficient of radon may vary in an extremely wide range, from 1·10(-12) to 5·10(-5) m(2)/s. The uncertainty of radon diffusion coefficient estimation depends on the permeability of the sample and varies from about 5% (for the most permeable materials) to 40% (for less permeable materials, such as radon-proof membranes). Copyright © 2014. Published by Elsevier Ltd.

Assessment of metal contamination in the biota of four rivers experiencing varying degrees of human impact.

Science.gov (United States)

Bielmyer-Fraser, Gretchen K; Waters, Matthew Neal; Duckworth, Christina G; Patel, Pratik P; Webster, Benjamin Cole; Blocker, Amber; Crummey, Cliff Hunter; Duncan, Aundrea Nicole; Nwokike, Somuayiro Nadia; Picariello, Codie Richard; Ragan, James T; Schumacher, Erika L; Tucker, Rebecca Lea; Tuttle, Elizabeth Ann; Wiggins, Charlie Rufus

2017-01-01

Urbanization, agriculture, and other land transformations can affect water quality, decrease species biodiversity, and increase metal and nutrient concentrations in aquatic systems. Metal pollution, in particular, is a reported consequence of elevated anthropogenic inputs, especially from urbanized areas. The objectives of this study were to quantify metal (Cu, Al, Cd, Ni, and Pb) concentrations in the waters and biota of four streams in South Georgia, USA, and relate metal concentrations to land use and abiotic and biotic stream processes. Additionally, macrophytes, invertebrates, and fish were identified to assess biodiversity at each site. Metal concentrations in the three trophic levels differed among sites and species, correlating to differences in land use surrounding the rivers. The highest metal concentrations (except Al) were found in the streams most impacted by urbanization and development. Al concentrations were highest in streams surrounded by land dominated by forested areas. Metal content in macrophytes reflected metal concentrations in the water and was at least three orders of magnitude higher than any other trophic level. Despite metal concentration differences, all four streams contained similar water quality and were healthy based on macroinvertebrate community structure. This study provides insight into the impact of urbanization and the fate and effects of metals in river ecosystems with varying degrees of anthropogenic impact.

Petroleum hydrocarbon concentrations in ten commercial fish species along Tamilnadu coast, Bay of Bengal, India.

Science.gov (United States)

Veerasingam, S; Venkatachalapathy, R; Raja, P; Sudhakar, S; Rajeswari, V; Asanulla, R Mohamed; Mohan, R; Sutharsan, P

2011-05-01

The aim of the present study was to evaluate the distribution of petroleum hydrocarbons in ten commercial fish species and water samples in three estuaries along Tamilnadu coast, Bay of Bengal, India. Fish and water samples collected from Tamilnadu coast, India, were extracted and analyzed for petroleum hydrocarbons by ultraviolet fluorescence (UVF) spectroscopy. The petroleum hydrocarbon concentration (PHC) in coastal waters and fish species varied between 2.28 and 14.02 μg/l and 0.52 and 2.05 μg/g, respectively. The highest PHC concentration was obtained in Uppanar estuarine waters (14.02 ± 0.83) and the lowest was observed in Vellar estuarine waters (2.28 ± 0.25). Among the ten fish species, Sardinella longiceps have high PHC concentration from all the locations. This study suggests that S. longiceps can be used as a good biological indicator for petroleum hydrocarbon pollution in water. The concentration of petroleum hydrocarbons in coastal waters along Tamilnadu coast is markedly higher than that in the background, but there is no evidence for its increase in fish of this region. From a public health point, petroleum hydrocarbon residue levels in all fish samples analyzed in this study are considerably lower than the hazardous levels. At present, as Tamilnadu coastal area is in a rapid development stage of new harbour, chemical industries, power plants, oil exploration and other large-scale industries, further assessment of petroleum hydrocarbons and the various hydrodynamic conditions acting in the region are to be studied in detail and continuous pollution monitoring studies should be conducted for improving the aquatic environment. The results will also be useful for pollution monitoring program along the coastal region and also to check the levels of petroleum hydrocarbons.

Measurement of Alpha Emitters Concentration in Imported Cigarettes

International Nuclear Information System (INIS)

Nasser Allah, Z.K.; Musa, W.A.; AL-Rawi, A.A.S.

2011-01-01

The aime of this study was to measured the alpha emitters concentration of (15) different kinds of imported cigarettes. the nuclear reaction used U-235(n, f) obtained by the bombardment of U-235 with thermal neutrons from (Am B e)neutron source with thermal flux of(5*10 3 n.cm -2 .s -1 ). The Results obtained showed the values of the Uranium concentration, and varies from (0.041 ppm) in five stares kind to (2.374ppm) in Machbeth (chocolate) 100's kind. All the result obtained are within the limit levels as given by UNSCAR data

Rapid determination of uranium in natural waters by fthermal emission mass spectrometry

International Nuclear Information System (INIS)

Ferguson, J.R.; Caylor, J.D.; Rogers, E.R.; Cole, S.H.

1977-03-01

A method has been developed to rapidly analyze natural water samples for part-per-trillion (ng/l) concentrations of uranium using a custom-built thermal-emission mass spectrometer. The filtered water sample is spiked with 233 U as an internal standard and extracted with a 2 percent solution of TOPO (trioctylphosphine oxide) in carbon tetrachloride. An aliquot of the organic phase is evaporated and the uranium in the residue extracted with aqueous ammonium carbonate. A 5j-μl aliquot is taken and dried on a flat uranium concentration of 3 ng/l will yield a count rate greater than three times the standard deviation, plus the mean of the background, and is defined as the lowest determinable concentration. The standard deviation of the method is 3 percent at accuracy of the method has been evaluated by comparing the results with a fluorescence procedure. There is very good agreement for water samples with uranium concentrations from 200 to 1000 ng/l. The mass spectrometer is a 6-in. -radius, 60-degree-sector instrument equipped for ion counting and having a vacuum system allowing rapid sample changing while maintaining a high source vacuum. A multiplexer and high-voltage s witch provide synchronized peak switching and scaler gating for monitoring three isotopes of uranium 238, 235, and 233. With this instrument, an analyst can achieve an analysis rate in excess of 50 samples per eight-hour shift

Rapid and long-term effects of water deficit on gas exchange and hydraulic conductance of silver birch trees grown under varying atmospheric humidity.

Science.gov (United States)

Sellin, Arne; Niglas, Aigar; Õunapuu-Pikas, Eele; Kupper, Priit

2014-03-24

Effects of water deficit on plant water status, gas exchange and hydraulic conductance were investigated in Betula pendula under artificially manipulated air humidity in Eastern Estonia. The study was aimed to broaden an understanding of the ability of trees to acclimate with the increasing atmospheric humidity predicted for northern Europe. Rapidly-induced water deficit was imposed by dehydrating cut branches in open-air conditions; long-term water deficit was generated by seasonal drought. The rapid water deficit quantified by leaf (ΨL) and branch water potentials (ΨB) had a significant (P gas exchange parameters, while inclusion of ΨB in models resulted in a considerably better fit than those including ΨL, which supports the idea that stomatal openness is regulated to prevent stem rather than leaf xylem dysfunction. Under moderate water deficit (ΨL≥-1.55 MPa), leaf conductance to water vapour (gL), transpiration rate and leaf hydraulic conductance (KL) were higher (P water deficit (ΨLwater availability, i.e. due to higher soil water potential in H treatment. Two functional characteristics (gL, KL) exhibited higher (P water deficit in trees grown under increased air humidity. The experiment supported the hypothesis that physiological traits in trees acclimated to higher air humidity exhibit higher sensitivity to rapid water deficit with respect to two characteristics - leaf conductance to water vapour and leaf hydraulic conductance. Disproportionate changes in sensitivity of stomatal versus leaf hydraulic conductance to water deficit will impose greater risk of desiccation-induced hydraulic dysfunction on the plants, grown under high atmospheric humidity, in case of sudden weather fluctuations, and might represent a potential threat in hemiboreal forest ecosystems. There is no trade-off between plant hydraulic capacity and photosynthetic water-use efficiency on short time scale.

Artifacts in measuring aerosol uptake kinetics: the roles of time, concentration and adsorption

Directory of Open Access Journals (Sweden)

L. H. Renbaum

2011-07-01

Full Text Available In laboratory studies of organic aerosol particles reacting with gas-phase oxidants, high concentrations of radicals are often used to study on the timescale of seconds reactions which may be occurring over days or weeks in the troposphere. Implicit in this approach is the assumption that radical concentration and time are interchangeable parameters, though this has not been established. Here, the kinetics of OH- and Cl-initiated oxidation reactions of model single-component liquid (squalane and supercooled (brassidic acid and 2-octyldodecanoic acid organic aerosols are studied by varying separately the radical concentration and the reaction time. Two separate flow tubes with residence times of 2 and 66 s are used, and [OH] and [Cl] are varied by adjusting either the laser photolysis fluence or the radical precursor concentration ([O₃] or [Cl₂], respectively used to generate the radicals. It is found that the rates measured by varying the radical concentration and the reaction time are equal only if the precursor concentrations are the same in the two approaches. Further, the rates depend on the concentrations of the precursor species with a Langmuir-type functional form suggesting that O₃ and Cl₂ saturate the surface of the liquid particles. It is believed that the presence of O₃ inhibits the rate of OH reaction, perhaps by reacting with OH radicals or by O₃ or intermediate species blocking surface sites, while Cl₂ enhances the rate of Cl reaction by participating in a radical chain mechanism. These results have important implications for laboratory experiments in which high concentrations of gas-phase oxidants are used to study atmospheric reactions over short timescales and may explain the variability in recent measurements of the reactive uptake of OH on squalane particles in reactor systems used in this and other laboratories.

Dynamics of soil CO 2 efflux under varying atmospheric CO 2 concentrations reveal dominance of slow processes

Science.gov (United States)

Dohyoung Kim; Ram Oren; James S. Clark; Sari Palmroth; A. Christopher Oishi; Heather R. McCarthy; Chris A. Maier; Kurt Johnsen

2017-01-01

We evaluated the effect on soil CO2 efflux (FCO2) of sudden changes in photosynthetic rates by altering CO2 concentration in plots subjected to +200 ppmv for 15 years. Five-day intervals of exposure to elevated CO2 (eCO2) ranging 1.0–1.8 times ambient did not affect FCO2. FCO2 did not decrease until 4 months after termination of the long-term eCO2 treatment, longer...

Aerosol Number Concentrations and Visibility during Dense Fog over a Subtropical Urban Site

Directory of Open Access Journals (Sweden)

Manju Mohan

2014-01-01

Full Text Available There is now enough evidence of greater frequencies and extent of fog formation in urban areas. These could easily be linked to rapid increase in aerosol number concentration (ANC peculiar to polluted urban environments. It is therefore pertinent to study ANC and visibility alongside the meteorological parameters in order to investigate the relationships which may possibly exist between these parameters especially during foggy conditions. This study based on field measurements of ANC for aerosol spectrum varying from 0.3 µm to 20 µm attempts to investigates whether a threshold ANC could be associated with a given visibility range during low visibility conditions including dense fog episodes. Thus, the present work explores relationship between ANC size spectrum and visibility (100 m–4500 m in a polluted urban environment in India with specific reference to episodes of dense fog during winter period. The study depicts a threshold minimum value of ANC during foggy conditions. A power relationship between ANC and visibility is obtained. Further, aerosol number distribution and size distribution function are also studied and empirical relation is compared with previous studies. Further work is suggested to strengthen the findings presented here.

Spacetime-varying couplings and Lorentz violation

International Nuclear Information System (INIS)

Kostelecky, V. Alan; Lehnert, Ralf; Perry, Malcolm J.

2003-01-01

Spacetime-varying coupling constants can be associated with violations of local Lorentz invariance and CPT symmetry. An analytical supergravity cosmology with a time-varying fine-structure constant provides an explicit example. Estimates are made for some experimental constraints

Optoacoustic monitoring of blood hemoglobin concentration: a pilot clinical study

Science.gov (United States)

Petrova, Irina Y.; Esenaliev, Rinat O.; Petrov, Yuriy Y.; Brecht, Hans-Peter F.; Svensen, Christer H.; Olsson, Joel; Deyo, Donald J.; Prough, Donald S.

2005-07-01

The optoacoustic technique is noninvasive, has high spatial resolution, and potentially can be used to measure the total hemoglobin concentration ([THb]) continuously and accurately. We performed in vitro measurements in blood and in vivo tests in healthy volunteers. Our clinical protocol included rapid infusion of intravenous saline to simulate rapid change in the [THb] during fluid therapy or surgery. Optoacoustic measurements were made from the wrist area overlying the radial artery for more than 1 h. The amplitude of the optoacoustic signal generated in the radial artery closely followed the [THb] measured directly in concurrently collected blood samples.

Impact of Furfural on Rapid Ethanol Production Using a Membrane Bioreactor

Directory of Open Access Journals (Sweden)

Mohammad J. Taherzadeh

2013-03-01

Full Text Available A membrane bioreactor was developed to counteract the inhibition effect of furfural in ethanol production. Furfural, a major inhibitor in lignocellulosic hydrolyzates, is a highly toxic substance which is formed from pentose sugars released during the acidic degradation of lignocellulosic materials. Continuous cultivations with complete cell retention were performed at a high dilution rate of 0.5 h−1. Furfural was added directly into the bioreactor by pulse injection or by addition into the feed medium to obtain furfural concentrations ranging from 0.1 to 21.8 g L−1. At all pulse injections of furfural, the yeast was able to convert the furfural very rapidly by in situ detoxification. When injecting 21.8 g L−1 furfural to the cultivation, the yeast converted it by a specific conversion rate of 0.35 g g−1 h−1. At high cell density, Saccharomyces cerevisiae could tolerate very high furfural levels without major changes in the ethanol production. During the continuous cultures when up to 17.0 g L−1 furfural was added to the inlet medium, the yeast successfully produced ethanol, whereas an increase of furfural to 18.6 and 20.6 g L−1 resulted in a rapidly decreasing ethanol production and accumulation of sugars in the permeate. This study show that continuous ethanol fermentations by total cell retention in a membrane bioreactor has a high furfural tolerance and can conduct rapid in situ detoxification of medium containing high furfural concentrations.

Relationship between indoor radon concentrations and air exchange rate

International Nuclear Information System (INIS)

Wang Jingshu; Liu Yuyu; Yao Xiaohua; Meng Jianfeng; Zhang Yongyi; Wang Xiaohe; Yu Xiufen.

1995-01-01

The indoor concentration of radon and the air exchange rate were simultaneously measured in four empty rooms, made of brick and cement, which were located in different floors of dwelling houses in Taiyuan, Shanxi, China. SF 6 tracer gas decay method was used to measure the air exchange rate. Indoor radon was collected with the dimembrane method. When the ventilation rate increased, the concentration of radon dropped rapidly. Regression analysis indicated that the indoor concentration of radon was equal to the outdoor level of radon when the air exchange rate was greater than 3-4. SF 6 decay method was an effective and convenient method for measuring the air exchange rate. There was no marked difference in measurements obtained in different locations of a room. (N.K.)

In-plane impulse response of a curved bar with varying cross-section

International Nuclear Information System (INIS)

Suzuki, Katsuyoshi; Kosawada, Tadashi; Takahashi, Shin; Miyashita, Yasushi.

1984-01-01

The vibration problem of a curved bar, of which the center line is represented with a plane curve, is important for the aseismatic design of the piping system and structures in chemical and nuclear plants. The dynamic response problem of an in-plane curved bar has not been sufficiently examined. In this study, the in-plane impact response of an in-plane curved bar having varying cross section when impact load acts in the direction of the center of curvature was analyzed. First, the Lagrangian of a curved bar with varying cross section when general exciting distributed load acts in the direction of the center of curvature along the center line was determined by the classic theory, and from its stationary condition, the equations of motion and boundary conditions were derived. Next, the equations of motion were analyzed by eigen-function development method. In the example of numerical calculation, the variation of displacement and bending moment in course of time when stepwise concentrated impact load acts on a both ends fixed symmetric semi-elliptic arc bar was determined. Besides, the change of response due to the change of cross section and the change of the point of impact load application was clarified. Displacement and bending moment varied at a certain period with static value at the center. (Kako, I.)

Observation of reversible, rapid changes in drug susceptibility of hypoxic tumor cells in a microfluidic device

Energy Technology Data Exchange (ETDEWEB)

Germain, Todd; Ansari, Megan; Pappas, Dimitri, E-mail: d.pappas@ttu.edu

2016-09-14

Hypoxia is a major stimulus for increased drug resistance and for survival of tumor cells. Work from our group and others has shown that hypoxia increases resistance to anti-cancer compounds, radiation, and other damage-pathway cytotoxic agents. In this work we utilize a microfluidic culture system capable of rapid switching of local oxygen concentrations to determine changes in drug resistance in prostate cancer cells. We observed rapid adaptation to hypoxia, with drug resistance to 2 μM staurosporine established within 30 min of hypoxia. Annexin-V/Sytox Green apoptosis assays over 9 h showed 78.0% viability, compared to 84.5% viability in control cells (normoxic cells with no staurosporine). Normoxic cells exposed to the same staurosporine concentration had a viability of 48.6% after 9 h. Hypoxia adaptation was rapid and reversible, with Hypoxic cells treated with 20% oxygen for 30 min responding to staurosporine with 51.6% viability after drug treatment for 9 h. Induction of apoptosis through the receptor-mediated pathway, which bypasses anti-apoptosis mechanisms induced by hypoxia, resulted in 39.4 ± 7% cell viability. The rapid reversibility indicates co-treatment of oxygen with anti-cancer compounds may be a potential therapeutic target. - Highlights: • Microfluidic system switches rapidly between normoxia and hypoxia (5 min). • Observation of rapid adaptation of PC3 cells to hypoxia and normoxia (30 min). • Drug susceptibility in tumor cells restored after chip switched to normoxia for 30 min.

Measurements of tritium (HTO, TFWT, OBT) in environmental samples at varying distances from a nuclear generating station

Energy Technology Data Exchange (ETDEWEB)

Kotzer, T.G.; Workman, W.J.G

1999-12-01

Concentrations of tritium have been measured in environmental samples (vegetation, water, soil, air) from sites distal and proximal to a CANDU nuclear generating station in Southern Ontario (OPG-Pickering). Levels of tissue-free water tritium (TFWT) and organically bound tritium (OBT) in vegetation are as high as 24,000 TU immediately adjacent to the nuclear generating station and rapidly decrease to levels of tritium which are comparable to natural ambient concentrations for tritium in the environment (approximately {<=} 60 TU). Tritium concentrations (OBT, TFTW) have also been measured in samples of vegetation and tree rings growing substantial distances away from nuclear generating stations and are within a factor of 1 to 2 of the ambient levels of tritium measured in precipitation in several parts of Canada (approximately {<=}30 TU). (author)

Measurements of tritium (HTO, TFWT, OBT) in environmental samples at varying distances from a nuclear generating station

International Nuclear Information System (INIS)

Kotzer, T.G.; Workman, W.J.G.

1999-12-01

Concentrations of tritium have been measured in environmental samples (vegetation, water, soil, air) from sites distal and proximal to a CANDU nuclear generating station in Southern Ontario (OPG-Pickering). Levels of tissue-free water tritium (TFWT) and organically bound tritium (OBT) in vegetation are as high as 24,000 TU immediately adjacent to the nuclear generating station and rapidly decrease to levels of tritium which are comparable to natural ambient concentrations for tritium in the environment (approximately ≤ 60 TU). Tritium concentrations (OBT, TFTW) have also been measured in samples of vegetation and tree rings growing substantial distances away from nuclear generating stations and are within a factor of 1 to 2 of the ambient levels of tritium measured in precipitation in several parts of Canada (approximately ≤30 TU). (author)

Relationship between oxygen concentration, respiration and filtration rate in blue mussel Mytilus edulis

Science.gov (United States)

Tang, Baojun; Riisgård, Hans Ulrik

2018-03-01

The large water-pumping and particle-capturing gills of the filter-feeding blue mussel Mytilus edulis are oversized for respiratory purposes. Consequently, the oxygen uptake rate of the mussel has been suggested to be rather insensitive to decreasing oxygen concentrations in the ambient water, since the diffusion rate of oxygen from water flowing through the mussel determines oxygen uptake. We tested this hypothesis by measuring the oxygen uptake in mussels exposed to various oxygen concentrations. These concentrations were established via N2-bubbling of the water in a respiration chamber with mussels fed algal cells to stimulate fully opening of the valves. It was found that mussels exposed to oxygen concentrations decreasing from 9 to 2 mg O2/L resulted in a slow but significant reduction in the respiration rate, while the filtration rate remained high and constant. Thus, a decrease of oxygen concentration by 78% only resulted in a 25% decrease in respiration rate. However, at oxygen concentrations below 2 mg O2/L M. edulis responded by gradually closing its valves, resulting in a rapid decrease of filtration rate, concurrent with a rapid reduction of respiration rate. These observations indicated that M. edulis is no longer able to maintain its normal aerobic metabolism at oxygen concentration below 2 mg O2/L, and there seems to be an energy-saving mechanism in bivalve molluscs to strongly reduce their activity when exposed to low oxygen conditions.

314 EFFECT OF VARYING CONCENTRATION OF AUXINS AND ...

African Journals Online (AJOL)

Osondu

2012-06-12

Jun 12, 2012 ... West and Central Africa countries have adopted the massive cultivation of the crop. The plant is found to incur little or no carbon debt hence it offers immediate ... These were made into cuttings of two lengths: 30 and 60cm using a meter measuring tape. The cuttings were pre-treated with two types of growth.

Rapid monitoring of gaseous radionuclides using a portable spectrometer

International Nuclear Information System (INIS)

Chung, C.; Tsai, C.H.

1995-01-01

A field gamma ray spectrometer, consisting of a portable high purity germanium detector, portable multichannel analyser, and a notebook computer, was used to conduct in situ rapid scanning of radioactive Ar, Kr and Xe isotopes in the air around a nuclear facility. The portable gamma ray spectrometer was calibrated using Ar, Kr, and Xe radioisotopes, activated in a research reactor and released in a sealed chamber. The unit was further tested inside the reactor containment to monitor the concentration of 41 Ar. In a typical one hour field measurement, the detection limits for some rare gas radionuclides corresponded to dose rates around 0.1 nSv.h -1 , which is far less than the dose rate induced by derived air concentrations imposed by the authority. The dose rate due to ground level concentrations of gaseous radionuclides dispersed from a source, such a nuclear facility or nuclear test, can be monitored in a short period using the portable unit. (Author)

NEIGHBORHOOD IMMIGRANT CONCENTRATION, ACCULTURATION, AND CULTURAL ALIENATION IN FORMER SOVIET IMMIGRANT WOMEN.

Science.gov (United States)

Miller, Arlene Michaels; Birman, Dina; Zenk, Shannon; Wang, Edward; Sorokin, Olga; Connor, Jorgia

2009-01-01

Several acculturation theories note the importance of surrounding context, but few studies describe neighborhood influences on immigrant adaptation. The purpose of this study was to examine relationships among neighborhood immigrant concentration, acculturation, and alienation for 151 women aged 44-80 from the former Soviet Union who lived in the US fewer than 13 years. Participants resided in 65 census tracts in the Chicago area with varying concentrations of Russian-speaking and diverse immigrants. Results from self-report questionnaires suggest that the effect of acculturation on alienation varies depending on neighborhood characteristics. The study also demonstrates the complexity of individual and contextual influences on immigrant adoption. Understanding these relationships is important for developing community-based and neighborhood-level interventions to enhance the mental health of immigrants.

Spatiotemporal variation of radon and carbon dioxide concentrations in an underground quarry: coupled processes of natural ventilation, barometric pumping and internal mixing.

Science.gov (United States)

Perrier, Frédéric; Richon, Patrick

2010-04-01

Radon-222 and carbon dioxide concentrations have been measured during several years at several points in the atmosphere of an underground limestone quarry located at a depth of 18 m in Vincennes, near Paris, France. Both concentrations showed a seasonal cycle. Radon concentration varied from 1200 to 2000 Bq m(-3) in summer to about 800-1400 Bq m(-3) in winter, indicating winter ventilation rates varying from 0.6 to 2.5 x 10(-6) s(-1). Carbon dioxide concentration varied from 0.9 to 1.0% in summer, to about 0.1-0.3% in winter. Radon concentration can be corrected for natural ventilation using temperature measurements. The obtained model also accounts for the measured seasonal variation of carbon dioxide. After correction, radon concentrations still exhibit significant temporal variation, mostly associated with the variation of atmospheric pressure, with coupling coefficients varying from -7 to -26 Bq m(-3) hPa(-1). This variation can be accounted for using a barometric pumping model, coupled with natural ventilation in winter, and including internal mixing as well. After correction, radon concentrations exhibit residual temporal variation, poorly correlated between different points, with standard deviations varying from 3 to 6%. This study shows that temporal variation of radon concentrations in underground cavities can be understood to a satisfactory level of detail using non-linear and time-dependent modelling. It is important to understand the temporal variation of radon concentrations and the limitations in their modelling to monitor the properties of natural or artificial underground settings, and to be able to assess the existence of new processes, for example associated with the preparatory phases of volcanic eruptions or earthquakes. Copyright 2009 Elsevier Ltd. All rights reserved.

The Transboundary Aquifer Management Challenge: Linking Landscape Patterns and Groundwater Nitrate Concentrations in the Abbotsford-Sumas Aquifer, USA/Canada

Science.gov (United States)

Gallagher, T.; Gergel, S. E.

2015-12-01

Changes in land use and landscape pattern can have an array of impacts on aquatic systems, including impacts which span international waters and borders. Globally, agricultural land use patterns and practices are among the factors responsible for elevated nitrate concentrations in groundwater aquifers. Coordination of landscape monitoring across trans-boundary aquifers is needed to monitor and address contamination issues as landscape patterns can vary widely among different political jurisdictions. Landscape indicators, which quantify the amount and arrangement of land cover (such as proportion and abundance of land cover types), are one such way to improve our understanding of cross-border aquatic system interactions. In Western North America, the Abbotsford-Sumas Aquifer (ASA) spans the US-Canada border and provides drinking water for over 100,000 people. Intensive agriculture combined with high precipitation and well-drained soils make this aquifer susceptible to nitrate leaching. To understand how landscape patterns influence nitrate concentrations, we ask: Which landscape indicators correlate most strongly with elevated nitrate concentrations? A seamless cross-border land cover mosaic was created by harmonizing a variety of US and Canadian geodata. Auxiliary high spatial resolution imagery (e.g., 5m RapidEye and historical Google Earth) were used to quantify fine-scale landscape features (such as number of farm field renovations) with suspected mechanistic links to nitrate sources. We examined groundwater nitrate concentrations in shallow wells (screens Environment Canada. Surrounding each well, terrestrial zones of influence (aligned with the directional flow of groundwater) were delineated within which landscape patterns were characterized. Multiple regression was used to compare the strength of relationships between land use practices and nitrate concentrations. Preliminary results show strong positive correlations between area of raspberry renovations and

Adaptive Importance Sampling with a Rapidly Varying Importance Function

International Nuclear Information System (INIS)

Booth, Thomas E.

2000-01-01

It is known well that zero-variance Monte Carlo solutions are possible if an exact importance function is available to bias the random walks. Monte Carlo can be used to estimate the importance function. This estimated importance function then can be used to bias a subsequent Monte Carlo calculation that estimates an even better importance function; this iterative process is called adaptive importance sampling.To obtain the importance function, one can expand the importance function in a basis such as the Legendre polynomials and make Monte Carlo estimates of the expansion coefficients. For simple problems, Legendre expansions of order 10 to 15 are able to represent the importance function well enough to reduce the error geometrically by ten orders of magnitude or more. The more complicated problems are addressed in which the importance function cannot be represented well by Legendre expansions of order 10 to 15. In particular, a problem with a cross-section notch and a problem with a discontinuous cross section are considered

Spatial variation of epoxyscillirosidine concentrations in Moraea pallida (yellow tulp in South Africa

Directory of Open Access Journals (Sweden)

Christo J. Botha

2013-05-01

Full Text Available Moraea pallida (yellow tulp poisoning is economically the most important intoxication of livestock in South Africa. Poisoning varies according to locality, climatic conditions and growth stage of the plant. The primary objective of this study was to determine the concentration of the toxic principle, epoxyscillirosidine, in yellow tulp leaves and to ascertain the variability of epoxyscillirosidine concentrations within and between different locations. A secondary objective was to utilise Geographic Information Systems in an attempt to explain the variability in toxicity. Flowering yellow tulp plants were collected at 26 sampling points across 20 districts of South Africa. The leaves of five plants per sampling point were extracted and submitted for liquid chromatography/mass spectrometry analysis. A large variation in mean epoxyscillirosidine concentrations, ranging from 3.32 μg/g – 238.27 μg/g, occurred between different geographical regions. The epoxyscillirosidine concentrations also varied tremendously between individual plants (n= 5 collected at the same sampling point, with up to a 24 times difference between the lowest and highest concentration detected. No generalised correlation between epoxyscillirosidine concentrations and soil elemental concentrations could be established. However, samples obtained from the north-eastern part of the sampling region tended to have higher epoxyscillirosidine concentrations compared to samples obtained from the south-western part of the sampling region. Higher toxin concentrations in the northeast were associated with statistically significant higher soil concentrations of iron, bismuth, bromide, cadmium, chromium, rubidium, tellurium, thallium, titanium and zinc, whilst soil concentrations of strontium and soil pH, were significantly lower. This study corroborated the contention that epoxyscillirosidine concentration in yellow tulp fluctuates and may explain the variability in toxicity.

Providing a diet deficient in valine but with excess leucine results in a rapid decrease in feed intake and modifies the postprandial plasma amino acid and α-keto acid concentrations in pigs.

Science.gov (United States)

Gloaguen, M; Le Floc'h, N; Corrent, E; Primot, Y; van Milgen, J

2012-09-01

Indispensable AA are involved in the control of feed intake. When a diet deficient in Val is offered to pigs, feed intake is typically reduced. This effect is aggravated when dietary Leu is supplied in excess of the requirement. If an unbalanced supply of branched-chain AA (BCAA) is harmful, an anorectic response may serve as a mechanism to prevent this situation. We verified this hypothesis by measuring the voluntary feed intake of a balanced diet offered during the 30-min period 1 h after ingestion of a test meal deficient or not in Val (Val- and Val+) with an excess of Leu. Twelve and four 6-wk-old crossbred female pigs were used in Exp. 1 and 2, respectively. Prior ingestion of the Val- test meal resulted in a 14% reduction in feed intake compared with that observed after ingestion of the Val+ test meal (P = 0.06) in Exp. 1, indicating that the signal to reduce feed intake occurred within 1 h. It is possible that the plasma concentration of the limiting AA serves as a signal for the dietary AA deficiency. We therefore determined the postprandial plasma concentrations of BCAA and their α-keto acids after ingestion of Val- and Val+ in 4 pigs in Exp. 2. After ingestion of the Val- diet, plasma concentrations of Val and its keto acid were reduced compared with values observed after ingestion of the Val+ diet. The peak concentration occurred earlier after ingestion of the Val- diet compared with that of the Val+ diet. Although the plasma concentration increased after the meal, it declined rapidly in pigs offered Val-, and the Val concentration 4 h after ingestion of the meal was even less than that observed in the fasted state. In conclusion, it appears that the pig is able to detect a deficient supply of Val within 1 h after ingestion. The plasma concentration of Val or its concentration relative to the other BCAA during the postprandial period may act as a signal indicating the AA deficiency.

A method for the rapid generation of nonsequential light-response curves of chlorophyll fluorescence.

Science.gov (United States)

Serôdio, João; Ezequiel, João; Frommlet, Jörg; Laviale, Martin; Lavaud, Johann

2013-11-01

Light-response curves (LCs) of chlorophyll fluorescence are widely used in plant physiology. Most commonly, LCs are generated sequentially, exposing the same sample to a sequence of distinct actinic light intensities. These measurements are not independent, as the response to each new light level is affected by the light exposure history experienced during previous steps of the LC, an issue particularly relevant in the case of the popular rapid light curves. In this work, we demonstrate the proof of concept of a new method for the rapid generation of LCs from nonsequential, temporally independent fluorescence measurements. The method is based on the combined use of sample illumination with digitally controlled, spatially separated beams of actinic light and a fluorescence imaging system. It allows the generation of a whole LC, including a large number of actinic light steps and adequate replication, within the time required for a single measurement (and therefore named "single-pulse light curve"). This method is illustrated for the generation of LCs of photosystem II quantum yield, relative electron transport rate, and nonphotochemical quenching on intact plant leaves exhibiting distinct light responses. This approach makes it also possible to easily characterize the integrated dynamic light response of a sample by combining the measurement of LCs (actinic light intensity is varied while measuring time is fixed) with induction/relaxation kinetics (actinic light intensity is fixed and the response is followed over time), describing both how the response to light varies with time and how the response kinetics varies with light intensity.

A Rapid Process for Fabricating Gas Sensors

Directory of Open Access Journals (Sweden)

Chun-Ching Hsiao

2014-07-01

Full Text Available Zinc oxide (ZnO is a low-toxicity and environmentally-friendly material applied on devices, sensors or actuators for “green” usage. A porous ZnO film deposited by a rapid process of aerosol deposition (AD was employed as the gas-sensitive material in a CO gas sensor to reduce both manufacturing cost and time, and to further extend the AD application for a large-scale production. The relative resistance change (△R/R of the ZnO gas sensor was used for gas measurement. The fabricated ZnO gas sensors were measured with operating temperatures ranging from 110 °C to 180 °C, and CO concentrations ranging from 100 ppm to 1000 ppm. The sensitivity and the response time presented good performance at increasing operating temperatures and CO concentrations. AD was successfully for applied for making ZnO gas sensors with great potential for achieving high deposition rates at low deposition temperatures, large-scale production and low cost.

Synthesis of different-sized silver nanoparticles by simply varying reaction conditions with leaf extracts of Bauhinia variegata L.

Science.gov (United States)

Kumar, V; Yadav, S K

2012-03-01

Green synthesis of nanoparticles is one of the crucial requirements in today's climate change scenario all over the world. In view of this, leaf extract (LE) of Bauhinia variegata L. possessing strong antidiabetic and antibacterial properties has been used to synthesise silver nanoparticles (SNP) in a controlled manner. Various-sized SNP (20-120 nm) were synthesised by varying incubation temperature, silver nitrate and LE concentrations. The rate of SNP synthesis and their size increased with increase in AgNO(3) concentration up to 4 mM. With increase in LE concentration, size and aggregation of SNP was increased. The size and aggregation of SNP were also increased at temperatures above and below 40°C. This has suggested that size and dispersion of SNP can be controlled by varying reaction components and conditions. Polarity-based fractionation of B. variegata LE has suggested that only water-soluble fraction is responsible for SNP synthesis. Fourier transform infrared spectroscopy analysis revealed the attachment of polyphenolic and carbohydrate moieties to SNP. The synthesised SNPs were found stable in double distilled water, BSA and phosphate buffer (pH 7.4). On the contrary, incubation of SNP with NaCl induced aggregation. This suggests the safe use of SNP for various in vivo applications.

Time-varying multiplex network: Intralayer and interlayer synchronization

Science.gov (United States)

Rakshit, Sarbendu; Majhi, Soumen; Bera, Bidesh K.; Sinha, Sudeshna; Ghosh, Dibakar

2017-12-01

A large class of engineered and natural systems, ranging from transportation networks to neuronal networks, are best represented by multiplex network architectures, namely a network composed of two or more different layers where the mutual interaction in each layer may differ from other layers. Here we consider a multiplex network where the intralayer coupling interactions are switched stochastically with a characteristic frequency. We explore the intralayer and interlayer synchronization of such a time-varying multiplex network. We find that the analytically derived necessary condition for intralayer and interlayer synchronization, obtained by the master stability function approach, is in excellent agreement with our numerical results. Interestingly, we clearly find that the higher frequency of switching links in the layers enhances both intralayer and interlayer synchrony, yielding larger windows of synchronization. Further, we quantify the resilience of synchronous states against random perturbations, using a global stability measure based on the concept of basin stability, and this reveals that intralayer coupling strength is most crucial for determining both intralayer and interlayer synchrony. Lastly, we investigate the robustness of interlayer synchronization against a progressive demultiplexing of the multiplex structure, and we find that for rapid switching of intralayer links, the interlayer synchronization persists even when a large number of interlayer nodes are disconnected.

An investigation of factors influencing indoor radon concentrations

International Nuclear Information System (INIS)

Majborn, B.; Soerensen, A.; Nielsen, S.P.; Boetter-Jensen, L.

1988-05-01

Variations in indoor radon concentrations and some influencing factors have been studied during a two-year period (1986-1987) in 16 almost identical single-family houses.The annual average radon concentration in the houses varied from about 50 to about 400 Bq/m 3 . Variations in soil characteristics and radon concentration in soil gas could not be directly related to the variations of the average indoor radon concentrations. Most of the houses showed a ''normal'' seasonal variation of the radon concentration with a maximum in the winter and minimum in the summer. A deviating seasonal variation was found in three of the houses. Hourly data obtained in one unoccupied house during a period of 2-1/2 months showed no or only weak correlations between the indoor radon concentration and meteorological factors. However, for most of the houses, the seasonal variation of the indoor radon concentration was well correlated with the average indoor-outdoor temperature difference on a 2-month basis. It was demonstrated that the radon concentration can be strongly reduced in the Risoe houses if a district-heating duct, which is connected to all the houses, is ventilated, so that a slightly lowered pressure is maintained in the duct. 5 taps., 24 ill. (author)

Spall Strength Measurements of Concrete for Varying Aggregate Sizes

International Nuclear Information System (INIS)

Chhabildas, Lalit C.; Kipp, Marlin E.; Reinhart, William D.; Wilson, Leonard T.

1999-01-01

Controlled impact experiments have been performed to determine the spall strength of four different concrete compositions. The four concrete compositions are identified as, 'SAC-5, CSPC', (''3/4'') large, and (''3/8'') small, Aggregate. They differ primarily in aggregate size but with average densities varying by less than five percent. Wave profiles from sixteen experiments, with shock amplitudes of 0.07 to 0.55 GPa, concentrate primarily within the elastic regime. Free-surface particle velocity measurements indicate consistent pullback signals in the release profiles, denoting average span strength of approximately 40 MPa. It is the purpose of this paper to present spall measurements under uniaxial strain loading. Notwithstanding considerable wave structure that is a unique characteristic to the heterogeneous nature of the scaled concrete, the spall amplitudes appear reproducible and consistent over the pressure range reported in this study

Rapid separation of bacteria from blood - Chemical aspects.

Science.gov (United States)

Alizadeh, Mahsa; Wood, Ryan L; Buchanan, Clara M; Bledsoe, Colin G; Wood, Madison E; McClellan, Daniel S; Blanco, Rae; Ravsten, Tanner V; Husseini, Ghaleb A; Hickey, Caroline L; Robison, Richard A; Pitt, William G

2017-06-01

To rapidly diagnose infectious organisms causing blood sepsis, bacteria must be rapidly separated from blood, a very difficult process considering that concentrations of bacteria are many orders of magnitude lower than concentrations of blood cells. We have successfully separated bacteria from red and white blood cells using a sedimentation process in which the separation is driven by differences in density and size. Seven mL of whole human blood spiked with bacteria is placed in a 12-cm hollow disk and spun at 3000rpm for 1min. The red and white cells sediment more than 30-fold faster than bacteria, leaving much of the bacteria in the plasma. When the disk is slowly decelerated, the plasma flows to a collection site and the red and white cells are trapped in the disk. Analysis of the recovered plasma shows that about 36% of the bacteria is recovered in the plasma. The plasma is not perfectly clear of red blood cells, but about 94% have been removed. This paper describes the effects of various chemical aspects of this process, including the influence of anticoagulant chemistry on the separation efficiency and the use of wetting agents and platelet aggregators that may influence the bacterial recovery. In a clinical scenario, the recovered bacteria can be subsequently analyzed to determine their species and resistance to various antibiotics. Copyright © 2017 Elsevier B.V. All rights reserved.

Concentration and detection of hepatitis A virus and its indicator from artificial seawater using zeolite.

Science.gov (United States)

Cormier, Jiemin; Janes, Marlene

2016-09-01

Hepatitis A virus (HAV) infection is the leading worldwide cause of acute viral hepatitis, and outbreaks caused by this virus often occur in fecal polluted waters. Rapid concentration and detection of viral contamination in water environments can prevent economic loss and can identify the source of contamination within a short time. However, conventional methods for virus concentration are often laborious, time consuming, and subject to clogging. Furthermore, most methods require a secondary concentration step to reduce the final volume of samples. We developed a method to concentrate HAV from seawater using zeolite in aid of rapid detection. In this method,artificial seawater was inoculated with HAV (7-8 log TCID50) and filtered with zeolite. The viruses were then eluted from zeolite with sodium dodecyl sulfate and detected via real-time PCR (qPCR). Zeolite was able to concentrate HAV from artificial seawater with ∼99% efficiency in less than 5min and was more efficient in seawater than in fresh water. The entire concentration and detection can be done in approximately 2h. Compared to existing methods, this method eliminated the need for a secondary concentration step as well as the necessity to modify the pH or salinity of the seawater during concentration, and was simple and inexpensive. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatial distribution of chlordanes and PCB congeners in soil in Cedar Rapids, Iowa, USA

International Nuclear Information System (INIS)

Martinez, Andres; Erdman, Nicholas R.; Rodenburg, Zachary L.; Eastling, Paul M.; Hornbuckle, Keri C.

2012-01-01

Residential soils from Cedar Rapids, Iowa, USA were collected and analyzed for chlordanes and polychlorinated biphenyls (PCBs). This study is one of the very few urban soil investigations in the USA. The chlordanes concentrations ranged from 0 to 7500 ng g −1 dry weight (d.w.), with a mean and standard deviation of 130 ± 920 ng g −1 d.w., which is about 1000 times larger than background levels. ΣPCB concentrations ranged from 3 to 1200 ng g −1 d.w., with a mean and standard deviation of 56 ± 160 ng g −1 d.w. and are about 10 times higher than world-wide background levels. Both groups exhibit considerable variability in chemical patterns and site-to-site concentrations. Although no measurements of dioxins were carried out, the potential toxicity due to the 12 dioxin-like PCBs found in the soil is in the same order of magnitude of the provisional threshold recommended by USEPA to perform soil remediation. - Graphical Abstract: Spatial location and measured concentrations of ΣPCB (left, 64 sites) and chlordanes (right, 66 sites) (ng g −1 d.w.) in soil from Cedar Rapids, Iowa. Samples were collected in August 2008. Estimated flood area was obtained from the Linn County Auditor's Office. Highlights: ► Chlordanes and PCBs congeners were measured in surficial soil from Cedar Rapids, Iowa. ► Measured values for both chemical groups are similar to other urban/industrial site around the world. ► This is one of the few urban soil studies in the USA. ► TEQs values are in the same order of magnitude of the provisional threshold recommended by USEPA to perform soil remediation. - Chlordane compounds (trans-, cis- and trans-nonachlor) and PCBs (164 peaks for 209 congeners) were measured in the soils of a small medium-sized American city.

Determination of radon and radium concentrations in drinking water samples around the city of Kutahya

International Nuclear Information System (INIS)

Sahin, L.; Cetinkaya, H.; Murat Sac, M.; Ichedef, M.

2013-01-01

The concentration of radium and radon has been determined in drinking water samples collected from various locations of Kutahya city, Turkey. The water samples are taken from public water sources and tap water, with the collector chamber method used to measure the radon and radium concentration. The radon concentration ranges between 0.1 and 48.6±1.7 Bq l -1 , while the radium concentration varies from a minimum detectable activity of -1 in Kutahya city. In addition to the radon and radium levels, parameters such as pH, conductivity and temperature of the water, humidity, pressure, elevation and the coordinates of the sampling points have also been measured and recorded. The annual effective dose from radon and radium due to typical water usage has been calculated. The resulting contribution to the annual effective dose due to radon ingestion varies between 0.3 and 124.2 μSv y -1 ; the contribution to the annual effective dose due to radium ingestion varies between 0 and 143.3 μSv y -1 ; the dose contribution to the stomach due to radon ingestion varies between 0.03 and 14.9 μSv y -1 . The dose contribution due to radon inhalation ranges between 0.3 and 122.5 μSv y -1 , assuming a typical transfer of radon in water to the air. For the overwhelming majority of the Kutahya population, it is determined that the average radiation exposure from drinking water is less than 73.6μmSv y -1 . (authors)

Circular economy practices among Chinese manufacturers varying in environmental-oriented supply chain cooperation and the performance implications.

Science.gov (United States)

Zhu, Qinghua; Geng, Yong; Lai, Kee-hung

2010-06-01

The rapidly growing industrial activities in emerging economies such as China have been causing resource depletion and pollution problems. This reality requires China to adopt an integrated management approach to resolve the conflict between industrial development and environmental protection, and the concept of circular economy (CE) serves this purpose. In this paper, we examine if different types of manufacturing enterprises on environmental-oriented supply chain cooperation (ESCC) exist. We also determine if the Chinese manufacturer types varying in ESCC differ in their implementation of the CE practices towards achieving the CE-targeted goals on improving both environmental and economic performance. Our cluster analytic results with multivariate analysis of variance (MANOVA) among the four identified types of Chinese manufacturers varying in environmental-oriented supply chain cooperation highlight the importance to intensify the cooperation with upstream and downstream supply chain partners for a CE initiative to succeed. (c) 2010 Elsevier Ltd. All rights reserved.

Rapid Analysis of Copper Ore in Pre-Smelter Head Flow Slurry by Portable X-ray Fluorescence.

Science.gov (United States)

Burnett, Brandon J; Lawrence, Neil J; Abourahma, Jehad N; Walker, Edward B

2016-05-01

Copper laden ore is often concentrated using flotation. Before the head flow slurry can be smelted, it is important to know the concentration of copper and contaminants. The concentration of copper and other elements fluctuate significantly in the head flow, often requiring modification of the concentrations in the slurry prior to smelting. A rapid, real-time analytical method is needed to support on-site optimization of the smelter feedstock. A portable, handheld X-ray fluorescence spectrometer was utilized to determine the copper concentration in a head flow suspension at the slurry origin. The method requires only seconds and is reliable for copper concentrations of 2.0-25%, typically encountered in such slurries. © The Author(s) 2016.

Model evaluation of denitrification under rapid infiltration basin systems.

Science.gov (United States)

Akhavan, Maryam; Imhoff, Paul T; Andres, A Scott; Finsterle, Stefan

2013-09-01

Rapid Infiltration Basin Systems (RIBS) are used for disposing reclaimed wastewater into soil to achieve additional treatment before it recharges groundwater. Effluent from most new sequenced batch reactor wastewater treatment plants is completely nitrified, and denitrification (DNF) is the main reaction for N removal. To characterize effects of complex surface and subsurface flow patterns caused by non-uniform flooding on DNF, a coupled overland flow-vadose zone model is implemented in the multiphase flow and reactive transport simulator TOUGHREACT. DNF is simulated in two representative soils varying the application cycle, hydraulic loading rate, wastewater quality, water table depth, and subsurface heterogeneity. Simulations using the conventional specified flux boundary condition under-predict DNF by as much as 450% in sand and 230% in loamy sand compared to predictions from the coupled overland flow-vadose zone model, indicating that simulating coupled flow is critical for predicting DNF in cases where hydraulic loading rates are not sufficient to spread the wastewater over the whole basin. Smaller ratios of wetting to drying time and larger hydraulic loading rates result in greater water saturations, more anoxic conditions, and faster water transport in the vadose zone, leading to greater DNF. These results in combination with those from different water table depths explain why reported DNF varied with soil type and water table depth in previous field investigations. Across all simulations, cumulative percent DNF varies between 2 and 49%, indicating that NO₃ removal in RIBS may vary widely depending on operational procedures and subsurface conditions. These modeling results improve understanding of DNF in RIBS and suggest operational procedures that may improve NO₃ removal. Copyright © 2013 Elsevier B.V. All rights reserved.

Leachability of cesium from cemented evaporator concentrates and ion-exchange resins

International Nuclear Information System (INIS)

Muurinen, A.

1985-03-01

Leachabilities of cesium from cemented evaporator concentrates and ion-exchange resins were measured. The standard draft of the International Organization for Standardization (ISO, 1979) for long-term leach testing was followed in the research. Three resin concretes and three concentrate concretes were tested. Deionized water and groundwater were used as leachants. The leaching temperature was 20-23 deg C. The incremental leach rate at the end of the three and a half year test varied between 5x10 -12 - 15x10 -12 m/s and the cumulative activity fraction leached between 1.5x10 -3 - 6x10 -3 m. The apparent diffusion coefficients in groundwater varied between 10 -9 - 10 -8 m/day. Because of the cracking the specimens cannot, however, be regarded as whole blocks, but the effects of cracking should be taken into account. (author)

Temperature varying photoconductivity of GeSn alloys grown by chemical vapor deposition with Sn concentrations from 4% to 11%

Energy Technology Data Exchange (ETDEWEB)

Hart, John; Hazbun, Ramsey; Gupta, Jay; Kolodzey, James [Department of Electrical Engineering, University of Delaware, 140 Evans Hall, Newark, Delaware 19716 (United States); Adam, Thomas [College of Nanoscale Science and Engineering, SUNY, Albany, New York 12203 (United States); Kim, Yihwan; Huang, Yi-Chiau [Applied Materials, Sunnyvale, California 94085 (United States); Reznicek, Alexander [IBM Research at Albany Nanotech, Albany, New York 12203 (United States)

2016-03-07

Pseudomorphic GeSn layers with Sn atomic percentages between 4.5% and 11.3% were grown by chemical vapor deposition using digermane and SnCl{sub 4} precursors on Ge virtual substrates grown on Si. The layers were characterized by x-ray diffraction rocking curves and reciprocal space maps. Photoconductive devices were fabricated, and the dark current was found to increase with Sn concentration. The responsivity of the photoconductors was measured at a wavelength of 1.55 μm using calibrated laser illumination at room temperature and a maximum value of 2.7 mA/W was measured for a 4.5% Sn device. Moreover, the responsivity for higher Sn concentration was found to increase with decreasing temperature. Spectral photoconductivity was measured using Fourier transform infrared spectroscopy. The photoconductive absorption edge continually increased in wavelength with increasing tin percentage, out to approximately 2.4 μm for an 11.3% Sn device. The direct band gap was extracted using Tauc plots and was fit to a bandgap model accounting for layer strain and Sn concentration. This direct bandgap was attributed to absorption from the heavy-hole band to the conduction band. Higher energy absorption was also observed, which was thought to be likely from absorption in the light-hole band. The band gaps for these alloys were plotted as a function of temperature. These experiments show the promise of GeSn alloys for CMOS compatible short wave infrared detectors.

Temperature varying photoconductivity of GeSn alloys grown by chemical vapor deposition with Sn concentrations from 4% to 11%

International Nuclear Information System (INIS)

Hart, John; Hazbun, Ramsey; Gupta, Jay; Kolodzey, James; Adam, Thomas; Kim, Yihwan; Huang, Yi-Chiau; Reznicek, Alexander

2016-01-01

Pseudomorphic GeSn layers with Sn atomic percentages between 4.5% and 11.3% were grown by chemical vapor deposition using digermane and SnCl 4 precursors on Ge virtual substrates grown on Si. The layers were characterized by x-ray diffraction rocking curves and reciprocal space maps. Photoconductive devices were fabricated, and the dark current was found to increase with Sn concentration. The responsivity of the photoconductors was measured at a wavelength of 1.55 μm using calibrated laser illumination at room temperature and a maximum value of 2.7 mA/W was measured for a 4.5% Sn device. Moreover, the responsivity for higher Sn concentration was found to increase with decreasing temperature. Spectral photoconductivity was measured using Fourier transform infrared spectroscopy. The photoconductive absorption edge continually increased in wavelength with increasing tin percentage, out to approximately 2.4 μm for an 11.3% Sn device. The direct band gap was extracted using Tauc plots and was fit to a bandgap model accounting for layer strain and Sn concentration. This direct bandgap was attributed to absorption from the heavy-hole band to the conduction band. Higher energy absorption was also observed, which was thought to be likely from absorption in the light-hole band. The band gaps for these alloys were plotted as a function of temperature. These experiments show the promise of GeSn alloys for CMOS compatible short wave infrared detectors.

Temperature varying photoconductivity of GeSn alloys grown by chemical vapor deposition with Sn concentrations from 4% to 11%

Science.gov (United States)

Hart, John; Adam, Thomas; Kim, Yihwan; Huang, Yi-Chiau; Reznicek, Alexander; Hazbun, Ramsey; Gupta, Jay; Kolodzey, James

2016-03-01

Pseudomorphic GeSn layers with Sn atomic percentages between 4.5% and 11.3% were grown by chemical vapor deposition using digermane and SnCl4 precursors on Ge virtual substrates grown on Si. The layers were characterized by x-ray diffraction rocking curves and reciprocal space maps. Photoconductive devices were fabricated, and the dark current was found to increase with Sn concentration. The responsivity of the photoconductors was measured at a wavelength of 1.55 μm using calibrated laser illumination at room temperature and a maximum value of 2.7 mA/W was measured for a 4.5% Sn device. Moreover, the responsivity for higher Sn concentration was found to increase with decreasing temperature. Spectral photoconductivity was measured using Fourier transform infrared spectroscopy. The photoconductive absorption edge continually increased in wavelength with increasing tin percentage, out to approximately 2.4 μm for an 11.3% Sn device. The direct band gap was extracted using Tauc plots and was fit to a bandgap model accounting for layer strain and Sn concentration. This direct bandgap was attributed to absorption from the heavy-hole band to the conduction band. Higher energy absorption was also observed, which was thought to be likely from absorption in the light-hole band. The band gaps for these alloys were plotted as a function of temperature. These experiments show the promise of GeSn alloys for CMOS compatible short wave infrared detectors.

Varying effects of geomorphic change on floodplain inundation and forest communities

Science.gov (United States)

Keim, R.; Johnson, E. L.; Edwards, B. L.; King, S. L.; Hupp, C. R.

2015-12-01

Overbank flooding in floodplains is an important control on vegetation, but effects of changing flooding are difficult to predict because sensitivities of plant communities to multidimensional flooding (frequency, depth, duration, and timing) are not well understood. We used HEC-RAS to model the changing flooding regime in the lower White River floodplain, Arkansas, in response to rapid incision of the Mississippi River in the 1930s, and quantified flood frequency, depth, and duration by forest community type. Incision has decreased flooding especially in terms of frequency, which is one of the most important variables for ecological processes. Modeled depth-duration curves varied more among floodplain reaches than among forest communities within the same reach, but forest communities are now arranged in accordance with new flood regimes in place after river incision. Forest responses to subtle geomorphic change are slower than other vegetation communities, so detection of the full ramifications of ecohydrologic change may require decades.

Effect of borax concentration on the structure of Poly(Vinyl Alcohol) gels

Science.gov (United States)

Lawrence, Mathias B.; Desa, J. A. E.; Aswal, V. K.

2012-06-01

Poly(Vinyl Alcohol) hydrogels cross-linked with varying concentrations of borax have been studied using Small-Angle Neutron Scattering and X-Ray Diffraction. The intensity of scattering increases with borax concentration from 1 mg/ml up to 2 mg/ml and falls thereafter for 4 mg/ml, increasing again for a concentration of 10 mg/ml. The mesoscopic structural changes that cause these trends in the SANS data are in keeping with the variations in the X-ray diffraction patterns pertaining to structures within the PVA chains.

Microstructural development in a rapidly solidified Al-Fe-V-Si alloy

International Nuclear Information System (INIS)

Park, W.J.; Baek, E.R.; Lee, Sunghak; Kim, N.J.

1991-01-01

TEM is used to investigate microstructural development in a rapidly solidified Al-Fe-V-Si alloy. The as-cast microstructure of a rapidly solidified Al-Fe-V-Si alloy was found to vary depending on casting conditions and also through the thickness of ribbon. For completely Zone A ribbon, intercellular phase consists of a microquasi-crystalline phase, while for the Zone A and Zone B mixed ribbon, it consists of a silicide phase. In either case, formation of globular particles of a cluster microquasi-crystalline phase is observed near the air side of the ribbon. Annealing study shows significant differences in the final microstructure depending on the initial status of the ribbon. Completely Zone A ribbon, whose microstructure is composed of a microquasi-crystalline phase, results in a very coarse microstructure after annealing as compared to the Zone A and Zone B mixed ribbon. This result has important implications for the development of high-performance elevated-temperature Al alloys. 12 refs

Lutein Supplementation Increases Breast Milk and Plasma Lutein Concentrations in Lactating Women and Infant Plasma Concentrations but Does Not Affect Other Carotenoids 1 2 3

OpenAIRE

Sherry, Christina L.; Oliver, Jeffery S.; Renzi, Lisa M.; Marriage, Barbara J.

2014-01-01

Lutein is a carotenoid that varies in breast milk depending on maternal intake. Data are lacking with regard to the effect of dietary lutein supplementation on breast milk lutein concentration during lactation and subsequent plasma lutein concentration in breast-fed infants. This study was conducted to determine the impact of lutein supplementation in the breast milk and plasma of lactating women and in the plasma of breast-fed infants 2–3 mo postpartum. Lutein is the dominant carotenoid in t...

Airstream Fractionation of Vesicular-Arbuscular Mycorrhizal Fungi: Concentration and Enumeration of Propagules

OpenAIRE

Tommerup, Inez C.

1982-01-01

Spores and fragments of vesicular-arbuscular mycorrhizal fungi in dry soils were concentrated up to 100-fold when the soils were partitioned by fluidization and elutriation with a series of upward airstreams at progressively increasing velocities. The propagules were transported with the finer soil particles according to their equivalent spherical diameters. The system was used to predict the transport of propagules by wind. Concentrated propagules were rapidly separated from the soil particl...

Rapid susceptibility testing of Mycobacterium tuberculosis by bioluminescence assay of mycobacterial ATP

International Nuclear Information System (INIS)

Nilsson, L.E.; Hoffner, S.E.; Ansehn, S.

1988-01-01

Mycobacterial growth was monitored by bioluminescence assay of mycobacterial ATP. Cultures of Mycobacterium tuberculosis H37Rv and of 25 clinical isolates of the same species were exposed to serial dilutions of ethambutol, isoniazid, rifampin, and streptomycin. A suppression of ATP, indicating growth inhibition, occurred for susceptible but not resistant strains within 5 to 7 days of incubation. Breakpoint concentrations between susceptibility and resistance were determined by comparing these results with those obtained by reference techniques. Full agreement was found in 99% of the assays with the resistance ratio method on Lowenstein-Jensen medium, and 98% of the assays were in full agreement with the radiometric system (BACTEC). A main advantage of the bioluminescence method is its rapidity, with results available as fast as with the radiometric system but at a lower cost and without the need for radioactive culture medium. The method provides kinetic data concerning drug effects within available in vivo drug concentrations and has great potential for both rapid routine susceptibility testing and research applications in studies of drug effects on mycobacteria

Computer-controlled system for rapid soil analysis of 226Ra

International Nuclear Information System (INIS)

Doane, R.W.; Berven, B.A.; Blair, M.S.

1984-01-01

A computer-controlled multichannel analysis system has been developed by the Radiological Survey Activities Group at Oak Ridge National Laboratory (ORNL) for the Department of Energy (DOE) in support of the DOE's remedial action programs. The purpose of this system is to provide a rapid estimate of the 226 Ra concentration in soil samples using a 6 x 9-in. NaI(Tl) crystal containing a 3.25-in. deep by 3.5-in. diameter well. This gamma detection system is controlled by a mini-computer with a dual floppy disk storage medium. A two-chip interface was also designed at ORNL which handles all control signals generated from the computer keyboard. These computer-generated control signals are processed in machine language for rapid data transfer and BASIC language is used for data processing

Effects of barium concentration on oropharyngeal swallow timing measures.

Science.gov (United States)

Stokely, Shauna L; Molfenter, Sonja M; Steele, Catriona M

2014-02-01

Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between "thin" (40 % w/v concentration) and "ultrathin" (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; mean age = 31 years) each performed a series of three noncued 5-ml swallows each of ultrathin and thin liquid barium solutions in videofluoroscopy. Timing measures were compared between barium concentrations using a mixed-model ANOVA. The measures of interest were stage transition duration, pharyngeal transit time, and duration of upper esophageal sphincter opening. Significant differences were observed in the timing measures of swallowing with respect to barium concentration. In all cases, longer durations were seen with the higher barium concentration. Barium concentration influences timing parameters in healthy swallowing, even between ultrathin and thin concentrations. Clinicians need to understand and control for the impact of different barium stimuli on swallowing physiology.

Morphological and voltammetric characterization of different concentrations of spin coated Nafion-Ru(bpy)2+3 thin films

International Nuclear Information System (INIS)

Tuason, B S B; Tiong-Palisoc, S; Tiamzon-Natividad, M

2015-01-01

Different concentrations of Ru(bpy) 2+ 3 were successfully deposited on ITO coated glass substrates employing a simple method using a spin coater. The surface morphology was determined by scanning electron microscopy (SEM). The transport mechanism and the diffusion coefficient of the redox mediators within the films were characterized using cyclic voltammetry (CV). The concentrations were varied by dissolving different amounts of the redox mediator in methanol and 5% Nafion. SEM micrographs showed that the roughness of the surface increased with concentration of redox mediator. CV showed successful incorporation of Ru(bpy) 2+ 3 . The order of the magnitude of the diffusion coefficients confirmed that the redox mediators were immobilized within the Nafion thin film. The resulting amount of redox mediator immobilized can be manipulated by simply varying the concentration of the casting solution. (paper)

A thermal model for photovoltaic panels under varying atmospheric conditions

International Nuclear Information System (INIS)

Armstrong, S.; Hurley, W.G.

2010-01-01

The response of the photovoltaic (PV) panel temperature is dynamic with respect to the changes in the incoming solar radiation. During periods of rapidly changing conditions, a steady state model of the operating temperature cannot be justified because the response time of the PV panel temperature becomes significant due to its large thermal mass. Therefore, it is of interest to determine the thermal response time of the PV panel. Previous attempts to determine the thermal response time have used indoor measurements, controlling the wind flow over the surface of the panel with fans or conducting the experiments in darkness to avoid radiative heat loss effects. In real operating conditions, the effective PV panel temperature is subjected to randomly varying ambient temperature and fluctuating wind speeds and directions; parameters that are not replicated in controlled, indoor experiments. A new thermal model is proposed that incorporates atmospheric conditions; effects of PV panel material composition and mounting structure. Experimental results are presented which verify the thermal behaviour of a photovoltaic panel for low to strong winds.

Vitamin B@d12@@ concentrations in Mandovi and Zuari estuaries

Digital Repository Service at National Institute of Oceanography (India)

De; Rajendran, A.

Bioassay method using @iCyclotella nana@@ (clone 13) was employed for the estimation of Vitamin B@d12@@ in Mandovi and Zuari estuaries. At the mouth of the Mandovi estuary, B@d12@@ concentration varied between 0.38 and 7.0 ng/l in surface water...

New method and installation for rapid determination of radon diffusion coefficient in various materials

International Nuclear Information System (INIS)

Tsapalov, Andrey; Gulabyants, Loren; Livshits, Mihail; Kovler, Konstantin

2014-01-01

The mathematical apparatus and the experimental installation for the rapid determination of radon diffusion coefficient in various materials are developed. The single test lasts not longer than 18 h and allows testing numerous materials, such as gaseous and liquid media, as well as soil, concrete and radon-proof membranes, in which diffusion coefficient of radon may vary in an extremely wide range, from 1·10 −12 to 5·10 −5 m 2 /s. The uncertainty of radon diffusion coefficient estimation depends on the permeability of the sample and varies from about 5% (for the most permeable materials) to 40% (for less permeable materials, such as radon-proof membranes). - Highlights: • The new method and installation for determination of radon diffusion coefficient D are developed. • The measured D-values vary in an extremely wide range, from 5×10 -5 to 1×10 -12 m 2 /s. • The materials include water, air, soil, building materials and radon-proof membranes. • The duration of the single test does not exceed 18 hours. • The measurement uncertainty varies from 5% (in permeable materials) to 40% (in radon gas barriers)

Rapid quantification of TBP and TBP degradation product ratios by FTIR-ATR

International Nuclear Information System (INIS)

Gillens, A.R.; Powell, B.A.; Clemson University, Clemson, SC

2013-01-01

Tri-n-butyl phosphate (TBP) is the key complexant within the plutonium and uranium reduction extraction process used to extract uranium and plutonium from used nuclear fuel. During reprocessing TBP degrades to dibutyl phosphate (DBP), butyl acid phosphate (MBP), butanol, and phosphoric acid over time. A method for rapidly monitoring TBP degradation is needed for the support of nuclear forensics. Therefore, a Fourier transform infrared spectrometry-attenuated total reflectance (FTIR-ATR) technique was developed to determine approximate peak intensity ratios of TBP and its degradation products. The technique was developed by combining variable concentrations of TBP, DBP, and MBP to simulate TBP degradation. This method is achieved by analyzing selected peak positions and peak intensity ratios of TBP and DBP at different stages of degradation. The developed technique was tested on TBP samples degraded with nitric acid. In mock degradation samples, the 1,235 cm -1 peak position shifts to 1,220 cm -1 as the concentration of TBP decreases and DBP increases. Peak intensity ratios of TBP positions at 1,279 and 1,020 cm -1 relative to DBP positions at 909 and 1,003 cm -1 demonstrate an increasing trend as the concentration of DBP increases. The same peak intensity ratios were used to analyze DBP relative to MBP whereas a decreasing trend is seen with increasing DBP concentrations. The technique developed from this study may be used as a tool to determine TBP degradation in nuclear reprocessing via a rapid FTIR-ATR measurement without gas chromatography analysis. (author)

Concentration Dependence of Gold Nanoparticles for Fluorescence Enhancement

Science.gov (United States)

Solomon, Joel; Wittmershaus, Bruce

Noble metal nanoparticles possess a unique property known as surface plasmon resonance in which the conduction electrons oscillate due to incoming light, dramatically increasing their absorption and scattering of light. The oscillating electrons create a varying electric field that can affect nearby molecules. The fluorescence and photostability of fluorophores can be enhanced significantly when they are near plasmonic nanoparticles. This effect is called metal enhanced fluorescence (MEF). MEF from two fluorescence organic dyes, Lucifer Yellow CH and Riboflavin, was measured with different concentrations of 50-nm colloidal gold nanoparticles (Au-NP). The concentration range of Au-NP was varied from 2.5 to 250 pM. To maximize the interaction, the dyes were chosen so their emission spectra had considerable overlap with the absorption spectra of the Au-NP, which is common in MEF studies. If the dye molecules are too close to the surface of Au-NP, fluorescence quenching can occur instead of MEF. To try to observe this difference, silica-coated Au-NP were compared to citrate-based Au-NP; however, fluorescence quenching was observed with both Au-NP. This material is based upon work supported by the National Science Foundation under Grant Number NSF-ECCS-1306157.

Rapid response systems.

Science.gov (United States)

Lyons, Patrick G; Edelson, Dana P; Churpek, Matthew M

2018-07-01

Rapid response systems are commonly employed by hospitals to identify and respond to deteriorating patients outside of the intensive care unit. Controversy exists about the benefits of rapid response systems. We aimed to review the current state of the rapid response literature, including evolving aspects of afferent (risk detection) and efferent (intervention) arms, outcome measurement, process improvement, and implementation. Articles written in English and published in PubMed. Rapid response systems are heterogeneous, with important differences among afferent and efferent arms. Clinically meaningful outcomes may include unexpected mortality, in-hospital cardiac arrest, length of stay, cost, and processes of care at end of life. Both positive and negative interventional studies have been published, although the two largest randomized trials involving rapid response systems - the Medical Early Response and Intervention Trial (MERIT) and the Effect of a Pediatric Early Warning System on All-Cause Mortality in Hospitalized Pediatric Patients (EPOCH) trial - did not find a mortality benefit with these systems, albeit with important limitations. Advances in monitoring technologies, risk assessment strategies, and behavioral ergonomics may offer opportunities for improvement. Rapid responses may improve some meaningful outcomes, although these findings remain controversial. These systems may also improve care for patients at the end of life. Rapid response systems are expected to continue evolving with novel developments in monitoring technologies, risk prediction informatics, and work in human factors. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of Sample Handling Effects on Serum Vitamin E and Cholesterol Concentrations in Alpacas

Directory of Open Access Journals (Sweden)

Andrea S. Lear

2014-01-01

Full Text Available Clinical cases of vitamin E deficiencies have been diagnosed in camelids and may indicate that these species are more sensitive to inadequate vitamin E in hay-based diets compared to other ruminant and equine species. In bovine, cholesterol has been reported to affect vitamin E concentrations. In order to evaluate vitamin E deficiencies in camelids, the effects of collection and storage of the blood samples prior to processing were necessary. Reports vary as to factors affecting vitamin E and cholesterol in blood samples, and diagnostic laboratories vary in instructions regarding sample handling. Blood was collected from healthy alpacas and processed under conditions including exposure to fluorescent light, serum and red blood cell contact, tube stopper contact, temperature, and hemolysis. Serum vitamin E and cholesterol concentrations were then measured. Statistical analyses found that the vitamin E concentrations decreased with prolonged contact with the tube stopper and with increasing hemolysis. Vitamin E concentration variations were seen with other factors but were not significant. Time prior to serum separation and individual animal variation was found to alter cholesterol concentrations within the sample, yet this finding was clinically unremarkable. No correlation was seen between vitamin E and cholesterol concentration, possibly due to lack of variation of cholesterol.

Patterns of radionuclide concentrations in life-cycle of birds

International Nuclear Information System (INIS)

Lebedeva, N.V.; Beloglazov, M.V.

1995-01-01

Breeding populations of Great Tit Parus major and Pied Flycatcher Ficedida hypoleuca was studied to determine radionuclide ( 137 Cs, 90 Sr) concentrations in bodies and foods (contents of gastrointestinal tracts) at different stages of the life-cycle and radiation effects upon the populations. The study was carried out in 1989--1992 near Chernobyl (in two areas with differed contamination levels: 90 Ci/km 2 , 5 Ci/km 2 ) and East-Ural radioactive trace (Russia) (1,500 Ci/km 2 , 2 Ci/km 2 ). Concentrations of 90 Sr in egg shells of Great Tit collected near Chernobyl were 65 times higher in the more radioactive area than in the less contaminated area and varied from 56.6 to 79.7 Bq/g. Concentration of 90 Sr in the contents of gastrointestinal tracts were from 0 to 10.8 Bq/g. Concentrations of radionuclides in the food increased in the sequence ''nestlings 90 Sr content in bodies of nestlings varied from 1 to 5 Bq/g at contaminated site and from 0.2 to 0.5 Bq/g at less polluted area, from 1 to 9 Bq/g and from 0.1 to 0.5 Bq/g in fledglings relatively in two areas. It was assumed that the ration of pairs numbers and breeding success of Pied Flycatcher (East-Ural) on the control site was significantly higher than that on contaminated site. The pathology in development of Pied Flycatcher's nestling was recorded. The radiation influenced on age-structure of bird populations decreasing the ratio of the young

Degeneration of rapid eye movement sleep circuitry underlies rapid eye movement sleep behavior disorder.

Science.gov (United States)

McKenna, Dillon; Peever, John

2017-05-01

During healthy rapid eye movement sleep, skeletal muscles are actively forced into a state of motor paralysis. However, in rapid eye movement sleep behavior disorder-a relatively common neurological disorder-this natural process is lost. A lack of motor paralysis (atonia) in rapid eye movement sleep behavior disorder allows individuals to actively move, which at times can be excessive and violent. At first glance this may sound harmless, but it is not because rapid eye movement sleep behavior disorder patients frequently injure themselves or the person they sleep with. It is hypothesized that the degeneration or dysfunction of the brain stem circuits that control rapid eye movement sleep paralysis is an underlying cause of rapid eye movement sleep behavior disorder. The link between brain stem degeneration and rapid eye movement sleep behavior disorder stems from the fact that rapid eye movement sleep behavior disorder precedes, in the majority (∼80%) of cases, the development of synucleinopathies such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, which are known to initially cause degeneration in the caudal brain stem structures where rapid eye movement sleep circuits are located. Furthermore, basic science and clinical evidence demonstrate that lesions within the rapid eye movement sleep circuits can induce rapid eye movement sleep-specific motor deficits that are virtually identical to those observed in rapid eye movement sleep behavior disorder. This review examines the evidence that rapid eye movement sleep behavior disorder is caused by synucleinopathic neurodegeneration of the core brain stem circuits that control healthy rapid eye movement sleep and concludes that rapid eye movement sleep behavior disorder is not a separate clinical entity from synucleinopathies but, rather, it is the earliest symptom of these disorders. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and

Safety and Effectiveness of Bone Marrow Cell Concentrate in the Treatment of Chronic Critical Limb Ischemia Utilizing a Rapid Point-of-Care System

Directory of Open Access Journals (Sweden)

Venkatesh Ponemone

2017-01-01

Full Text Available Critical limb ischemia (CLI is the end stage of lower extremity peripheral vascular disease (PVD in which severe obstruction of blood flow results in ischemic rest pain, ulcers and/or gangrene, and a significant risk of limb loss. This open-label, single-arm feasibility study evaluated the safety and therapeutic effectiveness of autologous bone marrow cell (aBMC concentrate in revascularization of CLI patients utilizing a rapid point-of-care device. Seventeen (17 no-option CLI patients with ischemic rest pain were enrolled in the study. Single dose of aBMC, prepared utilizing an intraoperative point-of-care device, the Res-Q™ 60 BMC system, was injected intramuscularly into the afflicted limb and patients were followed up at regular intervals for 12 months. A statistically significant improvement in Ankle Brachial Index (ABI, Transcutaneous Oxygen Pressure (TcPO2, mean rest pain and intermittent claudication pain scores, wound/ ulcer healing, and 6-minute walking distance was observed following aBMC treatment. Major amputation-free survival (mAFS rate and amputation-free rates (AFR at 12 months were 70.6% and 82.3%, respectively. In conclusion, aBMC injections were well tolerated with improved tissue perfusion, confirming the safety, feasibility, and preliminary effectiveness of aBMC treatment in CLI patients.

Rapid Field-Usable Cyanide Sensor Development for Blood and Saliva

Science.gov (United States)

2013-12-01

flexible which lead to tearing. This issue will be eliminated in the manufacturing process with the use of a plastic material (i.e., the use of...designed and manufactured by Falcon Plastics using their fused deposition modeling FDM Printing Technology (i.e., rapid prototyping or 3D printing). The...at low, medium, and high QC concentrations was 14%, 22%, and 27%, respectively. Acidification of the swine plasma before spiking in α-KgCN, did not

Dependence of samarium-soil interaction on samarium concentration: Implications for environmental risk assessment.

Science.gov (United States)

Ramírez-Guinart, Oriol; Salaberria, Aitor; Vidal, Miquel; Rigol, Anna

2018-03-01

The sorption and desorption behaviour of samarium (Sm), an emerging contaminant, was examined in soil samples at varying Sm concentrations. The obtained sorption and desorption parameters revealed that soil possessed a high Sm retention capacity (sorption was higher than 99% and desorption lower than 2%) at low Sm concentrations, whereas at high Sm concentrations, the sorption-desorption behaviour varied among the soil samples tested. The fractionation of the Sm sorbed in soils, obtained by sequential extractions, allowed to suggest the soil properties (pH and organic matter solubility) and phases (organic matter, carbonates and clay minerals) governing the Sm-soil interaction. The sorption models constructed in the present work along with the sorption behaviour of Sm explained in terms of soil main characteristics will allow properly assessing the Sm-soil interaction depending on the contamination scenario under study. Moreover, the sorption and desorption K d values of radiosamarium in soils were strongly correlated with those of stable Sm at low concentrations (r = 0.98); indicating that the mobility of Sm radioisotopes and, thus, the risk of radioactive Sm contamination can be predicted using data from low concentrations of stable Sm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mobility of Iron-Cyanide Complexes in a Humic Topsoil under Varying Redox Conditions

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Thilo Rennert

2009-01-01

Full Text Available The potentially toxic Fe-CN complexes ferricyanide, [FeIII(CN6]3−, and ferrocyanide, [FeII(CN6]4−, undergo a variety of redox processes in soil, which affect their mobility. We carried out microcosm experiments with suspensions of a humic topsoil (pH 5.3; Corg 107 g kg-1 to which we added ferricyanide (20 mg l-1. We varied the redox potential (EH from −280 to 580 mV by using O2, N2 and glucose. The decrease of EH led to decreasing concentrations of Fe-CN complexes and partial reductive dissolution of (hydrous Fe and Mn oxides. The dynamics of aqueous Fe-CN concentrations was characterized by decreasing concentrations when the pH rose and the EH dropped. We attribute these dependencies to adsorption on organic surfaces, for which such a pH/EH behavior has been shown previously. Adsorption was reversible, because when the pH and EH changed into the opposite direction, desorption occurred. This study demonstrates the possible impact of soil organic matter on the fate of Fe-CN complexes in soil.

Effect of different levels of rapidly degradable carbohydrates calculated by a simple rumen model on performance of lactating dairy cows.

Science.gov (United States)

Doorenbos, J; Martín-Tereso, J; Dijkstra, J; van Laar, H

2017-07-01

Aggregating rumen degradation characteristics of different carbohydrate components into the term modeled rapidly degradable carbohydrates (mRDC) can simplify diet formulation by accounting for differences in rate and extent of carbohydrate degradation within and between feedstuffs. This study sought to evaluate responses of lactating dairy cows to diets formulated with increasing levels of mRDC, keeping the supply of other nutrients as constant as possible. The mRDC content of feedstuffs was calculated based on a simple rumen model including soluble, washable, and nonwashable but potentially degradable fractions, as well as the fractional degradation and passage rates, of sugar, starch, neutral detergent fiber, and other carbohydrates. The mRDC term effectively represents the total amount of carbohydrates degraded in the rumen within 2 h after ingestion. Fifty-two lactating Holstein cows (of which 4 were rumen fistulated) were assigned to 4 treatments in a 4 × 4 Latin square design. Treatments were fed as a total mixed ration consisting of 25.4% corn silage, 23.1% grass silage, 11.6% grass hay, and 39.9% concentrate on a dry matter basis. Differences in mRDC were created by exchanging nonforage neutral detergent fiber-rich ingredients (mainly sugar beet pulp) with starch-rich ingredients (mainly wheat) and by exchanging corn (slowly degradable starch) with wheat (rapidly degradable starch) in the concentrate, resulting in 4 treatments that varied in dietary mRDC level of 167, 181, 194, or 208 g/kg of dry matter. Level of mRDC did not affect dry matter intake. Fat- and protein-corrected milk production and milk fat and lactose yield were greatest at 181 mRDC and decreased with further increases in mRDC. Milk protein yield and concentration increased with increasing mRDC level. Mean rumen pH and diurnal variation in ruminal pH did not differ between treatments. Total daily meal time and number of visits per meal were smaller at 181 and 194 mRDC. Despite milk

Biphasic stimulation of cellular calcium concentration by 3,5,3'-triiodothyronine in rat thymocytes

International Nuclear Information System (INIS)

Segal, J.

1988-01-01

3,5,3'-Triiodothyronine (T 3 ) produced a rapid and transient increase in 45 Ca uptake and cytoplasmic free calcium concentration in rat thymocytes, which is the most rapid effect of T 3 in this system. This effect was manifested in cells suspended in medium containing 1 mM calcium. The T 3 effect on 45 Ca uptake was evident at 15-30 s, reached maximum at 30-60 s, and returned to control values at 5 min. The T 3 effect on cytoplasmic free calcium concentration was seen after 30 s, reached maximum at 7 min, and returned to control values after 24 min. In cells suspended in Ca 2+ -free medium, T 3 produced a similar rapid increase in 45 Ca uptake, which was sustained for at least 60 min, but T 3 failed to change cytoplasmic free calcium concentration. Alprenolol (10 μM) blocked the stimulatory effects of T 3 on these two functions in a similar fashion. From these results, the authors suggest that in rat thymocytes T 3 influences cellular calcium economy through a biphasic mechanism in which T 3 first increases calcium uptake which, in turn, if followed by a release of calcium from intracellular pool(s), resulting in a further increase in cytoplasmic free calcium concentration and the activation of Ca 2+ -regulated systems. Moreover, the present study provides further support for the postulate that in the rat thymocyte calcium serves as the first messenger for the plasma membrane-mediated stimulatory effects of T 3 on several metabolic functions

A topological approach to migration and visualization of time-varying volume data

International Nuclear Information System (INIS)

Fujishiro, Issei; Otsuka, Rieko; Hamaoka, Aya; Takeshima, Yuriko; Takahashi, Shigeo

2004-01-01

Rapid advance in high performance computing and measurement technologies has recently made it possible to produce a stupendous amount of time-varying volume datasets in various disciplines. However, there exist a few known visual exploration tools which allow us to investigate the core of their complex behavior effectively. In this article, our previous approach to topological volume skeletonization is extended to capture the topological skeleton of a 4D volumetric field in terms of critical timing. A cyclic information drilldown scheme, termed T-map, is presented, where a wide choice of information visualization techniques are deployed so that the users are allowed to repeatedly squeeze partial spatiotemporal domains of interest until the size gets fitted into an available computing storage space, prior to topologically-accentuated visualization of the pinpointed volumetric domains. A case study with datasets from atomic collision research is performed to illustrate the feasibility of the present method. (author)

KOH concentration effect on the cycle life of nickel-hydrogen cells. IV - Results of failure analysis

Science.gov (United States)

Lim, H. S.; Verzwyvelt, S. A.

1990-01-01

Potassium hydroxide concentration effects on the cycle life of a Ni/H2 cell have been studied by carrying out a cycle life test on ten Ni/H2 boiler plate cells which contain electrolytes of various KOH concentrations. Failure analyses of these cells were carried out after completion of the life test, which accumulated up to 40,000 cycles at an 80-percent depth of discharge over a period of 3.7 years. These failure analyses included studies on changes of electrical characteristics of test cells, and component analyses after disassembly of the cell. The component analyses included visual inspections, dimensional changes, capacity measurements of nickel electrodes, scanning electron microscopy, surface area measurements, and chemical analyses. Results have indicated that failure mode and change in the nickel electrode varied as the concentration was varied, especially when the concentration was changed from 31 percent or higher to 26 percent or lower.

Rapid assessment of rice seed availability for wildlife in harvested fields

Science.gov (United States)

Halstead, B.J.; Miller, M.R.; Casazza, Michael L.; Coates, P.S.; Farinha, M.A.; Benjamin, Gustafson K.; Yee, J.L.; Fleskes, J.P.

2011-01-01

Rice seed remaining in commercial fields after harvest (waste rice) is a critical food resource for wintering waterfowl in rice-growing regions of North America. Accurate and precise estimates of the seed mass density of waste rice are essential for planning waterfowl wintering habitat extents and management. In the Sacramento Valley of California, USA, the existing method for obtaining estimates of availability of waste rice in harvested fields produces relatively precise estimates, but the labor-, time-, and machineryintensive process is not practical for routine assessments needed to examine long-term trends in waste rice availability. We tested several experimental methods designed to rapidly derive estimates that would not be burdened with disadvantages of the existing method. We first conducted a simulation study of the efficiency of each method and then conducted field tests. For each approach, methods did not vary in root mean squared error, although some methods did exhibit bias for both simulations and field tests. Methods also varied substantially in the time to conduct each sample and in the number of samples required to detect a standard trend. Overall, modified line-intercept methods performed well for estimating the density of rice seeds. Waste rice in the straw, although not measured directly, can be accounted for by a positive relationship with density of rice on the ground. Rapid assessment of food availability is a useful tool to help waterfowl managers establish and implement wetland restoration and agricultural habitat-enhancement goals for wintering waterfowl. ?? 2011 The Wildlife Society.

Modelling the removal of p-TSA (para-toluenesulfonamide) during rapid sand filtration used for drinking water treatment.

Science.gov (United States)

Meffe, Raffaella; Kohfahl, Claus; Holzbecher, Ekkehard; Massmann, Gudrun; Richter, Doreen; Dünnbier, Uwe; Pekdeger, Asaf

2010-01-01

A finite element model was set-up to determine degradation rate constants for p-TSA during rapid sand filtration (RSF). Data used for the model originated from a column experiment carried out in the filter hall of a drinking water treatment plant in Berlin (Germany). Aerated abstracted groundwater was passed through a 1.6m long column-shaped experimental sand filter applying infiltration rates from 2 to 6mh(-1). Model results were fitted to measured profiles and breakthrough curves of p-TSA for different infiltration rates using both first-order reaction kinetics and Michaelis-Menten kinetics. Both approaches showed that degradation rates varied both in space and time. Higher degradation rates were observed in the upper part of the column, probably related to higher microbial activity in this zone. Measured and simulated breakthrough curves revealed an adaption phase with lower degradation rates after infiltration rates were changed, followed by an adapted phase with more elevated degradation rates. Irrespective of the mathematical approach and the infiltration rate, degradation rates were very high, probably owing to the fact that filter sands have been in operation for decades, receiving high p-TSA concentrations with the raw water.

Grapevine species from varied native habitats exhibit differences in embolism formation/repair associated with leaf gas exchange and root pressure.

Science.gov (United States)

Knipfer, Thorsten; Eustis, Ashley; Brodersen, Craig; Walker, Andrew M; McElrone, Andrew J

2015-08-01

Drought induces xylem embolism formation, but grapevines can refill non-functional vessels to restore transport capacity. It is unknown whether vulnerability to embolism formation and ability to repair differ among grapevine species. We analysed in vivo embolism formation and repair using x-ray computed microtomography in three wild grapevine species from varied native habitats (Vitis riparia, V. arizonica, V. champinii) and related responses to measurements of leaf gas exchange and root pressure. Vulnerability to embolism formation was greatest in V. riparia, intermediate in V. arizonica and lowest in V. champinii. After re-watering, embolism repair was rapid and pronounced in V. riparia and V. arizonica, but limited or negligible in V. champinii even after numerous days. Similarly, root pressure measured after re-watering was positively correlated with drought stress severity for V. riparia and V. arizonica (species exhibiting embolism repair) but not for V. champinii. Drought-induced reductions in transpiration were greatest for V. riparia and least in V. champinii. Recovery of transpiration after re-watering was delayed for all species, but was greatest for V. champinii and most rapid in V. arizonica. These species exhibit varied responses to drought stress that involve maintenance/recovery of xylem transport capacity coordinated with root pressure and gas exchange responses. © 2014 John Wiley & Sons Ltd.

The impact of aluminium smelter shut-down on the concentration of fluoride in vegetation and soils

International Nuclear Information System (INIS)

Brougham, Kate M.; Roberts, Stephen R.; Davison, Alan W.; Port, Gordon R.

2013-01-01

Although a great deal is known about the deposition of fluoride on vegetation, and the hazards associated with uptake by grazing herbivores, little is known about what happens to the concentration of fluoride in vegetation and soil at polluted sites once deposition ceases. The closure of Anglesey Aluminium Metals Ltd smelter, in September 2009, provided a unique opportunity to study fluoride loading once deposition stopped. Fluoride was monitored in plants and soil within 1 km of the former emission source. Fluoride concentrations in a range of plant material had decreased to background levels of 10 mg F kg −1 after 36 weeks. Concentrations of fluoride in mineral-rich soils decreased steadily demonstrating their limited potential to act as contaminating sources of fluoride for forage uptake. There were significant differences in the rate of decline of fluoride concentrations between plant species. -- Highlights: •The impact of aluminium smelter closure on fluoride concentrations was investigated. •Concentrations in forage decreased rapidly to safe levels for livestock grazing. •The concentrations in some species declined to background levels within a year. •Significant interspecies differences in fluoride decline are described. •Mineral-rich soils have limited potential as contaminating sources for forage. -- Fluoride is hazardous to grazing herbivores, but when deposition stops, F-levels in plants and soil fall rapidly, some returning to background concentrations within a year

Infection of the malaria mosquito, Anopheles gambiae, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence

Directory of Open Access Journals (Sweden)

Lwetoijera Dickson W

2009-12-01

Full Text Available Abstract Background Entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana isolates have been shown to infect and reduce the survival of mosquito vectors. Methods Here four different bioassays were conducted to study the effect of conidia concentration, co-formulation, exposure time and persistence of the isolates M. anisopliae ICIPE-30 and B. bassiana I93-925 on infection and survival rates of female Anopheles gambiae sensu stricto. Test concentrations and exposure times ranged between 1 × 107 - 4 × 1010 conidia m-2 and 15 min - 6 h. In co-formulations, 2 × 1010 conidia m-2 of both fungus isolates were mixed at ratios of 4:1, 2:1, 1:1,1:0, 0:1, 1:2 and 1:4. To determine persistence, mosquitoes were exposed to surfaces treated 1, 14 or 28 d previously, with conidia concentrations of 2 × 109, 2 × 1010 or 4 × 1010. Results Mosquito survival varied with conidia concentration; 2 × 1010 conidia m-2 was the concentration above which no further reductions in survival were detectable for both isolates of fungus. The survival of mosquitoes exposed to single and co-formulated treatments was similar and no synergistic or additive effects were observed. Mosquitoes were infected within 30 min and longer exposure times did not result in a more rapid killing effect. Fifteen min exposure still achieved considerable mortality rates (100% mortality by 14 d of mosquitoes, but at lower speed than with 30 min exposure (100% mortality by 9 d. Conidia remained infective up to 28 d post-application but higher concentrations did not increase persistence. Conclusion Both fungus isolates are effective and persistent at low concentrations and short exposure times.

Selection of antibiotic resistance at very low antibiotic concentrations.

Science.gov (United States)

Sandegren, Linus

2014-05-01

Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic varies in different body compartments during treatment, and low concentrations of antibiotics are found in sewage water, soils, and many water environments due to natural production and contamination from human activities. Selection of resistance at non-lethal antibiotic concentrations (below the wild-type minimum inhibitory concentration) occurs due to differences in growth rate at the particular antibiotic concentration between cells with different tolerance levels to the antibiotic. The minimum selective concentration for a particular antibiotic is reached when its reducing effect on growth of the susceptible strain balances the reducing effect (fitness cost) of the resistance determinant in the resistant strain. Recent studies have shown that resistant bacteria can be selected at concentrations several hundred-fold below the lethal concentrations for susceptible cells. Resistant mutants selected at low antibiotic concentrations are generally more fit than those selected at high concentrations but can still be highly resistant. The characteristics of selection at low antibiotic concentrations, the potential clinical problems of this mode of selection, and potential solutions will be discussed.

Dosimetric evaluation of the interplay effect in respiratory-gated RapidArc radiation therapy

International Nuclear Information System (INIS)

Riley, Craig; Yang, Yong; Li, Tianfang; Zhang, Yongqian; Heron, Dwight E.; Huq, M. Saiful

2014-01-01

Purpose: Volumetric modulated arc therapy (VMAT) with gating capability has had increasing adoption in many clinics in the United States. In this new technique, dose rate, gantry rotation speed, and the leaf motion speed of multileaf collimators (MLCs) are modulated dynamically during gated beam delivery to achieve highly conformal dose coverage of the target and normal tissue sparing. Compared with the traditional gated intensity-modulated radiation therapy technique, this complicated beam delivery technique may result in larger dose errors due to the intrafraction tumor motion. The purpose of this work is to evaluate the dosimetric influence of the interplay effect for the respiration-gated VMAT technique (RapidArc, Varian Medical Systems, Palo Alto, CA). Our work consisted of two parts: (1) Investigate the interplay effect for different target residual errors during gated RapidArc delivery using a one-dimensional moving phantom capable of producing stable sinusoidal movement; (2) Evaluate the dosimetric influence in ten clinical patients’ treatment plans using a moving phantom driven with a patient-specific respiratory curve. Methods: For the first part of this study, four plans were created with a spherical target for varying residual motion of 0.25, 0.5, 0.75, and 1.0 cm. Appropriate gating windows were applied for each. The dosimetric effect was evaluated using EDR2 film by comparing the gated delivery with static delivery. For the second part of the project, ten gated lung stereotactic body radiotherapy cases were selected and reoptimized to be delivered by the gated RapidArc technique. These plans were delivered to a phantom, and again the gated treatments were compared to static deliveries by the same methods. Results: For regular sinusoidal motion, the dose delivered to the target was not substantially affected by the gating windows when evaluated with the gamma statistics, suggesting the interplay effect has a small role in respiratory-gated Rapid

Dosimetric evaluation of the interplay effect in respiratory-gated RapidArc radiation therapy.

Science.gov (United States)

Riley, Craig; Yang, Yong; Li, Tianfang; Zhang, Yongqian; Heron, Dwight E; Huq, M Saiful

2014-01-01

Volumetric modulated arc therapy (VMAT) with gating capability has had increasing adoption in many clinics in the United States. In this new technique, dose rate, gantry rotation speed, and the leaf motion speed of multileaf collimators (MLCs) are modulated dynamically during gated beam delivery to achieve highly conformal dose coverage of the target and normal tissue sparing. Compared with the traditional gated intensity-modulated radiation therapy technique, this complicated beam delivery technique may result in larger dose errors due to the intrafraction tumor motion. The purpose of this work is to evaluate the dosimetric influence of the interplay effect for the respiration-gated VMAT technique (RapidArc, Varian Medical Systems, Palo Alto, CA). Our work consisted of two parts: (1) Investigate the interplay effect for different target residual errors during gated RapidArc delivery using a one-dimensional moving phantom capable of producing stable sinusoidal movement; (2) Evaluate the dosimetric influence in ten clinical patients' treatment plans using a moving phantom driven with a patient-specific respiratory curve. For the first part of this study, four plans were created with a spherical target for varying residual motion of 0.25, 0.5, 0.75, and 1.0 cm. Appropriate gating windows were applied for each. The dosimetric effect was evaluated using EDR2 film by comparing the gated delivery with static delivery. For the second part of the project, ten gated lung stereotactic body radiotherapy cases were selected and reoptimized to be delivered by the gated RapidArc technique. These plans were delivered to a phantom, and again the gated treatments were compared to static deliveries by the same methods. For regular sinusoidal motion, the dose delivered to the target was not substantially affected by the gating windows when evaluated with the gamma statistics, suggesting the interplay effect has a small role in respiratory-gated RapidArc therapy. Varied results were

Comparison of continuous wave, spin echo, and rapid scan EPR of irradiated fused quartz

International Nuclear Information System (INIS)

Mitchell, Deborah G.; Quine, Richard W.; Tseitlin, Mark; Meyer, Virginia; Eaton, Sandra S.; Eaton, Gareth R.

2011-01-01

The E' defect in irradiated fused quartz has spin lattice relaxation times (T 1 ) about 100-300 μs and spin-spin relaxation times (T 2 ) up to about 200 μs, depending on the concentration of defects and other species in the sample. These long relaxation times make it difficult to record an unsaturated continuous wave (CW) electron paramagnetic resonance (EPR) signal that is free of passage effects. Signals measured at X-band (∼9.5 GHz) by three EPR methods: conventional slow-scan field-modulated EPR, rapid scan EPR, and pulsed EPR, were compared. To acquire spectra with comparable signal-to-noise, both pulsed and rapid scan EPR require less time than conventional CW EPR. Rapid scan spectroscopy does not require the high power amplifiers that are needed for pulsed EPR. The pulsed spectra, and rapid scan spectra obtained by deconvolution of the experimental data, are free of passage effects.

A predictive model for the chemical vapor deposition of polysilicon in a cold wall, rapid thermal system

Energy Technology Data Exchange (ETDEWEB)

Toprac, A.J.; Trachtenberg, I.; Edgar, T.F. (Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering)

1994-06-01

The chemical vapor deposition of polysilicon from thermally activated silane in a cold wall, single-wafer rapid thermal system was studied by experimentation at a variety of low pressure conditions, including very high temperatures. The effect of diluent gas on polysilicon deposition rates was examined using hydrogen, helium, and krypton. A mass-transfer model for the chemical vapor deposition of polysilicon in a cold wall, rapid thermal system was developed. This model was used to produce an empirical rate expression for silicon deposition from silane by regressing kinetic parameters to fit experimental data. The resulting model provided accurate predictions over widely varying conditions in the experimental data.

Variations of Rn-222 concentration in the Bratislava air

International Nuclear Information System (INIS)

Holy, K.; Bohm, R.; Polaskova, A.

1996-01-01

222 Rn is produced by alpha decay of 222 Ra in roil. A small fraction of totally produced 222 Rn escapes from coil particles into soil air. Then 222 Rn is transported predominantly by molecular diffusion into outdoor atmosphere. The radon concentration in the outdoor atmosphere is not stable. It varies irregularly depending on meteorological conditions. However there were found out regular daily and remand variations of 222 Rn concentration in outdoor atmosphere. These variations were measured in numerous works and results are summarized f.e. in work of Gesell. A simple model described the annual variations of 222 Rn concentration war published by Minato. A mathematical analysis of daily course of 222 Rn concentration in outdoor atmosphere was realized by Garzon et al. Some results of our study of 222 Rn variations in outdoor atmosphere of Bratislava are shown in this report. (author)

Current-induced spin polarization in InGaAs and GaAs epilayers with varying doping densities

Science.gov (United States)

Luengo-Kovac, M.; Huang, S.; Del Gaudio, D.; Occena, J.; Goldman, R. S.; Raimondi, R.; Sih, V.

2017-11-01

The current-induced spin polarization and momentum-dependent spin-orbit field were measured in InxGa1 -xAs epilayers with varying indium concentrations and silicon doping densities. Samples with higher indium concentrations and carrier concentrations and lower mobilities were found to have larger electrical spin generation efficiencies. Furthermore, current-induced spin polarization was detected in GaAs epilayers despite the absence of measurable spin-orbit fields, indicating that the extrinsic contributions to the spin-polarization mechanism must be considered. Theoretical calculations based on a model that includes extrinsic contributions to the spin dephasing and the spin Hall effect, in addition to the intrinsic Rashba and Dresselhaus spin-orbit coupling, are found to reproduce the experimental finding that the crystal direction with the smaller net spin-orbit field has larger electrical spin generation efficiency and are used to predict how sample parameters affect the magnitude of the current-induced spin polarization.

41Ar-concentration measurements at the Finnish TRIGA Mark II

International Nuclear Information System (INIS)

Tamminen, A.

1970-01-01

41 Ar-concentrations in the reactor hall and in the Ar-ventilation duct of FiR-1 (IRIGA Mark II, 250 kW) have been measured during normal operation conditions. Additional measurements have been performed varying Ar-ventilation and hall ventilation flow. A γ- and background compensated thin window proportional detector and a β-Geiger detector for 41 Ar-measurements are described. The hall concentration has also been estimated from background measurements with an unshielded Ge(Li)-detector. The saturation concentration in the reactor hall with and without the hall ventilation is about 1 x 10 -7 μCi/cm 3 and 3 x 10 -7 μCi/cm 3 , respectively. (author)

Effects of preferential concentration on direct radiation transmission in a turbulent duct flow

Science.gov (United States)

Villafane, Laura; Banko, Andrew; Kim, Ji Hoon; Elkins, Chris; Eaton, John

2017-11-01

Inertial particles in turbulent flows preferentially concentrate, giving rise to spatial and temporal fluctuations of particle number density that affect radiation transmission through the medium. Positive particle correlations enhance direct transmission when compared to the exponential attenuation predicted by the Beer's Law for randomly distributed particles. In the context of a particle based solar receiver, this work studies the effects of preferential concentration and optical depth on direct transmission through a particle laden turbulent duct flow. Time resolved measurements of transmission through the mixture were performed for various particle loadings and Reynolds numbers, thus varying particle correlation lengths, optical depth and concentration fluctuations. These measurements were made using a photodiode to record the transmission of a collimated laser beam along the wall bisector of the duct. A synchronized high-speed camera provided particle positions along most of the beam path. Average and fluctuating radiation transmission results are compared to predictions derived from the imaged number density fields and to simplified analytical models. Simplified models are able to capture the correct trends with varying loading and preferential concentration. This work is funded by the Department of Energy's National Nuclear Security Administration, Grant #DE-NA0002373-1.

Assessment of pregnancy status of Asian elephants (Elephas maximus) by measurement of progestagen and glucocorticoid and their metabolite concentrations in serum and feces, using enzyme immunoassay (EIA).

Science.gov (United States)

Kajaysri, Jatuporn; Nokkaew, Weerapun

2014-03-01

The study was to find patterns of progestagen (progesterone and its metabolite) and glucocorticoid and their metabolite concentrations in serum and feces of pregnant Asian elephants (Elephas maximus). The 5 female Asian domestic elephants were naturally mated until pregnancy. After that, blood and feces samples were collected monthly during pregnancy for progestagen, glucocorticoid and their metabolites analysis by enzyme immunoassay (EIA). The results showed the serum progestagen concentration during gestation was 2.11 ± 0.60 to 18.44 ± 2.28 ng/ml. Overall, serum progestagen concentration rose from the 1st month to reach peak in the 11th month, after which it declined to its lowest level in the 22nd month of pregnancy. Fecal progestagen concentration varied from 1.18 ± 0.54 to 3.35 ± 0.45 µg/g during pregnancy. In general, fecal progestagen concentration increased from the 1st month to its highest level in the 12th month. After this, it declined reaching its lowest point in the 22nd month of pregnancy. Glucocorticoid hormones and their metabolite concentrations both in serum and feces fluctuated from low to medium throughout almost the entire pregnancy period and then rapidly increased around the last week before calving. Our study suggests that this profile of progestagen and glucocorticoid hormones and their metabolite concentration levels in serum and feces can be used to assess the pregnancy status of Asian elephants. If serum and fecal progestagen concentrations were found in very low levels and glucocorticoid and their metabolite concentrations were found in very high levels, it was indicated that the cow elephant would calve within 7 days.

Loading regimen required to rapidly achieve therapeutic trough plasma concentration of teicoplanin and evaluation of clinical features

Directory of Open Access Journals (Sweden)

Seki M

2012-11-01

Full Text Available Masafumi Seki,1,* Kaori Yabuno,1,2,* Koji Miyawaki,1,2 Yoshihiro Miwa,2 Kazunori Tomono11Division of Infection Control and Prevention, 2Department of Pharmacy, Osaka University Hospital, Suita, Osaka, Japan*These authors contributed equally to this workBackground: A trough concentration of >20 mg/L is considered the optimal dosage of teicoplanin required to ensure early therapeutic effects against methicillin-resistant Staphylococcus aureus (MRSA infections including those in patients who develop febrile neutropenia after chemotherapy. This study determines appropriate initial doses during the first 2 days of administration and evaluates the therapeutic target teicoplanin trough concentration.Method: A 2-day regimen was evaluated in patients treated with 600 mg and 1200 mg or 1200 mg and 600 mg (total 1800 mg, Group 1, 800 mg and 800 mg (total 1600 mg, Group 2, and 800 mg and 400 mg (total 1200 mg, Group 3 of teicoplanin on Days 1 and 2, respectively. We also compared the efficiency and adverse effects at trough concentrations of 15–20 mg/L (Group A, n = 28 with >20 mg/L (Group B, n = 27 of teicoplanin, and also compared them with those on the similar concentrations of vancomycin (Groups C and D, n = 50 and 34, respectively.Results: The mean trough concentrations of teicoplanin on Days 4 or 5 were 22.2, 17.5, and 16.2 mg/L in Groups 1, 2, and 3, respectively. The clinical efficiency was 85.7%, 81.5%, 92.0%, and 91.5%, in Groups A, B, C, and D, respectively. The rates of adverse effects were not high in teicoplanin (nephrotoxicity, 7.1% and 3.7%, and hepatotoxicity, 14.3% and 11.1% in Groups A and B, respectively. However, more adverse effects tended to arise in patients who received vancomycin in nephrotoxicity (14.0% and 11.8%, in Groups C and D, respectively.Conclusion: These results suggest that the 2-day regimens with total 1800 mg achieved the most effective therapeutic trough plasma concentration of teicoplanin (20 mg/L. However, 15–20

Individual differences in detecting rapidly presented fearful faces.

Directory of Open Access Journals (Sweden)

Dandan Zhang

Full Text Available Rapid detection of evolutionarily relevant threats (e.g., fearful faces is important for human survival. The ability to rapidly detect fearful faces exhibits high variability across individuals. The present study aimed to investigate the relationship between behavioral detection ability and brain activity, using both event-related potential (ERP and event-related oscillation (ERO measurements. Faces with fearful or neutral facial expressions were presented for 17 ms or 200 ms in a backward masking paradigm. Forty-two participants were required to discriminate facial expressions of the masked faces. The behavioral sensitivity index d' showed that the detection ability to rapidly presented and masked fearful faces varied across participants. The ANOVA analyses showed that the facial expression, hemisphere, and presentation duration affected the grand-mean ERP (N1, P1, and N170 and ERO (below 20 Hz and lasted from 100 ms to 250 ms post-stimulus, mainly in theta band brain activity. More importantly, the overall detection ability of 42 subjects was significantly correlated with the emotion effect (i.e., fearful vs. neutral on ERP (r = 0.403 and ERO (r = 0.552 measurements. A higher d' value was corresponding to a larger size of the emotional effect (i.e., fearful--neutral of N170 amplitude and a larger size of the emotional effect of the specific ERO spectral power at the right hemisphere. The present results suggested a close link between behavioral detection ability and the N170 amplitude as well as the ERO spectral power below 20 Hz in individuals. The emotional effect size between fearful and neutral faces in brain activity may reflect the level of conscious awareness of fearful faces.

Fatty Acid and Cholesterol Concentrations in Usually Consumed Fish in Brazil

Directory of Open Access Journals (Sweden)

Carlos Scherr

2015-02-01

Full Text Available Background: Several studies have demonstrated clinical benefits of fish consumption for the cardiovascular system. These effects are attributed to the increased amounts of polyunsaturated fatty acids in these foods. However, the concentrations of fatty acids may vary according to region. Objective: The goal of this study was to determine the amount of,cholesterol and fatty acids in 10 Brazilian fishes and in a non-native farmed salmon usually consumed in Brazil. Methods: The concentrations of cholesterol and fatty acids, especially omega-3, were determined in grilled fishes. Each fish sample was divided in 3 sub-samples (chops and each one was extracted from the fish to minimize possible differences in muscle and fat contents. Results: The largest cholesterol amount was found in white grouper (107.6 mg/100 g of fish and the smallest in badejo (70 mg/100 g. Omega-3 amount varied from 0.01 g/100 g in badejo to 0.900 g/100 g in weakfish. Saturated fat varied from 0.687 g/100 g in seabass to 4.530 g/100 g in filhote. The salmon had the greatest concentration of polyunsaturated fats (3.29 g/100 g and the highest content of monounsaturated was found in pescadinha (5.98 g/100 g. Whiting and boyfriend had the best omega-6/omega 3 ratios respectively 2.22 and 1.19, however these species showed very little amounts of omega-3. Conclusion: All studied Brazilian fishes and imported salmon have low amounts of saturated fat and most of them also have low amounts of omega-3.

Leaf Senescence, Root Morphology, and Seed Yield of Winter Oilseed Rape (Brassica napus L. at Varying Plant Densities

Directory of Open Access Journals (Sweden)

Ming Li

2017-01-01

Full Text Available In this study, the yield and yield components were studied using a conventional variety Zhongshuang 11 (ZS 11 and a hybrid variety Zhongyouza 12 (ZYZ 12 at varying plant densities. The increase in plant density led to an initial increase in seed yield and pod numbers per unit area, followed by a decrease. The optimal plant density was 58.5 × 104 plants ha−1 in both ZS 11 and ZYZ 12. The further researches on physiological traits showed a rapid decrease in the green leaf area index (GLAI and chlorophyll content and a remarkable increase in malondialdehyde content in high plant density (HPD population than did the low plant density (LPD population, which indicated the rapid leaf senescence. However, HPD had higher values in terms of pod area index (PAI, pod photosynthesis, and radiation use efficiency (RUE after peak anthesis. A significantly higher level of dry matter accumulation and nitrogen utilization efficiency were observed, which resulted in higher yield. HPD resulted in a rapid decrease in root morphological parameters (root length, root tips, root surface area, and root volume. These results suggested that increasing the plant density within a certain range was a promising option for high seed yield in winter rapeseed in China.

Rapid sonochemical preparation of shape-selective lead iodide

International Nuclear Information System (INIS)

Huang, Baojun; He, Qin; Fa, Wenjun; Li, Pinjiang; Zhang, Yange; Zheng, Zhi

2012-01-01

Graphical abstract: SEM morphologies of various PbI2 products obtained with the iodine concentration of 6.7 g/L and irradiation time of 1 minute at the reaction temperatures of 35 °C (a), 25 °C (b), and 15 °C (c). Highlights: ► PbI 2 with various morphologies were rapidly formed at room temperature. ► We could well control the morphologies of PbI 2 by changing reaction conditions. ► The PbI 2 films could better resist rolling in a liquid media. -- Abstract: Lead iodide (PbI 2 ) films/crystals with various nano/micro morphologies (e.g., Nanoflake, block and microrod) were rapidly synthesized by taking advantage of a simple sonochemical method. The PbI 2 crystals with uniform nanoflake structures could be fabricated directly on lead foils with the irradiation time as short as 36 s via interfacial reaction between lead foils and elemental iodine in ethanol at ambient temperature. It was found experimentally that the morphologies of the resulting thin films/crystals could be well controlled by the adjustment of several parameters including irradiation time, reaction solvents, iodine concentration, ultrasonic power, and reaction temperature. Most importantly, the resultant PbI 2 films are stable enough to resist rolling under the drastic ultrasound irradiation in a liquid media. This method is believed to be the fastest way for in situ fabrication of morphology-controlled semiconductor films on various metal substrates for subsequent applications related to the other metal iodide or metal sulfide semiconductor films.

A RAPID Method for Blood Processing to Increase the Yield of Plasma Peptide Levels in Human Blood.

Science.gov (United States)

Teuffel, Pauline; Goebel-Stengel, Miriam; Hofmann, Tobias; Prinz, Philip; Scharner, Sophie; Körner, Jan L; Grötzinger, Carsten; Rose, Matthias; Klapp, Burghard F; Stengel, Andreas

2016-04-28

Research in the field of food intake regulation is gaining importance. This often includes the measurement of peptides regulating food intake. For the correct determination of a peptide's concentration, it should be stable during blood processing. However, this is not the case for several peptides which are quickly degraded by endogenous peptidases. Recently, we developed a blood processing method employing Reduced temperatures, Acidification, Protease inhibition, Isotopic exogenous controls and Dilution (RAPID) for the use in rats. Here, we have established this technique for the use in humans and investigated recovery, molecular form and circulating concentration of food intake regulatory hormones. The RAPID method significantly improved the recovery for (125)I-labeled somatostatin-28 (+39%), glucagon-like peptide-1 (+35%), acyl ghrelin and glucagon (+32%), insulin and kisspeptin (+29%), nesfatin-1 (+28%), leptin (+21%) and peptide YY3-36 (+19%) compared to standard processing (EDTA blood on ice, p processing, while after standard processing 62% of acyl ghrelin were degraded resulting in an earlier peak likely representing desacyl ghrelin. After RAPID processing the acyl/desacyl ghrelin ratio in blood of normal weight subjects was 1:3 compared to 1:23 following standard processing (p = 0.03). Also endogenous kisspeptin levels were higher after RAPID compared to standard processing (+99%, p = 0.02). The RAPID blood processing method can be used in humans, yields higher peptide levels and allows for assessment of the correct molecular form.

Observation of reversible, rapid changes in drug susceptibility of hypoxic tumor cells in a microfluidic device.

Science.gov (United States)

Germain, Todd; Ansari, Megan; Pappas, Dimitri

2016-09-14

Hypoxia is a major stimulus for increased drug resistance and for survival of tumor cells. Work from our group and others has shown that hypoxia increases resistance to anti-cancer compounds, radiation, and other damage-pathway cytotoxic agents. In this work we utilize a microfluidic culture system capable of rapid switching of local oxygen concentrations to determine changes in drug resistance in prostate cancer cells. We observed rapid adaptation to hypoxia, with drug resistance to 2 μM staurosporine established within 30 min of hypoxia. Annexin-V/Sytox Green apoptosis assays over 9 h showed 78.0% viability, compared to 84.5% viability in control cells (normoxic cells with no staurosporine). Normoxic cells exposed to the same staurosporine concentration had a viability of 48.6% after 9 h. Hypoxia adaptation was rapid and reversible, with Hypoxic cells treated with 20% oxygen for 30 min responding to staurosporine with 51.6% viability after drug treatment for 9 h. Induction of apoptosis through the receptor-mediated pathway, which bypasses anti-apoptosis mechanisms induced by hypoxia, resulted in 39.4 ± 7% cell viability. The rapid reversibility indicates co-treatment of oxygen with anti-cancer compounds may be a potential therapeutic target. Copyright © 2016 Elsevier B.V. All rights reserved.

Stress concentration factors for an internally pressurized circular vessel containing a radial U-notch

International Nuclear Information System (INIS)

Carvalho, E.A. de

2005-01-01

This paper evaluates the stress concentration factors for an internally pressurized cylinder containing a radial U-notch along its length. This work studies the cases where the external to internal radius ratio (Ψ) is equal to 1.26, 1.52, 2.00, and 3.00 and the notch radius to internal radius ratio (Φ) is fixed and equal to 0.026. The U-notch depth varies from 0.1 to 0.6 of the wall thickness. Results are also presented for a fixed size semi-circular notch. Hoop stresses at the external wall are presented, showing regions where the stress matches the nominal one and the favourable places to install strain sensors. The finite element method is used to determine the stress concentration factors (K t ) for the above described situations and for a special case where a varying semi-circular notch is present with Ψ=3.00. This notch depth varies from 0.013 to 0.3 of the wall thickness. It is pointed out that even relatively small notches introduce large stress concentrations and disrupt the hoop stress distribution all over the cross section. Results are also compared to an example found in the literature for semi-circular notches and K t curves for both cases present the same shape

On the resistivity of metal-tellurium alloys for low concentrations of tellurium

International Nuclear Information System (INIS)

Gorecki, J.

1982-04-01

The resistivity and thermoelectric power of metal-tellurium liquid alloys have been discussed for the case of small tellurium concentration. Nearly free electron model of conduction band has been used. The rapid increase of resistivity in transition metal-tellurium alloys has been predicted. (author)

Inhibition of fatty acid mobilization by arterial free fatty acid concentration

DEFF Research Database (Denmark)

Madsen, J; Bülow, J; Nielsen, N E

1986-01-01

Subcutaneous, inguinal adipose tissue from dogs was perfused with blood in which the free fatty acid (FFA) concentration was varied corresponding to FFA/albumin molar ratios between 1 and 6. Otherwise the composition of the perfusate was kept constant. In order to stimulate lipolysis, isoprenaline...

Seasonal variations in hepatic Cd and Cu concentrations and in the sub-cellular distribution of these metals in juvenile yellow perch (Perca flavescens)

International Nuclear Information System (INIS)

Kraemer, Lisa D.; Campbell, Peter G.C.; Hare, Landis

2006-01-01

Temporal fluctuations in metal (Cd and Cu) concentrations were monitored over four months (May to August) in the liver of juvenile yellow perch (Perca flavescens) sampled from four lakes situated along a metal concentration gradient in northwestern Quebec: Lake Opasatica (reference lake, low metal concentrations), Lake Vaudray (moderate metal concentrations) and lakes Osisko and Dufault (high metal levels). The objectives of this study were to determine if hepatic metal concentrations and metal-handling strategies at the sub-cellular level varied seasonally. Our results showed that Cd and Cu concentrations varied most, in both absolute and relative values, in fish with the highest hepatic metal concentrations, whereas fish sampled from the reference lake did not show any significant variation. To examine the sub-cellular partitioning of these two metals, we used a differential centrifugation technique that allowed the separation of cellular debris, metal detoxified fractions (heat-stable proteins such as metallothionein) and metal sensitive fractions (heat-denaturable proteins (HDP) and organelles). Whereas Cd concentrations in organelle and HDP fractions were maintained at low concentrations in perch from Lakes Opasatica and Vaudray, concentrations in these sensitive fractions were higher and more variable in perch from Lakes Dufault and Osisko, suggesting that there may be some liver dysfunction in these two fish populations. Similarly, Cu concentrations in these sensitive fractions were higher and more variable in perch from the two most Cu-contaminated lakes (Dufault and Osisko) than in perch from the other two lakes, suggesting a breakdown of homeostatic control over this metal. These results suggest not only that metal concentrations vary seasonally, but also that concentrations vary most in fish from contaminated sites. Furthermore, at the sub-cellular level, homeostatic control of metal concentrations in metal-sensitive fractions is difficult to maintain in