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Sample records for phyto chemical study

  1. Plectranthus amboinicus-mediated silver, gold, and silver-gold nanoparticles: phyto-synthetic, catalytic, and antibacterial studies

    Science.gov (United States)

    Purusottam Reddy, B.; Mallikarjuna, K.; Narasimha, G.; Park, Si-Hyun

    2017-08-01

    Bio-based green nanotechnology aims to characterize compounds from natural sources and establish efficient routes for the preparation of nontoxic materials that have applicability in biodegradable and biocompatible devices. The present study has investigated the use of Plectranthus amboinicus leaf extracts as reducing and capping materials for the green fabrication of silver, gold, and silver-gold (Ag, Au, and Ag/Au) metal and bimetallic nanoparticles. The catalytic behavior of these phyto-inspired nanoparticles was then assessed in terms of the reduction of 4-nitrophenol. Transmission electron microscopy was used to investigate the shape, morphology, distribution, and diameter of the phytomolecules capped with Ag, Au, and Ag/Au metal nanoparticles. The nature of the crystallinity of the nanoparticles was studied by small area electron diffraction (SAED) and x-ray diffraction analysis (XRD), and Fourier transform infrared (FTIR) spectroscopy was used to study the reduction and stabilizing involvement of the phyto-organic moieties in aqueous medium. The phyto-inspired Ag and Ag/Au nanoparticles demonstrated good antibacterial properties toward Gram-negative Escherichia coli and Pseudomonas spp. and Gram-positive Bacillus spp. and Staphylococcus spp. microorganisms using the well diffusion method. Notably, the Ag nanoparticles were shown to possess effective antibacterial properties.

  2. Phyto-Chemical Evaluation and Anti-oxidant potentiality of Cycas beddomei Dyer Male cone aqueous Extract

    Directory of Open Access Journals (Sweden)

    Mahendra Nath Mitta

    2014-06-01

    Full Text Available Cycas beddomei Dyer, an endemic and critically endangered, tropical, dry deciduous, dioecious gymnosperm present in varied region of adjunct areas of Tirumala Hillocks, Seshachalam Biosphere Reserve, Eastern ghats, India. The objective of the study was to investigate antioxidant capacity of aqueous extracts of microsporophylls of male cones of Cycas beddomei. This study deals with the quantitative estimation of phytoconstituents viz., Total Phenolic Content (TPC, Total Flavonoid Content (TFC, Total Flavonols (TF, Total Proanthocyanidins (TPA, Extraction Yield (EY , Quantitative analysis soluble carbohydrates, Starch, Crude fibre, Proteins, Moisture, Ash and Mineral composition of aqueous extract of male cone of cycas beddomei has been carried out. Moreover, the assessment of antioxidant capacity by standard established calorimetric methods viz., DPPH assay, TAC and ABTS assay. Entire data has evaluated statistically. Results depicted High contents of TPC, TFC, TF and TPA and exerted anti-radical aptitude. Significant correlation has been found between quantities of phyto-constituents and anti-oxidant assays. With the results, it is confirmed that the logistics of aqueous cone extract of Cycas beddomei as potential anti-oxidant by evaluating the bioavailability of phytoconstituents and provided scientific base as a valuable natural antioxidant and therapeutic agent.

  3. Greenhouse studies on the phyto-extraction capacity of Cynodon nlemfuensis for lead and cadmium under irrigation with treated wastewater

    Science.gov (United States)

    Madyiwa, S.; Chimbari, M. J.; Schutte, C. F.; Nyamangara, J.

    For over 30 years, discharge of sewage effluent and sludge on pasturelands has been used in Zimbabwe as a cheap method for secondary treatment of wastewater without any monitoring of accumulation of heavy metals in soils and grasses, let alone in animals grazing on the pastures. Cynodon nlemfuensis (star grass) has been the main grass planted on the wastewater irrigated pasturelands. This study was conducted to assess the capacity of star grass to accumulate lead (Pb) and cadmium (Cd) and develop models incorporating grass yield, metal uptake and soil bio-available (EDTA extractable) metal content, that could be used to determine critical grass and soil concentrations at which grass productivity declines. Star grass was planted in 30 fertilized pots containing sandy soil within a greenhouse. The pots consisted of nine treatments of varying levels of added inorganic Pb and Cd subjected to treated wastewater application and one control that had no added metals and received water application only. The elements were applied to the soils once just after planting the grass. Chemical analyses showed that star grass had a relatively high phyto-extraction capacity of Pb and Cd, comparable to that of hyper-accumulating grasses such as Lolium perenne (rye grass). It accumulated Pb and Cd to levels far beyond the recommended maximum limits for pasture grass. Analysis of variance on log-normal transformed data showed that bio-available soil metal concentrations correlated strongly with grass metal content and grass metal content correlated strongly with the yield. There was however a weak correlation between the yield and bio-available soil levels. The yield versus grass metal content models that were developed for the first crop and re-growth predicted similar critical metal concentrations and yields. Using the critical grass metal concentrations in the soil bio-available metal concentration versus grass metal concentration models allowed for the prediction of the

  4. Phyto chemical Screening, Antibacterial, Antifungal and Anthelmintic Activity of Morinda citrifolia stem

    Directory of Open Access Journals (Sweden)

    Dr. D. Gopala Krishna

    2013-05-01

    Full Text Available In the present study, the Petroleum Ether and Alcoholic extract of Morinda citrifolia L. (Noni stem were subjected to preliminary screening for Antimicrobial and Aanthelmintic activity. The alcoholic extract exhibited significant Anti bacterial, Antifungal activity, comparable to the standard drug Tetracycline. The Petroleum Ether and Alcoholic extract were evaluated for Anthelmintic activity on adult Indian Earthworms, ‘Pheretima posithuma’. The Alcoholic extract produced more significant Anthelmintic activity than Petroleum ether extract and the activities are comparable with the reference drug Piperazine citrate

  5. Screening of phyto-chemical constituents, trace metals and antimicrobial efficiency of Cissus vitiginea

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    V. Subramani

    2014-06-01

    Full Text Available The present study focused on the phytochemical constituents, antimicrobial activity and trace metal concentrations of the Cissus vitiginea plant leaves which were collected from the Tiruchirappalli district, southern India. Preliminary phytochemical screening of leaves extracts revealed the presence of the bioactive compounds, such as steroids, triterpenoids, glycosides, sugar, alkaloids, flavonoids, tannins, amino acid, and coumarin in the leaves. The bacterial and fungal strains were tested for antimicrobial sensitivity against C. vitiginea using the disc diffusion method. The methanol extracts of the plant leaves exhibited the higher zone of inhibition against bacterial strains than fungal strains. The trace metal concentrations were analyzed form the powered plant leaves by 797 VA Computrace voltametry, Metrohm. The average concentrations of Cd, Cr, Cu, Fe, Ni, Pb and Zn were 0.05, BDL, 018, 0.38, BDL, BDL and 0.48 mg kg-1, respectively. The bioactive compounds responsible for these antimicrobial activities could be isolated and identified to develop a new drug of pharmaceutical interest.

  6. Glucoxylan-mediated green synthesis of gold and silver nanoparticles and their phyto-toxicity study.

    Science.gov (United States)

    Iram, Fozia; Iqbal, Mohammad S; Athar, Muhammad M; Saeed, Muhammad Z; Yasmeen, Abida; Ahmad, Riaz

    2014-04-15

    A green synthesis of gold and silver nanoparticles having exceptional high stability is reported. The synthesis involves the use of glucoxylans isolated from seeds of Mimosa pudica and excludes the use of conventional reducing and capping agents. The average particle sizes were 40 and 6 nm for gold and silver, respectively. The size of gold particles obtained in this work is suitable for drug delivery as they are non-cytotoxic. In phyto-toxicity tests the gold and silver nanoparticles did not show any significant effect on germination of radish seeds, whereas in radish seedling root growth assay the two particles behaved differently. The silver nanoparticles exhibited a concentration-dependent stimulatory effect on root length, whereas the gold nanoparticles had no significant effect in this test. The likely mechanism of these effects is discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Importance of metadata in bio/phyto-remediation Studies: a way to channelize future research through meta-analysis

    Directory of Open Access Journals (Sweden)

    Muhammad Arslan

    2016-08-01

    Full Text Available Meta-analysis is a modern statistical approach that combines the results from multiple studies to enhance the power of data, improves the quality of estimates, and the magnitude of the effect of a treatment. In bio/phyto-remediation studies, some authors adopt general ways to present research outcomes such as percentages, means, and graphs.  This type of data has multiple limits, non-availability of comparative statistical significance and publication bias are the most imperative. In addition, such data creates big hindrances to perform metaanalysis in a cluster of other studies. Consequently, such datasets restrict the statistical comparison between similar studies, and quantitative assessment of variables. Hence, newcomers in the field of bioremediation find it difficult to design effective test protocols, and at the end, have to content with unconvincing results. Therefore, we suggest presentation of actual data along with statistical analyses of observations, and comparison with the control for robust translation of results. Otherwise, the authors must be directed to publish original datasets as supporting material or appendices with the manuscript.

  8. In situ assessment of phyto and zooavailability of trace elements: A complementary approach to chemical extraction procedures.

    Science.gov (United States)

    Pauget, Benjamin; Faure, Olivier; Conord, Cyrille; Crini, Nadia; de Vaufleury, Annette

    2015-07-15

    For an accurate risk assessment of sites contaminated by trace elements (TE), measurements of bioavailability must be performed. This is routinely achieved using the standardized 0.01M CaCl2 method. However, the suitability of chemical extractions as proxies of bioavailability is questionable. We analyzed the correlations between chemically estimated TE bioavailability and TE actually accumulated by coupling plant and snails bioindicators. Results showed a better correlation between plant TE contents and CaCl2 fraction while total soil concentration better explained snail TE contents. However in both cases chemical measures were not suitable to predict TE accumulation and bioavailability. Considering the soil properties only improve the estimation of Cr, Ni and Pb accumulation by plants while for snails, TE contents in viscera were dependent both on soil and plant contents and soil properties. It highlights the complementarities of biomonitoring methods to assess bioavailability. This dual approach allows a "physiologically defined" evaluation of bioavailability. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Phyto/rhizoremediation studies using long-term PCB-contaminated soil.

    Science.gov (United States)

    Mackova, Martina; Prouzova, Petra; Stursa, Petr; Ryslava, Edita; Uhlik, Ondrej; Beranova, Katarina; Rezek, Jan; Kurzawova, Veronika; Demnerova, Katerina; Macek, Tomas

    2009-11-01

    Polychlorinated biphenyls (PCBs) represent a large group of recalcitrant environmental pollutants, differing in the number of chlorine atoms bound to biphenyl ring. Due to their excellent technological properties, PCBs were used as heat-transfer media, for filling transformers and condensers, as paint additives, etc. With increasing knowledge of their toxicity, transfer to food chains and accumulation in living organisms, their production ended in most countries in the 1970s and in 1984 in the former Czechoslovakia. But even a quarter of century after the PCB production ceased, from contaminated areas, the volatile PCBs evaporate and contaminate much larger areas even at very distant parts of the world. For this reason, PCBs still represent a global problem. The main method of PCB removal from contaminated environment is at present the expensive incineration at high temperatures. With the aim of finding effective alternative approaches, we are studying biological methods for PCB removal from the environment. In this paper, we summarise 10 years of studies using long-term PCB-contaminated soil from a dumpsite in South Bohemia, targeted for the use of plants (phytoremediation) and their cooperation with microorganisms in the root zone (rhizoremediation). Long-term contaminated soil from Lhenice dumpsite, more than hundred kilograms of homogenised material, was used in microcosms (pots and buckets), and field plots were established at the site. Tested plants include among others tobacco, black nightshade, horseradish, alfalfa and willow. Aseptic plant cell and tissue cultures were from the collection of the IOCB. Microorganisms were our own isolates. The paper summarises experiments done between 1998 and 2008 with real contaminated soil, both vegetated and non-vegetated. PCB analysis was performed by GC-ECD, metabolic products identified mostly using 2D-GC/MS-MS and synthetic standards, whereas molecular methods included quantitative PCR and sequencing. The soil was

  10. Proximate And Phyto-Chemical Contents Of Selected Leave Meals As Alternative Feed Ingredients For Fish Feed Production

    Directory of Open Access Journals (Sweden)

    Ayegba, E. O.

    2016-06-01

    Full Text Available The present study evaluates the nutritional potential of four different plant leaves as alternative to conventional feed ingredients for fish feed production. These leaves include; moringa leaf meal, leucaena leaf meal, sweet potato leaf meal, groundnut leaf meal, and cassava leaf. The crude protein content of the ingredients ranged from 21.88 to 36.05% and the crude lipid contents were recorded as 2.13 to 3.84% with moringa leave meal having the highest value. All the tested ingredients contained phytic acid (10.69 to 16.49 mg/100g, oxalate (494.00 to 879.50 mg/100g tannin (52.78 to 136.93 mg/100g and cyanide (4.36 to 10.53 mg/100g with moringa also having higher content of these antinutrients. It however expected that with appropriate processing methods this ingredients can be made more suitable for incorporation in fish feed.

  11. STUDY ON PHYTO-EXTRACTION BALANCE OF ZN, CD AND PB FROM MINE-WASTE POLLUTED SOILS BY USING FESTUCA ARUNDINACEA AND LOLIUM PERENNE SPECIES

    Directory of Open Access Journals (Sweden)

    B. LIXANDRU

    2013-07-01

    Full Text Available Through the cultivation of tall fescue (Festuca arundinacea and of perennial ryegrass for two years on a chernozem type of soil, in the Banat's plain area we investigated the phyto-extraction potential of Zn, Cd and Pb. In the experimental plot it has been incorporated a quantity of 20 kg of mine-waste per square meter, in a mass ratio of 1:2,5. The mine-waste polluting "contribution" was of 1209 mg Zn / kg d.s., 4.70 mg Cd / kg d.s. and 188.2 mg Pb / kg d.s. The metals content in the soil was determined at the two moments of biomass harvesting, and through balance calculations we could establish the phyto-extraction efficiency of the two foragegrasses species. The obtained results indicate that Festuca arundinacea has an average phyto-extraction yield of 50% for Zn and Cd in the soil; in the case of an ionic excess of 3,5 to 4 times, the phyto-extraction efficiency is reduced, more obvious in the case of Pb (lead ions. The species Lolium perenne registers a yield of almost 92% in the process of phyto-extraction of Zn. The yield values for Cd si Pb are lower, but comparable with the control plot. Unlike Festuca arundinacea, the Lollium perenne species tolerates better the Cd and Pb ionic excess.

  12. 土壤中砷的植物有效性研究进展%Study Advances in Phyto-availability of Arsenic in Soil

    Institute of Scientific and Technical Information of China (English)

    林志灵; 张杨珠; 曾希柏; 李莲芳

    2011-01-01

    土壤中砷的植物有效性研究是开展污染诊断、评估环境健康风险及开展砷污染土壤修复的重要依据.土壤中砷的危害一方面与其在土壤中的含量、有效性和结合形态有关,另一方面与植物对砷的富集能力有关.土壤中砷对植物的有效性主要与有效态砷的含量相关,土壤有效态砷的数量是土壤中砷污染状况的真实反映;富集系数是植物中砷含量与土壤中砷含量的比值,它可大致反映植物在相同土壤砷浓度条件下对砷的吸收能力.高砷风险区宜选种对砷富集能力较差的作物品种.%The study on phyto-availability of arsenic in soil is a foundation for pollution diagnosis, risk assessment of environmental health and the remediation of arsenic-contaminated soil. The arsenic damage not only relates to the concentration, the availability and the combination forms of arsenic in soil, but also relate to the bioaccumulation ability of plant to arsenic. Arsenic phyto-availability mainly relates to available arsenic concentration in soil, and the available arsenic concentration in soil directly reflects arsenic contamination status of soil. The accumulation index is the ratio of arsenic concentration in plant to arsenic concentration in soil, which generally reflects the adsorption capacity of different plants to arsenic at the same arsenic concentration condition. Plants with lower accumulation capacity of arsenic are suitable to plant in high-arsenic risk area.

  13. The phyto-remediation of radioactively contaminated land - a feasible approach or just bananas?

    Energy Technology Data Exchange (ETDEWEB)

    Nesbitt, Victoria A [Nuvia Limited, The Library, Didcot, Oxfordshire, OX11 0RL (United Kingdom)

    2013-07-01

    Soil is an essential component of all terrestrial ecosystems and is under increasing threat from human activity. Techniques available for removing radioactive contamination from soil and aquatic substrates are limited and often costly to implement; particularly over large areas. Frequently, bulk soil removal, with its attendant consequences, is a significant component of the majority of contamination incidents. Alternative techniques capable of removing contamination or exposure pathways without damaging or removing the soil are therefore of significant interest. An increasing number of old nuclear facilities are entering 'care and maintenance', with significant ground contamination issues. Phyto-remediation - the use of plants' natural metabolic processes to remediate contaminated sites is one possible solution. Its key mechanisms include phyto-extraction and phyto-stabilisation. These are analogues of existing remedial techniques. Further, phyto-remediation can improve soil quality and stability and restore functionality. Information on the application of phyto-remediation in the nuclear industry is widely distributed over an extended period of time and sources. It is therefore difficult to quickly and effectively identify which plants would be most suitable for phyto-remediation on a site by site basis. In response, a phyto-remediation tool has been developed to address this issue. Existing research and case studies were reviewed to understand the mechanisms of phyto-remediation, its effectiveness and the benefits and limitations of implementation. The potential for cost recovery from a phyto-remediation system is also briefly considered. An overview of this information is provided here. From this data, a set of matrices was developed to guide potential users through the plant selection process. The matrices take the user through a preliminary screening process to determine whether the contamination present at their site is amenable to phyto

  14. Imaging corn plants with PhytoPET, a modular PET system for plant biology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.; Kross, B.; McKisson, J.; McKisson, J. E.; Weisenberger, A. G.; Xi, W.; Zorn, C.; Bonito, G.; Howell, C. R.; Reid, C. D.; Crowell, A.; Cumberbatch, L. C.; Topp, C.; Smith, M. F.

    2013-11-01

    PhytoPET is a modular positron emission tomography (PET) system designed specifically for plant imaging. The PhytoPET design allows flexible arrangements of PET detectors based on individual standalone detector modules built from single Hamamatsu H8500 position sensitive photomultiplier tubes and pixelated LYSO arrays. We have used the PhytoPET system to perform preliminary corn plant imaging studies at the Duke University Biology Department Phytotron. Initial evaluation of the PhytoPET system to image the biodistribution of the positron emitting tracer {sup 11}C in corn plants is presented. {sup 11}CO{sub 2} is loaded into corn seedlings by a leaf-labeling cuvette and translocation of {sup 11}C-sugars is imaged by a flexible arrangement of PhytoPET modules on each side. The PhytoPET system successfully images {sup 11}C within corn plants and allows for the dynamic measurement of {sup 11}C-sugar translocation from the leaf to the roots.

  15. Comparative in vitro anti-tick efficacy of commercially available products and newly developed phyto-formulations against field collected and resistant tick lines of Rhipicephalus (Boophilus) microplus.

    Science.gov (United States)

    Ajith Kumar, K G; Sharma, Anil Kumar; Kumar, Sachin; Ray, D D; Rawat, A K S; Srivastava, Sharad; Ghosh, Srikant

    2016-12-01

    Rhipicephalus (Boophilus) microplus is considered as one of the most widely distributed tick species ecto-parasitizing on livestock and causes fatal diseases with significant production loss. To address the problem of controlling acaricide resistant tick infestations on animals, attention has been paid to develop eco-friendly phyto-acaricides. The present study was undertaken to evaluate the comparative anti-tick activities of commercially available herbal and chemical products with chemically characterized phyto-formulations developed recently against field ticks and resistant tick lines of R. (B.) microplus. The chemical product Butox(®) Vet was found nearly passive against all the tested resistant tick lines. However, one of the commercial polyherbal product, Zerokeet(®) showed an efficacy (E%) of 41.8-75.4 % ([Formula: see text]) using recommended dilution (1:2) against field ticks and resistant tick lines. However, the other commercial product, Erina(®) EP has very limited efficacy against all the tested tick. In comparison, the newly developed phyto-formulation, NBA/13/B/2 and NAC-01 conferred an E% of 82.4-91.3 % ([Formula: see text]) and 62.3-94.6 % ([Formula: see text]), respectively, against tested resistant ticks. Results indicated higher marketing potentiality of newly developed formulation in the existing tick problem scenario.

  16. Variations in fatty acid composition, glucosinolate profile and some phyto chemical contents in selected oil seed rape (Brassica napus L.) cultivars

    Energy Technology Data Exchange (ETDEWEB)

    El-Din Saad El-Beltag, H.; Mohamed, A. A.

    2010-07-01

    Rapeseed (Brassica napus L.) is now the third most important source of edible oil in the world after soybean and palm oil. In this study seeds of five different rapeseed cultivars namely; pactol, silvo, topas, serw 4 and serw 6 were evaluated for their fatty acid composition, glucosinolate profile, amino acids, total tocopherols and phenolic content. Among all cultivars significant variability in fatty acids were observed. The oleic acid (C18:1) ranged from 56.31% to 58.67%, linoleic acid (C18:2) from 10.52% to 13.74%, {alpha}-linolenic acid (C18:3) from 8.83% to 10.32% and erucic acid (22:1) from 0.15% to 0.91%. The glucosinolate profile of rapeseed was also separated and identified using high-performance liquid chromatography. Small variations in the glucosinolate profile were observed among all tested cultivars; however, progoitrin and gluconapin were the major glucosinolate found. Additionally, silvo cultivar showed the highest total glucosinolate contents (5.97 {mu}mol/g dw). Generally, the contents of aspartic, glutamic, arginine and leucine were high, while the contents of tyrosine and isoleucine were low among all cultivars. For total tocopherols, the results indicated that both serw 6 and pactol cultivars had the highest total tocopherol contents (138.3 and 102.8 mg/100 g oil, respectively). Total phenolic contents varied from 28.0 to 35.4 mg/g dw. The highest total phenolic content was found in topas while the lowest value was detected in serw 6. These parameters; fatty acid contents, glucosinolate profile and amino acids together with total tocopherols and phenolic contents, could be taken into consideration by oilseed rape breeders as selection criteria for developing genotypes with modified seed quality traits in Brassica napus L. (Author)

  17. Selection of the Methods of Soil Analysis for Phyto-available Arsenic

    Science.gov (United States)

    Yoon, Junghwan; Lee, Dan-Bi; Kim, Kwon-Rae; Kim, Won-Il; Kim, Kye-Hoon

    2016-04-01

    Arsenic (As) is a trace element of major public health concern. Many of As contaminated agricultural lands in the Republic of Korea (ROK) are located at the areas nearby abandoned mines. Therefore, management of contaminated agricultural lands is important for safe crop cultivation. In ROK, soils contaminated with As have managed according to the As concentration determined after aqua regia digestion (total As). Many soil scientists reported that management of As in soils by phyto-available As is more effective than that by total As for safety of the crop cultivation point-of-view since As concentration in crops has a significant correlation with phyto-available As. Therefore, this study was carried out to select method of soil analysis for phyto-available As. For that purpose, five extracting solutions (0.1M Ca(NO?), 0.1M (NH?)?HPO?), 0.5M EDTA, Mehlich 3, 0.5M NaHCO?) were examined with 35 soil samples used for cultivation of three crops (bean, red pepper, rice). Correlation analysis was conducted between phyto-available As concentrations in soils and As concentration in edible part of the crops. Results of the correlation analysis showed that phyto-available As concentrations in soils using Mehlich 3 solution and As concentrations in edible part of red pepper and rice were significantly correlated. For soils used for bean cultivation, Mehlich 3 (R

  18. Phyto-oestrogens and their metabolites in milk produced on two pastures with different botanical compositions

    DEFF Research Database (Denmark)

    Adler, S. A.; Purup, S.; Hansen-Møller, J.;

    2014-01-01

    Phyto-oestrogens are a group of secondary plant metabolites that may bind to oestrogen receptors and exert oestrogenic or anti-oestrogenic effects in humans and can protect against cancer diseases. When ingested by dairy cows, phyto-oestrogens can be metabolised and transferred to the milk....... The objective of this study was to assess the effects of grazing a recently established pasture containing red clover (Trifolium pratense L.) and an older pasture containing a variety of sown and unsown plant species on milk concentrations of phyto-oestrogens. Sixteen Norwegian Red dairy cows [mean (standard...... deviation); body weight 599 (45.1). kg, stage of lactation 73 (15.0) d in milk, milk yield 29.9 (2.90) kg/d at the start of the experiment] were divided into two groups and grazed either a short-term pasture (SP) or a long-term pasture (LP). The SP was representative of organically managed leys in Norway...

  19. Phyto stabilization of cadmium contaminated soils by Lupinus uncinatus Schldl

    Energy Technology Data Exchange (ETDEWEB)

    Ehsan, M.; Santamaria-Delgado, K.; Vazquez-Alarcon, A.; Alderete-Chavez, A.; Cruz de la, N.; Jaen-Contreras, D.; Augustine Molumeli, P.

    2009-07-01

    Phyto remediation offers the benefits of being in situ, low cost and environmentally sustainable. Lupinus species is starting to generate interest for phyto remediation of soils showing intermediate metal pollution. The aim of this study was to explore the accumulating behavior and tolerance of Lupinus uncinatus Schldl. towards increasing Cd concentrations in soil. For this purpose the effects of different Cd treatments on plant growth, survival, metal tolerance, Cd accumulation and distribution in various plant organs were investigated. An 18 week pot trial was performed under greenhouse conditions. Cd was added as CdCl{sub 2}.2{sub 1}/2H{sub 2}O at the rate of 0, 3, 6 and 9 mg Cd kg{sup -}1 soil at three different occasions (after 4th, 12th and 15th week of plant growth) with four replicates. The Cd treatments applied, thus, were 9, 18 and 27 mg kg{sup -}1. Cd inhibited plant height and number of leaves and induced a significant change in dry matter yield of roots, stems and leaves. Metal tolerance indices of 88, 82 and 49% were obtained for 9, 18 and 27 mg Cd kg{sup -}1 treatments. The maximal shoot Cd concentration (stem+leaves) of 540 mg Cd kg{sup -}1 dry matter was found at 27 mg Cd kg{sup -}1 treatment. The poor translocation of Cd from roots to shoot was evident from shoot:root ratios <1. The present work is the first report about the growth performance of L. uncinatus under Cd stress, its degree of tolerance and pattern of Cd accumulation in response to varying Cd treatments in soil suggesting the use of L. uncinatus for phyto stabilization and revegetation of Cd polluted soils. (Author)

  20. Investigating the role of natural phyto-oestrogens on bone health in postmenopausal women

    NARCIS (Netherlands)

    Valtueña, S.; Cashman, K.; Robins, S.P.; Cassidy, A.; Kardinaal, A.; Branca, F.

    2003-01-01

    Research on the bone effects of natural phyto-oestrogens after menopause is at a relatively early stage. Published studies are few, difficult to compare and often inconclusive, due in part to design weaknesses. Currently, many questions remain to be answered including to what extent a safe daily int

  1. Investigating the role of natural phyto-oestrogens on bone health in postmenopausal women

    NARCIS (Netherlands)

    Valtueña, S.; Cashman, K.; Robins, S.P.; Cassidy, A.; Kardinaal, A.; Branca, F.

    2003-01-01

    Research on the bone effects of natural phyto-oestrogens after menopause is at a relatively early stage. Published studies are few, difficult to compare and often inconclusive, due in part to design weaknesses. Currently, many questions remain to be answered including to what extent a safe daily int

  2. Phyto-oestrogen excretion and rate of bone loss in postmenopausal women

    NARCIS (Netherlands)

    Kardinaal, A.F.M.; Morton, M.S.; Brüggemann-Rotgans, I.E.M.; Beresteijn, E.C.H. van

    1998-01-01

    Objective: The hypothesis was tested that the rate of postmenopausal bone loss is inversely associated with long-term urinary excretion of phyto-oestrogens, as a marker of habitual dietary intake. Design: Secondary analysis of a 10-year follow-up study (1979-1989) among postmenopausal women in the N

  3. Chemical Industry Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  4. Death study of Spartina alteniflora in a phyto remediation process with landfarming soil; Estudo da mortalidade da Spartina alteniflora no processo de fitorremediacao em solo 'landfarming'

    Energy Technology Data Exchange (ETDEWEB)

    Correia, Thayna M. Brandao; Viana, Francine; Machado, Maria Isabel; Baisch, Paulo; Costa, Cesar [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The oil pollution and its products is, nowadays, the major preoccupation of modern society, the environmentalists and, predominantly, the companies, because, beside loose money, the pollute companies can be pressed by the society and damage their image. Therefore, many techniques to repair oil impacted environments have being studied and improved. Into the most utilized techniques, phyto remediation, technique that uses vegetable species to make the process of degradation of oil organic and inorganic components faster, is a good alternative, because it's cheaper and the risk of second contamination is lower. In an acclimatized greenhouse, were transplanted in a landfarming soil, samples of a salt marsh specie, Spartina alteniflora, a very common specie in South of Brazil. The experiment had duration of 90 days and for about 20% of the samples died, three times the value of the control experiment. The conclusion of this paper is that even with high values of mortality, this salt marsh specie is very strong and can be use in remediation processes. (author)

  5. Cultural and wild plant species as bio indicators and phyto-remedies of PHC contaminated soils in Russia

    Energy Technology Data Exchange (ETDEWEB)

    Breus, I.; Larionova, N.; Semenova, E.; Breus, V. [Kazan State Univ., Dept. of Geography and Geoecology (Russian Federation)

    2005-07-01

    The biological indicators are widely used along with the chemical and physical soil characteristics for the ecological risk assessment for soils during and after anthropogenic impacts. In many cases it often happens that only biological indicators are capable of establishing the physiological activity of contaminant complex in soil and of revealing the critical levels of soil contamination. Bio-testing is often used to determine the toxicity of various environmental objects - soils, waters, sediments and wastes. Firstly bio-testing demands the selection of testable biological organisms adequate to studying objects. The test objects must be representative for a given contaminated ecosystem community which is influenced by toxicants. So one can obtain data adequate to the real situation and also minimise the mistakes during the extrapolation of data obtained in bio-testing. Among bio-testing methods the methods of soil toxicity determination using high plants gained wide distribution. And moreover, if such plants are relatively tolerant to soil contamination and can accumulate sufficient plant biomass, it is possible to expect their phyto-remediation effect, which can be realized by different mechanisms. But the experimental investigations of the plant use for soil remediation in Russia are now still under development. The aims of this work were: i) the determination and selection of informative bio-indicative parameters could be used for evaluation of PHC (petroleum hydrocarbons) - soil contamination levels; ii) the choose of test plants based on these values; and iii) the revelation of the possible phyto-remediation effects in soil contaminated with PHC.In laboratory experiments the phyto-toxicity of soil contaminated with PHC was evaluated in relation to 35 plant species and sorts traditional and non-traditional for Russia and cultivated for fodder green biomass purposes, and also for some wild plant species. The following parameters were determined in the

  6. Effectiveness of medication / auricular therapy / phyto-therapy combination in the treatment of hypertensive patients

    Directory of Open Access Journals (Sweden)

    José Ramón Martínez Pérez

    2015-10-01

    Full Text Available Background: hypertension is one of the main cardiovascular risk factors, so its control improves the life expectancy of patients.Objective: to assess the effects of a treatment combining medication with auricular therapy and phyto-therapy in hypertensive patients assisted at the health area of ”Romárico Oro” Polyclinic, in Puerto Padre, Las Tunas province.Methods: an intervention study was carried out in 68 hypertensive patients of the health area of “Romárico Oro” Polyclinic in Puerto Padre from April, 2013 to April, 2014. The patients were distributed at random into two equal groups; the first received medication combined with auricular therapy and phyto-therapy, while the second one received only medication. The statistical analysis was done by means of Statistic system, t-student and Chi-Square tests were used and p< or =0.05 was considered as level of statistical significance.Results: by the end of the intervention, 73, 53% of the patients of the group with the combination of drug treatment and auricular therapy and phyto-therapy were controlled. In this group, the diastolic filling pressure diminished to 2, 2 mm Hg and the systolic gradient to 3, 66 mm, regarding the group treated only with drugs. Only one patient, representing the 2, 94% showed adverse reaction to the natural and traditional treatment.Conclusions: the combination of medication with auricular therapy and phyto-therapy proved to be effective, corroborated by a significant decrease of quantity of crisis, diastolic and systolic filling pressure values and increase of number of patients with their disease controlled; the report of only one complication shows the innocuousness of the auricular therapy and phyto-therapy treatment.

  7. Improvement to the PhytoDOAS method for identification of coccolithophores using hyper-spectral satellite data

    Directory of Open Access Journals (Sweden)

    A. Sadeghi

    2012-11-01

    Full Text Available The goal of this study was to improve PhytoDOAS, which is a new retrieval method for quantitative identification of major phytoplankton functional types (PFTs using hyper-spectral satellite data. PhytoDOAS is an extension of the Differential Optical Absorption Spectroscopy (DOAS, a method for detection of atmospheric trace gases, developed for remote identification of oceanic phytoplankton groups. Thus far, PhytoDOAS has been successfully exploited to identify cyanobacteria and diatoms over the global ocean from SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY hyper-spectral data. This study aimed to improve PhytoDOAS for remote identification of coccolithophores, another functional group of phytoplankton. The main challenge for retrieving more PFTs by PhytoDOAS is to overcome the correlation effects between different PFT absorption spectra. Different PFTs are composed of different types and amounts of pigments, but also have pigments in common, e.g. chl a, causing correlation effects in the usual performance of the PhytoDOAS retrieval. Two ideas have been implemented to improve PhytoDOAS for the PFT retrieval of more phytoplankton groups. Firstly, using the fourth-derivative spectroscopy, the peak positions of the main pigment components in each absorption spectrum have been derived. After comparing the corresponding results of major PFTs, the optimized fit-window for the PhytoDOAS retrieval of each PFT was determined. Secondly, based on the results from derivative spectroscopy, a simultaneous fit of PhytoDOAS has been proposed and tested for a selected set of PFTs (coccolithophores, diatoms and dinoflagellates within an optimized fit-window, proven by spectral orthogonality tests. The method was then applied to the processing of SCIAMACHY data over the year 2005. Comparisons of the PhytoDOAS coccolithophore retrievals in 2005 with other coccolithophore-related data showed similar patterns in their

  8. Phyto toxic effects of Euphorbia dracunculoides: a weed of rainfed chickpea-chickpea cropping system

    Energy Technology Data Exchange (ETDEWEB)

    Shance, S.; Tranveer, A.; Javaid, M. M.; Chaudhry, K. M.; Aziz, A.; Khaliq, A.; Chaudhry, M. N.; Pervez, M. A.; Awan, I. U.

    2011-07-01

    Phyto toxic effect occurs when plants release chemicals that inhibit neighbouring plants. Phyto toxic effects of aqueous extracts of different parts of Euphorbia dracunculoides L. (green spurge) at two concentrations, and its infested soil were investigated on germination and seedling growth of chickpea (Cicer arietinum L.). The fruit extract at 1:20 (w/v) concentration caused maximum reduction (12%) in germination of chickpea seeds while leaf extract at 1:10 (w/v) concentration resulted in maximum mean germination time value and minimum germination index of chickpea seeds. All the traits of chickpea seedling growth including emergence were adversely affected by the aqueous extracts at both concentrations. Further, the inhibition of chickpea seedling growth was more pronounced with 1:10 (w/v) concentration whereas the lower concentration (1:20 w/v) showed stimulatory effect on shoot length, seedling vigor index and chlorophyll contents of chickpea seedlings. The leaf extract at 1:10 (w/v) concentration proved most harmful to seedling growth and chlorophyll contents (76% reduction) of chickpea. Soil beneath the E. dracunculoides plants significantly reduced emergence (23%), seedling vigor index (55%) and chlorophyll content (19%) of chickpea but a significant increase in N (6%), P (16%) and K (4%) contents of chickpea seedlings was recorded. Thus it can be concluded that E. dracunculoides contains compounds in its tissues which may cause phyto toxic effects on chickpea under field conditions. (Author) 31 refs.

  9. Critical review of health effects of soyabean phyto-oestrogens in post-menopausal women

    DEFF Research Database (Denmark)

    Cassidy, A.; Albertazzi, P.; Nielsen, I. L.

    2006-01-01

    A consensus view of soyabean phyto-oestrogens in clinical interventions in post-menopausal women is presented that is based on data from the EU-funded project Phytohealth. The phyto-oestrogens, primarily genistein and daidzein, were given as soyabean-protein isolates, whole-soyabean foods...... or extracts, supplements or pure compounds. A comprehensive literature search was conducted with well-defined inclusion or exclusion criteria. For areas for which substantial research exists only placebo-controlled double-blind randomised controlled trials (RCT) conducted on healthy post-menopausal women were...... included. For emerging areas all available human studies in post-menopausal women were reviewed. In order to make cross comparisons between studies the doses of isoflavones were calculated as aglycone equivalents. There is a suggestion, but no conclusive evidence, that isoflavones from the sources studied...

  10. Phyto-adaptogens protect against environmental stress-induced death of embryos from the freshwater snail Lymnaea stagnalis.

    Science.gov (United States)

    Boon-Niermeijer, E K; van den Berg, A; Wikman, G; Wiegant, F A

    2000-10-01

    The main purpose of the studies presented in this paper is twofold: 1) to evaluate whether phyto-adaptogens (Acanthopanax senticosus and Rhodiola rosea) are able to exert a protective action against stress-induced death of embryos of the pond snail Lymnaea stagnalis; and 2) whether a possible protective action by phyto-adaptogens can be explained by the induction of heat shock proteins. Enhancement in resistance by phyto-adaptogens was studied by applying plant extracts for a period of 20 hours to 3-day old larvae of the pond snail Lymnaea stagnalis. Subsequently they were exposed to a high and toxic dose of different environmental stressors. The following stress conditions were selected: a physical stress condition (heat shock: 43 degrees C for 4 minutes), an oxidative stress condition (superoxide radicals induced by menadione (600 microM for 2 hours)) and heavy metal-induced stress (copper (150 microM for 1 hour) or cadmium (20 microM during 1 hour)). Both Acanthopanax and Rhodiola exert a strong protective action against a lethal heat shock. These adaptogens also significantly protect against the negative effect of superoxide radicals as induced by menadione. With respect to the protective action against exposure to heavy metals a small but significant protection was observed against intoxication with copper or cadmium by the phyto-adaptogens. In summary, there appears to be a difference in efficiency in enhancing resistance to the various stress conditions used (heat shock>menadione>copper>cadmium). Based on the results presented in this paper, we can conclude that phyto-adaptogens are able to enhance the resistance against the different stress conditions tested in developing individuals of Lymnaea. Although the degree to which resistance is enhanced appears to depend on the type of stressor applied, our results confirm the definition of phyto-adaptogens as being universal enhancers of non-specific resistance against different kinds of stress conditions. With

  11. Quantitative observation of cyanobacteria and diatoms from space using PhytoDOAS on SCIAMACHY data

    OpenAIRE

    Bracher, A.; M. Vountas; T. Dinter; Burrows, J. P.; Röttgers, R.; I. Peeken

    2009-01-01

    In this study the technique of Differential Optical Absorption Spectroscopy (DOAS) has been adapted for the retrieval of the absorption and biomass of two major phytoplankton groups (PhytoDOAS) from data of the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) satellite sensor. SCIAMACHY measures back scattered solar radiation in the UV-Vis-NIR spectral regions with a high spectral resolution (0.2 to 1.5 nm). In order to identify phytoplankton absorption charac...

  12. Effect of forage on the content of phyto-oestrogens in bovine milk

    DEFF Research Database (Denmark)

    Andersen, Charlotte; Weisbjerg, Martin Riis; Hansen-Møller, Jens

    2009-01-01

    ) affects the concentration of phyto-oestrogens in bovine milk. Sixteen Danish Holstein cows were assigned to a 4 × 4 latin square design with four cows per treatment per period of 3 weeks. The four treatment diets were lucerne silage (LS), 2/3 lucerne silage and 1/3 maize silage (2/3LS), 1/3 lucerne silage...... and 2/3 maize silage (1/3LS) and GCS. Milk was collected at the end of each period and feed samples on day 6, 13 and 20 in each experimental period. Milk and pooled feed samples were analysed for the concentration of isoflavones, coumestans and lignans. The content of isoflavones was higher......Phyto-oestrogens are believed to have a range of beneficial effects on predominant Western diseases. A few studies on phyto-oestrogens in milk exist and show that the composition can be affected by feeding. Therefore, the aim was to study how feeding of lucerne and grass/clover silages (GCSs...

  13. Biological removal of phyto-sterols in pulp mill effluents.

    Science.gov (United States)

    Mahmood-Khan, Zahid; Hall, Eric R

    2013-12-15

    Phyto-sterols and extractives found in pulp mill effluents are suspected to cause endocrine abnormalities in receiving water fish. The control of sterols in pulp mill effluents through biological secondary wastewater treatment was studied using two lab-scale bioreactor systems. After achieving a stable performance, both bioreactor systems successfully removed (>90%) sterols and the estimated biodegradation was up to 80%. Reactor 1 system operating at 6.7 ± 0.2 pH effectively treated pulp mill effluent sterols spiked up to 4500 μg/L in 11 h HRT and 11 day SRT. However, Reactor 2 system operating at 7.6 ± 0.2 pH performed relatively poorly. Retention time reductions beyond critical values deteriorated the performance of treatment systems and quickly reduced the sterols biodegradation. The biodegradation loss was indicated by mixed liquor sterols content that started increasing. This biodegradation loss was compensated by the increased role of bio-adsorption and the overall sterols removal remained relatively high. Hence, a relatively small (20-30%) loss in the overall sterols removal efficiency did not fully reflect the associated major (60-70%) loss in the sterols biodegradation because the amount of sterols accumulated in the sludge due to adsorption increased so the estimate of sterols removal through adsorption increased from 30-40% to 70-80% keeping the overall sterols removal still high.

  14. Proliferative effect of whey from cows' milk varying in phyto-oestrogens in human breast and prostate cancer cells.

    Science.gov (United States)

    Nielsen, Tina S; Höjer, Annika; Gustavsson, Anne-Maj; Hansen-Møller, Jens; Purup, Stig

    2012-05-01

    Intake of dietary phyto-oestrogens has received a great deal of attention owing to their potential influence on hormone-sensitive cancers such as breast and prostate cancer. Cows' milk contains phyto-oestrogens and the content varies according to the composition of the feed and the type and amount of legumes used. In this study we evaluated the proliferative effect of milk (whey) with different phyto-oestrogen content in human breast (MCF-7) and prostate cancer cells (PC-3). Milk was obtained from cows fed either a birdsfoot trefoil-timothy silage based ration (B1) or two different red clover silage based diets (R1 and R2) resulting in total phyto-oestrogen contents of 403, 1659 and 1434 ng/ml for the B1, R1 and R2 diets, respectively. Whey was produced from the milk and added to cell culture medium in concentrations up to 10% for MCF-7 cells and 5% for PC-3 cells. Cell proliferation was measured fluorometrically after 7 d for MCF-7 cells and 5 d for PC-3 cells. There was no significant difference in the proliferative effect of whey from the different dietary treatments at any of the whey concentrations tested. An anti-proliferative effect (Pwhey was seen when tested in the presence of 10 pM oestradiol in the medium. This effect was independent of dietary treatment of cows. Whey induced a significant (Pmilk decreased PC-3 cell proliferation, and therefore the stimulatory effect of whey in PC-3 cells is believed to be mediated by other bioactives than equol. In conclusion, our results suggest that using whey in these proliferation assays, it was not possible to discriminate between milk with high or low levels of phyto-oestrogens.

  15. Effects of phyto-oestrogens on veal calf prostate histology

    NARCIS (Netherlands)

    Groot, M.J.

    2006-01-01

    In veal calf production plant-based proteins are frequently included in milk replacer fed to the animals. Since soy products, which are mostly used, are known for their high levels of phyto-oestrogens, the effects of these feeds on the veal calf prostate were examined. Goal was to determine whether

  16. Prediction of the phyto-availability of two radionuclides ({sup 63}Ni and {sup 99}Tc) in soils; Prediction de la phytodisponibilite de deux radionucleides ({sup 63}Ni et {sup 99}Tc) dans les sols

    Energy Technology Data Exchange (ETDEWEB)

    Denys, S

    2001-10-01

    A thorough knowledge of the behavior of long-lived radionuclides in the biosphere is needed for the safety assessment of deep underground nuclear waste repositories. Soils support terrestrial food chains and are thus a key compartment in the determination of transfers of radionuclides to Man. Tyre prediction of soil-to-plant transfers is based on the characterization of the phyto-availability of radionuclides in soils by taking into account all the transfer processes inside the soil profile. The aim of this study was to predict phyto-availability of radionuclides in cultivated soils. The phyto-availability of two radionuclides varying in their mobility, {sup 63}Ni and {sup 99}Tc, was studied a the level of the sieved soil sample and of the cultivated soil profile. Three soils showing contrasted hydraulic and physico-chemical properties were sampled in order to isolate undisturbed soil cores (50 cm x 50 cm): a rendzina, a clayey colluvial soil and a sandy-loam acidic soil. The cores were placed in a greenhouse and equipped with porous cups and leachate collectors in order to sample soil solution and drainage water. The first year, maize (Zea mays L.) was grown and irrigated. Soils were contaminated once on the surface by irrigation at the beginning of the summer season. After harvest, in early October, winter wheat (Triticum aestivum L.) was sawn. The cores were again contaminated in March: once in the case of {sup 63}Ni and three tinges for {sup 99}Tc. Transfers of radionuclides to water and aerial parts of crops were monitored throughout the two-year experiment. Results showed that the phyto-availability of radionuclides can be estimated from that of chemical or isotopic analogues ire the case of simple or multiple contamination. {sup 63}Ni is diluted in the pool of isotopically exchangeable Ni{sup 2+} ions in the soils. {sup 99}TcO{sub 4}- is diluted in the pool of available NO{sub 3}- ions. Radionuclides stayed in the upper layer of the soils until harvest due

  17. [Phyto-adaptogens--protection against stress?].

    Science.gov (United States)

    Levin, Orna

    2015-03-01

    The term adaptogen was invented in the former USSR. An adaptogen increases body resistance to physically, chemically or biologically noxious factors, thereby having a normalizing effect on body functions and inflicting no harm. Most of the research took place in the USSR and in Scandinavian countries and was not published in English. In the last decades, some research has been performed in Western Europe and in the USA and was also published in English. From the research it is possible to learn about the efficacy of the adaptogen use as a single dose and on long term use and the differences between the various adaptogens. In this article there is a review of the studies and explanations of the adaptogenic activity. Adaptogenic effects on different functions in humans and animals are mentioned

  18. PHYTO-CHEMICAL CONSTITUENTS FROM STEM OF TARAXACUM OFFICINALE WEBER

    National Research Council Canada - National Science Library

    Shirin Khan; Kiran Duby; Rashmi Jain; Umesh Kumar Vishwakarma

    2016-01-01

      A new flavone glycoside 1 m. p. 223-225 degrees Celsius, m. f. C^sub 34^H^sub 42^O^sub 2^0, (M+) 770 (FABMS) has been isolated from the stems of Taraxacum Officinal weber along with one known compound Taxifolin...

  19. Phyto-vesicles:conduit between conventional and novel drug delivery system

    Institute of Scientific and Technical Information of China (English)

    Nidhi Mishra; Narayan P Yadav; Jaya Gopal Meher; Priyam Sinha

    2012-01-01

    Objective: To discuss the preparation, characterization, targeting and formulation aspect of phospholipids based drug delivery system i.e. Phyto-vesicles. Methods: The methods of phyto-vesicles preparation on R & D scale and different analytical techniques to characterize them have been discussed. Result: Phyto-vesicles are the advanced form of herbal drug delivery systems as its structure includes water soluble head and two fat soluble tails which act as an effective emulsifier. Conclusion: It is concluded that phytovesicular delivery system has improved pharmacokinetic and pharmacodynamic parameter as compared to conventional system Therefore, phyto-vesicles are called as conduit between conventional and novel drug delivery system.

  20. Validity of a web-based dietary questionnaire designed especially to measure the intake of phyto-oestrogens

    OpenAIRE

    Nybacka, Sanna; Bertéus Forslund, Heléne; Hedelin, Maria

    2016-01-01

    A diet questionnaire (DQ) designed to assess habitual diet and phyto-oestrogen intake was developed. This study aimed to examine the validity of the DQ in men, with and without having prostate cancer. The DQ was validated against alkylresorcinol metabolites measured in urine as objective biomarkers of whole grain wheat and rye (WG) intake, and a 4-d estimated food record (FR) was used for relative comparison. Participants (n 61) completed both methods and provided spot urine samples. We found...

  1. Phyto-liposomes as nanoshuttles for water-insoluble silybin-phospholipid complex.

    Science.gov (United States)

    Angelico, Ruggero; Ceglie, Andrea; Sacco, Pasquale; Colafemmina, Giuseppe; Ripoli, Maria; Mangia, Alessandra

    2014-08-25

    Among various phospholipid-mediated drug delivery systems (DDS) suitable for topic and oral administration, phytosome technology represents an advanced innovation, widely used to incorporate standardized bioactive polyphenolic phytoconstituents into phospholipid molecular complexes. In order to extend their potential therapeutic efficiency also to other routes of administration, we proposed a novel phytosome carrier-mediated vesicular system (phyto-liposome) as DDS for the flavonolignan silybin (SIL), a natural compound with multiple biological activities related to its hepatoprotective, anticancer and antioxidant (radical scavenging) effects. We screened the optimum fraction of its phytosome, available in the market as Siliphos™, into liposomes prepared by extrusion, such that vesicle sizes and charges, monitored through dynamic light scattering and laser doppler velocimetry, satisfied several quality requirements. Special emphasis was placed on the study of host-guest interaction by performing UV-vis absorption, spectrofluorimetry and NMR experiments both in aqueous and non-polar solvents to probe the effect of the presence of phospholipids on the electronic properties of SIL and its propensity to engage H bonding with the lipid headpolar groups. Finally, fluorescence microscopy observations confirmed the ability of phyto-liposomes to be internalized in human hepatoma cells, which was promising for their potential application in the treatment of acute or chronic liver diseases.

  2. Application of phyto-indication and radiocesium indicative methods for microrelief mapping

    Science.gov (United States)

    Panidi, E.; Trofimetz, L.; Sokolova, J.

    2016-04-01

    Remote sensing technologies are widely used for production of Digital Elevation Models (DEMs), and geomorphometry techniques are valuable tools for DEM analysis. One of the broadly used applications of these technologies and techniques is relief mapping. In the simplest case, we can identify relief structures using DEM analysis, and produce a map or map series to show the relief condition. However, traditional techniques might fail when used for mapping microrelief structures (structures below ten meters in size). In this case high microrelief dynamics lead to technological and conceptual difficulties. Moreover, erosion of microrelief structures cannot be detected at the initial evolution stage using DEM modelling and analysis only. In our study, we investigate the possibilities and specific techniques for allocation of erosion microrelief structures, and mapping techniques for the microrelief derivatives (e.g. quantitative parameters of microrelief). Our toolset includes the analysis of spatial redistribution of the soil pollutants and phyto-indication analysis, which complement the common DEM modelling and geomorphometric analysis. We use field surveys produced at the test area, which is arable territory with high erosion risks. Our main conclusion at the current stage is that the indicative methods (i.e. radiocesium and phyto-indication methods) are effective for allocation of the erosion microrelief structures. Also, these methods need to be formalized for convenient use.

  3. The Effects of EDTA and H2SO4 on Phyto-extraction of Pb from contaminated Soils by Radish

    Directory of Open Access Journals (Sweden)

    T. Mansouri

    2016-10-01

    Full Text Available Introduction: Soil contamination by heavy metals is one of the most important environmental concerns in many parts of the world. The remediation of soil contaminated with heavy metals is necessary to prevent the entry of these metals into the human food chain. Phyto-extraction is an effective, cheap and environmental friendly method which uses plants for cleaning contaminated soils. The plants are used for phytoremediation should have high potential for heavy metals uptake and produce enormous amount of biomass. A major problem facing phyto-extraction method is the immobility of heavy metals in soils. Chemical phyto-extraction is a method in which different acids and chelating substances are used to enhance the mobility of heavy metals in soil and their uptake by plants. The aims of this study were: (a to determine the potential of radish to extract Pb from contaminated soils and (b to assess the effects of different soil amendment (EDTA and H2SO4 to enhance plant uptake of the heavy metal and (c to study the effects of different levels of soil Pb on radish growth and Pb concentrations of above and below ground parts of this plant. Materials and Methods: Soil samples were air dried and passed through a 2 mm sieve and analysed for some physico-chemical properties and then artificially contaminated with seven levels of lead (0, 200, 400, 600, 800 and 1000 mg/kg using Pb(NO32 salt and then planted radish. During the growth period of radish and after the initiation of root growth, the plants were treated with three levels of sulfuric acid (0, 750 and 1500 mg/kg or three levels of EDTA (0, 10 and 20 mg/kg through irrigation water. At the end of growth period, the above and below ground parts of the plants were harvested, washed, dried and digested using a mixture of HNO3, HCl, and H2O2. The concentrations of Pb, N, P and K in plant extracts were measured. Statistical analysis of data was performed using MSTATC software and comparison of means was

  4. The application of irradiation to phyto sanitary problems

    Energy Technology Data Exchange (ETDEWEB)

    Ross, R.T. [USDA/APHIS/PPQ. Department of Agriculture, Room 1630 Soagribg, 1400 Independence Ave. Sw. Mail Code Stop 3438, 20250 Washington D.C. (United States)

    1997-12-31

    The first formally adopted regulatory policy for irradiation as a phyto sanitary treatment in the United States was issued in 1989 and was based on Title 7 of the Code of Federal Regulations. These regulations authorized irradiation as a quarantine treatment for papayas intended for movement from the State of Hawaii to the continental United States (U.S.), Guam, Puerto Rico, and the U.S. Virgin Islands. This authorization was specific for commodity, place of origin, and program, but was designed for a complex of three fruit flies rather than a single pest. Routine commercial shipments were never realized under this regulation due to the lack of a treatment facility in Hawaii. However, the authorization has proven useful from the standpoint of beginning to establish policies for irradiation as a phyto sanitary treatment in the United States. The United States Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), Plant Protection and Quarantine (PPQ) remains dedicated to using the most up-to-date, appropriate and least intrusive technology to provide quarantine security. The need for alternative treatments for pests mitigation systems is greater than ever. Global trade pressures and the possible loss of methyl bromide make it imperative that all practical treatment options be explored. Since 1989 irradiation treatment concepts have matured significantly. Technological advances, greater experience, and an increasingly larger body of research indicate that irradiation has important potential as a treatment for quarantine pest problems. It is in this light that PPQ is expanding its regulatory framework, is addressing irradiation treatment options, and is developing comprehensive policy statements intended to facilitate the development and formalization of new treatments for phyto sanitary applications. (Author)

  5. Enhanced phyto-extraction of cadmium and zinc using rapeseed

    Energy Technology Data Exchange (ETDEWEB)

    Ghani, M.; Slycken, S.V.; Meers, E.; Tack, F.M.G. [Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent University, Ghent (Belgium); Naz, F. [National Insect Museum, National Agricultural Research Centre, Islamabad (Pakistan); Ali, S. [Agriculture Department, University of Haripur, Haripur (Pakistan)

    2013-07-01

    In a green house pot experiment, the effects of three amendments, sulphur (S), ammonium sulphate ((NH{sub 4}){sub 2}SO{sub 4}) and ethylenediaminetetracetic acid (EDTA) were tested for phyto-extraction of Cd and Zn by rapeseed (Brassica napus L.). Elemental sulphur was applied as 20.00, 60.00, and 120.00 mg.kg{sup -1} soil. EDTA was tested at a dose of 585.00 mg.kg{sup -1} soil, and (NH{sub 4}){sub 2}SO{sub 4}) at a rate of 0.23 mg.kg{sup -1} soil. All treatments received a base fertilization (Hogland) before sowing. Plants were harvested after 51 days of growth and shoot dry matter and soil samples were analysed for metal contents. All amendments caused a significant increase in Cd and Zn contents in plant shoots of all treatments than control treatment. Further, EDTA was most effective for extraction metals concentrations in shoot biomass but the plants showed significant signs of toxicity and yield were severely depressed. The addition of sulfur favorably influenced plant biomass production. The fertilized ammonium sulfate treatment resulted in the highest phyto-extraction of Cd and Zn and the amounts of these metals accumulated in plant shoot exceeded by a factor of 4 and 3 respectively. Finally, Brassica napus could be used for soil remediation keeping its other uses which will make the contaminated site income generating source for the farmers. (authors)

  6. PHYTO SOMES: A NOVEL PHYTO-PHOSPHOLIPID CARRIERS FOR HERBAL DRUG DELIVERY

    Directory of Open Access Journals (Sweden)

    Thurapati Pandu Raju

    2011-06-01

    Full Text Available Advanced biochemical and pre-clinical studies have proved the potential of plant flavonoids, polyphenolics and other hydrophilic natural compounds for the treatment of skin disorders, different types of carcinoma, anti-aging and many other areas of therapeutics and preventive medicine. The hydrophilic nature and unique chemical structure of these compounds pose major challenge because of their poor bioavailability through the skin or gut. The bioavailability can be improved by the use of delivery systems, which can enhance the rate and the extent of drug solubilizing into aqueous intestinal fluids as well as the capacity to cross the lipid rich biomembranes. Phospholipid based drug delivery systems have been found promising for the effective and efficacious herbal drug delivery. Complexing the polyphenolic phytoconstituents in molar ratio with phosphatidylcholine results into a new herbal drug delivery system- "Phytosome". Phytosomes show better pharmacokinetic and therapeutic profile than conventional herbal extracts.

  7. PHYTO-PHARMACOLOGICAL REVIEW OF ARGYREIA NERVOSA

    Directory of Open Access Journals (Sweden)

    A. Krishnaveni

    2011-02-01

    Full Text Available Herbal medicines are the significant and reliable sources for treating various diseases. Argyreia nervosa is traditionally used in wound healing, syphilius,diuretics,rheumatic affections, leucohorrhoea.,cerebral disorders, ulcers, as anti-tumour and to prevent contraception.Phytoconstituents such as flavanoids, steroids, ergoline alkaloids and triterpenoids were identified. Pharmacological studies proved its anticonvulsant, immunomodulatory, hypotensive, anti- inflammatory and nootropic effect.The present form of article highlights the phytochemical and pharmacological studies including traditional practice of Argyreia nervosa have been carried out so far.

  8. Recovery of mining sludges by phyto remediation; Recuperacion de lodos procedentes de actividades mineralurgicas mediante fitorremediacion

    Energy Technology Data Exchange (ETDEWEB)

    Llarri, A.; Rubio, A.; Fernandez-Revuelta, B.

    2001-07-01

    Remediation of mining waste from ferric leaching process has been studied. A characterisation of the sludge formed in the neutralisation of leaching liquors was made up to determine the availability of phyto remediation techniques to remedy this soil. The sludge, with a high content in heavy metals such as copper, arsenic and zinc, and a high concentration in cations as sodium product of neutralisation process, and strongly basic, is not available for planting. The study was done with two objectives, the first a control of correct yield accord to climatic conditions and soil properties, and the second the determination the plant species capacity to absorb soil toxic ions, principally dissolved due to rainfall and leaching. The results obtained show a high resistance of shrub species versus floral species and a high tolerance of wild species to the removal of heavy metals in this type of soil. (Author) 15 refs.

  9. CASSIA TORA: A PHYTO-PHARMACOLOGICAL OVERVIEW

    Directory of Open Access Journals (Sweden)

    Das Chandan

    2011-04-01

    Full Text Available Cassia tora, a popular Indian medicinal plant, has long been used in Ayurvedic system of medicine. The plant has been found to possess diverse number of pharmacological activities. The present paper gives an account of updated information on its phytochemical and pharmacological activities. The review reveals that wide range of phytochemical constituents have been isolated from the plant and it possess important activities like laxative, skin diseases, ringworm, eye diseases, liver complaint, dysentery and anthelmentic. Various other activities like antioxidant, hypoglycemic, hypolipidemic, antinociceptive, antiplasmodial, antifungal & antimicrobial, hyperlipemia & hypotensive have also been reported. These reports are very encouraging and indicate that herb should be studied more extensively for its therapeutic benefits.

  10. The effect of glicerol and sorbitol plasticizers toward disintegration time of phyto-capsules

    Science.gov (United States)

    Pudjiastuti, Pratiwi; Hendradi, Esti; Wafiroh, Siti; Harsini, Muji; Darmokoesoemo, Handoko

    2016-03-01

    The aim of research is determining the effect of glycerol and sorbitol toward the disintegration time of phyto-capsules, originated capsules from plant polysaccharides. Phyto-capsules were made from polysaccharides and 0.5% (v/v) of glycerol and sorbitol of each. The seven capsules of each were determined the disintegration time using Erweka disintegrator. The mean of disintegration time of phyto-capsules without plasticizers, with glycerol and sorbitol were 25'30"; 45'15" and 35'30" respectively. The color and colorless gelatin capsules showed the mean of disintegration time 7'30" and 2'35" respectively.

  11. PhytoREF: a reference database of the plastidial 16S rRNA gene of photosynthetic eukaryotes with curated taxonomy.

    Science.gov (United States)

    Decelle, Johan; Romac, Sarah; Stern, Rowena F; Bendif, El Mahdi; Zingone, Adriana; Audic, Stéphane; Guiry, Michael D; Guillou, Laure; Tessier, Désiré; Le Gall, Florence; Gourvil, Priscillia; Dos Santos, Adriana L; Probert, Ian; Vaulot, Daniel; de Vargas, Colomban; Christen, Richard

    2015-11-01

    Photosynthetic eukaryotes have a critical role as the main producers in most ecosystems of the biosphere. The ongoing environmental metabarcoding revolution opens the perspective for holistic ecosystems biological studies of these organisms, in particular the unicellular microalgae that often lack distinctive morphological characters and have complex life cycles. To interpret environmental sequences, metabarcoding necessarily relies on taxonomically curated databases containing reference sequences of the targeted gene (or barcode) from identified organisms. To date, no such reference framework exists for photosynthetic eukaryotes. In this study, we built the PhytoREF database that contains 6490 plastidial 16S rDNA reference sequences that originate from a large diversity of eukaryotes representing all known major photosynthetic lineages. We compiled 3333 amplicon sequences available from public databases and 879 sequences extracted from plastidial genomes, and generated 411 novel sequences from cultured marine microalgal strains belonging to different eukaryotic lineages. A total of 1867 environmental Sanger 16S rDNA sequences were also included in the database. Stringent quality filtering and a phylogeny-based taxonomic classification were applied for each 16S rDNA sequence. The database mainly focuses on marine microalgae, but sequences from land plants (representing half of the PhytoREF sequences) and freshwater taxa were also included to broaden the applicability of PhytoREF to different aquatic and terrestrial habitats. PhytoREF, accessible via a web interface (http://phytoref.fr), is a new resource in molecular ecology to foster the discovery, assessment and monitoring of the diversity of photosynthetic eukaryotes using high-throughput sequencing.

  12. Phyto-treatment of domestic waste water using artificial marshes

    Energy Technology Data Exchange (ETDEWEB)

    Vaca, Rodrigo; Sanchez, Fabian [Oleoducto de Crudos Pesados (OCP), Quito (Ecuador)

    2009-12-19

    The phyto-treatment of domestic waste water by the use of artificial marshes system consists in beds of treatment working in series, this beds are constituted basically by inverse filters of inert granular material where the nutrients are cached from the residual water. Most of the treatment is carried in roots steams and leaves of defined species of plants. The rest of the treatment is performed by anaerobic and aerobic bacteria that grow within the beds. In the proximities of the roots and the area near the bed surface, aerobic processes take place and in deepest zones, anaerobic processes take place. It is desirable that the aerobic process will be the predominant one, mainly to avoid bad odors; this is obtained with the correct selection of plants which must have dense and deep roots. The economic factor is also important for the selection of this type of treatment system, the cost of operation and maintenance is minimum compared with other type of systems. The operation cost is practically zero because it is not required provision of electrical energy for its operation; energy used is the solar energy through the photosynthesis process. The maintenance is reduced to pruning and cleaning that can be performed twice a year. The goals of this paper is to show our experiences during the construction, stabilization and operation of these systems installed in 13 OCP locations with different types of weather and explain the conclusions arrived after construction and operation; present this kind of systems as an alternative of economic wastewater treatment in terms of construction, operation and maintenance and as environment friendly treatment. (author)

  13. Phyto-crystallization of palladium through reduction process using Cinnamom zeylanicum bark extract

    Energy Technology Data Exchange (ETDEWEB)

    Sathishkumar, M.; Sneha, K.; Kwak, In Seob; Mao, Juan [Environmental Biotechnology National Research Laboratory, School of Chemical Engineering, Research Institute of Industrial Technology, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Tripathy, S.J. [Nanoparticulate Materials Laboratory, Division of Advanced Materials Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Yun, Y.-S., E-mail: ysyun@chonbuk.ac.kr [Environmental Biotechnology National Research Laboratory, School of Chemical Engineering, Research Institute of Industrial Technology, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2009-11-15

    In this paper we studied the potential of nanocrystalline palladium particle production using Cinnamom zeylanicum bark extract (CBE) as the biomaterial for the first time. We studied the effects of biomaterial dosage, pH and temperature on nanoparticle formation; none of these factors had a major effect on the size and shape of the nanoparticles formed. Transmission electron microscopy (TEM) observations confirmed the synthesis of nano-sized palladium particles. More or less uniformly sized palladium nanoparticles were synthesized with an average size ranging from 15 to 20 nm. It was found that the zeta potential of these formed palladium nanoparticles was negative, and that it increased with an increase in pH. Energy dispersive X-ray (EDX) analysis results confirmed the significant presence of palladium. Of the palladium ions, 60% were reduced to a zero valent form by CBE. Terpenoids are believed to play an important role in palladium nanoparticle biosynthesis through the reduction of palladium ions. Currently, however, the exact mechanism for the synthesis of palladium nanoparticles is unclear. Our protocol for the phyto-synthesis of palladium nanoparticles under moderate pH and room temperature offers a new means to develop environmentally benign nanoparticles.

  14. [Morphological characterization of experimental parodontitis during its treatment with a phyto-preparation uno de gato].

    Science.gov (United States)

    Miminoshvili, Sh M; Gvamichava, T A; Mdinaradze, N L

    2007-06-01

    Examination of new methods of treatment of parodontitis is stipulated by the significant increase in the number of patients with parodontitis. Experiments were conducted on white outbred male rats weighing 150-200 gr, which were divided into three groups. The first group was a reference one (n=20). The second group includes induced parodontitis (n=15) and the third group includes induced parodontitis with the treatment of uno de gato (n=19). We simulated parodontitis in the following way: on the lower nippers in the field of a neck we attached a ligature causing mechanical damage. We used a intramuscular injection of Nembutal as a means of narcotization (0.1 ml-10 g per mass). The present work is dedicated to morphological studies of the structures of damaged parodontium during its treatment with a phyto-preparation uno de gato. The undertaken treatment has demonstrated partial restoration of the mucous tunic of the gum. Newly formed capillaries were found in the connective tissue. The fibroblasts are mostly mature and collagen-producing. Thus, the study has demonstrated that there is a certain tendency of the tissue restoration and the treatment has produced the best therapeutic results.

  15. Impact of warming on phyto-bacterioplankton coupling and bacterial community composition in experimental mesocosms.

    Science.gov (United States)

    von Scheibner, Markus; Dörge, Petra; Biermann, Antje; Sommer, Ulrich; Hoppe, Hans-Georg; Jürgens, Klaus

    2014-03-01

    Global warming is assumed to alter the trophic interactions and carbon flow patterns of aquatic food webs. The impact of temperature on phyto-bacterioplankton coupling and bacterial community composition (BCC) was the focus of the present study, in which an indoor mesocosm experiment with natural plankton communities from the western Baltic Sea was conducted. A 6 °C increase in water temperature resulted, as predicted, in tighter coupling between the diatom-dominated phytoplankton and heterotrophic bacteria, accompanied by a strong increase in carbon flow into bacterioplankton during the phytoplankton bloom phase. Suppressed bacterial development at cold in situ temperatures probably reflected lowered bacterial production and grazing by protists, as the latter were less affected by low temperatures. BCC was strongly influenced by the phytoplankton bloom stage and to a lesser extent by temperature. Under both temperature regimes, Gammaproteobacteria clearly dominated during the phytoplankton peak, with Glaciecola sp. as the single most abundant taxon. However, warming induced the appearance of additional bacterial taxa belonging to Betaproteobacteria and Bacteroidetes. Our results show that warming during an early phytoplankton bloom causes a shift towards a more heterotrophic system, with the appearance of new bacterial taxa suggesting a potential for utilization of a broader substrate spectrum.

  16. STUDIES OF PHARMACOGNOSTICAL PROFILES OF DANSONIA DIGITATA linn.

    Science.gov (United States)

    Vijayakirubha, T; Ramprasath, D; Karunambigai, K; Nagavalli, D; Hemalatha, S

    2004-10-01

    The macroscopic characters of the whole plant, physical constant values, extractive values, preliminary phyto-chemical tests, fluorescence characters under ultra-violet light after treatment with different reagents of the powdered leaves form the tree of Adansonia digitata linn., [Bombacaceae] were studied to fix some pharmacognostical parameters. Preliminary phytochemical screening on the methanolic extract of the plant was also performed. These studies will help in identification of this plant for further research.

  17. Choosing tree genotypes for phytoremediation of landfill leachate using phyto-recurrent selection

    Science.gov (United States)

    Jill A. Zalesny; Ronald S., Jr. Zalesny; Adam H. Wiese; Richard B. Hall

    2007-01-01

    Information about the response of poplar (Populus spp.) genotypes to landfill leachate irrigation is needed, along with efficient methods for choosing genotypes based on leachate composition. Poplar clones were irrigated during three cycles of phyto-recurrent selection to test whether genotypes responded differently to leachate and water, and to test...

  18. Use of mycorrhizal fungi for the phyto stabilisation of radio contaminated environment (European project myrrh): overview on the scientific achievements

    Energy Technology Data Exchange (ETDEWEB)

    Dupre De Boulois, H.; Leyval, C.; Joner, E.J.; Jakobsen, I.; Chen, B.; Roos, P.; Thiry, I.; Rufyikiri, G.; Delvaux, B.; Declerck, S. [Universite catholique de Louvain, Mycotheque de l' Universite catholique de Louvain (MUCL), Unite de Microbiologie, Louvain-la-Neuve (Belgium)

    2004-07-01

    Because plants significantly affect radionuclides (RN) cycling and further dispersion into the biosphere, it is important to understand the biological factors influencing RN plant uptake, accumulation and redistribution. In this respect, mycorrhizal fungi which are intimately associated with plant roots and constitute an active continuum at the soil-plant interface are of particular interest. The European project MYRRH (Use of Mycorrhizal fungi for the phyto-stabilisation of radio-contaminated environment) was aimed to highlight the role of these soil micro-organisms. Both ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi were considered and experiments were performed using naturally or artificially contaminated substrates with radiocaesium (Cs) or uranium (U) under pot culture or in vitro conditions. Results obtained under in vitro conditions demonstrated that AM fungal hyphae could take up and trans-locate Cs and U towards roots. However, this translocation was low for both elements. In particular, for Cs, uptake and translocation were not even perceptible using a classical pot culture system, but these contrasting results should be related to the growth conditions (e.g. concentration of potassium) used. The efficiency of translocation (rate of translocation per unit area) of both elements under in vitro conditions was higher than the one of roots. The in vitro studies also showed that the intra-radical AM fungal structures might contribute to Cs and U accumulation within mycorrhizal roots. Under pot culture conditions, AM fungi appeared to significantly reduce root to shoot translocation of U. Under the same conditions, ECM transport of Cs was demonstrated, and appeared to be dependent on the fungal species. As we established that mycorrhizal fungi could influence RN plant acquisition, accumulation and redistribution, a better estimation of the potential use of mycorrhizal fungi for the phyto-remediation of RN-contaminated areas is now available and

  19. Quantitative observation of cyanobacteria and diatoms from space using PhytoDOAS on SCIAMACHY data

    Directory of Open Access Journals (Sweden)

    A. Bracher

    2009-05-01

    Full Text Available In this study the technique of Differential Optical Absorption Spectroscopy (DOAS has been adapted for the retrieval of the absorption and biomass of two major phytoplankton groups (PhytoDOAS from data of the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY satellite sensor. SCIAMACHY measures back scattered solar radiation in the UV-Vis-NIR spectral regions with a high spectral resolution (0.2 to 1.5 nm. In order to identify phytoplankton absorption characteristics in the SCIAMACHY data in the range of 430 to 500 nm, phytoplankton absorption spectra measured in-situ during two different RV "Polarstern" expeditions were used. The two spectra have been measured in different ocean regions where different phytoplankton groups (cyanobacteria and diatoms dominated the phytoplankton composition. Results clearly show distinct absorption characteristics of the two phytoplankton groups in the SCIAMACHY spectra. Using these results in addition to calculations of the light penetration depth derived from DOAS retrievals of the inelastic scattering (developed by Vountas et al., 2007, globally distributed pigment concentrations for these characteristic phytoplankton groups for two monthly periods (February–March 2004 and October–November 2005 were determined. This satellite information on cyanobacteria and diatoms distribution clearly matches the concentrations based on high pressure liquid chromatography (HPLC pigment analysis of collocated water samples and concentrations derived from a global model analysis with the NASA Ocean Biogeochemical Model (Gregg et al., 2003; Gregg and Casey 2007. The quantitative assessment of the distribution of key phytoplankton groups from space enables various biogeochemical regions to be distinguished and will be of great importance for the global modeling of marine ecosystems and biogeochemical cycles which enables the impact of climate change in the oceanic biosphere to be estimated.

  20. Quantitative observation of cyanobacteria and diatoms from space using PhytoDOAS on SCIAMACHY data

    Directory of Open Access Journals (Sweden)

    A. Bracher

    2008-11-01

    Full Text Available In this study the technique Differential Optical Absorption Spectroscopy (DOAS has been adapted for the retrieval of the absorption and biomass of two major phytoplankton groups (PhytoDOAS from data of the satellite sensor Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY. SCIAMACHY measures back scattered solar radiation in the UV-Vis-NIR spectral region with a high spectral resolution (0.2 to 1.5 nm. In order to identify phytoplankton absorption characteristics in SCIAMACHY data in the range of 430 to 500 nm, phytoplankton absorption spectra measured in-situ during two different RV "Polarstern" expeditions were used. The two spectra have been measured in different ocean regions where different phytoplankton groups (cyanobacteria and diatoms dominated the phytoplankton composition. Results show clearly different absorption characteristics of the phytoplankton groups in the SCIAMACHY spectra. Globally distributed pigment concentrations for these characteristic phytoplankton groups for two monthly periods (February–March 2004 and October–November 2005 were derived from these differential absorptions by including the information of the sensor's optical paths within the water column (i.e. light penetration depth according to Vountas et al. (2007 derived from DOAS fits of inelastic scattering. The satellite retrieved information on cyanobacteria and diatoms distribution matches well the concentrations measured at collocated water samples with HPLC technique and concentrations derived from the global model analysis with the NOBM model (Gregg et al., 2003; Gregg and Casey, 2007. Identifying quantitative distribution of key phytoplankton groups from space allow to distinguish various biogeochemical provinces and will be of great importance for the global modelling of marine ecosystem and biogeochemical cycles addressing climate changes in the oceanic biosphere.

  1. Chemical biology approaches for studying posttranslational modifications.

    Science.gov (United States)

    Yang, Aerin; Cho, Kyukwang; Park, Hee-Sung

    2017-09-13

    Posttranslational modification (PTM) is a key mechanism for regulating diverse protein functions, and thus critically affects many essential biological processes. Critical for systematic study of the effects of PTMs is the ability to obtain recombinant proteins with defined and homogenous modifications. To this end, various synthetic and chemical biology approaches, including genetic code expansion and protein chemical modification methods, have been developed. These methods have proven effective for generating site-specific authentic modifications or structural mimics, and have demonstrated their value for in vitro and in vivo functional studies of diverse PTMs. This review will discuss recent advances in chemical biology strategies and their application to various PTM studies.

  2. Phyto-oestrogens and their metabolites in milk produced on two pastures with different botanical compositions

    DEFF Research Database (Denmark)

    Adler, S. A.; Purup, S.; Hansen-Møller, J.

    2014-01-01

    Phyto-oestrogens are a group of secondary plant metabolites that may bind to oestrogen receptors and exert oestrogenic or anti-oestrogenic effects in humans and can protect against cancer diseases. When ingested by dairy cows, phyto-oestrogens can be metabolised and transferred to the milk...... deviation); body weight 599 (45.1). kg, stage of lactation 73 (15.0) d in milk, milk yield 29.9 (2.90) kg/d at the start of the experiment] were divided into two groups and grazed either a short-term pasture (SP) or a long-term pasture (LP). The SP was representative of organically managed leys in Norway...

  3. Phyto-remediation potential of Ipomoea aquatica for Cr(VI) mitigation.

    Science.gov (United States)

    Weerasinghe, Aruni; Ariyawnasa, Sanduni; Weerasooriya, Rohan

    2008-01-01

    Phyto-remedial efficiency of Ipomoea aquatica was examined at different experimental conditions for a period of 3 months. This plant was selected due to its easy establishment, tolerance and growing easiness. In all trials, the I. aquatica was grown in coir dust to ensure an inert medium. Essential growth nutrients were supplied externally using Albert solution. Once plant growth conditions were fixed, the model system was spiked with Cr(VI) solution in the range of 7-90 ppm. Up to 28 ppm Cr(VI), I. aquatica exhibits uniform absorption characteristics showing over 75% removal of added Cr(VI). At this stage I. aquatica was not affected and it showed no toxicity symptoms. Therefore, it is suited as a potential phyto-remediant. Further I. aquatica is a vegetable particularly in Asian region; therefore caution has to be taken when selecting it for human consumption due to its high chromium accumulation capacity.

  4. METABOLIC PROFILE OF COW BLOOD UNDER THE TREATMENT OF OVARIES HYPOFUNCTION BY HORMONAL AND PHYTO-PREPARATIONS

    Directory of Open Access Journals (Sweden)

    Kornyat S.

    2015-08-01

    Full Text Available For the correction of reproductive function of cows with ovarian hypofunction practices use a number of hormones. Recently, to stimulate reproductive function using herbal medicines that have gonadotropic effect or stimulate secretion of steroid hormones who try to use to increase fertility. Therefore, we carried out an attempt to develop a method of regulation of reproductive function of the ovaries of cows using combination therapies that can provide effective treatment by studying the biochemical parameters of animals. The cows were divided depending on the treatment to control and two experimental groups of 5 animals in each group. Groups were formed by the following treatment regimens indicated pathology. Cows control group treated by next scheme: day 1 — intramuscular injection drug in vitro at a dose of 10 ml; day 2 —PMSG intramuscular administration of the drug at a dose of 500 IU; day 3 —intramuscular injection drug Surfahon at a dose of 50 mg. Cows from experimental group 1 was injected intramuscularly liposomal drug based on herbal (Rhodiola rosea, Salvia; Animals from second experimental group were injected intramuscularly liposomal drug based on phyto-substances (Rhodiola rosea, Salvia with gonadotropin-releasing hormone (Surfahon. Analysis of biochemical parameters of blood serum of cows with ovarian hypofunction found low concentrations of estradiol-17-β and progesterone. Between the control and experimental groups concentration of progesterone and estradiol-17-β differ within 10%, which indicates the same level of disease in all animals selected. Level carotene, ascorbic acid and cholesterol in all groups was within the physiological norm and differed slightly. It was established that the treatment of cows with hypofunction ovaries in the experimental group 1 progesterone level 7 days after treatment was 11.5, and 2 - on 41,4% (p <0,01 higher than in the control group animals, indicating that the revitalization of the

  5. PhytoSFDM version 1.0.0: Phytoplankton Size and Functional Diversity Model

    Science.gov (United States)

    Acevedo-Trejos, Esteban; Brandt, Gunnar; Smith, S. Lan; Merico, Agostino

    2016-11-01

    Biodiversity is one of the key mechanisms that facilitate the adaptive response of planktonic communities to a fluctuating environment. How to allow for such a flexible response in marine ecosystem models is, however, not entirely clear. One particular way is to resolve the natural complexity of phytoplankton communities by explicitly incorporating a large number of species or plankton functional types. Alternatively, models of aggregate community properties focus on macroecological quantities such as total biomass, mean trait, and trait variance (or functional trait diversity), thus reducing the observed natural complexity to a few mathematical expressions. We developed the PhytoSFDM modelling tool, which can resolve species discretely and can capture aggregate community properties. The tool also provides a set of methods for treating diversity under realistic oceanographic settings. This model is coded in Python and is distributed as open-source software. PhytoSFDM is implemented in a zero-dimensional physical scheme and can be applied to any location of the global ocean. We show that aggregate community models reduce computational complexity while preserving relevant macroecological features of phytoplankton communities. Compared to species-explicit models, aggregate models are more manageable in terms of number of equations and have faster computational times. Further developments of this tool should address the caveats associated with the assumptions of aggregate community models and about implementations into spatially resolved physical settings (one-dimensional and three-dimensional). With PhytoSFDM we embrace the idea of promoting open-source software and encourage scientists to build on this modelling tool to further improve our understanding of the role that biodiversity plays in shaping marine ecosystems.

  6. Phyto-Pharmacology of Ziziphus jujuba Mill- A plant review

    Directory of Open Access Journals (Sweden)

    R T Mahajan

    2009-01-01

    Full Text Available Herbs have always been the natural form of medicine in India. Medicinal plants have curative properties due to presence of various complex chemical substances of different composition which contain secondary metabolites such as alkaloids, flavonoids, terpenoids, saponin and phenolic compounds distributed in different parts of the plants. Ziziphus jujuba Mill, a member of the family Rhamnaceae, commonly known as Bor, is used traditionally as tonic and aphrodisiac and sometimes as Hypnotic-sedative and Anxiolytic, anticancer (Melanoma cells, Antifungal, Antibacterial, Antiulcer, Anti-inflammatory, Cognitive, Antispastic, Antifertility/contraception, Hypotensive and Antinephritic, Cardiotonic, Antioxidant, Immunostimulant, and Wound healing properties. It possesses allied compounds viz. Ascorbic acid, thiamine, riboflavin-bioflavonoids and Pectin A and various chemical substances like Mauritine-A; Amphibine-H; Jubanine-A; Jubanine-B; Mucronine-D and Nummularine-B. Sativanine-E. Frangufoline, Ziziphine-A to Q, betulinic acid colubrinic acid, alphitolic acid, 3-O-cis-p-coumaroylalphitolic acid, 3-O-transp-coumaroylalphitolic acid, 3-O-cis-p-coumaroylmaslinic acid, 3-O-trans-pcoumaroylmaslinic acid, oleanolic acid, betulonic acid, oleanonic acid, zizyberenalic acid and betulinic acid, jujubosides A, B, A1 B1 and C and acetyljujuboside B and the protojujubosides A, B and B1, saponin, ziziphin, from the dried leaves of Z. jujube - 3-O-a-L-rhamnopyranosyl (1-2-a-arabinopyranosyl-20-O- (2,3-di-O-acetyl-a-L-rhamnopyranosyl jujubogenin. Saponin from leaves and stem are 3-O- ((2-O- alpha - D - furopyranosyl - 3-O- beta - D -glucopyranosyl - alpha - L - arabinopyranosyl jujubogenin and (6′′′-sinapoylspinosin, 6′′′-feruloylspinosin and 6′′′-p-coumaroylspinosin. The present review discusses photo-chemistry, pharmacology, medicinal properties and biological activities of Za jujuba and its usage in different ailments.

  7. Dietary whey reduces energy intake and alters hypothalamic gene expression in obese phyto-oestrogen-deprived male rats.

    Science.gov (United States)

    Andreoli, María F; Stoker, Cora; Lazzarino, Gisela P; Canesini, Guillermina; Luque, Enrique H; Ramos, Jorge G

    2016-09-01

    Removing dietary phyto-oestrogens in adult male rats causes obesity and diabetes. As whey proteins have been reported to reduce food intake and improve glucose homoeostasis, we investigated whether they could attenuate susceptibility to obesity and diabetes due to phyto-oestrogen deprivation. To this end, thirty male Wistar rats were fed a high-phyto-oestrogen (HP) or a phyto-oestrogen-free (PF) diet for 10 weeks; six rats from each group were killed. The remaining HP animals (six animals) continued receiving the HP diet for 6 weeks. The remaining PF rats (twelve rats) were divided in two groups: one was given the PF diet and the other a variation of the PF diet plus whey protein (PF-W). Body weight, food intake and adipose tissue weights were recorded. Hypothalamic mRNA expressions of orexigenic (neuropeptide Y, agouti-related protein (AgRP)) and anorexigenic (pro-opiomelanocortin (POMC), cocaine-amphetamine-related transcript (CART)) neuropeptides were quantified by real-time PCR. Serum glucose, insulin and total thyroxine (T4), thyroid-stimulating hormone, testosterone and oestradiol were assessed. After 10 weeks of PF diet, increased body weight, adiposity and energy intake, with up-regulation of AgRP and down-regulation of POMC', were observed. Longer treatment exacerbated these results, increased total T4 levels, reduced oestradiol levels and impaired glucose homoeostasis. PF-W reduced energy intake and increased POMC expression; however, body weight and adiposity remained unchanged. PF-W could not prevent the hormonal changes or the high circulating glucose levels induced by phyto-oestrogen deprivation, but reduced fasting insulin. These data demonstrate that, although 6 weeks of whey administration could not prevent obesity in phyto-oestrogen-deprived rats, the reduction in energy intake and circulating insulin could be beneficial with longer treatments.

  8. Computational pharmacokinetics and in vitro-in vivo correlation of anti-diabetic synergistic phyto-composite blend

    Institute of Scientific and Technical Information of China (English)

    Baishakhi; De; Koushik; Bhandari; Nishant; Chakravorty; Ranjan; Mukherjee; Rohit; Gundamaraju; Rajeev; K; Singla; Prakash; Katakam; Shanta; K; Adiki; Biswajoy; Ghosh; Analava; Mitra

    2015-01-01

    Despite tremendous strides in modern medicine stringent control over insulin resistance or restoration of normoglycemia has not yet been achieved.With the growth of molecular biology,omics technologies,docking studies,and in silico pharmacology,modulators of enzymes and receptors affecting the molecular pathogenesis of the disease are being considered as the latest targets for anti-diabetic therapy.Therapeutic molecular targets are now being developed basing on the up or down regulation of different signaling pathways affecting the disease.Phytosynergistic antidiabetic therapy is in vogue both with classical and non-classical medicinal systems.However its chemoprofiling,structural and pharmacokinetic validation awaits providing recognition to such formulations for international acceptance.Translational health research with its focus on benchside product development and its sequential transition to patient bedside puts the pharma RDs to a challenge to develop bio-waiver protocols.Pharmacokinetic simulation models and establishment of in vitro-in vivo correlation can help to replace in vivo bioavailability studies and provide means of quality control for scale up and post approval modification.Thisreview attempts to bring different shades highlighting phyto-synergy,molecular targeting of antidiabetic agents via different signaling pathways and bio-waiver studies under a single umbrella.

  9. Effects of plant stanol ester consumption on fasting plasma oxy(phyto)sterol concentrations as related to fecal microbiota characteristics.

    Science.gov (United States)

    Baumgartner, Sabine; Mensink, Ronald P; Smet, Els De; Konings, Maurice; Fuentes, Susana; de Vos, Willem M; Plat, Jogchum

    2016-03-03

    Information regarding dietary effects on plasma oxyphytosterol concentrations as well as on the origin of oxyphytosterols is scarce. We hypothesized that plant sterols are oxidized in the intestinal lumen, mediated by microbial activity, followed by uptake into the circulation. To address this hypothesis, we carried out, a randomized, double blind, crossover study in 13 healthy subjects, who consumed for 3 weeks control and plant stanol ester enriched margarines (3.0g/d plant stanols) separated by a 4-week wash-out period. Plasma oxy(phyto)sterols were determined via GC-MS/MS, while microbiota analyses were performed on fecal DNA using a phylogenetic microarray to assess microbial composition and diversity. Plasma plant sterol concentrations did not correlate with plasma oxyphytosterols concentrations at baseline. Plant stanol consumption reduced serum sitosterol and campesterol concentrations (-37% and -38%), respectively (pmicrobiota composition and diversity of the faecal contents were not different between the two periods, we observed significant correlations between several specific bacterial groups and plasma plant sterol, but not with plasma oxyphytosterol concentrations. In conclusion, plant stanol ester consumption reduced serum plant sterol and plasma oxyphytosterol concentrations, while intestinal microbiota composition and diversity were not changed. To definitely answer the effects of microbiota on oxyphytosterol formation, future studies could examine oxyphytosterol concentrations after changing intestinal microbial composition or by measuring intestinal oxyphytosterol formation after providing labelled non-oxidized plant sterols.

  10. Studying chemical reactivity in a virtual environment.

    Science.gov (United States)

    Haag, Moritz P; Reiher, Markus

    2014-01-01

    Chemical reactivity of a set of reactants is determined by its potential (electronic) energy (hyper)surface. The high dimensionality of this surface renders it difficult to efficiently explore reactivity in a large reactive system. Exhaustive sampling techniques and search algorithms are not straightforward to employ as it is not clear which explored path will eventually produce the minimum energy path of a reaction passing through a transition structure. Here, the chemist's intuition would be of invaluable help, but it cannot be easily exploited because (1) no intuitive and direct tool for the scientist to manipulate molecular structures is currently available and because (2) quantum chemical calculations are inherently expensive in terms of computational effort. In this work, we elaborate on how the chemist can be reintroduced into the exploratory process within a virtual environment that provides immediate feedback and intuitive tools to manipulate a reactive system. We work out in detail how this immersion should take place. We provide an analysis of modern semi-empirical methods which already today are candidates for the interactive study of chemical reactivity. Implications of manual structure manipulations for their physical meaning and chemical relevance are carefully analysed in order to provide sound theoretical foundations for the interpretation of the interactive reactivity exploration.

  11. Phyto-availability and speciation change of heavy metals in soils amended with lignin as micro-fertilizer

    Institute of Scientific and Technical Information of China (English)

    WANG; Songxue; ZHANG; Shuzhen; SHAN; Xiaoquan; MU; Huanzh

    2005-01-01

    Lignin is a primary byproduct from the black liquor treatment in paper making industries, its application as micro-fertilizer in agricultural land might provide a promising alternative to sewage discharge. However, application of such a micro-fertilizer might affect the soil properties and result in soil pollution. In this study, the effects of lignin application on phytoavailability and speciation change of heavy metals in soils were investigated. Greenhouse experiments showed that lignin application improved the growth of winter wheat (Triticum aestivum L.) in all three soils investigated. The increase of the biomass for wheat shoot was 59.7%, 39.8% and 12.3% for Beijing soil, Jiangxi soil and Dongbei soil, respectively. In contrast, lignin amendment decreased the concentrations of heavy metals in wheat shoots from 2.2% to 61.0%. Sequential extraction procedure of a three-step BCR was used to investigate the fraction distribution. The extractable fractions were specified as fraction B1: water soluble, exchangeable and carbonate bound or weakly specifically adsorbed; B2: Fe-Mn oxide bound; B3: organic matter and sulfide bound. The results showed that lignin application led to the redistribution of heavy metals in each fraction. Generally, heavy metals decreased in B1 and B2 fractions and increased in B3 fraction. Upon the results short-term application of lignin in agricultural land not only improves the growth of wheat but also reduces the phyto-abailability of heavy metal in wheat.

  12. Los productos fito-farmacéuticos en la acuicultura - The phyto-farmaceuticals products in aquaculture

    Directory of Open Access Journals (Sweden)

    Silveira-Coffigny, Raquel.

    2006-08-01

    Full Text Available .- Los productos fito-farmacéuticos, para el control y la prevención de enfermedades de organismos acuáticos, se han identificado como la terapia del futuro en la patología acuática. Sin embargo, teniendo en cuenta la efectividad y la inocuidad de estos medicamentos, las investigaciones en este campo y el empleo de los mismos por el sector productivo son aún insuficientes. En el presente estudio se realizó una breve descripción de las propiedades terapéuticas de los ingredientes activos de las plantas medicinales que pueden ser empleadas en la acuicultura, y se mencionan las plantas que han sido utilizadas en varias regiones del mundo en el control de los agentes patógenos de peces y crustáceos de cultivo. The phyto-farmaceuticals products for the therapy and prevention of aquatic organism diseases have been identified like of the future therapy in the aquatic pathology. Nevertheless, considering the efficacy and large safety factor of these medicines, the investigations in this field and the use of such by the productive sector they are still insufficient. The present study is a brief description of the therapeutic properties of the active ingredients of medicinal plants that can be used in aquaculture, as well as the plants that have been used in several regions of the world in the control of pathogenic agents of aquatic organisms.

  13. Study of chemical and radiation induced carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Chmura, A.

    1995-11-01

    The study of chemical and radiation induced carcinogenesis has up to now based many of its results on the detection of genetic aberrations using the fluorescent in situ hybridization (FISH) technique. FISH is time consuming and this tends to hinder its use for looking at large numbers of samples. We are currently developing new technological advances which will increase the speed, clarity and functionality of the FISH technique. These advances include multi-labeled probes, amplification techniques, and separation techniques.

  14. Theoretical studies of chemical reaction dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, G.C. [Argonne National Laboratory, IL (United States)

    1993-12-01

    This collaborative program with the Theoretical Chemistry Group at Argonne involves theoretical studies of gas phase chemical reactions and related energy transfer and photodissociation processes. Many of the reactions studied are of direct relevance to combustion; others are selected they provide important examples of special dynamical processes, or are of relevance to experimental measurements. Both classical trajectory and quantum reactive scattering methods are used for these studies, and the types of information determined range from thermal rate constants to state to state differential cross sections.

  15. Kinetic studies of elementary chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Durant, J.L. Jr. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    This program concerning kinetic studies of elementary chemical reactions is presently focussed on understanding reactions of NH{sub x} species. To reach this goal, the author is pursuing experimental studies of reaction rate coefficients and product branching fractions as well as using electronic structure calculations to calculate transition state properties and reaction rate calculations to relate these properties to predicted kinetic behavior. The synergy existing between the experimental and theoretical studies allow one to gain a deeper insight into more complex elementary reactions.

  16. Phyto remediation and decontamination of soils; Fitodecontaminazione e risanamento dei suoli

    Energy Technology Data Exchange (ETDEWEB)

    Miceli, A. [Lecce Univ., Lecce (Italy). Dipt. di Biologia

    2001-02-01

    Contaminated soils pose an environmental problem which may be solved by the emerging phyto remediation technology. This cost-effective plant-based approach to remediation takes advantages of the ability of plants to concentrate toxic compounds from the environment and to metabolize them in the tissues. Toxic heavy metals are major targets for the phyto remediation. The use of this environmentally friendly technology is described in this work. [Italian] Negli ultimi tempi, uno dei problemi ambientali di maggior rilievo e' l'aumentato numero di suoli contaminati. La contaminazione dei siti e dei terreni puo' derivare da una serie di fonti, tra cui: eccessive applicazioni di fertilizzanti, pesticidi, insetticidi (terreni agricoli); sversamenti, perdite di prodotti chimici e combustibili; smaltimento di rifiuti pericolosi o industriali senza adeguato controllo ambientale; percolato da discariche di rifiuti solidi urbani; fall-out atmosferico. La phytoremediation (fitodecontaminazione) utilizza alcune specie di piante verdi per risanare i terreni contaminati da inquinanti o per contenere la loro dispersione nell'ambiente.

  17. Phyto-saponins as a natural adjuvant for delivery of agromaterials through plant cuticle membranes.

    Science.gov (United States)

    Chapagain, Bishnu P; Wiesman, Zeev

    2006-08-23

    With growing use of synthetic adjuvants in modern agriculture, their impacts on the environment are being questioned. In a search for an environmentally safe phyto-adjuvant, we have investigated natural glycosidic saponin for delivery of agromaterials through plant cuticle membranes. Four saponin preparations from Quillaja saponaria bark (QE), obtained from Sigma-Aldrich, and Balanites aegyptiaca fruit mesocarp (ME), kernel (KE), and root (RE), isolated and characterized in our laboratory, were used for testing the delivery of [14C]-2,4-dichlorophenoxyacetic acid (2,4-D) across isolated intact astomatous adaxial Citrus grandis leaf cuticle membranes (CMs). The results showed that both Q. saponaria and B. aegyptiaca saponin preparations enhanced delivery of 2,4-D through CMs. Among the saponin preparations, ME exhibited a significantly higher level of delivery of 2,4-D with a concentration effect (2% being the highest). Transmission electron microscope (TEM) and dynamic light scattering (DLS) characterization of these saponin preparations in aqueous solution clearly demonstrated the formation of nanoscale vesicles. Various possibilities for a natural amphiphatic phyto-saponin as a delivery adjuvant through CMs are discussed.

  18. RIPEN FRUITS OF INDIAN GINSENG: PHYTO-CHEMICAL AND PHARMACOLOGICAL EXAMINATION AGAINST HUMAN AND PLANT PATHOGENS

    Directory of Open Access Journals (Sweden)

    Premlata Singariya

    2012-05-01

    Full Text Available The ripen fruit extracts of Withania somniferawere evaluated against medically importantbacteria viz.Proteusmerabilis, Klebsiella pnemoniae, Agerobacterium tumefaciens(plant pathogenandone fungi Aspergillus niger.The dried and powdered ripen fruits were successively extracted with a seriesof non polar to polar solvents using soxhlet assembly. The antimicrobial assay was done by both discdiffusion and broth dilution methods. Glacial acetic acid extract of W. somniferashow highest activityagainst A. tumefaciens(plant pathogen and water extract againstK. pnemoniaeto varying degrees in theterms of high inhibition zone and activity index. A. tumefacienswas the most susceptible organism incompare to the other organism. Gentamycin and Ketoconazole, the standard antibacterial and antifungalused was effective against the bacteria and fungi. The extract of W. somniferaalso significantly (P>0.005inhibited the bacterial and fungal growth. The inhibitory effect is very identical in magnitude andcomparable with that of standard antibiotics used.

  19. Influence of cultivation regime of an arbuscular mycorrhizal fungal isolate on its symbiotic efficacy in phyto restoration of disturbed ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, R. S.; Vosatka, M.; Castro, P. M. L.; Dodd, J. C.

    2009-07-01

    Arbuscular mycorrhizal fungi (AMF), from the Phylum Glomeromycota, are a group of soil organisms that forms symbiotic associations with plant roots and can contribute to increase plant biomass and promote phyto restoration of disturbed ecosystems. The influence of cultivation regime of a Glomus geosporum isolate, obtained from a highly alkaline anthropogenic sediment, on its symbiotic efficacy was investigated. (Author)

  20. Phyto-pharmacology of Celastrus paniculatus: An Overview

    Directory of Open Access Journals (Sweden)

    M. Bhanumathy

    2010-07-01

    Full Text Available Celastrus paniculatus (CP, a traditional Ayurvedic medicinal plant used for centuries as a memory enhancing, anti-inflammatory, analgesic, sedative and antiepileptic agent. The seed extract has been extensively investigated in several laboratories for their neuropharmacological effects and a number of reports are available confirming their nootropic action. In addition, researchers have evaluated the anti-inflammatory, anticonvulsant and other pharmacological effects of CP preparations/extracts. Therefore, in view of the important activities performed by this plant, investigation must be continued in the recently observed actions described in this paper. Moreover, clinical studies have to be encouraged, also to evidence any side effects and possible interactions between this herbal medicine and synthetic drugs.

  1. Phyto-gegographycal analysis of Divčibare

    Directory of Open Access Journals (Sweden)

    Popović Ivana

    2005-01-01

    Full Text Available The aim of phytogeographical analysis is to determine the plant species origin, genesis and migrations. The study results contribute to the knowledge of phytogeographical classification of the particular regions. Different chorions, by their effects, determine the flora structure and composition. The aim of the floristic research of Divčibare was to identify the diversity of flora in this region, i.e., in a wider sense, the diversity of flora in Serbia. Phytogeographical analysis was based on floristic research. The identified plant species were classified into the corresponding floral elements, area groups and area types. The data on diversity and the degree of representation in the flora of Divčibare were obtained based on the percentage of each area type. It was concluded that the flora of Divčibare has a transitional, Central European-Mediterranean-Pontic character.

  2. Levantamento fitossociológico em pastagens Phyto-sociological assessment of pasture

    Directory of Open Access Journals (Sweden)

    M.H. Inoue

    2012-03-01

    Full Text Available O objetivo do presente trabalho foi identificar a comunidade daninha presente em áreas de pastagens. O levantamento fitossociológico foi realizado nos meses de novembro e dezembro de 2009 em três regiões: duas localizadas no município de Tangará da Serra-MT (região A = áreas próximas à cidade; e região B = áreas presentes no Assentamento Antonio Conselheiro e uma no município de Barra do Bugres-MT (região C. Em cada região foram analisadas cinco propriedades, tendo cada uma 10 parcelas de 25 m². Nas parcelas, foram realizadas a contagem e identificação das espécies daninhas. Os dados foram analisados por meio de cálculos de densidade, frequência, abundância, densidade relativa, frequência relativa, abundância relativa, índice de valor de importância (IVI e índice de similaridade. Foram identificadas 38 espécies daninhas, distribuídas em 18 famílias, sendo Asteraceae (7, Fabaceae (6, Arecaceae (3, Euforbiaceae (3 e Poaceae (3 as mais representativas em número de espécies. As espécies que mais ocorreram na área foram: região A - Sida spp. (IVI 127,93 e Eragrostis plana (IVI: 42,18; região B - Eragrostis plana (IVI: 54,78, Mimosa wedelliana (IVI:52,39 e Sida spp. (IVI: 50,30; e região C - Sida spp. (IVI: 73,92 e Mimosa wedelliana (IVI: 26,55. Houve similaridade expressiva entre as regiões A e B (52,63% e entre as regiões B e C (50,98%.Objective of this study was to identify the weed community in areas of pasture. The phyto-sociological survey was conducted during November and December, 2009 in three regions: two located in Tangará da Serra-MT (region A = areas surrounding the town; and region B = areas in the Antonio Conselheiro Settlement and one area in Barra of the Bugres-MT (region C. Five properties were analyzed in each region, each containing 10 plots of 25 m2. The weed species were counted and identified in the plots. Data were analyzed by calculating density, frequency, abundance, relative density

  3. Intraprostatische Phytoöstrogen-Gewebsspiegel in verschiedenen österreichischen Regionen im BPH- und Prostatakarzinomgewebe

    Directory of Open Access Journals (Sweden)

    Brössner C

    2006-01-01

    Full Text Available Einleitung: Zahlreiche Studien weisen darauf hin, daß die niedrige Inzidenz an Erkrankungen der Prostata (BPH und/oder Prostatakarzinom in asiatischen Ländern unter anderem am hohen Konsum an Phytoöstrogenen liegt. Weiters suggerieren jüngste Studien, daß das Prostatavolumen mit der Höhe der intraprostatischen Genisteinspiegel (= ein Phytoöstrogen negativ korreliert [1, 2]. Die intraprostatischen Genisteinspiegel sind bei asiatischen Männern im Vergleich zu österreichischen Männern um ein Vielfaches höher. Uns interessierte die Frage, ob analog zum Ost-West-Gefälle in unterschiedlichen geographischen Regionen Österreichs unterschiedlich hohe Gewebsspiegel nachweisbar sind. In einer Subgruppenanalyse evaluierten wir Unterschiede zwischen städtischem und ländlichem Umfeld. Material und Methodik: Prostatagewebechips von 103 österreichischen Männern von 3 verschiedenen Zentren (Graz, Salzburg, Oberwart wurden im Rahmen einer TUR-P oder radikalen Prostatektomie gewonnen und bei –40 °C gelagert. Davon wurden Enterolacton- (repräsentativ für die Gruppe der Lignane und Genisteinspiegel (repräsentativ für die Gruppe der Isoflavone mittels "monoclonal antibody based immunoassay" bestimmt und verglichen. Jede Messung wurde pro Patient doppelt durchgeführt. Ergebnisse: Die Enterolacton-Gewebsspiegel waren vergleichbar bei Männern, die in urbanem (median 19,1 ng/g dry weight; range 1,6–76,4 oder ruralem Umfeld lebten (median 15,7; range 0,6–140,6, p = 0,99. Ebenso vergleichbar waren für diese Gruppen die Werte für Genistein: 9,3 (range 0,1–156,7 und 20,5 (range 4,6–47,4, p = 0,77. Bei Männern, die in verschiedenen österreichischen geographischen Regionen lebten, waren ebenfalls keine Unterschiede zwischen den beiden Parametern Enterolacton und Genistein (p = 0,1 bzw. p = 0,65 zu finden. Schlußfolgerung: Generell sind innerhalb der untersuchten Gruppen die intraprostatischen Phytoöstrogenspiegel vergleichbar. Unter den

  4. Preparation of briquettes on the basis of desintegrated phyto-materials and the admixture of fine-grained coal and coke

    Directory of Open Access Journals (Sweden)

    Jakabský Štefan

    2002-03-01

    Full Text Available The contribution deals with the preparation of small-diameter briquettes on the basis of desintegrated phyto-materials and the admixture of coal and coke. The phyto-materials are classified as a dry biomass that can be, on the one hand, the wastes from wood-working industry,(sawdust, chips, bark, etc. or dried mass from the plant production and, on the other hand, the mass of quick-growing plants cultivated on special plantations. In present time this renewable energy resource attracts attention by its heating value ranging from 10 to 16 MJ.kg-1 (EkoWATT, 2001, a low ash content of 0.5 – 6.5 % and by a low sulphur content in a water free sample of 0.05 –0.12 %.As a phyto-material the spruce sawdusts having a grain size of –2 mm were used. The admixture of brown coal, hard coal and coke with a grain size of 0.040 mm was added to the sawdust and in such way prepared mixtures were subjected to briquetting with the aim to obtain small-diameter briquettes. The influence of admixtures amount on the density, and the suitable briquetting press have been studied. A saleability of briquettes on the basis of phyto-materials is conditioned by their density that must be higher than 1,000 kg.m-3. Thus, an adding of denser material with a relatively high calorific value would enable to attain the required density as well as to retain and/or to improve the main utility properties, i.e. calorific value and ash content.The adding evinces itself in an enhancement of briquetting press, but also density of obtained briquettes is often much higher that required by the market. It was showed that in the case of clear spruce sawdust the density of 1,059 kg.m-3 under the briquetting press of 250 MPa can be attained. According to other results, an admixture of brown coal is not very favourable because briquetting press exceeds the value of 300 MPa. As to hard coal adding, the presses under 250 MPa were achieved at the content of 25 – 30 %. The density of these

  5. Heavy metal sequestration by humic substances during phyto-treatment of sewage sludges

    Energy Technology Data Exchange (ETDEWEB)

    Peruzzi, E.; Doni, S.; Macci, C.; Ceccanti, B.; Masciandaro, G.

    2009-07-01

    The presence of heavy metals in sludges stabilized in a reed bed system, may affect their use for agricultural purposes; however, the environmental impact of sludges depends on the availability and phyto toxicity of their heavy metal. The aim of this paper was to determine the effectiveness of a reed bed (Phragmites Australia) sludge treatment system in two urban wastewater treatment plants in Italy after two-year period of operation: by estimating the process of sludge stabilization, following conventional and non conventional parameters related with the evolution of organic matter quality (Water soluble Carbon, Dehydrogenase activity, Fulvic Acids, Humic Acids, Pyrolytic indices or organic matter Mineralization and Humification); by following the heavy metal speciation bioavailability in sludges. (Author)

  6. Phyto-remediation of contaminated soils; La phytoremediation des sols contamines

    Energy Technology Data Exchange (ETDEWEB)

    Morel, J.L. [Ecole Nationale Superieure Agronomie et des Industries Alimentaires, 54 - Vandoeuvre les Nancy (France)

    2002-09-01

    Plants provide new ways for soil remediation. The activity of living roots (absorption, exudation of organic compounds, action on physical soil properties) contribute to decrease the negative effects of pollutants, as they are stabilised or eliminated (extraction or degradation). In the presence of plants, hydrocarbons, a rather ubiquitous group of soil pollutants, are degraded faster than in bare soil. Hydrocarbon degrading bacteria are stimulated by root exudates, which also create favourable conditions for co-metabolism. Also, the fragmentation of aggregates as well as the release of surfactants increase the exposure of organic pollutants to microorganism degradation. The phyto-remediation technology is efficient to reduce the dissemination of pollutants. On historically contaminated soils, effects are generally discrete within a short period of time and may be more effective in the long run. (author)

  7. Phyto-mediated nanostructured carriers based on dual vegetable actives involved in the prevention of cellular damage

    Energy Technology Data Exchange (ETDEWEB)

    Istrati, D.; Lacatusu, I.; Bordei, N.; Badea, G.; Oprea, O. [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No. 1, 011061 Bucharest (Romania); Stefan, L.M. [National Institute of Research and Development for Biological Sciences, Splaiul Independentei Street No. 296, 060031 Bucharest (Romania); Stan, R. [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No. 1, 011061 Bucharest (Romania); Badea, N., E-mail: nicoleta.badea@gmail.com [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No. 1, 011061 Bucharest (Romania); Meghea, A. [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No. 1, 011061 Bucharest (Romania)

    2016-07-01

    The growing scientific interest in exploitation of vegetable bioactives has raised a number of questions regarding their imminent presence in pharmaceutical formulations. This study intends to demonstrate that a dual combination between vegetable oil (e.g. thistle oil, safflower oil, sea buckthorn oil) and a carrot extract represents an optimal approach to formulate safe carrier systems that manifest cell regeneration effect and promising antioxidant and anti-inflammatory activity. Inclusion of both natural actives into lipid carriers imparted a strong negative charge on the nanocarrier surface (up to − 45 mV) and displayed average sizes of 70 nm to 140 nm. The entrapment efficiency of carrot extract into nanostructured carriers ranged between 78.3 and 88.3%. The in vitro release study has demonstrated that the entrapment of the extract represents a viable way for an equilibrated release of carotenoids. Besides the excellent antioxidant properties (e.g. scavenging up to 98% of the free oxygen radicals), the results of cellular integrity (e.g. cell viability of 133%) recommend these nanocarriers based on dual carrot extract–bioactive oil as a promising trend for the treatment of certain disorders in which oxidative stress plays a prominent role. In addition, the lipid nanocarriers based on safflower oil and sea buckthorn oil demonstrated an anti-inflammatory effect on LPS induced THP-1 macrophages, by inhibiting the secretion of two pro-inflammatory cytokines, IL-6 and TNF-α. - Highlights: • Safety phyto-mediated nanostructured carriers (NLC) based on two kinds of bioactives • Carrot extract incorporation into nanostructured carriers ranged from 78 to 88.3%. • High antioxidant activity of NLC by scavenging up to 98% free oxygen radicals • Extract entrapment represents a viable way for an equilibrated release of carotenoids. • Remarkable regenerative effect of L929 cell, with a proliferation of 133.4%.

  8. 40 CFR 792.135 - Physical and chemical characterization studies.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Physical and chemical characterization... A Study § 792.135 Physical and chemical characterization studies. (a) All provisions of the GLPs shall apply to physical and chemical characterization studies designed to determine...

  9. PHYSICO-CHEMICAL PROFILE OF CISSUS QUADRANGULARIS L. VAR-I IN DIFFERENT SOILS

    OpenAIRE

    Kumar, T. Sathish; Jegadeesan, M.

    2006-01-01

    The aerial parts of Cissus quadrangularis L. var-I collected from different soils were chemically analyzed for setting the standard to be of use in Indian Traditional Systems of medicine. Extractive value, ash value, loss on draying, powder analysis, qualitative and quantitative phyto-chemical estimation were estimated.

  10. Validity of a web-based dietary questionnaire designed especially to measure the intake of phyto-oestrogens.

    Science.gov (United States)

    Nybacka, Sanna; Bertéus Forslund, Heléne; Hedelin, Maria

    2016-01-01

    A diet questionnaire (DQ) designed to assess habitual diet and phyto-oestrogen intake was developed. This study aimed to examine the validity of the DQ in men, with and without having prostate cancer. The DQ was validated against alkylresorcinol metabolites measured in urine as objective biomarkers of whole grain wheat and rye (WG) intake, and a 4-d estimated food record (FR) was used for relative comparison. Participants (n 61) completed both methods and provided spot urine samples. We found a statistically significant correlation between the DQ and FR for reported whole grain intake and isoflavonoids, as well as for intake of macronutrients, except protein. The correlation coefficient between the two methods was on average r 0·30, lowest for lignans (r -0·11) and highest for alcohol (r 0·65). Reported energy intake was lower in the DQ compared with FR (8523 v. 9249 kJ (2037 v. 2211 kcal), respectively; P = 0·014). Bland-Altman plots showed an acceptable agreement; most cases were within the limits (95 % CI) of agreement on reported energy intake, as well as intake of macronutrients, except protein (which was underestimated in the DQ compared with the FR). The correlation of alkylresorcinol with WG intake was statistically significant in the DQ (r 0·31, P = 0·015), but not in the FR (r 0·18, P = 0·12) and the weighted κ was 0·29 and 0·11, respectively. In conclusion, the results showed that the DQ have a reasonable validity for measuring WG intake and most nutrients, and, after some adjustments regarding protein intake assessment have been made, the DQ will be a promising tool.

  11. Quantum chemical studies of estrogenic compounds

    Science.gov (United States)

    Quantum chemical methods are potent tools to provide information on the chemical structure and electronic properties of organic molecules. Modern computational chemistry methods have provided a great deal of insight into the binding of estrogenic compounds to estrogenic receptors (ER), an important ...

  12. Fast, linked, and open – the future of taxonomic publishing for plants: launching the journal PhytoKeys

    Directory of Open Access Journals (Sweden)

    Lyubomir Penev

    2010-11-01

    Full Text Available The paper describes the focus, scope and the rationale of PhytoKeys, a newly established, peer-reviewed, open-access journal in plant systematics. PhytoKeys is launched to respond to four main challenges of our time: (1 Appearance of electronic publications as amendments or even alternatives to paper publications; (2 Open Access (OA as a new publishing model; (3 Linkage of electronic registers, indices and aggregators that summarize information on biological species through taxonomic names or their persistent identifiers (Globally Unique Identifiers or GUIDs; currently Life Science Identifiers or LSIDs; (4 Web 2.0 technologies that permit the semantic markup of, and semantic enhancements to, published biological texts. The journal will pursue cutting-edge technologies in publication and dissemination of biodiversity information while strictly following the requirements of the current International Code of Botanical Nomenclature (ICBN.

  13. System chemical biology studies of endocrine disruptors

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Oprea, Tudor I.

    Endocrine disrupting chemicals (EDCs) alter hormonal balance and other physiological systems through inappropriate developmental or adult exposure, perturbing the reproductive function of further generations. While disruption of key receptors (e.g., estrogen, androgen, and thyroid) at the ligand...

  14. Maize growth and soil heavy metal changes after application of phyto-treated sewage sludge%污泥植物处理后对玉米生长及土壤重金属含量的影响

    Institute of Scientific and Technical Information of China (English)

    许田芬; 谢方文; 丘锦荣; 卫泽斌; 郭晓方; 吴启堂

    2012-01-01

    In order to study the effect of the application of phyto-treated sewage sludge on heavy metals in soil and maize (Zea mays) growth, experiments in plots with successive maize crops after applying the phyto-treated sludge were conducted with the monitoring of heavy metals in soil and crop. Results showed that the application of sludge to soil was still beneficial to maize during 2 years and the maize biomass with sludge was better than that of control. The treatment with mono-crop treated sludge resulted in the highest yield. Concerning the concentrations of Zn, Cd, Cu and Pb in maize, all harvests of corn and the stem and leaves of maize could be used as animal feeds during 2 years. But only the corn grains of the third harvest and there-after could be conformed to the food standards. The concentrations of heavy metals in soil declined with time, the annual disappearance rates were 32%-35% for Zn, 28%-33% for Cd, 18%-30% for Cu and 15%-23% for Pb, and the disappearance rates were higher for the sludge treated soils than that of control and the chemical fertilizer treated soils. The total concentrations of Zn and Pb in the up-soil layer treated with sludge did not show significant difference with the control after 2 years.%为了探明植物处理后污泥作为肥料施用后对后续作物和土壤的影响,将植物处理后的污泥混于土壤,种植后续作物玉米(Zea mays),测定作物产量以及土壤和作物的重金属含量.结果表明,污泥施用2a后仍有肥效,其玉米生物量显著大于无污泥的对照处理,且单种植物处理后的污泥肥效要优于无植物或套种处理的污泥.施用污泥后的2a内,4季玉米的茎叶和籽粒Zn、Cd、Cu和Pb含量均符合饲料标准;但第3季以后玉米籽粒才可作为食用.施用污泥后土壤重金属含量随时间而下降,Zn的年消失率为32%~35%,Cd为28%~33%,Cu为18%~30%,Pb为15%~23%;施用污泥的土壤重金属年下降率高于对照和化

  15. A photometric study of chemically peculiar stars with the STEREO satellites. I. Magnetic chemically peculiar stars

    CERN Document Server

    Wraight, K T; Netopil, M; Paunzen, E; Rode-Paunzen, M; Bewsher, D; Norton, A J; White, G J

    2011-01-01

    About 10% of upper main sequence stars are characterised by the presence of chemical peculiarities, often found together with a structured magnetic field. The atmospheres of most of those chemically peculiar stars present surface spots, leading to photometric variability caused by rotational modulation. The study of the light curves of those stars therefore, permits a precise measurement of their rotational period, which is important to study stellar evolution and to plan further detailed observations. We analysed the light curves of 1028 chemically peculiar stars obtained with the STEREO spacecraft. We present here the results obtained for the 337 magnetic chemically peculiar stars in our sample. Thanks to the cadence and stability of the photometry, STEREO data are perfectly suitable to study variability signals with a periodicity typical of magnetic chemically peculiar stars. Using a matched filter algorithm and then two different period searching algorithms, we compiled a list of 82 magnetic chemically pe...

  16. Effect of phyto-synthesized silver nanoparticles on developmental stages of malaria vector, Anopheles stephensi and dengue vector, Aedes aegypti

    OpenAIRE

    Madanagopal Nalini; Mahalingam Lena; Palanisamy Sumathi; Chandran Sundaravadivelan

    2017-01-01

    Rapidly synthesized phyto-mediated silver nanoparticles (Ag NPs) using Artemisia nilagirica aqueous leaf filtrate has been confirmed through UV–visible spectrophotometer. The synthesized Ag NPs were further characterized using Fourier transform infra-red (FTIR), X-ray diffraction analysis (XRD) to determine the present of functional groups and average particle size (6.723 nm with cubic nature), respectively. Spherical shape (≤30 nm) of Ag NPs was confirmed by scanning electron microscopy (SEM...

  17. Electron transport studies of chemical nanostructures

    Science.gov (United States)

    Liang, Wenjie

    2005-11-01

    In this thesis, I present electron transport studies of chemical nanostructures: single-walled carbon nanotubes (SWNTs) and single molecules. In chemical nanostructures, coulomb blockade and electronic energy level quantization dominate electron transport properties. High order correlated transport processes also play an important role in those nanostructures that are strongly coupled to electrodes. The electron transport spectra of SWNTs are investigated as a function of coupling strength of nanotube-electrode contacts. Measurements of nanotube devices at different coupling regimes showed distinct transport phenomena, including coulomb charging and electron level quantization, the experimental determination of all Hartree-Fock parameters that govern the electronic structure of metallic nanotubes and the demonstration of Fabry-Perot resonators based on the interference of electron waves. The presence of defects is important in low dimensional materials, for instance 1D SWNTs. A scanned gate microscopy (SGM) is used to locate defect center on SWNTs and study electron resonant scattering by defects. The reflection coefficient at the peak of a scattering resonance is determined to be ˜0.5 at room temperature. An intra-tube quantum-dot device formed by two defects was demonstrated by low-temperature transport measurements. Transport investigation of semiconducting SWNTs transistors shows large hysteresis effect upon gate voltage sweeping, which came from local charge redistribution around semiconducting SWNTs. A nonvolatile charge storage memory operating at room temperature was realized. Single molecule transistors incorporating different molecule (divanadium molecule [(N,N',N ″-trimethyl-1,4,7-triazacyclononane)2V2(CN) 4(mu-C4N4)], ferrocene and nickelocene) molecule, were achieved utilizing electromigration-induced break junction technique. Transport spectrum of divanadium molecules showed strange Kondo resonance where individual divanadium molecule serves as

  18. 40 CFR 160.135 - Physical and chemical characterization studies.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Physical and chemical characterization... and chemical characterization studies. (a) All provisions of the GLP standards shall apply to physical... physical and chemical characteristics of a test, control, or reference substance: § 160.31 (c), (d), and...

  19. Experimental study of chemical concentration variation of ASP flooding

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A physical modeling system of long slim tube was established. Several pressure measuring and sampling points were laid out at different positions along the tube. Through real-time measurements of pressures and chemical concentrations at different points, the mass transfer and chemical concentration of ASP flooding in porous media are studied. The concentration of chemicals declines gradually during the fluid flow from the inlet to the outlet of the model. The concentration increases in the front edge of the slug faster than the concentration decreases in the rear edge of the slug. The concentration variation of the chemicals is an asymmetrical and offset process. The order of motion velocities of the chemicals from fast to slow is polymer, alkali and surfactant. The motion lag and comprehensive diffusion are strong in the vicinity of the inlet, the motion velocities of the chemicals are high, the difference of flow velocities among the three chemicals is significant and the chromatographic separation of the chemicals is obvious. In the area near the outlet, the comprehensive diffusion and motion lag become weak, the concentrations of the chemicals decrease, the motion velocities of the chemicals are slow, the difference among the motion velocities of the chemicals becomes small, the chromatographic separation is not obvious, the adsorption and retention of chemicals gradually increase as the chemical slug moves further along the tube, the adsorption and retention of polymer is the most serious.

  20. Study of Endocrine Disrupting Chemicals in Environment

    Directory of Open Access Journals (Sweden)

    Zoltán Juvancz

    2008-06-01

    Full Text Available Endocrine disrupting chemicals (EDC cause more and more seriousenvironmental pollutions. The EDCs show only ng-μg/l concentration level in theenvironment, therefore their determinations require multistep sample preparationprocesses and highly sophisticated instrumentation. This paper discuss the EDC effects,and show examples for determination of such compounds.

  1. SOME QUANTUM CHEMICAL STUDY ON THE STRUCTURAL ...

    African Journals Online (AJOL)

    Preferred Customer

    Formula. Formula weight. (gmol-1) ... Quantum chemical calculations (Density Functional Theory, B3LYP/6-31G (d)) were used to purposed the ... correlation functional [B3LYP/6-31G(d)]) calculations were done by using Gaussian 03 program ...

  2. Chemical approaches to studying stem cell biology

    Institute of Scientific and Technical Information of China (English)

    Wenlin Li; Kai Jiang; Wanguo Wei; Yan Shi; Sheng Ding

    2013-01-01

    Stem cells,including both pluripotent stem cells and multipotent somatic stem cells,hold great potential for interrogating the mechanisms of tissue development,homeostasis and pathology,and for treating numerous devastating diseases.Establishment of in vitro platforms to faithfully maintain and precisely manipulate stem cell fates is essential to understand the basic mechanisms of stem cell biology,and to translate stem cells into regenerative medicine.Chemical approaches have recently provided a number of small molecules that can be used to control cell selfrenewal,lineage differentiation,reprogramming and regeneration.These chemical modulators have been proven to be versatile tools for probing stem cell biology and manipulating cell fates toward desired outcomes.Ultimately,this strategy is promising to be a new frontier for drug development aimed at endogenous stem cell modulation.

  3. Physical-chemical studies of transuranium elements

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J.R.

    1991-01-01

    Major advances in our continuing program to determine, interpret, and correlate the basic chemical and physical properties of the transuranium elements are summarized. Research topics include: Molar enthalpies of formation of BaCmO{sub 3} and BaCfO{sub 3}; luminescence of europium oxychloride at various pressures; and anti-stokes luminescence of selected actinide (III) compounds. 42 refs., 4 figs., 2 tabs.

  4. Studies on Chemical Constituents From Artabotrys Hainanensis

    Institute of Scientific and Technical Information of China (English)

    CHEN Guangying; SONG Xiao-Ping; HAN Chang-ri

    2004-01-01

    Artabotrys Hainanensis R.E. Fries are plants of the Annonaccac family artabotrys genus,which includes an estimated 100 types of plants distributed mainly in the tropical zone and the subtropics areas. Four types of the plants are discovered in our country, two of which, A.Hongkongensis Hance and A. hexapetalus (Linn. F.) Bhandari, in Guangdong Province, and the other two, A. Pilosus and A. Hainanensis R.E. Fries, in Hainan Province. The latter are widely distributed in Hainan Island with very rich reserves. They have long been used among the ordinary people as medicinal plants with antipyretic, antidotal, antiphlogistic and analgesic effects and are often used for malaria. Scholars from home and abroad have paid much attention to the plants of the Annonaccac family for their containing anti-tumor activities, and after early or late research of the chemical constituents of the root, stem (derm), leaf and fruit of many types of plants of Artabotrys genus, more than 40 compounds including alkaloid, flavone and terpenoid have been isolated and obtained. Artabotrys Hainanensis R.E. Fries are Hainan endemic plants and there has been no report on the research of their chemical constituents and biological activities so far. In order to find new constituents of pharmacologic activity, we have researched the chemical constituents of the leaf and stem.The crude drugs were collected from Hainan Jianfeng Mountain and were identified as Artabotrys Hainanensis R.E. Fries of the Annonaccac family artabotrys genus. Its sample specimen is now kept in Chemistry Department of Hainan Normal University.After isolation and identification of constituent, six compounds were isolated from the leaf of Artabotrys Hainanensis R.E. Fries and elucidated as β -sitosterol (Ⅰ), catechin (Ⅱ), mangiferin (Ⅲ),(Ⅳ), (Ⅴ), (Ⅵ). All the compounds were obtained from this plant for the first time. Compounds Ⅱ, Ⅲ,Ⅳ, Ⅴ and Ⅵ were obtained from the genus of Artabotrys for the first time.

  5. System chemical biology studies of endocrine disruptors

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Oprea, Tudor I.

    Endocrine disrupting chemicals (EDCs) alter hormonal balance and other physiological systems through inappropriate developmental or adult exposure, perturbing the reproductive function of further generations. While disruption of key receptors (e.g., estrogen, androgen, and thyroid) at the ligand...... binding domain (LBD) has been associated with EDCs, a significant number of EDCs do not appear to influence the LBDs of these receptors. Therefore, we evaluated the potential biological effects of EDCs in humans with the aim to rationalize the etiology of certain disorders associated with the reproductive...

  6. Polyketide stereocontrol: a study in chemical biology

    Science.gov (United States)

    2017-01-01

    The biosynthesis of reduced polyketides in bacteria by modular polyketide synthases (PKSs) proceeds with exquisite stereocontrol. As the stereochemistry is intimately linked to the strong bioactivity of these molecules, the origins of stereochemical control are of significant interest in attempts to create derivatives of these compounds by genetic engineering. In this review, we discuss the current state of knowledge regarding this key aspect of the biosynthetic pathways. Given that much of this information has been obtained using chemical biology tools, work in this area serves as a showcase for the power of this approach to provide answers to fundamental biological questions.

  7. THE STUDY OF CHEMICAL COMPOSITION FOR ANIMAL FATS DURING STORAGE

    OpenAIRE

    Flavia Pop; Cornel Laslo

    2009-01-01

    In this article the chemical composition for 3 types of animal fats (pork fat, beef tallow and buffalo tallow), following the variation of saturated and unsaturated fatty acids proportion during freezing storage was studied. Determination of chemical composition of animal fats is important in establishing organoleptic and physico-chemical parameters, the variation of them in time, nature and proportion of fatty acids conferring specific characteristics to them. For pork fat was determined the...

  8. [Studies on chemical constituents of Saussurea laniceps].

    Science.gov (United States)

    Dawa, Zhuo-Ma; Zhou, Yan; Bai, Yang; Gesang, Suo-Lang; Xie, Ping; Ding, Li-Sheng

    2008-05-01

    To investigate the chemical constituents of Saussurea laniceps. The ethanol extract of S. laniceps was separated by means of silica gel chromatography. The compounds isolated from the plant were identified by their spectral evidence. Fifteen compounds were isolated and identified as beta-stiosterol (1), umbelliferone (2), 4-hydroxyacetophenone (3), scopoletin (4), isoscopoletin (5), xuelianlactone (6), methyl 3-(2', 4'-dihydroxyphenyl) propanoate (7), apigenin (8), neoechinulin A (9), daucosterol (10), scopolin (11), xuelianlactone 8-O-beta-D-glcuoside (12), apigenin 7-glcuoside (13), apigenin 7-lutinoside (14) and syringin (15). Compounds 5-15 were isolated from S. laniceps, and among them, 7 and 9 were isolated from genus Saussurea for the first time.

  9. [Studies on chemical compounds of Chlorella sorokiniana].

    Science.gov (United States)

    Zhang, Ling; Liu, Ping-huai; Wu, Jiao-na; Yang, Guo-fu; Suo, Yang-yang; Luo, Ning; Chen, Chen

    2015-04-01

    Chemical constituents of Chlorella sorokiniana were isolated and purified by repeated column chromatographies, over silicagel and Sephadex LH-20. Their structures were identified on the basis of physicochemical properties and spectroscopic data analysis. Five compounds were obtained from the petroleum ether extract of Chlorella sorokiniana, and their structures were identified as (22E, 24R)-5alpha, 3beta-epidioxiergosta-6, 22-dien-3beta-ol(1),(24S)-ergosta-7-en-3beta-ol(2), loliolide(3), stigmasta-7,22-dien-3beta,5alpha,6alpha-triol(4), and 3beta-hydroxy-5alpha,6alpha-epoxy-7-megastigmen-9-one(5). The main liposoluble fractions from Chlorella sorokiniana maiuly contain fatty acids, alkyl acids and olefine acids. Components 1-5 were isolated from the genus Chlorella for the first time.

  10. Guide méthodologique. Version actualisée de ZooPhytoImage avec refonte de l’interface graphique. Action 9. FlowCam ZooPhytoImage. Livrable n°1. Rapport final

    OpenAIRE

    Grosjean, Philippe

    2014-01-01

    Zoo/PhytoImage 4 is an « open source » software based on R and ImageJ. It processes numerical images of plankton particles digitized using a FlowCAM, a flat-bed scanner, microor macrophotos, etc. The general concept consists in the individual outlining of particles on the pictures, followed by their measurements (so-called « attributes ») such the size, the shape, transparency, textures, etc. These attributes are then used by a classification tool to automatically predict the taxonomic gro...

  11. New legal regime for phyto sanitary products; Un nuevo regimen juridico para los envases de productos fitosanitarios

    Energy Technology Data Exchange (ETDEWEB)

    Poveda Gomez, P.

    2001-07-01

    In the Cabinet celebrated on he 14 degree centigree of December of 2001, the Government approved an important Royal Decree by means of which a new legal regime for phyto sanitary products of agricultural use was settled down. Its high-priority objective is to assure that the packaging waste generated after their use would be gathered without harming the environment and the public health, also guaranteeing that its final management will be carried out by means of the more correct methods environmentally. (Author)

  12. Chemical Physics: A Subject for Study at University?

    Science.gov (United States)

    Dunmur, D. A.

    1982-01-01

    Traces development of chemical physics as a distinct discipline and reviews its position as a subject for study in United Kingdom universities. Reports results of a survey of chemical physics courses and graduates (1975-1980), including employment data on these graduates. (Author/JN)

  13. Feasibility and effectiveness of chemical bile duct embolization for chemical hepatectomy:a preliminary study

    Institute of Scientific and Technical Information of China (English)

    Fu-Yu Li; Ning Li; Li-Sheng Jiang; Jing-Qiu Cheng; Nan-Sheng Cheng; Xing-Wu Wu; Sheng He

    2006-01-01

    BACKGROUND: The high operative risk of hepatectomy for specially located intrahepatic stones is still a problem to be solved. This study was undertaken to investigate the feasibility and effectiveness of chemical bile duct embolization for chemical hepatectomy. METHODS: Oxybenzene or absolute ethanol plus N-butyl-cyanoacrylate was employed for embolization. The feasibility, effectiveness and mechanism of chemical hepatectomy were preliminarily analyzed histologically or by Fas, TIMP-1, TGF-β1, and collagenⅠ. RESULTS:Oxybenzene plus cyanonacrylate can preferably destroy and embolize the intrahepatic biliary duct, leading to the disappearance of hepatocytes in the periphery of embolized lobe and the achievement of effective chemical hepatectomy. The expressions of Fas, TIMP-1 and TGF-β1 in oxybenzene embolism group (88.90±38.10, 619.43± 183.42, 185.22±70.39) and ethanol embolism group (72.39± 29.51, 407.55±134.74, 163.56±51.75) were higher than those of biliary duct-ligated group (26.31±12.07, 195.31±107.67, 74.84±40.73) (P CONCLUSION: The effect of chemical hepatectomy may be achieved by chemical bile duct embolization.

  14. Chemical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  15. Quantum-chemical studies on porphyrins, fullerenes and carbon nanostructures

    CERN Document Server

    Loboda, Oleksandr

    2014-01-01

    ​This book presents theoretical studies of electronic structure, optical and spectroscopic properties of a number of compounds. It presents new, faster calculation methods for applications in quantum-chemical theory of electronic structures.

  16. Study on New Approaches for extended chemical management and REACH

    DEFF Research Database (Denmark)

    Lee, Jihyun

    2014-01-01

    For several decades, the use of chemicals has been rapidly increasing and widely spread in our daily life. To cope with this trend, the paradigm of chemical management system has changed: from hazard criteria which is based on their intrinsic hazardous properties, to the actual risk of chemicals...... which is based on both the hazard of the substance and the possible exposure level of human to the substance, and from single substance-oriented to multiple chemical (e.g. mixture toxicity)–oriented management system (EC, 2012; Moeller and Biwer, 2014). This study aims to examine the limitations...... of existing chemical regulations in view of protecting vulnerable populations from “excessive total risk” and to explore the possibilities for improvement. Firstly, the completeness of the REACH exposure scenario was reviewed with the finding that the current scenario does not take into account territorial...

  17. A greenhouse study on arsenic remediation potential of Vetiver grass (Vetiveria Zizanioides) as a function of soil physico-chemical properties

    Science.gov (United States)

    Quispe, M. A.; Datta, R.; Sarkar, D.; Sharma, S.

    2006-05-01

    arsenic (0, 45, 225 and 450 mgAs/kg soil). Vetiver plants were grown for a period of 4 months, harvested at two time periods (2 months and 4 months). Plant biomass, shoot and root lengths, arsenic accumulation in roots and shoots were measured. Total and exchangeable arsenic was correlated with phyto-extracted arsenic. In addition, 3 important antioxidant enzyme activities were measured in root and shoot tissues, viz., Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidases (GPx) to evaluate the effect of arsenic stress on vetiver plants. This study will provide information on the capability of vetiver grass to remediate sites contaminated with arsenic as a function of soil physico- chemical properties.

  18. Chemical constituents of Gustavia Augusta L. (Lecythidaceae); Constituintes quimicos de Gustavia Augusta L. (Lecythidaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Afonso Duarte Leao de; Rocha, Arnaldo F. Imbiriba da; Pinheiro, Maria Lucia Belem; Andrade, Carlos Humberto de S.; Galotta, Ana Lucia de A. Queiroz; Santos, Maria do Perpetuo Socorro S. dos [Amazonas Univ., Manaus, AM (Brazil). Dept. de Quimica]. E-mail: afonsodlsouza@yahoo.com.br

    2001-08-01

    The Gustavia augusta is used in the folk medicine against leishmaniasis and showed anti-inflammatory action. The phyto chemical studies of the plant stem bark have led to the isolation of (22E)-stigmasta-7,22-dien-3{beta}-ol, 24{alpha}(S)-ethyl-5{alpha}-colesta-7, trans-22-dien-3-one, D-friedoolean-14-en-3{beta}-ol, D-friedoolean-14-en-3-one and D-friedoolean-14-en-3{alpha}-ol along with stigmasterol, {alpha}-amyrin, {beta}-amyrin, lupeol, 3{alpha}-hydroxy-lupeol and betulinic acid. The structures of these compounds were identified by IR, GC/M S, {sup 1} H and {sup 1} {sup 3} C NMR spectral analysis and comparison with literature data. (author)

  19. CHEMICALS

    CERN Document Server

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  20. Study on scattering properties of tissues with hyperosmotic chemical agents

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Optical properties of biological tissue are variable due to the changes of micro-structures and scattering constituents after hyperosmotic chemical agents permeates into tissue. The changes of optical properties of biological tissue are due to the refractive indices matching between the scatterers with high refractive index and the ground substances, which reduce scattering of tissue. The main reasons are that permeated semipermeable chemical agents with higher refractive index than the ground substances of tissuemakes the refractive index of ground substances of tissue higher by the enhancement of the permeated concentration. We studied on the collimated transmittance changes of light penetrating biological tissue after the hyperosmotic chemical agents administrates with different concentration.

  1. Study of Intelligent Secure Chemical Inventory Management System

    Science.gov (United States)

    Shukran, Mohd Afizi Mohd; Naim Abdullah, Muhammad; Nazri Ismail, Mohd; Maskat, Kamaruzaman; Isa, Mohd Rizal Mohd; Shahfee Ishak, Muhammad; Adib Khairuddin, Muhamad

    2017-08-01

    Chemical inventory management system has been experiencing a new revolution from traditional inventory system which is manual to an automated inventory management system. In this paper, some review of the classic and modern approaches to chemical inventory management system has been discussed. This paper also describe about both type of inventory management. After a comparative analysis of the traditional method and automated method, it can be said that both methods have some distinctive characteristics. Moreover, the automated inventory management method has higher accuracy of calculation because the calculations are handled by software, eliminating possible errors and saving time. The automated inventory system also allows users and administrators to track the availability, location and consumption of chemicals. The study of this paper can provide forceful review analysis support for the chemical inventory management related research.

  2. Cutaneous chemical burns in children - a comparative study.

    Science.gov (United States)

    Hardwicke, Joseph; Bechar, Janak; Bella, Husam; Moiemen, Naiem

    2013-12-01

    Exposure to chemicals is an unusual causation of cutaneous burns in children. The aim of this study is to look at childhood chemical burns and compare this to adult chemical burns from the same population. A total of 2054 patients were referred to the pediatric burns unit during the study period. This included 24 cutaneous chemical burns, equating to an incidence of 1.1%. Over half of the injuries occurred in the domestic setting. The mean total body surface area (TBSA) affected was 1.9%. When compared to a cohort of adult patients from the same population with cutaneous chemical burns, the TBSA affected was identical (1.9%) but distribution favored the buttock and perineum in children, rather than the distal lower limb in adults. Children presented earlier, had lower rates of surgical intervention and had a shorter length of stay in hospital (p Chemical burns in children are rare, but are becoming more common in our region. It is important to be aware of the characteristic distribution, etiology and need to identify children at risk of child protection issues.

  3. A chemical EOR benchmark study of different reservoir simulators

    Science.gov (United States)

    Goudarzi, Ali; Delshad, Mojdeh; Sepehrnoori, Kamy

    2016-09-01

    chemical design for field-scale studies using commercial simulators. The benchmark tests illustrate the potential of commercial simulators for chemical flooding projects and provide a comprehensive table of strengths and limitations of each simulator for a given chemical EOR process. Mechanistic simulations of chemical EOR processes will provide predictive capability and can aid in optimization of the field injection projects. The objective of this paper is not to compare the computational efficiency and solution algorithms; it only focuses on the process modeling comparison.

  4. Radiation chemical study on benzaldehyde-chlorobenzene system. A novel radiation chemical route for benzophenone formation

    Energy Technology Data Exchange (ETDEWEB)

    Sife-Eldeen, Kh.A. [National Center for Radiation Research and Technology, Nasr City, Cairo (Egypt)

    2009-07-01

    The effects of reactants molar ratio, absorbed dose, and absorbed dose rate were studied on benzaldehyde-chlorobenzene system. Irradiation products were identified by GC/MS analysis and their quantities were determined by GC analysis. Study of the reactants molar ratio effect indicates important aspects of the radiation chemistry of this system. It was observed that the yields of the major products increase as absorbed dose increase. On the other hand, these yields decrease as dose rate increases. Which reflects that the major products are formed via inter-spur reactions i.e. in the bulk of the medium. The mechanisms of the formation of the products were suggested. Benzophenone is one of the main products of this system. Therefore, this study gives a spot of light on a novel radiation chemical route for benzophenone formation. The radiation chemical yield (G-value) of benzophenone was determined at different dose rates. (orig.)

  5. Enrichment and Phyto-remediation Characteristics of Heavy Metals in Cinder Contaminated Soil for Eupatorium adenophorum%紫茎泽兰对煤渣污染土壤重金属的富集·修复特性

    Institute of Scientific and Technical Information of China (English)

    侯洪波; 刘忆明; 杨保海; 许志敏

    2013-01-01

    [目的]为了检测紫茎泽兰对煤渣污染土壤中重金属的富集、修复特性.[方法]采用火焰原子吸收法测定样品中重金属含量.[结果]土壤中金属含量大小顺序为Fe >Mg>Cu >Ni >Cr>Mn >Ni,Cr污染达到Ⅱ级标准;紫茎泽兰对重金属有一定的富集作用,特别是对Mg、Cr、Ni、Pb的富集系数均大于1,对Cr的转运系数为1.333.[结论]紫茎泽兰可以作为煤渣污染土壤Cr的修复植物.%[Objective]The research aimed to study the enrichment and phyto-remediation characteristics of heavy metals in cinder contaminated soil for Eupatorium adenophorum. [Method] 6 kinds of heavy mentals were measured by atomic absorption. [Result] The order of the heavy metal content was Fe > Mg > Cu > Ni > Cr > Mn > Ni. The concent of Cr reached the country' s II standard. Eupatorium adenophorum could enrich heavy mentals. EFsofMg, Cr, Ni and Pb were above 1.0. TF of Cr was 1. 333. [Conclusion] Eupatorium adenophorum could be used as a plant of phyto-remediation in cinder contaminated soil.

  6. Use of agro-industrial organic sludge amendment to remediate degraded soil: chemical and eco(geno)toxicological differences between fresh and stabilized sludge and establishment of application rates.

    Science.gov (United States)

    Chiochetta, Claudete G; Cotelle, Sylvie; Masfaraud, Jean-François; Toumi, Hela; Quaranta, Gaetana; Adani, Fabrizio; Radetski, Claudemir M

    2016-02-01

    Soil degraded by coal mining activities can be remediated by amendment with agro-industrial organic sludge. However, the environmental impacts associated with this management practice must be properly addressed. In this context, the objective of this study was to evaluate the eco(geno)toxicity of a fresh and a stabilized sludge before use in a laboratory soil remediation test. Chemical analysis of the complex mixtures (degraded soil, fresh sludge, and stabilized sludge) was carried out, as well as a battery of eco(geno)toxicity tests on microbiological enzymes (fluorescein hydrolysis), earthworms, and higher plants (including Vicia faba genotoxicity test), according to published methodologies. The results of these tests showed that fresh sludge was more toxic than sludge stabilized over 6 months toward earthworms and higher plants (lettuce, corn, and wild cabbage), while phyto(geno)toxicity tests with V. faba indicated the same genotoxicity levels for the two types of sludge. In the soil remediation simulation using different mixtures of degraded soil and stabilized sludge, the proportions of 50:50% (dry weight basis) provided the lowest phyto(geno)toxicity effects and this mixture can be used for the revegetation of the contaminated site.

  7. Chemical studies on hot springs in Ehime Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Mitarai, K. (Ehime Prefecture Research Institute of Public Health, Japan)

    1971-12-01

    One hundred and twenty-seven hot springs in Ehime Prefecture, which are primarily located in the Dogo area, were studied. The waters were subjected to chemical analysis and the springs were surveyed in-situ for hydrogen ion concentration, total soluble component, temperature, and F ion concentration. About 80% of the springs were slightly alkaline and the major soluble component was NaHCO/sub 3/ or NaCl. Fifty percent of the springs contained more than 2 ppm of F ion. The chemical components were closely related to area geology.

  8. [Studies on chemical constituents of leaves of Cassia angustifolia].

    Science.gov (United States)

    He, Wen-fei; Lu, Jin-cai; Yu, Xiao-min; Ding, You-mei

    2007-09-01

    To study the chemical constituents of the leaves of Cassia angustifolia Vahl. Solvents extraction and various chromatographic methods were applied to separate and purify its constituents. The structures were elucidated on the basis of chemical evidence and spectral analysis. Six compounds were obtained and identified as cholesterol (I), kampferol-3-rutinoside (II), calyxanthone (III), 3-methoxy-4-hydroxy-benzoic acid (IV), p-dimethylaminobenzaldehyde (V), 3,4-dihydroxybenzoic acid (VI). Six compounds ( I -VI) are obtained from this plant for the first time.

  9. Chemical Reactivity Theory Study of Advanced Glycation Endproduct Inhibitors.

    Science.gov (United States)

    Frau, Juan; Glossman-Mitnik, Daniel

    2017-02-02

    Several compounds with the known ability to perform as inhibitors of advanced glycation endproducts (AGE) have been studied with Density Functional Theory (DFT) through the use of anumberofdensityfunctionalswhoseaccuracyhasbeentestedacrossabroadspectrumofdatabases in Chemistry and Physics. The chemical reactivity descriptors for these systems have been calculated through Conceptual DFT in an attempt to relate their intrinsic chemical reactivity with the ability to inhibit the action of glycating carbonyl compounds on amino acids and proteins. This knowledge could be useful in the design and development of new drugs which can be potential medicines for diabetes and Alzheimer's disease.

  10. [Scanning electron microscope study of chemically disinfected endodontic files].

    Science.gov (United States)

    Navarro, G; Mateos, M; Navarro, J L; Canalda, C

    1991-01-01

    Forty stainless steel endodontic files were observed at scanning electron microscopy after being subjected to ten disinfection cycles of 10 minutes each one, immersed in different chemical disinfectants. Corrosion was not observed on the surface of the files in circumstances that this study was made.

  11. Comparative Studies of Physico-chemical Properties of Some ...

    African Journals Online (AJOL)

    Akorede

    ABSTRACT: The aim of this study was to evaluate some physico-chemical properties of four major general purpose ... In the year 2006 alone, four cases of such collapses .... (ASTM, 1986). The percentage SiO2 was calculated using. Eqn (11).

  12. Preliminary study of chemical compositional data from Amazon ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Toyota, Rosimeiri G.; Munita, Casimiro S.; Luz, Fabio A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: rosimeiritoy@yahoo.com.br; Neves, Eduardo G. [Museu de Arqueologia e Etnolgia, Sao Paulo, SP (Brazil)]. E-mail: egneves@usp.br; Oliveira, Paulo M.S. [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Inst. de Matematica e Estatistica]. E-mail: poliver@usp.br

    2005-07-01

    Eighty seven ceramic samples from Acutuba, Lago Grande and Osvaldo archaeological sites located in the confluence of the rivers Negro and Solimoes were submitted to chemical analysis using instrumental neutron activation analysis to determine As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Rb, Na, Nd, Sb, Sc, Sm, Ta, Tb, Th, Yb, Zn, and U. The database were studied using the Mahalanobis distance, and discriminant analysis. The results showed that the ceramics of each site differ from each other in chemical composition and that they form three different groups. Chemical classification of the ceramics suggests that vessels were made locally, as only ceramics from the same area show homogeneity of data. (author)

  13. Studying chemical reactions in biological systems with MBN Explorer

    DEFF Research Database (Denmark)

    Sushko, Gennady B.; Solov'yov, Ilia A.; Verkhovtsev, Alexey V.

    2016-01-01

    The concept of molecular mechanics force field has been widely accepted nowadays for studying various processes in biomolecular systems. In this paper, we suggest a modification for the standard CHARMM force field that permits simulations of systems with dynamically changing molecular topologies....... for studying processes where rupture of chemical bonds plays an essential role, e.g., in irradiation- or collision-induced damage, and also in transformation and fragmentation processes involving biomolecular systems....

  14. Communicating serum chemical concentrations to study participants: follow up survey

    Directory of Open Access Journals (Sweden)

    Louis Germaine M

    2010-05-01

    Full Text Available Abstract Background A considerable literature now supports the importance of effective communication with study participants, including how best to develop communication plans focusing on the uncertainty of health risks associated with particular environmental exposures. Strategies for communicating individual concentrations of environmental chemicals in human biological samples in the absence of clearly established safe or hazardous levels have been discussed from a conceptual basis and to a lesser extent from an empirical basis. We designed and evaluated an empirically based communication strategy for women of reproductive age who previously participated in a prospective study focusing on persistent environmental chemicals and reproductive outcomes. Methods A cohort of women followed from preconception through pregnancy or up to 12 menstrual cycles without pregnancy was given their individual serum concentrations for lead, dichloro-2,2-bisp-chlorophenyl ethylene, and select polychlorinated biphenyl congeners. Two versions of standardized letters were prepared depending upon women's exposure status, which was characterized as low or high. Letters included an introduction, individual concentrations, population reference values and guidance for minimizing future exposures. Participants were actively monitored for any questions or concerns following receipt of letters. Results Ninety-eight women were sent letters informing them of their individual concentrations to select study chemicals. None of the 89 (91% participating women irrespective of exposure status contacted the research team with questions or concerns about communicated exposures despite an invitation to do so. Conclusions Our findings suggest that study participants can be informed about their individual serum concentrations without generating unnecessary concern.

  15. Quantum-chemical studies of metal oxides for photoelectrochemical applications

    Science.gov (United States)

    Persson, P.; Bergström, R.; Ojamäe, L.; Lunell, S.

    A review of recent research, as well as new results, are presented on transition metal oxide clusters, surfaces, and crystals. Quantum-chemical calculations of clusters of first row transition metal oxides have been made to evaluate the accuracy of ab initio and density functional calculations. Adsorbates on metal oxide surfaces have been studied with both ab initio and semi-empirical methods, and results are presented for the bonding and electronic interactions of large organic adsorbates, e.g. aromatic molecules, on Ti02 and ZnO. Defects and intercalation, notably of H, Li, and Na in Ti02 have been investigated theoretically. Comparisons with experiments are made throughout to validate the calculations. Finally, the role of quantum-chemical calculations in the study of metal oxide based photoelectrochemical devices, such as dyesensitized solar cells and electrochromic displays. is discussed.

  16. PhytoCRISP-Ex: a web-based and stand-alone application to find specific target sequences for CRISPR/CAS editing.

    Science.gov (United States)

    Rastogi, Achal; Murik, Omer; Bowler, Chris; Tirichine, Leila

    2016-07-01

    With the emerging interest in phytoplankton research, the need to establish genetic tools for the functional characterization of genes is indispensable. The CRISPR/Cas9 system is now well recognized as an efficient and accurate reverse genetic tool for genome editing. Several computational tools have been published allowing researchers to find candidate target sequences for the engineering of the CRISPR vectors, while searching possible off-targets for the predicted candidates. These tools provide built-in genome databases of common model organisms that are used for CRISPR target prediction. Although their predictions are highly sensitive, the applicability to non-model genomes, most notably protists, makes their design inadequate. This motivated us to design a new CRISPR target finding tool, PhytoCRISP-Ex. Our software offers CRIPSR target predictions using an extended list of phytoplankton genomes and also delivers a user-friendly standalone application that can be used for any genome. The software attempts to integrate, for the first time, most available phytoplankton genomes information and provide a web-based platform for Cas9 target prediction within them with high sensitivity. By offering a standalone version, PhytoCRISP-Ex maintains an independence to be used with any organism and widens its applicability in high throughput pipelines. PhytoCRISP-Ex out pars all the existing tools by computing the availability of restriction sites over the most probable Cas9 cleavage sites, which can be ideal for mutant screens. PhytoCRISP-Ex is a simple, fast and accurate web interface with 13 pre-indexed and presently updating phytoplankton genomes. The software was also designed as a UNIX-based standalone application that allows the user to search for target sequences in the genomes of a variety of other species.

  17. Study of interfacial phenomena for bio/chemical sensing applications

    Science.gov (United States)

    Min, Hwall

    This work presents the fundamental study of biological and chemical interfacial phenomena and (bio)chemical sensing applications using high frequency resonator arrays. To realize a versatile (bio)chemical sensing system for the fundamental study as well as their practical applications, the following three distinct components were studied and developed: i) detection platforms with high sensitivity, ii) novel innovative sensing materials with high selectivity, iii) analytical model for data interpretation. 8-pixel micromachined quartz crystal resonator (muQCR) arrays with a fundamental resonance frequency of 60 ¡V 90 MHz have been used to provide a reliable detection platform with high sensitivity. Room temperature ionic liquid (RTIL) has been explored and integrated into the sensing system as a smart chemical sensing material. The use of nanoporous gold (np-Au) enables the combination of the resonator and surface-enhanced Raman spectroscopy for both quantitative and qualitative measurement. A statistical model for the characterization of resonator behavior to study the protein adsorption kinetics is developed by random sequential adsorption (RSA) approach with the integration of an effective surface depletion theory. The investigation of the adsorption kinetics of blood proteins is reported as the fundamental study of biological phenomena using the proposed sensing system. The aim of this work is to study different aspects of protein adsorption and kinetics of adsorption process with blood proteins on different surfaces. We specifically focus on surface depletion effect in conjunction with the RSA model to explain the observed adsorption isotherm characteristics. A number of case studies on protein adsorption conducted using the proposed sensing system has been discussed. Effort is specifically made to understand adsorption kinetics, and the effect of surface on the adsorption process as well as the properties of the adsorbed protein layer. The second half of the

  18. Chemical elements in invertebrate orders for environmental quality studies

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Marcelo R.L.; Franca, Elvis J.; Paiva, Jose D.S.; Hazin, Clovis A., E-mail: marcelo_rlm@hotmail.com, E-mail: ejfranca@cnen.gov.br, E-mail: dan-paiva@hotmail.com, E-mail: chazin@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Fonseca, Felipe Y.; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio A., E-mail: felipe-yamada@hotmail.com, E-mail: lis@cena.usp.br, E-mail: mabacchi@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2013-07-01

    Among the biomonitors of environmental quality, there is a lack of studies on using invertebrates to evaluate quantitatively chemical elements in ecosystems. This group of animals is quite numerous, widely distributed and adaptable to the most diverse environmental conditions. These features are very useful for the environmental quality assessment, as well as the several occurring insect-plant interactions performing essential functions in ecosystems. The objective of this work is to study the variability of chemical composition of invertebrate orders for using in environmental quality monitoring studies. Instrumental neutron activation analysis - INAA was applied to determine some nutrients and trace elements in invertebrate samples. Sampling by pitfall traps was carried out in riverine ecosystems from the urban area from the Piracicaba Municipality, State of Sao Paulo, Brazil. Invertebrate and reference material samples were irradiated in the nuclear research reactor IEA-R1, Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN. Fragments of a Ni-Cr alloy were irradiated for monitoring the thermal neutron flux. Hymenoptera order was considered the most representative according to the total number of sampled species (about 60%). Significant amounts of Ba, Br, Fe and Sc were found in invertebrates of the order Opiliones. Potassium, rubidium and zinc were highly accumulated in species from Blattodea order, indicating a consistent pattern of accumulation for this invertebrate order. Taking into account the abundance of Hymenoptera order, the chemical composition of its species was significant different at the 95% confidence level for Br and Na in the sampled locals. (author)

  19. The chemical shock tube as a tool for studying high-temperature chemical kinetics

    Science.gov (United States)

    Brabbs, Theodore A.

    1986-01-01

    Although the combustion of hydrocarbons is our primary source of energy today, the chemical reactions, or pathway, by which even the simplest hydro-carbon reacts with atmospheric oxygen to form CO2 and water may not always be known. Furthermore, even when the reaction pathway is known, the reaction rates are always under discussion. The shock tube has been an important and unique tool for building a data base of reaction rates important in the combustion of hydrocarbon fuels. The ability of a shock wave to bring the gas sample to reaction conditions rapidly and homogeneously makes shock-tube studies of reaction kinetics extremely attractive. In addition to the control and uniformity of reaction conditions achieved with shock-wave methods, shock compression can produce gas temperatures far in excess of those in conventional reactors. Argon can be heated to well over 10 000 K, and temperatures around 5000 K are easily obtained with conventional shock-tube techniques. Experiments have proven the validity of shock-wave theory; thus, reaction temperatures and pressures can be calculated from a measurement of the incident shock velocity. A description is given of the chemical shock tube and auxiliary equipment and of two examples of kinetic experiments conducted in a shock tube.

  20. NATO Advanced Study Institute on Advances in Chemical Reaction Dynamics

    CERN Document Server

    Capellos, Christos

    1986-01-01

    This book contains the formal lectures and contributed papers presented at the NATO Advanced Study Institute on. the Advances in Chemical Reaction Dynamics. The meeting convened at the city of Iraklion, Crete, Greece on 25 August 1985 and continued to 7 September 1985. The material presented describes the fundamental and recent advances in experimental and theoretical aspects of, reaction dynamics. A large section is devoted to electronically excited states, ionic species, and free radicals, relevant to chemical sys­ tems. In addition recent advances in gas phase polymerization, formation of clusters, and energy release processes in energetic materials were presented. Selected papers deal with topics such as the dynamics of electric field effects in low polar solutions, high electric field perturbations and relaxation of dipole equilibria, correlation in picosecond/laser pulse scattering, and applications to fast reaction dynamics. Picosecond transient Raman spectroscopy which has been used for the elucidati...

  1. [Studies on the chemical constituents of Rumex crispus].

    Science.gov (United States)

    Fan, Ji-ping; Zhang, Zhen-liang

    2009-12-01

    To study the chemical constituents of Rumex crispus. Compounds were isolated and purified repeatedly by silica gel, Sephadex gel and ODS C18 column chromatographies, and structure identifications of compounds were carried out by physical, chemical methods and spectral data. Fifteen compounds were obtained from the petroleum ether and ethyl acetate fractions of R. crispus, and were identified as beta-sitosterol(1), hexadecanoic acid(2), hexadecanoic-2,3-dihydroxy propyleste(3), chrysophanol(4), physcion(5), emodin(6), chrysophanol-8-O-beta-D-glucopyranoside(7), physcion-8-O-beta-D-glucopyranoside(8), emodin-8O-beta-D-glucopyranoside(9), gallic acid(10), (+)-catechin(11), kaempferol(12), quercetin(13), kaempferol-3-O-alpha-L-rhamnopyranoside(14), quercetin-3-O-alpha-L-rhamnopyranoside(15). Compounds 3,8-12,14 and 15 are obtained from R. crispus for the first time.

  2. Chemical Approaches to Studying Labile Amino Acid Phosphorylation.

    Science.gov (United States)

    Marmelstein, Alan M; Moreno, Javier; Fiedler, Dorothea

    2017-04-01

    Phosphorylation of serine, threonine, and tyrosine residues is the archetypal posttranslational modification of proteins. While phosphorylation of these residues has become standard textbook knowledge, phosphorylation of other amino acid side chains is underappreciated and minimally characterized by comparison. This disparity is rooted in the relative instability of these chemically distinct amino acid side chain moieties, namely phosphoramidates, acyl phosphates, thiophosphates, and phosphoanhydrides. In the case of the O-phosphorylated amino acids, synthetic constructs were critical to assessing their stability and developing tools for their study. As the chemical biology community has become more aware of these alternative phosphorylation sites, methodology has been developed for the synthesis of well-characterized standards and close mimics of these phosphorylated amino acids as well. In this article, we review the synthetic chemistry that is a prerequisite to progress in this field.

  3. Spectroscopic and quantum chemical calculation study on 2-ethoxythiazole molecule

    Science.gov (United States)

    Avcı, Davut; Dede, Bülent; Bahçeli, Semiha; Varkal, Döndü

    2017-06-01

    In this study, the 2-ethoxythiazole molecule (C5H7NSO) which is a member of the five-membered heterocyles with one nitrogen atom group has been investigated by using the experimental UV-vis (in three different solvents) and FT-IR spectral results as well as some magnetic properties. Furthermore, the calculated molecular geometric parameters, vibrational wavenumbers, HOMO-LUMO energies, 1H and 13C NMR chemical shift values and natural bond orbitals (NBO) of the title molecule have been calculated at the B3LYP and HSEH1PBE levels of theory with the 6-311++G(d,p) basis set. The spectral results obtained from the quantum chemical calculations are in good agreement with the experimental results.

  4. Workers' perception of chemical risks: a focus group study.

    Science.gov (United States)

    Hambach, Ramona; Mairiaux, Philippe; François, Guido; Braeckman, Lutgart; Balsat, Alain; Van Hal, Guido; Vandoorne, Chantal; Van Royen, Paul; van Sprundel, Marc

    2011-02-01

    Workers' perceptions with respect to health and safety at work are rarely taken into account when considering the development of prevention programs. The aim of this study was to explore workers' perceptions of chemical risks at the workplace, in order to investigate the prerequisites for a workplace health program. A qualitative study was conducted involving seven focus groups of 5-10 participants (blue-collar workers) each. All groups were homogeneous in terms of sex, work status, language, and company membership. Results showed that several factors have an important influence on workers' perception of chemical risks. Workers assess risks by means of both sensory and empirical diagnosis and are concerned about the long-term health consequences. They perceive the threat of chemical risks as high. Despite this, they are resigned to accepting the risks. Existing formal sources of information are rarely consulted because they are judged to be difficult to understand and not user friendly. Instead, workers tend to obtain information from informal sources. Communication problems with and lack of trust in prevention advisers and hierarchy are frequently mentioned. Workers feel that their specific knowledge of their working conditions and their proposals for practical, cost-effective solutions to improve health and safety at the workplace are insufficiently taken into account. The use of focus groups yielded a useful insight into workers' perceptions of chemical risks. Our findings suggest that training programs for prevention advisers should include topics such as understanding of workers' perceptions, usefulness of a participatory approach, and communication and education skills. © 2010 Society for Risk Analysis.

  5. Quantum Chemical Study on Reaction of Acetaldehyde with Hydroxyl Radical

    Institute of Scientific and Technical Information of China (English)

    LI,Ming(李明); ZHANG,Jin-Sheng(张金生); SHEN,Wei(申伟); MENG,Qing-Xi(孟庆喜)

    2004-01-01

    The reaction of acetaldehyde with hydroxyl radical was studied by means of quantum chemical methods. The geometries for all the stationary points on the potential energy surfaces were optimized fully, respectively, at the G3MP2, G3, and MP2/6-311++G(d,p) levels. Single-point energies of all the species were calculated at the QCISD/6-311 + +G(d,p) level. The mechanism of the reaction studied was confirmed. The predicted product is acetyl radical that is in agreement with the experiment.

  6. Evidence for Alteration in Chemical and Physical Properties of Water and Modulation of its Biological Functions by Sunlight Transmitted through Color Ranges of the Visible Spectrum-A Novel Study

    Directory of Open Access Journals (Sweden)

    M. Rajeswara Rao

    2005-08-01

    Full Text Available We investigated the changes in the properties of water when exposed to sunlight for 40 days. We hypothesize and prove that solar irradiation to water entraps electromagnetic radiation as potential energy, which becomes kinetic energy in various systems. It is postulated that photochemically-induced energy transfers, associated with individual spectral emission of visible spectrum of solar light, exert diverse influences on biological systems. Bottles of distilled water, individually wrapped in spectral-colored cellophane were exposed to sunlight and compared to an unwrapped bottle to determine chemical and physical changes as well as modifications of biological properties. Each bottle of water was named according to the color of cellophane paper with letter E (stands for exposed as a prefix with (E-violet, E-indigo, E-blue, E-green, E-yellow, E-orange, and Ered. E-control (without wrap was exposed to polychromatic sunlight. This study addresses two main issues viz., the chemical and physical changes in E-water and its effect on biological activities. Chemical and physical composition analysis using inductively coupled plasma atomic emission spectrometry; physical conductance by a Wheatstone Bridge type conductivity meter; osmolarity by a vapor pressure osmometer; and, salt solubility profile of 10% sodium bicarbonate were determined. Furthermore, testing the effect of E-waters on human lymphocyte proliferation, mosquito larvae hatching and seed germination determined the functional role of solar radiation through specific spectrum/s of visible light on various biological processes. We found that water exposed to visible spectral emissions of sunlight had an altered elemental composition, electrical conductance, osmolarity and salt-solubility, as well as differences in bio-modulatory effects. A gradual increase in leaching of Boron from Eviolet to E-red was noted. E-indigo showed maximal increase in electrical conductance and maximal salt

  7. Chemical functionalization of graphene via aryne cycloaddition: a theoretical study.

    Science.gov (United States)

    Zhao, Jing-xiang; Wang, Hong-xia; Gao, Bo; Wang, Xiao-guang; Cai, Qing-hai; Wang, Xuan-zhang

    2012-06-01

    Chemical functionalization of graphene provides a promising route to improve its solubility in water and organic solvents as well as modify its electronic properties, thus significantly expanding its potential applications. In this article, by using density functional theory (DFT) methods, we have studied the effects of the chemical functionalization of graphenes via aryne cycloaddition on its properties. We found that the adsorption of an isolated aryne group on the graphene sheet is very weak with the adsorption energy of -0.204 eV, even though two new single C-C interactions are formed between the aryne group and the graphene. However, the interaction of graphene with the aryne group can be greatly strengthened by (i) substituting the H-atoms in aryne group with F-, Cl-, -NO(2) (electron-withdrawing capability), or CH(3)-group (electron-donating capability), and (ii) increasing the coverage of the adsorbed aryne groups on the graphene sheet. As expected, the strongest bonding is found on the graphene edges, in which the adsorbed aryne groups prefer to be far away from each other. Interestingly, chemical functionalization with aryne groups leads to an opening of the band gap of graphene, which is dependent on the coverage of the adsorbed aryne groups. The present work provides an insight into the modifications of graphene with aryne groups in experiment.

  8. Relative influence of chemical and non-chemical stressors on invertebrate communities: a case study in the Danube River.

    Science.gov (United States)

    Rico, Andreu; Van den Brink, Paul J; Leitner, Patrick; Graf, Wolfram; Focks, Andreas

    2016-11-15

    A key challenge for the ecological risk assessment of chemicals has been to evaluate the relative contribution of chemical pollution to the variability observed in biological communities, as well as to identify multiple stressor groups. In this study we evaluated the toxic pressure exerted by >200 contaminants to benthic macroinvertebrates in the Danube River using the Toxic Unit approach. Furthermore, we evaluated correlations between several stressors (chemical and non-chemical) and biological indices commonly used for the ecological status assessment of aquatic ecosystems. We also performed several variation partitioning analyses to evaluate the relative contribution of contaminants and other abiotic parameters (i.e. habitat characteristics, hydromorphological alterations, water quality parameters) to the structural and biological trait variation of the invertebrate community. The results of this study show that most biological indices significantly correlate to parameters related to habitat and physico-chemical conditions, but showed limited correlation with the calculated toxic pressure. The calculated toxic pressure, however, showed little variation between sampling sites, which complicates the identification of pollution-induced effects. The results of this study show that the variation in the structure and trait composition of the invertebrate community are mainly explained by habitat and water quality parameters, whereas hydromorphological alterations play a less important role. Among the water quality parameters, physico-chemical parameters such as suspended solids, nutrients or dissolved oxygen explained a larger part of the variation in the invertebrate community as compared to metals or organic contaminants. Significant correlations exist between some physico-chemical measurements (e.g. nutrients) and some chemical classes (i.e. pharmaceuticals, chemicals related to human presence) which constitute important multiple stressor groups. This study

  9. Useof phyto-attractant in monitoring and controlling gypsy moth%利用植物源引诱剂监测与控制舞毒蛾

    Institute of Scientific and Technical Information of China (English)

    李菁; 骆有庆; 石娟; 周娇; 王先礼; 马凌云; 陈超

    2011-01-01

    Trunk window traps baiting with plant volatile compounds from damaged Larix gmelinii (Rupr.) Rupr. branches were applied in L. gmelinii forests in Aershan area, Inner-Mongolia. The effects of phytoattractant, sex pheromone and their combination were used to test the effect of phyto-attractant on gypsy moth and the interaction of phyto-attractant and sex pheromone. The experiment was carried out in nine forest stands covering young, middle-aged and mature forests. Traps were also used in five other forests to test the effective distance of phyto-attractant. The results showed that the phyto-attractant could not exceed the attractive level of the sex pheromone except when the population size of the gypsy moth is very large. The phyto-attractant had an obvious synergistic effect on the sex pheromone. Gypsy moths 90 m away from the traps could be attracted with an optimum distance around 70 m. All of the attracted moths were males, most of which are virginal or not fully mated. The plant volatile compound had an obvious effect in monitoring and controlling the gypsy moth as a phyto-attractant, but it can also be applied as an accessory ingredient of sex pheromone in the management of the moth. The results also supported that our phyto-attractant can be developed as a pesticide for gypsy moth.%在内蒙古阿尔山林业局兴安落叶松纯林内,选取受害兴安落叶松针叶的挥发物并复配成引诱剂(植物源引诱剂),测定其对舞毒蛾成虫的引诱效果。试验一利用窗式诱捕器携带4种诱芯:1)植物源引诱剂(引诱剂I),2)舞毒蛾性信息素(引诱剂Ⅱ),3)前两者之结合(引诱剂Ⅲ),4)空白对照于9块样地(幼、中龄林和成熟林各3块)进行测定。试验二利用窗式诱捕器携带第1种诱芯在5块新样地中测定了植物源引诱剂的有效距离。试验三通过观测诱集到的舞毒蛾成虫交配或产卵(精子)状况从而确定植物源引诱剂

  10. Evaluating the role of vegetation on the transport of contaminants associated with a mine tailing using the Phyto-DSS.

    Science.gov (United States)

    Cano-Reséndiz, Omar; de la Rosa, Guadalupe; Cruz-Jiménez, Gustavo; Gardea-Torresdey, Jorge L; Robinson, Brett H

    2011-05-15

    We identified contaminants associated with the Cata mine tailing depot located in the outskirts of the city of Guanajuato, Mexico. We also investigated strategies for their phytomanagement. Silver and antimony were present at 39 and 31 mg kg(-1), respectively, some twofold higher than the Dutch Intervention Values. Total and extractable boron (B) occurred at concentrations of 301 and 6.3 mg L(-1), respectively. Concentrations of B in soil solution above 1.9 mg L(-1) have been shown to be toxic to plants. Plant growth may also be inhibited by the low concentrations of extractable plant nutrients. Analysis of the aerial portions of Aloe vera (L. Burm.f.) revealed that this plant accumulates negligible concentrations of the identified contaminants. Calculations using a whole system model (Phyto-DSS) showed that establishing a crop of A. vera would have little effect on the drainage or leaching from the site. However, this plant would reduce wind and water erosion and potentially produce valuable cosmetic products. In contrast, crops of poplar, a species that is tolerant to high soil B concentrations, would mitigate leaching from this site. Alternate rows of trees could be periodically harvested and be used for timber or bioenergy.

  11. Two-stage phyto-microremediation of tannery effluent by Spirodela polyrrhiza (L.) Schleid. and chromium resistant bacteria.

    Science.gov (United States)

    Singh, Asha; Vyas, Dhiraj; Malaviya, Piyush

    2016-09-01

    Two-stage sequential treatment of tannery effluent was conducted employing a wetland plant, Spirodela polyrrhiza (L.) Schleid., and chromium (Cr) resistant bacterial strains. The bacterial strains were isolated from Cr-enriched environmental matrices and rhizosphere of Spirodela polyrrhiza. The phyto-rhizoremediation of tannery effluent by Spirodela and its rhizospheric bacteria (Cellulomonas biazotea APBR1-6, Bacillus safensis APBR2-12, Staphylococcus warneri APBR3-5, Microbacterium oleivorans APBR2-6), followed by microremediation by Cr resistant bacteria (Micrococcus luteus APBS5-1, Bacillus pumilus APBS5-2, Bacillus flexus APBE3-1, Virgibacillus sediminis APBS6-1) resulted in reduction of pollution parameters [COD (81.2%), total Cr (97.3%), Cr(VI) (99.3%), Pb(II) (97.0%), Ni (95.7%)]. The LC-MS analysis showed that many pollutants detected in untreated tannery effluent were diminished after bioremediation or long chains of alcohol polyethoxylates viz. C18EO6 in untreated effluent were broken down into smaller unit of alcohol polyethoxylate ((+)HHO[CH2CH2O]H), indicating that bacteria and Spirodela polyrrhiza, alongwith its rhizospheric associates utilized them as carbon and energy source. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Evaluating the role of vegetation on the transport of contaminants associated with a mine tailing using the Phyto-DSS

    Energy Technology Data Exchange (ETDEWEB)

    Cano-Resendiz, Omar [Departamento de Ingenieria Quimica, Universidad de Guanajuato, Noria Alta s/n, CP 36050 Guanajuato (Mexico); Rosa, Guadalupe de la, E-mail: delarosa@quijote.ugto.mx [Departamento de Ingenieria Quimica, Universidad de Guanajuato, Noria Alta s/n, CP 36050 Guanajuato (Mexico); Cruz-Jimenez, Gustavo [Departamento de Farmacia, Universidad de Guanajuato, Noria Alta s/n, CP 36050 Guanajuato (Mexico); Gardea-Torresdey, Jorge L. [Chemistry Department and Environmental Science and Engineering, Ph.D. Program, The University of Texas at El Paso, 500 W. University Ave., 79968 El Paso, TX (United States); Robinson, Brett H. [Agriculture and Life Sciences, Lincoln University, P.O. Box 84 Lincoln, Canterbury 7646 (New Zealand)

    2011-05-15

    We identified contaminants associated with the Cata mine tailing depot located in the outskirts of the city of Guanajuato, Mexico. We also investigated strategies for their phytomanagement. Silver and antimony were present at 39 and 31 mg kg{sup -1}, respectively, some twofold higher than the Dutch Intervention Values. Total and extractable boron (B) occurred at concentrations of 301 and 6.3 mg L{sup -1}, respectively. Concentrations of B in soil solution above 1.9 mg L{sup -1} have been shown to be toxic to plants. Plant growth may also be inhibited by the low concentrations of extractable plant nutrients. Analysis of the aerial portions of Aloe vera (L. Burm.f.) revealed that this plant accumulates negligible concentrations of the identified contaminants. Calculations using a whole system model (Phyto-DSS) showed that establishing a crop of A. vera would have little effect on the drainage or leaching from the site. However, this plant would reduce wind and water erosion and potentially produce valuable cosmetic products. In contrast, crops of poplar, a species that is tolerant to high soil B concentrations, would mitigate leaching from this site. Alternate rows of trees could be periodically harvested and be used for timber or bioenergy.

  13. [Study on the chemical constituents in Pouzolzia zeylanica].

    Science.gov (United States)

    Fu, Ming; Niu, You-Ya; Yu, Juan; Kong, Qing-Tong

    2012-11-01

    To study the chemical constituents of Pouzolzia zeylanica. Many chromatography means were used in separation and purification, and the structures of all compounds were identified by the means of spectroscopic analysis and physicochemical properties. 14 compounds were elucidated as: beta-sitosterol (1), daucosterol (2), oleanolic acid (3), epicatechin (4), alpha-amyrin (5), eugenyl-beta-rutinoside (6), 2alpha, 3alpha, 19alpha-trihydroxyurs-12-en-28-oic (7), scopolin (8), scutellarein-7-O-alpha-L-rhamnoside (9), scopoletin (10), quercetin (11), quercetin-3-O-beta-D-glucoside (12), apigenin (13), 2alpha-hydroxyursolic acid (14). All compounds are obtained from this plant for the first time.

  14. Studies on the Chemical Constituents and Bioactivities of Tripterygium Wilfordii

    Institute of Scientific and Technical Information of China (English)

    LI; YuanChao

    2001-01-01

    Tripterygium wilfordii Hook (TW) is a medicinal plant distributed widely in southern china. This plant was recently found to possess anti-inflammatory, antitumor and immunosuppressive activities. Some preparation of the plant root has been used for the treatment of rheumatoid arthritis, systemic acne rosacea, nephritis and some skin diseases. Chemical studies on this plant and its preparation have shown they contain a large number of sesquiterpenoid, diterpenoids, triterpenoids and alkaloids in which some diterpene triepoxy lactones such as triptolide and triptonide etc are considered as mainly active compounds.  ……

  15. Studies on the Chemical Constituents and Bioactivities of Tripterygium Wilfordii

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Tripterygium wilfordii Hook (TW) is a medicinal plant distributed widely in southern china. This plant was recently found to possess anti-inflammatory, antitumor and immunosuppressive activities. Some preparation of the plant root has been used for the treatment of rheumatoid arthritis, systemic acne rosacea, nephritis and some skin diseases. Chemical studies on this plant and its preparation have shown they contain a large number of sesquiterpenoid, diterpenoids, triterpenoids and alkaloids in which some diterpene triepoxy lactones such as triptolide and triptonide etc are considered as mainly active compounds.

  16. Solid-State NMR Studies of Chemically Lithiated CFx

    Science.gov (United States)

    Leifer, N. D.; Johnson, V. S.; Ben-Ari, R.; Gan, H.; Lehnes, J. M.; Guo, R.; Lu, W.; Muffoletto, B. C.; Reddy, T.; Stallworth, P. E.; Greenbaum, S. G.

    2010-01-01

    Three types of fluorinated carbon, all in their original form and upon sequential chemical lithiations via n-butyllithium, were investigated by 13C and 19F solid-state NMR methods. The three starting CFx materials [where x = 1 (nominally)] were fiber based, graphite based, and petroleum coke based. The aim of the current study was to identify, at the atomic/molecular structural level, factors that might account for differences in electrochemical performance among the different kinds of CFx. Differences were noted in the covalent F character among the starting compounds and in the details of LiF production among the lithiated samples. PMID:20676233

  17. Matrix isolation as a tool for studying interstellar chemical reactions

    Science.gov (United States)

    Ball, David W.; Ortman, Bryan J.; Hauge, Robert H.; Margrave, John L.

    1989-01-01

    Since the identification of the OH radical as an interstellar species, over 50 molecular species were identified as interstellar denizens. While identification of new species appears straightforward, an explanation for their mechanisms of formation is not. Most astronomers concede that large bodies like interstellar dust grains are necessary for adsorption of molecules and their energies of reactions, but many of the mechanistic steps are unknown and speculative. It is proposed that data from matrix isolation experiments involving the reactions of refractory materials (especially C, Si, and Fe atoms and clusters) with small molecules (mainly H2, H2O, CO, CO2) are particularly applicable to explaining mechanistic details of likely interstellar chemical reactions. In many cases, matrix isolation techniques are the sole method of studying such reactions; also in many cases, complexations and bond rearrangements yield molecules never before observed. The study of these reactions thus provides a logical basis for the mechanisms of interstellar reactions. A list of reactions is presented that would simulate interstellar chemical reactions. These reactions were studied using FTIR-matrix isolation techniques.

  18. Comparative Study of the Phytoprostane and Phytofuran Content of indica and japonica Rice (Oryza sativa L.) Flours.

    Science.gov (United States)

    Pinciroli, M; Domínguez-Perles, R; Abellán, A; Guy, A; Durand, T; Oger, C; Galano, J M; Ferreres, F; Gil-Izquierdo, A

    2017-10-03

    Phytoprostanes and phytofurans (PhytoPs and PhytoFs, respectively) are nonenzymatic lipid peroxidation products derived from α-linolenic acid (C18:3 n-3), considered biomarkers of oxidative degradation in plant foods. The present work profiled these compounds in white and brown grain flours and rice bran from 14 rice cultivars of the subspecies indica and japonica by ultrahigh performance liquid chromatography coupled to electrospray ionization and triple quadrupole mass spectrometry. For PhytoPs, the average concentrations were higher in rice bran (0.01-9.35 ng g(-1)) than in white and brown grain flours (0.01-1.17 ng g(-1)). In addition, the evaluation of rice flours for the occurrence PhytoFs evidenced average values 1.77, 4.22, and 10.30 ng g(-1) dw in rice bran, brown grain flour, and white grain flour, respectively. A significant correlation was observed between total and individual compounds. The concentrations retrieved suggest rice bran as a valuable source of PhytoPs and PhytoFs that should be considered in further studies on bioavailability and bioactivity of such compounds.

  19. Antimicrobial Activity and Chemical Composition of Three Essential Oils Extracted from Mediterranean Aromatic Plants.

    Science.gov (United States)

    Elshafie, Hazem S; Sakr, Shimaa; Mang, Stefania M; Belviso, Sandra; De Feo, Vincenzo; Camele, Ippolito

    2016-11-01

    There is a growing interest in essential oils (EOs) as possible alternatives for traditional chemical pesticides. This study was carried out to characterize the chemical composition of the three EOs extracted from Verbena officinalis, Majorana hortensis, and Salvia officinalis using gas chromatography (GC) and GC-mass spectrometry (GC-MS) and to evaluate in vitro their efficacy against some phyto or human pathogens. The antifungal activity was investigated against Colletotrichum acutatum and Botrytis cinerea in comparison with Azoxystrobin as a large spectrum fungicide. Antibacterial activity was evaluated against Bacillus megaterium, Bacillus mojavensis, and Clavibacter michiganensis (G+ve) and Escherichia coli, Xanthomonas campestris, Pseudomonas savastanoi, and P. syringae pv. phaseolicola (G-ve) compared to a synthetic antibiotic tetracycline. Minimum inhibitory concentration was evaluated against the above tested fungi using 96-well microplate method. Results showed that the chemical structure of the three studied EOs was mainly composed of monoterpene compounds and all oils belong to the chemotype carvacrol/thymol. Results of GC analysis identified 64 compounds, which were identified based on their mass to charge ratio. Furthermore, the different concentrations of studied EOs inhibited the growth of tested microorganism in a dose-dependent manner.

  20. Vibrational spectroscopic studies of Isoleucine by quantum chemical calculations.

    Science.gov (United States)

    Moorthi, P P; Gunasekaran, S; Ramkumaar, G R

    2014-04-24

    In this work, we reported a combined experimental and theoretical study on molecular structure, vibrational spectra and NBO analysis of Isoleucine (2-Amino-3-methylpentanoic acid). The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments, thermodynamics properties, NBO analyses, NMR chemical shifts and ultraviolet-visible spectral interpretation of Isoleucine have been studied by performing MP2 and DFT/cc-pVDZ level of theory. The FTIR, FT-Raman spectra were recorded in the region 4000-400 cm(-1) and 3500-50 cm(-1) respectively. The UV-visible absorption spectra of the compound were recorded in the range of 200-800 nm. Computational calculations at MP2 and B3LYP level with basis set of cc-pVDZ is employed in complete assignments of Isoleucine molecule on the basis of the potential energy distribution (PED) of the vibrational modes, calculated using VEDA-4 program. The calculated wavenumbers are compared with the experimental values. The difference between the observed and calculated wavenumber values of most of the fundamentals is very small. (13)C and (1)H nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method and compared with experimental results. The formation of hydrogen bond was investigated in terms of the charge density by the NBO calculations. Based on the UV spectra and TD-DFT calculations, the electronic structure and the assignments of the absorption bands were carried out. Besides, molecular electrostatic potential (MEP) were investigated using theoretical calculations.

  1. Chemical reaction and dust formation studies in laboratory hydrocarbon plasmas.

    Science.gov (United States)

    Hippler, Rainer; Majumdar, Abhijit; Thejaswini, H. C.

    Plasma chemical reaction studies with relevance to, e.g., Titan's atmosphere have been per-formed in various laboratory plasmas [1,2]. Chemical reactions in a dielectric barrier discharge at medium pressure of 250-300 mbar have been studied in CH4 /N2 and CH4 /Ar gas mixtures by means of mass spectrometry. The main reaction scheme is production of H2 by fragmenta-tion of CH4 , but also production of larger hydrocarbons like Cn Hm with n up to 10 including formation of different functional CN groups is observed. [1] A. Majumdar and R. Hippler, Development of dielectric barrier discharge plasma processing apparatus for mass spectrometry and thin film deposition, Rev. Sci. Instrum. 78, 075103 (2007) [2] H.T. Do, G. Thieme, M. Frühlich, H. Kersten, and R. Hippler, Ion Molecule and Dust Particle Formation in Ar/CH4 , Ar/C2 H2 and Ar/C3 H6 Radio-frequency Plasmas, Contrib. Plasma Phys. 45, No. 5-6, 378-384 (2005)

  2. Combined spectroscopic and quantum chemical studies of ezetimibe

    Science.gov (United States)

    Prajapati, Preeti; Pandey, Jaya; Shimpi, Manishkumar R.; Srivastava, Anubha; Tandon, Poonam; Velaga, Sitaram P.; Sinha, Kirti

    2016-12-01

    Ezetimibe (EZT) is a hypocholesterolemic agent used for the treatment of elevated blood cholesterol levels as it lowers the blood cholesterol by blocking the absorption of cholesterol in intestine. Study aims to combine experimental and computational methods to provide insights into the structural and vibrational spectroscopic properties of EZT which is important for explaining drug substance physical and biological properties. Computational study on molecular properties of ezetimibe is presented using density functional theory (DFT) with B3LYP functional and 6-311++G(d,p) basis set. A detailed vibrational assignment has been done for the observed IR and Raman spectra of EZT. In addition to the conformational study, hydrogen bonding and molecular docking studies have been also performed. For conformational studies, the double well potential energy curves have been plotted for the rotation around the six flexible bonds of the molecule. UV absorption spectrum was examined in methanol solvent and compared with calculated one in solvent environment (IEF-PCM) using TD-DFT/6-31G basis set. HOMO-LUMO energy gap of both the conformers have also been calculated in order to predict its chemical reactivity and stability. The stability of the molecule was also examined by means of natural bond analysis (NBO) analysis. To account for the chemical reactivity and site selectivity of the molecules, molecular electrostatic potential (MEPS) map has been plotted. The combination of experimental and calculated results provide an insight into the structural and vibrational spectroscopic properties of EZT. In order to give an insight for the biological activity of EZT, molecular docking of EZT with protein NPC1L1 has been done.

  3. Corrosion study in the chemical air separation (MOLTOX trademark ) process

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Doohee; Wong, Kai P.; Archer, R.A.; Cassano, A.A.

    1988-12-01

    This report presents the results of studies aimed at solving the corrosion problems encountered during operation of the MOLTOX{trademark} pilot plant. These studies concentrated on the screening of commercial and developmental alloys under conditions simulating operation conditions in this high temperature molten salt process. Process economic studies were preformed in parallel with the laboratory testing to ensure that an economically feasible solution would be achieved. In addition to the above DOE co-funded studies, Air Products and Chemicals pursued proprietary studies aimed at developing a less corrosive salt mixture which would potentially allow the use of chemurgically available alloys such as stainless steels throughout the system. These studies will not be reported here; however, the results of corrosion tests in the new less corrosive salt mixtures are reported. Because our own studies on salt chemistry impacts heavily on the overall process and thereby has an influence on the experimental work conducted under this contract, some of the studies discussed here were impacted by our own proprietary data. Therefore, the reasons behind some of the experiments presented herein will not be explained because that information is proprietary to Air Products. 14 refs., 42 figs., 21 tabs.

  4. [Studies on the chemical constituents from Inula cappa (II)].

    Science.gov (United States)

    Guo, Qi-lei; Yang, Jun-shan; Liu, Jian-xun

    2007-01-01

    To study the chemical constituents of the root of Inula cappa. The compounds were isolated and purified by recrystallization and chromatography with silica gel column and Sephadex LH-20 column. Their structures were identified by physico-chemical properties and spectral analysis. Seven compounds were isolated as scopolin (I), octacosanoic acid (II), tritriacontane (III), (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxydocosanosylamino]-octadecane-1,3,4-triol(IV),(2S,3S,4R,8E)-2-[(2'R)-2'-hydroxytricosanosylamino]-octadecane-1,3,4-triol(V), (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxytetracosanosylamino]-octadecane-1,3,4-triol(VI), (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxypentacosanosylamino]-octadecane-1,3,4-triol(VIII), (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxyhexacosanosylamino]-octadecane-1,3,4-triol(VIII). All compounds were isolated from Inula cappa for the first time.

  5. Sensitivity study of SMILES-2 for chemical species

    Science.gov (United States)

    Suzuki, Makoto; Manago, Naohiro; Ozeki, Hiroyuki; Ochiai, Satoshi; Baron, Philippe

    2015-10-01

    Sensitivity studies of temperature and chemical species (Observed by ISS/JEM/SMILES: O3, HCl, ClO, HO2, BrO, HNO3, CH3CN, and Not observed by SMILES: Temperature, H2O, N2O, NO2, NO, CH3Cl, CO, H2CO, OH and O-atom) was carried out for the SMILES-2 proposal, a sub-mm and THz observation of limb emission from space over the spectral region from 400 GHz to 2.5 THz. Tentative but optimal candidate of frequency bands to cover these species was selected with 3 SIS (Superconductor-Insulator-Superconductor) mixers; SIS-1 (485-489 GHz + 523-527 GHz), SIS-2 (623-627 GHz + 648-652 GHz), SIS-3 (557 GHz + 576.3 GHz) and 2 HEB (Hot Electron Bolometer); HEB-1 (1.8 THz OH) and HEB-2 (2.06 THz O-atom). Temperature can be retrieved with 1 K precision and 1 km vertical resolution from 15 to 120 km. Other chemical species also showed very high single scan precision (random error) comparable to statistical standard error of previous satellite measurements.

  6. Diuretic Properties and Chemical Constituent Studies on Stauntonia brachyanthera

    Directory of Open Access Journals (Sweden)

    Xuan Li Liu

    2015-01-01

    Full Text Available The pharmacological evaluation demonstrated that the extracts from the stem of S. brachyanthera could significantly increase the outputs of urine of rats compared to those of furosemide treated group, and the effect could last for a longer period of time. The best effect appeared in the first two hours, which scientifically confirmed the diuretic effect of the plant. The comparative pharmacognosy study showed that the characters of the crude drugs of the stem of S. brachyanthera were similar to those of Akebia caulis. Further systemic work on its chemical constituents by chromatographic methods and NMR elucidations led to the isolation of 10 triterpenoids, 6 flavonoids, 4 lignanoids, and 3 phenylethanoid glycosides, whose structural types were much similar to those of A. quinata. Among them, 7 compounds were firstly reported in the genus of Stauntonia and calceolarioside B was the common characteristic constituent in both plants. From the similar pharmacognosy characters, pharmacological effects, and chemical constituents, it could be concluded that S. brachyanthera have a great possibility to be a succedaneum of Akebia caulis, whose supply is extremely short in recent years.

  7. Studies on high chemical reactivity of nano-NaH

    Institute of Scientific and Technical Information of China (English)

    FAN Yinheng; ZOU Yunling; JIN Dan; WU Qiang; LIU Tong; XU Jie

    2007-01-01

    A comparison between the initial reaction rates of nanometric and commercial Nail has been studied in four test reactions: 1) hydrogenolysis of chlorobenzene; 2) selec-tive reduction of cinnamaldehyde to cinnamyl alcohol; 3)metallation of dimethyl sulfoxide; and 4) catalytic hydroge-nation ofolefins. The experimental results indicate that when Nail is used as a chemical reagent in the first three reactions,the initial reaction rates of nano-NaH is 230, 120 and 110 times higher than those of the commercial ones respectively,and it is in agreement with the difference in specific surface areas between these two forms of Nail. When Nail is used as a catalyst component together with Cp2TiCl2 in the fourth reaction, catalyst with nano-NaH gives extremely high activity in the hydrogenation of olefins, while the one with commercial Nail gives no activity at all even ifa large amount of the commercial Nail is used to make the total surface area equivalent to that of nano-NaH. Thus, it is evident that although large specific surface area is important for nano-Nail to be used as a catalyst component, high surface energy with surface defects seems to be more important. The largespecific surface and the activated surface of nano-NaH withhigh surface energy should be the main factors for thei rextremely high chemical reactivity, while whether the former or the latter one plays a leading role depends on the type of reactions involved.

  8. Quantum chemical study on asymmetric catalysis reduction of imine

    Institute of Scientific and Technical Information of China (English)

    LI; Ming; (李明); TIAN; Anmin; (田安民)

    2003-01-01

    The quantum chemical method is employed to study the enantioselective reduction of imine with borane catalyzed by chiral oxazaborolidine. All the structures are optimized completely at the B3LYP/6-31G(d) level. The catalysis property of oxazaborolidine is notable. The reduction goes mainly through the formations of the catalyst-borane adduct, the catalyst-borane-imine adduct, and the catalyst-amidoborane adduct and the dissociation of the catalyst-amidoborane adduct with the regeneration of the catalyst. The controlling step for the reduction is the dissociation of the catalyst-amidoborane adduct. The main reduced product predicted theoretically is (R )-sec- ondary amine, which is in agreement with the experiment.

  9. [Studies on chemical constituents in seeds of Cicer arietinum].

    Science.gov (United States)

    Tan, Yong-xia; Sun, Yu-hua; Chen, Ruo-yun

    2007-08-01

    To study the chemical constituents in seeds of Cicer arietinum, so that to find bioactive natural products. Dried and sprouted seeds of C. arietinum were extracted with ethanol of various concentrations respectively, then isolated and purified by silica gel, macroreticular resin D 101, Sephadex LH -20 gel column chromatography, and structures of compounds were identified by spectral analysis. Nine compounds have been isolated and identified: 3-hydroxy-olean-12-ene (1), biochanin A-7-O-beta-D-glucoside (2), cerebroside (3), 1-ethyl-alpha-L-galactoside (4), uridine (5), adenosine (6), trytophan (7), biochanin A (8), fomononetin (9). Compounds 1, 3, 4, 6, 7 were isolated from genus Cicer for the first time.

  10. Quantum Chemical Study on the Corrosion Inhibition of Some Oxadiazoles

    Directory of Open Access Journals (Sweden)

    Hong Ju

    2015-01-01

    Full Text Available Quantum chemical calculations based on DFT method were performed on three nitrogen-bearing heterocyclic compounds used as corrosion inhibitors for the mild steel in acid media to determine the relationship between the molecular structure of inhibitors and inhibition efficiency. The structural parameters, such as energy and distribution of highest occupied molecular orbital (HOMO and lowest unoccupied molecular orbital (LUMO, the charge distribution of the studied inhibitors, the absolute electronegativity (χ values, and the fraction of electrons (ΔN transfer from inhibitors to mild steel were also calculated and correlated with inhibition efficiencies. The results showed that the inhibition efficiency of inhibitors increased with the increase in energy of HOMO and decrease in energy gap of frontier molecular orbital, and the areas containing N and O atoms are most possible sites for bonding the steel surface by donating electrons to the mild steel.

  11. Study of physical chemical characteristics of a shungite

    OpenAIRE

    Maira Kazankapova; A. Bekzhanova; Sergey Efremov; Mikhail Nauryzbayev

    2012-01-01

    The physico-chemical characteristics of shungite from the field of Kazakhstan ("Bakyrchik") and Russia ("Zazhegino") was studied by elemental analysis, IR- spectroscopy and electron microscopy. The content of carbon in the schungite field "Zazhegino" is 28,0-31,0 %,  in the field "Bakyrchik" - 15,0-19,0 %, in schungite concentrate  "Bakyrchik" is 40,0 ± 2,0 %.  IR-spectroscopic analysis have been shown that carboxyl groups appear in addition to the concentrate of polycyclic hydrocarbons conta...

  12. Chemical treatment of zinc surface and its corrosion inhibition studies

    Indian Academy of Sciences (India)

    S K Rajappa; T V Venkatesha; B M Praveen

    2008-02-01

    The surface treatment of zinc and its corrosion inhibition was studied using a product (BTSC) formed in the reaction between benzaldehyde and thiosemicarbozide. The corrosion behaviour of chemically treated zinc surface was investigated in aqueous chloride–sulphate medium using galvanostatic polarization technique. Zinc samples treated in BTSC solution exhibited good corrosion resistance. The measured electrochemical data indicated a basic modification of the cathode reaction during corrosion of treated zinc. The corrosion protection may be explained on the basis of adsorption and formation of BTSC film on zinc surface. The film was binding strongly to the metal surface through nitrogen and sulphur atoms of the product. The formation of film on the zinc surface was established by surface analysis techniques such as scanning electron microscopy (SEM–EDS) and Fourier transform infrared spectroscopy (FTIR).

  13. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: CORROSION STUDIES RESULTS: FY2010

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.

    2010-09-29

    Due to the need to close High Level Waste storage tanks, chemical cleaning methods are needed for the removal of sludge heel materials remaining at the completion of mechanical tank cleaning efforts. Oxalic acid is considered the preferred cleaning reagent for heel dissolution of iron-based sludge. However, the large quantity of chemical reagents added to the tank farm from oxalic acid based cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acidic systems may be required for specific waste components that have low solubility in oxalic acid, and as a means to reduce oxalic acid usage in general. Electrochemical corrosion studies were conducted with 1 wt. % oxalic acid at mineral acid concentrations above and below the optimal conditions for this oxalic acid concentration. Testing environments included pure reagents, pure iron and aluminum phases, and sludge simulants. Mineral acid concentrations greater than 0.2 M and temperatures greater than 50 C result in unacceptably high corrosion rates. Results showed that manageable corrosion rates of carbon steel can be achieved at dilute mineral acid concentrations (i.e. less than 0.2 M) and low temperatures based on the contact times involved. Therefore, it is recommended that future dissolution and corrosion testing be performed with a dilute mineral acid and a less concentrated oxalic acid (e.g., 0.5 wt.%) that still promotes optimal dissolution. This recommendation requires the processing of greater water volumes than those for the baseline process during heel dissolution, but allows for minimization of oxalic acid additions. The following conclusions can be drawn from the test results: (1) In both nitric and sulfuric acid based reagents, the low temperature and

  14. [Study of quantum-pharmacological chemical characteristics of quercetin].

    Science.gov (United States)

    Zahorodnyĭ, M I

    2007-01-01

    It was established in the previous studies that quercetin prevented the development and caused faster regression of ulcers, petechia and anabroses in rats, which were induced by diclofenac taking. In the group of patients taking diclofenac together with quercetin, the ulcers and dyspeptic events were less found. The application of quercetin normalizes the function and metabolism of cartilage tissue of rabbits with an experimental osteoarthrosis and in patients with osteoartrosis. Quantum-chemical properties of molecule quercetin were studied using the methods of molecular mechanics MM+ and ab initio 6-31G*, and also semiempirical method. The following indices were investigated: distance between atoms (A), the distribution of electronic density of only external valency electrons, distribution of electrostatic potential; common energy of the exertion of molecule (kkal/mmol); binding energy (kkal/mmol); electron energy (kkal/mmol); energy of nucleus-nucleus interaction (kkal/mmol); formation heat (kkal/mmol); atomic charge (eB); value of the dipole moment of molecule (D); localization and energy of highest occupied orbital (HOMO) and the lowest unoccupied (LUMO) molecular orbital (eB) of quercetin miolecule; the value of absolute rigidity of chemical structure of bioflavonoid. It was shown, that bioflavonoid quercetin belongs to mild reagents, has nucleophilic properties, can react with alkaline, unsaturated and aromatic compounds,. Polar substitutes in the quercetine molecule influence on the distribution of superficial valency electrons and localization of HOMO and LUMO. The energy value of quercetin LUMO enables us to refer quercetine to the reducing agent and it is illustrated by antioxidant properties of this medicine.

  15. Effect of phyto-synthesized silver nanoparticles on developmental stages of malaria vector, Anopheles stephensi and dengue vector, Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Madanagopal Nalini

    2017-09-01

    Full Text Available Rapidly synthesized phyto-mediated silver nanoparticles (Ag NPs using Artemisia nilagirica aqueous leaf filtrate has been confirmed through UV–visible spectrophotometer. The synthesized Ag NPs were further characterized using Fourier transform infra-red (FTIR, X-ray diffraction analysis (XRD to determine the present of functional groups and average particle size (6.723 nm with cubic nature, respectively. Spherical shape (≤30 nm of Ag NPs was confirmed by scanning electron microscopy (SEM. Bio-efficacy of these nanoparticles showed larvicidal and pupicidal properties than the aqueous leaf extract treatment alone against developmental stages (I–IV instars and pupa of malaria vector Anopheles stephensi and dengue vector Aedes aegypti at 0.25% concentration level. The LC50 (LCL:UCL at 95% confidence limit values of I–IV instar and pupa of An. stephensi were recorded at 0.343 (0.261:0.405, 0.169 (0.025:0.263, 0.198 (0.105:0.265, 0.141 (0.045:0.205 and 0.050 (0.606:0.224 % respectively and for Ae. aegypti (I–IV instar and pupa 0.460 (0.364:0.537, 0.352 (0.239:0.432, 0.331 (0.833:0.549, 0.217 (0.228:0.378 and 0.161 (0.630:0.356 % were observed, after 24 h exposure. The first report of present investigation revealed that the rapid biological synthesis of silver nanoparticles using A. nilagirica leaf filtrate would be an effective potential alternative green larvicide for the control of mosquitoes at the developmental stages with eco-friendly approach.

  16. Determination of the Michaelis-Menten kinetics and the genes expression involved in phyto-degradation of cyanide and ferri-cyanide.

    Science.gov (United States)

    Yu, Xiao-Zhang; Zhang, Xue-Hong

    2016-07-01

    Hydroponic experiments were conducted with different species of plants (rice, maize, soybean and willow) exposed to ferri-cyanide to investigate the half-saturation constant (K M ) and the maximal metabolic capacity (v max ) involved in phyto-assimilation. Three varieties for each testing species were collected from different origins. Measured concentrations show that the uptake rates responded biphasically to ferri-cyanide treatments by showing increases linearly at low and almost constant at high concentrations from all treatments, indicating that phyto-assimilation of ferri-cyanide followed the Michaelis-Menten kinetics. Using non-linear regression, the highest v max was by rice, followed by willows. The lowest v max was found for soybean. All plants, except maize (DY26) and rice (XJ12), had a similar K M value, suggesting the same enzyme was active in phyto-assimilation of ferri-cyanide. Transcript level, by real-time quantitative PCR, of enzymes involved in degradation of cyanides showed that the analyzed genes were differently expressed during different cyanides exposure. The expression of CAS and ST genes responded positively to KCN exposure, suggesting that β-CAS and ST pathways were two possible pathways for cyanide detoxification in rice. The transcript level of NIT and ASPNASE genes also showed a remarkable up-regulation to KCN, implying the contribution to the pool of amino acid aspartate, which is an end product of CN metabolism. Up-regulation of GS genes suggests that acquisition of ammonium released from cyanide degradation may be an additional nitrogen source for plant nutrition. Results also revealed that the expressions of these genes, except for GS, were relatively constant during iron cyanide exposure, suggesting that they are likely metabolized by plants through a non-defined pathway rather than the β-CAS pathway.

  17. Radiation and quantum chemical studies of chalcone derivatives.

    Science.gov (United States)

    Gaikwad, P; Priyadarsini, K I; Naumov, S; Rao, B S M

    2010-08-05

    The reactions of oxidizing radicals ((*)OH, Br(2)(*-), and SO(4)(*-)) with -OH-, -CH(3)-, or -NH(2)-substituted indole chalcones and hydroxy benzenoid chalcones were studied by radiation and quantum chemical methods. The (*)OH radical was found to react by addition at diffusion-controlled rates (k = 1.1-1.7 x 10(10) dm(3) mol(-1) s(-1)), but Br(2)(*-) radical reacted by 2 orders of magnitude lower. Quantum chemical calculations at the B3LYP/6-31+G(d,p) level of theory have shown that the (C2-OH)(*), (C11-OH)(*), and (C10-OH)(*) adducts of the indole chalcones and the (C7-OH)(*) and (C8-OH)(*) adducts of the hydroxy benzenoid chalcones are more stable with DeltaH = -39 to -28 kcal mol(-1) and DeltaG = -32 to -19 kcal mol(-1). This suggests that (*)OH addition to the alpha,beta-unsaturated bond is a major reaction channel in both types of chalcones and is barrierless. The stability and lack of dehydration of the (*)OH adducts arise from two factors: strong frontier orbital interaction due to the low energy gap between interacting orbitals and the negligible Coulombic repulsion due to small absolute values of Mulliken charges. The transient absorption spectrum measured in the (*)OH radical reaction with all the indole chalcone derivatives exhibited a maximum at 390 nm, which is in excellent agreement with the computed value (394 nm). The formation of three phenolic products under steady-state radiolysis is in line with the three stable (*)OH adducts predicted by theory. Independent of the substituent, identical spectra (lambda(max) = 330-360 and approximately 580 nm) were obtained on one-electron oxidation of the three indole chalcones. MO calculations predict the deprotonation from the -NH group is more efficient than from the substituent due to the larger electron density on the N1 atom forming the chalcone indolyl radical. Its reduction potential was determined to be 0.56 V from the ABTS(*-)/ABTS(2-) couple. In benzenoid chalcones, the (*)OH adduct spectrum is

  18. Studies of Trace Gas Chemical Cycles Using Observations, Inverse Methods and Global Chemical Transport Models

    Science.gov (United States)

    Prinn, Ronald G.

    2001-01-01

    For interpreting observational data, and in particular for use in inverse methods, accurate and realistic chemical transport models are essential. Toward this end we have, in recent years, helped develop and utilize a number of three-dimensional models including the Model for Atmospheric Transport and Chemistry (MATCH).

  19. A chemical study of the photodissociation region NGC 7023

    Science.gov (United States)

    Fuente, A.; Martin-Pintado, J.; Cernicharo, J.; Bachiller, R.

    1993-09-01

    To investigate the effects of the UV radiation on the chemistry of nitrogenated molecules in molecular clouds, we have carried out an observational study of the photodissociation region (PDR) associated with the reflection nebula NGC 7023. We mapped a region of 3' × 3' over the PDR in millimeter transitions of 12CO, 13CO, C18O, HCO+, HCN, HNC and N2H+. Spectra of CS, CN and C2H and of the rarer isotopic species H13CO+, H13CN, and HN13C, were also obtained at selected positions. We find evidences of selective photodissociation in the estimated 13CO/C15O ratio. Furthermore, all molecular abundances, except those of CN and perhaps C2H, decrease towards the star, and significant gradients in the values of some molecular abundance ratios (the HNC/HCN ratio decreases by a factor of 5, the N2H+/HCO+ ratio decreases by a factor of 12, the CN/HCN ratio increases by a factor of 8 and the (CN+HCN+HNC)/NH3 ratio increases by a factor of 30 towards the star position) reveal the existence of important chemical changes in this direction. Chemical equilibrium model calculations have been also carried out in order to interpret the observed behavior. Our results show that the variations found in molecular abundances cannot be explained by the kinetic temperature and/or the hydrogen density gradients measured in this region. The observed behavior is well explained by the influence of the stellar UV radiation on the chemistry of the molecular gas if the emission arises in a region at a visual extinction between 6 and 10 mag from the star. Molecular destruction in this region (Aυ ˜ 6 mag) is due mainly to reactions with H+, C, H, C+, O, and to electronic recombination. The CN/HCN ratio is suggested as a tracer of enhanced UV fields.

  20. The Iron Blast Furnace: A Study in Chemical Thermodynamics.

    Science.gov (United States)

    Treptow, Richard S.; Jean, Luckner

    1998-01-01

    Discusses the furnace from a chemical thermodynamics perspective. Examines the enthalpy, entropy, and free energy change for each reaction of importance. These properties are interpreted on the molecular level then used to deduce the conditions necessary for each reaction to occur in its intended direction. Chemical kinetics is also discussed.…

  1. Sustainability Indicators for Chemical Processes: III. Biodiesel Case Study

    Science.gov (United States)

    The chemical industry is one of the most important business sectors, not only economically, but also societally; as it allows humanity to attain higher standards and quality of life. Simultaneously, chemical products and processes can be the origin of potential human health and ...

  2. Material Development Study for a Hazardous Chemical Protective Clothing Outfit

    Science.gov (United States)

    1980-08-01

    chemicals was technical grade or better (>90%) and were used without further purification. Specialty chemicals including formuations such as agri- cultural...polycarbon- ate. Teflon yarn is available for sewing seams. Bonding patches over the seams would be required to cover holes left from sewing. Because

  3. The Iron Blast Furnace: A Study in Chemical Thermodynamics.

    Science.gov (United States)

    Treptow, Richard S.; Jean, Luckner

    1998-01-01

    Discusses the furnace from a chemical thermodynamics perspective. Examines the enthalpy, entropy, and free energy change for each reaction of importance. These properties are interpreted on the molecular level then used to deduce the conditions necessary for each reaction to occur in its intended direction. Chemical kinetics is also discussed.…

  4. On the front line of modern data-management and Open Access publishing: Two years of PhytoKeys – the fastest growing journal in plant systematics

    Directory of Open Access Journals (Sweden)

    W. John Kress

    2012-12-01

    Full Text Available PhytoKeys was launched on the 1st of November 2010 as a novel, peer-reviewed, open-access outlet for plant biodiversity research and since then the journal quickly gained the support of the international botanical community and has been showing a continuous to growth in reputation and volume. This Editorial describes how PhytoKeys continues to evolve its editorial workflow, constantly implementing new and improved publishing and dissemination technologies, thus always being on point for digital biodiversity science.

  5. Alternative Enhanced Chemical Cleaning Basic Studies Results FY09

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M.; King, W.

    2010-05-05

    Due to the need to close waste storage tanks, chemical cleaning methods are needed for the effective removal of the heels. Oxalic acid is the preferred cleaning reagent for sludge heel dissolution, particularly for iron-based sludge, due to the strong complexing strength of the oxalate. However, the large quantity of oxalate added to the tank farm from oxalic acid based chemical cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acid systems may be required for specific waste components with low solubility in oxalic acid and as a means to reduce oxalic acid usage in general. Solubility tests were conducted using non-radioactive, pure metal phases known to be the primary phases present in High Level Waste sludge. The metal phases studied included the aluminum phases gibbsite and boehmite and the iron phases magnetite and hematite. Hematite and boehmite are expected to be the most difficult iron and aluminum phases to dissolve. These mineral phases have been identified in both SRS and Hanford High Level Waste sludge. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids. The results of the solubility tests indicate that oxalic and sulfuric acids are more effective for the dissolution of the primary sludge phases. For boehmite, elevated temperature will be required to promote effective phase dissolution in the acids studied. Literature reviews, thermodynamic modeling, and experimental results have all confirmed that pH control using a supplemental proton source (additional acid) is critical for minimization of oxalic acid usage during the dissolution of hematite. These results emphasize the importance of pH control in optimizing hematite dissolution in oxalic acid and may explain the somewhat

  6. Chemical and biological warfare: General studies. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    The bibliography contains citations concerning federally sponsored and conducted studies into chemical and biological warfare operations and planning. These studies cover areas not addressed in other parts of this series. The topics include production and storage of agents, delivery techniques, training, military and civil defense, general planning studies, psychological reactions to chemical warfare, evaluations of materials exposed to chemical agents, and studies on banning or limiting chemical warfare. Other published searches in this series on chemical warfare cover detection and warning, defoliants, protection, and biological studies, including chemistry and toxicology. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  7. Chemical and biological warfare: General studies. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The bibliography contains citations concerning federally sponsored and conducted studies into chemical and biological warfare operations and planning. These studies cover areas not addressed in other parts of this series. The topics include production and storage of agents, delivery techniques, training, military and civil defense, general planning studies, psychological reactions to chemical warfare, evaluations of materials exposed to chemical agents, and studies on banning or limiting chemical warfare. Other published searches in this series on chemical warfare cover detection and warning, defoliants, protection, and biological studies, including chemistry and toxicology.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  8. NATO Advanced Study Institute on Chemical Transport in Melasomatic Processes

    CERN Document Server

    1987-01-01

    As indicated on the title page, this book is an outgrowth of the NATO Advanced Study Institute (ASI) on Chemical Transport in Metasomatic Processes, which was held in Greece, June 3-16, 1985. The ASI consisted of five days of invited lectures, poster sessions, and discussion at the Club Poseidon near Loutraki, Corinthia, followed by a two-day field trip in Corinthia and Attica. The second week of the ASI consisted of an excursion aboard M/S Zeus, M/Y Dimitrios II, and the M/S Irini to four of the Cycladic Islands to visit, study, and sample outstanding exposures of metasomatic activity on Syros, Siphnos, Seriphos, and Naxos. Nine­ teen invited lectures and 10 session chairmen/discussion leaders participated in the ASI, which was attended by a total of 92 professional scientists and graduate stu­ dents from 15 countries. Seventeen of the invited lectures and the Field Excursion Guide are included in this volume, together with 10 papers and six abstracts representing contributed poster sessions. Although more...

  9. Quantum chemical studies of photochromic properties of benzoxazine compound

    Energy Technology Data Exchange (ETDEWEB)

    Toliautas, Stepas, E-mail: stepas.toliautas@ff.stud.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Sulskus, Juozas, E-mail: juozas.sulskus@ff.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Valkunas, Leonas, E-mail: leonas.valkunas@ff.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Institute of Physics, Center for Physical Sciences and Technology, Savanoriu 231, LT-02300 Vilnius (Lithuania); Vengris, Mikas, E-mail: mikas.vengris@ff.vu.lt [Department of Quantum Electronics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Photochromic indolo-benzoxazine compound is studied. Black-Right-Pointing-Pointer Advanced LC-TDDFT and GMC-QDPT methods are used for excited state calculations. Black-Right-Pointing-Pointer Oxazine ring opens upon UV light excitation. Black-Right-Pointing-Pointer Fragments of the compound assume structures similar to the ions of separate molecules. Black-Right-Pointing-Pointer Multiple pathways of the photo-induced reaction are expected. -- Abstract: Molecular electronic structure of ground and excited states of a photochromic indolo[2,1-b][1,3]benzoxazine compound incorporating closed-ring system, which opens upon UV light excitation, was studied using various quantum chemical methods. Three local minima of the ground electronic state potential energy surface and related transition states were identified along the path of rotation of 4-nitrophenol group. Additionally, three local minima of the excited electronic states were located. The evaluated transition energy barriers between local ground-state minima nearest to the initial structure of the investigated molecule are less than 2 k{sub B}T, making open structures likely to revert to the initial structure by thermalization. Results obtained using ab initio GMC-QDPT method were explored and compared to the widely used TD-DFT and semi-empiric ZINDO methods.

  10. Chemical studies of single-walled carbon nanotubes

    CERN Document Server

    Xu, C

    2001-01-01

    WCl sub 6 has also been introduced into arc-vapourised SWNTs. Chapter 6 gives the details for all the experimental work of the thesis. of H sub 2 have also been studied. Chapter four describes the various processes used to purify arc-vapourised SWNTs on a laboratory scale. Two potentially scalable processes have also been studied. Both acid and gas oxidants have been used to purify SWNTs grown in the CVD method. The chemical resistance of CVD SWNTs (48 h of conc. HNO sub 3 treatment) has been shown for the first time. Various assembly behaviours of purified SWNTs, including loop and spiral structures, straight long bundles or somewhat aligned structures, are also described. Chapter five presents the filling of arc-vapourised SWNTs with LnX sub n (X = Cl, Br and I, n = 2 or 3) using the capallarity method at high temperature (570-910 deg C). The first example of a polycrystalline structure within SWNTs filled with a single material (SmCl sub 3) has been provided. Fullerenes within SWNTs in the SWNT samples ext...

  11. Quantum chemical studies on the reactivity of oxazole derivatives

    Science.gov (United States)

    Hosseinzadeh, Behzad; Eskandari, Khalil; Zarandi, Maryam; Asli, Reza

    2016-11-01

    The quantum chemical study of the reactivity of a series of oxazole derivatives substituted at 2, 4, and 5 positions was performed using B3LYP/6-311++G( d, p) and MP2/6-311++G( d, p) levels of theory. Different substituents have been applied to cover a wide range of electronic effects. On the basis of Fukui functions, oxazole derivatives in the gas phase are found to be suitable nucleophilic sites. For the most of studied substituents, it was observed that the calculated Fukui function f k - values at the N-position are small in case of electron-withdrawing substituents, resulting a preferred N-position for hard reactions. In contrast, large f k - values in case of electron-donating groups show a preferred N-position for soft reactions. These two local reactivity descriptors predicted the reactivity of the electron-rich oxazoles sequence to be 2-substituted oxazoles > 5-substituted oxazoles > 4-substituted oxazoles, where due to resonance effect, the reactivity toward electrophilic attack at the pyridine nitrogen atom is enhanced by electron donor substituents.

  12. Phyto chemical study and evaluation of allelopathy in Memora peregrina, 'ciganinha', Bignoniaceae, an invading species in pastures in Mato Grosso do Sul, Brazil; Estudo fitoquimico e avaliacao alelopatica de Memora peregrina - 'ciganinha' - Bignoniaceae, uma especie invasora de pastagens em Mato Grosso do Sul

    Energy Technology Data Exchange (ETDEWEB)

    Grassi, Rafaela Ferreira [Mato Grosso do Sul Univ., Campo Grande, MS (Brazil). Dept. de Quimica; Resende, Ubirazilda Maria [Mato Grosso do Sul Univ., Campo Grande, MS (Brazil). Dept. de Biologia; Silva, Walciane da; Macedo, Maria Ligia Rodrigues [Mato Grosso do Sul Univ., Campo Grande, MS (Brazil). Dept. de Ciencias Naturais; Butera, Ana Paola; Tulli, Elayne de Oliveira; Saffran, Francis Paes; Siqueira, Joao Maximo de [Mato Grosso do Sul Univ., Campo Grande, MS (Brazil). Dept. de Farmacia-Bioquamica]. E-mail: jmaximo@nin.ufms.br

    2005-04-01

    Memora peregrina (local name: 'ciganinha' - Bignoniaceae) is a weed that often invades pastures in the Brazilian state of Mato Grosso do Sul. From its leaves and subterranean parts, the following compounds were isolated: allantoin (20.7 w/w in subterranean parts), the iridoid 6{beta}-hydroxyipolamiide, hyperin, 3'-O-methylhyperin, 4-hydroxy-N-methylproline, {beta}-sitosterol, {alpha}-amirin and {beta}-amirin, and lupeol. Allantoin exhibited an activity of inducing germination in seeds of Lactuca sativa used as a biological model, and the iridoid showed moderate activity in the larval development of Anagasta kuehniella. These results, associated with this plant's behavior, are suggestive of the occurrence of adaptive and competitive strategies in relation to other plant species. (author)

  13. Ocean Acidification Affects the Phyto-Zoo Plankton Trophic Transfer Efficiency.

    Science.gov (United States)

    Cripps, Gemma; Flynn, Kevin J; Lindeque, Penelope K

    2016-01-01

    The critical role played by copepods in ocean ecology and biogeochemistry warrants an understanding of how these animals may respond to ocean acidification (OA). Whilst an appreciation of the potential direct effects of OA, due to elevated pCO2, on copepods is improving, little is known about the indirect impacts acting via bottom-up (food quality) effects. We assessed, for the first time, the chronic effects of direct and/or indirect exposures to elevated pCO2 on the behaviour, vital rates, chemical and biochemical stoichiometry of the calanoid copepod Acartia tonsa. Bottom-up effects of elevated pCO2 caused species-specific biochemical changes to the phytoplanktonic feed, which adversely affected copepod population structure and decreased recruitment by 30%. The direct impact of elevated pCO2 caused gender-specific respiratory responses in A.tonsa adults, stimulating an enhanced respiration rate in males (> 2-fold), and a suppressed respiratory response in females when coupled with indirect elevated pCO2 exposures. Under the combined indirect+direct exposure, carbon trophic transfer efficiency from phytoplankton-to-zooplankton declined to < 50% of control populations, with a commensurate decrease in recruitment. For the first time an explicit role was demonstrated for biochemical stoichiometry in shaping copepod trophic dynamics. The altered biochemical composition of the CO2-exposed prey affected the biochemical stoichiometry of the copepods, which could have ramifications for production of higher tropic levels, notably fisheries. Our work indicates that the control of phytoplankton and the support of higher trophic levels involving copepods have clear potential to be adversely affected under future OA scenarios.

  14. Ocean Acidification Affects the Phyto-Zoo Plankton Trophic Transfer Efficiency

    Science.gov (United States)

    Cripps, Gemma; Flynn, Kevin J.; Lindeque, Penelope K.

    2016-01-01

    The critical role played by copepods in ocean ecology and biogeochemistry warrants an understanding of how these animals may respond to ocean acidification (OA). Whilst an appreciation of the potential direct effects of OA, due to elevated pCO2, on copepods is improving, little is known about the indirect impacts acting via bottom-up (food quality) effects. We assessed, for the first time, the chronic effects of direct and/or indirect exposures to elevated pCO2 on the behaviour, vital rates, chemical and biochemical stoichiometry of the calanoid copepod Acartia tonsa. Bottom-up effects of elevated pCO2 caused species-specific biochemical changes to the phytoplanktonic feed, which adversely affected copepod population structure and decreased recruitment by 30%. The direct impact of elevated pCO2 caused gender-specific respiratory responses in A.tonsa adults, stimulating an enhanced respiration rate in males (> 2-fold), and a suppressed respiratory response in females when coupled with indirect elevated pCO2 exposures. Under the combined indirect+direct exposure, carbon trophic transfer efficiency from phytoplankton-to-zooplankton declined to < 50% of control populations, with a commensurate decrease in recruitment. For the first time an explicit role was demonstrated for biochemical stoichiometry in shaping copepod trophic dynamics. The altered biochemical composition of the CO2-exposed prey affected the biochemical stoichiometry of the copepods, which could have ramifications for production of higher tropic levels, notably fisheries. Our work indicates that the control of phytoplankton and the support of higher trophic levels involving copepods have clear potential to be adversely affected under future OA scenarios. PMID:27082737

  15. Study and interpretation of the chemical characteristics of natural water

    Science.gov (United States)

    Hem, John David

    1985-01-01

    The chemical composition of natural water is derived from many different sources of solutes, including gases and aerosols from the atmosphere, weathering and erosion of rocks and soil, solution or precipitation reactions occurring below the land surface, and cultural effects resulting from human activities. Broad interrelationships among these processes and their effects can be discerned by application of principles of chemical thermodynamics. Some of the processes of solution or precipitation of minerals can be closely evaluated by means of principles of chemical equilibrium, including the law of mass action and the Nernst equation. Other processes are irreversible and require consideration of reaction mechanisms and rates. The chemical composition of the crustal rocks of the Earth and the composition of the ocean and the atmosphere are significant in evaluating sources of solutes in natural freshwater.

  16. USI/Chemplex/Quantum Chemical Co. Outfall Study, 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Sediment samples collected in 1987 from the Quantum Chemical Corporation outfall on the Upper Mississippi River detected 14 polycyclic aromatic hydrocarbons (PAH's)....

  17. Periodic quantum chemical studies on anhydrous and hydrated acid clinoptilolite.

    Science.gov (United States)

    Valdiviés Cruz, Karell; Lam, Anabel; Zicovich-Wilson, Claudio M

    2014-08-07

    Periodic quantum chemistry methods as implemented in the crystal09 code were considered to study acid clinoptilolite (HEU framework type), both anhydrous and hydrated. The most probable location of acid sites and water molecules together with other structural details has been the object of particular attention. Calculations were performed at hybrid and pristine DFT levels of theory with a VDZP quality basis set in order to compare performances. It arises that PBE0 provides the best agreement with experimental data as concerns structural features and the most stable Al distribution in the framework. The role of the water molecule distribution in the stability of the systems, the most probable structure that they induce in the material, and their eventual influence on further chemical modification processes, such as dealumination, are discussed in detail. Results show that, apart from the usually considered interactions of water molecules with the zeolite framework, that is, a H-bond with Brönsted acid sites and coordination with framework Al as Lewis ones, it is necessary to consider cooperation of other weaker effects so as to fully understand the hydration effect in this kind of materials.

  18. Forcing an entire bifurcation diagram: Case studies in chemical oscillators

    Science.gov (United States)

    Kevrekidis, I. G.; Aris, R.; Schmidt, L. D.

    1986-12-01

    We study the finite amplitude periodic forcing of chemical oscillators. In particular, we examine systems that, when autonomous, (i.e. for zero forcing amplitude) exhibit a single stable oscillation. Using one of the system parameters as a forcing variable by varying it periodically, we show through extensive numerical work how the bifurcation diagram of the autonomous system with respect to this parameter affects the qualitative response of the full forced system. As the forcing variable oscillates around its midpoint, its instantaneous values may cross points (such as Hopf bifurcation poiints) of the autonomous bifurcation diagram so that the characterization of the system as a simple forced oscillator is no longer valid. Such a neighboring Hopf bifurcation of the unforced system is found to set the scene for the interaction of resonance horns and the loss of tori in the full forced system as the amplitude of the forcing grows. Our test case presented here is the Continuous Stirred Tank Reactor (CSTR) with periodically forced coolant temperature.

  19. Studies on the Chemical Constituents from Marine Bryozoan Cryptosula pallasiana

    Directory of Open Access Journals (Sweden)

    Xiang-Rong Tian

    2015-06-01

    Full Text Available The aim of this study was to investigate the chemical constituents of marine bryozoan Cryptosula pallasiana inhabiting Huang Island of China. Three aromatic compounds, p-methylsulfonylmethyl-phenol (1, p-hydroxybenzaldehyde (4 and methylparaben (5, nine alkaloids, 7-bromoquinolin-4(1H-one (2, 7-bromo-2,4(1H,3H-quinazolinedione (3, benzamide (6, phenylacetamide (7, 4(3H-quinazolinone (8, thymine (9, uracil (10, hypoxanthine (11 and tryptophan (12, together with two glycerol derivatives, glycerol (13 and monoheneicosanoin (14, were isolated for the first time from this marine bryozoan. Among the isolates, compounds 1 and 2 were new natural products, and their spectral traits were reported for the first time. The structures of the two compounds were elucidated by extensive spectroscopic analyses, including HR-ESI-MS, EI-MS, 1D- and 2D-NMR techniques. The isolated compounds 1–3 were evaluated for their cytotoxicity against HL-60 human myeloid leukemia cell line. The results showed that bromated alkaloid (3 appeared strong cytotoxicity against HL-60 cells with IC 50 value of 11.87 µg/mL, while compounds 1 and 2 were inactivity.

  20. Study of physical chemical characteristics of a shungite

    Directory of Open Access Journals (Sweden)

    Maira Kazankapova

    2012-05-01

    Full Text Available The physico-chemical characteristics of shungite from the field of Kazakhstan ("Bakyrchik" and Russia ("Zazhegino" was studied by elemental analysis, IR- spectroscopy and electron microscopy. The content of carbon in the schungite field "Zazhegino" is 28,0-31,0 %,  in the field "Bakyrchik" - 15,0-19,0 %, in schungite concentrate  "Bakyrchik" is 40,0 ± 2,0 %.  IR-spectroscopic analysis have been shown that carboxyl groups appear in addition to the concentrate of polycyclic hydrocarbons containing methylene groups. Analysis of electron microscopy have been shown that as a result of enrichment by carbon, shungite can get a more developed surface structure and porosity.

  1. Rodent-repellent studies. III. Advanced studies in the evaluation of chemical repellents

    Science.gov (United States)

    Bellack, E.; DeWitt, J.B.

    1949-01-01

    In order to bridge the gap between preliminary screening of chemicals for potential rodent repellency and the application ofthese compounds to paper cartons, more advanced studies in the evaluation ofpromising materials have been carried out. These studies have resulted in: (1) a modification of the food acceptance technique which eliminates doubtful compounds and also provides a closer analogy to the ultimate goal, and (2) a method for rapidly testing chemicals incorporated in paper. When the results of these latter tests are expressed as a function of time, it can be shown that a distinct correlation exists between the deterrency exhibited by treated paper and the repellency of treated food.

  2. Innovative electronic publication in plant systematics: PhytoKeys and the changes to the “Botanical Code” accepted at the XVIII International Botanical Congress in Melbourne

    Directory of Open Access Journals (Sweden)

    W. John Kress

    2011-09-01

    Full Text Available PhytoKeys was established less than a year ago in response to four main publication challenges of our time: (1 the appearance of electronic publications as amendments or even alternatives to paper publications; (2 Open Access (OA as a new publishing model; (3 the linkage of electronic registers, indices, and aggregators, which summarize information on biological species through taxonomic names or their persistent identifiers; and (4 Web 2.0 technologies, which permit the semantic markup of, and semantic enhancements to, published biological texts. The appearance of the journal was concomitant with lively discussions on the validity of nomenclatural acts published electronically (Knapp and Wright 2010, Knapp et al. 2010, Penev et al. 2010, Chapman et al. 2010. At the XVIII International Botanical Congress in Melbourne in July 2011 (IBC 2011 these discussions culminated in the decision to amend the International Code of Botanical Nomenclature to allow electronic-only publishing of new taxa. Even before the end of the Congress and formal acceptance of the changes PhytoKeys was able to publish a report on the main outcomes of the Nomenclature Section on electronic publishing (Miller et al. 2011.

  3. On Chemical Modeling an Alchemical Process: The Use of Combined Chemical Methods in a Historical Study

    Science.gov (United States)

    Rodygin, Mikhail Yu.; Rodygin, Irene V.

    1997-08-01

    Laboratory work is an important component of a course in the History of Chemistry and Alchemy, though it can only be illustrative and not comprehensive. The course should exercise both the cognitive and research abilities of an university student. Therefore methods of modeling are of prime importance at this stage of instruction. Modeling can be both a priori and experimental. The experiment can use the alchemist's materials, or it can reproduce the procedure with modern reagents. A good example for the use of this method is a recipe for the preparation of the Philosopher's Stone attributed to Lullius and cited by J. Ripley in Liber Duodecium Portarum. Thus, the Ripley's recipe is not only considered to be the first indication of the existence of acetone, but it may also indicate the formation of acetyl acetone and its derivatives. Thus, as far as the history of alchemy is concerned, the use of an experimental model not only allows us to solve a number of specific problems such as recipe interpretation and product identification, but it allows also to probe the essence of alchemical work. The combination of empirical and speculative modelings leads to the interaction of the exact methods of chemistry with the broad historico-chemical generalizations, thus introducing some additional dimensions to the definition of historico-chemical practice.

  4. A Study on Physical Dispersion and Chemical Modification of Graphene

    Energy Technology Data Exchange (ETDEWEB)

    Yim, Eun-Chae; Kim, Seong-Jun [Chonnam National University, Gwangju (Korea, Republic of)

    2015-12-15

    Graphene has a wide spectrum on its application field due to various and excellent physical properties. However, it is very difficult to apply that graphene exists as lump or fold condition in general organic solvents. Besides, graphene was difficult to maintain as uniform condition due to chemical inert and distributions with various size and shapes. Therefore, this study was focused to study dispersion and modifying methods of aggregated graphene. The dispersion methods contain as follow: i) physical milling using glass bead, ii) co-treatment of glass bead and ultrasonic waves, iii) dispersion in organic solvents, iv) modifying with dry-ice. Milling using glass bead with size 2.5 mm was effective to be size decrease of 36.4% in comparison with control group. Mixed treatment of glass bead (size 2.5 mm) and ultrasonic waves (225W, 10 min) showed relative size decrease of 76%, suggesting that the size decrease depends on the size of glass bead, intensity of ultrasonic waves and treatment time. Solvents of Ethyl acetate (EA) and Isoprophyl alcohol (IPA) were used in order to improve dispersion by modifying surface of graphene. IPA of them showed a favorable dispersion with more -CO functional groups in the FT-IR analysis. On the other hand, the oxygen content of graphene surface modified by dry-ice was highly increased from 0.8 to 4.9%. From the results, it was decided that the favorable dispersion state for a long time was obtained under the condition of -CO functional group increase in IPA solvent.

  5. PHYTO-REMEDIATION OF LEAD-CONTAMINATED SOIL USING AMARANTHUS CRUENTUS

    OpenAIRE

    Opeolu, B.O.; Bamgbose, O; Arowolo, T.A.; Kadiri, S.J.

    2005-01-01

    Previous studies have shown that some vegetables have the ability to absorb metals from soil. Since they are early maturity species, they possess the potential to be used as phytoremediating agents. Also, synthetic chelates have been found to induce lead desorption from soil matrix, thereby enhancing uptake into plant tissues. Therefore, a study was carried out to determine the potential of Amaranthus cruentus as a soil lead remediating plant. The experiment was carried out using a randomized...

  6. The achievement of good chemical status: an impossible mission for local water managers?

    Science.gov (United States)

    La Jeunesse, Isabelle; Jadas-Hécart, Alain; Landry, David

    2017-04-01

    The European Water Framework Directive (2000) required to achieve good ecological and chemical status in surface waters of the EU Member States in 2015. For pesticides, this means ensuring that concentrations in rivers do not exceed 0.1 μg/L per molecule and 0.5 µg/L for the sum of the concentrations of the different molecules found. At national scale, EcoPhyto plan (2008) aimed to reduce pesticide use by 50% within 10. This plan has been revised and postponed to 2025 as observed pesticide use is varying between years and concentrations in river did not decrease as expected. Although vineyards cover a small percentage of agricultural land surfaces, they contribute to 20% of national pesticide use. The presence of pesticides in rivers surrounding wine territories is therefore a current environmental concern. Thus, the recovery of the water quality requires local action programs to reduce pesticide contamination in rivers. The Layon catchment comprises 13% of vineyard. It is therefore subject to an action program led by the local water committee: the SAGE Layon-Aubance-Louet. Its goal is to ensure pesticide concentrations are reduced to 1 µg/L in 2018 and 0.5 µg/L in 2027. In this context, one of the actions of the SAGE, with the assistance of the University of Angers, addresses the study of peaks in pesticide concentrations during runoff events in a small catchment covered by vineyards. Between 2009 and 2016, one of the two farmers has converted to organic farming with consequent decreases in pesticides input to the case study which thus complied with the EcoPhyto objectives. Results demonstrate first a peak intensity of pesticides in runoff waters in relation with the date of application with a decrease of concentrations during time after the treatment and second a relation between peaks of SPM and pesticides. Transfer of pesticides in this catchment is strongly linked to runoff. Thus, even if the increase of grass surface within vineyard improves the soil

  7. IDENTIFICATION OF PHYTO-COMPONENTS AND ITS BIOLOGICAL ACTIVITIES OF ALOE VERA THROUGH THE GAS CHROMATOGRAPHY-MASS SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    P.T.V Lakshmi

    2011-05-01

    Full Text Available In this study, the bioactive components of Aloe vera leaves have been evaluated using GC/MS. The chemical compositions of the n-hexane extract of Aloe vera were investigated using Perkin-Elmer Gas Chromatography–Mass Spectrometry, while the mass spectra of the compounds found in the extract was matched with the National Institute of Standards and Technology (NIST library. GC/MS analysis of n-hexane extract of Aloe vera revealed the existence of twenty six bioactive compounds. The results of this study offer a platform of using Aloe vera as herbal drug for cancer studies.

  8. Chemical bonding in TiSb(2) and VSb(2): a quantum chemical and experimental study.

    Science.gov (United States)

    Armbrüster, Marc; Schnelle, Walter; Schwarz, Ulrich; Grin, Yuri

    2007-08-06

    The chemical bonding in the isostructural intermetallic compounds TiSb2 and VSb2, crystallizing in the CuAl2 type, was investigated by means of quantum chemical calculations, particularly the electron localization function (ELF), as well as by Raman spectroscopy, Hall effect and conductivity measurements on oriented single crystals, and high-pressure X-ray powder diffraction. The homogeneity ranges of the compounds were determined by powder X-ray diffraction, WDXS, and DSC measurements. TiSb2 exhibits no significant homogeneity range, while VSb2 shows a small homogeneity range of approximately 0.3 at. %. According to the ELF calculations, the Sb atoms form dumbbells via a two-center two-electron bond, while the T atoms (T = Ti, V) build up chains along the crystallographic c-axis. Both building units are connected by covalent T-Sb-T three-center bonds, thus forming a three-dimensional network. The strength of the bonds involving Sb was determined by fitting a force constant model to the vibrational mode frequencies observed by polarized Raman measurements on oriented single crystals. The resulting bond order of the Sb2 dumbbells is 1, while the strength of the three-center bonds resembles a bond order of 1.5. The weak pressure dependence of the c/a ratio confirms the slightly different bonding picture in TiSb2 compared to that in CuAl2. Electrical transport measurements show the presence of free charge carriers, as well as a metal-like temperature dependence of the electrical resistivity.

  9. Using the hidden isotopic heterogeneity in phyto- and zooplankton to unmask disparity in trophic carbon transfer

    NARCIS (Netherlands)

    Pel, R.; Hoogveld, H.L.; Floris, V.

    2003-01-01

    In this study, we show that natural phototrophic populations can be probed individually for their in situ d13C signature by linking fluorescence-activated cell sorting and isotope-ratio mass spectrometry (IRMS) using in-line pyrolytic methylation. This novel methodology greatly improved the resoluti

  10. Laser studies of chemical reaction and collision processes

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, G. [Columbia Univ., New York, NY (United States)

    1993-12-01

    This work has concentrated on several interrelated projects in the area of laser photochemistry and photophysics which impinge on a variety of questions in combustion chemistry and general chemical kinetics. Infrared diode laser probes of the quenching of molecules with {open_quotes}chemically significant{close_quotes} amounts of energy in which the energy transferred to the quencher has, for the first time, been separated into its vibrational, rotational, and translational components. Probes of quantum state distributions and velocity profiles for atomic fragments produced in photodissociation reactions have been explored for iodine chloride.

  11. EXPERIMENTAL STUDY OF CHEMICAL CHOLECYSTECTOMY: OBSERVATION OF PATHOLOGICAL CHANGES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: TO verify through animal experiment the validity of chemical cholecystectomy . Methods: The experimental objects seven healthy juvenile pigs,hardener was infused into the gallbladder,after infusion the samples were collected by pathoiogical examination , according to the different duration under anesthestize. Reslts:The mucous destructive and digestive process remained with one week, the inflammatory reacton in two weeks,the chronic inflatoy reaction compained a a great deal of granu lation tissue and scar formation occurred in 4th-8th week,10 weeks latter,the inflmmatory reaction reduced ,and scar tissue formed. Conclusion: Chemical cholecystectomy is safe and reliable in clinical.

  12. EXPERIMENTAL STUDY OF CHEMICAL CHOLECYSTECTOMY OF PATHOLOGIC OBSERVATION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective:To verify through animal experiment the validity of chemical cholecystectomy.Mothods:The expermental objects seven healthy juvenile pigs,hardener was infused into the gallbladder,after infusion the sapmles were collected by pathological examination,according to the different duration under anesthestize.Results:The mucous destructive and digestive process remained with one week,the inflammatory reaction in two weeks,the chronic inflammatory reaction compained a great deal of granulation tissue and scar formation occurred in 4th-8th week,10 weeks latter,the inflammatory reaction reduced,and scar tissue formed.Conlusion:Chemical cholecystecomy is safe and reliable in clinic.

  13. [Study on chemical constituents from flowers of Ailanthus altissima].

    Science.gov (United States)

    Lou, Ke-Qin; Tang, Wen-Zhao; Wang, Xiao-Jing

    2012-10-01

    To isolate and identify the chemical constituents from the flowers of Ailanthus altissima. Macroporous adsorptive resins (DM130), Silica gel, Sephadex LH-20, ODS were employed for the isolation and purification of chemical constituents. The structures were identified on the basis of spectral data and physicochemical examination. Eight compounds were isolated and identified as follows: brevifolin (1), brevifolin carboxylic acid (2), methyl brevifolin carboxylate (3), ellagic acid (4), diethyl-2,2',3,3',4,4'- hexahydroxybiphenyl-6,6'-dicarboxylate (5), rutin (6), gallic acid (7), ethyl gallate (8). Compounds 1 -5 are isolated from this genus for the first time.

  14. Caffeic acid, a phyto polyphenol mitigates fluoride induced hepatotoxicity in rats: A possible mechanism.

    Science.gov (United States)

    Kanagaraj, Vishnu Vignesh; Panneerselvam, Lakshmikanthan; Govindarajan, Vimal; Ameeramja, Jaishabanu; Perumal, Ekambaram

    2015-01-01

    Fluoride induced hepatotoxicity has been extensively studied in both humans and animals. However, the mechanism underlying in the hepatotoxicity of experimental fluorosis remains obscure. The severity of fluoride toxicity was reduced by oral administration of certain plant derived antioxidants. Caffeic acid (CA) a polyphenolic compound has diverse range of pharmacological activity in the biological system. Therefore, the present study was aimed to investigate the protective mechanism of CA, against fluoride induced hepatotoxicity in rats. The rats were treated with 300 ppm of NaF via drinking water ad libitum alone and in combination with CA at a dose of 50 mg/kg daily for 30 days by oral intubation. CA treatment significantly prevented fluoride induced hepatic damage as evident from the histopathological studies and declined levels of serum fluoride and liver marker enzymes. A significant decrease in the levels of enzymatic (SOD2, CAT, GPx, and GSTpi class) and nonenzymatic (GSH and Vitamin C) antioxidants along with increased ROS, lipid peroxidation, protein carbonyl content, and nitrate levels by fluoride were also prevented in these groups. In addition, CA inhibits fluoride induced apoptosis by altering the Bax and caspase-3p20 expressions. Further, fluoride induced upregulation of Nox4, p38α MAPK, Hsp60, and downregulation of Hsp27 are the indicators for the detection of oxidative damage, apoptosis, and mitochondrial stress was also modulated by CA. These findings reveal that CA supplementation has a protective effect against fluoride induced hepatotoxicity in rats.

  15. [Studies on chemical constitutents in roots of Jasminum sambac].

    Science.gov (United States)

    Zhang, Zheng-fu; Bian, Bao-lin; Yang, Jian; Tian, Xiu-feng

    2004-03-01

    To isolate and identify the chemical constitutents in roots of Jasminum sambac. The compounds were isolated by means of chromatography and the structures were identified on the basis of physical and spectral data. Dotriacontanoic acid, dotriacontanol, oleanolic acid, daucosterol and hesperidin were elucidated. All compounds were found in this plant for the first time.

  16. Role of phyto-stabilised silver nanoparticles in suppressing adjuvant induced arthritis in rats.

    Science.gov (United States)

    Mani, Aparna; Vasanthi, C; Gopal, V; Chellathai, Darling

    2016-12-01

    The present study was aimed to evaluate the anti-arthritic effects of silver nanoparticles synthesised using Piper nigrum extract and to further establish its mechanism of action in a rat model of adjuvant induced arthritis (AA). Adjuvant arthritis was induced by injecting complete Freund's adjuvant (0.1mL) into the left hind paw of 36 albino Wistar rats (n=6). Silver nanoparticles stabilised with Piper nigrum extract (25 and 50mg/kg). Commercial silver nanoparticles (50mg/kg) and methotrexate (0.1mg/kg) were administered by intraperitoneal route from day 11 to day 22 on alternate days. It was found that treatment with silver nanoparticles stabilised with Piper nigrum (S-AgNPs) significantly reduced the paw edema and alleviated the histopathological changes of cell infiltration, synovial hyperplasia, bone and cartilage destruction. Furthermore, the phytostabilised silver nanoparticles (S-AgNPs) inhibited the protein expression of NF-kβ p65 and TNF-α as evidenced by immunohistochemistry analysis. Our current findings suggest that silver nanoparticles stabilised with Piper nigrum extract (S-AgNPs) have potent anti-arthritic activity which is mediated by inhibition of TNF-α and suppression of pro-inflammatory cytokines that are secreted in response to activated transcription factors of NF-kβ. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Phyto-Extraction of Nickel by Linum usitatissimum in Association with Glomus intraradices.

    Science.gov (United States)

    Amna; Masood, Sajid; Syed, Jabir Hussain; Munis, Muhammad Farooq Hussain; Chaudhary, Hassan Javed

    2015-01-01

    Plants show enhanced phytoremediation of heavy metal contaminated soils particularly in response to fungal inoculation. Present study was conducted to find out the influence of Nickel (Ni) toxicity on plant biomass, growth, chlorophyll content, proline production and metal accumulation by L. usitatissimum (flax) in the presence of Glomus intraradices. Flax seedlings of both inoculated with G. intraradices and non-inoculated were exposed to different concentrations i.e., 250, 350 and 500 ppm of Ni at different time intervals. Analysis of physiological parameters revealed that Ni depressed the growth and photosynthetic activity of plants. However, the inoculation of plants with arbuscular mycorrhizae (G. intraradices) partially helped in the alleviation of Ni toxicity as indicated by improved plant growth under Ni stress. Ni uptake of non- mycorrhizal flax plants was increased by 98% as compared to control conditions whereas inoculated plants showed 19% more uptake when compared with the non-inoculated plants. Mycorrhizal plants exhibited increasing capacity to remediate contaminated soils along with improved growth. Thus, AM assisted phytoremediation helps in the accumulation of Ni in plants to reclaim Ni toxic soils. Based on our findings, it can be concluded that the role of flax plants and mycorrhizal fungi is extremely important in phytoremediation.

  18. Quantum chemical studies of trace gas adsorption on ice nanoparticles

    Science.gov (United States)

    Schrems, Otto; Ignatov, Stanislav K.; Gadzhiev, Oleg B.; Masunov, Artem E.

    2013-04-01

    We have investigated the interaction of atmospheric trace gases with crystalline water ice particles of nanoscale size by modern quantum chemical methods. Small ice particles which can be formed in different altitudes play an important role in chemistry and physics of the Earth atmosphere. Knowledge about the uptake and incorporation of atmospheric trace gases in ice particles as well as their interactions with water molecules is very important for the understanding of processes at the air/ice interface. The interaction of the atmospheric trace gases with atmospheric ice nanoparticles is also an important issue for the development of modern physicochemical models. Usually, the interactions between trace gases and small particles considered theoretically apply small-size model complexes or the surface models representing only fragments of the ideal surface. Ice particles consisting of 48, 72, 216 and 270 water molecules with a distorted structure of hexagonal water ice Ih were studied using the new SCC-DFTBA method combining well the advantages of the DFT theory and semiempirical methods of quantum chemistry. The largest clusters correspond to the minimal nanoparticle size which are considered to be crystalline as determined experimentally. The clusters up to (H2O)72 were studied at the B3LYP/6-31++G(d,p) and B3LYP/6-311++G(2d,2p) levels. The larger clusters were studied using DFTBA and DFTB+ methods. Several adsorption complexes for the (H2O)270 water ice cluster were optimized at the RI-BLYP/6-31+G(d) theory level to verify the DFTB+ results. Trace gas molecules were coordinated on different sites of the nanoparticles corresponding to different ice Ih crystal planes: (0001), (10-10), (11-20). As atmospheric trace gases we have chosen CO, CO2, HCO*, HCOH*, HCHO, HCOOH and (HCO)2. which are the possible products and intermediates of the UV photolysis of organic molecules such as HCHCHO adsorbed on the ice surface. The structures of the corresponding coordination

  19. Factors associated with chemical burns in Zhejiang province, China: An epidemiological study

    Directory of Open Access Journals (Sweden)

    Jiang Rui M

    2011-09-01

    Full Text Available Abstract Background Work-related burns are common among occupational injuries. Zhejiang Province is an industrial area with a high incidence of chemical burns. We aimed to survey epidemiological features of chemical burns in Zhejiang province to determine associated factors and acquire data for developing a strategy to prevent and treat chemical burns. Methods Questionnaires were developed, reviewed and validated by experts, and sent to 25 hospitals in Zhejiang province to prospectively collect data of 492 chemical burn patients admitted during one year from Sept. 1, 2008 to Aug. 31, 2009. Questions included victims' characteristics and general condition, injury location, causes of accident, causative chemicals, total body surface area burn, concomitant injuries, employee safety training, and awareness level of protective measures. Surveys were completed for each of burn patients by burn department personnel who interviewed the hospitalized patients. Results In this study, 417 victims (87.61% got chemical burn at work, of which 355 victims (74.58% worked in private or individual enterprises. Most frequent chemicals involved were hydrofluoric acid and sulfuric acid. Main causes of chemical injury accidents were inappropriate operation of equipment or handling of chemicals and absence of or failure to use effective individual protection. Conclusions Most chemical burns are preventable occupational injuries that can be attributed to inappropriate operation of equipment or handling of chemicals, lack of employee awareness about appropriate action and lack of effective protective equipment and training. Emphasis on safety education and protection for workers may help protect workers and prevent chemical burns.

  20. Accelerating Wave Function Convergence in Interactive Quantum Chemical Reactivity Studies

    CERN Document Server

    Mühlbach, Adrian H; Reiher, Markus

    2015-01-01

    The inherently high computational cost of iterative self-consistent-field (SCF) methods proves to be a critical issue delaying visual and haptic feedback in real-time quantum chemistry. In this work, we introduce two schemes for SCF acceleration. They provide a guess for the initial density matrix of the SCF procedure generated by extrapolation techniques. SCF optimizations then converge in fewer iterations, which decreases the execution time of the SCF optimization procedure. To benchmark the proposed propagation schemes, we developed a test bed for performing quantum chemical calculations on sequences of molecular structures mimicking real-time quantum chemical explorations. Explorations of a set of six model reactions employing the semi-empirical methods PM6 and DFTB3 in this testing environment showed that the proposed propagation schemes achieved speedups of up to thirty percent as a consequence of a reduced number of SCF iterations.

  1. Models of chemical biosignatures - a vibrational spectroscopic study

    Science.gov (United States)

    Bödeker, B.; Böttger, U.; Hübers, H.-W.; deVera, J.-P.; Fox, S.; Strasdeit, H.

    2013-09-01

    Investigating possible biosignatures is of central interest in the search for the oldest traces of terrestrial life. Possible biosignatures are: (i) physical structures, such as fossilized single-celled or colonyforming microorganisms; (ii) biomolecules and their altered residues (chemical biosignatures); (iii) altered element, isotope and mineral compositions in former microbial habitats and related effects caused by metabolic activity [1]. New insights in this field of research are also important in the search for life on other planets and moons, especially Mars. However, abiotically formed organic compounds are widely distributed in the universe. Therefore, in future Mars missions, it will be essential to know whether organic molecules are actually of biological origin. Here, we describe the syntheses and spectroscopic (Raman and infrared) properties of artificial chemical biosignatures that might help answering this question.

  2. [Studies on chemical constituents from bark of Morus nigra].

    Science.gov (United States)

    Wang, Lei; Wang, Hong-Qing; Chen, Ruo-Yun

    2007-12-01

    To investigate the chemical constituents in the barks of Morus nigra. The nine compounds were isolated and purified by column chromatography over silica gel, LH -20 and preparative HPLC and their structures were identified by various spectroscopic methods. The nine compounds were isolated and identified as olcancolic acid , apigenin, cyclocommunol, morusin, cyclomorusin, kuwanon C, daucosterol, ursolic acid, 63-sitosterol. Olcancolic acid, apingenin, cyclocommunol, morusin, cyclomorusin, kuwanon C, daucosterol were firstly isolated from the M. nigra.

  3. Chemical and pharmacological studies of the plants from genus Celastrus.

    Science.gov (United States)

    Su, Xiao-Hui; Zhang, Man-Li; Zhan, Wen-Hong; Huo, Chang-Hong; Shi, Qing-Wen; Gu, Yu-Cheng; Kiyota, Hiromasa

    2009-02-01

    The plants of genus Celastrus, distributed in Asia, have been used as natural insecticides and folk medicines to treat fever, chill, joint pain, edema, rheumatoid arthritis, and bacterial infection in China for a long time. This contribution reviews the chemical constituents, isolated from the plants in genus Celastrus in the past few decades, and their biological activities. The compounds listed are sesquiterpenes (beta-agarofurans), diterpenes, triterpenes, alkaloids, and flavonoids.

  4. [Studies on the chemical constituents of Dendrobium loddigesii rolfe].

    Science.gov (United States)

    Li, M F; Hirata, Y; Xu, G J; Niwa, M; Wu, H M

    1991-01-01

    According to IR, UV, MS and NMR spectra of the compounds isolated from the fresh stem of Dendrobium loddigesii Rolfe (a Chinese medicine), 3 constituents were identified. They are shihunidine, shihunine and dendrophenol (4,4'- dihydroxy-3,3',5-trimethoxybibenzyl). Chemical reactions showed that shihunidine was derived from shihunine during isolation. Shihunidine and shihunine were shown to be inhibitors of Na+, K+-ATPase of the rat kidney.

  5. Chemical Arsenal for the Study of O-GlcNAc

    Directory of Open Access Journals (Sweden)

    Eun J. Kim

    2011-02-01

    Full Text Available The concepts of both protein glycosylation and cellular signaling have been influenced by O-linked-β-N-acetylglucosamine (O-GlcNAc modification (O-GlcNAcylation on the hydroxyl group of serine or threonine residues. Unlike conventional protein glycosylation, O-GlcNAcylation is localized in the nucleocytoplasm and its cycling is a dynamic process that operates in a highly regulated manner in response to various cellular stimuli. These characteristics render O-GlcNAcylation similar to phosphorylation, which has long been considered a major regulatory mechanism in cellular processes. Various efficient chemical approaches and novel mass spectrometric (MS techniques have uncovered numerous O-GlcNAcylated proteins that are involved in the regulation of many important cellular events. These discoveries imply that O-GlcNAcylation is another major regulator of cellular signaling. However, in contrast to phosphorylation, which is regulated by hundreds of kinases and phosphatases, dynamic O-GlcNAc cycling is catalyzed by only two enzymes: uridine diphospho-N-acetyl-glucosamine:polypeptide β-N-acetylglucosaminyl transferase (OGT and β-D-N-acetylglucosaminidase (OGA. Many useful chemical tools have recently been used to greatly expand our understanding of the extensive crosstalk between O-GlcNAcylation and phosphorylation and hence of cellular signaling. This review article describes the various useful chemical tools that have been developed and discusses the considerable advances made in the O-GlcNAc field.

  6. Quantifying the uncertainties of chemical evolution studies. II. Stellar yields

    CERN Document Server

    Romano, D; Tosi, M; Matteucci, F

    2010-01-01

    This is the second paper of a series which aims at quantifying the uncertainties in chemical evolution model predictions related to the underlying model assumptions. Specifically, it deals with the uncertainties due to the choice of the stellar yields. We adopt a widely used model for the chemical evolution of the Galaxy and test the effects of changing the stellar nucleosynthesis prescriptions on the predicted evolution of several chemical species. We find that, except for a handful of elements whose nucleosynthesis in stars is well understood by now, large uncertainties still affect the model predictions. This is especially true for the majority of the iron-peak elements, but also for much more abundant species such as carbon and nitrogen. The main causes of the mismatch we find among the outputs of different models assuming different stellar yields and among model predictions and observations are: (i) the adopted location of the mass cut in models of type II supernova explosions; (ii) the adopted strength ...

  7. Bandwidth Study on Energy Use and Potential Energy Saving Opportunities in U.S. Chemical Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Sabine Brueske, Caroline Kramer, Aaron Fisher

    2015-06-01

    Energy bandwidth studies of U.S. manufacturing sectors can serve as foundational references in framing the range (or bandwidth) of potential energy savings opportunities. This bandwidth study examines energy consumption and potential energy savings opportunities in U.S. chemical manufacturing. The study relies on multiple sources to estimate the energy used in the production of 74 individual chemicals, representing 57% of sector-wide energy consumption. Energy savings opportunities for individual chemicals and for 15 subsectors of chemicals manufacturing are based on technologies currently in use or under development; these potential savings are then extrapolated to estimate sector-wide energy savings opportunity.

  8. Incorporating transgenerational testing and epigenetic mechanisms into chemical testing and risk assessment: A survey of transgenerational responses in environmental chemical studies

    Science.gov (United States)

    A number of environmental chemicals have been shown to alter markers of epigenetic change. Some published multi-generation rodent studies have identified effects on F2 and greater generations after chemical exposures solely to F0 dams, but were not focused on chemical safety. We ...

  9. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: BASIC STUDIES RESULTS FY2010

    Energy Technology Data Exchange (ETDEWEB)

    King, W.; Hay, M.

    2011-01-24

    In an effort to develop and optimize chemical cleaning methods for the removal of sludge heels from High Level Waste tanks, solubility tests have been conducted using nonradioactive, pure metal phases. The metal phases studied included the aluminum phase gibbsite and the iron phases hematite, maghemite, goethite, lepidocrocite, magnetite, and wustite. Many of these mineral phases have been identified in radioactive, High Level Waste sludge at the Savannah River and Hanford Sites. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids and a variety of other complexing organic acids. The results of the solubility tests indicate that mixtures of oxalic acid with either nitric or sulfuric acid are the most effective cleaning solutions for the dissolution of the primary metal phases in sludge waste. Based on the results, optimized conditions for hematite dissolution in oxalic acid were selected using nitric or sulfuric acid as a supplemental proton source. Electrochemical corrosion studies were also conducted (reported separately; Wiersma, 2010) with oxalic/mineral acid mixtures to evaluate the effects of these solutions on waste tank integrity. The following specific conclusions can be drawn from the test results: (1) Oxalic acid was shown to be superior to all of the other organic acids evaluated in promoting the dissolution of the primary sludge phases. (2) All iron phases showed similar solubility trends in oxalic acid versus pH, with hematite exhibiting the lowest solubility and the slowest dissolution. (3) Greater than 90% hematite dissolution occurred in oxalic/nitric acid mixtures within one week for two hematite sources and within three weeks for a third hematite sample with a larger average particle size. This dissolution rate appears acceptable for waste tank cleaning applications. (4) Stoichiometric dissolution of iron phases in oxalic acid (based on the oxalate concentration) and the formation of the preferred 1:1 Fe to oxalate complex

  10. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: BASIC STUDIES RESULTS FY2010

    Energy Technology Data Exchange (ETDEWEB)

    King, W.; Hay, M.

    2011-01-24

    In an effort to develop and optimize chemical cleaning methods for the removal of sludge heels from High Level Waste tanks, solubility tests have been conducted using nonradioactive, pure metal phases. The metal phases studied included the aluminum phase gibbsite and the iron phases hematite, maghemite, goethite, lepidocrocite, magnetite, and wustite. Many of these mineral phases have been identified in radioactive, High Level Waste sludge at the Savannah River and Hanford Sites. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids and a variety of other complexing organic acids. The results of the solubility tests indicate that mixtures of oxalic acid with either nitric or sulfuric acid are the most effective cleaning solutions for the dissolution of the primary metal phases in sludge waste. Based on the results, optimized conditions for hematite dissolution in oxalic acid were selected using nitric or sulfuric acid as a supplemental proton source. Electrochemical corrosion studies were also conducted (reported separately; Wiersma, 2010) with oxalic/mineral acid mixtures to evaluate the effects of these solutions on waste tank integrity. The following specific conclusions can be drawn from the test results: (1) Oxalic acid was shown to be superior to all of the other organic acids evaluated in promoting the dissolution of the primary sludge phases. (2) All iron phases showed similar solubility trends in oxalic acid versus pH, with hematite exhibiting the lowest solubility and the slowest dissolution. (3) Greater than 90% hematite dissolution occurred in oxalic/nitric acid mixtures within one week for two hematite sources and within three weeks for a third hematite sample with a larger average particle size. This dissolution rate appears acceptable for waste tank cleaning applications. (4) Stoichiometric dissolution of iron phases in oxalic acid (based on the oxalate concentration) and the formation of the preferred 1:1 Fe to oxalate complex

  11. A Rapid Compression Expansion Machine (RCEM) for studying chemical kinetics: Experimental principle and first applications

    CERN Document Server

    Werler, Marc; Maas, Ulrich

    2016-01-01

    A novel extension of a rapid compression machine (RCM), namely a Rapid Compression Expansion Machine (RCEM), is described and its use for studying chemical kinetics is demonstrated. Like conventional RCMs, the RCEM quickly compresses a fuel/air mixture by pushing a piston into a cylinder; the resulting high temperatures and pressures initiate chemical reactions. In addition, the machine can rapidly expand the compressed gas in a controlled way by pulling the piston outwards again. This freezes chemical activity after a pre-defined reaction duration, and therefore allows a convenient probe sampling and ex-situ gas analysis of stable species. The RCEM therefore is a promising instrument for studying chemical kinetics, including also partially reacted fuel/air mixtures. The setup of the RCEM, its experimental characteristics and its use for studying chemical reactions are outlined in detail. To allow comparisons of RCEM results with predictions of chemical reaction mechanisms, a simple numerical model of the RCE...

  12. On the study of nonlinear dynamics of complex chemical reaction systems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With ever-increasing attentions being paid to complex systems such as the life system, soft matter, and nano-systems, theoretical studies of non-equilibrium nonlinear problems involved in chemical dynamics are now of general interest. In this mini-review, we mainly give a brief introduction to some frontier topics in this field, namely, nonlinear state-state dynamics, nonlinear chemical dynamics on complex networks, and nonlinear dynamics in mesoscopic chemical reaction systems. Deep study of these topics will make great contribution to discovering new laws of chemical dynamics, to exploring new control methods of complex chemical processes, to figuring out the very roles of chemical processes in the life system, and to crosslinking the scientific study of chemistry, physics and biology.

  13. Collagen-curcumin interaction - A physico-chemical study

    Indian Academy of Sciences (India)

    N Nishad Fathima; R Saranya Devi; K B Rekha; Aruna Dhathathreyan

    2009-07-01

    Curcumin is a widely used therapeutic agent with a wide spectrum of biological and physiological applications like wound healing and interacts with the skin protein, collagen. This work reports the effect of curcumin on various physico-chemical properties of collagen. The results suggest that significant changes in viscosity and surface tension occur on collagen interacting with curcumin. Secondary structure analysis using circular dichroism shows that curcumin does not alter the triple helical structure of collagen. Increasing concentration of curcumin resulted in aggregation of the protein. Further, curcumin imparts high level of thermal stability to collagen with shrinkage temperature of collagen increasing from 60 to 90°C.

  14. An Experimental Study on Electro Chemical Machining of Microelectrode

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liao-yuan; LIU Yao

    2006-01-01

    Puts forward a new method in machining microelectrode by electro chemical machining (ECM) and plastic deformed theory. Theprocedure of this method is to machine the microelectrode according to the basic rule of ECM theory at first. Then, with the change of ECM machining parameters, one of the microelectrode ends is exerted by a load. As a result, the elastic and plastic deformation is produced at the machining section and the microelectrode diameter is reduced.It has been proved that the proposed method can determine the optimum machining parameters to machine the microelectrode of Cu.

  15. Physico-Chemical Study of Barium (II) Dipivaloylmethanate Nature

    OpenAIRE

    Fedotova, N.; Igumenov, I.; Mamatyuk, V.; Sidorenko, G.

    1995-01-01

    A physico-chemical research of bis-(dipivaloylmethanato)baryum(II) (Ba(thd)2) has been carried out from the point of its use in CVD process as a precursor (thermal stability, immunity to external effects and etc.). The optimal conditions for synthesis, purification and storage have been found. It has been shown, that the sublimated product presents a mixture of several modifications with the main phase of a composition Ba4(th)8. At a lowered pressure the sublimated product is preserved withou...

  16. Structural studies of chemical constituents of Thithonia Tagetiflora Desv (Asteraceae)

    DEFF Research Database (Denmark)

    Ngoc Huynh, Vinh; Nguyen Thi Hoai, Thu; Phi Phung Nguyen, Kim

    2013-01-01

    Tithonia tagetiflora Desv. (Asteraceae) is a widespread plant in Vietnam, and the species of Tithonia are known as plants containing many biologically active compounds. However, T. tagetiflora's chemical composition remains mostly unknown. Therefore, we now report the structural elucidation of tw......)-roseoside (4), and one glutinane type triterpene, epi-glutinol (5), from the leaves of T. tagetiflora. Their structures are established by 1D and 2D NMR spectroscopy, as well as ESI-MS analysis and comparison with literature data...

  17. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study.

    Science.gov (United States)

    Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan; Dirksen, Asger; Elberling, Jesper

    2011-06-01

    Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0.006). Our results suggest that individuals with self-reported chemical sensitivity show increased non-allergic cutaneous reactions based on day 2 readings of patch tests.

  18. Studies on modelling of bubble driven flows in chemical reactors

    Energy Technology Data Exchange (ETDEWEB)

    Grevskott, Sverre

    1997-12-31

    Multiphase reactors are widely used in the process industry, especially in the petrochemical industry. They very often are characterized by very good thermal control and high heat transfer coefficients against heating and cooling surfaces. This thesis first reviews recent advances in bubble column modelling, focusing on the fundamental flow equations, drag forces, transversal forces and added mass forces. The mathematical equations for the bubble column reactor are developed, using an Eulerian description for the continuous and dispersed phase in tensor notation. Conservation equations for mass, momentum, energy and chemical species are given, and the k-{epsilon} and Rice-Geary models for turbulence are described. The different algebraic solvers used in the model are described, as are relaxation procedures. Simulation results are presented and compared with experimental values. Attention is focused on the modelling of void fractions and gas velocities in the column. The energy conservation equation has been included in the bubble column model in order to model temperature distributions in a heated reactor. The conservation equation of chemical species has been included to simulate absorption of CO{sub 2}. Simulated axial and radial mass fraction profiles for CO{sub 2} in the gas phase are compared with measured values. Simulations of the dynamic behaviour of the column are also presented. 189 refs., 124 figs., 1 tab.

  19. Synthesis and quantum chemical studies of metalloorganics for electro-optical studies

    Science.gov (United States)

    Deepthi, S.; Jha, A.; Kumar, Ch. Ravi Shankar

    2017-07-01

    The dynamic nature of molecular materials are functional due to their nonlinear optical properties. Nonlinearity arising due to intermolecular interactions as self assembling phenomena between organic and metallic nanoparticles is of interest. The insight of this phenomena is attributed both by experimental and quantum chemical studies. Vibration studies performed by FTIR reveal intermolecular bonding forming metalloorganic POMZ with PAA and zinc oxide. These wave numbers were in agreement with theoretical studies performed by Gaussian 03v software package with B3LYP/6-31G basis set. Nonlinear optical properties such as energy difference, dipole moment, electronegativity, electrophylicity index and polarizability were attributed for electrical and optical properties of the material.

  20. CH 1 Introduction to Chemistry. Study Guide to Minicourse I - 13 Chemical Reaction Principles.

    Science.gov (United States)

    Schlenker, Richard

    Provided is a study guide for an introductory minicourse to the principles of chemical reactions. This written text is designed to accompany a series of audio tapes and 35mm slides which the student studies at his own pace. The course presents chemical kinetics, reaction mechanisms, reaction rates, and equilibrium. (SL)

  1. Use of the LITEE Lorn Manufacturing Case Study in a Senior Chemical Engineering Unit Operations Laboratory

    Science.gov (United States)

    Abraham, Nithin Susan; Abulencia, James Patrick

    2011-01-01

    This study focuses on the effectiveness of incorporating the Laboratory for Innovative Technology and Engineering Education (LITEE) Lorn Manufacturing case into a senior level chemical engineering unit operations course at Manhattan College. The purpose of using the case study is to demonstrate the relevance of ethics to chemical engineering…

  2. Compost and sulfur affect the mobilization and phyto-availability of Cd and Ni to sorghum and barnyard grass in a spiked fluvial soil.

    Science.gov (United States)

    Shaheen, Sabry M; Balbaa, Ali A; Khatab, Alaa M; Rinklebe, Jörg

    2017-04-25

    Soil reclamation via additives can cause contradictory effects on the mobilization of toxic elements in soils under dry and wet conditions. Therefore, our aim was to investigate the impact of compost and sulfur in two rates (1.25 and 2.5%) on fractionation, mobilization, and phyto-availability of cadmium (Cd) and nickel (Ni) to sorghum (dry soil) and barnyard grass (wet soil) in a fluvial soil spiked with 25 mg Cd or 200 mg Ni/kg soil. Compost decreased the solubility and mobilization of Cd (especially in dry soil) and Ni (in both soils). Sulfur increased the solubility of Cd (31% in dry soil-49% in wet soil) and Ni (4.6% in wet soil-8.7% in dry soil). Sulfur altered the carbonate fraction of Cd to the soluble fraction and the residual fraction of Cd and Ni to the non-residual fraction. Compost decreased Cd and increased Ni in sorghum, but enhanced Cd and degraded Ni in grass. Sulfur increased Cd and Ni in both plants, and the increasing rate of Cd was higher in grass than in sorghum, while Ni was higher in sorghum than in grass. These results suggest that compost can be used as an immobilizing agent for Cd in the dry soil and Ni in the wet soil; however, it might be used as mobilizing agent for Cd in the wet soil and Ni in the dry soil. Sulfur (with rate 2.5%) can be used for enhancing the phyto-extraction of Cd and Ni (especially Cd) from contaminated alkaline soils.

  3. [Study of chemical constituents in active parts of Mentha spicata III].

    Science.gov (United States)

    Chen, Guang-Tong; Gao, Hui-Yuan; Zheng, Jian; Wu, Bin; Yang, Xiao-Ke; Wu, Li-Jun

    2006-04-01

    To study the chemical constituents of Mentha spicata. The chemical constituents were isolated by silica gel column chromatography, and identified by physical and chemical characters and spectroscopic analysis. Compounds I - V were obtained and their structures were elucidated as protocatechuic aldehyde (I), protocatechuic acid (II), chrysoeriol (III), 5, 6-dihydroxy-7, 8, 3', 4'-tetramethoxyflavone (IV), nodifloretin (V). Compound I and II were first isolated from the genus Mentha. Compound Ill, IV and V were isolated from M. spicata for the first time.

  4. Physico-chemical study of barium (II) dipivaloylmethanate nature

    Energy Technology Data Exchange (ETDEWEB)

    Fedotova, N.E. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. of Inorganic Chemistry; Igumenov, I.K. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. of Inorganic Chemistry; Mamatyuk, V.I. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. of Inorganic Chemistry; Sidorenko, G.V. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. of Inorganic Chemistry

    1995-06-01

    A physico-chemical research of bis-(dipivaloylmethanato)barium(II) (Ba(thd){sub 2}) has been carried out from the point of its use in CVD processes as a precursor (thermal stability, immunity to external effects and etc.). The optimal conditions for synthesis, purification and storage have been found. It has been shown, that the sublimated product presents a mixture of several modifications with the main phase of a composition Ba{sub 4}(thd){sub 8}. At a lowered pressure the sublimated product is preserved without decomposition for a long time. In the air it is a monomer of a composition Ba(thd){sub 2}*2H{sub 2}O, decomposing in the course of time with forming a free ligand or a diketone (C{sub 8}H{sub 21}O{sub 2}) depending on the way of purification of the initial compound. (orig.).

  5. TREATMENT TANK CORROSION STUDIES FOR THE ENHANCED CHEMICAL CLEANING PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.

    2011-08-24

    Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than

  6. TREATMENT TANK CORROSION STUDIES FOR THE ENHANCED CHEMICAL CLEANING PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.

    2011-08-24

    Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than

  7. Quantum chemical studies on structural, vibrational, nonlinear optical properties and chemical reactivity of indigo carmine dye

    Science.gov (United States)

    El-Mansy, M. A. M.

    2017-08-01

    Structural and vibrational spectroscopic studies were performed on indigo carmine (IC) isomers using FT-IR spectral analysis along with DFT/B3LYP method utilizing Gaussian 09 software. GaussView 5 program has been employed to perform a detailed interpretation of vibrational spectra. Simulation of infrared spectra has led to an excellent overall agreement with the observed spectral patterns. Mulliken population analyses on atomic charges, MEP, HOMO-LUMO, NLO, first order hyperpolarizability and thermodynamic properties have been examined by (DFT/B3LYP) method with the SDD basis set level. Density of state spectra (DOS) were calculated using GaussSum 3 at the same level of theory. Molecular modeling approved that DOS Spectra are the most significant tools for differentiating between two IC isomers so far. Moreover, The IC isomers (cis-isomer) have shown an extended applicability for manufacturing both NLO and photovoltaic devices such as solar cells.

  8. [Multifrequency vestibular study after vestibular neurotomy and chemical labyrinthectomy].

    Science.gov (United States)

    Morel, N; Dumas, G; Righini, C; Karkas, A; Hitter, A; Schmerber, S

    2008-06-01

    Vestibular neurotomy (VN) and chemical labyrinthectomy (CL) are the two most common techniques of vestibular deafferention to treat patients with intractable vertigo. A long-term evaluation of vestibular function has been performed with a variety of vestibular tests to find out whether there persisted any residual vestibular function after each technique. We called in all patients who have been treated for the last 10 years and have no known vestibular disease in the non treated ear. Low frequencies were analyzed with caloric tests, medium frequencies with the head-shaking test and head-impulse test, and high frequencies with the skull vibration test. The otolithic function was explored with the subjective vertical visual analysis and otolithic myogenic evoked potentials. Nine patients treated with VN and 12 with CL presented to our department. We were thus able to compare VN and CL patients with a group of 10 normal patients and another group of nine patients that had had a translabyrinthine approach for an acoustic neuroma. We found out that vestibular responses did persist in seven out of nine (78 %) patients after VN and 11 out of 12 (92 %) patients after CL. On the other hand, no vestibular response was detected following resection of vestibular schwannoma through a translabyrinthine approach. We came to the conclusion that the two latter techniques, unlike vestibulocochlear nerve section via the translabyrinthine approach, are only incomplete methods of vestibular deafferention.

  9. Interfacial studies of chemical-vapor-infiltrated ceramic matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, J.J. (United Technologies Research Center, East Hartford, CT (USA))

    1990-06-15

    The objective of this program was to investigate the fiber-matrix interfacial chemistry in chemical-vapor-infiltrated SiC matrix composites utilizing NICALON SiC and Nextel 400 mullite fibers and how this interface influences composite properties such as strength, toughness and environmental stability. The SiC matrix was deposited using three different reactants: methyldichlorosilane, methyltrichlorosilane and dimethyldichlorosilane. It was found that by varying the reactant gas flow rates, the ratio of carrier gas to reactant gas, the type of carrier gas (hydrogen or argon), the flushing gas used in the reactor prior to deposition (hydrogen or argon) or the type of silane reactant gas used, the composition of the deposited SiC could be varied from very silicon rich (75 at.%) to carbon rich (60%) to almost pure carbon. Stoichiometric SiC was found to bond very strongly to both NICALON and Nextel fibers, resulting in a weak and brittle composite. A thin carbon interfacial layer deposited either deliberately by the decomposition of methane or inadvertently by the introduction of argon into the reactor prior to silane flow resulted in a weakly bonded fiber-matrix interface and strong and tough composites. However, composites with this type of interface were not oxidatively stable. Preliminary results point ot the use of a carbon-rich SiC (mixture of carbon plus SiC) interfacial zone to achieve a relatively weak, crack-deflecting fiber-matrix bond but also exhibiting oxidative stability. (orig.).

  10. Study of Aerosol Chemical Composition Based on Aerosol Optical Properties

    Science.gov (United States)

    Berry, Austin; Aryal, Rudra

    2015-03-01

    We investigated the variation of aerosol absorption optical properties obtained from the CIMEL Sun-Photometer measurements over three years (2012-2014) at three AERONET sites GSFC; MD Science_Center and Tudor Hill, Bermuda. These sites were chosen based on the availability of data and locations that can receive different types of aerosols from land and ocean. These absorption properties, mainly the aerosol absorption angstrom exponent, were analyzed to examine the corresponding aerosol chemical composition. We observed that the retrieved absorption angstrom exponents over the two sites, GSFC and MD Science Center, are near 1 (the theoretical value for black carbon) and with low single scattering albedo values during summer seasons indicating presence of black carbon. Strong variability of aerosol absorption properties were observed over Tudor Hill and will be analyzed based on the air mass embedded from ocean side and land side. We will also present the seasonal variability of these properties based on long-range air mass sources at these three sites. Brent Holben, NASA GSFC, AERONET, Jon Rodriguez.

  11. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals

    NARCIS (Netherlands)

    Brink, van den N.W.; Arblaster, J.A.; Bowman, S.R.; Conder, J.M.; Elliott, J.E.; Johnson, M.S.; Muir, D.C.G.; Natal-da-Luz, Tiago; Rattner, B.A.; Sample, B.E.; Shore, R.F.

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To ai

  12. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals

    NARCIS (Netherlands)

    Brink, van den N.W.; Arblaster, J.A.; Bowman, S.R.; Conder, J.M.; Elliott, J.E.; Johnson, M.S.; Muir, D.C.G.; Natal-da-Luz, Tiago; Rattner, B.A.; Sample, B.E.; Shore, R.F.

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To

  13. [Advances in studies on chemical constituents and biological activities of Desmodium species].

    Science.gov (United States)

    Liu, Chao; Wu, Ying; Zhang, Qian-Jun; Kang, Wen-Yi; Zhang, Long; Zhou, Qing-Di

    2013-12-01

    The chemical constituents isolated from Desmodium species (Leguminosae) included terpenoids, flavonoids, steroids, alkaloids compounds. Modem pharmacological studies have showed that the Desmodium species have antioxidant, antibacterial, anti-inflammatory, hepatoprotective, diuretic, antipyretic, analgesic and choleretic activity. This article mainly has reviewed the research advances of chemical constituents and biological activities of Desmodium species since 2003.

  14. Immunotoxic effects of chemicals: A matrix for occupational and environmental epidemiological studies.

    NARCIS (Netherlands)

    Veraldi, Angela; Costantini, Adele Seniori; Bolejack, Vanessa; Miligi, Lucia; Vineis, Paolo; Loveren, Henk van

    2006-01-01

    BACKGROUND: Many biological and chemical agents have the capacity to alter the way the immune system functions in human and animals. This study evaluates the immunotoxicity of 20 substances used widely in work environments. METHODS: A systematic literature search on the immunotoxicity of 20 chemical

  15. Single-collision studies of energy transfer and chemical reaction

    Energy Technology Data Exchange (ETDEWEB)

    Valentini, J.J. [Columbia Univ., New York, NY (United States)

    1993-12-01

    The research focus in this group is state-to-state dynamics of reaction and energy transfer in collisions of free radicals such as H, OH, and CH{sub 3} with H{sub 2}, alkanes, alcohols and other hydrogen-containing molecules. The motivation for the work is the desire to provide a detailed understanding of the chemical dynamics of prototype reactions that are important in the production and utilization of energy sources, most importantly in combustion. The work is primarily experimental, but with an important and growing theoretical/computational component. The focus of this research program is now on reactions in which at least one of the reactants and one of the products is polyatomic. The objective is to determine how the high dimensionality of the reactants and products differentiates such reactions from atom + diatom reactions of the same kinematics and energetics. The experiments use highly time-resolved laser spectroscopic methods to prepare reactant states and analyze the states of the products on a single-collision time scale. The primary spectroscopic tool for product state analysis is coherent anti-Stokes Raman scattering (CARS) spectroscopy. CARS is used because of its generality and because the extraction of quantum state populations from CARS spectra is straightforward. The combination of the generality and easy analysis of CARS makes possible absolute cross section measurements (both state-to-state and total), a particularly valuable capability for characterizing reactive and inelastic collisions. Reactant free radicals are produced by laser photolysis of appropriate precursors. For reactant vibrational excitation stimulated Raman techniques are being developed and implemented.

  16. Electrical and magnetoresistivity studies in chemical solution deposited La

    Energy Technology Data Exchange (ETDEWEB)

    Angappane, S.; Murugaraj, P.; Sethupathi, K.; Rangarajan, G.; Sastry, V. S.; Chakkaravarthi, A. Arul; Ramasamy, P.

    2001-06-01

    High quality magnetoresistive La{sub (1{minus}x)}Ca{sub x}MnO{sub 3} thin films have been prepared by the chemical solution deposition technique. A solution of propionate precursors of lanthanum, calcium, and manganese in propionic acid was used for this purpose. Films of varying compositions (x varying from 0.1 to 0.4) were spin coated on to LaAlO{sub 3}(100) and SrTiO{sub 3}(100) substrates at room temperature and pyrolyzed in the temperature range 600{endash}850{degree}C. For fixed compositions, annealing at higher temperatures shifts the insulator{endash}metal transition temperature (T{sub I{endash}M}) to higher values accompanied by a reduction in the resistivity values. The T{sub I{endash}M} variation for different x values was found to be less pronounced in the compositions x=0.2, 0.3, and 0.4. Typical T{sub I{endash}M} values of 283 K and 290 K were obtained for La{sub 0.7}Ca{sub 0.3}MnO{sub 3} coated on LaAlO{sub 3} and SrTiO{sub 3} substrates, respectively, when annealed at 850{degree}C. The substrate effect was found to be more pronounced for the x value 0.1 which showed two peaks (one at 271 K and another at 122 K) in the {rho}-T curve. The roles of substrate mismatch, composition variation, and annealing temperatures are discussed. {copyright} 2001 American Institute of Physics.

  17. Undisclosed chemicals--implications for risk assessment: a case study from the mining industry.

    Science.gov (United States)

    Singh, Khareen; Oates, Christopher; Plant, Jane; Voulvoulis, Nikolaos

    2014-07-01

    Many of the chemicals used in industry can be hazardous to human health and the environment, and some formulations can have undisclosed ingredients and hazards, increasing the uncertainty of the risks posed by their use. The need for a better understanding of the extent of undisclosed information in chemicals arose from collecting data on the hazards and exposures of chemicals used in typical mining operations (copper, platinum and coal). Four main categories of undisclosed chemicals were defined (incomplete disclosure; chemicals with unspecific identities; relative quantities of ingredients not stated; and trade secret ingredients) by reviewing material safety data sheet (MSDS) omissions in previous studies. A significant number of chemicals (20% of 957 different chemicals) across the three sites had a range of undisclosed information, with majority of the chemicals (39%) having unspecific identities. The majority of undisclosed information was found in commercially available motor oils followed by cleaning products and mechanical maintenance products, as opposed to reagents critical to the main mining processes. All three types of chemicals had trade secrets, unspecific chemical identities and incomplete disclosures. These types of undisclosed information pose a hindrance to a full understanding of the hazards, which is made worse when combined with additional MSDS omissions such as acute toxicity endpoints (LD50) and/or acute aquatic toxicity endpoints (LC50), as well as inadequate hazard classifications of ingredients. The communication of the hazard information in the MSDSs varied according to the chemical type, the manufacturer and the regulations governing the MSDSs. Undisclosed information can undermine occupational health protection, compromise the safety of workers in industry, hinder risk assessment procedures and cause uncertainty about future health. It comes down to the duty of care that industries have towards their employees. With a wide range of

  18. Chemical and quantitive study of hepatotoxins from fresh water ...

    African Journals Online (AJOL)

    Aghomotsegin

    2015-07-22

    Jul 22, 2015 ... Recently, studies on the classification and characterization of ... of Saudi Arabia. In this study we isolated and ..... city for Science and Technology, General directorate of research .... Spirulina platensis in axenic cultures. Bull.

  19. Chemical Risk Evaluation: A Case Study in an Automotive Air Conditioner Production Facility

    Directory of Open Access Journals (Sweden)

    Tengku Hanidza T.I.

    2010-01-01

    Full Text Available There has been limited knowledge on worker’s exposure to chemicals used in the automotive industries. The purpose of this study is to assess chemical risk and to determine the adequacy of the existing control measures to reduce chemical exposure. A cross sectional survey was conducted in a factory involving installation and servicing of automotive air conditioner units. Qualitative exposure assessment was carried out following the Malaysian Chemical Health Risk Assessment Manual (CHRA. There were 180 employees, 156 workers worked in the production line, which constitutes six work units Tube fin pressed, Brazing, Welding, Final assembly, Piping and Kit II. From the chemical risk evaluation for each work unit, 26 chemical compounds were used. Most of the chemicals were irritants (eye and skin and some were asphyxiants and sensitizers. Based on the work assignment, 93 out of 180 (51.67% of the workers were exposed to chemicals. The highest numbers of workers exposed to chemicals were from the Brazing section (22.22% while the Final Assembly section was the lowest (1.67%. Health survey among the workers showed occurrence of eye irritation, skin irritation, and respiratory irritation, symptoms usually associated with chemical exposure. Using a risk rating matrix, several work process were identified as having ‘significant risk’. For these areas, the workers are at risk of adverse health effects since chemical exposure is not adequately controlled. This study recommends corrective actions be taken in order to control the level of exposure and to provide a safe work environment for workers.

  20. A study of the chemical composition of peat humic acids by adsorption liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Proskuryakov, V.A.; Surasinkha, S.; Platonova, M.V.; Taran, N.A. [Lev Tolstoi State Pedagogical University, Tula (Russian Federation)

    1998-12-01

    The chemical composition of peat humic acids was studied in detail by IR and UV spectroscopy, elemental, emission spectral X-ray fluorescence, and structural-group analyses, cryoscopy, and capillary gas chromatography.

  1. DS-OPTIMAL DESIGNS FOR STUDYING COMBINATIONS OF CHEMICALS USING MULTIPLE FIXED-RATIO RAY EXPERIMENTS

    Science.gov (United States)

    ABSTRACT Detecting and characterizing interactions among chemicals is an important environmental issue. Traditional factorial designs become infeasible as the number of compounds under study increases. Ray designs, which reduce the amount of experimental effort, can be...

  2. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study

    DEFF Research Database (Denmark)

    Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan;

    2011-01-01

    Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate...... the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened...... sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two...

  3. Theoretical studies of the dynamics of chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, A.F. [Argonne National Laboratory, IL (United States)

    1993-12-01

    Recent research effort has focussed on several reactions pertinent to combustion. The formation of the formyl radical from atomic hydrogen and carbon monoxide, recombination of alkyl radicals and halo-alkyl radicals with halogen atoms, and the thermal dissociation of hydrogen cyanide and acetylene have been studied by modeling. In addition, the inelastic collisions of NCO with helium have been investigated.

  4. Theoretical Studies in Chemical Kinetics - Annual Report, 1970.

    Science.gov (United States)

    Karplus, Martin

    1970-10-01

    The research performed includes (a) Alkali-Halide, Alkali-Halide (MX, M’X’) Exchange Reactions; (b) Inversion Problem; (c) Quantum Mechanics of Scattering Processes, (d) Transition State Analysis of Classical Trajectories, (e) Differential Cross Sections from Classical Trajectories; and (f) Other Studies.

  5. Chemical Study of the Essential Oil of Mutisia Friesiana

    Directory of Open Access Journals (Sweden)

    J. De la Fuente

    2000-03-01

    Full Text Available The composition of essential oil of Mutisia friesiana (Asteracae was studied. The oil is a complex system in which 127 compounds were identified. The major components are monoterpenes: b-phellandrene, (Z-β-ocimene, α and β-pinene and sabinene.

  6. Using chemical approaches to study selenoproteins - focus on thioredoxin reductases

    OpenAIRE

    Hondal, Robert J.

    2009-01-01

    The study of selenocysteine-containing proteins is difficult due to the problems associated with the heterologous production of these proteins. These problems are due to the intricate recoding mechanism used by cells to translate the UGA codon as a sense codon for selenocysteine. The process is further complicated by the fact that eukaryotes and prokaryotes have different UGA recoding machineries.

  7. study of phytoplanktonin relation to physico- chemical properties of a ...

    African Journals Online (AJOL)

    (Babatunde et al., 2014), without phytoplankton, the diversity and abundance of aquatic life ... (mussels, oysters, scallops and clams), and small fish. These animals provide ... Studies on phytoplankton algae of Lotic effluents environment and fresh water in ... influence of physicochemical parameter of water on phytoplankton ...

  8. Physico-Chemical Studies of the Pvc K+ - Selective Membrane

    Directory of Open Access Journals (Sweden)

    Ana COROIAN

    2002-12-01

    Full Text Available A plasticized ion-selective membrane based on PVC matrix which tricrezylphosphate (TCP and containing K+ - ionophores (dibenzo-18-crown-6 and decyl-18-crown-6 was used to obtain a potentiometric potassium sensor. The potassium selective membranes were characterized in terms of their electrochemical and physical properties, surface morphology and structural parameters. The a.c. impedance, UV/VIS analysis of the membranes was also studied.

  9. Preliminary Problem Definition Study on Munitions-Related Chemicals.

    Science.gov (United States)

    1979-04-01

    literature; how- S ever, Sander et al. (1975a, b) studied the effect of N-nitrosomorpholine in a series of experiments with cress plants (Lepidiwu sativum...Adenomas by Amines or Ureas Plus Nitrite and by N-Nitroso Compounds: Effect of Ascorbate, Gallic Acid, Thiocyanate, and Caffine ," j. Nat’l Cancer instit...Washington, D.C. Garber, K. (1970), "Air Pollution by Heavy-Metal-Containing Dusts. Effects on Plants ." LandAirt, Forsch, Sonderh., 25, 59-68

  10. Single Particle Analysis by Combined Chemical Imaging to Study Episodic Air Pollution Events in Vienna

    Science.gov (United States)

    Ofner, Johannes; Eitenberger, Elisabeth; Friedbacher, Gernot; Brenner, Florian; Hutter, Herbert; Schauer, Gerhard; Kistler, Magdalena; Greilinger, Marion; Lohninger, Hans; Lendl, Bernhard; Kasper-Giebl, Anne

    2017-04-01

    The aerosol composition of a city like Vienna is characterized by a complex interaction of local emissions and atmospheric input on a regional and continental scale. The identification of major aerosol constituents for basic source appointment and air quality issues needs a high analytical effort. Exceptional episodic air pollution events strongly change the typical aerosol composition of a city like Vienna on a time-scale of few hours to several days. Analyzing the chemistry of particulate matter from these events is often hampered by the sampling time and related sample amount necessary to apply the full range of bulk analytical methods needed for chemical characterization. Additionally, morphological and single particle features are hardly accessible. Chemical Imaging evolved to a powerful tool for image-based chemical analysis of complex samples. As a complementary technique to bulk analytical methods, chemical imaging can address a new access to study air pollution events by obtaining major aerosol constituents with single particle features at high temporal resolutions and small sample volumes. The analysis of the chemical imaging datasets is assisted by multivariate statistics with the benefit of image-based chemical structure determination for direct aerosol source appointment. A novel approach in chemical imaging is combined chemical imaging or so-called multisensor hyperspectral imaging, involving elemental imaging (electron microscopy-based energy dispersive X-ray imaging), vibrational imaging (Raman micro-spectroscopy) and mass spectrometric imaging (Time-of-Flight Secondary Ion Mass Spectrometry) with subsequent combined multivariate analytics. Combined chemical imaging of precipitated aerosol particles will be demonstrated by the following examples of air pollution events in Vienna: Exceptional episodic events like the transformation of Saharan dust by the impact of the city of Vienna will be discussed and compared to samples obtained at a high alpine

  11. Empirical Force Fields for Mechanistic Studies of Chemical Reactions in Proteins.

    Science.gov (United States)

    Das, A K; Meuwly, M

    2016-01-01

    Following chemical reactions in atomistic detail is one of the most challenging aspects of current computational approaches to chemistry. In this chapter the application of adiabatic reactive MD (ARMD) and its multistate version (MS-ARMD) are discussed. Both methods allow to study bond-breaking and bond-forming processes in chemical and biological processes. Particular emphasis is put on practical aspects for applying the methods to investigate the dynamics of chemical reactions. The chapter closes with an outlook of possible generalizations of the methods discussed.

  12. An Investigative Study of Safety Management Practices in Chemical-Related Industries

    Science.gov (United States)

    Lewers, Sarah Grace

    Industrial chemicals are a major part of the United States economic growth and impact every product that we use in everyday life. Some of the major products produced by chemical-related industries are plastics, textiles, petroleum, paper and important metals. Governmental regulations like those created by the Occupational Safety and Health Organization (OSHA), Environmental Protection Agency (EPA) and the U.S. Chemical Safety and Hazard Investigation Board are vital to a chemical-related industries' safety management. Contributing to and helping to drive economic growth, the enforcement of proper safety practices is a necessity. This study was conducted to investigate and assess various safety management practices in selected chemical-related industries. The research design involved the use of a questionnaire/survey method in which a random sample of participants completed a questionnaire related to the variables of interest. Random sampling helps to ensure the generalizability of the survey results. The target population consisted of a subset of employees currently working for plants, businesses and organizations in chemical-related industries. To collect the data, surveys were given to employees in various positions at chemical-related industries such as basic chemicals, specialty chemicals, agricultural chemicals, pharmaceuticals and consumer products. A set of criteria was created to establish the qualification to be recognized as a chemical-related industry. The questionnaire/survey was reviewed by the Institutional Review Board at NC A&T State University to meet necessary regulation guidelines for research involving human subjects. The results showed that 60.22% or more than half of the respondents have worked with their company and organization for over thirty years providing the ability to see the progression of chemical-related industry safety management practices over time. Over eighty percent (80.66%) or 146 respondents agreed that their company or

  13. Physico-chemical studies for strontium sulfate radiation dosimeter

    Directory of Open Access Journals (Sweden)

    M.A.H. Rushdi

    2015-04-01

    Full Text Available Anhydrous strontium sulfate (SrSO4 has shown a promise candidate as a dosimeter for low dose applications producing unique EPR signals with γ-rays which it has a linear response relationship (r2 = 0.999 in the range of 1–100 Gy. The present study extended to evaluate the properties of strontium sulfate dosimeter in intermediate dose range of technology applications. It was observed that the intensity of the EPR signal at g = 2.01081 increases with a 3rd polynomial function in the range of 0.10–15 kGy. In addition, the radical (SO4− provides a stable signal with a good reproducibility (0.107%. Other physics characteristic including the collision of mass stopping power dependence of the system and the effect of atomic number in different energy regions were investigated. The uncertainty budget for high doses has obtained from the measurement with value of 3.57% at 2σ confidence level.

  14. Chemical Biology Studies on Molecular Diversity of Annonaceous Acetogenins

    Institute of Scientific and Technical Information of China (English)

    Yao Zhu-Jun

    2004-01-01

    Annonaceous acetogenins, isolated from the Annonaceae plants, have been attracting worldwide attention in recent years due to their biological activities, especially as growth inhibitors of certain tumor ceils [ 1 ]. They have been shown to function by blocking complex I in mitochondria [2] as well as ubiquinone-linked NADPH oxidase in the cells of specific tumor cell lines, including some multidrug-resistant ones [3]. These features make these acetogenins excellent leads for the new antitumor agents. In our previous work, the compounds 1a to 1d (Figure 1), which relies on structure simplification while maintaining all essential functionalities of the acetogenins, was in vitro tested against several human solid tumor cell lines and showed interesting cell selectivity [4]. All four analogues show remarkable activity against the HCT-8 and HT-29 cell lines, while compound 1c was found the best [4bi. In order to further investigate the effects of key structural features, a convergent parallel fragments assembly strategy was developed [4e]. In addition, the biological relevancies of typical annonaceous acetogenin mimetics were also studied [4f].

  15. The role of mathematical modelling in chemical and food engineering studies

    OpenAIRE

    Brandão, Teresa R. S.; Silva, Cristina L. M.

    2003-01-01

    The role of mathematical modelling in chemical and food engineering studies is briefly and consistently presented. The main goal was to give a short global overview of the relevant aspects involved in modelling processes. Food engineering problems are generally highlighted. It must be emphasised that the following matter should not be analysed in a narrow perspective. The mathematical modelling field, in chemical and food engineering subjects, is very wide and this paper just presents the ...

  16. Consumer products as sources of chemical exposures to children: case study of triclosan.

    Science.gov (United States)

    Ginsberg, Gary L; Balk, Sophie J

    2016-04-01

    Consumer products are often overlooked as sources of children's exposures to toxic chemicals. Various regulatory bodies have developed lists of chemicals of concern that can be found in products contacted by children. However, this information has not been summarized for health practitioners. This review organizes such chemicals and products into four categories, with the antibacterial agent triclosan used to illustrate the potential risks to children from a common ingredient in consumer products. Biomonitoring, house dust, indoor air, and product testing document children's exposures to a wide variety of chemicals. An increasing number of epidemiology studies have shown associations between these exposures and health effects in children. Triclosan is an example of a chemical contained in high contact products (e.g., soaps, lotions, and toothpaste) not necessarily designed for children. Triclosan exposure in children has been associated with increased responsiveness to airway allergens, with it also capable of endocrine disruption. However, the utility and necessity of this chemical in consumer products has not been demonstrated in most cases. Triclosan and the other examples provided show that a changing marketplace with little regulatory oversight of chemical uses can lead to unanticipated exposures and potential health risks to children.

  17. An Informatics Approach to Evaluating Combined Chemical Exposures from Consumer Products: A Case Study of Asthma-Associated Chemicals and Potential Endocrine Disruptors.

    Science.gov (United States)

    Gabb, Henry A; Blake, Catherine

    2016-08-01

    Simultaneous or sequential exposure to multiple environmental stressors can affect chemical toxicity. Cumulative risk assessments consider multiple stressors but it is impractical to test every chemical combination to which people are exposed. New methods are needed to prioritize chemical combinations based on their prevalence and possible health impacts. We introduce an informatics approach that uses publicly available data to identify chemicals that co-occur in consumer products, which account for a significant proportion of overall chemical load. Fifty-five asthma-associated and endocrine disrupting chemicals (target chemicals) were selected. A database of 38,975 distinct consumer products and 32,231 distinct ingredient names was created from online sources, and PubChem and the Unified Medical Language System were used to resolve synonymous ingredient names. Synonymous ingredient names are different names for the same chemical (e.g., vitamin E and tocopherol). Nearly one-third of the products (11,688 products, 30%) contained ≥ 1 target chemical and 5,229 products (13%) contained > 1. Of the 55 target chemicals, 31 (56%) appear in ≥ 1 product and 19 (35%) appear under more than one name. The most frequent three-way chemical combination (2-phenoxyethanol, methyl paraben, and ethyl paraben) appears in 1,059 products. Further work is needed to assess combined chemical exposures related to the use of multiple products. The informatics approach increased the number of products considered in a traditional analysis by two orders of magnitude, but missing/incomplete product labels can limit the effectiveness of this approach. Such an approach must resolve synonymy to ensure that chemicals of interest are not missed. Commonly occurring chemical combinations can be used to prioritize cumulative toxicology risk assessments. Gabb HA, Blake C. 2016. An informatics approach to evaluating combined chemical exposures from consumer products: a case study of asthma

  18. An Informatics Approach to Evaluating Combined Chemical Exposures from Consumer Products: A Case Study of Asthma-Associated Chemicals and Potential Endocrine Disruptors

    Science.gov (United States)

    Gabb, Henry A.; Blake, Catherine

    2016-01-01

    exposures from consumer products: a case study of asthma-associated chemicals and potential endocrine disruptors. Environ Health Perspect 124:1155–1165; http://dx.doi.org/10.1289/ehp.1510529 PMID:26955064

  19. A photometric study of chemically peculiar stars with the STEREO satellites. II. Non-magnetic chemically peculiar stars

    CERN Document Server

    Paunzen, E; Fossati, L; Netopil, M; White, G J; Bewsher, D

    2012-01-01

    We have analysed the photometric data obtained with the STEREO spacecraft for 558 non-magnetic chemically peculiar (CP) stars to search for rotational and pulsational variability. Applying the Lomb-Scargle and the phase dispersion minimisation methods, we have detected photometric variability for 44 objects from which 35 were previously unknown. The new objects are all bright stars on the Ecliptic Plane (magnitude range 4.7 < V < 11.7) and will therefore be of great interest to studies of stellar structure and evolution. In particular, several show multiple signals consistent with hybrid delta Scuti and gamma Doradus pulsation, with different periodicities allowing very different regions of the stellar interior to be studied. There are two subgroups of stars in our sample: the cool metallic line Am (CP1) and the hot HgMn (CP3) stars. These objects fall well inside the classical instability strip where delta Scuti, gamma Doradus and slowly pulsating B-type stars are located. We also expect to find period...

  20. Blaptica dubia as sentinels for exposure to chemical warfare agents - a pilot study.

    Science.gov (United States)

    Worek, Franz; Seeger, Thomas; Neumaier, Katharina; Wille, Timo; Thiermann, Horst

    2016-11-16

    The increased interest of terrorist groups in toxic chemicals and chemical warfare agents presents a continuing threat to our societies. Early warning and detection is a key component for effective countermeasures against such deadly agents. Presently available and near term solutions have a number of major drawbacks, e.g. lack of automated, remote warning and detection of primarily low volatile chemical warfare agents. An alternative approach is the use of animals as sentinels for exposure to toxic chemicals. To overcome disadvantages of vertebrates the present pilot study was initiated to investigate the suitability of South American cockroaches (Blaptica dubia) as warning system for exposure to chemical warfare nerve and blister agents. Initial in vitro experiments with nerve agents showed an increasing inhibitory potency in the order tabun - cyclosarin - sarin - soman - VX of cockroach cholinesterase. Exposure of cockroaches to chemical warfare agents resulted in clearly visible and reproducible reactions, the onset being dependent on the agent and dose. With nerve agents the onset was related to the volatility of the agents. The blister agent lewisite induced signs largely comparable to those of nerve agents while sulfur mustard exposed animals exhibited a different sequence of events. In conclusion, this first pilot study indicates that Blaptica dubia could serve as a warning system to exposure of chemical warfare agents. A cockroach-based system will not detect or identify a particular chemical warfare agent but could trigger further actions, e.g. specific detection and increased protective status. By designing appropriate boxes with (IR) motion sensors and remote control (IR) camera automated off-site warning systems could be realized.

  1. Using Physiologically-Based Pharmacokinetic Models to Incorporate Chemical and Non-Chemical Stressors into Cumulative Risk Assessment: A Case Study of Pesticide Exposures

    Directory of Open Access Journals (Sweden)

    Jonathan I. Levy

    2012-05-01

    Full Text Available Cumulative risk assessment has been proposed as an approach to evaluate the health risks associated with simultaneous exposure to multiple chemical and non-chemical stressors. Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD models can allow for the inclusion and evaluation of multiple stressors, including non-chemical stressors, but studies have not leveraged PBPK/PD models to jointly consider these disparate exposures in a cumulative risk context. In this study, we focused on exposures to organophosphate (OP pesticides for children in urban low-income environments, where these children would be simultaneously exposed to other pesticides (including pyrethroids and non-chemical stressors that may modify the effects of these exposures (including diet. We developed a methodological framework to evaluate chemical and non-chemical stressor impacts on OPs, utilizing an existing PBPK/PD model for chlorpyrifos. We evaluated population-specific stressors that would influence OP doses or acetylcholinesterase (AChE inhibition, the relevant PD outcome. We incorporated the impact of simultaneous exposure to pyrethroids and dietary factors on OP dose through the compartments of metabolism and PD outcome within the PBPK model, and simulated combinations of stressors across multiple exposure ranges and potential body weights. Our analyses demonstrated that both chemical and non-chemical stressors can influence the health implications of OP exposures, with up to 5-fold variability in AChE inhibition across combinations of stressor values for a given OP dose. We demonstrate an approach for modeling OP risks in the presence of other population-specific environmental stressors, providing insight about co-exposures and variability factors that most impact OP health risks and contribute to children’s cumulative health risk from pesticides. More generally, this framework can be used to inform cumulative risk assessment for any compound impacted by

  2. A new chemical scheme to study carbon-rich exoplanet atmospheres

    CERN Document Server

    Venot, Olivia; Agúndez, Marcelino; Decin, Leen; Bounaceur, Roda

    2015-01-01

    Atmospheres with a high C/O ratio are expected to contain an important quantity of hydrocarbons, including heavy molecules (with more than 2 carbon atoms). To study correctly these C-rich atmospheres, a chemical scheme adapted to this composition is necessary. We have implemented a chemical scheme that can describe the kinetics of species with up to 6 carbon atoms. This chemical scheme has been developed with specialists of combustion and validated through experiments on a wide range of T and P. This chemical network is available on the online database KIDA. We have created a grid of 12 models to explore different thermal profiles and C/O ratios. For each of them, we have compared the chemical composition determined with a C0-C2 chemical scheme (species with up to 2 carbon atoms) and with the C0-C6 scheme. We found no difference in the results obtained with the two schemes when photolyses are not included in the model, whatever the temperature of the atmosphere. In contrast, when there is photochemistry, diff...

  3. Occupational exposure to chemicals and fetal growth: the Generation R Study.

    NARCIS (Netherlands)

    Snijder, C.A.; Roeleveld, N.; Velde, E. te; Steegers, E.A.P.; Raat, H.; Hofman, A.; Jaddoe, V.W.; Burdorf, A.

    2012-01-01

    BACKGROUND: Developmental diseases, such as birth defects, growth restriction and preterm delivery, account for >25% of infant mortality and morbidity. Several studies have shown that exposure to chemicals during pregnancy is associated with adverse birth outcomes. The aim of this study was to

  4. Occupational exposure to chemicals and fetal growth: The Generation R Study

    NARCIS (Netherlands)

    C.A. Snijder (Claudia); N. Roeleveld (Nel); E.R. te Velde (Egbert); E.A.P. Steegers (Eric); H. Raat (Hein); A. Hofman (Albert); V.W.V. Jaddoe (Vincent); A. Burdorf (Alex)

    2012-01-01

    textabstractBackground Developmental diseases, such as birth defects, growth restriction and preterm delivery, account for >25 of infant mortality and morbidity. Several studies have shown that exposure to chemicals during pregnancy is associated with adverse birth outcomes. The aim of this study

  5. IR study on surface chemical properties of catalytic grown carbon nanotubes and nanofibers

    Institute of Scientific and Technical Information of China (English)

    Li-hua TENG; Tian-di TANG

    2008-01-01

    In this study, the surface chemical properties of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) grown by catalytic decomposition of methane on nickel and cobalt based catalysts were studied by DRIFT (Diffuse Reflectance Infrared Fourier Transform) and transmission Infrared (IR) spectroscopy. The results show that the surface exists not only carbon-hydrogen groups, but also carboxyl, ketene or quinone (carbonyl) oxygen-containing groups. These functional groups were formed in the process of the material growth, which result in large amount of chemical defect sites on the walls.

  6. Physico-chemical studies of radiation effects in cells: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Powers, E.L.

    1987-03-01

    The career of Dr. E.L. Powers, a pioneer in the development of radiobiology, is reviewed. His initial research involved the effects of radiation and certain chemicals on Paramecium, associated ultrastructural studies on protozoan cells, responses of Rickettsia and bacteriophage to irradiation, and the development of techniques for studying bacterial spores. These efforts established the basic radiation biology of the spore and its importance in understanding the effects of free radicals, oxygen, and water. His recent research extended work on the dry spore to the very wet spore and to other selected chemical systems in aqueous suspension. 126 refs., 2 figs.

  7. Chemical compatibility study of Cooley L18KU, Herculite, and Elephant Mat with Hanford tank waste

    Energy Technology Data Exchange (ETDEWEB)

    Mercado, J.E.

    1998-06-23

    An independent chemical compatibility review of various wrapping and absorbent/padding materials was conducted to evaluate resistance to chemicals and constituents present in liquid waste from the Hanford underground tanks. These materials will be used to wrap long-length contaminated equipment when such equipment is removed from the tanks and prepared for transportation and subsequent disposal or storage. The materials studied were Cooley L18KU, Herculite, and Elephant Mat. The study concludes that these materials are appropriate for use in this application.

  8. Biogeochemical cycling and phyto- and bacterioplankton communities in a large and shallow tropical lagoon (Términos Lagoon, Mexico) under 2009-2010 El Niño Modoki drought conditions

    Science.gov (United States)

    Conan, Pascal; Pujo-Pay, Mireille; Agab, Marina; Calva-Benítez, Laura; Chifflet, Sandrine; Douillet, Pascal; Dussud, Claire; Fichez, Renaud; Grenz, Christian; Gutierrez Mendieta, Francisco; Origel-Moreno, Montserrat; Rodríguez-Blanco, Arturo; Sauret, Caroline; Severin, Tatiana; Tedetti, Marc; Torres Alvarado, Rocío; Ghiglione, Jean-François

    2017-03-01

    The 2009-2010 period was marked by an episode of intense drought known as the El Niño Modoki event. Sampling of the Términos Lagoon (Mexico) was carried out in November 2009 in order to understand the influence of these particular environmental conditions on organic matter fluxes within the lagoon's pelagic ecosystem and, more specifically, on the relationship between phyto- and bacterioplankton communities. The measurements presented here concern biogeochemical parameters (nutrients, dissolved and particulate organic matter [POM], and dissolved polycyclic aromatic hydrocarbons [PAHs]), phytoplankton (biomass and photosynthesis), and bacteria (diversity and abundance, including PAH degradation bacteria and ectoenzymatic activities). During the studied period, the water column of the Términos Lagoon functioned globally as a sink and, more precisely, as a nitrogen assimilator. This was due to the high production of particulate and dissolved organic matter (DOM), even though exportation of autochthonous matter to the Gulf of Mexico was weak. We found that bottom-up control accounted for a large portion of the variability of phytoplankton productivity. Nitrogen and phosphorus stoichiometry mostly accounted for the heterogeneity in phytoplankton and free-living prokaryote distribution in the lagoon. In the eastern part, we found a clear decoupling between areas enriched in dissolved inorganic nitrogen near the Puerto Real coastal inlet and areas enriched in phosphate (PO4) near the Candelaria estuary. Such a decoupling limited the potential for primary production, resulting in an accumulation of dissolved organic carbon and nitrogen (DOC and DON, respectively) near the river mouths. In the western part of the lagoon, maximal phytoplankton development resulted from bacterial activity transforming particulate organic phosphorus (PP) and dissolved organic phosphorus (DOP) to available PO4 and the coupling between Palizada River inputs of nitrate (NO3) and PP. The

  9. A qualitative study of high school students' pre- and post instructional conceptions in chemical bonding

    Science.gov (United States)

    Wang, Renhong

    This study investigated high school students' understanding of chemical bonding prior to and after formal chemistry instruction. Two sets of clinical interviews were conducted prior to and after formal instructions on the topic of chemical bonding using a teacher-as-researcher protocol. Twenty-two students enrolled in a New York Regents Chemistry course were interviewed. Six students participated in the pilot study and the other sixteen were involved in the full study. Oral and pictorial data from the interviews were collected and analyzed in two parts; first, the students' conceptual understanding of chemical bonding including common themes, ideas and misconceptions were identified; second, profiles of each student were made to determine conceptual changes due to formal instruction. The findings showed that students were not familiar with the basic components and structure of atoms, especially the electrostatic properties of the sub-atomic particles. Inter-particle distance, rather than the electrostatic forces between particles, was believed to be the determining cause of the state of matter of a substance. The role of repulsive and attractive electrostatic forces in chemical bonding was not recognized. Students were unable to accurately describe the underlying scientific concepts for all types of chemical bonding and revealed a number of misconceptions, which were resistant to change by instruction. Specific areas of difficulty included the accurate descriptions of ionic bonding, covalent bonding and hydrogen bonding. Further, almost all the students could not use electrostatic forces to explain three states of water and phase changes and most students were unable to describe the energy that was released or absorbed due to bond formation or breaking. Student difficulties stemmed from a lack of understanding of some of the underlying, fundamental chemistry, such as the basic atomic structure, the particulate nature of mater and the role of electrostatic forces in

  10. Identity method to study chemical fluctuations in relativistic heavy-ion collisions

    CERN Document Server

    Gazdzicki, M; Mackowiak, M; Mrowczynski, St

    2011-01-01

    Event-by-event fluctuations of the chemical composition of the hadronic final state of relativistic heavy-ion collisions carry valuable information on the properties of strongly interacting matter produced in the collisions. However, in experiments incomplete particle identification distorts the observed fluctuation signals. The effect is quantitatively studied and a new technique for measuring chemical fluctuations, the identity method, is proposed. The method fully eliminates the effect of incomplete particle identification. The application of the identity method to experimental data is explained.

  11. Chemical studies of elements with Z ≥ 104 in liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Nagame, Yuichiro, E-mail: nagame.yuichiro@jaea.go.jp [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Kratz, Jens Volker [Institut für Kernchemie, Johannes Gutenberg-Universität Mainz, Fritz-Straßmann-Weg 2, 55128 Mainz (Germany); Schädel, Matthias [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan)

    2015-12-15

    Recent studies of the chemical separation and characterization experiments of the first three transactinide elements, rutherfordium (Rf), dubnium (Db), and seaborgium (Sg), conducted atom-at-a-time in liquid phases, are reviewed. A short description on experimental techniques based on partition methods, specifically automated rapid chemical separation systems, is also given. A newly developed experimental approach to investigate single atoms of the heaviest elements with an electrochemical method is introduced. Perspectives for liquid-phase chemistry experiments on heavier elements are briefly discussed.

  12. Quantum chemical study on the corrosion inhibition property of some heterocyclic azole derivatives

    Directory of Open Access Journals (Sweden)

    N. Anusuya

    2015-09-01

    Full Text Available Quantum chemical calculations based on density functional theory (DFT method were performed on heterocyclic azole derivatives as corrosion inhibitors for mild steel in acid media to investigate the relationship between molecular structure of the inhibitors and the corresponding inhibition efficiencies (%. Quantum chemical parameters most relevant to their potential action as corrosion inhibitors have been calculated in the non-protonated and protonated forms in aqueous phase for comparison. Results obtained in this study indicate thatin acidic media, both the protonated and non-protonated forms of the azoles represent the better actual experimental situation.

  13. Selected bibliography for the extraction of uranium from seawater: chemical process and plant design feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Binney, S.E.; Polkinghorne, S.T.; Jante, R.R.; Rodman, M.R.; Chen, A.C.T.; Gordon, L.I.

    1979-02-01

    A selected annotated bibliography of 521 references was prepared as a part of a feasibility study of the extraction of uranium from seawater. For the most part, these references are related to the chemical processes whereby the uranium is removed from the seawater. A companion docment contains a similar bibliography of 471 references related to oceanographic and uranium extraction plant siting considerations, although some of the references are in common. The bibliography was prepared by computer retrieval from Chemical Abstracts, Nuclear Science Abstracts, Energy Data Base, NTIS, and Oceanic Abstracts. References are listed by author, country of author, and selected keywords.

  14. Green chemicals : A Kinetic Study on the Conversion of Glucose to Levulinic Acid

    NARCIS (Netherlands)

    Girisuta, B.; Janssen, L.P.B.M.; Heeres, H.J.

    2006-01-01

    Levulinic acid has been identified as a promising green, biomass derived platform chemical. A kinetic study on one of the key steps in the conversion of biomass to levulinic acid, i.e., the acid catalysed decomposition of glucose to levulinic acid has been performed. The experiments were performed i

  15. Parameter estimation in chemical engineering ; a case study for resin production

    NARCIS (Netherlands)

    Stortelder, W.J.H.

    1996-01-01

    In this report we present a study on parameter estimation in the field of resin production. The mathematical model of the chemical process contains a set of 12 differential algebraic equations (DAEs) and 16 unknown parameters; 8 series of measurements are available, performed under different initial

  16. A detailed comparative study between chemical and bioactive properties of Ganoderma lucidum from different origins

    NARCIS (Netherlands)

    Stojkovic, D.S.; Barros, L.; Calhelha, R.C.; Glamoclija, J.; Ciric, A.; Griensven, van L.J.L.D.; Sokovic, M.; Ferreira, I.C.F.R.

    2014-01-01

    A detailed comparative study on chemical and bioactive properties of wild and cultivated Ganoderma lucidum from Serbia (GS) and China (GCN) was performed. This species was chosen because of its worldwide use as medicinal mushroom. Higher amounts of sugars were found in GS, while higher amounts of or

  17. The Competence of Modelling in Learning Chemical Change: A Study with Secondary School Students

    Science.gov (United States)

    Oliva, José Mª; del Mar Aragón, María; Cuesta, Josefa

    2015-01-01

    The competence of modelling as part of learning about chemical change is analysed in a sample of 35 secondary students, ages 14-15 years, during their study of a curricular unit on this topic. The teaching approach followed is model based, with frequent use of analogies and mechanical models (fruits and bowls, Lego pieces, balls of plasticine,…

  18. Chemical compatibility study of lithium titanate with Indian reduced activation ferritic martensitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Sonak, Sagar, E-mail: sagarsonak@gmail.com [Fusion Reactor Materials Section, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Jain, Uttam [Fusion Reactor Materials Section, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Haldar, Rumu [Material Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kumar, Sanjay [Fusion Reactor Materials Section, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2015-11-15

    Highlights: • Chemical compatibility between Li{sub 2}TiO{sub 3} and Indian RAFM steel has been studied at ITER operating temperature. • The lithium titanate chemically reacted with ferritic martensitic steel to form a brittle and non-adherent oxide layer. • The layer grew in a parabolic manner as a function of heating time. • Diffusion of oxygen (from Li{sub 2}TiO{sub 3}) appears to be controlling the oxide layer. - Abstract: Chemical compatibility between lithium titanate and Indian reduced activation ferritic-martensitic steel (In-RAFMS) was studied for the first time under ITER operating temperature. Lithium titanate required for the study was synthesized in-house. Coupons of In-RAFMS were packed inside lithium titanate powder and heated at 550 °C up to 900 h under inert argon atmosphere. The lithium titanate chemically reacted with ferritic martensitic steel to form a brittle and non-adherent oxide layer. The layer grew in a parabolic manner as a function of heating time. Microstructural and phase evolution of this oxide layer was studied using XRD, SEM and EPMA. Iron and chromium enriched zones were found within the oxide layer. Diffusion of oxygen (from Li{sub 2}TiO{sub 3}) appears to be controlling the oxide layer.

  19. Effect of Continuous Assessment on Learning Outcomes on Two Chemical Engineering Courses: Case Study

    Science.gov (United States)

    Tuunila, R.; Pulkkinen, M.

    2015-01-01

    In this paper, the effect of continuous assessment on the learning outcomes of two chemical engineering courses is studied over a several-year period. Average grades and passing percentages of courses after the final examination are reported and also student feedback on the courses is collected. The results indicate significantly better learning…

  20. CO[subscript 2] Rebreathing: An Undergraduate Laboratory to Study the Chemical Control of Breathing

    Science.gov (United States)

    Domnik, N. J.; Turcotte, S. E.; Yuen, N. Y.; Iscoe, S.; Fisher, J. T.

    2013-01-01

    The Read CO[subscript]2 rebreathing method (Read DJ. "A clinical method for assessing the ventilatory response to carbon dioxide." "Australas Ann Med" 16: 20-32, 1967) provides a simple and reproducible approach for studying the chemical control of breathing. It has been widely used since the modifications made by Duffin and…

  1. Kinetic Study of the Chemical Vapor Deposition of Tantalum in Long Narrow Channels

    DEFF Research Database (Denmark)

    Mugabi, James Atwoki; Eriksen, Søren; Petrushina, Irina

    2016-01-01

    A kinetic study of the chemical vapor deposition of tantalum in long narrow channels is done to optimize the industrial process for the manufacture of tantalum coated plate heat exchangers. The developed model fits well at temperatures between 750 and 850 °C, and in the pressure range of25–990 mb...

  2. Experimental studies of thermal and chemical interactions between molten aluminum and water

    Energy Technology Data Exchange (ETDEWEB)

    Farahani, A.A.; Corradini, M.L. [Univ. of Wisconsin, Madison, WI (United States)

    1995-09-01

    The possibility of rapid physical and chemical aluminum/water interactions during a core melt accident in a noncommercial reactor (e.g., HFIR, ATR) has resulted in extensive research to determine the mechanism by which these interactions occur and propagate on an explosive time scale. These events have been reported in nuclear testing facilities, i.e., during SPERT 1D experiment, and also in aluminum casting industries. Although rapid chemical reactions between molten aluminum and water have been subject of many studies, very few reliable measurements of the extent of the chemical reactions have thus far been made. We have modified an existing 1-D shock tube facility to perform experiments in order to determine the extent of the explosive thermal/chemical interactions between molton aluminum and water by measuring important physical quantities such as the maximum dynamic pressure and the amount of the generated hydrogen. Experimental results show that transient pressures greater than 69 MPa with a rise time of less than 125 {mu}sec can occur as the result of the chemical reaction of 4.2 grams of molton aluminum (approximately 15% of the total mass of the fuel of 28 grams) at 980 C with room temperature water.

  3. Study on Incompatibility of Traditional Chinese Medicine: Evidence from Formula Network, Chemical Space, and Metabolism Room

    Directory of Open Access Journals (Sweden)

    Wei Long

    2013-01-01

    Full Text Available A traditional Chinese medicine (TCM formula network including 362 TCM formulas was built by using complex network methodologies. The properties of this network were analyzed including network diameter, average distance, clustering coefficient, and average degree. Meanwhile, we built a TCM chemical space and a TCM metabolism room under the theory of chemical space. The properties of chemical space and metabolism room were calculated and analyzed. The properties of the medicine pairs in “eighteen antagonisms and nineteen mutual inhibitors,” an ancient rule for TCM incompatibility, were studied based on the TCM formula network, chemical space, and metabolism room. The results showed that the properties of these incompatible medicine pairs are different from those of the other TCM based on the analysis of the TCM formula network, chemical space, and metabolism room. The lines of evidence derived from our work demonstrated that the ancient rule of TCM incompatibility, “eighteen antagonisms and nineteen mutual inhibitors,” is probably scientifically based.

  4. Isotope effects on chemical shifts in the study of intramolecular hydrogen bonds

    DEFF Research Database (Denmark)

    Hansen, Poul Erik

    2015-01-01

    The paper deals with the use of isotope effects on chemical shifts in characterizing intramolecular hydrogen bonds. Both so-called resonance-assisted (RAHB) and non-RAHB systems are treated. The importance of RAHB will be discussed. Another very important issue is the borderline between “static......” and tautomeric systems. Isotope effects on chemical shifts are particularly useful in such studies. All kinds of intramolecular hydrogen bonded systems will be treated, typical hydrogen bond donors: OH, NH, SH and NH+, typical acceptors C=O, C=N, C=S C=N−. The paper will be deal with both secondary and primary...... isotope effects on chemical shifts. These two types of isotope effects monitor the same hydrogen bond, but from different angles...

  5. Chemometric studies of chemical compounds in five cultivars of potatoes from Tenerife.

    Science.gov (United States)

    Casañas, Ricardo; González, Mónica; Rodríguez, Elena; Marrero, Antonio; Díaz, Carlos

    2002-03-27

    A statistical study of correlation and multivariate analysis on the chemical composition of five cultivars of potatoes harvested in Tenerife was carried out to establish the relationships between the chemical compounds and, therefore, to differentiate the samples according to traditional and recent importation potatoes, cultivars, and species/subspecies. A large number of significant correlations between the chemical compounds were found, which suggests biochemical relationships among them. After factor analysis, the dimension space was reduced from 24 variables to eight factors, accounting for 77.2% of the total variance. Starch, moisture, organic acids, and metals are the variables that make it possible to characterize the system without losing very much information. Total differentiation of potato samples according to the criteria species/subspecies and cultivars was obtained using discriminant analysis with all the variables. However, with only four variables (weight of tuber, starch, amylose, and glucose + fructose) it is possible to differentiate between the traditional and recent importation potatoes.

  6. Construction of a microbial natural product library for chemical biology studies.

    Science.gov (United States)

    Kato, Naoki; Takahashi, Shunji; Nogawa, Toshihiko; Saito, Tamio; Osada, Hiroyuki

    2012-04-01

    The RIKEN Natural Products Depository (NPDepo) is a public depository of small molecules. Currently, the NPDepo chemical library contains 39,200 pure compounds, half of which are natural products and their derivatives. In order to reinforce the uniqueness of our chemical library, we have improved our strategies for the collection of microbial natural products. Firstly, a microbial metabolite fraction library coupled with an MP (microbial products) plot database provides a powerful resource for the efficient isolation of microbial metabolites. Secondly, biosynthetic studies of microbial metabolites have enabled us to not only access ingenious biosynthetic machineries, but also obtain a variety of biosynthetic intermediates. Our chemical library contributes to the discovery of molecular probes for increasing our understanding of complex biological processes and for eventually developing new drug leads.

  7. A statistical-chemical and thermodynamic approach to the study of lunar mineralogy

    Science.gov (United States)

    Saxena, S. K.; Walter, L. S.

    1974-01-01

    Principal components analysis is used to study the chemical compositions of pyroxenes of five Apollo 12 specimens. Important correlations are recognized in the variation of oxide weight per cent. These correlations indicating substitutional relationships can be interpreted as representative of stable and metastable trends of crystallization by using crystal-chemical and thermodynamic information. The per cent variance of pyroxene groups with characteristic trends in each specimen can be evaluated and interpreted in terms of history of crystallization. Distribution of Fe and Mg in certain pairs of olivine and pyroxene, which are found in contact in the rock and which may have crystallized simultaneously, is useful in recognizing the tendency towards chemical equilibrium in Fe-Mg distribution during a limited interval in the liquidus or subsolidus stages.

  8. Evaluation of the grass mixture (Faestuca Rubra, Cynodon Dactylon, Lolium Multiflorum and Pennisetum sp.) as Sb phyto-stabilizer in tailings and Sb-rich soils.

    Science.gov (United States)

    Aurora Armienta, M.; Beltrán-Villavicencio, Margarita; Ruiz-Villalobos, Carlos E.; Labastida, Israel; Ceniceros, Nora; Cruz, Olivia; Aguayo, Alejandra

    2017-04-01

    Green house experiments were carried out to evaluate the growth and Sb assimilation of a grass assemblage: Faestuca Rubra, Cynodon Dactylon, Lolium Multiflorum and Pennisetum sp, in tailings and Sb-rich soils. Tailings and soil samples were obtained at the Mexican historical mining zone of Zimapán, Central México. More than 6 tailings impoundments are located at the town outskirts and constitute a contamination source from windblown and waterborne deposit on soils, besides acid mine drainage. Four substrates were used in the experiments: 100% tailings, 20% tailings + 80% soil, 50% tailings + 50% soil , and a soil sample far from tailings as a background. Concentrations of Sb ranged from 310 mg/kg to 413 mg/kg in tailings. A pH of 7.43, 1.27% organic matter, and high concentrations of N, K and P indicated adequate conditions for plant growth. The grass assemblage was raised during 21 days as indicated by OECD (Organisation for Economic Co-operation and Development) Guideline 208 Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test. The highest Sb concentrations were measured in plants grown on tailings with 139 mg/kg in the aerial part and 883 mg/kg in roots. Concentrations of Sb decreased as the proportion of tailings diminished with 22.1 mg/kg in the aerial part and 10 mg/kg in roots corresponding to the plants grown in the 20 % tailings + 80% soil . Bioaccumulation (BAC) and bioconcentration factors (BF) of plants grown on tailings (BAC= 0.42, BCF=3.93) indicated their suitability as a phyto-stabilization option. The grass mixture may be thus applied to control windblown particulate tailings taking advantage to their tolerance to high Sb levels.

  9. "Fito-hormônios": ciência e natureza no tratamento do climatério "Phyto-hormones": Science and nature in the treatment of menopause

    Directory of Open Access Journals (Sweden)

    Ivone Manzali de Sá

    2012-01-01

    Full Text Available Um novo produto chamado "fito-hormônio" foi elaborado para substituir a terapia de reposição hormonal (TRH nos últimos anos. Este desenvolvimento está associado a dois contextos históricos, a saber: o anúncio dos riscos associados à terapia de reposição hormonal (TRH para mulheres no climatério no ano de 2002, e uma mudança de percepção do público consumidor e laboratórios farmacêuticos a respeito das plantas medicinais. Algumas plantas já utilizadas por comunidades tradicionais para sintomas associados ao climatério foram pesquisadas cientificamente nas últimas décadas e, como resultado, uma nova categoria de medicamento foi constituída. A partir das teorias ator-rede e de translação, de Bruno Latour, analisa-se a construção desta categoria de medicamento, e como a ideia de "natural" foi ressignificada pelos atores envolvidos na rede sócio-técnica.A new product called "phyto-hormone" was designed to replace the hormone replacement therapy (HRT in recent years. This development is associated with two historical contexts: the announcement of the risks associated with hormone replacement therapy (HRT for postmenopausal women in 2002, and a change in public perception of consumers and pharmaceutical companies about medicinal plants. Some plants used by traditional communities for symptoms associated with menopause have been scientifically researched in recent decades and, as a result, a new category of medicine was established. From the actor-network theory and translation, Bruno Latour analyzes the construction of this class of drug, and how the idea of "natural" was re-signified by the actors involved in the socio-technical network.

  10. Reconnaissance of Field Sites for the Study of Chemical Weathering on the Guayana Shield, South America

    Energy Technology Data Exchange (ETDEWEB)

    Steefell, C I

    2003-02-01

    Despite the fact that chemical weathering of silicate rocks plays an important role in the draw-down of CO{sub 2} over geologic time scales (Berner and Berner, 1996), the overall controls on the rate of chemical weathering are still not completely understood. Lacking a mechanistic understanding of these controls, it remains difficult to evaluate a hypothesis such as that presented by Raymo and Ruddiman (1992), who suggested that enhanced weathering and CO{sub 2} draw-down resulting from the uplift of the Himalayas contributed to global cooling during the Cenozoic. At an even more fundamental level, the three to four order of magnitude discrepancy between laboratory and field weathering rates is still unresolved (White et al., 1996). There is as yet no comprehensive, mechanistic model for silicate chemical weathering that considers the coupled effects of precipitation, vadose zone flow, and chemical reactions. The absence of robust process models for silicate weathering and the failure to resolve some of these important questions may in fact be related-the controls on the overall rates of weathering cannot be understood without considering the weathering environment as one in which multiple, time-dependent chemical and physical processes are coupled (Malmstrom, 2000). Once chemical weathering is understood at a mechanistic process level, the important controls on chemical weathering (physical erosion, temperature, precipitation) can be folded into larger scale models tracking the global carbon cycle. Our goal in this study was to carry out the preliminary work needed to establish a field research site for chemical weathering om the Cuayana Shield in South America. The Guayana Shield is a Precambrian province greater than 1.5 billion years old covering portions of Venezuela, Guyana (the country), Surinam, French Guiana, and Brazil (Figure 1). More important than the age of the rocks themselves, however, is the age of the erosion surface developed on the Shield, with

  11. Quantitative global studies of reactomes and metabolomes using a vectorial representation of reactions and chemical compounds

    Directory of Open Access Journals (Sweden)

    Triviño Juan C

    2010-04-01

    Full Text Available Abstract Background Global studies of the protein repertories of organisms are providing important information on the characteristics of the protein space. Many of these studies entail classification of the protein repertory on the basis of structure and/or sequence similarities. The situation is different for metabolism. Because there is no good way of measuring similarities between chemical reactions, there is a barrier to the development of global classifications of "metabolic space" and subsequent studies comparable to those done for protein sequences and structures. Results In this work, we propose a vectorial representation of chemical reactions, which allows them to be compared and classified. In this representation, chemical compounds, reactions and pathways may be represented in the same vectorial space. We show that the representation of chemical compounds reflects their physicochemical properties and can be used for predictive purposes. We use the vectorial representations of reactions to perform a global classification of the reactome of the model organism E. coli. Conclusions We show that this unsupervised clustering results in groups of enzymes more coherent in biological terms than equivalent groupings obtained from the EC hierarchy. This hierarchical clustering produces an optimal set of 21 groups which we analyzed for their biological meaning.

  12. A spectroelectrochemical and chemical study on oxidation of hydroxycinnamic acids in aprotic medium

    Energy Technology Data Exchange (ETDEWEB)

    Petrucci, Rita [Dipartimento di Ingegneria Chimica M.M.P.M., Universita di Roma ' La Sapienza' , via del Castro Laurenziano 7, I-00161 Rome (Italy)]. E-mail: rita.petrucci@uniroma1.it; Astolfi, Paola [Dipartimento di Scienze dei Materiali e della Terra, Universita Politecnica delle Marche, via Brecce Bianche, I-60131 Ancona (Italy); Greci, Lucedio [Dipartimento di Scienze dei Materiali e della Terra, Universita Politecnica delle Marche, via Brecce Bianche, I-60131 Ancona (Italy); Firuzi, Omidreza [Dipartimento di Farmacologia delle Sostanze Naturali e Fisiologia Generale, Universita di Roma ' La Sapienza' , p.le Aldo Moro 5, I-00185 Rome (Italy); Saso, Luciano [Dipartimento di Farmacologia delle Sostanze Naturali e Fisiologia Generale, Universita di Roma ' La Sapienza' , p.le Aldo Moro 5, I-00185 Rome (Italy); Marrosu, Giancarlo [Dipartimento di Ingegneria Chimica M.M.P.M., Universita di Roma ' La Sapienza' , via del Castro Laurenziano 7, I-00161 Rome (Italy)

    2007-02-01

    Electrochemical and chemical oxidation of hydroxycinnamic acids (HCAs) was studied to investigate the mechanisms occurring in their antioxidant activities in a protons poor medium. Electrolyses and chemical reactions were followed on-line by monitoring the UV-spectral changes with time; final solutions were analysed by HPLC-MS. Anodic oxidation of mono- and di-HCAs, studied by cyclic voltammetry and controlled potential electrolyses, occurs via a reversible one-step two-electrons process, yielding the corresponding stable phenoxonium cation. A cyclization product was also proposed, as supported by ESR studies. Chemical oxidation with lead dioxide leads to different oxidation products according to the starting substrate. Di-HCAs like chlorogenic and rosmarinic acids and the ethyl ester of caffeic acid gave the corresponding neutral o-quinones, while mono-HCAs like cumaric, ferulic and sinapinic acids yielded the corresponding unstable neutral phenoxyl radical, as supported by the formation of dimerization products evidenced by HPLC-MS. In the case of caffeic acid, traces of the dimerization product suggest that the neutral phenoxyl radical may competitively undergo dimerization or decomposition of the neutral quinone. Chemical oxidation of HCAs was also followed by ESR spectroscopy: the di-HCAs radical anions were generated and detected, whereas among the mono-HCAs only the phenoxyl radical of the sinapinic acid was recorded.

  13. Chronic uranium exposure and growth toxicity for phytoplankton. Dose-effect relationship: first comparison of chemical and radiological toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Gilbin, R.; Pradines, C.; Garnier-Laplace, J. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    The bioavailability of uranium for freshwater organisms, as for other dissolved metals, is closely linked to chemical speciation in solution (U aqueous speciation undergoes tremendous changes in the presence of ligands commonly found in natural waters e.g. carbonate, phosphate, hydroxide and natural organic matter). For the studied chemical domain, short-term uranium uptake experiments have already shown that the free uranyl ion concentration [UO{sub 2}{sup 2+}] is a good predictor of uranium uptake by the green algae Chlamydomonas reinhardtii, as predicted by the Free Ion Activity Model. In agreement with these results, acidic pH and low ligands concentrations in water enhance uranium bioavailability and consequently its potential chronic effects on phytoplankton. Moreover, uranium is known to be both radio-toxic and chemo-toxic. The use of different isotopes of uranium allows to expose organisms to different radiological doses for the same molar concentration: e.g. for a given element concentration (chemical dose), replacing depleted U by U-233 obviously leads to an enhanced radiological delivered dose to organisms (x10{sup 4}). In this work we established relationships between uranium doses (depleted uranium and 233-U ) and effect on the growth rate of the green algae Chlamydomonas reinhardtii. Uranium bioaccumulation was also monitored. Growth rate was measured both in classical batch (0-72 hrs) and continuous (turbidostat) cultures, the latter protocol allowing medium renewal to diminish exudates accumulation and speciation changes in the medium. The differences in effects will be, if possible, related to the development of defence mechanisms against the formation of reactive oxygen species (forms of glutathione) and the production of phyto-chelatins (small peptides rich in cystein that play an important role in the homeostasis and the detoxication of metals in cells). (author)

  14. Concept Studies of Micro-Pump for Chemical Concentration in Handheld Micro Sensors

    Science.gov (United States)

    2007-11-02

    This report summarizes the preliminary results of a short-term innovative research project on the concept study of micro pumps for chemical...main objective of the work is to study the feasibility of certain micro pumping concepts and their potential integration with the sensing material and... micro pumps is demonstrated, although the quantitative assessment of the pumping system is still elusive, partly because of lack of specifications. The

  15. Idaho Chemical Processing Plant and Plutonium-Uranium Extraction Plant phaseout/deactivation study

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, M.W. [Westinghouse Idaho Nuclear Co., Idaho Falls, ID (United States); Thompson, R.J. [Westinghouse Hanford Co., Richland, WA (United States)

    1994-01-01

    The decision to cease all US Department of Energy (DOE) reprocessing of nuclear fuels was made on April 28, 1992. This study provides insight into and a comparison of the management, technical, compliance, and safety strategies for deactivating the Idaho Chemical Processing Plant (ICPP) at Westinghouse Idaho Nuclear Company (WINCO) and the Westinghouse Hanford Company (WHC) Plutonium-Uranium Extraction (PUREX) Plant. The purpose of this study is to ensure that lessons-learned and future plans are coordinated between the two facilities.

  16. Chemical mixtures and environmental effects: a pilot study to assess ecological exposure and effects in streams

    Science.gov (United States)

    Buxton, Herbert T.; Reilly, Timothy J.; Kuivila, Kathryn M.; Kolpin, Dana W.; Bradley, Paul M.; Villeneuve, Daniel L.; Mills, Marc A.

    2015-01-01

    Assessment and management of the risks of exposure to complex chemical mixtures in streams are priorities for human and environmental health organizations around the world. The current lack of information on the composition and variability of environmental mixtures and a limited understanding of their combined effects are fundamental obstacles to timely identification and prevention of adverse human and ecological effects of exposure. This report describes the design of a field-based study of the composition and biological activity of chemical mixtures in U.S. stream waters affected by a wide range of human activities and contaminant sources. The study is a collaborative effort by the U.S. Geological Survey and the U.S. Environmental Protection Agency. Scientists sampled 38 streams spanning 24 States and Puerto Rico. Thirty-four of the sites were located in watersheds impacted by multiple contaminant sources, including industrial and municipal wastewater discharges, crop and animal agricultural runoff, urban runoff, and other point and nonpoint contaminant sources. The remaining four sites were minimally development reference watersheds. All samples underwent comprehensive chemical and biological characterization, including sensitive and specific direct analysis for over 700 dissolved organic and inorganic chemicals and field parameters, identification of unknown contaminants (environmental diagnostics), and a variety of bioassays to evaluate biological activity and toxicity.

  17. A study on natural and anthropogenic changes of chemical compositions in the Nakdong river in Korea

    Science.gov (United States)

    Kim, J.; Choi, H. B.; Choi, U. K.; Lee, J.

    2016-12-01

    The Nakdong river is the longest river in South Korea and about sixty metalliferous mines have been operated since the 1930s. So, the environmental issues have occurred due to mine tailings, which were derived from mining activities located in the basin. In this study, thirty three river samples were collected from branches affected by tailings of each eleven-mine and main stream that meets the branches. Field parameters were measured in situ and major cations, anions, trace elements and water isotopes were determined at the Korea Basic Science Institute. The purpose of this study was, thus, to evaluate whether the mines positioned upper catchment affect on chemical variations of the Nakdong river where bedrocks mostly consist of quartize. Most water samples that dominantly were influenced by chemical weathering are on a weathering line [HCO3+2 SO4 : 2 (Ca + Mg) = 1:1]. However, six samples have shown excess sulfate that were below the 1:1 line and these samples were mostly from the streams around the Seokpo refinery and Sambo mine branch, which were consistent with the results by principle component analysis (PCA). Also, three samples near farmlands can be separated into a group by PCA because of high concentrations of nitrate. Based on the chemical and PCA results, we believe that the chemical compositions of the river have been affected by the mine tailings and agricultural contaminants. However, it is necessary to understand how the contaminants were derived from other inputs, such as synthetic fertilizer, soil, and atmospheric deposition.

  18. Studying the Permian Cross-section (Volga Region) Using Chemical and Isotopic Investigations

    Science.gov (United States)

    Gareev, B. I.; Batalin, G. A.; Nurgalieva, N. G.; Nourgaliev, D. K.

    2016-12-01

    This paper presents a study of international important site: the cross-section of Permian system's Urzhumian Stagein the ravine "Pechischy". Outcrop is located on the right bank of the Volga River (about 10 km West of Kazan). Ithas local, regional and planetary correlation features and also footprints of different geographical scale events.The main objective in the research is the deep study of sediments using chemical and isotopic investigations. XRFspectrometer was used for chemical investigations of samples. Chemistry of carbonates and clastic rocks includesthe analysis of chemical elements, compounds, petrochemical (lithogeochemical) modules for the interpretationof the genesis of lithotypes. For the review of the geochemistry of stable isotopes of carbon (oxygen) we usedIRMS. The main objective is the nature of the isotope fractionation issues, to addressing the issues of stratigraphyand paleogeography.The measurements have shown the variability of chemical parameters in cross-section. It gives us opportunity tosee small changes in sedimentation and recognize the factors that influence to the process.The work was carried out according to the Russian Government's Program of Competitive Growth of KazanFederal University, supported by the grant provided to the Kazan State University for performing the state programin the field of scientific research.

  19. Chemical bath deposition of CdS thin films: An approach to the chemical mechanism through study of the film microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Dona, J.M.; Herrero, J. [CIEMAT, Madrid (Spain). Inst. de Energias Renovables

    1997-11-01

    Many papers have been published lately on chemical bath deposition of CdS (CBD-CdS) thin films and related materials due to the promising results obtained using CBD-CdS for the fabrication of thin-film solar cells. In spite of this little of the research proposes a realistic chemical mechanism for the deposition process based on the determination of kinetic parameters. In this paper the authors present an exhaustive study of the CBD-CdS kinetic from which they propose a new chemical mechanism which agrees with the kinetic parameters determined supported by heterogeneous catalysis concepts. Simultaneously, the dependence of the deposited film structure on the kinetic variables is studied and the results obtained corroborate the proposed mechanism. These studies have allowed the authors to establish a standard set of conditions for the fabrication of homogeneous and continuous very thin CdS films.

  20. Assessment of infant exposure to food chemicals: the French Total Diet Study design.

    Science.gov (United States)

    Hulin, M; Bemrah, N; Nougadère, A; Volatier, J L; Sirot, V; Leblanc, J C

    2014-01-01

    As part of the previous French Total Diet Studies (TDS) focusing on exposure to food chemicals in the population aged 3 years and older, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) launched a specific TDS on infants to complete its overall chemical food safety programme for the general population. More than 500 chemical substances were analysed in food products consumed by children under 3 years old, including nutrients, several endocrine disruptors resulting from human activities (polychlorinated biphenyls, dioxins and furans, brominated flame retardants, perfluoroalkyl acids, pesticide residues, etc.) or migrating from food contact materials such as bisphenol A or phthalates, but also natural substances such as mycotoxins, phytoestrogens and steroids. To obtain a representative and general view of infant food consumption, food items were selected based on results of a national consumption survey conducted specifically on this population. Moreover, a specific study on food was conducted on 429 households to determine which home-cooking practices are employed to prepare food consumed by infants. Overall, the targeted chemical substances were analysed in more than 450 food samples, representing the purchase and home-cooking practices of over 5500 food products. Foods included common foods such as vegetables, fruit or cakes as well as specific infant foods such as infant formula or jarred baby food. The sampling plan covered over 80% of the total diet. Specificities in infant food consumption and habits were therefore considered to define this first infant TDS. This study, conducted on a large scale and focusing on a particularly sensitive population, will provide accurate information on the dietary exposure of children under 3 years to food chemicals, especially endocrine disruptors, and will be particularly useful for risk assessment analysis under the remit of ANSES' expert committees.

  1. The inadequacies of pre-market chemical risk assessment's toxicity studies-the implications.

    Science.gov (United States)

    Tweedale, Anthony C

    2017-01-01

    Industry provides essentially all the data for most (pre-market) chemical risk assessments (RA); academics study a chemical once it is marketed. For two randomly-chosen high production chemicals, despite new European Union mandates to evaluate all data, just 13% of the herbicide bentazon and 15% of the flame-retardant hexabromocyclododecane's published toxicity studies were found in their pre-market RA, and a systematic review on bentazon concludes it has greater hazards than indicated in its RA. More important, for both, academia's toxicity studies were designated as lower quality than industries were, despite showing hazards at lower doses. The accuracy of industry's test methods is analyzed and found to be replicable but insensitive, thus inaccurate. The synthetic pharmaceutical industry originated them, and by 1983 the Organization for Economic Cooperation & Development mandated their test guidelines (TG) methods be accepted for any new study for pre-market RA. For existing studies, industry's "Klimisch" criterion is universally used to evaluate quality, but it only states that TG studies produce the best data. However, no TG can answer the realistic exposure effect hypotheses of academics; therefore, crucially in pre-market RA, tens of thousands of published experimental findings (increasingly at low dose) are ignored to determine the safe dose. Few appreciate this, so scientific debate on the most accurate elements of toxicity tests is urgently indicated. Copyright © 2016 John Wiley & Sons, Ltd.

  2. The chemical state of arsenic in minerals of environmental interest--an XPS and an XAES study.

    Science.gov (United States)

    Atzei, Davide; Da Pelo, Stefania; Elsener, Bernhard; Fantauzzi, Marzia; Frau, Franco; Pierfranco, Lattanzi; Rossi, Antonella

    2003-01-01

    A systematic analytical study using X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger electron spectroscopy (XAES) has been carried out to characterize the chemical state of arsenic in complex environmental samples. The conventional approach, which relies on the chemical shift of the core levels As3d, provides ambiguous results in determining the chemical environment of arsenic. A more accurate approach, based on the Auger parameter and on the Wagner (Chemical State) plot, which combines AsLMM kinetic energy and As3d binding energy, was adopted. This novel method for determining the chemical state of arsenic was employed to completely characterize arsenic in complex environmental samples.

  3. A study of suitability of some conventional chemical preservatives and natural antimicrobial compounds in allelopathic research

    Directory of Open Access Journals (Sweden)

    Plamen Marinov-Serafimov

    2015-12-01

    Full Text Available The impact of three conventional chemical preservatives (sodium benzoate, potassium sorbate and salicylic acid and a natural antimicrobial compound (thymol on germination, dynamics of growth and accumulation of fresh biomass (g per seedling of Lactuca sativa L., cultivar Great Lakes, was studied under laboratory conditions. The tested conventional chemical preservatives demonstrated strong inhibitory effects (GI 27.1-0.0% on germination and initial development of L. sativa, and they cannot be used in allelopathic studies in the laboratory. An addition of thymol at 0.5-1.0 ‰ concentration showed no inhibitory effect (GI varied 81.7-84.6% on germination and initial development of L. sativa. Thymol can therefore be used as a natural antimicrobial compound in allelopathic studies in the laboratory.

  4. Development of an apparatus to study chemical reactions at high temperature - a progress report

    Energy Technology Data Exchange (ETDEWEB)

    Sturzenegger, M.; Schelling, Th.; Steiner, E.; Wuillemin, D. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    TREMPER is an apparatus that was devised to study kinetic and thermodynamic aspects of high-temperature reactions under concentrated solar irradiation. The design allows investigations on solid or liquid samples under inert or reactive atmospheres. The working temperature is adjustable; the upper limit that has yet been reached is about 1900 K. TREMPER will facilitate chemical reactivity studies on a temperature level that is difficult to access by other means. First experiments were conducted to study the decomposition of manganese oxide MnO{sub 2}. Chemical analysis of exposed samples confirmed that the parent MnO{sub 2} was decomposed to mixtures of Mn O and Mn{sub 3}O{sub 4}. The amount of Mn O ranged from 60 mol-% in air to 86 mol-% under inert atmosphere. (author) 1 fig., 1 tab., 2 refs.

  5. Chemical Oxidative Polymerization of 2-Aminothiazole in Aqueous Solution: Synthesis, Characterization and Kinetics Study

    Directory of Open Access Journals (Sweden)

    Hua Zou

    2016-11-01

    Full Text Available The chemical oxidative polymerization of 2-aminothiazole (AT was studied in aqueous solution using copper chloride (CuCl2 as an oxidant. The effect of varying the reaction temperature, reaction time and oxidant/monomer molar ratio on the polymer yield was investigated. The resulting poly(2-aminothiazoles (PATs were characterized by FTIR, 1H NMR, UV-vis, gel permeation chromatography, scanning electron microscopy, thermogravimetric analysis and four-point probe electrical conductivity measurements. Compared with a previous study, PATs with higher yield (81% and better thermal stability could be synthesized. The chemical oxidative polymerization kinetics of AT were studied for the first time. The orders of the polymerization reaction with respect to monomer concentration and oxidant concentration were found to be 1.14 and 0.97, respectively, and the apparent activation energy of the polymerization reaction was determined to be 21.57 kJ/mol.

  6. A study on the effect of chemically synthesized magnetite nanoparticles on earthworm: Eudrilus eugeniae

    Science.gov (United States)

    Samrot, Antony V.; Justin, C.; Padmanaban, S.; Burman, Ujjala

    2016-12-01

    Most look into the benefits of the nanoparticles, but keeping aside the benefits; this study focuses on the impacts of nanoparticles on living systems. Improper disposal of nanoparticles into the environment is a subject of pollution or nano-pollution which in turn affects the flora and fauna in the ecosystem, particularly soil ecosystem. Thus, this study was done to understand the impacts of chemically synthesized magnetite nanoparticles on earthworm—Eudrilus eugeniae, a soil-dependent organism which acquires food and nutrition from decaying matters. The chemically synthesized magnetite nanoparticles were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Earthworms were allowed to interact with different concentrations of synthesized nanoparticles and the effect of the nanoparticles was analysed by studying the phenotypic changes followed by histology and inductively coupled plasma optical emission spectrometry analyses.

  7. A study on the effect of chemically synthesized magnetite nanoparticles on earthworm: Eudrilus eugeniae

    Science.gov (United States)

    Samrot, Antony V.; Justin, C.; Padmanaban, S.; Burman, Ujjala

    2017-02-01

    Most look into the benefits of the nanoparticles, but keeping aside the benefits; this study focuses on the impacts of nanoparticles on living systems. Improper disposal of nanoparticles into the environment is a subject of pollution or nano-pollution which in turn affects the flora and fauna in the ecosystem, particularly soil ecosystem. Thus, this study was done to understand the impacts of chemically synthesized magnetite nanoparticles on earthworm— Eudrilus eugeniae, a soil-dependent organism which acquires food and nutrition from decaying matters. The chemically synthesized magnetite nanoparticles were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Earthworms were allowed to interact with different concentrations of synthesized nanoparticles and the effect of the nanoparticles was analysed by studying the phenotypic changes followed by histology and inductively coupled plasma optical emission spectrometry analyses.

  8. The JACS study I: characteristics of a population of chemically dependent Jewish men and women.

    Science.gov (United States)

    Vex, S L; Blume, S B

    2001-01-01

    In order to learn more about chemically dependent Jewish people, and to help dispel the misinformation about them, the authors surveyed individuals who were part of the JACS database. Data from 379 questionnaires were analyzed and compared with the findings of two general population surveys of Jews and a previous study of Jewish alcoholics. Seventy-one percent of respondents reported dependence on more than one substance. Alcohol was found to be the most prevalent drug of both primary (54.7%) and secondary (24.5%) dependence. The male:female ratios for all chemical dependents (1.08:1) and alcohol dependents (1:1.006) were lower than observed in national studies of American alcoholic populations, as was also found in a previous study of Jewish alcoholics. The hypotheses that alcoholic Jews suffer from lack of education, poor income, alienation or loss of religious conviction failed to be supported by the JACS study. Alcohol is the drug of choice for chemically dependent Jews. The JACS survey does not support previous ideas about causes of Jewish alcoholism. The relatively large proportion of women found deserves further study.

  9. Chemically-doped graphene with improved surface plasmon characteristics: an optical near-field study.

    Science.gov (United States)

    Zheng, Zebo; Wang, Weiliang; Ma, Teng; Deng, Zexiang; Ke, Yanlin; Zhan, Runze; Zou, Qionghui; Ren, Wencai; Chen, Jun; She, Juncong; Zhang, Yu; Liu, Fei; Chen, Huanjun; Deng, Shaozhi; Xu, Ningsheng

    2016-10-01

    One of the most fascinating and important merits of graphene plasmonics is their tunability over a wide range. While chemical doping has proven to be a facile and effective way to create graphene plasmons, most of the previous studies focused on the macroscopic behaviors of the plasmons in chemically-doped graphene and little was known about their nanoscale responses and related mechanisms. Here, to the best of our knowledge, we present the first experimental near-field optical study on chemically-doped graphene with improved surface plasmon characteristics. By using a scattering-type scanning near-field optical microscope (s-SNOM), we managed to show that the graphene plasmons can be tuned and improved using a facile chemical doping method. Specifically, the plasmon interference patterns near the edge of the monolayer graphene were substantially enhanced via nitric acid (HNO3) exposure. The plasmon-related characteristics can be deduced by analyzing such plasmonic fringes, which exhibited a longer plasmon wavelength and reduced plasmon damping rate. In addition, the local carrier density and therefore the Fermi energy level (EF) of graphene can be obtained from the plasmonic nano-imaging, which indicated that the enhanced plasmon oscillation originated from the injection of free holes into graphene by HNO3. These findings were further corroborated by theoretical calculations using density functional theory (DFT). We believe that our findings provide a clear nanoscale picture on improving graphene plasmonics by chemical doping, which will be helpful for optimizing graphene plasmonics and for elucidating the mechanisms of two-dimensional light confinement by atomically thick materials.

  10. Chemical closure study on hygroscopic properties of urban aerosol particles in Sapporo, Japan.

    Science.gov (United States)

    Aggarwal, Shankar Gopala; Mochida, Michihiro; Kitamori, Yasuyuki; Kawamura, Kimitaka

    2007-10-15

    To assess the link between hygroscopicity of atmospheric particles and the chemical composition, we performed a chemical closure study on the hygroscopicity of organic-inorganic mixed particles nebulized from water extracts of ambient aerosols collected in Sapporo, Japan during summer 2005. The hygroscopicity of 100 nm particles was measured using a hygroscopicity tandem differential mobility analyzer (HTDMA) at 5-95% relative humidity. The chemical analyses of the extracts showed that inorganic salts accounted for 32-84% of the water-soluble fraction and that the remaining was water-soluble organic matter (WSOM). The liquid water content (LWC) of particles was primarily governed by the relative abundance of inorganic salts in particles. The chemical closure with a thermodynamic model did not indicate a significant perturbation of LWC by WSOM at 85% RH with the consideration of the uncertainties estimated. However, a positive perturbation by WSOM was suggested at 50% RH. Individual oxygenated compounds identified using gas chromatography were not abundant enough to substantially increase the LWC at 85% RH.

  11. Comparison of toxicity values across zebrafish early life stages and mammalian studies: Implications for chemical testing.

    Science.gov (United States)

    Ducharme, Nicole A; Reif, David M; Gustafsson, Jan-Ake; Bondesson, Maria

    2015-08-01

    With the high cost and slow pace of toxicity testing in mammals, the vertebrate zebrafish has become a tractable model organism for high throughput toxicity testing. We present here a meta-analysis of 600 chemicals tested for toxicity in zebrafish embryos and larvae. Nineteen aggregated and 57 individual toxicity endpoints were recorded from published studies yielding 2695 unique data points. These data points were compared to lethality and reproductive toxicology endpoints analyzed in rodents and rabbits and to exposure values for humans. We show that although many zebrafish endpoints did not correlate to rodent or rabbit acute toxicity data, zebrafish could be used to accurately predict relative acute toxicity through the rat inhalation, rabbit dermal, and rat oral exposure routes. Ranking of the chemicals based on toxicity and teratogenicity in zebrafish, as well as human exposure levels, revealed that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo(a)pyrene, and chlorpyrifos ranked in the top nine of all chemicals for these three categories, and as such should be considered high priority chemicals for testing in higher vertebrates.

  12. A comparative study on the raft chemical properties of various alginate antacid raft-forming products.

    Science.gov (United States)

    Dettmar, Peter W; Gil-Gonzalez, Diana; Fisher, Jeanine; Flint, Lucy; Rainforth, Daniel; Moreno-Herrera, Antonio; Potts, Mark

    2017-09-13

    Research to measure the chemical characterization of alginate rafts for good raft performance and ascertain how formulation can affect chemical parameters. A selection of alginate formulations was investigated all claiming to be proficient raft formers with significance between products established and ranked. Procedures were selected which demonstrated the chemical characterization allowing rafts to effectively impede the reflux into the esophagus or in severe cases to be refluxed preferentially into the esophagus and exert a demulcent effect, with focus of current research on methods which complement previous studies centered on physical properties. The alginate content was analyzed by a newly developed HPLC method. Methods were used to determine the neutralization profile and the acid neutralization within the raft determined along with how raft structure affects neutralization. Alginate content of Gaviscon Double Action (GDA) within the raft was significantly superior (p Alginate formulations require three chemical reactions to take place simultaneously: transformation to alginic acid, sodium carbonate reacting to form carbon dioxide, calcium releasing free calcium ions to bind with alginic acid providing strength to raft formation. GDA was significantly superior (p <.0001) to all other comparators.

  13. Chemical stimulation of gas condensate reservoirs: An experimental and simulation study

    Science.gov (United States)

    Kumar, Viren

    Well productivity in gas condensate reservoirs is reduced by condensate banking when the bottom hole flowing pressure drops below the dewpoint pressure. Several methods have been proposed to restore gas production rates after a decline due to condensate blocking. Gas injection, hydraulic fracturing, horizontal wells and methanol injection have been tried with limited success. These methods of well stimulation either offer only temporary productivity restoration or are applicable only in some situations. Wettability alteration of the rock in the near well bore region is an economic and efficient method for the enhancement of gas-well deliverability. Altering the wettability of porous media from strongly water-wet or oil-wet to intermediate-wet decreases the residual liquid saturations and results in an increase in the relative permeability to gas. Such treatments also increase the mobility and recovery of condensate from the reservoir. This study validates the above hypothesis and provides a simple and cost-efficient solution to the condensate blocking problem. Screening studies were carried out to identify the chemicals based on structure, solubility and reactivity at reservoir temperature and pressure. Experiments were performed to evaluate these chemicals to improve gas and condensate relative permeabilities. The improvement in relative permeability after chemical treatment was quantified by performing high pressure and high temperature coreflood experiments in Berea sandstone, Texas Cream limestone and reservoir cores using synthetic gas mixtures at reservoir conditions. Experiments were done at high flow rates and for long time periods to evaluate the durability of the treatment. Single well simulation studies were conducted to demonstrate the performance of the chemical treatment in the field. The experimental relative permeability data was modeled using a trapping number dependent relative permeability model and incorporated in the simulations. Effect of

  14. Extended Functional Groups (EFG: An Efficient Set for Chemical Characterization and Structure-Activity Relationship Studies of Chemical Compounds

    Directory of Open Access Journals (Sweden)

    Elena S. Salmina

    2015-12-01

    Full Text Available The article describes a classification system termed “extended functional groups” (EFG, which are an extension of a set previously used by the CheckMol software, that covers in addition heterocyclic compound classes and periodic table groups. The functional groups are defined as SMARTS patterns and are available as part of the ToxAlerts tool (http://ochem.eu/alerts of the On-line CHEmical database and Modeling (OCHEM environment platform. The article describes the motivation and the main ideas behind this extension and demonstrates that EFG can be efficiently used to develop and interpret structure-activity relationship models.

  15. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals.

    Science.gov (United States)

    van den Brink, Nico W; Arblaster, Jennifer A; Bowman, Sarah R; Conder, Jason M; Elliott, John E; Johnson, Mark S; Muir, Derek C G; Natal-da-Luz, Tiago; Rattner, Barnett A; Sample, Bradley E; Shore, Richard F

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To aid scientific and regulatory discourse on the application of terrestrial field data in this manner, this article provides practical recommendations regarding the generation and interpretation of terrestrial field data. Currently, biota-to-soil-accumulation factors (BSAFs), biomagnification factors (BMFs), and bioaccumulation factors (BAFs) are the most suitable bioaccumulation metrics that are applicable to bioaccumulation assessment evaluations and able to be generated from terrestrial field studies with relatively low uncertainty. Biomagnification factors calculated from field-collected samples of terrestrial carnivores and their prey appear to be particularly robust indicators of bioaccumulation potential. The use of stable isotope ratios for quantification of trophic relationships in terrestrial ecosystems needs to be further developed to resolve uncertainties associated with the calculation of terrestrial trophic magnification factors (TMFs). Sampling efforts for terrestrial field studies should strive for efficiency, and advice on optimization of study sample sizes, practical considerations for obtaining samples, selection of tissues for analysis, and data interpretation is provided. Although there is still much to be learned regarding terrestrial bioaccumulation, these recommendations provide some initial guidance to the present application of terrestrial field data as a line of evidence in the assessment of chemical bioaccumulation potential and a resource to inform laboratory and modeling efforts.

  16. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals

    Science.gov (United States)

    van den Brink, Nico W.; Arblaster, Jennifer A.; Bowman, Sarah R.; Conder, Jason M.; Elliott, John E.; Johnson, Mark S.; Muir, Derek C.G.; Natal-da-Luz, Tiago; Rattner, Barnett A.; Sample, Bradley E.; Shore, Richard F.

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To aid scientific and regulatory discourse on the application of terrestrial field data in this manner, this article provides practical recommendations regarding the generation and interpretation of terrestrial field data. Currently, biota-to-soil-accumulation factors (BSAFs), biomagnification factors (BMFs), and bioaccumulation factors (BAFs) are the most suitable bioaccumulation metrics that are applicable to bioaccumulation assessment evaluations and able to be generated from terrestrial field studies with relatively low uncertainty. Biomagnification factors calculated from field-collected samples of terrestrial carnivores and their prey appear to be particularly robust indicators of bioaccumulation potential. The use of stable isotope ratios for quantification of trophic relationships in terrestrial ecosystems needs to be further developed to resolve uncertainties associated with the calculation of terrestrial trophic magnification factors (TMFs). Sampling efforts for terrestrial field studies should strive for efficiency, and advice on optimization of study sample sizes, practical considerations for obtaining samples, selection of tissues for analysis, and data interpretation is provided. Although there is still much to be learned regarding terrestrial bioaccumulation, these recommendations provide some initial guidance to the present application of terrestrial field data as a line of evidence in the assessment of chemical bioaccumulation potential and a resource to inform laboratory and modeling efforts.

  17. Study physico-chemical of the sand of the western ERG (Western South Algeria)

    Energy Technology Data Exchange (ETDEWEB)

    Allam, M.; Tafraoui, A. [Faculty of sciences and technology, University of Bechar (Algeria)], email: allammessaouda@yahoo.fr

    2011-07-01

    Silica is gaining increasing importance as it is the base for the production of pure silicon, for which several applications are under development in the electronic and solar energy sectors. The aim of this study is to characterize the sand taken from the Western Erg of Algeria to determine the percentage of silicon it contains. Characterization was done through physical analysis to determine the granulometry of the sand. A chemical analysis was next performed, using diffraction of X-rays and a scanning electron microscope to determine the chemical composition of the sand. Results showed that the sand is mainly made of quartz in the form of rounded and subbarrondis grains and that silicon is prevalent, accounting for 98% of the composition. This study demonstrated that sand from the Western Erg of Algeria is rich in silicon and could be used for silicon production.

  18. Physico-chemical and biological study of the river Chittar at Courtallam, Tamil Nadu (India).

    Science.gov (United States)

    Murugesan, A G; Perumal, C Muthum; Ruby, John

    2007-04-01

    Courtallam Falls of the river Chittar in Tamil Nadu (India) is a place of tourist attraction during the southwest monsoon season. Particularly, in this season high input of detergents and other anthropogenic activities tend to bring in undesirable materials into the water body, whereby the pristine quality is altered. Therefore, a study was undertaken in the peak southwest tourist season to assess physico-chemical and biological quality of the river Chittar. After carrying out analytical study of various water samples, it was found that although the river was not found highly polluted, biological quality was found significantly poor. Excluding sulphate, all the other physico-chemical parameters analyzed were found within the permissible limits. However, the total and faecal coliforms exceeded the permissible limits, indicating a poor status of the river.

  19. Molecular dynamics study of phase separation in fluids with chemical reactions.

    Science.gov (United States)

    Krishnan, Raishma; Puri, Sanjay

    2015-11-01

    We present results from the first d=3 molecular dynamics (MD) study of phase-separating fluid mixtures (AB) with simple chemical reactions (A⇌B). We focus on the case where the rates of forward and backward reactions are equal. The chemical reactions compete with segregation, and the coarsening system settles into a steady-state mesoscale morphology. However, hydrodynamic effects destroy the lamellar morphology which characterizes the diffusive case. This has important consequences for the phase-separating structure, which we study in detail. In particular, the equilibrium length scale (ℓ(eq)) in the steady state suggests a power-law dependence on the reaction rate ε:ℓ(eq)∼ε(-θ) with θ≃1.0.

  20. Enhancing the functionality of cotton fabric by physical and chemical pre-treatments: A comparative study.

    Science.gov (United States)

    Gargoubi, Sondes; Tolouei, Ranna; Chevallier, Pascale; Levesque, Lucie; Ladhari, Neji; Boudokhane, Chedly; Mantovani, Diego

    2016-08-20

    Recently, antimicrobial and decontaminating textiles, such as cotton a natural carbohydrate polymer, are generating more attention. Plant materials used for natural dyes are expected to impart biofunctional properties and high added valued functional textiles. In the current study, surface modification of cotton to maximize the dye amount on the surface has been investigated. Physical modification using nitrogen-hydrogen plasma, chemical modification using chitosan and chemical modification using dopamine as biopolymers imparting amino groups were explored. Furthermore, dye exhaustion of curcumin, as a natural functional dye has been studied. Dye stability tests were also performed after fabric washing using hospital washing protocol to predict the durability of the functionalizations. The results demonstrated that cotton surfaces treated with dopamine exhibit a high level of dye uptake (78%) and a good washing fastness. The use of non-toxic and natural additives during cotton finishing process could give the opportunity of cradle to cradle design for antimicrobial textile industries.

  1. STUDY REGARDING SOME PHYSICAL - CHEMICAL CHARACTERISTICS OF THE YOGHURT WITH RED BEETROOT JUICE

    Directory of Open Access Journals (Sweden)

    Natalia Prodaniuc

    2009-12-01

    Full Text Available The study presents some physical - chemical characteristics of the beetroot juice yoghurt. The following determinations were carried out: the determination of the acidity by titration with sodium hydroxide ( NaOH N/10, the determination of the fat content by the acid-butirometric method and the determination of the dry substance using the drying oven with a 102 °C temperature.

  2. Chemical Studies on Plant Polyphenols and Formation of Black Tea Polyphenols

    OpenAIRE

    田中, 隆

    2008-01-01

    Recent biological and pharmacological studies strongly suggested that plant polyphenols in foods, beverages and crude drugs have various health benefits. However, still there are chemically uncharacterized polyphenols, especially those with large molecular weights. The typical example is black tea polyphenols. Four tea catechins of fresh tea leaves are enzymatically oxidized in tea fermentation process of black tea manufacture to give a complex mixture of the oxidation products. Despite many ...

  3. A Study on Chemical Compositions and Fiber Characteristics of Two Sympodial Bamboos

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The chemical composition and fiber characteristics of two sympodial bamboos have been studied in this paper. Based on analysis results, it is shown that the Whangee (D. Membranaceus Munro) bamboo is better than Yunnanicus bamboo(D. yunnaicus Hsueh et D. Z. Li) in utilization because of its higher specific gravity, better fiber length and its distribution rule and higher wall/lumen ratio, and that the Whangee bamboo is more suitable for papermaking and panel processing used in house construction. In addi...

  4. A new method to study lattice QCD at finite temperature and chemical potential

    CERN Document Server

    Fodor, Z

    2002-01-01

    Due to the sign problem, it is exponentially difficult to study QCD on the lattice at finite chemical potential. In this letter we propose a method --an overlap ensuring multi-parameter reweighting technique-- to solve the problem. We apply this method and give the phase diagram of four-flavor QCD obtained on lattices 4^4 and 4\\cdot6^3. Our results are based on {\\cal{O}}(10^3-10^4) configurations.

  5. Study of sensory diversity and redundancy to encode for chemical mixtures

    Science.gov (United States)

    Gutiérrez-Gálvez, Agustín; Fernandez, Luis; Marco, Santiago

    2011-09-01

    Inspired by sensory diversity and redundancy at the olfactory epithelium, we have built a large chemical sensor array based on commercial MOX sensors. Different sensor families along with temperature modulation accounts for sensory diversity, whereas sensors of the same family combined with different load resistors provide redundancy to the system. To study the encoding of odor mixtures, a data collection consisting on the response of the array to 3 binary mixtures of ethanol, acetone, and butanone with 18 different concentration ratios is obtained.

  6. Time-lapse camera studies of sea-disposed chemical munitions in Hawaii

    Science.gov (United States)

    Edwards, Margo H.; Fornari, Daniel J.; Rognstad, Mark R.; Kelley, Christopher D.; Mah, Christopher L.; Davis, Logan K.; Flores, Kyle R. M.; Main, Erin L.; Bruso, Natalie L.

    2016-06-01

    The interactions between fauna and sea-disposed munitions provide important evidence regarding whether munitions constituents affect the health of the ocean environment and its inhabitants. To date few studies of these interactions have been conducted at deep-water disposal sites; typically observations of fauna in the vicinity of sea-disposed munitions are limited to the few minutes or hours required to collect physical samples at a specific location. During the 2012 Hawaii Undersea Military Munitions Assessment (HUMMA) field program we deployed two deep-sea time-lapse camera systems with the objectives of cataloging the diversity of fauna visiting sea-disposed chemical munitions and observing faunal behavior and physiology. Over the 1- and 3-day deployments we recorded 28 different species of fishes, crustaceans, mollusks, cnidarians, and echinoderms at the two sites. Both cameras captured the previously undocumented behavior of brisingid sea stars repositioning themselves along chemical munitions casings. Despite the fact that brisingid sea stars are able to move, for the duration of both time-lapse experiments they remained on chemical munitions casings. We interpret this result to indicate that the advantages of residing on a hard substrate slightly elevated above the seafloor outweigh the effects of chemical munitions constituents for brisingid sea stars. One type of physiological anomaly observed on several arms of the brisingid sea stars at the time-lapse sites led to the collection and examination of six specimens. As reported by Mah (2015. Deep Sea Res. II, 2015, XX-XX), these physiological features are the result of parasitic crustaceans and are not caused by chemical munitions constituents.

  7. GC-MS studies of the chemical composition of two inedible mushrooms of the genus Agaricus

    Directory of Open Access Journals (Sweden)

    Gjosheva Melania

    2007-12-01

    Full Text Available Abstract Background Mushrooms in the genus Agaricus have worldwide distribution and include the economically important species A. bisporus. Some Agaricus species are inedible, including A. placomyces and A. pseudopratensis, which are similar in appearance to certain edible species, yet are known to possess unpleasant odours and induce gastrointestinal problems if consumed. We have studied the chemical composition of these mushrooms using GC-MS. Results Our GC-MS studies on the volatile fractions and butanol extracts resulted in the identification of 44 and 34 compounds for A. placomyces and A. pseudopratensis, respectively, including fatty acids and their esters, amino acids, and sugar alcohols. The most abundant constituent in the volatiles and butanol were phenol and urea respectively. We also identified the presence of ergosterol and two Δ7-sterols. In addition, 5α,8α-Epidioxi-24(ξ-methylcholesta-6,22-diene-3β-ol was isolated for the first time from both mushrooms. Our study is therefore the first report on the chemical composition of these two species. Conclusion The results obtained contribute to the knowledge of the chemical composition of mushrooms belonging to the Agaricus genus, and provide some explanation for the reported mild toxicity of A. placomyces and A. pseudopratensis, a phenonomenon that can be explained by a high phenol content, similar to that found in other Xanthodermatei species.

  8. STUDY REGARDING THE CORELATION BETWEEN SOMATIC CELLS COUNT AND MAJOR CHEMICAL COMPOUNDS IN RAW MILK

    Directory of Open Access Journals (Sweden)

    S. ACATINCĂI

    2013-12-01

    Full Text Available This study approaches the dynamic of somatic cells number and chemical composition of milk during 13 months of control. The study also investigates the correlations between the number of somatic cells and some chemical parameters in milk. Studies were carried out on Romanian Black and White cows between March 2005 and March 2006 at the Didactical farm of the Banat University of Agricultural Sciences Timisoara. As quality indicator, the number of somatic cells has different values among the controls. Average values for the 13 months of control, with the exception of three controls, were below maximum limit admitted from 1th of January 2007 (600000 SCC/ml milk. There weren’t any significant differences for SCC between the two seasons. Chemical parameters in milk varied in close limits and the differences were not significant, with one exception for fat percent. Fat percent is higher (p<0.05 in the cold season 3.87% compared with 3.55% during the warm season. Somatic cells number is weak correlated with lactose and strong correlated with proteins.

  9. The JaCVAM international validation study on the in vivo comet assay: Selection of test chemicals.

    Science.gov (United States)

    Morita, Takeshi; Uno, Yoshifumi; Honma, Masamitsu; Kojima, Hajime; Hayashi, Makoto; Tice, Raymond R; Corvi, Raffaella; Schechtman, Leonard

    2015-07-01

    The Japanese Center for the Validation of Alternative Methods (JaCVAM) sponsored an international prevalidation and validation study of the in vivo rat alkaline pH comet assay. The main objective of the study was to assess the sensitivity and specificity of the assay for correctly identifying genotoxic carcinogens, as compared with the traditional rat liver unscheduled DNA synthesis assay. Based on existing carcinogenicity and genotoxicity data and chemical class information, 90 chemicals were identified as primary candidates for use in the validation study. From these 90 chemicals, 46 secondary candidates and then 40 final chemicals were selected based on a sufficiency of carcinogenic and genotoxic data, differences in chemical class or genotoxic or carcinogenic mode of action (MOA), availability, price, and ease of handling. These 40 chemicals included 19 genotoxic carcinogens, 6 genotoxic non-carcinogens, 7 non-genotoxic carcinogens and 8 non-genotoxic non-carcinogens. "Genotoxicity" was defined as positive in the Ames mutagenicity test or in one of the standard in vivo genotoxicity tests (primarily the erythrocyte micronucleus assay). These chemicals covered various chemicals classes, MOAs, and genotoxicity profiles and were considered to be suitable for the purpose of the validation study. General principles of chemical selection for validation studies are discussed.

  10. Molecular Beam Studies of Hot Atom Chemical Reactions: Reactive Scattering of Energetic Deuterium Atoms

    Science.gov (United States)

    Continetti, R. E.; Balko, B. A.; Lee, Y. T.

    1989-02-01

    A brief review of the application of the crossed molecular beams technique to the study of hot atom chemical reactions in the last twenty years is given. Specific emphasis is placed on recent advances in the use of photolytically produced energetic deuterium atoms in the study of the fundamental elementary reactions D + H{sub 2} -> DH + H and the substitution reaction D + C{sub 2}H{sub 2} -> C{sub 2}HD + H. Recent advances in uv laser and pulsed molecular beam techniques have made the detailed study of hydrogen atom reactions under single collision conditions possible.

  11. Treatability study report for remediation of chemical warfare agent contaminated soils using peroxysulfate ex-situ treatment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pugh, J.R.; Grinstead, J.H.; Farley, J.A.; Enlow, P.D.; Kelly, D.A.

    1996-07-01

    This laboratory scale study examines the feasibility of using peroxysulfate based oxidants to remediate soils contaminated with GB, Hi, and VX. The project was conducted with chemical warfare agent simulants. The study concludes that peroxysulfates, and particularly peroxydisulfate, can degrade chemical warfare agent simulants in soil and recommends continuing research.

  12. Study of chemical additives in the cementation of radioactive waste of PWR reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Vanessa Mota; Tello, Cledola Cassia Oliveira de, E-mail: tellocc@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Cementation is a very useful process to solidify radioactive wastes. Depending on the waste it can be necessary to use of chemical additives (admixtures) to improve the cementation process and its product. Admixtures are materials, other than cement, aggregate and water, that are added either before or during the mixing to alter some properties, such as workability, curing temperature range, and setting time. However there are a large variety of these materials that are frequently changed or taken out of the market. In this changeable scenario it is essential to know the commercially available materials and their characteristics. In this research the effects of chemical admixtures in the solidification process has been studied. For the tests it was prepared a solution simulating the evaporator concentrate waste, cemented by two different formulations, and three chemical admixtures from two manufacturers. The tested admixtures were accelerators, set retarders and super plasticizers. The experiments were organized by a planning factorial 23 to quantify the effects of formulations, of the admixtures, its quantity and manufacturer in properties of the paste and products. The measured parameters were the density, the viscosity and the setting time of the paste, and the product compressive strength. The parameter evaluated in this study was the compressive strength at age of 28 days, is considered essential security issues relating to the handling, transport and storage of cemented waste product. The results showed that the addition of accelerators improved the compressive strength of the cemented products. (author)

  13. Melting behavior of typical thermoplastic materials--an experimental and chemical kinetics study.

    Science.gov (United States)

    Wang, Nan; Tu, Ran; Ma, Xin; Xie, Qiyuan; Jiang, Xi

    2013-11-15

    A medium-scale melting experiment rig was designed and constructed in this study. A detailed experimental study was conducted on the melting behavior and the chemical kinetic characteristics of three typical thermoplastic materials, including polypropylene (PP), polyethylene (PE) and polystyrene (PS). It is observed that the thermal decomposition of the thermoplastic materials mainly consists of three stages: the initial heating stage, the melting-dominated stage and the gasification-dominated stage. Melting of the materials examined takes place within a certain temperature range. The melting temperature of PS is the lowest, moreover, it takes the shortest time to be completely liquefied. To quantitatively represent the chemical kinetics, an nth-order reaction model was employed to interpret the thermal decomposition behavior of the materials. The calculated reaction order is largely in accordance with the small-scale thermal gravimetric analysis (TGA). The small difference between the results and TGA data suggests that there are some limitations in the small-scale experiments in simulating the behavior of thermoplastic materials in a thermal hazard. Therefore, investigating the thermal physical and chemical properties of the thermoplastic materials and their thermal hazard prevention in medium or large-scale experiments is necessary for the fire safety considerations of polymer materials. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. FE-SEM COMPARATIVE STUDY ON SURFACE MODIFICATION OF WOOL FIBER AFTER DIFFERENT CHEMICAL TREATMENTS

    Directory of Open Access Journals (Sweden)

    BONET-ARACIL Marilés

    2016-05-01

    Full Text Available Wool surface comprehends numerous scales which are responsible of certain undesirable behavior of this fiber during its use and maintenance. One of the most significant issues is related to shrinkage, caused during washing, as a consequence of friction between the fibers. Chemical modification of wool is considered a useful option to avoid these kind of circumstances. During the last years, multiple alternatives for chemical modification of wool have been studied, comprising enzymes or acids amongst others. In this case of study, three different treatments were carried out in order to evaluate wool morphological appearance. The first treatment was an oxidative procedure, containing Basolan DC and sodium acetate as the main components. The second treatment was accomplished using Lanaperm VPO, a commercial finishing agent for wool fiber that claims to soften its surface. The third finishing process was performed employing Siligen FA, a commercial agent intended to act as an antimigrant for dye baths and also provide a smoother and regular surface. After said treatments, microphotographs of all treated and untreated fibers were taken so that a comparison between final appearance could be done. Analyzing results and conclusions, it can be stated that chemical modification of fiber does change its surface appearance and, consequently, its behaviour. Oxidation, Lanaperm, Siligen, wool cuticle, scales

  15. Theoretical research program to study chemical reactions in AOTV bow shock tubes

    Science.gov (United States)

    Taylor, Peter R.

    1993-01-01

    The main focus was the development, implementation, and calibration of methods for performing molecular electronic structure calculations to high accuracy. These various methods were then applied to a number of chemical reactions and species of interest to NASA, notably in the area of combustion chemistry. Among the development work undertaken was a collaborative effort to develop a program to efficiently predict molecular structures and vibrational frequencies using energy derivatives. Another major development effort involved the design of new atomic basis sets for use in chemical studies: these sets were considerably more accurate than those previously in use. Much effort was also devoted to calibrating methods for computing accurate molecular wave functions, including the first reliable calibrations for realistic molecules using full CI results. A wide variety of application calculations were undertaken. One area of interest was the spectroscopy and thermochemistry of small molecules, including establishing small molecule binding energies to an accuracy rivaling, or even on occasion surpassing, the experiment. Such binding energies are essential input to modeling chemical reaction processes, such as combustion. Studies of large molecules and processes important in both hydrogen and hydrocarbon combustion chemistry were also carried out. Finally, some effort was devoted to the structure and spectroscopy of small metal clusters, with applications to materials science problems.

  16. A comprehensive chemical abundance study of the outer halo globular cluster M 75

    CERN Document Server

    Kacharov, Nikolay; McWilliam, Andrew

    2013-01-01

    Context: M 75 is a relatively young Globular Cluster (GC) found at 15 kpc from the Galactic centre at the transition region between the inner and outer Milky Way halos. Aims: Our aims are to perform a comprehensive abundance study of a variety of chemical elements in this GC such as to investigate its chemical enrichment history in terms of early star formation, and to search for any multiple populations. Methods: We have obtained high resolution spectroscopy with the MIKE instrument at the Magellan telescope for 16 red giant stars. Their membership within the GC is confirmed from radial velocity measurements. Our chemical abundance analysis is performed via equivalent width measurements and spectral synthesis, assuming local thermodynamic equilibrium (LTE). Results: We present the first comprehensive abundance study of M 75 to date. The cluster is metal-rich ([Fe/H]=-1.16+/-0.02 dex, [alpha/Fe]=+0.30+/-0.02 dex), and shows a marginal spread in [Fe/H] of 0.07 dex, typical of most GCs of similar luminosity. A ...

  17. Experimental and quantum chemical studies on corrosion inhibition performance of fluconazole in hydrochloric acid solution

    Indian Academy of Sciences (India)

    P Malekmohammadi Nouri; M M Attar

    2015-04-01

    The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also used to calculate some electronic properties of the molecule in neutral and protonated form in order to find any correlation between the inhibition effect and molecular structure of FLU molecule. The results showed that FLU can act as a good corrosion inhibitor for steel in hydrochloric acid solution at different temperatures and it can inhibit steel corrosion up to 95%. The adsorption followed the Langmuir isotherm and the thermodynamic parameters were also determined and discussed. Quantum chemical studies showed that in adsorption process of FLU molecules, nitrogen and oxygen atoms and benzene ring act as active centres.

  18. Synergetic Surface and Chemical Durability Study of the Aesthetically Enhanced Natural Quartz by Heat Treatment

    Science.gov (United States)

    Sahoo, Rakesh K.; Rout, Prajna P.; Singh, Saroj K.; Mishra, Barada K.; Mohapatra, Birendra K.

    2017-03-01

    The change in surface behavior of natural quartz stone before and after heat treatment with metal oxides such as: cobalt oxide (Co3O4) and copper oxide (Cu2O) under vacuum and open atmosphere has been investigated. The surface feature, bulk density and hardness value of quartz changed after heat treatment, converting to a high value product. Difference in crystallinity of quartz, pre- and post-heat treatment was obtained through X-ray diffraction (XRD) study. The electron probe microanalysis results clearly explicated the diffusion of metal ion in quartz matrix exposed under vacuum atmosphere but as coating on the surface under open atmosphere. The structural transformation of quartz after heat treatment has been observed from the XRD data and well corroborated with the nanoindentation results. Durability of such quartz to chemical hazardous environment was observed. Thus, this communication demonstrates the change in physical and chemical characteristics of natural quartz stone after heat treatment under different atmosphere.

  19. Chemical exposures and Parkinson's disease: a population-based case-control study.

    Science.gov (United States)

    Frigerio, Roberta; Sanft, Kevin R; Grossardt, Brandon R; Peterson, Brett J; Elbaz, Alexis; Bower, James H; Ahlskog, J Eric; de Andrade, Mariza; Maraganore, Demetrius M; Rocca, Walter A

    2006-10-01

    The putative association between pesticide exposures and Parkinson's disease (PD) remains controversial. We identified all subjects who developed PD in Olmsted County, Minnesota, from 1976 through 1995, and matched them by age (+/- 1 year) and sex to general population controls. We assessed exposures to chemical products by means of telephone interview with cases, controls, or their proxies (149 cases; 129 controls). Exposure to pesticides related or unrelated to farming was associated with PD in men (odds ratio, 2.4; 95% confidence interval, 1.1-5.4; P = 0.04). The association remained significant after adjustment for education or smoking. Analyses for the other six categories of industrial and household chemicals were all nonsignificant. This population-based study suggests a link between pesticides use and PD that is restricted to men. Pesticides may interact with other genetic or nongenetic factors that are different in men and women.

  20. Study on interface behavior of 3D composites reinforced with chemically connected CNTs using molecular dynamics

    Science.gov (United States)

    Yang, Lin; He, Xiaodong; Tong, Liyong

    2009-07-01

    In this study, we used several molecular dynamic models to simulate the pull-out process of a carbon nanotube (CNT) that is assumed to be chemically connected to a carbon fiber, and to calculate the CNTs' geometry variation, displacement, energy and stress during this process. In the simulation, the CNTs' elongation and necking phenomena have been noted prior to the movement of the CNT's end embedded in resin. The simulation yields a CNT's plastic constitutive model in the pull-out process. The fracture resistance capability of a chemically connected CNT is then discussed. In the simulation of shearing, the prediction of the CNTs' capability of shear resistance has been conducted. Finally, by comparing the experiment result with the simulation, we predict the amido link break before the CNT pull-out in the shearing test.

  1. Synergetic Surface and Chemical Durability Study of the Aesthetically Enhanced Natural Quartz by Heat Treatment

    Science.gov (United States)

    Sahoo, Rakesh K.; Rout, Prajna P.; Singh, Saroj K.; Mishra, Barada K.; Mohapatra, Birendra K.

    2017-01-01

    The change in surface behavior of natural quartz stone before and after heat treatment with metal oxides such as: cobalt oxide (Co3O4) and copper oxide (Cu2O) under vacuum and open atmosphere has been investigated. The surface feature, bulk density and hardness value of quartz changed after heat treatment, converting to a high value product. Difference in crystallinity of quartz, pre- and post-heat treatment was obtained through X-ray diffraction (XRD) study. The electron probe microanalysis results clearly explicated the diffusion of metal ion in quartz matrix exposed under vacuum atmosphere but as coating on the surface under open atmosphere. The structural transformation of quartz after heat treatment has been observed from the XRD data and well corroborated with the nanoindentation results. Durability of such quartz to chemical hazardous environment was observed. Thus, this communication demonstrates the change in physical and chemical characteristics of natural quartz stone after heat treatment under different atmosphere.

  2. A PRELIMINARY PHYSICO-CHEMICAL ASSAY OF GOKSHURA-PUNARNAVA BASTI – A PILOT STUDY

    Directory of Open Access Journals (Sweden)

    Ramteke Rajkala

    2011-02-01

    Full Text Available Tribulus terrestris Linn belonging to Zygophyllaceae family commonly known as Goksura is used in Ayurvedic system of medicine; commonly known as Puncture vine. The plant is considered as Diuretic used in Diabetes mellitus and heart diseases. Boerhaavia diffusa Linn belonging to Nyctaginaceae family known as Hogweed and in Ayurveda named as Punarnava. It is also well known for its diuretic and rejuvenating action. Gokshura and Punarnava have been practiced on urinary tract disorders since ancient time. This has been proven that Basti route is provided better effect in short term administration. As this Basti is combination of these only two drugs; this initial attempt was made to evaluate its physico-chemical profile. Pharmacognostically authenticated Tribulus terrestris and Boerhaavia diffusa was used for the preparation of Basti and it was analyzed through qualitative and quantitative analysis for physico-chemical parameters. Fingerprints of Thin Layer Chromatography (TLC d High- Performance Thin Layer Chromatography study (HPTLC also carried out.

  3. Structural and Optical Study of Chemical Bath Deposited Nano-Structured CdS Thin Films

    Science.gov (United States)

    Kumar, Suresh; Sharma, Dheeraj; Sharma, Pankaj; Sharma, Vineet; Barman, P. B.; Katyal, S. C.

    2011-12-01

    CdS is commonly used as window layer in polycrystalline solar cells. The paper presents a structural and optical study of CdS nano-structured thin films. High quality CdS thin films are grown on commercial glass by means of chemical bath deposition. It involves an alkaline solution of cadmium salt, a complexant, a chalcogen source and a non-ionic surfactant. The films have been prepared under various process parameters. The chemically deposited films are annealed to estimate its effect on the structural and optical properties of films. These films (as -deposited and annealed) have been characterized by means of XRD, SEM and UV-Visible spectrophotometer. XRD of films show the nano-crystalline nature. The energy gap of films is found to be of direct in nature.

  4. Determination of Chemical Compositions on Adult Kidney Stones—A Spectroscopic Study

    Science.gov (United States)

    Raju, K.; Rakkappan, C.

    2008-11-01

    The chemical compositions of the kidney stones of both the sexes of patients, aged from 40 to 70, living in and around Chidambaram town are determined by using FT-IR and X-RD technique. The kidney stone samples used in the present study were procured from the Rajah Muthiah Medical College and Hospital, Annamalai University. The FT-IR spectra of different kidney stone samples were recorded in the range of 4000-400 cm-1. By identifying the characteristic frequency, the chemical compositions of the samples are determined. The results analyzed by FTIR technique were confirmed by X-RD method, in which the recorded X-ray diffractogram are compared with JCPDS files using search match method. Further analysis of XRD pattern also reveals the same.

  5. Chemical and ultrastructural studies of lignocellulose biodegradation during Agaricus bisporus cultivation.

    Science.gov (United States)

    Zhang, Rui; Wang, Hexiang; Liu, Qinghong; Ng, TziBun

    2014-01-01

    During Agaricus bisporus cultivation, lignocellulose degradation is the result of the activity of both the mushroom and microbial communities developed during the composting. To investigate the lignocellulose degradation in detail from the beginning to the end of the process, the functional groups of cellulose, hemicellulose, and lignin have been studied with Fourier transform infrared spectroscopy and the morphological changes of lignocelluloses were elucidated with scanning electron microscopy. The aperture of lignin and cellulose increased to enable the mycelia of A. bisporus to penetrate into the medium and to degrade lignocelluloses in a more direct way. The chemical structure changes implied a preferential use of lignin that could make for better use of cellulose to boost growth of A. bisporus. Changes in chemical structure together with ultrastructural changes induced by the microbial flora during cultivation substrate production by the composting substrate are important in promoting the utilization of lignocelluloses by A. bisporus.

  6. Studies on Physico Chemical Parameters of 5 water bodies of Ranchi (Jharkhand

    Directory of Open Access Journals (Sweden)

    Mouli Chakroborty

    2017-05-01

    Full Text Available Aquatic ecosystems are particularly vulnerable to environmental change and many are, at present, severely degraded. The availability of good quality water is an indispensable feature for preventing disease and improving quality of life. The physico-chemical properties will also help in the identification of sources of pollution, for conducting further investigations on the ecobiological impacts and also for initiating necessary steps for remedial actions in case of polluted water bodies. Therefore, the nature and health of any aquatic community are an expression of quality of the water. The present study has been undertaken to evaluate physico-chemical parameters (pH, alkalinity, dissolved oxygen, free carbon dioxide, sulphate content, chloride content and phosphate content in 5 water bodies in and around Ranchi – Patratu Dam, Kanke dam, Dhruwa dam, Ranchi Lake, Line-tank Lake.

  7. A Molecular Electron Density Theory Study of the Chemical Reactivity of Cis- and Trans-Resveratrol.

    Science.gov (United States)

    Frau, Juan; Muñoz, Francisco; Glossman-Mitnik, Daniel

    2016-12-01

    The chemical reactivity of resveratrol isomers with the potential to play a role as inhibitors of the nonenzymatic glycation of amino acids and proteins, both acting as antioxidants and as chelating agents for metallic ions such as Cu, Al and Fe, have been studied by resorting to the latest family of Minnesota density functionals. The chemical reactivity descriptors have been calculated through Molecular Electron Density Theory encompassing Conceptual DFT. The active sites for nucleophilic and electrophilic attacks have been chosen by relating them to the Fukui function indices, the dual descriptor f ( 2 ) ( r ) and the electrophilic and nucleophilic Parr functions. The validity of "Koopmans' theorem in DFT" has been assessed by means of a comparison between the descriptors calculated through vertical energy values and those arising from the HOMO and LUMO values.

  8. Stratospheric Sampling and In Situ Atmospheric Chemical Element Analysis During Meteor Showers: A Resource Study

    Science.gov (United States)

    Noever, David A.

    2000-01-01

    Resources studies for asteroidal mining evaluation have depended historically on remote sensing analysis for chemical elements. During the November 1998 Leonids meteor shower, a stratospheric balloon and various low-density capture media were used to sample fragments from Comet Tempel-Tuttle debris during a peak Earth crossing. The analysis not only demonstrates how potential sampling strategies may improve the projections for metals or rare elements in astromining, but also benchmarks materials during low temperature (-60 F), high dessication environments as seen during atmospheric exposure. The results indicate high aluminum, magnesium and iron content for various sampled particles recovered, but generalization to the sporadic meteors expected from asteroidal sources will require future improvements in larger sampling volumes before a broad-use strategy for chemical analysis can be described. A repeat of the experimental procedure is planned for the November 1999 Leonids' shower, and various improvements for atmospheric sampling will be discussed.

  9. [Study on the chemical compositions of VOCs emitted by cooking oils based on GC-MS].

    Science.gov (United States)

    He, Wan-Qing; Nie, Lei; Tian, Gang; Li, Jing; Shao, Xia; Wang, Min-Yan

    2013-12-01

    Volatile organic compounds (VOCs) are key precursors of ozone and secondary organic aerosols in air, and the differences in the compositions of VOCs lead to their different contribution to atmospheric reaction. Cooking oil fume is one of the important sources of atmospheric VOCs, and its chemical compositions are distinct under different conditions of oil types, food types, cooking methods and heating temperatures etc. In this study, the production of cooking oil fume was simulated by heating typical pure vegetable oils (peanut oil, sunflower oil, soybean oil, olive oil and blend oil) at different temperatures in beakers to investigate the chemical compositions of VOCs. The emitted VOCs were sampled with a Tenax adsorption tube and analyzed using GC-MS after thermal desorption. According to spectral library search and map analysis, using area normalized semi-quantitative method, preliminary qualitative and quantitative tests were conducted for the specific components of VOCs under different conditions.

  10. Chemical review and studies related to species from the genus Tynanthus (Bignoniaceae

    Directory of Open Access Journals (Sweden)

    Fernanda Colombi Cansian

    2015-09-01

    Full Text Available Species from the Bignoniaceae Family, including the genus Tynanthus, are very prevalent in the tropical Americas, with specimens found in a large part of the Brazilian territory. These plants are commonly used in traditional medicine for several purposes, and some studies have described their chemical structure, in addition to other reports related to some species from this genus. This review aimed to gather information from published works concerning species of the genus Tynanthus, as well as to detect flaws in research related to these plants, which may have great biological and pharmaceutical importance. Also, this review points out some common chemical characteristics of these species, providing information that may help new researchers to improve their knowledge about these plants.

  11. The Study of Chemical and Tensile Strength of Luffa Fruit’s Fibers

    Directory of Open Access Journals (Sweden)

    Fatemeh Ashourisavadkouhi

    2016-03-01

    Full Text Available Luffa cylindrica is a fruit belonging to family of cucurbitaceae. Many member of this family have been screened for their medical potential. Luffa have medical characteristics such as anti-inflammatory, antiallergic, antibacterial, stimulant for immune system and high strength which made researcher to think about it as a source for dental material specifically suture material. The objective of the present study is to determine the chemical components of methanolic, aqueous extract and its essence. In addition we aimed to investigate aimed at investigation the tensile strength of the luffa cylindrica (loofah fibers. The extract were prepared and screened via GC MS for determination of the luffa’s chemical component, which detected the chemicals according to their molecular weight, revealed the presence of alkaloids, carbohydrates, flavonoids and phenolics compound. The physicochemical parameters determined in the present work along with the texture analyzer CT3 profile showed that the luffa fibers have a high tensile strength. According to the texture analyzer’s test, were done on 20 prepared single luffa fiber and statistically analyzed by SPSS, the mean value of tensile strength of the tested specimen were 2086 pascal. Our study revealed that the luffa cylindrica’s fiber by having named chemicals showed its high medical potential. High tensile strength of luffa fiber (8.363 newton which is equal or even higher than of some suturing material like polyglycolic acid, polyglactin and polyglycolid-co-caprolactinto that are available and use now a days. Luffa fiber by having all these characteristics would be use as dental material such as suturing material, dental floss or even bristle of dental brush if more research done on this fruits.

  12. A Study on Physico-Chemical Parameters of Koilsagar Project, Mahabubnagar District, Telangana.

    Directory of Open Access Journals (Sweden)

    S. Suresh

    2015-03-01

    Full Text Available A physiological background makes it quite evident that water is an important ecological factor in the life of organisms. In the present study water samples were collected from Koilsagar project, Mahabubnagar district in every month during June, 2013 to May, 2014. The Physico-Chemical parameters were studied included Temperature, pH, Total Dissolved Solids (TDS, Turbidity, Hardness, Alkalinity, Phosphate, Chloride, Nitrate, Calcium and Magnesium. The results indicate that the Koilsagar project water is nonpolluted and it can be used for Domestic, irrigation and pisciculture.

  13. Physical chemical studies of dispersed aluminosilicate wastes for obtaining the burned building materials

    Science.gov (United States)

    Iuriev, I. Y.; Skripnikova, N. K.; Volokitin, G. G.; Volokitin, O. G.; Lutsenko, A. V.; Kosmachev, P. V.

    2015-01-01

    This paper presents results of the studies that determined that grinding can be one of the ways to modify aluminosilicate wastes. The optimal grinding modes were defined in laboratory conditions. Physical and chemical studies of modified ashes were carried out by means of X-ray phase analysis, differential thermal analysis and microscopy. The results have shown that modified ashes of thermal power stations when being applied in production of ceramic brick influence positively the processing properties of raw materials and the ready products.

  14. Bioaccumulation and phyto-translocation of arsenic, chromium and zinc by Jatropha curcas L.: impact of dairy sludge and biofertilizer.

    Science.gov (United States)

    Yadav, Santosh Kumar; Juwarkar, Asha A; Kumar, G Phani; Thawale, Prashant R; Singh, Sanjeev K; Chakrabarti, Tapan

    2009-10-01

    The present study was planned to remediate the metalloid and metal contaminated soil by using non-edible and economic plant species Jatropha curcas L. The experiment was conducted on pots to improve the survival rate, metal tolerance and growth response of the plant on soil; having different concentrations of arsenic, chromium and zinc. The soil was amended with dairy sludge and bacterial inoculum (Azotobacter chroococcum) as biofertilizer. The results of the study showed that the bioaccumulation potential was increased with increase in metalloid and metal concentration in soil system. Application of dairy sludge significantly reduces the DTPA-extractable As, Cr and Zn concentration in soil. The application of organic amendment stabilizes the As, Cr and Zn and reduced their uptake in plant tissues.

  15. Chemical constituents and toxicological studies of leaves from Mimosa caesalpiniifolia Benth., a Brazilian honey plant

    Science.gov (United States)

    Monção, Nayana Bruna Nery; Costa, Luciana Muratori; Arcanjo, Daniel Dias Rufino; Araújo, Bruno Quirino; Lustosa, Maria do Carmo Gomes; Rodrigues, Klinger Antônio da França; Carvalho, Fernando Aécio de Amorim; Costa, Amilton Paulo Raposo; Lopes Citó, Antônia Maria das Graças

    2014-01-01

    Background: Mimosa caesalpiniifolia Benth. (Leguminosae) is widely found in the Brazilian Northeast region and markedly contributes to production of pollen and honey, being considered an important honey plant in this region. Objective: To investigate the chemical composition of the ethanol extract of leaves from M. caesalpiniifolia by GC-MS after derivatization (silylation), as well as to evaluate the in vitro and in vivo toxicological effects and androgenic activity in rats. Materials and Methods: The ethanol extract of leaves from Mimosa caesalpiniifolia was submitted to derivatization by silylation and analyzed by gas chromatography-mass spectrometry (GC-MS) to identification of chemical constituents. In vitro toxicological evaluation was performed by MTT assay in murine macrophages and by Artemia salina lethality assay, and the in vivo acute oral toxicity and androgenic evaluation in rats. Results: Totally, 32 components were detected: Phytol-TMS (11.66%), lactic acid-2TMS (9.16%), α-tocopherol-TMS (7.34%) and β-sitosterol-TMS (6.80%) were the major constituents. At the concentrations analyzed, the ethanol extract showed low cytotoxicity against brine shrimp (Artemia salina) and murine macrophages. In addition, the extract did not exhibit any toxicological effect or androgenic activity in rats. Conclusions: The derivatization by silylation allowed a rapid identification of chemical compounds from the M. caesalpiniifolia leaves extract. Besides, this species presents a good safety profile as observed in toxicological studies, and possess a great potential in the production of herbal medicines or as for food consumption. PMID:25298660

  16. Calcium incorporation in graphene oxide particles: A morphological, chemical, electrical, and thermal study

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Kelly L.S. [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias (Brazil); Instituto de Química, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 149, 21941-909 Rio de Janeiro (Brazil); Curti, Raphael V.; Araujo, Joyce R.; Landi, Sandra M.; Ferreira, Erlon H.M.; Neves, Rodrigo S.; Kuznetsov, Alexei; Sena, Lidia A. [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias (Brazil); Archanjo, Braulio S., E-mail: bsarchanjo@inmetro.gov.br [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias (Brazil); Achete, Carlos A. [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias (Brazil); Departamento de Engenharia Metalúrgica e de Materiais, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro (Brazil)

    2016-07-01

    Surface chemical modification and functionalization are common strategies used to provide new properties or functionalities to a material or to enhance existing ones. In this work, graphene oxide prepared using Hummers' method has been chemically modified with calcium ions by immersion in a calcium carbonate solution. Transmission electron microscopy analyses showed that graphene oxide (GO) and calcium incorporated graphene oxide have a morphology similar to an ultra-thin membrane composed of overlapping sheets. X-ray diffraction and Fourier-infrared spectroscopy show that calcium carbonate residue was completely removed by hydrochloric acid washes. Energy dispersive X-ray spectroscopy mapping showed spatially homogeneous calcium in Ca-incorporated graphene oxide sample after HCl washing. This Ca is mainly ionic according to X-ray photoelectron spectroscopy, and its incorporation promoted a small reduction in the graphene oxide structure, corroborated also by four-point probe measurements. A thermal study shows a remarkable increase in the GO stability with the presence of Ca{sup 2+} ions. - Highlights: • Graphene oxide has been chemically modified with Ca ions by immersion in a CaCO{sub 3} solution. • GO–Ca has morphology similar to an ultra-thin membrane composed of overlapping sheets. • CaCO{sub 3} residue was completely removed by acid washes, leaving only ionic calcium. • EDS maps show that Ca incorporation is spatially homogeneous in GO structure. • Thermal analyses show a remarkable increase in GO stability after Ca incorporation.

  17. Numerical study of chemical reactions in a surface microdischarge tube with mist flow based on experiment

    Science.gov (United States)

    Shibata, T.; Nishiyama, H.

    2014-03-01

    Recently, a water treatment method of spraying solution into a discharge region has been developed and shows high energy efficiency. In this study, a simulation model of a water treatment method using a surface microdischarge (SMD) tube with mist flow is proposed for further understanding the detailed chemical reactions. Our model has three phases (plasma, gas and liquid) and three simulation steps. The carrier gas is humid air including 2% or 3% water vapour. The chemical species diffusion characteristics in the SMD tube and the concentrations in a droplet are clarified in a wide pH interval. The simulation results show that the chemical species generated on the SMD tube inner wall are diffused to the central axis and dissolved into fine droplets. Especially, OH radicals dissolve into droplets a few mm away from the SMD tube wall because of acidification of the droplets. Furthermore, the hydrogen peroxide density, which is the most important indicator of a radical reaction in water, is influenced by the initial solution pH. This pH dependence results from ozone self-decomposition in water.

  18. Quantification of contributions of molecular fragments for eye irritation of organic chemicals using QSAR study.

    Science.gov (United States)

    Kar, Supratik; Roy, Kunal

    2014-05-01

    The eye irritation potential of chemicals has largely been evaluated using the Draize rabbit-eye test for a very long time. The Draize eye-irritation data on 38 compounds established by the European Center for Ecotoxicology and Toxicology of Chemicals (ECETOC) has been used in the present quantitative structure-activity relationship (QSAR) analysis in order to predict molar-adjusted eye scores (MES) and determine possible structural requisites and attributes that are primarily responsible for the eye irritation caused by the studied solutes. The developed model was rigorously validated internally as well as externally by applying principles of the Organization for Economic Cooperation and Development (OECD). The test for applicability domain was also carried out in order to check the reliability of the predictions. Important fragments contributing to higher MES values of the solutes were identified through critical analysis and interpretation of the developed model. Considering all the identified structural attributes, one can choose or design safe solutes with low eye irritant properties. The presented approach suggests a model for use in the context of virtual screening of relevant solute libraries. The developed QSAR model can be used to predict existing as well as future chemicals falling within the applicability domain of the model in order to reduce the use of animals.

  19. [Studies on biotransformation of chemical constituents of tongmai formula by human intestinal flora].

    Science.gov (United States)

    Wu, Shuai; Xu, Wei; Yang, Xiu-Wei

    2013-10-01

    To study the chemical constituents in Tongmai formula (TMF) after biotransformation by human intestinal flora (HIF), water extract of TMF was anaerobically incubated with HIF at 37 degrees C. Column chromatographic methods over silica gel, Sephadex LH-20 and semi-preparative high-performance liquid chromatography as well as recrystallization were used to isolate and purify the chemical constituents in TMF after biotransformation by HIF. The chemical structures of isolated compounds were identified on the basis of MS and NMR data. Twenty-six compounds were obtained and identified as phenylpropionic acid (1), 6"-O-acetylpuerarin (2), formononetin(3), daidzein(4), p-hydroxyphenylpropionic acid (5), 3-indolepropionic acid (6), genistein (7), isoformononetin (8), isoononin (9), a mixture of (-)-puerol B-2"-O-glucopyranoside (10a) and (+) -puerol B-2"-O-glucopyranoside (10b), 8-hydroxydaidzein (11), puerol A (12), 3'-methoxy-6"-O-acetylpuerarin (13), 6"-O-acetyldaidzin (14), 3'-methoxydaidzin (15), puerol B (16), 3-methyluracil (17), genistin (18), daidzin (19), 3'-methoxypuerarin (20), mirificin (21), swertiamarin (22) , daidzein-7, 4'-O-glucoside (23), adenine (24), 3'-hydroxypuerarin (25), and puerarin (26). After biotransformation by HIF, the glycosides in TMF were transformed into aglycone and/or less glycosyl compounds along with some hydroxylation and demethylation reactions. Therefore, the glycosides in the TMF are the pro-drug.

  20. Experimental and Chemical Kinetic Modeling Study of Dimethylcyclohexane Oxidation and Pyrolysis

    KAUST Repository

    Eldeeb, Mazen A.

    2016-08-30

    A combined experimental and chemical kinetic modeling study of the high-temperature ignition and pyrolysis of 1,3-dimethylcyclohexane (13DMCH) is presented. Ignition delay times are measured behind reflected shock waves over a temperature range of 1049–1544 K and pressures of 3.0–12 atm. Pyrolysis is investigated at average pressures of 4.0 atm at temperatures of 1238, 1302, and 1406 K. By means of mid-infrared direct laser absorption at 3.39 μm, fuel concentration time histories are measured under ignition and pyrolytic conditions. A detailed chemical kinetic model for 13DMCH combustion is developed. Ignition measurements show that the ignition delay times of 13DMCH are longer than those of its isomer, ethylcyclohexane. The proposed chemical kinetic model predicts reasonably well the effects of equivalence ratio and pressure, with overall good agreement between predicted and measured ignition delay times, except at low dilution levels and high pressures. Simulated fuel concentration profiles agree reasonably well with the measured profiles, and both highlight the influence of pyrolysis on the overall ignition kinetics at high temperatures. Sensitivity and reaction pathway analyses provide further insight into the kinetic processes controlling ignition and pyrolysis. The work contributes toward improved understanding and modeling of the oxidation and pyrolysis kinetics of cycloalkanes.

  1. Exploring site-specific chemical interactions at surfaces: a case study on highly ordered pyrolytic graphite

    Science.gov (United States)

    Dagdeviren, Omur E.; Götzen, Jan; Altman, Eric I.; Schwarz, Udo D.

    2016-12-01

    A material’s ability to interact with approaching matter is governed by the structural and chemical nature of its surfaces. Tailoring surfaces to meet specific needs requires developing an understanding of the underlying fundamental principles that determine a surface’s reactivity. A particularly insightful case occurs when the surface site exhibiting the strongest attraction changes with distance. To study this issue, combined noncontact atomic force microscopy and scanning tunneling microscopy experiments have been carried out, where the evolution of the local chemical interaction with distance leads to a contrast reversal in the force channel. Using highly ordered pyrolytic graphite surfaces and metallic probe tips as a model system, we find that at larger tip-sample distances, carbon atoms exhibit stronger attractions than hollow sites while upon further approach, hollow sites become energetically more favorable. For the tunneling current that is recorded at large tip-sample separations during acquisition of a constant-force image, the contrast is dominated by the changes in tip-sample distance required to hold the force constant (‘cross-talk’) at smaller separations the contrast turns into a convolution of this cross-talk and the local density of states. Analysis shows that the basic factors influencing the force channel contrast reversal are locally varying decay lengths and an onset of repulsive forces that occurs for distinct surface sites at different tip-sample distances. These findings highlight the importance of tip-sample distance when comparing the relative strength of site-specific chemical interactions.

  2. Comparative Evaluation of Various Flower Extracts of Grewia asiatica for Phyto-Compounds and Anti-Bacterial Efficacy

    OpenAIRE

    2016-01-01

    Grewia asiatica is known traditionally for the treatment of various human ailments. Present study was carried out to evaluate the effect of various polarities of solvents on extraction and their bioactivity. Among all twelve extracts methanol, aqueous, ethanol, chloroform and acetone extracts showed the moderate to higher presence of all phytocompounds. Whereas, maximum phenolic (22.19±0.42 μg/mg equivalent to Gallic acid) and Flavonoid content (52.31±0.1 μg/mg equivalent to q...

  3. Quality of life in chemical warfare survivors with ophthalmologic injuries: the first results form Iran Chemical Warfare Victims Health Assessment Study

    Directory of Open Access Journals (Sweden)

    Soroush Mohammad

    2009-01-01

    Full Text Available Abstract Background Iraq used chemical weapons extensively against the Iranians during the Iran-Iraq war (1980–1988. The aim of this study was to assess the health related quality of life (HRQOL in people who had ophthalmologic complications due to the sulfur mustard gas exposure during the war. Methods The Veterans and Martyrs Affair Foundation (VMAF database indicated that there were 196 patients with severe ophthalmologic complications due to chemical weapons exposure. Of these, those who gave consent (n = 147 entered into the study. Quality of life was measured using the 36-item Short Form Health Survey (SF-36 and scores were compared to those of the general public. In addition logistic regression analysis was performed to indicate variables that contribute to physical and mental health related quality of life. Results The mean age of the patients was 44.8 (SD = 8.7 ranging from 21 to 75 years. About one-third of the cases (n= 50 reported exposure to chemical weapons more than once. The mean exposure duration to sulfur mustard gas was 21.6 years (SD = 1.2. The lowest scores on the SF-36 subscales were found to be: the role physical and the general health. Quality of life in chemical warfare victims who had ophthalmologic problems was significantly lower than the general public (P Conclusion The study findings suggest that chemical warfare victims with ophthalmologic complications suffer from poor health related quality of life. It seems that the need for provision of health and support for this population is urgent. In addition, further research is necessary to measure health related quality of life in victims with different types of disabilities in order to support and enhance quality of life among this population.

  4. An acetyltransferase conferring tolerance to toxic aromatic amine chemicals: molecular and functional studies.

    Science.gov (United States)

    Martins, Marta; Rodrigues-Lima, Fernando; Dairou, Julien; Lamouri, Aazdine; Malagnac, Fabienne; Silar, Philippe; Dupret, Jean-Marie

    2009-07-10

    Aromatic amines (AA) are a major class of environmental pollutants that have been shown to have genotoxic and cytotoxic potentials toward most living organisms. Fungi are able to tolerate a diverse range of chemical compounds including certain AA and have long been used as models to understand general biological processes. Deciphering the mechanisms underlying this tolerance may improve our understanding of the adaptation of organisms to stressful environments and pave the way for novel pharmaceutical and/or biotechnological applications. We have identified and characterized two arylamine N-acetyltransferase (NAT) enzymes (PaNAT1 and PaNAT2) from the model fungus Podospora anserina that acetylate a wide range of AA. Targeted gene disruption experiments revealed that PaNAT2 was required for the growth and survival of the fungus in the presence of toxic AA. Functional studies using the knock-out strains and chemically acetylated AA indicated that tolerance of P. anserina to toxic AA was due to the N-acetylation of these chemicals by PaNAT2. Moreover, we provide proof-of-concept remediation experiments where P. anserina, through its PaNAT2 enzyme, is able to detoxify the highly toxic pesticide residue 3,4-dichloroaniline in experimentally contaminated soil samples. Overall, our data show that a single xenobiotic-metabolizing enzyme can mediate tolerance to a major class of pollutants in a eukaryotic species. These findings expand the understanding of the role of xenobiotic-metabolizing enzyme and in particular of NATs in the adaptation of organisms to their chemical environment and provide a basis for new systems for the bioremediation of contaminated soils.

  5. Effects of seven chemicals on DNA damage in the rat urinary bladder: a comet assay study.

    Science.gov (United States)

    Wada, Kunio; Yoshida, Toshinori; Takahashi, Naofumi; Matsumoto, Kyomu

    2014-07-15

    The in vivo comet assay has been used for the evaluation of DNA damage and repair in various tissues of rodents. However, it can give false-positive results due to non-specific DNA damage associated with cell death. In this study, we examined whether the in vivo comet assay can distinguish between genotoxic and non-genotoxic DNA damage in urinary bladder cells, by using the following seven chemicals related to urinary bladder carcinogenesis in rodents: N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN), glycidol, 2,2-bis(bromomethyl)-1,3-propanediol (BMP), 2-nitroanisole (2-NA), benzyl isothiocyanate (BITC), uracil, and melamine. BBN, glycidol, BMP, and 2-NA are known to be Ames test-positive and they are expected to produce DNA damage in the absence of cytotoxicity. BITC, uracil, and melamine are Ames test-negative with metabolic activation but have the potential to induce non-specific DNA damage due to cytotoxicity. The test chemicals were administered orally to male Sprague-Dawley rats (five per group) for each of two consecutive days. Urinary bladders were sampled 3h after the second administration and urothelial cells were analyzed by the comet assay and subjected to histopathological examination to evaluate cytotoxicity. In the urinary bladders of rats treated with BBN, glycidol, and BMP, DNA damage was detected. In contrast, 2-NA induced neither DNA damage nor cytotoxicity. The non-genotoxic chemicals (BITC, uracil, and melamine) did not induce DNA damage in the urinary bladders under conditions where some histopathological changes were observed. The results indicate that the comet assay could distinguish between genotoxic and non-genotoxic chemicals and that no false-positive responses were obtained.

  6. [Study on the association between environmental chemical elements and fluorosis caused by coal-fire pollution].

    Science.gov (United States)

    Jiao, Yong-zhuo; Mu, Li-hong; Wang, Ying-xiong; Yan, Wei; Zhong, Zhao-hui; Li, Li

    2012-12-01

    To understand the distribution of chemical elements in soil. To investigate the differences between patients under different state of fluorosis and normal population after preventive measurement was implemented to get rid of some chemical elements and to lower the urine fluoride levels so as to illustrate the pathogenesis of the disease. Both ecological and comparative studies had been used to analyze the rates and levels of chemical elements. Teeth and skeletal from the patients with fluorosis and controls were taken and florin ion-selective-electrode method was used to determine urine the content of fluorine. Atomic Absorption Spectrometry was used to determine the copper, zinc, calcium, magnesium and iron contents in the whole blood. Differences of contents were analyzed. In Wushan county, the soil contents of nickel (r = 0.553, P = 0.050), iodine (r = 0.571, P = 0.041), fluorine (r = 0.303, P = 0.005), pH value (r = 0.304, P = 0.005) and the rates of fluorosis showed weaker positive relationship. In Fengjie county, the soil contents of mercury (r = 0.285, P = 0.001), nickel (r = 0.212, P = 0.00) and the rates of fluorosis also showed weaker positive relationship. In Wushan county, the urine fluoride level in the patients group [(0.64 ± 0.34) mg/L] was higher than that in the control group [(0.44 ± 0.59) mg/L], (P elements as Zn, Ca and Mg were in shortage, might be affected by these chemical elements that related with fluorosis.

  7. Phyto-mediated nanostructured carriers based on dual vegetable actives involved in the prevention of cellular damage.

    Science.gov (United States)

    Istrati, D; Lacatusu, I; Bordei, N; Badea, G; Oprea, O; Stefan, L M; Stan, R; Badea, N; Meghea, A

    2016-07-01

    The growing scientific interest in exploitation of vegetable bioactives has raised a number of questions regarding their imminent presence in pharmaceutical formulations. This study intends to demonstrate that a dual combination between vegetable oil (e.g. thistle oil, safflower oil, sea buckthorn oil) and a carrot extract represents an optimal approach to formulate safe carrier systems that manifest cell regeneration effect and promising antioxidant and anti-inflammatory activity. Inclusion of both natural actives into lipid carriers imparted a strong negative charge on the nanocarrier surface (up to -45mV) and displayed average sizes of 70nm to 140nm. The entrapment efficiency of carrot extract into nanostructured carriers ranged between 78.3 and 88.3%. The in vitro release study has demonstrated that the entrapment of the extract represents a viable way for an equilibrated release of carotenoids. Besides the excellent antioxidant properties (e.g. scavenging up to 98% of the free oxygen radicals), the results of cellular integrity (e.g. cell viability of 133%) recommend these nanocarriers based on dual carrot extract-bioactive oil as a promising trend for the treatment of certain disorders in which oxidative stress plays a prominent role. In addition, the lipid nanocarriers based on safflower oil and sea buckthorn oil demonstrated an anti-inflammatory effect on LPS induced THP-1 macrophages, by inhibiting the secretion of two pro-inflammatory cytokines, IL-6 and TNF-α.

  8. [Chemical and behavioural addiction of medical students. Comparative study in Lebanese students].

    Science.gov (United States)

    Moaouad, J; Kazour, F; Haddad, R; Rouhayem, J; Chammai, R; Richa, S

    2012-12-01

    Evaluate chemical and behavioural dependence of medical students, and compare it to a control group (students in non-medical faculties), in order to underline the harmful effect of university on medical students' dependence. A three-part questionnaire was distributed to a sample of 140 medical students at the Saint-Joseph university of Beirut (USJ), and to 140 students in many other USJ faculties, and filled in anonymously. The first part is about demographic criteria and the second and third parts are respectively about chemical and behavioural dependence, based on DSM IV criteria. There is no statistically significant difference between the two studied populations concerning the dependence on alcohol, cannabis, sedatives, opiates, amphetamines, workaholism, gambling and Internet. However, the prevalence of addiction to caffeine, cocaine, nicotine; sexual addiction, and compulsive buying are significantly lower in medical students when compared to the control group. Men, compared to women, did not show significantly higher levels of dependence on chemical substances. Workaholism is not significantly more prevalent in women. Sexual addiction and compulsive buying are not significantly higher in men. However, pathological gambling and Internet addiction are significantly more prevalent in men. Finally, this study does not show a variation in dependence through the years of medical studies. Most studies show that medical students have high levels of dependence on alcohol, opiates and sedatives. The results of our study show greater dependence on caffeine followed by nicotine, alcohol and sedatives. Medical students in our population did not reveal higher dependence rates compared to other university students. Overall, substance addiction in medical students may be related to the stress of medical studies, and easy access to drugs and prescriptions. These factors may be balanced by perfectionist traits, ethical standards and knowledge of adverse effects seen in

  9. The ECVAM international validation study on in vitro tests for acute skin irritation: selection of test chemicals.

    Science.gov (United States)

    Eskes, Chantra; Cole, Thomas; Hoffmann, Sebastian; Worth, Andrew; Cockshott, Amanda; Gerner, Ingrid; Zuang, Valérie

    2007-12-01

    The ECVAM-funded skin irritation validation study (SIVS) was initiated in 2003, with the aim to evaluate whether the EpiDerm, EPISKIN and the SIFT alternative methods were able to reliably identify skin irritant and non-irritant chemicals, and could therefore be candidates for replacing the rabbit Draize test for skin irritation. The primary goal of the study was to evaluate the predictive capacity of the assays with regard to the EU classification system, which employs the risk phrases, "R38", for skin irritants, and "no label" for non-irritants. A secondary objective was the retrospective analysis of the data, to assess whether the in vitro tests would be able to discriminate between strong irritants (category 2), mild irritants (category 3) and non-irritants (no category), as defined by the OECD and United Nations proposal for a Globally Harmonised System (GHS) for the classification and labelling of dermal irritancy. A Chemicals Selection Sub-Committee (CSSC) was appointed to identify test chemicals to be used in the SIVS, for which existing, high quality in vivo data were available, with which to correlate the in vitro measurements. Since chemicals from the European Centre for the Ecotoxicology and Toxicology of Chemicals (ECETOC) database of reference chemicals for skin irritation/skin corrosion had been extensively used in preceding studies, the CSSC made use of novel sources for potential test chemicals. The first source of chemicals screened was the New Chemicals Database (NCD), which is the central archive within the EU notification scheme for 'new' commercial chemicals. Data registered in the NCD originate from standard assays, submitted in compliance with the legislation which regulates the marketing of industrial chemicals, and are subject to quality assurance by the competent authorities of the EU Member States. In addition, to obtain 'existing' chemicals which were readily available from major manufacturing and/or distribution sources, additional

  10. Determination of fatty acid, tocopherol and phyto sterol contents of the oils of various poppy (Papaver somniferum L.) seeds.

    Energy Technology Data Exchange (ETDEWEB)

    Enric, H.; Tekin, A.; Musa Ozcan, M.

    2009-07-01

    The fatty acid, tocopherol and sterol contents of the oils of several poppy seeds were investigated. The main fatty acids in poppy seed oils were linoleic (687.6-739.2 g kg{sup -}1), oleic (141.3-192.8 g kg{sup -}1) and palmitic (76.8-92.8 g kg{sup -}1). The oils contained an appreciable amount of {gamma}-tocopherol (195.37-280.85 mg kg{sup -}1), with a mean value of 261.31 mg kg-1 and {alpha}-tocopherol (21.99-45.83 mg kg{sup -}1), with a mean value of 33.03 mg kg{sup -}1. The concentrations of total sterol ranged from 1099.84 mg kg{sup -}1 (K.pembe) to 4816.10 mg kg-1 (2. sinif beyaz), with a mean value of 2916.20 mg kg{sup -}1. The major sterols were {beta}-sitosterol, ranging from 663.91 to 3244.39 mg kg{sup -}1; campesterol, ranging from 228.59 to 736.50 mg kg{sup -}1; and {delta}{sup 5}-avenasterol, ranging from 103.90 to 425.02 mg kg{sup -}1. The studied varieties of poppy seeds from Turkey were found to be a potential source of valuable oil. (Author) 31 refs.

  11. Heavy metals phyto-assessment in commonly grown vegetables: water spinach (I. aquatica) and okra (A. esculentus).

    Science.gov (United States)

    Ng, Chuck Chuan; Rahman, Md Motior; Boyce, Amru Nasrulhaq; Abas, Mhd Radzi

    2016-01-01

    The growth response, metal tolerance and phytoaccumulation properties of water spinach (Ipomoea aquatica) and okra (Abelmoschus esculentus) were assessed under different contaminated spiked metals: control, 50 mg Pb/kg soil, 50 mg Zn/kg soil and 50 mg Cu/kg soil. The availability of Pb, Zn and Cu metals in both soil and plants were detected using flame atomic absorption spectrometry. The concentration and accumulation of heavy metals from soil to roots and shoots (edible parts) were evaluated in terms of translocation factor, accumulation factor and tolerance index. Okra recorded the highest accumulation of Pb (80.20 mg/kg) in its root followed by Zn in roots (35.70 mg/kg) and shoots (34.80 mg/kg) of water spinach, respectively. Different accumulation trends were observed with, Pb > Zn > Cu in okra and Zn > Pb > Cu in water spinach. Significant differences (p < 0.01) of Pb, Zn and Cu accumulation were found in both water spinach and okra cultivated among tested treatments. However, only the accumulation of Pb metal in the shoots of water spinach and okra exceeded the maximum permissible levels of the national Malaysian Food Act 1983 and Food Regulations 1985 (2006) as well as the international Codex Alimentarius Commission limits. This study has shown that both water spinach and okra have good potential as Pb and Zn phytoremediators.

  12. Comparative Evaluation of Various Flower Extracts of Grewia asiatica for Phyto-Compounds and Anti-Bacterial Efficacy

    Directory of Open Access Journals (Sweden)

    Ritu Shukla

    2016-11-01

    Full Text Available Grewia asiatica is known traditionally for the treatment of various human ailments. Present study was carried out to evaluate the effect of various polarities of solvents on extraction and their bioactivity. Among all twelve extracts methanol, aqueous, ethanol, chloroform and acetone extracts showed the moderate to higher presence of all phytocompounds. Whereas, maximum phenolic (22.19±0.42 μg/mg equivalent to Gallic acid and Flavonoid content (52.31±0.1 μg/mg equivalent to quercetin were observed in methanolic extract followed by aqueous and other extracts. Interestingly, the antibacterial assay was also identified methanolic extract as a potential bacterial growth inhibitor which showed significant zone of inhibition against Pseudomonas aeruginosa (3.3±0.04 cm, Vibrio cholera (3.0±0.08 cm and Salmonella abony (3.0±0.05 cm at concentration 20 mg/ml and best minimum inhibitory concentration was observed against Escherichia coli (0.5±0.03 mg/ml. Furthermore, the potential methanolic extract of flower was identified via Gas chromatography and mass spectrometry (GC-MS analysis revealed compound 3,4- Altrosan having maximum (35.78% percent area in the spectrum. The present investigation showed that methanolic extract of Grewia asiatica flower showed significant antibacterial inhibition compared with other solvents extracts.

  13. 78 FR 68461 - Guidance for Industry: Studies To Evaluate the Utility of Anti-Salmonella Chemical Food Additives...

    Science.gov (United States)

    2013-11-14

    ... food additives beyond chemical food additives, and to cover all food for animals, including pet food... HUMAN SERVICES Food and Drug Administration Guidance for Industry: Studies To Evaluate the Utility of Anti- Salmonella Chemical Food Additives in Feeds; Request for Comments AGENCY: Food and Drug...

  14. STUDY OF STANDARD OPERATING PROCEDURE OF NAAG BHASMA IN RELATION TO ITS PHYSICO-CHEMICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Lagad C. E.

    2012-03-01

    Full Text Available Standard operating procedures (SOPs should to be designed, implemented and set for all Ayurvedic drugs one by one for globalization Ayurveda. In this study, an attempt has been made to introduce SOP for preparation of Naag Bhasma [NB] & its analytical study. Study was conducted in the Department of Rasa Shastra under the postgraduate research programme is being presented. The pharmaceutical processing of NB was performed by following Samanya Shodhana, Jarana, Marana of Naag [Pb] & its analytical study. Naga Bhasma was prepared in two batches namely Batch A & B. In this method purified Haratala (Orpiment were taken as media. The percentage loss in the Naga Bhasma in Batch A was 63%, while in case of Batch B was 60.5%. Raw drugs, in process materials and the final products were analyzed physico-chemically and comparison was drawn to lay down pharmacopoeial standards. The average percentage purity of Naga decreased from 99.46% to 86.57% after Shodhana. The percentage of (Pb lead in Naga Bhasma was 58.4% and 57.89% respectively in Batch A and B. Both the Bhasmas were in PbS form chemically with other elements like Ca, Si, Fe, Al, K, As, Mg, Ni, Mn, Cd, Zn in trace amount.

  15. Dynamics and Kinetics Study of "In-Water" Chemical Reactions by Enhanced Sampling of Reactive Trajectories.

    Science.gov (United States)

    Zhang, Jun; Yang, Y Isaac; Yang, Lijiang; Gao, Yi Qin

    2015-11-12

    High potential energy barriers and engagement of solvent coordinates set challenges for in silico studies of chemical reactions, and one is quite commonly limited to study reactions along predefined reaction coordinate(s). A systematic protocol, QM/MM MD simulations using enhanced sampling of reactive trajectories (ESoRT), is established to quantitatively study chemical transitions in complex systems. A number of trajectories for Claisen rearrangement in water and toluene were collected and analyzed, respectively. Evidence was found that the bond making and breaking during this reaction are concerted processes in solutions, preferentially through a chairlike configuration. Water plays an important dynamic role that helps stabilize the transition sate, and the dipole-dipole interaction between water and the solute also lowers the transition barrier. The calculated rate coefficient is consistent with the experimental measurement. Compared with water, the reaction pathway in toluene is "narrower" and the reaction rate is slower by almost three orders of magnitude due to the absence of proper interactions to stabilize the transition state. This study suggests that the "in-water" nature of the Claisen rearrangement in aqueous solution influences its thermodynamics, kinetics, as well as dynamics.

  16. [Technology upgrades and exposure to chemical agents: results of the PPTP study in the footwear industry].

    Science.gov (United States)

    Gianoli, Enrica; Brusoni, Daniela; Cornaggia, Nicoletta; Saretto, Gianni

    2012-01-01

    In the present work the chemical compositions of the products used in shoes manufacturing are reported. The data were collected over the period 2004-2007 in 156 shoe factories in Vigevano area during a study aiming the evaluation of safety conditions and occupational exposure to hazardous chemicals of the employees. The study was part of a regional project for "Occupational cancer prevention in the footwear industry". In the first phase of the study an information form on production cycle, products used and their composition was filled during preliminary audit. In the second phase of the study an in depth qualitative/quantitative evaluation of professional exposure was conducted in 13 selected shoe factories. Data analysis showed the increase in use of water-based adhesives at expense of solvent-based adhesives, the reduction to less than 3.5 weight %, and up to 1 weight %, of n-hexane concentration in solvent mixtures, the increase in use of products containing less hazardous ketones, esters, cyclohexane and heptane. Only in very few cases, products containing from 4 to 12 weight% of toluene were used. These data attest a positive trend in workers risks prevention in shoes industry.

  17. Effects of farmyard manure and phosphorus on zinc transformations and phyto-availability in two alfisols of India.

    Science.gov (United States)

    Rupa, T R; Srinivasa Rao, Ch; Subba Rao, A; Singh, Muneshwar

    2003-05-01

    Laboratory pot experiments were run to study the effects of added zinc (Zn) with and without farmyard manure (FYM) and phosphorus (P) on Zn transformations in two Alfisols, together with Zn uptake by wheat plants grown up to 60 days. In the first experiment the treatments included four levels of Zn (0, 3.75, 7.5 and 15 mgkg(-1) soil) and two levels of FYM (0 and 10 tha(-1)), and in the second experiment five levels of P (0, 20, 40, 80 and 160 mgkg(-1) soil) and one level of Zn (7.5 mgkg(-1) soil). The soils were sequentially fractionated into water-soluble plus exchangeable (CA-Zn), inorganically bound (AAC-Zn), organically bound (PYR-Zn), oxide bound (OX-Zn) and residual (RES-Zn) forms. The effect of added FYM was more evident on the OX-Zn fraction and the percentage utilization of Zn by wheat was the greatest with the addition of FYM alone at the rate of 10 tha(-1) (1.95-2.38%) in comparison to other treatment combinations. Among the levels, application of 7.5 mg Zn kg(-1) soil showed the maximum increase in different fractions of soil Zn and significantly increased the Zn utilization by wheat (0.87-1.17%) as compared to other Zn levels (0.58-0.88%). On an average, about 85% of the added Zn was recovered in different fractions in Zn treated pots. However, the recovery per cent of the added Zn was significantly higher at Zn level 7.5 (95%) mgkg(-1) soil than at 3.75 (87%) and 15 (73%) mg Zn kg(-1) soil levels. Phosphorus additions up to 40 mgkg(-1) soil increased the plant-available Zn in soils whereas at higher P levels plant-available forms decreased with a concominant increase in the inert forms. At 160 mg P kg(-1) soil, the P effect was more pronounced in the shoot than in the root, suggesting that a higher P level inhibits Zn translocation from root to upper plant parts. Path analysis showed that the organically (PYR-Zn) and inorganically bound (AAC-Zn) Zn fractions were the predominant fractions that influenced the Zn availability to plants.

  18. Chemical properties and morphology of Marine Aerosol in the Mediterranean atmosphere: a mesocosm study

    Science.gov (United States)

    D'Anna, Barbara; Sellegri, Karine; Charrière, Bruno; Sempéré, Richard; Mas, Sébastien; Marchand, Nicolas; George, Christian; Même, Aurèlie; R'mili, Badr; Delmont, Anne; Schwier, Allison; Rose, Clémence; Colomb, Aurèlie; Pey, Jorge; Langley Dewitt, Helen

    2014-05-01

    The Mediterranean Sea is a special marine environment characterized by low biological activity and high anthropogenic pressure. It is often difficult to discriminate the contribution of Primary Sea Salt Aerosol formed at the sea surface from background level of the aerosol. An alternative tool to study the sea-air exchanges in a controlled environment is provided by the mesocosms, which represent an important link between field studies and laboratory experiments. The sea-air transfer of particles and gases was investigated in relation to water chemical composition and biological activity during a mesocosm experiment within the SAM project (Sources of marine Aerosol in the Mediterranean) at the Oceanographic and Marine Station STARESO in Western Corsica (May 2013). Three 2 m mesocosms were filled with screened (treatments: one was left unchanged as control and two were enriched by addition of nitrates and phosphates respecting Redfield ratio (N:P = 16). The evolution of the three systems was followed for 20 days. The set of sensors in each mesocosm was allowed to monitor, at high frequency (every 10 min), the water temperature, conductivity, pH, incident light, fluorescence of chlorophyll a and dissolved oxygen concentration. The mesocosm seawaters were daily sampled for chemical (colored dissolved organic matter, particulate matter and related polar compounds, transparent polysaccharides and nutrients concentration) and biological (chlorophyll a, virus, phytoplankton and zooplankton) analyses. Both dissolved and gaseous VOCs were also analyzed. In addition, few liters of seawater from each mesocosm were daily and immediately collected and transferred to a bubble-bursting apparatus to simulate nascent sea spray aerosol. On-line chemical analysis of the sub-micrometer fraction was performed by a TOF-AMS (Aerodyne). Off-line analysis included TEM-EDX for morphology and size distribution studies and a hybrid quadrupole-orbitrap mass spectrometer (Thermo Fischer) for

  19. Assessing occupational exposure to chemicals in an international epidemiological study of brain tumours.

    Science.gov (United States)

    van Tongeren, Martie; Kincl, Laurel; Richardson, Lesley; Benke, Geza; Figuerola, Jordi; Kauppinen, Timo; Lakhani, Ramzan; Lavoué, Jérôme; McLean, Dave; Plato, Nils; Cardis, Elisabeth

    2013-06-01

    The INTEROCC project is a multi-centre case-control study investigating the risk of developing brain cancer due to occupational chemical and electromagnetic field exposures. To estimate chemical exposures, the Finnish Job Exposure Matrix (FINJEM) was modified to improve its performance in the INTEROCC study and to address some of its limitations, resulting in the development of the INTEROCC JEM. An international team of occupational hygienists developed a crosswalk between the Finnish occupational codes used in FINJEM and the International Standard Classification of Occupations 1968 (ISCO68). For ISCO68 codes linked to multiple Finnish codes, weighted means of the exposure estimates were calculated. Similarly, multiple ISCO68 codes linked to a single Finnish code with evidence of heterogeneous exposure were refined. One of the key time periods in FINJEM (1960-1984) was split into two periods (1960-1974 and 1975-1984). Benzene exposure estimates in early periods were modified upwards. The internal consistency of hydrocarbon exposures and exposures to engine exhaust fumes was improved. Finally, exposure to polycyclic aromatic hydrocarbon and benzo(a)pyrene was modified to include the contribution from second-hand smoke. The crosswalk ensured that the FINJEM exposure estimates could be applied to the INTEROCC study subjects. The modifications generally resulted in an increased prevalence of exposure to chemical agents. This increased prevalence of exposure was not restricted to the lowest categories of cumulative exposure, but was seen across all levels for some agents. Although this work has produced a JEM with important improvements compared to FINJEM, further improvements are possible with the expansion of agents and additional external data.

  20. Impact of self-reported multiple chemical sensitivity on everyday life: a qualitative study

    DEFF Research Database (Denmark)

    Skovbjerg, Sine; Brorson, Stig; Rasmussen, Alice;

    2009-01-01

    on everyday life are limited. OBJECTIVE: To describe the impact of MCS on everyday life, strategies for managing the condition, and experiences with healthcare management. METHODS: A focus group study was conducted, including two interviews with a sample of six women and six men between 27 and 78 years of age......, a duration of MCS of at least 1 year, and with different occupational conditions. RESULTS: MCS may severely influence different aspects of everyday life, including lifestyle, social relations, and occupational conditions. Avoiding common airborne chemicals was the most prevalent coping strategy, which...

  1. Electrical property studies on chemically processed polypyrolle/aluminum doped ZnO based hybrid heterostructures

    Science.gov (United States)

    Mohan Kumar, G.; Ilanchezhiyan, P.; Madhan Kumar, A.; Yuldashev, Sh. U.; Kang, T. W.

    2016-04-01

    A hybrid structure based on p-type polypyrolle (PPy) and n-type aluminum (Al) doped ZnO nanorods was successfully constructed. The effect of Al doping on material properties of wurtzite structured ZnO were studied using several analytical techniques. To establish the desired hybrid structure, pyrrole monomers were polymerized on hydrothermally grown Al doped ZnO nanorods by chemical polymerization. The current⿿voltage characteristics on the fabricated PPy/Al doped ZnO heterostructures were found to exhibit excellent rectifying characteristics under dark and illumination conditions. The obtained results augment the prescribed architecture to be highly suitable for high-sensitivity optoelectronic applications.

  2. CDIO Projects in DTU’s Chemical and Biochemical B.Eng. Study Program

    DEFF Research Database (Denmark)

    Clement, Karsten; Harris, Pernille; Agersø, Yvonne

    2011-01-01

    The aim of this paper is to describe how the CDIO standards [1] have influenced the cross-disciplinary projects that are part of the study plan for the Chemical and Biochemical B.Eng. program. Four projects are described: The 1st semester design-build project on cleaning of waste water from a power...... plant, the 2nd semester laboratory project concerning antimicrobial resistant E. coli bacteria in retail meats, the 3rd semester project on unit operations in enzyme production, the 4th semester project on the fermentation and purification part of enzyme production....

  3. Computational study of p53 regulation via the chemical master equation

    Science.gov (United States)

    Vo, Huy D.; Sidje, Roger B.

    2016-06-01

    A stochastic model of cellular p53 regulation was established in Leenders, and Tuszynski (2013 Front. Oncol. 3 1-16) to study the interactions of p53 with MDM2 proteins, where the stochastic analysis was done using a Monte Carlo approach. We revisit that model here using an alternative scheme, which is to directly solve the chemical master equation (CME) by an adaptive Krylov-based finite state projection method that combines the stochastic simulation algorithm with other computational strategies, namely Krylov approximation techniques to the matrix exponential, divide and conquer, and aggregation. We report numerical results that demonstrate the extend of tackling the CME with this combination of tools.

  4. Chemical Capping Synthesis of Nickel Oxide Nanoparticles and their Characterizations Studies

    CERN Document Server

    rifaya, M Nowsath; Alagar, M; 10.5923/j.nn.20120205.01

    2012-01-01

    This work reports aspect related to chemical capping synthesis of nano-sized particles of nickel oxide. It is a simple, novel and cost effective method. The average particle size, specific surface area, crystallinity index are estimated from XRD analysis. The structural, functional groups and optical characters are analyzed with using of SEM, FTIR and UV- visible techniques. XRD studies confirm the presence of high degree of crystallinity nature of nickel oxide nanoparticles. Their particle size is found to be 12 nm and specific surface area (SSA) is 74m2 g-1. The optical band gap energy value 3.83ev has also been determined from UV-vis spectrum.

  5. Studies on non-oxide coating on carbon fibers using plasma enhanced chemical vapor deposition technique

    Science.gov (United States)

    Patel, R. H.; Sharma, S.; Prajapati, K. K.; Vyas, M. M.; Batra, N. M.

    2016-05-01

    A new way of improving the oxidative behavior of carbon fibers coated with SiC through Plasma Enhanced Chemical Vapor Deposition technique. The complete study includes coating of SiC on glass slab and Stainless steel specimen as a starting test subjects but the major focus was to increase the oxidation temperature of carbon fibers by PECVD technique. This method uses relatively lower substrate temperature and guarantees better stoichiometry than other coating methods and hence the substrate shows higher resistance towards mechanical and thermal stresses along with increase in oxidation temperature.

  6. Study on NO2 absorption by ascorbic acid and various chemicals

    Institute of Scientific and Technical Information of China (English)

    LI Wei; WU Cheng-zhi; FANG He-liang; SHI Yao; LEI Le-cheng

    2006-01-01

    Study on NO2 absorption aimed at seeking a better NO2 absorption chemical at pH 4.5~7.0 for application to existing wet flue gas desulfurization (FGD). The results from the double-stirred reactor indicated thru ascorbic acid has very high absorption rate at this pH range. The rate constant of ascorbic acid reaction with NO2 (0~1000× 10-6 mol/mol) is about 3.54× 106 mol/(L.s)at pH 5.4~6.5 at 55 ℃.

  7. Study of Cu-Inhibitor State for Post-Chemical Mechanical Polishing Cleaning

    Science.gov (United States)

    Harada, Ken; Ito, Atsushi; Kawase, Yasuhiro; Suzuki, Toshiyuki; Hara, Makoto; Sakae, Rina; Kimura, Chiharu; Aoki, Hidemitsu

    2011-05-01

    In order to reduce corrosion on the Cu surface in post-chemical mechanical polishing (CMP) cleaning, controlling the state of inhibitor layers is indispensable. In this study, to investigate the behavior of inhibitor layers in the cleaning process, Cu-benzotriazole (BTA) layers on CuOX were analyzed by electrochemical measurements and surface analysis. Electrochemical measurements revealed that Cu(I)-BTA can prevent corrosion more efficiently than Cu(II)-BTA, and surface analysis revealed that the Cu(I)-BTA layer is thin, whereas the Cu(II)-BTA layer is bulky. The Cu(I)-BTA layer is effective in preventing corrosion of the Cu surface.

  8. Lifetimes of organic photovoltaics: Combining chemical and physical characterisation techniques to study degradation mechanisms

    DEFF Research Database (Denmark)

    Norrman, K.; Larsen, N.B.; Krebs, Frederik C

    2006-01-01

    Degradation mechanisms of a photovoltaic device with an Al/C-60/C-12-PSV/PEDOT:PSS/ITO/glass geometry was studied using a combination of in-plane physical and chemical analysis techniques: TOF-SIMS, AFM, SEM, interference microscopy and fluorescence microscopy. A comparison was made between...... a device being stored in darkness in air and a device that had been subjected to illumination under simulated sunlight (1000 Wm(-2), AM1.5) in air. It was found that oxygen diffuses through pinholes in the aluminium electrode. If stored in air in the dark the oxidation is limited to the C-60 layer...

  9. Study of physico-chemical characteristics of water bodies around Jaipur.

    Science.gov (United States)

    Srivastava, Neera; Agrawal, Meena; Tyagi, Anupama

    2003-04-01

    The present study has been undertaken to evaluate physico-chemical parameters (pH, temperature, dissolved oxygen, free carbon dioxide, alkalinity and hardness) and zinc concentration in water bodies in and around Jaipur. Water samples from Jalmachal Lake, Nevta Lake, Amer Lake and Ramgarh Lake were analysed. Results reveal that the water of Jalmahal Lake is most polluted due to high pH, hardness, alkalinity, free carbon dioxide, zinc content, and a low level of dissolved oxygen. Contrarily Ramgarh Lake is least polluted, as it has high dissolved oxygen and low pH, alkalinity, free carbon dioxide, hardness and zinc content.

  10. A Study on the Structural Analysis of Controllability in Chemical Processes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.W.; Kim, Y.S.; Yoon, E.S. [Division of Chemical Engineering, Seoul National University, Seoul (Korea)

    1999-04-01

    Chemical processes are highly nonlinear, multivariable systems and have complex structures. However, the controllability evaluation procedures are complicated, and the required information is very often unknown at the early design stage. Therefore, it is necessary to develop a procedure to evaluate and enhance controllability while designing processes and plants. To evaluate controllability in the design stage, it is most efficient to analyze process structure. Relative order can be used as a measure of 'physical closeness' between input and output variable. Structural controllability analysis using relative order is shown to be effective in a case study of heat exchanger network synthesis. 9 refs., 3 figs.

  11. Tuning the chemical activity through PtAu nanoalloying: a first principles study

    KAUST Repository

    Mokkath, Junais Habeeb

    2013-06-21

    The electronic structure and adsorption properties of 1.5 nm sized Pt, Au, and PtAu nanoclusters are studied by density functional theory. We explain the recent experimental finding that 20% Au content in PtAu nanoparticles is optimal to induce a dramatically different catalytic behavior. Our results show that the d-band center together with the density of states at the Fermi energy can be used as an indicator of the chemical activity of PtAu nanoclusters. The most favorable adsorption sites on the cluster surfaces as a function of the Pt/Au ratio are identified using atomic H as a probe.

  12. Studies on chemical bath deposited zinc sulphide thin films with special optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Ladar, Maria [Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 400028 Cluj-Napoca (Romania); ' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania); Popovici, Elisabeth-Jeanne [' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania)]. E-mail: jennypopovici@yahoo.com; Baldea, Ioan [Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 400028 Cluj-Napoca (Romania); Grecu, Rodica [' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania); Indrea, Emil [National Institute for R and D of Isotopic and Molecular Technology, Donath 71-103, 400293 Cluj-Napoca (Romania)

    2007-05-31

    Adherent and uniform zinc sulphide thin films were deposited on optical glass platelets from chemical bath containing thiourea, zinc acetate, ammonia and sodium citrate. The samples, as they were prepared were investigated by UV-vis absorption/reflection spectroscopy, fluorescence spectroscopy and X-ray diffraction. The effects of growth conditions such as reagent concentration and deposition technique (mono- and multi-layer) on optical and structural properties of the ZnS thin films have been studied. The ability of ZnS films to exhibit luminescent properties has also been investigated.

  13. Formation and thermodynamics of gaseous germanium and tin vanadates: a mass spectrometric and quantum chemical study.

    Science.gov (United States)

    Shugurov, S M; Panin, A I; Lopatin, S I; Emelyanova, K A

    2015-06-07

    The stabilities of gaseous germanium and tin vanadates were confirmed by high temperature mass spectrometry, and its structures were determined by quantum chemical calculations. A number of gas-phase reactions involving these gaseous salts were studied. On the basis of the equilibrium constants, the standard formation enthalpies of gaseous GeV2O6 (-1520 ± 42 kJ mol(-1)) and SnV2O6 (-1520 ± 43 kJ mol(-1)) were determined at a temperature of 298 K.

  14. LInking EDCs in maternal Nutrition to Child health (LINC study) – protocol for prospective cohort to study early life exposure to environmental chemicals and child health

    OpenAIRE

    de Cock, Marijke; Quaak, Ilona; Sugeng, Eva J.; Legler, Juliette; van de Bor, Margot

    2016-01-01

    Background The presence of chemicals in the environment is ubiquitous. Human biomonitoring studies have shown that various chemicals can be detected in the majority of the population, including pregnant women. These compounds may pass the placenta, and reach the fetus. This early life exposure in particular may be detrimental as some chemicals may disrupt the endocrine system, which is involved in various processes during development. The LINC study is a prospective birth cohort designed to s...

  15. CHEMICAL ACTIVATION OF MOLECULES BY METALS: EXPERIMENTAL STUDIES OF ELECTRON DISTRIBUTIONS AND BONDING

    Energy Technology Data Exchange (ETDEWEB)

    LICHTENBERGER, DENNIS L.

    2002-03-26

    This research program is directed at obtaining detailed experimental information on the electronic interactions between metals and organic molecules. These interactions provide low energy pathways for many important chemical and catalytic processes. A major feature of the program is the continued development and application of our special high-resolution valence photoelectron spectroscopy (UPS), and high-precision X-ray core photoelectron spectroscopy (XPS) instrumentation for study of organometallic molecules in the gas phase. The study involves a systematic approach towards understanding the interactions and activation of bound carbonyls, C-H bonds, methylenes, vinylidenes, acetylides, alkenes, alkynes, carbenes, carbynes, alkylidenes, alkylidynes, and others with various monometal, dimetal, and cluster metal species. Supporting ligands include -aryls, alkoxides, oxides, and phosphines. We are expanding our studies of both early and late transition metal species and electron-rich and electron-poor environments in order to more completely understand the electronic factors that serve to stabilize particular organic fragments and intermediates on metals. Additional new directions for this program are being taken in ultra-high vacuum surface UPS, XPS, scanning tunneling microscopy (STM) and atomic force microscopy (AFM) experiments on both physisorbed and chemisorbed organometallic thin films. The combination of these methods provides additional electronic structure information on surface-molecule and molecule-molecule interactions. A very important general result emerging from this program is the identification of a close relationship between the ionization energies of the species and the thermodynamics of the chemical and catalytic reactions of these systems.

  16. Studies on Sono-Chemical Biodiesel Production Using Smoke Deposited Nano MgO Catalyst

    Directory of Open Access Journals (Sweden)

    P. Sivakumar

    2013-12-01

    Full Text Available The comprehensive study of smoke deposited nano sized MgO as a catalyst for biodiesel production was investigated. The transesterification reaction was studied under constant ultrasonic mixing for different parameters like catalyst quantity, methanol oil molar ratio, reaction temperature and reaction time. An excellent result of conversion was obtained at 1.5 wt% catalyst; 5:1 methanol oil molar ratio at 55°C, a conversion of 98.7% was achieved after 45 min. The conversion was three to five times higher than those are reported for laboratory MgO in literature. This was mainly due to the enhancement of surface area of the catalyst and the activity of ultrasonic waves. Catalyst is easily recovered and reused up to eight times with easy regeneration steps.  © 2013 BCREC UNDIP. All rights reservedReceived: 18th March 2013; Revised: 20th August 2013; Accepted: 9th September 2013[How to Cite: Sivakumar, P., Sankaranarayanan, S., Renganathan, S., Sivakumar, P. (2013. Studies on Sono-Chemical Biodiesel Production Using Smoke Deposited Nano MgO Catalyst. Bulletin of Chemical Re-action Engineering & Catalysis, 8 (2: 89-96.(doi:10.9767/bcrec.8.2.4628.89-96][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.2.4628.89-96

  17. Comparative performance studies between tunable filter and push-broom chemical imaging systems

    Science.gov (United States)

    Malinen, Jouko; Saari, Heikki; Kemeny, Gabor; Shi, Zhenqi; Anderson, Carl

    2010-04-01

    This paper reports instrument characterization measurements, which were recently arranged to provide comparative information on different hyperspectral chemical imaging systems. Three different instruments were studied covering both tunable filter and push-broom techniques: The first instrument MatrixNIRTM is based on a LCTF tunable filter and InGaAs camera and covers wavelengths from 1000 to 1700 nm. The second one SisuCHEMATM is based on push-broom technology and MCT camera operating from 1000 to 2500 nm. The third system is an instrument prototype from VTT Technical Research Centre of Finland exploiting high speed Fabry-Perot interferometer and MCT camera, currently calibrated from 1260 to 2500 nm. The characterization procedure was designed to study instrumental noise, signal-to-noise ratio, linearity and spectral as well as spatial resolution. Finally, a pharmaceutical tablet sample was measured with each instrument to demonstrate speed of measurement in a typical application. In spite of differences in wavelength ranges and camera technologies used, the results provide interesting information on relative instrumental advantages and disadvantages, which may be useful for selecting appropriate instrumentation for defined applications. Further, an additional aim of this study is to compare the high speed Fabry-Perot imaging technology under development against the established chemical imaging techniques available on the market today.

  18. 铅锌矿区污染土壤的植物淋洗剂筛选研究%Screening of Phyto-eluents for Contaminated Soil in Pb-Zn Mining Area

    Institute of Scientific and Technical Information of China (English)

    曹雅茹; 张世熔; 陈月; 王贵胤; 李婷

    2015-01-01

    Soil washing is a frequently used soil remediation technique. The key to this technique is washing agents. The objective of this study is to screen eco-friendly washing agents—phyto-eluents. We collected 14 plant species, ground the aboveground biomass to powders (﹤2 mm), and made washing agents using distilled water. Then the washing efficiencies of Pb and Zn by these washing agents were exam-ined under different concentrations, pH and contact time. At 25℃and 200 r·min-1 rotational oscillation, the washing efficiencies of Pb by these agents showed either continuous increases or initial increase and then decreases as the agent concentrations increased, whereas those of Zn displayed gradual increases or slight changes with the agent concentrations. Increasing pH apparently reduced the removal efficiencies of two metals. The effect of contacting time on the removal efficiencies of two metals showed gradual increase, slight changes or decline pat-terns. Among these 14 plants, Coriaria nepalensis proved to have a better removal efficiency, with the removal efficiencies of Pb and Zn be-ing 23.78%and 77.03%, respectively, at 5%eluent, pH 4.0 and a reaction time of 8 h. Therefore, C. nepalensis could be used as an envi-ronmental-friendly eluent for Pb-Zn contaminated soils.%高效绿色淋洗剂的筛选是土壤淋洗技术开发的重要内容之一。本文以汉源某铅锌矿区污染土壤为对象,将14种植物地上部分风干研磨过2 mm筛后蒸馏水浸提24 h,采用振荡淋洗的方法研究浸提液在不同浓度、pH和作用时间下对铅锌复合污染土壤中铅和锌的提取效果。结果表明,在25℃、200 r·min-1恒温振荡条件下,14种植物淋洗剂对土壤铅锌的淋洗效率不同(P﹤0.05):随着淋洗剂浓度的增加,其对土壤铅的淋洗率呈逐渐增加和先增后减两种变化趋势,对土壤锌的淋洗率则呈逐渐增加和变化趋势不明显;淋洗率随着pH增加总体降低;14种

  19. Levantamento fitossociológico em pastagens degradadas sob condições de várzea Phyto-sociological assessment of degraded pastures under flooded low land conditions

    Directory of Open Access Journals (Sweden)

    L.D. Tuffi Santos

    2004-09-01

    (Setaria anceps cv. Kazungula pasture which had been established in the previous rainy season, with forage being affected by the slow growth of the plants. For the phyto-sociological study, the inventory square method was applied through a square of 1,0 m², randomly placed 19 times in area 1 and 41 times in area 2. The species found were identified and recorded. In the Angola-grass pasture, 27 species were identified, distributed in 11 families; in the Setaria grass pasture, 34 species were identified, distributed in 13 families. The most representative families in number of species were: Poaceae (11; Asteraceae (6; Papilionoideae (5; Malvaceae and Euphorbiaceae (4. The most frequent species were: Cynodon dactylon, Sida rhombifolia, Cyperus esculentus, Mimosa pudica, Senna occidentalis, Setaria anceps cv. Kazungula and Paspalum urvillei. In general, both areas were infested with weeds, including toxic, spinescent and rather unpalatable plants, reducing the animal support capacity of the pastures and preventing adequate utilization of the areas by the cattle.

  20. Chromium in urban sediment particulates: an integrated micro-chemical and XANES study

    Science.gov (United States)

    Taylor, Kevin; Byrne, Patrick; Hudson-Edwards, Karen

    2015-04-01

    Chromium is generally common within the urban sediment cascade as a result of abundant industrial and transport-related sources. The risks that Cr-bearing particles pose to ecosystems and humans depend on the solid phase chemical speciation of Cr in the particles. In this study, we use bulk chemical digests, sequential chemical extraction analysis, electron microscopy, electron microprobe and microfocus XANES analysis to describe the solid-phase speciation of Cr in urban particulate matter from both aquatic sediment and road dust sediment (RDS) in Manchester, UK. Cr-bearing grains within RDS are predominantly iron oxide grains, commonly of goethite or haematite mineralogy, but Cr-bearing silicate glass grains are also present. Iron oxide glass grains most likely have sorbed Cr, and derive from the rusting of Cr-steel particles from vehicles. Electron microprobe analysis indicates concentrations of Cr up to 3200 μg/g in these grains, and XANES analysis indicates that Cr(III) is the dominant oxidation state, with some trace amounts of Cr(VI). Cr-bearing grains within aquatic sediments are dominated by alumino-silicate glass grains derived from industrial waste. These grains contain Cr-rich areas with up to 19% Cr2O3 and XANES analysis indicates that Cr is present as Cr(III). The dominance of Cr(III) in these urban particulate grains suggests limited bioavailability or toxicity. However, the presence within two markedly different grain types (iron oxides and silicate glasses) indicates that the long-term geochemical behaviour and environmental risk of RDS and the aquatic sediments studied are likely to be quite different. These findings highlight the importance of understanding sources of metal contaminants in urban environments and the geochemical processes that affect their transfer through the urban sediment cascade and the wider river basin.

  1. Intubation performance using different laryngoscopes while wearing chemical protective equipment: a manikin study

    Science.gov (United States)

    Schröder, H; Zoremba, N; Rossaint, R; Deusser, K; Stoppe, C; Coburn, M; Rieg, A; Schälte, G

    2016-01-01

    Objectives This study aimed to compare visualisation of the vocal cords and performance of intubation by anaesthetists using four different laryngoscopes while wearing full chemical protective equipment. Setting Medical simulation center of a university hospital, department of anaesthesiology. Participants 42 anaesthetists (15 females and 27 males) completed the trial. The participants were grouped according to their professional education as anaesthesiology residents with experience of 5 years. Interventions In a manikin scenario, participants performed endotracheal intubations with four different direct and indirect laryngoscopes (Macintosh (MAC), Airtraq (ATQ), Glidescope (GLS) and AP Advance (APA)), while wearing chemical protective gear, including a body suit, rubber gloves, a fire helmet and breathing apparatus. Primary and secondary outcome measures With respect to the manikin, setting time to complete ‘endotracheal intubation’ was defined as primary end point. Glottis visualisation (according to the Cormack-Lehane score (CLS) and impairments caused by the protective equipment, were defined as secondary outcome measures. Results The times to tracheal intubation were calculated using the MAC (31.4 s; 95% CI 26.6 to 36.8), ATQ (37.1 s; 95% CI 28.3 to 45.9), GLS (35.4 s; 95% CI 28.7 to 42.1) and APA (23.6 s; 95% CI 19.1 to 28.1), respectively. Intubation with the APA was significantly faster than with all the other devices examined among the total study population (pevaluated as an easily manageable device for anaesthetists with varying degrees of experience (low to high), providing good visualisation in scenarios that require the use of chemical protective equipment. PMID:27008688

  2. Feasibility study of sulfates as oxygen carriers for chemical looping processes

    Directory of Open Access Journals (Sweden)

    Ganesh Kale

    2012-12-01

    Full Text Available The operational feasibility temperature range of chemical looping combustion (CLC and chemical looping reforming (CLR of the fuels methane, propane, iso-octane and ethanol was explored using the common sulphates

  3. A Framework for Assessing Chemical/Nonchemical Interactions: A Case Study of Lead and Psychosocial Stress

    Science.gov (United States)

    Chemical and nonchemical stressors may contribute to negative health consequences in certain individuals. Nonchemical stressors include poverty, crowding, noise, and exposure to violence. Research has suggested that some nonchemical stressors may alter chemical toxicity. We propo...

  4. Study on the key problems of interaction between microwave and chemical reaction

    Institute of Scientific and Technical Information of China (English)

    YANG Xiaoqing; HUANG Kama

    2007-01-01

    Microwave has been found as an efficient heating method in chemical industry.However,in present days the interaction between microwave and chemical reactions has not been deeply understood,which restricts a wider application of high power microwave in chemical industry.In this Paper,the key problems of interaction between microwave and chemical reaction are investigated,such as complex effective permittivity of chemical reaction,simulation of microwave heating on chemical reaction and non-thermal effect of microwave,which will enhance further knowledge of the mechanism of interaction between microwave and chemical reaction.Moreover,such an analysis is beneficial for handling with difficulties in application of microwave chemical industry.

  5. Study on the association between environmental chemical elements and fluorosis caused by coal-fire pollution

    Institute of Scientific and Technical Information of China (English)

    焦永卓

    2013-01-01

    Objective To understand the distribution of chemical elements in soil,to investigate the differences between patients under different state of fluorosis and normal population after preventive measurement was implemented to get rid of some chemical elements and to lower

  6. Chemical, biological, morphoanatomical and antimicrobial study of Ocotea puchury-major Mart.

    Science.gov (United States)

    Leporatti, Maria Lucia; Pintore, Giorgio; Foddai, Marzia; Chessa, Mario; Piana, Andrea; Petretto, Giacomo Luigi; Masia, Maria Dolores; Mangano, Giuseppe; Nicoletti, Marcello

    2014-01-01

    Ocotea puchury-major Mart. is a tree native to the Brazilian rain forest, where it is popularly known as puxurì. In local folk medicine the leaves are used for their sedative, gastroenteric and antireumatic properties. The morphoanatomical study determined those features useful in distinguishing this species from other closely related taxa. Chemical analysis was focused on the study of the volatile oil. Gas chromatography-mass spectrometry analyses indicated safrol as the main compound of the volatile oil (39%). The results confirm and authenticate the use of its leaves in folk medicine. Furthermore, safrol is economically important as the starting material for hemisynthesis of several products. The antimicrobial activity of the essential oil was studied which showed promising activity against environmental microorganisms as well as anti-inflammatory activity.

  7. Selecting the right bird model in experimental studies on endocrine disrupting chemicals

    Directory of Open Access Journals (Sweden)

    Veerle L.B. Jaspers

    2015-05-01

    Full Text Available Birds have been used as model species in ecotoxicological research for decades but have only recently been included in toxicity testing schemes. However, the avian fauna is very diverse. Given this diversity the ecology, behavior and reproduction should be considered when selecting the appropriate bird model in ecotoxicological studies. This article focusses on choosing the right bird model species for experimental studies with endocrine disrupting chemicals (EDCs. EDCs have been associated with adverse effects on the reproduction and development in birds and other wildlife. In addition, new EDCs continue to emerge and the concern for potential effects in humans and wildlife is calling for increased toxicity testing and hence appropriate model species. Common bird model species used in ecotoxicological studies investigating EDCs will be reviewed. In addition, considerations for selecting the right bird model, along with potential drawbacks and restrictions on the use of certain species will be discussed.

  8. Studying chemical reactions in biological systems with MBN Explorer: implementation of molecular mechanics with dynamical topology

    CERN Document Server

    Sushko, Gennady B; Verkhovtsev, Alexey V; Volkov, Sergey N; Solov'yov, Andrey V

    2015-01-01

    The concept of molecular mechanics force field has nowadays been widely accepted for studying various processes in biomolecular systems. In this paper we suggest a modification for the standard CHARMM force field, that permits simulations of systems with dynamically changing molecular topologies. The implementation of the modified force field was carried out in the popular program MBN Explorer, and, to support the development, in this paper we provide several case studies where dynamical topology is necessary. In particular, it is shown, that the modified molecular mechanics force field can be applied for studying processes where rupture of chemical bonds plays an essential role, e.g., in irradiation or collision induced damage, transformation and fragmentation processes involving biomolecular systems.

  9. A NEW TOOL FOR THE STUDY OF RESONANCE IN CHEMICAL EDUCATION

    Directory of Open Access Journals (Sweden)

    Francisco Torrens

    2014-03-01

    Full Text Available The objective of this study is to present a computer-based project, for which our program POLAR and our version of PAPID were written for the study of the subject of resonance in chemistry. Both algorithms allow a better didactic strategy and methodological adaptation for the study of molecular properties in chemical education. Teachers will find the options of POLAR and PAPID useful for demonstrations. It is still to be explored the methodological application of these computational programs enriching the present teaching techniques. Implementing new algorithms in learning situations is technically simple, but checking their usefulness in teaching practice is extraordinarily complex and requires a research that has hardly begun. The topic of resonance in chemistry represents an opportunity for the integration of teaching and research into the European Space for Higher Education.

  10. In vivo studies on chemically induced aneuploidy in mouse somatic and germinal cells.

    Science.gov (United States)

    Leopardi, P; Zijno, A; Bassani, B; Pacchierotti, F

    1993-05-01

    Within the context of a coordinated program to study aneuploidy induction sponsored by the European Community, nine chemicals were tested in mouse bone marrow and spermatocytes after intraperitoneal injection. In somatic cells, cell progression delay, hyperploidy, polyploidy induction and induction of micronucleated polychromatic erythrocyte (MnPCE) were studied. In germ cells hyperploidy induction was evaluated. The chemicals selected were: colchicine (COL), econazole (EZ), hydroquinone (HQ), thiabendazole (TB), diazepam (DZ), chloral hydrate (CH), cadmium chloride (CD), pyrimethamine (PY) and thimerosal (TM). Using literature data on c-mitotic effects in bone marrow as a reference, the same doses were tested in somatic and germ cells in order to compare the effects induced. Bone marrow cells were sampled 18 or 24 h after treatment. Germ cells were sampled 6, 8 or 18 h after treatment. Effects of COL and HQ in bone marrow have been reported elsewhere. Somatic effects were induced by CH (hyperploidy and cell cycle lengthening), TB (MnPCEs and cell cycle lengthening) and by PY (MnPCEs). EZ, DZ, CD and TM did not induce any kind of somatic effects. An increase in the incidence of hyperploid spermatocytes was induced by COL, at three dose levels, and by one dose of HQ and TB. All the other chemicals did not induce germinal aneuploidy at any dose or time tested. The hyperploidy control frequency ranged between 0.4 and 1.0% in somatic cells and from 0.3 to 0.9% in germ cells. In both somatic and germ cells, the maximum yield of induced hyperploidy did not exceed 3.5%. The time period of target cell sensitivity is probably restricted and this, associated with the heterogeneity and the asynchrony of cellular maturation processes, may account for our data. Under these circumstances, the negative data should be interpreted with some caution, particularly in germ cells, where additional indicators of chemical-cell interaction and cell cycle effects were not provided by

  11. Chemical aging of m-xylene secondary organic aerosol: laboratory chamber study

    Directory of Open Access Journals (Sweden)

    J. H. Seinfeld

    2011-09-01

    Full Text Available Secondary organic aerosol (SOA can reside in the atmosphere for a week or more. While its initial formation from the gas-phase oxidation of volatile organic compounds tends to take place in the first few hours after emission, SOA can continue to evolve chemically over its atmospheric lifetime. Simulating this chemical aging over an extended time in the laboratory has proven to be challenging. We present here a procedure for studying SOA aging in laboratory chambers that is applied to achieve 36 h of oxidation. The formation and evolution of SOA from the photooxidation of m-xylene under low-NOx conditions and in the presence of either neutral or acidic seed particles is studied. In SOA aging, increasing molecular functionalization leads to less volatile products and an increase in SOA mass, whereas gas-phase or particle-phase fragmentation chemistry results in more volatile products and a loss of SOA. The challenge is to discern from measured chamber variables the extent to which these processes are important for a given SOA system. In the experiments conducted, m-xylene SOA mass increased over the initial 12-h of photooxidation and decreased beyond that time. The oxidation of the SOA, as manifested in the O:C elemental ratio and fraction of organic ion detected at m/z 44 measured by the Aerodyne aerosol mass spectrometer, decreased during the first 5 h of reaction, reached a minimum, and then increased continuously until the 36 h termination. This behavior is consistent with an initial period in which, as the mass of SOA increases, products of higher volatility partition to the aerosol phase, followed by an aging period in which gas- and particle-phase reaction products become increasingly more oxidized. After about 12–13 h, the SOA mass reaches a maximum and decreases, suggesting the existence of fragmentation chemistry. When irradiation is stopped 12.4 h into one experiment, and OH generation ceases, no loss of SOA is observed, indicating

  12. Comparative studies of chemically synthesized and RF plasma-polymerized poly(-toluidine)

    Indian Academy of Sciences (India)

    Shama Islam; G B V S Lakshmi; M Zulfequar; M Husain; Azher M Siddiqui

    2015-04-01

    Poly(-toluidine) (POT) polymer was synthesized by chemical method and RF plasma polymerization at a radio frequency (RF) power input of 15 W on ultrasonically cleaned glass and silicon wafer substrates. These samples were characterized by DC conductivity measurements, UV–visible, XRD and FTIR techniques. The DC-conductivity was measured at 410 K, which was found to increase by two orders of magnitude for thin film as compared to pellet samples. It has been observed that the activation energy increases for RF plasma-polymerized POT. Transmission and reflectance spectra were studied for measuring optical constants like absorption coefficient (), extinction coefficient (), optical band gap (g), Urbach energy (e), and refractive index (). From XRD studies, one can infer that the samples grown by both the methods are amorphous in nature. The results indicate that the structures of plasma-polymerized POT are rather different from polymers synthesized by conventional chemical methods, due to a higher degree of cross-linking and branching reactions in plasma polymerization. This makes them suitable for various electroactive devices. A higher and more stable conductivity can be obtained with RF plasma-polymerized POT which is much smoother and more uniform.

  13. Study of chemical additives in the cementation of radioactive waste of PWR reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Vanessa Mota; Tello, Cledola Cassia Oliveira de, E-mail: vanessamotavieira@gmail.com, E-mail: tellocc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2012-03-15

    In this research it has been studied the effects of chemical admixtures in the cementation process of radioactive wastes. These additives are used to improve the properties of waste cementation process, both of the paste and of the solidified product. However there are a large variety of these materials that are frequently changed or taken out of the market. Then it is essential to know the commercially available materials and their effects. The tests were carried out with a solution simulating the evaporator concentrate waste coming from PWR nuclear reactors. It was cemented using two formulations, A and B, incorporating higher or lower amount of waste, respectively. It was added chemical admixtures from two manufacturers (S and H), which were: accelerators, set retarders and superplasticizers. The experiments were organized by a factorial design 23. The measured parameters were: the viscosity, the setting time, the paste and product density and the compressive strength. The parameter evaluated in this study was the compressive strength at age of 28 days, is considered essential security issues relating to the handling, transport and storage of cemented waste product. The results showed that the addition of accelerators improved the compressive strength of the cemented products. (author)

  14. Sequential repetitive chemical reduction technique to study size-property relationships of graphene attached Ag nanoparticle

    Science.gov (United States)

    Haider, M. Salman; Badejo, Abimbola Comfort; Shao, Godlisten N.; Imran, S. M.; Abbas, Nadir; Chai, Young Gyu; Hussain, Manwar; Kim, Hee Taik

    2015-06-01

    The present study demonstrates a novel, systematic and application route synthesis approach to develop size-property relationship and control the growth of silver nanoparticles (AgNPs) embedded on reduced graphene oxide (rGO). A sequential repetitive chemical reduction technique to observe the growth of silver nanoparticles (AgNPs) attached to rGO, was performed on a single solution of graphene oxide (GO) and silver nitrate solution (7 runs, R1-R7) in order to manipulate the growth and size of the AgNPs. The physical-chemical properties of the samples were examined by RAMAN, XPS, XRD, SEM-EDAX, and HRTEM analyses. It was confirmed that AgNPs with diameter varying from 4 nm in first run (R1) to 50 nm in seventh run (R7) can be obtained using this technique. A major correlation between particle size and activities was also observed. Antibacterial activities of the samples were carried out to investigate the disinfection performance of the samples on the Gram negative bacteria (Escherichia coli). It was suggested that the sample obtained in the third run (R3) exhibited the highest antibacterial activity as compared to other samples, toward disinfection of bacteria due to its superior properties. This study provides a unique and novel application route to synthesize and control size of AgNPs embedded on graphene for various applications.

  15. Studies on percutaneous penetration of chemicals - Impact of storage conditions for excised human skin.

    Science.gov (United States)

    Dennerlein, Kathrin; Schneider, Désirée; Göen, Thomas; Schaller, Karl Heinz; Drexler, Hans; Korinth, Gintautas

    2013-03-01

    According to international guidelines skin penetration experiments can be carried out using freshly excised or frozen stored skin. However, this recommendation refers to data obtained in experiments with human cadaver skin. In our study, the percutaneous penetration of the occupationally relevant chemicals anisole, cyclohexanone and 1,4-dioxane was investigated for freshly excised as well as for 4 and 30 days at -20°C stored human skin using the diffusion cell technique. As indicator for the impairment of skin barrier by freezing cholesterol dissolution was determined in the solvents in exposure chambers of diffusion cells. Considering the percutaneously penetrated amounts, the following ranking was determined: 1,4-dioxane>anisole>cyclohexanone (decline to a factor of 5.9). The differences of fluxes between freshly excised and frozen stored skin (4 and 30 days) were not significant (p>0.05). Cholesterol dissolved from the skin indicates no significant differences between freshly excised and frozen stored skin. This study shows that freezing of human skin for up to 30 days does not alter the skin barrier function and the permeability of chemicals.

  16. A Pilot Study To Define Chemical Coping in Cancer Patients Using the Delphi Method

    OpenAIRE

    Kwon, Jung Hye; Hui, David; Bruera, Eduardo

    2015-01-01

    Background: “Chemical coping” is a commonly used term in the pain and palliative care literature, but is heterogeneously defined. We conducted a Delphi survey among palliative care and pain specialists internationally to identify a consensus definition for “chemical coping with opioids” and warning signs for chemical coping.

  17. Two-phase reactive transport of an oil-soluble chemical: an NMR study

    NARCIS (Netherlands)

    Castelijns, H.J.

    2007-01-01

    An oil-soluble chemical (OSC) is a chemical substance which is soluble and chemically inert in oil, but reacts with water to form a gel. Application of an OSC can be found in oil- and gas production. An increased water production, which usually occurs in mature oil fields, can be remedied by

  18. Two-phase reactive transport of an oil-soluble chemical: an NMR study

    NARCIS (Netherlands)

    Castelijns, H.J.

    2007-01-01

    An oil-soluble chemical (OSC) is a chemical substance which is soluble and chemically inert in oil, but reacts with water to form a gel. Application of an OSC can be found in oil- and gas production. An increased water production, which usually occurs in mature oil fields, can be remedied by injecti

  19. Two-phase reactive transport of an oil-soluble chemical: an NMR study

    NARCIS (Netherlands)

    Castelijns, H.J.

    2007-01-01

    An oil-soluble chemical (OSC) is a chemical substance which is soluble and chemically inert in oil, but reacts with water to form a gel. Application of an OSC can be found in oil- and gas production. An increased water production, which usually occurs in mature oil fields, can be remedied by injecti

  20. Savannah River Site chemical, metal, and pesticide (CMP) waste vitrification treatability studies

    Energy Technology Data Exchange (ETDEWEB)

    Cicero, C.A.

    1997-01-13

    Numerous Department of Energy (DOE) facilities, as well as Department of Defense (DOD) and commercial facilities, have used earthen pits for disposal of chemicals, organic contaminants, and other waste materials. Although this was an acceptable means of disposal in the past, direct disposal into earthen pits without liners or barriers is no longer a standard practice. At the Savannah River Site (SRS), approximately three million pounds of such material was removed from seven chemical, metal, and pesticide disposal pits. This material is known as the Chemical, Metal, and Pesticide (CMP) Pit waste and carries several different listed waste codes depending on the contaminants in the respective storage container. The waste is not classified as a mixed waste because it is believed to be non-radioactive; however, in order to treat the material in a non-radioactive facility, the waste would first have to be screened for radioactivity. The Defense Waste Processing Technology (DWPT) Section of the Savannah River Technology Center (SRTC) was requested by the DOE-Savannah River (SR) office to determine the viability of vitrification of the CMP Pit wastes. Radioactive vitrification facilities exist which would be able to process this waste, so the material would not have to be analyzed for radioactive content. Bench-scale treatability studies were performed by the DWPT to determine whether a homogeneous and durable glass could be produced from the CMP Pit wastes. Homogeneous and durable glasses were produced from the six pits sampled. The optimum composition was determined to be 68.5 wt% CMP waste, 7.2 wt% Na{sub 2}O, 9 wt% CaO, 7.2 wt% Li{sub 2}O and 8.1 wt% Fe{sub 2}O{sub 3}. This glass melted at 1,150 C and represented a two fold volume reduction.

  1. Mineralogical, chemical and physical study of potential buffer and backfill materials from ABM. Test Package 1

    Energy Technology Data Exchange (ETDEWEB)

    Kumpulainen, S.; Kiviranta, L. (B and Tech Oy, Helsinki (Finland))

    2011-07-15

    In the ABM experiment, three test packages with centre steel heaters surrounded by stacks of compacted bentonite rings of various clay materials were placed in boreholes in Aespoe tunnel. The first parcel was saturated with Aespoe groundwater and the heater was turned on simultaneously with the start of saturation. This parcel was excavated 30 months after its installation. Chemical, mineralogical and physical properties of the MX-80, Dep-CaN, Asha and Friedland clay samples from the ABM parcel 1 were analysed and compared to reference samples. Chemical analyses (ICP-AES, C, CO{sub 3}, S, water soluble SO{sub 4}, Fe2+/Fe3+), exchangeable cation analyses, mineralogical analyses (XRD, FTIR) and selective extractions were used to determine changes in the chemistry and mineralogy of ABM materials. Swelling pressure and hydraulic conductivity measurements were performed both for extracted samples and for ground and recompacted samples. Major changes in exchangeable cation composition were observed in all samples originating from equilibration with Aespoe groundwater and interactions with equilibrated waters from neighbouring block materials. Some minor changes in chemical composition were observed as well. Increases in soluble sulphate content in the vicinity of the heater were thought to result from precipitation of sulphate salts. Decreases in sodium content and increases in calcium content were ascribed to changes in exchangeable cations. Interaction with iron was observed to occur only in the close vicinity (first few mm) of the heater. No significantly measureable change in mineralogical composition was seen in any of the studied materials. Extracted Dep-CaN samples showed a slight decrease in swelling pressure. However, when the material was ground, compacted and measured again the swelling pressure was fully recovered. No related change in hydraulic conductivities was observed. (orig.)

  2. Chemical kinetics on thermal decompositions of cumene hydroperoxide in cumene studied by calorimetry: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Duh, Yih-Shing, E-mail: yihshingduh@yahoo.com.tw [Department of Occupation Safety and Health, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, 35664, Taiwan, ROC (China); Department of Safety, Health and Environmental Engineering, National United University, No. 1 Lien-Da, Miaoli, 36052, Taiwan, ROC (China)

    2016-08-10

    Highlights: • Chemical kinetics on thermal decompositions of CHP are conducted and summarized. • Kinetics agrees well between data from DSC and adiabatic calorimetry. • Ea is determined to be about 120 kJ mol{sup −1} by various calorimetry. • LogA (A in s{sup −1}) is determined to be about 11.8 by various calorimetry. - Abstract: Study on chemical kinetics related to the thermal decomposition of cumene hydoperoxide (CHP) in cumene is summarized in this work. It is of great importance to gather and compare the differences between these kinetic parameters for further substantial applications in the chemical industry and process safety. CHP has been verified to possess an autocatalytic behavior by using microcalorimetry (such as TAM and C-80) operated at isothermal mode in the temperature range from 70 °C to 120 °C. However, it exhibits a reaction of n-th order detected by non-isothermal DSC scanning and adiabatic calorimeter. By the isothermal aging tests, activation energy and frequency factor in logA(s{sup −1}) were averaged to be (117.3 ± 5.9) kJ mol{sup −1}and (11.4 ± 0.3), respectively. Kinetic parameters acquired from data of interlaboratories by using heat-flow calorimetry, the averaged activation energy and frequency factor in logA(s{sup −1}) were (119.3 ± 11.3) kJ mol{sup −1}and (12.0 ± 0.2), respectively. On the analogy of results from adiabatic calorimetry, the activation energy and frequency factor in logA(s{sup −1}) were respectively averaged to be (122.4 ± 9.2) kJ mol{sup −1}and (11.8 ± 0.8). Five sets of kinetic models in relation to autocatalytic reactions are collected and discussed as well.

  3. Study of features of physical and chemical properties of household chemicals on population dynamics of Blattella Germanica (L. in Kyiv

    Directory of Open Access Journals (Sweden)

    Георгій Васильович Кобеньок

    2015-11-01

    Full Text Available The importance of studying the ecology of premises is to study the negative impact on the domestic environment some environmental factors of anthropogenic origin. In the article the possibility of using the method of biological indication is considered to analyze environmental risks emerging in the artificial environment of modern premises. For example of Blattella Germanica (L. it is investigated the possible effect of the toxic properties of synthetic detergents to negative fluctuations in the population of this species of insects-sinanthropus

  4. Contaminant and nutrient concentrations of natural ingredient rat and mouse diet used in chemical toxicology studies.

    Science.gov (United States)

    Rao, G N; Knapka, J J

    1987-08-01

    The NIH-07 open formula natural ingredient rat and mouse ration is the standard diet for chemical toxicity and carcinogenicity studies conducted for the National Toxicology Program (NTP). Contaminant and nutrient concentrations were determined in 2 to 94 lots of this diet used in the NTP toxicology studies. All nutrient concentrations were equivalent to or greater than the requirements for rats and mice as set forth by the National Research Council. Aflatoxins, Hg, chlorinated hydrocarbons except methoxychlor, organophosphates except malathion, estrogenic activity, and Salmonella sp. were not present at the detectable levels. Fluorine, As, Cd, Pb, Se, N-nitrosodimethylamine, N-nitrosopyrrolidine, N-nitrosomorpholine, nitrate, nitrite, butylated hydroxyanisole, butylated hydroxytoluene, ethylene dibromide, methoxychlor, malathion, and trypsin inhibitor activity were present at or above the detectable levels. Five lots of diet had nitrosamine content of 100 to 273 ppb and 7 lots had 2.08 to 3.37 ppm of Pb. All other lots of NIH-07 diet used for NTP toxicology studies contained low levels of the contaminants. After determination of the contaminant concentrations in the 94 lots of diet and the contaminant concentrations in natural ingredients used in formulating NIH-07 diet, maximum allowable levels of contaminants were established and a flexible scoring system for acceptability of each lot of diet for chemical toxicology studies was developed. By prescreening ingredients such as fish meal for heavy metals and nitrosamines, and applying the flexible scoring system proposed, more than 95% of the lots of NIH-07 diet produced during the last 3 years had scores of greater than or equal to 95 out of 100 points and were considered acceptable for toxicology studies.

  5. The Oxford-Diamond In Situ Cell for studying chemical reactions using time-resolved X-ray diffraction.

    Science.gov (United States)

    Moorhouse, Saul J; Vranješ, Nenad; Jupe, Andrew; Drakopoulos, Michael; O'Hare, Dermot

    2012-08-01

    A versatile, infrared-heated, chemical reaction cell has been assembled and commissioned for the in situ study of a range of chemical syntheses using time-resolved energy-dispersive X-ray diffraction (EDXRD) on Beamline I12 at the Diamond Light Source. Specialized reactor configurations have been constructed to enable in situ EDXRD investigation of samples under non-ambient conditions. Chemical reactions can be studied using a range of sample vessels such as alumina crucibles, steel hydrothermal autoclaves, and glassy carbon tubes, at temperatures up to 1200 °C.

  6. The Oxford-Diamond In Situ Cell for studying chemical reactions using time-resolved X-ray diffraction

    Science.gov (United States)

    Moorhouse, Saul J.; Vranješ, Nenad; Jupe, Andrew; Drakopoulos, Michael; O'Hare, Dermot

    2012-08-01

    A versatile, infrared-heated, chemical reaction cell has been assembled and commissioned for the in situ study of a range of chemical syntheses using time-resolved energy-dispersive X-ray diffraction (EDXRD) on Beamline I12 at the Diamond Light Source. Specialized reactor configurations have been constructed to enable in situ EDXRD investigation of samples under non-ambient conditions. Chemical reactions can be studied using a range of sample vessels such as alumina crucibles, steel hydrothermal autoclaves, and glassy carbon tubes, at temperatures up to 1200 °C.

  7. Opportunities and challenges in single-molecule and single-particle fluorescence microscopy for mechanistic studies of chemical reactions

    Science.gov (United States)

    Cordes, Thorben; Blum, Suzanne A.

    2013-12-01

    In recent years, single-molecule and single-particle fluorescence microscopy has emerged as a tool to investigate chemical systems. After an initial lag of over a decade with respect to biophysical studies, this powerful imaging technique is now revealing mechanisms of 'classical' organic reactions, spatial distribution of chemical reactivity on surfaces and the phase of active catalysts. The recent advance into commercial imaging systems obviates the need for home-built laser systems and thus opens this technique to traditionally trained synthetic chemists. We discuss the requisite photophysical and chemical properties of fluorescent reporters and highlight the main challenges in applying single-molecule techniques to chemical questions. The goal of this Perspective is to provide a snapshot of an emerging multidisciplinary field and to encourage broader use of this young experimental approach that aids the observation of chemical reactions as depicted in many textbooks: molecule by molecule.

  8. Opportunities and challenges in single-molecule and single-particle fluorescence microscopy for mechanistic studies of chemical reactions.

    Science.gov (United States)

    Cordes, Thorben; Blum, Suzanne A

    2013-12-01

    In recent years, single-molecule and single-particle fluorescence microscopy has emerged as a tool to investigate chemical systems. After an initial lag of over a decade with respect to biophysical studies, this powerful imaging technique is now revealing mechanisms of 'classical' organic reactions, spatial distribution of chemical reactivity on surfaces and the phase of active catalysts. The recent advance into commercial imaging systems obviates the need for home-built laser systems and thus opens this technique to traditionally trained synthetic chemists. We discuss the requisite photophysical and chemical properties of fluorescent reporters and highlight the main challenges in applying single-molecule techniques to chemical questions. The goal of this Perspective is to provide a snapshot of an emerging multidisciplinary field and to encourage broader use of this young experimental approach that aids the observation of chemical reactions as depicted in many textbooks: molecule by molecule.

  9. Success and Failures of Acquisitions: A Case Study for a Chemical Company

    Directory of Open Access Journals (Sweden)

    Shainaaz MOOSA MUSTAFFA

    2017-05-01

    Full Text Available The purpose of this study was to perform a universal inspection of the processes adopted in acquisitions by concentrating on attributes which are speedily implemented in the industry. The approach to this research study was based on literature reviews to gain knowledge on the causes of failure and the factors attributed to the success of acquisitions in the case study concerning a chemical company. This method was applied to identify if the failures and successes researched are shown in the case study. The research study firstly looked at various approaches to acquisitions, namely, the pre-acquisition, post-acquisition and integration phases together with the motives for acquisitions. The study delves further into factors influencing the failures and successes of acquisitions. A notable body of research was consulted to focus on these factors. The research study highlights a framework incorporating the management of post-integration strategy concurrently with the people and the organisational goals. The key findings showed that the company lacked a formal integration plan, cultural integration, ad proper communication plans. This resulted in staff unrest and high attrition of staff from deal announcement date up to post integration, leading to high resistance from staff and poor people integration. The company did however achieve financial success through synergy realisation. This positive outcome could have been achieved quicker with the proper integration plans within the different phases of the acquisition. The knowledge attained from this study will hopefully add to the body of knowledge on acquisitions.

  10. The XPS study of physical and chemical forms of neptunium group on the surface of minerals

    Directory of Open Access Journals (Sweden)

    Teterin Anton Yu.

    2010-01-01

    Full Text Available The sorption behavior and the physical and chemical forms of neptunium on the surface of minerals of the two chlorate samples, biotite and kaolin, with different contents of Fe(II was studied. The liquid-liquid extraction and the X-ray photoelectron spectroscopy were employed to identify the valence forms of neptunium. On the basis of the obtained data the quantitative elemental composition of the surface of the studied minerals, as well as the ionic composition of the formed neptunium complexes was determined. It was shown that the Np(IV and Np(VI containing compounds did not form, while the complexes Np(VO+ -hydroxyl did form on the surface. The oxygen ions bonded with iron and oxygen belonging to water and/or of carboxyl were suggested to be present in the equatorial plane of the neptunyl group NpO+.

  11. Cosmic-ray chemical composition from the geomagnetic effect on EAS muons: A simulation study

    CERN Document Server

    Dey, Rajat K

    2016-01-01

    The effect of the geomagnetic Lorentz force on extensive air shower (EAS) charged muon components has been studied in a Monte Carlo (MC) generated simulated data sample. This geomagnetic field (GF) affects the paths of the secondary charged muons in the EAS, causing a local contrast or asymmetry in the abundance of positive and negative muons which is noticeable for some azimuthal and zenith angles. Consequent upon, a transverse separation of positive and negative muons cores of EAS is observed at different azimuthal positions through the EAS core. In the present study using a simulated data sample it is found that the transverse or lateral muon core separation (LMCS) and its maximum value (MLMCS) are quite sensitive to the nature of shower initiating particles, particularly for inclined showers and hence in principle the parameters can be exploited to the measurement of primary cosmic-ray (CR) chemical composition. Possibility of practical realization of the stated method in a real experiment is briefly disc...

  12. A numerical study of three-dimensional droplets spreading on chemically patterned surfaces

    KAUST Repository

    Zhong, Hua

    2016-09-26

    We study numerically the three-dimensional droplets spreading on physically flat chemically patterned surfaces with periodic squares separated by channels. Our model consists of the Navier-Stokes-Cahn-Hilliard equations with the generalized Navier boundary conditions. Stick-slip behavior and con-tact angle hysteresis are observed. Moreover, we also study the relationship between the effective advancing/receding angle and the two intrinsic angles of the surface patterns. By increasing the volume of droplet gradually, we find that the advancing contact line tends gradually to an equiangular octagon with the length ratio of the two adjacent sides equal to a fixed value that depends on the geometry of the pattern.

  13. Pectin gelation with chlorhexidine: Physico-chemical studies in dilute solutions.

    Science.gov (United States)

    Lascol, Manon; Bourgeois, Sandrine; Guillière, Florence; Hangouët, Marie; Raffin, Guy; Marote, Pedro; Lantéri, Pierre; Bordes, Claire

    2016-10-05

    Low methoxyl pectin is known to gel with divalent cations (e.g. Ca(2+), Zn(2+)). In this study, a new way of pectin gelation in the presence of an active pharmaceutical ingredient, chlorhexidine (CX), was highlighted. Thus chlorhexidine interactions with pectin were investigated and compared with the well-known pectin/Ca(2+) binding model. Gelation mechanisms were studied by several physico-chemical methods such as zeta potential, viscosity, size measurements and binding isotherm was determined by Proton Nuclear Magnetic Resonance Spectroscopy ((1)H NMR). The binding process exhibited similar first two steps for both divalent ions: a stoichiometric monocomplexation of the polymer followed by a dimerization step. However, stronger interactions were observed between pectin and chlorhexidine. Moreover, the dimerization step occurred under stoichiometric conditions with chlorhexidine whereas non-stoichiometric conditions were involved with calcium ions. In the case of chlorhexidine, an additional intermolecular binding occurred in a third step.

  14. Studies on the chemical synthesis and characterization of lead oxide nanoparticles with different organic capping agents

    Energy Technology Data Exchange (ETDEWEB)

    Arulmozhi, K. T., E-mail: arulsheelphy@gmail.com [Physics Wing (DDE), Annamalai University, Tamil Nadu, India - 608 002 (India); Mythili, N. [Department of Physics, Annamalai University, Tamil Nadu, India - 608 002 (India)

    2013-12-15

    Lead oxide (PbO) nanoparticles were chemically synthesized using Lead (II) acetate as precursor. The effects of organic capping agents such as Oleic acid, Ethylene Diamine Tetra Acetic acid (EDTA) and Cetryl Tri Methyl Butoxide (CTAB) on the size and morphology of the nanoparticles were studied. Characterization techniques such as X-ray diffraction (XRD), Fourier Transform-Infrared spectroscopy (FT-IR), Photoluminescence (PL) Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDS) and Transmission Electron Microscopy (TEM) were used to analyse the prepared nanoparticles for their physical, structural and optical properties. The characterization studies reveal that the synthesized PbO nanoparticles had well defined crystalline structure and sizes in the range of 25 nm to 36 nm for capping agents used and 40 nm for pure PbO nanoparticles.

  15. Physico-chemical studies of indium tin oxide-coated fiber optic biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Konry, Tania [Department of Biotechnology Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva, 84105 (Israel); Marks, Robert S. [Department of Biotechnology Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva, 84105 (Israel) and National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva, 84105 (Israel)]. E-mail: rsmarks@bgumail.bgu.ac.il

    2005-12-01

    Our recent studies have shown that thin films of indium tin oxide (Into) could be deposited onto non-conductive optical fiber tips, which were then used as working electrodes for the electrochemical deposition of polymers with reactive groups (biotin), so as to create a biosensor. Physico-chemical properties of ITO thin films (260 nm) deposited by radio frequency (r.f.) sputtering onto fiber optics have been studied and compared to the existing literature on a flat glass surface. The film properties vary particularly for different oxygen pressures used during deposition. The microstructure of these thin films is determined using X-ray diffraction, transmission electron microscopy, scanning electron microscopy and atomic force microscopy.

  16. Chronological and chemical studies on several differentiated meteorites. Bunkashita inseki no kagakuteki/nendaigakuteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, K. (The Inst. of Physical and Chemical Research, Saitama (Japan). Earth Science Lab.)

    1994-03-24

    Materials on the earth generally pass though the metamorphosing, igneous and the weathering action in a long time, meteorites were considered to faithfully reflect occurrence from the birth to the first stage of the solar system according to the chemical composition. Meteorites are divided into the original chondrites and the differentiated meteorites. In the studies on the origin and evolution of planets, the differentiated meteorites can mainly give the important informations. In the differentiated meteorites, the lithic material is called as achondrites, only five to six kinds have been known until now. With the development of recent researches, discover of meteorites related to the origin of Mars and moon, kinds of meteorites become variety, and studies are also more detailed. In this paper, concerning to the origin of three kinds of achondrites such as eucrites, howardites and diogenites in the differentiated meteorites, the age measurement made by authors was mainly described. 21 refs., 10 figs., 2 tabs.

  17. Studies on the chemical synthesis and characterization of lead oxide nanoparticles with different organic capping agents

    Directory of Open Access Journals (Sweden)

    K. T. Arulmozhi

    2013-12-01

    Full Text Available Lead oxide (PbO nanoparticles were chemically synthesized using Lead (II acetate as precursor. The effects of organic capping agents such as Oleic acid, Ethylene Diamine Tetra Acetic acid (EDTA and Cetryl Tri Methyl Butoxide (CTAB on the size and morphology of the nanoparticles were studied. Characterization techniques such as X-ray diffraction (XRD, Fourier Transform-Infrared spectroscopy (FT-IR, Photoluminescence (PL Field Emission Scanning Electron Microscopy (FE-SEM, Energy Dispersive Spectroscopy (EDS and Transmission Electron Microscopy (TEM were used to analyse the prepared nanoparticles for their physical, structural and optical properties. The characterization studies reveal that the synthesized PbO nanoparticles had well defined crystalline structure and sizes in the range of 25 nm to 36 nm for capping agents used and 40 nm for pure PbO nanoparticles.

  18. Chemical differences between voided and bladder urine in the aye-aye (Daubentonia madagascariensis): implications for olfactory communication studies.

    Science.gov (United States)

    Delbarco-Trillo, Javier; Harelimana, Innocent H; Goodwin, Thomas E; Drea, Christine M

    2013-07-01

    Urine serves a communicative function in many mammalian species. In some species, the signaling function of urine can be enhanced by the addition of chemical compounds from glands along the distal portion of the urogenital tract. Although urine marking is the main mode of chemical communication in many primate species, there has been no study of the contribution of urogenital secretions to the chemical complexity of primate urine. Here, we compared the chemical composition of bladder urine versus voided urine in the aye-aye, Daubentonia madagascariensis, a strepsirrhine primate that relies on urine in intraspecific communication. Both types of urine, collected from each of 11 aye-ayes representing both sexes of varying adult ages, underwent headspace analysis via gas chromatography and mass spectrometry. Although the average number of compounds was similar in bladder and voided urine, 17% of the compounds detected occurred exclusively in voided urine (but only in a subset of individuals). An overall measure of chemical complexity (using a nonmetric multidimensional scaling analysis) showed that both types of urine were chemically different at the individual level. There was no apparent sex or age differences in the chemical components found in aye-aye urine. Nonetheless, the individual dissimilarities between bladder urine and voided urine indicate chemical contributions from structures along the urogenital tract and offer further support for the relevance of urinary communication in the aye-aye.

  19. a Design of Experiment Study of the Nucleation of Chemical Vapor Deposited Diamond Films.

    Science.gov (United States)

    Tang, Chi

    1995-01-01

    Because of its property, diamond has a unique role in the semiconductor and tool industry. As diamond synthesis technology advances, more and more applications are emerging. However, in order to take advantage of its exceptional property, reliable control of nucleation and growth must be accomplished. In this study, the author systematically studies the nucleation process in chemical vapor deposition (CVD) of diamonds. Among many important intricacies concerning diamond nucleation on foreign surfaces, this study addresses the following issues: the role of ultrasonic pre-treatment in CVD; the correlation between hot filament chemical vapor deposition (HFCVD) and microwave assisted chemical vapor deposition (MACVD) control parameters and the nucleation processes; the role of biasing substrates on the nucleation density in MACVD; the correlation between parameters of biasing substrates and the nucleation density; the reliable control of nucleation in CVD diamond synthesis. To achieve the goal of this research, a multi -purpose deposition system was built enabling the author to eliminate unnecessary variables in the deposition process. To ensure the accuracy of the nucleation effects of parameters investigated, great effort was made to calibrate measurement instruments so that noise or fluctuations in the experiments were minimized. The implementation of design of experiments (DOE), a systematic investigating technique, vastly improved the efficiency of this study over the less sophisticated empirical approach. In addition, DOE allowed the author to quantitatively estimate the effects of control parameters. Finally, diamond deposition was confirmed by Scanning Electron microscope, Micro Raman Scattering and Rutherford Backscattering. This research has successfully implemented DOE in estimating the effects of diamond nucleation quantitatively. The mechanism of ultrasonic pre-treatment is explained, and its effects are ascribed to seeding. The effects of primary CVD

  20. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study

    DEFF Research Database (Denmark)

    Linneberg, Allan; Thyssen, Jacob Pontoppidan; Dirksen, Asger

    2011-01-01

    the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened...... for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical...... most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0...

  1. Kinetic and thermodynamic studies on biosorption of Cu(Ⅱ) by chemically modified orange peel

    Institute of Scientific and Technical Information of China (English)

    FENG Ning-chuan; GUO Xue-yi; LIANG Sha

    2009-01-01

    Cu(H) biosorption by orange peel that was chemically modified with sodium hydroxide and calcium chloride was investigated. The effects of temperature, contact time, initial concentration of metal ions and pH on the biosorption of Cu( II) ions were assessed. Thermodynamic parameters including change of free energy(△G~Θ), enthalpy (△H~Θ) and entropy(△S~Θ) during the biosorption were determined. The results show that the biosorption process of Cu( II) ions by chemically treated orange peel is feasible, spontaneous and exothermic under studied conditions. Equilibrium is well described by Langmuir equation with the maximum biosorption capacity(q_m) for Cu( II) as 72.73 mg/g and kinetics is found to fit pseudo-second order type biosorption kinetics. As the temperature increases from 16 ℃ to 60 ℃, copper biosorption decreases. The loaded biosorbent is regenerated using HC1 solution for repeatedly use for five times with little loss of biosorption capacity.

  2. Effects of digestate on soil chemical and microbiological properties: A comparative study with compost and vermicompost.

    Science.gov (United States)

    Gómez-Brandón, María; Juárez, Marina Fernández-Delgado; Zangerle, Matthias; Insam, Heribert

    2016-01-25

    Anaerobic digestion has become increasingly popular as an alternative for recycling wastes from different origins. Consequently, biogas residues, most of them with unknown chemical and biological composition, accrue in large quantities and their application into soil has become a widespread agricultural practise. The aim of this study was to evaluate the effects of digestate application on the chemical and microbiological properties of an arable soil in comparison with untreated manure, compost and vermicompost. Once in the soil matrix either the addition of compost or digestate led to an increased nitrification rate, relative to unamended and manure-treated soil, after 15 and 60 days of incubation. Faecal coliform and E. coli colony forming units (CFUs) were not detected in any of the amended soils after 60 days. The highest number of Clostridium perfringens CFUs was recorded in manure-amended soil at the beginning of the experiment and after 15 days; whilst after 60 days the lowest CFU number was registered in digestate-treated soil. Denaturing gradient gel electrophoresis patterns also showed that besides the treatment the date of sampling could have contributed to modifications in the soil ammonia-oxidising bacteria community, thereby indicating that the soil itself may influence the community diversity more strongly than the treatments.

  3. Alternative Chemical Cleaning Methods for High Level Waste Tanks: Simulant Studies

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); King, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hay, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-11-19

    Solubility testing with simulated High Level Waste tank heel solids has been conducted in order to evaluate two alternative chemical cleaning technologies for the dissolution of sludge residuals remaining in the tanks after the exhaustion of mechanical cleaning and sludge washing efforts. Tests were conducted with non-radioactive pure phase metal reagents, binary mixtures of reagents, and a Savannah River Site PUREX heel simulant to determine the effectiveness of an optimized, dilute oxalic/nitric acid cleaning reagent and pure, dilute nitric acid toward dissolving the bulk non-radioactive waste components. A focus of this testing was on minimization of oxalic acid additions during tank cleaning. For comparison purposes, separate samples were also contacted with pure, concentrated oxalic acid which is the current baseline chemical cleaning reagent. In a separate study, solubility tests were conducted with radioactive tank heel simulants using acidic and caustic permanganate-based methods focused on the “targeted” dissolution of actinide species known to be drivers for Savannah River Site tank closure Performance Assessments. Permanganate-based cleaning methods were evaluated prior to and after oxalic acid contact.

  4. Glaciological and chemical studies on ice cores from Hans Tausen ice cap, Greenland

    DEFF Research Database (Denmark)

    Clausen, H.B.; Stampe, Mia; Hammer, C.U.

    2001-01-01

    The paper presents studies of various chemical and isotopical parameters from ice cores drilled in the northernmost located ice cap, Hans Tausen Iskappe, Pearyland, Greenland (HT). The 346 m main core (MC95) was drilled to bedrock in 1995 as well as a 35 m shallow core (SC95). A 60 m shallow core...... exist along the 1995 cores (MC95 and SC95) and finally detailed records of dust and water soluble ion concentrations exist on selected parts of MC95. To determine a time scale for the ice core is an important prerequisite for the interpretation of other records. The age scale is based on acid layers......, caused by known volcanic eruptions, and by comparison of the chemical composition of these layers to that found in ice cores from other arctic locations. The total b-activity data from SC75 and SC76 provide fixed points to the time scale because a pronounced increase in total b-activity is related...

  5. Physico-chemical characterization of steel slag. Study of its behavior under simulated environmental conditions.

    Science.gov (United States)

    Navarro, Carla; Díaz, Mario; Villa-García, María A

    2010-07-15

    The chemical and mineralogical composition of steel slag produced in two ArcelorMittal steel plants located in the North of Spain, as well as the study of the influence of simulated environmental conditions on the properties of the slag stored in disposal areas, was carried out by elemental chemical analysis, XRF, X-ray diffraction, thermal analysis, and scanning electron microscopy with EDS analyzer. Spectroscopic characterization of the slag was also performed by using FTIR spectroscopy. Due to the potential uses of the slag as low cost adsorbent for water treatment and pollutants removal, its detailed textural characterization was carried out by nitrogen adsorption-desorption at 77 K and mercury intrusion porosimetry. The results show that the slag is a crystalline heterogeneous material whose main components are iron oxides, calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate), elemental iron, and quartz. The slags are porous materials with specific surface area of 11 m(2)g(-1), containing both mesopores and macropores. Slag exposure to simulated environmental conditions lead to the formation of carbonate phases. Carbonation reduces the leaching of alkaline earth elements as well as the release of the harmful trace elements Cr (VI) and V. Steel slags with high contents of portlandite and calcium silicates are potential raw materials for CO(2) long-term storage.

  6. A Comparative Study of Fibrillated Fibers from Different Mechanical and Chemical Pulps

    Directory of Open Access Journals (Sweden)

    Panu Lahtinen

    2014-02-01

    Full Text Available Fibrillation of chemical and mechanical pulps with different lignin contents was studied. The pulps were ion exchanged into their sodium form prior to fibrillation and fibrillated with an increasing level of energy using high-shear friction grinding. The fibrillated samples were characterized for their chemical composition, morphology, rheological properties, and water retention capacity. All pulps had a distinct tendency to form fibrillated material under high shear and compression. The lignin-containing kraft pulps fibrillated easily, and the resulting material can be utilized in applications where high viscosity, water retention capacity, and reinforcement are desired. Fibrillation of mechanical pulps resulted in more heterogeneous samples, which included fiber fragments, branched fibrillar structures, and flake-like particles. This material showed relatively low viscosity and water retention capacity when compared to the samples made from kraft pulps. Chemi-thermomechanical pulp (CTMP, when used as the raw material, yielded a more homogeneous organic filler-like material than did thermomechanical pulp (TMP.

  7. Synthesis and characterization studies of MgO:CuO nanocrystals by wet-chemical method

    Science.gov (United States)

    Kaviyarasu, K.; Maria Magdalane, C.; Anand, K.; Manikandan, E.; Maaza, M.

    2015-05-01

    In this report, we examine the progress in adapting these nanomaterials for several predominantly photonics device fabrication by wet-chemical method. Nanocomposite of magnesium oxide (MgO) with copper oxide (CuO) doped nanoparticles were characterized by X-ray powder diffraction (XRD) and the observed peaks are quite agreeable with the pure phase cubic structure. High-resolution transmission electron microscopic (HR-TEM) results reveal that the resultant nanopowders are porous and agglomerated with polycrystalline nano-entities. Field emission of selected-area electron diffraction (SAED) studies showed that the average size of the nanoparticles were 20 nm. Photoluminescence spectra of MgO:CuO were investigated, showing emission peaks around 375 nm relating to new energy levels induced by defects or defect levels generation and confocal micro-Raman images indicated that the chemical molecular vibrational band structure and morphology of the product which is spherical shaped nanoparticles with an average particle size of ∼25 nm with standard deviation. The electrochemical response of MgO:CuO which is proves that the nano-copper/magnesium has high functionality due to the small size and it has higher electrochemical activity without any modifications.

  8. Quantum chemical study on the stability of honeybee queen pheromone against atmospheric factors.

    Science.gov (United States)

    Shi, Rongwei; Liu, Fanglin

    2016-06-01

    The managed honeybee, Apis mellifera, has been experienced a puzzling event, termed as colony collapse disorder (CCD), in which worker bees abruptly disappear from their hives. Potential factors include parasites, pesticides, malnutrition, and environmental stresses. However, so far, no definitive relationship has been established between specific causal factors and CCD events. Here we theoretically test whether atmospheric environment could disturb the chemical communication between the queen and their workers in a colony. A quantum chemistry method has been used to investigate for the stability of the component of A. mellifera queen mandibular pheromone (QMP), (E)-9-keto-2-decenoic acid (9-ODA), against atmospheric water and free radicals. The results show that 9-ODA is less likely to react with water due to the high barrier heights (~36.5 kcal · mol(-1)) and very low reaction rates. However, it can easily react with triplet oxygen and hydroxyl radicals because of low or negative energy barriers. Thus, the atmospheric free radicals may disturb the chemical communication between the queen and their daughters in a colony. Our pilot study provides new insight for the cause of CCD, which has been reported throughout the world.

  9. STUDIES ON THE CHEMICAL STRUCTURES OF ACTIVATED CARBON FIBERS BY SOLID STATE NMR

    Institute of Scientific and Technical Information of China (English)

    FURuowen; HuangWenqiang; 等

    1999-01-01

    The solid state C13-NMR spectra of different ACFs from various precursor fibers were recorded in this paper,The effects of activation conditions on chemical structures of ACFs,as well as the changes of chemical structures during carbonization and redox reaction were inverstigated by NMR technique,At same time,the soild state P31-NMR spectra of ACFS are studied.The C13-NMR spectra of ACFs can be divided into six bands that are assigned to methyl and methylene groups,hydroxyl and ether groups.acetal (or methylenedioxy) carbon,graphite-like aromatic carbon structure,phenol,and quinone groups,respectively.Only phosphorous pentoxide exists on ACFs and CFs.Moreover,most of them are stuck over the crystal face but not at the edge of graphite-like micro-crystal.The carbonization and activation conditions affect the C13-NMR spectra of ACFs.The experimental rsults indicate that the redox reaction of ACFs with oxidants greatly consumes C-H group.

  10. Chemical and histological studies of wild and hatchery salmon in fresh water

    Science.gov (United States)

    Wood, E.M.; Yasutake, W.T.; Halver, J.E.; Woodall, A.N.

    1960-01-01

    In a study of coho salmon (Oncorhynchus kisutch), the gross chemical and histological changes occurring over a 14-month period spent in fresh water were determined. The determinations were made at 3-month intervals on: 1) hatchery-reared fish, 2) fish hatchery-reared for 3, 6, 9, and 12 months and then planted in a controlled stream for the remainder of the period; and 3) an indigenous group of wild fish in this stream. Wild fish showed high incidence of tissue damage from spinose hairs of the moth larva, Halisidota argentata. Hatchery fish were similarly affected with the severity and incidence of lesions varying directly with the time of exposure of the larvae in the wild environment. Both groups of fish were heavily parasitized by sporozoan organisms in the kidney and spinal cord. Kidney disease appeared in both wild and planted hatchery fish. The gross chemical composition of hatchery fish transformed rapidly after planting to that of the wild fish. Although the initial rate of fat loss is essentially constant for all hatchery groups after planting, fish that were hatchery reared for 9 to 12 months did not complete the transformation to the wild-type body composition by the time of downstream migration at 14 months.

  11. Quantum chemical computations, vibrational spectroscopic analysis and antimicrobial studies of 2,3-Pyrazinedicarboxylic acid.

    Science.gov (United States)

    Beaula, T Joselin; Packiavathi, A; Manimaran, D; Joe, I Hubert; Rastogi, V K; Jothy, V Bena

    2015-03-05

    Density Functional Theory (DFT) calculations at B3PW91 level with 6-311G (d) basis sets were carried out for 2,3-Pyrazinedicarboxylic acid (PDCA) to analyze in detail the equilibrium geometries and vibrational spectra. Calculations reveal that the optimized geometry closely resembles the experimental XRD data. Vibrational spectra were analyzed on the basis of potential energy distribution (PED) of each vibrational mode, which provides quantitative as well as qualitative interpretation of IR and Raman spectra. Information about size, shape, charge density distribution and site of chemical reactivity of the molecule were obtained by mapping electron density isosurface with the electrostatic potential surface (ESP). Based on optimized ground state geometries, NBO analysis was performed to study donor-acceptor (bond-antibond) interactions. TD-DFT analysis was also performed to calculate energies, oscillator strength of electronic singlet-singlet transitions and the absorption wavelengths. The (13)C and (1)H nuclear magnetic resonance (NMR) chemical shifts of the molecule in the ground state were calculated by gauge independent atomic orbital (GIAO) method and compared with the experimental values. PDCA was screened for its antimicrobial activity and found to exhibit antifungal and antibacterial effects. Molecular docking was also performed for the different receptors.

  12. Comparative Study of Chemical Composition and Biological Activity of Yellow, Green, Brown, and Red Brazilian Propolis

    Science.gov (United States)

    Machado, Christiane Schineider; Mokochinski, João Benhur; de Lira, Tatiana Onofre; de Oliveira, Fátima de Cassia Evangelista; Cardoso, Magda Vieira; Ferreira, Roseane Guimarães; Sawaya, Alexandra Christine Helena Frankland; Ferreira, Antonio Gilberto; Pessoa, Cláudia; Cuesta-Rubio, Osmany; Monteiro, Marta Chagas; de Campos, Mônica Soares

    2016-01-01

    The chemical composition and biological activity of a sample of yellow propolis from Mato Grosso do Sul, Brazil (EEP-Y MS), were investigated for the first time and compared with green, brown, and red types of Brazilian propolis and with a sample of yellow propolis from Cuba. Overall, EEP-Y MS had different qualitative chemical profiles, as well as different cytotoxic and antimicrobial activities when compared to the other types of propolis assessed in this study and it is a different chemotype of Brazilian propolis. Absence of phenolic compounds and the presence of mixtures of aliphatic compounds in yellow propolis were determined by analysing 1H-NMR spectra and fifteen terpenes were identified by GC-MS. EEP-Y MS showed cytotoxic activity against human tumour strain OVCAR-8 but was not active against Gram-negative or Gram-positive bacteria. Our results confirm the difficulty of establishing a uniform quality standard for propolis from diverse geographical origins. The most appropriate pharmacological applications of yellow types of propolis must be further investigated. PMID:27525023

  13. Numerical study of hypersonic flows over reentry configurations with different chemical nonequilibrium models

    Science.gov (United States)

    Hao, Jiaao; Wang, Jingying; Lee, Chunhian

    2016-09-01

    Effects of two different 11-species chemical reaction models on hypersonic reentry flow simulations are numerically investigated. These two models were proposed by Gupta (1990) and Park (1990) [12,15], respectively. In this study, two typical configurations, the RAM-C II vehicle and FIRE II capsule, are selected as test cases, whose thermo-chemical nonequilibrium flowfields are computed by a multi-block finite volume code using a two-temperature model (a translational-rotational temperature and a vibrational-electron-electronic temperature). In the RAM-C II case, it is indicated that although electron number density distributions of the two reaction models appear in a similar trend, their values are distinctively different. Results of the Gupta's model show a better agreement with the electrostatic probe data, while those of the Park's model are more consistent with the reflectometers data. Both models give similar temperature distributions. In the FIRE II case, the two models yield significantly different distribution profiles of ions and electrons, whose differences could reach an order of magnitude. In addition, an abnormal nonequilibrium relaxation process in the shock layer is found in the FIRE II flowfield simulated by the Gupta's model, which proves to be a consequence of electron impact ionization reactions.

  14. Hybrid density functional study on lattice vibration, thermodynamic properties, and chemical bonding of plutonium monocarbide

    Science.gov (United States)

    Rong, Yang; Bin, Tang; Tao, Gao; BingYun, Ao

    2016-06-01

    Hybrid density functional theory is employed to systematically investigate the structural, magnetic, vibrational, thermodynamic properties of plutonium monocarbide (PuC and PuC0.75). For comparison, the results obtained by DFT, DFT + U are also given. For PuC and PuC0.75, Fock-0.25 hybrid functional gives the best lattice constants and predicts the correct ground states of antiferromagnetic (AFM) structure. The calculated phonon spectra suggest that PuC and PuC0.75 are dynamically stable. Values of the Helmholtz free energy ΔF, internal energy ΔE, entropy S, and constant-volume specific heat C v of PuC and PuC0.75 are given. The results are in good agreement with available experimental or theoretical data. As for the chemical bonding nature, the difference charge densities, the partial densities of states and the Bader charge analysis suggest that the Pu-C bonds of PuC and PuC0.75 have a mixture of covalent character and ionic character. The effect of carbon vacancy on the chemical bonding is also discussed in detail. We expect that our study can provide some useful reference for further experimental research on the phonon density of states, thermodynamic properties of the plutonium monocarbide. Project supported by the National Natural Science Foundation of China (Grant Nos. 21371160 and 21401173).

  15. Reduction of Nitroaromatic Compounds on the Surface of Metallic Iron: Quantum Chemical Study

    Directory of Open Access Journals (Sweden)

    Jerzy Leszczynski

    2002-07-01

    Full Text Available Abstract: The initial reduction steps of nitroaromatic compounds on the surface of metallic iron have been studied theoretically using nitrobenzene (NB as a representative of nitroaromatic compounds. The quantum chemical cluster approximation within the semiempirical Neglect of Diatomic Differential Overlap for Metal Compounds method was applied to model the Fe(110 crystallographic surface, taken as a representative reactive surface for granular iron. This surface was modeled as a 39-atom two-layer metal cluster with rigid geometry. The associative and dissociative adsorption of nitrobenzene was considered. Based on our quantum chemical analysis, we suggest that the direct electron donation from the metal surface into the π* orbital of NB is a decisive factor responsible for subsequent transformation of the nitro group. Molecularly adsorbed NB interacts with metal iron exclusively through nitro moiety oxygens which occupy tri-coordinated positions on surface The charge transfer from metal to NB of approximately 2 atomic units destablizes the nitro group. As a result, the first dissociation of the N-O bond goes through a relatively low activation barrier. The adsorbed nitrosobenzene is predicted to be a stable surface species, though still quiet labile.

  16. Comparative Studies on Methane Upgradation of Biogas by Removing of Contaminant Gases Using Combined Chemical Methods

    Directory of Open Access Journals (Sweden)

    Muhammad Rashed Al Mamun

    2015-07-01

    Full Text Available Biogas, which generated from renewable sources can be used as a sustainable energy to achieve resourceful targets of biofuel for internal combustion engines. This process can be achieved in combined absorption and adsorption chemical way. This method can be employed by aqueous solutions of calcium hydroxide, activated carbon, iron(II chloride, silica gel and sodium sulfate respectively. The presence of CO2, H2S and H2O in the biogas has lowering the calorific value and detrimental corrosion effects on the metal components. Removal of these contaminants from the biogas can therefore significantly improve the gas quality. A comparison study was investigated using combined chemical methods of improving the calorific value of biogas. Experiment results revealed that the aqueous solution used effectively in reacting with CO2 in biogas (over 85-90% removal efficiency, creating CH4 enriched biogas. The removal efficiency was the highest in method 1, where efficiency results were 91.5%, 97.1% and 91.8%, for CO2, H2S, and H2O, respectively. The corresponding CH4 enrichment was 97.5%. These results indicate that the method 1 is more suitable compare to method 2. However, both methane enrichment processes might be useful for cleaning and upgrading methane quality in biogas.

  17. Comparative Study of Chemical Composition and Biological Activity of Yellow, Green, Brown, and Red Brazilian Propolis.

    Science.gov (United States)

    Machado, Christiane Schineider; Mokochinski, João Benhur; de Lira, Tatiana Onofre; de Oliveira, Fátima de Cassia Evangelista; Cardoso, Magda Vieira; Ferreira, Roseane Guimarães; Sawaya, Alexandra Christine Helena Frankland; Ferreira, Antonio Gilberto; Pessoa, Cláudia; Cuesta-Rubio, Osmany; Monteiro, Marta Chagas; de Campos, Mônica Soares; Torres, Yohandra Reyes

    2016-01-01

    The chemical composition and biological activity of a sample of yellow propolis from Mato Grosso do Sul, Brazil (EEP-Y MS), were investigated for the first time and compared with green, brown, and red types of Brazilian propolis and with a sample of yellow propolis from Cuba. Overall, EEP-Y MS had different qualitative chemical profiles, as well as different cytotoxic and antimicrobial activities when compared to the other types of propolis assessed in this study and it is a different chemotype of Brazilian propolis. Absence of phenolic compounds and the presence of mixtures of aliphatic compounds in yellow propolis were determined by analysing (1)H-NMR spectra and fifteen terpenes were identified by GC-MS. EEP-Y MS showed cytotoxic activity against human tumour strain OVCAR-8 but was not active against Gram-negative or Gram-positive bacteria. Our results confirm the difficulty of establishing a uniform quality standard for propolis from diverse geographical origins. The most appropriate pharmacological applications of yellow types of propolis must be further investigated.

  18. Comparative Study of Chemical Composition and Biological Activity of Yellow, Green, Brown, and Red Brazilian Propolis

    Directory of Open Access Journals (Sweden)

    Christiane Schineider Machado

    2016-01-01

    Full Text Available The chemical composition and biological activity of a sample of yellow propolis from Mato Grosso do Sul, Brazil (EEP-Y MS, were investigated for the first time and compared with green, brown, and red types of Brazilian propolis and with a sample of yellow propolis from Cuba. Overall, EEP-Y MS had different qualitative chemical profiles, as well as different cytotoxic and antimicrobial activities when compared to the other types of propolis assessed in this study and it is a different chemotype of Brazilian propolis. Absence of phenolic compounds and the presence of mixtures of aliphatic compounds in yellow propolis were determined by analysing 1H-NMR spectra and fifteen terpenes were identified by GC-MS. EEP-Y MS showed cytotoxic activity against human tumour strain OVCAR-8 but was not active against Gram-negative or Gram-positive bacteria. Our results confirm the difficulty of establishing a uniform quality standard for propolis from diverse geographical origins. The most appropriate pharmacological applications of yellow types of propolis must be further investigated.

  19. Quantum chemical study of a derivative of 3-substituted dithiocarbamic flavanone

    Science.gov (United States)

    Gosav, Steluta; Paduraru, Nicoleta; Maftei, Dan; Birsa, Mihail Lucian; Praisler, Mirela

    2017-02-01

    The aim of this work is to characterize a quite novel 3-dithiocarbamic flavonoid by vibrational spectroscopy in conjunction with Density Functional Theory (DFT) calculations. Quantum mechanics calculations of energies, geometries and vibrational wavenumbers in the ground state were carried out by using hybrid functional B3LYP with 6-311G(d,p) as basis set. The results indicate a remarkable agreement between the calculated molecular geometries, as well as vibrational frequencies, and the corresponding experimental data. In addition, a complete assignment of all the absorption bands present in the vibrational spectrum has been performed. In order to assess its chemical potential, quantum molecular descriptors characterizing the interactions between the 3-dithiocarbamic flavonoid and its biological receptors have been computed. The frontier molecular orbitals and the HOMO-LUMO energy gap have been used in order to explain the way in which the new molecule can interact with other species and to characterize its molecular chemical stability/reactivity. The molecular electrostatic potential (MEP) map, computed in order to identify the sites of the studied flavonoid that are most likely to interact with electrophilic and nucleophilic species, is discussed.

  20. Parental occupational exposure to endocrine disrupting chemicals and male genital malformations: A study in the danish national birth cohort study

    Directory of Open Access Journals (Sweden)

    Kaerlev Linda

    2011-01-01

    Full Text Available Abstract Background Sex hormones closely regulate development of the male genital organs during fetal life. The hypothesis that xenobiotics may disrupt endogenous hormonal signalling has received considerable scientific attention, but human evidence is scarce. Objectives We analyse occurrence of hypospadias and cryptorchidism according to maternal and paternal occupational exposure to possible endocrine disrupting chemicals. Methods We conducted a follow-up study of 45,341 male singleton deliveries in the Danish National Birth Cohort during 1997-2009. Information on work during pregnancy was obtained by telephone interviews around gestational week 16. Parents' job titles were classified according to DISCO-88. A job exposure matrix for endocrine disrupting chemicals (EDCs was implemented to assess occupational exposures. The Medical Birth and National Hospital Register provided data on congenital anomalies diagnosed at birth or during follow-up, which ended in 2009. Crude and adjusted hazard ratios (HR were obtained from Cox regression models. Results Among all pregnancies, 6.3% were classified as possibly or probably exposed to EDCs. The most prevalent occupations conferring possible exposure were cleaners, laboratory technicians, hairdressers and agricultural workers (58% of all potentially exposed. The final cumulative incidence of cryptorchidism in boys was 2.2% (1002 cases, and of hypospadias 0.6% (262 cases. The occurrence of hypospadias increased when mothers were probably [HRa = 1.8 (95% CI 1.0-2.6] or possibly exposed to one or more EDCs [HRa = 2.6 (95% CI 1.8-3.4. Possible paternal exposure to heavy metals increased the risk of hypospadias [HRa 2.2 (95% CI: 1.0-3.4] and cryptorchidism [HRa 1.9 (95% CI: 1.1-2.7]. None of the exposure groups reached statistical significance. Conclusion The study provides some but limited evidence that occupational exposure to possible endocrine disrupting chemicals during pregnancy increases the risk of

  1. Studying Chemical Reactions, One Bond at a Time, with Single Molecule AFM Techniques

    Science.gov (United States)

    Fernandez, Julio M.

    2008-03-01

    The mechanisms by which mechanical forces regulate the kinetics of a chemical reaction are unknown. In my lecture I will demonstrate how we use single molecule force-clamp spectroscopy and protein engineering to study the effect of force on the kinetics of thiol/disulfide exchange. Reduction of disulfide bond via the thiol/disulfide exchange chemical reaction is crucial in regulating protein function and is of common occurrence in mechanically stressed proteins. While reduction is thought to proceed through a substitution nucleophilic bimolecular (SN2) reaction, the role of a mechanical force in modulating this chemical reaction is unknown. We apply a constant stretching force to single engineered disulfide bonds and measure their rate of reduction by dithiothreitol (DTT). We find that while the reduction rate is linearly dependent on the concentration of DTT, it is exponentially dependent on the applied force, increasing 10-fold over a 300 pN range. This result predicts that the disulfide bond lengthens by 0.34 å at the transition state of the thiol/disulfide exchange reaction. In addition to DTT, we also study the reduction of the engineered disulfide bond by the E. coli enzyme thioredoxin (Trx). Thioredoxins are enzymes that catalyze disulfide bond reduction in all organisms. As before, we apply a mechanical force in the range of 25-450 pN to the engineered disulfide bond substrate and monitor the reduction of these bonds by individual enzymes. In sharp contrast with the data obtained with DTT, we now observe two alternative forms of the catalytic reaction, the first requiring a reorientation of the substrate disulfide bond, causing a shortening of the substrate polypeptide by 0.76±0.07 å, and the second elongating the substrate disulfide bond by 0.21±0.01 å. These results support the view that the Trx active site regulates the geometry of the participating sulfur atoms, with sub-ångström precision, in order to achieve efficient catalysis. Single molecule

  2. Chemical crosslinking and mass spectrometry studies of the structure and dynamics of membrane proteins and receptors.

    Energy Technology Data Exchange (ETDEWEB)

    Haskins, William E.; Leavell, Michael D.; Lane, Pamela; Jacobsen, Richard B.; Hong, Joohee; Ayson, Marites J.; Wood, Nichole L.; Schoeniger, Joseph S.; Kruppa, Gary Hermann; Sale, Kenneth L.; Young, Malin M.; Novak, Petr

    2005-03-01

    Membrane proteins make up a diverse and important subset of proteins for which structural information is limited. In this study, chemical cross-linking and mass spectrometry were used to explore the structure of the G-protein-coupled photoreceptor bovine rhodopsin in the dark-state conformation. All experiments were performed in rod outer segment membranes using amino acid 'handles' in the native protein sequence and thus minimizing perturbations to the native protein structure. Cysteine and lysine residues were covalently cross-linked using commercially available reagents with a range of linker arm lengths. Following chemical digestion of cross-linked protein, cross-linked peptides were identified by accurate mass measurement using liquid chromatography-fourier transform mass spectrometry and an automated data analysis pipeline. Assignments were confirmed and, if necessary, resolved, by tandem MS. The relative reactivity of lysine residues participating in cross-links was evaluated by labeling with NHS-esters. A distinct pattern of cross-link formation within the C-terminal domain, and between loop I and the C-terminal domain, emerged. Theoretical distances based on cross-linking were compared to inter-atomic distances determined from the energy-minimized X-ray crystal structure and Monte Carlo conformational search procedures. In general, the observed cross-links can be explained by re-positioning participating side-chains without significantly altering backbone structure. One exception, between C3 16 and K325, requires backbone motion to bring the reactive atoms into sufficient proximity for cross-linking. Evidence from other studies suggests that residues around K325 for a region of high backbone mobility. These findings show that cross-linking studies can provide insight into the structural dynamics of membrane proteins in their native environment.

  3. Deuterated detergents for structural and functional studies of membrane proteins: Properties, chemical synthesis and applications.

    Science.gov (United States)

    Hiruma-Shimizu, Kazumi; Shimizu, Hiroki; Thompson, Gary S; Kalverda, Arnout P; Patching, Simon G

    2015-01-01

    Detergents are amphiphilic compounds that have crucial roles in the extraction, purification and stabilization of integral membrane proteins and in experimental studies of their structure and function. One technique that is highly dependent on detergents for solubilization of membrane proteins is solution-state NMR spectroscopy, where detergent micelles often serve as the best membrane mimetic for achieving particle sizes that tumble fast enough to produce high-resolution and high-sensitivity spectra, although not necessarily the best mimetic for a biomembrane. For achieving the best quality NMR spectra, detergents with partial or complete deuteration can be used, which eliminate interfering proton signals coming from the detergent itself and also eliminate potential proton relaxation pathways and strong dipole-dipole interactions that contribute line broadening effects. Deuterated detergents have also been used to solubilize membrane proteins for other experimental techniques including small angle neutron scattering and single-crystal neutron diffraction and for studying membrane proteins immobilized on gold electrodes. This is a review of the properties, chemical synthesis and applications of detergents that are currently commercially available and/or that have been synthesized with partial or complete deuteration. Specifically, the detergents are sodium dodecyl sulphate (SDS), lauryldimethylamine-oxide (LDAO), n-octyl-β-D-glucoside (β-OG), n-dodecyl-β-D-maltoside (DDM) and fos-cholines including dodecylphosphocholine (DPC). The review also considers effects of deuteration, detergent screening and guidelines for detergent selection. Although deuterated detergents are relatively expensive and not always commercially available due to challenges associated with their chemical synthesis, they will continue to play important roles in structural and functional studies of membrane proteins, especially using solution-state NMR.

  4. Some Sensitivity Studies of Chemical Transport Simulated in Models of the Soil-Plant-Litter System

    Energy Technology Data Exchange (ETDEWEB)

    Begovich, C.L.

    2002-10-28

    Fifteen parameters in a set of five coupled models describing carbon, water, and chemical dynamics in the soil-plant-litter system were varied in a sensitivity analysis of model response. Results are presented for chemical distribution in the components of soil, plants, and litter along with selected responses of biomass, internal chemical transport (xylem and phloem pathways), and chemical uptake. Response and sensitivity coefficients are presented for up to 102 model outputs in an appendix. Two soil properties (chemical distribution coefficient and chemical solubility) and three plant properties (leaf chemical permeability, cuticle thickness, and root chemical conductivity) had the greatest influence on chemical transport in the soil-plant-litter system under the conditions examined. Pollutant gas uptake (SO{sub 2}) increased with change in plant properties that increased plant growth. Heavy metal dynamics in litter responded to plant properties (phloem resistance, respiration characteristics) which induced changes in the chemical cycling to the litter system. Some of the SO{sub 2} and heavy metal responses were not expected but became apparent through the modeling analysis.

  5. Some sensitivity studies of chemical transport simulated in models of the soil-plant-litter system

    Energy Technology Data Exchange (ETDEWEB)

    Begovich, C.L.; Luxmoore, R.J.

    1979-09-01

    Fifteen parameters in a set of five coupled models describing carbon, water, and chemical dynamics in the soil-plant-litter system were varied in a sensitivity analysis of model response. Results are presented for chemical distribution in the components of soil, plants, and litter along with selected responses of biomass, internal chemical transport (xylem and phloem pathways), and chemical uptake. Response and sensitivity coefficients are presented for up to 102 model outputs in an appendix. Two soil properties (chemical distribution coefficient and chemical solubility) and three plant properties (leaf chemical permeability, cuticle thickness, and root chemical conductivity) had the greatest influence on chemical transport in the soil-plant-litter system under the conditions examined. Pollutant gas uptake (SO/sub 2/) increased with change in plant properties that increased plant growth. Heavy metal dynamics in litter responded to plant properties (phloem resistance, respiration characteristics) which induced changes in the chemical cycling to the litter system. Some of the SO/sub 2/ and heavy metal responses were not expected but became apparent through the modeling analysis.

  6. A study on manufacturing technology of materials for fine chemical industry use (muscovite, sericite)

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jung-Il; Shin, Hee-Young; Hwang, Seon-Kook; Ahn, Ji-Hwan; Bae, Kwang-Hyun [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1997-12-01

    For the technical development on utilization of unused mineral resources, the study was carried out on the highly purification and mineral processing of domestic Sericite and Muscovite. This study was also carried out to make the functional materials for the use of fine chemical industry. Scope and content of study: 1) A study on the high purification and mineral processing for sericite and muscovite. 2) A study on the surface treatment of fine particles of sericite and muscovite. EDAX analysis on surface treated Mica shows that absorbed area on mica surface appears about 56 wt% when reaction period of 75 min. The result on image analysis on the surface treated mica comparing with that of EDAX analysis appears that the material was stabilized when passing the 1st yielding point. The dry process of surface modification on mica was applied by using {Theta}-composer. The result shows that whiteness of the mica increases upto 91 at 20 min. grinding period. Polymer microcapsulation was carried out on the mica surface. The result shows that materials appear excellent hydrophobic property which is one of important factors for making cosmetics. Based on the applying test of mineral processing on Dong-jin mica, the result shows that high quality mica is recovered. Especially, lithium mica produced in the mine will be further studied in the next year project. (author). 26 refs., 36 tabs., 61 figs.

  7. Pharmacognostical and Phyto-physicochemical profile of the leaves of Piper betle L. var Pachaikodi (Piperaceae) - Valuable assessment of its quality

    Institute of Scientific and Technical Information of China (English)

    KPeriyanayagam; MJagadeesan; SKavimani; TVetriselvan

    2012-01-01

    Objective: To study in detail the micromorphology and physicochemical analysis of the leaves of Piper betle L. var Pachaikodi family Piperaceae. Methods: Macroscopy, microscopy, physicochemical analysis, preliminary phytochemical screening and other WHO recommended parameters for standardizations were performed. Results: Leaves are cordate, alternate 12-18cm long and 9-11 cm broad. Aromatic, dark green with entire margin, acuminate apex and unequal base with stout petiole (5-6.5cm).Microscopic evaluation revealed the presence of cyclocytic stomata in lower epidermis and apostomatic upper epidermis, hypodermis, secretory cells, pearl glandular trichomes, xylem vessels, phloem, fibres. Vein islet numbers, vein termination numbers, stomatal number, stomatal index and other physico chemical tests like ash values, loss on drying, extractive values were determined. Preliminary phytochemical screening showed the presence of steroids, tannins, proteins and aminoacids, flavonoids, terpenoids, mucilage, volatile oil, saponin , carbohydrates and absence of alkaloids, fixed oil. Conclusions: The microscopic using histological identification , microscopic constants and other physico chemical examinations of the leaves of Piper betle L. var pachaikodi can be used as a rapid, inexpensive botanical identification technique and is useful in standardization, hence would be of immense value in authentication of the leaf.

  8. Effect of chemical degradation on fluxes of reactive compounds – a study with a stochastic Lagrangian transport model

    Directory of Open Access Journals (Sweden)

    J. Rinne

    2012-06-01

    Full Text Available In the analyses of VOC fluxes measured above plant canopies, one usually assumes the flux above canopy to equal the exchange at the surface. Thus one assumes the chemical degradation to be much slower than the turbulent transport. We used a stochastic Lagrangian transport model in which the chemical degradation was described as first order decay in order to study the effect of the chemical degradation on above canopy fluxes of chemically reactive species. With the model we explored the sensitivity of the ratio of the above canopy flux to the surface emission on several parameters such as chemical lifetime of the compound, friction velocity, stability, and canopy density. Our results show that friction velocity and chemical lifetime affected the loss during transport the most. The canopy density had a significant effect if the chemically reactive compound was emitted from the forest floor. We used the results of the simulations together with oxidant data measured during HUMPPA-COPEC-2010 campaign at a Scots pine site to estimate the effect of the chemistry on fluxes of three typical biogenic VOCs, isoprene, α-pinene, and β-caryophyllene. Of these, the chemical degradation had a major effect on the fluxes of the most reactive species β-caryophyllene, while the fluxes of α-pinene were affected during nighttime. For these two compounds representing the mono- and sesquiterpenes groups, the effect of chemical degradation had also a significant diurnal cycle with the highest chemical loss at night. The different day and night time loss terms need to be accounted for, when measured fluxes of reactive compounds are used to reveal relations between primary emission and environmental parameters.

  9. Adsorption studies of methylene blue and phenol onto vetiver roots activated carbon prepared by chemical activation

    Energy Technology Data Exchange (ETDEWEB)

    Altenor, Sandro [COVACHIMM, EA 3592 Universite des Antilles et de la Guyane, BP 250, 97157 Pointe a Pitre Cedex, Guadeloupe (France); LAQUE, Universite Quisqueya d' Haiti, Port-au-Prince (Haiti); Carene, Betty [COVACHIMM, EA 3592 Universite des Antilles et de la Guyane, BP 250, 97157 Pointe a Pitre Cedex, Guadeloupe (France); Emmanuel, Evens [LAQUE, Universite Quisqueya d' Haiti, Port-au-Prince (Haiti); Lambert, Jacques; Ehrhardt, Jean-Jacques [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement, UMR 7564 CNRS-Nancy Universities, 405 rue de Vandoeuvre, F 54600 Villers-les-Nancy Cedex (France); Gaspard, Sarra, E-mail: sgaspard@univ-ag.fr [COVACHIMM, EA 3592 Universite des Antilles et de la Guyane, BP 250, 97157 Pointe a Pitre Cedex, Guadeloupe (France)

    2009-06-15

    Vetiver roots have been utilized for the preparation of activated carbon (AC) by chemical activation with different impregnation ratios of phosphoric acid, X{sub P} (g H{sub 3}PO{sub 4}/g precursor): 0.5:1; 1:1 and 1.5:1. Textural characterization, determined by nitrogen adsorption at 77 K shows that mixed microporous and mesoporous structures activated carbons (ACs) with high surface area (>1000 m{sup 2}/g) and high pore volume (up to 1.19 cm{sup 3}/g) can be obtained. The surface chemical properties of these ACs were investigated by X-ray photoelectron spectroscopy (XPS) and Boehm titration. Their textural and chemical characteristics were compared to those of an AC sample obtained by steam activation of vetiver roots. Classical molecules used for characterizing liquid phase adsorption, phenol and methylene blue (MB), were used. Adsorption kinetics of MB and phenol have been studied using commonly used kinetic models, i.e., the pseudo-first-order model, the pseudo-second-order model, the intraparticle diffusion model and as well the fractal, BWS (Brouers, Weron and Sotolongo) kinetic equation. The correlation coefficients (R{sup 2}) and the normalized standard deviation {Delta}q (%) were determined showing globally, that the recently derived fractal kinetic equation could best describe the adsorption kinetics for the adsorbates tested here, indicating a complex adsorption mechanism. The experimental adsorption isotherms of these molecules on the activated carbon were as well analysed using four isotherms: the classical Freundlich, Langmuir, Redlich-Peterson equations, but as well the newly published deformed Weibull Brouers-Sotolongo isotherm. The results obtained from the application of the equations show that the best fits were achieved with the Brouers-Sotolongo equation and with the Redlich-Peterson equation. Influence of surface functional groups towards MB adsorption is as well studied using various ACs prepared from vetiver roots and sugar cane bagasse

  10. Adsorption studies of methylene blue and phenol onto vetiver roots activated carbon prepared by chemical activation.

    Science.gov (United States)

    Altenor, Sandro; Carene, Betty; Emmanuel, Evens; Lambert, Jacques; Ehrhardt, Jean-Jacques; Gaspard, Sarra

    2009-06-15

    Vetiver roots have been utilized for the preparation of activated carbon (AC) by chemical activation with different impregnation ratios of phosphoric acid, X(P) (gH(3)PO(4)/g precursor): 0.5:1; 1:1 and 1.5:1. Textural characterization, determined by nitrogen adsorption at 77K shows that mixed microporous and mesoporous structures activated carbons (ACs) with high surface area (>1000 m(2)/g) and high pore volume (up to 1.19 cm(3)/g) can be obtained. The surface chemical properties of these ACs were investigated by X-ray photoelectron spectroscopy (XPS) and Boehm titration. Their textural and chemical characteristics were compared to those of an AC sample obtained by steam activation of vetiver roots. Classical molecules used for characterizing liquid phase adsorption, phenol and methylene blue (MB), were used. Adsorption kinetics of MB and phenol have been studied using commonly used kinetic models, i.e., the pseudo-first-order model, the pseudo-second-order model, the intraparticle diffusion model and as well the fractal, BWS (Brouers, Weron and Sotolongo) kinetic equation. The correlation coefficients (R(2)) and the normalized standard deviation Deltaq (%) were determined showing globally, that the recently derived fractal kinetic equation could best describe the adsorption kinetics for the adsorbates tested here, indicating a complex adsorption mechanism. The experimental adsorption isotherms of these molecules on the activated carbon were as well analysed using four isotherms: the classical Freundlich, Langmuir, Redlich-Peterson equations, but as well the newly published deformed Weibull Brouers-Sotolongo isotherm. The results obtained from the application of the equations show that the best fits were achieved with the Brouers-Sotolongo equation and with the Redlich-Peterson equation. Influence of surface functional groups towards MB adsorption is as well studied using various ACs prepared from vetiver roots and sugar cane bagasse. Opposite effects governing MB

  11. [Historical review on chemical and medical studies of globefish toxin before World War II].

    Science.gov (United States)

    Suehiro, M

    1994-01-01

    "Fugu," a species of globefish has eaten by Japanese people for a long time, so globefish poisoning in Japan has been prevalent. Figures are shown in the Annual Food Poisoning Report collected and issued by health service authorities of Japanese Government since 1879. These reports prompted Dr. Yoshizumi Tahara, National Institute of Hygienic Sciences to conduct a chemical investigation of the toxic substance of globefish in 1884. However, the analysis was very difficult and his report of investigation was delayed. Before publication of the report of Dr. Tahara, pharmacological and toxicological studies of globefish poisoning were reported by three research groups from the Facultly of Medicine, University of Tokyo in 1889. These reports concluded that globefish poison has curare-like activity and its distribution was limited to specific organs such as the ovaries and the liver. Dr. Tahara successfully isolated the poison from aqueaous extract of ovaries of globefish by precipitation with lead acetate in the presence of ammonia. He presented the results at the monthly meeting of the Pharmaceutical Society of Japan in July 1894. He continued the studies and established an improved method for extraction and purification suitable for large-scale production. Finally, he confirmed that globefish contains only one toxic substance and named it Tetrodotoxin (TTX) in 1909. He elucidated the chemical nature of TTX as follows: 1) TTX is an amorphous hygroscopic powder and its character is neither alkaloid nor protein. 2) The possibility of TTX being a protamine was excluded by chemical analysis. Before the discovery ot TTX, according to folklore, globefish was regarded as medicine for leprosy because flesh of globefish contaminated with a sublethal dose of toxic substance alleviated the neuralgia of patients affected with leprosy. The clinical effect of TTX prepared by Tahara's method to suppress severe neuralgia due to leprosy and to reduce muscle spasms due to tetanus were

  12. Dynamic behavior of chemical reactivity indices in density functional theory: A Bohn-Oppenheimer quantum molecular dynamics study

    Indian Academy of Sciences (India)

    Shubin Liu

    2005-09-01

    Dynamic behaviors of chemical concepts in density functional theory such as frontier orbitals (HOMO/LUMO), chemical potential, hardness, and electrophilicity index have been investigated in this work in the context of Bohn-Oppenheimer quantum molecular dynamics in association with molecular conformation changes. Exemplary molecular systems like CH$^{+}_{5}$ , Cl- (H2O)30 and Ca2+ (H2O)15 are studied at 300 K in the gas phase, demonstrating that HOMO is more dynamic than LUMO, chemical potential and hardness often fluctuate concurrently. It is argued that DFT concepts and indices may serve as a good framework to understand molecular conformation changes as well as other dynamic phenomena.

  13. A molecular line study towards massive extended green object clumps in the southern sky: chemical properties

    CERN Document Server

    Yu, Naiping

    2016-01-01

    We present a molecular line study towards 31 extended green object (EGO) clumps in the southern sky using data from MALT90 (Millimetre Astronomy Legacy Team 90 GHz). According to previous multiwavelength observations, we divide our sample into two groups: massive young stellar objects (MYSOs) and HII regions. Our results seem to support that N2H+ and C2H emissions mainly come from the gas inside quiescent clumps. In addition, we also find that the [N2H+]/[H13CO+] and [C2H]/[H13CO+] relative abundance ratios decrease from MYSOs to HII regions. These results suggest depletion of N2H+ and C2H in the late stages of massive-star formation, probably caused by the formation of HII regions inside. N2H+ and C2H might be used as chemical clocks for massive-star formation by comparing with other molecules such as H13CO+ and HC3N.

  14. [Comparative study of chemical composition of pomegranate peel pomegranates inside and pomegranate seeds].

    Science.gov (United States)

    Zhou, Qian; Sun, Li-Li; Dai, Yan-Peng; Wang, Liang; Su, Ben-Zheng

    2013-07-01

    An HPLC fingerprint of pomegranate peel was established. Using chromatographic conditions, we compared the chemical composition of pomegranate peel, inside and seeds, and simultaneously determined the contents of gallic acid and ellagic acid. By comparison, we found that there were no significant differences between pomegranate peel and inside, but there was a big difference between pomegranate seeds and another two. The contents of gallic acid and ellagic acid of pomegranate peel respectively were 0.33%, 0.59%, while in pomegranate inside the result respectively were 0.52%, 0.38%. Content of ellagic acid from pomegranate seeds was only 0.01%. By study, we thought that when pomegranate peel was processed, pomegranate seeds should be removed, while pomegranate inside could be retained on the premise of full drying.

  15. Raman imaging to study structural and chemical features of the dentin enamel junction

    Science.gov (United States)

    Alebrahim, M. Anwar; Krafft, C.; Popp, J.

    2015-10-01

    The structure and chemical features of the human dentin enamel junction (DEJ) were characterized using Raman spectroscopic imaging. Slices were prepared from 10 German, and 10 Turkish teeth. Raman images were collected at 785 nm excitation and the average Raman spectra were calculated for analysis. Univariate and multivariate spectral analysis were applied for investigation. Raman images were obtained based on the intensity ratios of CH at 1450 cm-1 (matrix) to phosphate at 960 cm-1 (mineral), and carbonate to phosphate (1070/960) ratios. Different algorithms (HCA, K-means cluster and VCA) also used to study the DEJ. The obtained results showed that the width of DEJ is about 5 pm related to univariate method while it varies from 6 to 12 μm based on multivariate spectral technique. Both spectral analyses showed increasing in carbonate content inside the DEJ compared to the dentin, and the amide I (collagen) peak in dentin spectra is higher than DEJ spectra peak.

  16. Low thrust chemical orbit to orbit propulsion system propellant management study

    Science.gov (United States)

    Dergance, R. H.; Hamlyn, K. M.; Tegart, J. R.

    1981-01-01

    Low thrust chemical propulsion systems were sized for transfer of large space systems from LEO to GEO. The influence of propellant combination, tankage and insulation requirements, and propellant management techniques on the LTPS mass and volume were studied. Liquid oxygen combined with hydrogen, methane or kerosene were the propellant combinations. Thrust levels of 445, 2230, and 4450 N were combined with 1, 4 and 8 perigee burn strategies. This matrix of systems was evaluated using multilayer insulation and spray-on-foam insulation systems. Various combinations of toroidal, cylindrical with ellipsoidal domes, and ellipsoidal tank shapes were investigated. Results indicate that low thrust (445 N) and single perigee burn approaches are considerably less efficient than the higher thrust level and multiple burn strategies. A modified propellant settling approach minimized propellant residuals and decreased system complexity, in addition, the toroid/ellipsoidal tank combination was predicted to be shortest.

  17. A quantum chemical study on hydrogen radical reactions with methane and silane

    Science.gov (United States)

    Sato, Kota; Kojima, Kuniharu; Kawasaki, Masashi; Matsuzaki, Yoshio; Hirano, Tsuneo; Nakano, Masatake; Koinuma, Hideomi

    1989-03-01

    A quantum chemical study on the reaction of CH4 , CF4 , SiH4 , and SiF4 with a hydrogen radical is performed on the basis of an ab initio molecular orbital calculation to predict the photochemical reactivity of methane, silane, and their analogues. The transition state geometry of the reactions is determined by employing a 3-21G basis set. The total energies of reactant molecules at the initial, transition, and final states are calculated by employing a 6-31G** basis set. The exponential parts of the rate constants of these reactions determined from these energies on the basis of the transition state theory are in good agreement with the experimentally obtained relative rates of the reaction. The present calculation was consistent with the experimental results of photochemical reactions for methane and silane derivatives.

  18. A PRELIMINARY PHARMACOGNOSTICAL AND PHYSICO CHEMICAL ASSAY OF HARIDRA KHANDA GRANULES: A PILOT STUDY

    Directory of Open Access Journals (Sweden)

    Chaudhari Varsha M.

    2011-06-01

    Full Text Available Haridra Khanda is mentioned in the management of skin diseases like Urticaria (Udarda Shitpitta Kotha. Most of the ingredients are having properties to control allergic condition and improve Vyadhikshamatva (Immuno-modulatory. Pratishyaya (Rhinitis is one of the common problem since ancient days; among all type of Rhinitis, Vataja type simulates the Allergic Rhinitis in modern medical literature of ENT. To overcome the problem of fungus formation in Khanda and AvalehaKalpana, Haridra Khanda has been prepared in granules form. In this study, effort has been done to overcome from the controversy regarding ingredients in the finished product and tried to make it standardized as per guidelines of API. Pharmacognostically authenticated raw drugs were used for the preparation of granules and it was analyzed through qualitative and quantitative analysis of Physico – chemical parameters. It is inferred that the formulation meets the minimum qualitative standards as reported in the API and AFI at a preliminary level.

  19. Soft-deodorization of virgin olive oil: Study of the changes of quality and chemical composition.

    Science.gov (United States)

    Aparicio-Ruiz, Ramón; Romero, Inmaculada; García-González, Diego L; Oliver-Pozo, Celia; Aparicio, Ramón

    2017-04-01

    The potential adulteration of extra virgin olive oil (EVOO) with soft-deodorized virgin olive oil (VOO) has raised the interest of researchers in investigating this fraud in recent years. The objective of this study was to determine chemical changes occurring after a soft-deodorization process in terms of volatiles, fatty acid ethyl esters (FAEEs) and pyropheophytins (PPPs) concentrations in VOOs. After testing several conditions (80, 100 and 130°C, for 30 and 60min), the parameters of 100°C and 60min were considered as the optima. These conditions allowed removing volatiles responsible for sensory defects with low losses of total phenols (14%-32%), and values of PPPs (11.83%) and FAEEs (34.53mg/kg) lower than the limits of standard regulations. The experiments show that soft-deodorized VOOs could be added up to 50% to EVOOs and current standard methods would not detect this kind of adulteration.

  20. Study of the chemical structure of petroleum asphaltenes by spectral methods

    Energy Technology Data Exchange (ETDEWEB)

    Posadov, I.A.; Pokonova, Yu.V.; Khusidman, M.B.; Gitlin, I.G.; Proskuryakov, V.A.

    1977-03-01

    Results of nuclear magnetic resonance (NMR), ultraviolet (UV), and infrared (IR) spectroscopy studies of the chemical and supermolecular structure of asphaltene concentrates isolated from petroleum residues are reported. Considerable intensity of a characteristic series of absorption bands at 750, 810, 870, 1560, 1600, and 3030 cm/sup -1/ is interpreted as indicative of aromatic structures; while the bands at 870 and 810 cm/sup -1/ are taken as evidence of the predominant presence of highly substituted aromatic rings which are apparently included in alicyclic structures but do not form polynuclear condensed aromatic systems. The bathochromic shift of the electronic absorption spectrum in the region of 250-600 nm and the weak inflection at 300-310 nm are attributed to the partial condensation of the aromatic rings with predominance of fragments of the bi- and tricyclic types. The percentage content of various organic groups, the degree of polycondensation, the degree of potential for substitution, and the elementary composition are reported.