Screening of Actinomycetes from mangrove ecosystem for L-asparaginase activity and optimization by response surface methodology.

PubMed

Usha, Rajamanickam; Mala, Krishnaswami Kanjana; Venil, Chidambaram Kulandaisamy; Palaniswamy, Muthusamy

2011-01-01

Marine actinomycetes were isolated from sediment samples collected from Pitchavaram mangrove ecosystem situated along the southeast coast of India. Maximum actinomycete population was noted in rhizosphere region. About 38% of the isolates produced L-asparaginase. One potential strain KUA106 produced higher level of enzyme using tryptone glucose yeast extract medium. Based on the studied phenotypic characteristics, strain KUA106 was identified as Streptomyces parvulus KUA106. The optimization method that combines the Plackett-Burman design, a factorial design and the response surface method, which were used to optimize the medium for the production of L-asparaginase by Streptomycetes parvulus. Four medium factors were screened from eleven medium factors by Plackett-Burman design experiments and subsequent optimization process to find out the optimum values of the selected parameters using central composite design was performed. Asparagine, tryptone, d) extrose and NaCl components were found to be the best medium for the L-asparaginase production. The combined optimization method described here is the effective method for screening medium factors as well as determining their optimum level for the production of L-asparaginase by Streptomycetes parvulus KUAP106.

Oxidation State Specific Generation of Arsines from Methylated Arsenicals Based on L- Cysteine Treatment in Buffered Media for Speciation Analysis by Hydride Generation - Automated Cryotrapping - Gas Chromatography-Atomic Absorption Spectrometry with the Multiatomizer

PubMed Central

Matoušek, Tomáš; Hernández-Zavala, Araceli; Svoboda, Milan; Langrová, Lenka; Adair, Blakely M.; Drobná, Zuzana; Thomas, David J.; Stýblo, Miroslav; Dědina, Jiří

2008-01-01

An automated system for hydride generation - cryotrapping- gas chromatography - atomic absorption spectrometry with the multiatomizer is described. Arsines are preconcentrated and separated in a Chromosorb filled U-tube. An automated cryotrapping unit, employing nitrogen gas formed upon heating in the detection phase for the displacement of the cooling liquid nitrogen, has been developed. The conditions for separation of arsines in a Chromosorb filled U-tube have been optimized. A complete separation of signals from arsine, methylarsine, dimethylarsine, and trimethylarsine has been achieved within a 60 s reading window. The limits of detection for methylated arsenicals tested were 4 ng l−1. Selective hydride generation is applied for the oxidation state specific speciation analysis of inorganic and methylated arsenicals. The arsines are generated either exclusively from trivalent or from both tri- and pentavalent inorganic and methylated arsenicals depending on the presence of L-cysteine as a prereductant and/or reaction modifier. A TRIS buffer reaction medium is proposed to overcome narrow optimum concentration range observed for the L-cysteine modified reaction in HCl medium. The system provides uniform peak area sensitivity for all As species. Consequently, the calibration with a single form of As is possible. This method permits a high-throughput speciation analysis of metabolites of inorganic arsenic in relatively complex biological matrices such as cell culture systems without sample pretreatment, thus preserving the distribution of tri- and pentavalent species. PMID:18521190

Optimization of the isolation and cultivation of Cyprinus carpio primary hepatocytes.

PubMed

Yanhong, Fan; Chenghua, He; Guofang, Liu; Haibin, Zhang

2008-10-01

The aquatic environment is affected by numerous chemical contaminants. There is an increasing need to identify these chemicals and to evaluate their potential toxicity towards aquatic life. In this research we optimized techniques for primary cell culture of Cyprinus carpio hepatocytes as one adjunct model for ecotoxicological evaluation of the potential hazards of xenobiotics in the aquatic environment. In this study, Cyprinus carpio hepatocytes were isolated by mechanical separation, two-step collagenase perfusion, and pancreatin digestion. The hepatocytes or parenchymal cells could be separated from cell debris and from non-parenchymal cells by low-speed centrifugation (Percoll gradient centrifugation). The harvested hepatocytes were suspended in DMEM, M199 (cultured in 5% CO(2)), or L-15 (cultured without 5% CO(2)) medium then cultured at 17, 27, or 37 degrees C. Cell yield was counted by use of a hemocytometer, and the viability of the cells was assessed by use of the Trypan blue exclusion test. Results from these studies showed that the best method of isolation was pancreatin digestion (the cell yield was 2.7 x 10(8) per g (liver weight) and the viability was 98.4%) and the best medium was M199 (cultured in 5% CO(2)) or L-15 (cultured without 5% CO(2)). The optimum culture temperature was 27 degrees C. The primary hepatocytes culture of Cyprimus carpio grew well and satisfied requirements for most toxicological experiments in this condition.

[Solid-state fermentation with Penicillium sp. PT95 for carotenoid production].

PubMed

Han, J; Xu, J

1999-04-01

A preliminary study on solid-state fermentation (SSF) with Penicillium sp PT95 for carotenoid production was performed. The results showed that the production of carotenoid in sclerotia of PT95 was more efficient in corn meal medium than in either wheat bran medium or cottonseed hull medium. Addition of nitrogen and carbon sources as well as vegetable oil to media was required for increasing the dry weight of sclerotia and carotenoid yield. Among several tested compounds for nitrogen and carbon sources, sodium nitrate and maltose were the best. Through orthogonal experiments, the optimum culture medium was obtained by supplement of NaNO3 3g, maltose 10 g, soybean oil 2.5 g to per liter of salt solution. Under the optimum culture conditions, the sclerotia dry weight increased from 5.36 g to 9.70 g per 100 g dry substrate, the carotenoid yield from 2149 micrograms to 5260 micrograms per 100 g dry substrate, the proportion of beta-carotene in carotenoids from 61.4% to 71.3%.

Characterization of Alicyclobacillus disufldooxidans HIB4 Isolated from an Acid Mine Drainage Treatment Plant

NASA Astrophysics Data System (ADS)

Suto, Koichi; Joe, Seong Jin; Inoue, Chihiro; Chida, Tadashi

2006-05-01

A heterotrophic bacterium, designated as HIB4, having an ability to oxidize ferrous iron was isolated from the sample of an enrichment culture with 9K medium, by using the modified WAYE (washed agarose/yeast extract) medium with ferrous sulphate. This isolate was identified as Alicyclobacillus disulfidooxidans from 16S rDNA sequence analysis. The isolate grew and oxidized ferrous iron in an inorganic medium containing 0.02 % (w/v) of yeast extract and Ferrous iron oxidation occurred at the almost end of its logarithmic phase. Yeast extract was an essential substrate for the isolate because the isolate could not grow or oxidize ferrous iron without yeast extract. However, higher concentration of yeast extract inhibited the growth of the isolate. On the other hand, it was confirmed that the isolate was able to grow without ferrous ion so that it did not get any energy by ferrous ion oxidation. Its optimum concentration of yeast extract was 0.02% (w/v) at the concentration of ferrous ion 0.08mol/liter. Its optimum pH was 1.5 and the optimum temperature was 30 °C These physiological characteristics were completely different from A. disulfidooxidans SD-11 which is the type strain.

Optimization of Lactobacillus acidophilus cultivation using taro waste and evaluation of its biological activity.

PubMed

Hsieh, Shu-Chen; Liu, Jui-Ming; Pua, Xiao-Hui; Ting, Yuwen; Hsu, Ren-Jun; Cheng, Kuan-Chen

2016-03-01

In this study, taro waste (TW) was utilized for Lactobacillus acidophilus BCRC 14079 cultivation and the anti-tumor and immune-modulatory properties of heat-killed cells (HKCs), cytoplasmic fraction (CF), and exopolysaccharide (EPS) were evaluated. The optimum liquefaction enzyme dosage, temperature, and time determined by Box-Behnken design response surface methodology (BBD-RSM) were 9 mL/L of α-amylase, 79.2 °C, and 5 h of reaction, respectively. The optimum temperature and reaction time for saccharification were determined as 60 °C and 3 h. The optimum medium, CGMY1 medium, constitutes of TW hydrolysate containing 37 g/L of glucose, 25 g/L of corn gluten meal (CGM), and 1 g/L of yeast extract (YE). Results of MTT assay showed that HKCs and EPS from CGM medium exhibited the highest anti-proliferative in HT-29 (IC50 of HKCs, 467.25 μg/mL; EPS, 716.10 μg/mL) and in Caco-2 cells (IC50 of EPS, 741.60 μg/mL). Luciferase-based NF-ΚB and COX-2 systems indicated HKCs from CGM medium stimulated the highest expression of luciferin in both systems. The luciferase activities by using 100 and 500 μg/mL of HKCs from CGM were 24.30- and 45.83-fold in NF-ΚB system and 11.54- and 4.93-fold in COX-2 system higher than the control. In conclusion, this study demonstrated the potential of TW medium for L. acidophilus cultivation and the production of non-viable probiotics with enhanced biological activities.

Food production and gas exchange system using blue-green alga (spirulina) for CELSS

NASA Technical Reports Server (NTRS)

Oguchi, Mitsuo; Otsubo, Koji; Nitta, Keiji; Hatayama, Shigeki

1987-01-01

In order to reduce the cultivation area required for the growth of higher plants in space adoption of algae, which have a higher photosynthetic ability, seems very suitable for obtaining oxygen and food as a useful source of high quality protein. The preliminary cultivation experiment for determining optimum cultivation conditions and for obtaining the critical design parameters of the cultivator itself was conducted. Spirulina was cultivated in the 6 liter medium containing a sodium hydrogen carbonate solution and a cultivation temperature controlled using a thermostat. Generated oxygen gas was separated using a polypropyrene porous hollow fiber membrane module. Through this experiment, oxygen gas (at a concentration of more than 46 percent) at a rate of 100 to approx. 150 ml per minute could be obtained.

System and method for treatment of a medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Surinder Prabhjot; Acharya, Harish Radhakrishna; Perry, Robert James

2017-05-23

A system and method for treatment of a medium is disclosed. The system includes a plurality of separator zones and a plurality of heat transfer zones. Each of the separator zone and the heat transfer zone among the plurality of separator zones and heat transfer zones respectively, are disposed alternatively in a flow duct. Further, each separator zone includes an injector device for injecting a sorbent into the corresponding separator zone. Within the corresponding separator zone, the injected sorbent is reacted with a gaseous medium flowing in the flow duct, so as to generate a reacted gaseous medium and amore » reacted sorbent. Further, each heat transfer zone exchanges heat between the reacted gaseous medium fed from the corresponding separator zone and a heat transfer medium.« less

Evaluation of Physarum polycephalum plasmodial growth and lipid production using rice bran as a carbon source.

PubMed

Tran, Hanh; Stephenson, Steven; Pollock, Erik

2015-08-01

The myxomycete Physarum polycephalum appears to have remarkable potential as a lipid source for biodiesel production. The present study evaluated the use of rice bran as a carbon source and determined the medium components for optimum growth and lipid production for this organism. Optimization of medium components by response surface methodology showed that rice bran and yeast extract had significant influences on lipid and biomass production. The optimum medium consisted of 37.5 g/L rice bran, 0.79 g/L yeast extract and 12.5 g/L agar, and this yielded 7.5 g/L dry biomass and 0.9 g/L lipid after 5 days. The biomass and lipid production profiles revealed that these parameters increased over time and reached their maximum values (10.5 and 1.26 g/L, respectively) after 7 days. Physarum polycephalum growth decreased on the spent medium but using the latter increased total biomass and lipid concentrations to 14.3 and 1.72 g/L, respectively. An effective method for inoculum preparation was developed for biomass and lipid production by P. polycephalum on a low-cost medium using rice bran as the main carbon source. These results also demonstrated the feasibility of scaling up and reusing the medium for additional biomass and lipid production.

Formation of glycosidases in batch and continuous culture of Bacteroides fragilis.

PubMed Central

Berg, J O; Nord, C E; Wadström, T

1978-01-01

Nine strains of bacteroides fragilis were cultivated in stirred fermentors and tested for their ability to produce glycosidases. B. fragilis subsp. vulgatus B70 was used for optimizing the production of glycosidases. The highest bacterial yield was obtained in proteose peptone-yeast extract medium. The optimum pH for maximal bacterial yield was 7.0, and the optimum temperature for growth was 37 degrees C. The formation of glycosidases was optimal between pH 6.5 and 7.5, and the optimum temperature for synthesis of glycosidases was between 33 and 37 degrees C. Culture under controlled conditions in fermentors gave more reproducible production of glycosidases than static cultures in bottles. The strain was also grown in continuous culture at a dilution rate of 0.1 liter/h at pH 7.0 and 37 degrees C with a yield of 2.0 mg of dry weight per ml in the complex medium. The formation of glycosidases remained constant during the entire continuous process. PMID:25044

Optimization of Exopolysaccharide Production by Lactobacillus delbrueckii subsp. bulgaricus RR Grown in a Semidefined Medium

PubMed Central

Kimmel, Stacy A.; Roberts, Robert F.; Ziegler, Gregory R.

1998-01-01

The optimal fermentation temperature, pH, and Bacto-casitone (Difco Laboratories, Detroit, Mich.) concentration for production of exopolysaccharide by Lactobacillus delbrueckii subsp. bulgaricus RR in a semidefined medium were determined by using response surface methods. The design consisted of 20 experiments, 15 unique combinations, and five replications. All fermentations were conducted in a fermentor with a 2.5-liter working volume and were terminated when 90% of the glucose in the medium had been consumed. The population of L. delbrueckii subsp. bulgaricus RR and exopolysaccharide content were measured at the end of each fermentation. The optimum temperature, pH, and Bacto-casitone concentration for exopolysaccharide production were 38°C, 5, and 30 g/liter, respectively, with a predicted yield of 295 mg of exopolysaccharide/liter. The actual yield under these conditions was 354 mg of exopolysaccharide/liter, which was within the 95% confidence interval (217 to 374 mg of exopolysaccharide/liter). An additional experiment conducted under optimum conditions showed that exopolysaccharide production was growth associated, with a specific production at the endpoint of 101.4 mg/g of dry cells. Finally, to obtain material for further characterization, a 100-liter fermentation was conducted under optimum conditions. Twenty-nine grams of exopolysaccharide was isolated from centrifuged, ultrafiltered fermentation broth by ethanol precipitation. PMID:9464404

Optimization of Fermentation Medium for Extracellular Lipase Production from Aspergillus niger Using Response Surface Methodology

PubMed Central

Jia, Jia; Yang, Xiaofeng; Wu, Zhiliang; Zhang, Qian; Lin, Zhi; Guo, Hongtao; Lin, Carol Sze Ki; Wang, Jianying; Wang, Yunshan

2015-01-01

Lipase produced by Aspergillus niger is widely used in various industries. In this study, extracellular lipase production from an industrial producing strain of A. niger was improved by medium optimization. The secondary carbon source, nitrogen source, and lipid were found to be the three most influential factors for lipase production by single-factor experiments. According to the statistical approach, the optimum values of three most influential parameters were determined: 10.5 g/L corn starch, 35.4 g/L soybean meal, and 10.9 g/L soybean oil. Using this optimum medium, the best lipase activity was obtained at 2,171 U/mL, which was 16.4% higher than using the initial medium. All these results confirmed the validity of the model. Furthermore, results of the Box-Behnken Design and quadratic models analysis indicated that the carbon to nitrogen (C/N) ratio significantly influenced the enzyme production, which also suggested that more attention should be paid to the C/N ratio for the optimization of enzyme production. PMID:26366414

Improved optimization of polycyclic aromatic hydrocarbons (PAHs) mixtures resolution in reversed-phase high-performance liquid chromatography by using factorial design and response surface methodology.

PubMed

Andrade-Eiroa, Auréa; Diévart, Pascal; Dagaut, Philippe

2010-04-15

A new procedure for optimizing PAHs separation in very complex mixtures by reverse phase high performance (RPLC) is proposed. It is based on changing gradually the experimental conditions all along the chromatographic procedure as a function of the physical properties of the compounds eluted. The temperature and speed flow gradients allowed obtaining the optimum resolution in large chromatographic determinations where PAHs with very different medium polarizability have to be separated. Whereas optimization procedures of RPLC methodologies had always been accomplished regardless of the physico-chemical properties of the target analytes, we found that resolution is highly dependent on the physico-chemical properties of the target analytes. Based on resolution criterion, optimization process for a 16 EPA PAHs mixture was performed on three sets of difficult-to-separate PAHs pairs: acenaphthene-fluorene (for the optimization procedure in the first part of the chromatogram where light PAHs elute), benzo[g,h,i]perylene-dibenzo[a,h]anthracene and benzo[g,h,i]perylene-indeno[1,2,3-cd]pyrene (for the optimization procedure of the second part of the chromatogram where the heavier PAHs elute). Two-level full factorial designs were applied to detect interactions among variables to be optimized: speed flow, temperature of column oven and mobile-phase gradient in the two parts of the studied chromatogram. Experimental data were fitted by multivariate nonlinear regression models and optimum values of speed flow and temperature were obtained through mathematical analysis of the constructed models. An HPLC system equipped with a reversed phase 5 microm C18, 250 mm x 4.6mm column (with acetonitrile/water mobile phase), a column oven, a binary pump, a photodiode array detector (PDA), and a fluorimetric detector were used in this work. Optimum resolution was achieved operating at 1.0 mL/min in the first part of the chromatogram (until 45 min) and 0.5 mL/min in the second one (from 45 min to the end) and by applying programmed temperature gradient (15 degrees C until 30 min and progressively increasing temperature until reaching 40 degrees C at 45 min). (c) 2009 Elsevier B.V. All rights reserved.

Optimization of the isolation and cultivation of Cyprinus carpio primary hepatocytes

PubMed Central

Yanhong, Fan; Chenghua, He; Guofang, Liu

2008-01-01

The aquatic environment is affected by numerous chemical contaminants. There is an increasing need to identify these chemicals and to evaluate their potential toxicity towards aquatic life. In this research we optimized techniques for primary cell culture of Cyprinus carpio hepatocytes as one adjunct model for ecotoxicological evaluation of the potential hazards of xenobiotics in the aquatic environment. In this study, Cyprinus carpio hepatocytes were isolated by mechanical separation, two-step collagenase perfusion, and pancreatin digestion. The hepatocytes or parenchymal cells could be separated from cell debris and from non-parenchymal cells by low-speed centrifugation (Percoll gradient centrifugation). The harvested hepatocytes were suspended in DMEM, M199 (cultured in 5% CO2), or L-15 (cultured without 5% CO2) medium then cultured at 17, 27, or 37 °C. Cell yield was counted by use of a hemocytometer, and the viability of the cells was assessed by use of the Trypan blue exclusion test. Results from these studies showed that the best method of isolation was pancreatin digestion (the cell yield was 2.7 × 108 per g (liver weight) and the viability was 98.4%) and the best medium was M199 (cultured in 5% CO2) or L-15 (cultured without 5% CO2). The optimum culture temperature was 27 °C. The primary hepatocytes culture of Cyprimus carpio grew well and satisfied requirements for most toxicological experiments in this condition. PMID:19002769

[The Influence of New Medium with RGD on Cell Growth,Cell Fusion and Expression of Exogenous Gene].

PubMed

Wang, Pei-Pei; Wei, Da-Peng; Zhu, Tong-Bo

2018-03-01

To investigate the influence of a new culture medium added with RGD on cell growth,cell fusion and expression of exogenous gene. A new medium was prepared by adding different concentrations of RGD to ordinary culture medium. The optimum concentration of RGD was determined by observation of the growth of human pancreatic epithelial cell line HPDE6-C7. After determining the optimum concentration of RGD,different concentrations of cells HPDE6-C7 (5×10 4 ,10 5 ,5×10 5 mL －1 ) were inoculated in the two mediums. The morphology,adherence,growth and density of the cells were observed by inverted microscope; The ratio of clone formation and the positive rate of cloning were compared between the two cultures after fusion; The fluorescence intensity after the transfection of plasmid with green fluorescent protein ( GFP ) and the protein expression after transfection of plasmid with KRAS were observed to campare the expression of exogenous genes between the new medium with ordinary medium. Firstly,the optimal concentration of RGD was 10 ng/mL. Compared with the normal medium,the cultured cells with RGD had better morphology,adhesion and faster proliferation. In addition,both of the number and positive rate of clones formed in the new medium were significantly higher than that in the ordinary medium ( P <0.05);The fluorescence intensity after transfection of exogenous gene GFP in the new medium was significantly higher than that in normal medium ( P <0.05); Expression level of exogenous gene KRAS of the new medium was also significantly higher than that in normal medium. The new culture medium has highlighted advantages in cell growth,cell fusion and expression of exogenous genes. RGD peptide has widely prospect and potential value in the cell culture. Copyright© by Editorial Board of Journal of Sichuan University (Medical Science Edition).

21 CFR 864.8500 - Lymphocyte separation medium.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lymphocyte separation medium. 864.8500 Section 864.8500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... medium. (a) Identification. A lymphocyte separation medium is a device used to isolate lymphocytes from...

21 CFR 864.8500 - Lymphocyte separation medium.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Lymphocyte separation medium. 864.8500 Section 864.8500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... medium. (a) Identification. A lymphocyte separation medium is a device used to isolate lymphocytes from...

21 CFR 864.8500 - Lymphocyte separation medium.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Lymphocyte separation medium. 864.8500 Section 864.8500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... medium. (a) Identification. A lymphocyte separation medium is a device used to isolate lymphocytes from...

21 CFR 864.8500 - Lymphocyte separation medium.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Lymphocyte separation medium. 864.8500 Section 864.8500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... medium. (a) Identification. A lymphocyte separation medium is a device used to isolate lymphocytes from...

21 CFR 864.8500 - Lymphocyte separation medium.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Lymphocyte separation medium. 864.8500 Section 864.8500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... medium. (a) Identification. A lymphocyte separation medium is a device used to isolate lymphocytes from...

Novozyme 435-catalyzed efficient acylation of 3-n-butylphthalide in organic medium.

PubMed

He, Laping; Sun, Jiong; Xu, Yan; Sun, Zhihao; Zheng, Changge

2008-01-01

Novozyme 435 could catalyze efficient acylation of 3-n-butylphthalide in organic medium. The conversion of 3-n-butylphthalide increased with the increase of hydrophobicity of solvent below that of hexane. The more available solvent was hexane. Salt hydride could control fixed water activity. The optimum water activity was 0.62. And the optimum of reaction time, velocity of agitation, dosage of Novozyme 435 and acetic anhydride to 3-n-butylphtrhalide molar ratio were 48 hours, 150 rpm, 8 mg/mL and 8:1, respectively. The conversion of 48.9% could be obtained at a water activity of 0.62 in hexane. Furthermore, Novozyme 435 had an enantioselective acylation of racemic 3-n-butylphthalide by original analysis.

Carboxydobrachium pacificum gen. nov., sp. nov., a new anaerobic, thermophilic, CO-utilizing marine bacterium from Okinawa Trough.

PubMed

Sokolova, T G; González, J M; Kostrikina, N A; Chernyh, N A; Tourova, T P; Kato, C; Bonch-Osmolovskaya, E A; Robb, F T

2001-01-01

A new anaerobic, thermophilic, CO-utilizing marine bacterium, strain JMT, was isolated from a submarine hot vent in Okinawa Trough. Cells of strain JMT were non-motile thin straight rods, sometimes branching, with a cell wall of the Gram-positive type, surrounded with an S-layer. Chains of three to five cells were often observed. The isolate grew chemolithotrophically on CO, producing equimolar quantities of H2 and CO2 (according to the equation CO+H2O-->CO2+H2) and organotrophically on peptone, yeast extract, starch, cellobiose, glucose, galactose, fructose and pyruvate, producing H2, acetate and CO2. Growth was observed from 50 to 80 degrees C with an optimum at 70 degrees C. The optimum pH was 6.8-7.1. The optimum concentration of sea salts in the medium was 20.5-25.5 g l(-1). The generation time under optimal conditions was 7.1 h. The DNA G+C content was 33 mol %. Growth of isolate JMT was not inhibited by penicillin, but ampicillin, streptomycin, kanamycin and neomycin completely inhibited growth. The results of 16S rDNA sequence analysis revealed that strain JMT belongs to the Thermoanaerobacter phylogenetic group within the Bacillus-Clostridium subphylum of Gram-positive bacteria but represents a separate branch of this group. On the basis of morphological and physiological features and phylogenetic data, this isolate should be assigned to a new genus, for which the name Carboxydobrachium is proposed. The type species is Carboxydobrachium pacificum; the type strain is JMT (= DSM 12653T).

Rapid determination of water- and fat-soluble vitamins with microemulsion electrokinetic chromatography.

PubMed

Yin, Changna; Cao, Yuhua; Ding, Shaodong; Wang, Yun

2008-06-06

A rapid, reliable and reproducible method based on microemulsion electrokinetic chromatography (MEEKC) for simultaneous determination of 13 kinds of water- and fat-soluble vitamins has been developed in this work. A novel microemulsion system consisting of 1.2% (w/w) sodium lauryl sulphate (SDS), 21% (v/v) 1-butanol, 18% (v/v) acetonitrile, 0.8% (w/w) n-hexane, 20mM borax buffer (pH 8.7) was applied to improve selectivity and efficiency, as well as shorten analysis time. The composition of microemulsion used as the MEEKC running buffer was investigated thoroughly to obtain stable separation medium, as well as the optimum determination conditions. Acetonitrile as the organic solvent modifier, pH of the running buffer and 1-butanol as the co-surfactant played the most important roles for the separation of the fat-soluble vitamins, water-soluble vitamins and stabilization of system, respectively. The 13 water- and fat-soluble vitamins were baseline separated within 30 min. The system was applied to determine water- and fat-soluble vitamins in commercial multivitamin pharmaceutical formulation, good accuracy and precision were obtained with recoveries between 97% and 105%, relative standard derivations (RSDs) less than 1.8% except vitamin C, and acceptable quantitative results corresponding to label claim.

Influence of Nutritional Conditions on Production of l-Glutamine by Flavobacterium rigense

PubMed Central

Nabe, Koichi; Ujimaru, Toshihiko; Yamada, Shigeki; Chibata, Ichiro

1981-01-01

The nutritional conditions for the production of l-glutamine by Flavobacterium rigense strain 703 were investigated. The optimum concentration of ammonia for achieving the highest yield of l-glutamine (25 mg/ml of broth) was relatively broad, from 0.9 to 1.6%, whereas fumaric acid had a narrow optimum range, near 5.5%. High concentration of inorganic ions such as chloride or sulfate ion clearly inhibited cell growth. Therefore, ammonium salts other than (NH4)2-fumarate were unsuitable for the highest production. The optimum concentration of (NH4)2-fumarate was 7%. To reduce the concentration of fumaric acid in the medium, many substances were evaluated as substitutes. The fumaric acid concentration required for highest l-glutamine yield could not be replaced by any one of the compounds tested. However, part of fumaric acid could be replaced with succinic acid and cupric ion; 4% (NH4)2-fumarate plus 2.5% succinic acid or 5% (NH4)2-fumarate plus 1 mM cupric ion produced results similar to 7% (NH4)2-fumarate in the fermentation medium. PMID:16345682

Learning to wait: A laboratory investigation

USGS Publications Warehouse

Oprea, R.; Friedman, D.; Anderson, S.T.

2009-01-01

Human subjects decide when to sink a fixed cost C to seize an irreversible investment opportunity whose value V is governed by Brownian motion. The optimal policy is to invest when V first crosses a threshold V* = (1 + w*) C, where the wait option premium w* depends on drift, volatility, and expiration hazard parameters. Subjects in the Low w* treatment on average invest at values quite close to optimum. Subjects in the two Medium and the High w* treatments invested at values below optimum, but with the predicted ordering, and values approached the optimum by the last block of 20 periods. ?? 2009 The Review of Economic Studies Limited.

Simultaneous Multiple-Location Separation Control

NASA Technical Reports Server (NTRS)

Greenblatt, David (Inventor)

2009-01-01

A method of controlling a shear layer for a fluid dynamic body introduces first periodic disturbances into the fluid medium at a first flow separation location. Simultaneously, second periodic disturbances are introduced into the fluid medium at a second flow separation location. A phase difference between the first and second periodic disturbances is adjusted to control flow separation of the shear layer as the fluid medium moves over the fluid dynamic body.

Fuel alcohol biosynthesis by Zymomonas anaerobia: optimization studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kosaric, N.; Ong, S.L.; Davnjak, Z.

1982-03-01

The optimum operating conditions for growth and ethanol production of Zymomonas anaerobia ATCC 29501 were established. The optimum pH range and temperature were found to be 5.0-6.0 and 35/sup 0/C, respectively. Based on the results obtained from the temperature optimization study, an Arrhenius-type temperature relationship for the specific growth rate was developed. The growth and ethanol production of this microbe also have been optimized in terms of concentrations of glucose, essential nutrients, and minerals. With optimum medium and operating conditions, an ethanol concentration of 96 g/L was obtained in 23h. Both growth and ethanol yield coefficients in dependence on initialmore » glucose concentrations were determined.« less

Fuel alcohol biosynthesis by Zymomonas anaerobia: optimization studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kosaric, N.; Ong, S.L.; Duvnjak, Z.

1982-03-01

The optimum operating conditions for growth and ethanol production of Zymomonas anaerobia ATCC 29501 were established. The optimum pH range and temperature were found to be 5.0-6.0 and 35 degrees C, respectively. Based on the results obtained from the temperature optimization study, an Arrhenius-type temperature relationship for the specific growth rate was developed. The growth and ethanol production of this microbe also have been optimized in terms of concentrations of glucose, essential nutrients, and minerals. With optimum medium and operating conditions, an ethanol concentration of 96 g/L was obtained in 23 hours. Both growth and ethanol yield coefficients in dependencemore » on initial glucose concentrations were determined. (Refs. 16).« less

Nutrient requirements and other factors involved in the culture of human kidney cells on microcarrier beads

NASA Technical Reports Server (NTRS)

Lewis, Marian L.; Morrison, Dennis R.

1987-01-01

The culture of human kidney cells on microcarrier beads in the Bioprocessing Laboratory at the Johnson Space Center is described. These were the first series of studies performed before and during 1983 to determine optimum conditions, including medium type, bead type and density. The composition of several medium types and the molecular weights of some common culture medium supplements and cellular proteins are included. The microgravity cell-to-bead attachment experiment performed on Space Transportation System Flight 8 is described.

Automatic temperature adjustment apparatus

DOEpatents

Chaplin, James E.

1985-01-01

An apparatus for increasing the efficiency of a conventional central space heating system is disclosed. The temperature of a fluid heating medium is adjusted based on a measurement of the external temperature, and a system parameter. The system parameter is periodically modified based on a closed loop process that monitors the operation of the heating system. This closed loop process provides a heating medium temperature value that is very near the optimum for energy efficiency.

Biofunctionalized nanofibrous membranes as super separators of protein and enzyme from water.

PubMed

Homaeigohar, Shahin; Dai, Tianhe; Elbahri, Mady

2013-09-15

Here, we report development of a novel biofunctionalized nanofibrous membrane which, despite its macroporous structure, is able to separate even trace amounts (as low as 2mg/L) of biomolecules such as protein and enzyme from water with an optimum efficiency of ~90%. Such an extraordinary protein selectivity at this level of pollutant concentration for a nanofibrous membrane has never been reported. In the current study, poly(acrylonitrile-co-glycidyl methacrylate) (PANGMA) electrospun nanofibers are functionalized by a bovine serum albumin (BSA) protein. This membrane is extraordinarily successful in removal of BSA protein and Candida antarctica Lipase B (Cal-B) enzyme from a water based solution. Despite a negligible non-specific adsorption of both BSA and Cal-B to the PANGMA nanofibrous membrane (8%), the separation efficiency of the biofunctionalized membrane for BSA and Cal-B reaches to 88% and 81%, respectively. The optimum separation efficiency at a trace amount of protein models is due to the water-induced conformational change of the biofunctional agent. The conformational change not only exposes more functional groups available to catch the biomolecules but also leads to swelling of the nanofibers thereby a higher steric hindrance for the solutes. Besides the optimum selectivity, the biofunctionalized membranes are highly wettable thereby highly water permeable. Copyright © 2013 Elsevier Inc. All rights reserved.

Characterization of bioimprinted tannase and its kinetic and thermodynamics properties in synthesis of propyl gallate by transesterification in anhydrous medium.

PubMed

Nie, Guangjun; Zheng, Zhiming; Gong, Guohong; Zhao, Genhai; Liu, Yan; Song, Junying; Dai, Jun

2012-08-01

Tannase has been extensively applied to synthesize gallic acid esters. Bioimprinting technique can evidently enhance transesterification-catalyzing performance of tannase. In order to promote the practical utilization of the modified tannase, a few enzymatic characteristics of the enzyme and its kinetic and thermodynamics properties in synthesis of propyl gallate by transesterification in anhydrous medium have been studied. The investigations of pH and temperature found that the imprinted tannase holds an optimum activity at pH 5.0 and 40 °C. On the other hand, the bioimprinting technique has a profound enhancing effect on the adapted tannase in substrate affinity and thermostability. The kinetic and thermodynamic analyses showed that the modified tannase has a longer half-time of 1,710 h at 40 °C; the kinetic constants, the activation energy of reversible thermal inactivation, and the activation energy of irreversible thermal inactivation, respectively, are 0.054 mM, 17.35 kJ mol(-1), and 85.54 kJ mol(-1) with tannic acid as a substrate at 40 °C; the free energy of Gibbs (ΔG) and enthalpy (ΔH) were found to be 97.1 and 82.9 kJ mol(-1) separately under the same conditions.

Special Features of Induction Annealing of Friction Stir Welded Joints of Medium-Alloy Steels

NASA Astrophysics Data System (ADS)

Priymak, E. Yu.; Stepanchukova, A. V.; Bashirova, E. V.; Fot, A. P.; Firsova, N. V.

2018-01-01

Welded joints of medium-alloy steels XJY750 and 40KhN2MA are studied in the initial condition and after different variants of annealing. Special features of the phase transformations occurring in the welded steels are determined. Optimum modes of annealing are recommended for the studied welded joints of drill pipes, which provide a high level of mechanical properties including the case of impact loading.

Axisymmetrical separator for separating particulate matter from a fluid carrying medium

DOEpatents

Linhardt, Hans D.

1984-09-04

A separator for separating particles carried in a fluid carrying medium is disclosed. The separator includes an elongated duct and associated openings incorporated in a solid body. The duct is axisymmetrical relative to its longitudinal axis, and includes a curved wall portion having a curved cross-section taken along the longitudinal axis. An axisymmetrical opening located downstream of the curved wall portion leads from the duct into an axisymmetrical channel which is substantially radially disposed relative to the longitudinal axis. Continuation of the duct downstream of the opening is a discharge portion which is substantially colinear with the longitudinal axis. In operation, a substantial majority of the fluid carrying medium leaves the duct radially through the opening and channel in a state substantially free of particles. A remaining small portion of the fluid carrying medium and a substantial majority of the particles are channelled into the discharge portion by centrifugal forces arising due to travel of the particles along the curved walls. For industrial scale separation of particles from a fluid carrying medium, such as for the clean-up of stack gases, an array of several hundred to several thousand of the separators is provided.

Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry.

PubMed

Wang, Chong-Qing; Wang, Hui; Liu, You-Nian

2015-01-01

Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by froth flotation combined with alkaline pretreatment was investigated for recycling industry. The effect of process variables was estimated by L9 (3(4)) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10 wt% sodium hydroxide, 20 min and 70°C. After alkaline pretreatment under optimum conditions, flotation separation PET from acrylonitrile-butadiene-styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of froth flotation and sink float separation was designed. This study facilitates industrial application of plastics flotation and provides technical insights into recycling of waste plastics. Copyright © 2014 Elsevier Ltd. All rights reserved.

Process for separating nitrogen from methane using microchannel process technology

DOEpatents

Tonkovich, Anna Lee [Marysville, OH; Qiu, Dongming [Dublin, OH; Dritz, Terence Andrew [Worthington, OH; Neagle, Paul [Westerville, OH; Litt, Robert Dwayne [Westerville, OH; Arora, Ravi [Dublin, OH; Lamont, Michael Jay [Hilliard, OH; Pagnotto, Kristina M [Cincinnati, OH

2007-07-31

The disclosed invention relates to a process for separating methane or nitrogen from a fluid mixture comprising methane and nitrogen, the process comprising: (A) flowing the fluid mixture into a microchannel separator, the microchannel separator comprising a plurality of process microchannels containing a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the methane or nitrogen is sorbed by the sorption medium, and removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing the methane or nitrogen from the sorption medium and removing the desorbed methane or nitrogen from the microchannel separator. The process is suitable for upgrading methane from coal mines, landfills, and other sub-quality sources.

Separation process using microchannel technology

DOEpatents

Tonkovich, Anna Lee [Dublin, OH; Perry, Steven T [Galloway, OH; Arora, Ravi [Dublin, OH; Qiu, Dongming [Bothell, WA; Lamont, Michael Jay [Hilliard, OH; Burwell, Deanna [Cleveland Heights, OH; Dritz, Terence Andrew [Worthington, OH; McDaniel, Jeffrey S [Columbus, OH; Rogers, Jr; William, A [Marysville, OH; Silva, Laura J [Dublin, OH; Weidert, Daniel J [Lewis Center, OH; Simmons, Wayne W [Dublin, OH; Chadwell, G Bradley [Reynoldsburg, OH

2009-03-24

The disclosed invention relates to a process and apparatus for separating a first fluid from a fluid mixture comprising the first fluid. The process comprises: (A) flowing the fluid mixture into a microchannel separator in contact with a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the first fluid is sorbed by the sorption medium, removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing first fluid from the sorption medium and removing desorbed first fluid from the microchannel separator. The process and apparatus are suitable for separating nitrogen or methane from a fluid mixture comprising nitrogen and methane. The process and apparatus may be used for rejecting nitrogen in the upgrading of sub-quality methane.

High Aflatoxin Production on a Chemically Defined Medium 1

PubMed Central

Reddy, T. V.; Viswanathan, L.; Venkitasubramanian, T. A.

1971-01-01

Aspergillus parasiticus ATCC 15517 produced 28 to 30 mg of aflatoxin per 100 ml of a medium containing sucrose, asparagine, and salts in stationary and shaken cultures. In the absence of asparagine in the medium, the toxin yields fell drastically, and the thin-layer chromatograms of the chloroform extracts of the cultures indicated the total absence of aflatoxin G1 and the presence of new intense blue and green fluorescent bands having RF values lower than aflatoxins. Initial pH was critical and had to be around 4.5 for good growth and high toxin production on this medium. Optimum concentrations of KH2PO4 and MgSO4·7H2O in the medium were much lower than those normally used in fungal growth media. PMID:5119206

Optimization of marine waste based-growth media for microbial lipase production using mixture design methodology.

PubMed

Sellami, Mohamed; Kedachi, Samiha; Frikha, Fakher; Miled, Nabil; Ben Rebah, Faouzi

2013-01-01

Lipase production by Staphylococcus xylosus and Rhizopus oryzae was investigated using a culture medium based on a mixture of synthetic medium and supernatants generated from tuna by-products and Ulva rigida biomass. The proportion of the three medium components was optimized using the simplex-centroid mixture design method (SCMD). Results indicated that the experimental data were in good agreement with predicted values, indicating that SCMD was a reliable method for determining the optimum mixture proportion of the growth medium. Maximal lipase activities of 12.5 and 23.5 IU/mL were obtained with a 50:50 (v:v) mixture of synthetic medium and tuna by-product supernatant for Staphylococcus xylosus and Rhizopus oryzae, respectively. The predicted responses from these mixture proportions were also validated experimentally.

Investigation of earthquake factor for optimum tuned mass dampers

NASA Astrophysics Data System (ADS)

Nigdeli, Sinan Melih; Bekdaş, Gebrail

2012-09-01

In this study the optimum parameters of tuned mass dampers (TMD) are investigated under earthquake excitations. An optimization strategy was carried out by using the Harmony Search (HS) algorithm. HS is a metaheuristic method which is inspired from the nature of musical performances. In addition to the HS algorithm, the results of the optimization objective are compared with the results of the other documented method and the corresponding results are eliminated. In that case, the best optimum results are obtained. During the optimization, the optimum TMD parameters were searched for single degree of freedom (SDOF) structure models with different periods. The optimization was done for different earthquakes separately and the results were compared.

Some further characteristics of the growth of Naegleria fowleri and N. gruberi in axenic culture.

PubMed

Cerva, L

1978-01-01

The effects of pH, various viscosity of the medium, changed ratio between the concentrations of dissolved and corpuscular components in the medium, and dissolved inorganic salts on the growth of axenic cultures of Naegleria fowleri and N. gruberi have been studied. The cultures were grown in liquid CALYG and BCS media. The pH optimum was 6.5 for N. fowleri and 6.0--6.5 for N. gruberi. No negative influence on the growth of N. fowleri was observed even at 0.5% concentration of highly viscous methylcellulose, whereas the growth of N. gruberi was distinctly inhibited by more than 0.2% of methycellulose. N. fowleri preferred the osmotorphic and N. gruberi phagotrophic nutrition in the given system of cultivation. The growth of both Naegleria species was inhibited by 0.1 N concentration of sodium chloride and potassium chloride without any significant difference in the tolerance. The inhibitory effect of these salts correlated primarily with the concentration of chloride anion. The ability to grow in a medium with increased viscosity and the preference for osmotrophic nutrtion are, besides the higher temperature optimum determined earlier, further characteristics of the pathogenic species N. fowleri.

[A new species of Blastocystis anseri (Protista: Rhizopoda) from domestic geese].

PubMed

Belova, L M

1992-01-01

A new species, Blastocystis anseri, was found in domestic goose. Sizes of blastocyst in culture are 7.5-46.2 x 7.5-46.2 m. Method of cultivation of Blastocystis anseri on biphase egg medium was worked out. Liquid phase can be made of Hank's solution or 199 medium with an addition of 30-40% hen or bovine serum. Optimum temperature for cultivation is 39 +/- 0.5 degree, ph 7.0-7.2.

Selection and optimization of Bacillus atrophaeus inoculum medium and its effect on spore yield and thermal resistance.

PubMed

Sella, Sandra Regina B R; Dlugokenski, Regina Elizabete F; Guizelini, Belquis P; Vandenberghe, Luciana P S; Medeiros, Adriane B P; Pandey, Ashok; Soccol, Carlos Ricardo

2008-12-01

Bacillus atrophaeus's spores are used as biological indicators to monitor sterilization processes and as a Bacillus anthracis surrogate in the development and validation of biosafety methods. The regular use of biological indicators to evaluate the efficiency of sterilization processes is a legal requirement for health services. However, its high cost hinders its widespread use. Aiming at developing a cost-effective inoculum medium, soybean molasses and nutrient-supplemented vinasse were evaluated for their effectiveness in solid-state fermentation (SSF). In biomass production, the results demonstrated that all tested compositions favor growth by providing the nutritional demands of the microorganism. Optimum casein peptone and soybean molasses concentration (1.0%, 2.5%, or 4.0%) was determined by a 2((2-0)) factorial experimental design. The results have showed a positive influence of peptone on biomass production. In order to define peptone final concentration (4.0% or 6.0%), a 2(2) factorial experimental design was used. An optimized medium containing 4.0% soybean molasses and 4.0% casein peptone was similar in performance to a synthetic control medium (tryptone soy broth) in dry-heat thermal-resistant spore production by SSF. An experiment performed under optimum SSF conditions resulted in 1.9 x 10(10) CFU g(-1) dry matter with D (160 degrees C) = 5.2 +/- 0.2 min.

Study on Separation of Structural Isomer with Magneto-Archimedes method

NASA Astrophysics Data System (ADS)

Kobayashi, T.; Mori, T.; Akiyama, Y.; Mishima, F.; Nishijima, S.

2017-09-01

Organic compounds are refined by separating their structural isomers, however each separation method has some problems. For example, distillation consumes large energy. In order to solve these problems, new separation method is needed. Considering organic compounds are diamagnetic, we focused on magneto-Archimedes method. With this method, particle mixture dispersed in a paramagnetic medium can be separated in a magnetic field due to the difference of the density and magnetic susceptibility of the particles. In this study, we succeeded in separating isomers of phthalic acid as an example of structural isomer using MnCl2 solution as the paramagnetic medium. In order to use magneto-Archimedes method for separating materials for food or medicine, we proposed harmless medium using oxygen and fluorocarbon instead of MnCl2 aqueous solution. As a result, the possibility of separating every structural isomer was shown.

Process for separation and preconcentration of radium from water

DOEpatents

Dietz, Mark; Horwitz, E. Philip; Chiarizia, Renato; Bartsch, Richard A.

1999-01-01

A process for preconcentrating and separating radium from a contaminated solution containing at least water and radium includes the steps of adding a quantity of a water-soluble macrocyclic polyether to the contaminated solution to form a combined solution. An acid is added to the combined solution to form an acidic combined solution having an ›H.sup.+ ! concentration of about 0.5M. The acidic combined solution is contacted with a sulfonic acid-based strong acid cation exchange medium or a organophilic sulfonic acid medium having a plurality of binding sites thereon to bind the radium thereto and to form a radium-depleted solution. The radium-depleted solution is separated from the strong acid cation exchange medium or organophilic sulfonic acid medium. The radium remaining bound to the exchange medium or organophilic reagent is then stripped from the exchange medium or organophilic medium and the activity of the radium is measured.

Process for separation and preconcentration of radium from water

DOEpatents

Dietz, M.; Horwitz, E.P.; Chiarizia, R.; Bartsch, R.A.

1999-01-26

A process for preconcentrating and separating radium from a contaminated solution containing at least water and radium includes the steps of adding a quantity of a water-soluble macrocyclic polyether to the contaminated solution to form a combined solution. An acid is added to the combined solution to form an acidic combined solution having an [H{sup +}] concentration of about 0.5M. The acidic combined solution is contacted with a sulfonic acid-based strong acid cation exchange medium or a organophilic sulfonic acid medium having a plurality of binding sites thereon to bind the radium thereto and to form a radium-depleted solution. The radium-depleted solution is separated from the strong acid cation exchange medium or organophilic sulfonic acid medium. The radium remaining bound to the exchange medium or organophilic reagent is then stripped from the exchange medium or organophilic medium and the activity of the radium is measured. 24 figs.

Capillary zone electrophoresis for analysis of phytochelatins and other thiol peptides in complex biological samples derivatized with monobromobimane.

PubMed

Perez-Rama, Mónica; Torres Vaamonde, Enrique; Abalde Alonso, Julio

2005-02-01

A new method to improve the analysis of phytochelatins and their precursors (cysteine, gamma-Glu-Cys, and glutathione) derivatized with monobromobimane (mBrB) in complex biological samples by capillary zone electrophoresis is described. The effects of the background electrolyte pH, concentration, and different organic additives (acetonitrile, methanol, and trifluoroethanol) on the separation were studied to achieve optimum resolution and number of theoretical plates of the analyzed compounds in the electropherograms. Optimum separation of the thiol peptides was obtained with 150 mM phosphate buffer at pH 1.60. Separation efficiency was improved when 2.5% v/v methanol was added to the background electrolyte. The electrophoretic conditions were 13 kV and capillary dimensions with 30 cm length from the inlet to the detector (38 cm total length) and 50 microm inner diameter. The injection was by pressure at 50 mbar for 17 s. Under these conditions, the separation between desglycyl-peptides and phytochelatins was also achieved. We also describe the optimum conditions for the derivatization of biological samples with mBrB to increase electrophoretic sensitivity and number of theoretical plates. The improved method was shown to be simple, reproducible, selective, and accurate in measuring thiol peptides in complex biological samples, the detection limit being 2.5 microM glutathione at a wavelength of 390 nm.

Cell Separations in Microgravity and Development of a Space Bioreactor

NASA Technical Reports Server (NTRS)

Morrison, D. R.

1985-01-01

A bioreactor optimized for operations in space is now being developed. The current research is focused on determining the optimum cell-bead ratios, medium content and proper maintenance conditions required to keep living cell specimens alive and healthy for the entire flight. The bioreactor development project has recently added a microprocessor/computer to the JSC prototype for control and data analysis. Appropriate new technology is being combined with the current bioreactor designs and tested to determine what specific features must be included in the fabrication of a bioreactor designed to operate for STS demonstration tests. Considerations include: (1) circulation and resupply of culture media; (2) sensors required to monitor temperature, cell growth, mass transport, and oxygen consumption; and (3) inflight control of shear stress on cells, gas transfer in microgravity, diffusion, and intracellular transport. These data and results from the JSC prototype bioreactor test will be used for the design and construction of a small space bioreactor for the Orbiter middeck.

A nanosilver-based spectrophotometric method for determination of malachite green in surface water samples.

PubMed

Sahraei, R; Farmany, A; Mortazavi, S S; Noorizadeh, H

2013-07-01

A new spectrophotometric method is reported for the determination of nanomolar level of malachite green in surface water samples. The method is based on the catalytic effect of silver nanoparticles on the oxidation of malachite green by hexacyanoferrate (III) in acetate-acetic acid medium. The absorbance is measured at 610 nm with the fixed-time method. Under the optimum conditions, the linear range was 8.0 × 10(-9)-2.0 × 10(-7) mol L(-1) malachite green with a correlation coefficient of 0.996. The limit of detection (S/N = 3) was 2.0 × 10(-9) mol L(-1). Relative standard deviation for ten replicate determinations of 1.0 × 10(-8) mol L(-1) malachite green was 1.86%. The method is featured with good accuracy and reproducibility for malachite green determination in surface water samples without any pre-concentration and separation step.

Isolation, characterization and chromatography based purification of antibacterial compound isolated from rare endophytic actinomycetes Micrococcus yunnanensis.

PubMed

Ranjan, Ravi; Jadeja, Vasantba

2017-10-01

Endophytic actinomycetes are considered as one of the relatively unexplored potential sources in search of antibiotic producer against antibiotic resistant pathogens. A potent strain isolated from Catharanthus roseus that displays antibacterial potential against antibiotic resistant human pathogen Staphylococcus aureus was characterized and designated as Micrococcus yunnanensis strain rsk5. Rsk5 is capable of producing optimum antibacterial metabolites on starch casein medium at 30 °C, pH 5 and 2% NaCl condition. The crude antibacterial agent was extracted from fermentation broth by ethyl acetate and separated by TLC using chloroform-methanol (24:1, v/v) solvent system with R f value of 0.26. It was partially purified by flash chromatography, followed by HPLC and analyzed by ultraviolet visible spectrophotometer to get absorption maxima at 208.4 nm. The ESI-MS spectra showed molecular ion peaks at m / z 472.4 [M-H], which does not match with any known antibacterial compound.

A green method using a micellar system for determination of andrographolide and dehydroandrographolide in human plasma.

PubMed

Zhao, Qi; Ding, Jie; Jin, Haiyan; Ding, Lan; Ren, Nanqi

2013-04-01

A method based on cloud point extraction (CPE) coupled with high-performance liquid chromatography separation and ultraviolet (UV) detection was developed to determine andrographolide and dehydroandrographolide in human plasma. The nonionic surfactant Triton X-114 was chosen as the extraction medium. Variable parameters affecting the CPE efficiency were evaluated and optimized, such as concentrations of Triton X-114 and NaCl, pH, equilibration temperature and equilibration time. A Zorbax SB C18 column (250 × 4.6 mm i.d., 5 µm) was used for separation of the two analytes at 30°C. The UV detection was performed at 254 nm. Under the optimum conditions, the limits of detection of andrographolide and dehydroandrographolide are 0.032 and 0.019 µg/mL, respectively. The intra-day and inter-day precisions expressed as relative standard deviation ranged from 3.2 to 7.3% and from 2.9 and 8.6%. The recoveries of andrographolide and dehydroandrographolide were in the range of 76.8-98.6% at three fortified concentrations of 0.1, 0.5 and 1.0 µg/mL. This method was efficient, environmentally friendly, rapid and inexpensive for the extraction and determination of andrographolide and dehydroandrographolide in human plasma.

Studies with sample conductivity, insertion rates, and particle deflection in a continuous flow electrophoresis system

NASA Technical Reports Server (NTRS)

Williams, G., Jr.

1982-01-01

The continuous flow electrophoresis system makes electrophoresis possible in a free-flowing film of aqueous electrolyte medium. The sample continuously enters the electrolyte at the top of the chamber and is subjected to the action of a lateral dc field. This divides the sample into fractions since each component has a distinctive electrophoretic mobility. Tests were made using monodisperse polystyrene latex microspheres to determine optimum sample conductivity, insertion rates and optimum electric field applications as baseline data for future STS flight experiments. Optimum sample flow rates for the selected samples were determined to be approximately 26 micro-liters/min. Experiments with samples in deionized water yielded best results and voltages in the 20 V/cm to 30 V/cm range were optimum. Deflections of formaldehyde fixed turkey and bovine erythrocytes were determined using the continuous flow electrophoresis system. The effects of particle interactions on sample resolution and migration in the chamber was also evaluated.

Microbial mediated preparation, characterization and optimization of gold nanoparticles

PubMed Central

Barabadi, Hamed; Honary, Soheila; Ebrahimi, Pouneh; Mohammadi, Milad Ali; Alizadeh, Ahad; Naghibi, Farzaneh

2014-01-01

The need for eco-friendly and cost effective methods for nanoparticles synthesis is developing interest in biological approaches which are free from the use of toxic chemicals as byproducts. This study aimed to biosynthesize and optimize the size of gold nanoparticles which produced by biotechnological method using Penicillium crustosum isolated from soil. Initially, Penicillium crustosum was grown in fluid czapek dox broth on shaker at 28 °C and 200 rpm for ten days and then the supernatant was separated from the mycelia to convert AuCl4 solution into gold nanoparticles. The synthesized nanoparticles in the optimum conditions were formed with fairly well-defined dimensions and good monodispersity. The characterizations were done by using different methods (UV-Visible Spectroscopy, Fluorescence, FT-IR, AFM (Atomic Force Microscopy) and DLS (Dynamic Light Scattering). The bioconversion was optimized by Box-Behnken experimental design. The results show that the effective factors in this process were concentration of AuCl4, pH of medium and temperature of shaker incubator. The R2 value was calculated to be 0.9999 indicating the accuracy and ability of the polynomial model. It can be concluded that the use of multivariate analysis facilitated to find out the optimum conditions for the biosynthesis of gold nanoparticles induced by Penicillium crustosum in a time and cost effective process. The current approach suggested that rapid synthesis of gold nanoparticles would be suitable for developing a biological process for mass scale production of formulations. PMID:25763059

Microbial mediated preparation, characterization and optimization of gold nanoparticles.

PubMed

Barabadi, Hamed; Honary, Soheila; Ebrahimi, Pouneh; Mohammadi, Milad Ali; Alizadeh, Ahad; Naghibi, Farzaneh

2014-01-01

The need for eco-friendly and cost effective methods for nanoparticles synthesis is developing interest in biological approaches which are free from the use of toxic chemicals as byproducts. This study aimed to biosynthesize and optimize the size of gold nanoparticles which produced by biotechnological method using Penicillium crustosum isolated from soil. Initially, Penicillium crustosum was grown in fluid czapek dox broth on shaker at 28 °C and 200 rpm for ten days and then the supernatant was separated from the mycelia to convert AuCl₄ solution into gold nanoparticles. The synthesized nanoparticles in the optimum conditions were formed with fairly well-defined dimensions and good monodispersity. The characterizations were done by using different methods (UV-Visible Spectroscopy, Fluorescence, FT-IR, AFM (Atomic Force Microscopy) and DLS (Dynamic Light Scattering). The bioconversion was optimized by Box-Behnken experimental design. The results show that the effective factors in this process were concentration of AuCl₄, pH of medium and temperature of shaker incubator. The R(2) value was calculated to be 0.9999 indicating the accuracy and ability of the polynomial model. It can be concluded that the use of multivariate analysis facilitated to find out the optimum conditions for the biosynthesis of gold nanoparticles induced by Penicillium crustosum in a time and cost effective process. The current approach suggested that rapid synthesis of gold nanoparticles would be suitable for developing a biological process for mass scale production of formulations.

Comparison of phthalic acid removal from aqueous solution by electrochemical methods: Optimization, kinetic and sludge study.

PubMed

Sandhwar, Vishal Kumar; Prasad, Basheshwar

2017-12-01

In this work, comparative study between electrochemical processes such as electrocoagulation (EC), peroxi-coagulation (PC) and peroxi-electrocoagulation (PEC) was performed for the removal of phthalic acid (PA) and chemical oxygen demand (COD) from aqueous medium. Initially, acid treatment was studied at various pH (1-3) and temperature (10-55 °C). Subsequently, the supernatant was re-treated by electrochemical processes such as EC, PC and PEC separately. Independent parameters viz. pH, current density (CD), electrolyte concentration (m), electrode gap (g), H 2 O 2 concentration and electrolysis time (t) were optimized by Central Composite Design (CCD) for these electrochemical processes. All three processes were compared based on removal, energy consumption, kinetic analysis, operating cost and sludge characteristics. In this study, PEC process was found more efficient among EC, PC and PEC processes in order to get maximum removal, minimum energy consumption and minimum operating cost. Maximum removal of PA- 68.21%, 74.36%, 82.25% & COD- 64.79%, 68.15%, 75.21% with energy consumption - 120.95, 97.51, 65.68 (kWh/kg COD removed) were attained through EC, PC and PEC processes respectively at their corresponding optimum conditions. Results indicated that PA and COD removals are in order of PEC > PC > EC under optimum conditions. First order kinetic model was found able to describe the degradation kinetics and provided best correlation for the removal rate within the acceptable error range. Copyright © 2017 Elsevier Ltd. All rights reserved.

Centrifuge apparatus

DOEpatents

Sartory, Walter K.; Eveleigh, John W.

1976-01-01

A method and apparatus for operating a continuous flow blood separation centrifuge are provided. The hematocrit of the entrant whole blood is continuously maintained at an optimum constant value by the addition of plasma to the entrant blood. The hematocrit of the separated red cells is monitored to indicate the degree of separation taking place, thereby providing a basis for regulating the flow through the centrifuge.

Screening of Ganoderma strains with high polysaccharides and ganoderic acid contents and optimization of the fermentation medium by statistical methods.

PubMed

Wei, Zhen-hua; Duan, Ying-yi; Qian, Yong-qing; Guo, Xiao-feng; Li, Yan-jun; Jin, Shi-he; Zhou, Zhong-Xin; Shan, Sheng-yan; Wang, Chun-ru; Chen, Xue-Jiao; Zheng, Yuguo; Zhong, Jian-Jiang

2014-09-01

Polysaccharides and ganoderic acids (GAs) are the major bioactive constituents of Ganoderma species. However, the commercialization of their production was limited by low yield in the submerged culture of Ganoderma despite improvement made in recent years. In this work, twelve Ganoderma strains were screened to efficiently produce polysaccharides and GAs, and Ganoderma lucidum 5.26 (GL 5.26) that had been never reported in fermentation process was found to be most efficient among the tested stains. Then, the fermentation medium was optimized for GL 5.26 by statistical method. Firstly, glucose and yeast extract were found to be the optimum carbon source and nitrogen source according to the single-factor tests. Ferric sulfate was found to have significant effect on GL 5.26 biomass production according to the results of Plackett-Burman design. The concentrations of glucose, yeast extract and ferric sulfate were further optimized by response surface methodology. The optimum medium composition was 55 g/L of glucose, 14 g/L of yeast extract, 0.3 g/L of ferric acid, with other medium components unchanged. The optimized medium was testified in the 10-L bioreactor, and the production of biomass, IPS, total GAs and GA-T enhanced by 85, 27, 49 and 93 %, respectively, compared to the initial medium. The fermentation process was scaled up to 300-L bioreactor; it showed good IPS (3.6 g/L) and GAs (670 mg/L) production. The biomass was 23.9 g/L in 300-L bioreactor, which was the highest biomass production in pilot scale. According to this study, the strain GL 5.26 showed good fermentation property by optimizing the medium. It might be a candidate industrial strain by further process optimization and scale-up study.

Optimization of multi-element airfoils for maximum lift

NASA Technical Reports Server (NTRS)

Olsen, L. E.

1979-01-01

Two theoretical methods are presented for optimizing multi-element airfoils to obtain maximum lift. The analyses assume that the shapes of the various high lift elements are fixed. The objective of the design procedures is then to determine the optimum location and/or deflection of the leading and trailing edge devices. The first analysis determines the optimum horizontal and vertical location and the deflection of a leading edge slat. The structure of the flow field is calculated by iteratively coupling potential flow and boundary layer analysis. This design procedure does not require that flow separation effects be modeled. The second analysis determines the slat and flap deflection required to maximize the lift of a three element airfoil. This approach requires that the effects of flow separation from one or more of the airfoil elements be taken into account. The theoretical results are in good agreement with results of a wind tunnel test used to corroborate the predicted optimum slat and flap positions.

L-Asparaginase Production by Streptomyces griseus

PubMed Central

DeJong, Peter J.

1972-01-01

Streptomyces griseus ATCC 10137 synthesizes about 1 IU of L-asparaginase/100 ml of a 4% peptone medium. The enzyme has a pH optimum of 8.5 which is comparable to that of the L-asparaginase derived from Escherichia coli which has antitumor properties. PMID:4626231

The Case Mix of Patients Presenting with Full-Thickness Macular Holes and Progression before Surgery: Implications for Optimum Management.

PubMed

Madi, Haifa A; Dinah, Christiana; Rees, Jon; Steel, David H W

2015-01-01

Analysis of pre-operative spectral domain optical coherence tomography (SD-OCT) characteristics of full-thickness macular holes (FTMH) and effect on optimum management. We retrospectively reviewed SD-OCT characteristics of a consecutive cohort of patients waitlisted for FTMH surgery and categorized them by current evidence-based treatments. Out of the 106 holes analysed, 36 were small, 40 medium and 30 large. Initially, 33 holes had vitreomacular adhesion (VMA). 41 holes were analysed for change in characteristics with a median duration of 8 weeks between the scans. The number of small or medium holes decreased from 20 to 6 and that of large holes doubled. The number of holes with VMA halved. Smaller hole size (p = 0.014) and being phakic (p = 0.048) were associated with a larger increase in size. The strongest predictor of hole progression into a different surgical management category was the presence of VMA. FTMH characteristics can change significantly pre-operatively and affect optimal treatment choice.

Isolation of Endotoxin Eliminating Lactic Acid Bacteria and a Property of Endotoxin Eliminating Protein.

PubMed

Kondo, Ayaka; Asami, Kyoko; Suda, Yoshihito; Shimoyamada, Makoto; Kanauchi, Makoto

2016-06-01

Recently, many scholars have reported lactic acid bacteria (LAB) functions, such as anticancer activity and anti-inflammatory activity for intestines. To decrease inflammatory substances such as endotoxins, LAB consumed safely with meals were isolated from food and food ingredients. First, LAB were isolated as 168 strains of bacillus LAB (49 strain) and coccus LAB (119 strains) from food ingredients and fermented foods such as rice, rice bran, malt, grains, miso soy paste, and some pickles. Their LAB (168 strains) were cultivated in medium containing endotoxin from Escherichia coli O18 LPS at 15 and 30 °C for 64 h to identify endotoxin-eliminating LAB. Consequently, the AK-23 strain was screened as an endotoxin-eliminating LAB strain. The strain decreased endotoxin in YP medium without sugar at 30 °C for 64 h until 9% of endotoxin. The strain was identified as Pediococcus pentosaceus according to morphological characteristics such as its cell shape, physiological characteristics related to its fermentation type, assimilation of sugars, pH tolerance, optimum growth temperature, and molecular biological characteristics as its homology to 16S rRNA. To investigate the location of the endotoxin-eliminating substance, 4 fractions were separated from AK-23 cells as extracellular, cell wall digestion, cytoplasm, and cell membrane fractions. The endotoxin-decreasing substance, located on a cell wall, was identified as a 217 kDa protein. © 2016 Institute of Food Technologists®

Experimental investigation of magnetically actuated separation using tangential microfluidic channels and magnetic nanoparticles.

PubMed

Munir, Ahsan; Zhu, Zanzan; Wang, Jianlong; Zhou, Hong Susan

2014-06-01

A novel continuous switching/separation scheme of magnetic nanoparticles (MNPs) in a sub-microlitre fluid volume surrounded by neodymium permanent magnet is studied in this work using tangential microfluidic channels. Polydimethylsiloxane tangential microchannels are fabricated using a novel micromoulding technique that can be done without a clean room and at much lower cost and time. Negligible switching of MNPs is seen in the absence of magnetic field, whereas 90% of switching is observed in the presence of magnetic field. The flow rate of MNPs solution had dramatic impact on separation performance. An optimum value of the flow rate is found that resulted in providing effective MNP separation at much faster rate. Separation performance is also investigated for a mixture containing non-magnetic polystyrene particles and MNPs. It is found that MNPs preferentially moved from lower microchannel to upper microchannel resulting in efficient separation. The proof-of-concept experiments performed in this work demonstrates that microfluidic bioseparation can be efficiently achieved using functionalised MNPs, together with tangential microchannels, appropriate magnetic field strength and optimum flow rates. This work verifies that a simple low-cost magnetic switching scheme can be potentially of great utility for the separation and detection of biomolecules in microfluidic lab-on-a-chip systems.

Pore size engineering applied to starved electrochemical cells and batteries

NASA Technical Reports Server (NTRS)

Abbey, K. M.; Thaller, L. H.

1982-01-01

To maximize performance in starved, multiplate cells, the cell design should rely on techniques which widen the volume tolerance characteristics. These involve engineering capillary pressure differences between the components of an electrochemical cell and using these forces to promote redistribution of electrolyte to the desired optimum values. This can be implemented in practice by prescribing pore size distributions for porous back-up plates, reservoirs, and electrodes. In addition, electrolyte volume management can be controlled by incorporating different pore size distributions into the separator. In a nickel/hydrogen cell, the separator must contain pores similar in size to the small pores of both the nickel and hydrogen electrodes in order to maintain an optimum conductive path for the electrolyte. The pore size distributions of all components should overlap in such a way as to prevent drying of the separator and/or flooding of the hydrogen electrode.

Effect of fermentation parameters on bio-alcohols production from glycerol using immobilized Clostridium pasteurianum: an optimization study.

PubMed

Khanna, Swati; Goyal, Arun; Moholkar, Vijayanand S

2013-01-01

This article addresses the issue of effect of fermentation parameters for conversion of glycerol (in both pure and crude form) into three value-added products, namely, ethanol, butanol, and 1,3-propanediol (1,3-PDO), by immobilized Clostridium pasteurianum and thereby addresses the statistical optimization of this process. The analysis of effect of different process parameters such as agitation rate, fermentation temperature, medium pH, and initial glycerol concentration indicated that medium pH was the most critical factor for total alcohols production in case of pure glycerol as fermentation substrate. On the other hand, initial glycerol concentration was the most significant factor for fermentation with crude glycerol. An interesting observation was that the optimized set of fermentation parameters was found to be independent of the type of glycerol (either pure or crude) used. At optimum conditions of agitation rate (200 rpm), initial glycerol concentration (25 g/L), fermentation temperature (30°C), and medium pH (7.0), the total alcohols production was almost equal in anaerobic shake flasks and 2-L bioreactor. This essentially means that at optimum process parameters, the scale of operation does not affect the output of the process. The immobilized cells could be reused for multiple cycles for both pure and crude glycerol fermentation.

Experimental study on the performance of the vapor injection refrigeration system with an economizer for intermediate pressures

NASA Astrophysics Data System (ADS)

Moon, Chang-Uk; Choi, Kwang-Hwan; Yoon, Jung-In; Kim, Young-Bok; Son, Chang-Hyo; Ha, Soo-Jung; Jeon, Min-Ju; An, Sang-Young; Lee, Joon-Hyuk

2018-04-01

In this study, to investigate the performance characteristics of vapor injection refrigeration system with an economizer at an intermediate pressure, the vapor injection refrigeration system was analyzed under various experiment conditions. As a result, the optimum design data of the vapor injection refrigeration system with an economizer were obtained. The findings from this study can be summarized as follows. The mass flow rate through the compressor increases with intermediate pressure. The compression power input showed an increasing trend under all the test conditions. The evaporation capacity increased and then decreased at the intermediate pressure, and as such, it became maximum at the given intermediate pressure. The increased mass flow rate of the by-passed refrigerant enhanced the evaporation capacity at the low medium pressure range, but the increased saturation temperature limited the subcooling degree of the liquid refrigerant after the application of the economizer when the intermediate pressure kept rising, and degenerated the evaporation capacity. The coefficient of performance (COP) increased and then decreased with respect to the intermediate pressures under all the experiment conditions. Nevertheless, there was an optimum intermediate pressure for the maximum COP under each experiment condition. Therefore, the optimum intermediate pressure in this study was found at -99.08 kPa, which is the theoretical standard medium pressure under all the test conditions.

Optimization of water absorbing exopolysaccharide production on local cheap substrates by Bacillus strain CMG1403 using one variable at a time approach.

PubMed

Muhammadi; Afzal, Muhammad

2014-01-01

Optimum culture conditions, and carbon and nitrogen sources for production of water absorbing exopolysaccharide by Bacillus strain CMG1403 on local cheap substrates were determined using one variable at a time approach. Carbon source was found to be sole substrate for EPS biosynthesis in the presence of yeast extract that supported the growth only and hence, indirectly enhanced the EPS yield. Whereas, urea only coupled with carbon source could enhance the EPS production but no effect on growth. The maximum yield of EPS was obtained when Bacillus strain CMG1403 was grown statically in neutral minimal medium with 25% volumetric aeration at 30°C for 10 days. Under these optimum conditions, a maximum yield of 2.71±0.024, 3.82±0.005, 4.33±0.021, 4.73±0.021, 4.85±0.024, and 5.52±0.016 g/L culture medium was obtained with 20 g (sugar) of sweet whey, glucose, fructose, sucrose, cane molasses and sugar beet the most efficient one respectively as carbon sources. Thus, the present study showed that under optimum culture conditions, the local cheap substrates could be superior and efficient alternatives to synthetic carbon sources providing way for an economical production of water absorbing EPS by indigenous soil bacterium Bacillus strain CMG1403.

Fabrication and test of inorganic/organic separators. [for silver zinc batteries

NASA Technical Reports Server (NTRS)

Smatko, J. S.

1974-01-01

Completion of testing and failure analysis of MDC 40 Ahr silver zinc cells containing largely inorganic separators was accomplished. The results showed that the wet stand and cycle life objectives of the silver zinc cell development program were accomplished. Building, testing and failure analysis of two plate cells employing three optimum separators selected on the basis of extensive screening tests, was performed. The best separator material as a result of these tests was doped calcium zirconate.

Effects of N6-benzylaminopurine and Indole Acetic Acid on In Vitro Shoot Multiplication, Nodule-like Meristem Proliferation and Plant Regeneration of Malaysian Bananas (Musa spp.)

PubMed Central

Sipen, Philip; Davey, Michael R

2012-01-01

Different concentrations of N6-benzylaminopurine (BAP) and indole acetic acid (IAA) in Murashige and Skoog based medium were assessed for their effects on shoot multiplication, nodule-like meristem proliferation and plant regeneration of the Malaysian banana cultivars Pisang Mas, Pisang Nangka, Pisang Berangan and Pisang Awak. BAP at 1–14 mg L−1 with or without 0.2 mg L−1 IAA, or BAP at 7–14 mg L−1 with the same concentration of IAA, was evaluated for shoot multiplication from shoot tips and the proliferation of nodule-like meristems from scalps, respectively. Plant regeneration from scalps was assessed using 1 mg L−1 BAP and 0.2 mg L−1 IAA separately, or a combination of these two growth regulators. Data on shoot multiplication, the proliferation of nodule-like meristems with associated plant regeneration were recorded after 30 days of culture. A maximum of 5 shoots per original shoot tip was achieved on medium supplemented with BAP at 5 mg L−1 (Pisang Nangka), 6 mg L−1 (Pisang Mas and Pisang Berangan), or 7 mg L−1 (Pisang Awak), with 0.2 mg L−1 IAA. BAP at 11 mg L−1 with 0.2 mg L−1 IAA induced the most highly proliferating nodule-like meristems in the four banana cultivars. Plant regeneration from scalps was optimum in all cases on medium containing 1 mg L−1 BAP and 0.2 mg L−1 IAA. This is the first report on the successful induction of highly proliferating nodule-like meristems and plant regeneration from scalps of the Malaysian banana cultivars Pisang Mas, Pisang Nangka, Pisang Berangan and Pisang Awak. PMID:24575235

Optimum conditions for L-glutaminase production by actinomycete strain isolated from estuarine fish, Chanos chanos (Forskal, 1775).

PubMed

Sivakumar, K; Sahu, Maloy Kumar; Manivel, P R; Kannan, L

2006-03-01

Actinomycetes were isolated from skin, gills and gut contents of estuarine fish. Chanos chanos using Kuster's agar medium. Out of 20 strains tested, the strain LG-10 which was tentatively identified as Streptomyces rimosus showed L-glutaminase activity. Optimum production of L-glutaminase enzyme (17.51 IU/ml) was observed after 96 h of incubation at 27 degrees C, pH 9 and glucose and malt extract as carbon and nitrogen sources, respectively. The present study indicated scope for the use of S. rimosus as an ideal organism for the industrial production of extracellular L-glutaminase.

Applicability of Separation Potentials to Determining the Parameters of Cascade Efficiency in Enrichment of Ternary Mixtures

NASA Astrophysics Data System (ADS)

Palkin, V. A.; Igoshin, I. S.

2017-01-01

The separation potentials suggested by various researchers for separating multicomponent isotopic mixtures are considered. An estimation of their applicability to determining the parameters of the efficiency of enrichment of a ternary mixture in a cascade with an optimum scheme of connection of stages made up of elements with three takeoffs is carried out. The separation potential most precisely characterizing the separative power and other efficiency parameters of stages and cascade schemes has been selected based on the results of the estimation made.

Comparison of Xylo-oligosaccharides production by autohydrolysis of fibers separated from ground corn flour and DDGS

USDA-ARS?s Scientific Manuscript database

Xylo-oligosaccharides (XOS) are known to have beneficial health properties, and are considered to be functional food ingredients. The objective of this study is to compare corn fibers separated from ground corn flour and distillers dried grains with solubles (DDGS) for XOS yield and optimum authoyd...

A determination of the optimum time of year for remotely classifying marsh vegetation from LANDSAT multispectral scanner data. [Louisiana

NASA Technical Reports Server (NTRS)

Butera, M. K. (Principal Investigator)

1978-01-01

The author has identified the following significant results. A technique was used to determine the optimum time for classifying marsh vegetation from computer-processed LANDSAT MSS data. The technique depended on the analysis of data derived from supervised pattern recognition by maximum likelihood theory. A dispersion index, created by the ratio of separability among the class spectral means to variability within the classes, defined the optimum classification time. Data compared from seven LANDSAT passes acquired over the same area of Louisiana marsh indicated that June and September were optimum marsh mapping times to collectively classify Baccharis halimifolia, Spartina patens, Spartina alterniflora, Juncus roemericanus, and Distichlis spicata. The same technique was used to determine the optimum classification time for individual species. April appeared to be the best month to map Juncus roemericanus; May, Spartina alterniflora; June, Baccharis halimifolia; and September, Spartina patens and Distichlis spicata. This information is important, for instance, when a single species is recognized to indicate a particular environmental condition.

Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chong-Qing; Wang, Hui, E-mail: huiwang1968@163.com; Liu, You-Nian

Highlights: • Factors of NaOH treatment were studied by orthogonal and single factor experiments. • Mechanism of alkaline treatment for facilitating flotation was manifested. • Flotation separation of PET was achieved with high purity and efficiency. • A flow sheet of purification PET from MWP was designed. - Abstract: Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by froth flotation combined with alkalinemore » pretreatment was investigated for recycling industry. The effect of process variables was estimated by L{sub 9} (3{sup 4}) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10 wt% sodium hydroxide, 20 min and 70 °C. After alkaline pretreatment under optimum conditions, flotation separation PET from acrylonitrile–butadiene–styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of froth flotation and sink float separation was designed. This study facilitates industrial application of plastics flotation and provides technical insights into recycling of waste plastics.« less

Isotope separation by selective charge conversion and field deflection

DOEpatents

Hickman, Robert G.

1978-01-01

A deuterium-tritium separation system wherein a source beam comprised of positively ionized deuterium (D.sup.+) and tritium (T.sup.+) is converted at different charge-exchange cell sections of the system to negatively ionized deuterium (D.sup.-) and tritium (T.sup.-). First, energy is added to the beam to accelerate the D.sup.+ ions to the velocity that is optimum for conversion of the D.sup.+ ions to D.sup.- ions in a charge-exchange cell. The T.sup.+ ions are accelerated at the same time, but not to the optimum velocity since they are heavier than the D.sup.+ ions. The T.sup.+ ions are, therefore, not converted to T.sup.- ions when the D.sup.+ ions are converted to D.sup.- ions. This enables effective separation of the beam by deflection of the isotopes with an electrostatic field, the D.sup.- ions being deflected in one direction and the T.sup.+ ions being deflected in the opposite direction. Next, more energy is added to the deflected beam of T.sup.+ ions to bring the T.sup.+ ions to the optimum velocity for their conversion to T.sup.- ions. In a particular use of the invention, the beams of D.sup.- and T.sup.- ions are separately further accelerated and then converted to energetic neutral particles for injection as fuel into a thermonuclear reactor. The reactor exhaust of D.sup.+ and T.sup.+ and the D.sup.+ and T.sup.+ that was not converted in the respective sections is combined with the source beam and recycled through the system to increase the efficiency of the system.

Solid-substrate bioprocessing of cow dung for the production of carboxymethyl cellulase by Bacillus halodurans IND18.

PubMed

Vijayaraghavan, P; Prakash Vincent, S G; Dhillon, G S

2016-02-01

The production of carboxymethyl cellulase (CMCase) by Bacillus halodurans IND18 under solid substrate fermentation (SSF) using cow dung was optimized through two level full factorial design and second order response surface methodology (RSM). The central composite design (CCD) was employed to optimize the vital fermentation parameters, such as pH of the substrate, concentration of nitrogen source (peptone) and ion (sodium dihydrogen phosphate) sources in medium for achieving higher enzyme production. The optimum medium composition was found to be 1.46% (w/w) peptone, 0.095% (w/w) sodium dihydrogen phosphate and pH 8.0. The model prediction of 4210IU/g enzyme activity at optimum conditions was verified experimentally as 4140IU/g. The enzyme was active over a broad temperature range (40-60±1°C) and pH (7.0-9.0) with maximal activity at 60±1°C and pH 8.0. This study demonstrated the potential of cow dung as novel substrate for CMCase production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Optimum Waveforms for Differential Ion Mobility Spectrometry (FAIMS)

PubMed Central

Shvartsburg, Alexandre A.; Smith, Richard D.

2009-01-01

Differential mobility spectrometry or field asymmetric waveform ion mobility spectrometry (FAIMS) is a new tool for separation and identification of gas-phase ions, particularly in conjunction with mass-spectrometry. In FAIMS, ions are filtered by the difference between mobilities in gases (K) at high and low electric field intensity (E) using asymmetric waveforms. An infinite number of possible waveform profiles make maximizing the performance within engineering constraints a major issue for FAIMS technology refinement. Earlier optimizations assumed the non-constant component of mobility to scale as E2, producing the same result for all ions. Here we show that the optimum profiles are defined by the full series expansion of K(E) that includes terms beyond the 1st that is proportional to E2. For many ion/gas pairs, the first two terms have different signs, and the optimum profiles at sufficiently high E in FAIMS may differ substantially from those previously reported, improving the resolving power by up to 2.2 times. This situation arises for some ions in all FAIMS systems, but becomes more common in recent miniaturized devices that employ higher E. With realistic K(E) dependences, the maximum waveform amplitude is not necessarily optimum and reducing it by up to ∼20 – 30% is beneficial in some cases. The present findings are particularly relevant to targeted analyses where separation depends on the difference between K(E) functions for specific ions. PMID:18585054

Electrochemical Oxidation of Resorcinol in Aqueous Medium Using Boron-Doped Diamond Anode: Reaction Kinetics and Process Optimization with Response Surface Methodology

PubMed Central

Körbahti, Bahadır K.; Demirbüken, Pelin

2017-01-01

Electrochemical oxidation of resorcinol in aqueous medium using boron-doped diamond anode (BDD) was investigated in a batch electrochemical reactor in the presence of Na2SO4 supporting electrolyte. The effect of process parameters such as resorcinol concentration (100–500 g/L), current density (2–10 mA/cm2), Na2SO4 concentration (0–20 g/L), and reaction temperature (25–45°C) was analyzed on electrochemical oxidation using response surface methodology (RSM). The optimum operating conditions were determined as 300 mg/L resorcinol concentration, 8 mA/cm2 current density, 12 g/L Na2SO4 concentration, and 34°C reaction temperature. One hundred percent of resorcinol removal and 89% COD removal were obtained in 120 min reaction time at response surface optimized conditions. These results confirmed that the electrochemical mineralization of resorcinol was successfully accomplished using BDD anode depending on the process conditions, however the formation of intermediates and by-products were further oxidized at much lower rate. The reaction kinetics were evaluated at optimum conditions and the reaction order of electrochemical oxidation of resorcinol in aqueous medium using BDD anode was determined as 1 based on COD concentration with the activation energy of 5.32 kJ/mol that was supported a diffusion-controlled reaction. PMID:29082225

Single Cell Protein Production by Saccharomyces cerevisiae Using an Optimized Culture Medium Composition in a Batch Submerged Bioprocess.

PubMed

Hezarjaribi, Mehrnoosh; Ardestani, Fatemeh; Ghorbani, Hamid Reza

2016-08-01

Saccharomyces cerevisiae PTCC5269 growth was evaluated to specify an optimum culture medium to reach the highest protein production. Experiment design was conducted using a fraction of the full factorial methodology, and signal to noise ratio was used for results analysis. Maximum cell of 8.84 log (CFU/mL) was resulted using optimized culture composed of 0.3, 0.15, 1, and 50 g L(-1) of ammonium sulfate, iron sulfate, glycine, and glucose, respectively at 300 rpm and 35 °C. Glycine concentration (39.32 % contribution) and glucose concentration (36.15 % contribution) were determined as the most effective factors on the biomass production, while Saccharomyces cerevisiae growth had showed the least dependence on ammonium sulfate (5.2 % contribution) and iron sulfate (19.28 % contribution). The most interaction was diagnosed between ammonium sulfate and iron sulfate concentrations with interaction severity index of 50.71 %, while the less one recorded for glycine and glucose concentration was equal to 8.12 %. An acceptable consistency of 84.26 % was obtained between optimum theoretical cell numbers determined by software of 8.91 log (CFU/mL), and experimentally measured one at optimal condition confirms the suitability of the applied method. High protein content of 44.6 % using optimum culture suggests that Saccharomyces cerevisiae is a good commercial case for single cell protein production.

Development and validation spectroscopic methods for the determination of lomefloxacin in bulk and pharmaceutical formulations

NASA Astrophysics Data System (ADS)

El-Didamony, A. M.; Hafeez, S. M.

2016-01-01

Four simple, sensitive spectrophotometric and spectrofluorimetric methods (A-D) for the determination of antibacterial drug lomefloxacin (LMFX) in pharmaceutical formulations have been developed. Method A is based on formation of ternary complex between Pd(II), eosin and LMFX in the presence of methyl cellulose as surfactant and acetate-HCl buffer pH 4.0. Spectrophotometrically, under the optimum conditions, the ternary complex showed absorption maximum at 530 nm. Methods B and C are based on redox reaction between LMFX and KMnO4 in acid and alkaline media. In indirect spectrophotometry method B the drug solution is treated with a known excess of KMnO4 in H2SO4 medium and subsequent determination of unreacted oxidant by reacting it with safronine O in the same medium at λmax = 520 nm. Direct spectrophotometry method C involves treating the alkaline solution of LMFX with KMnO4 and measuring the bluish green product at 604 nm. Method D is based on the chelation of LMFX with Zr(IV) to produce fluorescent chelate. At the optimum reaction conditions, the drug-metal chelate showed excitation maxima at 280 nm and emission maxima at 443 nm. The optimum experimental parameters for the reactions have been studied. The validity of the described procedures was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed methods were successfully applied for the determination of the selected drug in pharmaceutical preparations with good recoveries.

Lubrication and thermal characteristics of mechanical seal with porous surface based on cavitation

NASA Astrophysics Data System (ADS)

Huilong, Chen; Muzi, Zuo; Tong, Liu; Yu, Wang; Cheng, Xu; Qiangbo, Wu

2014-04-01

The theory model of mechanical seals with laser-textured porous surface (LST-MS) was established. The liquid film of LST-MS was simulated by the Fluent software, using full cavitation model and non-cavitation model separately. Dynamic mesh technique and relationship between viscosity and temperature were applied to simulate the internal flow field and heat characteristics of LST-MS, based on the more accurate cavitation model. Influence of porous depth ratio porous diameter ɛ and porous density SP on lubrication performance and the variation of lubrication and thermal properties with shaft speed and sealing pressure were analyzed. The results indicate that the strongest hydrodynamic pressure effect and the biggest thickness of liquid film are obtained when ɛ and SP are respectively about 0.025 and 0.5 which were thought to be the optimum value. The frictional heat leads to the increase of liquid film temperature and the decrease of medium viscosity with the shaft speed increasing. The hydrodynamic pressure effect increases as shaft speed increasing, however it decreases as the impact of frictional heat.

High intensity high charge state ion beam production with an evaporative cooling magnet ECRIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, W., E-mail: luwang@impcas.ac.cn; Qian, C.; Sun, L. T.

2016-02-15

LECR4 (Lanzhou ECR ion source No. 4) is a room temperature electron cyclotron resonance ion source, designed to produce high current, high charge state ion beams for the SSC-LINAC injector (a new injector for sector separated cyclotron) at the Institute of Modern Physics. LECR4 also serves as a PoP machine for the application of evaporative cooling technology in accelerator field. To achieve those goals, LECR4 ECR ion source has been optimized for the operation at 18 GHz. During 2014, LECR4 ion source was commissioned at 18 GHz microwave of 1.6 kW. To further study the influence of injection stage tomore » the production of medium and high charge state ion beams, in March 2015, the injection stage with pumping system was installed, and some optimum results were produced, such as 560 eμA of O{sup 7+}, 620 eμA of Ar{sup 11+}, 430 eμA of Ar{sup 12+}, 430 eμA of Xe{sup 20+}, and so on. The comparison will be discussed in the paper.« less

Monitored separation device

NASA Technical Reports Server (NTRS)

Fox, George Edward (Inventor); Jackson, George William (Inventor); Willson, Richard Coale (Inventor)

2011-01-01

A device for separating and purifying useful quantities of particles comprises: a. an anolyte reservoir connected to an anode, the anolyte reservoir containing an electrophoresis buffer; b. a catholyte reservoir connected to a cathode, the catholyte reservoir also containing the electrophoresis buffer; c. a power supply connected to the anode and to the cathode; d. a column having a first end inserted into the anolyte reservoir, a second end inserted into the catholyte reservoir, and containing a separation medium; e. a light source; f. a first optical fiber having a first fiber end inserted into the separation medium, and having a second fiber end connected to the light source; g. a photo detector; h. a second optical fiber having a third fiber end inserted into the separation medium, and having a fourth fiber end connected to the photo detector; and i. an ion-exchange membrane in the anolyte reservoir.

Method for Monitored Separation and Collection of Biological Materials

NASA Technical Reports Server (NTRS)

Fox, George Edward (Inventor); Jackson, George William (Inventor); Willson, Richard Coale (Inventor)

2014-01-01

A device for separating and purifying useful quantities of particles comprises: (a) an anolyte reservoir connected to an anode, the anolyte reservoir containing an electrophoresis buffer; (b) a catholyte reservoir connected to a cathode, the catholyte reservoir also containing the electrophoresis buffer; (c) a power supply connected to the anode and to the cathode; (d) a column having a first end inserted into the anolyte reservoir, a second end inserted into the catholyte reservoir, and containing a separation medium; (e) a light source; (f) a first optical fiber having a first fiber end inserted into the separation medium, and having a second fiber end connected to the light source; (g) a photo detector; (h) a second optical fiber having a third fiber end inserted into the separation medium, and having a fourth fiber end connected to the photo detector; and (i) an ion-exchange membrane in the anolyte reservoir.

Optimization of a natural medium for cellulase by a marine Aspergillus niger using response surface methodology.

PubMed

Xue, Dong-Sheng; Chen, Hui-Yin; Lin, Dong-Qiang; Guan, Yi-Xin; Yao, Shan-Jing

2012-08-01

The components of a natural medium were optimized to produce cellulase from a marine Aspergillus niger under solid state fermentation conditions by response surface methodology. Eichhornia crassipes and natural seawater were used as a major substrate and a source of mineral salts, respectively. Mineral salts of natural seawater could increase cellulase production. Raw corn cob and raw rice straw showed a significant positive effect on cellulase production. The optimum natural medium consisted of 76.9 % E. crassipes (w/w), 8.9 % raw corn cob (w/w), 3.5 % raw rice straw (w/w), 10.7 % raw wheat bran (w/w), and natural seawater (2.33 times the weight of the dry substrates). Incubation for 96 h in the natural medium increased the biomass to the maximum. The cellulase production was 17.80 U/g the dry weight of substrates after incubation for 144 h. The natural medium avoided supplying chemicals and pretreating substrates. It is promising for future practical fermentation of environment-friendly producing cellulase.

Improvement of Aconitum napellus micropropagation by liquid culture on floating membrane rafts.

PubMed

Watad, A A; Kochba, M; Nissim, A; Gaba, V

1995-03-01

An efficient method was developed using floating membrane rafts (Liferaft(™)) for the micropropagation of Aconitum napellus (Ranunculaceae), a cut flower crop with a low natural propagation rate. This was achieved by introducing shoot tips into culture on Murashige and Skoog's (1962) solid medium, or liquid medium-supported rafts, supplemented by different levels of benzyl adenine (BA). Optimum shoot proliferation on solid medium required 4mg/l BA, whereas for expiants supported on rafts optimal proliferation was achieved at 0.25mg/l BA. Maximum shoot proliferation was found using the floating rafts (propagation ratio of 4.2 per month), 45% higher than the maximum value on solid medium. A similar value could be obtained on solid medium after a period of 2 months. The optimal response to BA was similar for fresh weight gain and shoot length. Growth in a shallow layer of liquid in shake flasks gives a similar shoot multiplication rate to that on floating rafts; however, submerged leaves brown and die.

A serum-free medium for colony growth and hyaluronic acid production by Streptococcus zooepidemicus NJUST01.

PubMed

Zhang, Jianfa; Ding, Xia; Yang, Liuyan; Kong, Zhiming

2006-08-01

A hyaluronic acid (HA)-producing strain, Streptococcus zooepidemicus NJUST01, can grow in a serum-free agar medium, with starch as exclusive carbon source, but not glucose, sucrose, dextrine, xylose, or lactose. In this starch medium, the strain NJUST01 reproduced successively at 37 degrees C for 60 generations, with no obvious variation on morphology and physiology, but colonies of the strain after 60th generation could not produce a clear hemolytic zone on sheep blood agar plates. Hyaluronic acid production by the strain NJUST01 was analyzed relative to the starch medium. Employing a multifactor cross experiment, an optimum medium revealed for hyaluronic acid production was composed of 5% starch, 0.3% glucose, 0.5% peptone, 0.15% MgSO4, and 2.0% K2HPO4. The amount of HA 6.7 g/l was obtained in batch fermentation on a rotary shaker at 37 degrees C, 220 rpm for 36 h.

Medium-chain fatty acid synthesis in lactating-rabbit mammary gland. Intracellular concentration and specificity of medium-chain acyl thioester hydrolase.

PubMed Central

Knudsen, J

1979-01-01

The concentration of medium-chain acyl thioester hydrolase and of fatty acid synthetase was determined by rocket immunoelectrophoresis in nine different particle-free supernatant fractions from lactating-rabbit mammary gland. The molar ratio of the hydrolase to fatty acid synthetase was 1.99 +/- 0.66 (mean +/- S.D.). A rate-limiting concentration of malonyl-CoA was required to ensure the predominant synthesis of medium-chain fatty acids when 2 mol of the hydrolase was added per mol of fatty acid synthetase. The interaction of the hydrolase with fatty acid synthetase was concentration-dependent, though an optimum concentration of hydrolase to synthetase could not be obtained. The lactating-rabbit mammary gland hydrolase altered the pattern of fatty acids synthesized by fatty acid synthetases prepared from cow, goat, sheep and rabbit lactating mammary glands, rabbit liver and cow adipose tissue. PMID:574008

Biofiltration of methanol in an organic biofilter using peanut shells as medium.

PubMed

Ramirez-Lopez, E M; Corona-Hernandez, J; Avelar-Gonzalez, F J; Omil, F; Thalasso, F

2010-01-01

Biofiltration consists of a filter-bed of organic matter serving both as carrier for the active biomass and as nutrient supply, through which the polluted gas passes. The selection of a suitable medium material is of major importance to ensure optimum biofilter efficiency. Peanut shells are an agricultural byproduct locally available in large quantities at a low price in most tropical and sub-tropical countries. A previous study showed that peanut shells are physically and chemically suitable for biofiltration. This paper presents the results obtained during a six month biofiltration experiment using peanut shells as medium and methanol as air pollutant. It is shown that peanut shells are potentially suitable as biofiltration medium, since degradation rates of up to 30 kg MeOH/m(3)d with an empty bed residence time of 19s was obtained. The biofilter showed a good resistance to shock load and no operational problems were observed.

Evaluation of the effect of antiarthritic drugs on the secretion of proteoglycans by lapine chondrocytes using a novel assay procedure.

PubMed Central

Collier, S; Ghosh, P

1989-01-01

A new method is described for separating free 35SO4-- from 35SO4 labelled proteoglycans synthesised by rabbit articular chondrocytes cultured in the presence of excess 35SO4--. The procedure uses the low solubility product of barium sulphate to remove, by precipitation, free 35SO4-- from culture medium. Optimum recovery of 35SO4 labelled proteoglycans was achieved after papain digestion to release 35SO4-glycosaminoglycans, and addition of chondroitin sulphate before the precipitation step. Using this assay, we studied the effect of six drugs-indomethacin, diclofenac, sodium pentosan polysulphate, glycosaminoglycan polysulphate ester, tiaprofenic acid, and ketoprofen-on the secretion into the medium of labelled proteoglycans by lapine chondrocytes. The six drugs were tested at 0.1, 1, 10, 50, and 100 micrograms/ml over four consecutive 48 hour culture periods. A consistent concentration-response pattern was found for the four non-steroidal anti-inflammatory drugs (NSAIDs) studied. Generally they inhibited proteoglycan secretion at 50 and 100 micrograms/ml but had no effect at lower concentrations. Inhibition of secretion was strongest with indomethacin and diclofenac at 50 and 100 micrograms/ml. In contrast with the NSAIDs studied, the two sulphated polysaccharides (sodium pentosan polysulphate and glycosaminoglycan polysulphate ester) at low concentrations increased proteoglycan secretion by chondrocytes, with maximal stimulation occurring at 1 microgram/ml. Sodium pentosan polysulphate, but not glycosaminoglycan polysulphate ester, showed inhibitory activity at 50 and 100 micrograms/ml. PMID:2471470

Copolymers For Capillary Gel Electrophoresis

DOEpatents

Liu, Changsheng; Li, Qingbo

2005-08-09

This invention relates to an electrophoresis separation medium having a gel matrix of at least one random, linear copolymer comprising a primary comonomer and at least one secondary comonomer, wherein the comonomers are randomly distributed along the copolymer chain. The primary comonomer is an acrylamide or an acrylamide derivative that provides the primary physical, chemical, and sieving properties of the gel matrix. The at least one secondary comonomer imparts an inherent physical, chemical, or sieving property to the copolymer chain. The primary and secondary comonomers are present in a ratio sufficient to induce desired properties that optimize electrophoresis performance. The invention also relates to a method of separating a mixture of biological molecules using this gel matrix, a method of preparing the novel electrophoresis separation medium, and a capillary tube filled with the electrophoresis separation medium.

Exo-polygalacturonase production by Bacillus subtilis CM5 in solid state fermentation using cassava bagasse

PubMed Central

Swain, Manas R.; Kar, Shaktimay; Ray, Ramesh C.

2009-01-01

The purpose of this investigation was to study the effect of Bacillus subtilis CM5 in solid state fermentation using cassava bagasse for production of exo-polygalacturonase (exo-PG). Response surface methodology was used to evaluate the effect of four main variables, i.e. incubation period, initial medium pH, moisture holding capacity (MHC) and incubation temperature on enzyme production. A full factorial Central Composite Design was applied to study these main factors that affected exo-PG production. The experimental results showed that the optimum incubation period, pH, MHC and temperature were 6 days, 7.0, 70% and 50°C, respectively for optimum exo-PG production. PMID:24031409

Bioleaching of heavy metals from sewage sludge using Acidithiobacillus thiooxidans

NASA Astrophysics Data System (ADS)

Wen, Ye-Ming; Lin, Hong-Yan; Wang, Qing-Ping; Chen, Zu-Liang

2010-11-01

Acidithiobacillus thiooxidans was isolated from sewage sludge using the incubation in the Waksman liquor medium and the inoculation in Waksman solid plate. It was found that the optimum conditions of the bioleaching included solid concentration 2%, sulfur concentration 5 gṡL-1 and cell concentration 10%. The removal efficiency of Cr, Cu, Pb and Zh in sewage sludge, which was obtained from waste treatment plant, Jinshan, Fuzhou, was 43.65%, 96.24%, 41.61% and 96.50% in the period of 4˜10 days under the optimum conditions, respectively. After processing using the proposed techniques, the heavy metals in sewage sludge did meet the requirement the standards of nation.

STUDIES ON THE DEVELOPMENT OF MOUSE EMBRYOS IN VITRO

PubMed Central

BRINSTER, RALPH L.

2016-01-01

Summary The interactions of a number of possible energy sources for in-vitro development of 2-cell mouse ova were examined using statistical experimental designs. These experiments indicated that glucose has no beneficial effect on development when employed with the optimum concentration of pyruvate. Optimum concentrations of pyruvate and oxaloacetate when employed together resulted in a significantly lower response than when either compound was employed alone. It was found that the best medium for the development of 2-cell mouse ova into blastocysts contained 2·5 to 5·0 × 10−4 M-pyruvate + 2·5 to 5·0 × 10−2 M-lactate. PMID:5836270

Experimental realization of spatially separated entanglement with continuous variables using laser pulse trains

PubMed Central

Zhang, Yun; Okubo, Ryuhi; Hirano, Mayumi; Eto, Yujiro; Hirano, Takuya

2015-01-01

Spatially separated entanglement is demonstrated by interfering two high-repetition squeezed pulse trains. The entanglement correlation of the quadrature amplitudes between individual pulses is interrogated. It is characterized in terms of the sufficient inseparability criterion with an optimum result of in the frequency domain and in the time domain. The quantum correlation is also observed when the two measurement stations are separated by a physical distance of 4.5 m, which is sufficiently large to demonstrate the space-like separation, after accounting for the measurement time. PMID:26278478

Separation of the stereoisomers of the main metabolite of a non-steroidal anti-inflammatory drug, flobufen, by chiral high-performance liquid chromatography.

PubMed

Wsól, V; Fell, A F; Kvasnicková, E; Hais, I M

1997-02-07

The major metabolite of a novel non-steroidal anti-inflammatory drug, DL-4-(2',4'-difluorobiphenyl-4-yl)-2-oxo-2-methylbutanoic acid (flobufen, I), namely 4-(2',4'-difluorobiphenyl-4-yl)-2-methyl-gamma-butyrolactone (4-dihydroflobufen lactone, III), has four stereoisomers consisting of two racemic pairs of enantiomers. Of three chiral stationary phases tested, Cyclobond I beta-RSP (Astec) (beta-cylodextrin derivatized with R,S-hydroxypropyl) was best able to separate the (+2)(--) racemate, with a liquid phase containing acetonitrile as modifier and triethylamine acetate as buffer. Using the Box-Wilson Central Composite Design for three factors, an optimum combination of pH and concentrations of the modifier and buffer was eventually obtained. A chromatographic response function based on a combination of the Kaiser peak separation function, Pi, and retention time of the second eluting enantiomer, tRL, served as a response criterion for the process of optimization. The optimum conditions developed for the (+2)(--) racemate were also found to be suitable for separating the (+-)(-+) racemate, for which earlier studies had shown the separation to be more facile. Separation of the four stereoisomers of III, for which the chiral chromatographic system optimized in this study is proposed as the second stage, is targeted at a biochemical study of the stereoisomeric metabolism of I.

Environmental friendly crush-magnetic separation technology for recycling metal-plated plastics from end-of-life vehicles.

PubMed

Xue, Mianqiang; Li, Jia; Xu, Zhenming

2012-03-06

Metal-plated plastics (MPP), which are important from the standpoint of aesthetics or even performance, are increasingly employed in a wide variety of situations in the automotive industry. Serious environmental problems will be caused if they are not treated appropriately. Therefore, recycling of MPP is an important subject not only for resource recycling but also for environmental protection. This work represents a novel attempt to deal with the MPP. A self-designed hammer crusher was used to liberate coatings from the plastic substrate. The size distribution of particles was analyzed and described by the Rosin-Rammler function model. The optimum retaining time of materials in the crusher is 3 min. By this time, the liberation rate of the materials can reach 87.3%. When the density of the suspension is 31,250 g/m(3), the performance of liberation is the best. Two-step magnetic separation was adopted to avoid excessive crushing and to guarantee the quality of products. Concerning both the separation efficiency and grade of products, the optimum rotational speed of the magnetic separator is 50-70 rpm. On the basis of the above studies about the liberating and separating behavior of the materials, a continuous recycling system (the technology of crush-magnetic separation) is developed. This recycling system provides a feasible method for recycling MPP efficiently, economically, and environmentally.

Biosurfactant production by Bacillus subtilis using corn steep liquor as culture medium

PubMed Central

Gudiña, Eduardo J.; Fernandes, Elisabete C.; Rodrigues, Ana I.; Teixeira, José A.; Rodrigues, Lígia R.

2015-01-01

In this work, biosurfactant production by Bacillus subtilis #573 was evaluated using corn steep liquor (CSL) as culture medium. The best results were obtained in a culture medium consisting of 10% (v/v) of CSL, with a biosurfactant production of about 1.3 g/l. To the best of our knowledge, this is the first report describing biosurfactant production by B. subtilis using CSL as culture medium. Subsequently, the effect of different metals (iron, manganese, and magnesium) on biosurfactant production was evaluated using the medium CSL 10%. It was found that for all the metals tested, the biosurfactant production was increased (up to 4.1, 4.4, and 3.5 g/l for iron, manganese, and magnesium, respectively). When the culture medium was supplemented with the optimum concentration of the three metals simultaneously, the biosurfactant production was increased up to 4.8 g/l. Furthermore, the biosurfactant exhibited a good performance in oil recovery assays when compared with chemical surfactants, which suggests its possible application in microbial enhanced oil recovery or bioremediation. PMID:25705209

Optimization Recovery of Yttrium Oxide in Precipitation, Extraction, and Stripping Process

NASA Astrophysics Data System (ADS)

Perwira, N. I.; Basuki, K. T.; Biyantoro, D.; Effendy, N.

2018-04-01

Yttrium oxide can be used as a dopant control rod of nuclear reactors in YSH material and superconductors. Yttrium oxide is obtained in the Xenotime mineral derived from byproduct of tin mining PT Timah Bangka which contain rare earth elements (REE) dominant Y, Dy, and Gd whose content respectively about 29.53%, 7.76%, and 2.58%. Both usage in the field of nuclear and non-nuclear science and technology is need to pure from the impurities. The presence of impurities in the yttrium oxide may affect the characteristic of the material and the efficiency of its use. Thus it needs to be separated by precipitation and extraction-stripping and calcination in the making of the oxide. However, to obtain higher levels of Yttrium oxide, it is necessary to determine the optimum conditions for its separation. The purpose of this research was to determine the optimum pH of precipitation, determine acid media and concentration optimum in extraction and stripping process and determine the efficiency of the separation of Y from REE concentrate. This research was conducted with pH variation in the precipitation process that pHs were 4 - 8, the difference of acid media for the extraction process, i.e., HNO3, HCl and H2SO4 with each concentration of 0,5 M; 1 M; 1,5 M; and 2 M and for stripping process were HNO3, HCl, and H2SO4 with each concentration of 1 M; 2M; and 3 M. Based on the result, the optimum pH of precipitation process was 6,5, the optimumacid media was HNO3 0,5 M, and for stripping process media was HNO3 3 M. The efficiency of precipitation process at pH 6,5 was 69,53 %, extraction process was 96.39% and stripping process was 4,50%. The separation process from precipitation to extraction had increased the purity and the highest efficiency recovery of Y was in the extraction process and obtained Y2O3 purer compared to the feed with the Y2O3 content of 92.87%.

An experimental strategy validated to design cost-effective culture media based on response surface methodology.

PubMed

Navarrete-Bolaños, J L; Téllez-Martínez, M G; Miranda-López, R; Jiménez-Islas, H

2017-07-03

For any fermentation process, the production cost depends on several factors, such as the genetics of the microorganism, the process condition, and the culture medium composition. In this work, a guideline for the design of cost-efficient culture media using a sequential approach based on response surface methodology is described. The procedure was applied to analyze and optimize a culture medium of registered trademark and a base culture medium obtained as a result of the screening analysis from different culture media used to grow the same strain according to the literature. During the experiments, the procedure quantitatively identified an appropriate array of micronutrients to obtain a significant yield and find a minimum number of culture medium ingredients without limiting the process efficiency. The resultant culture medium showed an efficiency that compares favorably with the registered trademark medium at a 95% lower cost as well as reduced the number of ingredients in the base culture medium by 60% without limiting the process efficiency. These results demonstrated that, aside from satisfying the qualitative requirements, an optimum quantity of each constituent is needed to obtain a cost-effective culture medium. Study process variables for optimized culture medium and scaling-up production for the optimal values are desirable.

Dispersive liquid-liquid microextraction of quinolones in porcine blood: Optimization of extraction procedure and CE separation using experimental design.

PubMed

Vera-Candioti, Luciana; Teglia, Carla M; Cámara, María S

2016-10-01

A dispersive liquid-liquid microextraction procedure was developed to extract nine fluoroquinolones in porcine blood, six of which were quantified using a univariate calibration method. Extraction parameters including type and volume of extraction and dispersive solvent and pH, were optimized using a full factorial and a central composite designs. The optimum extraction parameters were a mixture of 250 μL dichloromethane (extract solvent) and 1250 μL ACN (dispersive solvent) in 500 μL of porcine blood reached to pH 6.80. After shaking and centrifugation, the upper phase was transferred in a glass tube and evaporated under N 2 steam. The residue was resuspended into 50 μL of water-ACN (70:30, v/v) and determined by CE method with DAD, under optimum separation conditions. Consequently, a tenfold enrichment factor can potentially be reached with the pretreatment, taking into account the relationship between initial sample volume and final extract volume. Optimum separation conditions were as follows: BGE solution containing equal amounts of sodium borate (Na 2 B 4 O 7 ) and di-sodium hydrogen phosphate (Na 2 HPO 4 ) with a final concentration of 23 mmol/L containing 0.2% of poly (diallyldimethylammonium chloride) and adjusted to pH 7.80. Separation was performed applying a negative potential of 25 kV, the cartridge was maintained at 25.0°C and the electropherograms were recorded at 275 nm during 4 min. The hydrodynamic injection was performed in the cathode by applying a pressure of 50 mbar for 10 s. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lipolysis of natural long chain and synthetic medium chain galactolipids by pancreatic lipase-related protein 2.

PubMed

Amara, Sawsan; Barouh, Nathalie; Lecomte, Jérôme; Lafont, Dominique; Robert, Sylvie; Villeneuve, Pierre; De Caro, Alain; Carrière, Frédéric

2010-04-01

Monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) are the most abundant lipids in nature, mainly as important components of plant leaves and chloroplast membranes. Pancreatic lipase-related protein 2 (PLRP2) was previously found to express galactolipase activity, and it is assumed to be the main enzyme involved in the digestion of these common vegetable lipids in the gastrointestinal tract. Most of the previous in vitro studies were however performed with medium chain synthetic galactolipids as substrates. It was shown here that recombinant guinea pig (Cavia porcellus) as well as human PLRP2 hydrolyzed at high rates natural DGDG and MGDG extracted from spinach leaves. Their specific activities were estimated by combining the pH-stat technique, thin layer chromatography coupled to scanning densitometry and gas chromatography. The optimum assay conditions for hydrolysis of these natural long chain galactolipids were investigated and the optimum bile salt to substrate ratio was found to be different from that established with synthetic medium chains MGDG and DGDG. Nevertheless the length of acyl chains and the nature of the galactosyl polar head of the galactolipid did not have major effects on the specific activities of PLRP2, which were found to be very high on both medium chain [1786+/-100 to 5420+/-85U/mg] and long chain [1756+/-208 to 4167+/-167U/mg] galactolipids. Fatty acid composition analysis of natural MGDG, DGDG and their lipolysis products revealed that PLRP2 only hydrolyzed one ester bond at the sn-1 position of galactolipids. PLRP2 might be used to produce lipid and free fatty acid fractions enriched in either 16:3 n-3 or 18:3 n-3 fatty acids, both found at high levels in galactolipids. 2010 Elsevier B.V. All rights reserved.

Use of RSM for the multivariate, simultaneous multiobjective optimization of the operating conditions of aliphatic carboxylic acids ion-exclusion chromatography column: Quantitative study of hydrodynamic, isotherm, and thermodynamic behavior.

PubMed

Shojaeimehr, Tahereh; Rahimpour, Farshad; Schwarze, Michael; Repke, Jens-Uwe; Godini, Hamid Reza; Wozny, Günter

2018-04-15

The present study evaluates the capability of ion exclusion chromatography (IEC) of short chain aliphatic carboxylic acids using a cation exchange column (8% sulfonated cross-linked styrene-divinylbenzene copolymer) in different experimental conditions. Since one of the prerequisites to the development of an efficient carboxylic acid separation process is to obtain the optimum operational conditions, response surface methodology (RSM) was used to develop an approach to evaluate carboxylic acids separation process in IEC columns. The effect of the operating conditions such as column temperature, sulfuric acid concentration as the mobile phase, and the flow rate was studied using Central Composite Face (CCF) design. The optimum operating conditions for the separate injection of lactic acid and acetic acid is temperature of 75 °C, sulfuric acid concentration of 0.003 N for both acids and flow rate of 0.916 (0.886) mL/min for acetic acid (lactic acid). Likewise, the optimum conditions for the simultaneous injection of acetic and lactic acid mixture are the column temperature of 68 °C, sulfuric acid concentration of 0.0003 N, and flow rate of 0.777 mL/min. In the next step, the adsorption equilibria of acetic acid and lactic acid on the stationary phase were investigated through a series of Frontal Analysis (FA), Frontal Analysis by Characteristic Points (FACP), and using Langmuir isotherm model. The results showed an excellent agreement between the model and experimental data. Finally, the results of thermodynamic studies proved that the IEC process for separation of acetic and lactic acid is a spontaneous, feasible, exothermic, and random process with a physical adsorption mechanism. The results of the current paper can be a valuable information in the stages of designing IEC columns for separation of aliphatic carboxylic acids. Copyright © 2018 Elsevier B.V. All rights reserved.

Separating biological cells

NASA Technical Reports Server (NTRS)

Brooks, D. E.

1979-01-01

Technique utilizing electric field to promote biological cell separation from suspending medium in zero gravity increases speed, reduces sedimentation, and improves efficiency of separation in normal gravity.

[The relationship of the saturation density of multilayer cell cultures to their mass exchange with the medium].

PubMed

Akatov, V S; Lavrovskaia, V P

1991-01-01

Chinese hamster fibroblasts (CHF) and NIH 3T3 cells were cultured on a glass substrate at different distances from the porous membrane separating the cells from the perfusing medium. It is shown that with perfusion of medium above the membrane there is no movement of the medium near the cells. In both the types of culture, the cells grow in multilayers, however the multilayer character of growth in CHF is more pronounced than in NIH 3T3 cells. The saturation density of the cultures depends on the cell-membrane separation, and at separations of no more than 0.2 mm exceeds the saturation density in the monolayer by 8-10 fold. The dependences of the saturation density on separation are different for CHE and NIH 3T3 cells, indicating qualitative differences in the inhibition of cell growth in monolayers between these cultures. The results obtained indicate that the inhibition of cell growth in monolayer is due to mass exchange limitations, rather than to intercellular contact interactions.

Electrophoretic separator for purifying biologicals

NASA Technical Reports Server (NTRS)

1976-01-01

This technique separates a single narrow zone of sample mixture in an electrolyte medium into many zones containing a single component of the mixture and electrolyte between them. Since the densities of the separated zones generally differ from that of the intervening medium, such systems are gravitationally unstable and stabilization is required. The various techniques for stabilization include using the capillary space provided by thin films, the interstices of solid material such as filter paper and a variety of gel-forming substances.

Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

DOEpatents

Golden, Jeffry

2007-02-13

A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacts a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

DOEpatents

Mincher, Bruce J.; Curry, Randy Dale; Clevenger, Thomas E.; Golden, Jeffry

2003-05-27

A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacts a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

DOEpatents

Mincher, Bruce J.; Curry, Randy Dale; Clevenger, Thomas E.; Golden, Jeffry

2000-01-01

A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacting a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

Recycling of rare earth particle by mini-hydrocyclones.

PubMed

Yu, Jian-Feng; Fu, Jian; Cheng, Hao; Cui, Zhengwei

2017-03-01

Mini-hydrocyclones were applied to separate the fine rare earth particles from the suspensions. The effects of the flow rate, split ratio, and feed concentration on the total separation efficiency and grade separation efficiency were studied. The combined effects of the flow rate (1200-1600L/h), split ratio (20-60%) and concentration (0.6-1.0wt%) on the total separation efficiency in mini-hydrocyclones were investigated using a response surface methodology. The optimum operating parameters for a total separation efficiency of 92.5% were: feed flow rate=1406L/h, split ratio=20%, and feed concentration=1wt%. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of swabs and transport media for the recovery of Yersinia pestis.

PubMed

Gilbert, Sarah E; Rose, Laura J; Howard, Michele; Bradley, Meranda D; Shah, Sanjiv; Silvestri, Erin; Schaefer, Frank W; Noble-Wang, Judith

2014-01-01

The Government Accountability Office report investigating the surface sampling methods used during the 2001 mail contamination with Bacillus anthracis brought to light certain knowledge gaps that existed regarding environmental sampling with biothreat agents. Should a contamination event occur that involves non-spore forming biological select agents, such as Yersinia pestis, surface sample collection and processing protocols specific for these organisms will be needed. Two Y. pestis strains (virulent and avirulent), four swab types (polyester, macrofoam, rayon, and cotton), two pre-moistening solutions, six transport media, three temperatures, two levels of organic load, and four processing methods (vortexing, sonicating, combined sonicating and vortexing, no agitation) were evaluated to determine the conditions that would yield the highest percent of cultivable Y. pestis cells after storage. The optimum pre-moistening agent/transport media combination varied with the Y. pestis strain and swab type. Directly inoculated macrofoam swabs released the highest percent of cells into solution (93.9% recovered by culture) and rayon swabs were considered the second best swab option (77.0% recovered by culture). Storage at 4°C was found to be optimum for all storage times and transport media. In a worst case scenario, where the Y. pestis strain is not known and sample processing and analyses could not occur until 72h after sampling, macrofoam swabs pre-moistened with PBS supplemented with 0.05% Triton X-100 (PBSTX), stored at 4°C in neutralizing buffer (NB) as a transport medium (PBSTX/NB) or pre-moistened with NB and stored in PBSTX as a transport medium (NB/PBSTX), then vortexed 3min in the transport medium, performed significantly better than all other conditions for macrofoam swabs, regardless of strain tested (mean 12 - 72h recovery of 85.9-105.1%, p<0.001). In the same scenario, two combinations of pre-moistening medium/transport medium were found to be optimal for rayon swabs stored at 4°C (p<0.001), then sonicated 3min in the transport medium; PBSTX/PBSTX and NB/PBSTX (mean 12-72h recovery of 83.7-110.1%). © 2013.

Study of cultivation and growth rate kinetic for mixed cultures of local microalgae as third generation (G-3) bioethanol feedstock in thin layer photobioreactor

NASA Astrophysics Data System (ADS)

Prihastuti Yuarrina, Wahyu; Surya Pradana, Yano; Budiman, Arief; Majid, Akmal Irfan; Indarto; Agus Suyono, Eko

2018-05-01

The increasing use of fossil fuels causes the depletion in supply and contributes to climate change by GHG emissions into the atmosphere. Microalgae indicate as renewable and sustainable energy sources as they have a high potential for producing large amounts of biomass for third-generation biofuels (bioethanol and biodiesel) feedstock. However, there are several parameters which should be considered for microalgae cultivation, such as environmental conditions, medium composition and microalgae species. The aim of this research was to study cultivation of mixed microalgae cultures (Glagah consortium and Arthrospira maxima) in a thin layer photobioreactor. Farmpion medium, Bold’s Basal Medium (BBM) and Thoriq Eko Arief (TEA) medium were investigated as cultivation medium for bioethanol feedstock for 7 days. The results showed that the highest dry weight concentration of microalgae was in Farmpion medium (0.35 mg/ml) and the highest carbohydrate concentration of microalgae was in BBM (0.14 mg/ml). Thus, the optimum medium of microalgae cultivation for bioethanol feedstock was BBM because of the highest carbohydrate-dry weight ratio (0.88). In addition, mathematical approach by using Contois model was used to find out the growth rate of microalgae cultivation in each medium.

Application of statistical experimental design for optimisation of bioinsecticides production by sporeless Bacillus thuringiensis strain on cheap medium.

PubMed

Ben Khedher, Saoussen; Jaoua, Samir; Zouari, Nabil

2013-01-01

In order to overproduce bioinsecticides production by a sporeless Bacillus thuringiensis strain, an optimal composition of a cheap medium was defined using a response surface methodology. In a first step, a Plackett-Burman design used to evaluate the effects of eight medium components on delta-endotoxin production showed that starch, soya bean and sodium chloride exhibited significant effects on bioinsecticides production. In a second step, these parameters were selected for further optimisation by central composite design. The obtained results revealed that the optimum culture medium for delta-endotoxin production consists of 30 g L(-1) starch, 30 g L(-1) soya bean and 9 g L(-1) sodium chloride. When compared to the basal production medium, an improvement in delta-endotoxin production up to 50% was noted. Moreover, relative toxin yield of sporeless Bacillus thuringiensis S22 was improved markedly by using optimised cheap medium (148.5 mg delta-endotoxins per g starch) when compared to the yield obtained in the basal medium (94.46 mg delta-endotoxins per g starch). Therefore, the use of optimised culture cheap medium appeared to be a good alternative for a low cost production of sporeless Bacillus thuringiensis bioinsecticides at industrial scale which is of great importance in practical point of view.

Application of statistical experimental design for optimisation of bioinsecticides production by sporeless Bacillus thuringiensis strain on cheap medium

PubMed Central

Ben Khedher, Saoussen; Jaoua, Samir; Zouari, Nabil

2013-01-01

In order to overproduce bioinsecticides production by a sporeless Bacillus thuringiensis strain, an optimal composition of a cheap medium was defined using a response surface methodology. In a first step, a Plackett-Burman design used to evaluate the effects of eight medium components on delta-endotoxin production showed that starch, soya bean and sodium chloride exhibited significant effects on bioinsecticides production. In a second step, these parameters were selected for further optimisation by central composite design. The obtained results revealed that the optimum culture medium for delta-endotoxin production consists of 30 g L−1 starch, 30 g L−1 soya bean and 9 g L−1 sodium chloride. When compared to the basal production medium, an improvement in delta-endotoxin production up to 50% was noted. Moreover, relative toxin yield of sporeless Bacillus thuringiensis S22 was improved markedly by using optimised cheap medium (148.5 mg delta-endotoxins per g starch) when compared to the yield obtained in the basal medium (94.46 mg delta-endotoxins per g starch). Therefore, the use of optimised culture cheap medium appeared to be a good alternative for a low cost production of sporeless Bacillus thuringiensis bioinsecticides at industrial scale which is of great importance in practical point of view. PMID:24516462

Separation of Flame and Nonflame-retardant Plastics Utilizing Magneto-Archimedes Method

NASA Astrophysics Data System (ADS)

Misawa, Kohei; Kobayashi, Takayuki; Mori, Tatsuya; Mishima, Fumihito; Akiyama, Yoko; Nishijima, Shigehiro

2017-07-01

In physical recycling process, the quality of recycled plastics becomes usually poor in case various kinds of plastic materials are mixed. In order to solve the problem, we tried to separate flame and nonflame-retardant plastics used for toner cartridges as one example of mixed plastics by using magneto-Archimedes method. By using this method, we can control levitation and settlement of the particles in the medium by controlling the density and magnetic susceptibility of the medium and the magnetic field. In this study, we introduced the separation system of plastics by the combination of wet type specific gravity separation and magneto-Archimedes separation. In addition, we examined continuous and massive separation by introducing the system which can separate the plastics continuously in the flowing fluid.

Tindallia Californiensis sp. nov.: A New Halo-Alkaliphilic Primary Anaerobe, Isolated from Meromictic soda Mono Lake in California and the Correction of Diagnosis for Genus Tindallia

NASA Technical Reports Server (NTRS)

Pikuta, Elena; Marsic, Damien; Hoover, Richard B.; Kevbrin, Vadim; Whitman, William B.; Krader, Paul; Cleland, Dave; Six, N. Frank (Technical Monitor)

2002-01-01

A novel extremely halo-alkaliphilic, bacterium strain APO (sup T) was isolated from sediments of the athalassic, meromictic, soda Mono Lake in California. Gram positive, spore-forming, slightly curved rods with sizes 0.6-0.7x 2.5-4.0 micrometers which occur singly, in pairs or short curved chains. Cells, are motile by singular subcentral flagellum. Strain APO (sup T) is mesophilic: growth was observed over the temperature range of +10 C to +48 C (optimum +37 C), NaCl concentration range 1-20 %, wt/vol (optimum 3-5%, wt/vol) and pH range 8.0-11.0 (optimum pH 9.5). The novel isolate is strictly halo-alkaliphilic, requires sodium chloride in medium, obligately anaerobic and catalase-negative. Strain APO (sup T) is organo-heterotroph with fermentative type of metabolism, and uses as substrates: peptone, badotryptone, casamino acids, yeast extract, L-serine, L-lysine, L-histidine, L-arginine, and pyruvate. The main end products of growth on peptone medium were: lactate, acetate, propionate, and ethanol. Strain APO (sup T) is resistant to kanamycin, but sensitive to chloramphenicol, tetracycline, and gentamycin. The sum of G+C in DNA is 44.4 mol% (by HPLC method). On the bait of physiological and molecular properties, the isolate was considered as novel species of genus Tindallia; and the name Tindallia californiensis sp. nov., is proposed for new isolate (type strain APO (sup T) - ATCC BAA_393(sup T) = DSMZ 14871 (sup T)).

Regeneration and molecular characterization of an intergeneric hybrid between Graphium putredinis and Trichoderma harzianum by protoplasmic fusion.

PubMed

Savitha, S; Sadhasivam, S; Swaminathan, K

2010-01-01

The fungal strains Graphium putredinis and Trichoderma harzianum were selected as parents for fusant development. Protoplasts were isolated using the combination of lysing enzymes Novozym 234 and cellulase with 0.6M KCl as osmotic stabilizer. The optimum conditions for release of viable protoplasts from the fungal mycelium viz. age of the mycelium, lytic enzymes, osmotic stabilizers, pH, incubation period and regeneration medium were determined. Intergeneric protoplast fusion was carried out using 50% polyethylene glycol with calcium chloride (CaCl(2)) and glycine buffer and the conditions for effective protoplast fusion, viz. fusogen, osmotic stabilizer, pH, incubation period and regeneration medium were optimized. At optimum conditions, the regeneration frequency of the fused protoplasts on potato dextrose agar (PDA) medium and fusion frequency were calculated. The regeneration frequency on non-selective (PDA) and selective media (PDA amended with starch) was determined for the parental and fusant strains in which, fusant showed a higher rate of regeneration. Fusant formation was confirmed by morphological markers (colony morphology and spore size and shape) and genetical markers like, mycelial protein pattern, restriction digestion pattern and random amplified polymorphic DNA (RAPD) analysis. The efficiency of these parental strains and their intergeneric fusant in the production of hydrolytic enzymes - amylases (treatment plant for sago factory effluent), cellulases (bioethanol), xylanases (bleaching agents for waste paper pulp) and proteases (additives in commercial detergents) - have probable applications in various industrial processes. (c) 2010 Elsevier Inc. All rights reserved.

Concomitant production of detergent compatible enzymes by Bacillus flexus XJU-1.

PubMed

Niyonzima, Francois N; More, Sunil S

2014-01-01

A soil screened Bacillus flexus XJU-1 was induced to simultaneously produce alkaline amylase, alkaline lipase and alkaline protease at their optimum levels on a common medium under submerged fermentation. The basal cultivation medium consisted of 0.5% casein, 0.5% starch and 0.5% cottonseed oil as an inducer for protease, amylase, and lipase, respectively. The casein also served as nitrogen source for all 3 enzymes. The starch was also found to act as carbon source additive for both lipase and protease. Maximum enzyme production occurred on fermentation medium with 1.5% casein, 1.5% soluble starch, 2% cottonseed oil, 2% inoculum size, initial pH of 11.0, incubation temperature of 37 °C and 1% soybean meal as a nitrogen source supplement. The analysis of time course study showed that 24 h was optimum incubation time for amylase whereas 48 h was the best time for both lipase and protease. After optimization, a 3.36-, 18.64-, and 27.33-fold increase in protease, amylase and lipase, respectively was recorded. The lipase was produced in higher amounts (37.72 U/mL) than amylase and protease about 1.27 and 5.85 times, respectively. As the 3 enzymes are used in detergent formulations, the bacterium can be commercially exploited to secrete the alkaline enzymes for use in detergent industry. This is the first report for concomitant production of 3 alkaline enzymes by a bacterium.

Polyacrylamide medium for the electrophoretic separation of biomolecules

DOEpatents

Madabhushi, Ramakrishna S.; Gammon, Stuart A.

2003-11-11

A polyacryalmide medium for the electrophoretic separation of biomolecules. The polyacryalmide medium comprises high molecular weight polyacrylamides (PAAm) having a viscosity average molecular weight (M.sub.v) of about 675-725 kDa were synthesized by conventional red-ox polymerization technique. Using this separation medium, capillary electrophoresis of BigDye DNA sequencing standard was performed. A single base resolution of .about.725 bases was achieved in .about.60 minute in a non-covalently coated capillary of 50 .mu.m i.d., 40 cm effective length, and a filed of 160 V/cm at 40.degree. C. The resolution achieved with this formulation to separate DNA under identical conditions is much superior (725 bases vs. 625 bases) and faster (60 min. vs. 75 min.) to the commercially available PAAm, such as supplied by Amersham. The formulation method employed here to synthesize PAAm is straight-forward, simple and does not require cumbersome methods such as emulsion polymerizaiton in order to achieve very high molecular weights. Also, the formulation here does not require separation of PAAm from the reaction mixture prior to reconstituting the polymer to a final concentration. Furthermore, the formulation here is prepared from a single average mol. wt. PAAm as opposed to the mixture of two different average mo. wt. PAAm previously required to achieve high resolution.

Physiological Requirements for the Production of the Biopolymer Elsinan by Species of Elsinoe

DTIC Science & Technology

1989-06-01

and corn syrup produced elsinan with a MW distribution of about 2 million. However, 0.29 M sucrose was shown in time studies to be a suitable carbon...4.6 1259 1.8 E-80 Lactose (0.29 M) 14.3 - - E-81 Maltose (0.29 M) 11.8 2250 1.9 E-82 Sol. Starch (10%) 33.3 774 11.6 E-83 Corn Syrup (10%) 6.6 2012...and amounts of cEarbon, nitrogen, and phosphate. A medium was devised for the optimum yields of high (>2 milliohn)-v-medium (1-2 million), and low (<I

Bioleaching of copper oxide ore by Pseudomonas aeruginosa

NASA Astrophysics Data System (ADS)

Shabani, M. A.; Irannajad, M.; Azadmehr, A. R.; Meshkini, M.

2013-12-01

Bioleaching is an environmentally friendly method for extraction of metal from ores. In this study, bioleaching of copper oxide ore by Pseudomonas aeruginosa was investigated. Pseudomonas aeruginosa is a heterotrophic bacterium that can produce various organic acids in an appropriate culture medium, and these acids can operate as leaching agents. The parameters, such as particle size, glucose percentage in the culture medium, bioleaching time, and solid/liquid ratio were optimized. Optimum bioleaching conditions were found as follows: particle size of 150-177 μm, glucose percentage of 6%, bioleaching time of 8 d, and solid/liquid ratio of 1:80. Under these conditions, 53% of copper was extracted.

Physical, Chemical and Mineralogical Characteristics of Important Mississippi Soils

Treesearch

R. R. Bruce; W. A. Raney; W. M. Broadfoot; H. B. Vanderford

1958-01-01

To realize the crop production potential of soils it is necessary to first have a knowledge of their chemical, physical and biological properties and reactions and then to so alter these properties and reactions to effect a medium optimum for plant growth. In the past, soils have been classified primarily on the basis of physical characteristics observable in the field...

Physics of chemoreception.

PubMed Central

Berg, H C; Purcell, E M

1977-01-01

Statistical fluctuations limit the precision with which a microorganism can, in a given time T, determine the concentration of a chemoattractant in the surrounding medium. The best a cell can do is to monitor continually the state of occupation of receptors distributed over its surface. For nearly optimum performance only a small fraction of the surface need be specifically adsorbing. The probability that a molecule that has collided with the cell will find a receptor is Ns/(Ns + pi a), if N receptors, each with a binding site of radius s, are evenly distributed over a cell of radius a. There is ample room for many indenpendent systems of specific receptors. The adsorption rate for molecules of moderate size cannot be significantly enhanced by motion of the cell or by stirring of the medium by the cell. The least fractional error attainable in the determination of a concentration c is approximately (TcaD) - 1/2, where D is diffusion constant of the attractant. The number of specific receptors needed to attain such precision is about a/s. Data on bacteriophage absorption, bacterial chemotaxis, and chemotaxis in a cellular slime mold are evaluated. The chemotactic sensitivity of Escherichia coli approaches that of the cell of optimum design. PMID:911982

Effect of Processing Variables on Tensile Modulus and Morphology of Polyethylene/Clay Nanocomposites Prepared in an Internal Mixer

NASA Astrophysics Data System (ADS)

Ujianto, O.; Jollands, M.; Kao, N.

2018-03-01

A comparative study on effect of internal mixer on high density Polyethylene (HDPE)/clay nanocomposites preparation was done. Effect of temperature, rotor rotation (rpm), and mixing time, as well as rotor type (Roller and Banbury) on mechanical properties and morphology of HDPE/clay nanocomposites were studied using Box-Behnken experimental design. The model was developed according to secant modulus and confirmed to morphology analysis using Transmission Electron Microscopy (TEM). The finding suggests that there is different mechanisms occurred in each rotor to improve the mechanical properties. The mechanism in Roller is medium shear and medium diffusion, while Banbury is high shear and low diffusion. The difference in mechanism to disperse the clay particles attribute to the different optimum processing conditions in each rotor. The settings for roller samples are predicted around mid temperature, mid speed, and mid mixing time. There is no optimum setting for Banbury within the processing boundaries. The best settings for Banbury are at low, high, low settings. The morphology results showed a hybrid composite structure, with some exfoliations and some intercalations. There was a correlation between better mechanical properties and morphology with more exfoliation and thinner intercalated particles.

Pseudorandom dynamics of frequency combs in free-running quantum cascade lasers

NASA Astrophysics Data System (ADS)

Henry, Nathan; Burghoff, David; Yang, Yang; Hu, Qing; Khurgin, Jacob B.

2018-01-01

Recent research has shown that free-running quantum cascade lasers are capable of producing frequency combs in midinfrared and THz regions of the spectrum. Unlike familiar frequency combs originating from mode-locked lasers, these do not require any additional optical elements inside the cavity and have temporal characteristics that are dramatically different from the periodic pulse train of conventional combs. Frequency combs from quantum cascade lasers are characterized by the absence of sharp pulses and strong frequency modulation, periodic with the cavity round trip time but lacking any periodicity within that period. To explicate for this seemingly perplexing behavior, we develop a model of the gain medium using optical Bloch equations that account for hole burning in spectral, spatial, and temporal domains. With this model, we confirm that the most efficient mode of operation of a free-running quantum cascade laser is indeed a pseudorandom frequency-modulated field with nearly constant intensity. We show that the optimum modulation period is commensurate with the gain recovery time of the laser medium and the optimum modulation amplitude is comparable to the gain bandwidth, behavior that has been observed in the experiments.

Determination of active ingredients in corn silk, leaf, and kernel by capillary electrophoresis with electrochemicaI detection.

PubMed

Lin, Miao; Chu, Qing-Cui; Tian, Xiu-Hui; Ye, Jian-Nong

2007-01-01

Corn has been known for its accumulation of flavones and phenolic acids. However, many parts of corn, except kernel, have not drawn much attention. In this work, a method based on capillary zone electrophoresis with electrochemical detection has been used for the separation and determination of epicatechin, rutin, ascorbic acid (Vc), kaempferol, chlorogenic acid, and quercetin in corn silk, leaf, and kernel. The distribution comparison of the ingredients among silk, leaf, and kernel is discussed. Several important factors--including running buffer acidity, separation voltage, and working electrode potential--were evaluated to acquire the optimum analysis conditions. Under the optimum conditions, the analytes could be well separated within 19 min in a 40-mmol/L borate buffer (pH 9.2). The response was linear over three orders of magnitude with detection limits (S/N = 3) ranging from 4.97 x 10(-8) to 9.75 x 10(-8) g/mL. The method has been successfully applied for the analysis of corn silk, leaf, and kernel with satisfactory results.

Separation of tartronic and glyceric acids by simulated moving bed chromatography.

PubMed

Coelho, Lucas C D; Filho, Nelson M L; Faria, Rui P V; Ferreira, Alexandre F P; Ribeiro, Ana M; Rodrigues, Alírio E

2018-08-17

The SMB unit developed by the Laboratory of Separation and Reaction Engineering (FlexSMB-LSRE ® ) was used to perform tartronic acid (TTA) and glyceric acid (GCA) separation and to validate the mathematical model in order to determine the optimum operating parameters of an industrial unit. The purity of the raffinate and extract streams in the experiments performed were 80% and 100%, respectively. The TTA and GCA productivities were 79 and 115 kg per liter of adsorbent per day, respectively and only 0.50 cubic meters of desorbent were required per kilogram of products. Under the optimum operating conditions, which were determined through an extensive simulation study based on the mathematical model developed to predict the performance of a real SMB unit, it was possible to achieve a productivity of 86 kg of TTA and 176 kg of GCA per cubic meter of adsorbent per day (considering the typical commercial purity value of 97% for both compounds) with an eluent consumption of 0.30 cubic meters per kilogram of products. Copyright © 2018 Elsevier B.V. All rights reserved.

Separation medium containing thermally exfoliated graphite oxide

NASA Technical Reports Server (NTRS)

Prud'homme, Robert K. (Inventor); Aksay, Ilhan A. (Inventor); Herrera-Alonso, Margarita (Inventor)

2012-01-01

A separation medium, such as a chromatography filling or packing, containing a modified graphite oxide material, which is a thermally exfoliated graphite oxide with a surface area of from about 300 m.sup.2/g to 2600 m.sup.2/g, wherein the thermally exfoliated graphite oxide has a surface that has been at least partially functionalized.

Impact of vane size and separation on radiometric forces for microactuation

NASA Astrophysics Data System (ADS)

Gimelshein, Natalia; Gimelshein, Sergey; Ketsdever, Andrew; Selden, Nathaniel

2011-04-01

A kinetic approach is used to study the feasibility of increasing the efficiency of microactuators that use radiometric force through etching holes in a single radiometer vane. It has been shown that a radiometer that consists of small vanes is capable of producing at least an order of magnitude larger force than a single-vane radiometer that takes up the same area. The optimum gap between the vanes is found to be slightly smaller than the vane size, with the optimum Knudsen number of about 0.05 based on the vane height.

Analytical study of electrical disconnect system for use on manned and unmanned missions

NASA Technical Reports Server (NTRS)

Rosener, A. A.; Lenda, J. A.; Trummer, R. O.; Jonkoniec, T. G.

1977-01-01

The program to survey existing electrical connector availability, and establish an optimum connector design for maintainable spacecraft substation interfaces is reported. Functional and operational requirements are given along with the results of the documentation survey, which disclosed that the MSFC series connectors have the preferred features of current connector technology. Optimum design concepts for EVA tasks, modules serviced by manipulators, and for manipulators independent of other servicing units are presented. It is concluded that separate connector designs are required for spacecraft replaceable modules, and for crewman EVA.

Optimization of radar imaging system parameters for geological analysis

NASA Technical Reports Server (NTRS)

Waite, W. P.; Macdonald, H. C.; Kaupp, V. H.

1981-01-01

The use of radar image simulation to model terrain variation and determine optimum sensor parameters for geological analysis is described. Optimum incidence angle is determined by the simulation, which evaluates separately the discrimination of surface features possible due to terrain geometry and that due to terrain scattering. Depending on the relative relief, slope, and scattering cross section, optimum incidence angle may vary from 20 to 80 degrees. Large incident angle imagery (more than 60 deg) is best for the widest range of geological applications, but in many cases these large angles cannot be achieved by satellite systems. Low relief regions require low incidence angles (less than 30 deg), so a satellite system serving a broad range of applications should have at least two selectable angles of incidence.

Statistical optimization of medium components for the production of Antrodia cinnamomea AC0623 in submerged cultures.

PubMed

Chang, Chien-Yu; Lee, Chun-Lin; Pan, Tzu-Ming

2006-10-01

The nutritional medium requirement for biomass and triterpenoid production by Antrodia cinnamomea AC0623 strain was optimized. Box-Behnken was applied to optimize biomass and triterpenoid production. According to response surface methodology (RSM), the optimum concentrations of N-source were determined. The results indicate that when a submerged culture in shake flasks was operated at 28 degrees C, initial pH 5.5, and rotation speed 105 rpm, the biomass and triterpenoid content in dry basis could be increased to 3.20% (w/w) and 31.8 mg/g, respectively. The experiments were further scaled up to 100- and 700-l fermentors. Higher content of triterpenoids (63.0 mg/g) was obtained in 700-l fermentations by means of the control of cultural conditions and the modification of medium composition based on the RSM.

Vermicomposting of source-separated human faeces by Eisenia fetida: effect of stocking density on feed consumption rate, growth characteristics and vermicompost production.

PubMed

Yadav, Kunwar D; Tare, Vinod; Ahammed, M Mansoor

2011-06-01

The main objective of the present study was to determine the optimum stocking density for feed consumption rate, biomass growth and reproduction of earthworm Eisenia fetida as well as determining and characterising vermicompost quantity and product, respectively, during vermicomposting of source-separated human faeces. For this, a number of experiments spanning up to 3 months were conducted using soil and vermicompost as support materials. Stocking density in the range of 0.25-5.00 kg/m(2) was employed in different tests. The results showed that 0.40-0.45 kg-feed/kg-worm/day was the maximum feed consumption rate by E. fetida in human faeces. The optimum stocking densities were 3.00 kg/m(2) for bioconversion of human faeces to vermicompost, and 0.50 kg/m(2) for earthworm biomass growth and reproduction. Copyright © 2011 Elsevier Ltd. All rights reserved.

Study of phenformin metabolism in rat liver microsomes by HPLC, CE and on-line HPLC-electrospray ionization mass spectrometry.

PubMed

Llambias, E B; Luo, J

1996-01-01

Methods for the analysis of phenformin and its metabolite by high-performance liquid chromatography (HPLC), capillary electrophoresis (CE) and high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESIMS) are developed. The effects of pH, buffer concentration and proportion of organic modifier on the retention of the compounds in HPLC have been studied. The optimum condition was used for the separation and identification of phenformin and its metabolite in microsomal metabolism by HPLC-ESIMS. A simple CE method is also described for the separation of these compounds. Optimum incubation conditions and cofactor requirements for the formation of 4-hydroxyphenformin by microsomal preparations of rat liver were determined. A linear response in the formation of product was found with increasing concentrations of protein and up to 15 min incubation. High concentrations of phenformin inhibited its metabolite formation, and K(m) was 4 microM.

Optimization of critical medium components using response surface methodology for phenazine-1-carboxylic acid production by Pseudomonas sp. M-18Q.

PubMed

Yuan, Li-Li; Li, Ya-Qian; Wang, Yi; Zhang, Xue-Hong; Xu, Yu-Quan

2008-03-01

The optimal flask-shaking batch fermentation medium for phenazine-1-carboxylic acid (PCA) production by Pseudomonas sp. M-18Q, a qscR chromosomal inactivated mutant of the strain M18 was studied using statistical experimental design and analysis. The Plackett-Burman design (PBD) was used to evaluate the effects of eight medium components on the production of PCA, which showed that glucose and soytone were the most significant ingredients (P<0.05). The steepest ascent experiment was adopted to determine the optimal region of the medium composition. The optimum composition of the fermentation medium for maximum PCA yield, as determined on the basis of a five-level two-factor central composite design (CCD), was obtained by response surface methodology (RSM). The high correlation between the predicted and observed values indicated the validity of the model. A maximum PCA yield of 1240 mg/l was obtained at 17.81 g/l glucose and 11.47 g/l soytone, and the production was increased by 65.3% compared with that using the original medium, which was at 750 mg/l.

Acetylcholine suppresses shoot formation and callusing in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby.

PubMed

Bamel, Kiran; Gupta, Rajendra; Gupta, Shirish C

2016-06-02

We present experimental evidence to show that acetylcholine (ACh) causes decrease in shoot formation in leaf explants of tomato (Lycopersicon esculentum Miller var Pusa Ruby) when cultured on shoot regeneration medium. The optimum response was obtained at 10(-4) M ACh-enriched medium. ACh also causes decrease in percentage of cultures forming callus and reduces the callus mass. Inhibitors of enzymatic hydrolysis of ACh, neostigmine and physostigmine, also suppresses callogenesis and caulogenesis. On the other hand, the breakdown products of Ach, choline and acetate, do not alter the morphogenic response induced on the shoot regeneration medium. Neostigmine showed optimal reduction in shoot formation at 10(-5) M. The explants cultured on neostigmine augmented medium showed decline in the activity of ACh hydrolyzing enzyme acetylcholinesterase. ACh and neostigmine added together showed marked reduction in callus mass. These results strongly support the role of ACh as a natural regulator of morphogenesis in tomato plants.

Acetylcholine suppresses shoot formation and callusing in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby

PubMed Central

Bamel, Kiran; Gupta, Rajendra; Gupta, Shirish C.

2016-01-01

ABSTRACT We present experimental evidence to show that acetylcholine (ACh) causes decrease in shoot formation in leaf explants of tomato (Lycopersicon esculentum Miller var Pusa Ruby) when cultured on shoot regeneration medium. The optimum response was obtained at 10−4 M ACh-enriched medium. ACh also causes decrease in percentage of cultures forming callus and reduces the callus mass. Inhibitors of enzymatic hydrolysis of ACh, neostigmine and physostigmine, also suppresses callogenesis and caulogenesis. On the other hand, the breakdown products of Ach, choline and acetate, do not alter the morphogenic response induced on the shoot regeneration medium. Neostigmine showed optimal reduction in shoot formation at 10−5 M. The explants cultured on neostigmine augmented medium showed decline in the activity of ACh hydrolyzing enzyme acetylcholinesterase. ACh and neostigmine added together showed marked reduction in callus mass. These results strongly support the role of ACh as a natural regulator of morphogenesis in tomato plants. PMID:27348536

Determination of optimum threshold values for EMG time domain features; a multi-dataset investigation

NASA Astrophysics Data System (ADS)

Nlandu Kamavuako, Ernest; Scheme, Erik Justin; Englehart, Kevin Brian

2016-08-01

Objective. For over two decades, Hudgins’ set of time domain features have extensively been applied for classification of hand motions. The calculation of slope sign change and zero crossing features uses a threshold to attenuate the effect of background noise. However, there is no consensus on the optimum threshold value. In this study, we investigate for the first time the effect of threshold selection on the feature space and classification accuracy using multiple datasets. Approach. In the first part, four datasets were used, and classification error (CE), separability index, scatter matrix separability criterion, and cardinality of the features were used as performance measures. In the second part, data from eight classes were collected during two separate days with two days in between from eight able-bodied subjects. The threshold for each feature was computed as a factor (R = 0:0.01:4) times the average root mean square of data during rest. For each day, we quantified CE for R = 0 (CEr0) and minimum error (CEbest). Moreover, a cross day threshold validation was applied where, for example, CE of day two (CEodt) is computed based on optimum threshold from day one and vice versa. Finally, we quantified the effect of the threshold when using training data from one day and test data of the other. Main results. All performance metrics generally degraded with increasing threshold values. On average, CEbest (5.26 ± 2.42%) was significantly better than CEr0 (7.51 ± 2.41%, P = 0.018), and CEodt (7.50 ± 2.50%, P = 0.021). During the two-fold validation between days, CEbest performed similar to CEr0. Interestingly, when using the threshold values optimized per subject from day one and day two respectively, on the cross-days classification, the performance decreased. Significance. We have demonstrated that threshold value has a strong impact on the feature space and that an optimum threshold can be quantified. However, this optimum threshold is highly data and subject driven and thus do not generalize well. There is a strong evidence that R = 0 provides a good trade-off between system performance and generalization. These findings are important for practical use of pattern recognition based myoelectric control.

Determination of optimum threshold values for EMG time domain features; a multi-dataset investigation.

PubMed

Kamavuako, Ernest Nlandu; Scheme, Erik Justin; Englehart, Kevin Brian

2016-08-01

For over two decades, Hudgins' set of time domain features have extensively been applied for classification of hand motions. The calculation of slope sign change and zero crossing features uses a threshold to attenuate the effect of background noise. However, there is no consensus on the optimum threshold value. In this study, we investigate for the first time the effect of threshold selection on the feature space and classification accuracy using multiple datasets. In the first part, four datasets were used, and classification error (CE), separability index, scatter matrix separability criterion, and cardinality of the features were used as performance measures. In the second part, data from eight classes were collected during two separate days with two days in between from eight able-bodied subjects. The threshold for each feature was computed as a factor (R = 0:0.01:4) times the average root mean square of data during rest. For each day, we quantified CE for R = 0 (CEr0) and minimum error (CEbest). Moreover, a cross day threshold validation was applied where, for example, CE of day two (CEodt) is computed based on optimum threshold from day one and vice versa. Finally, we quantified the effect of the threshold when using training data from one day and test data of the other. All performance metrics generally degraded with increasing threshold values. On average, CEbest (5.26 ± 2.42%) was significantly better than CEr0 (7.51 ± 2.41%, P = 0.018), and CEodt (7.50 ± 2.50%, P = 0.021). During the two-fold validation between days, CEbest performed similar to CEr0. Interestingly, when using the threshold values optimized per subject from day one and day two respectively, on the cross-days classification, the performance decreased. We have demonstrated that threshold value has a strong impact on the feature space and that an optimum threshold can be quantified. However, this optimum threshold is highly data and subject driven and thus do not generalize well. There is a strong evidence that R = 0 provides a good trade-off between system performance and generalization. These findings are important for practical use of pattern recognition based myoelectric control.

Conveyor Performance based on Motor DC 12 Volt Eg-530ad-2f using K-Means Clustering

NASA Astrophysics Data System (ADS)

Arifin, Zaenal; Artini, Sri DP; Much Ibnu Subroto, Imam

2017-04-01

To produce goods in industry, a controlled tool to improve production is required. Separation process has become a part of production process. Separation process is carried out based on certain criteria to get optimum result. By knowing the characteristics performance of a controlled tools in separation process the optimum results is also possible to be obtained. Clustering analysis is popular method for clustering data into smaller segments. Clustering analysis is useful to divide a group of object into a k-group in which the member value of the group is homogeny or similar. Similarity in the group is set based on certain criteria. The work in this paper based on K-Means method to conduct clustering of loading in the performance of a conveyor driven by a dc motor 12 volt eg-530-2f. This technique gives a complete clustering data for a prototype of conveyor driven by dc motor to separate goods in term of height. The parameters involved are voltage, current, time of travelling. These parameters give two clusters namely optimal cluster with center of cluster 10.50 volt, 0.3 Ampere, 10.58 second, and unoptimal cluster with center of cluster 10.88 volt, 0.28 Ampere and 40.43 second.

Permeability recovery of damaged water sensitive core using ultrasonic waves.

PubMed

Khan, Nasir; Pu, Chunsheng; Li, Xu; He, Yanlong; Zhang, Lei; Jing, Cheng

2017-09-01

It is imperative to recover the well productivity lose due to formation damage nearby wellbore during variant well operations. Some indispensable issues in conventional techniques make ultrasonic technology more attractive due to simple, reliable, favorable, cost-effective, and environment friendly nature. This study proposes the independent and combined use of ultrasonic waves and chemical agents for the treatment of already damaged core samples caused by exposure to distilled water. Results elucidate that ultrasonic waves with optimum (20kHz, 1000W) instead of maximum frequency and power worked well in the recovery owing to peristaltic transport caused by matching of natural frequency with acoustic waves frequency. In addition, hundred minutes was investigated as optimum irradiation time which provided ample time span to detach fine loosely suspended particles. However, further irradiation adversely affected the damaged permeability recovery. Moreover, permeability improvement attributes to cavitation due to ultrasonic waves propagation through fluid contained in porous medium and thermal energy generated by three different ways. Eventually, experimental outcomes indicated that maximum (25.3%) damaged permeability recovery was witnessed by applying ultrasonic waves with transducer #2 (20kHz and 1000W) and optimum irradiation timeframe (100min). This recovery was further increased to 45.8% by applying chemical agent and optimum ultrasonic waves simultaneously. Copyright © 2017 Elsevier B.V. All rights reserved.

In-situ polymerized PLOT columns III: divinylbenzene copolymers and dimethacrylate homopolymers

NASA Technical Reports Server (NTRS)

Shen, T. C.; Fong, M. M.

1994-01-01

Studies of divinylbenzene copolymers and dimethacrylate homopolymers indicate that the polymer pore size controls the separation of water and ammonia on porous-layer-open-tubular (PLOT) columns. To a lesser degree, the polarity of the polymers also affects the separation of a water-ammonia gas mixture. Our results demonstrate that the pore size can be regulated by controlling the cross-linking density or the chain length between the cross-linking functional groups. An optimum pore size will provide the best separation of water and ammonia.

Toward an Optimum Decision-Making Structure in Colleges: A Literature Review and Interpretation

ERIC Educational Resources Information Center

Helsabeck, Robert E.

1972-01-01

It seems that what is indicated for policies affecting student participation in campus governance is a mixed model, involving both communitarian structures for some decisions and a separation of powers for others. (Author)

Fluxgate magnetometers for outer planets exploration

NASA Technical Reports Server (NTRS)

Acuna, M. H.

1974-01-01

The exploration of the interplanetary medium and the magnetospheres of the outer planets requires the implementation of magnetic field measuring instrumentation with wide dynamic range, high stability, and reliability. The fluxgate magnetometers developed for the Pioneer 11 and Mariner-Jupiter-Saturn missions are presented. These instruments cover the range of .01 nT to 2 million nT with optimum performance characteristics and low power consumption.

Active Camouflage for Infantry Headwear Applications

DTIC Science & Technology

2007-02-01

incorporates a rewriteable display medium. Military, academic, and commercial groups are aiming at developing OLEDs for full- color flexible displays...as shown in Figure 7. Figure 7: Organic LED Prototype shown on a Flexible surface (Kincade, 2004). OLEDs are self-luminous and do not require...brighter, more stable color displays. The OLED manufacturing process is much more amenable to retaining optimum performance on a flexible surface

Combination of novel coalescing oil water separator and electrocoagulation technique for treatment of petroleum compound contaminated groundwater.

PubMed

Oladzad, Sepideh; Fallah, Narges; Nasernejad, Bahram

2017-07-01

In the present study a combination of a novel coalescing oil water separator (COWS) and electrocoagulation (EC) technique was used for treatment of petroleum product contaminated groundwater. In the first phase, COWS was used as the primary treatment. Two different types of coalescing media and two levels of flow rates were examined in order to find the optimum conditions. The effluent of COWS was collected in optimum conditions and was treated using an EC process in the second phase of the research. In this phase, preliminary experiments were conducted in order to investigate the effect of EC reaction time and sedimentation time on chemical oxygen demand (COD) removal efficiency. Best conditions for EC reaction time and sedimentation time were obtained to be 5 min and 30 min, respectively. Response surface methodology was applied to evaluate the effect of initial pH, current density and aeration rate on settling velocity (V s ) and effluent COD. The optimum conditions, for achieving maximum values of V s as well as the values of effluent COD, in the range of results were obtained at conditions of 7, 34 mA·cm -2 and 1.5 L·min -1 for initial pH, current density and aeration rate, respectively.

Out of the Blue and Into the Black: Creation of the United States Space Force.

DTIC Science & Technology

1998-03-01

organizational diagnosis as a theorem for strategic change. An autopsy of related research and literature was conducted in order to establish justification for a separate service to advance space power for the nation. The first dimension examined is the medium of space. Defining the medium, along with such areas as airpower and space power establishes a factual foundation from which to launch the idea of a separate service. Reasoning for and against a separate service is presented, including application of the Organizational Diagnosis to the Air

Purification and properties of beta-galactosidase from Aspergillus nidulans.

PubMed

Díaz, M; Pedregosa, A M; de Lucas, J R; Torralba, S; Monistrol, I F; Laborda, F

1996-12-01

Beta-Galactosidase from mycelial extract of Aspergillus nidulans has been purified by substrate affinity chromatography and used to obtain anti-beta-galactosidase polyclonal antibodies. A. nidulans growing in lactose as carbon source synthesizes one active form of beta-galactosidase which seems to be a multimeric enzyme of 450 kDa composed of monomers with 120 and 97 kDa. Although the enzyme was not released to the culture medium, some enzymatic activity was detected in a cell-wall extract, thus suggesting that it can be an extracellular enzyme. Beta-Galactosidase of A. nidulans is a very unstable enzyme with an optimum pH value of 7.5 and an optimum temperature of 30 degrees C. It was only active against beta-galactoside substrates like lactose and p-nitrophenyl-beta-D-galactoside (PNPG).

Preliminary study of optimum ductburning turbofan engine cycle design parameters for supersonic cruising

NASA Technical Reports Server (NTRS)

Fishbach, L. H.

1978-01-01

The effect of turbofan engine overall pressure ratio, fan pressure ratio, and ductburner temperature rise on the engine weight and cruise fuel consumption for a mach 2.4 supersonic transport was investigated. Design point engines, optimized purely for the supersonic cruising portion of the flight where the bulk of the fuel is consumed, are considered. Based on constant thrust requirements at cruise, fuel consumption considerations would favor medium by pass ratio engines (1.5 to 1.8) of overall pressure ratio of about 16. Engine weight considerations favor low bypass ratio (0.6 or less) and low wverall pressure ratio (8). Combination of both effects results in bypass ratios of 0.6 to 0.8 and overall pressure ratio of 12 being the overall optimum.

Identification of terrain cover using the optimum polarimetric classifier

NASA Technical Reports Server (NTRS)

Kong, J. A.; Swartz, A. A.; Yueh, H. A.; Novak, L. M.; Shin, R. T.

1988-01-01

A systematic approach for the identification of terrain media such as vegetation canopy, forest, and snow-covered fields is developed using the optimum polarimetric classifier. The covariance matrices for various terrain cover are computed from theoretical models of random medium by evaluating the scattering matrix elements. The optimal classification scheme makes use of a quadratic distance measure and is applied to classify a vegetation canopy consisting of both trees and grass. Experimentally measured data are used to validate the classification scheme. Analytical and Monte Carlo simulated classification errors using the fully polarimetric feature vector are compared with classification based on single features which include the phase difference between the VV and HH polarization returns. It is shown that the full polarimetric results are optimal and provide better classification performance than single feature measurements.

Synthesis of glyceryl ferulate by immobilized ferulic acid esterase.

PubMed

Matsuo, Takemasa; Kobayashi, Takashi; Kimura, Yukitaka; Tsuchiyama, Moriyasu; Oh, Tadanobu; Sakamoto, Tatsuji; Adachi, Shuji

2008-12-01

Glyceryl ferulate was synthesized by the condensation of ferulic acid with glycerol using Pectinase PL "Amano" from Aspergillus niger, which contained ferulic acid esterase, to improve the water-solubility of ferulic acid. The optimum reaction medium was glycerol/0.1 M acetate buffer, pH 4.0, (98:2 v/v). The enzyme immobilized onto Chitopearl BCW3003 exhibited the highest activity among the those immobilized onto various kinds of Chitopearl BCW resins. The optimum temperature for the immobilized enzyme was 50 degrees C, and it could be reused at least five times without a significant loss in activity for the synthesis of glyceryl ferulate in batch reaction. Storage of the reaction mixture at 25 degrees C improved the molar fraction of glyceryl ferulate relative to the dissolved ferulic residues.

Highly thermostable, thermophilic, alkaline, SDS and chelator resistant amylase from a thermophilic Bacillus sp. isolate A3-15.

PubMed

Arikan, Burhan

2008-05-01

A thermostable alkaline alpha-amylase producing Bacillus sp. A3-15 was isolated from compost samples. There was a slight variation in amylase synthesis within the pH range 6.0 and 12.0 with an optimum pH of 8.5 (8mm zone diameter in agar medium) on starch agar medium. Analyses of the enzyme for molecular mass and amylolytic activity were carried out by starch SDS-PAGE electrophoresis, which revealed two independent bands (86,000 and 60,500 Da). Enzyme synthesis occurred at temperatures between 25 and 65 degrees C with an optimum of 60 degrees C on petri dishes. The partial purification enzyme showed optimum activity at pH 11.0 and 70 degrees C. The enzyme was highly active (95%) in alkaline range of pH (10.0-11.5), and it was almost completely active up to 100 degrees C with 96% of the original activity remaining after heat treatment at 100 degrees C for 30 min. Enzyme activity was enhanced in the presence of 5mM CaCl2 (130%) and inhibition with 5mM by ZnCl2, NaCl, Na-sulphide, EDTA, PMSF (3mM), Urea (8M) and SDS (1%) was obtained 18%, 20%, 36%, 5%, 10%, 80% and 18%, respectively. The enzyme was stable approximately 70% at pH 10.0-11.0 and 60 degrees C for 24h. So our result showed that the enzyme was both, highly thermostable-alkaline, thermophile and chelator resistant. The A3-15 amylase enzyme may be suitable in liquefaction of starch in high temperature, in detergent and textile industries and in other industrial applications.

Further analyses of human kidney cell populations separated on the Space Shuttle

NASA Technical Reports Server (NTRS)

Stewart, Robin M.; Todd, Paul; Cole, Kenneth D.; Morrison, Dennis R.

1992-01-01

Cultured human embryonic kidney cells were separated into electrophoretic subpopulations in laboratory experiments and in two separation experiments on the STS-8 (Challenger) Space Shuttle flight using the mid-deck Continuous Flow Electrophoretic Separator (CFES). Populations of cells from each fraction were cultured for the lifetime of the cells, and supernatant medium was withdrawn and replaced at 4-day intervals. Withdrawn medium was frozen at -120 C for subsequent analysis. Enzyme assays, antibodies and gel electrophoresis were used as analytical tools for the detection and quantization of plasminogen activators in these samples. These assays of frozen-culture supernatant fluids confirmed the electrophoretic separation of plasminogen-activator-producing cells from nonproducing cells, the isolation of cells capable of sustained production, and the separation of cells that produce different plasminogen activators from one other.

Characteristics of eugenol loaded chitosan-tripolyphosphate particles as affected by initial content of eugenol and their in-vitro release characteristic

NASA Astrophysics Data System (ADS)

Cahyono, B.; A’yun, Qurrotu; Suzery, M.; Hadiyanto

2018-04-01

The aim of this research was to determine encapsulation efficiency, loading capacity and controlled release of eugenol loaded chitosan-tpp products which prepared by coaservation method. The characteristic of eugenol-loaded chitosan showed that %EE and % LC increased by increasing the initial eugenol content. The optimum of %EE (72.63%) and %LC (43.96%) were obtained at the ratio of chitosan to eugenol of 1:1.5. The FTIR spectrum showed the characteristic peaks of eugenol appearing on spectrum of eugenol encapsulated and blue-shift in the hydroxyl band from 3425.58 cm-1 in chitosan-tpp to 3417.86 cm-1 and 3394.72 cm-1 in eugenol loaded chitosan-tpp indicating that eugenol was successfully encapsulated. The surface morphologies of freeze-dried particles with the optimum %EE showed that more surface roughness and porosity than plain particles. Furthermore, the in vitro release of particles with minimum and optimum %EE were also investigated in acid (Simulated Gastric Fluid) and base (Simulated Intestinal Fluid) medium at ambient temperature.

Production and Properties of a Thermostable, pH-Stable Exo-Polygalacturonase Using Aureobasidium pullulans Isolated from Saharan Soil of Algeria Grown on Tomato Pomace.

PubMed

Bennamoun, Leila; Hiligsmann, Serge; Dakhmouche, Scheherazad; Ait-Kaki, Amel; Labbani, Fatima-Zohra Kenza; Nouadri, Tahar; Meraihi, Zahia; Turchetti, Benedetta; Buzzini, Pietro; Thonart, Philippe

2016-10-29

Polygalacturonase is a valuable biocatalyst for several industrial applications. Production of polygalacturonase using the Aureobasidium pullulans stain isolated from Saharan soil of Algeria was investigated. Its capacity to produce polygalacturonase was assessed under submerged culture using tomato pomace as an abundant agro-industrial substrate. Optimization of the medium components, which enhance polygalacturonase activity of the strain Aureobasidium pullulans , was achieved with the aid of response surface methodology. The composition of the optimized medium was as follows: tomato pomace 40 g/L, lactose 1.84 g/L, CaCl₂0.09 g/L and pH 5.16. Practical validation of the optimum medium provided polygalacturonase activity of 22.05 U/mL, which was 5-fold higher than in unoptimized conditions. Batch cultivation in a 20 L bioreactor performed with the optimal nutrients and conditions resulted in a high polygalacturonase content (25.75 U/mL). The enzyme showed stability over a range of temperature (5-90 °C) with an optimum temperature of 60 °C with pH 5.0, exhibiting 100% residual activity after 1h at 60 °C. This enzyme was stable at a broad pH range (5.0-10). The enzyme proved to be an exo-polygalacturonase, releasing galacturonic acid by hydrolysis of polygalacturonic acid. Moreover, the exo-polygalacturonase was able to enhance the clarification of both apple and citrus juice. As a result, an economical polygalacturonase production process was defined and proposed using an industrial food by-product.

Production and Properties of a Thermostable, pH—Stable Exo-Polygalacturonase Using Aureobasidium pullulans Isolated from Saharan Soil of Algeria Grown on Tomato Pomace

PubMed Central

Bennamoun, Leila; Hiligsmann, Serge; Dakhmouche, Scheherazad; Ait-Kaki, Amel; Labbani, Fatima-Zohra Kenza; Nouadri, Tahar; Meraihi, Zahia; Turchetti, Benedetta; Buzzini, Pietro; Thonart, Philippe

2016-01-01

Polygalacturonase is a valuable biocatalyst for several industrial applications. Production of polygalacturonase using the Aureobasidium pullulans stain isolated from Saharan soil of Algeria was investigated. Its capacity to produce polygalacturonase was assessed under submerged culture using tomato pomace as an abundant agro-industrial substrate. Optimization of the medium components, which enhance polygalacturonase activity of the strain Aureobasidium pullulans, was achieved with the aid of response surface methodology. The composition of the optimized medium was as follows: tomato pomace 40 g/L, lactose 1.84 g/L, CaCl20.09 g/L and pH 5.16. Practical validation of the optimum medium provided polygalacturonase activity of 22.05 U/mL, which was 5-fold higher than in unoptimized conditions. Batch cultivation in a 20 L bioreactor performed with the optimal nutrients and conditions resulted in a high polygalacturonase content (25.75 U/mL). The enzyme showed stability over a range of temperature (5–90 °C) with an optimum temperature of 60 °C with pH 5.0, exhibiting 100% residual activity after 1h at 60 °C. This enzyme was stable at a broad pH range (5.0–10). The enzyme proved to be an exo-polygalacturonase, releasing galacturonic acid by hydrolysis of polygalacturonic acid. Moreover, the exo-polygalacturonase was able to enhance the clarification of both apple and citrus juice. As a result, an economical polygalacturonase production process was defined and proposed using an industrial food by-product. PMID:28231166

Design issues for optimum solar cell configuration

NASA Astrophysics Data System (ADS)

Kumar, Atul; Thakur, Ajay D.

2018-05-01

A computer based simulation of solar cell structure is performed to study the optimization of pn junction configuration for photovoltaic action. The fundamental aspects of photovoltaic action viz, absorption, separation collection, and their dependence on material properties and deatails of device structures is discussed. Using SCAPS 1D we have simulated the ideal pn junction and shown the effect of band offset and carrier densities on solar cell performance. The optimum configuration can be achieved by optimizing transport of carriers in pn junction under effect of field dependent recombination (tunneling) and density dependent recombination (SRH, Auger) mechanisms.

A Resonant Damping Study Using Piezoelectric Materials

NASA Technical Reports Server (NTRS)

Min, J. B.; Duffy, K. P.; Choi, B. B.; Morrison, C. R.; Jansen, R. H.; Provenza, A. J.

2008-01-01

Excessive vibration of turbomachinery blades causes high cycle fatigue (HCF) problems requiring damping treatments to mitigate vibration levels. Based on the technical challenges and requirements learned from previous turbomachinery blade research, a feasibility study of resonant damping control using shunted piezoelectric patches with passive and active control techniques has been conducted on cantilever beam specimens. Test results for the passive damping circuit show that the optimum resistive shunt circuit reduces the third bending resonant vibration by almost 50%, and the optimum inductive circuit reduces the vibration by 90%. In a separate test, active control reduced vibration by approximately 98%.

l-Asparaginase from Proteus vulgaris1

PubMed Central

Tosa, Tetsuya; Sano, Ryujiro; Yamamoto, Kozo; Nakamura, Masatoshi; Ando, Katsuko; Chibata, Ichiro

1971-01-01

To produce an immunologically and enzymologically new type of l-asparaginase, 108 strains of bacteria were screened for enzyme production. As a result, 13 bacteria belonging to the genera Alcaligenes, Bacterium, and Proteus were found to produce l-asparaginases in high levels. Among these l-asparaginases, partially purified l-asparaginases from B. cadaveris and P. vulgaris showed antitumor activity. A partially purified l-asparaginase preparation of P. vulgaris did not react with the antibody of Escherichia colil-asparaginase on the Ouchterlony agar plate. Culture conditions for the production of l-asparaginase by P. vulgaris were investigated in detail. The enzyme was produced in high yields when cells were grown aerobically in a medium containing sodium fumarate and corn steep liquor. The addition of glucose or ammonium ion to the medium, however, resulted in depressed production of l-asparaginase. Under the optimum conditions, 3,700 international units of l-asparaginase was obtained from 1 liter of culture medium. Images PMID:5000866

Production of Mushroom Mycelium as a Protein and Fat Source in Submerged Culture in Medium of Vinasse

PubMed Central

Falanghe, H.

1962-01-01

Of ten mushroom cultures investigated, only Agaricus campestris, Boletus indecisus, and Tricholoma nudum were capable of growing in submerged culture in medium of vinasse with added salts. Higher fermentative efficiencies were found under these conditions than in medium containing molasses or waste sulfite liquor. A. campestris showed a better capacity to produce protein but, since B. indecisus is capable of developing greater mycelium weight, its fermentative efficiencies are comparable. Both microorganisms could be grown in medium of vinasse with greatly varied amounts, producing higher mycelial weight in media with greater vinasse. The capacity of B. indecisus and A. campestris to utilize the noncarbohydrate fraction in total solids, instead of the total carbohydrates when they are in smaller amount, was observed in medium containing vinasse. B. indecisus and A. campestris were easily separated by filtration from the medium, although T. nudum was difficult to separate by this procedure. In experiments with A. campestris, the adaptative capacity of the organism to vinasse was demonstrated. PMID:13962715

Scheduling the blended solution as industrial CO2 absorber in separation process by back-propagation artificial neural networks.

PubMed

Abdollahi, Yadollah; Sairi, Nor Asrina; Said, Suhana Binti Mohd; Abouzari-lotf, Ebrahim; Zakaria, Azmi; Sabri, Mohd Faizul Bin Mohd; Islam, Aminul; Alias, Yatimah

2015-11-05

It is believe that 80% industrial of carbon dioxide can be controlled by separation and storage technologies which use the blended ionic liquids absorber. Among the blended absorbers, the mixture of water, N-methyldiethanolamine (MDEA) and guanidinium trifluoromethane sulfonate (gua) has presented the superior stripping qualities. However, the blended solution has illustrated high viscosity that affects the cost of separation process. In this work, the blended fabrication was scheduled with is the process arranging, controlling and optimizing. Therefore, the blend's components and operating temperature were modeled and optimized as input effective variables to minimize its viscosity as the final output by using back-propagation artificial neural network (ANN). The modeling was carried out by four mathematical algorithms with individual experimental design to obtain the optimum topology using root mean squared error (RMSE), R-squared (R(2)) and absolute average deviation (AAD). As a result, the final model (QP-4-8-1) with minimum RMSE and AAD as well as the highest R(2) was selected to navigate the fabrication of the blended solution. Therefore, the model was applied to obtain the optimum initial level of the input variables which were included temperature 303-323 K, x[gua], 0-0.033, x[MDAE], 0.3-0.4, and x[H2O], 0.7-1.0. Moreover, the model has obtained the relative importance ordered of the variables which included x[gua]>temperature>x[MDEA]>x[H2O]. Therefore, none of the variables was negligible in the fabrication. Furthermore, the model predicted the optimum points of the variables to minimize the viscosity which was validated by further experiments. The validated results confirmed the model schedulability. Accordingly, ANN succeeds to model the initial components of the blended solutions as absorber of CO2 capture in separation technologies that is able to industries scale up. Copyright © 2015 Elsevier B.V. All rights reserved.

Method for sequential injection of liquid samples for radioisotope separations

DOEpatents

Egorov, Oleg B.; Grate, Jay W.; Bray, Lane A.

2000-01-01

The present invention is a method of separating a short-lived daughter isotope from a longer lived parent isotope, with recovery of the parent isotope for further use. Using a system with a bi-directional pump and one or more valves, a solution of the parent isotope is processed to generate two separate solutions, one of which contains the daughter isotope, from which the parent has been removed with a high decontamination factor, and the other solution contains the recovered parent isotope. The process can be repeated on this solution of the parent isotope. The system with the fluid drive and one or more valves is controlled by a program on a microprocessor executing a series of steps to accomplish the operation. In one approach, the cow solution is passed through a separation medium that selectively retains the desired daughter isotope, while the parent isotope and the matrix pass through the medium. After washing this medium, the daughter is released from the separation medium using another solution. With the automated generator of the present invention, all solution handling steps necessary to perform a daughter/parent radionuclide separation, e.g. Bi-213 from Ac-225 "cow" solution, are performed in a consistent, enclosed, and remotely operated format. Operator exposure and spread of contamination are greatly minimized compared to the manual generator procedure described in U.S. patent application Ser. No. 08/789,973, now U.S. Pat. No. 5,749,042, herein incorporated by reference. Using 16 mCi of Ac-225 there was no detectable external contamination of the instrument components.

In vitro cultivation of Hysterothylacium aduncum (Nematoda: Anisakidae) from 3rd-stage larvae to egg-laying adults.

PubMed

Iglesias, L; Valero, A; Gálvez, L; Benítez, R; Adroher, F J

2002-11-01

This is the first demonstration of the in vitro development of the 3rd-stage larvae (L3) of Hysterothylacium aduncum to the adult. This was achieved in a semi-defined medium that is easy to prepare and to reproduce. The L3, collected from the peritoneal cavity of horse mackerel (Trachurus trachurus), were individually inoculated into RPMI-1640 medium +20% heat-inactivated fetal bovine serum (IFBS). It has been demonstrated that the optimum temperature for development is around 13 degrees C and is stimulated by the presence of 5% CO2 in the growth atmosphere, increasing the percentage moulting to the 4th larval stage (L4) by 1.9-fold (from 44 to 82%) and the average survival of the nematodes by 1.6 times (from 60 to 96 days). When the larvae were grown at different pHs, optimum development occurred at pH 4.0. Under these conditions, all the larvae moulted to the L4 and more than two-thirds transformed to the adult stage--in which 25-30% of the females laid eggs--and reached an average survival of over 4 months. When this medium was supplemented with 1% (w/v) of commercial pepsin, all the larvae reached the adult stage, at least 45% of the females oviposited, laying around 12-fold more eggs per female than in the medium without pepsin. The mean size of the eggs (non-fertilized) obtained was 56.8 x 47.6 microm. The mean length of the adult males obtained was between 3.2 and 5.2 cm and the females were between 3.0 and 6.5 cm. The adult specimens were morphologically identified as Hysterothylacium aducum aduncum. This culture medium (RPMI-1640+20% (v/v) IFBS+1 commercial pepsin, at pH 4.0, 13 degrees C and 5% CO2 in air) could facilitate the identification of at least some of the larvae of the genus Hysterothylacium--and perhaps other anisakids--for which the specific identification and the biological study of these parasites is often difficult.

Dense Medium Ore Concentrates of Bois-Noirs; MINERAIS DES BOIS NOIRS CONCENTRES DE MILIEU DENSE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le Bris, J.; Leduc, M.

1959-01-01

The chemical treatment of uranium concentrates of BoisNoirs ore obtained by heavy medium are discussed. The first part deals with sulfuric acid attack on the concentrate, and the second part with the separation of the solution from residues by filtration. A third part deals with this separation by decantation. The fourth part deals with the carbonation of the pickling solutions obtained. (auth)

Experimental design data for the biosynthesis of citric acid using Central Composite Design method.

PubMed

Kola, Anand Kishore; Mekala, Mallaiah; Goli, Venkat Reddy

2017-06-01

In the present investigation, we report that statistical design and optimization of significant variables for the microbial production of citric acid from sucrose in presence of filamentous fungi A. niger NCIM 705. Various combinations of experiments were designed with Central Composite Design (CCD) of Response Surface Methodology (RSM) for the production of citric acid as a function of six variables. The variables are; initial sucrose concentration, initial pH of medium, fermentation temperature, incubation time, stirrer rotational speed, and oxygen flow rate. From experimental data, a statistical model for this process has been developed. The optimum conditions reported in the present article are initial concentration of sucrose of 163.6 g/L, initial pH of medium 5.26, stirrer rotational speed of 247.78 rpm, incubation time of 8.18 days, fermentation temperature of 30.06 °C and flow rate of oxygen of 1.35 lpm. Under optimum conditions the predicted maximum citric acid is 86.42 g/L. The experimental validation carried out under the optimal values and reported citric acid to be 82.0 g/L. The model is able to represent the experimental data and the agreement between the model and experimental data is good.

[In vitro flowering of cultures from a hybrid of Cymbidium goeringii and C. hybridium].

PubMed

Zheng, Li-Ming; Pang, Ji-Liang

2006-06-01

Wild-type female spring orchid (Cymbidium goeringii) was crossed with male Cymbidium hybridium. Over eight hundred protocorm clones were obtained from hybrid offsprings. Among them, one protocorm clone was identified to differentiate visible floral buds two months after subculture in vitro (Plate I). The protocorms and shoots derived from this clone were further used in studying the effects of abscisic acid (ABA) and paclobutrazol (PP333) pretreatment as well as different concentrations of 6-benzyladenine (6-BA) on floral bud differentiation. The optimum combination of hormones in floral bud induction was 6-BA 1.0 mg/L and NAA 0.1 mg/L, and total frequency of floral bud formation was up to 31% (Table 1). The optimum length of shoots used in floral bud induction was 1-2 cm, and the frequency of floral bud formation was 19% (Table 1). The increase in total frequency was not significant in floral bud induction from protocorms and shoots with length of 1-2 cm or 2-4 cm cultured on MS medium containing 6-BA 1.0 mg/L and NAA 0.1 mg/L after pretreatment on MS medium supplemented with ABA 0.5 mg/L and PP333 0.5 mg/L for 35 d (Table 2).

Light intensity alters the extent of arsenic toxicity in Helianthus annuus L. seedlings.

PubMed

Yadav, Geeta; Srivastava, Prabhat Kumar; Singh, Vijay Pratap; Prasad, Sheo Mohan

2014-06-01

The present study is aimed at assessing the extent of arsenic (As) toxicity under three different light intensities-optimum (400 μmole photon m(-2) s(-1)), sub-optimum (225 μmole photon m(-2) s(-1)), and low (75 μmole photon m(-2) s(-1))-exposed to Helianthus annuus L. var. DRSF-113 seedlings by examining various physiological and biochemical parameters. Irrespective of the light intensities under which H. annuus L. seedlings were grown, there was an As dose (low, i.e., 6 mg kg(-1) soil, As1; and high, i.e., 12 mg kg(-1) soil, As2)-dependent decrease in all the growth parameters, viz., fresh mass, shoot length, and root length. Optimum light-grown seedlings exhibited better growth performance than the sub-optimum and low light-grown seedlings; however, low light-grown plants had maximum root and shoot lengths. Accumulation of As in the plant tissues depended upon its concentration used, proximity of the plant tissue, and intensity of the light. Greater intensity of light allowed greater assimilation of photosynthates accompanied by more uptake of nutrients along with As from the medium. The levels of chlorophyll a, b, and carotenoids declined with increasing concentrations of As. Seedlings acquired maximum Chl a and b under optimum light which were more compatible to face As1 and As2 doses of As, also evident from the overall status of enzymatic (SOD, POD, CAT, and GST) and non-enzymatic antioxidant (Pro).

Novel nanocomposite Kevlar fabric membranes: Fabrication characterization, and performance in oil/water separation

NASA Astrophysics Data System (ADS)

Karimnezhad, Hanieh; Rajabi, Laleh; Salehi, Ehsan; Derakhshan, Ali Ashraf; Azimi, Sara

2014-02-01

Nanocomposite membranes with hydrophilic surface were fabricated for separation of oil (n-hexane) from oil/water emulsion. Three different nanomaterials namely, para-aminobenzoate alumoxane (PAB-A), boehmite-epoxide and polycitrate alumoxane (PC-A) were coated on the Kevlar fabric (support), according to a three-step dip-coating protocol. FTIR, SEM, TEM, UV/vis spectrophotometer, and wettability analyses were used to characterize the composite membranes. The three coating layers interacted chemically with one another and also physically with the Kevlar fabric. Water uptake measurements indicated that the membrane is a hydrophilic one. SEM and TEM analyses showed the smooth surface of the composite membrane and three-dimensional dendrimeric hyper-branched structure of (PC-A), respectively. A dead-end filtration setup was applied to test the membranes performance under natural gravity force. Effect of pH as an important variable affecting separation process was investigated with the neutral pH provided the optimum condition for the separation. Oil rejection and permeate fluxes were also monitored. The optimum flux and rejection obtained, were 7392 (Lm-2 h-1) and 89.06% at pH 7, respectively. Fouling occurred as a gel layer on the membrane surface. The deposited oil droplets on the surface of the membrane were successfully washed away with satisfactory permeate flux recovery (FRR = 88.88% at neutral pH), using hot distilled water and acidic solution as eluents.

Cherenkov and scintillation light separation on the TheiaR &D experiment

NASA Astrophysics Data System (ADS)

Caravaca, Javier; Land, Benjamin

2016-03-01

Identifying by separate the scintillation and Cherenkov light produced in a scintillation medium enables outstanding capabilities for future particle detectors, being the most relevant: allowing particle directionality information in a low energy threshold detector and improved particle identification. The TheiaR &D experiment uses an array of small and fast photomultipliers (PMTs) and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillation medium, based on the number of produced photoelectrons and the timing information. A charged particle ionizing a scintillation medium produces a prompt Cherenkov cone and late isotropic scintillation light, typically delayed by <1ns. The fast response of our PMTs and DAQ provides a precision well below the ns level, making possible the time separation. Furthermore, the usage of the new developed water-based liquid scintillators (WBLS) provides a medium with a tunable Cherenkov/Scintillation light yield ratio, enhancing the visibility of the dimer Cherenkov light in presence of the scintillation light. Description of the experiment, details of the analysis and preliminary results of the first months of running will be discussed.

Somatic embryogenesis of carrot in hormone-free medium: external pH control over morphogenesis

NASA Technical Reports Server (NTRS)

Smith, D. L.; Krikorian, A. D.

1990-01-01

Cultures of preglobular stage proembryos (PGSPs) were initiated from mechanically wounded mature zygotic embryos of carrot, Daucus carota, on a hormone-free, semisolid medium. These PGSPs have been maintained and multiplied for extended periods without their progression into later embryo stages on the same hormone-free medium containing 1 mM NH4+ as the sole nitrogen source. Sustained maintenance of cultures comprised exclusively of PGSPs was dependent on medium pH throughout the culture period. Best growth and multiplication of PGSP cultures occurred when the pH of unbuffered, hormone-free medium fell from 4.5 to 4 over a 2-week period or when buffered medium was titrated to pH 4. If the hormone-free medium was buffered to sustain a pH at or above 4.5, PGSPs developed into later embryo stages. Maintenance with continuous multiplication of PGSPs occurred equally well on medium containing NH4+ or NH4+ and NO3-, but growth was poor with NO3- alone. Additional observations on the effects of medium components such as various nitrogen sources and levels, sucrose concentration, semisolid supports, type of buffer, borate concentration, activated charcoal, and initial pH that permit optimum maintenance of the PGSPs or foster their continued developmental progression into mature embryos and plantlets are reported. The influence of the pH of the hormone-free medium as a determinant in maintaining cultures as PGSPs or allowing their continued embryonic development are unequivocally demonstrated by gross morphology, scanning electron microscopy, and histological preparations.

A low speed two-dimensional study of flow separation on the GA(W)-1 airfoil with 30-percent chord Fowler flap

NASA Technical Reports Server (NTRS)

Seetharam, H. C.; Wentz, W. H., Jr.

1977-01-01

Measurements of flow fields with low speed turbulent boundary layers were made for the GA(W)-1 airfoil with a 0.30 c Fowler flap deflected 40 deg at angles of attack of 2.7 deg, 7.7 deg, and 12.8 deg, at a Reynolds number of 2.2 million, and a Mach number of 0.13. Details of velocity and pressure fields associated with the airfoil flap combination are presented for cases of narrow, optimum and wide slot gaps. Extensive flow field turbulence surveys were also conducted employing hot-film anemometry. For the optimum gap setting, the boundaries of the regions of flow reversal within the wake were determined by this technique for two angles of attack. Local skin friction distributions for the basic airfoil and the airfoil with flap (optimum gap) were obtained using the razor blade technique.

Treatment of slaughter wastewater by coagulation sedimentation-anaerobic biological filter and biological contact oxidation process

NASA Astrophysics Data System (ADS)

Sun, M.; Yu, P. F.; Fu, J. X.; Ji, X. Q.; Jiang, T.

2017-08-01

The optimal process parameters and conditions for the treatment of slaughterhouse wastewater by coagulation sedimentation-AF - biological contact oxidation process were studied to solve the problem of high concentration organic wastewater treatment in the production of small and medium sized slaughter plants. The suitable water temperature and the optimum reaction time are determined by the experiment of precipitation to study the effect of filtration rate and reflux ratio on COD and SS in anaerobic biological filter and the effect of biofilm thickness and gas water ratio on NH3-N and COD in biological contact oxidation tank, and results show that the optimum temperature is 16-24°C, reaction time is 20 min in coagulating sedimentation, the optimum filtration rate is 0.6 m/h, and the optimum reflux ratio is 300% in anaerobic biological filter reactor. The most suitable biological film thickness range of 1.8-2.2 mm and the most suitable gas water ratio is 12:1-14:1 in biological contact oxidation pool. In the coupling process of continuous operation for 80 days, the average effluent’s mass concentrations of COD, TP and TN were 15.57 mg/L, 40 mg/L and 0.63 mg/L, the average removal rates were 98.93%, 86.10%, 88.95%, respectively. The coupling process has stable operation effect and good effluent quality, and is suitable for the industrial application.

High-speed reference-beam-angle control technique for holographic memory drive

NASA Astrophysics Data System (ADS)

Yamada, Ken-ichiro; Ogata, Takeshi; Hosaka, Makoto; Fujita, Koji; Okuyama, Atsushi

2016-09-01

We developed a holographic memory drive for next-generation optical memory. In this study, we present the key technology for achieving a high-speed transfer rate for reproduction, that is, a high-speed control technique for the reference beam angle. In reproduction in a holographic memory drive, there is the issue that the optimum reference beam angle during reproduction varies owing to distortion of the medium. The distortion is caused by, for example, temperature variation, beam irradiation, and moisture absorption. Therefore, a reference-beam-angle control technique to position the reference beam at the optimum angle is crucial. We developed a new optical system that generates an angle-error-signal to detect the optimum reference beam angle. To achieve the high-speed control technique using the new optical system, we developed a new control technique called adaptive final-state control (AFSC) that adds a second control input to the first one derived from conventional final-state control (FSC) at the time of angle-error-signal detection. We established an actual experimental system employing AFSC to achieve moving control between each page (Page Seek) within 300 µs. In sequential multiple Page Seeks, we were able to realize positioning to the optimum angles of the reference beam that maximize the diffracted beam intensity. We expect that applying the new control technique to the holographic memory drive will enable a giga-bit/s-class transfer rate.

Benefaction studies on the Hasan Celebi magnetite deposit, Turkey

USGS Publications Warehouse

Pressler, Jean W.; Akar, Ali

1972-01-01

Bench-scale and semicontinuous tests were performed on surface, trench, and diamond drill core samples from the Hasan Celebi low-grade magnetite deposit to determine the optimum benefication procedures utilizing wet magnetic separation techniques. Composite core samples typically contain about 27 percent recoverable magnetite and require crushing and grinding through 1 mm in size to insure satisfactory separation of the gangue from the magnetite. Regrinding and cleaning the magnetite concentrate to 80 percent minus 150-mesh is necessary to obtain an optimum of 66 percent iron. Semicontinuous pilot-plant testing with the wet magnetic drum using the recycled middling technique indicates that as much as 83 percent of the acid-soluble iron can be recovered into a concentrate containing 66 percent iron, with minimum deleterious elements. This represents 27 weight percent of the original ore. Further tests will continue when the Maden Tetkik ve Arama Enstitusu (MTA) receives 24 tons of bulk sample from an exploratory drift and cross-cut now being driven through a section of the major reserve area.

Optimization of gold ore Sumbawa separation using gravity method: Shaking table

NASA Astrophysics Data System (ADS)

Ferdana, Achmad Dhaefi; Petrus, Himawan Tri Bayu Murti; Bendiyasa, I. Made; Prijambada, Irfan Dwidya; Hamada, Fumio; Sachiko, Takahi

2018-04-01

Most of artisanal small gold mining in Indonesia has been using amalgamation method, which caused negative impact to the environment around ore processing area due to the usage of mercury. One of the more environmental-friendly method for gold processing is gravity method. Shaking table is one of separation equipment of gravity method used to increase concentrate based on difference of specific gravity. The optimum concentration result is influenced by several variables, such as rotational speed shaking, particle size and deck slope. In this research, the range of rotational speed shaking was between 100 rpm and 200 rpm, the particle size was between -100 + 200 mesh and -200 + 300 mesh and deck slope was between 3° and 7°. Gold concentration in concentrate was measured by EDX. The result shows that the optimum condition is obtained at a shaking speed of 200 rpm, with a slope of 7° and particle size of -100 + 200 mesh.

Removal of unburned carbon from coal fly ash using a pneumatic triboelectrostatic separator.

PubMed

Kim, J K; Cho, H C; Kim, S C

2001-01-01

A pneumatic triboelectrostatic beneficiation system of fly ash was studied using a continuous, bench-scale electroseparator composed of two vertical electrode plates and an ejector-tribocharger. Tests were conducted to evaluate the charge density and the separation efficiency at various operating conditions. It was found that the higher charge densities were obtained at (1) the air flow rate of 1.75 m3/min. (2) the feed rate of less than 50 kg/h. and (3) the relative humidity of less than 30% with use of a stainless ejector tribocharger. With these optimum conditions, the clean ash of less than LOI 3% was recovered with a yield over 75% when operated at the diffuser slit gap of 4mm, the diffuser outlet velocity of 16.1-18.6 m/s, and the distance of 15 cm between diffuser slit and splitter. The optimum feed rate was found to be 740 kg/h per m2 of electrode surface area, which can be used as a scale-up factor of electroseparator.

Facile fabrication of BiVO4 nanofilms with controlled pore size and their photoelectrochemical performances

NASA Astrophysics Data System (ADS)

Feng, Chenchen; Jiao, Zhengbo; Li, Shaopeng; Zhang, Yan; Bi, Yingpu

2015-12-01

We demonstrate a facile method for the rational fabrication of pore-size controlled nanoporous BiVO4 photoanodes, and confirmed that the optimum pore-size distributions could effectively absorb visible light through light diffraction and confinement functions. Furthermore, in situ X-ray photoelectron spectroscopy (XPS) reveals more efficient photoexcited electron-hole separation than conventional particle films, induced by light confinement and rapid charge transfer in the inter-crossed worm-like structures.We demonstrate a facile method for the rational fabrication of pore-size controlled nanoporous BiVO4 photoanodes, and confirmed that the optimum pore-size distributions could effectively absorb visible light through light diffraction and confinement functions. Furthermore, in situ X-ray photoelectron spectroscopy (XPS) reveals more efficient photoexcited electron-hole separation than conventional particle films, induced by light confinement and rapid charge transfer in the inter-crossed worm-like structures. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06584d

[Technological process of cell disruption for extracting astaxanthin from Phaffia rhodozyma by acid method under autoclave conditions].

PubMed

Lu, Baoju; Xiao, Anfeng; Lil, Lijun; Ni, Hui; Cai, Huinong; Su, Wenjin

2008-07-01

Phaffia rhodozyma is one of the organisms for production of astaxanthin, and the key process for extracting intracellular astaxanthin is cell disruption. In this work, cell disruption for extracting astaxanthin from Phaffia rhodozyma was studied with autoclave method at low acid concentration. The optimum disrupting conditions were: autoclave pressure 0.1 MPa, 121 degrees C; hydrochloric acid concentration 0.5 mol/L; liquid to material ratio (V/W) 30 mL/g dry cell weight and disruption time 2 min. Under the optimum conditions, medium scale experiment showed that astaxanthin and total carotenoids recovery from Phaffia rhodozyma were (84.8 +/- 3.2)% and (93.3 +/- 2)%, respectively. This new method can lead to no poisonous residues and get high extraction yield, which have good prospects to be put into industrial production.

Optimum satellite orbits for accurate measurement of the earth's radiation budget, summary

NASA Technical Reports Server (NTRS)

Campbell, G. G.; Vonderhaar, T. H.

1978-01-01

The optimum set of orbit inclinations for the measurement of the earth radiation budget from spacially integrating sensor systems was estimated for two and three satellite systems. The best set of the two were satellites at orbit inclinations of 80 deg and 50 deg; of three the inclinations were 80 deg, 60 deg and 50 deg. These were chosen on the basis of a simulation of flat plate and spherical detectors flying over a daily varying earth radiation field as measured by the Nimbus 3 medium resolution scanners. A diurnal oscillation was also included in the emitted flux and albedo to give a source field as realistic as possible. Twenty three satellites with different inclinations and equator crossings were simulated, allowing the results of thousand of multisatellite sets to be intercompared. All were circular orbits of radius 7178 kilometers.

Enhancement of 2,3-Butanediol Production by Klebsiella oxytoca PTCC 1402

PubMed Central

Anvari, Maesomeh; Safari Motlagh, Mohammad Reza

2011-01-01

Optimal operating parameters of 2,3-Butanediol production using Klebsiella oxytoca under submerged culture conditions are determined by using Taguchi method. The effect of different factors including medium composition, pH, temperature, mixing intensity, and inoculum size on 2,3-butanediol production was analyzed using the Taguchi method in three levels. Based on these analyses the optimum concentrations of glucose, acetic acid, and succinic acid were found to be 6, 0.5, and 1.0 (% w/v), respectively. Furthermore, optimum values for temperature, inoculum size, pH, and the shaking speed were determined as 37°C, 8 (g/L), 6.1, and 150 rpm, respectively. The optimal combinations of factors obtained from the proposed DOE methodology was further validated by conducting fermentation experiments and the obtained results revealed an enhanced 2,3-Butanediol yield of 44%. PMID:21318172

Isolation, Fractionation and Characterization of Catalase from Neurospora crassa (InaCC F226)

NASA Astrophysics Data System (ADS)

Suryani; Ambarsari, L.; Lindawati, E.

2017-03-01

Catalase from Indigenous isolate Neurospora crassa InaCC F226 has been isolated, fractionated and characterized. Production of catalase by Neurospora crassa was done by using PDA medium (Potato Dextrosa Agar) and fractionated with ammonium sulphate with 20-80% saturation. Fraction 60% was optimum saturation of ammonium sulphate and had highest specific activity 3339.82 U/mg with purity 6.09 times, total protein 0.920 mg and yield 88.57%. The optimum pH and temperature for catalase activity were at 40°C and pH 7.0, respectively. The metal ions that stimulated catalase activity acted were Ca2+, Mn2+ and Zn2+, and inhibitors were EDTA, Mg2+ and Cu2+. Based on Km and Vmax values were 0.2384 mM and 13.3156 s/mM.

A defined, glucose-limited mineral medium for the cultivation of Listeria spp.

PubMed

Schneebeli, Rudolf; Egli, Thomas

2013-04-01

Members of the genus Listeria are fastidious bacteria with respect to their nutritional requirements, and several minimal media described in the literature fail to support growth of all Listeria spp. Furthermore, strict limitation by a single nutrient, e.g., the carbon source, has not been demonstrated for any of the published minimal media. This is an important prerequisite for defined studies of growth and physiology, including "omics." Based on a theoretical analysis of previously published mineral media for Listeria, an improved, well-balanced growth medium was designed. It supports the growth, not only of all tested Listeria monocytogenes strains, but of all other Listeria species, with the exception of L. ivanovii. The growth performance of L. monocytogenes strain Scott A was tested in the newly designed medium; glucose served as the only carbon and energy source for growth, whereas neither the supplied amino acids nor the buffering and complexing components (MOPS [morpholinepropanesulfonic acid] and EDTA) supported growth. Omission of amino acids, trace elements, or vitamins, alone or in combination, resulted in considerably reduced biomass yields. Furthermore, we monitored the specific growth rates of various Listeria strains cultivated in the designed mineral medium and compared them to growth in complex medium (brain heart infusion broth [BHI]). The novel mineral medium was optimized for the commonly used strain L. monocytogenes Scott A to achieve optimum cell yields and maximum specific growth rates. This mineral medium is the first published synthetic medium for Listeria that has been shown to be strictly carbon (glucose) limited.

Optimization of circular plate separators with cross flow for removal of oil droplets and solid particles.

PubMed

Ngu, Hei; Wong, Kien Kuok; Law, Puong Ling

2012-04-01

A circular gravity-phase separator using coalescing medium with cross flow was developed to remove oil and suspended solids from wastewaters. Coalescence medium in the form of inclined plates promotes rising of oil droplets through coalescence and settling of solid particles through coagulation. It exhibits 22.67% higher removal of total suspended solids (TSS) compared to separators without coalescing medium. Moreover, it removed more than 70% of oil compared to conventional American Petroleum Institute separators, which exhibit an average of 33% oil removal. The flowrate required to attain an effluent oil concentration of 10 mg/L (Q(o10)) at different influent oil concentrations (C(io)) can be represented by Q(o10) x 10(-5) = -0.0012C(io) + 0.352. The flowrate required to attain an effluent TSS concentration of 50 mg/L (Q(ss50)) at different influent TSS concentrations (C(iss)) can be represented by Q(ss50) x 10(-5) = 1.0 x 10(6) C(iss)(-2.9576). The smallest removable solid particle size was 4.87 microm.

Enhancing Centrifugal Separation With Electrophoresis

NASA Technical Reports Server (NTRS)

Herrmann, F. T.

1986-01-01

Separation of biological cells by coil-planet centrifuge enhanced by electrophoresis. By itself, coil-planet centrifuge offers relatively gentle method of separating cells under low centrifugal force in physiological medium that keeps cells alive. With addition of voltage gradient to separation column of centrifuge, separation still gentle but faster and more complete. Since separation apparatus contains no rotary seal, probability of leakage, contamination, corrosion, and short circuits reduced.

High gradient magnetic beneficiation of dry pulverized coal via upwardly directed recirculating fluidization

DOEpatents

Eissenberg, David M.; Liu, Yin-An

1980-01-01

This invention relates to an improved device and method for the high gradient magnetic beneficiation of dry pulverized coal, for the purpose of removing sulfur and ash from the coal whereby the product is a dry environmentally acceptable, low-sulfur fuel. The process involves upwardly directed recirculating air fluidization of selectively sized powdered coal in a separator having sections of increasing diameters in the direction of air flow, with magnetic field and flow rates chosen for optimum separations depending upon particulate size.

CALUTRON RECEIVERS

DOEpatents

Lofgren, E.J.

1958-09-01

Improvements are described in isotope separation devices of the calutron type and, in particular, deals with a novel caiutron receiver which passes the optimum portions of the ion beam to a collecting chamber. In broad aspects the receiver provides means for pass delimited pontion of the beam and an elongated collecting pocket disposed to receive ions passed by the beam delimiting means. The collecting pocket is transversely partitioned into a plurality of ion receiving compartments respectively defined by a corresponding plurality of separately removable liner elements.

Functionalized Media and Methods of Making and Using Therefor

NASA Technical Reports Server (NTRS)

Huang, Yongsong (Inventor); Dillon, James (Inventor)

2017-01-01

Methods, compositions, devices and kits are provided herein for separating, scavenging, capturing or identifying a metal from a target using a medium or scaffold with a selenium-containing functional group. The medium or the scaffold including the selenium-containing functional group has affinity and specificity to metal ions or compounds having one or more metals, and efficiently separates, recovers, and scavenges of the metals from a target such as a sample, solution, suspension, or mixture.

Apparatus for separating particles utilizing engineered acoustic contrast capture particles

DOEpatents

Kaduchak, Gregory; Ward, Michael D

2014-10-21

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

Apparatus for separating particles utilizing engineered acoustic contrast capture particles

DOEpatents

Kaduchak, Gregory [Los Alamos, NM; Ward, Michael D [Los Alamos, NM

2011-12-27

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

Synthesis and antimicrobial activity of gold nanoparticle conjugates with cefotaxime

NASA Astrophysics Data System (ADS)

Titanova, Elena O.; Burygin, Gennady L.

2016-04-01

Gold nanoparticles (GNPs) have attracted significant interest as a novel platform for various applications to nanobiotechnology and biomedicine. The conjugates of GNPs with antibiotics and antibodies were also used for selective photothermal killing of protozoa and bacteria. Also the conjugates of some antibiotics with GNPs decreased the number of bacterial growing cells. In this work was made the procedure optimization for conjugation of cefotaxime (a third-generation cephalosporin antibiotic) with GNPs (15 nm) and we examined the antimicrobial properties of this conjugate to bacteria culture of E. coli K-12. Addition of cefotaxime solution to colloidal gold does not change their color and extinction spectrum. For physiologically active concentration of cefotaxime (3 μg/mL), it was shown that the optimum pH for the conjugation was more than 9.5. A partial aggregation of the GNPs in saline medium was observed at pH 6.5-7.5. The optimum concentration of K2CO3 for conjugation cefotaxime with GNPs-15 was 5 mM. The optimum concentration of cefotaxime was at 0.36 μg/mL. We found the inhibition of the growth of E. coli K12 upon application cefotaxime-GNP conjugates.

Topics in Chemical Instrumentation: An Introduction to Supercritical Fluid Chromatography--Part 2. Applications and Future Trends.

ERIC Educational Resources Information Center

Palmieri, Margo D.

1989-01-01

Discussed are selected application and future trends in supercritical fluid chromatography (SFC). The greatest application for SFC involves those analytes that are difficult to separate using GC or LC methods. Optimum conditions for SFC are examined. Provided are several example chromatograms. (MVL)

Chapter 7: Materials for Launch Vehicle Structures

NASA Technical Reports Server (NTRS)

Henson, Grant; Jone, Clyde S. III

2017-01-01

This chapter concerns materials for expendable and reusable launch vehicle (LV) structures. An emphasis is placed on applications and design requirements, and how these requirements are met by the optimum choice of materials. Structural analysis and qualification strategies, which cannot be separated from the materials selection process, are described.

Thiophilic paramagnetic particles as a batch separation medium for the purification of antibodies from various source materials.

PubMed

Dawes, Clive C; Jewess, Philip J; Murray, Deborah A

2005-03-15

A preparation of thiophilic agarose-based paramagnetic particles (T-Gel) has been developed with physical characteristics (particle size and particle density) that facilitate its use as a batch separation medium suitable for the large-scale purification and isolation of immunoglobulins. The medium was used to extract immunoglobulins from a wide range of starting materials, including sera, ascites fluid, tissue culture medium, and whole blood. None of these starting materials required pretreatment such as clarification by centrifugation or filtration prior to antibody extraction. The antibody purity obtained using T-Gel compared well with that obtained using protein A agarose column chromatography. Yields were approximately 30 mg of immunoglobulins per milliliter of T-Gel, and little was required in the way of specialist equipment. The method is uncomplicated and involves a roll mix extraction overnight, followed by magnetic separation to facilitate supernatant removal and subsequent washing of the particles. Elution of bound antibodies was carried out at neutral pH to yield a concentration of immunoglobulins that was approximately 7 mg/ml. The method was found to be applicable to antibody purification from the blood serum of seven different mammalian species and for all immunoglobulin classes.

A Memetic Algorithm for Global Optimization of Multimodal Nonseparable Problems.

PubMed

Zhang, Geng; Li, Yangmin

2016-06-01

It is a big challenging issue of avoiding falling into local optimum especially when facing high-dimensional nonseparable problems where the interdependencies among vector elements are unknown. In order to improve the performance of optimization algorithm, a novel memetic algorithm (MA) called cooperative particle swarm optimizer-modified harmony search (CPSO-MHS) is proposed in this paper, where the CPSO is used for local search and the MHS for global search. The CPSO, as a local search method, uses 1-D swarm to search each dimension separately and thus converges fast. Besides, it can obtain global optimum elements according to our experimental results and analyses. MHS implements the global search by recombining different vector elements and extracting global optimum elements. The interaction between local search and global search creates a set of local search zones, where global optimum elements reside within the search space. The CPSO-MHS algorithm is tested and compared with seven other optimization algorithms on a set of 28 standard benchmarks. Meanwhile, some MAs are also compared according to the results derived directly from their corresponding references. The experimental results demonstrate a good performance of the proposed CPSO-MHS algorithm in solving multimodal nonseparable problems.

Stationary and oscillatory convection of binary fluids in a porous medium.

PubMed

Augustin, M; Umla, R; Huke, B; Lücke, M

2010-11-01

We investigate numerically stationary convection and traveling wave structures of binary fluid mixtures with negative separation ratio in the Rayleigh-Bénard system filled with a porous medium. The bifurcation behavior of these roll structures is elucidated as well as the properties of the velocity, temperature, and concentration fields. Moreover, we discuss lateral averaged currents of temperature and concentration. Finally, we investigate the influence of the Lewis number, of the separation ratio, and of the normalized porosity on the bifurcation branches.

Fine coal cleaning via the micro-mag process

DOEpatents

Klima, Mark S.; Maronde, Carl P.; Killmeyer, Richard P.

1991-01-01

A method of cleaning particulate coal which is fed with a dense medium slurry as an inlet feed to a cyclone separator. The coal particle size distribution is in the range of from about 37 microns to about 600 microns. The dense medium comprises water and ferromagnetic particles that have a relative density in the range of from about 4.0 to about 7.0. The ferromagnetic particles of the dense medium have particle sizes of less than about 15 microns and at least a majority of the particle sizes are less than about 5 microns. In the cyclone, the particulate coal and dense-medium slurry is separated into a low gravity product stream and a high gravity produce stream wherein the differential in relative density between the two streams is not greater than about 0.2. The low gravity and high gravity streams are treated to recover the ferromagnetic particles therefrom.

Wavelength-resonant surface-emitting semiconductor laser

DOEpatents

Brueck, Steven R. J.; Schaus, Christian F.; Osinski, Marek A.; McInerney, John G.; Raja, M. Yasin A.; Brennan, Thomas M.; Hammons, Burrell E.

1989-01-01

A wavelength resonant semiconductor gain medium is disclosed. The essential feature of this medium is a multiplicity of quantum-well gain regions separated by semiconductor spacer regions of higher bandgap. Each period of this medium consisting of one quantum-well region and the adjacent spacer region is chosen such that the total width is equal to an integral multiple of 1/2 the wavelength in the medium of the radiation with which the medium is interacting. Optical, electron-beam and electrical injection pumping of the medium is disclosed. This medium may be used as a laser medium for single devices or arrays either with or without reflectors, which may be either semiconductor or external.

Optimization of growth for the hyperthermophilic archaeon Aeropyrum pernix on a small-batch scale.

PubMed

Milek, Igor; Cigic, Blaz; Skrt, Mihaela; Kaletunç, Gönül; Ulrih, Natasa Poklar

2005-09-01

Growth of Aeropyrum pernix, the first reported aerobic neutrophilic hyperthermophilic archaeon, was investigated under different cultivation parameters. Different sources of seawater, pH, and the cultivation methods were tested with the aim to improve the biomass production. A 1-L glass flask fitted with a condenser and air diffuser was used as a bioreactor. The optimum conditions for maximizing A. pernix biomass were obtained when Na2S2O3.5H2O (1 g/L) with added marine broth 2216 at pH 7.0 (20 mmol HEPES buffer/L) was used as a growing medium in a 1-L flask. The biomass production was 0.45 g dry cell mass/L in 40 h under the optimum conditions, which is more than the 0.42 g dry cell mass/L in 60 h previously obtained.

An optimization model for energy generation and distribution in a dynamic facility

NASA Technical Reports Server (NTRS)

Lansing, F. L.

1981-01-01

An analytical model is described using linear programming for the optimum generation and distribution of energy demands among competing energy resources and different economic criteria. The model, which will be used as a general engineering tool in the analysis of the Deep Space Network ground facility, considers several essential decisions for better design and operation. The decisions sought for the particular energy application include: the optimum time to build an assembly of elements, inclusion of a storage medium of some type, and the size or capacity of the elements that will minimize the total life-cycle cost over a given number of years. The model, which is structured in multiple time divisions, employ the decomposition principle for large-size matrices, the branch-and-bound method in mixed-integer programming, and the revised simplex technique for efficient and economic computer use.

Xanthan gum production using jackfruit-seed-powder-based medium: optimization and characterization.

PubMed

Felicia Katherine, R; Muthukumaran, C; Sharmila, G; Manoj Kumar, N; Tamilarasan, K; Jaiganesh, R

2017-08-01

Xanthan gum (XG) production by Xanthomonas campestris NCIM 2961 using jackfruit seed powder (JSP) as a novel substrate was reported. Central composite design (CCD) of response surface method (RSM) was used to evaluate the linear and interaction effects of five medium variables (JSP, peptone, citric acid, K 2 HPO 4 and KH 2 PO 4 ) for XG production. Maximum XG production (51.62 g/L) was observed at the optimum level of JSP (4 g/L), peptone (0.93 g/L), citric acid (0.26 g/L), K 2 HPO 4 (1.29 g/L) and KH 2 PO 4 (0.5 g/L). K 2 HPO 4 and KH 2 PO 4 were found as significant medium components, which served as buffering agents as well as nutrients for X. campestris growth. The obtained biopolymer was characterized as XG by XRD and FTIR analysis. Results of this study revealed that JSP was found to be a suitable low cost substrate for XG production.

In Vitro Flower Induction from Shoots Regenerated from Cultured Axillary Buds of Endangered Medicinal Herb Swertia chirayita H. Karst.

PubMed Central

Kamal, Barkha; Srivastava, Nidhi; Dobriyal, Anoop Kumar; Jadon, Vikash Singh

2014-01-01

In vitro flowering and effective micropropagation protocol were studied in Swertia chirayita, an important medicinal plant using axillary bud explants. The Murashige and Skoog's medium (MS) supplemented with benzyl amino purine (BAP) 1.0 mg L−1 and adenine sulfate 70.0 mg L−1 was found optimum for production of multiple shoots. In the present study, incubation of flowering cultures on BAP supplemented medium (during shoot multiplication) was found necessary for flowering (6 weeks). However, concentrations of auxins-like IBA (0–2.0 mg/L) were ineffective to form reproductive buds. Subculture duration, photoperiod, and carbon source type do have influence on the in vitro flowering. The mature purple flowers were observed when the cultures were maintained in the same medium. This is the very first report that describes in vitro flowering system to overcome problems associated with flower growth and development as well as lay foundation for fruit and seed production in vitro in Swertia chirayita. PMID:24707404

Simulations on false gain in recombination-pumped soft-X-ray lasers

NASA Astrophysics Data System (ADS)

Ozaki, T.; Kuroda, H.

1997-10-01

Numerical investigations are performed on false gain due to axial plasma expansion, which is expected to be important in initial proof-of-principle studies of recombination-pumped soft-X-ray lasers with extended capabilities. Modelling calculations of experiments with slab boron nitride targets reveal large false gain coefficients approaching 20 cm-1 in the case of plasmas with short active medium lengths. The false gain in the case of fiber targets is found to be of equal magnitude to that for slabs in the case of plasmas with less than 0.1 cm active medium lengths. Calculations for slab targets predict that adopting a tolerance of ǃ cm-1 for gain will severely restrict the time and the active medium length of the plasma that can be used for error-free observations, while those for fiber targets are found to be considerably relaxed. The effects of false gain in the 54.2 + Na Balmer ! laser is also investigated, again revealing the importance of this phenomena under optimum gain conditions.

Flotation removal of the microalga Nannochloropsis sp. using Moringa protein-oil emulsion: A novel green approach.

PubMed

Kandasamy, Ganesan; Shaleh, Sitti Raehanah Muhamad

2018-01-01

A new approach to recover microalgae from aqueous medium using a bio-flotation method is reported. The method involves utilizing a Moringa protein extract - oil emulsion (MPOE) for flotation removal of Nannochloropsis sp. The effect of various factors has been assessed using this method, including operating parameters such as pH, MPOE dose, algae concentration and mixing time. A maximum flotation efficiency of 86.5% was achieved without changing the pH condition of algal medium. Moreover, zeta potential analysis showed a marked difference in the zeta potential values when increase the MPOE dose concentration. An optimum condition of MPOE dosage of 50ml/L, pH 8, mixing time 4min, and a flotation efficiency of greater than 86% was accomplished. The morphology of algal flocs produced by protein-oil emulsion flocculant were characterized by microscopy. This flotation method is not only simple, but also an efficient method for harvesting microalgae from culture medium. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of the high-performance liquid chromatographic separation of a complex mixture containing urinary steroids, boldenone and bolasterone: application to urine samples.

PubMed

Gonzalo-Lumbreras, R; Izquierdo-Hornillos, R

2000-05-26

An HPLC separation of a complex mixture containing 13 urinary anabolics and corticoids, and boldenone and bolasterone (synthetic anabolics) has been carried out. The applied optimization method involved the use of binary, ternary and quaternary mobile phases containing acetonitrile, methanol or tetrahydrofuran as organic modifiers. The effect of different reversed-phase packings and temperature on the separation was studied. The optimum separation was achieved by using a water-acetonitrile (60:40, v/v) mobile phase in reversed-phase HPLC at 30 degrees C, allowing the separation of all the analytes in about 24 min. Calibration graphs were obtained using bolasterone or methyltestosterone as internal standards. Detection limits were in the range 0.012-0.107 microg ml(-1). The optimized separation was applied to the analysis, after liquid-liquid extraction, of human urine samples spiked with steroids.

Asymbiotic seed germination and in vitro conservation of Coelogyne nervosa A. Rich. an endemic orchid to Western Ghats.

PubMed

Abraham, Sonia; Augustine, Jomy; Thomas, T Dennis

2012-07-01

Coelogyne nervosa is an epiphytic orchid endemic to Western Ghats, South India. The mature seeds of C. nervosa were cultured on ½ MS (Murashige and Skoog), MS, Kn (Knudson) and VW (Vacin and Went) media to evaluate the seed germination response. Of the four basal media used, MS medium supported maximum seed germination. Further experiments to enhance seed germination were done on MS medium supplemented with various concentrations (10, 20, 30 and 40 %) of coconut water (CW). Thirty percent CW gave the highest response in terms of percent seed germination (96), fresh weight (7.2 mg/seedling) and protocorm length (15.2 mm). Since CW containing medium did not support further seedling growth, each seedling was isolated and cultured on MS medium supplemented with either BA (6-benzylaminopurine) or Kin (kinetin) alone (1.0-4.0 mg/l each) or in combination with NAA (1-naphthaleneacetic acid; 0.2-1.0 mg/l). Maximum growth was observed on MS medium supplemented with BA (3.0 mg/l) and NAA (0.5 mg/l). On this medium, the seedlings reached an average length of 3.6 cm with 2.8 well expanded green leaves per seedling. Similarly optimum, healthy, white root induction (3.3 roots/seedlings) was also observed on the same medium. The rooted seedlings were successfully transplanted to pots with 91 % success. The 2-year-old tissue culture derived plants produced normal flowers and fruits.

Determination of the optimum-size californium-252 neutron source for borehole capture gamma-ray analysis

USGS Publications Warehouse

Senftle, F.E.; Macy, R.J.; Mikesell, J.L.

1979-01-01

The fast- and thermal-neutron fluence rates from a 3.7 ??g 252Cf neutron source in a simulated borehole have been measured as a function of the source-to-detector distance using air, water, coal, iron ore-concrete mix, and dry sand as borehole media. Gamma-ray intensity measurements were made for specific spectral lines at low and high energies for the same range of source-to-detector distances in the iron ore-concrete mix and in coal. Integral gamma-ray counts across the entire spectrum were also made at each source-to-detector distance. From these data, the specific neutron-damage rate, and the critical count-rate criteria, we show that in an iron ore-concrete mix (low hydrogen concentration), 252Cf neutron sources of 2-40 ??g are suitable. The source size required for optimum gamma-ray sensitivity depends on the energy of the gamma ray being measured. In a hydrogeneous medium such as coal, similar measurements were made. The results show that sources from 2 to 20 ??g are suitable to obtain the highest gamma-ray sensitivity, again depending on the energy of the gamma ray being measured. In a hydrogeneous medium, significant improvement in sensitivity can be achieved by using faster electronics; in iron ore, it cannot. ?? 1979 North-Holland Publishing Co.

Influence of culture media and environmental factors on mycelial growth and sporulation of Lasiodiplodia theobromae (Pat.) Griffon and Maubl.

PubMed

Saha, A; Mandal, P; Dasgupta, S; Saha, D

2008-05-01

Lasiodiplodia theobromae, a common tea (Camellia sinensis) pathogen, usually does not sporulate or sporulates poorly in common media, which makes spore production difficult. In this study the effects of culture media, carbon source, nitrogen source, temperature, pH and light on mycelial growth and sporulation were evaluated. Among several carbon sources tested, glucose and sucrose were found superior for growth. Potassium nitrate supplemented media showed maximum growth amongst the tested inorganic nitrogen sources while peptone produced maximum growth among the tested organic nitrogen sources. Tea root extract supplemented potato dextrose agar medium was found to be the most suitable for mycelial growth and sporulation of L. theobromae. The fungus grow at temperatures ranging from 40 to 36 degrees C, with optimum growth at 28 degrees C and no growth was noted at 40 degrees C. There was no significant effect of different light period on growth of L. theobromae, but light enhanced sporulation. The fungus grow at pH 3.0-8.0 and optimum growth was observed at pH 6.0. Tea root extract supplemented potato dextrose agar medium with pH 6.0 was the most suitable for production of conidia of L. theobromae at 28 degrees C. Hence this media may be recommended for inoculum production for further studies.

Isolation, identification and characterization of indigenous fungi for bioremediation of hexavalent chromium, nickel and cobalt

NASA Astrophysics Data System (ADS)

Hernahadini, Nelis; Suhandono, Sony; Choesin, Devi N.; Chaerun, Siti K.; Kadarusman, Ade

2014-03-01

Waste from nickel mining of Sorowako in South Sulawesi contains hexavalent chromium, nickel and cobalt metals in high concentration and may have a negative impact to the environment. Common waste treatment systems such as chemical treatment using a reducing reagent may still have a negative impact. Bioremediation using fungi or bacteria becomes more popular because it is an environmentally friendly alternative. The purposes of this study are to isolate and identify indigenous fungi that are resistant to heavy metals (hexavalent chromium, nickel, and cobalt) and are capable of reducing the concentration of metals in mining wastes. Ten fungal isolates were successfully isolated from the soils and pond sediments in the area of nickel mining in Sorowako. Selection of superior isolate was carried out by growing all the isolates on PDA medium, which contained all of the three metals. One superior isolate was identified to be able to grow on medium with concentrations of 6400 ppm hexavalent chromium, 200 ppm nickel and 50 ppm cobalt. Molecular identification and phylogenetic studies of the isolate using fungal PCR primers developed to amplify the ITS (internal transcribed spacer) region showed that the isolate sequence was very close to Trichoderma atroviride with 99.8% similarity. Optimum incubation time for the uptake of hexavalent chromium was 3 days, nickel and cobalt was 5 days, respectively, with an optimum pH of 4.

D-alanine carboxypeptidase activity of Micrococcus lysodeikticus released into the protoplasting medium.

PubMed

Linder, R; Salton, M R

1975-06-16

Conversion of whole cells of Micrococcus lysodeikticus to protoplasts allowed the release of a soluble form of a D-alanine carboxypeptidase into the protoplasting medium. The enzyme cleaves the terminal D-alanine from the radioactively labelled UDP-N-acetylmuramyl-pentapeptide containing L-lysine as the diamino acid. However, the enzyme is only minimally active in this fraction so that it had to be enriched and partially purified before its properties could be studied. Chromatography on carboxymethyl-Sephadex removed the lysozyme used in the protoplasting of the cells. The material which was unadsorbed to the column was applied to an affinity chromatography column of Ampicillin-Sepharose. Most of the contaminating protein was washed from the column while the D-alanine carboxypeptidase adhered to the resin and could be eluted with 0.5 M Tris-HCl buffer pH 8.6. Some of the properties of the enzymic activity were studied using this preparation. The enzyme was activated by Mg2+ ions with a broad optimum from 15--35 mM. It was maximally active when NaCl at a concentrations of 0.06--0.08 M was added to the assay, and the pH curve was biphasic with an alkaline optimum. The Km for substrate was found to be 0.118 mM. Enzymic activity was completely inhibited by low concentrations of Ampicillin and penicillin G.

Production and characterization of thermostable alkaline protease of Bacillus subtilis (ATCC 6633) from optimized solid-state fermentation.

PubMed

Chatterjee, Joyee; Giri, Sudipta; Maity, Sujan; Sinha, Ankan; Ranjan, Ashish; Rajshekhar; Gupta, Suvroma

2015-01-01

Proteases are the most important group of enzymes utilized commercially in various arenas of industries, such as food, detergent, leather, dairy, pharmaceutical, diagnostics, and waste management, accounting for nearly 20% of the world enzyme market. Microorganisms of specially Bacillus genera serve as a vast repository of diverse set of industrially important enzymes and utilized for the large-scale enzyme production using a fermentation technology. Approximately 30%-40% of the cost of industrial enzymes originates from the cost of the growth medium. This study is attempted to produce protease from Bacillus subtilis (ATCC 6633) after optimization of various process parameters with the aid of solid-state fermentation using a cheap nutrient source such as wheat bran. B. subtilis (ATCC 6633) produces proteases of molecular weight 36 and 20 kDa, respectively, in the fermented medium as evident from SDS zymogram. Alkaline protease activity has been detected with optimum temperature at 50 °C and is insensitive to ethylenediaminetetraacetic acid. This thermostable alkaline protease exhibits dual pH optimum at 7 and 10 with moderate pH stability at alkaline pH range. It preserves its activity in the presence of detergent such as SDS, Tween 20, and Triton X-100 and may be considered as an effective additive to detergent formulation with some industrial importance. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Hormonal regulation of growth and life span of bullfrog tadpole tail epidermal cells cultured in vitro.

PubMed

Nishikawa, A; Yoshizato, K

1986-02-01

Epidermal cells were dissociated from tails of the bullfrog tadpole, Rana catesbeiana, and cultured to investigate their response to steroid and thyroid hormones. Charcoal-treated serum (CTS) was used in the growth medium when cells were to be grown in the absence of steroid and thyroid hormones. The cells could be maintained for 2 weeks with a small increase in cell number in medium that contained CTS (CTS medium). Addition of cortisol to CTS medium increased both cellular attachment to the culture dishes and the proliferation of the attached cells with an optimum concentration of 5 X 10(-7) M. The cells remained viable and attached for at least a week. Cortisol stimulated the rate of protein synthesis 1.8-fold but did not alter the rate of DNA synthesis. The cells did not proliferate in the medium containing triiodothyronine (T3) and detached themselves from the dish within 5 days, which occurred in a dose-dependent manner with a maximum effect at 10(-8) M. It drastically decreased the rate of DNA synthesis but did not influence the rate of protein synthesis. These responses of cells to cortisol and T3 may reflect growth and death of tail epidermal cells in vivo at metamorphosis.

A green ultrasonic-assisted liquid-liquid microextraction based on deep eutectic solvent for the HPLC-UV determination of ferulic, caffeic and cinnamic acid from olive, almond, sesame and cinnamon oil.

PubMed

Khezeli, Tahere; Daneshfar, Ali; Sahraei, Reza

2016-04-01

A simple, inexpensive and sensitive ultrasonic-assisted liquid-liquid microextraction method based on deep eutectic solvent (UALLME-DES) was used for the extraction of three phenolic acids (ferulic, caffeic and cinnamic) from vegetable oils. In a typical experiment, deep eutectic solvent as green extraction solvent was added to n-hexane (as a typical oil medium) containing target analytes. Subsequently, the extraction was accelerated by sonication. After the extraction, phase separation (DES rich phase/n-hexane phase) was performed by centrifugation. DES rich phase (lower phase) was withdrawn by a micro-syringe and submitted to isocratic reverse-phase HPLC with UV detection. Under optimum conditions obtained by response surface methodology (RSM) and desirability function (DF), the method has good linear calibration ranges (between 1.30 and 1000 µg L(-1)), coefficients of determination (r(2)>0.9949) and low limits of detection (between 0.39 and 0.63 µg L(-1)). This procedure was successfully applied to the determination of target analytes in olive, almond, sesame and cinnamon oil samples. The relative mean recoveries ranged from 94.7% to 104.6%. Copyright © 2015 Elsevier B.V. All rights reserved.

Novel extraction induced by microemulsion breaking: a model study for Hg extraction from Brazilian gasoline.

PubMed

Vicentino, Priscila O; Cassella, Ricardo J

2017-01-01

This paper proposes a novel approach for the extraction of Hg from Brazilian gasoline samples: extraction induced by microemulsion breaking (EIMB). In this approach, a microemulsion is formed by mixing the sample with n-propanol and HCl. Afterwards, the microemulsion is destabilized by the addition of water and the two phases are separated: (i) the top phase, containing the residual gasoline and (ii) the bottom phase, containing the extracted analyte in a medium containing water, n-propanol and the ethanol originally present in the gasoline sample. The bottom phase is then collected and the Hg is measured by cold vapor atomic absorption spectrometry (CV-AAS). This model study used Brazilian gasoline samples spiked with Hg (organometallic compound) to optimize the process. Under the optimum extraction conditions, the microemulsion was prepared by mixing 8.7mL of sample with 1.2mL of n-propanol and 0.1mL of a 10molL -1 HCl solution. Emulsion breaking was induced by adding 300µL of deionized water and the bottom phase was collected for the measurement of Hg. Six samples of Brazilian gasoline were spiked with Hg in the organometallic form and recovery percentages in the range of 88-109% were observed. Copyright © 2016 Elsevier B.V. All rights reserved.

Headspace and direct immersion solid phase microextraction procedures for selenite determination in urine, saliva and milk by gas chromatography mass spectrometry.

PubMed

Kapsimali, D C; Zachariadis, G A

2009-10-01

Two solid phase microextraction modes were investigated and compared for their performance on the determination of selenites in various biological liquids like human urine and saliva and various types of milk. Using sodium tetraethylborate (NaBEt(4)) as ethylating reagent, selenites are converted in situ to volatile diethylselenides (DESe) in aqueous medium. The derivative is collected in situ by solid phase microextraction (SPME) using a silica fiber coated with poly(dimethylsiloxane) (PDMS) either from the headspace (HS-SPME) or directly from the liquid phase (LP-SPME) and finally determined by capillary GC/MS. Under optimum conditions of SPME, the GC separation was also optimized. Between the two examined microextraction techniques, direct immersion of the PDMS fiber in the liquid phase was proved less satisfactory. In contrast, the headspace procedure appears to be more efficient. The quantification of selenites was achieved in SIM mode with good analytical performance. A non-fat milk powder certified reference material was analyzed to evaluate the accuracy of the method. The overall precision of the method was ranged between 6.2% and 9.7%. Detection limits achieved were 0.05microgL(-1) for human urine, 0.08microgL(-1) for saliva and 0.03-0.06microgL(-1) in various milk matrices.

Determination of rhodium in metallic alloy and water samples using cloud point extraction coupled with spectrophotometric technique

NASA Astrophysics Data System (ADS)

Kassem, Mohammed A.; Amin, Alaa S.

2015-02-01

A new method to estimate rhodium in different samples at trace levels had been developed. Rhodium was complexed with 5-(4‧-nitro-2‧,6‧-dichlorophenylazo)-6-hydroxypyrimidine-2,4-dione (NDPHPD) as a complexing agent in an aqueous medium and concentrated by using Triton X-114 as a surfactant. The investigated rhodium complex was preconcentrated with cloud point extraction process using the nonionic surfactant Triton X-114 to extract rhodium complex from aqueous solutions at pH 4.75. After the phase separation at 50 °C, the surfactant-rich phase was heated again at 100 °C to remove water after decantation and the remaining phase was dissolved using 0.5 mL of acetonitrile. Under optimum conditions, the calibration curve was linear for the concentration range of 0.5-75 ng mL-1 and the detection limit was 0.15 ng mL-1 of the original solution. The enhancement factor of 500 was achieved for 250 mL samples containing the analyte and relative standard deviations were ⩽1.50%. The method was found to be highly selective, fairly sensitive, simple, rapid and economical and safely applied for rhodium determination in different complex materials such as synthetic mixture of alloys and environmental water samples.

METHOD OF SEPARATING URANIUM SUSPENSIONS

DOEpatents

Wigner, E.P.; McAdams, W.A.

1958-08-26

A process is presented for separating colloidally dissed uranium oxides from the heavy water medium in upwhich they are contained. The method consists in treating such dispersions with hydrogen peroxide, thereby converting the uranium to non-colloidal UO/sub 4/, and separating the UO/sub 4/ sfter its rapid settling.

A Defined, Glucose-Limited Mineral Medium for the Cultivation of Listeria spp.

PubMed Central

Schneebeli, Rudolf

2013-01-01

Members of the genus Listeria are fastidious bacteria with respect to their nutritional requirements, and several minimal media described in the literature fail to support growth of all Listeria spp. Furthermore, strict limitation by a single nutrient, e.g., the carbon source, has not been demonstrated for any of the published minimal media. This is an important prerequisite for defined studies of growth and physiology, including “omics.” Based on a theoretical analysis of previously published mineral media for Listeria, an improved, well-balanced growth medium was designed. It supports the growth, not only of all tested Listeria monocytogenes strains, but of all other Listeria species, with the exception of L. ivanovii. The growth performance of L. monocytogenes strain Scott A was tested in the newly designed medium; glucose served as the only carbon and energy source for growth, whereas neither the supplied amino acids nor the buffering and complexing components (MOPS [morpholinepropanesulfonic acid] and EDTA) supported growth. Omission of amino acids, trace elements, or vitamins, alone or in combination, resulted in considerably reduced biomass yields. Furthermore, we monitored the specific growth rates of various Listeria strains cultivated in the designed mineral medium and compared them to growth in complex medium (brain heart infusion broth [BHI]). The novel mineral medium was optimized for the commonly used strain L. monocytogenes Scott A to achieve optimum cell yields and maximum specific growth rates. This mineral medium is the first published synthetic medium for Listeria that has been shown to be strictly carbon (glucose) limited. PMID:23377938

Data-driven mapping of hypoxia-related tumor heterogeneity using DCE-MRI and OE-MRI.

PubMed

Featherstone, Adam K; O'Connor, James P B; Little, Ross A; Watson, Yvonne; Cheung, Sue; Babur, Muhammad; Williams, Kaye J; Matthews, Julian C; Parker, Geoff J M

2018-04-01

Previous work has shown that combining dynamic contrast-enhanced (DCE)-MRI and oxygen-enhanced (OE)-MRI binary enhancement maps can identify tumor hypoxia. The current work proposes a novel, data-driven method for mapping tissue oxygenation and perfusion heterogeneity, based on clustering DCE/OE-MRI data. DCE-MRI and OE-MRI were performed on nine U87 (glioblastoma) and seven Calu6 (non-small cell lung cancer) murine xenograft tumors. Area under the curve and principal component analysis features were calculated and clustered separately using Gaussian mixture modelling. Evaluation metrics were calculated to determine the optimum feature set and cluster number. Outputs were quantitatively compared with a previous non data-driven approach. The optimum method located six robustly identifiable clusters in the data, yielding tumor region maps with spatially contiguous regions in a rim-core structure, suggesting a biological basis. Mean within-cluster enhancement curves showed physiologically distinct, intuitive kinetics of enhancement. Regions of DCE/OE-MRI enhancement mismatch were located, and voxel categorization agreed well with the previous non data-driven approach (Cohen's kappa = 0.61, proportional agreement = 0.75). The proposed method locates similar regions to the previous published method of binarization of DCE/OE-MRI enhancement, but renders a finer segmentation of intra-tumoral oxygenation and perfusion. This could aid in understanding the tumor microenvironment and its heterogeneity. Magn Reson Med 79:2236-2245, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

Efficient photocatalytic degradation of organic pollutants by magnetically recoverable nitrogen-doped TiO2 nanocomposite photocatalysts under visible light irradiation.

PubMed

Hamzezadeh-Nakhjavani, Sahar; Tavakoli, Omid; Akhlaghi, Seyed Parham; Salehi, Zeinab; Esmailnejad-Ahranjani, Parvaneh; Arpanaei, Ayyoob

2015-12-01

Preparation of novel nanocomposite particles (NCPs) with high visible-light-driven photocatalytic activity and possessing recovery potential after advanced oxidation process (AOP) is much desired. In this study, pure anatase phase titania (TiO2) nanoparticles (NPs) as well as three types of NCPs including nitrogen-doped titania (TiO2-N), titania-coated magnetic silica (Fe3O4 cluster@SiO2@TiO2 (FST)), and a novel magnetically recoverable TiO2 nanocomposite photocatalyst containing nitrogen element (Fe3O4 cluster@SiO2@TiO2-N (FST-N)) were successfully synthesized via a sol-gel process. The photocatalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM) with an energy-dispersive X-ray (EDX) spectroscopy analysis, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM). The photocatalytic activity of as-prepared samples was further investigated and compared with each other by degradation of phenol, as a model for the organic pollutants, in deionized (DI) water under visible light irradiation. The TiO2-N (55 ± 1.5%) and FST-N (46 ± 1.5%) samples exhibited efficient photocatalytic activity in terms of phenol degradation under visible light irradiation, while undoped samples were almost inactive under same operating conditions. Moreover, the effects of key operational parameters, the optimum sample calcination temperature, and reusability of FST-N NCPs were evaluated. Under optimum conditions (calcination temperature of 400 °C and near-neutral reaction medium), the obtained results revealed efficient degradation of phenol for FST-N NCPs under visible light irradiation (46 ± 1.5%), high yield magnetic separation and efficient reusability of FST-N NCPs (88.88% of its initial value) over 10 times reuse.

A flow method based on solvent extraction coupled on-line to a reversed micellar mediated chemiluminescence detection for selective determination of gold(III) and gallium(III) in water and industrial samples.

PubMed

Hasanin, Tamer H A; Okamoto, Yasuaki; Fujiwara, Terufumi

2016-02-01

A rapid and sensitive flow method, based on the combination of on-line solvent extraction with reversed micellar mediated chemiluminescence (CL) detection using rhodamine B (RB), was investigated for the selective determination of Au(III) and Ga(III) in aqueous solutions. 2.0 M HCl was the optimum for extracting Au(III) while a 5.0M HCl solution containing 2.5M LiCl was selected as an optimum acidic medium for extraction of Ga(III). The Au(III) and Ga(III) chloro-complex anions were extracted from the above aqueous acidic solutions into toluene as their ion-pair complexes with the protonated RBH(+) ion followed by membrane phase separation in a flow system. In a flow cell of a detector, the extract was mixed with the reversed micellar solution of cetyltrimethylammonium chloride (CTAC) in 1-hexanol-cyclohexane/water (1.0M HCl) containing 0.10 M cerium(IV) and 0.05 M lithium sulfate. Then uptake of the ion-pair by the CTAC reversed micelles and the subsequent CL oxidation of RB with Ce(IV) occurred easily and the CL signals produced were recorded. Using a flow injection system, a detection limit (DL) of 0.4 μM Au(III) and 0.6 μM Ga(III), and linear calibration graphs with dynamic ranges from the respective DLs to 10 μM for Au(III) and Ga(III) were obtained under the optimized experimental conditions. The relative standard deviations (n=6) obtained at 2.0 µM Au(III) and 4.0 µM Ga(III) were 3.0% and 2.4%, respectively. The presented CL methodology has been applied for the determination of Au(III) and Ga(III) in water and industrial samples with satisfactory results. Copyright © 2015 Elsevier B.V. All rights reserved.

Transient birefringence effects in electromagnetically induced transparency

NASA Astrophysics Data System (ADS)

Parshkov, O. M.

2015-11-01

We report the results of numerical modelling of transient birefringence that arises as a result of electromagnetically induced transparency on degenerate quantum transitions between the states with J = 0, 1 and 2 in the presence of the Doppler broadening of spectral lines. It is shown that in the case of a linearly polarised control field, the effect of transient birefringence leads to a decay of the input circularly polarised probe pulse into separate linearly polarised pulses inside a medium. In the case of a circularly polarised control field, the effect of transient birefringence manifests itself in a decay of the input linearly polarised probe pulse into separate circularly polarised pulses. It is shown that the distance that a probe pulse has to pass in a medium before decaying into subpulses is considerably greater in the first case than in the second. The influence of the input probe pulse power and duration on the process of spatial separation into individual pulses inside a medium is studied. A qualitative analysis of the obtained results is presented.

75 FR 30779 - Notice of Jointly Owned Invention Available for Licensing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-02

... substrate to the product in a reaction medium, introducing a run buffer into a separation channel having an inlet end, selectively introducing at least one of the substrate and the product of the reaction medium...

Biodegradation of PAHs in Soil: Influence of Initial PAHs Concentration

NASA Astrophysics Data System (ADS)

Kamil, N. A. F. M.; Talib, S. A.

2016-07-01

Most studies on biodegradation of Polycyclic Aromatic Hydrocarbons (PAHs) evaluate the effect of initial PAHs concentration in liquid medium. There are limited studies on evaluation in solid medium such as contaminated soil. This study investigated the potential of the bacteria, Corynebacterium urealyticum isolated from municipal sludge in degrading phenanthrene contaminated soil in different phenanthrene concentration. Batch experiments were conducted over 20 days in reactors containing artificially contaminated phenanthrene soil at different concentration inoculated with a bacterial culture. This study established the optimum condition for phenanthrene degradation by the bacteria under nonindigenous condition at 500 mg/kg of initial phenanthrene concentration. High initial concentration required longer duration for biodegradation process compared to low initial concentration. The bacteria can survive for three days for all initial phenanthrene concentrations.

The Release of Elements from Dental Casting Alloy into Cell-Culture Medium and Artificial Saliva

PubMed Central

Can, Gülşen; Akpınar, Gül; Aydın, Ahmet

2007-01-01

Objectives The biocompatibility of dental casting alloys is a critical issue because these alloys are in long-term intimate contact with oral tissues. Since the biocompatibility of alloys is not completely known; the release of elements from the alloys has been studied. The aim of this study was to compare the elemental release from dental casting alloy during exposure to artificial saliva and cell-culture medium. Materials and Methods Twenty specimens made from Ni-Cr alloy were provided in the form of 5 mm diameter discs, 2 mm in thickness with a 7 mm stem attached to one face to facilitate handling. Ten of twenty samples were polished separately using a conventional technique. The remaining ten samples were left sandblasted with 50 μm Al203. Ten samples (5 polished, 5 sandblasted) were separately placed into cell-culture wells with Dulbecco’s Modified Eagle’s Medium. The other ten samples were placed separately into cell-culture wells with artificial saliva. The samples were subjected in contact with these medium for 30 days. These medium were collected every 7 days. The cell-culture medium and artificial saliva without alloy samples were subjected to elemental analyses as a control. At the end of the exposure time, Atomic Absorption Spectrometry (AAS) was used to determine the release of elements from the alloys into all collected medium. Statistical analyses were assessed with two-way ANOVA. Results In general, the elemental release occurred with in all medium. The elemental releases of sandblasted alloys were higher than polished alloys. Artificial saliva was found to cause more release from the samples. In both media, Ni released from polished and sandblasted alloys were higher than Cr and Mo. Conlusions The results suggest that the release of elements from the alloys might have correlated with the environments and the surface of dental alloy. PMID:19212482

The release of elements from dental casting alloy into cell-culture medium and artificial saliva.

PubMed

Can, Gülşen; Akpınar, Gül; Aydın, Ahmet

2007-04-01

The biocompatibility of dental casting alloys is a critical issue because these alloys are in long-term intimate contact with oral tissues. Since the biocompatibility of alloys is not completely known; the release of elements from the alloys has been studied. The aim of this study was to compare the elemental release from dental casting alloy during exposure to artificial saliva and cell-culture medium. Twenty specimens made from Ni-Cr alloy were provided in the form of 5 mm diameter discs, 2 mm in thickness with a 7 mm stem attached to one face to facilitate handling. Ten of twenty samples were polished separately using a conventional technique. The remaining ten samples were left sandblasted with 50 mum Al(2)0(3). Ten samples (5 polished, 5 sandblasted) were separately placed into cell-culture wells with Dulbecco's Modified Eagle's Medium. The other ten samples were placed separately into cell-culture wells with artificial saliva. The samples were subjected in contact with these medium for 30 days. These medium were collected every 7 days. The cell-culture medium and artificial saliva without alloy samples were subjected to elemental analyses as a control. At the end of the exposure time, Atomic Absorption Spectrometry (AAS) was used to determine the release of elements from the alloys into all collected medium. Statistical analyses were assessed with two-way ANOVA. In general, the elemental release occurred with in all medium. The elemental releases of sandblasted alloys were higher than polished alloys. Artificial saliva was found to cause more release from the samples. In both media, Ni released from polished and sandblasted alloys were higher than Cr and Mo. The results suggest that the release of elements from the alloys might have correlated with the environments and the surface of dental alloy.

Single electron counting using a dual MCP assembly

NASA Astrophysics Data System (ADS)

Yang, Yuzhen; Liu, Shulin; Zhao, Tianchi; Yan, Baojun; Wang, Peiliang; Yu, Yang; Lei, Xiangcui; Yang, Luping; Wen, Kaile; Qi, Ming; Heng, Yuekun

2016-09-01

The gain, pulse height resolution and peak-to-valley ratio of single electrons detected by using a Chevron configured Microchannel Plate (MCP) assembly are studied. The two MCPs are separated by a 280 μm gap and are biased by four electrodes. The purpose of the study is to determine the optimum bias voltage arrangements for single electron counting. By comparing the results of various bias voltage combinations, we conclude that good performance for the electron counting can be achieved by operating the MCP assembly in saturation mode. In addition, by applying a small reverse bias voltage across the gap while adjusting the bias voltages of the MCPs, optimum performance of electron counting can be obtained.

Systems and methods for separating particles utilizing engineered acoustic contrast capture particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduchak, Gregory; Ward, Michael D.

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minimamore » for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.« less

Apparatus for separating particles utilizing engineered acoustic contrast capture particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduchak, Gregory; Ward, Michael D

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minimamore » for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.« less

Optimization of Culture Medium for the Growth of Candida sp. and Blastobotrys sp. as Starter Culture in Fermentation of Cocoa Beans (Theobroma cacao) Using Response Surface Methodology (RSM).

PubMed

Mahazar, N H; Zakuan, Z; Norhayati, H; MeorHussin, A S; Rukayadi, Y

2017-01-01

Inoculation of starter culture in cocoa bean fermentation produces consistent, predictable and high quality of fermented cocoa beans. It is important to produce healthy inoculum in cocoa bean fermentation for better fermented products. Inoculum could minimize the length of the lag phase in fermentation. The purpose of this study was to optimize the component of culture medium for the maximum cultivation of Candida sp. and Blastobotrys sp. Molasses and yeast extract were chosen as medium composition and Response Surface Methodology (RSM) was then employed to optimize the molasses and yeast extract. Maximum growth of Candida sp. (7.63 log CFU mL-1) and Blastobotrys sp. (8.30 log CFU mL-1) were obtained from the fermentation. Optimum culture media for the growth of Candida sp., consist of 10% (w/v) molasses and 2% (w/v) yeast extract, while for Blastobotrys sp., were 1.94% (w/v) molasses and 2% (w/v) yeast extract. This study shows that culture medium consists of molasses and yeast extract were able to produce maximum growth of Candida sp. and Blastobotrys sp., as a starter culture for cocoa bean fermentation.

Optimization of critical medium components using response surface methodology for biomass and extracellular polysaccharide production by Agaricus blazei.

PubMed

Liu, Gao-Qiang; Wang, Xiao-Ling

2007-02-01

Response surface methodology (RSM) was applied to optimize the critical medium ingredients of Agaricus blazei. A three-level Box-Behnken factorial design was employed to determine the maximum biomass and extracellular polysaccharide (EPS) yields at optimum levels for glucose, yeast extract (YE), and peptone. A mathematical model was then developed to show the effect of each medium composition and its interactions on the production of mycelial biomass and EPS. The model predicted the maximum biomass yield of 10.86 g/l that appeared at glucose, YE, peptone of 26.3, 6.84, and 6.62 g/l, respectively, while a maximum EPS yield of 348.4 mg/l appeared at glucose, YE, peptone of 28.4, 4.96, 5.60 g/l, respectively. These predicted values were also verified by validation experiments. The excellent correlation between predicted and measured values of each model justifies the validity of both the response models. The results of bioreactor fermentation also show that the optimized culture medium enhanced both biomass (13.91 +/- 0.71 g/l) and EPS (363 +/- 4.1 mg/l) production by Agaricus blazei in a large-scale fermentation process.

Reduction of turbulent boundary layer induced interior noise through active impedance control.

PubMed

Remington, Paul J; Curtis, Alan R D; Coleman, Ronald B; Knight, J Scott

2008-03-01

The use of a single actuator tuned to an optimum impedance to control the sound power radiated from a turbulent boundary layer (TBL) excited aircraft panel into the aircraft interior is examined. An approach to calculating the optimum impedance is defined and the limitations on the reduction in radiated power by a single actuator tuned to that impedance are examined. It is shown that there are too many degrees of freedom in the TBL and in the radiation modes of the panel to allow a single actuator to control the radiated power. However, if the panel modes are lightly damped and well separated in frequency, significant reductions are possible. The implementation of a controller that presents a desired impedance to a structure is demonstrated in a laboratory experiment, in which the structure is a mass. The performance of such a controller on an aircraft panel is shown to be effective, if the actuator impedance is similar to but not the same as the desired impedance, provided the panel resonances are well separated in frequency and lightly damped.

[TMOSKOVHE COMPARATIVE CHARACTERISTIC OF GROWTH MEDIUMS FOR SEPARATION OF CORYNEBACTERIA].

PubMed

Shepelin, A P; Polosenko, O V; Borisova, O Yu; Pimenova, A S; Gadua, N T

2016-01-01

The comparative tests of growth mediums for isolation and accumulation of diphtheria bacteria were implemented. The testing consisted of six series of growth medium "Corynebacagar" produced by the state research center of applied microbiology and biotechnology and three series of blood tellurite agar. The concluding results of identification of biological indicators of all series of growth nutrient mediums are presented The "Corynebacagar" is recommended for application in health care practice for primary inoculation of pathological material during implementation of cultural analysis on diphtheria.

30 CFR 75.902-4 - Attachment of ground conductors and ground check wires to equipment frames; use of separate...

Code of Federal Regulations, 2014 CFR

2014-07-01

... SAFETY STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits... from resistance grounded systems separate connections shall be used when practicable. ...

30 CFR 75.902-4 - Attachment of ground conductors and ground check wires to equipment frames; use of separate...

Code of Federal Regulations, 2013 CFR

2013-07-01

... SAFETY STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits... from resistance grounded systems separate connections shall be used when practicable. ...

30 CFR 75.902-4 - Attachment of ground conductors and ground check wires to equipment frames; use of separate...

Code of Federal Regulations, 2012 CFR

2012-07-01

... SAFETY STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits... from resistance grounded systems separate connections shall be used when practicable. ...

Ultrasensitive analysis of lysergic acid diethylamide and its C-8 isomer in hair by capillary zone electrophoresis in combination with a stacking technique and laser induced fluorescence detection.

PubMed

Airado-Rodríguez, Diego; Cruces-Blanco, Carmen; García-Campaña, Ana M

2015-03-25

This article deals with the development and validation of a novel capillary zone electrophoresis (CZE) with laser induced fluorescence detection method for the analysis of lysergic acid diethylamide (LSD) and its isomer iso-LSD in hair samples. The separation of both analytes has been achieved in less than 13 min in a 72-cm effective length capillary with 75-μm internal diameter. As running buffer 25 mM citrate, pH 6.0 has been employed and separation temperature and voltage of 20 °C and 13 kV respectively, were applied. Field amplified sample injection (FASI) has been employed for on-line sample preconcentration, using ultrapure water containing 117 μM H3PO4 as optimum injection medium. Injection voltage and time have been optimized by means of experimental design, obtaining values of 7 kV and 15s, respectively. Methylergonovine has been employed as internal standard in order to compensate irreproducibility from electrokinetic injection. The analytical method has been applied to hair samples, previous extraction of the target analytes by ultrasound assisted solid-liquid extraction at 40 °C for 2.5 h, employing acetonitrile as extracting solvent. Linear responses were found for LSD and iso-LSD in matrix-matched calibrations from around 0.400 up to 50.0 pg mg(-1). LODs (3 S/N) in the order of 0.100 pg mg(-1) were calculated for both analytes, obtaining satisfactory recovery percentages for this kind of sample. Copyright © 2015 Elsevier B.V. All rights reserved.

A Comparative Analysis between GaN-Based Current and Voltage Mode Class-D and E PAs for Communications

DTIC Science & Technology

2017-03-01

power level (5-10W) transmitters. The designs are analyzed and compared with respect to non-idealities such as bondwire effects and input signal duty...Hence, sub-optimum class- E/inverse class-E designs were implemented in this work and compared with respect to reduced duty cycle performance...inverse class E PA achieves 61.5% efficiency for medium power levels (37.7dBm) at 880MHz. The three designed PAs have been compared with respect to

Carbon fiber composite molecular sieve electrically regenerable air filter media

DOEpatents

Wilson, Kirk A.; Burchell, Timothy D.; Judkins, Roddie R.

1998-01-01

An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply airstream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium.

Kinetic performance of a 50mm long 1.8μm chiral column in supercritical fluid chromatography.

PubMed

Berger, Terry A

2016-08-12

Reduced plate heights (hr) of <2 were observed for the first time during the chiral separation of enantiomers, on sub-2μm particles with supercritical fluid chromatography (SFC). The enantiomers of trans-stilbene oxide, were separated on a 4.6×50mm, 1.8μm R,R-Whelk-O1 column, with hr as low as 1.93. The plumbing of a commercial SFC instrument was modified to create a low dispersion version. Without the modification performance was considerably worse. vanDeemter like plots of reduced plate height vs. flow rate, for trans-stilbene oxide, indicate that the optimum flow varied with% modifier. On a 4.6×250mm, 5μm R,R- Whelk-O1 column, the optimum flow was >4mL/min for 5% methanol in CO2, decreasing to <2mL/min for 40% methanol (more than a factor of 2). For a 4.6×50mm column packed with 1.8μm particles the optimum appeared to be near, or >5mL/min with 2.5%, 5%, and 10% methanol, decreasing to between 3 and 3.5mL/min at 40% methanol. This is the first time such shifts have been characterized. Since the solutes were the same in all cases, the differences are likely due to changes in solute diffusion coefficients caused by changes in modifier concentration, and pressure. Pump pressure requirements sometimes exceeded 500bar. It is shown that a 5mL/min flow rate is inadequate for use with 1.8μm particles in a 4.6mm ID column format. Instead, it is suggested to decrease the ID of the column to 3mm, where the optimum flow rates are on the order of 2mL/min with decreased tubing variance. Nevertheless, a number of sub-1min chromatograms are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

Spectral splitting of optical pulses inside a dispersive medium at a temporal boundary

DOE PAGES

Plansinis, Brent W.; Donaldson, William R.; Agrawal, Govind P.

2016-11-07

We show numerically that the spectrum of an optical pulse splits into multiple, widely separated, spectral bands when it arrives at a temporal boundary across which refractive index changes suddenly. At the same time, the pulse breaks into several temporally separated pulses traveling at different speeds. The number of such pulses depends on the dispersive properties of the medium. We study the effect of second- and third-order dispersion in detail but also consider briefly the impact of other higher-order terms. As a result, a temporal waveguide formed with two temporal boundaries can reflect the temporally separated pulses again and again,more » increasing the number of pulses trapped within the temporal waveguide.« less

Separation and counting of single molecules through nanofluidics, programmable electrophoresis, and nanoelectrode-gated tunneling and dielectric detection

DOEpatents

Lee, James W.; Thundat, Thomas G.

2006-04-25

An apparatus for carrying out the separation, detection, and/or counting of single molecules at nanometer scale. Molecular separation is achieved by driving single molecules through a microfluidic or nanofluidic medium using programmable and coordinated electric fields. In various embodiments, the fluidic medium is a strip of hydrophilic material on nonconductive hydrophobic surface, a trough produced by parallel strips of hydrophobic nonconductive material on a hydrophilic base, or a covered passageway produced by parallel strips of hydrophobic nonconductive material on a hydrophilic base together with a nonconductive cover on the parallel strips of hydrophobic nonconductive material. The molecules are detected and counted using nanoelectrode-gated electron tunneling methods, dielectric monitoring, and other methods.

Computation of the turbulent boundary layer downstream of vortex generators

NASA Astrophysics Data System (ADS)

Chang, Paul K.

1987-12-01

The approximate analysis of three-dimensional incompressible turbulent boundary layer downstream of vortex generators is presented. Extensive numerical computations are carried out to assess the effectiveness of single-row, counter-rotating vane-type vortex generators to alleviate flow separation lines. Flow separation downstream of the vortex generators on a thick airfoil are determined in terms of size, location, and arrangement of the vortex generators. These lines are compared with the separation line without the vortex generators. High efficiency is obtained with the moderately slender rectangular blade of the generator. The results indicate that separations is alleviated more effectively in the region closer to the symmetry axis of the generator than in the outer region of the symmetry axis. No optimum conditions for the alleviation of flow separation are established in this investigation, and no comparisons are made with other analytical results and experimental data.

Effect of surfactant species and electrophoretic medium composition on the electrophoretic behavior of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis.

PubMed

Fukai, Nao; Kitagawa, Shinya; Ohtani, Hajime

2017-07-01

We have recently demonstrated the separation of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis (NACZE) using a cationic surfactant of cetyltrimethylammonium chloride (CTAC). In this study, eight ionic surfactants were investigated for the separation of four synthetic polymers (polystyrene, polymethylmethacrylates, polybutadiene, and polycarbonate); only three surfactants (CTAC, dimethyldioctadecylammonium bromide, and sodium dodecylsulfate) caused their separation. The order of the interaction between the polymers and the surfactants depended on both the surfactant species and the composition of the electrophoretic medium. Their investigation revealed that the separation is majorly affected by the hydrophobic interactions between the polymers and the ionic surfactants. In addition, the electrophoretic behavior of polycarbonate suggested that electrostatic interaction also affects the selectivity of the polymers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-optimized superconductivity attainable by interlayer phase separation at cuprate interfaces.

PubMed

Misawa, Takahiro; Nomura, Yusuke; Biermann, Silke; Imada, Masatoshi

2016-07-01

Stabilizing superconductivity at high temperatures and elucidating its mechanism have long been major challenges of materials research in condensed matter physics. Meanwhile, recent progress in nanostructuring offers unprecedented possibilities for designing novel functionalities. Above all, thin films of cuprate and iron-based high-temperature superconductors exhibit remarkably better superconducting characteristics (for example, higher critical temperatures) than in the bulk, but the underlying mechanism is still not understood. Solving microscopic models suitable for cuprates, we demonstrate that, at an interface between a Mott insulator and an overdoped nonsuperconducting metal, the superconducting amplitude is always pinned at the optimum achieved in the bulk, independently of the carrier concentration in the metal. This is in contrast to the dome-like dependence in bulk superconductors but consistent with the astonishing independence of the critical temperature from the carrier density x observed at the interfaces of La2CuO4 and La2-x Sr x CuO4. Furthermore, we identify a self-organization mechanism as responsible for the pinning at the optimum amplitude: An emergent electronic structure induced by interlayer phase separation eludes bulk phase separation and inhomogeneities that would kill superconductivity in the bulk. Thus, interfaces provide an ideal tool to enhance and stabilize superconductivity. This interfacial example opens up further ways of shaping superconductivity by suppressing competing instabilities, with direct perspectives for designing devices.

Self-optimized superconductivity attainable by interlayer phase separation at cuprate interfaces

PubMed Central

Misawa, Takahiro; Nomura, Yusuke; Biermann, Silke; Imada, Masatoshi

2016-01-01

Stabilizing superconductivity at high temperatures and elucidating its mechanism have long been major challenges of materials research in condensed matter physics. Meanwhile, recent progress in nanostructuring offers unprecedented possibilities for designing novel functionalities. Above all, thin films of cuprate and iron-based high-temperature superconductors exhibit remarkably better superconducting characteristics (for example, higher critical temperatures) than in the bulk, but the underlying mechanism is still not understood. Solving microscopic models suitable for cuprates, we demonstrate that, at an interface between a Mott insulator and an overdoped nonsuperconducting metal, the superconducting amplitude is always pinned at the optimum achieved in the bulk, independently of the carrier concentration in the metal. This is in contrast to the dome-like dependence in bulk superconductors but consistent with the astonishing independence of the critical temperature from the carrier density x observed at the interfaces of La2CuO4 and La2−xSrxCuO4. Furthermore, we identify a self-organization mechanism as responsible for the pinning at the optimum amplitude: An emergent electronic structure induced by interlayer phase separation eludes bulk phase separation and inhomogeneities that would kill superconductivity in the bulk. Thus, interfaces provide an ideal tool to enhance and stabilize superconductivity. This interfacial example opens up further ways of shaping superconductivity by suppressing competing instabilities, with direct perspectives for designing devices. PMID:27482542

Development of green betaine-based deep eutectic solvent aqueous two-phase system for the extraction of protein.

PubMed

Li, Na; Wang, Yuzhi; Xu, Kaijia; Huang, Yanhua; Wen, Qian; Ding, Xueqin

2016-05-15

Six kinds of new type of green betaine-based deep eutectic solvents (DESs) have been synthesized. Deep eutectic solvent aqueous two-phase systems (DES-ATPS) were established and successfully applied in the extraction of protein. Betaine-urea (Be-U) was selected as the suitable extractant. Single factor experiments were carried out to determine the optimum conditions of the extraction process, such as the salt concentration, the mass of DES, the separation time, the amount of protein, the temperature and the pH value. The extraction efficiency could achieve to 99.82% under the optimum conditions. Mixed sample and practical sample analysis were discussed. The back extraction experiment was implemented and the back extraction efficiency could reach to 32.66%. The precision experiment, repeatability experiment and stability experiment were investigated. UV-vis, FT-IR and circular dichroism (CD) spectra confirmed that the conformation of protein was not changed during the process of extraction. The mechanisms of extraction were researched by dynamic light scattering (DLS), the measurement of the conductivity and transmission electron microscopy (TEM). DES-protein aggregates and embraces phenomenon play considerable roles in the separation process. All of these results indicated that betaine-based DES-ATPS may provide a potential substitute new method for the separation of proteins. Copyright © 2016 Elsevier B.V. All rights reserved.

Chromogenic agar medium for detection and isolation of Escherichia coli serogroups O26, O45, O103, O111, O121, and O145 from fresh beef and cattle feces.

PubMed

Kalchayanand, Norasak; Arthur, Terrance M; Bosilevac, Joseph M; Wells, James E; Wheeler, Tommy L

2013-02-01

Non-O157 Shiga toxin-producing Escherichia coli (STEC) strains are clinically important foodborne pathogens. Unlike E. coli O157:H7, these foodborne pathogens have no unique biochemical characteristics to readily distinguish them from other E. coli strains growing on plating media. In this study, a chromogenic agar medium was developed in order to differentiate among non-O157 STEC strains of serogroups O26, O45, O103, O111, O121, and O145 on a single agar medium. The ability of this chromogenic agar medium to select and distinguish among these pathogens is based on a combination of utilization of carbohydrates, b -galactosidase activity, and resistance to selective agents. The agar medium in combination with immunomagnetic separation was evaluated and successfully allowed for the detection and isolation of these six serogroups from artificially contaminated fresh beef. The agar medium in combination with immunomagnetic separation also allowed successful detection and isolation of naturally occurring non-O157 STEC strains present in cattle feces. Thirty-five strains of the top six non-O157 STEC serogroups were isolated from 1,897 fecal samples collected from 271 feedlot cattle. This chromogenic agar medium could help significantly in routine screening for the top six non-O157 STEC serogroups from beef cattle and other food.

Formulation and Statistical Optimization of Culture Medium for Improved Production of Antimicrobial Compound by Streptomyces sp. JAJ06

PubMed Central

Arul Jose, Polpass; Sivakala, Kunjukrishnan Kamalakshi; Jebakumar, Solomon Robinson David

2013-01-01

Streptomyces sp. JAJ06 is a seawater-dependent antibiotic producer, previously isolated and characterised from an Indian coastal solar saltern. This paper reports replacement of seawater with a defined salt formulation in production medium and subsequent statistical media optimization to ensure consistent as well as improved antibiotic production by Streptomyces sp. JAJ06. This strain was observed to be proficient to produce antibiotic compound with incorporation of chemically defined sodium-chloride-based salt formulation instead of seawater into the production medium. Plackett-Burman design experiment was applied, and three media constituents, starch, KBr, and CaCO3, were recognised to have significant effect on the antibiotic production of Streptomyces JAJ06 at their individual levels. Subsequently, Response surface methodology with Box-Behnken design was employed to optimize these influencing medium constituents for the improved antibiotic production of Streptomyces sp. JAJ06. A total of 17 experiments were conducted towards the construction of a quadratic model and a second-order polynomial equation. Optimum levels of medium constituents were obtained by analysis of the model and numerical optimization method. When the strain JAJ06 was cultivated in the optimized medium, the antibiotic activity was increased to 173.3 U/mL, 26.8% increase as compared to the original (136.7 U/mL). This study found a useful way to cultivate Streptomyces sp. JAJ06 for enhanced production of antibiotic compound. PMID:24454383

Automated Decisional Model for Optimum Economic Order Quantity Determination Using Price Regressive Rates

NASA Astrophysics Data System (ADS)

Roşu, M. M.; Tarbă, C. I.; Neagu, C.

2016-11-01

The current models for inventory management are complementary, but together they offer a large pallet of elements for solving complex problems of companies when wanting to establish the optimum economic order quantity for unfinished products, row of materials, goods etc. The main objective of this paper is to elaborate an automated decisional model for the calculus of the economic order quantity taking into account the price regressive rates for the total order quantity. This model has two main objectives: first, to determine the periodicity when to be done the order n or the quantity order q; second, to determine the levels of stock: lighting control, security stock etc. In this way we can provide the answer to two fundamental questions: How much must be ordered? When to Order? In the current practice, the business relationships with its suppliers are based on regressive rates for price. This means that suppliers may grant discounts, from a certain level of quantities ordered. Thus, the unit price of the products is a variable which depends on the order size. So, the most important element for choosing the optimum for the economic order quantity is the total cost for ordering and this cost depends on the following elements: the medium price per units, the stock cost, the ordering cost etc.

Effect of Light Intensity for Optimum Biomass and Lipid Production from Scenedesmus dimorphus (Turpin) Kützing

NASA Astrophysics Data System (ADS)

Kurniawati, F. N.; Mahajoeno, E.; Sunarto; Sari, S. L. A.

2017-07-01

One source of alternative energy substitute for petroleum raw materials is renewable vegetable oils known as biodiesel. Biodiesel can be produced from microalgae, since it was more efficient and environmentally friendly. Scenedesmus dimorphus (Turpin) Kützing was developed as a source of biodiesel since it had potential of high lipid production. The aims of this research were to know the rate of growth of Scenedesmus dimorphus in different lighting and the optimimum light intensity for biomass and lipid production. This research used a completely randomized design consisting of 3 treatments with 3 replications. Treatments in this research were the light intensity, i.e. 7,500, 10,000, and 12,500 lux. Scenedesmus dimorphus was grew in Bold’s Basal Medium (BBM). Parameters observed in this research were the cell number, biomass and lipid production of S. dimorphus. Data were analyzed by ANOVA followed by DMRT 5%. The results showed that the optimum growth rate of S. dimorphus was in the intensity of 12,500 lux that was 100.80 x 106 cells.ml-1. The optimum production of biomass and lipids was in treatment 12,500 lux i.e; 1.1407 g.L-1 and 0.2520 g.L-1 (22.28% dry weight).

Spirochaeta americana sp. nov.: A New Haloalkaliphilic, Obligately Anaerobic Spirochete Isolated from Soda Mono Lake, California

NASA Technical Reports Server (NTRS)

Hoover, Richard B.; Pikuta, Elena V.; Marsic, Damien; Whitman, William B.; Tang, Jane; Krader, Paul; Six, N. Frank (Technical Monitor)

2002-01-01

A novel obligately anaerobic, mesophilic, haloalkaliphilic spirochete, strain ASpG1, was isolated from sediments of the alkaline, hypersaline Mono Lake in California, U.S.A. The gram-negative cells are motile and spirochete-shaped with sizes of 0.22 x 10-15 micron. Growth was observed over the temperature range of 10 C to 44 C (optimum 37 C), NaCl concentration range of greater than 1 - 12 % (wt/vol) (optimum 3%), and pH range 7.5 - 10.5 (optimum pH 9.5). The novel isolate is strictly alkaliphilic, requires high concentrations of carbonate in the medium, and is capable of utilizing D-glucose, fructose, maltose, sucrose, starch, and D-mannitol. Main end products of glucose fermentation are: H2, acetate, ethanol, and formate. Strain AspG1 is resistant to kanamycin, but sensitive to chloramphenicol, gentamycin and tetracycline. The G+C content of its DNA is 58.5 mol%. On the basis of its physiological and molecular properties, the isolate appears to be a novel species among the genus Spirochaeta; and the name Spirochaeta americana sp. nov., is proposed for the taxon (type strain ASpG1(sup T) = ATCC BAA_392(sup T) = DSMZ 14872(sup T)).

Separation of mixed waste plastics via magnetic levitation.

PubMed

Zhao, Peng; Xie, Jun; Gu, Fu; Sharmin, Nusrat; Hall, Philip; Fu, Jianzhong

2018-06-01

Separation becomes a bottleneck of dealing with the enormous stream of waste plastics, as most of the extant methods can only handle binary mixtures. In this paper, a novel method that based on magnetic levitation was proposed for separating multiple mixed plastics. Six types of plastics, i.e., polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyamide 6 (PA6), polycarbonate (PC), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE), were used to simulate the mixed waste plastics. The samples were mixed and immersed into paramagnetic medium that placed into a magnetic levitation configuration with two identical NdFeB magnets with like-poles facing each other, and Fourier transform infrared (FTIR) spectroscopy was employed to verify the separation outputs. Unlike any conventional separation methods such as froth flotation and hydrocyclone, this method is not limited by particle sizes, as mixtures of different size fractions reached their respective equilibrium positions in the initial tests. The two-stage separation tests demonstrated that the plastics can be completely separated with purities reached 100%. The method has the potential to be industrialised into an economically-viable and environmentally-friendly mass production procedure, since quantitative correlations are determined, and the paramagnetic medium can be reused indefinitely. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development of a semidefined growth medium for Pedobacter cryoconitis BG5 using statistical experimental design.

PubMed

Ong, Magdalena; Ongkudon, Clarence M; Wong, Clemente Michael Vui Ling

2016-10-02

Pedobacter cryoconitis BG5 are psychrophiles isolated from the cold environment and capable of proliferating and growing well at low temperature regime. Their cellular products have found a broad spectrum of applications, including in food, medicine, and bioremediation. Therefore, it is imperative to develop a high-cell density cultivation strategy coupled with optimized growth medium for P. cryoconitis BG5. To date, there has been no published report on the design and optimization of growth medium for P. cryoconitis, hence the objective of this research project. A preliminary screening of four commercially available media, namely tryptic soy broth, R2A, Luria Bertani broth, and nutrient broth, was conducted to formulate the basal medium. Based on the preliminary screening, tryptone, glucose, NaCl, and K2HPO4 along with three additional nutrients (yeast extract, MgSO4, and NH4Cl) were identified to form the basal medium which was further analyzed by Plackett-Burman experimental design. Central composite experimental design using response surface methodology was adopted to optimize tryptone, yeast extract, and NH4Cl concentrations in the formulated growth medium. Statistical data analysis showed a high regression factor of 0.84 with a predicted optimum optical (600 nm) cell density of 7.5 using 23.7 g/L of tryptone, 8.8 g/L of yeast extract, and 0.7 g/L of NH4Cl. The optimized medium for P. cryoconitis BG5 was tested, and the observed optical density was 7.8. The cost-effectiveness of the optimized medium was determined as 6.25 unit prices per gram of cell produced in a 250-ml Erlenmeyer flask.

Carbon fiber composite molecular sieve electrically regenerable air filter media

DOEpatents

Wilson, K.A.; Burchell, T.D.; Judkins, R.R.

1998-10-27

An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply air stream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium. 3 figs.

Optimum detection of tones transmitted by a spacecraft

NASA Technical Reports Server (NTRS)

Simon, M. K.; Shihabi, M. M.; Moon, T.

1995-01-01

The performance of a scheme proposed for automated routine monitoring of deep-space missions is presented. The scheme uses four different tones (sinusoids) transmitted from the spacecraft (S/C) to a ground station with the positive identification of each of them used to indicate different states of the S/C. Performance is measured in terms of detection probability versus false alarm probability with detection signal-to-noise ratio as a parameter. The cases where the phase of the received tone is unknown and where both the phase and frequency of the received tone are unknown are treated separately. The decision rules proposed for detecting the tones are formulated from average-likelihood ratio and maximum-likelihood ratio tests, the former resulting in optimum receiver structures.

Cloning and heterologous expression of cellulose free thermostable xylanase from Bacillus brevis.

PubMed

Goswami, Girish K; Krishnamohan, Medichtrla; Nain, Vikrant; Aggarwal, Chetana; Ramesh, Bandarupalli

2014-01-01

Xylanase gene isolated from Bacillus brevis was expressed in E. coli BL21. Sequencing of the gene (Gen Bank accession number: HQ179986) showed that it belongs to family 11 xylanases. The recombinant xylanase was predominantly secreted to culture medium and showed mesophilic nature (optimum activity at 55°C and pH 7.0). The cell free culture medium exhibited 30 IU/ml xylanse activity. The enzyme did not show any cellulose activity and was active under wide range of temperature (40°C to 80°C) and pH (4 to 9). The enzyme showed considerable thermo stability and regained over 90% of activity, when returned to 55°C after boiling for 5 min. These physiochemical properties of B. brevis xylanse show high potential of its applications in paper and pulp industry.

Inverse Doppler shift and control field as coherence generators for the stability in superluminal light

NASA Astrophysics Data System (ADS)

Ghafoor, Fazal; Bacha, Bakht Amin; Khan, Salman

2015-05-01

A gain-based four-level atomic medium for the stability in superluminal light propagation using control field and inverse Doppler shift as coherence generators is studied. In regimes of weak and strong control field, a broadband and multiple controllable transparency windows are, respectively, identified with significantly enhanced group indices. The observed Doppler effect for the class of high atomic velocity of the medium is counterintuitive in comparison to the effect of the class of low atomic velocity. The intensity of each of the two pump fields is kept less than the optimum limit reported in [M. D. Stenner and D. J. Gauthier, Phys. Rev. A 67, 063801 (2003), 10.1103/PhysRevA.67.063801] for stability in the superluminal light pulse. Consequently, superluminal stable domains with the generated coherence are explored.

Utilization of coconut oil cake for the production of lipase using Bacillus coagulans VKL1.

PubMed

Gowthami, Palanisamy; Muthukumar, Karuppan; Velan, Manickam

2015-01-01

The overproduction of enzymes was performed by manipulating the medium components. In our study, solvent-tolerant thermophilic lipase-producing Bacillus coagulans was isolated from soil samples and a stepwise optimization strategy was employed to increase the lipase production using coconut oil cake basal medium. In the first step, the influence of pH, temperature, carbon source, nitrogen source and inducers on lipase activity was investigated by the One-Factor-At-A-Time (OFAT) method. In the second step, the three significant factors resulted from OFAT were optimized by the statistical approach (CCD).The optimum values of olive oil (0.5%), Tween 80 (0.6%) and FeSO4 (0.05%) was found to be responsible for a 3.2-fold increase in the lipase production identified by Central Composite Design.

Effect of pulsed electric fields upon accumulation of zinc in Saccharomyces cerevisiae.

PubMed

Pankiewicz, Urszula; Jamroz, Jerzy

2011-06-01

Cultures of Saccharomyces cerevisiae were treated with pulsed electric fields to improve accumulation of zinc in the biomass. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEFs of 1500 V and 10 microns pulse width, accumulation of zinc in the yeast biomass reached a maximum of 15.57 mg/g d.m. Under optimum zinc concentration (100 microgram/ml nutrient medium), its accumulation in the cells was higher by 63% in comparison with the control (without PEFs). That accumulation significantly correlated against zinc concentration in the medium. Neither multiple exposure of the cultures to PEFs nor intermittent supplementation of the cultures with zinc increased the zinc accumulation. The intermittent supplementation of the cultures with zinc and multiple exposures on PEFs could even reduce the accumulation efficiency, respectively, by 57% and 47%.

75 FR 78619 - Shipping Act, Merchant Marine, and Magnuson-Stevens Fishery Conservation and Management Act...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-16

... augmented harvest capacity can push effort into other fisheries. Although overall harvest levels may remain... should be restored to the peak levels of prior budget cycles. Response: The FFP receives two separate... any stock of fish (a) harvested below its optimum yield or (b) limited to a level of harvest or...

VENVAL : a plywood mill cost accounting program

Treesearch

Henry Spelter

1991-01-01

This report documents a package of computer programs called VENVAL. These programs prepare plywood mill data for a linear programming (LP) model that, in turn, calculates the optimum mix of products to make, given a set of technologies and market prices. (The software to solve a linear program is not provided and must be obtained separately.) Linear programming finds...

Contribution of Co2+ in increasing chlorophyll a concentration of Nannochloropsis salina in controlled Conwy medium

NASA Astrophysics Data System (ADS)

Hala, Y.; Taba, P.; Suryati, E.; Kasih, P.; Firman, N. F.

2018-03-01

A research in determining the contribution of Co2+ on the increase of chlorophyll a concentration of Nannochloropsis salina has been caried out. The cultivation of N. salina was conducted in the Conwy medium with a salinity of 5%o and 25%o and various Co2+ concentration (2, 4, and 8 ppm). In this research, Co2+ was exposed early in the cultivation of N. salina. The growth of N. salina was observed daily by counting the number of populations using a haemocytometer while the chlorophyll a concentration was determined by a Uv-Vis spectrophotometer. The results showed that the growth of N. salina in the control was higher than that in the medium containing Co2+. The optimum growth time was achieved on 15th days (5%) and 8th days (25%). In the cultivation medium with a salinity of 5%, Co2+ with a concentration of 2 ppm increased the chlorophyll a level while Co2+ with concentrations of 4 and 8 ppm decreased it. In the medium of cultivation with a salinity of 25%, the increase in chlorophyll a level was observed at Co2+ concentrations of 2 and 4 ppm whereas the decrease in chlorophyl a level was given at a concentration of 8 ppm. It can be concluded that at low concentrations, Co2+ increased the concentration of chlorophyll a in N. salina.

Medium components and culture conditions affect the thermotolerance of aerial conidia of fungal biocontrol agent Beauveria bassiana.

PubMed

Ying, S-H; Feng, M-G

2006-09-01

To produce more thermotolerable conidia of Beauveria bassiana, a well-known fungal biocontrol agent, by optimizing the medium components and culture conditions. The conidia produced on media including 0.5-6% glucose, sucrose or starch as carbon source and 50-300-microg ml(-1) Cu2+, Zn2+, Mn2+ or Fe3+ as additive to Sabouraud dextrose medium at 15-30 degrees C, pH 4-8 or KCl-adjusted water availabilities were exposed to 30-min wet heat stress at 48 degrees C. The medium components for conidial production with greatly enhanced thermotolerance included 4% glucose as optimum or 1% starch as alternative for the carbon source and < or =50-microg ml(-1) Mn2+ for the metal additive. The culture conditions were optimized as 25 degrees C and pH 5-6. Conidial thermotolerance decreased remarkably when sucrose and Fe3+ or Cu2+ were used in the cultures, but altered slightly when 50-200-microg ml(-1) Zn2+ were included. The tolerance of B. bassiana conidia to the thermal stress was significantly affected by the medium composition and culture conditions under which the conidia were produced. Proper treatment of small grains as mass production substrates for more glucose release and supplement of glucose or 50-microg ml(-1) Mn2+ are possible means to enhancing conidial thermotolerance and field persistence for improved insect control.

A quality by design (QbD) study on enoxaparin sodium loaded polymeric microspheres for colon-specific delivery.

PubMed

Hales, Dana; Vlase, Laurian; Porav, Sebastian Alin; Bodoki, Andreea; Barbu-Tudoran, Lucian; Achim, Marcela; Tomuță, Ioan

2017-03-30

The aim of this study was to apply quality by design (QbD) for pharmaceutical development of enoxaparin sodium microspheres for colon-specific delivery. The Process Parameters (CPPs) and Critical Quality Attributes (CQAs) were identified. A central composite experimental design was used in order to develop the design space of microspheres for colon-specific delivery that have the desired Quality Target Product Profile (QTPP). The CPPs studied were Eudragit® FS-30D/Eudragit® RS-PO ratio, poly(vinyl alcohol) (PVA) concentration and sodium chloride (NaCl) concentration. The encapsulation efficiency increased with NaCl concentration increase, the percentages of enoxaparin sodium reaching 94% for some formulations. Increasing the ratio Eudragit® FS-30D/Eudragit® RS-PO ensured a relatively complete release of enoxaparin sodium in the environment simulating the colonic pH. Based on these results, the optimum conditions were decided and the optimum formulation was prepared. The results obtained for the latter in terms of in vitro enoxaparin sodium release were good, the microparticles releasing only 9.42% enoxaparin sodium in acidic environment and 15.16% in the medium which simulated duodenal pH, but allowing the release of up to 89.24% in the medium which simulated colonic pH. The in vitro release profile of enoxaparin sodium was close to the ideal one, therefore the system was successfully designed using QbD approach. Copyright © 2017 Elsevier B.V. All rights reserved.

The separation of waste printed circuit board by dissolving bromine epoxy resin using organic solvent.

PubMed

Zhu, P; Chen, Y; Wang, L Y; Zhou, M; Zhou, J

2013-02-01

Separation of waste printed circuit boards (WPCBs) has been a bottleneck in WPCBs resource processing. In this study, the separation of WPCBs was performed using dimethyl sulfoxide (DMSO) as a solvent. Various parameters, which included solid to liquid ratio, temperature, WPCB sizes, and time, were studied to understand the separation of WPCBs by dissolving bromine epoxy resin using DMSO. Experimental results showed that the concentration of dissolving the bromine epoxy resin increased with increasing various parameters. The optimum condition of complete separation of WPCBs was solid to liquid ratio of 1:7 and WPCB sizes of 16 mm(2) at 145°C for 60 min. The used DMSO was vapored under the decompression, which obtained the regenerated DMSO and dissolved bromine epoxy resin. This clean and non-polluting technology offers a new way to separate valuable materials from WPCBs and prevent the environmental pollution of waste printed circuit boards effectively. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Influence of particle size and shell thickness of core-shell packing materials on optimum experimental conditions in preparative chromatography.

PubMed

Horváth, Krisztián; Felinger, Attila

2015-08-14

The applicability of core-shell phases in preparative separations was studied by a modeling approach. The preparative separations were optimized for two compounds having bi-Langmuir isotherms. The differential mass balance equation of chromatography was solved by the Rouchon algorithm. The results show that as the size of the core increases, larger particles can be used in separations, resulting in higher applicable flow rates, shorter cycle times. Due to the decreasing volume of porous layer, the loadability of the column dropped significantly. As a result, the productivity and economy of the separation decreases. It is shown that if it is possible to optimize the size of stationary phase particles for the given separation task, the use of core-shell phases are not beneficial. The use of core-shell phases proved to be advantageous when the goal is to build preparative column for general purposes (e.g. for purification of different products) in small scale separations. Copyright © 2015 Elsevier B.V. All rights reserved.

Cell design concepts for aqueous lithium-oxygen batteries: A model-based assessment

NASA Astrophysics Data System (ADS)

Grübl, Daniel; Bessler, Wolfgang G.

2015-11-01

Seven cell design concepts for aqueous (alkaline) lithium-oxygen batteries are investigated using a multi-physics continuum model for predicting cell behavior and performance in terms of the specific energy and specific power. Two different silver-based cathode designs (a gas diffusion electrode and a flooded cathode) and three different separator designs (a porous separator, a stirred separator chamber, and a redox-flow separator) are compared. Cathode and separator thicknesses are varied over a wide range (50 μm-20 mm) in order to identify optimum configurations. All designs show a considerable capacity-rate effect due to spatiotemporally inhomogeneous precipitation of solid discharge product LiOH·H2O. In addition, a cell design with flooded cathode and redox-flow separator including oxygen uptake within the external tank is suggested. For this design, the model predicts specific power up to 33 W/kg and specific energy up to 570 Wh/kg (gravimetric values of discharged cell including all cell components and catholyte except housing and piping).

Novel microfluidic device for the continuous separation of cancer cells using dielectrophoresis.

PubMed

Alazzam, Anas; Mathew, Bobby; Alhammadi, Falah

2017-03-01

We describe the design, microfabrication, and testing of a microfluidic device for the separation of cancer cells based on dielectrophoresis. Cancer cells, specifically green fluorescent protein-labeled MDA-MB-231, are successfully separated from a heterogeneous mixture of the same and normal blood cells. MDA-MB-231 cancer cells are separated with an accuracy that enables precise detection and counting of circulating tumor cells present among normal blood cells. The separation is performed using a set of planar interdigitated transducer electrodes that are deposited on the surface of a glass wafer and slightly protrude into the separation microchannel at one side. The device includes two parts, namely, a glass wafer and polydimethylsiloxane element. The device is fabricated using standard microfabrication techniques. All experiments are conducted with low conductivity sucrose-dextrose isotonic medium. The variation in response between MDA-MB-231 cancer cells and normal cells to a certain band of alternating-current frequencies is used for continuous separation of cells. The fabrication of the microfluidic device, preparation of cells and medium, and flow conditions are detailed. The proposed microdevice can be used to detect and separate malignant cells from heterogeneous mixture of cells for the purpose of early screening for cancer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method to prepare nanoparticles on porous mediums

DOEpatents

Vieth, Gabriel M [Knoxville, TN; Dudney, Nancy J [Oak Ridge, TN; Dai, Sheng [Knoxville, TN

2010-08-10

A method to prepare porous medium decorated with nanoparticles involves contacting a suspension of nanoparticles in an ionic liquid with a porous medium such that the particles diffuse into the pores of the medium followed by heating the resulting composition to a temperature equal to or greater than the thermal decomposition temperature of the ionic liquid resulting in the removal of the liquid portion of the suspension. The nanoparticles can be a metal, an alloy, or a metal compound. The resulting compositions can be used as catalysts, sensors, or separators.

Lift producing device exhibiting low drag and reduced ventilation potential and method for producing the same

NASA Technical Reports Server (NTRS)

Caldwell, Richard A. (Inventor)

1991-01-01

A lift producing device is disclosed which is adapted to be connected to a vehicle to provide lift to the vehicle when the vehicle is moved relative to a first fluid medium having a first density and viscosity and being in contact with a second fluid medium adjacent the vehicle. The second fluid medium has a second fluid density which is different from the first fluid density. The lift producing device comprises opposed first and second major surfaces joined at a longitudinally extending leading edge and at a longitudinally extending trailing edge, with at least a portion of the longitudinally extending leading edge being spaced from the longitudinally extending trailing edge by a predetermined mean chord length. When the vehicle is moved relative to the first fluid medium at a velocity within a range of predetermined velocities, with each of the velocities having a direction inclined from a plane extending through the leading edge and the trailing edge within a predetermined angular range, a region of high pressure is generated in the first fluid medium adjacent the first major surface and a region of low pressure is generated in the first fluid medium adjacent the second major surface. The lift producing device has a cross-sectional shape which will generate a pressure distribution around the device when the vehicle is moved relative to the first fluid medium at a velocity within the range of predetermined velocities such that the first fluid medium exhibits attached laminar flow along the device for a portion of the predetermined mean chord length from the leading edge to the trailing edge and will neither form a laminar separation bubble adjacent the second major surface of the device, nor exhibit turbulent separation adjacent the second major surface for substantially all of the predetermined mean chord length from the leading edge to the trailing edge. The portion along which attached laminar flow is maintained is the longest portion which will still fulfill the flow separation requirements. A method for producing the foil is also disclosed.

Atrazine and its metabolites degradation in mineral salts medium and soil using an enrichment culture.

PubMed

Kumar, Anup; Singh, Neera

2016-03-01

An atrazine-degrading enrichment culture was used to study degradation of atrazine metabolites viz. hydroxyatrazine, deethylatrazine, and deisopropylatrazine in mineral salts medium. Results suggested that the enrichment culture was able to degrade only hydroxyatrazine, and it was used as the sole source of carbon and nitrogen. Hydroxyatrazine degradation slowed down when sucrose and/or ammonium hydrogen phosphate were supplemented as the additional sources of carbon and nitrogen, respectively. The enrichment culture could degrade high concentrations of atrazine (up to 110 μg/mL) in mineral salts medium, and neutral pH was optimum for atrazine degradation. Further, except in an acidic soil, enrichment culture was able to degrade atrazine in three soil types having different physico-chemical properties. Raising the pH of acidic soil to neutral or alkaline enabled the enrichment culture to degrade atrazine suggesting that acidic pH inhibited atrazine-degrading ability. The study suggested that the enrichment culture can be successfully utilized to achieve complete degradation of atrazine and its persistent metabolite hydroxyatrazine in the contaminated soil and water.

Response surface optimization of medium components for naringinase production from Staphylococcus xylosus MAK2.

PubMed

Puri, Munish; Kaur, Aneet; Singh, Ram Sarup; Singh, Anubhav

2010-09-01

Response surface methodology was used to optimize the fermentation medium for enhancing naringinase production by Staphylococcus xylosus. The first step of this process involved the individual adjustment and optimization of various medium components at shake flask level. Sources of carbon (sucrose) and nitrogen (sodium nitrate), as well as an inducer (naringin) and pH levels were all found to be the important factors significantly affecting naringinase production. In the second step, a 22 full factorial central composite design was applied to determine the optimal levels of each of the significant variables. A second-order polynomial was derived by multiple regression analysis on the experimental data. Using this methodology, the optimum values for the critical components were obtained as follows: sucrose, 10.0%; sodium nitrate, 10.0%; pH 5.6; biomass concentration, 1.58%; and naringin, 0.50% (w/v), respectively. Under optimal conditions, the experimental naringinase production was 8.45 U/mL. The determination coefficients (R(2)) were 0.9908 and 0.9950 for naringinase activity and biomass production, respectively, indicating an adequate degree of reliability in the model.

Formulation of a minimal nutritional medium for enhanced lipid productivity in Chlorella sp. and Botryococcus sp. using response surface methodology.

PubMed

Vishwakarma, Rashi; Dhar, Dolly Wattal; Pabbi, Sunil

2018-03-01

Chlorella sp. MCC 7 and Botryococcus sp. MCC 31 were investigated to enable large-scale biodiesel production from minimal constituents in the growth medium. Response surface methodology (RSM) was used to maximise the biomass productivity and lipid yield using only nitrogen (N), phosphorus (P) and potassium (K) as urea, single super phosphate and muriate of potash. The optimum values were 0.42 g/L nitrogen; 0.14 g/L phosphorus and 0.22 g/L potassium for Chlorella sp.; and 0.46 g/L; 0.14 g/L and 0.25 g/L for Botryococcus sp. Lipid yield of 42% for Chlorella sp. and 52% in Botryococcus sp. was observed. An enhancement in lipid yield by approximately 55% for Chlorella sp. and 73% for Botryococcus sp. was registered as compared to original nutrient medium. Fourier transform infrared (FTIR) analysis of extracted lipids revealed characteristic bands for triglycerides. This study provided utilisation of a practicable nutrient recipe in the form of N, P, K input for enhanced lipid yield from the selected microalgal strains.

Polymeric membrane systems of potential use for battery separators

NASA Technical Reports Server (NTRS)

Philipp, W. H.

1977-01-01

Two membrane systems were investigated that may have potential use as alkaline battery separators. One system comprises two miscible polymers: a support polymer (e.g., polyvinyl formal) and an ion conductor such as polyacrylic acid. The other system involves a film composed of two immiscible polymers: a conducting polymer (e.g., calcium polyacrylate) suspended in an inert polymer support matrix, polyphenylene oxide. Resistivities in 45-percent potassium hydroxide and qualitative mechanical properties are presented for films comprising various proportions of conducting and support polymers. In terms of these parameters, the results are encouraging for optimum ratios of conducting to support polymers.

Carbon dioxide capture using resin-wafer electrodeionization

DOEpatents

Lin, YuPo J.; Snyder, Seth W.; Trachtenberg, Michael S.; Cowan, Robert M.; Datta, Saurav

2015-09-08

The present invention provides a resin-wafer electrodeionization (RW-EDI) apparatus including cathode and anode electrodes separated by a plurality of porous solid ion exchange resin wafers, which when in use are filled with an aqueous fluid. The apparatus includes one or more wafers comprising a basic ion exchange medium, and preferably includes one or more wafers comprising an acidic ion exchange medium. The wafers are separated from one another by ion exchange membranes. The fluid within the acidic and/or basic ion exchange wafers preferably includes, or is in contact with, a carbonic anhydrase (CA) enzyme to facilitate conversion of bicarbonate ion to carbon dioxide within the acidic medium. A pH suitable for exchange of CO.sub.2 is electrochemically maintained within the basic and acidic ion exchange wafers by applying an electric potential across the cathode and anode.

Sequence of Centromere Separation: Role of Centromeric Heterochromatin

PubMed Central

Vig, Baldev K.

1982-01-01

The late metaphase-early anaphase cells from various tissues of male Mus musculus, M. poschiavinus, M. spretus, M. castaneus, female and male Bos taurus (cattle) and female Myopus schisticolor (wood lemming) were analyzed for centromeres that showed separation into two daughter centromeres and those that did not show such separation. In all strains and species of mouse the Y chromosome is the first one to separate, as is the X or Y in the cattle. These sex chromosomes are devoid of constitutive heterochromatin, whereas all autosomes in these species carry detectable quantities. In cattle, the late replicating X chromosome appears to separate later than the active X. In the wood lemming the three pairs of autosomes with the least amount of centromeric constitutive heterochromatin separate first. These are followed by the separation of seven pairs of autosomes carrying medium amounts of constitutive heterochromatin. Five pairs of autosomes with the largest amounts of constitutive heterochromatin are the last in the sequence of separation. The sex chromosomes with medium amounts of constitutive heterochromatin around the centromere, and a very large amount of distal heterochromatin, separate among the very late ones but are not the last. These observations assign a specific role to centromeric constitutive heterochromatin and also indicate that nonproximal heterochromatin does not exert control over the sequence in which the centromeres in the genome separate. It appears that qualitative differences among various types of constitutive heterochromatin are as important as quantitative differences in controlling the separation of centromeres. PMID:6764903

Adaptive shoot and root responses collectively enhance growth at optimum temperature and limited phosphorus supply of three herbaceous legume species.

PubMed

Suriyagoda, Lalith D B; Ryan, Megan H; Renton, Michael; Lambers, Hans

2012-10-01

Studies on the effects of sub- and/or supraoptimal temperatures on growth and phosphorus (P) nutrition of perennial herbaceous species at growth-limiting P availability are few, and the impacts of temperature on rhizosphere carboxylate dynamics are not known for any species. The effect of three day/night temperature regimes (low, 20/13 °C; medium, 27/20 °C; and high, 32/25 °C) on growth and P nutrition of Cullen cinereum, Kennedia nigricans and Lotus australis was determined. The highest temperature was optimal for growth of C. cinereum, while the lowest temperature was optimal for K. nigricans and L. australis. At optimum temperatures, the relative growth rate (RGR), root length, root length per leaf area, total P content, P productivity and water-use efficiency were higher for all species, and rhizosphere carboxylate content was higher for K. nigricans and L. australis. Cullen cinereum, with a slower RGR, had long (higher root length per leaf area) and thin roots to enhance P uptake by exploring a greater volume of soil at its optimum temperature, while K. nigricans and L. australis, with faster RGRs, had only long roots (higher root length per leaf area) as a morphological adaptation, but had a higher content of carboxylates in their rhizospheres at the optimum temperature. Irrespective of the species, the amount of P taken up by a plant was mainly determined by root length, rather than by P uptake rate per unit root surface area. Phosphorus productivity was correlated with RGR and plant biomass. All three species exhibited adaptive shoot and root traits to enhance growth at their optimum temperatures at growth-limiting P supply. The species with a slower RGR (i.e. C. cinereum) showed only morphological root adaptations, while K. nigricans and L. australis, with faster RGRs, had both morphological and physiological (i.e. root carboxylate dynamics) root adaptations.

Simultaneous leaching of Pt, Pd and Rh from automotive catalytic converters in chloride-containing solutions

NASA Astrophysics Data System (ADS)

Hasani, M.; Khodadadi, A.; Koleini, S. M. J.; Saeedi, A. H.; Meléndez, A. M.

2017-01-01

Dissolution of platinum group metals (PGM; herein Pt, Pd and Rh) in different chloride-based leaching systems from spent auto catalysts was performed. Response surface methodology and a five-level-five-factor central composite design were used to evaluate the effects of 1) temperature, 2) liquid-to-solid ratio, 3) stirring speed, 4) acid concentration and 5) particle size on extraction yield of PGM by aqua regia. Analysis of variance was used to determine the optimum conditions and most significant factors affecting the overall metal extraction. In the optimum conditions, leaching of Pt, Pd and Rh was 91.58%, 93.49% and 60.15%, respectively. The effect of different oxidizing agents on the PGM dissolution in chloride medium was studied comparatively in the following leaching systems: a) aqua regia/sulfuric acid mixture, b) hydrogen peroxide in sulfuric acid (piranha solution), c) sodium hypochlorite and d) copper(II). Dissolution of Rh is increased in both aqua regia and hydrogen peroxide/hydrochloric acid solutions by adding sulfuric acid.

Production of a Pseudomonas lipase in n-alkane substrate and its isolation using an improved ammonium sulfate precipitation technique.

PubMed

Kanwar, Lambit; Gogoi, Binod Kumar; Goswami, Pranab

2002-09-01

Among the various lipidic and non-lipidic substances, normal alkanes within the chain lengths of C-12 to C-20 served as the best carbon substrates for the production of extracellular lipase by Pseudomonas species G6. Maximum lipase production of 25 U/ml of the culture broth was obtained by using n-hexadecane as the sole carbon substrate. The optimum pH of 8 and temperature of 34 + 1 degrees C were demonstrated for the production of lipase in n-hexadecane substrate. The optimum concentration of iron, which played a critical role on the lipase production, was found to be 0.25 mg/l. Lipase production could be enhanced to nearly 2.4-fold by using tributyrin at a concentration of 0.05% (v/v) in the culture medium. High recovery of the lipase protein (83%) from the culture broth was achieved by treating the culture supernatant with Silicone 21 Defoamer followed by ammonium sulfate (60% saturation) fractionation.

Corrosion Protection Of Mild Steel In Sea Water Using Chemical Inhibitor

NASA Astrophysics Data System (ADS)

Araoyinbo, Alaba O.; Salleh, Mohd Arif Anuar Mohd; Zulerwan Jusof, Muhammad

2018-03-01

The effect of sodium nitrite as a corrosion inhibitor of mild steel in sea water (i.e ASTM standard prepared sea water and sea water obtained from a local river) was investigated, using the weight loss technique. Different amount of sodium nitrite were prepared (i.e 2 % to 10 %) in the inhibition of the mild steel corrosion in sea water exposed to irradiation condition from sunlight exposure. The cut samples of mild steel were exposed to these corrosive media and the corresponding weight loss subsequently obtained was recorded at intervals of 1 to 4 weeks. It was observed that corrosion rate increases with the time of exposure to the corrosive medium exposed to sunlight and that sodium nitrite that was used at the chemical inhibitor was able to retard the corrosion rate of mild steel if the appropriate concentration is applied. The results obtained from the weight loss analysis shows that the optimum percentage of sodium nitrate in sea water that gives the optimum corrosion inhibition of mild steel is 4 %.

Influence of Nose Radius of Blunt Cones on Drag in Supersonic and Hypersonic Flows

NASA Astrophysics Data System (ADS)

Hemateja, A.; Teja, B. Ravi; Dileep Kumar, A.; Rakesh, S. G.

2017-08-01

The objects moving at high speeds encounter forces which tend to decelerate the objects. This resistance in the medium is termed as drag which is one of the major concerns while designing high speed aircrafts. Another key factor which influences the design is the heat transfer. The main challenge faced by aerospace industries is to design the shape of the flying object that travels at high speeds with optimum values of heat generation and drag. This study deals with computational analysis of sharp and blunt cones with varying cone angles and nose radii. The effect of nose radius on the drag is studied at supersonic and hypersonic flows and at various angles of attack. It is observed that as the nose radius is increased, the heat transfer reduces & the drag increases and vice-versa. Looking at the results, the optimum value of nose radius can be chosen depending on the need of the problem.

Enhanced production of laccase from Coriolus versicolor NCIM 996 by nutrient optimization using response surface methodology.

PubMed

Arockiasamy, Santhiagu; Krishnan, Indira Packialakshmi Gurusamy; Anandakrishnan, Nimalanandan; Seenivasan, Sabitha; Sambath, Agalya; Venkatasubramani, Janani Priya

2008-12-01

Plackett and Burman design criterion and central composite design were applied successfully for enhanced production of laccase by Coriolus versicolor NCIM 996 for the first time. Plackett and Burman design criterion was applied to screen the significance of ten nutrients on laccase production by C. versicolor NCIM 996. Out of the ten nutrients tested, starch, yeast extract, MnSO(4), MgSO(4) x 7H(2)O, and phenol were found to have significant effect on laccase production. A central composite design was applied to determine the optimum concentrations of the significant variables obtained from Plackett-Burman design. The optimized medium composition for production of laccase was (g/l): starch, 30.0; yeast extract, 4.53; MnSO(4), 0.002; MgSO(4) x 7H(2)O, 0.755; and phenol, 0.026, and the optimum laccase production was 6,590.26 (U/l), which was 7.6 times greater than the control.

Reductive smelting of spent lead-acid battery colloid sludge in a molten Na2CO3 salt

NASA Astrophysics Data System (ADS)

Hu, Yu-jie; Tang, Chao-bo; Tang, Mo-tang; Chen, Yong-ming

2015-08-01

Lead extraction from spent lead-acid battery paste in a molten Na2CO3 salt containing ZnO as a sulfur-fixing agent was studied. Some influencing factors, including smelting temperature, reaction time, ZnO and salt dosages, were investigated in detail using single-factor experiments. The optimum conditions were determined as follows: T = 880°C; t = 60 min; Na2CO3/paste mass ratio = 2.8:1; and the ZnO dosage is equal to the stoichiometric requirement. Under the optimum conditions, the direct recovery rate of lead reached 98.14%. The results suggested that increases in temperature and salt dosage improved the direct recovery rate of lead. XRD results and thermodynamic calculations indicated that the reaction approaches of lead and sulfur were PbSO4→Pb and PbSO4→ZnS, respectively. Sulfur was fixed in the form of ZnS, whereas the molten salt did not react with other components, serving only as a reaction medium.

Statistical optimization of process parameters for the production of tannase by Aspergillus flavus under submerged fermentation.

PubMed

Mohan, S K; Viruthagiri, T; Arunkumar, C

2014-04-01

Production of tannase by Aspergillus flavus (MTCC 3783) using tamarind seed powder as substrate was studied in submerged fermentation. Plackett-Burman design was applied for the screening of 12 medium nutrients. From the results, the significant nutrients were identified as tannic acid, magnesium sulfate, ferrous sulfate and ammonium sulfate. Further the optimization of process parameters was carried out using response surface methodology (RSM). RSM has been applied for designing of experiments to evaluate the interactive effects through a full 31 factorial design. The optimum conditions were tannic acid concentration, 3.22 %; fermentation period, 96 h; temperature, 35.1 °C; and pH 5.4. Higher value of the regression coefficient (R 2  = 0.9638) indicates excellent evaluation of experimental data by second-order polynomial regression model. The RSM revealed that a maximum tannase production of 139.3 U/ml was obtained at the optimum conditions.

The FPase properties and morphology changes of a cellulolytic bacterium, Sporocytophaga sp. JL-01, on decomposing filter paper cellulose.

PubMed

Wang, Xiuran; Peng, Zhongqi; Sun, Xiaoling; Liu, Dongbo; Chen, Shan; Li, Fan; Xia, Hongmei; Lu, Tiancheng

2012-01-01

Sporocytophaga sp. JL-01 is a sliding cellulose degrading bacterium that can decompose filter paper (FP), carboxymethyl cellulose (CMC) and cellulose CF11. In this paper, the morphological characteristics of S. sp. JL-01 growing in FP liquid medium was studied by Scanning Electron Microscope (SEM), and one of the FPase components of this bacterium was analyzed. The results showed that the cell shapes were variable during the process of filter paper cellulose decomposition and the rod shape might be connected with filter paper decomposing. After incubating for 120 h, the filter paper was decomposed significantly, and it was degraded absolutely within 144 h. An FPase1 was purified from the supernatant and its characteristics were analyzed. The molecular weight of the FPase1 was 55 kDa. The optimum pH was pH 7.2 and optimum temperature was 50°C under experiment conditions. Zn(2+) and Co(2+) enhanced the enzyme activity, but Fe(3+) inhibited it.

Optimisation of the reaction conditions for the production of cross-linked starch with high resistant starch content.

PubMed

Kahraman, Kevser; Koksel, Hamit; Ng, Perry K W

2015-05-01

The optimum reaction conditions (temperature and pH) for the preparation of cross-linked (CL) corn and wheat starches with maximum resistant starch (RS) content were investigated by using response surface methodology (RSM). According to the preliminary results, five levels were selected for reaction temperature (38-70 °C) and pH (10-12) in the main study. RS contents of the CL corn and wheat starch samples increased with increasing temperature and pH, and pH had a greater influence on RS content than had temperature. The maximum RS content (with a maximum p value of 0.4%) was obtained in wheat starch cross-linked at 38 °C and pH 12. In the case of CL corn starch, the optimum condition was 70 °C and pH 12. CL corn and wheat starch samples were also produced separately under the optimum conditions and their RS contents were 80.4% and 83.9%, respectively. These results were also in agreement with the values predicted by RSM. Copyright © 2014 Elsevier Ltd. All rights reserved.

Purification and biochemical characterization of glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and glutathione reductase from rat lung and inhibition effects of some antibiotics.

PubMed

Adem, Sevki; Ciftci, Mehmet

2016-12-01

G6PD, 6PGD and GR have been purified separately in the single step from rat lung using 2', 5'-ADP Sepharose 4B affinity chromatography. The purified enzymes showed a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weights of the enzymes were estimated to be 134 kDa for G6PD, 107 kDa for 6PGD and 121 kDa for GR by Sephadex G-150 gel filtration chromatography, and the subunit molecular weights was respectively found to be 66, 52 and 63 kDa by SDS-PAGE. Optimum pH, stable pH, optimum ionic strength, optimum temperature, KM and Vmax values for substrates were determined. Product inhibition studies were also performed. The enzymes were inhibited by levofloxacin, furosemide, ceftazidime, cefuroxime and gentamicin as in vitro with IC50 values in the range of 0.07-30.13 mM. In vivo studies demonstrated that lung GR was inhibited by furosemide and lung 6PGD was inhibited by levofloxacin.

Optimization of medium components and physicochemical parameters to simultaneously enhance microbial growth and production of lypolitic enzymes by Stenotrophomonas sp.

PubMed

Mazzucotelli, Cintia Anabela; Agüero, María Victoria; Del Rosario Moreira, María; Ansorena, María Roberta

2016-05-01

The optimization of lipase and esterase production (LP and EP) and bacterial growth (BG) of a Stenotrophomonas sp. strain was developed. For this purpose, the effect of five different medium components and three physicochemical parameters were evaluated using a Plackett-Burman statistical design. Among eight variables, stirring speed, pH, and peptone concentration were found to be the most effective factors on the three responses under evaluation. An optimization study applying Box-Behnken response surface methodology was used to study the interactive effects of the three selected variables on LP/EP and microorganism growth. Predicted models were found to be significant with high regression coefficients (90%-99%). By using the desirability function approach, the optimum condition applying simultaneous optimization of the three responses under study resulted to be: stirring speed of 100 rpm, pH of 7.5, and a peptone concentration of 10 g/L, with a desirability value of 0.977. Under these optimal conditions, it is possible to achieve in the optimized medium a 15-fold increase in esterase productivity, a 117-fold increase in lipase production, and a 9-log CFU/mL increase in BG, compared with the basal medium without agitation. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

A Novel Denitrifying Extreme Halophile That Grows in a Simple Mineral Salts Medium

NASA Technical Reports Server (NTRS)

Hochstein, L. I.; Oremland, R. S.; Gherna, R.; Cote, R.; Chang, Sherwood (Technical Monitor)

1995-01-01

An extremely halophilic bacterium (strain CH-1) was isolated from a saltern adjacent to San Francisco Bay. It grew in a mineral salts medium with ammonium and glucose as sole sources of nitrogen and carbon as well as energy, respectively Cells lysed at less than 10% NaCl and growth was most rapid in medium containing 20% NaCl. Cells were pieomorphic ranging from disc to ovoid-shaved and used a variety of carbohydrates as sole carbon sources. the utilization of certain carbon sources was controlled by temperature with some used at 37 degrees but not 45 C. CH-1 grew between 30 degrees and 50 C with the optimum at 45 C in the presence of 20% NaCl. CH-1 contained 2,3-di-O-isoprenyl glcerol diethers and was sensitive to aphidicofin. The major polar lipid was glucosyl-mannosyl-alucosyl diether, which is diagnostic of the Haloarcula. Thus CH-1 is an extreme halophile and a member of this genus. Among the novel characteristics of this organism was its ability to grow anaerobically in synthetic medium when nitrate was present which was only reduced to nitrous oxide. This organism should prove useful for studying denitrification and carbohydrate metabolism in the extreme halophiles; and to be a valuable resource for generic studies.

Melatonin accelerates maturation inducing hormone (MIH): induced oocyte maturation in carps.

PubMed

Chattoraj, Asamanja; Bhattacharyya, Sharmistha; Basu, Dipanjan; Bhattacharya, Shelley; Bhattacharya, Samir; Maitra, Saumen Kumar

2005-02-01

The present communication is an attempt to demonstrate the influence of melatonin on the action of maturation inducing hormone (MIH) on the maturation of oocytes in carps. The oocytes from gravid female major carp Labeo rohita were isolated and incubated separately in Medium 199 containing (a) only MIH (1 microg/ml), (b) only melatonin (at concentrations of 50, 100 or 500 pg/ml), and (c) both melatonin and MIH, but at different time intervals. In the latter group, melatonin was added to the incubating medium either (i) 4 h before addition of MIH, (ii) 2 h before addition of MIH, (iii) co-administered with MIH (0 h interval) or (iv) 2 h after addition of MIH. In each case, oocytes were further incubated for 4, 8, 12 or 16 h post- administration of MIH, and the effects of treatment on oocyte maturation were evaluated by considering the rate (%) of germinal vesicle breakdown (GVBD). Incubation of oocytes in a medium containing only melatonin did not result in GVBD of any oocyte. Nearly all the oocytes underwent GVBD when incubated with MIH for 16 h. Administration of melatonin along with MIH (at 0 h interval) or 2 h after addition of MIH did not result in any significant change in the rate of GVBD compared to that in a medium containing only MIH. However, it was quite interesting to observe that incubation of oocytes with melatonin especially 4 h prior to addition of MIH in the medium, led to an accelerated rate of GVBD in the oocytes. Experiments with the oocytes of another major carp Cyprinus carpio following an identical schedule depicted similar results except a difference in the optimum melatonin dose. In L. rohita, 50 pg/ml melatonin had maximum acceleratory effect on MIH-induced GVBD of oocytes, while it was 100 pg/ml in C. carpio. Further study revealed that pre-incubation with melatonin accelerates the action of MIH on the formation of a complex of two proteins (MPF), a regulatory component called cyclin B and the catalytic component protein kinase known as cyclin-dependent kinase, Cdk1. Densitometric analysis of the immunoblot data collected from the melatonin pre-treated MIH incubated oocytes showed that cyclin B level continued to increase even after 4 h of incubation, and reached the peak after 12 h. Moreover, determination of H1 kinase activity as an indicator of MPF activity in oocytes revealed that melatonin pre-incubation considerably increased MIH stimulation of histone H1 phosphorylation as compared to MIH alone. Thus, the present study demonstrates for the first time that prior incubation with melatonin accelerates the action of MIH on carp oocyte maturation.

Recycling of municipal solid waste incinerator fly ash by using hydrocyclone separation.

PubMed

Ko, Ming-Sheng; Chen, Ying-Liang; Wei, Pei-Shou

2013-03-01

The municipal solid waste incinerators (MSWIs) in Taiwan generate about 300,000 tons of fly ash annually, which is mainly composed of calcium and silicon compounds, and has the potential for recycling. However, some heavy metals are present in the MSWI fly ash, and before recycling, they need to be removed or reduced to make the fly ash non-hazardous. Accordingly, the purpose of this study was to use a hydrocyclone for the separation of the components of the MSWI fly ash in order to obtain the recyclable portion. The results show that chloride salts can be removed from the fly ash during the hydrocyclone separation process. The presence of a dense medium (quartz sand in this study) is not only helpful for the removal of the salts, but also for the separation of the fly ash particles. After the dense-medium hydrocyclone separation process, heavy metals including Pb and Zn were concentrated in the fine particles so that the rest of the fly ash contained less heavy metal and became both non-hazardous and recyclable. Copyright © 2012 Elsevier Ltd. All rights reserved.

A novel process for separation of hazardous poly(vinyl chloride) from mixed plastic wastes by froth flotation.

PubMed

Wang, Jianchao; Wang, Hui; Wang, Chongqing; Zhang, Lingling; Wang, Tao; Zheng, Long

2017-11-01

A novel method, calcium hypochlorite (CHC) treatment, was proposed for separation of hazardous poly(vinyl chloride) (PVC) plastic from mixed plastic wastes (MPWs) by froth flotation. Flotation behavior of single plastic indicates that PVC can be separated from poly(ethylene terephthalate) (PET), poly(acrylonitrile-co-butadiene-co-styrene) (ABS), polystyrene (PS), polycarbonate (PC) and poly(methyl methacrylate) (PMMA) by froth flotation combined with CHC treatment. Mechanism of CHC treatment was examined by contact angle measurement, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Under the optimum conditions, separation of PVC from binary plastics with different particle sizes is achieved efficiently. The purity of PC, ABS, PMMA, PS and PET is greater than 96.8%, 98.5%, 98.8%, 97.4% and 96.3%, respectively. Separation of PVC from multi-plastics was further conducted by two-stage flotation. PVC can be separated efficiently from MPWs with residue content of 0.37%. Additionally, reusing CHC solution is practical. This work indicates that separation of hazardous PVC from MPWs is effective by froth flotation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Study on Sumbawa gold recovery using centrifuge

NASA Astrophysics Data System (ADS)

Ferdana, A. D.; Petrus, H. T. B. M.; Bendiyasa, I. M.; Prijambada, I. D.; Hamada, F.; Sachiko, T.

2018-01-01

The Artisanal Small Gold Mining in Sumbawa has been processing gold with mercury (Hg), which poses a serious threat to the mining and global environment. One method of gold processing that does not use mercury is by gravity method. Before processing the ore first performed an analysis of Mineragraphy and analysis of compound with XRD. Mineragraphy results show that gold is associated with chalcopyrite and covelite and is a single particle (native) on size 58.8 μm, 117 μm up to 294 μm. characterization with XRD shows that the Sumbawa Gold Ore is composed of quartz, pyrite, pyroxene, and sericite compounds. Sentrifugation is one of separation equipment of gravity method to increase concentrate based on difference of specific gravity. The optimum concentration result is influenced by several variables, such as water flow rate and particle size. In this present research, the range of flow rate is 5 lpm and 10 lpm, the particle size - 100 + 200 mesh and -200 +300 mesh. Gold concentration in concentrate is measured by EDX. The result shows that the optimum condition is obtained at a separation with flow rate 5 lpm and a particle size of -100 + 200 mesh.

Removal of fluoride from water with powdered corn cobs.

PubMed

Parmar, S; Patel, Jignesh B; Sudhakar, Padmaja; Koshy, V J

2006-04-01

The adsorption of fluoride on corn cobs powder was investigated in the present study. Neat powdered corn cobs did not show remarkable adsorption but aluminium treated corn cobs had good adsorption capacity. The parameters studied include the contact time, concentration, temperature and pH. Near neutral pH was identified as the optimum condition of the medium, and 90 to 120 minutes was the best contact time for maximum fluoride adsorption. The adsorption process was found to follow Freundlich isotherm. The adsorption process was found to be exothermic as adsorption decreased with increasing temperature.

Thermostable saccharogenic amylase produced under submerged fermentation by filamentous fungus Penicillium purpurogenum.

PubMed

Silva, Tony Márcio; de Oliveira, Maurício; Somera, Alexandre Favarin; Jorge, João Atílio; Terenzi, Héctor Francico; de Lourdes T M Polizeli, Maria; Guimarães, Luis Henrique Souza

2011-07-01

The effect of several nutritional and environmental parameters on Penicillium purpurogenum growth and sacharogenic amylase production was analyzed. High enzyme levels (68.2 U mg(-1)) were obtained with Khanna medium at initial pH 6.0, incubated at 30°C for 144 hours. The optimum pH and temperature activities were 5.0 and 65°C, respectively. The enzyme presented a half-life (t50) of 60 min, at 65°C. Only glucose was detected after 24 hours of reaction using soluble starch as substrate.

Aspects on HTS applications in confined power grids

NASA Astrophysics Data System (ADS)

Arndt, T.; Grundmann, J.; Kuhnert, A.; Kummeth, P.; Nick, W.; Oomen, M.; Schacherer, C.; Schmidt, W.

2014-12-01

In an increasing number of electric power grids the share of distributed energy generation is also increasing. The grids have to cope with a considerable change of power flow, which has an impact on the optimum topology of the grids and sub-grids (high-voltage, medium-voltage and low-voltage sub-grids) and the size of quasi-autonomous grid sections. Furthermore the stability of grids is influenced by its size. Thus special benefits of HTS applications in the power grid might become most visible in confined power grids.

Electron transporting water-gated thin film transistors

NASA Astrophysics Data System (ADS)

Al Naim, Abdullah; Grell, Martin

2012-10-01

We demonstrate an electron-transporting water-gated thin film transistor, using thermally converted precursor-route zinc-oxide (ZnO) intrinsic semiconductors with hexamethyldisilazene (HMDS) hydrophobic surface modification. Water gated HMDS-ZnO thin film transistors (TFT) display low threshold and high electron mobility. ZnO films constitute an attractive alternative to organic semiconductors for TFT transducers in sensor applications for waterborne analytes. Despite the use of an electrolyte as gate medium, the gate geometry (shape of gate electrode and distance between gate electrode and TFT channel) is relevant for optimum performance of water-gated TFTs.

Xylanase production by a newly isolated Aspergillus niger SS7 in submerged culture.

PubMed

Bakri, Yasser; Al-Jazairi, Manal; Al-Kayat, Ghassan

2008-01-01

Xylanase production by a newly isolated Aspergillus niger SS7 was studied in submerged culture. The optimum initial pH for xylanase production was found to be 7.0. Different agricultural and industrial wastes were evaluated for their ability to induce xylanase production by this isolate. The best xylanase production (293.82 IU/ml) was recorded at 3% (w/v) corn cob hulls after 120 h of incubation. The Aspergillus niger SS7 isolate grown in a simple medium, proved to be a promising microorganism for xylanase production.

Characterization, culture medium optimization and antioxidant activity of an endophytic vitexin-producing fungus Dichotomopilus funicola Y3 from pigeon pea [Cajanus cajan (L.) Millsp.].

PubMed

Gu, C B; Ma, H; Ning, W J; Niu, L L; Han, H Y; Yuan, X H; Fu, Y J

2018-05-23

The aim of this study was to characterize a fungal endophyte Y3 from pigeon pea (Cajanus cajan [L.] Millsp), as a novel producer of vitexin, and its culture medium optimization and antioxidant activity. The endophyte from the leaves of pigeon pea was identified as Dichotomopilus funicola by the morphological and molecular characteristics. The most important medium variables affecting vitexin production in liquid culture of D. funicola Y3 were screened by Plackett-Burman design, and three culture medium constituents (i.e. L-phenylalanine, salicylic acid and CuSO 4 .5H 2 O) were identified to play significant roles in vitexin production. The most significant factors were further optimized using by central composite design with response surface methodology. The DPPH radical-scavenging assay indicated that fungal vitexin exhibited notable antioxidant activity with an EC 50 value of 164 μg l -1 . First, a novel endophyte Dichotomopilus funicola Y3, producing vitexin, was characterized from pigeon pea (Cajanus cajan[L.] Millsp.). The maximum vitexin yield was obtained as 78.86 mg l -1 under the optimum culture medium constituents: 0.06 g l -1 L-phenylalanine, 0.21 g l -1 salicylic acid, and 0.19 g l -1 CuSO 4 ·5H 2 O in medium, which is 4.59-fold higher than that in the unoptimized medium. Also, fungal vitexin clearly demonstrated its antioxidant potential. These findings provide an alternative source for large-scale production of vitexin by endophytic fungal fermentation and have a promising prospect in food and pharmaceutical industry. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Accuracy of the raw-data-based effective atomic numbers and monochromatic CT numbers for contrast medium with a dual-energy CT technique.

PubMed

Kawahara, Daisuke; Ozawa, Shuichi; Yokomachi, Kazushi; Tanaka, Sodai; Higaki, Toru; Fujioka, Chikako; Suzuki, Tatsuhiko; Tsuneda, Masato; Nakashima, Takeo; Ohno, Yoshimi; Nagata, Yasushi

2018-02-01

To evaluate the accuracy of raw-data-based effective atomic number (Z eff ) values and monochromatic CT numbers for contrast material of varying iodine concentrations, obtained using dual-energy CT. We used a tissue characterization phantom and varying concentrations of iodinated contrast medium. A comparison between the theoretical values of Z eff and that provided by the manufacturer was performed. The measured and theoretical monochromatic CT numbers at 40-130 keV were compared. The average difference between the Z eff values of lung (inhale) inserts in the tissue characterization phantom was 81.3% and the average Z eff difference was within 8.4%. The average difference between the Z eff values of the varying concentrations of iodinated contrast medium was within 11.2%. For the varying concentrations of iodinated contrast medium, the differences between the measured and theoretical monochromatic CT values increased with decreasing monochromatic energy. The Z eff and monochromatic CT numbers in the tissue characterization phantom were reasonably accurate. The accuracy of the raw-data-based Z eff values was higher than that of image-based Z eff values in the tissue-equivalent phantom. The accuracy of Z eff values in the contrast medium was in good agreement within the maximum SD found in the iodine concentration range of clinical dynamic CT imaging. Moreover, the optimum monochromatic energy for human tissue and iodinated contrast medium was found to be 70 keV. Advances in knowledge: The accuracy of the Z eff values and monochromatic CT numbers of the contrast medium created by raw-data-based, dual-energy CT could be sufficient in clinical conditions.

Development and use of Fourier self deconvolution and curve-fitting in the study of coal oxidation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, J.A.

1986-01-01

Techniques have been developed for modeling highly overlapped band multiplets. The method is based on a least-squares fit of spectra by a series of bands of known shape. Using synthetic spectra, it was shown that when bands are separated by less than their full width at half height (FWHH), valid analytical data can only be obtained after the width of each component band is narrowed by Fourier self deconvolution (FSD). The optimum method of spectral fitting determined from the study of synthetic spectra was then applied to the characterization of oxidized coals. A medium volatile bituminous coal which was airmore » oxidized at 200/sup 0/C for different lengths of time, was extracted with chloroform. A comparison of the infrared spectra of the whole coal and the extract indicated that the extracted material contains a smaller amount of carbonyl, ether, and ester groups, while the aromatic content is much higher. Oxidation does not significantly affect the aromatic content of the whole cola. Most of the aromatic groups in the CHCl/sub 3/ extract show evidence of reaction, however. The production of relatively large amounts of intramolecular aromatic anhydrides is seen in the spectrum of the extract of coals which have undergone extensive oxidation,while there is only a slight indication of this anhydride in the whole coal.« less

The influence of culture conditions on the identification of Mycobacterium species by MALDI-TOF MS profiling.

PubMed

Balážová, Tereza; Makovcová, Jitka; Šedo, Ondrej; Slaný, Michal; Faldyna, Martin; Zdráhal, Zbyněk

2014-04-01

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) represents a simple reliable approach for rapid bacterial identification based on specific peptide/protein fingerprints. However, cell-wall characteristics of mycobacterial species, and their well known stability, complicate MALDI-TOF MS profiling analysis. In this study, we tested two recently published protocols for inactivation and disruption of mycobacteria, and we also examined the influence of different culture conditions (four culture media and five cultivation times) on mass spectral quality and the discriminatory power of the method. We found a significant influence of sample pretreatment method and culture medium on species identification and differentiation for a total of 10 strains belonging to Mycobacterium phlei and Mycobacterium smegmatis. Optimum culture conditions yielding the highest identification success rate against the BioTyper database (Bruker Daltonics) and permitting the possibility of automatic acquisition of mass spectra were found to be distinct for the two mycobacterial species examined. Similarly, individual changes in growth conditions had diverse effects on the two species. For these reasons, thorough control over cultivation conditions should always be employed to maximize the performance and discriminatory power of MALDI-TOF MS profiling, and cultivation conditions must be optimized separately for individual groups of mycobacterial species/strains. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Determination of rhodium in metallic alloy and water samples using cloud point extraction coupled with spectrophotometric technique.

PubMed

Kassem, Mohammed A; Amin, Alaa S

2015-02-05

A new method to estimate rhodium in different samples at trace levels had been developed. Rhodium was complexed with 5-(4'-nitro-2',6'-dichlorophenylazo)-6-hydroxypyrimidine-2,4-dione (NDPHPD) as a complexing agent in an aqueous medium and concentrated by using Triton X-114 as a surfactant. The investigated rhodium complex was preconcentrated with cloud point extraction process using the nonionic surfactant Triton X-114 to extract rhodium complex from aqueous solutions at pH 4.75. After the phase separation at 50°C, the surfactant-rich phase was heated again at 100°C to remove water after decantation and the remaining phase was dissolved using 0.5mL of acetonitrile. Under optimum conditions, the calibration curve was linear for the concentration range of 0.5-75ngmL(-1) and the detection limit was 0.15ngmL(-1) of the original solution. The enhancement factor of 500 was achieved for 250mL samples containing the analyte and relative standard deviations were ⩽1.50%. The method was found to be highly selective, fairly sensitive, simple, rapid and economical and safely applied for rhodium determination in different complex materials such as synthetic mixture of alloys and environmental water samples. Copyright © 2014 Elsevier B.V. All rights reserved.

One-step solvothermal synthesis of TiO2-reduced graphene oxide nanocomposites with enhanced visible light photoreduction of Cr(VI)

NASA Astrophysics Data System (ADS)

Shaikh, Aasiya; Mishra, Shailendra Prasad; Mohapatra, Priyabrata; Parida, Smrutiranjan

2017-06-01

Hexavalent chromium, Cr(VI), is a mutagenic and carcinogenic heavy metal environmental pollutant. Photoreduction is one of the remediation methods of the hexavalent chromium Cr(VI), which necessitates design of an efficient catalyst for visible light performance. Here, we report a one-step solvothermal synthesis of TiO2-reduced graphene oxide (TiO2- xRGO) composite catalysts using a mild reducing agent, dimethylformamide (DMF). Nanoscale TiO2 particles in the size range of 4-9 nm were formed on the reduced graphene sheets. The formation of the composite catalysts was accompanied by the appearance of a large fluorescence quenching, which indicates an efficient separation of photogenerated electrons and holes. The composites displayed excellent photoreduction of Cr(VI) in the visible light, which was found to be a function of the weight percentage of RGO in the composite. At the optimum composition of TiO2- xRGO, a maximum removal rate of 96% was recorded, which was higher than that of the pristine TiO2, which showed no appreciable catalytic activity under the same condition. The performance degraded with increasing RGO content in the composite, which can be attributed to the higher electron-hole recombination on the RGO surface. The Cr(VI) photoreduction also exhibited a pH dependence. The highest removal rate was observed in the acidic medium.

Thermal gravitational separation of ternary mixture n-dodecane/isobutylbenzene/tetralin components in a porous medium

NASA Astrophysics Data System (ADS)

Larabi, Mohamed Aziz; Mutschler, Dimitri; Mojtabi, Abdelkader

2016-06-01

Our present work focuses on the coupling between thermal diffusion and convection in order to improve the thermal gravitational separation of mixture components. The separation phenomenon was studied in a porous medium contained in vertical columns. We performed analytical and numerical simulations to corroborate the experimental measurements of the thermal diffusion coefficients of ternary mixture n-dodecane, isobutylbenzene, and tetralin obtained in microgravity in the international space station. Our approach corroborates the existing data published in the literature. The authors show that it is possible to quantify and to optimize the species separation for ternary mixtures. The authors checked, for ternary mixtures, the validity of the "forgotten effect hypothesis" established for binary mixtures by Furry, Jones, and Onsager. Two complete and different analytical resolution methods were used in order to describe the separation in terms of Lewis numbers, the separation ratios, the cross-diffusion coefficients, and the Rayleigh number. The analytical model is based on the parallel flow approximation. In order to validate this model, a numerical simulation was performed using the finite element method. From our new approach to vertical separation columns, new relations for mass fraction gradients and the optimal Rayleigh number for each component of the ternary mixture were obtained.

The Study and Application of Hydrometallurgical Gold Leaching in the Analysis of Refractory Precious Metals

NASA Astrophysics Data System (ADS)

Yang, M.; Geng, X.; Wang, Y. L.; Li, D. X.

2017-05-01

Three orthogonal tests are separately designed for each hydrometallurgical gold leaching process to finding the optimum reaction conditions of melting gold and palladium in each process. Under the optimum condition, the determination amount of gold and palladium in aqua regia—hydrofluoric acid, Sodium thiosulfate, and potassium iodide reaches 2.87g/kg and 8.34 g/kg, 2.39g/kg and 8.12 g/kg, 2.51g/kg and 7.84g/kg. From the result, the content of gold and palladium using the leaching process of combining Aqua regia, hydrofluoric acid and hydrogen peroxide is relatively higher than the other processes. In addition, the experiment procedure of aqua regia digestion operates easily, using less equipment, and its period is short.

Nicotine promotes rooting in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby.

PubMed

Bamel, Kiran; Gupta, Rajendra; Gupta, Shrish C

2015-11-01

Nicotine promotes rooting in leaf explants of tomato (Lycopersicon esculentum Miller var. Pusa Ruby). Nicotine at 10(-9) to 10(-3) M concentrations was added to the MS basal medium. The optimum response (three-fold increase in rooting) was obtained at 10(-7) M nicotine-enriched MS medium. At the same level i.e. 10(-7) M Nicotine induced dramatic increase (11-fold) in the number of secondary roots per root. We have shown earlier that exogenous acetylcholine induces a similar response in tomato leaves. Since nicotine is an agonist of one of the two acetylcholine receptors in animals, its ability to simulate ACh action in a plant system suggests the presence of the same molecular mechanism operative in both, animal and plant cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Degradation of alachlor in aqueous solution by using hydrodynamic cavitation.

PubMed

Wang, Xikui; Zhang, Yong

2009-01-15

The degradation of alachlor aqueous solution by using hydrodynamic cavitation was systematically investigated. It was found that alachlor in aqueous solution can be deomposed with swirling jet-induced cavitation. The degradation can be described by a pseudo-first-order kinetics and the degradation rate was found to be 4.90x10(-2)min(-1). The effects of operating parameters such as fluid pressure, solution temperature, initial concentration of alachlor and medium pH on the degradation rates of alachlor were also discussed. The results showed that the degradation rates of alachlor increased with increasing pressure and decreased with increasing initial concentration. An optimum temperature of 40 degrees C existed for the degradation rate of alachlor and the degradation rate was also found to be slightly depend on medium pH. Many degradation products formed during the process, and some of them were qualitatively identified by GC-MS.

Multiphase Microstructure in a Metastability-Assisted Medium Carbon Alloy Steel

NASA Astrophysics Data System (ADS)

Liu, Cheng; Cui, Xixi; Yang, Chen

2018-05-01

A medium carbon alloy steel is processed by austenizing at 900 °C for 30 min, then rapid quenching into a patented quenching liquid and holding at 170 °C for 5 min, finally isothermally holding at 250 °C for different times. The morphology and mechanical properties are performed by using optical microscopy and scanning electron microscopy. A multiphase microstructure characterized by a mixture of lenticular prior martensite (PM), fine needle bainitic ferrite and filmy retained austenite (RA) is obtained. It is found that the PM formed firstly upon quenching can accelerate the subsequent bainitic transformation and promote refinement of multiphase colonies. The results show that an optimum mechanical property of a 4000.9 MPa bending strength and a 2030 MPa tensile strength is achieved at 250 °C for 120 min, which is attributed to the multiphase microstructural characteristics and a high product of the volume fraction of RA and the carbon content of austenite.

Comparative study of radiation emission without and with target in a 2.2 kJ plasma focus device

NASA Astrophysics Data System (ADS)

Khan, Muhammad Zubair; Ling, Yap Seong; San, Wong Chiow

2014-03-01

The radiation emission in a 2.2 kJ Mather-type dense plasma focus device is investigated using a five channel BPX65 PIN diode spectrometer. Estimated X-ray associated with the hollow anode without and with target in Argon gas medium is compared. At optimum conditions, the radiation emission from the system is found to be strongly influenced with target in hollow anode and the filling gas pressure. The maximum X-ray yield in 4π sr was obtained in case of hollow anode in argon gas medium with target "Lead" due to interaction of electron beam. Results indicated that an appropriate design of hollow anode with target could enhance the radiation emission by more intense interaction of expected electron beam with target. The outcomes are helpful in designing a plasma focus with enhanced X-ray radiation with improved shot to shot reproducibility in plasma focus device.

[Primary culture of human normal epithelial cells].

PubMed

Tang, Yu; Xu, Wenji; Guo, Wanbei; Xie, Ming; Fang, Huilong; Chen, Chen; Zhou, Jun

2017-11-28

The traditional primary culture methods of human normal epithelial cells have disadvantages of low activity of cultured cells, the low cultivated rate and complicated operation. To solve these problems, researchers made many studies on culture process of human normal primary epithelial cell. In this paper, we mainly introduce some methods used in separation and purification of human normal epithelial cells, such as tissue separation method, enzyme digestion separation method, mechanical brushing method, red blood cell lysis method, percoll layered medium density gradient separation method. We also review some methods used in the culture and subculture, including serum-free medium combined with low mass fraction serum culture method, mouse tail collagen coating method, and glass culture bottle combined with plastic culture dish culture method. The biological characteristics of human normal epithelial cells, the methods of immunocytochemical staining, trypan blue exclusion are described. Moreover, the factors affecting the aseptic operation, the conditions of the extracellular environment, the conditions of the extracellular environment during culture, the number of differential adhesion, and the selection and dosage of additives are summarized.

Protocol for in vitro somatic embryogenesis and regeneration of rice (Oryza sativa L.).

PubMed

Verma, Dipti; Joshi, Rohit; Shukla, Alok; Kumar, Pramod

2011-12-01

Development of highly efficient and reproducible plant regeneration system has tremendous potential to provide improved technology to assist in genetic transformation of indica rice cultivars for their further exploitation in selection. For the development of a highly reproducible regeneration system through somatic embryogenesis, mature embryos of highly popular rice cultivars i.e., Govind (for rainfed areas), Pusa Basmati-1 (aromatic basmati) and Jaya (for irrigated areas) were used. Optimum callus formation (%) to MS medium supplemented with 2, 4-D was obtained at 12.0 microM in Govind, 14.0 microM in Jaya and 15.0 microM in Pusa Basmati-1. All the cultivars showed good proliferation on MS medium without hormone. In Govind, highest embryogenic response was observed in MS medium supplemented with 2, 4-D (0.4 microM) + kinetin (0.4 microM), while in Pusa Basmati-1 with 2, 4-D (0.4 microM) + kinetin (2.0 microM) and in Jaya on hormone-free MS medium. Excellent embryo regeneration in Govind was observed on MS medium supplemented with low concentrations (1.1 microM) of BAP or hormone-free MS medium, while in Pusa Basmati-1 and Jaya embryogenesis was observed on MS medium supplemented with higher concentration of BAP (2.2 microM). Similarly, maximum plantlets with proliferated roots were observed in Govind on hormone-free MS medium, while in Pusa Basmati-1 and Jaya on MS medium supplemented with high concentration of NAA (4.0 microM). Developed plantlets were further successfully acclimatized and grown under pot culture up to maturity. Further the yield potential of in vitro developed plants was accessed at par to the direct seeded one under pot culture. Present, protocol standardizes somatic embryogenesis and efficient regeneration of agronomically important, high yielding and diverse indica rice cultivars which can be utilized as an efficient tool for molecular studies and genetic transformation in future.

Method of cleaning plastics using super and subcritical media

DOEpatents

Sawan, Samuel P.; Spall, W. Dale; Talhi, Abdelhafid

1998-05-26

A method for treating a plastic, such as polyethylene or polypropylene, to remove at least a portion of at least one contaminant includes combining the plastic with a supercritical medium, such as carbon dioxide or sulfur hexafluoride, whereby at least a portion of the contaminant dissolves in the supercritical medium. Alternatively, the plastic can be combined with a suitable liquid medium, such as carbon dioxide or liquid sulfur hexafluoride. At least a portion of the medium, containing the dissolved contaminant, is separated from the plastic, thereby removing at least a portion of the contaminant from the plastic.

Method of cleaning plastics using super and subcritical media

DOEpatents

Sawan, S.P.; Spall, W.D.; Talhi, A.

1998-05-26

A method for treating a plastic, such as polyethylene or polypropylene, to remove at least a portion of at least one contaminant includes combining the plastic with a supercritical medium, such as carbon dioxide or sulfur hexafluoride, whereby at least a portion of the contaminant dissolves in the supercritical medium. Alternatively, the plastic can be combined with a suitable liquid medium, such as carbon dioxide or liquid sulfur hexafluoride. At least a portion of the medium, containing the dissolved contaminant, is separated from the plastic, thereby removing at least a portion of the contaminant from the plastic. 10 figs.

Different treatment strategies for highly polluted landfill leachate in developing countries.

PubMed

Mahmud, Kashif; Hossain, Md Delwar; Shams, Shahriar

2012-11-01

The aim of this research was to determine appropriate treatment technique for effective treatment of heavily polluted landfill leachate. We accomplished several treatment experiments: (i) aerobic biological treatment, (ii) chemical coagulation, (iii) advanced oxidation process (AOP) and (iv) several combined treatment strategies. Efficiency of these treatment procedures were monitored by analysing COD and colour removal. Leachate used for this study was taken from Matuail landfill site at Dhaka city. With extended aeration process which is currently used in Matuail landfill site for leachate treatment, maximum COD and colour removal of 36% and 20%, respectively could be achieved with optimum retention period of 7 days. With optimum aluminium sulphate dose of 15,000 mg/L and pH value of 7.0, maximum COD and colour removals of 34% and 66%, respectively were observed by using chemical coagulation. With optimum pH of 5.0 and optimum dosages of reagents having H(2)O(2)/Fe(2+) molar ratio of 1.3 the highest removal of COD and colour were found 68% and 87%, respectively with sludge production of 55%. Fenton treatment which is an advanced oxidation process was the most successful between these three separate treatment procedures. Among the combined treatment options performed, extended aeration followed by Fenton method was the most suitable one. Copyright © 2011 Elsevier Ltd. All rights reserved.

Optimization of space manufacturing systems

NASA Technical Reports Server (NTRS)

Akin, D. L.

1979-01-01

Four separate analyses are detailed: transportation to low earth orbit, orbit-to-orbit optimization, parametric analysis of SPS logistics based on earth and lunar source locations, and an overall program option optimization implemented with linear programming. It is found that smaller vehicles are favored for earth launch, with the current Space Shuttle being right at optimum payload size. Fully reusable launch vehicles represent a savings of 50% over the Space Shuttle; increased reliability with less maintenance could further double the savings. An optimization of orbit-to-orbit propulsion systems using lunar oxygen for propellants shows that ion propulsion is preferable by a 3:1 cost margin over a mass driver reaction engine at optimum values; however, ion engines cannot yet operate in the lower exhaust velocity range where the optimum lies, and total program costs between the two systems are ambiguous. Heavier payloads favor the use of a MDRE. A parametric model of a space manufacturing facility is proposed, and used to analyze recurring costs, total costs, and net present value discounted cash flows. Parameters studied include productivity, effects of discounting, materials source tradeoffs, economic viability of closed-cycle habitats, and effects of varying degrees of nonterrestrial SPS materials needed from earth. Finally, candidate optimal scenarios are chosen, and implemented in a linear program with external constraints in order to arrive at an optimum blend of SPS production strategies in order to maximize returns.

Glycolipid class profiling by packed-column subcritical fluid chromatography.

PubMed

Deschamps, Frantz S; Lesellier, Eric; Bleton, Jean; Baillet, Arlette; Tchapla, Alain; Chaminade, Pierre

2004-06-18

The potential of packed-column subcritical fluid chromatography (SubFC) for the separation of lipid classes has been assessed in this study. Three polar stationary phases were checked: silica, diol, and poly(vinyl alcohol). Carbon dioxide (CO2) with methanol as modifier was used as mobile phase and detection performed by evaporative light scattering detection. The influence of methanol content, temperature, and pressure on the chromatographic behavior of sphingolipids and glycolipids were investigated. A complete separation of lipid classes from a crude wheat lipid extract was achieved using a modifier gradient from 10 to 40% methanol in carbon dioxide. Solute selectivity was improved using coupled silica and diol columns in series. Because the variation of eluotropic strength depending on the fluid density changes, a normalized separation factor product (NSP) was used to select the nature, the number and the order of the columns to reach the optimum glycolipid separation.

Organic contaminant separator

DOEpatents

Del Mar, P.

1993-12-28

A process is presented of sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium by (a) passing an initial aqueous medium including a minor amount of the organic contaminant through a composite tube comprised of a blend of a polyolefin and a polyester, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit the organic contaminant to adhere to the composite tube, (b) passing a solvent through the composite tube. The solvent is capable of separating the adhered organic contaminant from the composite tube. Further, an extraction apparatus is presented for sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium. The apparatus includes a composite tube comprised of a blend of a polyolefin and a polyester. The composite tube has an internal diameter of from about 0.1 to about 2.0 millimeters and has sufficient length to permit an organic contaminant contained within an aqueous medium passed therethrough to adhere to the composite tube. 2 figures.

Internal gas and liquid distributor for electrodeionization device

DOEpatents

Lin, YuPo J.; Snyder, Seth W.; Henry, Michael P.; Datta, Saurav

2016-05-17

The present invention provides a resin-wafer electrodeionization (RW-EDI) apparatus including cathode and anode electrodes separated by a plurality of porous solid ion exchange resin wafers, which when in use are filled with an aqueous fluid. The apparatus includes one or more wafers comprising a basic ion exchange medium, and preferably includes one or more wafers comprising an acidic ion exchange medium. The wafers are separated from one another by ion exchange membranes. The gas and aqueous fluid are introduced into each basic wafer via a porous gas distributor which disperses the gas as micro-sized bubbles laterally throughout the distributor before entering the wafer. The fluid within the acidic and/or basic ion exchange wafers preferably includes, or is in contact with, a carbonic anhydrase (CA) enzyme or inorganic catalyst to facilitate conversion of bicarbonate ion to carbon dioxide within the acidic medium.

Separation of mouse testis cells on a Celsep (TM) apparatus and their usefulness as a source of high molecular weight DNA or RNA

NASA Technical Reports Server (NTRS)

Wolgemuth, D. J.; Gizang-Ginsberg, E.; Engelmyer, E.; Gavin, B. J.; Ponzetto, C.

1985-01-01

The use of a self-contained unit-gravity cell separation apparatus for separation of populations of mouse testicular cells is described. The apparatus, a Celsep (TM), maximizes the unit area over which sedimentation occurs, reduces the amount of separation medium employed, and is quite reproducible. Cells thus isolated have been good sources for isolation of DNA, and notably, high molecular weight RNA.

Efficiency optimization of a closed indirectly fired gas turbine cycle working under two variable-temperature heat reservoirs

NASA Astrophysics Data System (ADS)

Ma, Zheshu; Wu, Jieer

2011-08-01

Indirectly or externally fired gas turbines (IFGT or EFGT) are interesting technologies under development for small and medium scale combined heat and power (CHP) supplies in combination with micro gas turbine technologies. The emphasis is primarily on the utilization of the waste heat from the turbine in a recuperative process and the possibility of burning biomass even "dirty" fuel by employing a high temperature heat exchanger (HTHE) to avoid the combustion gases passing through the turbine. In this paper, finite time thermodynamics is employed in the performance analysis of a class of irreversible closed IFGT cycles coupled to variable temperature heat reservoirs. Based on the derived analytical formulae for the dimensionless power output and efficiency, the efficiency optimization is performed in two aspects. The first is to search the optimum heat conductance distribution corresponding to the efficiency optimization among the hot- and cold-side of the heat reservoirs and the high temperature heat exchangers for a fixed total heat exchanger inventory. The second is to search the optimum thermal capacitance rate matching corresponding to the maximum efficiency between the working fluid and the high-temperature heat reservoir for a fixed ratio of the thermal capacitance rates of the two heat reservoirs. The influences of some design parameters on the optimum heat conductance distribution, the optimum thermal capacitance rate matching and the maximum power output, which include the inlet temperature ratio of the two heat reservoirs, the efficiencies of the compressor and the gas turbine, and the total pressure recovery coefficient, are provided by numerical examples. The power plant configuration under optimized operation condition leads to a smaller size, including the compressor, turbine, two heat reservoirs and the HTHE.

Characterization of Microparticle Separation Utilizing Electrokinesis within an Electrodeless Dielectrophoresis Chip

PubMed Central

Chiou, Chi-Han; Pan, Jia-Cheng; Chien, Liang-Ju; Lin, Yu-Ying; Lin, Jr-Lung

2013-01-01

This study demonstrated the feasibility of utilizing electrokinesis in an electrodeless dielectrophoresis chip to separate and concentrate microparticles such as biosamples. Numerical simulations and experimental observations were facilitated to investigate the phenomena of electrokinetics, i.e., electroosmosis, dielectrophoresis, and electrothermosis. Moreover, the proposed operating mode can be used to simultaneously convey microparticles through a microfluidic device by using electroosmotic flow, eliminating the need for an additional micropump. These results not only revealed that the directions of fluids could be controlled with a forward/backward electroosmotic flow but also categorized the optimum separating parameters for various microparticle sizes (0.5, 1.0 and 2.0 μm). Separation of microparticles can be achieved by tuning driving frequencies at a specific electric potential (90 Vpp·cm−1). Certainly, the device can be designed as a single automated device that carries out multiple functions such as transportation, separation, and detection for the realization of the envisioned Lab-on-a-Chip idea. PMID:23447009

Improvement in HPLC separation of acetic acid and levulinic acid in the profiling of biomass hydrolysate.

PubMed

Xie, Rui; Tu, Maobing; Wu, Yonnie; Adhikari, Sushil

2011-04-01

5-Hydroxymethylfurfural (HMF) and furfural could be separated by the Aminex HPX-87H column chromatography, however, the separation and quantification of acetic acid and levulinic acid in biomass hydrolysate have been difficult with this method. In present study, the HPLC separation of acetic acid and levulinic acid on Aminex HPX-87H column has been investigated by varying column temperature, flow rate, and sulfuric acid content in the mobile phase. The column temperature was found critical in resolving acetic acid and levulinic acid. The resolution for two acids increased dramatically from 0.42 to 1.86 when the column temperature was lowered from 60 to 30 °C. So did the capacity factors for levulinic acid that was increased from 1.20 to 1.44 as the column temperature dropped. The optimum column temperature for the separation was found at 45 °C. Variation in flow rate and sulfuric acid concentration improved not as much as the column temperature did. Published by Elsevier Ltd.

Research on acting mechanism and behavior of a gas bubble in the air dense medium fluidized bed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, X.; Chen, Q.; Yang, Y.

1996-12-31

Coal dry beneficiation with air-dense medium fluidized bed has now been established as a high efficiency dry separation technology, it is the application of fluidization technology to the coal preparation field. The tiny particle media forms an uniform and stable fluidized bed with a density acted by airflow, which is used to separate 80{micro}m to {approximately}6mm size coal. This technology has achieved satisfied industrialization results, and attracted the expert`s attention in the field. In fluidized bed, the interaction between gas and solid was mainly decided by the existence state of heavy media particles mass (position and distance) relative velocity ofmore » gas-solid two phase, as well turbulent action. A change of vertical gas-solid fluidizing state essentially is the one of a energy transforming process. For a coal separating process with air-dense medium fluidized bed, the gas bubble, producing a turbulent and stirring action in the bed, leads to two effects. It can promote a uniform distribution of heavy media particles, and a uniform and stability of a bed density. Otherwise it will decrease effective contacts between gas-solids two phases, producing a bigger gas bubble. Therefore controlling a gas bubble size in bed should be optimized. This paper analyzes mutual movement between gas-solid, and studies the gas bubble behavior in the bed. A mechanic mode and a separating process of coal in the bed is discussed. It aims to research the coal separating mechanism with air-dense fluidized bed.« less

The laboratory technology of discrete molecular separation: the historical development of gel electrophoresis and the material epistemology of biomolecular science, 1945-1970.

PubMed

Chiang, Howard Hsueh-hao

2009-01-01

Preparative and analytical methods developed by separation scientists have played an important role in the history of molecular biology. One such early method is gel electrophoresis, a technique that uses various types of gel as its supporting medium to separate charged molecules based on size and other properties. Historians of science, however, have only recently begun to pay closer attention to this material epistemological dimension of biomolecular science. This paper substantiates the historiographical thread that explores the relationship between modern laboratory practice and the production of scientific knowledge. It traces the historical development of gel electrophoresis from the mid-1940s to the mid-1960s, with careful attention to the interplay between technical developments and disciplinary shifts, especially the rise of molecular biology in this time-frame. Claiming that the early 1950s marked a decisive shift in the evolution of electrophoretic methods from moving boundary to zone electrophoresis, I reconstruct various trajectories in which scientists such as Oliver Smithies sought out the most desirable solid supporting medium for electrophoretic instrumentation. Biomolecular knowledge, I argue, emerged in part from this process of seeking the most appropriate supporting medium that allowed for discrete molecular separation and visualization. The early 1950s, therefore, marked not only an important turning point in the history of separation science, but also a transformative moment in the history of the life sciences as the growth of molecular biology depended in part on the epistemological access to the molecular realm available through these evolving technologies.

Optimization of fermentation conditions for green pigment production from Bacillus cereus M¹ 16 (MTCC 5521) and its pharmacological application.

PubMed

Banerjee, D; Mondal, A; Gupta, M; Guha, A K; Ray, L

2014-01-01

Optimal culture conditions for the production of green pigment was investigated. The optimal culture condition for the production of an extracellular green pigment by growing Bacillus cereus M(1) 16 (MTCC 5521) in a complex medium containing (g l(-1) ) Peptone-4.0, Beef Extract-9.0, NaCl-7.0, MgSO4 .7H2 O-1.0 and KH2 PO4 -5.0 was as follows pH-7.0 at 30°C for 72 h in a 5 l fermenter. Aeration rate and agitator speed had no effect on the pigment production. Thin layer chromatogram of the pigment extracted from the fermented broth with chloroform on silica gel GF254 using ethyl acetate and hexane (1 : 1) as solvent showed three fractions. The major fraction (C3 ) was separated out and identified as 9-methyl-1, 4, 5, 8-tetra-azaphenanthrene. Acute toxicity test revealed the nontoxic nature upto a dose of 2000 mg kg(-1) , b.wt., of mice. MTT assay showed the cytotoxic nature in HL60 cells having an IC50 of 2.47 mmol. So, this biopigment may have application in food, textile colorant and pharmaceutical industry. This study demonstrated the optimum production of a biopigment (9-methyl-1, 4, 5, 8-tetra-azaphenanthrene) by fermentation of a complex medium with Bacillus cereus M(1) 16 (MTCC 5521) in submerged fermentation. This is the first investigation of toxicity and cytotoxicity activities of this biopigment. The study showed that the purified pigment had no toxicity to healthy albino mice but a high cytotoxicity activity in HL60 cancer cell line in vitro. The biopigment had further displayed dyeing capability to both solidified agar and cotton cloth. Therefore, it may represent a nontoxic and natural alternative to chemical dyes and pigments. © 2013 The Society for Applied Microbiology.

Advanced coal cleaning meets acid rain emission limits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boron, D.J.; Matoney, J.P.; Albrecht, M.C.

1987-03-01

The following processes were selected for study: fine-coal, heavy-medium cyclone separation/flotation, advanced flotation, Dow true heavy liquid separation, Advanced Energy Dynamics (AED) electrostatic separation, and National Research Council of Canada oil agglomeration. Advanced coal cleaning technology was done for the state of New York to investigate methods to use high sulfur coal in view of anticipated lower SO/sub 2/ emission limits.

Cloning and high-level expression of β-xylosidase from Selenomonas ruminantium in Pichia pastoris by optimizing of pH, methanol concentration and temperature conditions.

PubMed

Dehnavi, Ehsan; Ranaei Siadat, Seyed Omid; Fathi Roudsari, Mehrnoosh; Khajeh, Khosro

2016-08-01

β-xylosidase and several other glycoside hydrolase family members, including xylanase, cooperate together to degrade hemicelluloses, a commonly found xylan polymer of plant-cell wall. β-d-xylosidase/α-l-arabinofuranosidase from the ruminal anaerobic bacterium Selenomonas ruminantium (SXA) has potential utility in industrial processes such as production of fuel ethanol and other bioproducts. The optimized synthetic SXA gene was overexpressed in methylotrophic Pichia pastoris under the control of alcohol oxidase I (AOX1) promoter and secreted into the medium. Recombinant protein showed an optimum pH 4.8 and optimum temperature 50 °C. Furthermore, optimization of growth and induction conditions in shake flask was carried out. Using the optimum expression condition (pH 6, temperature 20 °C and 1% methanol induction), protein production was increased by about three times in comparison to the control. The recombinant SXA we have expressed here showed higher turnover frequency using ρ-nitrophenyl β-xylopyranoside (PNPX) substrate, in contrast to most xylosidase experiments reported previously. This is the first report on the cloning and expression of a β-xylosidase gene from glycoside hydrolase (GH) family 43 in Pichia pastoris. Our results confirm that P. pastoris is an appropriate host for high level expression and production of SXA for industrial applications. Copyright © 2016. Published by Elsevier Inc.

Factors affecting yield and safety of protein production from cassava by Cephalosporium eichhorniae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mikami, Y.; Gregory, K.F.; Levadoux, W.L.

1982-01-01

The properties of C. eichhorniae 152 (ATCC 38255) affecting protein production from cassava carbohydrate, for use as an animal feed, were studied. This strain is a true thermophile, showing optimum growth at 45-47 degrees, maximum protein yield at 45 degrees, and no growth at 25 degrees. It has an optimum pH of approximately 3.8 and is obligately acidophilic, being unable to sustain growth at pH of more than or equal to 6.0 in a liquid medium, or pH of more than or equal to 7.0 on solid media. The optimum growth conditions of pH 3.8 and 45 degrees were stronglymore » inhibitive to potential contaminants. It rapidly hydrolyzed cassava starch. It did not utilize sucrose, but approximately 16% of the small sucrose component of cassava was chemically hydrolyzed during the process. Growth with cassava meal (50 g/l) was complete in approximately 20 h, yielding 22.5 g/l (dry biomass), containing 41% crude protein (48-50% crude protein in the mycelium) and 31% true protein (7.0 g/l). Resting and germinating spores (10 to the power of 6 - 10 to the power of 8 per animal) injected by various routes into normal and gamma-irradiated 6-week-old mice and 7-day-old chickens failed to initiate infections.« less

Spirochaeta americana sp. nov., a new haloalkaliphilic, obligately anaerobic spirochaete isolated from soda Mono Lake in California

NASA Technical Reports Server (NTRS)

Hoover, Richard B.; Pikuta, Elena V.; Bej, Asim K.; Marsic, Damien; Whitman, William B.; Tang, Jane; Krader, Paul

2003-01-01

A novel, obligately anaerobic, mesophilic, haloalkaliphilic spirochaete, strain ASpG1(T), was isolated from sediments of the alkaline, hypersaline Mono Lake in California, USA. Cells of the Gram-negative strain were motile and spirochaete-shaped with sizes of 0.2-0.22 x 8-18 microm. Growth of the strain was observed between 10 and 44 degrees C (optimum 37 degrees C), in 2-12% (w/v) NaCl (optimum 3% NaCl) and between pH 8 and 10.5 (optimum pH 9.5). The novel strain was strictly alkaliphilic, required high concentrations of carbonates in the medium and was capable of utilizing D-glucose, fructose, maltose, sucrose, starch and D-mannitol. End products of glucose fermentation were H2, acetate, ethanol and formate. Strain ASpG(T) was resistant to kanamycin and rifampicin, but sensitive to gentamicin, tetracycline and chloramphenicol. The G + C content of its DNA was 58.5 mol%. DNA-DNA hybridization analysis of strain ASpG1(T) with its most closely related species, Spirochaeta alkalica Z-7491(T), revealed a hybridization value of only 48.7%. On the basis of its physiological and molecular properties, strain ASpG1(T) appears to represent a novel species of the genus Spirochaeta, for which the name Spirochaeta americana is proposed (type strain ASpG1(T) =ATCC BAA-392(T) = DSM 14872(T)).

Preliminary study on biosynthesis and characterization of bacteria cellulose films from coconut water

NASA Astrophysics Data System (ADS)

Indrianingsih, A. W.; Rosyida, V. T.; Jatmiko, T. H.; Prasetyo, D. J.; Poeloengasih, C. D.; Apriyana, W.; Nisa, K.; Nurhayati, S.; Hernawan; Darsih, C.; Pratiwi, D.; Suwanto, A.; Ratih, D.

2017-12-01

Bacterial cellulose produced by Acetobacter xylinum is a unique type of bacterial cellulose. It contains more than 90% of water. A preliminary study had shown that bacterial cellulose films has remarkable mechanical properties. The aim of this study was to investigate the optimum condition such as percentage of carbon source, time of cultivation, and pH to produce bacterial cellulose films from local coconut water, and its characterization on morphology, swelling ability and tensile strength of dried bacterial cellulose. A. xylinum was grown on coconut water culture medium with addition of 3%, 5%, and 7% of sugar, while the cultivation time was vary from 3 days, 5 days and 7 days. pH condition was conducted in pH 3, pH 5 and pH 7. Bacterial cellulose samples were dried using oven with temperature of 100°C until the moisture content reached 4-5%. This study showed that several parameters for optimum condition to produce bacterial cellulose films from local waste of coconut water had been obtained (5% of carbon source; pH 5; and 7 day of incubation period). The electron microscopy also showed that dried bacterial cellulose films had pores covered by fibrils on the surface. Therefore, the present work proposes the optimum formula and condition that can be used based on properties of end product needed.

Nondestructive inspection assessment of eddy current and electrochemical analysis to separate inconel and stainless steel alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, D.G.; Sorensen, N.R.

1998-02-01

This report presents a nondestructive inspection assessment of eddy current and electrochemical analysis to separate inconel alloys from stainless steel alloys as well as an evaluation of cleaning techniques to remove a thermal oxide layer on aircraft exhaust components. The results of this assessment are presented in terms of how effective each technique classifies a known exhaust material. Results indicate that either inspection technique can separate inconel and stainless steel alloys. Based on the experiments conducted, the electrochemical spot test is the optimum for use by airframe and powerplant mechanics. A spot test procedure is proposed for incorporation into themore » Federal Aviation Administration Advisory Circular 65-9A Airframe & Powerplant Mechanic - General Handbook. 3 refs., 70 figs., 7 tabs.« less

Virtual-source diffusion approximation for enhanced near-field modeling of photon-migration in low-albedo medium.

PubMed

Jia, Mengyu; Chen, Xueying; Zhao, Huijuan; Cui, Shanshan; Liu, Ming; Liu, Lingling; Gao, Feng

2015-01-26

Most analytical methods for describing light propagation in turbid medium exhibit low effectiveness in the near-field of a collimated source. Motivated by the Charge Simulation Method in electromagnetic theory as well as the established discrete source based modeling, we herein report on an improved explicit model for a semi-infinite geometry, referred to as "Virtual Source" (VS) diffuse approximation (DA), to fit for low-albedo medium and short source-detector separation. In this model, the collimated light in the standard DA is analogously approximated as multiple isotropic point sources (VS) distributed along the incident direction. For performance enhancement, a fitting procedure between the calculated and realistic reflectances is adopted in the near-field to optimize the VS parameters (intensities and locations). To be practically applicable, an explicit 2VS-DA model is established based on close-form derivations of the VS parameters for the typical ranges of the optical parameters. This parameterized scheme is proved to inherit the mathematical simplicity of the DA approximation while considerably extending its validity in modeling the near-field photon migration in low-albedo medium. The superiority of the proposed VS-DA method to the established ones is demonstrated in comparison with Monte-Carlo simulations over wide ranges of the source-detector separation and the medium optical properties.

Recovery of metals from waste printed circuit boards by a mechanical method using a water medium.

PubMed

Duan, Chenlong; Wen, Xuefeng; Shi, Changsheng; Zhao, Yuemin; Wen, Baofeng; He, Yaqun

2009-07-15

Research on the recycling of waste printed circuit boards (PCB) is at the forefront of environmental pollution prevention and resource recycling. To effectively crush waste PCB and to solve the problem of secondary pollution from fugitive odors and dust created during the crushing process, a wet impacting crusher was employed to achieve comminution liberation of the PCB in a water medium. The function of water in the crushing process was analyzed. When using slippery hammerheads, a rotation speed of 1470 rpm, a water flow of 6m(3)/h and a sieve plate aperture of 2.2mm, 95.87% of the crushed product was sized less than 1mm. 94.30% of the metal was in this grade of product. Using smashed material graded -1mm for further research, a Falcon concentrator was used to recover the metal from the waste PCB. Engineering considerations were the liberation degree, the distribution ratio of the metal and a way to simplify the technology. The separation mechanism for fine particles of different densities in a Falcon concentrator was analyzed in detail and the separation process in the segregation and separation zones was deduced. Also, the magnitude of centrifugal acceleration, the back flow water pressure and the feed slurry concentration, any of which might affect separation results, were studied. A recovery model was established using Design-Expert software. Separating waste PCB, crushed to -1mm, with the Falcon separator gave a concentrated product graded 92.36% metal with a recovery of 97.05%. To do this the reverse water pressure was 0.05 MPa, the speed transducer frequency was set at 30 Hz and the feed density was 20 g/l. A flow diagram illustrating the new technique of wet impact crushing followed by separation with a Falcon concentrator is provided. The technique will prevent environmental pollution from waste PCB and allow the effective recovery of resources. Water was used as the medium throughout the whole process.

Deterministic control of broadband light through a multiply scattering medium via the multispectral transmission matrix

PubMed Central

Andreoli, Daria; Volpe, Giorgio; Popoff, Sébastien; Katz, Ori; Grésillon, Samuel; Gigan, Sylvain

2015-01-01

We present a method to measure the spectrally-resolved transmission matrix of a multiply scattering medium, thus allowing for the deterministic spatiospectral control of a broadband light source by means of wavefront shaping. As a demonstration, we show how the medium can be used to selectively focus one or many spectral components of a femtosecond pulse, and how it can be turned into a controllable dispersive optical element to spatially separate different spectral components to arbitrary positions. PMID:25965944

Optimum rocket propulsion for energy-limited transfer

NASA Technical Reports Server (NTRS)

Zuppero, Anthony; Landis, Geoffrey A.

1991-01-01

In order to effect large-scale return of extraterrestrial resources to Earth orbit, it is desirable to optimize the propulsion system to maximize the mass of payload returned per unit energy expended. This optimization problem is different from the conventional rocket propulsion optimization. A rocket propulsion system consists of an energy source plus reaction mass. In a conventional chemical rocket, the energy source and the reaction mass are the same. For the transportation system required, however, the best system performance is achieved if the reaction mass used is from a locally available source. In general, the energy source and the reaction mass will be separate. One such rocket system is the nuclear thermal rocket, in which the energy source is a reactor and the reaction mass a fluid which is heated by the reactor and exhausted. Another energy-limited rocket system is the hydrogen/oxygen rocket where H2/O2 fuel is produced by electrolysis of water using a solar array or a nuclear reactor. The problem is to choose the optimum specific impulse (or equivalently exhaust velocity) to minimize the amount of energy required to produce a given mission delta-v in the payload. The somewhat surprising result is that the optimum specific impulse is not the maximum possible value, but is proportional to the mission delta-v. In general terms, at the beginning of the mission it is optimum to use a very low specific impulse and expend a lot of reaction mass, since this is the most energy efficient way to transfer momentum. However, as the mission progresses, it becomes important to minimize the amount of reaction mass expelled, since energy is wasted moving the reaction mass. Thus, the optimum specific impulse will increase with the mission delta-v. Optimum I(sub sp) is derived for maximum payload return per energy expended for both the case of fixed and variable I(sub sp) engines. Sample missions analyzed include return of water payloads from the moons of Mars and of Saturn.

Antibody-immobilized column for quick cell separation based on cell rolling.

PubMed

Mahara, Atsushi; Yamaoka, Tetsuji

2010-01-01

Cell separation using methodological standards that ensure high purity is a very important step in cell transplantation for regenerative medicine and for stem cell research. A separation protocol using magnetic beads has been widely used for cell separation to isolate negative and positive cells. However, not only the surface marker pattern, e.g., negative or positive, but also the density of a cell depends on its developmental stage and differentiation ability. Rapid and label-free separation procedures based on surface marker density are the focus of our interest. In this study, we have successfully developed an antiCD34 antibody-immobilized cell-rolling column, that can separate cells depending on the CD34 density of the cell surfaces. Various conditions for the cell-rolling column were optimized including graft copolymerization, and adjustment of the column tilt angle, and medium flow rate. Using CD34-positive and -negative cell lines, the cell separation potential of the column was established. We observed a difference in the rolling velocities between CD34-positive and CD34-negative cells on antibody-immobilized microfluidic device. Cell separation was achieved by tilting the surface 20 degrees and the increasing medium flow. Surface marker characteristics of the isolated cells in each fraction were analyzed using a cell-sorting system, and it was found that populations containing high density of CD34 were eluted in the delayed fractions. These results demonstrate that cells with a given surface marker density can be continuously separated using the cell rolling column.

Effect of leading-edge load constraints on the design and performance of supersonic wings

NASA Technical Reports Server (NTRS)

Darden, C. M.

1985-01-01

A theoretical and experimental investigation was conducted to assess the effect of leading-edge load constraints on supersonic wing design and performance. In the effort to delay flow separation and the formation of leading-edge vortices, two constrained, linear-theory optimization approaches were used to limit the loadings on the leading edge of a variable-sweep planform design. Experimental force and moment tests were made on two constrained camber wings, a flat uncambered wing, and an optimum design with no constraints. Results indicate that vortex strength and separation regions were mildest on the severely and moderately constrained wings.

New procedure for epidermal cell isolation using kiwi fruit actinidin, and improved culture of melanocytes in the presence of leukaemia inhibitory factor and forskolin.

PubMed

Yarani, Reza; Mansouri, Kamran; Mohammadi-Motlagh, Hamid Reza; Bakhtiari, Mitra; Mostafaie, Ali

2013-06-01

Conventional isolation of epidermis from the dermis and disruption of epidermal sheets to liberate the cells, are performed using proteolytic enzymes such as thermolysin or collagenase. Selective population expansion of melanocytes is achieved by suppressing proliferation of keratinocytes and fibroblasts in epidermal cell suspensions, using phorbol esters and cholera toxin. Here, we introduce a new procedure for isolation of epidermal cells, using proteolytic activity of kiwi fruit actinidin, and also an improved growth medium for melanocytes in the presence of leukaemia inhibitory factor (LIF) and forskolin. Dermo-epidermal separation and epidermal sheet cell dispersion were performed using actinidin compared to conventional proteases including collagenase, thermolysin or trypsin. Thereafter, melanocyte culture was performed in two common media and one modified medium to discover optimization for these cells. We found that dermo-epidermal separation and epidermal sheet cell dispersion using kiwi fruit actinidin were considerably better than previously used methods, both from the aspect of less fibroblast and keratinocyte contamination, and of more viable native cells. Also, melanocytes proliferated better in phorbol ester- and cholera toxin-free proliferation medium supplemented with LIF and forskolin. Less contamination and higher numbers of viable cells were actinidin preferential for separation of epidermis and isolation of epidermal cells. Supplementation of LIF and forskolin to new medium increased proliferation potential of melanocytes in comparison to exogenous mitogens. © 2013 Blackwell Publishing Ltd.

Micropropagation and validation of genetic and biochemical fidelity amongst regenerants of Cassia angustifolia Vahl employing RAPD marker and HPLC.

PubMed

Chetri, Siva K; Sardar, Pratima Rani; Agrawal, Veena

2014-10-01

In vitro protocol has been established for clonal propagation of Cassia angustifolia Vahl which is an important source of anticancerous bioactive compounds, sennoside A and B. Nodal explants excised from field raised elite plant (showing optimum level of sennoside A and B) of C. angustifolia when reared on Murashige and Skoog's medium augmented with different cytokinins, viz. N(6)-benzyladenine (BA), N(6)-(2-isopentenyl) adenine (2iP) and 6-furfuryl aminopurine (Kn) differentiated multiple shoots in their axils. Of the three cytokinins, BA at 5 μM proved optimum for differentiating multiple shoots in 95 % cultures with an average of 9.14 shoots per explant within 8 weeks of culture. Nearly, 95 % of the excised in vitro shoots rooted on half strength MS medium supplemented with 10 μM indole-3-butyric acid (IBA). The phenotypically similar micropropagated plants were evaluated for their genetic fidelity employing random amplified polymorphic DNA (RAPD) markers. Eleven individuals, randomly chosen amongst a population of 120 regenerants were compared with the donor plant. A total of 36 scorable bands, ranging in size from 100 to 1,000 bp were generated amongst them by the RAPD primers. All banding profiles from micropropagated plants were monomorphic and similar to those of mother plant proving their true to the type nature. Besides, high performance liquid chromatography evaluation of the sennoside A and B content amongst leaves of the mature regenerants and the elite mother plant too revealed consistency in their content.

Optimization of flowrate for expansion of human embryonic stem cells in perfusion microbioreactors.

PubMed

Titmarsh, Drew; Hidalgo, Alejandro; Turner, Jennifer; Wolvetang, Ernst; Cooper-White, Justin

2011-12-01

Microfluidic systems create significant opportunities to establish highly controlled microenvironmental conditions for screening pluripotent stem cell fate. However, since cell fate is crucially dependent on this microenvironment, it remains unclear as to whether continual perfusion of culture medium supports pluripotent stem cell maintenance in feeder-free, chemically defined conditions, and further, whether optimum perfusion conditions exist for subsequent use of human embryonic stem cell (hESCs) in other microfludic systems. To investigate this, we designed microbioreactors based on resistive flow to screen hESCs under a linear range of flowrates. We report that at low rates (conditions where glucose transport is convection-limited with Péclet number <1), cells are affected by apparent nutrient depletion and waste accumulation, evidenced by reduced cell expansion and altered morphology. At higher rates, cells are spontaneously washed out, and display morphological changes which may be indicative of early-stage differentiation. However, between these thresholds exists a narrow range of flowrates in which hESCs expand comparably to the equivalent static culture system, with regular morphology and maintenance of the pluripotency marker TG30 in >95% of cells over 7 days. For MEL1 hESCs the optimum flowrate also coincided with the time-averaged medium exchange rate in static cultures, which may therefore provide a good first estimate of appropriate perfusion rates. Overall, we demonstrate hESCs can be maintained in microbioreactors under continual flow for up to 7 days, a critical outcome for the future development of microbioreactor-based screening systems and assays for hESC culture. Copyright © 2011 Crown in the right of Canada.

Influence of culture media and environmental factors on mycelial growth and pycnidial production of Sphaeropsis pyriputrescens.

PubMed

Kim, Y K; Xiao, C L; Rogers, J D

2005-01-01

Sphaeropsis pyriputrescens, the causal agent of Sphaeropsis rot of pears and apples, is a recently described species. In this study the effects of culture media, temperature, water potential, pH and light on mycelial growth and pycnidial production of S. pyriputrescens were evaluated. Apple juice agar and pear juice agar were most suitable for mycelial growth of all six isolates tested. Cornmeal agar was not suitable for either mycelial growth or pycnidial production. The fungus grew from -3 to 25 C, with optimum growth at 20 C and no growth at 30 C. The fungus grew at water potential as low as -5.6 MPa on potassium chloride-amended potato-dextrose agar (PDA). Hyphal extension was not observed at -7.3 MPa after 10 d incubation, but growth resumed when the inoculum plugs were placed on PDA. The fungus grew at pH 3.3-6.3 and optimum growth was at pH 3.3-4.2. No mycelial growth was observed at pH above 7.2 after 10 d incubation, but growth resumed when the inoculum plugs were transferred onto PDA. Regardless of medium tested, few pycnidia formed at 20 C in the dark. Pycnidial production was enhanced significantly by fluorescent light, but continuous light appeared to reduce pycnidial production, depending on the medium. Oatmeal agar (OMA) was most suitable for production of pycnidia and conidia. Pycnidia that formed on 3 wk old OMA cultures at 20 C under 12 h light/12 h dark produced abundant conidia, and the technique is recommended for inoculum production.

Morphological Simulation of Phase Separation Coupled Oscillation Shear and Varying Temperature Fields

NASA Astrophysics Data System (ADS)

Wang, Heping; Li, Xiaoguang; Lin, Kejun; Geng, Xingguo

2018-05-01

This paper explores the effect of the shear frequency and Prandtl number ( Pr) on the procedure and pattern formation of phase separation in symmetric and asymmetric systems. For the symmetric system, the periodic shear significantly prolongs the spinodal decomposition stage and enlarges the separated domain in domain growth stage. By adjusting the Pr and shear frequency, the number and orientation of separated steady layer structures can be controlled during domain stretch stage. The numerical results indicate that the increase in Pr and decrease in the shear frequency can significantly increase in the layer number of the lamellar structure, which relates to the decrease in domain size. Furthermore, the lamellar orientation parallel to the shear direction is altered into that perpendicular to the shear direction by further increasing the shear frequency, and also similar results for larger systems. For asymmetric system, the quantitative analysis shows that the decrease in the shear frequency enlarges the size of separated minority phases. These numerical results provide guidance for setting the optimum condition for the phase separation under periodic shear and slow cooling.

Computer Networking for Collegial Exchange among Teachers: A Summary of Findings and Recommendations. Technical Report.

ERIC Educational Resources Information Center

West, Mary Maxwell; McSwiney, Eileen

Asynchronous computer-based conferencing offers several unique capabilities as a medium. Participants can read and write messages at whatever time is convenient for them, groups can interact even though participants are geographically separated, and messages are available to readers almost instantly. Because the medium has served for over a decade…

Uptake of gentamicin by separated, viable renal tubules from rabbits.

PubMed

Barza, M; Murray, T; Hamburger, R J

1980-04-01

The proximal renal tubules have a marked affinity for gentamicin; they also are the major site of nephrotoxicity caused by this drug. The uptake of radiolabeled gentamicin in separated, viable renal tubules prepared by enzymatic digestion of rabbit kidneys was studied. The preparations showed rapid initial uptake of gentamicin followed by continued slower uptake. Accumulation was not affected by pH, but was significantly inhibited by ouabain, dinitrophenol, anoxia, and hypothermia in the absence of evident cellular damage. At gentamicin concentrations of greater than 50 microgram/ml in the medium, there was competition for drug uptake. Gentamicin efflux in tubules that were taken from a medium containing antibiotic and placed into antibiotic-free fluid was slow and incomplete. From these data it appears that gentamicin uptake by separated renal tubules occurs by a process that requires metabolic energy; thereafter, the drug resides in a poorly exchangeable cellular pool.

Studies on preparation of medium fat liquid dairy whitener from buffalo milk employing ultrafiltration process.

PubMed

Khatkar, Sunil Kumar; Gupta, Vijay Kumar; Khatkar, Anju Boora

2014-09-01

A study was conducted to develop good quality medium fat liquid dairy whitener from buffalo milk employing ultrafiltration (UF) process. The buffalo skim milk was UF concentrated to 4.05 to 4.18 (23.63 ± 0.30 % TS) fold and standardized to 10 % fat (on Dry Matter Basis) (i.e. formulation) and homogenized at 175.76 kg/cm(2). The addition of 0.4 % mixture of monosodium and disodium phosphate (2:1 w/w) improved the heat stability of homogenized formulation to an optimum of 66 min. The bland flavour of homogenized formulation with added 0.4 % mixture of monosodium phosphate and disodium phosphate (2:1 w/w) and 18 % sugar (on DMB) (i.e. medium fat liquid dairy whitener) was improved significantly (P < 0.01) with the addition of 0.2 % potassium chloride, but heat stability of medium fat liquid dairy whitener got reduced substantially (i.e. 19 min). With subsequent heat treatment to 85 °C for 5 min, heat stability of medium fat liquid dairy whitener got improved to reasonable level of 27 min. Whitening ability in terms of L* value of medium fat liquid dairy whitener in both tea and coffee was significantly (P < 0.01) better when homogenized at 175.76 kg/cm(2) vis-à-vis 140.61 kg/cm(2). Standardized medium fat liquid dairy whitener had significantly (P < 0.01) greater protein content (i.e. approximately 2.43 times) compared to market dairy whitener samples. At 2 % solids level, standardized medium fat liquid dairy whitener in tea/coffee fetched significantly (P < 0.01) better sensory attributes and instrumental whitening ability compared to market sample at 3 % solids level. There could be clear 33 % solids quantity saving in case of developed product compared to market dairy whitener sample.

Effect of wall cooling on the stability of compressible subsonic flows over smooth humps and backward-facing steps

NASA Technical Reports Server (NTRS)

Al-Maaitah, Ayman A.; Nayfeh, Ali, H.; Ragab, Saad A.

1989-01-01

The effect of wall cooling on the two-dimensional linear stability of subsonic flows over two-dimensional surface imperfections is investigated. Results are presented for flows over smooth humps and backward-facing steps with Mach numbers up to 0.8. The results show that, whereas cooling decreases the viscous instability, it increases the shear-layer instability and hence it increases the growth rates in the separation region. The coexistence of more than one instability mechanism makes a certain degree of wall cooling most effective. For the Mach numbers 0.5 and 0.8, the optimum wall temperatures are about 80 pct and 60 pct of the adiabatic wall temperature, respectively. Increasing the Mach number decreases the effectiveness of cooling slightly and reduces the optimum wall temperature.

Robust electromagnetic absorption by graphene/polymer heterostructures

NASA Astrophysics Data System (ADS)

Lobet, Michaël; Reckinger, Nicolas; Henrard, Luc; Lambin, Philippe

2015-07-01

Polymer/graphene heterostructures present good shielding efficiency against GHz electromagnetic perturbations. Theory and experiments demonstrate that there is an optimum number of graphene planes, separated by thin polymer spacers, leading to maximum absorption for millimeter waves Batrakov et al (2014 Sci. Rep. 4 7191). Here, electrodynamics of ideal polymer/graphene multilayered material is first approached with a well-adapted continued-fraction formalism. In a second stage, rigorous coupled wave analysis is used to account for the presence of defects in graphene that are typical of samples produced by chemical vapor deposition, namely microscopic holes, microscopic dots (embryos of a second layer) and grain boundaries. It is shown that the optimum absorbance of graphene/polymer multilayers does not weaken to the first order in defect concentration. This finding testifies to the robustness of the shielding efficiency of the proposed absorption device.

An efficient in vitro shoot regeneration from leaf petiolar explants and ex vitro rooting of Bixa orellana L.- A dye yielding plant.

PubMed

Mohammed, Arifullah; Chiruvella, Kishore K; Namsa, Nima D; Ghanta, Rama Gopal

2015-07-01

Bixa orellana L. (Bixaceae) is a multipurpose tree grown for the production of commercially important dyes. In the present study, an efficient, reproducible protocol was developed for direct plant regeneration from in vitro derived petiole explants of Bixa orellana L. Murashige and Skoog medium (MS) supplemented with 2-isopentenyl adenine (9.8 μM) and naphthalene acetic acid (10.7 μM) was found to be optimum for production of high frequency of shoot organogenesis. Subculturing of the shoots onto the fresh MS medium containing similar concentrations of 2-iP (9.8 μM) and NAA (10.7 μM) produced elongated shoots. Elongated shoots when placed onto MS medium supplemented with 1.7 μM indole-3-acetic acid and 14.7 μM 2-iP produced optimal rooting. Rooted plantlets were acclimatized and transplanted to the field successfully. Histological investigation revealed the origin of shoot primordia, from sub-epidermal cells of petiole explants. The regeneration protocol developed in this study can be useful for mass in vitro propagation and effective genetic transformation of commercially important edible dye yielding tree species.

Batch production of Pyranose 2-oxidase from Trametes versicolor (ATCC 11235) in medium with a lignocellulosic substrate and enzymatic bleaching of cotton fabrics.

PubMed

Pazarlioglu, Nurdan Kasikara; Erden, Emre; Ucar, M Cigdem; Akkaya, Alper; Sariisik, A Merih

2012-04-01

The aim of this work was to determine new, different and low-cost substrates that can be used for enzyme production from the white rot fungus Trametes versicolor (ATCC 11235) by taking advantage of the broad substrate specificity of pyranose 2-oxidase. In this report, we investigated the production of pyranose 2-oxidase from T. versicolor (ATCC 11235) using ten different agricultural residues such as clover straw, almond shells, hazelnut cobs, grass and others. Pyranose 2-oxidase activity was determined as 2.332 U/g at the 9th day in a submerged culture containing clover straw and tap water shaken at 150 rpm and 26°C, and the optimum clover straw concentration was determined to be 12 g/l. The effects of different glucose, nitrogen and phosphate sources on the production of pyranose 2-oxidase were studied in the clover straw medium. Analyses of biomass, protein, reduced sugar and nitrogen concentrations were also monitored in a clover straw medium that did not contain carbon or nitrogen and phosphate sources under the parameters determined. The produced pyranose 2-oxidase was used for improving the properties of cotton fabrics.

Preliminary study : optimization of pH and salinity for biosurfactant production from Pseudomonas aeruginosa in diesel fuel and crude oil medium

NASA Astrophysics Data System (ADS)

Ikhwani, A. Z. N.; Nurlaila, H. S.; Ferdinand, F. D. K.; Fachria, R.; Hasan, A. E. Z.; Yani, M.; Setyawati, I.; Suryani

2017-03-01

Biosurfactant is secondary metabolite surface active compound produced by microorganisms which is nontoxic and eco-friendly. Microorganism producing biosurfactant that is quite potential to use in many applications is from Pseudomonas aeruginosa strains. Good quality of biosurfactant production from microbes is supported by the suitable nutrients and environmental factors. The aim of this research was to obtain preliminary o data upon the optimum pH and salinity for the production of biosurfactant from Pseudomonas aeruginosa ATCC 15442 in diesel fuel and crude oil medium. P. aeruginosa ATCC 15442 cultured in diesel fuel and crude oil as carbon source showed biosurfactant activity. P.aeruginosa-derived biosurfactant was capable to form stable emulsion for 24 hours (EI24) in hydrocarbons n-hexane solutions. The particular biosurfactant showed EI24 highest value at pH 7 (31.02%) and 1% NaCl (24.00%) when P. aeruginosa was grown in 10% diesel fuel medium in mineral salt solution. As for the media crude oil, the highest EI24 value was at pH 6 (52.16%) and 1% NaCl (33.30%).

Approach toward enhancement of halophilic protease production by Halobacterium sp. strain LBU50301 using statistical design response surface methodology.

PubMed

Chuprom, Julalak; Bovornreungroj, Preeyanuch; Ahmad, Mehraj; Kantachote, Duangporn; Dueramae, Sawitree

2016-06-01

A new potent halophilic protease producer, Halobacterium sp. strain LBU50301 was isolated from salt-fermented fish samples ( budu ) and identified by phenotypic analysis, and 16S rDNA gene sequencing. Thereafter, sequential statistical strategy was used to optimize halophilic protease production from Halobacterium sp. strain LBU50301 by shake-flask fermentation. The classical one-factor-at-a-time (OFAT) approach determined gelatin was the best nitrogen source. Based on Plackett - Burman (PB) experimental design; gelatin, MgSO 4 ·7H 2 O, NaCl and pH significantly influenced the halophilic protease production. Central composite design (CCD) determined the optimum level of medium components. Subsequently, an 8.78-fold increase in corresponding halophilic protease yield (156.22 U/mL) was obtained, compared with that produced in the original medium (17.80 U/mL). Validation experiments proved the adequacy and accuracy of model, and the results showed the predicted value agreed well with the experimental values. An overall 13-fold increase in halophilic protease yield was achieved using a 3 L laboratory fermenter and optimized medium (231.33 U/mL).

Determination of kinetic parameters of 1,3-propanediol fermentation by Clostridium diolis using statistically optimized medium.

PubMed

Kaur, Guneet; Srivastava, Ashok K; Chand, Subhash

2012-09-01

1,3-propanediol (1,3-PD) is a chemical compound of immense importance primarily used as a raw material for fiber and textile industry. It can be produced by the fermentation of glycerol available abundantly as a by-product from the biodiesel plant. The present study was aimed at determination of key kinetic parameters of 1,3-PD fermentation by Clostridium diolis. Initial experiments on microbial growth inhibition were followed by optimization of nutrient medium recipe by statistical means. Batch kinetic data from studies in bioreactor using optimum concentration of variables obtained from statistical medium design was used for estimation of kinetic parameters of 1,3-PD production. Direct use of raw glycerol from biodiesel plant without any pre-treatment for 1,3-PD production using this strain investigated for the first time in this work gave results comparable to commercial glycerol. The parameter values obtained in this study would be used to develop a mathematical model for 1,3-PD to be used as a guide for designing various reactor operating strategies for further improving 1,3-PD production. An outline of protocol for model development has been discussed in the present work.

Photosynthetic Gas Exchange in the Closed Ecosystem for Space. Phase II, Part II. Studies on the Growth of Thermophilic Chlorella 71105

NASA Technical Reports Server (NTRS)

Leone, Donald E.

1961-01-01

Bench-scale studies with Chlorella pyrenoidosa 71105 were conducted in four- and eight-liter culture vessels, with and without recycling. It was established that the algal strain could be maintained for periods up to 72 days with supplemented re-cycled medium. In a factorial series of experiments, the highest yields were obtained with a 2.0% concentration of carbon dioxide, a 0.07 dilution factor (nutrient dilution rate/culture volume), and an 8.5 ft(exp -1) ratio of light surface to liquid culture volume. Optimum pH and concentrations of the constituents of the growth medium were determined in corollary test-tube studies. Other test-tube studies showed that the nutrient medium used for mass culture could be stored up to five weeks at 25 C or at refrigerator temperature (4 C) with little change in nitrogen-urea level. Algal suspensions stored at 4 C remained viable for periods of at least 12 weeks; growth resumed after a lag period when stored suspensions were cultured at 39 C. Streptomycin was found suitable for controlling a blue-green containment.

Medium and Small Aperture Speckle Interferometry for Geostationary On-Orbit-Servicing Space Surveillance

NASA Astrophysics Data System (ADS)

Scott, R.

On-Orbit-Servicing (OOS) in Geostationary Equatorial Orbit (GEO) is likely to become a space mission reality provoking new problems for the optical space surveillance community. OOS’ close-proximity flight of servicer and client satellites with separations less than 1 kilometer in GEO challenge the metric measurement capabilities of medium and small aperture space surveillance instruments. This paper describes an OOS monitoring technique based on Cross-Spectrum speckle interferometry to compensate for atmospheric turbulence and measure the OOS satellites’ differential relative position. Cross-Spectrum speckle interferometry, an astronomical technique developed to measure the astrometric positions of binary stars, was adapted to the geostationary OOS problem and was tested using Sloan i’ observations of co-located geostationary satellites. Medium (1.6m) and small (0.35m) aperture telescopes were used to observe these satellites undergoing optical conjunctions where their apparent line-of-sight separation narrowed within 5 arcseconds. During the initial development of the Cross-Spectrum approach some weaknesses were identified where particle strikes, faint background stars, anomalous fringe orientation angles and high relative angular rates corrupt the relative position measurement process. In this paper, newly adjusted compensation techniques to remedy these issues are described and the data is reprocessed. The Cross-Spectrum’s performance is shown to work well on closely-spaced GEO satellites with separations less than 3 arcseconds and evidence is shown suggesting the technique can measure satellite separations within 1.8 arcseconds.

In vivo differentiation of complementary contrast media at dual-energy CT.

PubMed

Mongan, John; Rathnayake, Samira; Fu, Yanjun; Wang, Runtang; Jones, Ella F; Gao, Dong-Wei; Yeh, Benjamin M

2012-10-01

To evaluate the feasibility of using a commercially available clinical dual-energy computed tomographic (CT) scanner to differentiate the in vivo enhancement due to two simultaneously administered contrast media with complementary x-ray attenuation ratios. Approval from the institutional animal care and use committee was obtained, and National Institutes of Health guidelines for the care and use of laboratory animals were observed. Dual-energy CT was performed in a set of iodine and tungsten solution phantoms and in a rabbit in which iodinated intravenous and bismuth subsalicylate oral contrast media were administered. In addition, a second rabbit was studied after intravenous administration of iodinated and tungsten cluster contrast media. Images were processed to produce virtual monochromatic images that simulated the appearance of conventional single-energy scans, as well as material decomposition images that separate the attenuation due to each contrast medium. Clear separation of each of the contrast media pairs was seen in the phantom and in both in vivo animal models. Separation of bowel lumen from vascular contrast medium allowed visualization of bowel wall enhancement that was obscured by intraluminal bowel contrast medium on conventional CT scans. Separation of two vascular contrast media in different vascular phases enabled acquisition of a perfectly coregistered CT angiogram and venous phase-enhanced CT scan simultaneously in a single examination. Commercially available clinical dual-energy CT scanners can help differentiate the enhancement of selected pairs of complementary contrast media in vivo. © RSNA, 2012.

In Vivo Differentiation of Complementary Contrast Media at Dual-Energy CT

PubMed Central

Mongan, John; Rathnayake, Samira; Fu, Yanjun; Wang, Runtang; Jones, Ella F.; Gao, Dong-Wei

2012-01-01

Purpose: To evaluate the feasibility of using a commercially available clinical dual-energy computed tomographic (CT) scanner to differentiate the in vivo enhancement due to two simultaneously administered contrast media with complementary x-ray attenuation ratios. Materials and Methods: Approval from the institutional animal care and use committee was obtained, and National Institutes of Health guidelines for the care and use of laboratory animals were observed. Dual-energy CT was performed in a set of iodine and tungsten solution phantoms and in a rabbit in which iodinated intravenous and bismuth subsalicylate oral contrast media were administered. In addition, a second rabbit was studied after intravenous administration of iodinated and tungsten cluster contrast media. Images were processed to produce virtual monochromatic images that simulated the appearance of conventional single-energy scans, as well as material decomposition images that separate the attenuation due to each contrast medium. Results: Clear separation of each of the contrast media pairs was seen in the phantom and in both in vivo animal models. Separation of bowel lumen from vascular contrast medium allowed visualization of bowel wall enhancement that was obscured by intraluminal bowel contrast medium on conventional CT scans. Separation of two vascular contrast media in different vascular phases enabled acquisition of a perfectly coregistered CT angiogram and venous phase–enhanced CT scan simultaneously in a single examination. Conclusion: Commercially available clinical dual-energy CT scanners can help differentiate the enhancement of selected pairs of complementary contrast media in vivo. © RSNA, 2012 PMID:22778447

[Impact of TDZ and NAA on adventitious bud induction and cluster bud multiplication in Tulipa edulis].

PubMed

Zhu, Li-Fang; Xu, Chao; Zhu, Zai-Biao; Yang, He-Tong; Guo, Qiao-Sheng; Xu, Hong-jian; Ma, Hong-Jian; Zhao, Gui-Hua

2014-08-01

To explore the method of explants directly induced bud and establish the tissue culture system of mutiple shoot by means of direct organogenesis, core bud and daughter bulbs (the top of bud stem expanded to form daughter bulb) of T. edulis were used as explants and treated with thidiazuron (TDZ) and 1-naphthlcetic acid (NAA). The results showed that the optimal medium for bud inducted form core bud and daughter bulb were MS + TDZ 2.0 mg x L(-1) + NAA 4.0 mg x L(-1) and MS +TDZ 2.0 mg x L(-1) + NAA 2.0 mg x L(-1) respectively, both of them had a bud induction rate of 72.92%, 79.22%. The optimal medium for cluster buds multiplication was MS + TDZ 0.2 mg x L(-1) + NAA 0.2 mg x L(-1), and proliferation coefficient was 2.23. After proliferation, cluster buds rooting occurred on MS medium with IBA 1.0 mg x L(-1) and the rooting rate was 52.6%, three to five seedlings in each plant. Using core bud and daughter bulb of T. edulis, the optimum medium for adventitious bud directly inducted from daughter bulb, core bud and cluster bud multiplication were screened out and the tissue culture system of multiple shoot by means of direct organogenesis was established.

Removal of gallium (III) ions from acidic aqueous solution by supercritical carbon dioxide extraction in the green separation process.

PubMed

Chou, Wei-Lung; Wang, Chih-Ta; Yang, Kai-Chiang; Huang, Yen-Hsiang

2008-12-15

Supercritical carbon dioxide extraction, which is a feasible "green" alternative, was applied in this study as a sample pretreatment step for the removal of gallium (III) ions from acidic aqueous solution. The effect of various process parameters, including various chelating agents, extraction pressure and temperature, dimensionless CO(2) volume, the concentration of the chelating agent, and the pH of the solution, governing the efficiency and throughput of the procedure were systematically investigated. The performance of the various chelating agents from different studies indicated that the extraction efficiency of supercritical CO(2) was in the order: thiopyridine (PySH)>thenoyltrifluoroacetone (TTAH)>acetylacetone (AcAcH). The optimal extraction pressure and temperature for the supercritical CO(2) extraction of gallium (III) with chelating agent PySH were found to be 70 degrees C and 3000psi, respectively. The optimum concentration of the chelating agent was found to be 50ppm. A value of 7.5 was selected as the optimum dimensionless CO(2) volume. The optimum pH of the solution for supercritical CO(2) extraction should fall in the range of 2.0-3.0.

Kinetic approach to the study of froth flotation applied to a lepidolite ore

NASA Astrophysics Data System (ADS)

Vieceli, Nathália; Durão, Fernando O.; Guimarães, Carlos; Nogueira, Carlos A.; Pereira, Manuel F. C.; Margarido, Fernanda

2016-07-01

The number of published studies related to the optimization of lithium extraction from low-grade ores has increased as the demand for lithium has grown. However, no study related to the kinetics of the concentration stage of lithium-containing minerals by froth flotation has yet been reported. To establish a factorial design of batch flotation experiments, we conducted a set of kinetic tests to determine the most selective alternative collector, define a range of pulp pH values, and estimate a near-optimum flotation time. Both collectors (Aeromine 3000C and Armeen 12D) provided the required flotation selectivity, although this selectivity was lost in the case of pulp pH values outside the range between 2 and 4. Cumulative mineral recovery curves were used to adjust a classical kinetic model that was modified with a non-negative parameter representing a delay time. The computation of the near-optimum flotation time as the maximizer of a separation efficiency (SE) function must be performed with caution. We instead propose to define the near-optimum flotation time as the time interval required to achieve 95%-99% of the maximum value of the SE function.

Effect of pH on simultaneous saccharification and isomerization by glucoamylase and glucose isomerase.

PubMed

Mishra, Abha; Debnath Das, Meera

2002-01-01

pH and temperature play critical roles in multistep enzymatic conversions. In such conversions, the optimal pH for individual steps differs greatly. In this article, we describe the production of glucoamylase (from Aspergillus oryzae MTCC152 in solid-state fermentation) and glucose isomerase (from Streptomyces griseus NCIM2020 in submerged fermentation), used in industries for producing high-fructose syrup. Optimum pH for glucoamylase was found to be 5.0. For glucose isomerase, the optimum pH ranged between 7.0 and 8.5, depending on the type of buffer used. Optimum temperature for glucoamylase and glucose isomerase was 50 and 60 degrees C, respectively. When both the enzymatic conversions were performed simultaneously at a compromised pH of 6.5, both the enzymes showed lowered activity. We also studied the kinetics at different pHs, which allows the two-step reaction to take place simultaneously. This was done by separating two steps by a thin layer of urease. Ammonia generated by the hydrolysis of urea consumed the hydrogen ions, thereby allowing optimal activity of glucose isomerase at an acidic pH of 5.0.

Isobar Separation in a Multiple-Reflection Time-of-Flight Mass Spectrometer by Mass-Selective Re-Trapping.

PubMed

Dickel, Timo; Plaß, Wolfgang R; Lippert, Wayne; Lang, Johannes; Yavor, Mikhail I; Geissel, Hans; Scheidenberger, Christoph

2017-06-01

A novel method for (ultra-)high-resolution spatial mass separation in time-of-flight mass spectrometers is presented. Ions are injected into a time-of-flight analyzer from a radio frequency (rf) trap, dispersed in time-of-flight according to their mass-to-charge ratios and then re-trapped dynamically in the same rf trap. This re-trapping technique is highly mass-selective and after sufficiently long flight times can provide even isobaric separation. A theoretical treatment of the method is presented and the conditions for optimum performance of the method are derived. The method has been implemented in a multiple-reflection time-of-flight mass spectrometer and mass separation powers (FWHM) in excess of 70,000, and re-trapping efficiencies of up to 35% have been obtained for the protonated molecular ion of caffeine. The isobars glutamine and lysine (relative mass difference of 1/4000) have been separated after a flight time of 0.2 ms only. Higher mass separation powers can be achieved using longer flight times. The method will have important applications, including isobar separation in nuclear physics and (ultra-)high-resolution precursor ion selection in multiple-stage tandem mass spectrometry. Graphical Abstract ᅟ.

Isobar Separation in a Multiple-Reflection Time-of-Flight Mass Spectrometer by Mass-Selective Re-Trapping

NASA Astrophysics Data System (ADS)

Dickel, Timo; Plaß, Wolfgang R.; Lippert, Wayne; Lang, Johannes; Yavor, Mikhail I.; Geissel, Hans; Scheidenberger, Christoph

2017-06-01

A novel method for (ultra-)high-resolution spatial mass separation in time-of-flight mass spectrometers is presented. Ions are injected into a time-of-flight analyzer from a radio frequency (rf) trap, dispersed in time-of-flight according to their mass-to-charge ratios and then re-trapped dynamically in the same rf trap. This re-trapping technique is highly mass-selective and after sufficiently long flight times can provide even isobaric separation. A theoretical treatment of the method is presented and the conditions for optimum performance of the method are derived. The method has been implemented in a multiple-reflection time-of-flight mass spectrometer and mass separation powers (FWHM) in excess of 70,000, and re-trapping efficiencies of up to 35% have been obtained for the protonated molecular ion of caffeine. The isobars glutamine and lysine (relative mass difference of 1/4000) have been separated after a flight time of 0.2 ms only. Higher mass separation powers can be achieved using longer flight times. The method will have important applications, including isobar separation in nuclear physics and (ultra-)high-resolution precursor ion selection in multiple-stage tandem mass spectrometry. [Figure not available: see fulltext.

Study of the production of alkaline keratinases in submerged cultures as an alternative for solid waste treatment generated in leather technology.

PubMed

Cavello, Ivana A; Chesini, Mariana; Hours, Roque A; Cavalitto, Sebastián F

2013-01-01

Six nonpathogenic fungal strains isolated from alkaline soils of Buenos Aires Province, Argentina (Acremonium murorum, Aspergillus sidowii, Cladosporium cladosporoides, Neurospora tetrasperma, Purpureocillium lilacinum (formerly Paecilomyces lilacinus), and Westerdikella dispersa) were tested for their ability to produce keratinolytic enzymes. Strains were grown on feather meal agar as well as in solid-state and submerged cultures, using a basal mineral medium and "hair waste" as sole sources of carbon and nitrogen. All the tested fungi grew on feather meal agar, but only three of them were capable of hydrolyzing keratin, producing clear zones. Among these strains, P. lilacinum produced the highest proteolytic and keratinolytic activities, both in solid-state and submerged fermentations. The medium composition and culture conditions for the keratinases production by P. lilacinum were optimized. Addition of glucose (5 g/l) and yeast extract (2.23 g/l) to the basal hair medium increased keratinases production. The optimum temperature and initial pH for the enzyme production were 28℃ and 6.0, respectively. A beneficial effect was observed when the original concentration of four metal ions, present in the basal mineral medium, was reduced up to 1:10. The maximum yield of the enzyme was 15.96 Uc/ml in the optimal hair medium; this value was about 6.5-fold higher than the yield in the basal hair medium. These results suggest that keratinases from P. lilacinum can be useful for biotechnological purposes such as biodegradation (or bioconversion) of hair waste, leading to a reduction of the environmental pollution caused by leather technology with the concomitant production of proteolytic enzymes and protein hydrolyzates.

Garcina cambogia leaf and seawater for tannase production by marine Aspergillus awamori BTMFW032 under slurry state fermentation.

PubMed

Beena, S P; Basheer, Soorej M; Bhat, Sarita G; Chandrasekaran, M

2011-12-01

Garcinia gummi-gutta (syn. G. cambogia, G. quaesita), known to have medicinal properties, was evaluated as a substrate and inducer for tannase production by a marine Aspergillus awamori BTMFW032, under slurry state fermentation using Czapekdox-minimal medium and sea water as the cultivation medium. Among the various natural tannin substrates evaluated, Garcinia leaf supported maximal tannase production. The cultivation conditions and components of the cultivation medium were optimized employing response surface methodology. The experimental results were fitted to a second-order polynomial model at a 92.2% level of significance (p < 0.0001). The maximal tannase activity was obtained in a slurry state medium containing 26.6%, w/v, Garcinia leaf, supplemented with 0.1% tannic acid as inducer. The optimum values of pH, temperature and inoculum concentration obtained were 5.0, 40 degrees C and 3%, respectively. A Box-Behnken model study of the fermentation conditions was carried out, and the best production of tannase was registered at 40 degrees C without agitation. Optimization strategy employing response surface methodology led to nearly 3-fold increase in the enzyme production from 26.2 U/mL obtained in unoptimized medium to 75.2 Units/mL in Box Behnken design, within 18 h of fermentation. It was observed that sea water could support maximal tannase production by A. awamori compared with other media suggesting that the sea water salts could have played an inducer role in expression of tannase encoding genes. To the best of our knowledge, this is the first report on production of tannase, an industrially important enzyme, utilizing Garcinia leaf as substrate under slurry state fermentation by marine A. awamori and sea water as the cultivation medium.

Separation of carbon nanotubes into chirally enriched fractions

DOEpatents

Doorn, Stephen K [Los Alamos, NM; Niyogi, Sandip [Los Alamos, NM

2012-04-10

A mixture of single-walled carbon nanotubes ("SWNTs") is separated into fractions of enriched chirality by preparing an aqueous suspension of a mixture of SWNTs and a surfactant, injecting a portion of the suspension on a column of separation medium having a density gradient, and centrifuging the column. In some embodiments, salt is added prior to centrifugation. In other embodiments, the centrifugation is performed at a temperature below room temperature. Fractions separate as colored bands in the column. The diameter of the separated SWNTs decreases with increasing density along the gradient of the column. The colored bands can be withdrawn separately from the column.

Signal processing system for electrotherapy applications

NASA Astrophysics Data System (ADS)

Płaza, Mirosław; Szcześniak, Zbigniew

2017-08-01

The system of signal processing for electrotherapeutic applications is proposed in the paper. The system makes it possible to model the curve of threshold human sensitivity to current (Dalziel's curve) in full medium frequency range (1kHz-100kHz). The tests based on the proposed solution were conducted and their results were compared with those obtained according to the assumptions of High Tone Power Therapy method and referred to optimum values. Proposed system has high dynamics and precision of mapping the curve of threshold human sensitivity to current and can be used in all methods where threshold curves are modelled.

Microslab - Waveguide medium for the future

NASA Astrophysics Data System (ADS)

Sequeira, H. B.

1986-09-01

'Microslab' technology, which has the transmission properties of both microstrip and dielectric slab waveguides, and which is aimed for use in MIMIC devices, is described. The Microslab configuration consists of a guiding layer bonded to a metallized dielectric substrate (slab) and a metallized dielectric rod, with the dielectric material and thicknesses chosen for minimal loss and dispersion and for optimum control of the propagating energy. The propagating energy is confined mainly to the guiding layer. The new technology has been used to couple a GaAs Gunn oscillator directly to a GaAs Microslab network to produce 0.25 mW at 141 GHz.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sai, P.M.S.; Ahmed, J.; Krishnaiah, K.

Activated carbon is produced from coconut shell char using steam or carbon dioxide as the reacting gas in a 100 mm diameter fluidized bed reactor. The effect of process parameters such as reaction time, fluidizing velocity, particle size, static bed height, temperature of activation, fluidizing medium, and solid raw material on activation is studied. The product is characterized by determination of iodine number and BET surface area. The product obtained in the fluidized bed reactor is much superior in quality to the activated carbons produced by conventional processes. Based on the experimental observations, the optimum values of process parameters aremore » identified.« less

Bubbles in Sediments

DTIC Science & Technology

1997-09-30

modeled as either an effective fluid, effective viscoelastic solid, or a saturated poroelastic medium. The analysis included only the breathing mode...separated for each model . Finally, if a sediment is modeled by Biot theory, which describes wave propagation in a saturated poroelastic medium, then two...theory to sediment acoustics . The predicted resonance behavior under each model is distinct, so an optical extinction measurement may provide an

Alkaline earth cation extraction from acid solution

DOEpatents

Dietz, Mark; Horwitz, E. Philip

2003-01-01

An extractant medium for extracting alkaline earth cations from an aqueous acidic sample solution is described as are a method and apparatus for using the same. The separation medium is free of diluent, free-flowing and particulate, and comprises a Crown ether that is a 4,4'(5')[C.sub.4 -C.sub.8 -alkylcyclohexano]18-Crown-6 dispersed on an inert substrate material.

The Role of Radial Clearance on the Performance of Foil Air Bearings

NASA Technical Reports Server (NTRS)

Radil, Kevin; Howard, Samuel; Dykas, Brian

2002-01-01

Load capacity tests were conducted to determine how radial clearance variations affect the load capacity coefficient of foil air bearings. Two Generation III foil air bearings with the same design but possessing different initial radial clearances were tested at room temperature against an as-ground PS304 coated journal operating at 30,000 rpm. Increases in radial clearance were accomplished by reducing the journal's outside diameter via an in-place grinding system. From each load capacity test the bearing load capacity coefficient was calculated from the rule-of-thumb (ROT) model developed for foil air bearings. The test results indicate that, in terms of the load capacity coefficient, radial clearance has a direct impact on the performance of the foil air bearing. Each test bearing exhibited an optimum radial clearance that resulted in a maximum load capacity coefficient. Relative to this optimum value are two separate operating regimes that are governed by different modes of failure. Bearings operating with radial clearances less than the optimum exhibit load capacity coefficients that are a strong function of radial clearance and are prone to a thermal runaway failure mechanism and bearing seizure. Conversely, a bearing operating with a radial clearance twice the optimum suffered only a 20 percent decline in its maximum load capacity coefficient and did not experience any thermal management problems. However, it is unknown to what degree these changes in radial clearance had on other performance parameters, such as the stiffness and damping properties of the bearings.

Influence of the Kinetics of Heat and Mass Transfer in a Binary-Rectification Column on the Realizability Range of its Regimes

NASA Astrophysics Data System (ADS)

Zaeva, M. A.; Tsirlin, A. M.; Sukin, I. A.

2018-05-01

The range of realizable rates of flows in a binary-rectification column in which heat is supplied into the boiler and is removed from the dephlegmator was investigated. It is shown that this range is determined by two characteristic parameters related to the kinetics of heat and mass transfer in the column and the composition of the mixture subjected to separation. The limiting capabilities of a cascade of two binary-rectification columns for the separation of a ternary mixture in it were considered. The conditions for an optimum sequence of separation of a mixture in this cascade and for a consistent arrangement of its heat and mass exchange surfaces and the relation between the ultimate production rate of the cascade and the total heat losses in it were determined.

Influence of the Kinetics of Heat and Mass Transfer in a Binary-Rectification Column on the Realizability Range of its Regimes

NASA Astrophysics Data System (ADS)

Zaeva, M. A.; Tsirlin, A. M.; Sukin, I. A.

2018-03-01

The range of realizable rates of flows in a binary-rectification column in which heat is supplied into the boiler and is removed from the dephlegmator was investigated. It is shown that this range is determined by two characteristic parameters related to the kinetics of heat and mass transfer in the column and the composition of the mixture subjected to separation. The limiting capabilities of a cascade of two binary-rectification columns for the separation of a ternary mixture in it were considered. The conditions for an optimum sequence of separation of a mixture in this cascade and for a consistent arrangement of its heat and mass exchange surfaces and the relation between the ultimate production rate of the cascade and the total heat losses in it were determined.

30 CFR 816.22 - Topsoil and subsoil.

Code of Federal Regulations, 2014 CFR

2014-07-01

... § 816.22 Topsoil and subsoil. (a) Removal. (1)(i) All topsoil shall be removed as a separate layer from... paragraph (b) of this section shall be removed as a separate layer from the area to be disturbed, and... soil medium is equal to, or more suitable for sustaining vegetation than, the existing topsoil, and the...

30 CFR 816.22 - Topsoil and subsoil.

Code of Federal Regulations, 2012 CFR

2012-07-01

... § 816.22 Topsoil and subsoil. (a) Removal. (1)(i) All topsoil shall be removed as a separate layer from... paragraph (b) of this section shall be removed as a separate layer from the area to be disturbed, and... soil medium is equal to, or more suitable for sustaining vegetation than, the existing topsoil, and the...

30 CFR 816.22 - Topsoil and subsoil.

Code of Federal Regulations, 2013 CFR

2013-07-01

... § 816.22 Topsoil and subsoil. (a) Removal. (1)(i) All topsoil shall be removed as a separate layer from... paragraph (b) of this section shall be removed as a separate layer from the area to be disturbed, and... soil medium is equal to, or more suitable for sustaining vegetation than, the existing topsoil, and the...

30 CFR 817.22 - Topsoil and subsoil.

Code of Federal Regulations, 2014 CFR

2014-07-01

... ACTIVITIES § 817.22 Topsoil and subsoil. (a) Removal. (1)(i) All topsoil shall be removed as a separate layer... accordance with paragraph (b) of this section shall be removed as a separate layer from the area to be... that the resulting soil medium is equal to, or more suitable for sustaining vegetation than, the...

30 CFR 817.22 - Topsoil and subsoil.

Code of Federal Regulations, 2012 CFR

2012-07-01

... ACTIVITIES § 817.22 Topsoil and subsoil. (a) Removal. (1)(i) All topsoil shall be removed as a separate layer... accordance with paragraph (b) of this section shall be removed as a separate layer from the area to be... that the resulting soil medium is equal to, or more suitable for sustaining vegetation than, the...

30 CFR 817.22 - Topsoil and subsoil.

Code of Federal Regulations, 2013 CFR

2013-07-01

... ACTIVITIES § 817.22 Topsoil and subsoil. (a) Removal. (1)(i) All topsoil shall be removed as a separate layer... accordance with paragraph (b) of this section shall be removed as a separate layer from the area to be... that the resulting soil medium is equal to, or more suitable for sustaining vegetation than, the...

Molecular-beam gas-sampling system

NASA Technical Reports Server (NTRS)

Young, W. S.; Knuth, E. L.

1972-01-01

A molecular beam mass spectrometer system for rocket motor combustion chamber sampling is described. The history of the sampling system is reviewed. The problems associated with rocket motor combustion chamber sampling are reported. Several design equations are presented. The results of the experiments include the effects of cooling water flow rates, the optimum separation gap between the end plate and sampling nozzle, and preliminary data on compositions in a rocket motor combustion chamber.

Redox flow cell development and demonstration project, calendar year 1976

NASA Technical Reports Server (NTRS)

1977-01-01

The major focus of the effort was the key technology issues that directly influence the fundamental feasibility of the overall redox concept. These issues were the development of a suitable semipermeable separator membrane for the system, the screening and study of candidate redox couples to achieve optimum cell performance, and the carrying out of systems analysis and modeling to develop system performance goals and cost estimates.

NASA/MSFC Large Stretch Press Study

NASA Technical Reports Server (NTRS)

Choate, M. W.; Nealson, W. P.; Jay, G. C.; Buss, W. D.

1985-01-01

The purpose of this study was to: A. assess and document the advantages/disadvantages of a government agency investment in a large stretch form press on the order of 5000 tons capacity (per jaw); B. develop a procurement specification for the press; and C. provide trade study data that will permit an optimum site location. Tasks were separated into four major elements: cost study, user survey, site selection, and press design/procurement specification.

Preparative Isolation and Purification of Flavone C-Glycosides from the Leaves of Ficus microcarpa L. f by Medium-Pressure Liquid Chromatography, High-Speed Countercurrent Chromatography, and Preparative Liquid Chromatography

PubMed Central

Wang, Xiaohong; Liang, Yong; Zhu, Licai; Xie, Huichun; Li, Hang; He, Junting; Pan, Man; Zhang, Tianyou; Ito, Yoichiro

2009-01-01

Combined with medium-pressure liquid chromatography (MPLC) and preparative high-performance liquid chromatography (perp-HPLC), high-speed countercurrent chromatography (HSCCC) was applied for separation and purification of flavone C-glycosides from the crude extract of leaves of Ficus microcarpae L. f. HSCCC separation was performed on a two-phase solvent system composed of methyl tert- butyl ether - ethyl acetate – 1-butanol – acetonitrile – 0.1% aqueous trifluoroacetic acid at a volume ratio of 1:3:1:1:5. Partially resolved peak fractions from HSCCC separation were further purified by preparative HPLC. Four well-separated compounds were obtained and their purities were determined by HPLC. The purities of these peaks were 97.28%, 97.20%, 92.23%, and 98.40%.. These peaks were characterized by ESI-MSn. According to the reference, they were identified as orientin (peak I), isovitexin-3″-O-glucopyranoside (peak II), isovitexin (peak III), and vitexin (peak IV), yielded 1.2 mg, 4.5 mg, 3.3 mg, and 1.8 mg, respectively. PMID:20190866

Effect of dope solution temperature on the membrane structure and membrane distillation performance

NASA Astrophysics Data System (ADS)

Nawi, N. I. M.; Bilad, M. R.; Nordin, N. A. H. M.

2018-04-01

Membrane distillation (MD) is a non-isothermal process applicable to purify water using hydrophobic membrane. Membrane in MD is hydrophobic, permeable to water vapor but repels liquid water. MD membrane is expected to pose high flux, high fouling and scaling resistances and most importantly high wetting resistance. This study develops flat-sheet polyvinylidene fluoride (PVDF) membrane by exploring both liquid-liquid and liquid-solid phase inversion technique largely to improve its wetting resistance and flux performance. We hypothesize that temperature of dope solution play roles in solid-liquid separation during membrane formation and an optimum balance between liquid-liquid and liquid-solid (crystallization) separation leads to highly performance PVDF membrane. Findings obtained from differential scanning calorimeter test show that increasing dope solution temperature reduces degree of PVDF crystallinity and suppresses formation of crystalline structure. The morphological images of the resulting membranes show that at elevated dope solution temperature (40, 60, 80 and 100°C), the spherulite-like structures are formed across the thickness of membranes ascribed from due to different type of crystals. The performance of direct-contact MD shows that the obtained flux of the optimum dope temperature (60°C) of 10.8 L/m2h is comparable to commercial PTFE-based MD membrane.

Recovery of Ni Metal from Spent Catalyst with Emulsion Liquid Membrane Using Cyanex 272 as Extractant

NASA Astrophysics Data System (ADS)

Yuliusman; Huda, M.; Ramadhan, I. T.; Farry, A. R.; Wulandari, P. T.; Alfia, R.

2018-03-01

In this study was conducted to recover nickel metal from spent nickel catalyst resulting from hydrotreating process in petroleum industry. The nickel extraction study with the emulsion liquid membrane using Cyanex 272 as an extractant to extract and separate nickel from the feed phase solution. Feed phase solution was preapred from spent catalyst using sulphuric acid. Liquid membrane consists of a kerosene as diluent, a Span 80 as surfactant, a Cyanex 272 as carrier and sulphuric acid solutions have been used as the stripping solution. The important parameters governing the permeation of nickel and their effect on the separation process have been studied. These parameters are surfactant concentration, extractant concentration feed phase pH. The optimum conditions of the emulsion membrane making process is using 0.06 M Cyanex 272, 8% w/v SPAN 80, 0.05 M H2SO4, internal phase extractant / phase volume ratio: 1/1, and stirring speed 1150 rpm for 60 Minute that can produce emulsion membrane with stability level above 90% after 4 hours. In the extraction process with optimum condition pH 6 for feed phase, ratio of phase emulsion/phase of feed: 1/2, and stirring speed 175 rpm for 15 minutes with result 81.51% nickel was extracted.

Effect of the Hartmann number on phase separation controlled by magnetic field for binary mixture system with large component ratio

NASA Astrophysics Data System (ADS)

Heping, Wang; Xiaoguang, Li; Duyang, Zang; Rui, Hu; Xingguo, Geng

2017-11-01

This paper presents an exploration for phase separation in a magnetic field using a coupled lattice Boltzmann method (LBM) with magnetohydrodynamics (MHD). The left vertical wall was kept at a constant magnetic field. Simulations were conducted by the strong magnetic field to enhance phase separation and increase the size of separated phases. The focus was on the effect of magnetic intensity by defining the Hartmann number (Ha) on the phase separation properties. The numerical investigation was carried out for different governing parameters, namely Ha and the component ratio of the mixed liquid. The effective morphological evolutions of phase separation in different magnetic fields were demonstrated. The patterns showed that the slant elliptical phases were created by increasing Ha, due to the formation and increase of magnetic torque and force. The dataset was rearranged for growth kinetics of magnetic phase separation in a plot by spherically averaged structure factor and the ratio of separated phases and total system. The results indicate that the increase in Ha can increase the average size of separated phases and accelerate the spinodal decomposition and domain growth stages. Specially for the larger component ratio of mixed phases, the separation degree was also significantly improved by increasing magnetic intensity. These numerical results provide guidance for setting the optimum condition for the phase separation induced by magnetic field.

Synthesis of Composit From Bamboo Fiber, Zeolite and Epoxy for Room Separation

NASA Astrophysics Data System (ADS)

Raihan Muhammad, Dhany; Basuki, Kris Tri; Wasito, Bangun; Suroso

2018-01-01

This research aims is to search a subtitute of the asbestos for the separator rontgen room using bamboo fiber filled with zeolite; which harden using epoxy it is all caused because the hazard of the asbestos to the human body. Bamboo stem degenerated using NaOH (20%) to get the bamboo fiber. Bamboo fiber added with CS2 (10 mL) to form xanthate cellulose. Xanthate Cellulose mixed with filler zeolite and harden of epoxy, layer by layer until getting the right width. The variant of the mass composition is 3: 0:1; 3: 0.25:0.75; 3 :0.5:0.5; 3: 0.75:0.25; 3: 1:0, and the variant of the temperature 28 °C 40 °C 60 °C 80 °C and 100 °C. The sample tested using microscopic method, impact test with Charpy method, corrosivity method, Electricity conduct method, thermal conduct method, and radiation resistance or attenuation method. The result shown the optimum composition of the composite it is at the variant 3 :0.5:0.5, with the optimum temperature is 40°C with the density of the sample is 1.5789 g/cm3. Impact resistance of the sample is 44 Joule. The Radiation resistance is 0.46, with the thermal conductivity of the sample is 0.016 Kkal/m.s.c. it shown that the sample is isolator. From the result is shown that the sample is can be a substitute for asbestos as material of the separator in the Rontgen room.

Automated microbial metabolism laboratory. [design of advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into test chambers

NASA Technical Reports Server (NTRS)

1974-01-01

The design and rationale of an advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into each of four test chambers are outlined. The feasibility for multiple addition tests was established and various details of the methodology were studied. The four chamber battery of tests include: (1) determination of the effect of various atmospheric gases and selection of that gas which produces an optimum response; (2) determination of the effect of incubation temperature and selection of the optimum temperature for performing Martian biochemical tests; (3) sterile soil is dosed with a battery of C-14 labeled substrates and subjected to experimental temperature range; and (4) determination of the possible inhibitory effects of water on Martian organisms is performed initially by dosing with 0.01 ml and 0.5 ml of medium, respectively. A series of specifically labeled substrates are then added to obtain patterns in metabolic 14CO2 (C-14)O2 evolution.

Effect of water activity and pH on growth and toxin production by Clostridium botulinum type G.

PubMed Central

Briozzo, J; de Lagarde, E A; Chirife, J; Parada, J L

1986-01-01

The combined effect of water activity (aw) and pH on growth and toxin production by Clostridium botulinum type G strain 89 was investigated. The minimum aw at which growth and toxin formation occurred was 0.965, for media in which the pH was adjusted with either sodium chloride or sucrose. The minimum pH (at the optimum aw) for growth and toxin production of C. botulinum type G was found to be 5.6. Optimum conditions for toxin activation were a trypsin concentration of 0.1%, a pH of the medium of 6.5, and an incubation for 45 min at 37 degrees C. These data did not show evidence of heat-labile spores, since a heat shock of 75 degrees C for 10 min did not significantly decrease the spore count of strain 89G in media at pH 7.0 or 5.6. It was frequently observed that cells grown at reduced aw or pH experienced severe morphological changes. PMID:3518631

16S rRNA-Based Identification of a Glucan-Hyperproducing Weissella confusa

PubMed Central

Shukla, Shraddha; Goyal, Arun

2011-01-01

A gram-positive, nonmotile, irregular, short, rod-shaped new strain of Weissella confusa bacterium was isolated from fermented cabbage. The isolate was physiologically and biochemically characterised. The 16S rDNA was amplified by polymerase chain reaction (PCR). The isolate was identified as Weissella confusa (GenBank accession number: GU138518.1) based on nucleotide homology and phylogenetic analysis. The isolate produces glucansucrase when grown in sucrose-supplemented culture medium which catalyses glucan formation. This novel isolate possesses high capacity of industrial use due to its high productivity of glucan (34 mg/mL) as compared to other strains reported. The optimum temperature for glucansucrase production was 25°C. The shaking condition gave an enzyme activity of 6.1 U/mL which was 1.5 times higher than that given by static condition (4.1 U/mL). The temperature 35°C, pH 5.4, and ionic strength 10–20 mM were optimum for enzyme assay. This investigation unraveled the abundance of industrially valuable microflora of the north east India. PMID:21603260

Extraction and Estimation of Secondary Metabolites from Date Palm Cell Suspension Cultures.

PubMed

Naik, Poornananda M; Al-Khayri, Jameel M

2017-01-01

The health benefits of dates arise from their content of phytochemicals, known for having pharmacological properties, including flavonoids, carotenoids, phenolic acids, sterols, procyanidins, and anthocyanins. In vitro cell culture technology has become an attractive means for the production of biomass and bioactive compounds. This chapter describes step-by-step procedures for the induction and proliferation of callus from date palm offshoots on Murashige and Skoog (MS) medium supplemented with plant growth regulators. Subsequently cell suspension cultures are established for optimum biomass accumulation, based on the growth curve developed by packed cell volume as well as fresh and dry weights. The highest production of biomass occurs at the 11th week after culturing. Moreover, this chapter describes methodologies for the extraction and analysis of secondary metabolites of date palm cell suspension cultures using high-performance liquid chromatography (HPLC). The optimum level of catechin, caffeic acid, apigenin, and kaempferol from the cell suspension cultures establishes after the 11th and 12th weeks of culture. This protocol is useful for scale-up production of secondary metabolites from date palm cell suspension cultures.

Stabilization of Black Cotton Soil Using Micro-fine Slag

NASA Astrophysics Data System (ADS)

Shukla, Rajesh Prasad; Parihar, Niraj Singh

2016-09-01

This work presents the results of laboratory tests conducted on black cotton soil mixed with micro-fine slag. Different proportions of micro-fine slag, i.e., 3, 6, 9, 12 and 15 % were mixed with the black cotton soil to improve soil characteristics. The improvement in the characteristics of stabilized soil was assessed by evaluating the changes in the physical and strength parameters of the soil, namely, the Atterberg limits, free swell, the California Bearing Ratio (CBR), compaction parameters and Unconfined Compressive Strength (UCS). The mixing of micro-fine slag decreases the liquid limit, plasticity index and Optimum Moisture Contents (OMC) of the soil. Micro-fine slag significantly increases the plastic limit, UCS and CBR of the soil up to 6-7 % mixing, but mixing of more slag led to decrease in the UCS and CBR of the soil. The unsoaked CBR increased by a substantial amount unlike soaked CBR value. The swell potential of the soil is reduced from medium to very low. The optimum amount of micro-fine slag is found to be approximately 6-7 % by the weight of the soil.

Experimental study of nonlinear ultrasonic behavior of soil materials during the compaction.

PubMed

Chen, Jun; Wang, Hao; Yao, Yangping

2016-07-01

In this paper, the nonlinear ultrasonic behavior of unconsolidated granular medium - soil during the compaction is experimentally studied. The second harmonic generation technique is adopted to investigate the change of microstructural void in materials during the compaction process of loose soils. The nonlinear parameter is measured with the change of two important environmental factors i.e. moisture content and impact energy of compaction. It is found the nonlinear parameter of soil material presents a similar variation pattern with the void ratio of soil samples, corresponding to the increased moisture content and impact energy. A same optimum moisture content is found by observing the variation of nonlinear parameter and void ratio with respect to moisture content. The results indicate that the unconsolidated soil is manipulated by a strong material nonlinearity during the compaction procedure. The developed experimental technique based on the second harmonic generation could be a fast and convenient testing method for the determination of optimum moisture content of soil materials, which is very useful for the better compaction effect of filled embankment for civil infrastructures in-situ. Copyright © 2016 Elsevier B.V. All rights reserved.

A quasi-universal medium to break the aerobic/anaerobic bacterial culture dichotomy in clinical microbiology.

PubMed

Dione, N; Khelaifia, S; La Scola, B; Lagier, J C; Raoult, D

2016-01-01

In the mid-19th century, the dichotomy between aerobic and anaerobic bacteria was introduced. Nevertheless, the aerobic growth of strictly anaerobic bacterial species such as Ruminococcus gnavus and Fusobacterium necrophorum, in a culture medium containing antioxidants, was recently demonstrated. We tested aerobically the culture of 623 bacterial strains from 276 bacterial species including 82 strictly anaerobic, 154 facultative anaerobic, 31 aerobic and nine microaerophilic bacterial species as well as ten fungi. The basic culture medium was based on Schaedler agar supplemented with 1 g/L ascorbic acid and 0.1 g/L glutathione (R-medium). We successively optimized this media, adding 0.4 g/L uric acid, using separate autoclaving of the component, or adding haemin 0.1 g/L or α-ketoglutarate 2 g/L. In the basic medium, 237 bacterial species and ten fungal species grew but with no growth of 36 bacterial species, including 22 strict anaerobes. Adding uric acid allowed the growth of 14 further species including eight strict anaerobes, while separate autoclaving allowed the growth of all tested bacterial strains. To extend its potential use for fastidious bacteria, we added haemin for Haemophilus influenzae, Haemophilus parainfluenzae and Eikenella corrodens and α-ketoglutarate for Legionella pneumophila. This medium allowed the growth of all tested strains with the exception of Mycobacterium tuberculosis and Mycobacterium bovis. Testing primoculture and more fastidious species will constitute the main work to be done, but R-medium coupled with a rapid identification method (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) will facilitate the anaerobic culture in clinical microbiology laboratories. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Development of selective and differential medium for Shigella sonnei using three carbohydrates (lactose, sorbitol, and xylose) and X-Gal.

PubMed

Na, G N; Kim, S A; Kwon, O C; Rhee, M S

2015-08-01

The aim of this study was to develop a new selective and differential medium for isolating Shigella sonnei (designated 3SD medium). The new medium was based on three carbohydrates (lactose, sorbitol, and xylose) and a chromogenic substrate (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside, X-Gal). S. sonnei cannot ferment lactose, sorbitol, or xylose, but can ferment X-Gal, which generates turquoise-blue colonies with rough edges. Other bacteria (54 strains of foodborne pathogens and spoilage bacteria) produced visually distinct colonies on 3SD medium (colorless or pink-violet colonies), or their growth was inhibited on 3SD medium. The optimum concentration of 50 mg/L X-Gal was selected because it yielded the highest level of morphological discrimination between S. sonnei and other bacteria, and this concentration was cost-effective. Bile salt concentration optimization was performed using healthy, heat-injured, and acid-injured S. sonnei. The recovery rate differed significantly depending on the bile salt concentration; media containing >1.0 g/L bile salt showed significantly lower recovery of stress-injured cells than medium containing 0.5 g/L bile salt (P<0.05). Growth of all Gram-positive bacteria was inhibited on medium containing 0.5 g/L bile salt; therefore, this concentration was used as the optimal concentration. Previous media used to isolate Shigella spp. (MacConkey, xylose lysine desoxycholate, and Salmonella-Shigella agar) showed poor performance when used to support the growth of injured S. sonnei cells, whereas 3SD medium supported a high growth rate of injured and healthy cells (equivalent to that obtained with nutrient-rich tryptic soy agar). To validate the performance of 3SD medium with real specimens, S. sonnei and other bacteria were spiked into samples such as untreated water, carrot, salad, and oyster. 3SD medium showed superior specificity (100%) and sensitivity (100%) for S. sonnei, and yielded no false-positive or false-negative results. Thus, the novel 3SD medium described herein is a powerful tool for the rapid and efficient selective isolation of S. sonnei in research and clinical laboratories, and the food industry. Copyright © 2015 Elsevier B.V. All rights reserved.

Multipulse technique exploiting the intermodulation of ultrasound waves in a nonlinear medium.

PubMed

Biagi, Elena; Breschi, Luca; Vannacci, Enrico; Masotti, Leonardo

2009-03-01

In recent years, the nonlinear properties of materials have attracted much interest in nondestructive testing and in ultrasound diagnostic applications. Acoustic nonlinear parameters represent an opportunity to improve the information that can be extracted from a medium such as structural organization and pathologic status of tissue. In this paper, a method called pulse subtraction intermodulation (PSI), based on a multipulse technique, is presented and investigated both theoretically and experimentally. This method allows separation of the intermodulation products, which arise when 2 separate frequencies are transmitted in a nonlinear medium, from fundamental and second harmonic components, making them available for improved imaging techniques or signal processing algorithms devoted to tissue characterization. The theory of intermodulation product generation was developed according the Khokhlov-Zabolotskaya-Kuznetsov (KZK) nonlinear propagation equation, which is consistent with experimental results. The description of the proposed method, characterization of the intermodulation spectral contents, and quantitative results coming from in vitro experimentation are reported and discussed in this paper.

Spectral method for the static electric potential of a charge density in a composite medium

NASA Astrophysics Data System (ADS)

Bergman, David J.; Farhi, Asaf

2018-04-01

A spectral representation for the static electric potential field in a two-constituent composite medium is presented. A theory is developed for calculating the quasistatic eigenstates of Maxwell's equations for such a composite. The local physical potential field produced in the system by a given source charge density is expanded in this set of orthogonal eigenstates for any position r. The source charges can be located anywhere, i.e., inside any of the constituents. This is shown to work even if the eigenfunctions are normalized in an infinite volume. If the microstructure consists of a cluster of separate inclusions in a uniform host medium, then the quasistatic eigenstates of all the separate isolated inclusions can be used to calculate the eigenstates of the total structure as well as the local potential field. Once the eigenstates are known for a given host and a given microstructure, then calculation of the local field only involves calculating three-dimensional integrals of known functions and solving sets of linear algebraic equations.

Compact cyclone filter train for radiological and hazardous environments

DOEpatents

Bench, Thomas R.

1998-01-01

A compact cyclone filter train for the removal of hazardous and radiologi particles from a gaseous fluid medium which permits a small cyclone separator to be used in a very small space envelope due to the arrangement of the filter housing adjacent to the separator with the cyclone separator and the filters mounted on a plate. The entire unit will have a hoist connection at the center of gravity so that the entire unit including the separator, the filters, and the base can be lifted and repositioned as desired.

Evaluation of different cooking conditions on broccoli (Brassica oleracea var. italica) to improve the nutritional value and consumer acceptance.

PubMed

Bongoni, Radhika; Verkerk, Ruud; Steenbekkers, Bea; Dekker, Matthijs; Stieger, Markus

2014-09-01

The objective of this study was to gain insights into the effect of the cooking method on the liking as well as the retention of glucosinolates in broccoli. With this knowledge it can be concluded whether the health aspects of broccoli be improved by the cooking method without deteriorating sensory perception. For this, broccoli was cooked by methods commonly applied by consumers: boiling with a cold (water) start; boiling with a hot (water) start; and steaming. Firmness, greenness and amount of total glucosinolates in cooked broccoli were instrumentally determined. Sensory evaluation by untrained consumers (n = 99) for liking and sensory attributes intensity rating were performed on broccoli cooked by steaming and boiling-cold start at three time points, which resulted in 'high', 'medium', 'low' firm broccoli samples. At the end of cooking, steaming showed an increase in the amount of total glucosinolates (+17%). Boiling-hot start (-41%) and boiling-cold start (-50%) showed a decrease in amount of total glucosinolates. Sensory evaluation did not show statistically significant differences between steaming and boiling-cold start in liking at 'high' and 'medium' firmness; and in the attribute intensity ratings (except for juiciness at 'medium' firmness, and flavour at 'medium' and 'low' firmness). This study demonstrates that medium firm broccoli showed optimum liking and that steaming compared to boiled-cold start showed higher amount of glucosinolates. It is concluded that the health aspects of broccoli can be improved without reducing the sensory aspects by optimising the cooking method.

Maximization of orbiter altitude at ALT interface airspeed, mission planning, mission analysis and software

NASA Technical Reports Server (NTRS)

Glenn, G. M.

1976-01-01

The determination of the separation initial conditions (i.e. incidence angle) that maximize orbiter altitude at the ALT interface airspeed is considered. Optimum altitude airspeed profiles are generated for each orbiter incidence angle and tailcone configuration. Results show that the highest separation altitude does not result in the highest altitude at ALT interface airspeed. The altitude attainable at ALT interface airspeed should therefore be considered in the selection of the initial conditions (i.e. incidence angle). Without violating any known constraints, the incidence angles that maximize orbiter altitude at the ALT interface airspeeds are 7.0 deg for ALT free flight 1 and 5.5 deg for ALT free flight 6.

Ultrashort pulse amplification in cryogenically cooled amplifiers

DOEpatents

Backus, Sterling J.; Kapteyn, Henry C.; Murnane, Margaret Mary

2004-10-12

A laser amplifier system amplifies pulses in a single "stage" from .about.10.sup.-9 joules to more than 10.sup.-3 joules, with average power of 1-10 watts, and beam quality M.sup.2 <2. The laser medium is cooled substantially below room temperature, as a means to improve the optical and thermal characteristics of the medium. This is done with the medium inside a sealed, evacuated or purged cell to avoid moisture or other materials condensing on the surface. A "seed" pulse from a separate laser is passed through the laser medium, one or more times, in any of a variety of configurations including single-pass, multiple-pass, and regenerative amplifier configurations.

Desulfonatronum paiuteum sp. nov.: A New Alkaliphilic, Sulfate-Reducing Bacterium, Isolated from Soda Mono Lake, California

NASA Technical Reports Server (NTRS)

Pikuta, Elena; Hoover, Richard B.; Marsic, Damien; Whitman, William; Cleland, David; Krader, Paul; Six, N. Frank (Technical Monitor)

2002-01-01

A novel alkaliphilic, sulfate reducing bacterium strain MLF1(sup T) was isolated from sediments of soda Mono Lake, California. Gram-negative vibrion cells, motile by singular polar flagellum, with sizes 0.5 - 0.6x 1.2 - 2.0 micron occurred singly, in pairs or short spirilla. Growth was observed over the temperature range of +15 C to +48 C (optimum +37 C), NaCl concentration range is greater than 1 - 7 %, wt/vol (optimum 3 %, wt/vol) and pH range 7.8 - 10.5 (optimum pH 9.0 - 9.4). The novel isolate is strictly alkaliphilic, requires high carbonate concentration in medium, obligately anaerobic and catalase negative. As electron donors strain MLF1(sup T) uses hydrogen, formate, ethanol. Sulfate, sulfite, and thiosulfate (but not sulfur or nitrate) can be used as electron acceptors. The sole end product of growth on formate was H2S. Strain MLF1(sup T) is resistant to kanamycin and gentamycin, but sensitive to chloramphenicol and tetracycline. Na2MoO4 inhibits growth of strain MLF1(sup T). The sum of G+C in DNA is 63.1 mol% (by HPLC method). On the basis of physiological and molecular properties, the isolate was considered as novel species of genus Desulfonatronum; and the name Desulfonatronum paiuteum sp. nov., is proposed (type strain MLF1(sup T) = ATCC BAA-395(sup T) = DSMZ 14708(sup T).

Spirochaeta Americana sp. Nov., A New Haloalkaliphilic, Obligately Anaerobic Spirochaete Isolated from Soda Mona Lake in California

NASA Technical Reports Server (NTRS)

Hoover, Richard B.; Pikuta, Elena V.; Bej, Asim K.; Marsic, Damien; Whitman, William B.; Tang, Jane; Krader, Paul

2003-01-01

A novel, obligately anaerobic, mesophilic, haloalkaliphilic spirochaete, strain ASpG1(sup T), was isolated from sediments of the alkaline, hypersaline Mono Lake in California, USA. Cells of the Gram-negative strain were motile and spirochaete-shaped with sizes of 0.2-0.22 x 8-18 microns. Growth of the strain was observed between 10 and 44 C (optimum 37 C), in 2-12% (w/v) NaCl (optimum 3 % NaCl) and between pH 8 and 10.5 (optimum pH 9.5). The novel strain was strictly alkaliphilic, required high concentrations of carbonates in the medium and was capable of utilizing D-glucose, fructose, maltose, sucrose, starch and D-mannitol. End products of glucose fermentation were H2, acetate, ethanol and formate. Strain ASpG1(sup T) was resistant to kanamycin and rifampicin, but sensitive to gentamicin, tetracycline and chloramphenicol. The G + C content of its DNA was 58.5 mol%. DNA-DNA hybridization analysis of strain ASpG1(sup T) with its most closely related species, Spirochaeta alkalica Z-7491(sup T) revealed a hybridization value of only 48.7 %. On the basis of its physiological and molecular properties, strain ASpG1(sup T) appears to represent a novel species of the genus Spirochaeta, for which the name Spirochaeta americana is proposed (type strain ASpG1(sup T) = ATCC 13AA-392(sup T) = DSM 14872(sup T)).

High-performance radial AMTEC cell design for ultra-high-power solar AMTEC systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hendricks, T.J.; Huang, C.

1999-07-01

Alkali Metal Thermal to Electric Conversion (AMTEC) technology is rapidly maturing for potential application in ultra-high-power solar AMTEC systems required by potential future US Air Force (USAF) spacecraft missions in medium-earth and geosynchronous orbits (MEO and GEO). Solar thermal AMTEC power systems potentially have several important advantages over current solar photovoltaic power systems in ultra-high-power spacecraft applications for USAF MEO and GEO missions. This work presents key aspects of radial AMTEC cell design to achieve high cell performance in solar AMTEC systems delivering larger than 50 kW(e) to support high power USAF missions. These missions typically require AMTEC cell conversionmore » efficiency larger than 25%. A sophisticated design parameter methodology is described and demonstrated which establishes optimum design parameters in any radial cell design to satisfy high-power mission requirements. Specific relationships, which are distinct functions of cell temperatures and pressures, define critical dependencies between key cell design parameters, particularly the impact of parasitic thermal losses on Beta Alumina Solid Electrolyte (BASE) area requirements, voltage, number of BASE tubes, and system power production for both maximum power-per-BASE-area and optimum efficiency conditions. Finally, some high-level system tradeoffs are demonstrated using the design parameter methodology to establish high-power radial cell design requirements and philosophy. The discussion highlights how to incorporate this methodology with sophisticated SINDA/FLUINT AMTEC cell modeling capabilities to determine optimum radial AMTEC cell designs.« less

Degradation of fipronil by Stenotrophomonas acidaminiphila isolated from rhizospheric soil of Zea mays.

PubMed

Uniyal, Shivani; Paliwal, Rashmi; Sharma, R K; Rai, J P N

2016-06-01

Fipronil is a widely used insecticide in agriculture and can cause potential health hazards to non-target soil invertebrates and nearby aquatic systems. In the present study, a fipronil degrading bacterium was isolated from fipronil contaminated soil, i.e. rhizospheric zone of Zea mays. Morphological, biochemical and molecular characterization of strain indicated that it clearly belongs to Stenotrophomonas acidaminiphila (accession no. KJ396942). A three-factor Box-Behnken experimental design combined with response surface modeling was employed to predict the optimum conditions for fipronil degradation. The optimum pH, temperature and total inocula biomass for the degradation of fipronil were 7.5, 35 °C and 0.175 g L -1 , respectively. The bacterial strain was able to metabolize 25 mg L -1 fipronil with 86.14 % degradation in Dorn's broth medium under optimum conditions. Metabolites formed as a result of fipronil degradation were characterized with gas liquid chromatograph. A novel fipronil degradation pathway was proposed for S. acidaminiphila on the basis of metabolites formed. Non-sterilized soil inoculated with S. acidaminiphila was found to follow first order kinetics with a rate constant of 0.046 d -1 . Fipronil sulfone, sulfide and amide were formed as the metabolites and were degraded below the quantifiable limit after 90 days of time period. Given the high fipronil degradation observed in the present study, S. acidaminiphila may have potential for use in bioremediation of fipronil contaminated soils.

Contribution to Conversion of CO2 to fuel by electro-photo-catalytic reduction in hydro-genocarbonated aqueous solution tion

NASA Astrophysics Data System (ADS)

Nezzal, Ghania; Benammar, Souad; Hamouni, Samia; Meziane, Dalila; Naama, Sabrina; Abdessemed, Djamel

2015-04-01

Referring to the last World Conference COPENHAGEN (2010), endorsed by the United Nations,to '' RISKS OF CLIMATE CHANGES ', states had not reached an agreement to work fairly, in an international program, to limit Carbon dioxide emissions into the atmosphere, to put off it, to the next (in 2015), the right decisions, despite the recommendations of the 'IPCC'. Based on the natural reaction of photosynthesis, which converts carbon dioxide in the presence of water and sun, to '' OSA'' ', it is natural that scientists believe to implement an artificial conversion of CO2 in a renewable energy faster. Our contribution focuses on the same goals, by a different line. In this perspective, nano-materials, catalysts, pervaporation membranes, pervaporation unit, and a photo-reactor prototype, have been made. A summary of the preliminary results presented: For example, are given the concentrations of the various species present in a aqueous solution of sodium hydrogen carbonate, 0.5M, saturated with CO2, at standard temperature and pressure: (CO2) = 1M; (H2CO3) = 0,038M; (HCO3-) = 0,336M; (CO3 --) = 0,34M; pH = 7.33, an overall concentration = 1,714M, more than three times that of the initial solution. It is in such conditions that the conversion of carbon dioxide by the hydrogen produced in situ by electrolysis, in fuel, must be done in the presence of catalyst, under UV radiation. For electrodes, a nano-porous layer was formed on their surface to receive the suitable catalyst. These lats prepared, are made of porous supports (montmorillonite, aluminum and silicon oxides) into which are inserted the metal precursor, by impregnation interactive, in Iron, cobalt, nickel salt solutions, cobalt, nickel. Their performance has been identified by the reduction of para- nitrophenol, to para-aminophenol in aqueous medium in the presence of sodium borohydride. This is the catalyst 'Cobalt supported by SiO2'' that gave the best conversion, 99.5% instead of 99.7%, for a platinum catalyst. The separation of hydrocarbon products, in the considered aqueous medium, continuously, has been studied to determine optimum conditions by pervaporation. For this purpose, membranes of poly-sulfone and poly-dimethylsiloxane, were prepared and characterized in terms of flow pervaporat (J), and solute / solvent separation factor (α). Thus, the developed membranes have equivalent performance to commercial membranes. More accurate results will be the subject of this communication.

Population level differences in thermal sensitivity of energy assimilation in terrestrial salamanders.

PubMed

Clay, Timothy A; Gifford, Matthew E

2017-02-01

Thermal adaptation predicts that thermal sensitivity of physiological traits should be optimized to thermal conditions most frequently experienced. Furthermore, thermodynamic constraints predict that species with higher thermal optima should have higher performance maxima and narrower performance breadths. We tested these predictions by examining the thermal sensitivity of energy assimilation between populations within two species of terrestrial-lungless salamanders, Plethodon albagula and P. montanus. Within P. albagula, we examined populations that were latitudinally separated by >450km. Within P. montanus, we examined populations that were elevationally separated by >900m. Thermal sensitivity of energy assimilation varied substantially between populations of P. albagula separated latitudinally, but did not vary between populations of P. montanus separated elevationally. Specifically, in P. albagula, the lower latitude population had a higher thermal optimum, higher maximal performance, and narrower performance breadth compared to the higher latitude population. Furthermore, across all individuals as thermal optima increased, performance maxima also increased, providing support for the theory that "hotter is better". Copyright © 2016 Elsevier Ltd. All rights reserved.

Active flow separation control by a position-based iterative learning control algorithm with experimental validation

NASA Astrophysics Data System (ADS)

Cai, Zhonglun; Chen, Peng; Angland, David; Zhang, Xin

2014-03-01

A novel iterative learning control (ILC) algorithm was developed and applied to an active flow control problem. The technique uses pulsed air jets to delay flow separation on a two-element high-lift wing. The ILC algorithm uses position-based pressure measurements to update the actuation. The method was experimentally tested on a wing model in a 0.9 m × 0.6 m low-speed wind tunnel at the University of Southampton. Compressed air and fast switching solenoid valves were used as actuators to excite the flow, and the pressure distribution around the chord of the wing was measured as a feedback control signal for the ILC controller. Experimental results showed that the actuation was able to delay the separation and increase the lift by approximately 10%-15%. By using the ILC algorithm, the controller was able to find the optimum control input and maintain the improvement despite sudden changes of the separation position.

Capillary electrochromatography and capillary electrochromatography-electrospray mass spectrometry for the separation of non-steroidal anti-inflammatory drugs.

PubMed

Desiderio, C; Fanali, S

2000-10-20

In this study capillary electrochromatography (CEC) was utilized for the separation of ten non-steroidal anti-inflammatory drugs (NSAIDs). Experiments were carried out in a commercially available CE instrument using a packed capillary with RP-18 silica particles where the stationary phase completely filled the capillary. The mobile phase consisted of a mixture of ammonium formate buffer pH 2.5 and acetonitrile. Selectivity and resolution were studied changing the pH and the concentration of the buffer, the acetonitrile content mobile phase and the capillary temperature. The optimum experimental conditions for CEC separation of the studied drug mixture were found using 50 mM ammonium formate pH 2.5-acetonitrile (40:60) at 25 degrees C. The CEC capillary was coupled to an electrospray mass spectrometer for the characterization of the NSAIDs. A mobile phase composed by the same buffer but with a higher concentration of acetonitrile (90%) was used in order to speed up the separation of analytes.

Experimental screening of porous materials for high pressure gas adsorption and evaluation in gas separations: application to MOFs (MIL-100 and CAU-10).

PubMed

Wiersum, Andrew D; Giovannangeli, Christophe; Vincent, Dominique; Bloch, Emily; Reinsch, Helge; Stock, Norbert; Lee, Ji Sun; Chang, Jong-San; Llewellyn, Philip L

2013-02-11

A high-throughput gas adsorption apparatus is presented for the evaluation of adsorbents of interest in gas storage and separation applications. This instrument is capable of measuring complete adsorption isotherms up to 40 bar on six samples in parallel using as little as 60 mg of material. Multiple adsorption cycles can be carried out and four gases can be used sequentially, giving as many as 24 adsorption isotherms in 24 h. The apparatus has been used to investigate the effect of metal center (MIL-100) and functional groups (CAU-10) on the adsorption of N(2), CO(2), and light hydrocarbons on MOFs. This demonstrates how it can serve to evaluate sample quality and adsorption reversibility, to determine optimum activation conditions and to estimate separation properties. As such it is a useful tool for the screening of novel adsorbents for different applications in gas separation, providing significant time savings in identifying potentially interesting materials.

Separation and purification of enzymes by continuous pH-parametric pumping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, S.Y.; Lin, C.K.; Juang, L.Y.

1985-10-01

Trypsin and chymotrypsin were separated from porcine pancreas extract by continuous pH-parametric pumping. CHOM (chicken ovomucoid) was convalently bound to laboratory-prepared crab chitin with glutaraldehyde to form an affinity adsorbent of trypsin. The pH levels of top and bottom feeds were 8.0 and 2.5, respectively. Similar inhibitor, DKOM (duck ovomucoid), and pH levels 8.0 and 2.0 for top and bottom feeds, respectively, were used for separation and purification of chymotrypsin. e-Amino caproyl-D-tryptophan methyl ester was coupled to chitosan to form an affinity adsorbent for stem bromelain. The pH levels were 8.7 and 3.0. Separation continued fairly well with high yield,more » e.g., 95% recovery of trypsin after continuous pumping of 10 cycles. Optimum operational conditions for concentration and purification of these enzymes were investigated. The results showed that the continuous pH-parametric pumping coupled with affinity chromatography is effective for concentration and purification of enzymes. 19 references.« less

High Dynamic Velocity Range Particle Image Velocimetry Using Multiple Pulse Separation Imaging

PubMed Central

Persoons, Tim; O’Donovan, Tadhg S.

2011-01-01

The dynamic velocity range of particle image velocimetry (PIV) is determined by the maximum and minimum resolvable particle displacement. Various techniques have extended the dynamic range, however flows with a wide velocity range (e.g., impinging jets) still challenge PIV algorithms. A new technique is presented to increase the dynamic velocity range by over an order of magnitude. The multiple pulse separation (MPS) technique (i) records series of double-frame exposures with different pulse separations, (ii) processes the fields using conventional multi-grid algorithms, and (iii) yields a composite velocity field with a locally optimized pulse separation. A robust criterion determines the local optimum pulse separation, accounting for correlation strength and measurement uncertainty. Validation experiments are performed in an impinging jet flow, using laser-Doppler velocimetry as reference measurement. The precision of mean flow and turbulence quantities is significantly improved compared to conventional PIV, due to the increase in dynamic range. In a wide range of applications, MPS PIV is a robust approach to increase the dynamic velocity range without restricting the vector evaluation methods. PMID:22346564

Analytical optimization of digital subtraction mammography with contrast medium using a commercial unit.

PubMed

Rosado-Méndez, I; Palma, B A; Brandan, M E

2008-12-01

Contrast-medium-enhanced digital mammography (CEDM) is an image subtraction technique which might help unmasking lesions embedded in very dense breasts. Previous works have stated the feasibility of CEDM and the imperative need of radiological optimization. This work presents an extension of a former analytical formalism to predict contrast-to-noise ratio (CNR) in subtracted mammograms. The goal is to optimize radiological parameters available in a clinical mammographic unit (x-ray tube anode/filter combination, voltage, and loading) by maximizing CNR and minimizing total mean glandular dose (D(gT)), simulating the experimental application of an iodine-based contrast medium and the image subtraction under dual-energy nontemporal, and single- or dual-energy temporal modalities. Total breast-entrance air kerma is limited to a fixed 8.76 mGy (1 R, similar to screening studies). Mathematical expressions obtained from the formalism are evaluated using computed mammographic x-ray spectra attenuated by an adipose/glandular breast containing an elongated structure filled with an iodinated solution in various concentrations. A systematic study of contrast, its associated variance, and CNR for different spectral combinations is performed, concluding in the proposal of optimum x-ray spectra. The linearity between contrast in subtracted images and iodine mass thickness is proven, including the determination of iodine visualization limits based on Rose's detection criterion. Finally, total breast-entrance air kerma is distributed between both images in various proportions in order to maximize the figure of merit CNR2/D(gT). Predicted results indicate the advantage of temporal subtraction (either single- or dual-energy modalities) with optimum parameters corresponding to high-voltage, strongly hardened Rh/Rh spectra. For temporal techniques, CNR was found to depend mostly on the energy of the iodinated image, and thus reduction in D(gT) could be achieved if the spectral energy of the noniodinated image is decreased and the breast-entrance air kerma is evenly distributed between both acquisitions. Predicted limits, in terms of iodine concentration, are found to guarantee the visualization of common clinical angiogenic concentrations in the breast.

Effect of addition of FSH, LH and proteasome inhibitor MG132 to in vitro maturation medium on the developmental competence of yak (Bos grunniens) oocytes.

PubMed

Xiao, Xiao; Zi, Xiang-Dong; Niu, Hui-Ran; Xiong, Xian-Rong; Zhong, Jin-Cheng; Li, Jian; Wang, Li; Wang, Yong

2014-04-22

The competence for embryonic development after IVF is low in the yak, therefore, we investigated the effects of supplementation of FSH, LH and the proteasome inhibitor MG132 in IVM media on yak oocyte competence for development after IVF. In Experiment 1, yak cumulus-oocyte complexes (COCs) were in vitro matured (IVM) in TCM-199 with 20% fetal calf serum (FCS), 1 microg/mL estradiol-17beta, and different combinations of LH (50 or 100 IU/mL) and FSH (0, 1, 5, 10 microg/mL) at 38.6 degrees C, 5% CO2 in air for 24 h. Matured oocytes were exposed to frozen-thawed, heparin-capacitated yak sperm. Presumptive zygotes were cultured in SOF medium containing 6 mg/ml BSA, 0.5 mg/mL myoinositol, 3% (v/v) essential amino acids, 1% nonessential amino acids and 100 μg/mL L-glutamine (48 h, 38.5 degrees C, 5% CO2, 5% O2, and 90% N2). In Experiment 2, cumulus cells were collected at the end of IVM to determine FSHR and LHR mRNA expression by real-time PCR. In Experiment 3 and 4, COCs were cultured in the presence or absence of the proteasomal inhibitor MG132 from either 0-6 h or 18-24 h after initiation of maturation. The optimum concentration of FSH and LH in IVM media was 5 microg/mL FSH and 50 IU/mL LH which resulted in the greatest cleavage (79.1%) and blastocyst rates (16.1%). Both FSHR and LHR mRNA were detected in yak cumulus cells after IVM. Treatment with MG132 early in maturation reduced (P<0.05) cleavage and blastocyst rates. Conversely, treatment with MG132 late in maturation improved (P<0.05) blastocyst rate. Optimal results with MG132 were achieved at a concentration of 10 microM. An optimum concentration of FSH and LH in IVM medium, and treatment with MG132 late in maturation can improve yak oocytes competence for development after IVF.

Solid-state fermentation of cornmeal with the basidiomycete Ganoderma lucidum for degrading starch and upgrading nutritional value.

PubMed

Han, J R; An, C H; Yuan, J M

2005-01-01

The objective of this research was to study the ability of the basidiomycete Ganoderma lucidum to degrade starch and upgrade nutritional value of cornmeal during solid-state fermentation (SSF). On the basal medium that consisted of cornmeal and salt solution, alpha-amylase activity of G. lucidum reached its maximum value of 267 U g(-1) of culture on day 20 after inoculation. Prolongation of fermentation time from 10 to 25 days increased significantly the degradation rate of starch and ergosterol yield (a kind of physiologically active substances of G. lucidum, also as an indicator of mycelial biomass) (P < 0.01). Supplementation of glucose, sucrose or maltose to the basal medium also caused a significant increase in either the degradation rate of starch or the ergosterol yield as compared with control (P < 0.01). Among five kinds of nitrogen sources supplemented, yeast extract, casamino acid and peptone were more effective than (NH4)2SO4 and NH4NO3, and yeast extract gave the highest degradation rate of starch and ergosterol yield, followed by peptone. Through orthogonal experiments, the theoretical optimum culture medium for SSF of this fungus was the following: 100 g cornmeal, ground to 30-mesh powder, moistened with 67 ml of nutrient salt solution supplemented with 3 g yeast extract and 7.5 g glucose per litre. Under the optimum culture condition, the degradation rate of starch reached its maximum values of 70.4%; the starch content of the fermented product decreased from 64.5 to 25.3%, while the reducing sugar content increased from 4.2 to 20.6%. SSF also produced a significant increase (P < 0.01) from 11.0 to 16.5% in protein content. After SSF by G. lucidum, the digesting and absorbing ratio of cornmeal was strikingly increased and some active substances originated from G. lucidum remained in the fermented product. This implied that cornmeal could be processed into many kinds of special functional foods by SSF of G. lucidum.

Education in the Mother-Tongue: A Nigerian Experiment--the Six-Year (Yoruba Medium) Primary Education Project at the University of Ife, Nigeria

ERIC Educational Resources Information Center

Fafunwa, A. Babs

1975-01-01

This project was launched as a medium of instruction throughout the six-year primary course, predicted on the hypotheses that the child benefits culturally, socially, linguistically and cognitively through native language instruction, and that his command of English will be improved if it is taught as a separate subject by a specially trained…

Single photons from a gain medium below threshold

NASA Astrophysics Data System (ADS)

Ghosh, Sanjib; Liew, Timothy C. H.

2018-06-01

The emission from a nonlinear photonic mode coupled weakly to a gain medium operating below threshold is predicted to exhibit antibunching. In the steady state regime, analytical solutions for the relevant observable quantities are found in accurate agreement with exact numerical results. Under pulsed excitation, the unequal time second-order correlation function demonstrates the triggered probabilistic generation of single photons well separated in time.

Airfoil Design and Optimization by the One-Shot Method

NASA Technical Reports Server (NTRS)

Kuruvila, G.; Taasan, Shlomo; Salas, M. D.

1995-01-01

An efficient numerical approach for the design of optimal aerodynamic shapes is presented in this paper. The objective of any optimization problem is to find the optimum of a cost function subject to a certain state equation (governing equation of the flow field) and certain side constraints. As in classical optimal control methods, the present approach introduces a costate variable (Lagrange multiplier) to evaluate the gradient of the cost function. High efficiency in reaching the optimum solution is achieved by using a multigrid technique and updating the shape in a hierarchical manner such that smooth (low-frequency) changes are done separately from high-frequency changes. Thus, the design variables are changed on a grid where their changes produce nonsmooth (high-frequency) perturbations that can be damped efficiently by the multigrid. The cost of solving the optimization problem is approximately two to three times the cost of the equivalent analysis problem.

Parameter optimization of electrochemical machining process using black hole algorithm

NASA Astrophysics Data System (ADS)

Singh, Dinesh; Shukla, Rajkamal

2017-12-01

Advanced machining processes are significant as higher accuracy in machined component is required in the manufacturing industries. Parameter optimization of machining processes gives optimum control to achieve the desired goals. In this paper, electrochemical machining (ECM) process is considered to evaluate the performance of the considered process using black hole algorithm (BHA). BHA considers the fundamental idea of a black hole theory and it has less operating parameters to tune. The two performance parameters, material removal rate (MRR) and overcut (OC) are considered separately to get optimum machining parameter settings using BHA. The variations of process parameters with respect to the performance parameters are reported for better and effective understanding of the considered process using single objective at a time. The results obtained using BHA are found better while compared with results of other metaheuristic algorithms, such as, genetic algorithm (GA), artificial bee colony (ABC) and bio-geography based optimization (BBO) attempted by previous researchers.

Optimization of Darrieus turbines with an upwind and downwind momentum model

NASA Astrophysics Data System (ADS)

Loth, J. L.; McCoy, H.

1983-08-01

This paper presents a theoretical aerodynamic performance optimization for two dimensional vertical axis wind turbines. A momentum type wake model is introduced with separate cosine type interference coefficients for the up and downwind half of the rotor. The cosine type loading permits the rotor blades to become unloaded near the junction of the upwind and downwind rotor halves. Both the optimum and the off design magnitude of the interference coefficients are obtained by equating the drag on each of the rotor halves to that on each of two cosine loaded actuator discs in series. The values for the optimum rotor efficiency, solidity and corresponding interference coefficients have been obtained in a closed form analytic solution by maximizing the power extracted from the downwind rotor half as well as from the entire rotor. A numerical solution was required when viscous effects were incorporated in the rotor optimization.

Multiple forms of endopeptidase activity from jojoba seeds.

PubMed

Wolf, M J; Storey, R D

1990-01-01

The cotyledons of 27 day post-germination jojoba seedlings (Simmondsia chinensis) contained five distinct endopeptidase activities separable by DEAE Bio-Gel and CM-cellulose ion exchange chromatography. The endopeptidases were purified 108- to 266-fold and their individuality was confirmed by activity-specific assays in native acrylamide gels along with differences in their Mr and catalytic properties. The five endopeptidases, which showed activity on model substrates and protein, were named EP Ia, EP Ib, EP II, EP III and EP IV. EP Ia was a serine proteinase with a pH optimum of ca 8 and Mr of 58,000. EP Ib, II and III were discrete cysteine proteinases showing pH optima of ca 6.8, 6.0 and 5.4 and Mr of 41,000, 47,000 and 35,000 respectively. EP IV was an aspartic acid proteinase with a ca pH optimum of 3.5 and Mr of 33,000.

Verification of high efficient broad beam cold cathode ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdel Reheem, A. M., E-mail: amreheem2009@yahoo.com; Radiation Physics Department, National Center for Radiation Research and Technology; Ahmed, M. M.

2016-08-15

An improved form of cold cathode ion source has been designed and constructed. It consists of stainless steel hollow cylinder anode and stainless steel cathode disc, which are separated by a Teflon flange. The electrical discharge and output characteristics have been measured at different pressures using argon, nitrogen, and oxygen gases. The ion exit aperture shape and optimum distance between ion collector plate and cathode disc are studied. The stable discharge current and maximum output ion beam current have been obtained using grid exit aperture. It was found that the optimum distance between ion collector plate and ion exit aperturemore » is equal to 6.25 cm. The cold cathode ion source is used to deposit aluminum coating layer on AZ31 magnesium alloy using argon ion beam current which equals 600 μA. Scanning electron microscope and X-ray diffraction techniques used for characterizing samples before and after aluminum deposition.« less

Airfoil optimization by the one-shot method

NASA Technical Reports Server (NTRS)

Kuruvila, G.; Taasan, Shlomo; Salas, M. D.

1994-01-01

An efficient numerical approach for the design of optimal aerodynamic shapes is presented in this paper. The objective of any optimization problem is to find the optimum of a cost function subject to a certain state equation (Governing equation of the flow field) and certain side constraints. As in classical optimal control methods, the present approach introduces a costate variable (Language multiplier) to evaluate the gradient of the cost function. High efficiency in reaching the optimum solution is achieved by using a multigrid technique and updating the shape in a hierarchical manner such that smooth (low-frequency) changes are done separately from high-frequency changes. Thus, the design variables are changed on a grid where their changes produce nonsmooth (high-frequency) perturbations that can be damped efficiently by the multigrid. The cost of solving the optimization problem is approximately two to three times the cost of the equivalent analysis problem.

Constraint-Based Local Search for Constrained Optimum Paths Problems

NASA Astrophysics Data System (ADS)

Pham, Quang Dung; Deville, Yves; van Hentenryck, Pascal

Constrained Optimum Path (COP) problems arise in many real-life applications and are ubiquitous in communication networks. They have been traditionally approached by dedicated algorithms, which are often hard to extend with side constraints and to apply widely. This paper proposes a constraint-based local search (CBLS) framework for COP applications, bringing the compositionality, reuse, and extensibility at the core of CBLS and CP systems. The modeling contribution is the ability to express compositional models for various COP applications at a high level of abstraction, while cleanly separating the model and the search procedure. The main technical contribution is a connected neighborhood based on rooted spanning trees to find high-quality solutions to COP problems. The framework, implemented in COMET, is applied to Resource Constrained Shortest Path (RCSP) problems (with and without side constraints) and to the edge-disjoint paths problem (EDP). Computational results show the potential significance of the approach.

30 CFR 77.902-3 - Attachment of ground conductors and ground check wires to equipment frames; use of separate...

Code of Federal Regulations, 2012 CFR

2012-07-01

... SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902-3 Attachment of ground conductors and ground check wires to... equipment receiving power from resistance grounded systems, separate connections shall be used. ...

30 CFR 77.902-3 - Attachment of ground conductors and ground check wires to equipment frames; use of separate...

Code of Federal Regulations, 2014 CFR

2014-07-01

... SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902-3 Attachment of ground conductors and ground check wires to... equipment receiving power from resistance grounded systems, separate connections shall be used. ...

30 CFR 77.902-3 - Attachment of ground conductors and ground check wires to equipment frames; use of separate...

Code of Federal Regulations, 2013 CFR

2013-07-01

... SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902-3 Attachment of ground conductors and ground check wires to... equipment receiving power from resistance grounded systems, separate connections shall be used. ...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nadel, G.L.; Malik, K.U.; Lew, D.B.

The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ({sup 14}C)AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ({sup 14}C)AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2{alpha}. Trace amounts of PGD2 and 6-keto-PGF1{alpha}more » but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10{sup {minus}7}, 10{sup {minus}7}M respectively). In contrast, dobutamine, norepinephrine, phenylnephrine and xylazine (up to 10{sup {minus}6}M) did not significantly increase PGE2 production. Isoproterenol-induced iPGE2 production was inhibited by a selective {beta}2 antagonist, butoxamine (70%: 10{sup {minus}7}M, 91%: 10{sup {minus}6}M) and somewhat reduced by {beta}1 antagonists practolol and metoprolol (30-64%:10{sup {minus}6}M). These data suggest that isoproterenol induced iPGE2 synthesis is primarily mediated via activation of {beta}2 adrenergic receptor.« less

[Phenotypic properties of Sulfobacillus thermotolerans: comparative aspects].

PubMed

Tsaplina, I A; Krasil'nikova, E N; Zhuravleva, A E; Egorova, M A; Zakharchuk, L M; Suzina, N E; Duda, V I; Bogdanova, T I; Stadnichuk, I N; Kondrat'eva, T F

2008-01-01

The phenotypic characteristics of the species Sulfobacillus thermotolerans Kr1(T), as dependent on the cultivation conditions, are described in detail. High growth rates (0.22-0.30 h(-1)) and high oxidative activity were recorded under optimum mixotrophic conditions at 40 degrees C on medium with inorganic (Fe(II), S(0), or pyrite-arsenopyrite concentrate) and organic (glucose and/or yeast extract) substrates. In cells grown under optimum conditions on medium with iron, hemes a, b, and, most probably, c were present, indicating the presence of the corresponding cytochromes. Peculiar extended structures in the form of cylindrical cords, never observed previously, were revealed; a mucous matrix, likely of polysaccharide nature, occurred around the cells. In the cells of sulfobacilli grown litho-, organo-, and mixotrophically at 40 degrees C, the enzymes of the three main pathways of carbon utilization and some enzymes of the TCA cycle were revealed. The enzyme activity was maximum under mixotrophic growth conditions. The growth rate in the regions of limiting temperatures (55 degrees C and 12-14 degrees C) decreased two- and tenfold, respectively; no activity of 6-phosphogluconate dehydrogenase, one of the key enzymes of the oxidative pentose phosphate pathway, could be revealed; and a decrease in the activity of almost all enzymes of glucose metabolism and of the TCA cycle was observed. The rate of 14CO2 fixation by cells under auto-, mixo-, and heterotrophic conditions constituted 31.8, 23.3, and 10.3 nmol/(h mg protein), respectively. The activities of RuBP carboxylase (it peaked during lithotrophic growth) and of carboxylases of heterotrophic carbon dioxide fixation were recorded. The physiological and biochemical peculiarities of the thermotolerant sulfobacillus are compared versus moderately thermophilic sulfobacilli.

Thermosyntropha lipolytica gen. nov., sp. nov., a lipolytic, anaerobic, alkalitolerant, thermophilic bacterium utilizing short- and long-chain fatty acids in syntrophic coculture with a methanogenic archaeum.

PubMed

Svetlitshnyi, V; Rainey, F; Wiegel, J

1996-10-01

Three strains of an anaerobic thermophilic organoheterotrophic lipolytic alkalitolerant bacterium, Thermosyntropha lipolytica gen. nov., sp. nov. (type strain JW/VS-265T; DSM 11003), were isolated from alkaline hot springs of Lake Bogoria (Kenya). The cells were nonmotile, non-spore forming, straight or slightly curved rods. At 60 degrees C the pH range for growth determined at 25 degrees C [pH25 degrees C] was 7.15 to 9.5, with an optimum between 8.1 and 8.9 (pH60 degrees C of 7.6 and 8.1). At a pH25 degrees C of 8.5 the temperature range for growth was from 52 to 70 degrees C, with an optimum between 60 and 66 degrees C. The shortest doubling time was around 1 h. In pure culture the bacterium grew in a mineral base medium supplemented with yeast extract, tryptone, Casamino Acids, betaine, and crotonate as carbon sources, producing acetate as a major product and constitutively a lipase. During growth in the presence of olive oil, free long-chain fatty acids were accumulated in the medium but the pure culture could not utilize olive oil, triacylglycerols, short- and long-chain fatty acids, and glycerol for growth. In syntrophic coculture (Methanobacterium strain JW/VS-M29) the lipolytic bacteria grew on triacylglycerols and linear saturated and unsaturated fatty acids with 4 to 18 carbon atoms, but glycerol was not utilized. Fatty acids with even numbers of carbon atoms were degraded to acetate and methane, while from odd-numbered fatty acids 1 mol of propionate per mol of fatty acid was additionally formed. 16S rDNA sequence analysis identified Syntrophospora and Syntrophomonas spp. as closest phylogenetic neighbors.

Ammonium nitrate and iron nutrition effects on some nitrogen assimilation enzymes and metabolites in Spirulina platensis.

PubMed

Esen, Merve; Ozturk Urek, Raziye

2015-01-01

The effect of various concentrations of ammonium nitrate (5-60 mM), an economical nitrogen source, on the growth, nitrate-ammonium uptake rates, production of some pigments and metabolites, and some nitrogen assimilation enzymes such as nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) in Spirulina platensis (Gamont) Geitler was investigated. Ten millimolars of ammonium nitrate stimulated the growth, production of pigments and the other metabolites, and enzyme activities, whereas 30 and 60 mM ammonium nitrate caused inhibition. In the presence of 10 mM ammonium nitrate, different concentrations of iron were tried in the growth media of S. platensis. After achieving the best growth, levels of metabolite and pigment production, and enzyme activities in the presence of 10 mM ammonium nitrate as a nitrogen source, different iron concentrations (10-100 µM) were tried in the growth medium of S. platensis. The highest growth, pigment and metabolite levels, and enzyme activities were determined in the medium containing 50 µM iron and 10 mM ammonium nitrate. In this optimum condition, the highest dry biomass level, chlorophyll a, and pyruvate contents were obtained as 55.42 ± 3.8 mg mL(-1) , 93.114 ± 7.9 µg g(-1) , and 212.5 ± 18.7 µg g(-1) , respectively. The highest NR, NiR, GS, and GOGAT activities were 67.16 ± 5.1, 777.92 ± 52, 0.141 ± 0.01, and 44.45 ± 3.6, respectively. Additionally, 10 mM ammonium nitrate is an economical and efficient nitrogen source for nitrogen assimilation of S. platensis, and 50 µM iron is optimum for the growth of S. platensis. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Atan1p-an extracellular tannase from the dimorphic yeast Arxula adeninivorans: molecular cloning of the ATAN1 gene and characterization of the recombinant enzyme.

PubMed

Böer, Erik; Bode, Rüdiger; Mock, Hans-Peter; Piontek, Michael; Kunze, Gotthard

2009-06-01

The tannase-encoding Arxula adeninivorans gene ATAN1 was isolated from genomic DNA by PCR, using as primers oligonucleotide sequences derived from peptides obtained after tryptic digestion of the purified tannase protein. The gene harbours an ORF of 1764 bp, encoding a 587-amino acid protein, preceded by an N-terminal secretion sequence comprising 28 residues. The deduced amino acid sequence was similar to those of tannases from Aspergillus oryzae (50% identity), A. niger (48%) and putative tannases from A. fumigatus (52%) and A. nidulans (50%). The sequence contains the consensus pentapeptide motif (-Gly-X-Ser-X-Gly-) which forms part of the catalytic centre of serine hydrolases. Expression of ATAN1 is regulated by the carbon source. Supplementation with tannic acid or gallic acid leads to induction of ATAN1, and accumulation of the native tannase enzyme in the medium. The enzymes recovered from both wild-type and recombinant strains were essentially indistinguishable. A molecular mass of approximately 320 kDa was determined, indicating that the native, glycosylated tannase consists of four identical subunits. The enzyme has a temperature optimum at 35-40 degrees C and a pH optimum at approximately 6.0. The enzyme is able to remove gallic acid from both condensed and hydrolysable tannins. The wild-type strain LS3 secreted amounts of tannase equivalent to 100 U/l under inducing conditions, while the transformant strain, which overexpresses the ATAN1 gene from the strong, constitutively active A. adeninivorans TEF1 promoter, produced levels of up to 400 U/l when grown in glucose medium in shake flasks. Copyright (c) 2009 John Wiley & Sons, Ltd.

Characterization of a Thermotolerant Phytase Produced by Rhizopus microsporus var. microsporus Biofilm on an Inert Support Using Sugarcane Bagasse as Carbon Source.

PubMed

Sato, Vanessa Sayuri; Jorge, João Atílio; Guimarães, Luis Henrique Souza

2016-06-01

The Rhizopus microsporus var. microsporus biofilm was able to produce increased levels of an extracellular thermotolerant phytase using polyethylene and viscose as an inert support in both modified NBRIP medium and modified Khanna medium containing sugarcane bagasse as the carbon source. The enzyme production was strictly regulated by the phosphorus content with optimal production at 0.5 mM of sodium phytate and KH2PO4. The extracellular phytase, RMPhy1, was purified 4.18-fold with 4.78 % recovery using DEAE-cellulose and CM-cellulose. A single protein band with a molecular mass of 35.4 kDa was obtained when the samples were subjected to 10 % SDS-PAGE. The optimum temperature for activity was 55 °C and the optimum pH was 4.5. R. microsporus var. microsporus phytase exhibited high stability at 30 and 40 °C with a half-life of 115 min at 60 °C. The enzyme activity increased in the presence of Ca (2+) and was inhibited by Zn(2+), arsenate, and sodium phosphate. Phytase demonstrated high substrate specificity for sodium phytate with K m = 0.72 mM and V max = 94.55 U/mg of protein and for p-NPP with K m = 0.04 mM and V max = 106.38 U/mg of protein. The enzyme also hydrolyzed ATP, AMPc, glucose 6-phosphate, glucose 1-phosphate, and UDPG. This is the first report on phytase characterization delivered with biofilm technology. The properties of the enzyme account for its high potential for use in biotechnology and the possibility of application in different industrial sectors as feed in the future.

A novel approach for rapidly and cost-effectively assessing toxicity of toxic metals in acidic water using an acidophilic iron-oxidizing biosensor.

PubMed

Yang, Shih-Hung; Cheng, Kuo-Chih; Liao, Vivian Hsiu-Chuan

2017-11-01

Contamination by heavy metals and metalloids is a serious environmental and health concern. Acidic wastewaters are often associated with toxic metals which may enter and spread into agricultural soils. Several biological assays have been developed to detect toxic metals; however, most of them can only detect toxic metals in a neutral pH, not in an acidic environment. In this study, an acidophilic iron-oxidizing bacterium (IOB) Strain Y10 was isolated, characterized, and used to detect toxic metals toxicity in acidic water at pH 2.5. The colorimetric acidophilic IOB biosensor was based on the inhibition of the iron oxidizing ability of Strain Y10, an acidophilic iron-oxidizing bacterium, by metals toxicity. Our results showed that Strain Y10 is acidophilic iron-oxidizing bacterium. Thiobacillus caldus medium (TCM) (pH 2.5) supplied with both S 4 O 6 2- and glucose was the optimum growth medium for Strain Y10. The optimum temperature and pH for the growth of Strain Y10 was 45 °C and pH 2.5, respectively. Our study demonstrates that the color-based acidophilic IOB biosensor can be semi-quantitatively observed by eye or quantitatively measured by spectrometer to detect toxicity from multiple toxic metals at pH 2.5 within 45 min. Our study shows that monitoring toxic metals in acidic water is possible by using the acidophilic IOB biosensor. Our study thus provides a novel approach for rapid and cost-effective detection of toxic metals in acidic conditions that can otherwise compromise current methods of chemical analysis. This method also allows for increased efficiency when screening large numbers of environmental samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular Characterization and Antimicrobial Activity of an Endolichenic Fungus, Aspergillus sp. Isolated from Parmelia caperata of Similipal Biosphere Reserve, India.

PubMed

Padhi, Srichandan; Das, Devaranjan; Panja, Suraj; Tayung, Kumananda

2017-06-01

Endolichenic fungi are microbes that inhabit healthy inner lichen tissues without any disease symptoms. They have been reported to produce new and interesting bioactive metabolites. In the present study, an endolichenic fungus frequently isolated from surface-sterilized lichen thallus of Parmelia caperata has been described. The fungus was identified as Aspergillus tubingensis based on morphological traits and ITS rDNA sequence. Crude metabolites extracted from the culture broth exhibited considerable antimicrobial activity against a panel of clinically significant human pathogens. The fungus showed optimum antimicrobial activity in PDB medium in day 7 of incubation period. PDB medium amended with 1 % NaCl and at alkaline pH was found to be optimal for antimicrobial metabolites production. Enhanced activity was observed when the fungus was exposed briefly to a heat shock of 60 °C during incubation. The metabolites showed optimum λ-max at 214 nm with an absorbance value of 1.589. Molecular characterization of the isolate was carried out by ITS phylogeny and ITS2 secondary structure analyses. The phylogenetic trees based on both ITS rDNA and ITS2 sequences showed the isolate within the clade A. tubingensis. Considering the ubiquity and ambiguity in identifying Aspergillus species of different lifestyles, a method to differentiate pathogenic and endophytic Aspergillus at species level was developed using ITS2 secondary structure analysis. The results showed common folding pattern in the secondary structures with a helix and a 5' dangling end found to be highly conserved. Certain features in the secondary structure like multi-bulges and a symmetric interior loop were observed to be unique which distinguish our isolate from other A. tubingensis.

Polymeric media comprising polybenzimidazoles N-substituted with organic-inorganic hybrid moiety

DOEpatents

Klaehn, John R [Idaho Falls, ID; Peterson, Eric S [Idaho Falls, ID; Wertsching, Alan K [Idaho Falls, ID; Orme, Christopher J [Shelley, ID; Luther, Thomas A [Idaho Falls, ID; Jones, Michael G [Pocatello, ID

2009-12-15

A PBI compound includes imidazole nitrogens at least a portion of which are substituted with an organic-inorganic hybrid moiety may be included in a separator medium. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2-- where R is selected from among methyl, phenyl, vinyl, and allyl. The separatory medium may exhibit an H.sub.2, Ar, N.sub.2, O.sub.2, CH.sub.3, or CO.sub.2 gas permeability greater than the gas permeability of a comparable separatory medium comprising the PBI compound without substitution. The separatory medium may further include an electronically conductive medium and/or ionically conductive medium. The separatory medium may be used as a membrane (semi-permeable, permeable, and non-permeable), a barrier, an ion exhcange media, a filter, a gas chromatography coating (such as stationary phase coating in affinity chromatography), etc.

Air cooled turbine component having an internal filtration system

DOEpatents

Beeck, Alexander R [Orlando, FL

2012-05-15

A centrifugal particle separator is provided for removing particles such as microscopic dirt or dust particles from the compressed cooling air prior to reaching and cooling the turbine blades or turbine vanes of a turbine engine. The centrifugal particle separator structure has a substantially cylindrical body with an inlet arranged on a periphery of the substantially cylindrical body. Cooling air enters centrifugal particle separator through the separator inlet port having a linear velocity. When the cooling air impinges the substantially cylindrical body, the linear velocity is transformed into a rotational velocity, separating microscopic particles from the cooling air. Microscopic dust particles exit the centrifugal particle separator through a conical outlet and returned to a working medium.

Selective Precipitation of Thorium lodate from a Tartaric Acid-Hydrogen Peroxide Medium Application to Rapid Spectrophotometric Determination of Thorium in Silicate Rocks and in Ores

USGS Publications Warehouse

Grimaldi, F.S.

1957-01-01

This paper presents a selective iodate separation of thorium from nitric acid medium containing d-tartaric acid and hydrogen peroxide. The catalytic decomposition of hydrogen peroxide is prevented by the use of 8quinolinol. A few micrograms of thorium are separated sufficiently clean from 30 mg. of such oxides as cerium, zirconium, titanium, niobium, tantalum, scandium, or iron with one iodate precipitation to allow an accurate determination of thorium with the thoronmesotartaric acid spectrophotometric method. The method is successful for the determination of 0.001% or more of thorium dioxide in silicate rocks and for 0.01% or more in black sand, monazite, thorite, thorianite, eschynite, euxenite, and zircon.

Multi-level of Fidelity Multi-Disciplinary Design Optimization of Small, Solid-Propellant Launch Vehicles

NASA Astrophysics Data System (ADS)

Roshanian, Jafar; Jodei, Jahangir; Mirshams, Mehran; Ebrahimi, Reza; Mirzaee, Masood

A new automated multi-level of fidelity Multi-Disciplinary Design Optimization (MDO) methodology has been developed at the MDO Laboratory of K.N. Toosi University of Technology. This paper explains a new design approach by formulation of developed disciplinary modules. A conceptual design for a small, solid-propellant launch vehicle was considered at two levels of fidelity structure. Low and medium level of fidelity disciplinary codes were developed and linked. Appropriate design and analysis codes were defined according to their effect on the conceptual design process. Simultaneous optimization of the launch vehicle was performed at the discipline level and system level. Propulsion, aerodynamics, structure and trajectory disciplinary codes were used. To reach the minimum launch weight, the Low LoF code first searches the whole design space to achieve the mission requirements. Then the medium LoF code receives the output of the low LoF and gives a value near the optimum launch weight with more details and higher fidelity.

Biosynthesis of medium chain length alkanes for bio-aviation fuel by metabolic engineered Escherichia coli.

PubMed

Wang, Meng; Nie, Kaili; Cao, Hao; Xu, Haijun; Fang, Yunming; Tan, Tianwei; Baeyens, Jan; Liu, Luo

2017-09-01

The aim of this work was to study the synthesis of medium-chain length alkanes (MCLA), as bio-aviation product. To control the chain length of alkanes and increase the production of MCLA, Escherichia coli cells were engineered by incorporating (i) a chain length specific thioesterase from Umbellularia californica (UC), (ii) a plant origin acyl carrier protein (ACP) gene and (iii) the whole fatty acid synthesis system (FASs) from Jatropha curcas (JC). The genetic combination was designed to control the product spectrum towards optimum MCLA. Decanoic, lauric and myristic acid were produced at concentrations of 0.011, 0.093 and 1.657mg/g, respectively. The concentration of final products nonane, undecane and tridecane were 0.00062mg/g, 0.0052mg/g, and 0.249mg/g respectively. Thioesterase from UC controlled the fatty acid chain length in a range of 10-14 carbons and the ACP gene with whole FASs from JC significantly increased the production of MCLA. Copyright © 2017 Elsevier Ltd. All rights reserved.

OPTIMIZATION OF ALKALINE Α-AMYLASE PRODUCTION BY THERMOPHILIC BACILL US SUBTILIS.

PubMed

Al-Johani, Nuha Bakeet; Al-Seeni, Madeha N; Ahmed, Youssri Mohamed

2017-01-01

Starch-degrading amylase enzyme is important in biotechnological applications as food, fermentation, textile, paper and pharmaceutical purposes. The aim of current study to isolate alkaline thermostable α-amylase bacteria and then study the composition of medium and culture conditions to optimize cells growth and a-amylase production. Thermophilic amylase producing bacterium was isolated from local hot water-springs in Gazan city Saudi Arabia. Phylogenetic analysis of 16 S rRNA sequence for the strain revealed that the strain have the same sequence of Bacillus subtilis . Maximum amylase production was observed, when B. subtilis cultured in medium containing starch at concentration 0.5%, and 10 g/L peptones as nitrogen source at pH 8.5 in when it was incubated for 48 h at 45°C. An amylase-producing bacterium were isolated from hot-spring water and was identified as B. subtilis . Amylase produced from B.subtilis had optimum temperature 45°C and pH 8.5 in shaking media.

Preparation of non-aggregating aqueous fullerenes in highly saline solutions with a biocompatible non-ionic polymer

NASA Astrophysics Data System (ADS)

Aich, Nirupam; Boateng, Linkel K.; Flora, Joseph R. V.; Saleh, Navid B.

2013-10-01

Size-tunable stable aqueous fullerenes were prepared with different concentrations of biocompatible block-copolymer pluronic (PA) F-127, ranging from 0.001% to 1% (w/v). Size uniformity increased with the increase in PA concentration, yielding optimum 58.8 ± 5.6 and 61.8 ± 5.6 nm nC60s and nC70s, respectively (0.10%w/v PA), as observed using a dynamic light scattering technique. Fullerene aqueous suspensions also manifested enhanced stability in saline solution, Dulbecco’s modified Eagle medium (DMEM), and Roswell Park Memorial Institute (RPMI) culture medium. Transmission electron microscopy was performed to elaborate on the morphology and size specificity of fullerene clusters. Physicochemical characterizations of the suspended fullerenes were performed through UV-vis spectroscopy and electrophoretic mobility measurements. PA molecules showed size restriction by encasement, as observed via molecular dynamics simulations. Such solubilization with controllable size and non-aggregating behavior can facilitate application enhancement and mechanistic environmental and toxicological studies of size-specific fullerenes.

[Gastric volvulus in children: five case reports].

PubMed

Ksia, A; Haggui, B; Mosbahi, S; Maazoun, K; Sahnoun, L; Chahed, J; Krichene, I; Mekki, M; Belghith, M; Nouri, A

2014-12-01

Gastric volvulus is an abnormal rotation of all or a part of the stomach around one of its axes. It is a rare cause of intestinal obstruction in children. This anomaly can be primary, due to abnormalities of the gastric ligaments, or secondary to other congenital malformations. We report on the cases of five children treated between January 1994 and December 2011, four boys and one girl, with a medium age of 7 months. Diagnosis was based on clinical features, particularly in the upper gastrointestinal Rx contrast study, which confirmed the diagnosis. Four out of the five children underwent laparoscopic surgery with fixation of the stomach. A diaphragmatic hernia was associated in one case. Antireflux surgery was performed in three cases, and a diaphragmatic defect was closed in one case. The follow-up was uneventful after a medium period of 7 years. good knowledge of this anomaly is the guarantee of early diagnosis and optimum treatment to ameliorate the prognosis. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Removal efficiency of Cr6+ by indigenous Pichia sp. isolated from textile factory effluent.

PubMed

Fernández, Pablo M; Martorell, María M; Fariña, Julia I; Figueroa, Lucia I C

2012-01-01

Resistance of the indigenous strains P. jadinii M9 and P. anomala M10, to high Cr(6+) concentrations and their ability to reduce chromium in culture medium was studied. The isolates were able to tolerate chromium concentrations up to 104 μg mL(-1). Growth and reduction of Cr(6+) were dependent on incubation temperature, agitation, Cr(6+) concentration, and pH. Thus, in both studied strains the chromium removal was increased at 30 °C with agitation. The optimum pH was different, with values of pH 3.0 and pH 7.0 in the case of P. anomala M10 and pH 7.0 using P. jadinii M9. Chromate reduction occurred both in intact cells (grown in culture medium) as well as in cell-free extracts. Chromate reductase activity could be related to cytosolic or membrane-associated proteins. The presence of a chromate reductase activity points out a possible role of an enzyme in Cr(6+) reduction.

Removal Efficiency of Cr6+ by Indigenous Pichia sp. Isolated from Textile Factory Effluent

PubMed Central

Fernández, Pablo M.; Martorell, María M.; Fariña, Julia I.; Figueroa, Lucia I. C.

2012-01-01

Resistance of the indigenous strains P. jadinii M9 and P. anomala M10, to high Cr6+ concentrations and their ability to reduce chromium in culture medium was studied. The isolates were able to tolerate chromium concentrations up to 104 μg mL−1. Growth and reduction of Cr6+ were dependent on incubation temperature, agitation, Cr6+ concentration, and pH. Thus, in both studied strains the chromium removal was increased at 30°C with agitation. The optimum pH was different, with values of pH 3.0 and pH 7.0 in the case of P. anomala M10 and pH 7.0 using P. jadinii M9. Chromate reduction occurred both in intact cells (grown in culture medium) as well as in cell-free extracts. Chromate reductase activity could be related to cytosolic or membrane-associated proteins. The presence of a chromate reductase activity points out a possible role of an enzyme in Cr6+ reduction. PMID:22629188

Antioxidative effect of lipophilized caffeic acid in fish oil enriched mayonnaise and milk.

PubMed

Alemán, Mercedes; Bou, Ricard; Guardiola, Francesc; Durand, Erwann; Villeneuve, Pierre; Jacobsen, Charlotte; Sørensen, Ann-Dorit Moltke

2015-01-15

The antioxidative effect of lipophilized caffeic acid was assessed in two different fish oil enriched food products: mayonnaise and milk. In both emulsion systems, caffeic acid esterified with fatty alcohols of different chain lengths (C1-C20) were better antioxidants than the original phenolic compound. The optimal chain length with respect to protection against oxidation was, however, different for the two food systems. Fish oil enriched mayonnaise with caffeates of medium alkyl chain length (butyl, octyl and dodecyl) added resulted in a better oxidative stability than caffeates with shorter (methyl) or longer (octadecyl) alkyl chains. Whereas in fish oil enriched milk emulsions the most effective caffeates were those with shorter alkyl chains (methyl and butyl) rather than the ones with medium and long chains (octyl, dodecyl, hexadecyl and eicosyl). These results demonstrate that there might be an optimum alkyl chain length for each phenolipid in each type of emulsion systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Filterability of the suspension from germanium precipitation with aqueous tannin extract solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mikhailov, N.F.; Petropol'skii, V.M.; Semenenko, L.E.

1978-01-01

We have already described the use of a neutral aqueous solution of tannin extract to recover germanium from collecting-mains liquor in coking plants. Further pilot commercial trials have encountered problems with the poor filterability of the precipitate obtained when germanium is extracted with this reagent in alkaline media. There are published references to the colloidal nature of the precipitated tannin-germanium complex. It is also known that the alkalinity of the medium influences the degree of association in colloidal systems to a marked extent. Accordingly, special research was needed to establish the relationship between the pH of the precipitation medium andmore » the filterability of the germanium deposit. Samples of collecting-mains liquor were taken from one of the southern coking plants to determine the optimum filtration behavior. The collecting-mains liquor should first be purged of volatile ammonia and then adjusted to pH = 6.5 to 6.7 for precipitation.« less

Production, thermal stability and immobilisation of inulinase from Fusarium oxysporum.

PubMed

Gupta, A K; Rathore, P; Kaur, N; Singh, R

1990-01-01

Fusarium oxysporum produced maximum extracellular inulinase after 9 days of its growth at 25 degrees C on a medium (pH 5.5) containing 3% fructan and 0.2% sodium nitrate. The level of this enzyme decreased on the addition of either glucose, fructose, galactose or sucrose to F. oxysporum already growing on a fructan-containing medium. A significant increase in invertase production which resulted in an increase of the invertase/inulinase (S/I) ratio, was observed on addition of inulin to this fungus growing on other carbon sources. Glycerol (10%) gave better protection to inulinase against thermal denaturation at 50 degrees C compared to ethylene glycol and sorbitol. Inulinase immobilised in polyacrylamide gel retained 45% of its original activity. The immobilised enzyme showed a higher optimum temperature (45 degrees C) compared to free enzyme (37 degrees C). The immobilised enzyme after storage at 25 degrees C for 96 h showed 58% activity. Thermal stability of entrapped inulinase increased in the presence of inulin.

Security writing application of thermal decomposition assisted NaYF4:Er3+/Yb3+ upconversion phosphor

NASA Astrophysics Data System (ADS)

Kumar, A.; Tiwari, S. P.; Esteves da Silva, Joaquim C. G.; Kumar, K.

2018-07-01

The authors have synthesized water-dispersible NaYF4:Er3+/Yb3+ upconversion particles via a thermal decomposition route and optimized the green upconversion emission through a concentration variation of the Yb3+ sensitizer. The prepared particles were found to be ellipsoid in shape having an average particle dimension of 600  ×  150 nm. It is observed that the sample with 18 mmol% Yb3+ ion concentration and 2 mmol% Er3+ ion gives optimum upconversion intensity in the green region under 980 nm excitation. Colloidal dispersibility of the sample in different solvents was checked and hexane was found to be the best medium for the prepared particles. The particle size of the sample was found to be suitable for the preparation of colloidal ink and security writing on a plain sheet of paper. This was demonstrated successfully using ink prepared in polyvinyl chloride gold medium.

Comparative study of radiation emission without and with target in a 2.2 kJ plasma focus device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Muhammad Zubair, E-mail: mzubairkhan-um76@yahoo.com; Ling, Yap Seong; San, Wong Chiow

The radiation emission in a 2.2 kJ Mather-type dense plasma focus device is investigated using a five channel BPX65 PIN diode spectrometer. Estimated X-ray associated with the hollow anode without and with target in Argon gas medium is compared. At optimum conditions, the radiation emission from the system is found to be strongly influenced with target in hollow anode and the filling gas pressure. The maximum X-ray yield in 4π sr was obtained in case of hollow anode in argon gas medium with target 'Lead' due to interaction of electron beam. Results indicated that an appropriate design of hollow anodemore » with target could enhance the radiation emission by more intense interaction of expected electron beam with target. The outcomes are helpful in designing a plasma focus with enhanced X-ray radiation with improved shot to shot reproducibility in plasma focus device.« less

Improving of lipid productivity of the oleaginous microalgae Chlorella pyrenoidosa via atmospheric and room temperature plasma (ARTP).

PubMed

Cao, Song; Zhou, Xu; Jin, Wenbiao; Wang, Feng; Tu, Renjie; Han, Songfang; Chen, Hongyi; Chen, Chuan; Xie, Guo-Jun; Ma, Fang

2017-11-01

In this study, an efficient screening program was established with ARTP. Five strains from oleaginous microalgae Chlorella pyrenoidosa were screened from mutant library after mutagenizing by ARTP. Among them, the optimal mutant strain was named as II-H6. In the BG11 medium, the OD 680 of II-H6 in stationary phase were increased by 32.08% than the original strain. Meanwhile, compared with the original strain, the dry weight and lipid productivity of II-H6 were increased by 22.07% and 16.85%, respectively. II-H6 showed a good genetic stability in BG11 medium and the optimum growth temperature and pH were 33°C and 9.0. 18S gene fragment length of II-H6 strain were 1886bp. Analysis of the gene fragment showed that the II-H6 strain had a close relationship to the original strain, and it belonged to the mutation within the genus Chlorella. Copyright © 2017 Elsevier Ltd. All rights reserved.

Handling Technique Development of Live Carp, Cyprinus carpio, In Cold Dry Styrofoam Box

NASA Astrophysics Data System (ADS)

Ketut Suwetja, I.; Salindeho, Netty; Gede Prabawa Suwetja, I.

2017-10-01

The study focused on several following aspects: temperature and time optimation for fainting, holding media optimation, temperature and time optimation for recovery, and their correlation with mortality rate of carp, Cyprinus carpio. Fainting occurred at the optimum time of 11 minutes and 03 seconds, temperature of 8°C, and holding time of 6 hours. Holding medium was rice husk. The fastest consciousness of the fish was found in 6 volt-aerated water medium. The fish consciousness after 6 hours of storing in the rice husk at the fainting temperature of 8°C was found faster (p < 0.05), 11 minutes and 15 seconds, than that added with 0.02% of clove oil, 25 minutes and 16 seconds. The fish mortality rate after 6 hours of storage in the rice husk at fainting temperature of 8°C was lower (p < 0.05), 46%, than that with addition of 0.02% of clove oil, 75%.

Production of an antibiotic enterocin from a marine actinobacteria strain H1003 by metal-stress technique with enhanced enrichment using response surface methodology.

PubMed

Hassan, Syed Shamsul; Shah, Sayed Asmat Ali; Pan, Chengqian; Fu, Leilei; Cao, Xun; Shi, Yutong; Wu, Xiaodan; Wang, Kuiwu; Wu, Bin

2017-01-01

Elicitation by chemical means including heavy metals is one of a new technique for drug discoveries. In this research, the effect of heavy metals on marine actinobacteria Streptomyces sp. H-1003 for the production of enterocin, with a strong broad spectrum activity, along optimized fermented medium was firstly investigated. The optimum metal stress conditions consisted of culturing marine actinobacteria strain H-1003 with addition of cobalt ions at 2mM in optimized Gause's medium having starch at 20mg/L for 10 days at 180 revolution/min. Under these conditions, enterocin production was enhanced with a value of 5.33mg/L, which was totally absent at the normal culture of strain H-1003 and much higher than other tested metal-stress conditions. This work triumphantly announced a prodigious effect of heavy metals on marine actinobacteria with fringe benefits as a key tool of enterocin production.

Development of a novel amide-silica stationary phase for the reversed-phase HPLC separation of different classes of phytohormones.

PubMed

Aral, Hayriye; Aral, Tarık; Ziyadanoğulları, Berrin; Ziyadanoğulları, Recep

2013-11-15

A novel amide-bonded silica stationary phase was prepared starting from N-Boc-phenylalanine, cyclohexylamine and spherical silica gel (4 µm, 60 Å). The amide ligand was synthesised with high yield. The resulting amide bonded stationary phase was characterised by SEM, IR and elemental analysis. The resulting selector bearing a polar amide group is used for the reversed-phase chromatography separation of different classes of thirteen phytohormones (plant hormones). The chromatographic behaviours of these analytes on the amide-silica stationary phase were compared with those of RP-C18 column under same conditions. The effects of different separation conditions, such as mobile phase, pH value, flow rate and temperature, on the separation and retention behaviours of the 13 phytohormones in this system were studied. The optimum separation was achieved using reversed-phase HPLC gradient elution with an aqueous mobile phase containing pH=6.85 potassium phosphate buffer (20 mM) and acetonitrile with a 22 °C column temperature. Under these experimental conditions, the 12 phytohormones could be separated and detected at 230 or 270 nm within 26 min. Copyright © 2013 Elsevier B.V. All rights reserved.

Chiral separation of phenylalanine and tryptophan by capillary electrophoresis using a mixture of β-CD and chiral ionic liquid ([TBA] [L-ASP]) as selectors.

PubMed

Yujiao, Wu; Guoyan, Wang; Wenyan, Zhao; Hongfen, Zhang; Huanwang, Jing; Anjia, Chen

2014-05-01

In this paper, a simple, effective and green capillary electrophoresis separation and detection method was developed for the quantification of underivatized amino acids (dl-phenylalanine; dl-tryptophan) using β-Cyclodextrin and chiral ionic liquid ([TBA] [l-ASP]) as selectors. Separation parameters such as buffer concentrations, pH, β-CD and chiral ionic liquid concentrations and separation voltage were investigated for the enantioseparation in order to achieve the maximum possible resolution. A good separation was achieved in a background electrolyte composed of 15 mm sodium tetraborate, 5 mm β-CD and 4 mm chiral ionic liquid at pH 9.5, and an applied voltage of 10 kV. Under optimum conditions, linearity was achieved within concentration ranges from 0.08 to 10 µg/mL for the analytes with correlation coefficients from 0.9956 to 0.9998, and the analytes were separated in less than 6 min with efficiencies up to 970,000 plates/m. The proposed method was successfully applied to the determination of amino acid enantiomers in compound amino acids injections, such as 18AA-I, 18AA-II and 3AA.

Unmanned. Evaluation of Bauer High Pressure Breathing Air P-5 Purification System

DTIC Science & Technology

1991-08-01

suspended in the compressed air . The molecular sieve is made to adsorb oil and water vapors. The second cylinder uses cartridge No. 058825 and is a...during compressor start up. This provides for optimum filtering, moisture separation and prevents compressed air return from the charged air storage...reciprocating, air -cooled unit. The compressor is rated to deliver 20 cfm of free air compressed to 5000 psig. - .. .. . .. ’,= .• .. . .. . -. . I

Hydrolyses of alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester.

PubMed

Kirkeby, S; Moe, D

1983-01-01

Using simultaneous coupling azo dye techniques kidney enzymes active against alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester are characterized. The enzymes show identical distribution in the section. The banding patterns in zymograms are the same after incubation with the different substrates. The enzymes might, however, be separated by difference in pH optimum, initial velocity and sensitivity to inhibitors and activators.

Foam separation of Rhodamine-G and Evans Blue using a simple separatory bottle system.

PubMed

Dasarathy, Dhweeja; Ito, Yoichiro

2017-09-29

A simple separatory glass bottle was used to improve separation effectiveness and cost efficiency while simultaneously creating a simpler system for separating biological compounds. Additionally, it was important to develop a scalable separation method so this would be applicable to both analytical and preparative separations. Compared to conventional foam separation methods, this method easily forms stable dry foam which ensures high purity of yielded fractions. A negatively charged surfactant, sodium dodecyl sulfate (SDS), was used as the ligand to carry a positively charged Rhodamine-G, leaving a negatively charged Evans Blue in the bottle. The performance of the separatory bottle was tested for separating Rhodamine-G from Evans Blue with sample sizes ranged from 1 to 12mg in preparative separations and 1-20μg in analytical separations under optimum conditions. These conditions including N 2 gas pressure, spinning speed of contents with a magnetic stirrer, concentration of the ligand, volume of the solvent, and concentration of the sample, were all modified and optimized. Based on the calculations at their peak absorbances, Rhodamine-G and Evans Blue were efficiently separated in times ranging from 1h to 3h, depending on sample volume. Optimal conditions were found to be 60psi N 2 pressure and 2mM SDS for the affinity ligand. This novel separation method will allow for rapid separation of biological compounds while simultaneously being scalable and cost effective. Published by Elsevier B.V.

Metrics for comparing plasma mass filters

NASA Astrophysics Data System (ADS)

Fetterman, Abraham J.; Fisch, Nathaniel J.

2011-10-01

High-throughput mass separation of nuclear waste may be useful for optimal storage, disposal, or environmental remediation. The most dangerous part of nuclear waste is the fission product, which produces most of the heat and medium-term radiation. Plasmas are well-suited to separating nuclear waste because they can separate many different species in a single step. A number of plasma devices have been designed for such mass separation, but there has been no standardized comparison between these devices. We define a standard metric, the separative power per unit volume, and derive it for three different plasma mass filters: the plasma centrifuge, Ohkawa filter, and the magnetic centrifugal mass filter.

Size separation of analytes using monomeric surfactants

DOEpatents

Yeung, Edward S.; Wei, Wei

2005-04-12

A sieving medium for use in the separation of analytes in a sample containing at least one such analyte comprises a monomeric non-ionic surfactant of the of the general formula, B-A, wherein A is a hydrophilic moiety and B is a hydrophobic moiety, present in a solvent at a concentration forming a self-assembled micelle configuration under selected conditions and having an aggregation number providing an equivalent weight capable of effecting the size separation of the sample solution so as to resolve a target analyte(s) in a solution containing the same, the size separation taking place in a chromatography or electrophoresis separation system.

Disk MHD generator study

NASA Technical Reports Server (NTRS)

Retallick, F. D.

1980-01-01

Directly-fired, separately-fired, and oxygen-augmented MHD power plants incorporating a disk geometry for the MHD generator were studied. The base parameters defined for four near-optimum-performance MHD steam power systems of various types are presented. The finally selected systems consisted of (1) two directly fired cases, one at 1920 K (2996F) preheat and the other at 1650 K (2500 F) preheat, (2) a separately-fired case where the air is preheated to the same level as the higher temperature directly-fired cases, and (3) an oxygen augmented case with the same generator inlet temperature of 2839 (4650F) as the high temperature directly-fired and separately-fired cases. Supersonic Mach numbers at the generator inlet, gas inlet swirl, and constant Hall field operation were specified based on disk generator optimization. System pressures were based on optimization of MHD net power. Supercritical reheat stream plants were used in all cases. Open and closed cycle component costs are summarized and compared.

Value contamination avoidance devices

NASA Technical Reports Server (NTRS)

Endicott, D. L.

1975-01-01

Mechanical redesign methods were used to minimize contamination damage of conventional fluid components and a contamination separator device was developed for long term reusable space vehicles. These were incorporated into an existing 50.8 mm poppet valve and tested for damage tolerance in a full size open loop flow system with gaseous and liquid nitrogen. Cyclic and steady flow conditions were tested with particles of 125 to 420 micrometers aluminum oxide dispersed in the test fluids. Nonflow life tests (100,000 cycles) were made with two valve configurations in gaseous hydrogen. The redesigned valve had an acceptable cycle life and improved tolerance to contamination damage when the primary sealing surfaces were coated with thin coatings of hard plastic (Teflon S and Kynar). Analytical studies and flow testing were completed of four different versions of the separator. overall separation efficiencies in the 55-90% range were measured with these non-optimum configurations.

Measurement of dielectric constant of organic solvents by indigenously developed dielectric probe

NASA Astrophysics Data System (ADS)

Keshari, Ajay Kumar; Rao, J. Prabhakar; Rao, C. V. S. Brahmmananda; Ramakrishnan, R.; Ramanarayanan, R. R.

2018-04-01

The extraction, separation and purification of actinides (uranium and plutonium) from various matrices are an important step in nuclear fuel cycle. One of the separation process adopted in an industrial scale is the liquid-liquid extraction or solvent extraction. Liquid-liquid extraction uses a specific ligand/extractant in conjunction with suitable diluent. Solvent extraction or liquid-liquid extraction, involves the partitioning of the solute between two immiscible phases. In most cases, one of the phases is aqueous, and the other one is an organic solvent. The solvent used in solvent extraction should be selective for the metal of interest, it should have optimum distribution ratio, and the loaded metal from the organic phase should be easily stripped under suitable experimental conditions. Some of the important physical properties which are important for the solvent are density, viscosity, phase separation time, interfacial surface tension and the polarity of the extractant.

Immunomagnetic separation for MEMS-based biosensor of waterborne pathogens detection

NASA Astrophysics Data System (ADS)

Guo, Jianjiang; Zhang, Rongbiao

2017-07-01

Rapid isolation and detection of special pathogens present in environmental drinking water is critical for water quality monitoring. Numerical analysis and experimental investigations on immunomagnetic capture and isolation of waterborne pathogens with magnetic nanoparticles (MNPs) in microfluidic channel are performed. A finite-element COMSOL-based model is established to demonstrate the novel method of on-chip capturing pathogens using MNPs together with periodic pulse magnetic field. Simulation results determine the optimum magnetic pole current and switching frequency for magnetic separation. With the magnetic isolation experiment platform built up, as a pathogen example of Escherichia coli O157:H7, the performance of the method is experimentally verified. Both numerical and experimental results are found to agree reasonably well. Results of these investigations show that the capture efficiency of the immunomagnetic separation method is more than 92%, which could be encouraging for the design and optimization of MEMS-based biosensor of waterborne pathogen detection.

Heavy metal removal from aqueous solutions using engineered magnetic biochars derived from waste marine macro-algal biomass.

PubMed

Son, Eun-Bi; Poo, Kyung-Min; Chang, Jae-Soo; Chae, Kyu-Jung

2018-02-15

Despite the excellent sorption ability of biochar for heavy metals, it is difficult to separate and reuse after adsorption when applied to wastewater treatment process. To overcome these drawbacks, we developed an engineered magnetic biochar by pyrolyzing waste marine macro-algae as a feedstock, and we doped iron oxide particles (e.g., magnetite, maghemite) to impart magnetism. The physicochemical characteristics and adsorption properties of the biochar were evaluated. When compared to conventional pinewood sawdust biochar, the waste marine algae-based magnetic biochar exhibited a greater potential to remove heavy metals despite having a lower surface area (0.97m 2 /g for kelp magnetic biochar and 63.33m 2 /g for hijikia magnetic biochar). Although magnetic biochar could be effectively separated from the solution, however, the magnetization of the biochar partially reduced its heavy metal adsorption efficiency due to the biochar's surface pores becoming plugged with iron oxide particles. Therefore, it is vital to determine the optimum amount of iron doping that maximizes the biochar's separation without sacrificing its heavy metal adsorption efficiency. The optimum concentration of the iron loading solution for the magnetic biochar was determined to be 0.025-0.05mol/L. The magnetic biochar's heavy metal adsorption capability is considerably higher than that of other types of biochar reported previously. Further, it demonstrated a high selectivity for copper, showing two-fold greater removal (69.37mg/g for kelp magnetic biochar and 63.52mg/g for hijikia magnetic biochar) than zinc and cadmium. This high heavy metal removal performance can likely be attributed to the abundant presence of various oxygen-containing functional groups (COOH and OH) on the magnetic biochar, which serve as potential adsorption sites for heavy metals. The unique features of its high heavy metal removal performance and easy separation suggest that the magnetic algae biochar can potentially be applied in diverse areas that require biosorbents for pollutant removal. Copyright © 2017 Elsevier B.V. All rights reserved.

Sub-1min separation in sequential injection chromatography for determination of synthetic water-soluble dyes in pharmaceutical formulation.

PubMed

Davletbaeva, Polina; Chocholouš, Petr; Bulatov, Andrey; Šatínský, Dalibor; Solich, Petr

2017-09-05

Sequential Injection Chromatography (SIC) evolved from fast and automated non-separation Sequential Injection Analysis (SIA) into chromatographic separation method for multi-element analysis. However, the speed of the measurement (sample throughput) is due to chromatography significantly reduced. In this paper, a sub-1min separation using medium polar cyano monolithic column (5mm×4.6mm) resulted in fast and green separation with sample throughput comparable with non-separation flow methods The separation of three synthetic water-soluble dyes (sunset yellow FCF, carmoisine and green S) was in a gradient elution mode (0.02% ammonium acetate, pH 6.7 - water) with flow rate of 3.0mLmin -1 corresponding with sample throughput of 30h -1 . Spectrophotometric detection wavelengths were set to 480, 516 and 630nm and 10Hz data collection rate. The performance of the separation was described and discussed (peak capacities 3.48-7.67, peak symmetries 1.72-1.84 and resolutions 1.42-1.88). The method was represented by validation parameters: LODs of 0.15-0.35mgL -1 , LOQs of 0.50-1.25mgL -1 , calibration ranges 0.50-150.00mgL -1 (r>0.998) and repeatability at 10.0mgL -1 of RSD≤0.98% (n=6). The method was used for determination of the dyes in "forest berries" colored pharmaceutical cough-cold formulation. The sample matrix - pharmaceuticals and excipients were not interfering with vis determination because of no retention in the separation column and colorless nature. The results proved the concept of fast and green chromatography approach using very short medium polar monolithic column in SIC. Copyright © 2017 Elsevier B.V. All rights reserved.

[Method of culturing microorganisms at constant concentrations of the nutrient components].

PubMed

Markvichev, N S; Manakov, M N

1985-01-01

A method for batch cultivation of microorganisms in a flow medium is described, characterized by slight changes in concentrations of medium components in time and by the absence of products of vital activity of microorganisms in the fermentation medium. The conditions are achieved due to application of a fermentation installation with a microfiltrative membrane that separates the cells of cultivated microorganisms from the culture fluid and due to increasing the flow rate to a value at which the inlet and outlet concentrations of the medium components are almost equal. The cells of cultivated microorganisms under such conditions remain in the fermentation medium volume. The system was called "Ekostat". If the process is performed in "Ekostat" system, a positive deviation from the logarithmic law is observed for the growth rate of the yeast Candida utilis VSB-651 on ethanol cultivation.

Aerosol mobility size spectrometer

DOEpatents

Wang, Jian; Kulkarni, Pramod

2007-11-20

A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

Organic containment separator

DOEpatents

Del Mar, Peter

1995-01-01

A process of sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium by (a) passing an initial aqueous medium including a minor amount of the organic contaminant through a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit the organic contaminant to adhere to the composite tube, (b) passing a solvent through the composite tube, said solvent capable of separating the adhered organic contaminant from the composite tube. Further, an extraction apparatus for sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium, said apparatus including a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit an organic contaminant contained within an aqueous medium passed therethrough to adhere to the composite tube is disclosed.

Organic contaminant separator

DOEpatents

Mar, Peter D.

1994-01-01

A process of sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium by (a) passing an initial aqueous medium including a minor amount of the organic contaminant through a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit the organic contaminant to adhere to the composite tube, (b) passing a solvent through the composite tube, said solvent capable of separating the adhered organic contaminant from the composite tube. Further, an extraction apparatus for sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium, said apparatus including a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit an organic contaminant contained within an aqueous medium passed therethrough to adhere to the composite tube is disclosed.

Flotation separation of polyvinyl chloride and polyethylene terephthalate plastics combined with surface modification for recycling.

PubMed

Wang, Chongqing; Wang, Hui; Fu, Jiangang; Zhang, Lingling; Luo, Chengcheng; Liu, Younian

2015-11-01

Surface modification with potassium permanganate (KMnO4) solution was developed for separation of polyvinyl chloride (PVC) and polyethylene terephthalate (PET) waste plastics. The floatability of PVC decreases with increasing of KMnO4 concentration, treatment time, temperature and stirring rate, while that of PET is unaffected. Fourier transform infrared (FT-IR) analysis confirms that mechanism of surface modification may be due to oxidization reactions occurred on PVC surface. The optimum conditions are KMnO4 concentration 1.25 mM/L, treatment time 50 min, temperature 60°C, stirring rate 300 r/min, frother concentration 17.5 g/L and flotation time 1 min. PVC and PET with different particle sizes were separated efficiently through two-stage flotation. Additionally, after ultrasonic assisted surface modification, separation of PVC and PET with different mass ratios was obtained efficiently through one-stage flotation. The purity and the recovery of the obtained products after flotation separation are up to 99.30% and 99.73%, respectively. A flotation process was designed for flotation separation of PVC and PET plastics combined with surface modification. This study provides technical insights into physical separation of plastic wastes for recycling industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Design of A Cyclone Separator Using Approximation Method

NASA Astrophysics Data System (ADS)

Sin, Bong-Su; Choi, Ji-Won; Lee, Kwon-Hee

2017-12-01

A Separator is a device installed in industrial applications to separate mixed objects. The separator of interest in this research is a cyclone type, which is used to separate a steam-brine mixture in a geothermal plant. The most important performance of the cyclone separator is the collection efficiency. The collection efficiency in this study is predicted by performing the CFD (Computational Fluid Dynamics) analysis. This research defines six shape design variables to maximize the collection efficiency. Thus, the collection efficiency is set up as the objective function in optimization process. Since the CFD analysis requires a lot of calculation time, it is impossible to obtain the optimal solution by linking the gradient-based optimization algorithm. Thus, two approximation methods are introduced to obtain an optimum design. In this process, an L18 orthogonal array is adopted as a DOE method, and kriging interpolation method is adopted to generate the metamodel for the collection efficiency. Based on the 18 analysis results, the relative importance of each variable to the collection efficiency is obtained through the ANOVA (analysis of variance). The final design is suggested considering the results obtained from two optimization methods. The fluid flow analysis of the cyclone separator is conducted by using the commercial CFD software, ANSYS-CFX.

Study on suitable for regeneration system of genetic transformation of kiwifruit

NASA Astrophysics Data System (ADS)

Yuan, Yun Xiang

2011-02-01

The stems of Actinidia Qinmei were taken as explants and induced callus formation after having gained the aseptic seedling in primary culture successfully, and then the calli were placed on different combinations regeneration medium. The results showed that the induction medium added 1 mg/L 6-BA and 0.1 mg/L NAA was beneficial to the callus induction in dark culture condition. The suitable regeneration medium was MS containing 2.0 mg/L 6BA, 0.1 mg/L NAA and 3% (W/V) sucrose, it could improve obviously the frequency of regenerated shoots. This method separated the callus induction from shoot regeneration and obtained more callus to optimize the regenerated medium, and also was advantageous to Kiwifruit genetic transformation.

Methods of using adsorption media for separating or removing constituents

DOEpatents

Tranter, Troy J [Idaho Falls, ID; Herbst, R Scott [Idaho Falls, ID; Mann, Nicholas R [Blackfoot, ID; Todd, Terry A [Aberdeen, ID

2011-10-25

Methods of using an adsorption medium to remove at least one constituent from a feed stream. The method comprises contacting an adsorption medium with a feed stream comprising at least one constituent and removing the at least one constituent from the feed stream. The adsorption medium comprises a polyacrylonitrile (PAN) matrix and at least one metal hydroxide homogenously dispersed therein. The adsorption medium may comprise from approximately 15 wt % to approximately 90 wt % of the PAN and from approximately 10 wt % to approximately 85 wt % of the at least one metal hydroxide. The at least one metal hydroxide may be selected from the group consisting of ferric hydroxide, zirconium hydroxide, lanthanum hydroxide, cerium hydroxide, titanium hydroxide, copper hydroxide, antimony hydroxide, and molybdenum hydroxide.

Compact cyclone filter train for radiological and hazardous environments

DOEpatents

Bench, T.R.

1998-04-28

A compact cyclone filter train is disclosed for the removal of hazardous and radiological particles from a gaseous fluid medium. This filter train permits a small cyclone separator to be used in a very small space envelope due to the arrangement of the filter housing adjacent to the separator with the cyclone separator and the filters mounted on a plate. The entire unit will have a hoist connection at the center of gravity so that the entire unit including the separator, the filters, and the base can be lifted and repositioned as desired. 3 figs.

On the geometry dependence of differential pathlength factor for near-infrared spectroscopy. I. Steady-state with homogeneous medium

PubMed Central

Piao, Daqing; Barbour, Randall L.; Graber, Harry L.; Lee, Daniel C.

2015-01-01

Abstract. This work analytically examines some dependences of the differential pathlength factor (DPF) for steady-state photon diffusion in a homogeneous medium on the shape, dimension, and absorption and reduced scattering coefficients of the medium. The medium geometries considered include a semi-infinite geometry, an infinite-length cylinder evaluated along the azimuthal direction, and a sphere. Steady-state photon fluence rate in the cylinder and sphere geometries is represented by a form involving the physical source, its image with respect to the associated extrapolated half-plane, and a radius-dependent term, leading to simplified formula for estimating the DPFs. With the source-detector distance and medium optical properties held fixed across all three geometries, and equal radii for the cylinder and sphere, the DPF is the greatest in the semi-infinite and the smallest in the sphere geometry. When compared to the results from finite-element method, the DPFs analytically estimated for 10 to 25 mm source–detector separations on a sphere of 50 mm radius with μa=0.01  mm−1 and μs′=1.0  mm−1 are on average less than 5% different. The approximation for sphere, generally valid for a diameter ≥20 times of the effective attenuation pathlength, may be useful for rapid estimation of DPFs in near-infrared spectroscopy of an infant head and for short source–detector separation. PMID:26465613

Evaluation of different conditions and culture media for the recovery of Aeromonas spp. from water and shellfish samples.

PubMed

Latif-Eugenín, F; Beaz-Hidalgo, R; Figueras, M J

2016-09-01

To perform a comparative study for determining the optimum culture method (direct plating or enrichment) and medium (ampicillin dextrin agar (ADA), starch ampicillin agar (SAA), bile salts irgasan brilliant green modified (BIBG-m)) for recovering Aeromonas species from water and shellfish samples. By direct culture, Aeromonas was detected in 65% (13/20) of the water samples and in 54·5% (6/11) of the shellfish samples. However, when a pre-enrichment step was included, the number of positive water samples increased to 75% (15/20) and the ones of shellfish to 90·1% (10/11). The enriched culture significantly favoured (P < 0·05) the isolation of Aeromonas allosaccharophila from water, Aeromonas salmonicida from shellfish and Aeromonas caviae from both types of samples. The most specific (P < 0·05) culture medium for detecting Aeromonas from water was ADA. However, no differences were observed in the case of shellfish samples (P > 0·05). Isolation of Aeromonas media from water was favoured (P < 0·05) in the ADA medium, while SAA enhanced (P < 0·05) the isolation of Aer. salmonicida from shellfish. The culture method and medium used influenced the recovery of some Aeromonas species from water and shellfish samples. This fact should be considered in future prevalence studies to avoid overestimating the above mentioned Aeromonas species. © 2016 The Society for Applied Microbiology.

Effect of medium components and culture conditions in Bacillus subtilis EA-CB0575 spore production.

PubMed

Posada-Uribe, Luisa F; Romero-Tabarez, Magally; Villegas-Escobar, Valeska

2015-10-01

Bacillus subtilis spores have important biotechnological applications; however, achieving both, high spore cell densities and sporulation efficiencies in fermentation, is poorly reported. In this study, medium components and culture conditions were optimized with different statistical methods to increase spore production of the plant growth promoting rhizobacteria B. subtilis EA-CB0575. Key medium components were determined with Plackett-Burman (PB) design, and the optimum concentration levels of two components (glucose, MgSO4·7H2O) were optimized with a full factorial and central composite design, achieving 1.37 × 10(9) CFU/mL of spore cell density and 93.5 % of sporulation efficiency in shake flask. The optimized medium was used to determine the effect of culture conditions on spore production at bioreactor level, finding that maintaining pH control did not affect significantly spore production, while the interaction of agitation and aeration rates had a significant effect on spore cell density. The overall optimization generated a 17.2-fold increase in spore cell density (8.78 × 10(9) CFU/mL) and 1.9-fold increase in sporulation efficiency (94.2 %) compared to that of PB design. These results indicate the potential of B. subtilis EA-CB0575 to produce both, high spore cell densities and sporulation efficiencies, with very low nutrient requirements and short incubation period which can represent savings of process production.

Investigating the Effect of Compaction Characteristics on the Erodibility of Cohesive Soils Using the JET Method

NASA Astrophysics Data System (ADS)

Asghari Tabrizi, A.; LaRocque, L. A.; Chaudhry, M.; Imran, J.

2013-12-01

Several flood disasters occur every year all over the world, mostly due to levee and dam failure which result in human fatalities as well as devastating economic damages. To model and predict earthen embankment failures for the preparation of emergency action plans and risk assessments, the soil erodibility by flowing water is an essential parameter. The determination of erodibility becomes even more complicated for cohesive soils because of the large number of parameters controlling their erosion behavior (e.g. clay content, plasticity, compaction effort, compaction water content) and the difficulty of estimating these parameters. In this study the effect of the compaction energy and compaction water content on the erodibility of a sandy loam soil was assessed. Soil samples were prepared in a standard diameter compaction mold, 101.6 mm, for three levels of compaction effort and water content (i.e. low, medium, and high) with two replications for each case (18 tests total) and examined using the jet erosion test (JET). Observations from qualitative and statistical analyses of the data are: 1) a wide range of erodibility, from very erodible to very resistant, was produced by changes in the compaction characteristics; 2) for a given compaction energy, the erosion resistance based on the detachment rate coefficient kd tends to become minimum near the optimum compaction water content. On the dry side of optimum compaction water content, kd decreases with steep gradients by increasing the water content, while it increases with a flatter gradient on the wet side; 3) At a given water content, the soil erosion resistance increases with compaction efforts; 4) compaction water content influences soil erosibility more than compaction energy, especially on the dry side of the optimum compaction water content; and 5) for a given compaction effort, the critical shear stress increases with water content up to an optimum water content and then it decreases which is in consistent with the kd trends.

Optimization of cultural conditions for biosurfactant production by Pleurotus djamor in solid state fermentation.

PubMed

Velioglu, Zulfiye; Ozturk Urek, Raziye

2015-11-01

Being eco-friendly, less toxic, more biodegradable and biocompatible, biological surfactants have higher activity and stability compared to synthetic ones. In spite of the fact that there are abundant benefits of biosurfactants over the synthetic congeners, the problem related with the economical and large scale production proceeds. The utilization of several industrial wastes in the production media as substrates reduces the production cost. This current study aims optimization of biosurfactant production conditions by Pleurotus djamor, grown on sunflower seed shell, grape wastes or potato peels as renewable cheap substrates in solid state fermentation. After determination of the best substrate for biosurfactant production, we indicate optimum size and amount of solid substrate, volume of medium, temperature, pH and Fe(2+) concentrations on biosurfactant production. In optimum conditions, by reducing water surface tension to 28.82 ± 0.3 mN/m and having oil displacement diameter of 3.9 ± 0.3 cm, 10.205 ± 0.5 g/l biosurfactant was produced. Moreover, chemical composition of biosurfactant produced in optimum condition was determined by FTIR. Lastly, laboratory's large-scale production was carried out in optimum conditions in a tray bioreactor designed by us and 8.9 ± 0.5 g/l biosurfactant was produced with a significant surface activity (37.74 ± 0.3 mN/m). With its economical suggestions and applicability of laboratory's large-scale production, this work indicates the possibility of using low cost agro-industrial wastes as renewable substrates for biosurfactant production. Therefore, using economically produced biosurfactant will reduce cost in several applications such as bioremediation, oil recovery and biodegradation of toxic chemicals. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.