Optimization of carrier multiplication for more effcient solar cells: the case of Sn quantum dots.

PubMed

Allan, Guy; Delerue, Christophe

2011-09-27

We present calculations of impact ionization rates, carrier multiplication yields, and solar-power conversion efficiencies in solar cells based on quantum dots (QDs) of a semimetal, α-Sn. Using these results and previous ones on PbSe and PbS QDs, we discuss a strategy to select QDs with the highest carrier multiplication rate for more efficient solar cells. We suggest using QDs of materials with a close to zero band gap and a high multiplicity of the bands in order to favor the relaxation of photoexcited carriers by impact ionization. Even in that case, the improvement of the maximum solar-power conversion efficiency appears to be a challenging task. © 2011 American Chemical Society

Fermentation of sugarcane bagasse and chicken manure to calcium carboxylates under thermophilic conditions.

PubMed

Fu, Zhihong; Holtzapple, Mark T

2010-09-01

Sugarcane bagasse and chicken manure were anaerobically fermented to carboxylic acids using a mixed culture of marine microorganisms at 55 degrees C. Using the MixAlco process--an example of consolidated bioprocessing--the resulting carboxylate salts can be converted to mixed alcohol fuels or gasoline. To enhance digestibility, sugarcane bagasse was lime pretreated with 0.1 g Ca(OH)(2)/g dry biomass at 100 degrees C for 2 h. Four-stage countercurrent fermentation of 80% sugarcane bagasse/20% chicken manure was performed at various volatile solids (VS) loading rates and liquid residence times. Calcium carbonate was used as a buffer during fermentation. The highest acid productivity of 0.79 g/(L day) occurred at a total acid concentration of 21.5 g/L. The highest conversion (0.59 g VS digested/g VS fed) and yield (0.18 g total acids/g VS fed) occurred at a total acid concentration of 15.5 g/L. The continuum particle distribution model (CPDM) predicted the experimental total acid concentrations and conversions at an average error of 10.14% and 12.68%, respectively. CPDM optimizations show that high conversion (>80%) and total acid concentration of 21.3 g/L are possible with 300 g substrate/(L liquid), 30 days liquid residence time, and 3 g/(L day) solid loading rate. Thermophilic fermentation has a higher acetate content (approximately 63 wt%) than mesophilic fermentation (approximately 39 wt%).

Catalytical Conversion of Carbohydrates into Lactic Acid via Hydrothermal Reaction

NASA Astrophysics Data System (ADS)

Wei, Zhen; Jin, Fangming; Zhang, Guangyi; Zhang, Shiping; Yao, Guodong

2010-11-01

This paper focuses on catalytical conversion of carbohydrates into lactic acid, under the hydrothermal conditions, which may have a promising future for its high speediness and effectiveness. The catalysis of ZnO was investigated to improve the lactic acid yields. The results showed that the lactic acid yields increased immensely by the addition of ZnO. The effects of the reaction time and the addition amount of ZnO on the conversion of carbohydrates to lactic acid were studied. The highest lactic acid yields reached up to 28% starting from glucose after the reaction time of 60 s under the conditions of 0.2 mmol ZnO, 300° C, the filling rate of 35%, and over 30% starting from fructose at the same temperature and filling rate when the reaction time of 40 s and 2.0 mmol ZnO were employed. The collaborative effects of ZnO and NaOH used as the catalysts together at the same time were also studied. Furthermore, the catalytic mechanism of ZnO in the hydrothermal conversion of carbohydrates into lactic acid was discussed.

Rates and Predictors of Conversion to Schizophrenia or Bipolar Disorder Following Substance-Induced Psychosis.

PubMed

Starzer, Marie Stefanie Kejser; Nordentoft, Merete; Hjorthøj, Carsten

2018-04-01

The authors investigated the rates of conversion to schizophrenia and bipolar disorder after a substance-induced psychosis, as well as risk factors for conversion. All patient information was extracted from the Danish Civil Registration System and the Psychiatric Central Research Register. The study population included all persons who received a diagnosis of substance-induced psychosis between 1994 and 2014 (N=6,788); patients were followed until first occurrence of schizophrenia or bipolar disorder or until death, emigration, or August 2014. The Kaplan-Meier method was used to obtain cumulative probabilities for the conversion from a substance-induced psychosis to schizophrenia or bipolar disorder. Cox proportional hazards regression models were used to calculate hazard ratios for all covariates. Overall, 32.2% (95% CI=29.7-34.9) of patients with a substance-induced psychosis converted to either bipolar or schizophrenia-spectrum disorders. The highest conversion rate was found for cannabis-induced psychosis, with 47.4% (95% CI=42.7-52.3) converting to either schizophrenia or bipolar disorder. Young age was associated with a higher risk of converting to schizophrenia. Self-harm after a substance-induced psychosis was significantly linked to a higher risk of converting to both schizophrenia and bipolar disorder. Half the cases of conversion to schizophrenia occurred within 3.1 years after a substance-induced psychosis, and half the cases of conversion to bipolar disorder occurred within 4.4 years. Substance-induced psychosis is strongly associated with the development of severe mental illness, and a long follow-up period is needed to identify the majority of cases.

Direct-Write Fabrication of Cellulose Nano-Structures via Focused Electron Beam Induced Nanosynthesis

PubMed Central

Ganner, Thomas; Sattelkow, Jürgen; Rumpf, Bernhard; Eibinger, Manuel; Reishofer, David; Winkler, Robert; Nidetzky, Bernd; Spirk, Stefan; Plank, Harald

2016-01-01

In many areas of science and technology, patterned films and surfaces play a key role in engineering and development of advanced materials. Here, we introduce a new generic technique for the fabrication of polysaccharide nano-structures via focused electron beam induced conversion (FEBIC). For the proof of principle, organosoluble trimethylsilyl-cellulose (TMSC) thin films have been deposited by spin coating on SiO2 / Si and exposed to a nano-sized electron beam. It turns out that in the exposed areas an electron induced desilylation reaction takes place converting soluble TMSC to rather insoluble cellulose. After removal of the unexposed TMSC areas, structured cellulose patterns remain on the surface with FWHM line widths down to 70 nm. Systematic FEBIC parameter sweeps reveal a generally electron dose dependent behavior with three working regimes: incomplete conversion, ideal doses and over exposure. Direct (FT-IR) and indirect chemical analyses (enzymatic degradation) confirmed the cellulosic character of ideally converted areas. These investigations are complemented by a theoretical model which suggests a two-step reaction process by means of TMSC → cellulose and cellulose → non-cellulose material conversion in excellent agreement with experimental data. The extracted, individual reaction rates allowed the derivation of design rules for FEBIC parameters towards highest conversion efficiencies and highest lateral resolution. PMID:27585861

Determining Aliasing in Isolated Signal Conditioning Modules

NASA Technical Reports Server (NTRS)

2009-01-01

The basic concept of aliasing is this: Converting analog data into digital data requires sampling the signal at a specific rate, known as the sampling frequency. The result of this conversion process is a new function, which is a sequence of digital samples. This new function has a frequency spectrum, which contains all the frequency components of the original signal. The Fourier transform mathematics of this process show that the frequency spectrum of the sequence of digital samples consists of the original signal s frequency spectrum plus the spectrum shifted by all the harmonics of the sampling frequency. If the original analog signal is sampled in the conversion process at a minimum of twice the highest frequency component contained in the analog signal, and if the reconstruction process is limited to the highest frequency of the original signal, then the reconstructed signal accurately duplicates the original analog signal. It is this process that can give birth to aliasing.

Wetland features and landscape context predict the risk of wetland habitat loss

Treesearch

Kevin J. Gutzwiller; Curtis H. Flather

2011-01-01

Wetlands generally provide significant ecosystem services and function as important harbors of biodiversity. To ensure that these habitats are conserved, an efficient means of identifying wetlands at risk of conversion is needed, especially in the southern United States where the rate of wetland loss has been highest in recent decades. We used multivariate adaptive...

Worldwide prevalence and incidence of osteoporotic vertebral fractures.

PubMed

Ballane, G; Cauley, J A; Luckey, M M; El-Hajj Fuleihan, G

2017-05-01

We investigated the prevalence and incidence of vertebral fractures worldwide. We used a systematic Medline search current to 2015 and updated as per authors' libraries. A total of 62 articles of fair to good quality and comparable methods for vertebral fracture identification were considered. The prevalence of morphometric vertebral fractures in European women is highest in Scandinavia (26%) and lowest in Eastern Europe (18%). Prevalence rates in North America (NA) for White women ≥50 are 20-24%, with a White/Black ratio of 1.6. Rates in women ≥50 years in Latin America are overall lower than Europe and NA (11-19%). In Asia, rates in women above ≥65 are highest in Japan (24%), lowest in Indonesia (9%), and in the Middle East, Lebanon, rates are 20%. The highest-lowest ratio between countries, within and across continents, varied from 1.4-2.6. Incidence data is less abundant and more heterogeneous. Age-standardized rates in studies combining hospitalized and ambulatory vertebral fractures are highest in South Korea, USA, and Hong Kong and lowest in the UK. Neither a North-South gradient nor a relation to urbanization is evident. Conversely, the incidence of hospitalized vertebral fractures in European patients ≥50 shows a North-South gradient with 3-3.7-fold variability. In the USA, rates in Whites are approximately 4-fold higher than in Blacks. Vertebral fractures variation worldwide is lower than observed with hip fractures, and some of highest rates are unexpectedly from Asia. Better quality representative studies are needed. We investigate the occurrence of vertebral fractures, worldwide, using published data current until the present. Worldwide, the variation in vertebral fractures is lower than observed for hip fractures. Some of the highest rates are from North America and unexpectedly Asia. The highest-lowest ratio between countries, within and across continents, varied from 1.4-2.6. Better quality representative data is needed.

Children’s Empathy Responses and their Understanding of Mother’s Emotions

PubMed Central

Tully, Erin C.; Donohue, Meghan Rose; Garcia, Sarah E.

2014-01-01

This study investigated children’s empathic responses to their mother’s distress to provide insight about child factors that contribute to parental socialization of emotions. Four- to six-year-old children (N=82) observed their mother’s sadness and anger during a simulated emotional phone conversation. Children’s facial negative affect was rated and their heart rate variability was recorded during the conversation, and their emotion understanding of the conversation was measured through their use of negative emotion words and perspective-taking themes (i.e., discussing the causes or resolution of mother’s emotions) in narrative accounts of the conversation. There were positive quadratic relationships between HRV and ratings of facial affect, narrative references to mother’s negative emotions, and perspective-taking themes. High and low HRV were associated with high facial negative affect, suggesting well-regulated sympathy and poorly regulated personal distress empathic responses, respectively. Moderate HRV was associated with low facial negative affect, suggesting minimal empathic engagement. High and low HRV were associated with the highest probabilities of both emotion understanding indicators, suggesting both sympathy and personal distress responses to mother’s distress facilitate understanding of mother’s emotions. Personal distress may motivate attempts to understand mother’s emotions as a self-soothing strategy, whereas sympathy-related attempts to understand may be motivated by altruism. PMID:24650197

Children's empathy responses and their understanding of mother's emotions.

PubMed

Tully, Erin C; Donohue, Meghan Rose; Garcia, Sarah E

2015-01-01

This study investigated children's empathic responses to their mother's distress to provide insight about child factors that contribute to parental socialisation of emotions. Four- to six-year-old children (N = 82) observed their mother's sadness and anger during a simulated emotional phone conversation. Children's facial negative affect was rated and their heart rate variability (HRV) was recorded during the conversation, and their emotion understanding of the conversation was measured through their use of negative emotion words and perspective-taking themes (i.e., discussing the causes or resolution of mother's emotions) in narrative accounts of the conversation. There were positive quadratic relationships between HRV and ratings of facial affect, narrative references to mother's negative emotions and perspective-taking themes. High and low HRV was associated with high facial negative affect, suggesting well-regulated sympathy and poorly regulated personal distress empathic responses, respectively. Moderate HRV was associated with low facial negative affect, suggesting minimal empathic engagement. High and low HRV were associated with the highest probabilities of both emotion understanding indicators, suggesting both sympathy and personal distress responses to mother's distress facilitate understanding of mother's emotions. Personal distress may motivate attempts to understand mother's emotions as a self-soothing strategy, whereas sympathy-related attempts to understand may be motivated by altruism.

Lipase-catalyzed transesterification of soybean oil and phytosterol in supercritical CO2.

PubMed

Hu, Lizhi; Llibin, Sun; Li, Jun; Qi, Liangjun; Zhang, Xu; Yu, Dianyu; Walid, Elfalleh; Jiang, Lianzhou

2015-12-01

The transesterification of phytosterol and soybean oil was performed using Novozym 435 in supercritical carbon dioxide (SC-CO2). The transesterification reaction was conducted in soybean oil containing 5-25% phytosterol at 55-95 °C and free-water solvent. The effects of temperature, reaction time, phytosterol concentration, lipase dosage and reaction pressure on the conversion rate of transesterification were investigated. The optimal reaction conditions were the reaction temperature (85 °C), reaction time (1 h), phytosterol concentration (5%), reaction pressure (8 Mpa) and lipase dosage (1%). The highest conversion rate of 92% could be achieved under the optimum conditions. Compared with the method of lipase-catalyzed transesterification of phytosterol and soybean oil at normal pressure, the transesterification in SC-CO2 reduced significantly the reaction temperature and reaction time.

Optimization of lipase-catalyzed synthesis of ginsenoside Rb1 esters using response surface methodology.

PubMed

Hu, Jiang-Ning; Lee, Jeung-Hee; Zhu, Xue-Mei; Shin, Jung-Ah; Adhikari, Prakash; Kim, Jae-Kyung; Lee, Ki-Teak

2008-11-26

In the lipase (Novozyme 435)-catalyzed synthesis of ginsenoside Rb1 esters, different acyl donors were found to affect not only the degree of conversion but also the regioselectivity. The reaction of acyl donors with short carbon chain was more effective, showing higher conversion than those with long carbon chain. Among the three solvent systems, the reaction in tert-amyl alcohol showed the highest conversion rate, while the reaction in the mixed solvent of t-BuOH and pyridine (1:1) had the lowest conversion rate. To allow the increase of GRb1 lipophilicity, we decided to further study the optimal condition of synthesis of GRb1 with vinyl decanoate with 10 carbon chain fatty acids in tert-amyl alcohol. Response surface methodology (RSM) was employed to optimize the synthesis condition. From the ridge analysis with maximum responses, the maximum GRb1 conversion was predicted to be 61.51% in a combination of factors (40.2 h, 52.95 degrees C, substrate mole ratio 275.57, and enzyme amount 39.81 mg/mL). Further, the adequacy of the predicted model was examined by additional independent experiments at the predicted maximum synthesis conditions. Results showed that the RSM was effective to optimize a combination of factors for lipase-catalyzed synthesis of ginsenoside Rb1 with vinyl decanoate.

The Case for Using SMS Technologies to Support Distance Education Students in South Africa: Conversations

ERIC Educational Resources Information Center

Viljoen, Jeanne-Marie; Du Preez, Carl; Cook, Antoinette

2005-01-01

The rate of adoption of mobile technologies in Africa's developing countries is amongst the highest in the world and by 2005 there may be almost 100 billion mobile users in Africa (Keegan, 2002; Brown, 2005). This is just one of the reasons why servicing distance students in this country through m-learning support tools should enjoy…

Contemporary divergence in early life history in grayling (Thymallus thymallus).

PubMed

Thomassen, Gaute; Barson, Nicola J; Haugen, Thrond O; Vøllestad, L Asbjørn

2011-12-13

Following colonization of new habitats and subsequent selection, adaptation to environmental conditions might be expected to be rapid. In a mountain lake in Norway, Lesjaskogsvatnet, more than 20 distinct spawning demes of grayling have been established since the lake was colonized, some 20-25 generations ago. The demes spawn in tributaries consistently exhibiting either colder or warmer temperature conditions during spawning in spring and subsequent early development during early summer. In order to explore the degree of temperature-related divergence in early development, a multi-temperature common-garden experiment was performed on embryos from four different demes experiencing different spring temperatures. Early developmental characters were measured to test if individuals from the four demes respond differently to the treatment temperatures. There was clear evidence of among-deme differences (genotype - environment interactions) in larval growth and yolk-to-body-size conversion efficiency. Under the cold treatment regime, larval growth rates were highest for individuals belonging to cold streams. Individuals from warm streams had the highest yolk-consumption rate under cold conditions. As a consequence, yolk-to-body-mass conversion efficiency was highest for cold-deme individuals under cold conditions. As we observed response parallelism between individuals from demes belonging to similar thermal groups for these traits, some of the differentiation seems likely to result from local adaptation The observed differences in length at age during early larval development most likely have a genetic component, even though both directional and random processes are likely to have influenced evolutionary change in the demes under study.

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

Sievers, David A.; Kuhn, Erik M.; Tucker, Melvin P.

In this study, the reaction conditions used during dilute-acid pretreatment of lignocellulosic biomass control the carbohydrate digestion yield and also hydrolyzate properties. Depending on the conversion route of interest, solid-liquid separation (SLS) may be required to split the hemicellulose-rich liquor from the cellulose-rich insoluble solids, and slurry properties are important for SLS. Corn stover was pretreated at different reaction conditions and the slurries were assessed for conversion yield and filtration performance. Increasing pretreatment temperature reduced the solids mean particle size and resulted in slower slurry filtration rates when vacuum filtered or pressure filtered. Corn stover pretreated at 165 °C formore » 10 min and with 1% H 2SO 4 exhibited the highest xylose yield and best filtration performance with a no-wash filtration rate of 80 kg/h m 2 and cake permeability of 15 x 10 -15.« less

Reading and Acting in the World: Conversations about Empathy

ERIC Educational Resources Information Center

Holland, Chris

2009-01-01

We live in a world of normalised violence. New Zealand has high statistics of child abuse and child deaths and in 2003 had one of the highest child-death rates in the OECD. To take serious note of these statistics is to recognise that children in many New Zealand classrooms are likely to have experienced violence directly, or to have witnessed it,…

LTR Retrotransposons Show Low Levels of Unequal Recombination and High Rates of Intraelement Gene Conversion in Large Plant Genomes

PubMed Central

Cossu, Rosa Maria; Casola, Claudio; Giacomello, Stefania; Vidalis, Amaryllis

2017-01-01

Abstract The accumulation and removal of transposable elements (TEs) is a major driver of genome size evolution in eukaryotes. In plants, long terminal repeat (LTR) retrotransposons (LTR-RTs) represent the majority of TEs and form most of the nuclear DNA in large genomes. Unequal recombination (UR) between LTRs leads to removal of intervening sequence and formation of solo-LTRs. UR is a major mechanism of LTR-RT removal in many angiosperms, but our understanding of LTR-RT-associated recombination within the large, LTR-RT-rich genomes of conifers is quite limited. We employ a novel read-based methodology to estimate the relative rates of LTR-RT-associated UR within the genomes of four conifer and seven angiosperm species. We found the lowest rates of UR in the largest genomes studied, conifers and the angiosperm maize. Recombination may also resolve as gene conversion, which does not remove sequence, so we analyzed LTR-RT-associated gene conversion events (GCEs) in Norway spruce and six angiosperms. Opposite the trend for UR, we found the highest rates of GCEs in Norway spruce and maize. Unlike previous work in angiosperms, we found no evidence that rates of UR correlate with retroelement structural features in the conifers, suggesting that another process is suppressing UR in these species. Recent results from diverse eukaryotes indicate that heterochromatin affects the resolution of recombination, by favoring gene conversion over crossing-over, similar to our observation of opposed rates of UR and GCEs. Control of LTR-RT proliferation via formation of heterochromatin would be a likely step toward large genomes in eukaryotes carrying high LTR-RT content. PMID:29228262

Preparation and characterization of mesoporous ZnO-ZrO2 doped by Cr, Nd and Dy as a catalyst for conversion of coumarin using ultrasensitive fluorometric method

NASA Astrophysics Data System (ADS)

Ibrahim, M. M.

2017-04-01

Doping of mesoporous ZnO-ZrO2 nanoparticles with transition metal and lanthanides (Cr, Nd, Dy) were used as a catalyst to develop an ultrasensitive fluorometric method for the conversion of non fluorescent coumarin to highly fluorescent 7-hydroxycoumarin using H2O2 or light. It was found that doped- ZnO-ZrO2 mixed oxide can catalyze the decomposition of H2O2 to produce •OH radicals, which in turn convert coumarin to 7-hydroxycoumarin. At contrast, the doping has deleterious effect on conversion of coumarin by light due to high band gap and high concentrations of doping increase the recombination rate of electron and holes. Doped mixed oxides prepared by impregnation method and characterized by studying their structural, surface and optical properties. Chromium doped ZnO-ZrO2 had the highest rate of formation of hydroxyl radical due to decomposition of H2O2 and therefore 7-hydroxycoumarin due to surface area, small crystal size and high redox potential.

Effects of sonication on co-precipitation synthesis and activity of copper manganese oxide catalyst to remove methane and sulphur dioxide gases.

PubMed

Yap, Yeow Hong; Lim, Mitchell S W; Lee, Zheng Yee; Lai, Kar Chiew; Jamaal, Muhamad Ashraf; Wong, Farng Hui; Ng, Hoon Kiat; Lim, Siew Shee; Tiong, T Joyce

2018-01-01

The utilisation of ultrasound in chemical preparation has been the focus of intense study in various fields, including materials science and engineering. This paper presents a novel method of synthesising the copper-manganese oxide (Hopcalite) catalyst that is used for the removal of volatile organic compounds and greenhouse gases like carbon monoxide. Several samples prepared under different conditions, with and without ultrasound, were subjected to a series of characterisation tests such as XRD, BET, FE-SEM, EDX, TPR-H 2 , TGA and FT-IR in order to establish their chemical and physical properties. A series of catalytic tests using a micro-reactor were subsequently performed on the samples in order to substantiate the aforementioned properties by analysing their ability to oxidise compressed natural gas (CNG), containing methane and sulphur dioxide. Results showed that ultrasonic irradiation of the catalyst led to observable alterations in its morphology: surfaces of the particles were noticeably smoothed and an increased in amorphicity was detected. Furthermore, ultrasonic irradiation has shown to enhance the catalytic activity of Hopcalite, achieving a higher conversion of methane relative to non-sonicated samples. Varying the ultrasonic intensity also produced appreciable effects, whereby an increase in intensity results in a higher conversion rate. The catalyst sonicated at the highest intensity of 29.7W/cm 2 has a methane conversion rate of 13.5% at 400°C, which was the highest among all the samples tested. Copyright © 2017 Elsevier B.V. All rights reserved.

Characteristic of an Organic Photodetector Fabricated With P3HT:ICBA Blending Materials for Indirect X-Ray Detection

NASA Astrophysics Data System (ADS)

Seon, Hyeji; Kim, Beomsu; Kang, Jungwon

2017-07-01

In this study, an organic conjugated polymer-based photodetector was investigated as a candidate for the indirecttype radiation detector. In order to improve the photon to charge conversion efficiency, we selected the fullerene derivative indeneC60-bisadduct (ICBA) as an n-type semiconductor. The optimal process condition was investigated while varying the P3HT:ICBA blending ratio and spin-rate. The detector at the condition of P3HT:ICBA = 3:2 blending ratio and 900 rpm spin-rate showed the highest sensitivity of 1.35 mC/Gy · cm2 and the highest PCE of 2.93%. Compared to the common P3HT:PCBM detector, the best P3HT:ICBA detector showed 27.36% enhancement of sensitivity and 27.68% enhancement of the PCE.

Effects of dilute-acid pretreatment conditions on filtration performance of corn stover hydrolyzate

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

Sievers, David A.; Kuhn, Erik M.; Tucker, Melvin P.

In this study, the reaction conditions used during dilute-acid pretreatment of lignocellulosic biomass control the carbohydrate digestion yield and also hydrolyzate properties. Depending on the conversion route of interest, solid-liquid separation (SLS) may be required to split the hemicellulose-rich liquor from the cellulose-rich insoluble solids, and slurry properties are important for SLS. Corn stover was pretreated at different reaction conditions and the slurries were assessed for conversion yield and filtration performance. Increasing pretreatment temperature reduced the solids mean particle size and resulted in slower slurry filtration rates when vacuum filtered or pressure filtered. Corn stover pretreated at 165 °C formore » 10 min and with 1% H 2SO 4 exhibited the highest xylose yield and best filtration performance with a no-wash filtration rate of 80 kg/h m 2 and cake permeability of 15 x 10 -15.« less

Effects of dilute-acid pretreatment conditions on filtration performance of corn stover hydrolyzate

DOE PAGES

Sievers, David A.; Kuhn, Erik M.; Tucker, Melvin P.; ...

2017-06-28

In this study, the reaction conditions used during dilute-acid pretreatment of lignocellulosic biomass control the carbohydrate digestion yield and also hydrolyzate properties. Depending on the conversion route of interest, solid-liquid separation (SLS) may be required to split the hemicellulose-rich liquor from the cellulose-rich insoluble solids, and slurry properties are important for SLS. Corn stover was pretreated at different reaction conditions and the slurries were assessed for conversion yield and filtration performance. Increasing pretreatment temperature reduced the solids mean particle size and resulted in slower slurry filtration rates when vacuum filtered or pressure filtered. Corn stover pretreated at 165 °C formore » 10 min and with 1% H 2SO 4 exhibited the highest xylose yield and best filtration performance with a no-wash filtration rate of 80 kg/h m 2 and cake permeability of 15 x 10 -15.« less

Evaluation of factors influencing the enantioselective enzymatic esterification of lactic acid in ionic liquid.

PubMed

Findrik, Zvjezdana; Németh, Gergely; Gubicza, László; Bélafi-Bakó, Katalin; Vasić-Rački, Durđa

2012-05-01

In this paper esterification of ethanol and lactic acid catalyzed by Candida antarctica B (Novozyme 435) in ionic liquid (Cyphos 104) was studied. The influence of different variables on lipase enantioselectivity and lactic acid conversion was investigated. The variables investigated were ionic liquid mass/lipase mass ratio, water content, alcohol excess and temperature. Using the Design Expert software 2(3) factorial experimental plan (two levels, three factors) was performed to ascertain the effect of selected variables and their interactions on the ethyl lactate enantiomeric excess and lactic acid conversion. The results of the experiments and statistical processing suggest that temperature and alcohol excess have the highest effect on the ethyl lactate enantiomeric excess, while temperature and water content have the highest influence on the lactic acid conversion. The statistical mathematical model developed on the basis of the experimental data showed that the highest enantiomeric excess achieved in the investigated variable range is 34.3%, and the highest conversion is 63.8% at the initial conditions of water content at 8%; 11-fold molar excess of alcohol and temperature at 30 °C.

High-frequency thermal-electrical cycles for pyroelectric energy conversion

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

Bhatia, Bikram; Damodaran, Anoop R.; Cho, Hanna

2014-11-21

We report thermal to electrical energy conversion from a 150 nm thick BaTiO{sub 3} film using pyroelectric cycles at 1 kHz. A microfabricated platform enables temperature and electric field control with temporal resolution near 1 μs. The rapid electric field changes as high as 11 × 10{sup 5 }kV/cm-s, and temperature change rates as high as 6 × 10{sup 5 }K/s allow exploration of pyroelectric cycles in a previously unexplored operating regime. We investigated the effect of phase difference between electric field and temperature cycles, and electric field and temperature change rates on the electrical energy generated from thermal-electrical cycles based on the pyroelectric Ericsson cycle. Complete thermodynamic cyclesmore » are possible up to the highest cycle rates tested here, and the energy density varies significantly with phase shifts between temperature and electric field waveforms. This work could facilitate the design and operation of pyroelectric cycles at high cycle rates, and aid in the design of new pyroelectric systems.« less

The analysis of 146 patients with difficult laparoscopic cholecystectomy.

PubMed

Bat, Orhan

2015-01-01

Laparoscopic cholecystectomy (LC) is very commonly performed surgical intervention. Acute or chronic cholecystitis, adhesions due to previous upper abdomen surgeries, Mirrizi's syndrome and obesity are common clinical conditions that can be associated with difficult cholecystectomy. In this study, we evaluated and scored the patients with difficult surgical exploration during laparoscopic cholecystectomy. All patients who underwent LC from 2010 to 2015 were retrospectively rewieved. According to intraoperative findings DLC cases were described and classified. Class I difficulty: Adhesion of omentum majus, transverse colon, duodenum to the fundus of the gallbladder. Class II difficulty: Adhesions in Calot's triangle and difficulty in dissection of cystic artery and cystic duct Class III difficulty: Difficulty in dissection of gallbladder bed (scleroathrophic gallbladder, hemorrhage from liver during dissection of gallbladder, chirotic liver). Class IV difficulty: Difficulty in exploration of gallbladder due to intraabdominal adhesions including technical problems. A total of 146 patients were operated with DLC. The most common difficulty type was Class I difficulty (88 patients/60.2%). Laparoscopic cholecystectomy was converted to laparotomy in 98 patients. Operation time was found to be related with conversion to open surgery (P<0.05). Wound infection rate was also statistically higher in conversion group (P<0.05). The opertion time was found to be longest with Class II difficulty. Conversion rate to open surgery was also highest with Class II difficulty group. Class II difficulty characterized by severe adhesions in calot's triangle is most serious problem among all DLC cases. They have longer operation time and higher conversion rate.

Effects of Furfural on the Respiratory Metabolism of Saccharomyces cerevisiae in Glucose-Limited Chemostats

PubMed Central

Sárvári Horváth, Ilona; Franzén, Carl Johan; Taherzadeh, Mohammad J.; Niklasson, Claes; Lidén, Gunnar

2003-01-01

Effects of furfural on the aerobic metabolism of the yeast Saccharomyces cerevisiae were studied by performing chemostat experiments, and the kinetics of furfural conversion was analyzed by performing dynamic experiments. Furfural, an important inhibitor present in lignocellulosic hydrolysates, was shown to have an inhibitory effect on yeast cells growing respiratively which was much greater than the inhibitory effect previously observed for anaerobically growing yeast cells. The residual furfural concentration in the bioreactor was close to zero at all steady states obtained, and it was found that furfural was exclusively converted to furoic acid during respiratory growth. A metabolic flux analysis showed that furfural affected fluxes involved in energy metabolism. There was a 50% increase in the specific respiratory activity at the highest steady-state furfural conversion rate. Higher furfural conversion rates, obtained during pulse additions of furfural, resulted in respirofermentative metabolism, a decrease in the biomass yield, and formation of furfuryl alcohol in addition to furoic acid. Under anaerobic conditions, reduction of furfural partially replaced glycerol formation as a way to regenerate NAD+. At concentrations above the inlet concentration of furfural, which resulted in complete replacement of glycerol formation by furfuryl alcohol production, washout occurred. Similarly, when the maximum rate of oxidative conversion of furfural to furoic acid was exceeded aerobically, washout occurred. Thus, during both aerobic growth and anaerobic growth, the ability to tolerate furfural appears to be directly coupled to the ability to convert furfural to less inhibitory compounds. PMID:12839784

Synthesis of structured lipids by lipase-catalyzed interesterification of triacetin with camellia oil methyl esters and preliminary evaluation of their plasma lipid-lowering effect in mice.

PubMed

Cao, Yu; Qi, Suijian; Zhang, Yang; Wang, Xiaoning; Yang, Bo; Wang, Yonghua

2013-03-25

Structured lipids (SLCTs triacylglycerols with short- and long-chain acyl residues) were synthesized by interesterification of triacetin and fatty acid methyl esters (FAMEs) from camellia oil, followed by molecular distillation for purification. Different commercial immobilized lipases (Lipozyme RM IM and Novozyme 435), the substrate molar ratios of FAMEs to triacetin, the reaction temperatures and the lipase amounts were studied for their efficiency in producing SLCTs. Results showed that Novozyme 435 was more suitable for this reaction system. Moreover, the optimal reaction conditions for the highest conversion of FAMEs and the highest LLS-TAGs (triacylglycerols with one short- and two long-chain acyl residues) yields were achieved at a molar ratio of FAMEs to triacetin of 3:1, 50 °C of reaction temperature and a lipase amount of 4% (w/v). Scale-up was conducted based on the optimized reaction conditions. Results showed that after 24 h of reaction , the conversion rate of FAMEs was 82.4% and the rate of disubstituted triacetin was 52.4 mol%. The final product yield rate was 94.6%. The effects of the synthesized SLCTs on the plasma lipid level of fasting mice were also studied. The SLCTs could effectively lessen the total triacylglycerol levels in plasma compared to the triacylglycerol group in fasting NIH mice. It suggested that this type of structured lipid might be beneficial for human health, especially for the prevention of obesity.

A Quantitative Study of Right Dislocation in Cantonese Spoken Discourse.

PubMed

Lai, Christy Choi-Ting; Law, Sam-Po; Kong, Anthony Pak-Hin

2017-12-01

Right Dislocation (RD) has been suggested to be a focus marking device carrying an affective function motivated by limited planning time in conversation. The current study investigated the effects of genre type, planning load and affective function on the use of RD in Cantonese monologues. Discourse data were extracted from a recently developed corpus of oral narratives in Cantonese Chinese containing language samples from 144 native Cantonese speakers evenly distributed in age, education levels and gender. Three genre types representing different structures, styles and degrees of topic familiarity were chosen for an RD analysis: procedural description, story-telling and recount of personal event. The results revealed that genre types and planning load influenced the rate of RD occurrence. (1) Specifically, the lowest proportion of RD occurred in procedural description, assumed to be the most structured genre; whereas the highest rate was found in personal event recount, considered to be the most stylized and less structured genre. (2) The highest proportion of RD appeared near the end of a narrative, where heavier cognitive load is demanded compared with the beginning of a narrative; moreover, RD also tended to co-occur with disfluency. (3) There was a high percentage of RD tokens in the personal event recount for expressing explicit emotions; and (4) a lower rate of occurrence of RD was found in monologues than previous studies based on conversations. The overall findings suggest that the use of RD is sensitive to genre structure and style, as well as planning load effects.

Metabolic Conversion of Ceramides in HeLa Cells - A Cholesteryl Phosphocholine Delivery Approach

PubMed Central

Kjellberg, Matti A.; Lönnfors, Max; Slotte, J. Peter; Mattjus, Peter

2015-01-01

Ceramides can be delivered to cultured cells without solvents in the form of complexes with cholesteryl phosphocholine. We have analysed the delivery of three different radiolabeled D-erythro-ceramides (C6-Cer, C10-Cer and C16-Cer) to HeLa cells, and followed their metabolism as well as the cell viability. We found that all three ceramides were successfully taken up by HeLa cells when complexed to CholPC in an equimolar ratio, and show that the ceramides show different rates of cellular uptake and metabolic fate. The C6-Cer had the highest incorporation rate, followed by C10-Cer and C16-Cer, respectively. The subsequent effect on cell viability strongly correlated with the rate of incorporation, where C6-Cer had the strongest apoptotic effects. Low-dose (1 μM) treatment with C6-Cer favoured conversion of the precursor to sphingomyelin, whereas higher concentrations (25–100 μM) yielded increased conversion to C6-glucosylceramide. Similar results were obtained for C10-Cer. In the lower-dose C16-Cer experiments, most of the precursor was degraded, whereas at high-dose concentrations the precursor remained un-metabolized. Using this method, we demonstrate that ceramides with different chain lengths clearly exhibit varying rates of cellular uptake. The cellular fate of the externally delivered ceramides are clearly connected to their rate of incorporation and their subsequent effects on cell viability may be in part determined by their chain length. PMID:26599810

Interactions Between Atmospheric Aerosols and Marine Boundary Layer Clouds on Regional and Global Scales

NASA Astrophysics Data System (ADS)

Wang, Zhen

Airborne aerosols are crucial atmospheric constituents that are involved in global climate change and human life qualities. Understanding the nature and magnitude of aerosol-cloud-precipitation interactions is critical in model predictions for atmospheric radiation budget and the water cycle. The interactions depend on a variety of factors including aerosol physicochemical complexity, cloud types, meteorological and thermodynamic regimes and data processing techniques. This PhD work is an effort to quantify the relationships among aerosol, clouds, and precipitation on both global and regional scales by using satellite retrievals and aircraft measurements. The first study examines spatial distributions of conversion rate of cloud water to rainwater in warm maritime clouds over the globe by using NASA A-Train satellite data. This study compares the time scale of the onset of precipitation with different aerosol categories defined by values of aerosol optical depth, fine mode fraction, and Angstrom Exponent. The results indicate that conversion time scales are actually quite sensitive to lower tropospheric static stability (LTSS) and cloud liquid water path (LWP), in addition to aerosol type. Analysis shows that tropical Pacific Ocean is dominated by the highest average conversion rate while subtropical warm cloud regions (far northeastern Pacific Ocean, far southeastern Pacific Ocean, Western Africa coastal area) exhibit the opposite result. Conversion times are mostly shorter for lower LTSS regimes. When LTSS condition is fixed, higher conversion rates coincide with higher LWP and lower aerosol index categories. After a general global view of physical property quantifications, the rest of the presented PhD studies is focused on regional airborne observations, especially bulk cloud water chemistry and aerosol aqueous-phase reactions during the summertime off the California coast. Local air mass origins are categorized into three distinct types (ocean, ships, and land) with their influences on cloud water composition examined and implications of wet deposition discussed. Chemical analysis of cloud water samples indicates a wide pH range between 2.92 and 7.58, with an average as 4.46. The highest pH values were observed north of San Francisco, coincident with the strongest land mass influence (e.g. Si, B, and Cs). Conversely, the lowest pH values were observed south of San Francisco where there is heavy ship traffic, resulting in the highest concentrations of sulfate, nitrate, V, Fe, Al, P, Cd, Ti, Sb, P, and Mn. The acidic cloud environment with influences from various air mass types can affect the California coastal aquatic ecosystem since it can promote the conversion of micronutrients to more soluble forms. Beyond characterization of how regional air mass sources affect cloud water composition, aircraft cloud water collection provides precious information on tracking cloud processing with specific species such as oxalic acid, which is the most abundant dicarboxylic acid in tropospheric aerosols. Particular attention is given to explore relationship between detected metals with oxalate aqueous-phase production mechanisms. A number of case flights show that oxalate concentrations drop by nearly an order of magnitude relative to samples in the same vicinity with similar environmental and cloud physical conditions. Such a unique feature was consistent with an inverse relationship between oxalate and Fe. In order to examine the hypothesis that oxalate decreasing is potentially related to existing of Fe, chemistry box model simulations were conducted. The prediction results show that the loss of oxalate due to the photolysis of iron oxalato complexes is likely a significant oxalate sink in the study region due to the ubiquity of oxalate precursors, clouds, and metal emissions from ships, the ocean, and continental sources.

Insight into Aluminum Sulfate-Catalyzed Xylan Conversion into Furfural in a γ-Valerolactone/Water Biphasic Solvent under Microwave Conditions.

PubMed

Yang, Tao; Zhou, Yi-Han; Zhu, Sheng-Zhen; Pan, Hui; Huang, Yao-Bing

2017-10-23

A simple and efficient biphasic system with an earth-abundant metal salt catalyst was used to produce furfural from xylan with a high yield of up to 87.8 % under microwave conditions. Strikingly, the metal salt Al 2 (SO 4 ) 3 exhibited excellent catalytic activity for xylan conversion, owing to a combination of Lewis and Brønsted acidity and its ability to promote good phase separation. The critical role of the SO 4 2- anion was first analyzed, which resulted in the aforementioned characteristics when combined with the Al 3+ cation. The mixed solvent system with γ-valerolactone (GVL) as the organic phase provided the highest furfural yield, resulting from its good dielectric properties and dissolving capacity, which facilitated the absorption of microwave energy and promoted mass transfer. Mechanistic studies suggested that the xylan-to-furfural conversion proceeded mainly through a hydrolysis-isomerization-dehydration pathway and the hexa-coordinated Lewis acidic [Al(OH) 2 (aq)] + species were the active sites for xylose-xylulose isomerization. Detailed kinetic studies of the subreaction for the xylan conversion revealed that GVL regulates the reaction rates and pathways by promoting the rates of the key steps involved for furfural production and suppressing the side reactions for humin production. Finally, the Al 2 (SO 4 ) 3 catalyst was used for the production of furfural from several lignocellulosic feedstocks, revealing its great potential for other biomass conversions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Distribution of polarization-entangled photonpairs produced via spontaneous parametric down-conversion within a local-area fiber network: theoretical model and experiment.

PubMed

Lim, Han Chuen; Yoshizawa, Akio; Tsuchida, Hidemi; Kikuchi, Kazuro

2008-09-15

We present a theoretical model for the distribution of polarization-entangled photon-pairs produced via spontaneous parametric down-conversion within a local-area fiber network. This model allows an entanglement distributor who plays the role of a service provider to determine the photon-pair generation rate giving highest two-photon interference fringe visibility for any pair of users, when given user-specific parameters. Usefulness of this model is illustrated in an example and confirmed in an experiment, where polarization-entangled photon-pairs are distributed over 82 km and 132 km of dispersion-managed optical fiber. Experimentally observed visibilities and entanglement fidelities are in good agreement with theoretically predicted values.

Unravelling biocomplexity of electroactive biofilms for producing hydrogen from biomass

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

Lewis, Alex J.; Campa, Maria F.; Hazen, Terry C.

Nature recruits various types of microbes to transform its waste products into reusable building blocks. In order to develop engineered systems to enable humans to generate useful products from complex sources such as biomass, a better understanding of the synergy between microbial species is necessary. Here we investigate a bioelectrochemical system for conversion of a complex biomass-derived pyrolysis stream into hydrogen via microbial electrolysis. Interaction between the exoelectrogens and fermentative organisms is key in this process. Comparing bioelectroconversion of a switchgrass-derived bio-oil aqueous phase (BOAP) with a model exoelectrogenic substrate, acetic acid, we demonstrate that fermentative breakdown of BOAP tomore » acetate is the limiting step in the syntophic conversion process. The anode microbial community displayed simultaneous conversion of sugar derivatives, phenolic compounds, carboxylic acids, etc. present in BOAP, but at differing rates through division of labor and syntrophic exchange. Maximum removal for BOAP reached 43 mg COD/h vs. 59 mg COD/h for pure acetic acid. Furthermore, maximum hydrogen production for BOAP reached 11 L/L-d vs. 35 L/L-day for pure acetic acid. Coulombic efficiency for both substrates was >80%. Unpoising of the anode haulted exoelectrogenesis and allowed fermentative processes to proceed resulting in acetic acid accumulation at the rate of 8.4 mg/h. Coupled to the simultaneous conversion of compounds present within BOAP, these results support the division of labor and syntrophic interactions suggested here. The hydrogen productivity is the highest achieved to date for a biomass-derived stream. The exoelectrogenic rates achieved signify that commercial feasibility can be achieved if fermentative rates can be improved.« less

Unravelling biocomplexity of electroactive biofilms for producing hydrogen from biomass

DOE PAGES

Lewis, Alex J.; Campa, Maria F.; Hazen, Terry C.; ...

2017-07-11

Nature recruits various types of microbes to transform its waste products into reusable building blocks. In order to develop engineered systems to enable humans to generate useful products from complex sources such as biomass, a better understanding of the synergy between microbial species is necessary. Here we investigate a bioelectrochemical system for conversion of a complex biomass-derived pyrolysis stream into hydrogen via microbial electrolysis. Interaction between the exoelectrogens and fermentative organisms is key in this process. Comparing bioelectroconversion of a switchgrass-derived bio-oil aqueous phase (BOAP) with a model exoelectrogenic substrate, acetic acid, we demonstrate that fermentative breakdown of BOAP tomore » acetate is the limiting step in the syntophic conversion process. The anode microbial community displayed simultaneous conversion of sugar derivatives, phenolic compounds, carboxylic acids, etc. present in BOAP, but at differing rates through division of labor and syntrophic exchange. Maximum removal for BOAP reached 43 mg COD/h vs. 59 mg COD/h for pure acetic acid. Furthermore, maximum hydrogen production for BOAP reached 11 L/L-d vs. 35 L/L-day for pure acetic acid. Coulombic efficiency for both substrates was >80%. Unpoising of the anode haulted exoelectrogenesis and allowed fermentative processes to proceed resulting in acetic acid accumulation at the rate of 8.4 mg/h. Coupled to the simultaneous conversion of compounds present within BOAP, these results support the division of labor and syntrophic interactions suggested here. The hydrogen productivity is the highest achieved to date for a biomass-derived stream. The exoelectrogenic rates achieved signify that commercial feasibility can be achieved if fermentative rates can be improved.« less

Synergetic and inhibition effects in carbon dioxide gasification of blends of coals and biomass fuels of Indian origin.

PubMed

Satyam Naidu, V; Aghalayam, P; Jayanti, S

2016-06-01

The present study investigates the enhancement of CO2 gasification reactivity of coals due to the presence of catalytic elements in biomass such as K2O, CaO, Na2O and MgO. Co-gasification of three Indian coal chars with two biomass chars has been studied using isothermal thermogravimetric analysis (TGA) in CO2 environment at 900, 1000 and 1100°C. The conversion profiles have been used to establish synergetic or inhibitory effect on coal char reactivity by the presence of catalytic elements in biomass char by comparing the 90% conversion time with and without biomass. It is concluded that both biomasses exhibit synergistic behavior when blended with the three coals with casuarina being more synergetic than empty fruit bunch. Some inhibitory effect has been noted for the high ash coal at the highest temperature with higher 90% conversion time for the blend over pure coal, presumably due to diffusional control of the conversion rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Land use and land cover change in the North Central Appalachians ecoregion

USGS Publications Warehouse

Napton, D.E.; Sohl, Terry L.; Auch, Roger F.; Loveland, Thomas R.

2003-01-01

The North Central Appalachians ecoregion, spanning northern Pennsylvania and southern New York, has a long history of land use and land cover change. Turn-of-the-century logging dramatically altered the natural landscape of the ecoregion, but subsequent regeneration returned the ecoregion to a forest dominated condition. To understand contemporary land use and land cover changes, the U.S. Geological Survey with NASA and the U.S. Environmental Protection Agency used a random sample of satellite remotely sensed data for 1973, 1980, 1986, 1992, and 2000 to estimate the rates and assess the primary drivers of change in the North Central Appalachians. The overall change was 6.2%. The 1973-1980 period had the lowest rate of change (1.5%); the highest rate (2.9%) occurred during the 1992-2000 period. The primary conversions were deforestation through harvesting and natural disturbance (i.e., tornados) followed by regeneration, and conversion of forests to mining and urban lands. The primary drivers of the change included changes in access, energy and forest prices, and attitudes toward the environment.

Quantifying risk of early relapse in patients with first demyelinating events: Prediction in clinical practice.

PubMed

Spelman, Tim; Meyniel, Claire; Rojas, Juan Ignacio; Lugaresi, Alessandra; Izquierdo, Guillermo; Grand'Maison, Francois; Boz, Cavit; Alroughani, Raed; Havrdova, Eva; Horakova, Dana; Iuliano, Gerardo; Duquette, Pierre; Terzi, Murat; Grammond, Pierre; Hupperts, Raymond; Lechner-Scott, Jeannette; Oreja-Guevara, Celia; Pucci, Eugenio; Verheul, Freek; Fiol, Marcela; Van Pesch, Vincent; Cristiano, Edgardo; Petersen, Thor; Moore, Fraser; Kalincik, Tomas; Jokubaitis, Vilija; Trojano, Maria; Butzkueven, Helmut

2017-09-01

Characteristics at clinically isolated syndrome (CIS) examination assist in identification of patient at highest risk of early second attack and could benefit the most from early disease-modifying drugs (DMDs). To examine determinants of second attack and validate a prognostic nomogram for individualised risk assessment of clinical conversion. Patients with CIS were prospectively followed up in the MSBase Incident Study. Predictors of clinical conversion were analysed using Cox proportional hazards regression. Prognostic nomograms were derived to calculate conversion probability and validated using concordance indices. A total of 3296 patients from 50 clinics in 22 countries were followed up for a median (inter-quartile range (IQR)) of 1.92 years (0.90, 3.71). In all, 1953 (59.3%) patients recorded a second attack. Higher Expanded Disability Status Scale (EDSS) at baseline, first symptom location, oligoclonal bands and various brain and spinal magnetic resonance imaging (MRI) metrics were all predictors of conversion. Conversely, older age and DMD exposure post-CIS were associated with reduced rates. Prognostic nomograms demonstrated high concordance between estimated and observed conversion probabilities. This multinational study shows that age at CIS onset, DMD exposure, EDSS, multiple brain and spinal MRI criteria and oligoclonal bands are associated with shorter time to relapse. Nomogram assessment may be useful in clinical practice for estimating future clinical conversion.

Optimization of enzymatic hydrolysis for ethanol production by simultaneous saccharification and fermentation of wastepaper.

PubMed

Sangkharak, Kanokphorn

2011-11-01

The present study investigated the development of high sugar production by optimization of an enzymatic hydrolysis process using both conventional and statistical methods, as well as the production of ethanol by the selected wastepaper source. Among four sources of pretreated wastepaper including office paper, newspaper, handbills and cardboard, office paper gave the highest values of cellulose (87.12%) and holocelluloses (89.07%). The effects of the amount of wastepaper, the pretreatment method and the type of enzyme on reducing sugar production from office paper were studied using conventional methods. The highest reducing sugar production (1851.28 µg L(-1); 37.03% conversion of glucose) was obtained from the optimal condition containing 40 mg of office paper, pretreated with stream explosion and hydrolysed with the combination of cellulase from Aspergillus niger and Trichoderma viride at the fixed loading rate of 20 FPU g(-1) sample. The effects of interaction of wastepaper amount and enzyme concentration as well as incubation time were studied by a statistical method using central composite design. The optimal medium composition consisted of 43.97 µg L(-1), 28.14 FPU g(-1) sample and 53.73 h of wastepaper, enzyme concentration and incubation time, respectively, and gave the highest amount of sugar production (2184.22 µg L(-1)) and percentage conversion of glucose (43.68%). The ethanol production from pretreated office paper using Saccharomyces cerevisiae in a simultaneous saccharification and fermentation process was 21.02 g L(-1) after 36 h of cultivation, corresponding to an ethanol volumetric production rate of 0.58 g ethanol L(-1) h(-1).

The analysis of 146 patients with difficult laparoscopic cholecystectomy

PubMed Central

Bat, Orhan

2015-01-01

Introduction: Laparoscopic cholecystectomy (LC) is very commonly performed surgical intervention. Acute or chronic cholecystitis, adhesions due to previous upper abdomen surgeries, Mirrizi’s syndrome and obesity are common clinical conditions that can be associated with difficult cholecystectomy. In this study, we evaluated and scored the patients with difficult surgical exploration during laparoscopic cholecystectomy. Material and Method: All patients who underwent LC from 2010 to 2015 were retrospectively rewieved. According to intraoperative findings DLC cases were described and classified. Class I difficulty: Adhesion of omentum majus, transverse colon, duodenum to the fundus of the gallbladder. Class II difficulty: Adhesions in Calot’s triangle and difficulty in dissection of cystic artery and cystic duct Class III difficulty: Difficulty in dissection of gallbladder bed (scleroathrophic gallbladder, hemorrhage from liver during dissection of gallbladder, chirotic liver). Class IV difficulty: Difficulty in exploration of gallbladder due to intraabdominal adhesions including technical problems. Results: A total of 146 patients were operated with DLC. The most common difficulty type was Class I difficulty (88 patients/60.2%). Laparoscopic cholecystectomy was converted to laparotomy in 98 patients. Operation time was found to be related with conversion to open surgery (P<0.05). Wound infection rate was also statistically higher in conversion group (P<0.05). The opertion time was found to be longest with Class II difficulty. Conversion rate to open surgery was also highest with Class II difficulty group. Conclusion: Class II difficulty characterized by severe adhesions in calot’s triangle is most serious problem among all DLC cases. They have longer operation time and higher conversion rate. PMID:26629124

Comparative study of activated carbon, natural zeolite, and green sand supports for CuOX and ZnO sites as ozone decomposition catalyst

NASA Astrophysics Data System (ADS)

Azhariyah, A. S.; Pradyasti, A.; Dianty, A. G.; Bismo, S.

2018-03-01

This research was based on ozone decomposition in industrial environment. Ozone is harmful to human. Therefore, catalysts were made as a mask filter to decompose ozone. Comparison studies of catalyst supports were done using Granular Activated Carbon (GAC), Natural Zeolite (NZ), and Green Sand (GS). GAC showed the highest catalytic activity compared to other supports with conversion of 98%. Meanwhile, the conversion using NZ was only 77% and GS had been just 27%. GAC had the highest catalytic activity because it had the largest pore volume, which is 0.478 cm3/g. So GAC was used as catalyst supports. To have a higher conversion in ozone decomposition, GAC was impregnated with metal oxide as the active site of the catalyst. Active site comparison was made using CuOX and ZnO as the active site. Morphology, composition, and crystal phase were analyzed using SEM-EDX, XRF, and XRD methods. Mask filter, which contained catalysts for ozone decomposition, was tested using a fixed bed reactor at room temperature and atmospheric pressure. The result of conversion was analyzed using iodometric method. CuOX/GAC and ZnO/GAC 2%-w showed the highest catalytic activity and conversion reached 100%. From the durability test, CuOX/GAC 2%-w was better than ZnO/GAC 2%-w because the conversion of ozone to oxygen reached 100% with the lowest conversion was 70% for over eight hours.

Mammalian keratin associated proteins (KRTAPs) subgenomes: disentangling hair diversity and adaptation to terrestrial and aquatic environments.

PubMed

Khan, Imran; Maldonado, Emanuel; Vasconcelos, Vítor; O'Brien, Stephen J; Johnson, Warren E; Antunes, Agostinho

2014-09-10

Adaptation of mammals to terrestrial life was facilitated by the unique vertebrate trait of body hair, which occurs in a range of morphological patterns. Keratin associated proteins (KRTAPs), the major structural hair shaft proteins, are largely responsible for hair variation. We exhaustively characterized the KRTAP gene family in 22 mammalian genomes, confirming the existence of 30 KRTAP subfamilies evolving at different rates with varying degrees of diversification and homogenization. Within the two major classes of KRTAPs, the high cysteine (HS) subfamily experienced strong concerted evolution, high rates of gene conversion/recombination and high GC content. In contrast, high glycine-tyrosine (HGT) KRTAPs showed evidence of positive selection and low rates of gene conversion/recombination. Species with more hair and of higher complexity tended to have more KRATP genes (gene expansion). The sloth, with long and coarse hair, had the most KRTAP genes (175 with 141 being intact). By contrast, the "hairless" dolphin had 35 KRTAPs and the highest pseudogenization rate (74% relative to the 19% mammalian average). Unique hair-related phenotypes, such as scales (armadillo) and spines (hedgehog), were correlated with changes in KRTAPs. Gene expression variation probably also influences hair diversification patterns, for example human have an identical KRTAP repertoire as apes, but much less hair. We hypothesize that differences in KRTAP gene repertoire and gene expression, together with distinct rates of gene conversion/recombination, pseudogenization and positive selection, are likely responsible for micro and macro-phenotypic hair diversification among mammals in response to adaptations to ecological pressures.

Effect of acid hydrolysis and fungal biotreatment on agro-industrial wastes for obtainment of free sugars for bioethanol production.

PubMed

El-Tayeb, T S; Abdelhafez, A A; Ali, S H; Ramadan, E M

2012-10-01

This study was designed to evaluate selected chemical and microbiological treatments for the conversion of certain local agro-industrial wastes (rice straw, corn stalks, sawdust, sugar beet waste and sugarcane bagasse) to ethanol. The chemical composition of these feedstocks was determined. Conversion of wastes to free sugars by acid hydrolysis varied from one treatment to another. In single-stage dilute acid hydrolysis, increasing acid concentration from 1 % (v/v) to 5 % (v/v) decreased the conversion percentage of almost all treated agro-industrial wastes. Lower conversion percentages for some treatments were obtained when increasing the residence time from 90 to 120 min. The two-stage dilute acid hydrolysis by phosphoric acid (1.0 % v/v) followed by sulphuric acid (1.0 % v/v) resulted in the highest conversion percentage (41.3 % w/w) on treated sugar beet waste. This treatment when neutralized, amended with some nutrients and inoculated with baker's yeast, achieved the highest ethanol concentration (1.0 % v/v). Formation of furfural and hydroxymethylfurfural (HMF) were functions of type of acid hydrolysis, acid concentration, residence time and feedstock type. The highest bioconversion of 5 % wastes (37.8 % w/w) was recorded on sugar beet waste by Trichoderma viride EMCC 107. This treatment when followed by baker's yeast fermentation, 0.41 % (v/v) ethanol and 8.2 % (v/w) conversion coefficient were obtained.

Effect of acid hydrolysis and fungal biotreatment on agro-industrial wastes for obtainment of free sugars for bioethanol production

PubMed Central

El-Tayeb, T.S.; Abdelhafez, A.A.; Ali, S.H.; Ramadan, E.M.

2012-01-01

This study was designed to evaluate selected chemical and microbiological treatments for the conversion of certain local agro-industrial wastes (rice straw, corn stalks, sawdust, sugar beet waste and sugarcane bagasse) to ethanol. The chemical composition of these feedstocks was determined. Conversion of wastes to free sugars by acid hydrolysis varied from one treatment to another. In single-stage dilute acid hydrolysis, increasing acid concentration from 1 % (v/v) to 5 % (v/v) decreased the conversion percentage of almost all treated agro-industrial wastes. Lower conversion percentages for some treatments were obtained when increasing the residence time from 90 to 120 min. The two-stage dilute acid hydrolysis by phosphoric acid (1.0 % v/v) followed by sulphuric acid (1.0 % v/v) resulted in the highest conversion percentage (41.3 % w/w) on treated sugar beet waste. This treatment when neutralized, amended with some nutrients and inoculated with baker’s yeast, achieved the highest ethanol concentration (1.0 % v/v). Formation of furfural and hydroxymethylfurfural (HMF) were functions of type of acid hydrolysis, acid concentration, residence time and feedstock type. The highest bioconversion of 5 % wastes (37.8 % w/w) was recorded on sugar beet waste by Trichoderma viride EMCC 107. This treatment when followed by baker’s yeast fermentation, 0.41 % (v/v) ethanol and 8.2 % (v/w) conversion coefficient were obtained. PMID:24031984

Cancer death rates in US congressional districts.

PubMed

Siegel, Rebecca L; Sahar, Liora; Portier, Kenneth M; Ward, Elizabeth M; Jemal, Ahmedin

2015-01-01

Knowledge of the cancer burden is important for informing and advocating cancer prevention and control. Mortality data are readily available for states and counties, but not for congressional districts, from which representatives are elected and which may be more influential in compelling legislation and policy. The authors calculated average annual cancer death rates during 2002 to 2011 for each of the 435 congressional districts using mortality data from the National Center for Health Statistics and population estimates from the US Census Bureau. Age-standardized death rates were mapped for all sites combined and separately for cancers of the lung and bronchus, colorectum, breast, and prostate by race/ethnicity and sex. Overall cancer death rates vary by almost 2-fold and are generally lowest in Mountain states and highest in Appalachia and areas of the South. The distribution is similar for lung and colorectal cancers, with the lowest rates consistently noted in districts in Utah. However, for breast and prostate cancers, while the highest rates are again scattered throughout the South, the geographic pattern is less clear and the lowest rates are in Hawaii and southern Texas and Florida. Within-state heterogeneity is limited, particularly for men, with the exceptions of Texas, Georgia, and Florida. Patterns also vary by race/ethnicity. For example, the highest prostate cancer death rates are in the West and north central United States among non-Hispanic whites, but in the deep South among African Americans. Hispanics have the lowest rates except for colorectal cancer in Wyoming, eastern Colorado, and northern New Mexico. These data can facilitate cancer control and stimulate conversation about the relationship between cancer and policies that influence access to health care and the prevalence of behavioral and environmental risk factors. © 2015 American Cancer Society.

Phosphate fertilizer affected rhizospheric soils: speciation of cadmium and phytoremediation by Chlorophytum comosum.

PubMed

Wang, Youbao; Zhu, Chengfeng; Yang, Hongfei; Zhang, Xiaowei

2017-02-01

Experiments were conducted to investigate the effect of phosphate fertilization on chemical speciation of cadmium (Cd) in the rhizospheric soil of Chlorophytum comosum, a potential cadmium hyperaccumulator. The results revealed that when 200 mg kg -1 phosphate was applied into the soil, the Cd contents in the exchangeable fraction (EXC), carbonate-binding fraction (CA), and Fe-Mn oxides-binding fraction (Fe-Mn) were the highest, and the Cd content in the residual fraction (RES) was the lowest. Phosphate fertilization could enhance Cd conversion from RES into CA and weak RES, thereby improving the bioavailability of Cd and enhancing Cd enrichment and adsorption by C. comosum. The total Cd content in the soil was reduced by 10.15 mg kg -1 in the planted group, which was significantly different from the control group (p < 0.01). The highest bioaccumulation coefficient (BC) values in root and aboveground parts appeared when the phosphate rates were 276 and 217 mg kg -1 , whereas the highest translocation factor (TF) occurred with a phosphate rate of 188 mg kg -1 . Phosphate fertilization facilitated phytoremediation of Cd-polluted soil by C. comosum.

Simultaneous saccharification and bioethanol production from corn cobs: Process optimization and kinetic studies.

PubMed

Sewsynker-Sukai, Yeshona; Gueguim Kana, E B

2018-08-01

This study investigates the simultaneous saccharification and fermentation (SSF) process for bioethanol production from corn cobs with prehydrolysis (PSSF) and without prehydrolysis (OSSF). Two response surface models were developed with high coefficients of determination (>0.90). Process optimization gave high bioethanol concentrations and bioethanol conversions for the PSSF (36.92 ± 1.34 g/L and 62.36 ± 2.27%) and OSSF (35.04 ± 0.170 g/L and 58.13 ± 0.283%) models respectively. Additionally, the logistic and modified Gompertz models were used to study the kinetics of microbial cell growth and ethanol formation under microaerophilic and anaerobic conditions. Cell growth in the OSSF microaerophilic process gave the highest maximum specific growth rate (µ max ) of 0.274 h -1 . The PSSF microaerophilic bioprocess gave the highest potential maximum bioethanol concentration (P m ) (42.24 g/L). This study demonstrated that microaerophilic rather than anaerobic culture conditions enhanced cell growth and bioethanol production, and that additional prehydrolysis steps do not significantly impact on the bioethanol concentration and conversion in SSF process. Copyright © 2018 Elsevier Ltd. All rights reserved.

Controlling initial biodegradation of magnesium by a biocompatible strontium phosphate conversion coating.

PubMed

Chen, X B; Nisbet, D R; Li, R W; Smith, P N; Abbott, T B; Easton, M A; Zhang, D-H; Birbilis, N

2014-03-01

A simple strontium phosphate (SrP) conversion coating process was developed to protect magnesium (Mg) from the initial degradation post-implantation. The coating morphology, deposition rate and resultant phases are all dependent on the processing temperature, which determines the protective ability for Mg in minimum essential medium (MEM). Coatings produced at 80 °C are primarily made up of strontium apatite (SrAp) with a granular surface, a high degree of crystallinity and the highest protective ability, which arises from retarding anodic dissolution of Mg in MEM. Following 14 days' immersion in MEM, the SrAp coating maintained its integrity with only a small fraction of the surface corroded. The post-degradation effect of uncoated Mg and Mg coated at 40 and 80 °C on the proliferation and differentiation of human mesenchymal stem cells was also studied, revealing that the SrP coatings are biocompatible and permit proliferation to a level similar to that of pure Mg. The present study suggests that the SrP conversion coating is a promising option for controlling the early rapid degradation rate, and hence hydrogen gas evolution, of Mg implants without adverse effects on surrounding cells and tissues. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Linking FRRF Derived Photophysiology with Carbon-based Primary Productivity: Insights from Concepts of Cellular Energy Allocation

NASA Astrophysics Data System (ADS)

Schuback, N.; Schallenberg, C.; Duckham, C.; Flecken, M.; Maldonado, M. T.; Tortell, P. D.

2016-02-01

Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation in photosystem II (ETRRCII), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETRRCII and carbon fixation provides important physiological insight into phytoplankton photosynthesis, and is critical for the application of FRRF as a primary productivity measurement tool. We present data from a series of experiments during which we simultaneously measured phytoplankton carbon fixation and ETRRCII in the iron-limited NE subarctic Pacific. Our results show significant variability of the derived conversion factor (Ve:C/nPSII), with highest values observed under conditions of excess excitation pressure at the level of photosystem II, caused by high light and/or low iron. Our results will be discussed in the context of metabolic plasticity, which evolved in phytoplankton to simultaneously maximize growth and provide photoprotection under fluctuating light and limiting nutrient availabilities. Because the derived conversion factor is associated with conditions of excess light, it correlates with the expression of non-photochemical quenching (NPQ) in the pigment antenna, also derived from FRRF measurements. Our results demonstrate a significant correlation between NPQ and the conversion factor Ve:C/nPSII, and the potential of this relationship to improve FRRF-based estimates of phytoplankton carbon fixation rates is discussed.

Diffusion affected magnetic field effect in exciplex fluorescence

NASA Astrophysics Data System (ADS)

Burshtein, Anatoly I.; Ivanov, Anatoly I.

2014-07-01

The fluorescence of the exciplex, 1[D+δA-δ], formed at contact of photoexcited acceptor 1A* with an electron donor 1D, is known to be very sensitive to an external magnetic field, reducing the spin conversion efficiency in the resulting geminate radical ion pair, 1, 3[D+…A-]. The relative increase of the exciplex fluorescence in the highest magnetic field compared to the lowest one, known as the magnetic field effect, crucially depends on the viscosity of the solvent. This phenomenon first studied experimentally is at first reproduced here theoretically. The magnetic field effect is shown to vanish in both limits of high and low solvent diffusivity reaching a maximum in between. It is also very sensitive to the solvent dielectric constant and to the exciplex and radical-ion pair conversion rates.

Diffusion affected magnetic field effect in exciplex fluorescence.

PubMed

Burshtein, Anatoly I; Ivanov, Anatoly I

2014-07-14

The fluorescence of the exciplex, (1)[D(+δ)A(-δ)], formed at contact of photoexcited acceptor (1)A(*) with an electron donor (1)D, is known to be very sensitive to an external magnetic field, reducing the spin conversion efficiency in the resulting geminate radical ion pair, (1, 3)[D(+)…A(-)]. The relative increase of the exciplex fluorescence in the highest magnetic field compared to the lowest one, known as the magnetic field effect, crucially depends on the viscosity of the solvent. This phenomenon first studied experimentally is at first reproduced here theoretically. The magnetic field effect is shown to vanish in both limits of high and low solvent diffusivity reaching a maximum in between. It is also very sensitive to the solvent dielectric constant and to the exciplex and radical-ion pair conversion rates.

Effect of Electric Field on CO2 Photoreduction by TiO2 Film

NASA Astrophysics Data System (ADS)

Huang, Zhengfeng; Cheng, Xudong; Dong, Peimei; Zhang, Xiwen

2017-02-01

To mitigate the greenhouse effect, many studies have been carried out to improve the CO2 conversion efficiency of TiO2. Modification of TiO2 has been intensively investigated, but the influence of an electric field on photoreduction by this material remains largely unknown. Accordingly, in this study, we explored the effect of an electric field on the photoreduction process using a porous TiO2-Ti material. The results indicated that the CO yield improved 85-fold (equivalent to 4772 μmol/g h) when a 30-kV voltage was applied during the reduction process. To make the electric field effect fully functional, we also explored the effect of water on the photoreduction process, finding that TiO2 showed the highest conversion rate when the humidity was controlled at 50% relative humidity (RH).

Grassland Management and Conversion into Grassland: Effects on Soil Carbon

DOE Data Explorer

Conant, Richard T. [Natural Resource Ecology Laboratory, Colorada State University, Fort Collins, CO (USA); Paustian, Keith [Natural Resource Ecology Laboratory, Colorada State University, Fort Collins, CO (USA); Elliott, Edward T. [Natural Resource Ecology Laboratory, Colorada State University, Fort Collins, CO (USA)

2003-01-01

Grasslands are heavily relied upon for food and forage production. A key component for sustaining production in grassland ecosystems is the maintenance of soil organic matter (SOM), which can be strongly influenced by management. Many management techniques intended to increase forage production may potentially increase SOM, thus sequestering atmospheric carbon (C). Further, conversion from either cultivation or native vegetation into grassland could also sequester atmospheric carbon. We reviewed studies examining the influence of improved grassland management practices and conversion into grasslands on soil C worldwide to assess the potential for C sequestration. Results from 115 studies containing over 300 data points were analyzed. Management improvements included fertilization (39%), improved grazing management (24%), conversion from cultivation (15%) and native vegetation (15%), sowing of legumes (4%) and grasses (2%), earthworm introduction (1%), and irrigation (1%). Soil C content and concentration increased with improved management in 74% of the studies, and mean soil C increased with all types of improvement. Carbon sequestration rates were highest during the first 40 y after treatments began and tended to be greatest in the top 10 cm of soil. Impacts were greater in woodland and grassland biomes than in forest, desert, rain forest, or shrubland biomes. Conversion from cultivation, the introduction of earthworms, and irrigation resulted in the largest increases. Rates of C sequestration by type of improvement ranged from 0.11 to 3.04 Mg C · ha^–1 y^–1, with a mean of 0.54 Mg C · ha ^–1 · y^–1, and were highly influenced by biome type and climate. We conclude that grasslands can act as a significant carbon sink with the implementation of improved management.

Application of Fourier transform infrared (FT-IR) spectroscopy to the study of the modification of epoxidized sunflower oil by acrylation.

PubMed

Irinislimane, Ratiba; Belhaneche-Bensemra, Naima

2012-12-01

Commercial sunflower oil was epoxidized at the laboratory-scale. The epoxidized sunflower oil (ESFO) was modified following the acrylation reaction. Modification was carried out simultaneously using acrylic acid (AA) and triethylamine (TEA). To optimize the reaction conditions, the effects of four temperatures (40, 60, 80, and 100 °C), the ESFO:AA (100:100) ratio, and 0.2% TEA were investigated. The rate of conversion was analyzed with both FT-IR and titration of the oxirane ring. After that, the temperature with the highest conversion was selected and used throughout for all modification reactions. Then, four ratios (100:100, 100:90, 100:80, and 100:75) of ESFO:AA were analyzed at four different concentrations of TEA (0.2, 0.3, 0.4, and 0.5%) to determine the best estimate for both the ESFO:AA ratio and the catalyst concentration. Conversion rate was analyzed using FT-IR spectroscopy by measuring the concentrations of ester, carbonyl, and alcohol groups. Moreover, oxirane-ring concentration was estimated using the titration method (with gentian violet as indicator) and FT-IR spectroscopy (epoxy ring absorptions at 1270 cm(-1) and 877 cm(-1)). Based on conversion yield, the optimum ESFO:AA ratio corresponds to 100:80; the best temperature reaction was at 60 °C, and the best TEA concentration was 0.2%. The critical amounts of reactants needed to reach maximum conversion were established. The final acid value of the acrylated ESFO after washing (pH = 7) was 2.1 mg potassium hydroxide (KOH)·g(-1). All results show that FT-IR spectroscopy is a simple, low-cost, rapid method for investigating the kinetics of a reaction.

Pore diffusion limits removal of monochloramine in treatment of swimming pool water using granular activated carbon.

PubMed

Skibinski, Bertram; Götze, Christoph; Worch, Eckhard; Uhl, Wolfgang

2018-04-01

Overall apparent reaction rates for the removal of monochloramine (MCA) in granular activated carbon (GAC) beds were determined using a fixed-bed reactor system and under conditions typical for swimming pool water treatment. Reaction rates dropped and quasi-stationary conditions were reached quickly. Diffusional mass transport in the pores was shown to be limiting the overall reaction rate. This was reflected consistently in the Thiele modulus, in the effect of temperature, pore size distribution and of grain size on the reaction rates. Pores <2.5 times the diameter of the monochloramine molecule were shown to be barely accessible for the monochloramine conversion reaction. GACs with a significant proportion of large mesopores were found to have the highest overall reactivity for monochloramine removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Selective nickel-catalyzed conversion of model and lignin-derived phenolic compounds to cyclohexanone-based polymer building blocks.

PubMed

Schutyser, Wouter; Van den Bosch, Sander; Dijkmans, Jan; Turner, Stuart; Meledina, Maria; Van Tendeloo, Gustaaf; Debecker, Damien P; Sels, Bert F

2015-05-22

Valorization of lignin is essential for the economics of future lignocellulosic biorefineries. Lignin is converted into novel polymer building blocks through four steps: catalytic hydroprocessing of softwood to form 4-alkylguaiacols, their conversion into 4-alkylcyclohexanols, followed by dehydrogenation to form cyclohexanones, and Baeyer-Villiger oxidation to give caprolactones. The formation of alkylated cyclohexanols is one of the most difficult steps in the series. A liquid-phase process in the presence of nickel on CeO2 or ZrO2 catalysts is demonstrated herein to give the highest cyclohexanol yields. The catalytic reaction with 4-alkylguaiacols follows two parallel pathways with comparable rates: 1) ring hydrogenation with the formation of the corresponding alkylated 2-methoxycyclohexanol, and 2) demethoxylation to form 4-alkylphenol. Although subsequent phenol to cyclohexanol conversion is fast, the rate is limited for the removal of the methoxy group from 2-methoxycyclohexanol. Overall, this last reaction is the rate-limiting step and requires a sufficient temperature (>250 °C) to overcome the energy barrier. Substrate reactivity (with respect to the type of alkyl chain) and details of the catalyst properties (nickel loading and nickel particle size) on the reaction rates are reported in detail for the Ni/CeO2 catalyst. The best Ni/CeO2 catalyst reaches 4-alkylcyclohexanol yields over 80 %, is even able to convert real softwood-derived guaiacol mixtures and can be reused in subsequent experiments. A proof of principle of the projected cascade conversion of lignocellulose feedstock entirely into caprolactone is demonstrated by using Cu/ZrO2 for the dehydrogenation step to produce the resultant cyclohexanones (≈80 %) and tin-containing beta zeolite to form 4-alkyl-ε-caprolactones in high yields, according to a Baeyer-Villiger-type oxidation with H2 O2 . © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Compact conductively cooled electro-optical Q-switched Nd:YAG laser

NASA Astrophysics Data System (ADS)

Li, Chaoyang; Lu, Chengqiang; Li, Chuan; Zang, Yannan; Yang, Zhen; Han, Song; Li, Ye; Yang, Ning; Shi, Junfeng; Zhou, Zewu

2017-11-01

We report on a compact conductively cooled high-repetition-rate nanosecond Nd:YAG laser. The oscillator was an laser diode side-pumped electro-optical (EO) Q-switched Nd:YAG rod laser adopting unstable cavity with a variable reflectivity mirror. A pulse train of 142 mJ with duration of 10 ns, repetition rate of 80 Hz at 1064 nm has been achieved. Maximum pulse energy was obtained at the pump energy of 1380 mJ, corresponding to the optical-optical conversion efficiency of 10.3%. The peak power was deduced to be 14.2 MW. The near-field pattern demonstrated a nearly super Gaussian flat top profile. To our knowledge, this is the highest repetition rate operation for a conductively cooled EO Q-switched Nd:YAG rod laser.

Enhanced the enzymatic hydrolysis efficiency of wheat straw after combined steam explosion and laccase pretreatment.

PubMed

Qiu, Weihua; Chen, Hongzhang

2012-08-01

Laccase, capable of selectively degrading lignin while keeping cellulose intact, has been widely applied for the modification and bio-bleaching of pulp. In this study Sclerotium sp. laccase (MSLac) was employed in combination with steam explosion to evaluate the effect of this treatment on cellulose hydrolysis. Combined steam explosion with laccase pretreatment enhanced the cellulose conversion rate of wheat straw no matter in the case of successive (MSLac-Cel) and simultaneous (MSLac+Cel) MSLac and cellulase hydrolysis. The highest cellulose conversion rate of 84.23% was obtained when steam-exploded wheat straw (SEWS) (1.3 MPa, 5 min) was treated by MSLac+Cel at a laccase loading of 0.55 U g(-1) substrate. FT-IR and SEM analyses indicated that MSLac oxidized the phenol and changed electron configuration of the ring, which contributed to loosening the compact wrap of lignin-carbohydrate complex and consequently enhancing the enzymatic hydrolysis efficiency of cellulose. This article provided a promising method for lignocellulose bio-pretreatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Montreal Cognitive Assessment Memory Index Score (MoCA-MIS) as a predictor of conversion from mild cognitive impairment to Alzheimer's disease.

PubMed

Julayanont, Parunyou; Brousseau, Mélanie; Chertkow, Howard; Phillips, Natalie; Nasreddine, Ziad S

2014-04-01

To assess the usefulness of the Montreal Cognitive Assessment (MoCA) total score (MoCA-TS) and Memory Index Score (MoCA-MIS) in predicting conversion to Alzheimer's disease (AD) in individuals with mild cognitive impairment (MCI). Retrospective chart review. Community-based memory clinic. Individuals meeting Petersen's MCI criteria (N = 165). Baseline MoCA scores at MCI diagnosis were collected from charts of eligible individuals with MCI, and MoCA-TS, MoCA-MIS, and a cognitive domain index score were calculated to assess their prognostic value in predicting conversion to AD. One hundred fourteen participants progressed to AD (MCI-AD), and 51 did not (nonconverters; MCI-NC); 90.5% of participants with MCI with a MoCA-TS less than 20/30 and a MoCA-MIS less than 7/15 at baseline converted to AD within the average follow-up period of 18 months, compared with 52.7% of participants with MCI above the cutoffs on both scores. Individuals with multiple-domain amnestic MCI had the highest AD conversion rates (73.9%). Identifying individuals with MCI at high risk of conversion to AD is important clinically and for selecting appropriate subjects for therapeutic trials. Individuals with MCI with a low MoCA-TS and a low newly devised memory index score (MoCA-MIS) are at greater risk of short-term conversion to AD. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

Effect of flow field on the performance of an all-vanadium redox flow battery

NASA Astrophysics Data System (ADS)

Kumar, S.; Jayanti, S.

2016-03-01

A comparative study of the electrochemical energy conversion performance of a single-cell all-vanadium redox flow battery (VRFB) fitted with three flow fields has been carried out experimentally. The charge-discharge, polarization curve, Coulombic, voltage and round-trip efficiencies of a 100 cm2 active area VRFB fitted with serpentine, interdigitated and conventional flow fields have been obtained under nearly identical experimental conditions. The effect of electrolyte circulation rate has also been investigated for each flow field. Stable performance has been obtained for each flow field for at least 40 charge/discharge cycles. Ex-situ measurements of pressure drop have been carried out using water over a range of Reynolds numbers. Together, the results show that the cell fitted with the serpentine flow field gives the highest energy efficiency, primarily due to high voltaic efficiency and also the lowest pressure drop. The electrolyte flow rate is seen to have considerable effect on the performance; a high round-trip energy efficiency of about 80% has been obtained at the highest flow rate with the serpentine flow field. The data offer interesting insights into the effect of electrolyte circulation on the performance of VRFB.

[Screening and optimization of cholesterol conversion strain].

PubMed

Fan, Dan; Xiong, Bingjian; Pang, Cuiping; Zhu, Xiangdong

2014-10-04

Bacterial strain SE-1 capable of transforming cholesterol was isolated from soil and characterized. The transformation products were identified. Fermentation conditions were optimized for conversion. Cholesterol was used as sole carbon source to isolate strain SE-1. Morphology, physiological and biochemical characteristics of strain SE-1 were studied. 16S rRNA gene was sequenced and subjected to phylogenetic analysis. Fermentation supernatants were extracted with chloroform, the transformation products were analyzed by silica gel thin layer chromatography and Sephadex LH20. Their structures were identified by 1H-NMR and 13C-NMR. Fermentation medium including carbon and nitrogen, methods of adding substrates and fermentation conditions for Strain SE-1 were optimized. Strain SE-1 was a Gram-negative bacterium, exhibiting the highest homologs to Burkholderia cepacia based on the physiological analysis. The sequence analysis of 16S rRNA gene of SE-1 strain and comparison with related Burkholderia show that SE-1 strain was very close to B. cepacia (Genbank No. U96927). The similarity was 99%. The result of silica gel thin layer chromatography shows that strain SE-1 transformed cholesterol to two products, 7beta-hydroxycholesterol and the minor product was 7-oxocholesterol. The optimum culture conditions were: molasses 5%, (NH4 )2SO4 0.3%, 4% of inoculation, pH 7.5 and 36 degrees C. Under the optimum culture condition, the conversion rate reached 34.4% when concentration of cholesterol-Tween 80 was 1 g/L. Cholesterol 7beta-hydroxylation conversion rate under optimal conditions was improved by 20.8%. Strain SE-1 isolated from soil is capable of converting cholesterol at lab-scale.

Vibrational energy flow controls internal conversion in a transition metal complex.

PubMed

Hedley, Gordon J; Ruseckas, Arvydas; Samuel, Ifor D W

2010-09-02

Internal conversion (IC) between excited electronic states is a fundamental photophysical process that is important for understanding protection from UV radiation, energy transfer pathways and electron injection in artificial photosynthetic systems and organic solar cells. We have studied IC between three singlet MLCT states in an iridium complex using femtosecond fluorescence spectroscopy. Very fast IC with a time constant of <20 fs is observed from the highest state and a much slower relaxation to the lowest energy singlet state on a 70 fs time scale. The abrupt slowdown of the relaxation rate occurs when there is >0.6 eV of vibrational energy stored in the complex that has to be dissipated by intramolecular vibrational redistribution before further IC to the lower energy states can occur. These results show that the ability to dissipate vibrational energy can control the relaxation process in this class of materials.

The efficacy of different commercially available demineralized bone matrix substances in an athymic rat model.

PubMed

Lee, Yu-Po; Jo, Mark; Luna, Mario; Chien, Bobby; Lieberman, Jay R; Wang, Jeffrey C

2005-10-01

Bone graft substitutes have been developed because there is a limited supply of autogenous graft and the harvesting of iliac crest bone graft is associated with significant morbidity. Currently, there are a number of different commercially available demineralized bone matrix (DBM) products available that have been prepared by different methods and have different carriers. The objective of this study was to compare eight different commercially available DBM products. Eight different DBMs were used to attempt a spinal fusion between the L4-L5 transverse processes in athymic rats. There were 10 rats in each group, and 5 rats were killed at both 4 and 8 weeks. Radiographic and histologic analyses were performed. Manual palpation testing was also performed. At 4 weeks, Osteofil Paste had the highest radiographic scores, whereas Grafton Putty had the best radiographic scores at 8 weeks. Conversely, the spines implanted with Allomatrix had the lowest radiographic scores at both 4 and 8 weeks. In regard to forming a spinal fusion confirmed by manual palpation, Osteofil Paste was the most effective at 4 weeks, whereas Grafton Flex and Grafton Putty had the highest rate of fusion at 8 weeks. Conversely, the lowest rates of fusion were seen in the Allomatrix and Grafton Crunch groups. Statistical analysis showed that there were significant differences among the groups seen on radiographs and by manual palpation. Qualitative differences could be appreciated between the groups histologically. Significant differences exist among commercially available DBMs in forming a spinal fusion in an athymic rat.

Rate of revisions or conversion after bariatric surgery over 10 years in the state of New York.

PubMed

Altieri, Maria S; Yang, Jie; Nie, Lizhou; Blackstone, Robin; Spaniolas, Konstantinos; Pryor, Aurora

2018-04-01

A primary measure of the success of a procedure is the whether or not additional surgery may be necessary. Multi-institutional studies regarding the need for reoperation after bariatric surgery are scarce. The purpose of this study is to evaluate the rate of revisions/conversions (RC) after 3 common bariatric procedures over 10 years in the state of New York. University Hospital, involving a large database in New York State. The Statewide Planning and Research Cooperative System database was used to identify all patients undergoing laparoscopic adjustable gastric banding (LAGB), sleeve gastrectomy (SG), and Roux-en-Y gastric bypass (RYGB) between 2004 and 2010. Patients were followed for RC to other bariatric procedures for at least 4 years (up to 2014). Multivariable cox proportional hazard regression analysis was performed to identify risk factors for additional surgery after each common bariatric procedure. Multivariable logistic regression was used to check the factors associated with having ≥2 follow-up procedures. There were 40,994 bariatric procedures with 16,444 LAGB, 22,769 RYGB, and 1781 SG. Rate of RC was 26.0% for LAGB, 9.8% for SG, and 4.9% for RYGB. Multiple RC ( = />2) were more common for LAGB (5.7% for LAGB, .5% for RYGB, and .2% for LSG). Band revision/replacements required further procedures compared with patients who underwent conversion to RYGB/SG (939 compared with 48 procedures). Majority of RC were not performed at initial institution (68.2% of LAGB patients, 75.9% for RYGB, 63.7% of SG). Risk factors for multiple procedures included surgery type, as LAGB was more likely to have multiple RC. Reoperation was common for LAGB, but less common for RYGB (4.9%) and SG (9.8%). RC rate are almost twice after SG than after RYGB. LAGB had the highest rate (5.7%) of multiple reoperations. Conversion was the procedure of choice after a failed LAGB. Copyright © 2018 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Assessment of soil erosion vulnerability in the heavily populated and ecologically fragile communities in Motozintla de Mendoza, Chiapas, Mexico

NASA Astrophysics Data System (ADS)

González-Morales, Selene B.; Mayer, Alex; Ramírez-Marcial, Neptalí

2018-06-01

Variability in physical rates and local knowledge of soil erosion was assessed across six rural communities in the Sierra Madre del Sur, Chiapas, Mexico. The average erosion rate estimated using the RUSLE model is 274 t ha-1 yr-1, with the estimated erosion rates ranging from 28 to 717 t ha-1 yr-1. These very high erosion rates are associated with high rainfall erosivity (17 000 MJ mm ha-1 h-1 yr-1) and steep slopes (mean slope = 67 %). Many of the highest soil erosion rates are found in communities that are dominated by forestland, but where most of the tree cover has been removed. Conversely, lower erosion rates are often found where corn is cultivated for most of the year. According to the results of the soil erosion KAP (knowledge, attitude and practices) survey, awareness of the concept of soil erosion was reasonably high in all of the communities, but awareness of the causes of erosion was considerably lower. More than half of respondents believed that reforestation is a viable option for reducing soil erosion, but only a third of respondents were currently implementing reforestation practices. Another third of the respondents indicated that they were not following any soil conservation practices. Respondents indicated that adoption of government reforestation efforts have been hindered by the need to clear their land to sell forest products or cultivate corn. Respondents also mentioned the difficulties involved with obtaining favorable tree stocks for reforestation. The KAP results were used to assess the overall level of motivation to solve soil erosion problems by compiling negative responses. The relationship between the magnitude of the soil erosion problem and the capacity to reduce soil erosion is inconsistent across the communities. One community, Barrio Vicente Guerrero, had the highest average negative response rate and the second highest soil erosion rate, indicating that this community is particularly vulnerable.

Increase in D-tagatose production rate by site-directed mutagenesis of L-arabinose isomerase from Geobacillus thermodenitrificans.

PubMed

Oh, Hyo-Jung; Kim, Hye-Jung; Oh, Deok-Kun

2006-02-01

Among single-site mutations of L-arabinose isomerase derived from Geobacillus thermodenitrificans, two mutants were produced having the lowest and highest activities of D-tagatose production. Site-directed mutagenesis at these sites showed that the aromatic ring at amino acid 164 and the size of amino acid 475 were important for D-tagatose production. Among double-site mutations, one mutant converted D-galactose into D-tagatose with a yield of 58% whereas the wild type gave 46% D-tagatose conversion after 300 min at 65 degrees C.

Influence of coffee and caffeine consumption on atrial fibrillation in hypertensive patients.

PubMed

Mattioli, A V; Farinetti, A; Miloro, C; Pedrazzi, P; Mattioli, G

2011-06-01

Coffee and caffeine are widely consumed in Western countries. Little information is available on the influence of coffee and caffeine consumption on atrial fibrillation (AF) in hypertensive patients. We sought to investigate the relationship between coffee consumption and atrial fibrillation with regard to spontaneous conversion of arrhythmia. A group of 600 patients presenting with a first known episode of AF was investigated, and we identified 247 hypertensive patients. The prevalence of nutritional parameters was assessed with a food frequency questionnaire. Coffee and caffeine intake were specifically estimated. Left ventricular hypertrophy was evaluated by electrocardiogram (ECG) and echocardiogram. Coffee consumption was higher in normotensive patients. High coffee consumers were more frequent in normotensive patients compared with hypertensive patients. On the other hand, the intake of caffeine was similar in hypertensive and normotensive patients, owing to a higher intake in hypertensive patients from sources other than coffee. Within normotensive patients, we report that non-habitual and low coffee consumers showed the highest probability of spontaneous conversion (OR 1.93 95%CI 0.88-3.23; p=0.001), whereas, within hypertensive patients, moderate but not high coffee consumers had the lowest probability of spontaneous conversion (OR 1.13 95%CI 0.67-1.99; p=0.05). Coffee and caffeine consumption influence spontaneous conversion of atrial fibrillation. Normotensive non-habitual coffee consumers are more likely to convert arrhythmia within 48h from the onset of symptoms. Hypertensive patients showed a U-shaped relationship between coffee consumption and spontaneous conversion of AF, moderate coffee consumers were less likely to show spontaneous conversion of arrhythmia. Patients with left ventricular hypertrophy showed a reduced rate of spontaneous conversion of arrhythmia. Copyright © 2009 Elsevier B.V. All rights reserved.

Does the Biosocial Model Explain the Emergence of Status Differences in Conversations among Unacquainted Men?

PubMed Central

Mazur, Allan; Welker, Keith M.; Peng, Bin

2015-01-01

Fifteen triads of unacquainted men conversed for ten minutes while stress was measured in real time by pulse rate and thumb blood volume (TBV). Salivary measures of testosterone (T), cortisol (C), and the stress-related enzyme alpha-amylase (AA) were measured at the beginning and end of the session. Fully or partially transitive status hierarchies formed in 14 triads. (Highest ranked man was scored 1, lowest 3, with ties allowed.) Ten of the triads participated in Study 1, where nothing was at stake in the casual conversation. Five additional triads were run in Study 2, intended to introduce competition by offering a $20 reward to the man afterward chosen as having led the conversation. Most results from the two studies are similar, suggesting that the $20 reward had little effect. Combining studies, pulse and TBV show that conversation is more stressful than watching a video beforehand. Within the conversation, speaking turns are more stressful than listening turns, especially among the lowest ranked men, less so among those higher in rank. This supports a stress-based mechanism for status allocation among humans. Apparently, human speech is a form of status signaling, homologous with nonlinguistic status signals used by other primates, as posited by the “biosocial model.” The biosocial model also posits that a physiological substrate (T, C, and AA) is related to dominance or status. Predicted effects are not replicated here, except for an inverse relationship between the stress enzyme AA and status. The mostly null results, obtained from conversations where there was little or nothing at stake, suggest that T and C (and their interaction) are not relevant to emergent status in the absence of serious competition. PMID:26588849

Land use change and its driving forces toward mutual conversion in Zhangjiakou City, a farming-pastoral ecotone in Northern China.

PubMed

Liu, Chao; Xu, Yueqing; Sun, Piling; Huang, An; Zheng, Weiran

2017-09-14

Land use/cover change (LUCC), a local environmental issue of global importance, and its driving forces have been crucial issues in geography and environmental research. Previous studies primarily focused on major driving factors in various land use types, with few explorations of differences between driving forces of mutual land use type conversions, especially in fragile eco-environments. In this study, Zhangjiakou City, in a farming-pastoral ecotone in Northern China, was taken as an example to analyze land use change between 1989 and 2015, and explore the driving forces of mutual land use type conversions using canonical correlation analysis. Satellite images and government statistics, including social-economic and natural data, were used as sources. Arable land, forestland, and grassland formed the main land use structure. From 1989 to 2015 forestland, orchard land, and construction land significantly increased, while arable land, grassland, unused land, and water areas decreased. Conversions from grassland to forestland; from arable land to orchard land, forestland and construction land; and from unused land to grassland and forestland were the primary land use changes. Among these, the conversion from grassland to forestland had the highest ranking. Average annual precipitation and per capita net income of rural residents positively affected the conversion of arable land to forestland and unused land to grassland. GDP, total population, and urbanization rate contributed most significantly to converting arable land to construction land; total retail sales of social consumer goods, average annual temperature, and GDP had important positive influences in converting arable land to orchard land.

Age-Related Trends in Hip Arthroscopy: A Large Cross-Sectional Analysis.

PubMed

Sing, David C; Feeley, Brian T; Tay, Bobby; Vail, Thomas P; Zhang, Alan L

2015-12-01

To analyze a large national private payer population in the United States for trends over time in hip arthroscopy by age groups and to determine the rate of conversion to total hip arthroplasty (THA) after hip arthroscopy. We performed a retrospective analysis using the PearlDiver private insurance patient record database from 2007 through 2011. Hip arthroscopy procedures including newly introduced codes such as osteochondroplasty of cam and pincer lesions and labral repair were queried. Hip arthroscopy incidence and conversion rates to THA were stratified by age. Chi-squared analysis was used for statistical comparison. Conversion to THA was evaluated using Kaplan-Meier analysis. From 2007 through 2011, 20,484,172 orthopaedic patients were analyzed. Hip arthroscopy was performed in 8,227 cases (mean annual incidence, 2.7 cases per 10,000 orthopaedic patients). The incidence of hip arthroscopies increased over 250% from 1.6 cases per 10,000 in 2007 to 4.0 cases per 10,000 in 2011 (P < .0001). Patients in the 40 to 49 age group made up 28% of cases, followed by patients ages 30 to 39 (22%) and 50 to 59 (19%). Patients under 30 years old showed the greatest increase in incidence from 2007 to 2011 (335%), but patients over 60 still had over a 200% increase. Labral debridement was the most common procedure (6,031 cases), and approximately 1.6 procedural codes were billed for every case performed. Labral repair was more common in patients under 30, while labral debridement was more common in older age groups (P = .046). Within 24 months of hip arthroscopy, 17% of patients older than 50 required conversion to THA, compared with <1% of patients under 30 (P < .0001). Hip arthroscopy procedures are increasing in popularity across all age groups, with patients ages 40 to 49 having the highest incidence in this large cross-sectional population, despite a high rate of early conversion to THA within 2 years in patients over 50. IV, cross-sectional study. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Hydrothermal liquefaction of Undaria pinnatifida residues to organic acids with recyclable trimethylamine.

PubMed

Chen, Yongxing; Ren, Xiulian; Wei, Qifeng; Guo, Jingjing

2016-12-01

This study investigated the effect of trimethylamine (TMA) on the hydrothermal liquefaction (HTL) process and the recycle of TMA. The results suggest that the peeling reaction occurred on the surface and the cleavage of cellulose leading to water-soluble substances and bio-oil. The highest content of organic acids was found in the water-soluble phase. Model compounds, different glucides with TMA were used to investigate the mechanism of the HTL. Results suggest that the OH - appeared to selectively interact with C-O-C bonds, and thus causing the key linkages of cellulose to become much easier to be cleaved under mild conditions. In addition, the conditions for TMA recovery were optimized and the highest TMA recovery rate reached 98.89%. The recovered TMA had the same properties as the original compound, and it was perfectly re-usable in the conversion process of HTL. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nephrectomy for benign disease in the UK: results from the British Association of Urological Surgeons nephrectomy database.

PubMed

Zelhof, Bachar; McIntyre, Iain G; Fowler, Sarah M; Napier-Hemy, Richard D; Burke, Daniel M; Grey, Ben R

2016-01-01

To summarize the practice of UK urologists with regard to nephrectomy for benign disease, documenting the indications, procedural techniques and outcomes. All patients undergoing nephrectomy for a benign condition in 2012 were identified from the British Association of Urological Surgeons (BAUS) nephrectomy database. Recorded variables included the technique of surgery, the type of minimally invasive procedure, operating time, blood loss, transfusion rate, conversion rate, intra- and postoperative complications and mortality rate. Cases were also sub-analysed according to their pathologies to determine the differences in complication rate between stone disease, pyelonephritis, non-functioning kidney and other benign lesions. To contextualize procedural complexity, the simple nephrectomy data were compared with those obtained from the BAUS stage T1 radical nephrectomy audit. A total of 1 093 nephrectomies were performed (537 non-functioning kidneys, 142 stone disease, 129 nephrectomies secondary to pyelonephritis and 285 cases with other benign conditions). Of these, 76% were performed laparoscopically. Blood loss >500 mL was noted in 74 cases with a 4.8% blood transfusion rate. The intra- and postoperative complication rates were 5.2 and 11.9%, respectively. Of the 847 minimally invasive procedures, the conversion rate was 5.9%. Patients with stone disease have the highest intra- and postoperative complications (9.9 and 23.9%, respectively) compared with other benign pathologies. The total number of T1 radical nephrectomies performed was 1 095. In comparison with T1 radical nephrectomy, simple nephrectomy carries an increased risk of conversion to an open procedure (1.8 times), a higher rate of blood transfusion (4.8 vs 2.8%), and a higher risk of intra- and postoperative complications (5.2 vs 3.7% and 11.9 vs 10%, respectively). The present study reports the largest series of nephrectomies performed for benign disease and the resultant data now support the bespoke preoperative counselling of patients. Furthermore, it confirms the commonly held view that simple nephrectomy can be more difficult than its radical counterpart. The authors suggest that the term 'simple nephrectomy' is changed to 'benign nephrectomy'. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

Mechanism for converting Al2O3-containing borate glass to hydroxyapatite in aqueous phosphate solution.

PubMed

Zhao, Di; Huang, Wenhai; Rahaman, Mohamed N; Day, Delbert E; Wang, Deping

2009-05-01

The effect of replacing varying amounts (0-2.5 mol.%) of B2O3 with Al2O3 in a borate glass on (1) the conversion of the glass to HA in an aqueous phosphate solution and (2) the compressive strength of the as-formed HA product was investigated. Samples of each glass (10 x 10 x 8 mm) were placed in 0.25 M K2HPO4 solution at 60 degrees C, and the conversion kinetics to HA were determined from the weight loss of the glass and the pH of the solution. The structure and composition of the solid reaction products were characterized using X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. While the conversion rate of the glass to HA decreased considerably with increasing Al2O3 content, the microstructure of the HA product became denser and the compressive strength of the HA product increased. The addition of SiO2 to the Al2O3-containing borate glass reversed the deterioration of the conversion rate, and produced a further improvement in the strength of the HA product. The compressive strength of the HA formed from the borate glass with 2.5 mol.% Al2O3 and 5 mol.% SiO2 was 11.1 +/- 0.2 MPa, which is equal to the highest strengths reported for trabecular bone. The results indicated that simultaneous additions of Al2O3 and SiO2 could be used to control the bioactivity of the borate glass and to enhance the mechanical strength of the HA product. Furthermore, the HA product formed from the glass containing both SiO2 and Al2O3 could be applied to bone repair.

Continuous Hydrolysis of Pectate by Immobilized Endo-polygalacturonase in a Continuously Stirred Tank Reactor.

PubMed

Iwasaki, K; Inoue, M; Matsubara, Y

1998-01-01

Enzymatic hydrolysis of pectate was carried out continuously to produce pectate oligosaccharides by immobilized endo-polygalacturonase in a continuous stirred tank reactor (CSTR) with high efficiency. The enzyme was immobilized on to chitosan beads by the absorption method, and the reaction was performed with an initial pectate concentration of 10 gl(-1) at 35°C and pH 4.0 at a dilution rate of 0.87-2.8 h(-1). The hydrolysis products mainly consisted of mono-, di-, tri-, tetra-, penta-, hexa- and heptasaccharides, with the highest conversion being 0.78. A higher volumetric production rate of the total hydrolyzate, which was dependent on the dilution rate, was obtained than that by a batch reaction. The hydrolysis process was mathematically modeled from the basic material balance and rate equations, and showed agreement between the simulated and experimental results. This reactor system was found to be effective for obtaining pectate oligosaccharides with a high production rate.

Transformation products and reaction pathways of carbamazepine during photocatalytic and sonophotocatalytic treatment.

PubMed

Jelic, A; Michael, I; Achilleos, A; Hapeshi, E; Lambropoulou, D; Perez, S; Petrovic, M; Fatta-Kassinos, D; Barcelo, D

2013-12-15

This study examines the degradation of the antiepileptic carbamazepine (CBZ) by sonolysis, TiO2-based heterogeneous photocatalysis under UV-A and simulated solar irradiation, and by the combined use of UV-A and ultrasound irradiation (i.e. sonophotocatalysis) in demineralized water, ground water and effluent wastewater. The processes were compared with respect to substrate conversion rate and the extent of DOC reduction as a measure of mineralization. CBZ was degraded following a pseudo-first order kinetics. Sonophotocatalysis provided the highest rate of CBZ transformation over the time-course of the experiment while the degree of DOC removal in pure water was similar for all the studied treatments (around 40%), and always lower than CBZ conversion. This indicated that a considerable organic load remained in the treated solutions that could also be attributed to the presence of persistent oxidation products. UPLC-(+ESI)-QToF-MS was employed to determine major CBZ-related transformation products. Several recalcitrant hydroxy- and keto-derivatives of CBZ were tentatively identified. A Daphnia magna bioassay was used to evaluate the potential toxicity of the samples collected at different time points showing that the mixtures were highly toxic to D. magna. Copyright © 2013. Published by Elsevier B.V.

Fastest Formation Routes of Nanocarbons in Solution Plasma Processes.

PubMed

Morishita, Tetsunori; Ueno, Tomonaga; Panomsuwan, Gasidit; Hieda, Junko; Yoshida, Akihito; Bratescu, Maria Antoaneta; Saito, Nagahiro

2016-11-14

Although solution-plasma processing enables room-temperature synthesis of nanocarbons, the underlying mechanisms are not well understood. We investigated the routes of solution-plasma-induced nanocarbon formation from hexane, hexadecane, cyclohexane, and benzene. The synthesis rate from benzene was the highest. However, the nanocarbons from linear molecules were more crystalline than those from ring molecules. Linear molecules decomposed into shorter olefins, whereas ring molecules were reconstructed in the plasma. In the saturated ring molecules, C-H dissociation proceeded, followed by conversion into unsaturated ring molecules. However, unsaturated ring molecules were directly polymerized through cation radicals, such as benzene radical cation, and were converted into two- and three-ring molecules at the plasma-solution interface. The nanocarbons from linear molecules were synthesized in plasma from small molecules such as C 2 under heat; the obtained products were the same as those obtained via pyrolysis synthesis. Conversely, the nanocarbons obtained from ring molecules were directly synthesized through an intermediate, such as benzene radical cation, at the interface between plasma and solution, resulting in the same products as those obtained via polymerization. These two different reaction fields provide a reasonable explanation for the fastest synthesis rate observed in the case of benzene.

Fastest Formation Routes of Nanocarbons in Solution Plasma Processes

PubMed Central

Morishita, Tetsunori; Ueno, Tomonaga; Panomsuwan, Gasidit; Hieda, Junko; Yoshida, Akihito; Bratescu, Maria Antoaneta; Saito, Nagahiro

2016-01-01

Although solution-plasma processing enables room-temperature synthesis of nanocarbons, the underlying mechanisms are not well understood. We investigated the routes of solution-plasma-induced nanocarbon formation from hexane, hexadecane, cyclohexane, and benzene. The synthesis rate from benzene was the highest. However, the nanocarbons from linear molecules were more crystalline than those from ring molecules. Linear molecules decomposed into shorter olefins, whereas ring molecules were reconstructed in the plasma. In the saturated ring molecules, C–H dissociation proceeded, followed by conversion into unsaturated ring molecules. However, unsaturated ring molecules were directly polymerized through cation radicals, such as benzene radical cation, and were converted into two- and three-ring molecules at the plasma–solution interface. The nanocarbons from linear molecules were synthesized in plasma from small molecules such as C2 under heat; the obtained products were the same as those obtained via pyrolysis synthesis. Conversely, the nanocarbons obtained from ring molecules were directly synthesized through an intermediate, such as benzene radical cation, at the interface between plasma and solution, resulting in the same products as those obtained via polymerization. These two different reaction fields provide a reasonable explanation for the fastest synthesis rate observed in the case of benzene. PMID:27841288

Surgical volume and conversion rate in laparoscopic hysterectomy: does volume matter? A multicenter retrospective cohort study.

PubMed

Keurentjes, José H M; Briët, Justine M; de Bock, Geertruida H; Mourits, Marian J E

2018-02-01

A multicenter, retrospective, cohort study was conducted in the Netherlands. The aim was to evaluate whether surgical volume of laparoscopic hysterectomies (LHs) performed by proven skilled gynecologists had an impact on the conversion rate from laparoscopy to laparotomy. In 14 hospitals, all LHs performed by 19 proven skilled gynecologists between 2007 and 2010 were included in the analysis. Surgical volume, conversion rate and type of conversion (reactive or strategic) were retrospectively assessed. To estimate the impact of surgical volume on the conversion rate, logistic regressions were performed. These regressions were adjusted for patient's age, Body Mass Index (BMI), ASA classification, previous abdominal surgery and the indication (malignant versus benign) for the LH. During the study period, 19 proven skilled gynecologists performed a total of 1051 LHs. Forty percent of the gynecologists performed over 20 LHs per year (median 17.3, range 5.4-49.5). Conversion to laparotomy occurred in 5.0% of all LHs (53 of 1051); 38 (3.6%) were strategic and 15 (1.4%) were reactive conversions. Performing over 20 LHs per year was significantly associated with a lower overall conversion rate (OR adjusted 0.43, 95% CI 0.24-0.77), a lower strategic conversion rate (OR adjusted 0.32, 95% CI 0.16-0.65), but not with a lower reactive conversion rate (OR adjusted 0.96, 95% CI 0.33-2.79). A higher annual surgical volume of LHs by proven skilled gynecologists is inversely related to the conversion rate to laparotomy, and results in a lower strategic conversion rate.

Cultural transformation toward patient safety: one conversation at a time.

PubMed

Moore, Martie L; Putman, Patrice A

2008-01-01

Patient safety has become a critical objective for nursing leaders within the healthcare setting. Changing the culture to ensure the highest level of communication and safety is a daunting task. Many of the contributing factors that lead to patient harm are rooted in conflict and ineffective conversations. This article shares the story of how 1 organization agreed to make a cultural transformation and the success it realized one conversation at a time.

Phosphorus and nitrate nitrogen in runoff following fertilizer application to turfgrass.

PubMed

Shuman, L M

2002-01-01

Intensively managed golf courses are perceived by the public as possibly adding nutrients to surface waters via surface transport. An experiment was designed to determine the transport of nitrate N and phosphate P from simulated golf course fairways of 'Tifway' bermudagrass [Cynodon dactylon (L.) Pers.]. Fertilizer treatments were 10-10-10 granular at three rates and rainfall events were simulated at four intervals after treatment (hours after treatment, HAT). Runoff volume was directly related to simulated rainfall amounts and soil moisture at the time of the event and varied from 24.3 to 43.5% of that added for the 50-mm events and 3.1 to 27.4% for the 25-mm events. The highest concentration and mass of phosphorus in runoff was during the first simulated rainfall event at 4 HAT with a dramatic decrease at 24 HAT and subsequent events. Nitrate N concentrations were low in the runoff water (approximately 0.5 mg L-1) for the first three runoff events and highest (approximately 1-1.5 mg L-1) at 168 HAT due to the time elapsed for conversion of ammonia to nitrate. Nitrate N mass was highest at the 4 and 24 HAT events and stepwise increases with rate were evident at 24 HAT. Total P transported for all events was 15.6 and 13.8% of that added for the two non-zero rates, respectively. Total nitrate N transported was 1.5 and 0.9% of that added for the two rates, respectively. Results indicate that turfgrass management should include applying minimum amounts of irrigation after fertilizer application and avoiding application before intense rain or when soil is very moist.

Realization of a mW-level 10.7-eV (λ = 115.6 nm) laser by cascaded third harmonic generation of a Yb:fiber CPA laser at 1-MHz.

PubMed

Zhao, Zhigang; Kobayashi, Yohei

2017-06-12

We demonstrate a 10.7-eV (λ = 115.6 nm) laser with mW levels of average power and a 1-MHz repetition rate, which was driven by the third harmonic radiation (THG), at 347 nm, of an Yb:fiber chirped pulse amplifier (CPA) laser. The 347 nm ultraviolet radiation was obtained by frequency conversion of the high power output of a 1-MHz Yb:fiber CPA, using beta barium borate (BBO) nonlinear crystals. The frequency converted output was focused down into a gas cell filled with a mixture of Ar and Xe, and was subjected to a second THG frequency conversion. The generated 10.7-eV laser was separated from the fundamental beam using a LiF prism and no further separation from other harmonic waves was required. The highest measured output power was ~80 μW, which corresponded to an average power of ~1.25 mW inside the gas cell when the transmission coefficients of the LiF optics were taken into account. The corresponding conversion efficiency from 347 nm down to 115.6 nm was ~2.5 × 10 -4 .

Biodiesel production from various oils under supercritical fluid conditions by Candida antartica lipase B using a stepwise reaction method.

PubMed

Lee, Jong Ho; Kwon, Cheong Hoon; Kang, Jeong Won; Park, Chulhwan; Tae, Bumseok; Kim, Seung Wook

2009-05-01

In this study, we evaluate the effects of various reaction factors, including pressure, temperature, agitation speed, enzyme concentration, and water content to increase biodiesel production. In addition, biodiesel was produced from various oils to establish the optimal enzymatic process of biodiesel production. Optimal conditions were determined to be as follows: pressure 130 bar, temperature 45 degrees C, agitation speed 200 rpm, enzyme concentration 20%, and water contents 10%. Among the various oils used for production, olive oil showed the highest yield (65.18%) upon transesterification. However, when biodiesel was produced using a batch system, biodiesel conversion yield was not increased over 65%; therefore, a stepwise reaction was conducted to increase biodiesel production. When a reaction medium with an initial concentration of methanol of 60 mmol was used and adjusted to maintain this concentration of methanol every 1.5 h during biodiesel production, the conversion yield of biodiesel was 98.92% at 6 h. Finally, reusability was evaluated using immobilized lipase to determine if this method was applicable for industrial biodiesel production. When biodiesel was produced repeatedly, the conversion rate was maintained at over 85% after eight reuses.

Profile of tuberculosis patients with delayed sputum smear conversion in the Pacific island of Vanuatu

PubMed Central

Viney, K.; Tarivonda, L.; Roseveare, C.; Tagaro, M.; Marais, B. J.

2014-01-01

Setting: National tuberculosis control programme, Vanuatu. Objective: To assess tuberculosis (TB) trends, characterise sputum smear-positive patients with non-conversion at 2 months and assess their treatment outcomes. Design: Evaluation of programme data over a 9-year period (2004–2012), comparing 2-month sputum non-converters (delayed converters) with sputum smear converters diagnosed in 2011 and 2012. Results: Annual TB case numbers were similar over the study period, with an average TB notification rate of 58 per 100 000 population. Of 417 sputum smear-positive cases, 74 (18%) were delayed converters. Delayed converters were more likely than converters (88% vs. 79%) to have had high pre-treatment sputum smear grades (OR 2.5, 95%CI 0.97–6.45). Among delayed converters, treatment adherence was high (99% good adherence), outcomes were generally good (90% treatment success, 85% cure, 4% treatment failure) and no drug resistance was detected. Deaths were unexpectedly common among converters (11/80, 14%), with significantly more deaths in Tafea than in Shefa Province (7/58 vs. 2/80, OR 5.35, 95%CI 1.07–26.79). Tafea Province also had the greatest number of delayed converters (30/74, 40.5%) and the highest TB incidence rate. Conclusion: Delayed sputum conversion was relatively uncommon, and was not associated with adverse outcomes or drug resistance. Regional differences require further investigation to better understand local factors that may compromise patient management. PMID:26477281

Recruitment Strategies and Costs Associated With Enrolling People With Insomnia and High Blood Pressure Into an Online Behavioral Sleep Intervention: A Single-Site Pilot Study.

PubMed

Routledge, Faye S; Davis, Tara D; Dunbar, Sandra B

Recruitment in clinical research is a common challenge and source of study failure. The reporting of recruitment methods and costs in hypertension trials is limited especially for smaller, single-site trials, online intervention trials, and trials using newer online recruitment strategies. The aims of this study are to describe and examine the feasibility of newer online-e-mail recruitment strategies and traditional recruitment strategies used to enroll participants with insomnia and high blood pressure into an online behavioral sleep intervention study (Sleeping for Heart Health). The 16 online-e-mail-based and traditional recruitment strategies used are described. Recruitment strategy feasibility was examined by study interest and enrollee yields, conversion rates, and costs (direct, remuneration, labor, and cost per enrollee). From August 2014 to October 2015, 183 people were screened and 58 (31.7%) enrolled in the study (51.1 ± 12.9 years, 63.8% female, 72.4% African American, 136 ± 12/88 ± 7 mm Hg, 87.9% self-reported hypertension, 67.2% self-reported antihypertensive medication use). The recruitment strategies yielding the highest enrollees were the university hospital phone waiting message system (25.4%), Craigslist (22.4%), and flyers (20.3%) at a per enrollee cost of $42.84, $98.90, and $128.27, respectively. The university hospital phone waiting message system (55.6%) and flyers (54.5%) had the highest interested participant to enrolled participant conversion rate of all recruitment strategies. Approximately 70% of all enrolled participants were recruited from the university hospital phone waiting message system, Craigslist, or flyers. Given the recruitment challenges that most researchers face, we encourage the documenting, assessing, and reporting of detailed recruitment strategies and associated recruitment costs so that other researchers may benefit.

Photo-induced second-order nonlinearity in stoichiometric silicon nitride waveguides

NASA Astrophysics Data System (ADS)

Porcel, Marco A. G.; Mak, Jesse; Taballione, Caterina; Schermerhorn, Victoria K.; Epping, Jörn P.; van der Slot, Peter J. M.; Boller, Klaus-J.

2017-12-01

We report the observation of second-harmonic generation in stoichiometric silicon nitride waveguides grown via low-pressure chemical vapour deposition. Quasi-rectangular waveguides with a large cross section were used, with a height of 1 {\\mu}m and various different widths, from 0.6 to 1.2 {\\mu}m, and with various lengths from 22 to 74 mm. Using a mode-locked laser delivering 6-ps pulses at 1064 nm wavelength with a repetition rate of 20 MHz, 15% of the incoming power was coupled through the waveguide, making maximum average powers of up to 15 mW available in the waveguide. Second-harmonic output was observed with a delay of minutes to several hours after the initial turn-on of pump radiation, showing a fast growth rate between 10$^{-4}$ to 10$^{-2}$ s$^{-1}$, with the shortest delay and highest growth rate at the highest input power. After this first, initial build-up, the second-harmonic became generated instantly with each new turn-on of the pump laser power. Phase matching was found to be present independent of the used waveguide width, although the latter changes the fundamental and second-harmonic phase velocities. We address the presence of a second-order nonlinearity and phase matching, involving an initial, power-dependent build-up, to the coherent photogalvanic effect. The effect, via the third-order nonlinearity and multiphoton absorption leads to a spatially patterned charge separation, which generates a spatially periodic, semi-permanent, DC-field-induced second-order susceptibility with a period that is appropriate for quasi-phase matching. The maximum measured second-harmonic conversion efficiency amounts to 0.4% in a waveguide with 0.9 x 1 {\\mu}m$^2$ cross section and 36 mm length, corresponding to 53 {\\mu}W at 532 nm with 13 mW of IR input coupled into the waveguide. The according $\\chi^{(2)}$ amounts to 3.7 pm/V, as retrieved from the measured conversion efficiency.

A pulsed single-frequency Nd:GGG/BaWO4 Raman laser

NASA Astrophysics Data System (ADS)

Liu, Zhaojun; Men, Shaojie; Cong, Zhenhua; Qin, Zengguang; Zhang, Xingyu; Zhang, Huaijin

2018-04-01

A single-frequency pulsed laser at 1178.3 nm was demonstrated in a crystalline Raman laser. A crystal combination of Nd:GGG and BaWO4 was selected to realize Raman conversion from a 1062.5 nm fundamental wave to a 1178.3 nm Stokes wave. An entangled cavity was specially designed to form an intracavity Raman configuration. Single-longitudinal-mode operation was realized by introducing two Fabry-Perot etalons into the Raman laser cavity. This laser operated at a pulse repetition rate of 50 Hz with 2 ms long envelopes containing micro pulses at a 30 kHz repetition rate. The highest output power was 41 mW with the micro pulse duration of 15 ns. The linewidth was measured to be less than 130 MHz.

Effect of the Molecular Nature of Mutation on the Efficiency of Intrachromosomal Gene Conversion in Mouse Cells

PubMed Central

Letsou, Anthea; Liskay, R. Michael

1987-01-01

With the intent of further exploring the nature of gene conversion in mammalian cells, we systematically addressed the effects of the molecular nature of mutation on the efficiency of intrachromosomal gene conversion in cultured mouse cells. Comparison of conversion rates revealed that all mutations studied were suitable substrates for gene conversion; however, we observed that the rates at which different mutations converted to wild-type could differ by two orders of magnitude. Differences in conversion rates were correlated with the molecular nature of the mutations. In general, rates of conversion decreased with increasing size of the molecular lesions. In comparisons of conversion rates for single base pair insertions and deletions we detected a genotype-directed path for conversion, by which an insertion was converted to wild-type three to four times more efficiently than was a deletion which maps to the same site. The data are discussed in relation to current theories of gene conversion, and are consistent with the idea that gene conversion in mammalian cells can result from repair of heteroduplex DNA (hDNA) intermediates. PMID:2828159

Assessing the potential additionality of certification by the Round table on Responsible Soybeans and the Roundtable on Sustainable Palm Oil

NASA Astrophysics Data System (ADS)

Garrett, Rachael D.; Carlson, Kimberly M.; Rueda, Ximena; Noojipady, Praveen

2016-04-01

Multi-stakeholder roundtables offering certification programs are promising voluntary governance mechanisms to address sustainability issues associated with international agricultural supply chains. Yet, little is known about whether roundtable certifications confer additionality, the benefits of certification beyond what would be expected from policies and practices currently in place. Here, we examine the potential additionality of the Round table on Responsible Soybeans (RTRS) and the Roundtable on Sustainable Palm Oil (RSPO) in mitigating conversion of native vegetation to cropland. We develop a metric of additionality based on business as usual land cover change dynamics and roundtable standard stringency relative to existing policies. We apply this metric to all countries with RTRS (n = 8) and RSPO (n = 12) certified production in 2013-2014, as well as countries that have no certified production but are among the top ten global producers in terms of soy (n = 2) and oil palm (n = 2). We find RSPO and RTRS both have substantially higher levels of stringency than existing national policies except in Brazil and Uruguay. In regions where these certification standards are adopted, the mean estimated rate of tree cover conversion to the target crop is similar for both standards. RTRS has higher mean relative stringency than the RSPO, yet RSPO countries have slightly higher enforcement levels. Therefore, mean potential additionality of RTRS and RSPO is similar across regions. Notably, countries with the highest levels of additionality have some adoption. However, with extremely low adoption rates (0.41% of 2014 global harvested area), RTRS likely has lower impact than RSPO (14%). Like most certification programs, neither roundtable is effectively targeting smallholder producers. To improve natural ecosystem protection, roundtables could target adoption to regions with low levels of environmental governance and high rates of forest-to-cropland conversion.

Effect of polyvinylpyrrolidone on mesoporous silica morphology and esterification of lauric acid with 1-butanol catalyzed by immobilized enzyme

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

Zhang, Jinyu; Zhou, Guowei, E-mail: guoweizhou@hotmail.com; Jiang, Bin

2014-05-01

Mesoporous silica materials with a range of morphology evolution, i.e., from curved rod-shaped mesoporous silica to straight rod-shaped mesoporous silica, were successfully prepared using polyvinylpyrrolidone (PVP) and triblock copolymer as dual template. The effects of PVP molecular weight and concentration on mesoporous silica structure parameters were studied. Results showed that surface area and pore volume continuously decreased with increased PVP molecular weight. Mesoporous silica prepared with PVP K30 also possessed larger pore diameter, interplanar spacing (d{sub 100}), and cell parameter (a{sub 0}) than that prepared with PVP K15 and PVP K90. In addition, with increased PVP concentration, d{sub 100} andmore » a{sub 0} continuously decreased. The mechanism of morphology evolution caused by the change in PVP concentration was investigated. The conversion rate of lauric acid with 1-butanol catalyzed by immobilized Porcine pancreatic lipase (PPL) was also evaluated. Results showed that PPL immobilized on amino-functionalized straight rod-shaped mesoporous silica maintained 50% of its esterification conversion rate even after five cycles of use with a maximum conversion rate was about 90.15%. - Graphical abstract: Curved rod-shaped mesoporous silica can be obtained at low and the highest PVP concentration, while straight rod-shaped mesoporous silica can be obtained at higher PVP concentration. - Highlights: • Mesoporous silica with morphology evolution from CRMS to SRMS were prepared. • Effects of PVP molecular weight and concentration on silica morphology were studied. • A possible mechanism for the formation of morphology evolution SiO{sub 2} was proposed. • Esterification of lauric acid with 1-butanol catalyzed by immobilized PPL.« less

Radiocarbon-depleted CO2 evidence for fuel biodegradation at the Naval Air Station North Island (USA) fuel farm site.

PubMed

Boyd, Thomas J; Pound, Michael J; Lohr, Daniel; Coffin, Richard B

2013-05-01

Dissolved CO(2) radiocarbon and stable carbon isotope ratios were measured in groundwater from a fuel contaminated site at the North Island Naval Air Station in San Diego, CA (USA). A background groundwater sampling well and 16 wells in the underground fuel contamination zone were evaluated. For each sample, a two end-member isotopic mixing model was used to determine the fraction of CO(2) derived from fossil fuel. The CO(2) fraction from fossil sources ranged from 8 to 93% at the fuel contaminated site, while stable carbon isotope values ranged from -14 to +5‰VPDB. Wells associated with highest historical and contemporary fuel contamination showed the highest fraction of CO(2) derived from petroleum (fossil) sources. Stable carbon isotope ratios indicated sub-regions on-site with recycled CO(2) (δ(13)CO(2) as high as +5‰VPDB) - most likely resulting from methanogenesis. Ancillary measurements (pH and cations) were used to determine that no fossil CaCO(3), for instance limestone, biased the analytical conclusions. Radiocarbon analysis is verified as a viable and definitive technique for confirming fossil hydrocarbon conversion to CO(2) (complete oxidation) at hydrocarbon-contaminated groundwater sites. The technique should also be very useful for assessing the efficacy of engineered remediation efforts and by using CO(2) production rates, contaminant mass conversion over time and per unit volume.

Wetlands and Agriculture in Africa: Major Sources of N2O?

NASA Astrophysics Data System (ADS)

Gettel, G. M.

2015-12-01

Papyrus wetlands in East Africa are rapidly being converted to agricultural production in an effort to increase food security. This conversion is often seasonal, with wetlands being used for grazing and crop production of maize, sugarcane, and rice during dry seasons, and flooding occurring during wet seasons. An important question with respect to greenhouse gas production is whether wetland conversion to agriculture increases N2O fluxes. This trend has been shown in temperate regions where increased N2O fluxes are positively related to low soil C:N ratios, especially when soil moisture content remains high. In order to examine whether denitrification contributes to N2O flux, we measured potential denitrification rates (PDR by acetylene block method) in intact papyrus wetlands and agricultural converted wetlands in Kenya, Tanzania, Uganda, and Rwanda, and also performed multivariate analysis to relate soil characteristics to PDR. Agricultural land-cover types included maize, sugarcane, rice, and grazing. Results showed that intact wetlands are potentially important sources of N2O, as PDR in papyrus vegetation were consistently the highest (p<0.05; 128 - 601 μg N2O g DW-1 hour-1) while grazing sites showed the lowest (0.1 - 0.5 μg N2O g DW-1 hour-1). Rates were second highest in rice fields (2.3 - 303 μg N2O g DW-1 hour-1), and intermediate in maize and sugarcane (6.5 - 75 μmg N2O g DW-1 hour-1 and 5 - 30 μg N2O g DW-1 hour-1 respectively). PDR across all sites was inversely related to soil C:N ratio, with nitrate consistently limiting PDR in the wetland sites while soil carbon limited PDR in agricultural sites. This is seemingly in contrast with other findings that show that lower C:N ratios result in high N2O fluxes from drained wetland sites. However, flux measurements along with more realistic process-based measurements of denitrification are urgently needed to more fully understand the effect of agricultural conversion of wetlands in East Africa.

Modelling and assessment of the electric field strength caused by mobile phone to the human head.

PubMed

Buckus, Raimondas; Strukcinskiene, Birute; Raistenskis, Juozas; Stukas, Rimantas

2016-06-01

Electromagnetic field exposure is the one of the most important physical agents that actively affects live organisms and environment. Active use of mobile phones influences the increase of electromagnetic field radiation. The aim of the study was to measure and assess the electric field strength caused by mobile phones to the human head. In this paper the software "COMSOL Multiphysics" was used to establish the electric field strength created by mobile phones around the head. The second generation (2G) Global System for Mobile (GSM) phones that operate in the frequency band of 900 MHz and reach the power of 2 W have a stronger electric field than (2G) GSM mobile phones that operate in the higher frequency band of 1,800 MHz and reach the power up to 1 W during conversation. The third generation of (3G) UMTS smart phones that effectively use high (2,100 MHz) radio frequency band emit the smallest electric field strength values during conversation. The highest electric field strength created by mobile phones is around the ear, i.e. the mobile phone location. The strength of mobile phone electric field on the phantom head decreases exponentially while moving sidewards from the center of the effect zone (the ear), and constitutes 1-12% of the artificial head's surface. The highest electric field strength values of mobile phones are associated with their higher power, bigger specific energy absorption rate (SAR) and lower frequency of mobile phone. The stronger electric field emitted by the more powerful mobile phones takes a higher percentage of the head surface. The highest electric field strength created by mobile phones is distributed over the user's ear.

Gas-Phase Synthesis of Dimethyl Carbonate from Methanol and Carbon Dioxide Over Co1.5pw12o40 Keggin-Type Heteropolyanion

PubMed Central

Aouissi, Ahmed; Al-Othman, Zeid Abdullah; Al-Amro, Amro

2010-01-01

The reactivity of Co1.5PW12O40 in the direct synthesis of dimethyl carbonate (DMC) from CO2 and CH3OH was investigated. The synthesized catalyst has been characterized by means of FTIR, XRD, TG, and DTA and tested in gas phase under atmospheric pressure. The effects of the reaction temperature, time on stream, and methanol weight hourly space velocity (MWHSV) on the conversion and DMC selectivity were investigated. The highest conversion (7.6%) and highest DMC selectivity (86.5%) were obtained at the lowest temperature used (200 °C). Increasing the space velocity MWHSV increased the selectivity of DMC, but decreased the conversion. A gain of 18.4% of DMC selectivity was obtained when the MWHSV was increased from 0.65 h−1 to 3.2 h−1. PMID:20480023

Effective count rates for PET scanners with reduced and extended axial field of view

NASA Astrophysics Data System (ADS)

MacDonald, L. R.; Harrison, R. L.; Alessio, A. M.; Hunter, W. C. J.; Lewellen, T. K.; Kinahan, P. E.

2011-06-01

We investigated the relationship between noise equivalent count (NEC) and axial field of view (AFOV) for PET scanners with AFOVs ranging from one-half to twice those of current clinical scanners. PET scanners with longer or shorter AFOVs could fulfill different clinical needs depending on exam volumes and site economics. Using previously validated Monte Carlo simulations, we modeled true, scattered and random coincidence counting rates for a PET ring diameter of 88 cm with 2, 4, 6, and 8 rings of detector blocks (AFOV 7.8, 15.5, 23.3, and 31.0 cm). Fully 3D acquisition mode was compared to full collimation (2D) and partial collimation (2.5D) modes. Counting rates were estimated for a 200 cm long version of the 20 cm diameter NEMA count-rate phantom and for an anthropomorphic object based on a patient scan. We estimated the live-time characteristics of the scanner from measured count-rate data and applied that estimate to the simulated results to obtain NEC as a function of object activity. We found NEC increased as a quadratic function of AFOV for 3D mode, and linearly in 2D mode. Partial collimation provided the highest overall NEC on the 2-block system and fully 3D mode provided the highest NEC on the 8-block system for clinically relevant activities. On the 4-, and 6-block systems 3D mode NEC was highest up to ~300 MBq in the anthropomorphic phantom, above which 3D NEC dropped rapidly, and 2.5D NEC was highest. Projected total scan time to achieve NEC-density that matches current clinical practice in a typical oncology exam averaged 9, 15, 24, and 61 min for the 8-, 6-, 4-, and 2-block ring systems, when using optimal collimation. Increasing the AFOV should provide a greater than proportional increase in NEC, potentially benefiting patient throughput-to-cost ratio. Conversely, by using appropriate collimation, a two-ring (7.8 cm AFOV) system could acquire whole-body scans achieving NEC-density levels comparable to current standards within long, but feasible, scan times.

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

Underwood, R.P.

As part of the DOE-sponsored contract Synthesis of Dimethyl Ether and Alternative Fuels in the Liquid Phase from Coal-Derived Syngas'' experimental evaluations of the one-step synthesis of alternative fuels were carried out. The objective of this work was to develop novel processes for converting coal-derived syngas to fuels or fuel additives. Building on a technology base acquired during the development of the Liquid Phase Methanol (LPMEOH) process, this work focused on the development of slurry reactor based processes. The experimental investigations, which involved bench-scale reactor studies, focused primarily on three areas: (1) One-step, slurry-phase syngas conversion to hydrocarbons or methanol/hydrocarbonmore » mixtures using a mixture of methanol synthesis catalyst and methanol conversion catalyst in the same slurry reactor. (2) Slurry-phase conversion of syngas to mixed alcohols using various catalysts. (3) One-step, slurry-phase syngas conversion to mixed ethers using a mixture of mixed alcohols synthesis catalyst and dehydration catalyst in the same slurry reactor. The experimental results indicate that, of the three types of processes investigated, slurry phase conversion of syngas to mixed alcohols shows the most promise for further process development. Evaluations of various mixed alcohols catalysts show that a cesium-promoted Cu/ZnO/Al[sub 2]O[sub 3] methanol synthesis catalyst, developed in Air Products' laboratories, has the highest performance in terms of rate and selectivity for C[sub 2+]-alcohols. In fact, once-through conversion at industrially practical reaction conditions yielded a mixed alcohols product potentially suitable for direct gasoline blending. Moreover, an additional attractive aspect of this catalyst is its high selectivity for branched alcohols, potential precursors to iso-olefins for use in etherification.« less

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

Underwood, R.P.

As part of the DOE-sponsored contract ``Synthesis of Dimethyl Ether and Alternative Fuels in the Liquid Phase from Coal-Derived Syngas`` experimental evaluations of the one-step synthesis of alternative fuels were carried out. The objective of this work was to develop novel processes for converting coal-derived syngas to fuels or fuel additives. Building on a technology base acquired during the development of the Liquid Phase Methanol (LPMEOH) process, this work focused on the development of slurry reactor based processes. The experimental investigations, which involved bench-scale reactor studies, focused primarily on three areas: (1) One-step, slurry-phase syngas conversion to hydrocarbons or methanol/hydrocarbonmore » mixtures using a mixture of methanol synthesis catalyst and methanol conversion catalyst in the same slurry reactor. (2) Slurry-phase conversion of syngas to mixed alcohols using various catalysts. (3) One-step, slurry-phase syngas conversion to mixed ethers using a mixture of mixed alcohols synthesis catalyst and dehydration catalyst in the same slurry reactor. The experimental results indicate that, of the three types of processes investigated, slurry phase conversion of syngas to mixed alcohols shows the most promise for further process development. Evaluations of various mixed alcohols catalysts show that a cesium-promoted Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst, developed in Air Products` laboratories, has the highest performance in terms of rate and selectivity for C{sub 2+}-alcohols. In fact, once-through conversion at industrially practical reaction conditions yielded a mixed alcohols product potentially suitable for direct gasoline blending. Moreover, an additional attractive aspect of this catalyst is its high selectivity for branched alcohols, potential precursors to iso-olefins for use in etherification.« less

Social conversational skills development in early implanted children.

PubMed

Guerzoni, Letizia; Murri, Alessandra; Fabrizi, Enrico; Nicastri, Maria; Mancini, Patrizia; Cuda, Domenico

2016-09-01

Social conversational skills are a salient aspect of early pragmatic development in young children. These skills include two different abilities, assertiveness and responsiveness. This study investigated the development of these abilities in early implanted children and their relationships with lexical development and some language-sensitive variables. Prospective, observational, nonrandomized study. Participants included 28 children with congenital profound sensorineural hearing loss. The mean age at device activation was 13.3 months (standard deviation [SD] ±4.2). The Social-Conversational Skills Rating Scale was used to evaluate assertiveness and responsiveness. The MacArthur-Bates Communicative Development Inventory (Words and Sentences form) was used to analyze the lexical development. The device experience was 12 months for each child, and the mean age at testing was 25.9 months (SD ±4.6). Assertiveness and responsiveness scores were within the normal range of normal-hearing age-matched peers. Age at cochlear implant activation exerted a significant impact, with the highest scores associated to the youngest patients. The residual correlations between assertiveness and responsiveness with the lexical development were positive and strongly significant (r = 0.69 and 0.73, respectively). Preoperative hearing threshold demonstrated an associated significant coefficient on the assertiveness score. Age at diagnosis and maternal education level were not correlated with the social conversational skills. Early-implanted children developed social conversational skills that are similar to normal-hearing peers matched for age 1 year after device activation. Social conversational skills and lexical development were strongly correlated, but the present study design cannot specify the direction of this relationship. Children with better preoperative residual hearing exhibited better assertive ability. 4 Laryngoscope, 126:2098-2105, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Design of hybrid nanoheterostructure systems for enhanced quantum and solar conversion efficiencies in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Kılıç, Bayram; Telli, Hakan; Tüzemen, Sebahattin; Başaran, Ali; Pirge, Gursev

2015-04-01

Dye sensitized solar cells (DSSCs) with an innovative design involving controlled-morphology vertically aligned (VA) ZnO nanowires within mesoporous TiO2 structures with ultrahigh surface area for implementation as photoanodes are herein reported. Although TiO2 nanostructures exhibit excellent power conversion efficiency, the electron transport rate is low owing to low electron mobility. To overcome this, ZnO nanowires with high electron mobility have been investigated as potential candidates for photoanodes. However, the power conversion efficiency of ZnO nanowires is still lower than that of TiO2 owing to their low internal surface area. Consequently, in this work, vertical growth of ZnO nanowires within mesoporous TiO2 structures is carried out to increase their solar power conversion efficiency. The photovoltaic performance of solar cells using ZnO nanowires, mesoporous TiO2, and TiO2/ZnO hybrid structures are compared. The VA TiO2/ZnO hybrid structures are found to provide direct electron transfer compared with the tortuous pathway of zero-dimensional nanostructures, resulting in an increased conversion efficiency. It is demonstrated that the light scattering of the photoanode film is increased and electron recombination is decreased when an appropriate amount of mesoporous TiO2 is used as a substrate for ZnO nanowires. The DSSC fabricated with the TiO2/ZnO hybrid photoanode prepared with 15.8 wt. % TiO2 showed the highest conversion efficiency of 7.30%, approximately 5%, 18%, and 40% higher than that of DSSCs fabricated with 3.99 wt. % TiO2, pure TiO2, and pure ZnO photoanodes, respectively.

High lactic acid and fructose production via Mn2+-mediated conversion of inulin by Lactobacillus paracasei.

PubMed

Petrov, Kaloyan; Popova, Luiza; Petrova, Penka

2017-06-01

Lactobacillus paracasei DSM 23505 is able to produce high amounts of lactic acid (LA) by simultaneous saccharification and fermentation (SSF) of inulin. Aiming to obtain the highest possible amounts of LA and fructose, the present study is devoted to evaluate the impact of bivalent metal ions on the process of inulin conversion. It was shown that Mn 2+ strongly increases the activity of the purified key enzyme β-fructosidase. In vivo, batch fermentation kinetics revealed that the high Mn 2+ concentrations accelerated inulin hydrolysis by raise of the inulinase activity, and increased sugars conversion to LA through enhancement of the whole glycolytic flux. The highest LA concentration and yield were reached by addition of 15 mM Mn 2+ -151 g/L (corresponding to 40% increase) and 0.83 g/g, respectively. However, the relative quantification by real-time reverse transcription assay showed that the presence of Mn 2+ decreases the expression levels of fosE gene encoding β-fructosidase. Contrariwise, the full exclusion of metal ions resulted in fosE gene expression enhancement, blocked fructose transport, and hindered fructose conversion thus leading to huge fructose accumulation. During fed-batch with optimized medium and fermentation parameters, the fructose content reached 35.9% (w/v), achieving yield of 467 g fructose from 675 g inulin containing chicory flour powder (0.69 g/g). LA received in course of the batch fermentation and fructose gained by the fed-batch are the highest amounts ever obtained from inulin, thus disclosing the key role of Mn 2+ as a powerful tool to guide inulin conversion to targeted bio-chemicals.

Mild cognitive impairment: baseline and longitudinal structural MR imaging measures improve predictive prognosis.

PubMed

McEvoy, Linda K; Holland, Dominic; Hagler, Donald J; Fennema-Notestine, Christine; Brewer, James B; Dale, Anders M

2011-06-01

To assess whether single-time-point and longitudinal volumetric magnetic resonance (MR) imaging measures provide predictive prognostic information in patients with amnestic mild cognitive impairment (MCI). This study was conducted with institutional review board approval and in compliance with HIPAA regulations. Written informed consent was obtained from all participants or the participants' legal guardians. Cross-validated discriminant analyses of MR imaging measures were performed to differentiate 164 Alzheimer disease (AD) cases from 203 healthy control cases. Separate analyses were performed by using data from MR images obtained at one time point or by combining single-time-point measures with 1-year change measures. Resulting discriminant functions were applied to 317 MCI cases to derive individual patient risk scores. Risk of conversion to AD was estimated as a continuous function of risk score percentile. Kaplan-Meier survival curves were computed for risk score quartiles. Odds ratios (ORs) for the conversion to AD were computed between the highest and lowest quartile scores. Individualized risk estimates from baseline MR examinations indicated that the 1-year risk of conversion to AD ranged from 3% to 40% (average group risk, 17%; OR, 7.2 for highest vs lowest score quartiles). Including measures of 1-year change in global and regional volumes significantly improved risk estimates (P = 001), with the risk of conversion to AD in the subsequent year ranging from 3% to 69% (average group risk, 27%; OR, 12.0 for highest vs lowest score quartiles). Relative to the risk of conversion to AD conferred by the clinical diagnosis of MCI alone, MR imaging measures yield substantially more informative patient-specific risk estimates. Such predictive prognostic information will be critical if disease-modifying therapies become available. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101975/-/DC1. RSNA, 2011

Magnetic field effect in fluorescence of excited fluorophore equilibrated with exciplex that reversibly dissociates into radical-ion pair undergoing the spin conversion.

PubMed

Dodin, Dmitry V; Ivanov, Anatoly I; Burshtein, Anatoly I

2012-07-14

The fluorescence of the photoexcited electron acceptor, (1)A∗, and the exciplex, (1)[D(+δ)A(-δ)] formed at contact of (1)A∗ with an electron donor (1)D, is known to be very sensitive to a magnetic field, assisting the spin conversion in the resulting geminate radical ion pair (RIP), (1, 3)[D(+)...A(-)]. The relative increase of the fluorescence in the highest magnetic field compared to the lowest one, known as the magnetic field effect, crucially depends on the dielectric constant of the solvent, ɛ. This phenomenon first studied experimentally is at first reproduced here theoretically by means of the so called integral encounter theory. It was shown to be very sensitive to the position of the exciplex energy level relative to the levels of exciplex precursors and the charged products of its dissociation. The results obtained strongly depend on the dielectric properties of the solvents as well as on the exciplex and RIP formation rates.

Highly Active and Selective Hydrogenation of CO2 to Ethanol by Ordered Pd-Cu Nanoparticles.

PubMed

Bai, Shuxing; Shao, Qi; Wang, Pengtang; Dai, Qiguang; Wang, Xingyi; Huang, Xiaoqing

2017-05-24

Carbon dioxide (CO 2 ) hydrogenation to ethanol (C 2 H 5 OH) is considered a promising way for CO 2 conversion and utilization, whereas desirable conversion efficiency remains a challenge. Herein, highly active, selective and stable CO 2 hydrogenation to C 2 H 5 OH was enabled by highly ordered Pd-Cu nanoparticles (NPs). By tuning the composition of the Pd-Cu NPs and catalyst supports, the efficiency of CO 2 hydrogenation to C 2 H 5 OH was well optimized with Pd 2 Cu NPs/P25 exhibiting high selectivity to C 2 H 5 OH of up to 92.0% and the highest turnover frequency of 359.0 h -1 . Diffuse reflectance infrared Fourier transform spectroscopy results revealed the high C 2 H 5 OH production and selectivity of Pd 2 Cu NPs/P25 can be ascribed to boosting *CO (adsorption CO) hydrogenation to *HCO, the rate-determining step for the CO 2 hydrogenation to C 2 H 5 OH.

Kinetics of enzymatic synthesis of liquid wax ester from oleic acid and oleyl alcohol.

PubMed

Radzi, Salina Mat; Mohamad, Rosfarizan; Basri, Mahiran; Salleh, Abu Bakar; Ariff, Arbakariya; Rahman, Mohammad Basyaruddin Abdul; Rahman, Raja Noor Zaliha Raja Abdul

2010-01-01

The kinetics of wax ester synthesis from oleic acid and oleyl alcohol using immobilized lipase from Candida antartica as catalyst was studied with different types of impeller (Rushton turbine and AL-hydrofoil) to create different mixing conditions in 2l stirred tank reactor. The effects of catalyst concentration, reaction temperature, and impeller tip speed on the synthesis were also evaluated. Rushton turbine impeller exhibited highest conversion rate at lower impeller tip speed as compared to AL-hydrofoil impeller. A second-order reversible kinetic model from single progress curve for the prediction of fractional conversion at given reaction time was proposed and the corresponding kinetic parameter values were calculated by non-linear regression method. The results from the simulation using the proposed model showed satisfactory agreement with the experimental data. Activation energy shows a value of 21.77 Kcal/mol. The thermodynamic parameters of the process, enthalpy and entropy, were 21.15 Kcal/mol and 52.07 cal/mol.K, respectively.

Distractions during critical phases of anaesthesia for caesarean section: an observational study.

PubMed

Jenkins, A; Wilkinson, J V; Akeroyd, M A; Broom, M A

2015-05-01

Aviation's 'sterile cockpit' rule holds that distractions on the flight deck should be kept at a minimum during critical phases of flight. To assess current practice at comparable points during obstetric regional anaesthesia, we measured ambient noise and distracting events during 30 caesarean sections in three phases: during establishment of regional anaesthesia; during testing of regional blockade; and after delivery of the fetal head. Mean (SD) noise levels were 62.5 (3.9) dB during establishment of blockade, 63.9 (4.1) dB during testing and 66.8 (5.0) dB after delivery (p < 0.001). The median rates of sudden, loud (> 70 dB) noises, non-clinical conversations and numbers of staff present in the operating theatre increased during each of the three phases. Conversely, entrances into, and exits from, theatre per minute were highest during establishment of regional anaesthesia and decreased over the subsequent two time periods (p < 0.001). © 2014 The Association of Anaesthetists of Great Britain and Ireland.

Diode pumped CW and passively Q-switched Nd:LGGG laser at 1062 nm

NASA Astrophysics Data System (ADS)

Yang, H.; Jia, Z. T.; Zhang, B. T.; He, J. L.; Liu, S. D.; Yang, Y.; Tao, X. T.

2012-05-01

We report a Nd:LGGG laser at 1062 nm in the operations of the continuous-wave (CW) and passively Q-switching. The maximum CW output power of 5.62 W was obtained, corresponding to an optical-to-optical conversion efficiency of 49.0% and slope efficiency of 55.9%. By using Cr4+:YAG with initial transmission of 94% as the saturable absorber, for the first time, we got the maximum passively Q-switched output power of 1.21 W, accompanied with a highest pulse repetition rate of 27.1 kHz and a shortest pulse width of 9.1 ns.

Analysis of hydrogen Lyman-alpha observations of the coma of Comet P/Halley near the perihelion

NASA Technical Reports Server (NTRS)

Smyth, William H.; Marconi, M. L.; Combi, Michael R.

1995-01-01

The pioneer Venus Orbiter Ultraviolet Spectrometer measurements of the Lyman-alpha intensity of atomic hydrogen excited by solar resonance scattering in the coma of Comet P/Halley acquired from December 28, 1985, to January 6, 1986, and from January 31, 1986, to March 6, 1986, are simulated with the Monte Carlo Particle Trajectory Model corrected for optical depth effects. Spatially detailed comparisons between data and model show excellent agreement and are used to infer that the highest cometary activity may not be at perihelion, but about 2 1/2 weeks before. An improved set of H2O production rates is presented for the period of time that the spectrometer was observing and is found to be consistent with the rates from other types of measurements. The apparent discrepancy between Stewart (1987) in early March and International Ultraviolet Explorer OH derived rates is resolved. The problem with the conversion of 18-cm OH radio brightness to H2O production rates is also discussed.

Impact of two different types of grassland-to-cropland-conversion on dynamics of soil organic matter mineralization and N2O emission

NASA Astrophysics Data System (ADS)

Roth, G.; Flessa, H.; Helfrich, M.; Well, R.

2012-04-01

Conversion of grassland to arable land often causes a decrease of soil organic matter stocks and it increases nitrate leaching and the emission of the greenhouse gases CO2 and N2O. Conversion methods which minimize the mechanical impact on the surface soil may reduce mineralization rates and greenhouse gas emissions. We determined the effect of two different types of grassland to maize conversion (a) plowing of the sward followed by seeding of maize and (b) chemical killing of the sward by glyphosate followed by direct seed of maize) on the mineralization of grassland derived organic matter, the release of nitrate and the emission of N2O. The field experiment was carried out at the research station Kleve which is located in North Rhine-Westphalia, Germany. A four times replicated plot experiment with the following treatments was set up in April 2010: (i) mechanical conversion of grassland to maize (ii) chemical conversion grassland to maize and (iii) continuous grassland as reference. Nitrogen fertilization was 137 kg N ha-1 for maize and 250 kg N ha-1 for grassland. Soil respiration and emission of N2O were measured weekly for one year using manual closed chambers and gas chromatography. Emission of CO2 from mineralization of grassland-derived organic matter was determined from the δ13C signature of soil respiration. Soil respiration was mainly fueled by mineralization of grassland-derived organic carbon. There was no effect of the type of grassland conversion on total mineralization of organic matter originating from grassland. Both grassland to maize conversion treatments exhibited very high soil nitrate concentrations one year after grassland conversion (about 250 kg NO3-N in 0 - 90 cm). Total N2O emission decreased in the order chemical conversion of grassland (25.5) > mechanical conversion of grassland (20.1) > permanent grassland (10.8). Emissions were highest after harvest of maize when soil moisture increased. The results show that both types of grassland-to-maize conversion resulted in a large surplus of soil nitrate which promotes nitrate leaching to the groundwater and indirect N2O emissions. In addition, it caused high direct N2O emissions. We found no evidence that grassland conversion without mechanical plowing is an option to reduce groundwater contamination and greenhouse gas emission to the atmosphere.

Calculation Methods and Conversions for Pesticide Application.

ERIC Educational Resources Information Center

Cole, Herbert, Jr.

This agriculture extension service publication from Pennsylvania State University consists of conversion tables and formulas for determining concentration and rate of application of pesticides. Contents include: (1) Area and volume conversions; (2) Important conversion formulae; (3) Conversions for rates of application; (4) Quantities of pesticide…

Potential future land use threats to California's protected areas

USGS Publications Warehouse

Wilson, Tamara Sue; Sleeter, Benjamin Michael; Davis, Adam Wilkinson

2015-01-01

Increasing pressures from land use coupled with future changes in climate will present unique challenges for California’s protected areas. We assessed the potential for future land use conversion on land surrounding existing protected areas in California’s twelve ecoregions, utilizing annual, spatially explicit (250 m) scenario projections of land use for 2006–2100 based on the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios to examine future changes in development, agriculture, and logging. We calculated a conversion threat index (CTI) for each unprotected pixel, combining land use conversion potential with proximity to protected area boundaries, in order to identify ecoregions and protected areas at greatest potential risk of proximal land conversion. Our results indicate that California’s Coast Range ecoregion had the highest CTI with competition for extractive logging placing the greatest demand on land in close proximity to existing protected areas. For more permanent land use conversions into agriculture and developed uses, our CTI results indicate that protected areas in the Central California Valley and Oak Woodlands are most vulnerable. Overall, the Eastern Cascades, Central California Valley, and Oak Woodlands ecoregions had the lowest areal percent of protected lands and highest conversion threat values. With limited resources and time, rapid, landscape-level analysis of potential land use threats can help quickly identify areas with higher conversion probability of future land use and potential changes to both habitat and potential ecosystem reserves. Given the broad range of future uncertainties, LULC projections are a useful tool allowing land managers to visualize alternative landscape futures, improve planning, and optimize management practices.

Pressure-enhanced ortho-para conversion in solid hydrogen up to 58 GPa.

PubMed

Eggert, J H; Karmon, E; Hemley, R J; Mao, A; Goncharov, A F

1999-10-26

We measured the ortho-para conversion rate in solid hydrogen by using Raman scattering in a diamond-anvil cell, extending previous measurements by a factor of 60 in pressure. We confirm previous experiments that suggested a decrease in the conversion rate above about 0.5 GPa. We observe a distinct minimum at 3 GPa followed by a drastic increase in the conversion rate to our maximum pressure of 58 GPa. This pressure enhancement of conversion is not predicted by previous theoretical treatments and must be due to a new conversion pathway.

Effect of dietary phosphorus on the growth and body components of juvenile Synechogobius hasta

NASA Astrophysics Data System (ADS)

Luo, Zhi; Li, Xiaodong; Gong, Shiyuan; Xi, Wenqiu; Li, Yali

2009-03-01

The effect of dietary phosphorus on the growth and body components of juvenile Synechogobius hasta was determined. Different percentages of dietary phosphorus (0.63, 0.77, 0.93, 1.06, 1.22 and 1.36) were tested by feeding the fish (body weight, 15.81 g ± 0.32 g; 20 individuals each group; 3 groups each percentage) at a surplus of 5%-10% above satiation for 35 d. Dietary phosphorus did not significantly affect the specific growth rate, feed intake, feed conversion ratio and protein efficiency rate. Nitrogen retention was found to be the highest in fish fed the diet containing 1.06% of phosphorus; however, this was not significantly different from other diets. Fish fed the diet containing 0.93% of phosphorus showed the highest phosphorus retention; similar phosphorus retention rates were found in fish fed the diets containing 0.77% and 1.06% of phosphorus. Fish fed the diet containing the highest percentage of dietary phosphorus were found to contain the least whole body lipid, lower than fish fed other diets ( P<0.05). The protein content increased from 18.59% to 19.55% (although not significant) with the decrease of body lipid content ( P>0.05). The contents of the whole body ash, whole body phosphorus and vertebrae phosphorus increased with dietary phosphorus percentage up to 1.06 ( P<0.05), reaching a plateau after that. Dietary phosphorus did not significantly influence the muscle components (protein, lipid and moisture). Condition factor and hepatosomatic index were the highest in fish fed the diet containing 0.63% of dietary phosphorus; however, this was not significantly different from those of other diets. The second-order polynomial regression of phosphorus retention against dietary phosphorus identified a breakpoint at 0.88% of dietary phosphorus. However, the dietary requirement of phosphorus for maintaining maximum phosphorus storage determined by broken-line analysis of the contents of whole body phosphorus, and ash and vertebrae phosphorus was 1.06% of the diet.

Old and stable soil organic matter is not necessarily chemically recalcitrant: Implications for modeling concepts and temperature sensitivity

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

Kleber, M.; Nico, P.S.; Plante, A.

2010-03-01

Soil carbon turnover models generally divide soil carbon into pools with varying intrinsic decomposition rates. Although these decomposition rates are modified by factors such as temperature, texture, and moisture, they are rationalized by assuming chemical structure is a primary controller of decomposition. In the current work, we use near edge X-ray absorption fine structure (NEXAFS) spectroscopy in combination with differential scanning calorimetry (DSC) and alkaline cupric oxide (CuO) oxidation to explore this assumption. Specifically, we examined material from the 2.3-2.6 kg L{sup -1} density fraction of three soils of different type (Oxisol, Alfisol, Inceptisol). The density fraction with the youngestmore » {sup 14}C age (Oxisol, 107 years) showed the highest relative abundance of aromatic groups and the lowest O-alkyl C/aromatic C ratio as determined by NEXAFS. Conversely, the fraction with the oldest C (Inceptisol, 680 years) had the lowest relative abundance of aromatic groups and highest O-alkyl C/aromatic C ratio. This sample also had the highest proportion of thermally labile materials as measured by DSC, and the highest ratio of substituted fatty acids to lignin phenols as indicated by CuO oxidation. Therefore, the organic matter of the Inceptisol sample, with a {sup 14}C age associated with 'passive' pools of carbon (680 years), had the largest proportion of easily metabolizable organic molecules with low thermodynamic stability, whereas the organic matter of the much younger Oxisol sample (107 years) had the highest proportion of supposedly stable organic structures considered more difficult to metabolize. Our results demonstrate that C age is not necessarily related to molecular structure or thermodynamic stability, and we suggest that soil carbon models would benefit from viewing turnover rate as codetermined by the interaction between substrates, microbial actors, and abiotic driving variables. Furthermore, assuming that old carbon is composed of complex or 'recalcitrant' compounds will erroneously attribute a greater temperature sensitivity to those materials than they may actually possess.« less

Cropland expansion changes deforestation dynamics in the southern Brazilian Amazon

PubMed Central

Morton, Douglas C.; DeFries, Ruth S.; Shimabukuro, Yosio E.; Anderson, Liana O.; Arai, Egidio; del Bon Espirito-Santo, Fernando; Freitas, Ramon; Morisette, Jeff

2006-01-01

Intensive mechanized agriculture in the Brazilian Amazon grew by >3.6 million hectares (ha) during 2001–2004. Whether this cropland expansion resulted from intensified use of land previously cleared for cattle ranching or new deforestation has not been quantified and has major implications for future deforestation dynamics, carbon fluxes, forest fragmentation, and other ecosystem services. We combine deforestation maps, field surveys, and satellite-based information on vegetation phenology to characterize the fate of large (>25-ha) clearings as cropland, cattle pasture, or regrowing forest in the years after initial clearing in Mato Grosso, the Brazilian state with the highest deforestation rate and soybean production since 2001. Statewide, direct conversion of forest to cropland totaled >540,000 ha during 2001–2004, peaking at 23% of 2003 annual deforestation. Cropland deforestation averaged twice the size of clearings for pasture (mean sizes, 333 and 143 ha, respectively), and conversion occurred rapidly; >90% of clearings for cropland were planted in the first year after deforestation. Area deforested for cropland and mean annual soybean price in the year of forest clearing were directly correlated (R2 = 0.72), suggesting that deforestation rates could return to higher levels seen in 2003–2004 with a rebound of crop prices in international markets. Pasture remains the dominant land use after forest clearing in Mato Grosso, but the growing importance of larger and faster conversion of forest to cropland defines a new paradigm of forest loss in Amazonia and refutes the claim that agricultural intensification does not lead to new deforestation. PMID:16973742

Extruded leftover food as animal feed: I. Effect of extruded feed on growth and feed utilization of tilapia (Oreochromis niloticus) in Saudi Arabia.

PubMed

Al-Ruqaie, Ibrahim M

2007-10-01

A Laboratory experiment was used to evaluate the effect of extruded leftover food as an alternate source of fish diet to Nile tilapia (Oreochromis niloticus, 76.75 +/- 1.27 g). Three experimental diets were used. Two extruded leftover food types [with minerals and vitamins (type-1) and without (type-2) were used to prepare two experimental treatments in duplicate as compared to a commercial tilapia diet (ARASCO) as a control. The final body weight and Specific Growth Rate (SGR) were not affected by different types of leftover feed. Whereas, the Feed Conversion Ratio (FCR) and the Protein Efficiency Ratio (PER) were significantly affected by the different feeds. The highest significant values of FCR was shown for fish fed with extruded leftover feed without premix, while Nile tilapia fed with control diet recorded the highest values of PER. The present study showed that the extruded leftover food could be used to prepare least cost diet for Nile tilapia.

Evaluation of humic fractions potential to produce bio-oil through catalytic hydroliquefaction.

PubMed

Lemée, L; Pinard, L; Beauchet, R; Kpogbemabou, D

2013-12-01

Humic substances were extracted from biodegraded lignocellulosic biomass (LCBb) and submitted to catalytic hydroliquefaction. The resulting bio-oils were compared with those of the initial biomass. Compared to fulvic and humic acids, humin presented a high conversion rate (74 wt.%) and the highest amount of liquid fraction (66 wt.%). Moreover it represented 78% of LCBb. Humin produced 43 wt.% of crude oil and 33 wt.% of hexane soluble fraction containing hydrocarbons which is a higher yield than those from other humic substances as well as from the initial biomass. Hydrocarbons were mainly aromatics, but humin produces the highest amount of aliphatics. Considering the quantity, the quality and the molecular composition of the humic fractions, a classification of the potential of the latter to produce fuel using hydroliquefaction process can be assess: Hu>AF>AH. The higher heating value (HHV) and oxygen content of HSF from humin were fully compatible with biofuel characteristics. Copyright © 2013 Elsevier Ltd. All rights reserved.

Metalorganic vapor phase epitaxial growth of red and infrared vertical-cavity surface-emitting laser diodes

NASA Astrophysics Data System (ADS)

Schneider, R. P.; Lott, J. A.; Lear, K. L.; Choquette, K. D.; Crawford, M. H.; Kilcoyne, S. P.; Figiel, J. J.

1994-12-01

Metalorganic vapor phase epitaxy (MOVPE) is used for the growth of vertical-cavity surface-emitting laser (VCSEL) diodes. MOVPE exhibits a number of important advantages over the more commonly-used molecular-beam epitaxial (MBE) techniques, including ease of continuous compositional grading and carbon doping for low-resistance p-type distributed Bragg reflectors (DBRs), higher growth rates for rapid throughput and greater versatility in choice of materials and dopants. Planar gain-guided red VCSELs based on AlGaInP/AlGaAs heterostructures lase continuous-wave at room temperature, with voltage thresholds between 2.5 and 3 V and maximum power outputs of over 0.3 mW. Top-emitting infra-red (IR) VCSELs exhibit the highest power-conversion (wall-plug) efficiencies (21%), lowest threshold voltage (1.47 V), and highest single mode power (4.4 mW from an 8 μm device) yet reported. These results establish MOVPE as a preferred growth technique for this important new family of photonic devices.

Speech Rate Entrainment in Children and Adults With and Without Autism Spectrum Disorder.

PubMed

Wynn, Camille J; Borrie, Stephanie A; Sellers, Tyra P

2018-05-03

Conversational entrainment, a phenomenon whereby people modify their behaviors to match their communication partner, has been evidenced as critical to successful conversation. It is plausible that deficits in entrainment contribute to the conversational breakdowns and social difficulties exhibited by people with autism spectrum disorder (ASD). This study examined speech rate entrainment in children and adult populations with and without ASD. Sixty participants including typically developing children, children with ASD, typically developed adults, and adults with ASD participated in a quasi-conversational paradigm with a pseudoconfederate. The confederate's speech rate was digitally manipulated to create slow and fast speech rate conditions. Typically developed adults entrained their speech rate in the quasi-conversational paradigm, using a faster rate during the fast speech rate conditions and a slower rate during the slow speech rate conditions. This entrainment pattern was not evident in adults with ASD or in children populations. Findings suggest that speech rate entrainment is a developmentally acquired skill and offers preliminary evidence of speech rate entrainment deficits in adults with ASD. Impairments in this area may contribute to the conversational breakdowns and social difficulties experienced by this population. Future work is needed to advance this area of inquiry.

Antimatter propulsion, status and prospects

NASA Technical Reports Server (NTRS)

Howe, Steven D.; Hynes, Michael V.

1986-01-01

The use of advanced propulsion techniques must be considered if the currently envisioned launch date of the manned Mars mission were delayed until 2020 or later. Within the next thirty years, technological advances may allow such methods as beaming power to the ship, inertial-confinement fusion, or mass-conversion of antiprotons to become feasible. A propulsion system with an ISP of around 5000 s would allow the currently envisioned mission module to fly to Mars in 3 months and would require about one million pounds to be assembled in Earth orbit. Of the possible methods to achieve this, the antiproton mass-conversion reaction offers the highest potential, the greatest problems, and the most fascination. Increasing the production rates of antiprotons is a high priority task at facilities around the world. The application of antiprotons to propulsion requires the coupling of the energy released in the mass-conversion reaction to thrust-producing mechanisms. Recent proposals entail using the antiprotons to produce inertial confinement fusion or to produce negative muons which can catalyze fusion. By increasing the energy released per antiproton, the effective cost, (dollars/joule) can be reduced. These proposals and other areas of research can be investigated now. These short term results will be important in assessing the long range feasibility of an antiproton powered engine.

Combined administration of low molecular weight sodium alginate boosted immunomodulatory, disease resistance and growth enhancing effects of Lactobacillus plantarum in Nile tilapia (Oreochromis niloticus).

PubMed

Van Doan, Hien; Hoseinifar, Seyed Hossein; Tapingkae, Wanaporn; Tongsiri, Sudaporn; Khamtavee, Pimporn

2016-11-01

The present study investigates the effects of combined or singular administration of low molecular weight sodium alginate (LWMSA) and Lactobacillus plantarum on innate immune response, disease resistance and growth performance of Nile tilapia (Oreochromis niloticus). Three hundred and twenty fish were supplied and randomly stocked in sixteen glass tanks (150 L) assigned to four treatments as follows: 0 g kg -1 LMWSA (Control, Diet 1), 10 g kg -1 LMWSA (Diet 2), 10 8  CFU g -1 L. plantarum (Diet 3), and 10 g kg -1 LMWSA + 10 8  CFU g -1 L. plantarum (Diet 4). Following 30 and 60 days of the feeding trial, serum lysozyme, phagocytosis, respiratory burst and alternative complement activities as well as growth performance parameters (specific growth rate, feed conversion ratio) were measured. Serum lysozyme, phagocytosis, respiratory burst, and alternative complement activities of fish were significantly stimulated by both LMWSA and L. plantarum diets, however, the highest innate immune response were observed in fish fed synbiotic diet. At the end of the experiment, eight fish per replication were randomly selected for a challenge test against Streptococcus agalactiae. The survival rate of the fish fed supplemented diets was significantly greater than the control treatment and the highest post challenge survival rate was observed in synbiotic diet. Furthermore, SGR and FCR were significantly improved in fish fed supplemented diets after 60 days and the highest growth performance was observed in fish fed synbiotic diet. These results suggest combined LMWSA and L. plantarum can be considered as a promising immunostimulant and growth enhancer in Nile tilapia diet. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pressure-enhanced ortho-para conversion in solid hydrogen up to 58 GPa

PubMed Central

Eggert, Jon H.; Karmon, Eran; Hemley, Russell J.; Mao, Ho-kwang; Goncharov, Alexander F.

1999-01-01

We measured the ortho-para conversion rate in solid hydrogen by using Raman scattering in a diamond-anvil cell, extending previous measurements by a factor of 60 in pressure. We confirm previous experiments that suggested a decrease in the conversion rate above about 0.5 GPa. We observe a distinct minimum at 3 GPa followed by a drastic increase in the conversion rate to our maximum pressure of 58 GPa. This pressure enhancement of conversion is not predicted by previous theoretical treatments and must be due to a new conversion pathway. PMID:10535910

Effect of bio-column composed of aged refuse on methane abatement--a novel configuration of biological oxidation in refuse landfill.

PubMed

Han, Dan; Zhao, Youcai; Xue, Binjie; Chai, Xiaoli

2010-01-01

An experimental bio-column composed of aged refuse was installed around the exhaust pipe as a new way to mitigate methane in refuse landfill. One of the objectives of this work was to assess the effect of aged refuse thickness in bio-column on reducing CH4 emissions. Over the study period, methane oxidation was observed at various thicknesses, 5 cm (small size), 10 cm (middle size) and 15 cm (large size), representing one to three times of pipeline diameters. The middle and large size both showed over 90% methane conversion, and the highest methane conversion rate of above 95% occurred in the middle-size column cell. Michaelis-Menten equation addressed the methanotrophs diffusion in different layers of the bio-columns. Maximum methanotrophic activity (Vmax) measured at the three thicknesses ranged from 6.4 x 10(-3) to 15.6 x 10(-3) units, and the half-saturation value (K(M)) ranged from 0.85% to 1.67%. Both the highest Vmax and K(M) were observed at the middle-size of the bio-column, as well as the largest methanotrophs population, suggesting a significant efficiency of methane mitigation happened in the optimum zone with greatest affinity and methanotrophic bacteria activities. Therefore, bio-column is a potential style for methane abatement in landfill, and the aged refuse both naturally formed and artificially placed in the column plays a critical role in CH4 emission.

A Semitransparent Inorganic Perovskite Film for Overcoming Ultraviolet Light Instability of Organic Solar Cells and Achieving 14.03% Efficiency.

PubMed

Chen, Weijie; Zhang, Jingwen; Xu, Guiying; Xue, Rongming; Li, Yaowen; Zhou, Yinhua; Hou, Jianhui; Li, Yongfang

2018-05-01

Organic solar cells (OSCs) can be unstable under ultraviolet (UV) irradiation. To address this issue and enhance the power conversion efficiency (PCE), an inorganic-perovskite/organic four-terminal tandem solar cell (TSC) based on a semitransparent inorganic CsPbBr 3 perovskite solar cell (pero-SC) as the top cell and an OSC as bottom cell is constructed. The high-quality CsPbBr 3 photoactive layer of the planar pero-SC is prepared with a dual-source vacuum coevaporation method, using stoichiometric precursors of CsBr and PbBr 2 with a low evaporation rate. The resultant opaque planar pero-SC exhibits an ultrahigh open-circuit voltage of 1.44 V and the highest reported PCE of 7.78% for a CsPbBr 3 -based planar pero-SC. Importantly, the devices show no degradation after 120 h UV light illumination. The related semitransparent pero-SC can almost completely filter UV light and well maintain photovoltaic performance; it additionally shows an extremely high average visible transmittance. When it is used to construct a TSC, the top pero-SC acting as a UV filter can utilize UV light for photoelectric conversion, avoiding the instability problem of UV light on the bottom OSC that can meet the industrial standards of UV-light stability for solar cells, and leading to the highest reported PCE of 14.03% for the inorganic-perovskite/organic TSC. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Great majority of recombination events in Arabidopsis are gene conversion events

PubMed Central

Yang, Sihai; Yuan, Yang; Wang, Long; Li, Jing; Wang, Wen; Liu, Haoxuan; Chen, Jian-Qun; Hurst, Laurence D.; Tian, Dacheng

2012-01-01

The evolutionary importance of meiosis may not solely be associated with allelic shuffling caused by crossing-over but also have to do with its more immediate effects such as gene conversion. Although estimates of the crossing-over rate are often well resolved, the gene conversion rate is much less clear. In Arabidopsis, for example, next-generation sequencing approaches suggest that the two rates are about the same, which contrasts with indirect measures, these suggesting an excess of gene conversion. Here, we provide analysis of this problem by sequencing 40 F2 Arabidopsis plants and their parents. Small gene conversion tracts, with biased gene conversion content, represent over 90% (probably nearer 99%) of all recombination events. The rate of alteration of protein sequence caused by gene conversion is over 600 times that caused by mutation. Finally, our analysis reveals recombination hot spots and unexpectedly high recombination rates near centromeres. This may be responsible for the previously unexplained pattern of high genetic diversity near Arabidopsis centromeres. PMID:23213238

Substrate reactivity as a function of the extent of reaction in the enzymatic hydrolysis of lignocellulose

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

Desai, S.G.; Converse, A.O.

1997-12-20

In an effort to better understand the role of the substrate in the rapid fall off in the rate of enzymatic hydrolysis of cellulose with conversion, substrate reactivity was measured as a function of conversion. These measurements were made by interrupting the hydrolysis of pretreated wood at various degrees of conversion; and, after boiling and washing, restarting the hydrolysis in fresh butter with fresh enzyme. The comparison of the restart rate per enzyme adsorbed with the initial rate per enzyme adsorbed, both extrapolated back to zero conversion, provides a measurement of the substrate reactivity without the complications of product inhibitionmore » or cellulase inactivation. The results indicate that the substrate reactivity falls only modestly as conversion increases. However, the restart rate is still higher than the rate of the uninterrupted hydrolysis, particularly at high conversion. Hence the authors conclude that the loss of substrate reactivity is not the principal cause for the long residence time required for complete conversion.« less

50 CFR Table 3 to Part 679 - Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut 3 Table 3 to Part 679 Wildlife and Fisheries FISHERY... Rates for Groundfish Species and Conversion Rates for Pacific Halibut ER28JA02.074 ER10JY02.000 ER28JA02...

Process Simulation and Techno-Economic Evaluation of Alternative Biorefinery Scenarios

NASA Astrophysics Data System (ADS)

Aizpurua Gonzalez, Carlos Ernesto

A biorefinery is a complex processing facility that uses sustainably produced biomass as feedstock to generate biofuels and chemical products using a wide variety of alternative conversion pathways. The alternative conversion pathways can be generally classified as either biochemical or thermochemical conversion. A biorefinery is commonly based on a core biomass conversion technology (pretreatment, hydrolysis, pyrolysis, etc.) followed by secondary processing stages that determine the specific product, and its recovery. In this study, techno-economic analysis of several different lignocellulosic biomass conversion pathways have been performed. First, a novel biochemical conversion, which used electron beam and steam explosion pretreatments for ethanol production was evaluated. This evaluation include both laboratory work and process modeling. Encouraging experimental results are obtained that showed the biomass had enhanced reactivity to the enzyme hydrolysis. The total sugar recovery for the hardwood species was 72% using 5 FPU/g enzyme dosage. The combination of electron beam and steam explosion provides an improvement in sugar conversion of more than 20% compared to steam explosion alone. This combination of pretreatments was modeled along with a novel ethanol dehydration process that is based on vapor permeation membranes. The economic feasibility of this novel pretreatment-dehydration technology was evaluated and compared with the dilute acid process proposed by NREL in 2011. Overall, the pretreatment-dehydration technology process produces the same ethanol yields (81 gal/bdton). However, the economics of this novel process does not look promising since the minimum ethanol selling price (MESP) to generate an internal rate of return of 10% is of 3.09 /gal, compared to 2.28 /gal for the base case. To enhance the economic potential of a biorefinery, the isolation of value-added co-products was incorporated into the base dilute acid biorefinery process. In this case the work focused on the ethanol extraction of the non-structural components of switchgrass prior to pretreatment and enzymatic hydrolysis. Promising results obtained with an Aspen PlusRTM model showed that a MESP of 2.5 /gal along with an assumed co-product selling price of 1 /Kg generated an 18% internal rate of return (IRR). In a second series of studies biomass fast pyrolysis and the bio-oil upgrading for the production of drop-in fuels was analyzed. Again, an Aspen PlusRTM based process model was used to evaluate the impacts of different biomass feedstock composition on the biofuel product. In this case the biofuel produced both a gasoline and diesel fraction. Model results showed that both the carbon and ash content of the biomass had an impact on the amount and price of the biofuel products. The highest biofuel yield were obtained with the hardwood (red maple) and perennial (switchgrass) feedstocks at about 48 gal/bdton of biomass, while the softwood (loblolly pine) provided 46 gal/bdton. Bark (acacia), the feedstock with the highest ash content, only provided 39 gal/bdton. But when the cost of these feedstocks was included the softwood is predicted to provide the lowest cost fuel, followed by the bark. As expected overall cost of the biofuel was dramatically impacted by the cost of the feedstock, and also by the use of a fraction of the intermediate bio-oil as the source of the hydrogen needed for upgrading the bio-oil to a hydrocarbon fuel product. Using hydrogen from natural gas instead of hydrogen from reforming the intermediate bio-oil reduced the estimated cost of the fuel product by $1.20/gal.

Resting heart rate and the risk of developing impaired fasting glucose and diabetes: the Kailuan prospective study

PubMed Central

Wang, Liang; Cui, Liufu; Wang, Yanxue; Vaidya, Anand; Chen, Shuohua; Zhang, Caifeng; Zhu, Ying; Li, Dongqing; Hu, Frank B; Wu, Shouling; Gao, Xiang

2015-01-01

Background: To investigate the association between resting heart rate and the risk of developing impaired fasting glucose (IFG), diabetes and conversion from IFG to diabetes. Methods: The prospective analysis included 73 357 participants of the Kailuan cohort (57 719 men and 15 638 women). Resting heart rate was measured via electrocardiogram in 2006. Incident diabetes was defined as either the fasting blood glucose (FBG) ≥ 7.0 mmol/l or new active use of diabetes medications during the 4-year follow-up period. IFG was defined as a FBG between 5.6 and 6.9 mmol/l. A meta-analysis including seven published prospective studies focused on heart rate and diabetes risk, and our current study was then conducted using random-effects models. Results: During 4 years of follow-up, 17 463 incident IFG cases and 4 649 incident diabetes cases were identified. The corresponding adjusted hazard ratios (HRs) for each 10 beats/min increase in heart rate were 1.23 [95% confidence interval (CI): 1.19, 1.27] for incident diabetes, 1.11 (95% CI: 1.09, 1.13) for incident IFG and 1.13 (95% CI: 1.08, 1.17) for IFG to diabetes conversion. The risks of incident IFG and diabetes were significantly higher among participants aged < 50 years than those aged ≥ 50 years (P-interaction < 0.02 for both). A meta-analysis confirmed the positive association between resting heart rate and diabetes risk (pooled HR for the highest vs lowest heart rate quintile = 1.59, 95% CI:1.27, 2.00; n = 8). Conclusion: Faster resting heart rate is associated with higher risk of developing IFG and diabetes, suggesting that heart rate could be used to identify individuals with a higher future risk of diabetes. PMID:26002923

High-efficiency diode-pumped actively Q-switched ceramic Nd:YAG/BaWO₄ Raman laser operating at 1666 nm.

PubMed

Zhang, H N; Chen, X H; Wang, Q P; Zhang, X Y; Chang, J; Gao, L; Shen, H B; Cong, Z H; Liu, Z J; Tao, X T; Li, P

2014-05-01

A diode-pumped actively Q-switched Raman laser employing BaWO4 as the Raman active medium and a ceramic Nd:YAG laser operating at 1444 nm as the pump source is demonstrated. The first-Stokes-Raman generation at 1666 nm is achieved. With a pump power of 20.3 W and pulse repetition frequency rate of 5 kHz, a maximum output power of 1.21 W is obtained, which is the highest output power for a 1.6 μm Raman laser. The corresponding optical-to-optical conversion efficiency is 6%; the pulse energy and peak power are 242 μJ and 8.96 kW, respectively.

4-GHz counters bring synthesizers up to speed

NASA Astrophysics Data System (ADS)

Lee, F.; Miller, R.

1984-06-01

The availability of digital IC counters built on GaAs makes direct frequency division in microwave synthesizers possible. Four GHz is the highest clock rate achievable in production designs. These devices have the ability to drive TTL/CMOS logic, and the counter can be connected directly to single-chip frequency synthesizers controllers. A complete microwave sythesizer is formed by two chips and a voltage-controlled oscillator (VCO). The advantages of GaAs are discussed along with flip-flop basics, aspects of device fabrication, and the characteristics of GaAs MESAFETs. Attention is given to a GaAs prescaler usable for direct conversion, four kinds of flip-flops in a divide-by-two mode, and seven-stage binary ripple counters.

Do conversations with virtual avatars increase feelings of social anxiety?

PubMed

Powers, Mark B; Briceno, Nicole F; Gresham, Robert; Jouriles, Ernest N; Emmelkamp, Paul M G; Smits, Jasper A J

2013-05-01

Virtual reality (VR) technology provides a way to conduct exposure therapy with patients with social anxiety. However, the primary limitation of current technology is that the operator is limited to pre-programed avatars that cannot be controlled to interact/converse with the patient in real time. The current study piloted new technology allowing the operator to directly control the avatar (including speaking) during VR conversations. Using an incomplete repeated measures (VR vs. in vivo conversation) design and random starting order with rotation counterbalancing, participants (N = 26) provided ratings of fear and presence during both VR and in vivo conversations. Results showed that VR conversation successfully elevated fear ratings relative to baseline (d = 2.29). Participants also rated their fear higher during VR conversation than during in vivo conversation (d = 0.85). However, in vivo conversation was rated as more realistic than VR conversation (d = 0.74). No participants dropped out and 100% completed both VR and in vivo conversations. Qualitative participant comments suggested that the VR conversations would be more realistic if they did not meet the actor/operator and if they were not in the same room as the participant. Overall, the data suggest that the novel technology allowing real time interaction/conversation in VR may prove useful for the treatment of social anxiety in future studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of Relationships between Growth Rate, Tree Size, Lignocellulose Composition, and Enzymatic Saccharification in Interspecific Corymbia Hybrids and Parental Taxa

DOE PAGES

Healey, Adam L.; Lee, David J.; Lupoi, Jason S.; ...

2016-11-18

In order for a lignocellulosic bioenergy feedstock to be considered sustainable,it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application,it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin,glucan,and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF) and parental species Corymbia torelliana and C. citriodora subspecies variegata and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7–21.3%) amongmore » parental and hybrid populations,whereas glucan content was clearly distinguished within C. citriodora subspecies variegata (52%) and HF148 (60%) as compared to other populations (28–38%). Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age,with Klason lignin content increasing with diameter breast height (DBH) (+0.12% per cm DBH increase),and glucan and xylan typically decreasing per DBH cm increase (-0.7 and -0.3%,respectively). Polysaccharide content within C. citriodora subspecies variegata and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass,with parental Corymbia torelliana and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass,respectively),with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%). Based on growth rate,biomass composition,and further optimization of enzymatic saccharification yield,high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production.« less

Evaluation of Relationships between Growth Rate, Tree Size, Lignocellulose Composition, and Enzymatic Saccharification in Interspecific Corymbia Hybrids and Parental Taxa

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

Healey, Adam L.; Lee, David J.; Lupoi, Jason S.

In order for a lignocellulosic bioenergy feedstock to be considered sustainable,it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application,it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin,glucan,and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF) and parental species Corymbia torelliana and C. citriodora subspecies variegata and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7–21.3%) amongmore » parental and hybrid populations,whereas glucan content was clearly distinguished within C. citriodora subspecies variegata (52%) and HF148 (60%) as compared to other populations (28–38%). Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age,with Klason lignin content increasing with diameter breast height (DBH) (+0.12% per cm DBH increase),and glucan and xylan typically decreasing per DBH cm increase (-0.7 and -0.3%,respectively). Polysaccharide content within C. citriodora subspecies variegata and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass,with parental Corymbia torelliana and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass,respectively),with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%). Based on growth rate,biomass composition,and further optimization of enzymatic saccharification yield,high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production.« less

Consumption and utilization of experimentally altered corn by southern armyworm: Iron, nitrogen, and cyclic hydroxamates.

PubMed

Manuwoto, S; Scriber, J M

1985-11-01

The effects of differential leaf water, leaf nitrogen and cyclic hydroxamate (DIMBOA) concentrations in corn seedlings were analyzed for a polyphagous insect, the southern armyworm (Spodoptera eridania Cram.). Six different combinations of nutrients and allelochemicals [DIMBOA = 2,4-dihydroxy-7-methoxy(2H)-benzoxazin-3(4H)-one] were generated using two corn genotypes (WF9 and CI3IA) and three fertility regimes (complete nutrient, Fe-deficient, and N-deficient solutions) in the University Biotron. Poorest larval growth was observed in the low-nitrogen treatments (1.2% and 1.7% leaf N) and was the result of both low consumption rates and high metabolic costs (low efficiency of conversion of digested food, ECD). Fastest growth rates were observed forthe larvae fed leaves from the high-nitrogen treatments (4.6% and 4.4% leaf N). It is noteworthy that these treatments also contained the highest concentration of cyclic hydroxamates, which are generally believed to be the primary defensive chemicals mediating resistance against the European corn borer,Ostrinia nubilalis (Hubner). If these hydroxamates do have any deleterious or costly effects (perhaps accounting for a large portion of metabolic expenditures), the high digestibility of the leaf tissue and the increased consumption rates more than compensate, resulting in rapid growth (growth rate = consumption rate × approximate digestibility × efficiency of conversion of the digested food). These studies illustrate that variation in key nutrients and allelochemicals within a single plant species (Zea mays L.) may have significantly different effects upon various potential leaf-chewing caterpillars, such as these armyworms versus corn borers (which cannot handle the cyclic hydroxamates, even if provided with young nutritious leaf tissues).

Evaluation of Relationships between Growth Rate, Tree Size, Lignocellulose Composition, and Enzymatic Saccharification in Interspecific Corymbia Hybrids and Parental Taxa.

PubMed

Healey, Adam L; Lee, David J; Lupoi, Jason S; Papa, Gabriella; Guenther, Joel M; Corno, Luca; Adani, Fabrizio; Singh, Seema; Simmons, Blake A; Henry, Robert J

2016-01-01

In order for a lignocellulosic bioenergy feedstock to be considered sustainable, it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application, it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin, glucan, and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF) and parental species Corymbia torelliana and C. citriodora subspecies variegata and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7-21.3%) among parental and hybrid populations, whereas glucan content was clearly distinguished within C. citriodora subspecies variegata (52%) and HF148 (60%) as compared to other populations (28-38%). Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age, with Klason lignin content increasing with diameter breast height (DBH) (+0.12% per cm DBH increase), and glucan and xylan typically decreasing per DBH cm increase (-0.7 and -0.3%, respectively). Polysaccharide content within C. citriodora subspecies variegata and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass, with parental Corymbia torelliana and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass, respectively), with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%). Based on growth rate, biomass composition, and further optimization of enzymatic saccharification yield, high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production.

Evaluation of Relationships between Growth Rate, Tree Size, Lignocellulose Composition, and Enzymatic Saccharification in Interspecific Corymbia Hybrids and Parental Taxa

PubMed Central

Healey, Adam L.; Lee, David J.; Lupoi, Jason S.; Papa, Gabriella; Guenther, Joel M.; Corno, Luca; Adani, Fabrizio; Singh, Seema; Simmons, Blake A.; Henry, Robert J.

2016-01-01

In order for a lignocellulosic bioenergy feedstock to be considered sustainable, it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application, it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin, glucan, and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF) and parental species Corymbia torelliana and C. citriodora subspecies variegata and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7–21.3%) among parental and hybrid populations, whereas glucan content was clearly distinguished within C. citriodora subspecies variegata (52%) and HF148 (60%) as compared to other populations (28–38%). Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age, with Klason lignin content increasing with diameter breast height (DBH) (+0.12% per cm DBH increase), and glucan and xylan typically decreasing per DBH cm increase (-0.7 and -0.3%, respectively). Polysaccharide content within C. citriodora subspecies variegata and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass, with parental Corymbia torelliana and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass, respectively), with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%). Based on growth rate, biomass composition, and further optimization of enzymatic saccharification yield, high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production. PMID:27917179

Catalytic Oxidation of Methane into Methanol over Copper-Exchanged Zeolites with Oxygen at Low Temperature

PubMed Central

2016-01-01

The direct catalytic conversion of methane to liquid oxygenated compounds, such as methanol or dimethyl ether, at low temperature using molecular oxygen is a grand challenge in C–H activation that has never been met with synthetic, heterogeneous catalysts. We report the first demonstration of direct, catalytic oxidation of methane into methanol with molecular oxygen over copper-exchanged zeolites at low reaction temperatures (483–498 K). Reaction kinetics studies show sustained catalytic activity and high selectivity for a variety of commercially available zeolite topologies under mild conditions (e.g., 483 K and atmospheric pressure). Transient and steady state measurements with isotopically labeled molecules confirm catalytic turnover. The catalytic rates and apparent activation energies are affected by the zeolite topology, with caged-based zeolites (e.g., Cu-SSZ-13) showing the highest rates. Although the reaction rates are low, the discovery of catalytic sites in copper-exchanged zeolites will accelerate the development of strategies to directly oxidize methane into methanol under mild conditions. PMID:27413787

Statistical optimization of recycled-paper enzymatic hydrolysis for simultaneous saccharification and fermentation via central composite design.

PubMed

Liu, Qing; Cheng, Ke-ke; Zhang, Jian-an; Li, Jin-ping; Wang, Ge-hua

2010-01-01

A central composite design of the response surface methodology (RSM) was employed to study the effects of temperature, enzyme concentration, and stirring rate on recycled-paper enzymatic hydrolysis. Among the three variables, temperature and enzyme concentration significantly affected the conversion efficiency of substrate, whereas stirring rate was not effective. A quadratic polynomial equation was obtained for enzymatic hydrolysis by multiple regression analysis using RSM. The results of validation experiments were coincident with the predicted model. The optimum conditions for enzymatic hydrolysis were temperature, enzyme concentration, and stirring rate of 43.1 degrees C, 20 FPU g(-1) substrate, and 145 rpm, respectively. In the subsequent simultaneous saccharification and fermentation (SSF) experiment under the optimum conditions, the highest 28.7 g ethanol l(-1) was reached in the fed-batch SSF when 5% (w/v) substrate concentration was used initially, and another 5% added after 12 h fermentation. This ethanol output corresponded to 77.7% of the theoretical yield based on the glucose content in the raw material.

Meiotic gene-conversion rate and tract length variation in the human genome.

PubMed

Padhukasahasram, Badri; Rannala, Bruce

2013-02-27

Meiotic recombination occurs in the form of two different mechanisms called crossing-over and gene-conversion and both processes have an important role in shaping genetic variation in populations. Although variation in crossing-over rates has been studied extensively using sperm-typing experiments, pedigree studies and population genetic approaches, our knowledge of variation in gene-conversion parameters (ie, rates and mean tract lengths) remains far from complete. To explore variability in population gene-conversion rates and its relationship to crossing-over rate variation patterns, we have developed and validated using coalescent simulations a comprehensive Bayesian full-likelihood method that can jointly infer crossing-over and gene-conversion rates as well as tract lengths from population genomic data under general variable rate models with recombination hotspots. Here, we apply this new method to SNP data from multiple human populations and attempt to characterize for the first time the fine-scale variation in gene-conversion parameters along the human genome. We find that the estimated ratio of gene-conversion to crossing-over rates varies considerably across genomic regions as well as between populations. However, there is a great degree of uncertainty associated with such estimates. We also find substantial evidence for variation in the mean conversion tract length. The estimated tract lengths did not show any negative relationship with the local heterozygosity levels in our analysis.European Journal of Human Genetics advance online publication, 27 February 2013; doi:10.1038/ejhg.2013.30.

Enhanced land subsidence in Galveston Bay, Texas: Interaction between sediment accumulation rates and relative sea level rise

NASA Astrophysics Data System (ADS)

Al Mukaimi, Mohammad E.; Dellapenna, Timothy M.; Williams, Joshua R.

2018-07-01

Galveston Bay is the second largest estuary along the northern Gulf of Mexico coast, with a watershed containing one of largest concentrations of petroleum and chemical industries globally, as well as Houston, the fifth largest metropolitan area in the USA. Throughout the last century, extensive groundwater extraction to support these industries and an expanding population has resulted in significantly enhanced land subsidence (0.6-3.0 cm yr-1). The highest subsidence rates observed in the bay are within the lower 15 km of the San Jacinto River/Houston Ship Channel region (SJR/HSC), with distal areas in East and West Galveston Bays having subsidence rates on the order of 0.2 cm yr-1. In order to investigate the impacts of subsidence on sedimentation, a series of 22 vibracores were collected throughout the bay, and 210Pb and 137Cs radioisotope geochronologies and grain size distributions were determined. Sediment accumulation rates are highest (1.9 ± 0.5 cm yr-1) in the SJR/HSC, and decrease (<0.6 cm yr-1) both seaward and towards low subsidence regions. These results indicate sedimentation rates are significantly (p < 0.01) higher in areas with elevated Relative Sea Level Rise (RSLR). However, throughout most of Galveston Bay sedimentation rates are lower (as much as 50%) than estimated RSLR, indicating a sediment accretionary deficit. In areas (e.g., Scott Bay) within the SJR/HSC, the bay has deepened by more than 1.5 m, suggesting that sediment accumulation cannot keep pace with RSLR. Ultimately, this has resulted in a loss of coastal wetlands and a conversion of marine habitats from relatively shallow to deeper water settings.

Degradation and mineralization of 2,4,6-trinitroresorcine in various photochemical systems.

PubMed

Khue, Do Ngoc; Chat, Nguyen Van; Minh, Do Binh; Lam, Tran Dai; Lan, Pham Hong; Loi, Vu Duc

2013-05-01

Comparison was observed for degradation and mineralization of the explosive 2,4,6-trinitroresorcine (TNR) in different photochemical systems TNR/UV, TNR/UV/TiO2, TNR/UV/H2O2, TNR/UV/O3, TNR/UV/TiO2/H2O2 and TNR/UV/TiO2/O3 using High Performance Liquid Chromatography coupled with Mass Spectrometry (HPLC/MS) and Total Organic Carbon (TOC) analysis. Addition of oxidizing agents such as H2O2 or O3 accelerated the rate of TNR conversion and mineralization. Highest reaction rate was obtained in TNR/UV/TiO2/H2O2 system. The intermediate products were characterized and identified by LS-MS technique. The similarity in intermediate products of TNR suggested the analogous reaction pathways of the TNR degradation by these different systems. Copyright © 2013 Elsevier B.V. All rights reserved.

High-throughput investigation of catalysts for JP-8 fuel cracking to liquefied petroleum gas.

PubMed

Bedenbaugh, John E; Kim, Sungtak; Sasmaz, Erdem; Lauterbach, Jochen

2013-09-09

Portable power technologies for military applications necessitate the production of fuels similar to LPG from existing feedstocks. Catalytic cracking of military jet fuel to form a mixture of C₂-C₄ hydrocarbons was investigated using high-throughput experimentation. Cracking experiments were performed in a gas-phase, 16-sample high-throughput reactor. Zeolite ZSM-5 catalysts with low Si/Al ratios (≤25) demonstrated the highest production of C₂-C₄ hydrocarbons at moderate reaction temperatures (623-823 K). ZSM-5 catalysts were optimized for JP-8 cracking activity to LPG through varying reaction temperature and framework Si/Al ratio. The reducing atmosphere required during catalytic cracking resulted in coking of the catalyst and a commensurate decrease in conversion rate. Rare earth metal promoters for ZSM-5 catalysts were screened to reduce coking deactivation rates, while noble metal promoters reduced onset temperatures for coke burnoff regeneration.

Heart rate variability and the anxious client: cardiac autonomic and behavioral associations with therapeutic alliance.

PubMed

Stratford, Trisha; Meara, Alan; Psychotherapy, M Gestalt; Lal, Sara

2014-08-01

This exploratory study was designed to investigate the link between a client's heart rate variability (HRV) and the forming of a therapeutic alliance (TA) during psychotherapy. Change in HRV is associated with many psychological and physiological situations, including cardiac mortality. Cardiac effects were evaluated during therapy in 30 symptomatically anxious clients using HRV during six weekly 1-hour therapy sessions (S1-S6). Therapeutic index (TI), a measure of TA, was evaluated using skin conductance resonance between client and therapist. The Working Alliance Inventory provides a subjective measure of TA. State and trait anxiety and mood states were also assessed. Most HRV parameters were highest during S4. The sympathovagal balance was highest in S1 but stabilized after S2. In S4, TI was linked to high HRV parameters. Overall higher anxiety levels seem to be associated to lower HRV parameters. Conversely, in S4, high HRV parameters were linked to higher mood scores. This study found that a subjective measure of TA contradicted the physiological outcome. Results suggest that physiological data collected during therapy are a more accurate barometer of TA forming. These research findings suggest a need for further research identifying physiological markers in clients with a variety of mental health disorders over long-term therapy.

Risk calculation variability over time in ocular hypertensive subjects.

PubMed

Song, Christian; De Moraes, Carlos Gustavo; Forchheimer, Ilana; Prata, Tiago S; Ritch, Robert; Liebmann, Jeffrey M

2014-01-01

To investigate the longitudinal variability of glaucoma risk calculation in ocular hypertensive (OHT) subjects. We reviewed the charts of untreated OHT patients followed in a glaucoma referral practice for a minimum of 60 months. Clinical variables collected at baseline and during follow-up included age, central corneal thickness (CCT), intraocular pressure (IOP), vertical cup-to-disc ratio (VCDR), and visual field pattern standard deviation (VFPSD). These were used to calculate the 5-year risk of conversion to primary open-angle glaucoma (POAG) at each follow-up visit using the Ocular Hypertension Treatment Study and European Glaucoma Prevention Study calculator (http://ohts.wustl.edu/risk/calculator.html). We also calculated the risk of POAG conversion based on the fluctuation of measured variables over time assuming the worst case scenarios (final age, highest PSD, lowest CCT, highest IOP, and highest VCDR) and best case scenarios (baseline age, lowest PSD, highest CCT, lowest IOP, and lowest VCDR) for each patient. Risk probabilities (%) were plotted against follow-up time to generate slopes of risk change over time. We included 27 untreated OHT patients (54 eyes) followed for a mean of 98.3±18.5 months. Seven individuals (25.9%) converted to POAG during follow-up. The mean 5-year risk of conversion for all patients in the study group ranged from 2.9% to 52.3% during follow-up. The mean slope of risk change over time was 0.37±0.81% increase/y. The mean slope for patients who reached a POAG endpoint was significantly greater than for those who did not (1.3±0.78 vs. 0.042±0.52%/y, P<0.01). In each patient, the mean risk of POAG conversion increased almost 10-fold when comparing the best case scenario with the worst case scenario (5.0% vs. 45.7%, P<0.01). The estimated 5-year risk of conversion to POAG among untreated OHT patients varies significantly during follow-up, with a trend toward increasing over time. Within the same individual, the estimated risk can vary almost 10-fold based on the variability of IOP, CCT, VCDR, and VFPSD. Therefore, a single risk calculation measurement may not be sufficient for accurate risk assessment, informed decision-making by patients, and physician treatment recommendations.

Towards cell-free isobutanol production: Development of a novel immobilized enzyme system.

PubMed

Grimaldi, Joseph; Collins, Cynthia H; Belfort, Georges

2016-01-01

Producing fuels and chemical intermediates with cell cultures is severely limited by low product concentrations (≤0.2%(v/v)) due to feedback inhibition, cell instability, and lack of economical product recovery processes. We have developed an alternate simplified production scheme based on a cell-free immobilized enzyme system. Two immobilized enzymes (keto-acid decarboxylase (KdcA) and alcohol dehydrogenase (ADH)) and one enzyme in solution (formate dehydrogenase (FDH) for NADH recycle) produced isobutanol titers 8 to 20 times higher than the highest reported titers with S. cerevisiae on a mol/mol basis. These high conversion rates and low protein leaching were achieved by covalent immobilization of enzymes (ADH) and enzyme fusions (fKdcA) on methacrylate resin. The new enzyme system without in situ removal of isobutanol achieved a 55% conversion of ketoisovaleric acid to isobutanol at a concentration of 0.135 (mole isobutanol produced for each mole ketoisovaleric acid consumed). Further increasing titer will require continuous removal of the isobutanol using an in situ recovery system. © 2015 American Institute of Chemical Engineers.

A Severity-Based Clinical Staging Model for the Psychosis Prodrome: Longitudinal Findings From the New York Recognition and Prevention Program.

PubMed

Carrión, Ricardo E; Correll, Christoph U; Auther, Andrea M; Cornblatt, Barbara A

2017-01-01

Clinical staging improved the possibility of intervening during the psychosis prodrome to limit progression of illness. The current study aimed to validate a novel 4-stage severity-based model with a focus on clinical change over time and risk for conversion to psychosis. One hundred seventy-one individuals at clinical high risk (CHR) for psychosis were followed prospectively (3 ± 1.6 y) as part of the Recognition and Prevention (RAP) program and divided into 4 diagnostic stages according to absence/presence and severity of attenuated positive symptoms. Twenty-two percent of the combined sample recovered (no prodromal symptoms) by study outcome. The negative symptoms only subgroup had the highest symptom stability (70%), but the lowest conversion rate at 5.9%. The subgroup with more severe baseline attenuated positive symptom levels had a higher conversion rate (28%) and a more rapid onset when compared to the moderate attenuated positive symptom subgroup (11%). Finally, the Schizophrenia-Like Psychosis (SLP) subgroup showed low stability (3%), with 49% developing a specific psychotic disorder. The proposed stage model provides a more finely grained classification system than the standard diagnostic approach for prodromal individuals. All 4 stages are in need of early intervention because of low recovery rates. The negative symptom only stage is possibly a separate clinical syndrome, with an increased risk of functional disability. Both subgroups with attenuated positive symptoms are appropriate for studying the mechanisms of psychosis risk, however, individuals with more severe baseline positive symptoms appear better suited to clinical trials. Finally, the SLP category represents an intermediate outcome group appropriate for preventative intervention research but questionable for inclusion in prodromal studies of mechanisms. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

5 CFR 534.406 - Conversion to the SES pay system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Conversion to the SES pay system. 534.406... UNDER OTHER SYSTEMS Pay and Performance Awards Under the Senior Executive Service § 534.406 Conversion... senior executive's converted rate of basic pay. Conversion to a new SES rate of basic pay is not...

Advanced Thermal Conversion Systems

DTIC Science & Technology

2015-03-18

increase electron emission from the cathode. A two-stage, PETE topping stage followed by a thermoelectric bottoming stage, is projected to have a...illustrated in the by the energy-band diagrams in Fig. 1. In that aspect, PETE converters are similar to photovoltaic (PV) cells, but unlike PV cells, PETE... photovoltaic cells at 3000x concentration (~38%). As shown in Fig. 2(b), the highest conversion efficiencies are obtained by using photo-cathodes

Multiple model approach to evaluation of accelerated carbonation for steelmaking slag in a slurry reactor.

PubMed

Pan, Shu-Yuan; Liu, Hsing-Lu; Chang, E-E; Kim, Hyunook; Chen, Yi-Hung; Chiang, Pen-Chi

2016-07-01

Basic oxygen furnace slag (BOFS) exhibits highly alkaline properties due to its high calcium content, which is beneficial to carbonation reaction. In this study, accelerated carbonation of BOFS was evaluated under different reaction times, temperatures, and liquid-to-solid (L/S) ratios in a slurry reactor. CO2 mass balance within the slurry reactor was carried out to validate the technical feasibility of fixing gaseous CO2 into solid precipitates. After that, a multiple model approach, i.e., theoretical kinetics and empirical surface model, for carbonation reaction was presented to determine the maximal carbonation conversion of BOFS in a slurry reactor. On one hand, the reaction kinetics of BOFS carbonation was evaluated by the shrinking core model (SCM). Calcite (CaCO3) was identified as a reaction product through the scanning electronic microscopy and X-ray diffraction analyses, which provided the rationale of applying the SCM in this study. The rate-limiting step of carbonation was found to be ash-diffusion controlled, and the effective diffusivity for carbonation of BOFS in a slurry reactor were determined accordingly. On the other hand, the carbonation conversion of BOFS was predicted by the response surface methodology (RSM) via a nonlinear mathematical programming. According to the experimental data, the highest carbonation conversion of BOFS achieved was 57% under an L/S ratio of 20 mL g(-1), a CO2 flow rate of 0.1 L min(-1), and a pressure of 101.3 kPa at 50 °C for 120 min. Furthermore, the applications and limitations of SCM and RSM were examined and exemplified by the carbonation of steelmaking slags. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of temperature and ration size on the growth, body composition, and energy content of juvenile coho salmon

USGS Publications Warehouse

Edsall, Thomas A.; Frank, Anthony M.; Rottiers, Donald V.; Adams, Jean V.

1999-01-01

Juvenile (postsmolt) coho salmon (Oncorhynchus kitsuch) were held in fresh water in the laboratory at 5, 10, 15, and 18A?C for 8 weeks and fed freshly thawed, juvenile alewives (Alosa pseudoharengus) at rates equal to 1 and 2 % of their wet body weight/day, and also at the ad libitum or unrestricted ration rate. Most rapid growth in weight (1.2% wet body weight/day) occurred among fish fed the ad libitum ration at 15A?C; growth was most rapid at about 10A?C for fish fed the 2% ration (0.7%/day), and the 1% ration (0.1%/day). Gross conversion efficiency was highest at 10A?C for all three ration levels. Gross body constituents and energy content of the test fish changed with temperature and ration during the study. Growth rate was positively related to lipid, energy content, and ration; lipid and energy content were positively related to water temperature; lipid, energy content, growth rate, ration, and water temperature were negatively related to water content; and protein was not related to any of the test variables. At the end of the study, water (68.7 to 76.4%) and lipid (3.5 to 10.4%) content were more variable than ash (1.8 to 3.1%), carbohydrate (0.1 to 1.9%), and protein (16.9 to 19.4%) content. Energy content of the fish increased with ration and was highest for each ration level at 15A?C.

Spectral reflectance properties of electroplated and converted zinc for use as a solar selective coating

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.; Curtis, H. B.; Gianelos, L.

1975-01-01

The spectral reflectance properties of electroplated and chemically converted zinc were measured for both chromate and chloride conversion coatings. The reflectance properties were measured for various times of conversion and for conversion at various chromate concentrations. The values of absorptance, integrated over the solar spectrum, and of infrared emittance, integrated over black body radiation at 250 F were then calculated from the measured reflectance values. The interdependent variations of absorptance and infrared emittance were plotted. The results indicate that the optimum combination of the highest absorptance in the solar spectrum and the lowest emittance in the infrared of the converted electroplated zinc is produced by chromate conversion at 1/2 concentration of the standard NEOSTAR chromate black solution for 0.50 minute or by chloride conversion for 0.50 minute.

Spectral reflectance properties of electroplated and converted zinc for use as a solar selective coating

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.; Curtis, H. B.; Gianelos, L.

1975-01-01

The spectral reflectance properties of electroplated and chemically converted zinc were measured for both chromate and chloride conversion coatings. The reflectance properties were measured for various times of conversion and for conversion at various chromate concentrations. The values of absorptance, alpha, integrated over the solar spectrum, and of infrared emittance, epsilon, integrated over black body radiation at 250 F were then calculated from the measured reflectance values. The interdependent variations of alpha and epsilon were plotted. The results indicate that the optimum combination of the highest absorptance in the solar spectrum and the lowest emittance in the infrared of the converted electroplated zinc is produced by chromate conversion at 1/2 concentration of the standard NEOSTAR chromate black solution for 0.50 minute or by chloride conversion for 0.50 minute.

Influencing the Conversation About Masculinity and Suicide: Evaluation of the Man Up Multimedia Campaign Using Twitter Data

PubMed Central

King, Kylie; Turnure, Jackie; Sukunesan, Suku; Phelps, Andrea; Pirkis, Jane

2018-01-01

Background It has been suggested that some dominant aspects of traditional masculinity are contributing to the high suicide rates among Australian men. We developed a three-episode documentary called Man Up, which explores the complex relationship between masculinity and suicide and encourages men to question socially imposed rules about what it means to be a man and asks them to open up, express difficult emotions, and seek help if and when needed. We ran a three-phase social media campaign alongside the documentary using 5 channels (Twitter, Facebook, Instagram, YouTube, and Tumblr). Objective This study aimed to examine the extent to which the Man Up Twitter campaign influenced the social media conversation about masculinity and suicide. Methods We used Twitter insights data to assess the reach of and engagement with the campaign (using metrics on followers, likes, retweets, and impressions) and to determine the highest and lowest performing tweets in the campaign (using an aggregated performance measure of reactions). We used original content tweets to determine whether the campaign increased the volume of relevant Twitter conversations (aggregating the number of tweets for selected campaign hashtags over time), and we used a subset of these data to gain insight into the main content themes with respect to audience engagement. Results The campaign generated a strong following that was engaged with the content of the campaign; over its whole duration, the campaign earned approximately 5000 likes and 2500 retweets and gained around 1,022,000 impressions. The highest performing tweets posted by the host included video footage and occurred during the most active period of the campaign (around the screening of the documentary). The volume of conversations in relation to commonly used hashtags (#MANUP, #ABCMANUP, #LISTENUP, and #SPEAKUP) grew in direct relation to the campaign activities, achieving strongest growth during the 3 weeks when the documentary was aired. Strongest engagement was found with content related to help-seeking, masculinity, and expressing emotions. A number of followers tweeted personal stories that revealed overwhelmingly positive perceptions of the content of the documentary and strongly endorsed its messages. Conclusions The Man Up Twitter campaign triggered conversations about masculinity and suicide that otherwise may not have happened. For some, this may have been game-changing in terms of shifting attitudes toward expressing emotions and reaching out to others for help. The campaign was particularly effective in disseminating information and promoting conversations in real time, an advantage that it had over more traditional health promotion campaigns. This sort of approach could well be adapted to other areas of mental (and physical) health promotion campaigns to increase their reach and effectiveness. PMID:29449203

Surveillance programme for uncompensated work-related diseases in France.

PubMed

Valenty, M; Homère, J; Lemaitre, A; Plaine, J; Ruhlman, M; Cohidon, C; Imbernon, E

2015-11-01

The surveillance programme for uncompensated work-related diseases (UWRDs) in France relies on a network of occupational physicians (OPs) who volunteer to report all UWRDs diagnosed during a biannual 2-week observation period. To describe this programme and the usefulness of its results. During the observation period, OPs record job title and employment sector for each worker. For each potential UWRD, they complete a one-page report form. Between 2007 and 2012, the number of reporting OPs ranged from 705 to 965 and they saw between 78884 and 114154 employees annually. The UWRD incidence rate reports varied from 5 to 5.3% for men and from 6.5 to 7.7% for women, with musculoskeletal disorders (MSDs) being most frequent, followed by mental ill-health. Incidence rates, except for hearing loss, were higher for women than men in all categories and, in 2012, were twice as high for women (3.1%) as for men (1.4%) for mental ill-health. Incidence rates in every category increased with age up to 54 years. The highest rates for MSDs were observed among blue-collar workers (6.9% in women and 4% in men in 2012) and the lowest rates in professionals/managers (1.1 and 0.4%, respectively). Conversely, the latter had the highest incidence of mental health disorders (5.9 and 3.3%). This 'Fortnight' protocol provides useful data on the frequency of diseases linked to employment and allows us to estimate the incidence of UWRDs, whether recognized as compensable or not, as well as their trends over time. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Systematization of Oncoplastic Surgery: Selection of Surgical Techniques and Patient-Reported Outcome in a Cohort of 1,035 Patients.

PubMed

Rezai, Mahdi; Knispel, Sarah; Kellersmann, Stephanie; Lax, Hildegard; Kimmig, Rainer; Kern, Peter

2015-10-01

Functional and aesthetic outcome after breast-conserving surgery are vital endpoints for patients with primary breast cancer. A large variety of oncoplastic techniques exist; however, it remains unclear which techniques yield the highest rates of local control at first surgery, omission of reexcision or subsequent mastectomy, and merits the highest degree of patient satisfaction. In this retrospective case cohort trial with a customized investigational questionnaire for assessment of patient satisfaction with the surgical result, we analyzed 1,035 patients with primary, unilateral breast cancer and oncoplastic surgery from 2004 to 2009. Analysis of patient reported outcome (PRO) revealed that 88 % of the cohort was satisfied with their aesthetic result using oncoplastic techniques following the concept presented. These results also were achieved in difficult tumor localizations, such as upper inner and lower inner quadrant. Conversion rate from breast-conserving therapy to secondary mastectomy was low at 7.2 % (n = 68/944 patients). The systematization of oncoplastic techniques presented-embedded in a multimodal concept of breast cancer therapy-facilitates tumor control with a few number of uncomplicated techniques adapted to tumor site and size with a median resection of 32 (range 11-793) g. Five-year recurrence rate in our cohort was 4.0 %. Patient's satisfaction was independent from age, body mass index, resection volume, tumor localization, and type of oncoplastic surgery (p > 0.05). We identified postoperative pain as an important negative impact factor on patient's satisfaction with the aesthetic result (p = 0.0001).

Novel Solid-State Solar Cell Based on Hole-Conducting MOF-Sensitizer Demonstrating Power Conversion Efficiency of 2.1.

PubMed

Ahn, Do Young; Lee, Deok Yeon; Shin, Chan Yong; Bui, Hoa Thi; Shrestha, Nabeen K; Giebeler, Lars; Noh, Yong-Young; Han, Sung-Hwan

2017-04-19

This work reports on designing of first successful MOF-sensitizer based solid-state photovoltaic device, perticularly with a meaningful output power conversion efficiency. In this study, an intrinsically conductive cobalt-based MOFs (Co-DAPV) formed by the coordination between Co (II) ions and a redox active di(3-diaminopropyl)-viologen (i.e., DAPV) ligand is investigated as sensitizer. Hall-effect measurement shows p-type conductivity of the Co-DAPV film with hole mobility of 0.017 cm 2 V -1 s -1 , suggesting its potential application as hole transporting sensitizer. Further, the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of Co-DAPV are well-matched to be suitably employed for sensitizing TiO 2 . Thus, by layer-by-layer deposition of hole conducting MOF-sensitizer onto mesoporous TiO 2 film, a power conversion efficiency of as high as 2.1% is achieved, which exceeds the highest efficiency values of MOF-sensitized liquid-junction solar cells reported so far.

Optimization of the nitrification process of wastewater resulting from cassava starch production.

PubMed

Fleck, Leandro; Ferreira Tavares, Maria Hermínia; Eyng, Eduardo; Orssatto, Fabio

2018-05-14

The present study has the objective of optimizing operational conditions of an aerated reactor applied to the removal of ammoniacal nitrogen from wastewater resulting from the production of cassava starch. An aerated reactor with a usable volume of 4 L and aeration control by rotameter was used. The airflow and cycle time parameters were controlled and their effects on the removal of ammoniacal nitrogen and the conversion to nitrate were evaluated. The highest ammoniacal nitrogen removal, of 96.62%, occurred under conditions of 24 h and 0.15 L min -1 L reactor -1 . The highest nitrate conversion, of 24.81%, occurred under conditions of 40.92 h and 0.15 L min -1  L reactor -1 . The remaining value of ammoniacal nitrogen was converted primarily into nitrite, energy, hydrogen and water. The optimal operational values of the aerated reactor are 29.25 h and 0.22 L min -1  L reactor -1 . The mathematical models representative of the process satisfactorily describe ammoniacal nitrogen removal efficiency and nitrate conversion, presenting errors of 2.87% and 3.70%, respectively.

Impact of Predicting Health Care Utilization Via Web Search Behavior: A Data-Driven Analysis.

PubMed

Agarwal, Vibhu; Zhang, Liangliang; Zhu, Josh; Fang, Shiyuan; Cheng, Tim; Hong, Chloe; Shah, Nigam H

2016-09-21

By recent estimates, the steady rise in health care costs has deprived more than 45 million Americans of health care services and has encouraged health care providers to better understand the key drivers of health care utilization from a population health management perspective. Prior studies suggest the feasibility of mining population-level patterns of health care resource utilization from observational analysis of Internet search logs; however, the utility of the endeavor to the various stakeholders in a health ecosystem remains unclear. The aim was to carry out a closed-loop evaluation of the utility of health care use predictions using the conversion rates of advertisements that were displayed to the predicted future utilizers as a surrogate. The statistical models to predict the probability of user's future visit to a medical facility were built using effective predictors of health care resource utilization, extracted from a deidentified dataset of geotagged mobile Internet search logs representing searches made by users of the Baidu search engine between March 2015 and May 2015. We inferred presence within the geofence of a medical facility from location and duration information from users' search logs and putatively assigned medical facility visit labels to qualifying search logs. We constructed a matrix of general, semantic, and location-based features from search logs of users that had 42 or more search days preceding a medical facility visit as well as from search logs of users that had no medical visits and trained statistical learners for predicting future medical visits. We then carried out a closed-loop evaluation of the utility of health care use predictions using the show conversion rates of advertisements displayed to the predicted future utilizers. In the context of behaviorally targeted advertising, wherein health care providers are interested in minimizing their cost per conversion, the association between show conversion rate and predicted utilization score, served as a surrogate measure of the model's utility. We obtained the highest area under the curve (0.796) in medical visit prediction with our random forests model and daywise features. Ablating feature categories one at a time showed that the model performance worsened the most when location features were dropped. An online evaluation in which advertisements were served to users who had a high predicted probability of a future medical visit showed a 3.96% increase in the show conversion rate. Results from our experiments done in a research setting suggest that it is possible to accurately predict future patient visits from geotagged mobile search logs. Results from the offline and online experiments on the utility of health utilization predictions suggest that such prediction can have utility for health care providers.

Impact of Predicting Health Care Utilization Via Web Search Behavior: A Data-Driven Analysis

PubMed Central

Zhang, Liangliang; Zhu, Josh; Fang, Shiyuan; Cheng, Tim; Hong, Chloe; Shah, Nigam H

2016-01-01

Background By recent estimates, the steady rise in health care costs has deprived more than 45 million Americans of health care services and has encouraged health care providers to better understand the key drivers of health care utilization from a population health management perspective. Prior studies suggest the feasibility of mining population-level patterns of health care resource utilization from observational analysis of Internet search logs; however, the utility of the endeavor to the various stakeholders in a health ecosystem remains unclear. Objective The aim was to carry out a closed-loop evaluation of the utility of health care use predictions using the conversion rates of advertisements that were displayed to the predicted future utilizers as a surrogate. The statistical models to predict the probability of user’s future visit to a medical facility were built using effective predictors of health care resource utilization, extracted from a deidentified dataset of geotagged mobile Internet search logs representing searches made by users of the Baidu search engine between March 2015 and May 2015. Methods We inferred presence within the geofence of a medical facility from location and duration information from users’ search logs and putatively assigned medical facility visit labels to qualifying search logs. We constructed a matrix of general, semantic, and location-based features from search logs of users that had 42 or more search days preceding a medical facility visit as well as from search logs of users that had no medical visits and trained statistical learners for predicting future medical visits. We then carried out a closed-loop evaluation of the utility of health care use predictions using the show conversion rates of advertisements displayed to the predicted future utilizers. In the context of behaviorally targeted advertising, wherein health care providers are interested in minimizing their cost per conversion, the association between show conversion rate and predicted utilization score, served as a surrogate measure of the model’s utility. Results We obtained the highest area under the curve (0.796) in medical visit prediction with our random forests model and daywise features. Ablating feature categories one at a time showed that the model performance worsened the most when location features were dropped. An online evaluation in which advertisements were served to users who had a high predicted probability of a future medical visit showed a 3.96% increase in the show conversion rate. Conclusions Results from our experiments done in a research setting suggest that it is possible to accurately predict future patient visits from geotagged mobile search logs. Results from the offline and online experiments on the utility of health utilization predictions suggest that such prediction can have utility for health care providers. PMID:27655225

Highly efficient and regioselective synthesis of dihydromyricetin esters by immobilized lipase.

PubMed

Li, Wei; Wu, Huan; Liu, Benguo; Hou, Xuedan; Wan, Duanji; Lou, Wenyong; Zhao, Jian

2015-04-10

Dihydromyricetin is the principle component of the Chinese herbal tea Teng-cha and a promising ingredient for functional food and nutraceuticals, but its low solubility limits its application potentials. This study explored enzymatic acylation of dihydromyricetin to improve its solubility in lipid systems. Acylation was achieved with several lipases with the synthesis of a major (>86%) product and a minor product. Isolation and purification of the products by preparative HPLC followed by LC-MS, (13)C NMR, (1)H NMR and 2 D-HSQC NMR analyses showed that the major product was a dihydromyricetin monoester with the acylation site at the 3-OH group of C ring. Quantum chemical calculations revealed that the 3-OH had the lowest antioxidant activity, and therefore acylation at this site was expected to have minimum impact on the antioxidant activity. Several factors, including solvent, acyl donor, enzyme origin, molar ratio of substrates and reaction temperature and time, exhibited significant effects on the initial rate, conversion yield and regioselectivity of the reaction. Acylation occurred only with vinyl acetate as the acyl donor, and highest conversion yields were achieved with immobilized Penicillium expansum lipase and Novozyme 435 with DMSO and acetonitrile being the best solvents. In general, the acylation results were found to be superior to previous reports on acylation of aglycone flavonoids with respects to conversion yield and regioselectivity. Copyright © 2015 Elsevier B.V. All rights reserved.

Lipase of Aspergillus niger NCIM 1207: A Potential Biocatalyst for Synthesis of Isoamyl Acetate.

PubMed

Mhetras, Nutan; Patil, Sonal; Gokhale, Digambar

2010-10-01

Commercial lipase preparations and mycelium bound lipase from Aspergillus niger NCIM 1207 were used for esterification of acetic acid with isoamyl alcohol to obtain isoamyl acetate. The esterification reaction was carried out at 30°C in n-hexane with shaking at 120 rpm. Initial reaction rates, conversion efficiency and isoamyl acetate concentration obtained using Novozyme 435 were the highest. Mycelium bound lipase of A. niger NCIM 1207 produced maximal isoamyl acetate formation at an alcohol/acid ratio of 1.6. Acetic acid at higher concentrations than required for the critical alcohol/acid ratio lower than 1.3 and higher than 1.6 resulted in decreased yields of isoamyl acetate probably owing to lowering of micro-aqueous environmental pH around the enzyme leading to inhibition of enzyme activity. Mycelium bound A. niger lipase produced 80 g/l of isoamyl acetate within 96 h even though extremely less amount of enzyme activity was used for esterification. The presence of sodium sulphate during esterification reaction at higher substrate concentration resulted in increased conversion efficiency when we used mycelium bound enzyme preparations of A. niger NCIM 1207. This could be due to removal of excess water released during esterification reaction by sodium sulphate. High ester concentration (286.5 g/l) and conversion (73.5%) were obtained within 24 h using Novozyme 435 under these conditions.

Two-stage conversion of crude glycerol to energy using dark fermentation linked with microbial fuel cell or microbial electrolysis cell.

PubMed

Chookaew, Teera; Prasertsan, Poonsuk; Ren, Zhiyong Jason

2014-03-25

Crude glycerol is a main byproduct of the biodiesel industry, and the beneficial use of waste glycerol has been a major challenge. This study characterises the conversion of crude glycerol into bioenergy such as H2 and electricity using a two-stage process linking dark fermentation with a microbial fuel cell (MFC) or microbial electrolysis cell (MEC). The results showed that fermentation achieved a maximum H2 rate of 332 mL/L and a yield of 0.55 mol H2/mol glycerol, accompanied by 20% of organic removal. Fed with the raw fermentation products with an initial COD of 7610 mg/L, a two-chamber MFC produced 92 mW/m(2) in power density and removed 50% of COD. The Columbic efficiency was 14%. When fed with 50% diluted fermentation product, a similar power output (90m W/m(2)) and COD removal (49%) were obtained, but the CE doubled to 27%. Similar substrates were used to produce H2 in two-chamber MECs, and the diluted influent had a higher performance, with the highest yield at 106 mL H2/g COD and a CE of 24%. These results demonstrate that dark fermentation linked with MFC/MEC can be a feasible option for conversion of waste glycerol into bioenergy. Copyright © 2013 Elsevier B.V. All rights reserved.

Electrical and optical modeling of poly(3-hexylthiophene):[6,6]-phenyl-C61 butyric acid methyl ester P3HT-PCBM bulk heterojunction solar cells

NASA Astrophysics Data System (ADS)

Brioua, Fathi; Remram, Mohamed; Nechache, Riad; Bourouina, Hicham

2017-11-01

In this work, we investigate a two-dimensional theoretical model for the photon conversion through an integration of the optical and electrical part of multilayer system in a bulk heterojunction solar cell based on poly(3-hexylthiophene) (P3HT)/6,6-phenyl C61-butyric acid methyl ester (PCBM) blend. The optical properties of the studied structure ITO/PEDOT:PSS/P3HT:PCBM/Ca/Al, such as the exciton generation rate and the electrical field distribution, are predicted at vicinity of the active layer and have been used to solve Poisson and continuity, drift-diffusion equations of the electrical model which characterize the electrical behavior of semiconductor device using finite element method (FEM). The electrical parameters such as power conversion efficiency (PCE), open voltage circuit ( V oc), short-circuit current density ( J sc) and fill factor (FF) are extracted from the current-voltage (J-V) characteristics under illumination and in dark conditions. Highest external quantum efficiency (IPCE), up to 60%, is obtained around 520 nm, while a power conversion efficiency (PCE) value of 3.62% is found to be in good agreement with the literature results. Integration of such theoretical approach into technological applications dealing with optoelectrical material performance will rapidly provide to the user accurate data outputs required for efficient validation of proof-of-concepts.

ZnCr2S4: Highly effective photocatalyst converting nitrate into N2 without over-reduction under both UV and pure visible light

NASA Astrophysics Data System (ADS)

Yue, Mufei; Wang, Rong; Cheng, Nana; Cong, Rihong; Gao, Wenliang; Yang, Tao

2016-08-01

We propose several superiorities of applying some particular metal sulfides to the photocatalytic nitrate reduction in aqueous solution, including the high density of photogenerated excitons, high N2 selectivity (without over-reduction to ammonia). Indeed, ZnCr2S4 behaved as a highly efficient photocatalyst, and with the assistance of 1 wt% cocatalysts (RuOx, Ag, Au, Pd, or Pt), the efficiency was greatly improved. The simultaneous loading of Pt and Pd led to a synergistic effect. It offered the highest nitrate conversion rate of ~45 mg N/h together with the N2 selectivity of ~89%. Such a high activity remained steady after 5 cycles. The optimal apparent quantum yield at 380 nm was 15.46%. More importantly, with the assistance of the surface plasma resonance effect of Au, the visible light activity achieved 1.352 mg N/h under full arc Xe-lamp, and 0.452 mg N/h under pure visible light (λ > 400 nm). Comparing to the previous achievements in photocatalytic nitrate removal, our work on ZnCr2S4 eliminates the over-reduction problem, and possesses an extremely high and steady activity under UV-light, as well as a decent conversion rate under pure visible light.

ZnCr2S4: Highly effective photocatalyst converting nitrate into N2 without over-reduction under both UV and pure visible light.

PubMed

Yue, Mufei; Wang, Rong; Cheng, Nana; Cong, Rihong; Gao, Wenliang; Yang, Tao

2016-08-03

We propose several superiorities of applying some particular metal sulfides to the photocatalytic nitrate reduction in aqueous solution, including the high density of photogenerated excitons, high N2 selectivity (without over-reduction to ammonia). Indeed, ZnCr2S4 behaved as a highly efficient photocatalyst, and with the assistance of 1 wt% cocatalysts (RuOx, Ag, Au, Pd, or Pt), the efficiency was greatly improved. The simultaneous loading of Pt and Pd led to a synergistic effect. It offered the highest nitrate conversion rate of ~45 mg N/h together with the N2 selectivity of ~89%. Such a high activity remained steady after 5 cycles. The optimal apparent quantum yield at 380 nm was 15.46%. More importantly, with the assistance of the surface plasma resonance effect of Au, the visible light activity achieved 1.352 mg N/h under full arc Xe-lamp, and 0.452 mg N/h under pure visible light (λ > 400 nm). Comparing to the previous achievements in photocatalytic nitrate removal, our work on ZnCr2S4 eliminates the over-reduction problem, and possesses an extremely high and steady activity under UV-light, as well as a decent conversion rate under pure visible light.

Enhanced acetic acid production from manalagi apple (Malus sylvestris mill) by mixed cultures of Saccharomyces cerevisiae and Acetobacter aceti in submerged fermentation

NASA Astrophysics Data System (ADS)

Rosada, K. K.

2018-05-01

The production of acetic acid from Manalagi apple was studied using a mixed culture of S. cerevisiae and A. aceti by submerged fermentation technique. Determination of the best conditions for producing acetic acid was performed by stratified optimization with variations that were made on the concentration of the initial sugar addition to the medium (0%, 10%, 20% w/v), the ratio of the number of inocula S. cerevisiae and A. aceti (7:3, 1:1, 3:7), and agitation rate (80 and 160 rpm). All experiments were done by using the initial pH medium of 4.5 and incubated at room temperature (28±2oC) for 14 days. The concentration of reducing sugar, alcohol, acetic acid, and the pH were measured every 48 hours. The efficiency of sugar conversion to acetic acid with the addition of initial sugar 0%, 10%, and20%were 233%, 46.6%, and 6.4% respectively after ten days of incubation. Overall, the result showed that the highest acetic acid was produced from Manalagi apple juice when no sugar was added, using seven parts of S. cerevisiae to three parts of A. aceti and agitation rate of 160 rpm on the tenth day of fermentation. Under these conditions, glucose conversion efficiency to acetic acid increased to 362%.

Comparison of complication and conversion rates between robotic-assisted and laparoscopic rectal resection for rectal cancer: which patients and providers could benefit most from robotic-assisted surgery?

PubMed

Ackerman, Stacey J; Daniel, Shoshana; Baik, Rebecca; Liu, Emelline; Mehendale, Shilpa; Tackett, Scott; Hellan, Minia

2018-03-01

To compare (1) complication and (2) conversion rates to open surgery (OS) from laparoscopic surgery (LS) and robotic-assisted surgery (RA) for rectal cancer patients who underwent rectal resection. (3) To identify patient, physician, and hospital predictors of conversion. A US-based database study was conducted utilizing the 2012-2014 Premier Healthcare Data, including rectal cancer patients ≥18 with rectal resection. ICD-9-CM diagnosis and procedural codes were utilized to identify surgical approaches, conversions to OS, and surgical complications. Propensity score matching on patient, surgeon, and hospital level characteristics was used to create comparable groups of RA\\LS patients (n = 533 per group). Predictors of conversion from LS and RA to OS were identified with stepwise logistic regression in the unmatched sample. Post-match results suggested comparable perioperative complication rates (RA 29% vs LS 29%; p = .7784); whereas conversion rates to OS were 12% for RA vs 29% for LS (p < .0001). Colorectal surgeons (RA 9% vs LS 23%), general surgeons (RA 13% vs LS 35%), and smaller bed-size hospitals (RA 14% vs LS 33%) have reduced conversion rates for RA vs LS (p < .0001). Statistically significant predictors of conversion included LS, non-colorectal surgeon, and smaller bed-size hospitals. Retrospective observational study limitations apply. Analysis of the hospital administrative database was subject to the data captured in the database and the accuracy of coding. Propensity score matching limitations apply. RA and LS groups were balanced with respect to measured patient, surgeon, and hospital characteristics. Compared to LS, RA offers a higher probability of completing a successful minimally invasive surgery for rectal cancer patients undergoing rectal resection without exacerbating complications. Male, obese, or moderately-to-severely ill patients had higher conversion rates. While colorectal surgeons had lower conversion rates from RA than LS, the reduction was magnified for general surgeons and smaller bed-size hospitals.

Effect of immediate or delayed light activation on curing kinetics and shrinkage stress of dual-cure resin cements.

PubMed

Faria-e-Silva, Andre; Boaro, Leticia; Braga, Roberto; Piva, Evandro; Arias, Vanessa; Martins, Luis

2011-01-01

This study evaluated the effect of light activation (absence, immediate, or delayed) on conversion kinetics and polymerization stress of three commercial dual-cured resin cements (Enforce, RelyX ARC, and Panavia F). Degree of conversion (DC) was monitored for 30 minutes using real-time near–Fourier transform infrared spectroscopy. The cement was mixed, placed on the spectrometer sample holder, and light activated either immediately or after five minutes (delayed light activation). When no light activation was performed, the materials were protected from light exposure (control). DC was evaluated at five and 30 minutes postmixture. Maximum rates of polymerization (Rp(max)) were obtained from the first derivative of the DC vs time curve. Polymerization stress was monitored for 30 minutes in 1-mm-thick specimens inserted between two cylinders attached to a universal testing machine. Data were submitted to analysis of variance/Tukey tests (α=0.05). Immediate light activation promoted the highest DC at five minutes. At 30 minutes, only RelyX ARC did not present a significant difference in DC between activation modes. Enforce and Panavia F presented higher Rp(max) for immediate and delayed light-activation, respectively. RelyX ARC showed similar Rp(max) for all activation modes. The absence of light activation resulted in the lowest stress followed by delayed light activation, while immediate light activation led to the highest values. RelyX ARC showed higher stress than Enforce, while the stress of Panavia F was similar to that of the others. Delayed light activation reduced the polymerization stress of the resin cements tested without jeopardizing DC.

Evaluation of Silica-Supported Metal and Metal Phosphide Nanoparticle Catalysts for the Hydrodeoxygenation of Guaiacol Under Ex Situ Catalytic Fast Pyrolysis Conditions

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

Griffin, Michael B.; Baddour, Frederick G.; Habas, Susan E.

A series of metal and metal phosphide catalysts were investigated for the hydrodeoxygenation of guaiacol under ex situ catalytic fast pyrolysis (CFP) conditions (350 °C, 0.5 MPa, 12 H 2:1 guaiacol, weight hourly space velocity 5 h $-$1). Ligand-capped Ni, Pt, Rh, Ni 2P, and Rh 2P nanoparticles (NPs) were prepared using solution-phase synthesis techniques and dispersed on a silica support. For the metal phosphide NP-catalysts, a synthetic route that relies on the decomposition of a single molecular precursor was employed. The reactivity of the NP-catalysts was compared to a series of reference materials including Ni/SiO 2 and Pt/SiO 2more » prepared using incipient wetness (IW) impregnation and a commercial (com) Pt/SiO 2 catalyst. The NP-Ni/SiO 2 catalyst exhibited the largest reduction in the oxygen mol% of the organic phase and outperformed the IW-Ni/SiO 2 material. Although it was less active for guaiacol conversion than NP-Ni/SiO 2, NP-Rh2P/SiO 2 demonstrated the largest production of completely deoxygenated products and the highest selectivity to anisole, benzene, and cyclohexane, suggesting that it is a promising catalyst for deoxygenation of aryl-OH bonds. Finally, the com-Pt/SiO 2 and IW-Pt/SiO 2 catalyst exhibited the highest normalized rate of guaiacol conversion per m 2 and per gram of active phase, respectively, but did not produce any completely deoxygenated products.« less

Mercury speciation and microbial transformations in mine wastes, stream sediments, and surface waters at the Almaden Mining District, Spain

USGS Publications Warehouse

Gray, John E.; Hines, Mark E.; Higueras, Pablo L.; Adatto, Isaac; Lasorsa, Brenda K.

2004-01-01

Speciation of Hg and conversion to methyl-Hg were evaluated in mine wastes, sediments, and water collected from the Almade??n District, Spain, the world's largest Hg producing region. Our data for methyl-Hg, a neurotoxin hazardous to humans, are the first reported for sediment and water from the Almade??n area. Concentrations of Hg and methyl-Hg in mine waste, sediment, and water from Almade??n are among the highest found at Hg mines worldwide. Mine wastes from Almade??n contain highly elevated Hg concentrations, ranging from 160 to 34 000 ??g/g, and methyl-Hg varies from <0.20 to 3100 ng/g. Isotopic tracer methods indicate that mine wastes at one site (Almadenejos) exhibit unusually high rates of Hg-methylation, which correspond with mine wastes containing the highest methyl-Hg concentrations. Streamwater collected near the Almade??n mine is also contaminated, containing Hg as high as 13 000 ng/L and methyl-Hg as high as 30 ng/L; corresponding stream sediments contain Hg concentrations as high as 2300 ??g/g and methyl-Hg concentrations as high as 82 ng/g. Several streamwaters contain Hg concentrations in excess of the 1000 ng/L World Health Organization (WHO) drinking water standard. Methyl-Hg formation and degradation was rapid in mines wastes and stream sediments demonstrating the dynamic nature of Hg cycling. These data indicate substantial downstream transport of Hg from the Almade??n mine and significant conversion to methyl-Hg in the surface environment.

Exploring tomato Solanum pennellii introgression lines for residual biomass and enzymatic digestibility traits.

PubMed

Caruso, G; Gomez, L D; Ferriello, F; Andolfi, A; Borgonuovo, C; Evidente, A; Simister, R; McQueen-Mason, S J; Carputo, D; Frusciante, L; Ercolano, M R

2016-04-05

Residual biomass production for fuel conversion represents a unique opportunity to avoid concerns about compromising food supply by using dedicated feedstock crops. Developing tomato varieties suitable for both food consumption and fuel conversion requires the establishment of new selection methods. A tomato Solanum pennellii introgression population was assessed for fruit yield, biomass phenotypic diversity, and for saccharification potential. Introgression lines 2-5, 2-6, 6-3, 7-2, 10-2 and 12-4 showed the best combination of fruit and residual biomass production. Lignin, cellulose, hemicellulose content and saccharification rate showed a wide variation in the tested lines. Within hemicellulose, xylose value was high in IL 6-3, IL 7-2 and IL 6-2, whereas arabinose showed a low content in IL 10-2, IL 6-3 and IL 2-6. The latter line showed also the highest ethanol potential production. Alkali pre-treatment resulted in the highest values of saccharification in most of lines tested, suggesting that chemical pretreatment is an important factor for improving biomass processability. Interestingly, extreme genotypes for more than one single trait were found, allowing the identification of better genotypes. Cell wall related genes mapping in genomic regions involved into tomato biomass production and digestibility variation highlighted potential candidate genes. Molecular expression profile of few of them provided useful information about challenged pathways. The screening of S. pennellii introgression population resulted very useful for delving into complex traits such as biomass production and digestibility. The extreme genotypes identified could be fruitfully employed for both genetic studies and breeding.

Evaluation of Silica-Supported Metal and Metal Phosphide Nanoparticle Catalysts for the Hydrodeoxygenation of Guaiacol Under Ex Situ Catalytic Fast Pyrolysis Conditions

DOE PAGES

Griffin, Michael B.; Baddour, Frederick G.; Habas, Susan E.; ...

2015-09-30

A series of metal and metal phosphide catalysts were investigated for the hydrodeoxygenation of guaiacol under ex situ catalytic fast pyrolysis (CFP) conditions (350 °C, 0.5 MPa, 12 H 2:1 guaiacol, weight hourly space velocity 5 h $-$1). Ligand-capped Ni, Pt, Rh, Ni 2P, and Rh 2P nanoparticles (NPs) were prepared using solution-phase synthesis techniques and dispersed on a silica support. For the metal phosphide NP-catalysts, a synthetic route that relies on the decomposition of a single molecular precursor was employed. The reactivity of the NP-catalysts was compared to a series of reference materials including Ni/SiO 2 and Pt/SiO 2more » prepared using incipient wetness (IW) impregnation and a commercial (com) Pt/SiO 2 catalyst. The NP-Ni/SiO 2 catalyst exhibited the largest reduction in the oxygen mol% of the organic phase and outperformed the IW-Ni/SiO 2 material. Although it was less active for guaiacol conversion than NP-Ni/SiO 2, NP-Rh2P/SiO 2 demonstrated the largest production of completely deoxygenated products and the highest selectivity to anisole, benzene, and cyclohexane, suggesting that it is a promising catalyst for deoxygenation of aryl-OH bonds. Finally, the com-Pt/SiO 2 and IW-Pt/SiO 2 catalyst exhibited the highest normalized rate of guaiacol conversion per m 2 and per gram of active phase, respectively, but did not produce any completely deoxygenated products.« less

The preparation of Fe2O3-ZSM-5 catalysts by metal-organic chemical vapour deposition method for catalytic wet peroxide oxidation of m-cresol.

PubMed

Yang, Yi; Zhang, Huiping; Yan, Ying

2018-03-01

Fe 2 O 3 -ZSM-5 catalysts (0.6 wt% Fe load) prepared by metal-organic chemical vapour deposition (MOCVD) method were evaluated in the catalytic wet peroxide oxidation (CWPO) of m -cresol in a batch reactor. The catalysts have a good iron dispersion and small iron crystalline size, and exhibit high stability during reaction. In addition, the kinetics of the reaction were studied and the initial oxidation rate equation was given. Catalysts were first characterized by N 2 adsorption-desorption isotherms, scanning electronic microscopy, energy-dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Results show that extra-framework Fe 3+ species (presenting in the form of Fe 2 O 3 ) are successfully loaded on ZSM-5 supports by MOCVD method. Performances of catalysts were tested and effects of different temperature, stirring rate, catalyst amount on hydrogen peroxide, m -cresol, total organic carbon (TOC) conversion and Fe leaching concentration were studied. Results reveal that catalytic activity increased with higher temperature, faster stirring rate and larger catalyst amount. In all circumstances, m -cresol conversion could reach 99% in 0.5-2.5 h, and the highest TOC removal (80.5%) is obtained after 3 h under conditions of 60°C, 400 r.p.m. and catalyst amount of 2.5 g l -1 . The iron-leaching concentrations are less than 1.1 mg l -1 under all conditions. The initial oxidation rate equation [Formula: see text] is obtained for m -cresol degradation with Fe 2 O 3 -ZSM-5 catalysts.

Up-Conversion Intersystem Crossing Rates in Organic Emitters for Thermally Activated Delayed Fluorescence: Impact of the Nature of Singlet vs Triplet Excited States.

PubMed

Samanta, Pralok K; Kim, Dongwook; Coropceanu, Veaceslav; Brédas, Jean-Luc

2017-03-22

The rates for up-conversion intersystem crossing (UISC) from the T 1 state to the S 1 state are calculated for a series of organic emitters with an emphasis on thermally activated delayed fluorescence (TADF) materials. Both the spin-orbit coupling and the energy difference between the S 1 and T 1 states (ΔE ST ) are evaluated, at the density functional theory (DFT) and time-dependent DFT levels. The calculated UISC rates and ΔE ST values are found to be in good agreement with available experimental data. Our results underline that small ΔE ST values and sizable spin-orbit coupling matrix elements have to be simultaneously realized in order to facilitate UISC and ultimately TADF. Importantly, the spatial separation of the highest occupied and lowest unoccupied molecular orbitals of the emitter, a widely accepted strategy for the design of TADF molecules, does not necessarily lead to a sufficient reduction in ΔE ST ; in fact, either a significant charge-transfer (CT) contribution to the T 1 state or a minimal energy difference between the local-excitation and charge-transfer triplet states is required to achieve a small ΔE ST . Also, having S 1 and T 1 states of a different nature is found to strongly enhance spin-orbit coupling, which is consistent with the El-Sayed rule for ISC rates. Overall, our results indicate that having either similar energies for the local-excitation and charge-transfer triplet states or the right balance between a substantial CT contribution to T 1 and somewhat different natures of the S 1 and T 1 states, paves the way toward UISC enhancement and thus TADF efficiency improvement.

Fabrication of a saturable absorber WS2 and its mode locking in solid-state laser

NASA Astrophysics Data System (ADS)

Zhang, Chun-Yu; Zhang, Ling; Tang, Xiao-Ying; Yang, Ying-Ying

2018-04-01

We report on a passively mode-locked Nd : LuVO4 laser using a type saturable absorber of tungsten disulfide (WS2) fabricated by chemical vapor deposition method. At the pump power of 3.3 W, 1.18-W average output power of continuous-wave mode-locked laser with optical conversion efficiency of 36% was achieved. To the best of our knowledge, this is the highest output power of passively mode-locked solid-state laser based on WS2. The repetition rate of passively mode-locked pulse was 80 MHz with the pulse energy of 14.8 nJ. Our experimental results show that WS2 is an excellent type of saturable absorber.

[Hydroxylamine conversion by anammox enrichment].

PubMed

Hu, Anhui; Zheng, Ping; Lu, Huifeng; Ding, Shuang; Wang, Caihua

2010-04-01

Hydroxylamine is an important intermediate product of anammox. This study was focused on the characteristics of hydroxylamine and nitrite conversions by anammox enrichment. The changes of nitrogenous substrates and related products with time were measured using batch tests with anammox enrichment as inoculum. Since hydroxylamine didn't react with nitrite in uninoculated control culture, these two compounds were chemically stable. Both of them decreased with time in anammox enrichment inoculated cultures, in which ammonia as intermediate product would be produced and converted with the maximum concentration being 0.338 mg/L. The total nitrogen concentration decreased from 4.694 mmol/L to 0.812 mmol/L with conversion rate 82.7% in the end. When hydroxylamine and nitrite concentrations were about 2.5 mmol/L respectively, the maximum specific sludge conversion rates of hydroxylamine was 0.535 mmol/(gVSS.h), which was 1.81 times bigger than that of ammonia in ammonia reaction system; the maximum specific sludge rate of total nitrogen was slightly higher than that in ammonia reaction system. When hydroxylamine concentration increased to 5.0 mmol/L, the hydroxylamine and nitrite conversion rates promoted by 26.7% and 120.7% respectively; and the maximum ammonia accumulated was 1.810 mmol/L. When nitrite concentration increased to 5.0 mmol/L, the hydroxylamine and nitrite conversion rates promoted by 6.9% and 9.0% respectively; and the maximum ammonia accumulated was 0.795 mmol/L. Anammox enrichment was capable of converting hydroxylamine and nitrite simultaneously and had the higher conversion rate of hydroxylamine than ammonia conversion rate. Hydroxylamine and nitrite conversion rates were less affected by increase in nitrite concentration, but more significantly influenced by increase in hydroxylamine. The maximum ammonia concentration accumulated would rise as the result of increasing both hydroxylamine and nitrite. The result of experiment was consistent with pathway model presented by van de Graaf AA.

Estimating forest conversion rates with annual forest inventory data

Treesearch

Paul C. Van Deusen; Francis A. Roesch

2009-01-01

The rate of land-use conversion from forest to nonforest or natural forest to forest plantation is of interest for forest certification purposes and also as part of the process of assessing forest sustainability. Conversion rates can be estimated from remeasured inventory plots in general, but the emphasis here is on annual inventory data. A new estimator is proposed...

Evaluation of correlation between glucan conversion and degree of delignification depending on pretreatment strategies using Jabon Merah.

PubMed

Jang, Soo-Kyeong; Jeong, Hanseob; Kim, Ho-Yong; Choi, June-Ho; Kim, Jong-Hwa; Koo, Bon-Wook; Choi, In-Gyu

2017-07-01

The main purpose of this study was to investigate the glucan conversion rate after enzymatic hydrolysis depending on the treatment methods and conditions with changes in the chemical composition of treated solid fraction of Jabon Merah. The glucan conversion rate (17.4%) was not significantly improved after liquid hot water treatment (1st step) even though most of the hemicellulose was dissolved into liquid hydrolysate. Subsequently, dilute acid, organosolv, and peracetic acid treatment (2nd step) was conducted under various conditions to enhance glucan conversion. Among the 2nd step treatment, the glucan conversion rate of organosolv (max. 46.0%) and peracetic acid treatment (max. 65.9%) was increased remarkably through decomposition of acid-insoluble lignin (AIL). Finally, the glucan conversion rate and AIL content were highly correlated, which was revealed by the R-squared value (0.84), but inhibitory factors including cellulose crystallinity must be considered for advanced glucan conversion from highly recalcitrant biomasses, such as Jabon Merah. Copyright © 2017 Elsevier Ltd. All rights reserved.

Absolute Position Encoders With Vertical Image Binning

NASA Technical Reports Server (NTRS)

Leviton, Douglas B.

2005-01-01

Improved optoelectronic patternrecognition encoders that measure rotary and linear 1-dimensional positions at conversion rates (numbers of readings per unit time) exceeding 20 kHz have been invented. Heretofore, optoelectronic pattern-recognition absoluteposition encoders have been limited to conversion rates <15 Hz -- too low for emerging industrial applications in which conversion rates ranging from 1 kHz to as much as 100 kHz are required. The high conversion rates of the improved encoders are made possible, in part, by use of vertically compressible or binnable (as described below) scale patterns in combination with modified readout sequences of the image sensors [charge-coupled devices (CCDs)] used to read the scale patterns. The modified readout sequences and the processing of the images thus read out are amenable to implementation by use of modern, high-speed, ultra-compact microprocessors and digital signal processors or field-programmable gate arrays. This combination of improvements makes it possible to greatly increase conversion rates through substantial reductions in all three components of conversion time: exposure time, image-readout time, and image-processing time.

Isolation and characterization of oxalotrophic bacteria from tropical soils.

PubMed

Bravo, Daniel; Braissant, Olivier; Cailleau, Guillaume; Verrecchia, Eric; Junier, Pilar

2015-01-01

The oxalate-carbonate pathway (OCP) is a biogeochemical set of reactions that involves the conversion of atmospheric CO2 fixed by plants into biomass and, after the biological recycling of calcium oxalate by fungi and bacteria, into calcium carbonate in terrestrial environments. Oxalotrophic bacteria are a key element of this process because of their ability to oxidize calcium oxalate. However, the diversity and alternative carbon sources of oxalotrophs participating to this pathway are unknown. Therefore, the aim of this study was to characterize oxalotrophic bacteria in tropical OCP systems from Bolivia, India, and Cameroon. Ninety-five oxalotrophic strains were isolated and identified by sequencing of the 16S rRNA gene. Four genera corresponded to newly reported oxalotrophs (Afipia, Polaromonas, Humihabitans, and Psychrobacillus). Ten strains were selected to perform a more detailed characterization. Kinetic curves and microcalorimetry analyses showed that Variovorax soli C18 has the highest oxalate consumption rate with 0.240 µM h(-1). Moreover, Streptomyces achromogenes A9 displays the highest metabolic plasticity. This study highlights the phylogenetic and physiological diversity of oxalotrophic bacteria in tropical soils under the influence of the oxalate-carbonate pathway.

Rate and predictors of conversion from unipolar to bipolar disorder: A systematic review and meta-analysis.

PubMed

Kessing, Lars Vedel; Willer, Inge; Andersen, Per Kragh; Bukh, Jens Drachman

2017-08-01

For the first time to present a systematic review and meta-analysis of the conversion rate and predictors of conversion from unipolar disorder to bipolar disorder. A systematic literature search up to October 2016 was performed. For the meta-analysis, we only included studies that used survival analysis to estimate the conversion rate. A total of 31 studies were identified, among which 11 used survival analyses, including two register-based studies. The yearly rate of conversion to bipolar disorder decreased with time from 3.9% in the first year after study entry with a diagnosis of unipolar disorder to 3.1% in years 1-2, 1.0% in years 2-5 and 0.8% in years 5-10. A total of eight risk factors were evaluated comprising gender, age at onset of unipolar disorder, number of depressive episodes, treatment resistance to antidepressants, family history of bipolar disorder, the prevalence of psychotic depression, the prevalence of chronic depression, and severity of depression. It was not possible to identify risk factors that were consistently or mainly confirmed to predict conversion across studies. The conversion rate from unipolar to bipolar disorder decreases with time. It was not possible to identify predictors of conversion that were consistently or mainly confirmed across studies, which may be due to variations in methodology across studies. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

5 CFR 531.221 - Maximum payable rate rule.

Code of Federal Regulations, 2010 CFR

2010-01-01

... before the reassignment. (ii) If the rate resulting from the geographic conversion under paragraph (c)(2... previous rate (i.e., the former special rate after the geographic conversion) with the rates on the current... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Maximum payable rate rule. 531.221...

Steady-State Thermal-Hydraulics Analyses for the Conversion of BR2 to Low Enriched Uranium Fuel

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

Licht, J.; Bergeron, A.; Dionne, B.

The code PLTEMP/ANL version 4.2 was used to perform the steady-state thermal-hydraulic analyses of the BR2 research reactor for conversion from Highly-Enriched to Low Enriched Uranium fuel (HEU and LEU, respectively). Calculations were performed to evaluate different fuel assemblies with respect to the onset of nucleate boiling (ONB), flow instability (FI), critical heat flux (CHF) and fuel temperature at beginning of cycle conditions. The fuel assemblies were characteristic of fresh fuel (0% burnup), highest heat flux (16% burnup), highest power (32% burnup) and highest burnup (46% burnup). Results show that the high heat flux fuel element is limiting for ONB,more » FI, and CHF, for both HEU and LEU fuel, but that the high power fuel element produces similar margin in a few cases. The maximum fuel temperature similarly occurs in both the high heat flux and high power fuel assemblies for both HEU and LEU fuel. A sensitivity study was also performed to evaluate the variation in fuel temperature due to uncertainties in the thermal conductivity degradation associated with burnup.« less

Mid-term results of concentrated autologous bone marrow aspirate transplantation for corticosteroid-associated osteonecrosis of the femoral head in systemic lupus erythematosus.

PubMed

Tomaru, Yohei; Yoshioka, Tomokazu; Sugaya, Hisashi; Shimizu, Yukiyo; Aoto, Katsuya; Wada, Hiroshi; Akaogi, Hiroshi; Yamazaki, Masashi; Mishima, Hajime

2018-04-28

We had previously established concentrated autologous bone marrow aspirate transplantation (CABMAT), a one-step, low-invasive, joint-preserving surgical technique for treating osteonecrosis of the femoral head (ONFH). This study aimed to evaluate the effects of CABMAT as a hip-preserving surgical approach, preventing conversion to total hip arthroplasty (THA) and femoral head collapse in patients with systemic lupus erythematosus (SLE). Since 2003, 52 SLE patients (8 male, 44 female, 92 hips, mean age 35.3 (16-77) (years) were treated with CABMAT. The mean follow-up period was 5.5 (0.7-14) years. Conversion rate to THA and its predicting factors were analyzed. The overall conversion rate to THA was 29% (27/92). Conversion rate to THA was 0% (0/3), 0% (0/4), 22% (9/41), and 41% (18/44) in types A, B, C1, and C2, respectively. Conversion rate to THA was 26% (5/19), 26% (6/23), 28% (11/39), 44% (4/9), and 50% (1/2) in stages 1, 2, 3A, 3B, and 4, respectively. In multivariate logistic regression analysis, sex, body mass index (BMI), pre-operative type, and pre-operative stage were significantly correlated with conversion to THA. The conversion rate to THA was lower than that in the natural course and core decompression, but was higher than that seen in other bone marrow transplantation and osteotomy. Since sex, pre-operative type, and pre-operative stage were significantly correlated with conversion to THA, it is suggested that the higher proportion of women, advanced stage (stage 3A or above), and advanced type (type C or above) in this study affected the THA conversion rate.

Risk factors for conversion from unipolar psychotic depression to bipolar disorder.

PubMed

Østergaard, Søren Dinesen; Straszek, Sune; Petrides, Georgios; Skadhede, Søren; Jensen, Signe Olrik Wallenstein; Munk-Jørgensen, Povl; Nielsen, Jimmi

2014-03-01

Patients with unipolar psychotic depression (PD) are at high risk of developing bipolar disorder (BD). This conversion has important implications for the choice of treatment. This study, therefore, aimed to identify risk factors associated with diagnostic conversion from PD to BD. We conducted a population-based, historical prospective cohort study by merging data from Danish registers. Patients assigned an ICD-10 diagnosis of PD between 1 January 1995 and 31 December 2007 were identified in the Danish Central Psychiatric Research Register and were followed until the development of BD, death, loss to follow-up, or 31 December 2007. Potential risk factors for conversion to BD, also defined through various Danish registers, were tested in multiple logistic regression analyses with risk expressed as adjusted odds ratios (AOR). We identified 8,588 patients with PD, of whom 609 (7.1%) developed BD during follow-up. The following characteristics were significantly associated with diagnostic conversion from PD to BD: early onset of PD [AOR = 0.99 (per year of increasing age), p = 0.044], recurrent depression [AOR = 1.02 (per episode), p = 0.036], living alone (AOR = 1.29, p = 0.007), receiving a disability pension (AOR = 1.55, p < 0.001), and the highest educational level being a technical education (AOR = 1.55, p < 0.001), short-cycle higher education (AOR = 2.65, p < 0.001), or medium-cycle higher education (AOR = 1.75, p < 0.001). Diagnostic conversion to BD was prevalent among patients with PD. The following characteristics were significantly associated with this conversion: early onset of PD, recurrent depression, living alone, receiving a disability pension, and the highest educational level being a technical education, short-cycle higher education, or medium-cycle higher education. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of Previous Abdominal Surgery on Laparoscopic Liver Resection: Analysis of Feasibility and Risk Factors for Conversion.

PubMed

Cipriani, Federica; Ratti, Francesca; Fiorentini, Guido; Catena, Marco; Paganelli, Michele; Aldrighetti, Luca

2018-03-28

Previous abdominal surgery has traditionally been considered an additional element of difficulty to later laparoscopic procedures. The aim of the study is to analyze the effect of previous surgery on the feasibility and safety of laparoscopic liver resection (LLR), and its role as a risk factor for conversion. After matching, 349 LLR in patients known for previous abdominal surgery (PS group) were compared with 349 LLR on patients with a virgin abdomen (NPS group). Subgroup analysis included 161 patients with previous upper abdominal surgery (UPS subgroup). Feasibility and safety were evaluated in terms of conversion rate, reasons for conversion and outcomes, and risk factors for conversion assessed via uni/multivariable analysis. Conversion rate was 9.4%, and higher for PS patients compared with NPS patients (13.7% versus 5.1%, P = .021). Difficult adhesiolysis resulted the commonest reason for conversion in PS group (5.7%). However, operative time (P = .840), blood loss (P = .270), transfusion (P = .650), morbidity rate (P = .578), hospital stay (P = .780), and R1 rate (P = .130) were comparable between PS and NPS group. Subgroup analysis confirmed higher conversion rates for UPS patients (23%) compared with both NPS (P = .015) and PS patients (P = .041). Previous surgery emerged as independent risk factor for conversion (P = .033), alongside the postero-superior location and major hepatectomy. LLR are feasible in case of previous surgery and proved to be safe and maintain the benefits of LLR carried out in standard settings. However, a history of surgery should be considered a risk factor for conversion.

Unplanned Robotic-Assisted Conversion-to-Open Colorectal Surgery is Associated with Adverse Outcomes.

PubMed

Lee, Yongjin F; Albright, Jeremy; Akram, Warqaa M; Wu, Juan; Ferraro, Jane; Cleary, Robert K

2018-06-01

Laparoscopic conversion-to-open colorectal surgery is associated with worse outcomes when compared to operations completed without conversion. Consequences of robotic conversion have not yet been determined. The purpose of this study is to compare short-term outcomes of converted robotic colorectal cases with those that are completed without conversion, as well as with cases done by the open approach. The ACS-NSQIP database was queried for patients who underwent robotic completed, robotic converted-to-open, and open colorectal resection between 2012 and 2015. Propensity scores were estimated using gradient-boosted machines and converted to weights. Generalized linear models were fit using propensity score-weighted data. A total of 25,253 patients met inclusion criteria-21,356 (84.5%) open, 3663 (14.5%) robotic completed, and 234 (0.9%) conversions. Conversion rate was 6.0%. Converted cases had significantly higher 30-day mortality rate, higher complication rate, and longer hospital length of stay than completed cases. Converted patients also had significantly higher rates of the following complications: surgical site infections, cardiac complications, deep venous thrombosis, postoperative ileus, postoperative re-intubation, renal failure, and 30-day reoperation. Compared to the open approach, converted patients had significantly more cardiac complications, postoperative reintubation, and longer operating times with no significant difference in 30-day mortality. Unplanned robotic conversion-to-open is associated with worse outcomes than completed cases and outcomes that more closely resemble traditional open colorectal surgery. Patients should be counseled with regard to minimally invasive conversion rates and outcomes. The continued pursuit of technological advancements that decrease the risk for conversion in minimally invasive colorectal surgery is clearly warranted.

Recent rates of forest harvest and conversion in North America

Treesearch

Jeffrey G. Masek; Warren B. Cohen; Donald Leckie; Michael A. Wulder; Rodrigo Vargas; Ben de Jong; Sean Healey; Beverly Law; Richard Birdsey; R. A. Houghton; David Mildrexler; Samuel Goward; W. Brad Smith

2011-01-01

Incorporating ecological disturbance into biogeochemical models is critical for estimating current and future carbon stocks and fluxes. In particular, anthropogenic disturbances, such as forest conversion and wood harvest, strongly affect forest carbon dynamics within North America. This paper summarizes recent (2000-2008) rates of extraction, including both conversion...

Effect of shrimp ( Litopenaeus vannamei) farming waste on the growth, digestion, ammonium-nitrogen excretion of sea cucumber ( Stichopus monotuberculatus)

NASA Astrophysics Data System (ADS)

Chen, Yanfeng; Luo, Peng; Hu, Chaoqun; Ren, Chunhua

2015-06-01

In this study, specific growth rate (SGR), ingestion rate (IR), food conversion ratio (FCR), apparent digestion ratio (ADR) and ammonium-nitrogen excretion were determined for sea cucumber ( Stichopus monotuberculatus) reared in plastic containers (70 L; 4 containers each diet treatment). Sea cucumbers were fed with five diets containing different amounts of farming waste from shrimp ( Litopenaeus vannamei) (100%, 75%, 50%, 25% and 0) and a formulated compound (20% sea mud and 80% powdered algae). Sea cucumbers grew faster when they were fed with diet D (25% shrimp waste and 75% formulated compound) than those fed with other diets. Although IR value of sea cucumber fed with diet A (shrimp waste) was higher than those fed with other diets, both the lowest SGR and the highest FCR occurred in this diet group. The highest and the lowest ADR occurred in diet E (formulated compound) and diet A group, respectively, and the same to ammonium-nitrogen excretion. The contents of crude protein, crude lipid and total organic matter (TOM) in feces decreased in comparison with corresponding diets. In the feces from different diet treatments, the contents of crude protein and TOM increased gradually as the contents of crude protein and TOM in diets increased, while crude lipid content decreased gradually as the crude lipid content in diets increased.

Influence of the metal addition for biohydrogen production from the conversion of palm oil mill effluent (POME) by anaerobic process

NASA Astrophysics Data System (ADS)

Gumilar, Andri; Syafila, Mindriany; Handajani, Marisa

2017-11-01

Biohydrogen is one of the main alternative fuels promising for the future. Bioconversion of the wastewater with the high concentration of organic using biological processes or microorganism by anaerobic processes can produce biogas which can be used as fuel instead of fossil fuels. In this study, palm oil mill effluent (POME) with the concentration of COD is 24,500 mg/L has been used as a substrate. The aim of this study was to determine the effect of metal addition for the formation of biohydrogen. Circulating bed reactor (CBR) is used with the flushing N2 1L/min for 24 hr and continued operates for 72 hr by internal biogas. The additional variation concentration of Fe(II) ion are 0.5; 1.0 and 2.5 mg/L, and Mg(II) are 0.5 and 1.5 mg/L were added by combination. The results showed that the combination of Fe(II) 1.0 mg/L and Mg(II) 1.5 mg/L produced the highest biohydrogen production is 17.12 %v/v and the rate of biohydrogen production is 0.010-0.233 % v/v /hr. Another combination of Fe(II) and Mg(II) provide results for the biohydrogen production is 10.46-16.37 %v/v with the highest rate of biohydrogen production is 0.008-0.278 %v/v/hr.

Converting positive and negative symptom scores between PANSS and SAPS/SANS.

PubMed

van Erp, Theo G M; Preda, Adrian; Nguyen, Dana; Faziola, Lawrence; Turner, Jessica; Bustillo, Juan; Belger, Aysenil; Lim, Kelvin O; McEwen, Sarah; Voyvodic, James; Mathalon, Daniel H; Ford, Judith; Potkin, Steven G; Fbirn

2014-01-01

The Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), and the Positive and Negative Syndrome Scale for Schizophrenia (PANSS) are the most widely used schizophrenia symptom rating scales, but despite their co-existence for 25 years no easily usable between-scale conversion mechanism exists. The aim of this study was to provide equations for between-scale symptom rating conversions. Two-hundred-and-five schizophrenia patients [mean age±SD=39.5±11.6, 156 males] were assessed with the SANS, SAPS, and PANSS. Pearson's correlations between symptom scores from each of the scales were computed. Linear regression analyses, on data from 176 randomly selected patients, were performed to derive equations for converting ratings between the scales. Intraclass correlations, on data from the remaining 29 patients, not part of the regression analyses, were performed to determine rating conversion accuracy. Between-scale positive and negative symptom ratings were highly correlated. Intraclass correlations between the original positive and negative symptom ratings and those obtained via conversion of alternative ratings using the conversion equations were moderate to high (ICCs=0.65 to 0.91). Regression-based equations may be useful for conversion between schizophrenia symptom severity as measured by the SANS/SAPS and PANSS, though additional validation is warranted. This study's conversion equations, implemented at http:/converteasy.org, may aid in the comparison of medication efficacy studies, in meta- and mega-analyses examining symptoms as moderator variables, and in retrospective combination of symptom data in multi-center data sharing projects that need to pool symptom rating data when such data are obtained using different scales. Copyright © 2013 Elsevier B.V. All rights reserved.

Phosphoenolpyruvate:glucose phosphotransferase system modification increases the conversion rate during L-tryptophan production in Escherichia coli.

PubMed

Liu, Lina; Chen, Sheng; Wu, Jing

2017-10-01

Escherichia coli FB-04(pta1), a recombinant L-tryptophan production strain, was constructed in our laboratory. However, the conversion rate (L-tryptophan yield per glucose) of this strain is somewhat low. In this study, additional genes have been deleted in an effort to increase the conversion rate of E. coli FB-04(pta1). Initially, the pykF gene, which encodes pyruvate kinase I (PYKI), was inactivated to increase the accumulation of phosphoenolpyruvate, a key L-tryptophan precursor. The resulting strain, E. coli FB-04(pta1)ΔpykF, showed a slightly higher L-tryptophan yield and a higher conversion rate in fermentation processes. To further improve the conversion rate, the phosphoenolpyruvate:glucose phosphotransferase system (PTS) was disrupted by deleting the ptsH gene, which encodes the phosphocarrier protein (HPr). The levels of biomass, L-tryptophan yield, and conversion rate of this strain, E. coli FB-04(pta1)ΔpykF/ptsH, were especially low during fed-batch fermentation process, even though it achieved a significant increase in conversion rate during shake-flask fermentation. To resolve this issue, four HPr mutations (N12S, N12A, S46A, and S46N) were introduced into the genomic background of E. coli FB-04(pta1)ΔpykF/ptsH, respectively. Among them, the strain harboring the N12S mutation (E. coli FB-04(pta1)ΔpykF-ptsHN12S) showed a prominently increased conversion rate of 0.178 g g -1 during fed-batch fermentation; an increase of 38.0% compared with parent strain E. coli FB-04(pta1). Thus, mutation of the genomic of ptsH gene provided an alternative method to weaken the PTS and improve the efficiency of carbon source utilization.

The exometabolome of Clostridium thermocellum reveals overflow metabolism at high cellulose loading

DOE PAGES

Holwerda, Evert K.; Thorne, Philip G.; Olson, Daniel G.; ...

2014-10-21

Background: Clostridium thermocellum is a model thermophilic organism for the production of biofuels from lignocellulosic substrates. The majority of publications studying the physiology of this organism use substrate concentrations of ≤10 g/L. However, industrially relevant concentrations of substrate start at 100 g/L carbohydrate, which corresponds to approximately 150 g/L solids. To gain insight into the physiology of fermentation of high substrate concentrations, we studied the growth on, and utilization of high concentrations of crystalline cellulose varying from 50 to 100 g/L by C. thermocellum. Results: Using a defined medium, batch cultures of C. thermocellum achieved 93% conversion of cellulose (Avicel)more » initially present at 100 g/L. The maximum rate of substrate utilization increased with increasing substrate loading. During fermentation of 100 g/L cellulose, growth ceased when about half of the substrate had been solubilized. However, fermentation continued in an uncoupled mode until substrate utilization was almost complete. In addition to commonly reported fermentation products, amino acids - predominantly L-valine and L-alanine - were secreted at concentrations up to 7.5 g/L. Uncoupled metabolism was also accompanied by products not documented previously for C. thermocellum, including isobutanol, meso- and RR/SS-2,3-butanediol and trace amounts of 3-methyl-1-butanol, 2-methyl-1-butanol and 1-propanol. We hypothesize that C. thermocellum uses overflow metabolism to balance its metabolism around the pyruvate node in glycolysis. In conclusion: C. thermocellum is able to utilize industrially relevant concentrations of cellulose, up to 93 g/L. We report here one of the highest degrees of crystalline cellulose utilization observed thus far for a pure culture of C. thermocellum, the highest maximum substrate utilization rate and the highest amount of isobutanol produced by a wild-type organism.« less

Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands.

PubMed

Dalcin Martins, Paula; Hoyt, David W; Bansal, Sheel; Mills, Christopher T; Tfaily, Malak; Tangen, Brian A; Finocchiaro, Raymond G; Johnston, Michael D; McAdams, Brandon C; Solensky, Matthew J; Smith, Garrett J; Chin, Yu-Ping; Wilkins, Michael J

2017-08-01

Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses, we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxes to the atmosphere. This research represents the first study of coupled geochemistry and microbiology within the PPR and demonstrates how the conversion of abundant labile DOC pools into methane results in some of the highest fluxes of this greenhouse gas to the atmosphere ever reported. Abundant DOC and sulfate additionally supported some of the highest sulfate reduction rates ever measured in terrestrial aquatic environments, which we infer to account for a large fraction of carbon mineralization in this system. Methane accumulations in zones of active sulfate reduction may be due to either the transport of free methane gas from deeper locations or the co-occurrence of methanogenesis and sulfate reduction. If both respiratory processes are concurrent, any competitive inhibition of methanogenesis by sulfate-reducing bacteria may be lessened by the presence of large labile DOC pools that yield noncompetitive substrates such as methanol. Our results reveal some of the underlying mechanisms that make PPR wetlands biogeochemical hotspots, which ultimately leads to their critical, but poorly recognized role in regional greenhouse gas emissions. © 2017 John Wiley & Sons Ltd.

Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands

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

Dalcin Martins, Paula; Hoyt, David W.; Bansal, Sheel

Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxesmore » to the atmosphere. This research represents the first study of coupled geochemistry and microbiology within the PPR, and demonstrates how the conversion of abundant labile DOC pools into methane results in some of the highest fluxes of this greenhouse gas to the atmosphere ever reported. Abundant DOC and sulfate additionally supported some of the highest sulfate reduction rates ever measured in terrestrial aquatic environments, which we infer to account for a large fraction of carbon mineralization in this system. Methane accumulations in zones of active sulfate reduction may be due to either the transport of free methane gas from deeper locations, or the co-occurrence of methanogenesis and sulfate reduction. If both respiratory processes are concurrent, any competitive inhibition of methanogenesis by sulfate-reducing bacteria may be lessened by the presence of large labile DOC pools that yield non-competitive substrates such as methanol. Our results reveal some of the underlying mechanisms that make PPR wetlands biogeochemical hotspots, which ultimately leads to their critical, but poorly recognized role in regional greenhouse gas emissions.« less

Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands

USGS Publications Warehouse

Martins, Paula; Hoyt, David W.; Bansal, Sheel; Mills, Christopher T.; Tfaily, Malak; Tangen, Brian; Finocchiaro, Raymond; Johnston, Michael D.; McAdams, Brandon C.; Solensky, Matthew J.; Smith, Garrett J.; Chin, Yu-Ping; Wilkins, Michael J.

2017-01-01

Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses, we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxes to the atmosphere. This research represents the first study of coupled geochemistry and microbiology within the PPR and demonstrates how the conversion of abundant labile DOC pools into methane results in some of the highest fluxes of this greenhouse gas to the atmosphere ever reported. Abundant DOC and sulfate additionally supported some of the highest sulfate reduction rates ever measured in terrestrial aquatic environments, which we infer to account for a large fraction of carbon mineralization in this system. Methane accumulations in zones of active sulfate reduction may be due to either the transport of free methane gas from deeper locations or the co-occurrence of methanogenesis and sulfate reduction. If both respiratory processes are concurrent, any competitive inhibition of methanogenesis by sulfate-reducing bacteria may be lessened by the presence of large labile DOC pools that yield noncompetitive substrates such as methanol. Our results reveal some of the underlying mechanisms that make PPR wetlands biogeochemical hotspots, which ultimately leads to their critical, but poorly recognized role in regional greenhouse gas emissions.

Efficient electrochemical CO2 conversion powered by renewable energy.

PubMed

Kauffman, Douglas R; Thakkar, Jay; Siva, Rajan; Matranga, Christopher; Ohodnicki, Paul R; Zeng, Chenjie; Jin, Rongchao

2015-07-22

The catalytic conversion of CO2 into industrially relevant chemicals is one strategy for mitigating greenhouse gas emissions. Along these lines, electrochemical CO2 conversion technologies are attractive because they can operate with high reaction rates at ambient conditions. However, electrochemical systems require electricity, and CO2 conversion processes must integrate with carbon-free, renewable-energy sources to be viable on larger scales. We utilize Au25 nanoclusters as renewably powered CO2 conversion electrocatalysts with CO2 → CO reaction rates between 400 and 800 L of CO2 per gram of catalytic metal per hour and product selectivities between 80 and 95%. These performance metrics correspond to conversion rates approaching 0.8-1.6 kg of CO2 per gram of catalytic metal per hour. We also present data showing CO2 conversion rates and product selectivity strongly depend on catalyst loading. Optimized systems demonstrate stable operation and reaction turnover numbers (TONs) approaching 6 × 10(6) molCO2 molcatalyst(-1) during a multiday (36 h total hours) CO2 electrolysis experiment containing multiple start/stop cycles. TONs between 1 × 10(6) and 4 × 10(6) molCO2 molcatalyst(-1) were obtained when our system was powered by consumer-grade renewable-energy sources. Daytime photovoltaic-powered CO2 conversion was demonstrated for 12 h and we mimicked low-light or nighttime operation for 24 h with a solar-rechargeable battery. This proof-of-principle study provides some of the initial performance data necessary for assessing the scalability and technical viability of electrochemical CO2 conversion technologies. Specifically, we show the following: (1) all electrochemical CO2 conversion systems will produce a net increase in CO2 emissions if they do not integrate with renewable-energy sources, (2) catalyst loading vs activity trends can be used to tune process rates and product distributions, and (3) state-of-the-art renewable-energy technologies are sufficient to power larger-scale, tonne per day CO2 conversion systems.

Simultaneous Hydrogen and Methane Production Through Multi-Phase Anaerobic Digestion of Paperboard Mill Wastewater Under Different Operating Conditions.

PubMed

Farghaly, Ahmed; Tawfik, Ahmed

2017-01-01

Multi-phase anaerobic reactor for H 2 and CH 4 production from paperboard mill wastewater was studied. The reactor was operated at hydraulic retention times (HRTs) of 12, 18, 24, and 36 h, and organic loading rates (OLRs) of 2.2, 1.5, 1.1, and 0.75 kg chemical oxygen demand (COD)/m 3  day, respectively. HRT of 12 h and OLR of 2.2 kg COD/m 3  day provided maximum hydrogen yield of 42.76 ± 14.5 ml/g COD removed and volumetric substrate uptake rate (-rS) of 16.51 ± 4.43 mg COD/L h. This corresponded to the highest soluble COD/total COD (SCOD/TCOD) ratio of 56.25 ± 3.3 % and the maximum volatile fatty acid (VFA) yield (Y VFA ) of 0.21 ± 0.03 g VFA/g COD, confirming that H 2 was mainly produced through SCOD conversion. The highest methane yield (18.78 ± 3.8 ml/g COD removed ) and -rS of 21.74 ± 1.34 mgCOD/L h were achieved at an HRT of 36 h and OLR of 0.75 kg COD/m 3  day. The maximum hydrogen production rate (HPR) and methane production rate (MPR) were achieved at carbon to nitrogen (C/N) ratio of 47.9 and 14.3, respectively. This implies the important effect of C/N ratio on the distinction between the dominant microorganism bioactivities responsible for H 2 and CH 4 production.

Diagnostic and prognostic value of amyloid PET textural and shape features: comparison with classical semi-quantitative rating in 760 patients from the ADNI-2 database.

PubMed

Ben Bouallègue, Fayçal; Vauchot, Fabien; Mariano-Goulart, Denis; Payoux, Pierre

2018-02-09

We evaluated the performance of amyloid PET textural and shape features in discriminating normal and Alzheimer's disease (AD) subjects, and in predicting conversion to AD in subjects with mild cognitive impairment (MCI) or significant memory concern (SMC). Subjects from the Alzheimer's Disease Neuroimaging Initiative with available baseline 18 F-florbetapir and T1-MRI scans were included. The cross-sectional cohort consisted of 181 controls and 148 AD subjects. The longitudinal cohort consisted of 431 SMC/MCI subjects, 85 of whom converted to AD during follow-up. PET images were normalized to MNI space and post-processed using in-house software. Relative retention indices (SUVr) were computed with respect to pontine, cerebellar, and composite reference regions. Several textural and shape features were extracted then combined using a support vector machine (SVM) to build a predictive model of AD conversion. Diagnostic and prognostic performance was evaluated using ROC analysis and survival analysis with the Cox proportional hazard model. The three SUVr and all the tested features effectively discriminated AD subjects in cross-sectional analysis (all p < 0.001). In longitudinal analysis, the variables with the highest prognostic value were composite SUVr (AUC 0.86; accuracy 81%), skewness (0.87; 83%), local minima (0.85; 79%), Geary's index (0.86; 81%), gradient norm maximal argument (0.83; 82%), and the SVM model (0.91; 86%). The adjusted hazard ratio for AD conversion was 5.5 for the SVM model, compared with 4.0, 2.6, and 3.8 for cerebellar, pontine and composite SUVr (all p < 0.001), indicating that appropriate amyloid textural and shape features predict conversion to AD with at least as good accuracy as classical SUVr.

Property evolution during vitrification of dimethacrylate photopolymer networks

PubMed Central

Abu-Elenain, Dalia; Lewis, Steven H.; Stansbury, Jeffrey W.

2013-01-01

Objectives This study seeks to correlate the interrelated properties of conversion, shrinkage, modulus and stress as dimethacrylate networks transition from rubbery to glassy states during photopolymerization. Methods An unfilled BisGMA/TEGDMA resin was photocured for various irradiation intervals (7–600 s) to provide controlled levels of immediate conversion, which was monitored continuously for 10 min. Fiber optic near-infrared spectroscopy permitted coupling of real-time conversion measurement with dynamic polymerization shrinkage (linometer), modulus (dynamic mechanical analyzer) and stress (tensometer) development profiles. Results The varied irradiation conditions produced final conversion ranging from 6 % to more than 60 %. Post-irradiation conversion (dark cure) was quite limited when photopolymerization was interrupted either at very low or very high levels of conversion while significant dark cure contributions were possible for photocuring reactions suspended within the post-gel, rubbery regime. Analysis of conversion-based property evolution during and subsequent to photocuring demonstrated that the shrinkage rate increased significantly at about 40 % conversion followed by late-stage suppression in the conversion-dependent shrinkage rate that begins at about 45–50 % conversion. The gradual vitrification process over this conversion range is evident based on the broad but well-defined inflection in the modulus versus conversion data. As limiting conversion is approached, modulus and, to a somewhat lesser extent, stress rise precipitously as a result of vitrification with the stress profile showing little if any late-stage suppression as seen with shrinkage. Significance Near the limiting conversion for this model resin, the volumetric polymerization shrinkage rate slows while an exponential rise in modulus promotes the vitrification process that appears to largely dictate stress development. PMID:24080378

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

Qu, Shiwei; Wang, Huan; Mo, Daize

A new family of thieno[3,4-b]thiophene benzodithiophene terpolymers (PBTClx) have been designed and synthesized, in which the chlorine/fluorine content has been adjusted and optimized. As the content of chlorine is increased in polymers, the twist angle between the donor and acceptor is increased, which leads to a diminishment in the planarity and conjugation. As a result, the UV vis absorption is continuous blue-shifted, and the band gap increases from 1.57 to 2.04 eV when the chlorinated moieties increased from 0 to 100%. The highest occupied molecular orbital (HOMO) levels of those polymers are decreased by increasing the content of chlorinated moiety,more » which opens a window to constantly modify the V-oc values and eventually meets a balance point for optimized solar energy conversion. The highest power conversion efficiency of 8.31% is obtained by using PBTCl25 as the donor and PC71BM as the acceptor in polymer solar cells (PSCs), in which the Voc increased from 0.79 to 0.82 V after 25% chlorinated monomer involved in copolymerization. Herein, the chlorine replacement could be a good method to further pump the solar conversion by increasing the open circuit voltage without reducing other factors of the polymer solar cells.« less

Natural mode of horizontal transmission of bovine leukemia virus (BLV): the potential role of tabanids (Tabanus spp.).

PubMed

Manet, G; Guilbert, X; Roux, A; Vuillaume, A; Parodi, A L

1989-10-01

In order to evaluate the potential role of hematophagous insects in the natural spreading of bovine leukemia virus (BLV) infection in cattle, a 2-year survey was carried out involving sequential serological tests on 3328 cattle in three different areas. A parallel entomological study was run over the same period, using continuous trapping, in order to determine both the density and variations of horsefly (Tabanus spp.) populations in the close vicinity of the herds. After statistical analysis, this space-time study showed that: (1) There is a significant positive geographical correlation between the rate of incidence of BLV infection and the density of the horsefly population. (2) Seasonal variations in the incidence rate exist; the highest rates are generally observed during summer (from July of September), and the lowest during winter, spring and early summer (from November to mid-July). (3) There is a time link between the rate of sero-conversion and the variations in activity of the horsefly population. All these data combined would appear to indicate that tabanids play a considerable role in the spread of BLV under natural conditions.

Studies on biomass char gasification and dynamics

NASA Astrophysics Data System (ADS)

You, Zhanping; You, Shijun; Ma, Xiaoyan

2018-01-01

The gasification performances of two kinds of biomass char by experiment methods are studied, including conversion rate and gasification gas component with temperature and time. Experimental results show that gasification temperature has important effects on the conversion rate and gas component. In the range of experimental temperature, char conversion rates are no more than 30.0%. The apparent activation energies and apparent reaction frequency factors of two biomass chars are obtained through kinetic studies.

Small bowel obstruction: A practical step-by-step evidence-based approach to evaluation, decision making, and management.

PubMed

Azagury, Dan; Liu, Rockson C; Morgan, Ashley; Spain, David A

2015-10-01

The initial goal of evaluating a patient with SBO is to immediately identify strangulation and need for urgent operative intervention, concurrent with rapid resuscitation. This relies on a combination of traditional clinical signs and CT findings. In patients without signs of strangulation, a protocol for administration of Gastrografin immediately in the emergency department efficiently sorts patients into those who will resolve their obstructions and those who will fail nonoperative management.Furthermore, because of the unique ability of Gastrografin to draw water into the bowel lumen, it expedites resolution of partial obstructions, shortening time to removal of nasogastric tube liberalization of diet, and discharge from the hospital. Implementation of such a protocol is a complex, multidisciplinary, and time-consuming endeavor. As such, we cannot over emphasize the importance of clear, open communication with everyone involved.If surgical management is warranted, we encourage an initial laparoscopic approach with open access. Even if this results in immediate conversion to laparotomy after assessment of the intra-abdominal status, we encourage this approach with a goal of 30% conversion rate or higher. This will attest that patients will have been given the highest likelihood of a successful laparoscopic LOA.

Results of land cover change detection analysis in and around Cordillera Azul National Park, Peru

USGS Publications Warehouse

Sleeter, Benjamin M.; Halsing, David L.

2005-01-01

The first product of the Optimizing Design and Management of Protected Areas for Conservation Project is a land cover change detection analysis based on Landsat thematic mapper (TM) and enhanced thematic mapper plus (ETM+) imagery collected at intervals between 1989 and 2002. The goal of this analysis was to quantify and analyze patterns of forest clearing, land conversion, and other disturbances in and around the Cordillera Azul National Park in Peru. After removing clouds and cloud shadows from the imagery using a series of automatic and manual processes, a Tasseled Cap Transformation was used to detect pixels of high reflectance, which were classified as bare ground and areas of likely forest clearing. Results showed a slow but steady increase in cleared ground prior to 1999 and a rapid and increasing conversion rate after that time. The highest concentrations of clearings have spread upward from the western border of the study area on the Huallaga River. To date, most disturbances have taken place in the buffer zone around the park, not within it, but the data show dense clearings occurring closer to the park border each year.

Protein Production Through Microbial Conversion of Rice Straw by Multi-Strain Fermentation.

PubMed

Jia, Jinru; Chen, Huayou; Wu, Bangguo; Cui, Fengjie; Fang, Hua; Wang, Hongcheng; Ni, Zhong

2018-06-20

Multi-strain mixed fermentation can provide a relatively complete lignocellulosic enzyme system compared with single-strain fermentation. This study was firstly to screen strains which have a strong ability to hydrolyse rice straw (RS) enzymatically and enrich true protein (TP). Then, the conditions in the process of SSF, including the optimum inoculum size of mixed strains, inoculation ratio, and different inoculation time of N. crassa 14-8, were optimized. The experimental results showed that the highest TP content could be obtained by using N. crassa 14-8, C. utilis, and P. chrysosporium as mixed strains, and 5 mM Mn 2+ and 50 mM veratryl alcohol were used as inducers of lignin peroxidase (LiP) to improve the efficiency of enzymatic hydrolysis. When N. crassa 14-8 was inoculated 1 day later than P. chrysosporium, the total inoculum size was 10%, and the optimum ratio of N. crassa 14-8 to P. chrysosporium was 1:2, the maximum TP yield (8.89%) was obtained, with 123.37% of its increase rate. This work proposed a technique with potential application in large-scale feedstuff protein conversion.

Startup of reactors for anoxic ammonium oxidation: experiences from the first full-scale anammox reactor in Rotterdam.

PubMed

van der Star, Wouter R L; Abma, Wiebe R; Blommers, Dennis; Mulder, Jan-Willem; Tokutomi, Takaaki; Strous, Marc; Picioreanu, Cristian; van Loosdrecht, Mark C M

2007-10-01

The first full-scale anammox reactor in the world was started in Rotterdam (NL). The reactor was scaled-up directly from laboratory-scale to full-scale and treats up to 750 kg-N/d. In the initial phase of the startup, anammox conversions could not be identified by traditional methods, but quantitative PCR proved to be a reliable indicator for growth of the anammox population, indicating an anammox doubling time of 10-12 days. The experience gained during this first startup in combination with the availability of seed sludge from this reactor, will lead to a faster startup of anammox reactors in the future. The anammox reactor type employed in Rotterdam was compared to other reactor types for the anammox process. Reactors with a high specific surface area like the granular sludge reactor employed in Rotterdam provide the highest volumetric loading rates. Mass transfer of nitrite into the biofilm is limiting the conversion of those reactor types that have a lower specific surface area. Now the first full-scale commercial anammox reactor is in operation, a consistent and descriptive nomenclature is suggested for reactors in which the anammox process is employed.

Optimization and modeling for the synthesis of sterol esters from deodorizer distillate by lipase-catalyzed esterification.

PubMed

Zhang, Xinyu; Yu, Jiang; Zeng, Aiwu

2017-03-01

In this paper, cotton seed oil deodorizer distillate (CSODD), was recovered to obtain fatty acid sterol ester (FASE), which is one of the biological activated substances added as human therapeutic to lower cholesterol. Esterification reactions were carried out using Candida rugosa lipase as a catalyst, and the conversion of phytosterol was optimized using response surface methodology. The highest conversion (90.8 ± 0.4%) was reached at 0.84 wt% enzyme load, 1:25 solvent/CSODD mass ratio, and 44.2 °C after 12 H reaction. A kinetic model based on the reaction rate equation was developed to describe the reaction process. The activation energy of the reaction was calculated to be 56.9 kJ/mol and the derived kinetic parameters provided indispensable basics for further study. The optimization and kinetic research of synthesizing FASE from deodorizer distillate provided necessary information for the industrial applications in the near future. Experimental results showed that the proposed process is a promising alternative to recycle sterol esters from vegetable oil deodorizer distillates in a mild, efficient, and environmental friendly method. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

A Mid-South Perspective: African American Faith-based Organizations, HIV, and Stigma.

PubMed

Otey, Tamara D; Miller, Wendy Renee

2016-01-01

Shelby County, Tennessee has the fastest growing rate of HIV infection in the state, and the majority of new infections are in African Americans. In 2011, a Centers for Disease Control and Prevention report stated that Memphis (the largest city in Shelby County) ranked seventh highest in new HIV infections. Little research has addressed HIV-related themes in African American culture that could hinder HIV prevention measures. Our qualitative study engaged African American, faith-based leaders in areas with high rates of HIV in meaningful conversations regarding their attitudes toward HIV and those who are infected. Although faith-based leaders felt they had a role in HIV prevention, only 4% in our study had participated in HIV prevention activities, but they were open to HIV prevention programs. We found that faith-based leaders had limited knowledge of health disparities and ongoing stigma concerning HIV, which served as a major barrier to HIV prevention. Copyright © 2016 Association of Nurses in AIDS Care. Published by Elsevier Inc. All rights reserved.

Effect of pretreatment severity in continuous steam explosion on enzymatic conversion of wheat straw: Evidence from kinetic analysis of hydrolysis time courses.

PubMed

Monschein, Mareike; Nidetzky, Bernd

2016-01-01

Focusing on continuous steam explosion, the influence of pretreatment severity due to varied acid loading on hydrolysis of wheat straw by Trichoderma reesei cellulases was investigated based on kinetic evaluation of the saccharification of each pretreated substrate. Using semi-empirical descriptors of the hydrolysis time course, key characteristics of saccharification efficiency were captured in a quantifiable fashion. Not only hydrolysis rates per se, but also the transition point of their bi-phasic decline was crucial for high saccharification degree. After 48h the highest saccharification was achieved for substrate pretreated at relatively low severity (1.2% acid). Higher severity increased enzyme binding to wheat straw, but reduced the specific hydrolysis rates. Higher affinity of the lignocellulosic material for cellulases does not necessarily result in increased saccharification, probably because of lignin modifications occurring at high pretreatment severities. At comparable severity, continuous pretreatment produced a substrate more susceptible to enzymatic hydrolysis than the batch process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Land-cover change in the conterminous United States from 1973 to 2000

USGS Publications Warehouse

Sleeter, Benjamin M.; Sohl, Terry L.; Loveland, Thomas R.; Auch, Roger F.; Acevedo, William; Drummond, Mark A.; Sayler, Kristi L.; Stehman, Stephen V.

2013-01-01

Land-cover change in the conterminous United States was quantified by interpreting change from satellite imagery for a sample stratified by 84 ecoregions. Gross and net changes between 11 land-cover classes were estimated for 5 dates of Landsat imagery (1973, 1980, 1986, 1992, and 2000). An estimated 673,000 km2(8.6%) of the United States’ land area experienced a change in land cover at least one time during the study period. Forest cover experienced the largest net decline of any class with 97,000 km2 lost between 1973 and 2000. The large decline in forest cover was prominent in the two regions with the highest percent of overall change, the Marine West Coast Forests (24.5% of the region experienced a change in at least one time period) and the Eastern Temperate Forests (11.4% of the region with at least one change). Agriculture declined by approximately 90,000 km2 with the largest annual net loss of 12,000 km2 yr−1 occurring between 1986 and 1992. Developed area increased by 33% and with the rate of conversion to developed accelerating rate over time. The time interval with the highest annual rate of change of 47,000 km2 yr−1 (0.6% per year) was 1986–1992. This national synthesis documents a spatially and temporally dynamic era of land change between 1973 and 2000. These results quantify land change based on a nationally consistent monitoring protocol and contribute fundamental estimates critical to developing understanding of the causes and consequences of land change in the conterminous United States.

Iron Oxide Films Prepared by Rapid Thermal Processing for Solar Energy Conversion

PubMed Central

Wickman, B.; Bastos Fanta, A.; Burrows, A.; Hellman, A.; Wagner, J. B.; Iandolo, B.

2017-01-01

Hematite is a promising and extensively investigated material for various photoelectrochemical (PEC) processes for energy conversion and storage, in particular for oxidation reactions. Thermal treatments during synthesis of hematite are found to affect the performance of hematite electrodes considerably. Herein, we present hematite thin films fabricated via one-step oxidation of Fe by rapid thermal processing (RTP). In particular, we investigate the effect of oxidation temperature on the PEC properties of hematite. Films prepared at 750 °C show the highest activity towards water oxidation. These films show the largest average grain size and the highest charge carrier density, as determined from electron microscopy and impedance spectroscopy analysis. We believe that the fast processing enabled by RTP makes this technique a preferred method for investigation of novel materials and architectures, potentially also on nanostructured electrodes, where retaining high surface area is crucial to maximize performance. PMID:28091573

Optimized formation of detergent micelles of beta-carotene and retinal production using recombinant human beta,beta-carotene 15,15'-monooxygenase.

PubMed

Kim, Nam-Hee; Kim, Yeong-Su; Kim, Hye-Jung; Oh, Deok-Kun

2008-01-01

The formation of beta-carotene detergent micelles and their conversion into retinal by recombinant human beta,beta-carotene 15,15'-monooxygenase was optimized under aqueous conditions. Toluene was the most hydrophobic among the organic solvents tested; thus, it was used to dissolve beta-carotene, which is a hydrophobic compound. Tween 80 was selected as the detergent because it supported the highest level of retinal production among all of the detergents tested. The maximum production of retinal was achieved in detergent micelles containing 200 mg/L of beta-carotene and 2.4% (w/v) Tween 80. Under these conditions, the recombinant enzyme produced 97 mg/L of retinal after 16 h with a conversion yield of 48.5% (w/w). The amount of retinal produced, which is the highest ever reported, is a result of the ability of our system to dissolve large amounts of beta-carotene.

Molecular inversion probe assay.

PubMed

Absalan, Farnaz; Ronaghi, Mostafa

2007-01-01

We have described molecular inversion probe technologies for large-scale genetic analyses. This technique provides a comprehensive and powerful tool for the analysis of genetic variation and enables affordable, large-scale studies that will help uncover the genetic basis of complex disease and explain the individual variation in response to therapeutics. Major applications of the molecular inversion probes (MIP) technologies include targeted genotyping from focused regions to whole-genome studies, and allele quantification of genomic rearrangements. The MIP technology (used in the HapMap project) provides an efficient, scalable, and affordable way to score polymorphisms in case/control populations for genetic studies. The MIP technology provides the highest commercially available multiplexing levels and assay conversion rates for targeted genotyping. This enables more informative, genome-wide studies with either the functional (direct detection) approach or the indirect detection approach.

Analysis of trickle-bed reactor for ethanol production from syngas using Clostridium ragsdalei

NASA Astrophysics Data System (ADS)

Devarapalli, Mamatha

The conversion of syngas components (CO, CO2 and H2) to liquid fuels such as ethanol involves complex biochemical reactions catalyzed by a group of acetogens such as Clostridium ljungdahlii, Clostridium carboxidivorans and Clostridium ragsdalei. The low ethanol productivity in this process is associated with the low solubility of gaseous substrates CO and H2 in the fermentation medium. In the present study, a 1-L trickle-bed reactor (TBR) was analyzed to understand its capabilities to improve the mass transfer of syngas in fermentation medium. Further, semi-continuous and continuous syngas fermentations were performed using C. ragsdalei to evaluate the ability of the TBR for ethanol production. In the mass transfer studies, using 6-mm glass beads, it was found that the overall mass transfer coefficient (kLa/V L) increased with the increase in gas flow rate from 5.5 to 130.5 sccm. Further, an increase in the liquid flow rate in the TBR decreased the kLa/VL due to the increase in liquid hold up volume (VL) in the packing. The highest kLa/VL values of 421 h-1 and 178 h-1 were achieved at a gas flow rate of 130.5 sccm for 6-mm and 3-mm glass beads, respectively. Semi-continuous fermentations were performed with repetitive medium replacement in counter-current and co-current modes. In semi-continuous fermentations with syngas consisting of 38% CO, 5% N2, 28.5% CO2 and 28.5% H2 (by volume), the increase in H2 conversion (from 18 to 55%) and uptake (from 0.7 to 2.2 mmol/h) were observed. This increase was attributed to more cell attachment in the packing that reduced CO inhibition to hydrogenase along the column length and increased the H2 uptake. The maximum ethanol produced during counter-current and co-current modes were 3.0 g/L and 5.7 g/L, respectively. In continuous syngas fermentation, the TBR was operated at dilution rates between 0.006 h-1and 0.012 h -1 and gas flow rates between 1.5 sccm and 18.9 sccm. The highest ethanol concentration of 13 g/L was achieved at dilution and gas flow rates of 0.012 h-1 and 18.9 sccm, respectively. The molar ratio of ethanol to acetic acid of 4:1 was obtained during continuous fermentation which was 7.7 times higher than in semi-continuous fermentations. The improvement of the reactor performance in continuous mode gives scope to explore the TBR as a potential bioreactor design for large scale biofuels production.

Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus).

PubMed

Sarker, Pallab K; Kapuscinski, Anne R; Lanois, Alison J; Livesey, Erin D; Bernhard, Katie P; Coley, Mariah L

2016-01-01

We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds.

Conversion from depression to bipolar disorder in a cohort of young people in England, 1999-2011: A national record linkage study.

PubMed

James, Anthony; Wotton, Clare J; Duffy, Anne; Hoang, Uy; Goldacre, Michael

2015-10-01

To estimate the conversion rate from unipolar depression (ICD10 codes F32-F33) to bipolar disorder (BP) (ICD10 codes F31) in an English national cohort. It was hypothesised that early-onset BP (age <18 years) is a more severe form of the disorder, with a more rapid, and higher rate of conversion from depression to BP. This record linkage study used English national Hospital Episode Statistics (HES) covering all NHS inpatient and day case admissions between 1999 and 2011. The overall rate of conversion from depression to BP for all ages was 5.65% (95% CI: 5.48-5.83) over a minimum 4-year follow-up period. The conversion rate from depression to BP increased in a linear manner with age from 10-14 years - 2.21% (95% C: 1.16-4.22) to 30-34 years - 7.06% (95% CI: 6.44-7.55) (F1,23=77.6, p=0.001, R(2)=0.77). The time to conversion was constant across the age range. The rate of conversion was higher in females (6.77%; 95% CI: 6.53-7.02) compared to males, (4.17%; 95% CI: 3.95-4.40) (χ(2)=194, p<0.0001), and in those with psychotic depression 8.12% (95% CI: 7.65-8.62) compared to non-psychotic depression 5.65% (95% CI: 5.48-5.83) (χ(2)=97.0, p<0.0001). The study was limited to hospital discharges and diagnoses were not standardised. Increasing conversion rate from depression to bipolar disorder with age, and constant time for conversion across the age range does not support the notion that early-onset BP is a more severe form of the disorder. Copyright © 2015 Elsevier B.V. All rights reserved.

Advanced nanostructured materials for energy storage and conversion

NASA Astrophysics Data System (ADS)

Hutchings, Gregory S.

Due to a global effort to reduce greenhouse gas emissions and to utilize renewable sources of energy, much effort has been directed towards creating new alternatives to fossil fuels. Identifying novel materials for energy storage and conversion can enable radical changes to the current fuel production infrastructure and energy utilization. The use of engineered nanostructured materials in these systems unlocks unique catalytic activity in practical configurations. In this work, research efforts have been focused on the development of nanostructured materials to address the need for both better energy conversion and storage, with applications toward Li-O2 battery electrocatalysts, electrocatalytic generation of H2, conversion of furfural to useful chemicals and fuels, and Li battery anode materials. Highly-active alpha-MnO2 materials were synthesized for use as bifunctional oxygen reduction (ORR) and evolution (OER) catalysts in Li-O2 batteries, and were evaluated under operating conditions with a novel in situ X-ray absorption spectroscopy configuration. Through detailed analysis of local coordination and oxidation states of Mn atoms at key points in the electrochemical cycle, a self-switching behavior affecting the bifunctional activity was identified and found to be critical. In an additional study of materials for lithium batteries, nanostructured TiO2 anode materials doped with first-row transition metals were synthesized and evaluated for improving battery discharge capacity and rate performance, with Ni and Co doping at low levels found to cause the greatest enhancement. In addition to battery technology research, I have also sought to find inexpensive and earth-abundant electrocatalysts to replace state-of-the-art Pt/C in the hydrogen evolution reaction (HER), a systematic computational study of Cu-based bimetallic electrocatalysts was performed. During the screening of dilute surface alloys of Cu mixed with other first-row transition metals, materials with ideal hydrogen binding energies were identified. Bulk alloy electrocatalysts with comparable compositions to the model surfaces were synthesized and tested for performance in alkaline, neutral, and acidic conditions. Cu-Ti was found to exhibit the lowest overpotentials and highest overall performance, and was redesigned as a nanoporous catalyst which achieved higher current at lower overpotentials than even commercial Pt/C, with remarkably high stability. Through applying design principles developed during the HER work, self-supported nanoporous Cu-Co alloy catalysts were synthesized for the improvement of product selectivity and overall conversion of reactants in furfural hydro(deoxy)genation. Under vapor-phase reaction conditions, it was found that adding 1% to 10% oxophilic Co in a solid solution with Cu enhanced overall conversion towards products. In particular, a Cu95Co5 alloy produced 64.9% yield of 2-methylfuran at a high sustained total conversion of 85.0% and under moderate temperature conditions, which is the highest 2-methylfuran production reported for non-precious catalysts. Further analysis at a wider range of temperature conditions and sustained reaction time on stream provided a more detailed understanding of the behavior of these nanoporous materials, and possible mechanistic explanations of the high activity for Cu-Co are proposed to aid in the design of new materials with even higher product selectivities.

Incidence of Diabetes and Prediabetes and Predictors of Progression Among Asian Indians: 10-Year Follow-up of the Chennai Urban Rural Epidemiology Study (CURES).

PubMed

Anjana, Ranjit Mohan; Shanthi Rani, Coimbatore Subramanian; Deepa, Mohan; Pradeepa, Rajendra; Sudha, Vasudevan; Divya Nair, Haridas; Lakshmipriya, Nagarajan; Subhashini, Sivasankaran; Binu, Valsalakumari Sreekumarannair; Unnikrishnan, Ranjit; Mohan, Viswanathan

2015-08-01

There are few data on the incidence rates of diabetes and prediabetes (dysglycemia) in Asian Indians. This article presents the incidence of diabetes and prediabetes and the predictors of progression in a population-based Asian Indian cohort. Data on progression to diabetes and prediabetes from 1,376 individuals, a subset of 2,207 of the Chennai Urban Rural Epidemiology Study (CURES) cohort (phase 3) with normal glucose tolerance (NGT) or prediabetes at baseline, who were followed for a median of 9.1 years (11,629 person-years), are presented. During follow-up, 534 died and 1,077 with NGT and 299 with prediabetes at baseline were reinvestigated in a 10-year follow-up study. Diabetes and prediabetes were diagnosed based on the American Diabetes Association criteria. Incidence rates were calculated and predictors of progression to prediabetes and/or diabetes were estimated using the Cox proportional hazards model. The incidence rates of diabetes, prediabetes, and "any dysglycemia" were 22.2, 29.5, and 51.7 per 1,000 person-years, respectively. Among those with NGT, 19.4% converted to diabetes and 25.7% to prediabetes, giving an overall conversion rate to dysglycemia of 45.1%. Among those with prediabetes, 58.9% converted to diabetes. Predictors of progression to dysglycemia were advancing age, family history of diabetes, 2-h plasma glucose, glycated hemoglobin (HbA1c), low HDL cholesterol, and physical inactivity. Asian Indians have one of the highest incidence rates of diabetes, with rapid conversion from normoglycemia to dysglycemia. Public health interventions should target modifiable risk factors to slow down the diabetes epidemic in this population. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

QoS mapping algorithm for ETE QoS provisioning

NASA Astrophysics Data System (ADS)

Wu, Jian J.; Foster, Gerry

2002-08-01

End-to-End (ETE) Quality of Service (QoS) is critical for next generation wireless multimedia communication systems. To meet the ETE QoS requirements, Universal Mobile Telecommunication System (UMTS) requires not only meeting the 3GPP QoS requirements [1-2] but also mapping external network QoS classes to UMTS QoS classes. There are four Quality of Services (QoS) classes in UMTS; they are Conversational, Streaming, Interactive and Background. There are eight QoS classes for LAN in IEEE 802.1 (one reserved). ATM has four QoS categories. They are Constant Bit Rate (CBR) - highest priority, short queue for strict Cell Delay Variation (CDV), Variable Bit Rate (VBR) - second highest priority, short queues for real time, longer queues for non-real time, Guaranteed Frame Rate (GFR)/ Unspecified Bit Rate (UBR) with Minimum Desired Cell Rate (MDCR) - intermediate priority, dependent on service provider UBR/ Available Bit Rate (ABR) - lowest priority, long queues, large delay variation. DiffServ (DS) has six-bit DS codepoint (DSCP) available to determine the datagram's priority relative to other datagrams and therefore, up to 64 QoS classes are available from the IPv4 and IPv6 DSCP. Different organisations have tried to solve the QoS issues from their own perspective. However, none of them has a full picture for end-to-end QoS classes and how to map them among all QoS classes. Therefore, a universal QoS needs to be created and a new set of QoS classes to enable end-to-end (ETE) QoS provisioning is required. In this paper, a new set of ETE QoS classes is proposed and a mappings algorithm for different QoS classes that are proposed by different organisations is given. With our proposal, ETE QoS mapping and control can be implemented.

Effects of dietary grape seed extract on growth performance, amino acid digestibility and plasma lipids and mineral content in broiler chicks.

PubMed

Chamorro, S; Viveros, A; Centeno, C; Romero, C; Arija, I; Brenes, A

2013-04-01

Polyphenols are chemically and biologically active compounds. Grape seed extracts (GSEs) have been widely used as a human food supplement for health promotion and disease prevention. However, there is little information regarding its application in animal feeds. An experiment was conducted to investigate the effect of inclusion of GSE at 0.025, 0.25, 2.5 and 5.0 g/kg in a wheat soya bean control diet on growth performance, protein and amino acid (AA) digestibility and plasma lipid and mineral concentrations in broiler chickens at 21 days of age. Performance was not affected by dietary treatment except in the case of birds fed the diet with the highest GSE concentration, which showed a worsening of weight gain and feed conversion. Apparent ileal digestibility (AID) of protein was significantly reduced in the birds fed the highest concentration of GSE, which also had a reduction on the AID of arginine, histidine, phenylalanine, cystine, glutamic acid and proline compared with those fed control diet. The inclusion of graded concentration of GSE in the chicken diets caused a significant linear decrease in the concentrations of plasma copper, iron and zinc. Plasma cholesterol, triglycerides and lipoproteins (high-density lipoprotein, low-density lipoprotein and very-low-density lipoprotein) concentrations were not affected by dietary GSE. In conclusion, this study demonstrated that incorporation of GSE in chicken diets up to 2.5 g/kg had no adverse effect on growth performance or protein and AA digestibility. Feed conversion was reduced and growth rate was retarded, when chickens were fed 5 g/kg of GSE. This study also indicated that grape polyphenols reduce the free plasma minerals.

A Carbon-Cotton Cathode with Ultrahigh-Loading Capability for Statically and Dynamically Stable Lithium–Sulfur Batteries

DOE PAGES

Chung, Sheng-Heng; Chang, Chi-Hao; Manthiram, Arumugam

2016-10-26

Sulfur exhibits a high theoretical capacity of 1675 mA h g -1 via a distinct conversion reaction, which is different from the insertion reactions in commercial lithium-ion batteries. In consideration of its conversion reaction battery chemistry, a custom design for electrode materials could establish the way for attaining high-loading capability while simultaneously maintaining high electrochemical utilization and stability. In this study, this process is undertaken by introducing carbon cotton as an attractive electrode-containment material for enhancing the dynamic and static stabilities of lithium-sulfur (Li-S) batteries. The carbon cotton possessing a hierarchical macro-/microporous architecture exhibits a high surface area of 805more » m 2 g -1 and high microporosity with a micropore area of 557 m 2 g -1. The macroporous channels allow the carbon cotton to load and stabilize a high amount of active material. The abundant microporous reaction sites spread throughout the carbon cotton facilitate the redox chemistry of the high-loading/content Li-S system. As a result, the high-loading carbon-cotton cathode exhibits (i) enhanced cycle stability with a good dynamic capacity retention of 70% after 100 cycles and (ii) improved cellstorage stability with a high static capacity retention of above 93% and a low time-dependent self-discharge rate of 0.12% per day after storing for a long period of 60 days. In conclusion, these carbon-cotton cathodes with the remarkably highest values reported so far of both sulfur loading (61.4 mg cm -2) and sulfur content (80 wt %) demonstrate enhanced electrochemical utilization with the highest areal, volumetric, and gravimetric capacities simultaneously.« less

A Carbon-Cotton Cathode with Ultrahigh-Loading Capability for Statically and Dynamically Stable Lithium–Sulfur Batteries

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

Chung, Sheng-Heng; Chang, Chi-Hao; Manthiram, Arumugam

Sulfur exhibits a high theoretical capacity of 1675 mA h g -1 via a distinct conversion reaction, which is different from the insertion reactions in commercial lithium-ion batteries. In consideration of its conversion reaction battery chemistry, a custom design for electrode materials could establish the way for attaining high-loading capability while simultaneously maintaining high electrochemical utilization and stability. In this study, this process is undertaken by introducing carbon cotton as an attractive electrode-containment material for enhancing the dynamic and static stabilities of lithium-sulfur (Li-S) batteries. The carbon cotton possessing a hierarchical macro-/microporous architecture exhibits a high surface area of 805more » m 2 g -1 and high microporosity with a micropore area of 557 m 2 g -1. The macroporous channels allow the carbon cotton to load and stabilize a high amount of active material. The abundant microporous reaction sites spread throughout the carbon cotton facilitate the redox chemistry of the high-loading/content Li-S system. As a result, the high-loading carbon-cotton cathode exhibits (i) enhanced cycle stability with a good dynamic capacity retention of 70% after 100 cycles and (ii) improved cellstorage stability with a high static capacity retention of above 93% and a low time-dependent self-discharge rate of 0.12% per day after storing for a long period of 60 days. In conclusion, these carbon-cotton cathodes with the remarkably highest values reported so far of both sulfur loading (61.4 mg cm -2) and sulfur content (80 wt %) demonstrate enhanced electrochemical utilization with the highest areal, volumetric, and gravimetric capacities simultaneously.« less

High performance dye-sensitized solar cells using graphene modified fluorine-doped tin oxide glass by Langmuir–Blodgett technique

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

Roh, Ki-Min; Jo, Eun-Hee; Chang, Hankwon

Since the introduction of dye-sensitized solar cells (DSSCs) with low fabrication cost and high power conversion efficiency, extensive studies have been carried out to improve the charge transfer rate and performance of DSSCs. In this paper, we present DSSCs that use surface modified fluorine-doped tin oxide (FTO) substrates with reduced graphene oxide (r-GO) sheets prepared using the Langmuir–Blodgett (LB) technique to decrease the charge recombination at the TiO{sub 2}/FTO interface. R-GO sheets were excellently attached on FTO surface without physical deformations such as wrinkles; effects of the surface coverage of r-GO on the DSSC performance were also investigated. By usingmore » graphene modified FTO substrates, the resistance at the interface of TiO{sub 2}/FTO was reduced and the power conversion efficiency was increased to 8.44%. - Graphical abstract: DSSCs with graphene modified FTO glass were fabricated with the Langmuir Blodgett technique. GO sheets were transferred to FTO at various surface pressures in order to change the surface density of graphene and the highest power conversion efficiency of the DSSC was 8.44%. - Highlights: • By LB technique, r-GO sheets were coated on FTO without physical deformation. • DSSCs were fabricated with, r-GO modified FTO substrates. • With surface modification by r-GO, the interface resistance of DSSC decreased. • Maximum PCE of the DSSC was increased up to 8.44%.« less

Linear constraint relations in biochemical reaction systems: I. Classification of the calculability and the balanceability of conversion rates.

PubMed

van der Heijden, R T; Heijnen, J J; Hellinga, C; Romein, B; Luyben, K C

1994-01-05

Measurements provide the basis for process monitoring and control as well as for model development and validation. Systematic approaches to increase the accuracy and credibility of the empirical data set are therefore of great value. In (bio)chemical conversions, linear conservation relations such as the balance equations for charge, enthalpy, and/or chemical elements, can be employed to relate conversion rates. In a pactical situation, some of these rates will be measured (in effect, be calculated directly from primary measurements of, e.g., concentrations and flow rates), as others can or cannot be calculated from the measured ones. When certain measured rates can also be calculated from other measured rates, the set of equations, the accuracy and credibility of the measured rates can indeed be improved by, respectively, balancing and gross error diagnosis. The balanced conversion rates are more accurate, and form a consistent set of data, which is more suitable for further application (e.g., to calculate nonmeasured rates) than the raw measurements. Such an approach has drawn attention in previous studies. The current study deals mainly with the problem of mathematically classifying the conversion rates into balanceable and calculable rates, given the subset of measured rates. The significance of this problem is illustrated with some examples. It is shown that a simple matrix equation can be derived that contains the vector of measured conversion rates and the redundancy matrix R. Matrix R plays a predominant role in the classification problem. In supplementary articles, significance of the redundancy matrix R for an improved gross error diagnosis approach will be shown. In addition, efficient equations have been derived to calculate the balanceable and/or calculable rates. The method is completely based on matrix algebra (principally different from the graph-theoretical approach), and it is easily implemented into a computer program. (c) 1994 John Wiley & Sons, Inc.

Influencing the Conversation About Masculinity and Suicide: Evaluation of the Man Up Multimedia Campaign Using Twitter Data.

PubMed

Schlichthorst, Marisa; King, Kylie; Turnure, Jackie; Sukunesan, Suku; Phelps, Andrea; Pirkis, Jane

2018-02-15

It has been suggested that some dominant aspects of traditional masculinity are contributing to the high suicide rates among Australian men. We developed a three-episode documentary called Man Up, which explores the complex relationship between masculinity and suicide and encourages men to question socially imposed rules about what it means to be a man and asks them to open up, express difficult emotions, and seek help if and when needed. We ran a three-phase social media campaign alongside the documentary using 5 channels (Twitter, Facebook, Instagram, YouTube, and Tumblr). This study aimed to examine the extent to which the Man Up Twitter campaign influenced the social media conversation about masculinity and suicide. We used Twitter insights data to assess the reach of and engagement with the campaign (using metrics on followers, likes, retweets, and impressions) and to determine the highest and lowest performing tweets in the campaign (using an aggregated performance measure of reactions). We used original content tweets to determine whether the campaign increased the volume of relevant Twitter conversations (aggregating the number of tweets for selected campaign hashtags over time), and we used a subset of these data to gain insight into the main content themes with respect to audience engagement. The campaign generated a strong following that was engaged with the content of the campaign; over its whole duration, the campaign earned approximately 5000 likes and 2500 retweets and gained around 1,022,000 impressions. The highest performing tweets posted by the host included video footage and occurred during the most active period of the campaign (around the screening of the documentary). The volume of conversations in relation to commonly used hashtags (#MANUP, #ABCMANUP, #LISTENUP, and #SPEAKUP) grew in direct relation to the campaign activities, achieving strongest growth during the 3 weeks when the documentary was aired. Strongest engagement was found with content related to help-seeking, masculinity, and expressing emotions. A number of followers tweeted personal stories that revealed overwhelmingly positive perceptions of the content of the documentary and strongly endorsed its messages. The Man Up Twitter campaign triggered conversations about masculinity and suicide that otherwise may not have happened. For some, this may have been game-changing in terms of shifting attitudes toward expressing emotions and reaching out to others for help. The campaign was particularly effective in disseminating information and promoting conversations in real time, an advantage that it had over more traditional health promotion campaigns. This sort of approach could well be adapted to other areas of mental (and physical) health promotion campaigns to increase their reach and effectiveness. ©Marisa Schlichthorst, Kylie King, Jackie Turnure, Suku Sukunesan, Andrea Phelps, Jane Pirkis. Originally published in JMIR Mental Health (http://mental.jmir.org), 15.02.2018.

Rates and drivers of mangrove deforestation in Southeast Asia, 2000-2012.

PubMed

Richards, Daniel R; Friess, Daniel A

2016-01-12

The mangrove forests of Southeast Asia are highly biodiverse and provide multiple ecosystem services upon which millions of people depend. Mangroves enhance fisheries and coastal protection, and store among the highest densities of carbon of any ecosystem globally. Mangrove forests have experienced extensive deforestation owing to global demand for commodities, and previous studies have identified the expansion of aquaculture as largely responsible. The proportional conversion of mangroves to different land use types has not been systematically quantified across Southeast Asia, however, particularly in recent years. In this study we apply a combined geographic information system and remote sensing method to quantify the key proximate drivers (i.e., replacement land uses) of mangrove deforestation in Southeast Asia between 2000 and 2012. Mangrove forests were lost at an average rate of 0.18% per year, which is lower than previously published estimates. In total, more than 100,000 ha of mangroves were removed during the study period, with aquaculture accounting for 30% of this total forest change. The rapid expansion of rice agriculture in Myanmar, and the sustained conversion of mangroves to oil palm plantations in Malaysia and Indonesia, are identified as additional increasing and under-recognized threats to mangrove ecosystems. Our study highlights frontiers of mangrove deforestation in the border states of Myanmar, on Borneo, and in Indonesian Papua. To implement policies that conserve mangrove forests across Southeast Asia, it is essential to consider the national and subnational variation in the land uses that follow deforestation.

Rates and drivers of mangrove deforestation in Southeast Asia, 2000–2012

PubMed Central

Richards, Daniel R.; Friess, Daniel A.

2016-01-01

The mangrove forests of Southeast Asia are highly biodiverse and provide multiple ecosystem services upon which millions of people depend. Mangroves enhance fisheries and coastal protection, and store among the highest densities of carbon of any ecosystem globally. Mangrove forests have experienced extensive deforestation owing to global demand for commodities, and previous studies have identified the expansion of aquaculture as largely responsible. The proportional conversion of mangroves to different land use types has not been systematically quantified across Southeast Asia, however, particularly in recent years. In this study we apply a combined geographic information system and remote sensing method to quantify the key proximate drivers (i.e., replacement land uses) of mangrove deforestation in Southeast Asia between 2000 and 2012. Mangrove forests were lost at an average rate of 0.18% per year, which is lower than previously published estimates. In total, more than 100,000 ha of mangroves were removed during the study period, with aquaculture accounting for 30% of this total forest change. The rapid expansion of rice agriculture in Myanmar, and the sustained conversion of mangroves to oil palm plantations in Malaysia and Indonesia, are identified as additional increasing and under-recognized threats to mangrove ecosystems. Our study highlights frontiers of mangrove deforestation in the border states of Myanmar, on Borneo, and in Indonesian Papua. To implement policies that conserve mangrove forests across Southeast Asia, it is essential to consider the national and subnational variation in the land uses that follow deforestation. PMID:26712025

Improving Donor Conversion Rates at a Level One Trauma Center: Impact of Best Practice Guidelines.

PubMed

Alban, Rodrigo F; Gibbons, Bobby L; Bershad, Vanessa L

2016-11-22

Organ availability is a consistently limiting factor in transplant surgery. A primary driver of this limitation is donor conversion rate, which is defined as the percentage of eligible donors for whom procurement is actually performed. An alternative way to increase organ availability is through improved utilization of organs from donors after cardiac death (DCD). Recently, a concerted, multidisciplinary effort has been made within our system to improve conversion rates and DCD utilization, thus increasing organ availability. Retrospective analysis of a prospectively collected database from TransLife, our local organ procurement organization (OPO), as well as the Orlando Regional Medical Center (ORMC) trauma registry, from 2009-2012 (up to 2013 for DCD). During which time, this organization implemented best practice guidelines to improve conversions and DCD utilization. We analyzed yearly conversion rates, DCD donations and population demographics before and after implementation of these policies. During the study period, donor conversion rates significantly improved from 58% in 2009 to 82% percent in 2012 hospital-wide (P<0.05); and from 50% in 2009 to 81% in 2012 among trauma patients alone (P<0.05). In addition, total organs transplanted increased from 13 to 31 organs (P<0.05) after implementation of best practice guidelines. No significant differences in trauma population demographics were noted during the study period. Based on our experience, the establishment of best practice policies for referral of potential donors, coupled with programs to educate hospital staff on the existence and importance of these policies, leads to significant improvement in donor conversion rates and increased utilization of DCD donors.

Conversion of carbon dioxide to carbon monoxide by pulse dielectric barrier discharge plasma

NASA Astrophysics Data System (ADS)

Wang, Taobo; Liu, Hongxia; Xiong, Xiang; Feng, Xinxin

2017-01-01

The conversion of carbon dioxide (CO2) to carbon monoxide (CO) was investigated in a non-thermal plasma dielectric barrier discharge (DBD) reactor, and the effects of different process conditions on the CO2 conversion were investigated. The results showed that the increase of input power could optimize the conversion of CO2 to CO. The CO2 conversion and CO yield were negatively correlated with the gas flow rate, but there was an optimum gas flow rate, that made the CO selectivity best. The carrier gas (N2, Ar) was conducive to the conversion of CO2, and the effect of N2 as carrier gas was better than Ar. The conversion of CO2 to CO was enhanced by addition of the catalyst (5A molecular sieve).

Strategies to achieve high-solids enzymatic hydrolysis of dilute-acid pretreated corn stover.

PubMed

Geng, Wenhui; Jin, Yongcan; Jameel, Hasan; Park, Sunkyu

2015-01-01

Three strategies were presented to achieve high solids loading while maximizing carbohydrate conversion, which are fed-batch, splitting/thickening, and clarifier processes. Enzymatic hydrolysis was performed at water insoluble solids (WIS) of 15% using washed dilute-acid pretreated corn stover. The carbohydrate concentration increased from 31.8 to 99.3g/L when the insoluble solids content increased from 5% to 15% WIS, while the final carbohydrate conversion was decreased from 78.4% to 73.2%. For the fed-batch process, a carbohydrate conversion efficiency of 76.8% was achieved when solid was split into 60:20:20 ratio, with all enzymes added first. For the splitting/thickening process, a carbohydrate conversion of 76.5% was realized when the filtrate was recycled to simulate a steady-state process. Lastly, the clarifier process was evaluated and the highest carbohydrate conversion of 81.4% was achieved. All of these results suggests the possibility of enzymatic hydrolysis at high solids to make the overall conversion cost-competitive. Copyright © 2015 Elsevier Ltd. All rights reserved.

Property evolution during vitrification of dimethacrylate photopolymer networks.

PubMed

Abu-elenain, Dalia A; Lewis, Steven H; Stansbury, Jeffrey W

2013-11-01

This study seeks to correlate the interrelated properties of conversion, shrinkage, modulus and stress as dimethacrylate networks transition from rubbery to glassy states during photopolymerization. An unfilled BisGMA/TEGDMA resin was photocured for various irradiation intervals (7-600 s) to provide controlled levels of immediate conversion, which was monitored continuously for 10 min. Fiber optic near-infrared spectroscopy permitted coupling of real-time conversion measurement with dynamic polymerization shrinkage (linometer), modulus (dynamic mechanical analyzer) and stress (tensometer) development profiles. The varied irradiation conditions produced final conversion ranging from 6% to more than 60%. Post-irradiation conversion (dark cure) was quite limited when photopolymerization was interrupted either at very low or very high levels of conversion while significant dark cure contributions were possible for photocuring reactions suspended within the post-gel, rubbery regime. Analysis of conversion-based property evolution during and subsequent to photocuring demonstrated that the shrinkage rate increased significantly at about 40% conversion followed by late-stage suppression in the conversion-dependent shrinkage rate that begins at about 45-50% conversion. The gradual vitrification process over this conversion range is evident based on the broad but well-defined inflection in the modulus versus conversion data. As limiting conversion is approached, modulus and, to a somewhat lesser extent, stress rise precipitously as a result of vitrification with the stress profile showing little if any late-stage suppression as seen with shrinkage. Near the limiting conversion for this model resin, the volumetric polymerization shrinkage rate slows while an exponential rise in modulus promotes the vitrification process that appears to largely dictate stress development. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Impact of savanna conversion to oil palm plantations on C stocks dynamics and soil fertility

NASA Astrophysics Data System (ADS)

Quezada, Juan Carlos; Guillaume, Thomas; Buttler, Alexandre; Ruegg, Johanna

2017-04-01

Large-scale expansion of oil palm cultivation on forested land in South-East Asia during the last decades lead to high negative environmental impacts. Because rainforests store high amount of C, their conversion to oil palm plantations results in large net CO2 emissions. Oil palm cultivation in tropical ecosystems such as savanna that store less C than forests is seen as an alternative to reduce greenhouse gas emissions of future oil palm development. While this option is more and more frequently mentioned, few data are available on the effective gain in C storage. Furthermore negative impact on soil organic carbon and soil fertility could offset gains of C storage in oil palm biomass. Here, we present results on aboveground and belowground C stocks and soil nutrient dynamics over a full rotation cycle of oil palm plantations established on tropical savanna grasslands. Three natural savanna grasslands as reference sites and 9 oil palm plantations ranging from two to twenty-seven years old were selected in the Llanos in Colombia. Oxisols were sampled down to 70 cm in each management zones of oil palm plantations (weeded circle, interrow, frond piles and harvesting path). Taking advantages of a shift from C4 to C3 vegetation, we quantified savanna-derived soil organic carbon (SOC) decomposition and oil palm-derived SOC stabilization rates and how they were affected by management practices (mineral fertilization, organic amendments, etc.). Results show that, in opposite to forest conversion, C storage increases when savannas are converted to oil palm plantations. Because soil C storage was very low in natural conditions, SOC changes had little effects on overall C storage. Substitution of savanna-derived SOC by oil palm-derived SOC was very fast in the topsoil and highest under frond pile and weeded circle where C and nutrients inputs are highest. However, stabilization of oil palm-derived SOC compensated loss of savanna-derived SOC rather than increased SOC stocks, indicating high SOC turnover. High turnover are explained by high nutrients inputs and little capacity of Oxisols to physically protect SOC. In conclusion, conversion of savanna to oil palm plantations results in a gain in ecosystem C storage as long as the cultivation lasts. Negative impacts on soil fertility are limited because savanna soils have low initial soil fertility. With more than 7 million ha of well-drained natural savanna grasslands, the Llanos could play a significant role in oil palm development. Nonetheless, a complete assessment of environmental impacts including biodiversity or water consumption is still necessary for the assessment on sustainability of the conversion of savanna to oil palm plantations.

State variation in rates of cesarean and VBAC delivery: 1989 and 1993.

PubMed

Clarke, S C; Taffel, S M

1996-01-01

There is wide variation among states in rates of cesarean and vaginal births after cesarean (VBAC) deliveries. In general, states in the South have the highest cesarean rates, states in the West have the lowest, and states in the Northeast and Midwest are intermediate. Louisiana had the highest overall rate in 1993 (27.7 per 100 births) while Alaska had the lowest rate (15.2). The majority of states had declines in their cesarean rate between 1989 and 1993. Patterns in primary cesarean rates are similar to those of the overall rate-states in the South generally have the highest rates while states in the West have the lowest rates. Primary cesarean rates ranged between a high of 19.6 in Louisiana to a low of 10.6 in Wisconsin. In general, states with low cesarean rates have among the highest rates of VBAC delivery. Alaska had the highest VBAC rate (40.0), which was almost quadruple the rate of Louisiana (11.2), the state with the lowest rate. Most states had substantial increases in VBAC rates between 1989 and 1993. When examining cesarean rates by maternal age and birth order, states with the highest overall rates also have among the highest age/birth order-specific rates. Cesarean rates were lowest for mothers under 25 years of age having a second or higher order birth in Alaska, 10.4, and highest for mothers 35 years of age or over having a first birth in Mississippi, 51.3. Standardized cesarean rates which were adjusted for differences between states in maternal age and birth order distributions did not diminish the variation among areas.

Land-use threats and protected areas: a scenario-based, landscape level approach

USGS Publications Warehouse

Wilson, Tamara S.; Sleeter, Benjamin M.; Sleeter, Rachel R.; Soulard, Christopher E.

2014-01-01

Anthropogenic land use will likely present a greater challenge to biodiversity than climate change this century in the Pacific Northwest, USA. Even if species are equipped with the adaptive capacity to migrate in the face of a changing climate, they will likely encounter a human-dominated landscape as a major dispersal obstacle. Our goal was to identify, at the ecoregion-level, protected areas in close proximity to lands with a higher likelihood of future land-use conversion. Using a state-and-transition simulation model, we modeled spatially explicit (1 km2) land use from 2000 to 2100 under seven alternative land-use and emission scenarios for ecoregions in the Pacific Northwest. We analyzed scenario-based land-use conversion threats from logging, agriculture, and development near existing protected areas. A conversion threat index (CTI) was created to identify ecoregions with highest projected land-use conversion potential within closest proximity to existing protected areas. Our analysis indicated nearly 22% of land area in the Coast Range, over 16% of land area in the Puget Lowland, and nearly 11% of the Cascades had very high CTI values. Broader regional-scale land-use change is projected to impact nearly 40% of the Coast Range, 30% of the Puget Lowland, and 24% of the Cascades (i.e., two highest CTI classes). A landscape level, scenario-based approach to modeling future land use helps identify ecoregions with existing protected areas at greater risk from regional land-use threats and can help prioritize future conservation efforts.

Starbon/High-Amylose Corn Starch-Supported N-Heterocyclic Carbene-Iron(III) Catalyst for Conversion of Fructose into 5-Hydroxymethylfurfural.

PubMed

Matharu, Avtar S; Ahmed, Suleiman; Almonthery, Badriya; Macquarrie, Duncan J; Lee, Yoon-Sik; Kim, Yohan

2018-02-22

Iron-N-heterocyclic carbene complexes (Fe-NHCs) have come to prominence because of their applicability in diverse catalytic reactions, ranging from C-C cross-coupling and C-X bond formation to substitution, reduction, polymerization, and dehydration reactions. The detailed synthesis, characterization, and application of novel heterogeneous Fe-NHC catalysts immobilized on mesoporous expanded high-amylose corn starch (HACS) and Starbon 350 (S350) for facile fructose conversion into 5-hydroxymethylfurfural (HMF) is reported. Both catalyst types showed good performance for the dehydration of fructose to HMF when the reaction was tested at 100 °C with varying time (10 min, 20 min, 0.5 h, 1 h, 3 h and 6 h). For Fe-NHC/S350, the highest HMF yield was 81.7 % (t=0.5 h), with a TOF of 169 h -1 , fructose conversion of 95 %, and HMF selectivity of 85.7 %, whereas for Fe-NHC/expanded HACS, the highest yield was 86 % (t=0.5 h), with a TOF of 206 h -1 , fructose conversion of 87 %, and HMF selectivity of 99 %. Iron loadings of 0.26 and 0.30 mmol g -1 were achieved for Fe-NHC/expanded starch and Fe-NHC/S350, respectively. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficient electrochemical CO 2 conversion powered by renewable energy

DOE PAGES

Kauffman, Douglas R.; Thakkar, Jay; Siva, Rajan; ...

2015-06-29

Here, the catalytic conversion of CO 2 into industrially relevant chemicals is one strategy for mitigating greenhouse gas emissions. Along these lines, electrochemical CO 2 conversion technologies are attractive because they can operate with high reaction rates at ambient conditions. However, electrochemical systems require electricity, and CO 2 conversion processes must integrate with carbon-free, renewable-energy sources to be viable on larger scales. We utilize Au 25 nanoclusters as renewably powered CO 2 conversion electrocatalysts with CO 2 → CO reaction rates between 400 and 800 L of CO 2 per gram of catalytic metal per hour and product selectivities betweenmore » 80 and 95%. These performance metrics correspond to conversion rates approaching 0.8–1.6 kg of CO 2 per gram of catalytic metal per hour. We also present data showing CO 2 conversion rates and product selectivity strongly depend on catalyst loading. Optimized systems demonstrate stable operation and reaction turnover numbers (TONs) approaching 6 × 10 6 mol CO 2 molcatalyst–1 during a multiday (36 hours total hours) CO 2electrolysis experiment containing multiple start/stop cycles. TONs between 1 × 10 6 and 4 × 10 6 molCO 2 molcatalyst–1 were obtained when our system was powered by consumer-grade renewable-energy sources. Daytime photovoltaic-powered CO 2 conversion was demonstrated for 12 h and we mimicked low-light or nighttime operation for 24 h with a solar-rechargeable battery. This proof-of-principle study provides some of the initial performance data necessary for assessing the scalability and technical viability of electrochemical CO 2 conversion technologies. Specifically, we show the following: (1) all electrochemical CO 2 conversion systems will produce a net increase in CO 2 emissions if they do not integrate with renewable-energy sources, (2) catalyst loading vs activity trends can be used to tune process rates and product distributions, and (3) state-of-the-art renewable-energy technologies are sufficient to power larger-scale, tonne per day CO 2 conversion systems.« less

Method to monitor HC-SCR catalyst NOx reduction performance for lean exhaust applications

DOEpatents

Viola, Michael B [Macomb Township, MI; Schmieg, Steven J [Troy, MI; Sloane, Thompson M [Oxford, MI; Hilden, David L [Shelby Township, MI; Mulawa, Patricia A [Clinton Township, MI; Lee, Jong H [Rochester Hills, MI; Cheng, Shi-Wai S [Troy, MI

2012-05-29

A method for initiating a regeneration mode in selective catalytic reduction device utilizing hydrocarbons as a reductant includes monitoring a temperature within the aftertreatment system, monitoring a fuel dosing rate to the selective catalytic reduction device, monitoring an initial conversion efficiency, selecting a determined equation to estimate changes in a conversion efficiency of the selective catalytic reduction device based upon the monitored temperature and the monitored fuel dosing rate, estimating changes in the conversion efficiency based upon the determined equation and the initial conversion efficiency, and initiating a regeneration mode for the selective catalytic reduction device based upon the estimated changes in conversion efficiency.

Design of wide-angle solar-selective absorbers using aperiodic metal-dielectric stacks.

PubMed

Sergeant, Nicholas P; Pincon, Olivier; Agrawal, Mukul; Peumans, Peter

2009-12-07

Spectral control of the emissivity of surfaces is essential in applications such as solar thermal and thermophotovoltaic energy conversion in order to achieve the highest conversion efficiencies possible. We investigated the spectral performance of planar aperiodic metal-dielectric multilayer coatings for these applications. The response of the coatings was optimized for a target operational temperature using needle-optimization based on a transfer matrix approach. Excellent spectral selectivity was achieved over a wide angular range. These aperiodic metal-dielectric stacks have the potential to significantly increase the efficiency of thermophotovoltaic and solar thermal conversion systems. Optimal coatings for concentrated solar thermal conversion were modeled to have a thermal emissivity <7% at 720K while absorbing >94% of the incident light. In addition, optimized coatings for solar thermophotovoltaic applications were modeled to have thermal emissivity <16% at 1750K while absorbing >85% of the concentrated solar radiation.

5 CFR 536.305 - Adjusting an employee's retained rate when a pay schedule is adjusted.

Code of Federal Regulations, 2010 CFR

2010-01-01

... conversion under § 536.303(b) or any other simultaneous pay action. The retained rate adjustment under... new retained rate must be determined under the geographic conversion rule in § 536.303(b). (4... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Adjusting an employee's retained rate...

Carbon stocks of intact mangroves and carbon emissions arising from their conversion in the Dominican Republic.

PubMed

Kauffman, J Boone; Heider, Chris; Norfolk, Jennifer; Payton, Frederick

2014-04-01

Mangroves are recognized to possess a variety of ecosystem services including high rates of carbon sequestration and storage. Deforestation and conversion of these ecosystems continue to be high and have been predicted to result in significant carbon emissions to the atmosphere. Yet few studies have quantified the carbon stocks or losses associated with conversion of these ecosystems. In this study we quantified the ecosystem carbon stocks of three common mangrove types of the Caribbean as well as those of abandoned shrimp ponds in areas formerly occupied by mangrove-a common land-use conversion of mangroves throughout the world. In the mangroves of the Montecristi Province in Northwest Dominican Republic we found C stocks ranged from 706 to 1131 Mg/ha. The medium-statured mangroves (3-10 m in height) had the highest C stocks while the tall (> 10 m) mangroves had the lowest ecosystem carbon storage. Carbon stocks of the low mangrove (shrub) type (< 3 m) were relatively high due to the presence of carbon-rich soils as deep as 2 m. Carbon stocks of abandoned shrimp ponds were 95 Mg/ha or approximately 11% that of the mangroves. Using a stock-change approach, the potential emissions from the conversion of mangroves to shrimp ponds ranged from 2244 to 3799 Mg CO2e/ha (CO2 equivalents). This is among the largest measured C emissions from land use in the tropics. The 6260 ha of mangroves and converted mangroves in the Montecristi Province are estimated to contain 3,841,490 Mg of C. Mangroves represented 76% of this area but currently store 97% of the carbon in this coastal wetland (3,696,722 Mg C). Converted lands store only 4% of the total ecosystem C (144,778 Mg C) while they comprised 24% of the area. By these metrics the replacement of mangroves with shrimp and salt ponds has resulted in estimated emissions from this region totaling 3.8 million Mg CO2e or approximately 21% of the total C prior to conversion. Given the high C stocks of mangroves, the high emissions from their conversion, and the other important functions and services they provide, their inclusion in climate-change mitigation strategies is warranted.

Double Z-scheme ZnO/ZnS/g-C3N4 ternary structure for efficient photocatalytic H2 production

NASA Astrophysics Data System (ADS)

Dong, Zhifang; Wu, Yan; Thirugnanam, Natarajan; Li, Gonglin

2018-02-01

In the present work, a novel ZnO/ZnS/g-C3N4 ternary nanocomposite with double Z-scheme heterojunction has been designed via a two-step facile chemical conversion route. The spherical ZnS nanoparticles were uniformly loaded onto ZnO nanoflowers surface. And then the ZnO/ZnS nanocomposite was further hybridized with g-C3N4 nanosheets. Ternary ZnO/ZnS/g-C3N4 nanocomposite displays the largest specific surface area (about 76.2 m2/g), which provides plentiful activated sites for photocatalytic reaction. Furthermore, the ternary material exhibits the highest methylene blue photodegradation rate of about 0.0218 min-1 and the optimum photocatalytic H2 production (1205 μmol/g) over water splitting at 4 h under solar light irradiation. Moreover, it showed the highest photocurrent effect and the minimum charge-transfer resistance. These results implied that the higher photoactivity of ZnO/ZnS/g-C3N4 nanocomposite could be attributed to the multi-steps charge transfer and effective electron-hole separation in the double Z-scheme system.

DiPOLE: a 10 J, 10 Hz cryogenic gas cooled multi-slab nanosecond Yb:YAG laser.

PubMed

Banerjee, Saumyabrata; Ertel, Klaus; Mason, Paul D; Phillips, P Jonathan; De Vido, Mariastefania; Smith, Jodie M; Butcher, Thomas J; Hernandez-Gomez, Cristina; Greenhalgh, R Justin S; Collier, John L

2015-07-27

The Diode Pumped Optical Laser for Experiments (DiPOLE) project at the Central Laser Facility aims to develop a scalable, efficient high pulse energy diode pumped laser amplifier system based on cryogenic gas cooled, multi-slab ceramic Yb:YAG technology. We present recent results obtained from a scaled down prototype laser system designed for operation at 10 Hz pulse repetition rate. At 140 K, the system generated 10.8 J of energy in a 10 ns pulse at 1029.5 nm when pumped by 48 J of diode energy at 940 nm, corresponding to an optical to optical conversion efficiency of 22.5%. To our knowledge, this represents the highest pulse energy obtained from a cryo cooled Yb laser to date and the highest efficiency achieved by a multi-Joule diode pumped solid state laser system. Additionally, we demonstrated shot-to-shot energy stability of 0.85% rms for the system operated at 7 J, 10 Hz during several runs lasting up to 6 hours, with more than 50 hours in total. We also demonstrated pulse shaping capability and report on beam, wavefront and focal spot quality.

Improving Donor Conversion Rates at a Level One Trauma Center: Impact of Best Practice Guidelines

PubMed Central

Gibbons, Bobby L; Bershad, Vanessa L

2016-01-01

Background Organ availability is a consistently limiting factor in transplant surgery. A primary driver of this limitation is donor conversion rate, which is defined as the percentage of eligible donors for whom procurement is actually performed. An alternative way to increase organ availability is through improved utilization of organs from donors after cardiac death (DCD). Recently, a concerted, multidisciplinary effort has been made within our system to improve conversion rates and DCD utilization, thus increasing organ availability. Study design Retrospective analysis of a prospectively collected database from TransLife, our local organ procurement organization (OPO), as well as the Orlando Regional Medical Center (ORMC) trauma registry, from 2009-2012 (up to 2013 for DCD). During which time, this organization implemented best practice guidelines to improve conversions and DCD utilization. We analyzed yearly conversion rates, DCD donations and population demographics before and after implementation of these policies. Results During the study period, donor conversion rates significantly improved from 58% in 2009 to 82% percent in 2012 hospital-wide (P<0.05); and from 50% in 2009 to 81% in 2012 among trauma patients alone (P<0.05). In addition, total organs transplanted increased from 13 to 31 organs (P<0.05) after implementation of best practice guidelines. No significant differences in trauma population demographics were noted during the study period. Conclusions Based on our experience, the establishment of best practice policies for referral of potential donors, coupled with programs to educate hospital staff on the existence and importance of these policies, leads to significant improvement in donor conversion rates and increased utilization of DCD donors. PMID:28018761

Retrospective Conversion of Three Library Collections.

ERIC Educational Resources Information Center

Johnson, Carolyn A.

1982-01-01

Reports on the retrospective conversion via OCLC of cataloging for three library collections at the University of South Carolina--the main, rare book, and historical collections. Backgrounds of the collections, conversion procedures, determinants of conversion rates, and cost factors are discussed. (Author/JL)

Isomerization of α-pinene in the terpentin oil with TCA/Natural Zeolite using microwave irradiation

NASA Astrophysics Data System (ADS)

Wijayati, N.; Supartono; Kusumastuti, E.

2018-04-01

The catalytic potensial of trichloroacetic acid (TCA)//Natural Zeolite in the isomerization of α-pinene in the terpentin oil was investigated. The purpose of this study is to investigate the influence of the power of microvawe on activity and selectivity of catalyst. The main product were champhene, terpinene, limonene, p-cymene, and terpinolene. The highest selectivity was 28.26% with a conversion of 23.25%, whereas the higher conversion was 98.99% with selectivity of 16.90% at room temperature using power of microwave 640 W.

Development of factors to convert frequency to rate for β-cell replication and apoptosis quantified by time-lapse video microscopy and immunohistochemistry

PubMed Central

Saisho, Yoshifumi; Manesso, Erica; Gurlo, Tatyana; Huang, Chang-jiang; Toffolo, Gianna M.; Cobelli, Claudio; Butler, Peter C.

2009-01-01

An obstacle to development of methods to quantify β-cell turnover from pancreas tissue is the lack of conversion factors for the frequency of β-cell replication or apoptosis detected by immunohistochemistry to rates of replication or apoptosis. We addressed this obstacle in islets from 1-mo-old rats by quantifying the relationship between the rate of β-cell replication observed directly by time-lapse video microscopy (TLVM) and the frequency of β-cell replication in the same islets detected by immunohistochemistry using antibodies against Ki67 and insulin in the same islets fixed immediately after TLVM. Similarly, we quantified the rate of β-cell apoptosis by TLVM and then the frequency of apoptosis in the same islets using TdT-mediated dUTP nick-end labeling and insulin. Conversion factors were developed by regression analysis. The conversion factor from Ki67 labeling frequency (%) to actual replication rate (%events/h) is 0.025 ± 0.003 h−1. The conversion factor from TdT-mediated dUTP nick-end labeling frequency (%) to actual apoptosis rate (%events/h) is 0.41 ± 0.05 h−1. These conversion factors will permit development of models to evaluate β-cell turnover in fixed pancreas tissue. PMID:18940937

Effective communication between ENT and primary care - a survey of outpatient correspondence.

PubMed

Addison, A B; Watts, S; Fleming, J

2015-06-01

To improve the quality of outpatient clinic communication between Otolaryngology and primary care doctors. Three example outpatient letters with identical content were created using different structure styles - full prose, headline subheadings with full prose and full subheadings throughout. Electronic questionnaires were sent out to 30 randomly selected General Practitioners in the area served by Western Sussex NHS Trust. The electronic mail study invite contained the initial GP referral, the three different letter formats and a link to the Sheffield Assessment for Letters (SAIL) questionnaire, which contained a 18-point checklist, 6 rating subheadings with a 10-point rating scale and a free text comment section. Study participants were asked to read the letters in the time usually afforded to outpatient letters in their routine practice, answer questions and then rate the letters. With a response rate of 66.7%, overall comparison of GP preferences demonstrated a significant variation between the three letter formats (Freidman P value = 0.0001). Post hoc multiple comparisons showed statistically significant preference for the headline subheading and prose letter compared to the full subheaded letter (P < 0.05). In assessing the letters for readability, comprehension, usefulness, informativeness and helpfulness, analysis showed significant preference for both fully subheaded and headline subheaded with full prose structures compared to the full prose letter. Although the headline subheadings and prose letter had the highest word count, it scored the highest in almost all the rating categories analysed. This study is the first published work to study primary care physician's preference for the structure of letters from secondary care. Prominent headline subheadings of diagnosis and management improve interpretation of content and comprehension and are helpful to GPs for co-ordinating patient management. Lack of subheadings or conversely an excess of subheadings may be a hindrance to effective communication between healthcare professionals. © 2014 John Wiley & Sons Ltd.

γ-Dodecelactone production from safflower oil via 10-hydroxy-12(Z)-octadecenoic acid intermediate by whole cells of Candida boidinii and Stenotrophomonas nitritireducens.

PubMed

Jo, Ye-Seul; An, Jung-Ung; Oh, Deok-Kun

2014-07-16

Candida boidinii was selected as a γ-dodecelactone producer because of the highest production of γ-dodecelactone from 10-hydroxy-12(Z)-octadecenoic acid among the 11 yeast strains tested. Under the reaction conditions of pH 5.5 and 25 °C with 5 g/L 10-hydroxy-12(Z)-octadecenoic acid and 30 g/L cells, whole C. boidinii cells produced 2.1 g/L γ-dodecelactone from 5 g/L 10-hydroxy-12(Z)-octadecenoic acid after 6 h, with a conversion yield of 64% (mol/mol) and a volumetric productivity of 350 mg/L/h. The production of γ-dodecelactone from safflower oil was performed by lipase hydrolysis reaction and two-step whole-cell biotransformation using Stenotrophomonas nitritireducens and C. boidinii. γ-Dodecelactone at 1.88 g/L was produced from 7.5 g/L safflower oil via 5 g/L 10-hydroxy-12(Z)-octadecenoic acid intermediate by these reactions after 8 h of reaction time, with a volumetric productivity of 235 mg/L/h and a conversion yield of 25% (w/w). To the best of the authors' knowledge, this is the highest volumetric productivity and conversion yield reported to date for the production of γ-lactone from natural oils.

Multicenter Trial of the VenaTech Convertible Vena Cava Filter.

PubMed

Hohenwalter, Eric J; Stone, James R; O'Moore, Paul V; Smith, Steven J; Selby, J Bayne; Lewandowski, Robert J; Samuels, Shaun; Kiproff, Paul M; Trost, David W; Madoff, David C; Handel, Jeremy; Gandras, Eric J; Vlahos, Athanasios; Rilling, William S

2017-10-01

To demonstrate rates of successful filter conversion and 6-month major device-related adverse events in subjects with converted caval filters. An investigational device exemption multicenter, prospective, single-arm study was performed at 11 sites enrolling 149 patients. The VenaTech Convertible Vena Cava Filter (B. Braun Interventional Systems, Inc, Bethlehem, Pennsylvania) was implanted in 149 patients with venous thromboembolism and contraindication to or failure of anticoagulation (n = 119), with high-risk trauma (n = 14), and for surgical prophylaxis (n = 16). When the patient was no longer at risk for pulmonary embolism as determined by clinical assessment, an attempt at filter conversion was made. Follow-up of converted patients (n = 93) was conducted at 30 days, 3 months, and 6 months after conversion. Patients who did not undergo a conversion attempt (n = 53) had follow-up at 6 months after implant. All implants were successful. One 7-day migration to the right atrium required surgical removal. Technical success rate for filter conversion was 92.7% (89/96). Mean time from placement to conversion was 130.7 days (range, 15-391 d). No major conversion-related events were reported. The mean conversion procedure time was 30.7 minutes (range, 7-135 min). There were 89 converted and 32 unconverted patients who completed 6-month follow-up with no delayed complications. The VenaTech Convertible filter has a high conversion rate and low 6-month device-related adverse event rate. Further studies are necessary to determine long-term safety and efficacy in both converted and unconverted patients. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

Gravity flow rate of solids through orifices and pipes

NASA Technical Reports Server (NTRS)

Gardner, J. F.; Smith, J. E.; Hobday, J. M.

1977-01-01

Lock-hopper systems are the most common means for feeding solids to and from coal conversion reactor vessels. The rate at which crushed solids flow by gravity through the vertical pipes and valves in lock-hopper systems affects the size of pipes and valves needed to meet the solids-handling requirements of the coal conversion process. Methods used to predict flow rates are described and compared with experimental data. Preliminary indications are that solids-handling systems for coal conversion processes are over-designed by a factor of 2 or 3.

Simultaneous wavelength conversion of ASK and DPSK signals based on four-wave-mixing in dispersion engineered silicon waveguides.

PubMed

Xu, Lin; Ophir, Noam; Menard, Michael; Lau, Ryan Kin Wah; Turner-Foster, Amy C; Foster, Mark A; Lipson, Michal; Gaeta, Alexander L; Bergman, Keren

2011-06-20

We experimentally demonstrate four-wave-mixing (FWM)-based continuous wavelength conversion of optical differential-phase-shift-keyed (DPSK) signals with large wavelength conversion ranges as well as simultaneous wavelength conversion of dual-wavelength channels with mixed modulation formats in 1.1-cm-long dispersion-engineered silicon waveguides. We first validate up to 100-nm wavelength conversion range for 10-Gb/s DPSK signals, showcasing the capability to perform phase-preserving operations at high bit rates in chip-scale devices over wide conversion ranges. We further validate the wavelength conversion of dual-wavelength channels modulated with 10-Gb/s packetized phase-shift-keyed (PSK) and amplitude-shift-keyed (ASK) signals; demonstrate simultaneous operation on multiple channels with mixed formats in chip-scale devices. For both configurations, we measure the spectral and temporal responses and evaluate the performances using bit-error-rate (BER) measurements.

The rate of meiotic gene conversion varies by sex and age

PubMed Central

Halldorsson, Bjarni V.; Hardarson, Marteinn T.; Kehr, Birte; Styrkarsdottir, Unnur; Gylfason, Arnaldur; Thorleifsson, Gudmar; Zink, Florian; Jonasdottir, Adalbjorg; Jonasdottir, Aslaug; Sulem, Patrick; Masson, Gisli; Thorsteinsdottir, Unnur; Helgason, Agnar; Kong, Augustine; Gudbjartsson, Daniel F.; Stefansson, Kari

2016-01-01

Meiotic recombination involves a combination of gene conversion and crossover events that along with mutations produce germline genetic diversity. Here, we report the discovery of 3,176 SNP and 61 indel gene conversions. Our estimate of the non-crossover (NCO) gene conversion rate (G) is 7.0 for SNPs and 5.8 for indels per Mb per generation, and the GC bias is 67.6%. For indels we demonstrate a 65.6% preference for the shorter allele. NCO gene conversions from mothers are longer than those from fathers and G is 2.17 times greater in mothers. Notably, G increases with the age of mothers, but not fathers. A disproportionate number of NCO gene conversions in older mothers occur outside double strand break (DSB) regions and in regions with relatively low GC content. This points to age-related changes in the mechanisms of meiotic gene conversions in oocytes. PMID:27643539

Biological production of acetic acid from waste gases with Clostridium ljungdahlii

DOEpatents

Gaddy, James L.

1998-01-01

A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration.

Clostridium stain which produces acetic acid from waste gases

DOEpatents

Gaddy, James L.

1997-01-01

A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration.

Clostridium strain which produces acetic acid from waste gases

DOEpatents

Gaddy, J.L.

1997-01-14

A method and apparatus are disclosed for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration. 4 figs.

Can quantum coherent solar cells break detailed balance?

NASA Astrophysics Data System (ADS)

Kirk, Alexander P.

2015-07-01

Carefully engineered coherent quantum states have been proposed as a design attribute that is hypothesized to enable solar photovoltaic cells to break the detailed balance (or radiative) limit of power conversion efficiency by possibly causing radiative recombination to be suppressed. However, in full compliance with the principles of statistical mechanics and the laws of thermodynamics, specially prepared coherent quantum states do not allow a solar photovoltaic cell—a quantum threshold energy conversion device—to exceed the detailed balance limit of power conversion efficiency. At the condition given by steady-state open circuit operation with zero nonradiative recombination, the photon absorption rate (or carrier photogeneration rate) must balance the photon emission rate (or carrier radiative recombination rate) thus ensuring that detailed balance prevails. Quantum state transitions, entropy-generating hot carrier relaxation, and photon absorption and emission rate balancing are employed holistically and self-consistently along with calculations of current density, voltage, and power conversion efficiency to explain why detailed balance may not be violated in solar photovoltaic cells.

Kinetics and mechanism of the oxidation of S(IV) by ozone in aqueous solution with particular reference to SO2 conversion in nonurban tropospheric clouds

NASA Technical Reports Server (NTRS)

Maahs, H. G.

1983-01-01

Results are presented from a laboratory study of the kinetics of the S(IV)-O3 reaction in aqueous solution, including measurements of the effects of UV radiation, dissolved transition metals, and an antioxidant (hydroquinone) on the rate. On the basis of the results, relative rates of S(IV) conversion by O3 in tropospheric cloud water are compared with those predicted for H2O2 and for O2. The reaction mechanism is discussed, with an outline given of the elements of a possible reaction scheme. Application of the rate constants obtained to SO2 conversion in cloud water predicts conversion rates by ozone to be competitive with those by H2O2 at pH above about 4.5 and to dominate at pH above about 5.5. It is pointed out that since these pH's are typical for nonurban tropospheric cloud water, ozone is a potentially important contributor to the overall oxidative conversion of SO2 to sulfate in the nonurban troposphere.

A Meta-Analysis of Global Urban Land Expansion

PubMed Central

Seto, Karen C.; Fragkias, Michail; Güneralp, Burak; Reilly, Michael K.

2011-01-01

The conversion of Earth's land surface to urban uses is one of the most irreversible human impacts on the global biosphere. It drives the loss of farmland, affects local climate, fragments habitats, and threatens biodiversity. Here we present a meta-analysis of 326 studies that have used remotely sensed images to map urban land conversion. We report a worldwide observed increase in urban land area of 58,000 km2 from 1970 to 2000. India, China, and Africa have experienced the highest rates of urban land expansion, and the largest change in total urban extent has occurred in North America. Across all regions and for all three decades, urban land expansion rates are higher than or equal to urban population growth rates, suggesting that urban growth is becoming more expansive than compact. Annual growth in GDP per capita drives approximately half of the observed urban land expansion in China but only moderately affects urban expansion in India and Africa, where urban land expansion is driven more by urban population growth. In high income countries, rates of urban land expansion are slower and increasingly related to GDP growth. However, in North America, population growth contributes more to urban expansion than it does in Europe. Much of the observed variation in urban expansion was not captured by either population, GDP, or other variables in the model. This suggests that contemporary urban expansion is related to a variety of factors difficult to observe comprehensively at the global level, including international capital flows, the informal economy, land use policy, and generalized transport costs. Using the results from the global model, we develop forecasts for new urban land cover using SRES Scenarios. Our results show that by 2030, global urban land cover will increase between 430,000 km2 and 12,568,000 km2, with an estimate of 1,527,000 km2 more likely. PMID:21876770

Incubation temperature, developmental biology, and the divergence of sockeye salmon (Oncorhynchus nerka) within Lake Washington

USGS Publications Warehouse

Hendry, A.P.; Hensleigh, J.E.; Reisenbichler, R.R.

1998-01-01

Sockeye salmon (Oncorhynchus nerka) introduced into Lake Washington in the 1930s and 1940s now spawn at several different sites and over a period of more than 3 months. To test for evolutionary divergence within this derived lineage, embryos that would have incubated in different habitats (Cedar River or Pleasure Point Beach) or at different times (October, November, or December in the Cedar River) were reared in the laboratory at 5, 9, and 12.5??C. Some developmental variation mirrored predictions of adaptive divergence: (i) survival at 12.5??C was highest for embryos most likely to experience such temperatures in the wild (Early Cedar), (ii) development rate was fastest for progeny of late spawners (Late Cedar), and (iii) yolk conversion efficiency was matched to natural incubation temperatures. These patterns likely had a genetic basis because they were observed in a common environment and could not be attributed to differences in egg size. The absolute magnitude of divergence in development rates was moderate (Late Cedar embryos emerged only 6 days earlier at 9??C) and some predictions regarding development rates were not supported. Nonetheless our results provide evidence of adaptive divergence in only 9-14 generations.

All-fibre photonic signal generator for attosecond timing and ultralow-noise microwave

PubMed Central

Jung, Kwangyun; Kim, Jungwon

2015-01-01

High-impact frequency comb applications that are critically dependent on precise pulse timing (i.e., repetition rate) have recently emerged and include the synchronization of X-ray free-electron lasers, photonic analogue-to-digital conversion and photonic radar systems. These applications have used attosecond-level timing jitter of free-running mode-locked lasers on a fast time scale within ~100 μs. Maintaining attosecond-level absolute jitter over a significantly longer time scale can dramatically improve many high-precision comb applications. To date, ultrahigh quality-factor (Q) optical resonators have been used to achieve the highest-level repetition-rate stabilization of mode-locked lasers. However, ultrahigh-Q optical-resonator-based methods are often fragile, alignment sensitive and complex, which limits their widespread use. Here we demonstrate a fibre-delay line-based repetition-rate stabilization method that enables the all-fibre photonic generation of optical pulse trains with 980-as (20-fs) absolute r.m.s. timing jitter accumulated over 0.01 s (1 s). This simple approach is based on standard off-the-shelf fibre components and can therefore be readily used in various comb applications that require ultra-stable microwave frequency and attosecond optical timing. PMID:26531777

Effects of Eryngii mushroom (Pleurotus eryngii) and Lactobacillus plantarum on growth performance, immunity and disease resistance of Pangasius catfish (Pangasius bocourti, Sauvage 1880).

PubMed

Van Doan, Hien; Doolgindachbaporn, Sompong; Suksri, Amnuaysilpa

2016-10-01

This study was conducted to evaluate the effects of Eryngii mushroom, Pleurotus eryngii (PE), and Lactobacillus plantarum single or combined on growth, innate immune response and disease resistance of the Pangasius catfish, Pangasius bocourti. Two hundred forty fish were divided into four treatments, i.e., 0 g kg(-1) PE (Control, Diet 1), 3 g kg(-1) PE (Diet 2), 10(8) cfu g(-1) L. plantarum (Diet 3) and 3 g kg(-1) PE + 10(8) cfu g(-1) L. plantarum (Diet 4). Fish were culture in glass tanks with water volume approximately of 150 l, and each treatment had four replications with 15 fish per replication. Following 30, 60 and 90 days of the feeding trial, specific growth rate (SGR), feed conversion ratio (FCR), serum lysozyme, phagocytosis and respiratory burst activities were measured. SGR and FCR were significantly improved in fish fed supplemented diets after 90 days of the feeding trial. Serum lysozyme, phagocytosis and respiratory burst activity of fish were significantly stimulated by both PE and L. plantarum diets; however, the highest innate immune response was observed in fish fed synbiotic diet. At the end of the experiment, five fish were randomly selected for a challenge test against Aeromonas hydrophila. The post-challenge survival rate of the fish fed supplemented diets was significantly greater than the control treatment, and the highest post-challenge survival rate was observed in synbiotic diet. The results revealed that dietary supplementation of PE and L. plantarum stimulated growth, immunity and disease resistance of the P. bocourti.

Empirical evaluation of inhibitory product, substrate, and enzyme effects during the enzymatic saccharification of lignocellulosic biomass.

PubMed

Smith, Benjamin T; Knutsen, Jeffrey S; Davis, Robert H

2010-05-01

The cellulose hydrolysis kinetics during batch enzymatic saccharification are typified by a rapid initial rate that subsequently decays, resulting in incomplete conversion. Previous studies suggest that changes associated with the solution, substrate, or enzymes may be responsible. In this work, kinetic experiments were conducted to determine the relative magnitude of these effects. Pretreated corn stover (PCS) was used as a lignocellulosic substrate likely to be found in a commercial saccharification process, while Avicel and Kraft lignin were used to create model substrates. Glucose inhibition was observed by spiking the reaction slurry with glucose during initial-rate experiments. Increasing the glucose concentration from 7 to 48 g/L reduced the cellulose conversion rate by 94%. When product sugars were removed using ultrafiltration with a 10 kDa membrane, the glucose-based conversion increased by 9.5%. Reductions in substrate reactivity with conversion were compared directly by saccharifying PCS and Avicel substrates that had been pre-reacted to different conversions. Reaction of substrate with a pre-conversion of 40% resulted in about 40% reduction in the initial rate of saccharification, relative to fresh substrate with identical cellulose concentration. Overall, glucose inhibition and reduced substrate reactivity appear to be dominant factors, whereas minimal reductions of enzyme activity were observed.

Advanced liquefaction using coal swelling and catalyst dispersion techniques. Volume 2, appendices. Final technical report, October 1, 1991--September 30, 1994

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

Curtis, C.W.; Chander, S.; Gutterman, C.

Liquefaction experiments were undertaken using subbituminous Black Thunder mine coal to observe the effects of aqueous SO{sub 2} coal beneficiation and the introduction of various coal swelling solvents and catalyst precursors. Aqueous SO{sub 2} beneficiation of Black Thunder coal removed alkali metals and alkaline earth metals, increased the sulfur content and increased the catalytic liquefaction conversion to THF solubles compared to untreated Black Thunder coal. The liquefaction solvent had varying effects on coal conversion, depending upon the type of solvent added. The hydrogen donor solvent, dihydroanthracene, was most effective, while a coal-derived Wilsonville solvent promoted more coal conversion than didmore » relatively inert 1-methylnaphthalene. Swelling of coal with hydrogen bonding solvents tetrahydrofuran (THF), isopropanol, and methanol, prior to reaction resulted in increased noncatalytic conversion of both untreated and SO{sub 2} treated Black Thunder coals, while dimethylsulfoxide (DMSO), which was absorbed more into the coal than any other swelling solvent, was detrimental to coal conversion. Swelling of SO{sub 2} treated coal before liquefaction resulted in the highest coal conversions; however, the untreated coal showed the most improvements in catalytic reactions when swelled in either THF, isopropanol, or methanol prior to liquefaction. The aprotic solvent DMSO was detrimental to coal conversion.« less

Risk-adjusted cesarean section rates for the assessment of physician performance in Taiwan: a population-based study.

PubMed

Tang, Chao-Hsiun; Wang, Han-I; Hsu, Chun-Sen; Su, Hung-Wen; Chen, Mei-Ju; Lin, Herng-Ching

2006-10-09

Over the past decade, about one-third of all births nationwide in Taiwan were delivered by cesarean section (CS). Previous studies in the US and Europe have documented the need for risk adjustment for fairer comparisons among providers. In this study, we set out to determine the impact that adjustment for patient-specific risk factors has on CS among different physicians in Taiwan. There were 172,511 live births which occurred in either hospitals or obstetrics/gynecology clinics between 1 January and 31 December 2003, and for whom birth certificate data could be linked with National Health Insurance (NHI) claims data, available as the sample for this study. Physicians were divided into four equivalent groups based upon the quartile distribution of their crude (actual) CS rates. Stepwise logistic regressions were conducted to develop a predictive model and to determine the expected (risk-adjusted) CS rate and 95% confidence interval (CI) for each physician. The actual rates were then compared with the expected CS rates to see the proportion of physicians whose actual rates were below, within, or above the predicted CI in each quartile. The proportion of physicians whose CS rates were above the predicted CI increased as the quartile moved to the higher level. However, more than half of the physicians whose actual rates were higher than the predicted CI were not in the highest quartile. Conversely, there were some physicians (40 of 258 physicians) in the highest quartile who were actually providing obstetric care that was appropriate to the risk. When a stricter standard was applied to the assessment of physician performance by excluding physicians in quartile 4 for predicting CS rates, as many as 60% of physicians were found to have higher CS rates than the predicted CI, and indeed, the CS rates of no physicians in either quartile 3 or quartile 4 were below the predicted CI. Overall, our study found that the comparison of unadjusted CS rates might not provide a valid reflection of the quality of obstetric care delivered by physicians, and may ultimately lead to biased judgments by purchasers. Our study has also shown that when we changed the standard of quality assessment, the evaluation results also changed.

5 CFR 532.405 - Use of highest previous rate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Use of highest previous rate. 532.405 Section 532.405 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Pay Administration § 532.405 Use of highest previous rate. (a)(1) Subject to the...

Patient safety culture assessment in oman.

PubMed

Al-Mandhari, Ahmed; Al-Zakwani, Ibrahim; Al-Kindi, Moosa; Tawilah, Jihane; Dorvlo, Atsu S S; Al-Adawi, Samir

2014-07-01

To illustrate the patient safety culture in Oman as gleaned via 12 indices of patient safety culture derived from the Hospital Survey on Patient Safety Culture (HSPSC) and to compare the average positive response rates in patient safety culture between Oman and the USA, Taiwan, and Lebanon. This was a cross-sectional research study employed to gauge the performance of HSPSC safety indices among health workers representing five secondary and tertiary care hospitals in the northern region of Oman. The participants (n=398) represented different professional designations of hospital staff. Analyses were performed using univariate statistics. The overall average positive response rate for the 12 patient safety culture dimensions of the HSPSC survey in Oman was 58%. The indices from HSPSC that were endorsed the highest included 'organizational learning and continuous improvement' while conversely, 'non-punitive response to errors' was ranked the least. There were no significant differences in average positive response rates between Oman and the United States (58% vs. 61%; p=0.666), Taiwan (58% vs. 64%; p=0.386), and Lebanon (58% vs. 61%; p=0.666). This study provides the first empirical study on patient safety culture in Oman which is similar to those rates reported elsewhere. It highlights the specific strengths and weaknesses which may stem from the specific milieu prevailing in Oman.

Benthic Primary Production Budget of a Caribbean Reef Lagoon (Puerto Morelos, Mexico)

PubMed Central

Naumann, Malik S.; Jantzen, Carin; Haas, Andreas F.; Iglesias-Prieto, Roberto; Wild, Christian

2013-01-01

High photosynthetic benthic primary production (P) represents a key ecosystem service provided by tropical coral reef systems. However, benthic P budgets of specific ecosystem compartments such as macrophyte-dominated reef lagoons are still scarce. To address this, we quantified individual and lagoon-wide net (Pn) and gross (Pg) primary production by all dominant functional groups of benthic primary producers in a typical macrophyte-dominated Caribbean reef lagoon near Puerto Morelos (Mexico) via measurement of O2 fluxes in incubation experiments. The photosynthetically active 3D lagoon surface area was quantified using conversion factors to allow extrapolation to lagoon-wide P budgets. Findings revealed that lagoon 2D benthic cover was primarily composed of sand-associated microphytobenthos (40%), seagrasses (29%) and macroalgae (27%), while seagrasses dominated the lagoon 3D surface area (84%). Individual Pg was highest for macroalgae and scleractinian corals (87 and 86 mmol O2 m−2 specimen area d−1, respectively), however seagrasses contributed highest (59%) to the lagoon-wide Pg. Macroalgae exhibited highest individual Pn rates, but seagrasses generated the largest fraction (51%) of lagoon-wide Pn. Individual R was highest for scleractinian corals and macroalgae, whereas seagrasses again provided the major lagoon-wide share (68%). These findings characterise the investigated lagoon as a net autotrophic coral reef ecosystem compartment revealing similar P compared to other macrophyte-dominated coastal environments such as seagrass meadows and macroalgae beds. Further, high lagoon-wide P (Pg: 488 and Pn: 181 mmol O2 m−2 lagoon area d−1) and overall Pg:R (1.6) indicate substantial benthic excess production within the Puerto Morelos reef lagoon and suggest the export of newly synthesised organic matter to surrounding ecosystems. PMID:24367570

Conversion tables for use with the National Fire-Danger Rating System in the Intermountain area

Treesearch

Dwight S. Stockstad; Richard J. Barney

1964-01-01

Two tables prepared for use with the National Fire-Danger Rating System replace 10 tables previously used with the Model-8 Fire-Danger Rating System. They provide for the conversion of Spread Index values at various altitudes, aspects, and times of day. A rate of spread table facilitates converting Spread Index values to chains per hour of perimeter increase for...

Low pressure catalytic co-conversion of biogenic waste (rapeseed cake) and vegetable oil.

PubMed

Giannakopoulou, Kanellina; Lukas, Michael; Vasiliev, Aleksey; Brunner, Christoph; Schnitzer, Hans

2010-05-01

Zeolite catalysts of three types (H-ZSM-5, Fe-ZSM-5 and H-Beta) were tested in the catalytic co-conversion of rapeseed cake and safflower oil into bio-fuel. This low pressure process was carried out at the temperatures of 350 and 400 degrees Celsius. The yields and compositions of the product mixtures depended on the catalyst nature and the process temperatures. The produced organic phases consisted mainly of hydrocarbons, fatty acids and nitriles. This mixture possessed improved characteristics (e.g. heating value, water content, density, viscosity, pH) compared with the bio-oils, making possible its application as a bio-fuel. The most effective catalyst, providing the highest yield of organic liquid phase, was the highly acidic/wide-pore H-Beta zeolite. The products obtained on this catalyst demonstrated the highest degree of deoxygenation and the higher HHV (Higher Heating Value). The aqueous liquid phase contained water-soluble carboxylic acids, phenols and heterocyclic compounds. Copyright 2009 Elsevier Ltd. All rights reserved.

Ceo2 Based Catalysts for the Treatment of Propylene in Motorcycle’s Exhaust Gases

PubMed Central

Pham, Phuong Thi Mai; Le Minh, Thang; Nguyen, Tien The; Van Driessche, Isabel

2014-01-01

In this work, the catalytic activities of several single metallic oxides were studied for the treatment of propylene, a component in motorcycles’ exhaust gases, under oxygen deficient conditions. Amongst them, CeO2 is one of the materials that exhibit the highest activity for the oxidation of C3H6. Therefore, several mixtures of CeO2 with other oxides (SnO2, ZrO2, Co3O4) were tested to investigate the changes in catalytic activity (both propylene conversion and CO2 selectivity). Ce0.9Zr0.1O2, Ce0.8Zr0.2O2 solid solutions and the mixtures of CeO2 and Co3O4 was shown to exhibit the highest propylene conversion and CO2 selectivity. They also exhibited good activities when tested under oxygen sufficient and excess conditions and with the presence of co-existing gases (CO, H2O). PMID:28788253

Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus)

PubMed Central

Sarker, Pallab K.; Kapuscinski, Anne R.; Lanois, Alison J.; Livesey, Erin D.; Bernhard, Katie P.; Coley, Mariah L.

2016-01-01

We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds. PMID:27258552

Synthesis of disaccharides using β-glucosidases from Aspergillus niger, A. awamori and Prunus dulcis.

PubMed

da Silva, Ayla Sant'Ana; Molina, Javier Freddy; Teixeira, Ricardo Sposina Sobral; Valdivieso Gelves, Luis G; Bon, Elba P S; Ferreira-Leitão, Viridiana S

2017-11-01

Glucose conversion into disaccharides was performed with β-glucosidases from Prunus dulcis (β-Pd), Aspergillus niger (β-An) and A. awamori (β-Aa), in reactions containing initial glucose of 700 and 900 g l -1 . The reactions' time courses were followed regarding glucose and product concentrations. In all cases, there was a predominant formation of gentiobiose over cellobiose and also of oligosaccharides with a higher molecular mass. For reactions containing 700 g glucose l -1 , the final substrate conversions were 33, 38, and 23.5% for β-An, β-Aa, and β-Pd, respectively. The use of β-An yielded 103 g gentiobiose l -1 (15.5% yield), which is the highest reported for a fungal β-glucosidase. The increase in glucose concentration to 900 g l -1 resulted in a significant increase in disaccharide synthesis by β-Pd, reaching 128 g gentiobiose l -1 (15% yield), while for β-An and β-Aa, there was a shift toward the synthesis of higher oligosaccharides. β-Pd and the fungal β-An and β-Aa β-glucosidases present quite dissimilar kinetics and selective properties regarding the synthesis of disaccharides; while β-Pd showed the highest productivity for gentiobiose synthesis, β-An presented the highest specificity.

Does quality improvement work? Evaluation of the Organ Donation Breakthrough Collaborative.

PubMed

Howard, David H; Siminoff, Laura A; McBride, Virginia; Lin, Monica

2007-12-01

The Organ Donation Breakthrough Collaborative is a quality improvement initiative to encourage adoption of "best practices" for identifying potential donors and obtaining consent for deceased organ donation. We evaluate the impact of the first phase on organ donation rates. We study donation rates in the 95 hospitals that participated in the first phase and a control group of 125 hospitals. We use a controlled pre/post design. The preperiod is the year before the start of the Collaborative (September 2002 to August 2003), the postperiod is the final 6 months of the first phase (March 2004 to August 2004). We use administrative data from the Organ Procurement and Transplantation Network to compute the conversion rate in each hospital group and time period. The conversion rate is the proportion of eligible donors who became actual donors. Preperiod conversion rates in Collaborative and control hospitals were similar: 52 and 51 percent, respectively. In the postperiod, the conversion rate increased to 60 percent among Collaborative hospitals and remained at 51 percent among control hospitals. The relative change was 8 percentage points (95 percent confidence interval: 2-13: p<.001). Our findings suggest that the Breakthrough Collaborative led to an increase in donation rates at participating hospitals.

The correlation between cellulose allomorphs (I and II) and conversion after removal of hemicellulose and lignin of lignocellulose.

PubMed

Song, Yanliang; Zhang, Jingzhi; Zhang, Xu; Tan, Tianwei

2015-10-01

H2SO4, NaOH and H3PO4 were applied to decompose lignocellulose samples (giant reeds, pennisetum and cotton stalks) to investigate the correlation between cellulose allomorphs (cellulose I and II) and conversion of cellulose. The effect of removal of hemicellulose and lignin on the surface morphology, crystallinity index (CrI), cellulose allomorphs (cellulose I and II), and enzymatic hydrolysis under different pretreatments was also studied. CrI caused by H3PO4 pretreatment reached 11.19%, 24.93% and 8.15% for the three samples, respectively. Corn stalk showed highest conversion of cellulose among three samples, irrespective of the pretreatment used. This accounted for the widely use of corn stalk as the renewable crop substrate to synthesize biofuels like ethanol. CrI of cellulose I (CrI-I) negatively affects cellulose conversion but CrI of cellulose II (CrI-II) positively affects cellulose conversion. It contributes to make the strategy to transform cellulose I to cellulose II and enhancing enzymatic hydrolysis of lignocellulose. Copyright © 2015 Elsevier Ltd. All rights reserved.

Retrospective Conversion: A Question of Time, Standards, and Purpose.

ERIC Educational Resources Information Center

Valentine, Phyllis A.; McDonald, David R.

1986-01-01

Examines the factors that determine the cost of retrospective conversion (definition of conversion, standards of acceptance, method of conversion, hit rate, standards for creation of machine-readable records for nonhits); reports results of cost study at University of Michigan library; and introduces an alternative strategy for discussion. Seven…

Mussel glue protein has an open conformation.

PubMed

Williams, T; Marumo, K; Waite, J H; Henkens, R W

1989-03-01

Both native glue protein from marine mussels and a synthetic nonhydroxylated analog were analyzed by far-uv CD under a variety of conditions. Analysis of the CD spectra using various models strongly suggest a primarily random coil structure for both forms of the protein, a fact also supported by the absence of spectral change for the glue protein upon dilution into 6 M guanidine hydrochloride. The nonhydroxylated analog, which consists of 20 repeats of the peptide sequence Ala-Lys-Pro-Ser-Tyr-Pro-Pro-Thr-Tyr-Lys, was further characterized by enzyme modification using mushroom tyrosinase. Enzymatic hydroxylation of tyrosines was found to be best fit by a model containing two rate constants, 5.6 (+/- 0.6) X 10(-3) and 7.2 (+/- 0.3) X 10(-2) min-1. At equilibrium, HPLC analysis of digests showed nearly 100% conversion of Tyr-9 and only 15 to 35% conversion of Tyr-5. The Chou and Fasman rules for predicting structure were applied to the repeat sequence listed above. The rules predict the absence of alpha helix and beta pleated sheets in the structure of this peptide. On the other hand, beta turns are predicted to be present with Tyr-5 being in the region of highest probability. These data suggest that the protein in solution has only a small amount of secondary structure.

Total robotic pancreaticoduodenectomy: a systematic review of the literature.

PubMed

Kornaropoulos, Michail; Moris, Demetrios; Beal, Eliza W; Makris, Marinos C; Mitrousias, Apostolos; Petrou, Athanasios; Felekouras, Evangelos; Michalinos, Adamantios; Vailas, Michail; Schizas, Dimitrios; Papalampros, Alexandros

2017-11-01

Pancreaticoduodenectomy (PD) is a complex operation with high perioperative morbidity and mortality, even in the highest volume centers. Since the development of the robotic platform, the number of reports on robotic-assisted pancreatic surgery has been on the rise. This article reviews the current state of completely robotic PD. A systematic literature search was performed including studies published between January 2000 and July 2016 reporting PDs in which all procedural steps (dissection, resection and reconstruction) were performed robotically. Thirteen studies met the inclusion criteria, including a total of 738 patients. Data regarding perioperative outcomes such as operative time, blood loss, mortality, morbidity, conversion and oncologic outcomes were analyzed. No major differences were observed in mortality, morbidity and oncologic parameters, between robotic and non-robotic approaches. However, operative time was longer in robotic PD, whereas the estimated blood loss was lower. The conversion rate to laparotomy was 6.5-7.8%. Robotic PD is feasible and safe in high-volume institutions, where surgeons are experienced and medical staff are appropriately trained. Randomized controlled trials are required to further investigate outcomes of robotic PD. Additionally, cost analysis and data on long-term oncologic outcomes are needed to evaluate cost-effectiveness of the robotic approach in comparison with the open technique.

Ultrastable, high efficiency picosecond green light generation using K3B6O10Br series nonlinear optical crystals

NASA Astrophysics Data System (ADS)

Hou, Z. Y.; Xia, M. J.; Wang, L. R.; Xu, B.; Yan, D. X.; Meng, L. P.; Liu, L. J.; Xu, D. G.; Zhang, L.; Wang, X. Y.; Li, R. K.; Chen, C. T.

2017-09-01

Two perovskite-structure K3B6O10Br1-x Cl x (x  =  0 and 0.5) series nonlinear optical crystals were thoroughly investigated for their picosecond 532 nm laser pulses abilities and high power outputs were achieved via second harmonic generation (SHG) technique for the first time. SHG conversion efficiency of 57.3% with a 13.2 mm length K3B6O10Br (KBB) crystal was achieved using a laser source of pulse repetition rate of 10 Hz and pulse width of 25 ps, which is the highest conversion efficiency of ps visible laser based on KBB crystal. And by employing an 80 MHz, 10 ps fundamental laser beam, maximum power outputs of 12 W with K3B6O10Br0.5Cl0.5 (KBBC) and 11.86 W with KBB crystals were successfully demonstrated. Furthermore, the standard deviation jitters of the average power outputs are less than 0.6% and 1.17% by KBB and KBBC, respectively, showing ultrastable power stabilities favorable for practical applications. In addition, the other optical parameters including acceptance angle and temperature bandwidth were also investigated.

Degradation of palm oil empty fruit bunch (EFB) into bio-oil in sub-and supercritical solvents

NASA Astrophysics Data System (ADS)

Sarwono, Rakhman; Pusfitasari, Eka Dian

2017-01-01

Hydrothemal Liquefaction (HTL) of empty fruit bunch (EFB) of palm oil in different solvents (water, ethanol and hexane) were comparatively investigated. Experiments were carried out in an autoclave in different EFB loading of 9%, 11%, and 13%. The temperature operation was 350 oC, without any catalysts and reaction time of 5 hours. The efficiency of above solvents in terms of conversion rate, soluble liquid and carbon products were found in this experiments. The water solvent gave higher conversion rate of 35 - 36.5 %, while hexane gave conversion of 17 - 25.25 %, and ethanol gave the lower conversion rate of 12.65 - 30.3%, respectively. Increasing the EFB load decreased the conversion rate for ethanol and hexane solvents, for water there are no significant change in the conversion rate. The bio-oil as soluble liquid produced were in order of water, ethanol, and hexane solvents, respectively. The chemical properties of bio-oil products were significantly affected by the type of liquefaction solvent. The compositional of bio-oil consists of mostly of a mixture of organic acids, ketones, and esters. The hexane and ethanol solvents resulted mostly organic acids. In water solvent resulted 2-pentanone, 4-hydroxy-4-methyl and others substances. According to the bio-oil results, organic solvents resulted higher HHV compared to water solvent. The higher heating value (HHV) of the carbon products were also comparatively, ethanol solvent resulted soluble liquid with higher HHV compared to the water solvent.

Communication nonaccommodation in family conversations about end-of-life health decisions.

PubMed

Scott, Allison M; Caughlin, John P

2015-01-01

Furthering our understanding of how communication can improve end-of-life decision making requires a shift in focus from whether people talk to how people talk about end-of-life health decisions. This study used communication accommodation theory to examine the extent to which communication nonaccommodation distinguished more from less successful end-of-life conversations among family members. We analyzed elicited conversations about end-of-life health decisions from 121 older parent/adult child dyads using outside ratings of communication over- and underaccommodation and self-reported conversational outcomes. Results of multilevel linear modeling revealed that outside ratings of underaccommodation predicted self-reported and partner-reported uncertainty, and ratings of overaccommodation predicted self-reported decision-making efficacy and change in concordance accuracy. We discuss the methodological, theoretical, and practical implications of these findings.

Different extraction pretreatments significantly change the flavonoid contents of Scutellaria baicalensis

PubMed Central

Yu, Chunhao; Qu, Fengyun; Mao, Yanyong; Li, Dong; Zhen, Zhong; Nass, Rachael; Calway, Tyler; Wang, Yunwei; Yuan, Chun-Su; Wang, Chong-Zhi

2014-01-01

Context Scutellaria baicalensis is one of the most commonly used medicinal herbs, especially in traditional Chinese medicine. However, compared to many pharmacological studies of this botanical, much less attention has been paid to the quality control of the herb’s pretreatment prior to extract preparation, an issue that may affect therapeutic outcomes. Objective The current study was designed to evaluate whether different pretreatment conditions change the contents of its four major flavonoids in the herb, i.e., two glycosides (baicalin and wogonoside) and two aglycons (baicalein and wogonin). Materials and methods An HPLC assay was used to quantify the contents of these four flavonoids. The composition changes of four flavonoids by different pretreatment conditions including solvent, treatment time, temperature, pH value, and herb/solvent ratio were evaluated. Results After selection of the first order time-curve kinetics, our data showed that at 50°C, 1:5 herb/water (in w/v) ratio and pH 6.67 yielded an optimal conversion rate from flavonoid glycosides to their aglycons. In this optimized condition, the contents of baicalin and wogonoside were decreased to 1/70 and 1/13, while baicalein and wogonin were increased 3.5 and 3.1 folds, respectively, compared to untreated herb. Discussion and conclusion The markedly variable conversion rates by different pretreatment conditions complicated the quality control of this herb, mainly due to the high amount of endogenous enzymes of S. baicalensis. Optimal pretreatment conditions obtained from this study could be used obtain the highest level of desired constituents to achieve better pharmacological effects. PMID:23738852

Different extraction pretreatments significantly change the flavonoid contents of Scutellaria baicalensis.

PubMed

Yu, Chunhao; Qu, Fengyun; Mao, Yanyong; Li, Dong; Zhen, Zhong; Nass, Rachael; Calway, Tyler; Wang, Yunwei; Yuan, Chun-Su; Wang, Chong-Zhi

2013-10-01

Scutellaria baicalensis Georgi (Labiatae) is one of the most commonly used medicinal herbs, especially in traditional Chinese medicine. However, compared to many pharmacological studies of this botanical, much less attention has been paid to the quality control of the herb's pretreatment prior to extract preparation, an issue that may affect therapeutic outcomes. The current study was designed to evaluate whether different pretreatment conditions change the contents of the four major flavonoids in the herb, i.e., two glycosides (baicalin and wogonoside) and two aglycones (baicalein and wogonin). A high-performance liquid chromatography assay was used to quantify the contents of these four flavonoids. The composition changes of four flavonoids by different pretreatment conditions, including solvent, treatment time, temperature, pH value and herb/solvent ratio were evaluated. After selection of the first order time-curve kinetics, our data showed that at 50 °C, 1:5 herb/water (in w/v) ratio and pH 6.67 yielded an optimal conversion rate from flavonoid glycosides to their aglycones. In this optimized condition, the contents of baicalin and wogonoside were decreased to 1/70 and 1/13, while baicalein and wogonin were increased 3.5- and 3.1-fold, respectively, compared to untreated herb. The markedly variable conversion rates by different pretreatment conditions complicated the quality control of this herb, mainly due to the high amount of endogenous enzymes of S. baicalensis. Optimal pretreatment conditions observed in this study could be used obtain the highest level of desired constituents to achieve better pharmacological effects.

Synthesis of bioadditives of fuels from biodiesel-derived glycerol by esterification with acetic acid on solid catalysts.

PubMed

Bedogni, Gabriel A; Acevedo, Mauro D; Aguzín, Federico; Okulik, Nora B; Padró, Cristina L

2017-07-07

In this paper, glycerol esterification with acetic acid (AA) was studied on several solid acid catalysts: Al 2 O 3 , Al-MCM-41, HPA/SiO 2 , HBEA, Amberlyst 15 and Amberlyst 36 with the aim of determining the reaction conditions and the nature of the surface acid sites required to produce selectively triacetylglycerol (triacetin). The acidity of the catalysts (nature, density and strength of acid sites) was characterized by temperature-programmed desorption of NH 3 and FTIR of adsorbed pyridine. Al 2 O 3 (Lewis acidity) did not show any activity in the reaction. In contrast, highest activity and selectivity to the triacetylated product (triacetin) were obtained on catalysts with Brønsted acidity: Amberlyst 15 and Amberlyst 36. The effect of temperature and molar ratio of AA to glycerol was studied, and the results showed that both parameters have a significant impact on the production of the desired product. Glycerol conversion rate and selectivity to triacetin increased when temperature or AA to glycerol molar ratio were increased, reaching a triacetin yield on Amberlyst 36 of 44% at 393 K and AA to glycerol molar ratio of 6. Deactivation and reusability of Amberlyst 36 were evaluated by performing consecutive catalytic tests. The presence of some irreversible deactivation due to sulfur loss was observed. In addition, the feasibility of using crude glycerol from biodiesel production as reactant was also investigated. Conversion of crude pretreated glycerol yielded values of triacetin and diacetin similar to those obtained with the commercial pure glycerol although at a lower rate.

Gene modification of the acetate biosynthesis pathway in Escherichia coli and implementation of the cell recycling technology to increase L-tryptophan production

PubMed Central

Bai, Fang; Chen, Ning; Bai, Gang

2017-01-01

The implementation of a novel cell recycling technology based on a special disk centrifuge during microbial fermentation process can continuously separate the product and harmful intermediates, while maintaining the cell viability owing to the installed cooling system. Acetate accumulation is an often encountered problem in L-tryptophan fermentation by Escherichia coli. To extend our previous studies, the current study deleted the key genes underlying acetate biosynthesis to improve l-tryptophan production. The deletion of the phosphotransacetylase (pta)–acetate kinase (ackA) pathway in a gltB (encoding glutamate synthase) mutant of E. coli TRTHB, led to the highest production of l-tryptophan (47.18 g/L) and glucose conversion rate (17.83%), with a marked reduction in acetate accumulation (1.22 g/L). This strain, TRTHBPA, was then used to investigate the effects of the cell recycling process on L-tryptophan fermentation. Four different strategies were developed concerning two issues, the volume ratio of the concentrated cell solution and clear solution and the cell recycling period. With strategy I (concentrated cell solution: clear solution, 1: 1; cell recycling within 24–30 h), L-tryptophan production and the glucose conversion rate increased to 55.12 g/L and 19.75%, respectively, 17.55% and 10.77% higher than those without the cell recycling. In addition, the biomass increased by 13.52% and the fermentation period was shortened from 40 h to 32 h. These results indicated that the cell recycling technology significantly improved L-tryptophan production by E. coli. PMID:28622378

Leveraging Distant Relatedness to Quantify Human Mutation and Gene-Conversion Rates

PubMed Central

Palamara, Pier Francesco; Francioli, Laurent C.; Wilton, Peter R.; Genovese, Giulio; Gusev, Alexander; Finucane, Hilary K.; Sankararaman, Sriram; Sunyaev, Shamil R.; de Bakker, Paul I.W.; Wakeley, John; Pe’er, Itsik; Price, Alkes L.

2015-01-01

The rate at which human genomes mutate is a central biological parameter that has many implications for our ability to understand demographic and evolutionary phenomena. We present a method for inferring mutation and gene-conversion rates by using the number of sequence differences observed in identical-by-descent (IBD) segments together with a reconstructed model of recent population-size history. This approach is robust to, and can quantify, the presence of substantial genotyping error, as validated in coalescent simulations. We applied the method to 498 trio-phased sequenced Dutch individuals and inferred a point mutation rate of 1.66 × 10−8 per base per generation and a rate of 1.26 × 10−9 for <20 bp indels. By quantifying how estimates varied as a function of allele frequency, we inferred the probability that a site is involved in non-crossover gene conversion as 5.99 × 10−6. We found that recombination does not have observable mutagenic effects after gene conversion is accounted for and that local gene-conversion rates reflect recombination rates. We detected a strong enrichment of recent deleterious variation among mismatching variants found within IBD regions and observed summary statistics of local sharing of IBD segments to closely match previously proposed metrics of background selection; however, we found no significant effects of selection on our mutation-rate estimates. We detected no evidence of strong variation of mutation rates in a number of genomic annotations obtained from several recent studies. Our analysis suggests that a mutation-rate estimate higher than that reported by recent pedigree-based studies should be adopted in the context of DNA-based demographic reconstruction. PMID:26581902

T-SPOT.TB Interferon-γ Release Assay Performance in Healthcare Worker Screening at Nineteen U.S. Hospitals.

PubMed

King, Thomas C; Upfal, Mark; Gottlieb, Andrew; Adamo, Philip; Bernacki, Edward; Kadlecek, Chris P; Jones, Jeffrey G; Humphrey-Carothers, Frances; Rielly, Albert F; Drewry, Pamela; Murray, Kathy; DeWitt, Marcie; Matsubara, Janet; O'Dea, Louis; Balser, John; Wrighton-Smith, Peter

2015-08-01

Interferon-γ release assays have significant advantages over tuberculin skin testing in many clinical situations. However, recent studies have called into question their reliability in serial testing of healthcare workers because of reportedly high rates of positivity and high conversion/reversion rates on retesting. To define the performance characteristics of the T-SPOT.TB test, an interferon-γ release assay, during serial screening programs of healthcare workers at 19 U.S. hospitals. A total of 42,155 T-SPOT.TB test results from healthcare workers at 19 geographically diverse hospitals obtained for routine tuberculosis screening programs were analyzed to determine the rates of positivity, reversion, and conversion in serial testing data. In 19,630 evaluable serial pairs from 16,076 healthcare workers, the mean test positivity rate was 2.3% (range, 0.0-27.4%). The mean conversion rate was 0.8% (range, 0.0-2.5%), and the mean reversion rate was 17.6%. Positivity and conversion rates correlated with known tuberculosis risk factors including age and sex. The observed specificity of the T-SPOT.TB test was at least 98.6%. The high concordance and test completion rates in this study suggest that the T-SPOT.TB test is a reliable tool for healthcare worker serial screening. As expected, the observed positivity rates were lower compared with the tuberculin skin test, likely reflecting the higher specificity of this test. Furthermore, the observed rates of conversion were low and significantly correlated with the geographic incidence of tuberculosis. Our findings suggest that the T-SPOT.TB test is an accurate and reliable way to screen healthcare workers.

Optimization of Neutral Atom Imagers

NASA Technical Reports Server (NTRS)

Shappirio, M.; Coplan, M.; Balsamo, E.; Chornay, D.; Collier, M.; Hughes, P.; Keller, J.; Ogilvie, K.; Williams, E.

2008-01-01

The interactions between plasma structures and neutral atom populations in interplanetary space can be effectively studied with energetic neutral atom imagers. For neutral atoms with energies less than 1 keV, the most efficient detection method that preserves direction and energy information is conversion to negative ions on surfaces. We have examined a variety of surface materials and conversion geometries in order to identify the factors that determine conversion efficiency. For chemically and physically stable surfaces smoothness is of primary importance while properties such as work function have no obvious correlation to conversion efficiency. For the noble metals, tungsten, silicon, and graphite with comparable smoothness, conversion efficiency varies by a factor of two to three. We have also examined the way in which surface conversion efficiency varies with the angle of incidence of the neutral atom and have found that the highest efficiencies are obtained at angles of incidence greater then 80deg. The conversion efficiency of silicon, tungsten and graphite were examined most closely and the energy dependent variation of conversion efficiency measured over a range of incident angles. We have also developed methods for micromachining silicon in order to reduce the volume to surface area over that of a single flat surface and have been able to reduce volume to surface area ratios by up to a factor of 60. With smooth micro-machined surfaces of the optimum geometry, conversion efficiencies can be increased by an order of magnitude over instruments like LENA on the IMAGE spacecraft without increase the instruments mass or volume.

Associations between Family Communication Patterns, Sibling Closeness, and Adoptive Status

PubMed Central

Samek, Diana R.; Rueter, Martha A.

2011-01-01

Previous research has demonstrated the protective effect of family and sibling closeness on child adjustment, but fewer studies have investigated how closeness is promoted within families. Guided by Family Communication Patterns Theory, we tested the association between family communication and sibling emotional and behavioral closeness, and whether adoptive status moderated this relationship. Participating families included 616 adoptive and non-adoptive families with two adolescent children. Hypotheses were tested using structural equation modeling. Sibling closeness was highest in families that emphasized both conversation and conformity and lowest in families that emphasized only conversation or neither conversation nor conformity. Emotional and behavioral closeness were differentially associated with adoption status, sibling age, and sibling gender. Few moderating effects of adoption status were found. Post hoc analyses showed moderating effects of sibling gender composition. PMID:21984844

Associations between Family Communication Patterns, Sibling Closeness, and Adoptive Status.

PubMed

Samek, Diana R; Rueter, Martha A

2011-10-01

Previous research has demonstrated the protective effect of family and sibling closeness on child adjustment, but fewer studies have investigated how closeness is promoted within families. Guided by Family Communication Patterns Theory, we tested the association between family communication and sibling emotional and behavioral closeness, and whether adoptive status moderated this relationship. Participating families included 616 adoptive and non-adoptive families with two adolescent children. Hypotheses were tested using structural equation modeling. Sibling closeness was highest in families that emphasized both conversation and conformity and lowest in families that emphasized only conversation or neither conversation nor conformity. Emotional and behavioral closeness were differentially associated with adoption status, sibling age, and sibling gender. Few moderating effects of adoption status were found. Post hoc analyses showed moderating effects of sibling gender composition.

High conversion efficiency distributed feedback laser from a dye-doped holographic transmission grating

NASA Astrophysics Data System (ADS)

Liu, Lijuan; Zhang, Guiyang; Kong, Xiaobo; Liu, Yonggang; Xuan, Li

2018-01-01

A high conversion efficiency distributed feedback (DFB) laser from a dye-doped holographic polymer dispersed liquid crystal (HPDLC) transmission grating structure was reported. The alignment polyimide (PI) films were used to control the orientation of the phase separated liquid crystals (LCs) to increase the refractive index difference between the LC and the polymer, so it can provide better light feedback. The lasing wavelength located at 645.8 nm near the maximum of the amplified spontaneous emission (ASE) spectrum with the lowest threshold 0.97 μ J/pulse and the highest conversion efficiency 1.6% was obtained. The laser performance under electric field were also investigated and illustrated. The simple configuration, one-step fabrication organic dye laser shows the potential to realize ultra-low cost plastic lasers.

49 CFR 583.14 - Currency conversion rate.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Currency conversion rate. 583.14 Section 583.14 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AUTOMOBILE PARTS CONTENT LABELING § 583.14 Currency...

49 CFR 583.14 - Currency conversion rate.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Currency conversion rate. 583.14 Section 583.14 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AUTOMOBILE PARTS CONTENT LABELING § 583.14 Currency...

49 CFR 583.14 - Currency conversion rate.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Currency conversion rate. 583.14 Section 583.14 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AUTOMOBILE PARTS CONTENT LABELING § 583.14 Currency...

49 CFR 583.14 - Currency conversion rate.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Currency conversion rate. 583.14 Section 583.14 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AUTOMOBILE PARTS CONTENT LABELING § 583.14 Currency...

49 CFR 583.14 - Currency conversion rate.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Currency conversion rate. 583.14 Section 583.14 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AUTOMOBILE PARTS CONTENT LABELING § 583.14 Currency...

Does nitrogen fertilization history affects short-term microbial responses and chemical properties of soils submitted to different glyphosate concentrations?

PubMed Central

Nivelle, Elodie; Chabot, Amélie; Roger, David; Spicher, Fabien; Lacoux, Jérôme; Nava-Saucedo, Jose-Edmundo; Catterou, Manuella; Tétu, Thierry

2017-01-01

The use of nitrogen (N) fertilizer and glyphosate-based herbicides is increasing worldwide, with agriculture holding the largest market share. The agronomic and socioeconomic utilities of glyphosate are well established; however, our knowledge of the potential effects of glyphosate applied in the presence or absence of long-term N fertilization on microbial functional activities and the availability of soil nutrients remains limited. Using an ex situ approach with soils that did (N+) or did not (N0) receive synthetic N fertilization for 6 years, we assessed the impact of different rates (no glyphosate, CK; field rate, FR; 100 × field rate, 100FR) of glyphosate application on biological and chemical parameters. We observed that, after immediate application (1 day), the highest dose of glyphosate (100FR) negatively affected the alkaline phosphatase (AlP) activity in soils without N fertilization history and decreased the cation exchange capacity (CEC) in N0 compared to CK and FR treatments with N+. Conversely, the 100FR application increased nitrate (NO3-) and available phosphorus (PO43-) regardless of N fertilization history. Then, after 8 and 15 days, the N+\\100FR and N+\\FR treatments exhibited the lowest values for dehydrogenase (DH) and AlP activities, respectively, while urease (URE) activity was mainly affected by N fertilization. After 15 days and irrespective of N fertilization history, the FR glyphosate application negatively affected the degradation of carbon substrates by microbial communities (expressed as the average well color development, AWCD). By contrast, the 100FR treatment positively affected AWCD, increasing PO43- by 5 and 16% and NO3- by 126 and 119% in the N+ and N0 treatments, respectively. In addition, the 100FR treatment resulted in an increase in the average net nitrification rate. Principal component analysis revealed that the 100FR glyphosate treatment selected microbial communities that were able to metabolize amine substrates. Overall, the lack of N fertilization in the 6 past years combined with the highest glyphosate application rate (100FR) induced the highest values of AWCD, functional diversity, NO3-, PO43- and nitrification. We concluded that the intensive use of N fertilization for 6 years may change the non-target effects of glyphosate application on enzyme activities. The functional activities, nitrification and nutrient contents were increased by glyphosate only when applied at 100 times the field application rate. PMID:28552945

Does nitrogen fertilization history affects short-term microbial responses and chemical properties of soils submitted to different glyphosate concentrations?

PubMed

Nivelle, Elodie; Verzeaux, Julien; Chabot, Amélie; Roger, David; Spicher, Fabien; Lacoux, Jérôme; Nava-Saucedo, Jose-Edmundo; Catterou, Manuella; Tétu, Thierry

2017-01-01

The use of nitrogen (N) fertilizer and glyphosate-based herbicides is increasing worldwide, with agriculture holding the largest market share. The agronomic and socioeconomic utilities of glyphosate are well established; however, our knowledge of the potential effects of glyphosate applied in the presence or absence of long-term N fertilization on microbial functional activities and the availability of soil nutrients remains limited. Using an ex situ approach with soils that did (N+) or did not (N0) receive synthetic N fertilization for 6 years, we assessed the impact of different rates (no glyphosate, CK; field rate, FR; 100 × field rate, 100FR) of glyphosate application on biological and chemical parameters. We observed that, after immediate application (1 day), the highest dose of glyphosate (100FR) negatively affected the alkaline phosphatase (AlP) activity in soils without N fertilization history and decreased the cation exchange capacity (CEC) in N0 compared to CK and FR treatments with N+. Conversely, the 100FR application increased nitrate (NO3-) and available phosphorus (PO43-) regardless of N fertilization history. Then, after 8 and 15 days, the N+\\100FR and N+\\FR treatments exhibited the lowest values for dehydrogenase (DH) and AlP activities, respectively, while urease (URE) activity was mainly affected by N fertilization. After 15 days and irrespective of N fertilization history, the FR glyphosate application negatively affected the degradation of carbon substrates by microbial communities (expressed as the average well color development, AWCD). By contrast, the 100FR treatment positively affected AWCD, increasing PO43- by 5 and 16% and NO3- by 126 and 119% in the N+ and N0 treatments, respectively. In addition, the 100FR treatment resulted in an increase in the average net nitrification rate. Principal component analysis revealed that the 100FR glyphosate treatment selected microbial communities that were able to metabolize amine substrates. Overall, the lack of N fertilization in the 6 past years combined with the highest glyphosate application rate (100FR) induced the highest values of AWCD, functional diversity, NO3-, PO43- and nitrification. We concluded that the intensive use of N fertilization for 6 years may change the non-target effects of glyphosate application on enzyme activities. The functional activities, nitrification and nutrient contents were increased by glyphosate only when applied at 100 times the field application rate.

A Cooperative Conversion Project from Vertical File Hardcopy to Jacketed Microfiche.

ERIC Educational Resources Information Center

Worden, Diane D.

1981-01-01

Describes a cooperative project to convert a library's hardcopy materials to microfiche, including the steps involved in conversion, conversion costs, sources of funding, and staff performance rates. Six references are listed. (FM)

Predictive models for conversion of prediabetes to diabetes.

PubMed

Yokota, N; Miyakoshi, T; Sato, Y; Nakasone, Y; Yamashita, K; Imai, T; Hirabayashi, K; Koike, H; Yamauchi, K; Aizawa, T

2017-08-01

To clarify the natural course of prediabetes and develop predictive models for conversion to diabetes. A retrospective longitudinal study of 2105 adults with prediabetes was carried out with a mean observation period of 4.7years. Models were developed using multivariate logistic regression analysis and verified by 10-fold cross-validation. The relationship between [final BMI minus baseline BMI] (δBMI) and incident diabetes was analyzed post hoc by comparing the diabetes conversion rate for low (< -0.31kg/m 2 ) and high δBMI (≥ -0.31kg/m 2 ) subjects after matching the two groups for the covariates. Diabetes developed in 252 (2.5%/year), and positive family history, male sex, higher systolic blood pressure, plasma glucose (fasting and 1h- and 2h-values during 75g OGTT), hemoglobin A1c (HbA1c) and alanine aminotransferase were significant, independent predictors for the conversion. By using a risk score (RS) that took account of all these variables, incident diabetes was predicted with an area under the ROC curve (95% CI) of 0.80 (0.70-0.87) and a specificity of prediction of 61.8% at 80% sensitivity. On division of the participants into high- (n=248), intermediate- (n=336) and low-risk (n=1521) populations, the conversion rates were 40.1%, 18.5% and 5.9%, respectively. The conversion rate was lower in subjects with low than high δBMI (9.2% vs 14.4%, p=0.003). Prediabetes conversion to diabetes could be predicted with accuracy, and weight reduction during the observation was associated with lowered conversion rate. Copyright © 2017 Elsevier Inc. All rights reserved.

Interaction of H2 @C60 and nitroxide through conformationally constrained peptide bridges.

PubMed

Garbuio, Luca; Li, Yongjun; Antonello, Sabrina; Gascón, José A; Lawler, Ronald G; Lei, Xuegong; Murata, Yasujiro; Turro, Nicholas J; Maran, Flavio

2014-01-01

We synthesized two molecular systems, in which an endofullerene C60 , incarcerating one hydrogen molecule (H2 @C60 ) and a nitroxide radical are connected by a folded 310 -helical peptide. The difference between the two molecules is the direction of the peptide orientation. The nuclear spin relaxation rates and the para → ortho conversion rate of the incarcerated hydrogen molecule were determined by (1) H NMR spectroscopy. The experimental results were analyzed using DFT-optimized molecular models. The relaxation rates and the conversion rates of the two peptides fall in the expected distance range. One of the two peptides is particularly rigid and thus ideal to keep the H2 @C60 /nitroxide separation, r, as large and controlled as possible, which results in particularly low relaxation and conversion rates. Despite the very similar optimized distance, however, the rates measured with the other peptide are considerably higher and thus are compatible with a shorter effective distance. The results strengthen the outcome of previous investigations that while the para → ortho conversion rates satisfactorily obey the Wigner's theory, the nuclear spin relaxation rates are in excellent agreement with the Solomon-Bloembergen equation predicting a 1/r(6) dependence. © 2013 The American Society of Photobiology.

FOLFOXIRI Plus Bevacizumab as Conversion Therapy for Patients With Initially Unresectable Metastatic Colorectal Cancer: A Systematic Review and Pooled Analysis.

PubMed

Tomasello, Gianluca; Petrelli, Fausto; Ghidini, Michele; Russo, Alessandro; Passalacqua, Rodolfo; Barni, Sandro

2017-07-13

The combination of fluorouracil, oxaliplatin, and irinotecan plus bevacizumab (FOLFOXIRI-Bev) is an established and effective first-line chemotherapy regimen for metastatic colorectal cancer. However, resection rates of metastases and overall survival with this schedule have never been systematically evaluated in published studies including, but not limited to, the TRIBE (TRIplet plus BEvacizumab) trial. To assess the clinical efficacy of FOLFOXIRI-Bev, including outcomes and rates of surgical conversions. A systematic review was conducted in October 2016 in concordance with the PRISMA guidelines of PubMed, the Cochrane Central Register of Controlled Trials, SCOPUS, Web of Science, Google Scholar, CINAHL, Ovid, and EMBASE using the terms FOLFOXIRI and bevacizumab and (colorectal cancer). Clinical trials, retrospective case series, and prospective case series that used FOLFOXIRI-Bev for the treatment of initially unresectable metastatic colorectal cancer in humans were included. Individual case reports and retrospective case series with fewer than 10 patients were excluded. Data were extracted independently by 2 reviewers on a predesigned, standardized form. Ultimately, data were aggregated to obtain the pooled effect size of efficacy, according to the random-effects model and weighted for the number of patients included in each trial. Median overall survival and progression-free survival, overall response rates, and rates of R0 surgical conversions and overall surgical conversions. Eleven FOLFOXIRI-Bev studies published between 2010 and 2016 met the inclusion criteria and were pooled for analysis. The studies included 889 patients, with 877 patients clinically evaluable for overall response rates. The objective response rate to FOLFOXIRI-Bev was 69% (95% CI, 65%-72%; I2 = 25%). The rate of overall surgical conversions was 39.1% (95% CI, 26.9%-52.8%), and the rate of R0 surgical conversions was 28.1% (95% CI, 18.1%-40.8%). Median pooled overall survival was 30.2 months (95% CI, 26.5-33.7 months) in 6 trials with data available, and progression-free survival was 12.4 months (95% CI, 10.0-14.3 months) in 9 trials with data available. In meta-regression analysis, variables significantly associated with conversion surgery were disease limited to the liver and a higher median number of cycles (close to 12). For patients with surgically unresectable metastatic colorectal cancer, FOLFOXIRI-Bev is associated with a significant overall response rate. Such an effective regimen leads to a probability of surgical conversion of distant metastases approaching 40%, with more than one-fourth of patients having an R0 resection.

Heralding efficiency and correlated-mode coupling of near-IR fiber-coupled photon pairs

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

Dixon, P. Ben; Rosenberg, Danna; Stelmakh, Veronika

We report on a systematic experimental study of heralding efficiency and generation rate of telecom-band infrared photon pairs generated by spontaneous parametric down-conversion and coupled to single mode optical fibers. We define the correlated-mode coupling efficiency--an inherent source efficiency--and explain its relation to heralding efficiency. For our experiment, we developed a reconfigurable computer controlled pump-beam and collection-mode optical apparatus which we used to measure the generation rate and correlated-mode coupling efficiency. The use of low-noise, high-efficiency superconducting-nanowire single-photon-detectors in this setup allowed us to explore focus configurations with low overall photon flux. The measured data agree well with theory andmore » we demonstrated a correlated-mode coupling efficiency of 97%±2%, which is the highest efficiency yet achieved for this type of system. These results confirm theoretical treatments and demonstrate that very high overall heralding efficiencies can, in principle, be achieved in quantum optical systems. We expect that these results and techniques will be widely incorporated into future systems that require, or benefit from, a high heralding efficiency.« less

Heralding efficiency and correlated-mode coupling of near-IR fiber-coupled photon pairs

DOE PAGES

Dixon, P. Ben; Rosenberg, Danna; Stelmakh, Veronika; ...

2014-10-06

We report on a systematic experimental study of heralding efficiency and generation rate of telecom-band infrared photon pairs generated by spontaneous parametric down-conversion and coupled to single mode optical fibers. We define the correlated-mode coupling efficiency--an inherent source efficiency--and explain its relation to heralding efficiency. For our experiment, we developed a reconfigurable computer controlled pump-beam and collection-mode optical apparatus which we used to measure the generation rate and correlated-mode coupling efficiency. The use of low-noise, high-efficiency superconducting-nanowire single-photon-detectors in this setup allowed us to explore focus configurations with low overall photon flux. The measured data agree well with theory andmore » we demonstrated a correlated-mode coupling efficiency of 97%±2%, which is the highest efficiency yet achieved for this type of system. These results confirm theoretical treatments and demonstrate that very high overall heralding efficiencies can, in principle, be achieved in quantum optical systems. We expect that these results and techniques will be widely incorporated into future systems that require, or benefit from, a high heralding efficiency.« less

Optimization of operating parameters for gas-phase photocatalytic splitting of H2S by novel vermiculate packed tubular reactor.

PubMed

Preethi, V; Kanmani, S

2016-10-01

Hydrogen production by gas-phase photocatalytic splitting of Hydrogen Sulphide (H2S) was investigated on four semiconductor photocatalysts including CuGa1.6Fe0.4O2, ZnFe2O3, (CdS + ZnS)/Fe2O3 and Ce/TiO2. The CdS and ZnS coated core shell particles (CdS + ZnS)/Fe2O3 shows the highest rate of hydrogen (H2) production under optimized conditions. Packed bed tubular reactor was used to study the performance of prepared photocatalysts. Selection of the best packing material is a key for maximum removal efficiency. Cheap, lightweight and easily adsorbing vermiculate materials were used as a novel packing material and were found to be effective in splitting H2S. Effect of various operating parameters like flow rate, sulphide concentration, catalyst dosage, light irradiation were tested and optimized for maximum H2 conversion of 92% from industrial waste H2S. Copyright © 2016 Elsevier Ltd. All rights reserved.

Medium Bandgap Conjugated Polymer for High Performance Polymer Solar Cells Exceeding 9% Power Conversion Efficiency.

PubMed

Jung, Jae Woong; Liu, Feng; Russell, Thomas P; Jo, Won Ho

2015-12-02

Two medium-bandgap polymers composed of benzo[1,2-b:4,5-b']dithiohpene and 2,1,3-benzothiadiazole with 6-octyl-thieno[3,2-b]thiophene as a π-bridge unit are synthesized and their photovoltaic properties are analyzed. The two polymers have deep highest occupied molecular orbital energy levels, high crystallinity, optimal bulk-heterojunction morphology, and efficient charge transport, resulting in a power conversion efficiency of as high as 9.44% for a single-junction polymer solar-cell device. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Boundary layer measurements of the OH radical in the vicinity of an isolated power plant plume - SO2 and NO2 chemical conversion times

NASA Technical Reports Server (NTRS)

Davis, D. D.; Philen, D.; Mcgee, T.; Heaps, W.

1979-01-01

Direct measurements of the OH radical in the vicinity of an isolated power plant plume are reported. These measurements were used to estimate the conversion time of SO2 to H2SO4-sulfate aerosol via the initiating step OH + SO2 + M yields HSO3. Using the near-high-noon measured value of OH (9.5 million per cu cm), resulted in a 1/e conversion time of 1.4 days. The latter lifetime would correspond to a conversion rate of about 2%/hr. When the lifetime calculation was modified to take into consideration the OH diurnal cycle, the 1/e conversion time for SO2 was found to be 4.4 days, giving an apparent overall rate of conversion of about 0.7%/hr. Similar calculations carried out for the conversion of NO2 to NHO3 resulted in 1/e lifetimes for NO2 of 2-3 h for midday time periods.

High-rate two-phase process for the anaerobic degradation of cellulose, employing rumen microorganisms for an efficient acidogenesis

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

Gijzen, H.J.; Zwart, K.B.; Verhagen, F.J.M.

1988-04-05

A novel two-stage anaerobic process for the microbial conversion of cellulose into biogas has been developed. In the first phase, a mixed population of rumen bacteria and ciliates was used in the hydrolysis and fermentation of cellulose. The volatile fatty acids (VFA) produced in this acidogenic reactor were subsequently converted into biogas in a UASB-type methanogenic reactor. A stepwise increase of the loading rate from 11.9 to 25.8 g volatile solids/L reactor volume/day (g VS/L/day) did not affect the degradation efficiency in the acidogenic reactor, whereas the methanogenic reactor appeared to be overloaded at the highest loading rate. Cellulose digestionmore » was almost complete at all loading rates applied. The two-stage anaerobic process was also tested with a closed fluid circuit. In this instance total methane production was 0.438 L CH/sub 4//g VS added, which is equivalent to 98% of the theoretical value. The application of rumen microorganisms in combination with a high-rate methane reactor is proposed as a means of efficient anaerobic degradation of cellulosic residues to methane. Because this newly developed two-phase system is based on processes and microorganisms from the ruminant, it will be referred to as Rumen Derived Anaerobic Digestion (RUDAD)-process.« less

24 CFR 972.124 - Standards for identifying public housing developments subject to required conversion.

Code of Federal Regulations, 2010 CFR

2010-04-01

... March 16, 2009, the specified vacancy rate is 15 percent. For a conversion analysis performed after that... housing developments subject to required conversion. 972.124 Section 972.124 Housing and Urban Development... INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT CONVERSION OF PUBLIC HOUSING TO TENANT-BASED...

Brief Report: A Scale for Rating Conversational Impairment in Autism Spectrum Disorder

ERIC Educational Resources Information Center

de Villiers, Jessica; Fine, Jonathan; Ginsberg, Gary; Vaccarella, Liezanne; Szatmari, Peter

2007-01-01

There are few well-standardized measures of conversational breakdown in Autism Spectrum Disorders (ASD). The study's objective was to develop a scale for measuring pragmatic impairments in conversations of individuals with ASD. We analyzed 46 semi-structured conversations of children and adolescents with high-functioning ASD using a functional…

Selling the story: narratives and charisma in adults with TBI.

PubMed

Jones, Corinne A; Turkstra, Lyn S

2011-01-01

To examine storytelling performance behaviours in adults with traumatic brain injury (TBI) and relate these behaviours to perceived charisma and desirability as a conversation partner. Seven adult males with traumatic brain injury (TBI) told their accident narratives to a male confederate. Ten male undergraduate students rated 1-minute video clips from the beginning of each narrative using the Charismatic Leadership Communication Scale (CLCS). Raters also indicated whether or not they would like to engage in conversation with each participant. Of the performative behaviours analysed, gestures alone significantly influenced CLCS ratings and reported likelihood of engaging in future conversation with the participant. Post-hoc analysis revealed that speech rate was significantly correlated with all of the preceding measures. There was a significant correlation between self- and other-ratings of charisma. The findings suggest that aspects of non-verbal performance, namely gesture use and speech rate, influence how charismatic an individual is perceived to be and how likely someone is to engage in conversation with that person. Variability in these performance behaviours may contribute to the variation in social outcomes seen in the TBI population.

Effect of gamma irradiation on the conversion of ginsenoside Rb1 to Rg3

NASA Astrophysics Data System (ADS)

Kim, Jae-Hun; Kwon, Sun-Kyu; Sung, Nak-Yun; Jung, Pil-Mun; Choi, Jong-il; Kim, Jae-Kyung; Sharma, Arun K.; Lee, Ju-Woon

2012-08-01

Ginsenosides, the most important secondary metabolites in ginseng, have various biological activities. Many studies have focused on the conversion of one of the major ginsenosides, Rb1, to the more active minor ginsenoside, Rg3. This study was carried out to investigate the effect of gamma irradiation on the conversion of Rb1 to Rg3. Rb1 solutions were gamma-irradiated at doses of 10 and 30 kGy and analyzed by high performance liquid chromatography (HPLC). HPLC chromatograms showed a decreased content of Rb1 with increasing irradiation dose, but the content of Rg3 was increased. The highest content of Rg3 was present in the 30 kGy-irradiated Rb1 sample. The cytotoxic effects tested in cancer cell lines were increased in the gamma-irradiated group. Therefore, these results suggest that gamma irradiation can be an effective method for the conversion of the ginsenoside Rb1 to Rg3.

Implications of land-use change on forest carbon stocks in the eastern United States

NASA Astrophysics Data System (ADS)

Puhlick, Joshua; Woodall, Christopher; Weiskittel, Aaron

2017-02-01

Given the substantial role that forests play in removing CO2 from the atmosphere, there has been a growing need to evaluate the carbon (C) implications of various forest management and land-use decisions. Although assessment of land-use change is central to national-level greenhouse gas monitoring guidelines, it is rarely incorporated into forest stand-level evaluations of C dynamics and trajectories. To better inform the assessment of forest stand C dynamics in the context of potential land-use change, we used a region-wide repeated forest inventory (n = 71 444 plots) across the eastern United States to assess forest land-use conversion and associated changes in forest C stocks. Specifically, the probability of forest area reduction between 2002-2006 and 2007-2012 on these plots was related to key driving factors such as proportion of the landscape in forest land use, distance to roads, and initial forest C. Additional factors influencing the actual reduction in forest area were then used to assess the risk of forest land-use conversion to agriculture, settlement, and water. Plots in forests along the Great Plains had the highest periodic (approximately 5 years) probability of land-use change (0.160 ± 0.075; mean ± SD) with forest conversion to agricultural uses accounting for 70.5% of the observed land-use change. Aboveground forest C stock change for plots with a reduction in forest area was -4.2 ± 17.7 Mg ha-1 (mean ± SD). The finding that poorly stocked stands and/or those with small diameter trees had the highest probability of conversion to non-forest land uses suggests that forest management strategies can maintain the US terrestrial C sink not only in terms of increased net forest growth but also retention of forest area to avoid conversion. This study highlights the importance of considering land-use change in planning and policy decisions that seek to maintain or enhance regional C sinks.

Biomass and Nitrogen Budgets During Larval Development of Lymantria dispar and Choristoneura fumiferana: Allometric Relationships

Treesearch

Michael E. Montgomery

1983-01-01

Spruce budworm larvae grew faster than gypsy moth larvae both in a temporal and relative sense. The budworm larvae had a higher relative growth rate (RGR), biomass conversion efficiency (EGI), and nitrogen utilization efficiency (NOE) than the gypsy moth larvae. As both species matured, relative growth rates, rates of consumption, and conversion efficiencies declined....

Gasification of empty fruit bunch with carbon dioxide in an entrained flow gasifier for syngas production

NASA Astrophysics Data System (ADS)

Rahmat, N. F. H.; Rasid, R. A.

2017-06-01

The main objectives of this work are to study the gasification of EFB in an atmospheric entrained flow gasifier, using carbon dioxide (CO2) as its gasifying agent and to determine the optimum gasification operating conditions, which includes temperature and the oxidant to fuel (OTF) ratio. These were evaluated in terms of important gasification parameters such as the concentration of hydrogen (H2) and carbon monoxide (CO) produced the syngas ratio H2/CO and carbon conversion. The gasification reactions take place in the presence of CO2 at very high reaction rate because of the high operating temperature (700°C - 900°C). The use of CO2 as the oxidant for gasification process can improve the composition of syngas produced as in the Boudouard reaction. Rise of reaction temperature which is 900°C will increase the concentration of both H2 & CO by up to 81 and 30 respectively, though their production were decreased after the OTF ratio of 0.6 for temperature 700°C & 800°C and OTF ratio 0.8 for temperature 750°C. The operating temperature must be higher than 850°C to ensure the Boudouard reaction become the more prominent reaction for the biomass gasification. The syngas ratio obtained was in the range of ≈ 0.6 - 2.4 which is sufficient for liquid fuel synthesis. For the carbon conversion, the highest fuel conversion recorded at temperature 850°C for all OTF ratios. As the OTF ratio increases, it was found that there was an increase in the formation of CO and H2. This suggests that to achieve higher carbon conversion, high operating temperature and OTF ratio are preferable. This study provides information on the optimum operating conditions for the gasification of biomass, especially the EFB, hence may upsurge the utilization of biomass waste as an energy source.

Predictors of delayed culture conversion among Ugandan patients.

PubMed

Atwine, Daniel; Orikiriza, Patrick; Taremwa, Ivan; Ayebare, Arnold; Logoose, Suzan; Mwanga-Amumpaire, Juliet; Jindani, Amina; Bonnet, Maryline

2017-04-24

Estimates of month-2 culture conversion, a proxy indicator of tuberculosis (TB) treatment efficacy in phase-2 trials can vary by culture-type and geographically with lower rates reported among African sites. The sub-study aimed at comparing TB detection rates of different culture media, within and across rifampicin-based regimens (R10, 15 and 20 mg/Kg) over a 6-month treatment follow-up period, and to establish predictors of month-2 culture non-conversion among HIV-negative TB patients enrolled at RIFATOX trial site in Uganda. Unlike in other Rifatox Trial sites, it is only in Uganda were Lowenstein-Jensen (LJ) and Mycobacteria growth indicator tube (MGIT) were used throughout 6-months for treatment monitoring. Conversion rates were compared at month-2, 4 and 6 across cultures and treatment-type. Binomial regression analysis performed for predictors of month-2 non-conversion. Of the 100 enrolled patients, 45% had converted based on combined LJ and MGIT by month-2, with no significant differences across treatment arms, p = 0.721. LJ exhibited higher conversion rates than MGIT at month-2 (58.4% vs 56.0%, p = 0.0707) and month-4 (98.9% vs 88.4%, p = 0.0391) respectively, more so within the high-dose rifampicin arms. All patients had converted by month-6. Time-to-TB detection (TTD) on MGIT and social service jobs independently predict month-2 non-conversion. The month-2 culture conversion used in phase 2 clinical trials as surrogate marker of treatment efficacy is influenced by the culture method used for monitoring mycobacterial response to TB treatment. Therefore, multi-centric TB therapeutic trials using early efficacy endpoint should use the same culture method across sites. The Time-to-detection of MTB on MGIT prior to treatment and working in Social service jobs bear an increased risk of culture non-conversion at month-2. ISRCTN ISRCTN55670677 . Registered 09th November 2010. Retrospectively registered.

Investigation of operating parameters on CO2 splitting by dielectric barrier discharge plasma

NASA Astrophysics Data System (ADS)

Pan, CHEN; Jun, SHEN; Tangchun, RAN; Tao, YANG; Yongxiang, YIN

2017-12-01

Experiments of CO2 splitting by dielectric barrier discharge (DBD) plasma were carried out, and the influence of CO2 flow rate, plasma power, discharge voltage, discharge frequency on CO2 conversion and process energy efficiency were investigated. It was shown that the absolute quantity of CO2 decomposed was only proportional to the amount of conductive electrons across the discharge gap, and the electron amount was proportional to the discharge power; the energy efficiency of CO2 conversion was almost a constant at a lower level, which was limited by CO2 inherent discharge character that determined a constant gap electric field strength. This was the main reason why CO2 conversion rate decreased as the CO2 flow rate increase and process energy efficiency was decreased a little as applied frequency increased. Therefore, one can improve the CO2 conversion by less feed flow rate or larger discharge power in DBD plasma, but the energy efficiency is difficult to improve.

Detailed kinetics of titanium nitride synthesis

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

Rode, H.; Hlavacek, V.

1995-02-01

A thermogravimetric analyzer is used to study the synthesis of TiN from Ti powder over a wide range of temperature, conversion and heating rate, and for two Ti precursor powders with different morphologies. Conversions to TiN up to 99% are obtained with negligible oxygen contamination. Nonisothermal initial rate and isothermal data are used in a nonlinear least-squares minimization to determine the most appropriate rate law. The logarithmic rate law offers an excellent agreement between the experimental and calculated conversions to TiN and can predict afterburning, which is an important experimentally observed phenomenon. Due to the form of the logarithmic ratemore » law, the observed activation energy is a function of effective particle size, extent of conversion, and temperature even when the intrinsic activation energy remains constant. This aspect explains discrepancies among activation energies obtained in previous studies. The frequently used sedimentation particle size is a poor measure of the powder reactivity. The BET surface area indicates the powder reactivity much better.« less

High repetition rate laser induced fluorescence applied to Surfatron Induced Plasmas

NASA Astrophysics Data System (ADS)

van der Mullen, J. J. A. M.; Palomares, J. M.; Carbone, E. A. D.; Graef, W.; Hübner, S.

2012-05-01

The reaction kinetics in the excitation space of Ar and the conversion space of Ar-molecule mixtures are explored using a combination of high rep-rate YAG-Dye laser systems with a well defined and easily controllable Surfatron Induced Plasma set-up. Applying the method of Saturation Time Resolved Laser Induced Fluorescence (SaTiRe-LIF), we could trace excitation and conversion channels and determine rates of electron and heavy particle excitation kinetics. The time resolved density disturbances observed in the Ar excitation space, which are initiated by the laser, reveal the excitation channels and corresponding rates; responses of the molecular radiation in Ar-molecule mixtures corresponds to the presence of conversion processes induced by heavy particle excitation kinetics.

Field trial of differential-phase-shift quantum key distribution using polarization independent frequency up-conversion detectors.

PubMed

Honjo, T; Yamamoto, S; Yamamoto, T; Kamada, H; Nishida, Y; Tadanaga, O; Asobe, M; Inoue, K

2007-11-26

We report a field trial of differential phase shift quantum key distribution (QKD) using polarization independent frequency up-conversion detectors. A frequency up-conversion detector is a promising device for achieving a high key generation rate when combined with a high clock rate QKD system. However, its polarization dependence prevents it from being applied to practical QKD systems. In this paper, we employ a modified polarization diversity configuration to eliminate the polarization dependence. Applying this method, we performed a long-term stability test using a 17.6-km installed fiber. We successfully demonstrated stable operation for 6 hours and achieved a sifted key generation rate of 120 kbps and an average quantum bit error rate of 3.14 %. The sifted key generation rate was not the estimated value but the effective value, which means that the sifted key was continuously generated at a rate of 120 kbps for 6 hours.

Photon up-conversion increases biomass yield in Chlorella vulgaris.

PubMed

Menon, Kavya R; Jose, Steffi; Suraishkumar, Gadi K

2014-12-01

Photon up-conversion, a process whereby lower energy radiations are converted to higher energy levels via the use of appropriate phosphor systems, was employed as a novel strategy for improving microalgal growth and lipid productivity. Photon up-conversion enables the utilization of regions of the solar spectrum, beyond the typical photosynthetically active radiation, that are usually wasted or are damaging to the algae. The effects of up-conversion of red light by two distinct sets of up-conversion phosphors were studied in the model microalgae Chlorella vulgaris. Up-conversion by set 1 phosphors led to a 2.85 fold increase in biomass concentration and a 3.2 fold increase in specific growth rate of the microalgae. While up-conversion by set 2 phosphors resulted in a 30% increase in biomass and 12% increase in specific intracellular neutral lipid, while the specific growth rates were comparable to that of the control. Furthermore, up-conversion resulted in higher levels of specific intracellular reactive oxygen species in C. vulgaris. Up-conversion of red light (654 nm) was shown to improve biomass yields in C. vulgaris. In principle, up-conversion can be used to increase the utilization range of the electromagnetic spectrum for improved cultivation of photosynthetic systems such as plants, algae, and microalgae. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly Efficient Spin-to-Charge Current Conversion in Strained HgTe Surface States Protected by a HgCdTe Layer

NASA Astrophysics Data System (ADS)

Noel, P.; Thomas, C.; Fu, Y.; Vila, L.; Haas, B.; Jouneau, P.-H.; Gambarelli, S.; Meunier, T.; Ballet, P.; Attané, J. P.

2018-04-01

We report the observation of spin-to-charge current conversion in strained mercury telluride at room temperature, using spin pumping experiments. We show that a HgCdTe barrier can be used to protect the HgTe from direct contact with the ferromagnet, leading to very high conversion rates, with inverse Edelstein lengths up to 2.0 ±0.5 nm . The influence of the HgTe layer thickness on the conversion efficiency is found to differ strongly from what is expected in spin Hall effect systems. These measurements, associated with the temperature dependence of the resistivity, suggest that these high conversion rates are due to the spin momentum locking property of HgTe surface states.

CT Evaluation of the progression of hypoattenuating nodular lesions in virus-related chronic liver disease.

PubMed

Takayasu, Kenichi; Muramatsu, Yukio; Mizuguchi, Yasunori; Okusaka, Takuji; Shimada, Kazuaki; Takayama, Tadatoshi; Sakamoto, Michiie

2006-08-01

The purpose of this study was to clarify the natural outcomes of hypoattenuating nodular lesions in patients with virus-related chronic liver disease depicted on dynamic CT. Sixty lesions (mean size, 1.3 cm) exhibiting hypoattenuation or isoattenuation in the arterial and delayed phases of dynamic CT were retrospectively evaluated with additional CT (mean, six examinations) for a mean period of 838 days. The primary end point was emergence of hyperattenuating areas within hypoattenuating lesions, a phenomenon called attenuation conversion. Cumulative attenuation conversion rates suggesting rates of malignant transformation were calculated with the Kaplan-Meier method, and factors affecting attenuation conversion rate were analyzed with the Cox proportional hazard model. Thirty-six (60%) of 60 hypoattenuating lesions developed to hyperattenuating lesions, 21 were unchanged, and three disappeared spontaneously. The 36 lesions that became hyperattenuating were divided into two subgroups according to lesion enhancement pattern: hyper-in-hypoattenuating (n = 25) and entirely hyperattenuating (n = 11). The cumulative attenuation conversion rates for the 60 hypoattenuating lesions were 15.8%, 44.3%, and 58.7% at 1, 2, and 3 years. The hyper-in-hypoattenuating lesions showed more rapid progression to entirely enhanced lesions. Positive results for hepatitis C viral antibody (p = 0.028) and initial lesion size (p = 0.007) showed a positive correlation with attenuation conversion rate. Hypoattenuating hepatic nodular lesions in chronic liver disease depicted on dynamic CT have high malignant potential and should be followed with special attention to conversion from hypoattenuation to hyperattenuation to determine the optimal timing of treatment.

Estimation of the Adenoma Detection Rate From the Polyp Detection Rate by Using a Conversion Factor in a Predominantly Hispanic Population.

PubMed

Elhanafi, Sherif; Ortiz, Arleen M; Yarlagadda, Anita; Tsai, Cindy; Eloliby, Mohamed; Mallawaarachchi, Indika; Dwivedi, Alok; Zuckerman, Marc J; Othman, Mohamed O

2015-08-01

Calculating the adenoma detection rate (ADR) is a complex process in contrast to the polyp detection rate (PDR) that can be easily calculated. The average adenoma to polyp detection rate quotient (APDRQ) was proposed as a conversion factor to estimate the ADR for individual endoscopists from the endoscopist's PDR. However, this conversion factor was not validated in different practice settings. To validate the use of the proposed conversion factor in a practice setting with a predominantly Hispanic population. We conducted a retrospective, cross-sectional study (December 2007 to November 2012) of screening colonoscopies at a university practice setting with an 86.9% Hispanic population. The actual ADR and PDR were calculated for all endoscopists. The weighted average of ADR to PDR ratio for each endoscopist was used to obtain APDRQ. The APDRQ was used as a conversion multiplier to estimate each endoscopist's ADR using the single endoscopist's PDR. A total of 2148 screening colonoscopies were included. The average PDR for the whole group was 36.9% (range, 11% to 49%). The actual ADR was estimated as 25.5% (range, 11% to 37%). The average APDRQ for our group was 0.68. The estimated ADR was 25.48% (range, 8% to 33%). There was a high correlation between actual ADR and the estimated ADR (Pearson correlation=0.92). In a practice setting with a predominantly Hispanic population, a conversion factor can be used to estimate ADR from PDR providing a high degree of correlation with the actual ADR.

Risk factors associated with conversion of laparoscopic simple closure in perforated duodenal ulcer.

PubMed

Kim, Ji-Hyun; Chin, Hyung-Min; Bae, You-Jin; Jun, Kyong-Hwa

2015-03-01

Precise patient selection criteria are necessary to guide the surgeon in selecting laparoscopic repair for patients with perforated peptic ulcers. The aims of this study are to report surgical outcomes after surgery for perforated duodenal ulcers and identify risk factors for predicting failure of laparoscopic simple closure for perforated duodenal ulcer. In total, 77 patients who underwent laparoscopic simple closure for perforated duodenal ulcers from January 2007 to September 2013 were retrospectively analyzed. Patients were divided into totally laparoscopic and conversion groups. The characteristics of patients, intraoperative findings, postoperative complications, conversion rates and suture leakage rates of each group were investigated. Laparoscopic repair was completed in 69 (89.6%) of 77 patients, while 8 (10.4%) underwent conversion to open repair. Patients in the conversion group had longer perforation time, larger perforation size, more suture leakage, longer hospital stay, and higher 30-day mortality rate than those in the totally laparoscopic group. The size of perforation was the only risk factor for conversion in multivariable analysis. Patients with an ulcer perforation size of ≥9 mm or with perforation duration of ≥12.5 h had a significantly increased risk for conversion and suture leakage. Ulcer size of ≥9 mm is a significant risk factor for predicting conversion in laparoscopic simple closure. Suture leakage is associated with ulcer size (9 mm) and duration of perforation (12.5 h). Copyright © 2015 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

A cure-rate model for the Shuttle filament-wound case

NASA Technical Reports Server (NTRS)

Cagliostro, D. E.; Islas, A.; Hsu, Ming-Ta

1987-01-01

An epoxy and carbon fiber composite has been used to produce a light-weight rocket case for the Space Shuttle. A kinetic model is developed which can predict the extent of epoxy conversion during the winding and curing of the case. The model accounts for both chemical and physical kinetics. In the model, chemical kinetics occur exclusively up to the time the transition temperature equals the reaction temperature. At this point the resin begins to solidify and the rate of this process limits the rate of epoxy conversion. A comparison of predicted and actual epoxy conversion is presented for isothermal and temperature programmed cure schedules.

Conversion to dementia in mild cognitive impairment diagnosed with DSM-5 criteria and with Petersen's criteria.

PubMed

Marcos, G; Santabárbara, J; Lopez-Anton, R; De-la-Cámara, C; Gracia-García, P; Lobo, E; Pírez, G; Menchón, J M; Palomo, T; Stephan, B C M; Brayne, C; Lobo, A

2016-05-01

In a background of revision of criteria for states of increased risk for progression to dementia, we compare the conversion rate to dementia and Alzheimer's disease (AD) of mild cognitive impairment (MCI) as diagnosed using DSM-5 (DSM-5-MCI) and Petersen's (P-MCI) criteria. A population representative cohort of 4057 dementia-free individuals 55+ years of age was followed up at 2.5 and 4.5 years in Zaragoza, Spain (ZARADEMP). Using the Geriatric Mental State- AGECAT for assessment, research psychiatrists diagnosed DSM-5-MCI and P-MCI following operationalized criteria. 'Conversion rate' (CR), 'annual conversion rate' (ACR), and incidence rate (IR) were calculated along with incidence rate ratio (IRR) to compare the performance of the intermediate cognitive definitions. At 4.5-year follow-up, in individuals aged 65+ years, ACRs for non-cases, P-MCI, and DSM-5-MCI were 0.8, 1.9 and 3.4, respectively, for global dementia. The IRRs were 2.9 and 5.3 for P-MCI and DSM5-MCI, respectively, being the non-cases the reference category. The corresponding values were slightly lower for AD. Conversion rate to dementia and AD was higher using DSM-5-MCI criteria than using Petersen's criteria. However, prediction of the construct still has some way to go, as most MCI individuals did not convert at 4.5-year follow-up. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes, structural characterization and catalytic activity on esterification reaction.

PubMed

Gönül, İlyas; Ay, Burak; Karaca, Serkan; Saribiyik, Oguz Yunus; Yildiz, Emel; Serin, Selahattin

2017-01-01

In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L)Cl 2 ]·2H 2 O (1) , [Co(L)Cl 2 (H 2 O) 2 ] (2) and [Ni(L)Cl 2 (H 2 O) 2 ] (3) , having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1 . The esterification of butanol gave butyl acetate with 100% selectivity.

Stable, high power, high efficiency picosecond ultraviolet generation at 355 nm in K3B6O10 Br crystal

NASA Astrophysics Data System (ADS)

Hou, Z. Y.; Wang, L. R.; Xia, M. J.; Yan, D. X.; Zhang, Q. L.; Zhang, L.; Liu, L. J.; Xu, D. G.; Zhang, D. X.; Wang, X. Y.; Li, R. K.; Chen, C. T.

2018-06-01

We demonstrate a high efficiency and high power picosecond ultraviolet source at 355 nm with stable output by sum frequency generation from a Nd:YAG laser using a type-I critically phase matched K3B6O10 Br crystal as nonlinear optical material. Conversion efficiency as high as 30.8% was achieved using a 25 ps laser at 1064 nm operated at 10 Hz. Similar work is done by using a 35 W 10 ps laser at 1064 nm as the pump source with a repetition rate of 80 MHz, and the highest average output power obtained was up to 5.3 W. In addition, the power stability of the 355 nm output power measurement shows that the standard deviation fluctuations of the average power are ±0.69% and ±0.91% at 3.0 W and 3.5 W, respectively.

Bioconversion of AHX to AOH by resting cells of Burkholderia contaminans CH-1.

PubMed

Choi, Jae-Hoon; Kikuchi, Ayaka; Pumkaeo, Panyapon; Hirai, Hirofumi; Tokuyama, Shinji; Kawagishi, Hirokazu

2016-10-01

Fairy rings are zones of stimulated grass growth owing to the interaction between a fungus and a plant. We previously reported the discovery of two novel plant-growth regulating compounds related to forming fairy rings, 2-azahypoxanthine (AHX) and 2-aza-8-oxohypoxanthine (AOH). In this study, a bacterial strain CH-1 was isolated from an airborne-contaminated nutrient medium containing AHX. The strain converted AHX to AOH and identified as Burkholderia contaminans based on the gene sequence of its 16S rDNA. The quantitative production of AOH by resting cells of the strain was achieved. Among seven Burkholderia species, two bacteria and two yeasts tested, B. contaminans CH-1 showed the highest rate of conversion of AHX to AOH. By batch system, up to 10.6 mmol AHX was converted to AOH using the resting cells. The yield of this process reached at 91%.

Biological production of acetic acid from waste gases with Clostridium ljungdahlii

DOEpatents

Gaddy, J.L.

1998-09-15

A method and apparatus are disclosed for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration. 5 figs.

Compact high-efficiency 100-W-level diode-side-pumped Nd:YAG laser with linearly polarized TEM00 mode output.

PubMed

Xu, Yi-Ting; Xu, Jia-Lin; Guo, Ya-Ding; Yang, Feng-Tu; Chen, Yan-Zhong; Xu, Jian; Xie, Shi-Yong; Bo, Yong; Peng, Qin-Jun; Cui, Dafu; Xu, Zu-Yan

2010-08-20

We present a compact high-efficiency and high-average-power diode-side-pumped Nd:YAG rod laser oscillator operated with a linearly polarized fundamental mode. The oscillator resonator is based on an L-shaped convex-convex cavity with an improved module and a dual-rod configuration for birefringence compensation. Under a pump power of 344 W, a linearly polarized average output power of 101.4 W at 1064 nm is obtained, which corresponds to an optical-to-optical conversion efficiency of 29.4%. The laser is operated at a repetition rate of 400 Hz with a beam quality factor of M(2)=1.14. To the best of our knowledge, this is the highest optical-to-optical efficiency for a side-pumped TEM(00) Nd:YAG rod laser oscillator with a 100-W-level output ever reported.

Glycolysis recycling of rigid waste polyurethane foam from refrigerators.

PubMed

Zhu, P; Cao, Z B; Chen, Y; Zhang, X J; Qian, G R; Chu, Y L; Zhou, M

2014-01-01

Rapid growth of rigid waste polyurethane (WPUR) foam from refrigerators attracts the attention all over the world. In this study, glycolysis was chosen to treat WPUR from scrapped refrigerators collected in Shanghai, China. Glycolysis reagents and catalysts were selected. The results indicated that the glycolysis efficiency of ethylene glycol (EG) was higher than that of diethylene glycol, and the catalytic efficiency of alkali metal salts (NaOH) was more excellent than that of triethanolamine and organic salts of alkali metal (NaAc). When EG was 100%WPUR as a glycolysis reagent and NaOH was 1%WPUR as a catalyst at a constant temperature of 197.85°C for 2 h, the glycolysis product had the highest glycolysis conversion rate. In order to maximize the recycling of WPUR, regenerative Polyurethane was performed by adding 10% distilled mixed polyol, which conformed to the QB/T 26689-2011 requirements.

Photosynthesis in chlorolichens: the influence of the habitat light regime.

PubMed

Piccotto, Massimo; Tretiach, Mauro

2010-11-01

The hypothesis that CO(2) gas exchange and chlorophyll a fluorescence (ChlaF) of lichens vary according to the light regimes of their original habitat, as observed in vascular plants, was tested by analysing the photosynthetic performance of 12 populations of seven dorsoventral, foliose lichens collected from open, south-exposed rocks to densely shaded forests. Light response curves were induced at optimum thallus water content and ChlaF emission curves at the species-specific photon flux at which the quantum yield of CO(2) assimilation is the highest and is saturating the photosynthetic process. Photosynthetic pigments were quantified in crude extracts. The results confirm that the maximum rate of gross photosynthesis is correlated with the chlorophyll content of lichens, which is influenced by light as well as by nitrogen availability. Like leaves, shade tolerant lichens emit more ChlaF than sun-loving ones, whereas the photosynthetic quantum conversion is higher in the latter.

Nitrogen availability and soil N2O emissions following conversion of forests to coffee in southern Sumatra

NASA Astrophysics Data System (ADS)

Verchot, Louis V.; Hutabarat, Lusida; Hairiah, Kurniatun; van Noordwijk, Meine

2006-12-01

Changes in land use impact on the N cycle with both local and global consequences. We examined how conversion of forest to agriculture in one catchment in southern Sumatra altered N availability and soil N2O emission. Measurements were made along a chronosequence of forest land converted to coffee gardens. A number of different management practices were also examined. Inorganic N stocks and N cycling rates were highest in the forest and lower in the coffee gardens. The forest and young conversion sites appeared to be N limited, whereas the older agricultural sites and the more intensively managed sites were not as strongly N limited. N2O emissions were low in the forest (<2 kgN ha-1yr-1) and increased sharply following deforestation. Emissions on recently cleared land were 4.6 kgN ha-1yr-1 and 8.4 kgN ha-1yr-1 in a 1-year-old coffee garden. Emissions in the older coffee gardens were lower with the lowest flux observed in a 10 year old site (1.8 kgN ha-1yr-1). We explored the effects of different types of management approaches that farmers are using in this landscape. Emissions in an 18-year-old multistrata coffee garden with a significant overstory of N fixing trees were 5 times greater (15.5 kg ha-1yr-1) than emissions from forests. We also found that intensive organic matter management produced high emissions. To understand the spatial and temporal variability of the N2O emissions we used the hole-in-the-pipe conceptual model. N2O fluxes were lowest on N limited sites. Soil water content also played an important role and emissions were highest when water filled pore space (WFPS) was between 85 and 95%. A number of formulations of this model have been applied in different ways over the years to explain spatial and temporal variation in the soil N-oxide flux, and in this study we found the mechanistic explanation useful. Our study suggests that land use change and intensification of agriculture in N limited highland landscapes may significantly increase the biosphere to atmosphere flux of N gases.

Joint DoD versus Navy Specific Lead Generation Advertising: Comparison of Conversion Rates to Quality Enlistments and Marginal Costs.

DTIC Science & Technology

1984-09-01

7D-Rt46 982 JOINT DOD VERSUS NAVY SPECIFIC LEAD GENERATION j/j ADVERTISING : COMPARISON OF..(U) J B FUGUR SCHOOL OF N BUSINESS DURHAM NC R C MOREY...REPORT I PEPIO0 COV9cO JOINT DOD VERSUS NAVY SPECIFIC LEAD GENERATION Technical Report ADVERTISING : Comparison of Conversion Rates to (0 Quality...block number) . Upper-Mental, High School Degree, enlistment contracts, national leads, Z Joint DOD advertising , Service Specific Advertising , conversion

Reduction and conversion of 2,4,6-trinitrotoluene (TNT) by sulfide under simulated anaerobic conditions.

PubMed

Qiao, Hua; Wang, He-ling; Feng, Hua-jun; Yao, Jun; Shen, Dong-sheng; Tang, Zhi-jian

2010-07-15

To account for the fast disappearance of TNT in anaerobic fermentative liquid, we investigated TNT (TNT(0)=50 mg/L) reduction by Na(2)S at 30+/-1 degrees C in two types of buffer systems, a phosphate buffer (PB, system A) and a CH(3)COOH-NaHCO(3) buffer (system B). The effects of pH, sulfide concentration and buffer system on the conversion and reaction rate of TNT were investigated. The effect of different variables on the conversion of TNT decreased in the following order: Na(2)S concentration>pH>buffer system. A kinetics study showed that TNT reduction by Na(2)S occurred in two stages separated by a change point. The observed rate constants of the first stage K(obs-1) were 1 order of magnitude lower than those of the second stage. The TNT conversion rate increased and the time to reach the change point became shorter with increasing Na(2)S concentration and pH. A 5-fold increase in Na(2)S concentration above the theoretical stoichiometric concentration was optimum. Observed rate constants of the first stage K(obs-1) were proportional to the hydrosulfide ion concentration and the conversion rate of TNT was greater and faster in buffer system B than in system A. 2010 Elsevier B.V. All rights reserved.

Hydrogenolysis of Glycerol to Propylene Glycol on Nanosized Cu-Zn-Al Catalysts Prepared Using Microwave Process.

PubMed

Kim, Dong Won; Ha, Sang Ho; Moon, Myung Jun; Lim, Kwon Taek; Ryu, Young Bok; Lee, Sun Do; Lee, Man Sig; Hong, Seong-Soo

2015-01-01

Cu-Zn-Al catalysts were prepared using microwave-assisted process and co-precipitation methods. The prepared catalysts were characterized by XRD, BET, XPS and TPD of ammonia and their catalytic activity for the hydrogenolysis of glycerol to propylene glycol was also examined. The XRD patterns of Cu/Zn/Al mixed catalysts show CuO and ZnO crystalline phase regardless of preparation method. The highest glycerol hydrogenolysis conversion is obtained with the catalyst having a Cu/Zn/Al ratio of 2:2:1. Hydrogen pre-reduction of catalysts significantly enhanced both glycerol conversions and selectivity to propylene glycol. The glycerol conversion increased with an increase of reaction temperature. However, the selectivity to propylene glycol increased with an increase of temperature, and then declined to 30.5% at 523 K.

DOSE COEFFICIENTS FOR LIVER CHEMOEMBOLISATION PROCEDURES USING MONTE CARLO CODE.

PubMed

Karavasilis, E; Dimitriadis, A; Gonis, H; Pappas, P; Georgiou, E; Yakoumakis, E

2016-12-01

The aim of the present study is the estimation of radiation burden during liver chemoembolisation procedures. Organ dose and effective dose conversion factors, normalised to dose-area product (DAP), were estimated for chemoembolisation procedures using a Monte Carlo transport code in conjunction with an adult mathematical phantom. Exposure data from 32 patients were used to determine the exposure projections for the simulations. Equivalent organ (H T ) and effective (E) doses were estimated using individual DAP values. The organs receiving the highest amount of doses during these exams were lumbar spine, liver and kidneys. The mean effective dose conversion factor was 1.4 Sv Gy -1 m -2 Dose conversion factors can be useful for patient-specific radiation burden during chemoembolisation procedures. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The effect of clay catalyst on the chemical composition of bio-oil obtained by co-pyrolysis of cellulose and polyethylene.

PubMed

Solak, Agnieszka; Rutkowski, Piotr

2014-02-01

Cellulose/polyethylene (CPE) mixture 3:1, w/w with and without three clay catalysts (K10 - montmorillonite K10, KSF - montmorillonite KSF, B - Bentonite) addition were subjected to pyrolysis at temperatures 400, 450 and 500°C with heating rate of 100°C/s to produce bio-oil with high yield. The pyrolytic oil yield was in the range of 41.3-79.5 wt% depending on the temperature, the type and the amount of catalyst. The non-catalytic fast pyrolysis at 500°C gives the highest yield of bio-oil (79.5 wt%). The higher temperature of catalytic pyrolysis of cellulose/polyethylene mixture the higher yield of bio-oil is. Contrarily, increasing amount of montmorillonite results in significant, almost linear decrease in bio-oil yield followed by a significant increase of gas yield. The addition of clay catalysts to CPE mixture has a various influence on the distribution of bio-oil components. The addition of montmorillonite K10 to cellulose/polyethylene mixture promotes the deepest conversion of polyethylene and cellulose. Additionally, more saturated than unsaturated hydrocarbons are present in resultant bio-oils. The proportion of liquid hydrocarbons is the highest when a montmorillonite K10 is acting as a catalyst. Copyright © 2013 Elsevier Ltd. All rights reserved.

Weighing up the benefits and harms of a new anti-cancer drug: a survey of Australian oncologists.

PubMed

Chim, L; Salkeld, G; Stockler, M R; Mileshkin, L

2015-08-01

Little is known about the relative importance that oncologists attribute to the benefits and harms of anti-cancer drugs when considering treatment options with their patients. To quantify the trade-offs made between overall survival, progression-free survival and adverse effects. A web-based survey elicited importance weights for the benefits and harms of bevacizumab or everolimus. Combining the importance weights with trial-based probabilities produced a score and ranking for each treatment option. A total of 40 responses was received for the bevacizumab scenario and 32 for the everolimus scenario. All respondents regarded overall survival and progression-free survival as the most important attributes - more important than avoiding the potential harms regardless of drugs. Among the potential harms, respondents allocated the highest mean importance weight to gastrointestinal (GI) perforation and rated absolute improvement in overall survival as 1.6 times and 2.3 times as important as avoiding GI perforation in the two versions of the bevacizumab scenario respectively. For the everolimus scenario, stomatitis and pneumonitis were allocated the highest mean importance weights with absolute improvement in overall survival rated as 2.2 times as important as avoiding stomatitis/pneumonitis. All 40 respondents (100%) favoured treatment option with bevacizumab to no bevacizumab based on respondents' determined weights for treatment attributes. The converse was found for everolimus with 22 (69%) of respondents preferring the 'no everolimus' option. Oncologists' preferences over the benefits and harms of treatment do, when combined with evidence of effect, influence treatment decisions for anti-cancer drugs. © 2015 Royal Australasian College of Physicians.

Exploring the limits of crop productivity. I. Photosynthetic efficiency of wheat in high irradiance environments

NASA Technical Reports Server (NTRS)

Bugbee, B. G.; Salisbury, F. B.

1988-01-01

The long-term vegetative and reproductive growth rates of a wheat crop (Triticum aestivum L.) were determined in three separate studies (24, 45, and 79 days) in response to a wide range of photosynthetic photon fluxes (PPF, 400-2080 micromoles per square meter per second; 22-150 moles per square meter per day; 16-20 hour photoperiod) in a near-optimum, controlled-environment. The CO2 concentration was elevated to 1200 micromoles per mole, and water and nutrients were supplied by liquid hydroponic culture. An unusually high plant density (2000 plants per square meter) was used to obtain high yields. Crop growth rate and grain yield reached 138 and 60 grams per square meter per day, respectively; both continued to increase up to the highest integrated daily PPF level, which was three times greater than a typical daily flux in the field. The conversion efficiency of photosynthesis (energy in biomass/energy in photosynthetic photons) was over 10% at low PPF but decreased to 7% as PPF increased. Harvest index increased from 41 to 44% as PPF increased. Yield components for primary, secondary, and tertiary culms were analyzed separately. Tillering produced up to 7000 heads per square meter at the highest PPF level. Primary and secondary culms were 10% more efficient (higher harvest index) than tertiary culms; hence cultural, environmental, or genetic changes that increase the percentage of primary and secondary culms might increase harvest index and thus grain yield. Wheat is physiologically and genetically capable of much higher productivity and photosynthetic efficiency than has been recorded in a field environment.

A set of observational measures for rating support and participation in conversation between adults with aphasia and their conversation partners.

PubMed

Kagan, Aura; Winckel, Joanne; Black, Sandra; Duchan, Judith Felson; Simmons-Mackie, Nina; Square, Paula

2004-01-01

Conversation partners of individuals with aphasia, including health care professionals, families, and others, play a role that is as important for communication as the language disorder suffered by individuals with aphasia. Two complementary measures designed to capture elements of conversation between adults with aphasia and their speaking conversation partners have been developed. The first measure provides an index of the conversation partner's skill in providing conversational support. The second provides an index of the level of participation in conversation by the person with aphasia. This article describes the development of the measures, including preliminary psychometric data, and discusses applications.

Feeding rates affect growth, intestinal digestive and absorptive capabilities and endocrine functions of juvenile blunt snout bream Megalobrama amblycephala.

PubMed

Xu, Chao; Li, Xiang-Fei; Tian, Hong-Yan; Jiang, Guang-Zhen; Liu, Wen-Bin

2016-04-01

This study aimed to investigate the optimal feeding rate for juvenile blunt snout bream (average initial weight 23.74 ± 0.09 g) based on the results on growth performance, intestinal digestive and absorptive capabilities and endocrine functions. A total of 840 fish were randomly distributed into 24 cages and fed a commercial feed at six feeding rates ranging from 2.0 to 7.0% body weight (BW)/day. The results indicated that weight gain rate increased significantly (P < 0.05) as feeding rates increased from 2.0 to 5.0% BW/day, but decreased with the further increasing feeding rates (P > 0.05). Protein efficiency ratio and nitrogen and energy retention all showed a similar trend. However, feed conversion ratio increased significantly (P < 0.05) with increasing feeding rates. Feeding rates have little effects (P > 0.05) on whole-body moisture, ash and protein contents, but significantly (P < 0.05) affect both lipid and energy contents with the highest values both observed in fish fed 4.0% BW/day. In addition, moderate ration sizes (2.0-4.0% BW/day) resulted in the enhanced activities of intestinal enzymes, including lipase, protease, Na(+), K(+)-ATPase, alkaline phosphatase and creatine kinase. Furthermore, the mRNA levels of growth hormone, insulin-like growth factors-I, growth hormone receptor and neuropeptide all increased significantly (P < 0.05) as feeding rates increased from 2.0 to 5.0% and 6.0% BW/day, but decreased significantly (P < 0.05) with the further increase in feeding rates, whereas both leptin and cholecystokinin expressions showed an opposite trend. Based on the broken-line regression analysis of SGR against feeding rates, the optimal feeding rate for juvenile blunt snout bream was estimated to be 4.57% BW/day.

Long-Term Climate Implications of Persistent Loss of Tropical Peat Carbon Following Land Use Conversion

NASA Astrophysics Data System (ADS)

Frolking, S. E.; Dommain, R.; Glaser, P. H.; Joos, F.; Jeltsch-Thommes, A.

2016-12-01

The climate mitigation potential of tropical peatlands has gained increased attention as Southeast Asian tropical peat swamp forests are being deforested, drained and burned at very high rates, causing globally significant carbon dioxide (CO2) emissions to the atmosphere. We used a simple force-restore model to represent the perturbation to the atmospheric CO2 and CH4 burdens, and net radiative forcing, resulting from long-term conversion of tropical peat swamp forests to oil palm or acacia plantations. Drainage ditches are installed in land-use conversion to both oil palm and acacia, leading to a persistent change in the system greenhouse gas balance with the atmosphere. Drainage causes the net CO2 exchange to switch from a weak sink (removal from the atmosphere) in the accumulating peat of a swamp forest to a relatively strong source as the peat is oxidized. CH4 emissions increase due to relatively high emissions from the ditches themselves. For these systems, persistent CO2 fluxes have a much stronger impact on atmospheric radiative forcing than do the CH4 fluxes. Prior to conversion, slow peat accumulation (net CO2 uptake) over millennia establishes a slowly increasing net radiative cooling perturbation to the atmosphere. Upon conversion, CO2 loss rates are 16-32 times higher than pre-conversion CO2 uptake rates. Rapid loss rates cause the net radiative forcing perturbation to quickly (decades) become a net warming, which can persist for many centuries after the peat has all been oxidized.

Atomic layer-by-layer thermoelectric conversion in topological insulator bismuth/antimony tellurides.

PubMed

Sung, Ji Ho; Heo, Hoseok; Hwang, Inchan; Lim, Myungsoo; Lee, Donghun; Kang, Kibum; Choi, Hee Cheul; Park, Jae-Hoon; Jhi, Seung-Hoon; Jo, Moon-Ho

2014-07-09

Material design for direct heat-to-electricity conversion with substantial efficiency essentially requires cooperative control of electrical and thermal transport. Bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3), displaying the highest thermoelectric power at room temperature, are also known as topological insulators (TIs) whose electronic structures are modified by electronic confinements and strong spin-orbit interaction in a-few-monolayers thickness regime, thus possibly providing another degree of freedom for electron and phonon transport at surfaces. Here, we explore novel thermoelectric conversion in the atomic monolayer steps of a-few-layer topological insulating Bi2Te3 (n-type) and Sb2Te3 (p-type). Specifically, by scanning photoinduced thermoelectric current imaging at the monolayer steps, we show that efficient thermoelectric conversion is accomplished by optothermal motion of hot electrons (Bi2Te3) and holes (Sb2Te3) through 2D subbands and topologically protected surface states in a geometrically deterministic manner. Our discovery suggests that the thermoelectric conversion can be interiorly achieved at the atomic steps of a homogeneous medium by direct exploiting of quantum nature of TIs, thus providing a new design rule for the compact thermoelectric circuitry at the ultimate size limit.

[Selective catalytic reduction of NOx over Pd/CeZr/TiO2/Al2O3 wire-mesh honeycomb catalysts].

PubMed

Sun, Hong; Quan, Xie; Zhang, Yao-bin; Zhao, Ya-zhi

2008-06-01

Pd/CeZr/TiO2/Al2O3 wire-mesh honeycomb catalyst was prepared by sol-gel and impregnation. Furthermore, selective catalytic reduction of NOx over Pd/CeZr/TiO2/Al2O3 wire-mesh honeycomb catalyst with propylene under lean burn condition was studied. The effects of the concentration of tetra-n-butyl titanate and dipcoat cycles on TiO2 washcoat were studied by SEM, and the effects of Pd concentration, O2 concentration and gas velocity on catalytic activity were investigated. The experimental results showed that the TiO2 washcoat on wire-mesh support is even and crack-free when the support is impregnated in 20.0% tetra- n-butyl titanate sol for 2 cycles. The NOx conversion decreases with Pd concentration increase. When Pd concentration is 0.23%, NOx conversion is highest. NOx conversion increases with oxygen concentration increase in the range of 1.5%-6.0%. However, when oxygen concentration is higher than 6.0%, NOx conversion decreases with increasing oxygen concentration. The NOx conversion decreases with gas velocity increase and its effect is severer at high temperature than low temperature.

Conversion of Nuclear Waste to Molten Glass: Cold-Cap Reactions in Crucible Tests

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

Xu, Kai; Hrma, Pavel; Rice, Jarrett A.

2016-05-23

The feed-to-glass conversion, which comprises complex chemical reactions and phase transitions, occurs in the cold-cap zone during nuclear waste vitrification. Knowledge of the chemistry and physics of feed-to-glass conversion will help us control the conversion path by changing the melter feed makeup to maximize the glass production rate. To investigate the conversion process, we analyzed heat-treated samples of a simulated high-level waste feed using X-ray diffraction, electron probe microanalysis – wavelength dispersive X-ray spectroscopy, leaching tests, and residual anion analysis. Feed dehydration, gas evolution, and borate phase formation occurred at temperatures below 700 °C before the emerging glass-forming melt wasmore » completely connected. Above 800 °C, intermediate aluminosilicate phases and quartz particles were gradually dissolving in the continuous borosilicate melt, which expanded into transient foam. Knowledge of the chemistry and physics of feed-to-glass conversion will help us control the conversion path by changing the melter feed makeup to maximize the glass production rate.« less

Vitamin C supplementation improve the sputum conversion culture rate in pulmonary tuberculosis treatment while rifampicin susceptible

NASA Astrophysics Data System (ADS)

Susanto, L.; Siregar, Y.; Kusumawati, L.

2018-03-01

The failure of first-line tuberculosis treatment greatly affects multiple drug-resistant tuberculosis. In vitro study of vitamin C induces the death of M. tuberculosis bacteria and accelerates healing of tuberculosis, so the multiple drug-resistant tuberculosis can be avoided. This research aimed to identify the effect of vitamin C as a supportive treatment on the sputum conversion rate. The randomizedand double group with a parallel design by matching pair method was used to collect samples. The first group was treated with standard tuberculosis treatment, and the other was given vitamin C supplementation. Vitamin C plasma level analyzation was performed before and after two months of treatment. Sputum conversion was evaluated every week for eight weeks. The comparison of vitamin C plasma level in pre and post-treatment group was significant (p=0.03) but not in the other group. There was no significant difference in vitamin C plasma level between two groups (p=0.21). The proportion of sputum conversion rate in both group in the first week was 0% vs. 9.6% (p=0.83) and the last week of study was 83.9% vs. 100% (p=0.02). In conclusion, vitamin C supplementation has effects in improving the healing process of tuberculosis patients as indicated by higher in sputum conversion rate.

Quantitative Validation of the Presto Blue Metabolic Assay for Online Monitoring of Cell Proliferation in a 3D Perfusion Bioreactor System.

PubMed

Sonnaert, Maarten; Papantoniou, Ioannis; Luyten, Frank P; Schrooten, Jan Ir

2015-06-01

As the fields of tissue engineering and regenerative medicine mature toward clinical applications, the need for online monitoring both for quantitative and qualitative use becomes essential. Resazurin-based metabolic assays are frequently applied for determining cytotoxicity and have shown great potential for monitoring 3D bioreactor-facilitated cell culture. However, no quantitative correlation between the metabolic conversion rate of resazurin and cell number has been defined yet. In this work, we determined conversion rates of Presto Blue, a resazurin-based metabolic assay, for human periosteal cells during 2D and 3D static and 3D perfusion cultures. Our results showed that for the evaluated culture systems there is a quantitative correlation between the Presto Blue conversion rate and the cell number during the expansion phase with no influence of the perfusion-related parameters, that is, flow rate and shear stress. The correlation between the cell number and Presto Blue conversion subsequently enabled the definition of operating windows for optimal signal readouts. In conclusion, our data showed that the conversion of the resazurin-based Presto Blue metabolic assay can be used as a quantitative readout for online monitoring of cell proliferation in a 3D perfusion bioreactor system, although a system-specific validation is required.

Quantitative Validation of the Presto Blue™ Metabolic Assay for Online Monitoring of Cell Proliferation in a 3D Perfusion Bioreactor System

PubMed Central

Sonnaert, Maarten; Papantoniou, Ioannis; Luyten, Frank P.

2015-01-01

As the fields of tissue engineering and regenerative medicine mature toward clinical applications, the need for online monitoring both for quantitative and qualitative use becomes essential. Resazurin-based metabolic assays are frequently applied for determining cytotoxicity and have shown great potential for monitoring 3D bioreactor-facilitated cell culture. However, no quantitative correlation between the metabolic conversion rate of resazurin and cell number has been defined yet. In this work, we determined conversion rates of Presto Blue™, a resazurin-based metabolic assay, for human periosteal cells during 2D and 3D static and 3D perfusion cultures. Our results showed that for the evaluated culture systems there is a quantitative correlation between the Presto Blue conversion rate and the cell number during the expansion phase with no influence of the perfusion-related parameters, that is, flow rate and shear stress. The correlation between the cell number and Presto Blue conversion subsequently enabled the definition of operating windows for optimal signal readouts. In conclusion, our data showed that the conversion of the resazurin-based Presto Blue metabolic assay can be used as a quantitative readout for online monitoring of cell proliferation in a 3D perfusion bioreactor system, although a system-specific validation is required. PMID:25336207

Production and reproduction of Fleckvieh, Brown Swiss, and 2 strains of Holstein-Friesian cows in a pasture-based, seasonal-calving dairy system.

PubMed

Piccand, V; Cutullic, E; Meier, S; Schori, F; Kunz, P L; Roche, J R; Thomet, P

2013-08-01

The first objective of this study was to compare the productive and reproductive performance of Holstein-Friesian (CH HF), Fleckvieh (CH FV), and Brown Swiss (CH BS) cows of Swiss origin with New Zealand Holstein-Friesian (NZ HF) cows in pasture-based compact-calving systems; NZ HF cows were chosen as the reference population for such grazing systems. The second objective was to analyze the relationships within and between breeds regarding reproductive performance, milk yield, and body condition score (BCS) dynamics. On 15 commercial Swiss farms, NZ HF cows were paired with Swiss cows over 3 yr. Overall, the study involved 259 complete lactations from 134 cows: 131 from 58 NZ HF, 40 from 24 CH HF, 43 from 27 CH FV, and 45 from 25 CH BS cows. All production parameters were affected by cow breed. Milk and energy-corrected milk yield over 270 d of lactation differed by 1,000 kg between the 2 extreme groups; CH HF having the highest yield and CH BS the lowest. The NZ HF cows had the greatest milk fat and protein concentrations over the lactation and exhibited the highest lactation persistency. Body weight differed by 90 kg between extreme groups; NZ HF and CH BS being the lightest and CH HF and CH FV the heaviest. As a result, the 2 HF strains achieved the highest milk production efficiency (270-d energy-corrected milk/body weight(0.75)). Although less efficient at milk production, CH FV had a high 21-d submission rate (86%) and a high conception rate within 2 inseminations (89%), achieving high pregnancy rates within the first 3 and 6 wk of the breeding period (65 and 81%, respectively). Conversely, poorer reproductive performance was recorded for CH HF cows, with NZ HF and CH BS being intermediate. Both BCS at nadir and at 100 d postpartum had a positive effect on the 6-wk pregnancy rate, even when breed was included in the model. The BCS at 100 d of lactation also positively affected first service conception rate. In conclusion, despite their high milk production efficiency, even in low-input systems, CH HF were not suited to pasture-based seasonal-calving production systems due to poor reproductive performance. On the contrary, CH FV fulfilled the compact-calving reproduction objectives and deserve further consideration in seasonal calving systems, despite their lower milk production potential. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

One-step synthesis of vertically aligned anatase thornbush-like TiO2 nanowire arrays on transparent conducting oxides for solid-state dye-sensitized solar cells.

PubMed

Roh, Dong Kyu; Chi, Won Seok; Ahn, Sung Hoon; Jeon, Harim; Kim, Jong Hak

2013-08-01

Herein, we report a facile synthesis of high-density anatase-phase vertically aligned thornbush-like TiO2 nanowires (TBWs) on transparent conducting oxide glasses. Morphologically controllable TBW arrays of 9 μm in length are generated through a one-step hydrothermal reaction at 200 °C over 11 h using potassium titanium oxide oxalate dehydrate, diethylene glycol (DEG), and water. The TBWs consist of a large number of nanoplates or nanorods, as confirmed by SEM and TEM imaging. The morphologies of TBWs are controllable by adjusting DEG/water ratios. TBW diameters gradually decrease from 600 (TBW600) to 400 (TBW400) to 200 nm (TBW200) and morphologies change from nanoplates to nanorods with an increase in DEG content. TBWs are utilized as photoanodes for quasi-solid-state dye-sensitized solar cells (qssDSSCs) and solid-state DSSCs (ssDSSCs). The energy-conversion efficiency of qssDSSCs is in the order: TBW200 (5.2%)>TBW400 (4.5%)>TBW600 (3.4%). These results can be attributed to the different surface areas, light-scattering effects, and charge transport rates, as confirmed by dye-loading measurements, reflectance spectroscopy, and incident photon-to-electron conversion efficiency and intensity-modulated photovoltage spectroscopy/intensity-modulated photocurrent spectroscopy analyses. TBW200 is further treated with a graft-copolymer-directed organized mesoporous TiO2 to increase the surface area and interconnectivity of TBWs. As a result, the energy-conversion efficiency of the ssDSSC increases to 6.7% at 100 mW cm(-2) , which is among the highest values for N719-dye-based ssDSSCs. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization of technological conditions for one-pot synthesis of (S)-alpha-cyano-3-phenoxybenzyl acetate in organic media.

PubMed

Zhang, Ting-Zhou; Yang, Li-Rong; Zhu, Zi-Qiang

2005-03-01

Optically active form of alpha-cyano-3-phenoxybenzyl (CPB) alcohol, building block of pyrethroid insecticides, was synthesized as its acetate by the combination of anion-exchange resin (D301)-catalyzed transcyanation between m-phenoxybenzaldehyde (m-PBA) and acetone cyanohydrin (AC), and lipase (from Alcaligenes sp.)-catalyzed enantioselective transesterification of the resulting cyanohydrin with vinyl acetate. Through optimizing technological conditions, the catalyzing efficiency was improved considerably compared to methods previously reported. Concentrations of CPB acetate were determined by gas chromatograph. The enantio excess (e.e.) values of CPB acetate were measured by NMR (nuclear magnetic resonance) method. Effects of solvents and temperatures on this reaction were studied. Cyclohexane was shown to be the best solvent among the three tested solvents. 55 degrees C was the optimal temperature for higher degree of conversion. External diffusion limitation was excluded by raising the rotational speed to 220 r/min. However, internal diffusion could not be ignored, since the catalyst (lipase) was an immobilized enzyme and its particle dimension was not made small enough. The reaction rate was substantially accelerated when the reactant (m-PBA) concentration was as high as 249 mmol/L, but decreased when the initial concentration of m-PBA reached to 277 mmol/L. It was also found that the catalyzing capability of recovered lipase was high enough to use several batches. Study of the mole ratio of AC to m-PBA showed that 2:1 was the best choice. The strategy of adding base catalyst D301 was found to be an important factor in improving the degree of conversion of the reaction from 20% to 80%. The highest degree of conversion of the reaction has reached up to 80%.

Phase Engineering of Perovskite Materials for High-Efficiency Solar Cells: Rapid Conversion of CH3NH3PbI3 to Phase-Pure CH3NH3PbCl3 via Hydrochloric Acid Vapor Annealing Post-Treatment.

PubMed

Zhou, Weiran; Zhou, Pengcheng; Lei, Xunyong; Fang, Zhimin; Zhang, Mengmeng; Liu, Qing; Chen, Tao; Zeng, Hualing; Ding, Liming; Zhu, Jun; Dai, Songyuan; Yang, Shangfeng

2018-01-17

Organometal halide CH 3 NH 3 PbI 3 (MAPbI 3 ) has been commonly used as the light absorber layer of perovskite solar cells (PSCs), and, especially, another halide element chlorine (Cl) has been often incorporated to assist the crystallization of perovskite film. However, in most cases, a predominant MAPbI 3 phase with trace of Cl - is obtained ultimately and the role of Cl involvement remains unclear. Herein, we develop a low-cost and facile method, named hydrochloric acid vapor annealing (HAVA) post-treatment, and realize a rapid conversion of MAPbI 3 to phase-pure MAPbCl 3 , demonstrating a new concept of phase engineering of perovskite materials toward efficiency enhancement of PSCs for the first time. The average grain size of perovskite film after HAVA post-treatment increases remarkably through an Ostwald ripening process, leading to a denser and smoother perovskite film with reduced trap states and enhanced crystallinity. More importantly, the generation of MAPbCl 3 secondary phase via phase engineering is beneficial for improving the carrier mobility with a more balanced carrier transport rate and enlarging the band gap of perovskite film along with optimized energy level alignment. As a result, under the optimized HAVA post-treatment time (2 min), we achieved a significant enhancement of the power conversion efficiency (PCE) of the MAPbI 3 -based planar heterojunction-PSC device from 14.02 to 17.40% (the highest PCE reaches 18.45%) with greatly suppressed hysteresis of the current-voltage response.

Direct 1H NMR evidence of spin-rotation coupling as a source of para → ortho-H2 conversion in diamagnetic solvents.

PubMed

Terenzi, Camilla; Bouguet-Bonnet, Sabine; Canet, Daniel

2017-04-21

At ambient temperature, conversion from 100% enriched para-hydrogen (p-H 2 ; singlet state) to ortho-hydrogen (o-H 2 ; triplet state) leads necessarily to the thermodynamic equilibrium proportions: 75% of o-H 2 and 25% of p-H 2 . When p-H 2 is dissolved in a diamagnetic organic solvent, conversion is very slow and can be considered as arising from nuclear spin relaxation phenomena. A first relaxation mechanism, specific to the singlet state and involving a combination of auto-correlation and cross correlation spectral densities, can be retained: randomly fluctuating magnetic fields due to inter-molecular dipolar interactions. We demonstrate here that (i) this dipolar mechanism is not sufficient for accounting for the para→ortho conversion rate, (ii) spin-rotation interaction, an intra-molecular mechanism, behaves similarly to random-field interaction and, thus, may be involved in the singlet relaxation rate. Also, as the para→ortho conversion is monitored by proton nuclear magnetic resonance (NMR) of dissolved o-H 2 (p-H 2 is NMR-silent), one has to account for H 2 exchange between the liquid phase and the gas phase within the NMR tube, as well as for dissolution effects. Experimental evidence of the above statements is brought here in the case of two organic solvents: acetone-d 6 and carbon disulfide. The observed temperature dependence of the para→ortho conversion rate shows that spin-rotation can be the dominant contribution to the p-H 2 relaxation rate in the absence of tangible dipolar interactions. Our findings shed new light on the "mysterious" mechanism of the para→ortho conversion which has been searched for several decades.

New ortho-para conversion mechanism in dense solid hydrogen.

PubMed

Strzhemechny, M A; Hemley, R J

2000-12-25

Analysis of recent measurements of striking changes in the rate of ortho-para conversion of solid H(2) up to 58 GPa shows that the conversion mechanism must differ from that at ambient pressure. A new conversion mechanism is identified in which the emerging excitations are coupled to the converting molecules via electric quadrupole-quadrupole rather than nuclear spin-spin interactions. The latter only initiates conversion while the coupling enhancement associated with the new mechanism is ensured by high compression and a gap closing, with the conversion energy diminishing strongly with increasing pressure.

Kinetic phase evolution of spinel cobalt oxide during lithiation

DOE PAGES

Li, Jing; He, Kai; Meng, Qingping; ...

2016-09-15

Spinel cobalt oxide has been proposed to undergo a multiple-step reaction during the electrochemical lithiation process. Understanding the kinetics of the lithiation process in this compound is crucial to optimize its performance and cyclability. In this work, we have utilized a low-angle annular dark-field scanning transmission electron microscopy method to visualize the dynamic reaction process in real time and study the reaction kinetics at different rates. We show that the particles undergo a two-step reaction at the single-particle level, which includes an initial intercalation reaction followed by a conversion reaction. At low rates, the conversion reaction starts after the intercalationmore » reaction has fully finished, consistent with the prediction of density functional theoretical calculations. At high rates, the intercalation reaction is overwhelmed by the subsequently nucleated conversion reaction, and the reaction speeds of both the intercalation and conversion reactions are increased. Phase-field simulations show the crucial role of surface diffusion rates of lithium ions in controlling this process. Furthermore, this work provides microscopic insights into the reaction dynamics in non-equilibrium conditions and highlights the effect of lithium diffusion rates on the overall reaction homogeneity as well as the performance.« less

Kinetic phase evolution of spinel cobalt oxide during lithiation

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

Li, Jing; He, Kai; Meng, Qingping

Spinel cobalt oxide has been proposed to undergo a multiple-step reaction during the electrochemical lithiation process. Understanding the kinetics of the lithiation process in this compound is crucial to optimize its performance and cyclability. In this work, we have utilized a low-angle annular dark-field scanning transmission electron microscopy method to visualize the dynamic reaction process in real time and study the reaction kinetics at different rates. We show that the particles undergo a two-step reaction at the single-particle level, which includes an initial intercalation reaction followed by a conversion reaction. At low rates, the conversion reaction starts after the intercalationmore » reaction has fully finished, consistent with the prediction of density functional theoretical calculations. At high rates, the intercalation reaction is overwhelmed by the subsequently nucleated conversion reaction, and the reaction speeds of both the intercalation and conversion reactions are increased. Phase-field simulations show the crucial role of surface diffusion rates of lithium ions in controlling this process. Furthermore, this work provides microscopic insights into the reaction dynamics in non-equilibrium conditions and highlights the effect of lithium diffusion rates on the overall reaction homogeneity as well as the performance.« less

Selling the story: Narratives and charisma in adults with TBI

PubMed Central

JONES, CORINNE A.; TURKSTRA, LYN S.

2015-01-01

Objective To examine storytelling performance behaviours in adults with traumatic brain injury (TBI) and relate these behaviours to perceived charisma and desirability as a conversation partner. Design and methods Seven adult males with traumatic brain injury (TBI) told their accident narratives to a male confederate. Ten male undergraduate students rated 1-minute video clips from the beginning of each narrative using the Charismatic Leadership Communication Scale (CLCS). Raters also indicated whether or not they would like to engage in conversation with each participant. Results Of the performative behaviours analysed, gestures alone significantly influenced CLCS ratings and reported likelihood of engaging in future conversation with the participant. Post-hoc analysis revealed that speech rate was significantly correlated with all of the preceding measures. There was a significant correlation between self- and other-ratings of charisma. Conclusions The findings suggest that aspects of non-verbal performance, namely gesture use and speech rate, influence how charismatic an individual is perceived to be and how likely someone is to engage in conversation with that person. Variability in these performance behaviours may contribute to the variation in social outcomes seen in the TBI population. PMID:21714624

Study of parameters affecting the conversion in a plug flow reactor for reactions of the type 2A→B

NASA Astrophysics Data System (ADS)

Beltran-Prieto, Juan Carlos; Long, Nguyen Huynh Bach Son

2018-04-01

Modeling of chemical reactors is an important tool to quantify reagent conversion, product yield and selectivity towards a specific compound and to describe the behavior of the system. Proposal of differential equations describing the mass and energy balance are among the most important steps required during the modeling process as they play a special role in the design and operation of the reactor. Parameters governing transfer of heat and mass have a strong relevance in the rate of the reaction. Understanding this information is important for the selection of reactor and operating regime. In this paper we studied the irreversible gas-phase reaction 2A→B. We model the conversion that can be achieved as function of the reactor volume and feeding temperature. Additionally, we discuss the effect of activation energy and the heat of reaction on the conversion achieved in the tubular reactor. Furthermore, we considered that dimerization occurs instantaneously in the catalytic surface to develop equations for the determination of rate of reaction per unit area of three different catalytic surface shapes. This data can be combined with information about the global rate of conversion in the reactor to improve regent conversion and yield of product.

Development of high intensity X-ray sources at the National Ignition Facility

NASA Astrophysics Data System (ADS)

May, M. J.; Colvin, J. D.; Kemp, G. E.; Barrios, M. A.; Widmann, K.; Benjamin, R.; Thorn, D.; Poole, P.; Blue, B.

2018-05-01

Laser heated plasmas have provided recently some of the most powerful and energetic nanosecond length laboratory sources of x-ray photons (Ephoton = 1-30 keV). The highest x-ray to laser conversion is currently accessible by using underdense (ne ˜ 0.25 nc) plasmas since optimal laser coupling is obtained in millimeter scale targets. The targets can have conversion efficiencies of up to 10%. Several types of targets can be used to produce underdense plasmas: metal lined cylindrical cavities, gas pipes, and most recently nano-wire foams. Both the experimental and simulation details of these high intensity x-ray sources are discussed.

Optical actuators for fly-by-light applications

NASA Astrophysics Data System (ADS)

Chee, Sonny H. S.; Liu, Kexing; Measures, Raymond M.

1993-04-01

A review of optomechanical interfaces is presented. A detailed quantitative and qualitative analysis of the University of Toronto Institute for Aerospace Studies (UTIAS) box, optopneumatics, optical activation of a bimetal, optical activation of the shape memory effect, and optical activation of the pyroelectric effects is given. The UTIAS box is found to display a good conversion efficiency and a high bandwidth. A preliminary UTIAS box design has achieved a conversion efficiency of about 1/6 of the theoretical limit and a bandwidth of 2 Hz. In comparison to previous optomechanical interfaces, the UTIAS box has the highest pressure development to optical power ratio (at least an order of magnitude greater).

A Methoxydiphenylamine-Substituted Carbazole Twin Derivative: An Efficient Hole-Transporting Material for Perovskite Solar Cells.

PubMed

Gratia, Paul; Magomedov, Artiom; Malinauskas, Tadas; Daskeviciene, Maryte; Abate, Antonio; Ahmad, Shahzada; Grätzel, Michael; Getautis, Vytautas; Nazeeruddin, Mohammad Khaja

2015-09-21

The small-molecule-based hole-transporting material methoxydiphenylamine-substituted carbazole was synthesized and incorporated into a CH3NH3PbI3 perovskite solar cell, which displayed a power conversion efficiency of 16.91%, the second highest conversion efficiency after that of Spiro-OMeTAD. The investigated hole-transporting material was synthesized in two steps from commercially available and relatively inexpensive starting reagents. Various electro-optical measurements (UV/Vis, IV, thin-film conductivity, hole mobility, DSC, TGA, ionization potential) have been carried out to characterize the new hole-transporting material. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The mangroves of the Zambezi Delta: increase in extent observed via satellite from 1994 to 2013

Treesearch

Aurelie C. Shapiro; Carl C. Trettin; Helga Kuchly; Sadroddin Alavinapanah; Salomao Bandeira

2015-01-01

Mangroves are recognized for their valued ecosystem services provision while having the highest carbon density among forested ecosystems. Yet they are increasingly threatened by deforestation, conversion to agriculture and development, reducing the benefits they provide for local livelihoods, coastal protection and climate change mitigation. Accordingly, accurate...

Improved pharmacokinetics of mercaptopurine afforded by a thermally robust hemihydrate.

PubMed

Kersten, Kortney M; Matzger, Adam J

2016-04-18

Structural and thermal data were obtained for a novel hemihydrate of 6-mercaptopurine. The hemihydrate shows increased solubility and bioavailability when compared to the monohydrate form, better stability against conversion in aqueous media than the anhydrate form, and a dehydration temperature of 240 °C, the highest of any known hydrate crystal.

Imidazolium- and Triazine-Based Porous Organic Polymers for Heterogeneous Catalytic Conversion of CO2 into Cyclic Carbonates.

PubMed

Zhong, Hong; Su, Yanqing; Chen, Xingwei; Li, Xiaoju; Wang, Ruihu

2017-12-22

CO 2 adsorption and concomitant catalytic conversion into useful chemicals are promising approaches to alleviate the energy crisis and effects of global warming. This is highly desirable for developing new types of heterogeneous catalytic materials containing CO 2 -philic groups and catalytic active sites for CO 2 chemical transformation. Here, we present an imidazolium- and triazine-based porous organic polymer with counter chloride anion (IT-POP-1). The porosity and CO 2 affinity of IT-POP-1 may be modulated at the molecular level through a facile anion-exchange strategy. Compared with the post-modified polymers with iodide and hexafluorophosphate anions, IT-POP-1 possesses the highest surface area and the best CO 2 uptake capacity with excellent adsorption selectivity over N 2 . The roles of the task-specific components such as triazine, imidazolium, hydroxyl, and counter anions in CO 2 absorption and catalytic performance were illustrated. IT-POP-1 exhibits the highest catalytic activity and excellent recyclability in solvent- and additive-free cycloaddition reaction of CO 2 with epoxides. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly efficient and completely flexible fiber-shaped dye-sensitized solar cell based on TiO2 nanotube array

NASA Astrophysics Data System (ADS)

Lv, Zhibin; Yu, Jiefeng; Wu, Hongwei; Shang, Jian; Wang, Dan; Hou, Shaocong; Fu, Yongping; Wu, Kai; Zou, Dechun

2012-02-01

A type of highly efficient completely flexible fiber-shaped solar cell based on TiO2 nanotube array is successfully prepared. Under air mass 1.5G (100 mW cm-2) illumination conditions, the photoelectric conversion efficiency of the solar cell approaches 7%, the highest among all fiber-shaped cells based on TiO2 nanotube arrays and the first completely flexible fiber-shaped DSSC. The fiber-shaped solar cell demonstrates good flexibility, which makes it suitable for modularization using weaving technologies.A type of highly efficient completely flexible fiber-shaped solar cell based on TiO2 nanotube array is successfully prepared. Under air mass 1.5G (100 mW cm-2) illumination conditions, the photoelectric conversion efficiency of the solar cell approaches 7%, the highest among all fiber-shaped cells based on TiO2 nanotube arrays and the first completely flexible fiber-shaped DSSC. The fiber-shaped solar cell demonstrates good flexibility, which makes it suitable for modularization using weaving technologies. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr11532h

Substitution of ethambutol with linezolid during the intensive phase of treatment of pulmonary tuberculosis: study protocol for a prospective, multicenter, randomized, open-label, phase II trial.

PubMed

Lee, Ji Yeon; Kim, Deog Kyeom; Lee, Jung-Kyu; Yoon, Ho Il; Jeong, Ina; Heo, Eunyoung; Park, Young Sik; Lee, Jae Ho; Park, Sung Soo; Lee, Sang-Min; Lee, Chang-Hoon; Lee, Jinwoo; Choi, Sun Mi; Park, Jong Sun; Joh, Joon-Sung; Cho, Young-Jae; Lee, Yeon Joo; Kim, Se Joong; Hwang, Young Ran; Kim, Hyeonjeong; Ki, Jongeun; Choi, Hyungsook; Han, Jiyeon; Ahn, Heejung; Hahn, Seokyung; Yim, Jae-Joon

2017-02-13

Linezolid, an oxazolidinone, substantially improves treatment outcomes of multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis. We started a trial to test whether the use of linezolid instead of ethambutol could increase the rate of sputum culture conversion as of 8 weeks of treatment in patients with drug-susceptible tuberculosis. This is a phase II, multicenter, randomized study with three arms. We are enrolling patients with pulmonary tuberculosis without rifampicin resistance screened by the Xpert MTB/RIF® assay. The standard treatment arm uses isoniazid (6 months), rifampicin (6 months), pyrazinamide (2 months), and ethambutol (2 months). Experimental arm 1 uses linezolid (600 mg/day) for 4 weeks instead of ethambutol. Experimental arm 2 uses linezolid (600 mg/day) for 2 weeks instead of ethambutol. The primary outcome is the sputum culture conversion rate on liquid media after 2 months of treatment. Secondary outcomes include the sputum culture conversion rate on solid media after 2 months of treatment, time to sputum culture conversion on liquid and solid media, cure rate, and treatment success rate. The frequencies of total adverse events (AEs) and serious AEs will be described and documented. Based on an α = 0.05 level of significance, a power of 85%, a 15% difference in the culture conversion rate after 2 months between the control arm and experimental arm 1 (75% vs. 90%), a 10% default (loss to follow-up) rate, and a 10% culture failure, the required number per arm was calculated to be 143 (429 in total). This trial will reveal the effectiveness and safety of 2 or 4 weeks of use of linezolid instead of ethambutol for patients with drug-susceptible pulmonary tuberculosis. If a new regimen including linezolid shows a higher culture conversion rate by week 8, and is safe, it could be tested as a 4-month antituberculosis treatment regimen in the future. ClincalTrials.gov, NCT01994460 . Registered on 13 November 2013.

Site-specific lead exposure from lead pellet ingestion in sentinel mallards

USGS Publications Warehouse

Rocke, T.E.; Brand, C.J.; Mensik, John G.

1997-01-01

We monitored lead poisoning from the ingestion of spent lead pellets in sentinel mallards (Anas platyhrynchos) at the Sacramento National Wildlife Refuge (SNWR), Willows, California for 4 years (1986-89) after the conversion to steel shot for waterfowl hunting on refuges in 1986. Sentinel mallards were held in 1.6-ha enclosures in 1 hunted (P8) and 2 non-hunted (T19 and TF) wetlands. We compared site-specific rates of lead exposure, as determined by periodic measurement of blood lead concentrations, and lead poisoning mortality between wetlands with different lead pellet densities, between seasons, and between male and female sentinels. In 1986, the estimated 2-week rate of lead exposure was significantly higher (P < 0.005) in P8 (43.8%), the wetland with the highest density of spent lead pellets (>2,000,000 pellets/ha), than in those with lower densities of lead pellets, T19 (18.1%; 173,200 pellets/ha) and TF (0.9%; 15,750 pellets/ha). The probability of mortality from lead poisoning was also significantly higher (P < 0.01) in sentinel mallards enclosed in P8 (0.25) than T19 (0) and TF (0) in 1986 and remained significantly higher (P < 0.001) during the 4-year study. Both lead exposure and the probability of lead poisoning mortality in P8 were significantly higher (P < 0.001) in the fall of 1986 (43.8%; 0.25), before hunting season, than in the spring of 1987 (21.6%; 0.04), after hunting season. We found no significant differences in the rates of lead exposure or lead poisoning mortality between male and female sentinel mallards. The results of this study demonstrate that in some locations, lead exposure and lead poisoning in waterfowl will continue to occur despite the conversion to steel shot for waterfowl hunting.

Metabolism of nC11 fatty acid fed to Trichoderma koningii and Penicillium janthinellum II: Production of intracellular and extracellular lipids.

PubMed

Monreal, Carlos M; Chahal, Amarpreet; Rowland, Owen; Smith, Myron; Schnitzer, Morris

2014-01-01

Little is known about the fungal metabolism of nC10 and nC11 fatty acids and their conversion into lipids. A mixed batch culture of soil fungi, T. koningii and P. janthinellum, was grown on undecanoic acid (UDA), a mixture of UDA and potato dextrose broth (UDA+PDB), and PDB alone to examine their metabolic conversion during growth. We quantified seven intracellular and extracellular lipid classes using Iatroscan thin-layer chromatography with flame ionization detection (TLC-FID). Gas chromatography with flame ionization detection (GC-FID) was used to quantify 42 individual fatty acids. Per 150 mL culture, the mixed fungal culture grown on UDA+PDB produced the highest amount of intracellular (531 mg) and extracellular (14.7 mg) lipids during the exponential phase. The content of total intracellular lipids represented 25% of the total biomass-carbon, or 10% of the total biomass dry weight produced. Fatty acids made up the largest class of intracellular lipids (457 mg/150 mL culture) and they were synthesized at a rate of 2.4 mg/h during the exponential phase, and decomposed at a rate of 1.8 mg/h during the stationary phase, when UDA+PDB was the carbon source. Palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2) and vaccenic acid (C18:1) accounted for >80% of the total intracellular fatty acids. During exponential growth on UDA+PDB, hydrocarbons were the largest pool of all extracellular lipids (6.5 mg), and intracellularly they were synthesized at a rate of 64 μg/h. The mixed fungal species culture of T. koningii and P. janthinellum produced many lipids for potential use as industrial feedstocks or bioproducts in biorefineries.

Mono- and tri-ester hydrogenolysis using tandem catalysis. Scope and mechanism.

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

Lohr, Tracy L.; Li, Zhi; Assary, Rajeev S.

The scope and mechanism of thermodynamically leveraged ester RC(O)O-R' bond hydrogenolysis by tandem metal triflate + supported Pd catalysts are investigated both experimentally and theoretically by DFT and energy span analysis. This catalytic system has a broad scope, with relative cleavage rates scaling as, tertiary 4 secondary 4 primary ester at 1 bar H-2, yielding alkanes and carboxylic acids with high conversion and selectivity. Benzylic and allylic esters display the highest activity. The rate law is nu = k[M(OTf )(n)](1)[ester](0)[H-2](0) with an H/D kinetic isotope effect = 6.5 +/- 0.5, implying turnover-limiting C-H scission following C-O cleavage, in agreement withmore » theory. Intermediate alkene products are then rapidly hydrogenated. Applying this approach with the very active Hf(OTf)(4) catalyst to bio-derived triglycerides affords near-quantitative yields of C-3 hydrocarbons rather than glycerol. From model substrates, it is found that RC(O)O-R' cleavage rates are very sensitive to steric congestion and metal triflate identity. For triglycerides, primary/external glyceryl CH2-O cleavage predominates over secondary/internal CH-O cleavage, with the latter favored by less acidic or smaller ionic radius metal triflates, raising the diester selectivity to as high as 48% with Ce(OTf)(3).« less

Social Valence in Children with Specific Language Impairment during Imitation-Based and Conversation-Based Language Intervention.

ERIC Educational Resources Information Center

Haley, Katarina L.; And Others

1994-01-01

Fifteen preschool children with specific language impairment engaged in typical language intervention activities during conversation-based and imitation-based language programs. A higher number of positive social valence ratings; higher frequency of smiling, laughing, and engagement; and higher rate of verbal initiations were noted within…

5 CFR 536.302 - Optional pay retention.

Code of Federal Regulations, 2010 CFR

2010-01-01

... conversion rule in § 536.303(a) before determining whether an employee's rate of basic pay otherwise would be... entitled to pay retention under § 536.301, but whose payable rate of basic pay otherwise would be reduced (after application of any applicable geographic conversion under § 536.303(a)) as the result of a...

5 CFR 9901.314 - National security compensation comparability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... conversion of such employees to the NSPS; and (2) Adjustments for normal step increases and rates of... disadvantaged in terms of the overall amount of compensation available as a result of conversion to the NSPS.... 5304, special rate supplement under 5 U.S.C. 5305, local market supplement under § 9901.332, or...

Lessons Learned With Laparoscopic Management of Complicated Grades of Acute Appendicitis

PubMed Central

Gomes, Carlos Augusto; Junior, Cleber Soares; Costa, Evandro de Freitas Campos; Alves, Paula de Assis Pereira; de Faria, Carolina Vieira; Cangussu, Igor Vitoi; Costa, Luisa Pires; Gomes, Camila Couto; Gomes, Felipe Couto

2014-01-01

Background Laparoscopy has not been consolidated as the approach of first choice in the management of complicated appendicitis. Methodological flaws and absence of disease stratification criteria have been implicated in that less evidence. The objective is to study the safe and effectiveness of laparoscopy in the management of complicated appendicitis according to laparoscopic grading system. Method From January 2008 to January 2011, 154 consecutive patients who underwent a laparoscopic appendectomy for complicated appendicitis were evaluated in the prospective way. The patient’s age ranged from 12 to 75 years old (31.7 ± 13.3) and 58.3% were male. Complicated appendicitis refers to gangrenous and/or perforated appendix and were graded as 3A (segmental necrosis), 3B (base necrosis), 4A (abscess), 4B (regional peritonitis) and 5 (diffuse peritonitis). The outcomes including operative time, infection complication, operative complications and conversion rate were chosen to evaluate the procedure. Results The grade 3A was the most frequent with 50 (32.4%) patients. The mean operative time was 69.4 ± 26.3 minutes. The grade 4A showed the highest mean operative time (80.1 ± 26.7 minutes). The wound and intra-abdominal infection rates were 2.6 and 4.6%, respectively. The base necrosis was the most important factor associated with the conversion (5.2%). The grades 4A and 5 were associated with greater possibility of intra-abdominal collection. There were no operative complications. Conclusion The laparoscopic management of all complicated grades of acute appendicitis is safe and effective and should be the procedure of first choice. The laparoscopic grading system allows us to assess patients in the same disease stage. PMID:24883151

A novel biocatalytic approach to acetylation of 1-β-D-arabinofuranosylcytosine by Aspergillus oryzae whole cell in organic solvents.

PubMed

Li, Xiao-Feng; Zhu, Zhen; Zhao, Guang-Lei; Yu, Yi-Gang; Lai, Fu-Rao; Wu, Hui

2012-01-01

Biocatalytic acylation of 1-β-D-arabinofuranosylcytosine (ara-C) was developed using whole cell of Aspergillus oryzae as a novel catalyst. (13)C nuclear magnetic resonance (NMR) analysis indicated that the whole-cell biocatalyst had more specific activity toward the 3'-hydroxyl group than 5'-hydroxyl group among the available hydroxyl groups in sugar moiety of ara-C. Except for glucose and maltose, 11 carbon sources supplemented to basal media, including Spans, Tweens, olive oil and oleic acid, exhibited notable enhancement effects on both the cell growth and the acylation reactions. It was suggested that the carbon sources containing controlled-release oleic acid were the important substrates for the production of fungal cell-bound lipase with specific activity, partially due to a gradual induction effect of their released oleic acid on the cell-bound lipase production. Despite the low initial reaction rate and substrate conversion, the addition of 2.0 g/l Span 80 resulted in a higher 3'-regioselectivity of the cells than 81%. By using Tween 85 at its optimum concentration of 5.0 g/l, however, the highest initial rates (3.2 mmol/l h) and substrate conversion (76%) of the whole-cell catalyzed acylation of ara-C can be achieved. It was also found that the 3'-regioselectivity of the cells showed observable increase by extending the culture time. And the activity of cell-bound lipase drastically increased in the early stage of cell growth and then declined in the late culture stage, whatever the culture media used. Our results thus indicated that A. oryzae whole cell was a promising green tool for biosynthesis of nucleoside esters with potential bioactivities.

Cloning and expression of the sucrose phosphorylase gene in Bacillus subtilis and synthesis of kojibiose using the recombinant enzyme.

PubMed

Wang, Miaomiao; Wu, Jing; Wu, Dan

2018-02-15

Kojibiose as a prebiotic and inhibitor of α-glucosidase exhibits potential for a wide range of applications in the food and medicine fields; however, large-scale separation and extraction of kojibiose from nature is difficult. Sucrose phosphorylase (SPase) can be used for the production of kojibiose, and currently, SPase is only heterologously expressed in E. coli, making it unsuitable for use in the food industry. However, Bacillus subtilis is generally considered to be a safe organism potentially useful for SPase expression. Here, for the first time, we heterologously expressed Bifidobacterium adolescentis SPase in a food-grade B. subtilis strain. The results showed that SPase was efficiently secreted into the extracellular medium in the absence of a signal peptide. After culturing the recombinant strain in a 3-L bioreactor, crude SPase yield and activity reached 7.5 g/L and 5.3 U/mL, respectively, the highest levels reported to date. The optimal reaction conditions for kojibiose synthesis catalyzed by recombinant SPase were as follows: 0.5 M sucrose, 0.5 M glucose, 0.02 U enzyme /mg all_substrates , pH 7.0, 50 °C, and 30 h. Furthermore, the substrate-conversion rate reached 40.01%, with kojibiose accounting for 104.45 g/L and selectivity for kojibiose production at 97%. Here, we successfully expressed SPase in B. subtilis in the absence of a signal peptide and demonstrated its secretion into the extracellular medium. Our results indicated high levels of recombinant enzyme expression, with a substrate-conversion rate of 40.01%. These results provide a basis for large-scale preparation of kojibiose by the recombinant SPase.

Patient Safety Culture Assessment in Oman

PubMed Central

Al-Mandhari, Ahmed; Al-Zakwani, Ibrahim; Al-Kindi, Moosa; Tawilah, Jihane; Dorvlo, Atsu S.S.; Al-Adawi, Samir

2014-01-01

Objective To illustrate the patient safety culture in Oman as gleaned via 12 indices of patient safety culture derived from the Hospital Survey on Patient Safety Culture (HSPSC) and to compare the average positive response rates in patient safety culture between Oman and the USA, Taiwan, and Lebanon. Methods This was a cross-sectional research study employed to gauge the performance of HSPSC safety indices among health workers representing five secondary and tertiary care hospitals in the northern region of Oman. The participants (n=398) represented different professional designations of hospital staff. Analyses were performed using univariate statistics. Results The overall average positive response rate for the 12 patient safety culture dimensions of the HSPSC survey in Oman was 58%. The indices from HSPSC that were endorsed the highest included ‘organizational learning and continuous improvement’ while conversely, ‘non-punitive response to errors’ was ranked the least. There were no significant differences in average positive response rates between Oman and the United States (58% vs. 61%; p=0.666), Taiwan (58% vs. 64%; p=0.386), and Lebanon (58% vs. 61%; p=0.666). Conclusion This study provides the first empirical study on patient safety culture in Oman which is similar to those rates reported elsewhere. It highlights the specific strengths and weaknesses which may stem from the specific milieu prevailing in Oman. PMID:25170407

Condensed phase conversion and growth of nanorods and other materials instead of from vapor

DOEpatents

Geohegan, David B.; Seals, Roland D.; Puretzky, Alex A.; Fan, Xudong

2010-10-19

Compositions, systems and methods are described for condensed phase conversion and growth of nanorods and other materials. A method includes providing a condensed phase matrix material; and activating the condensed phase matrix material to produce a plurality of nanorods by condensed phase conversion and growth from the condensed phase matrix material instead of from vapor. The compositions are very strong. The compositions and methods provide advantages because they allow (1) formation rates of nanostructures necessary for reasonable production rates, and (2) the near net shaped production of component structures.

Condensed phase conversion and growth of nanorods instead of from vapor

DOEpatents

Geohegan, David B.; Seals, Roland D.; Puretzky, Alex A.; Fan, Xudong

2005-08-02

Compositions, systems and methods are described for condensed phase conversion and growth of nanorods and other materials. A method includes providing a condensed phase matrix material; and activating the condensed phase matrix material to produce a plurality of nanorods by condensed phase conversion and growth from the condensed chase matrix material instead of from vacor. The compositions are very strong. The compositions and methods provide advantages because they allow (1) formation rates of nanostructures necessary for reasonable production rates, and (2) the near net shaped production of component structures.

26 CFR 1.305-6 - Distributions of convertible preferred.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the following conditions exist: (i) The conversion right must be exercised within a relatively short... the dividend rate, the redemption provisions, the marketability of the convertible stock, and the conversion price, it may be anticipated that some shareholders will exercise their conversion rights and some...

Smear Conversion, Treatment Outcomes and the Time of Default in Registered Tuberculosis Patients on RNTCP DOTS in Puducherry, Southern India

PubMed Central

Jayakumar, Niranjana; Gnanasekaran, Dhivyalakshmi

2014-01-01

Background: Revised National Tuberculosis Control Programme (RNTCP) in India has achieved improved cure rates. Objectives: This study describes the achievements under RNTCP in terms of conversion rates, treatment outcomes and pattern of time of default in patients on directly observed short-course treatment for Tuberculosis in Puducherry, Southern India. Settings: Retrospective cohort study; Tuberculosis Unit in District Tuberculosis Centre, Puducherry, India. Materials and Methods: Cohort analysis of patients of registered at the Tuberculosis Unit during 1st and 2nd quarter of the year 2011. Details about sputum conversion, treatment outcome and time of default were obtained from the tuberculosis register. Statistical Analysis: Kaplan-Meier plots & log rank tests. Results: RNTCP targets with respect to success rate (85.7%), death rate (2.7%) and failure rate (2.1%) in new cases have been achieved but the sputum conversion rate (88%) and default rate (5.9%) targets have not been achieved. The overall default rate for all registered TB patients was 7.4%; significantly higher in category II. In retreatment cases registered as treatment after default, the default rate was high (9%). The cumulative default rate; though similar in the initial two months of treatment; was consistently higher in category II as compared to that in category I. Nearly 40% of all defaulters interrupted treatment between the second and fourth month after treatment initiation. Conclusion: Defaulting from treatment is more common among the retreatment cases and usually occurs during the transition phase from intensive phase to continuation phase. PMID:25478371

The cost of conversion in robotic and laparoscopic colorectal surgery.

PubMed

Cleary, Robert K; Mullard, Andrew J; Ferraro, Jane; Regenbogen, Scott E

2018-03-01

Conversion from minimally invasive to open colorectal surgery remains common and costly. Robotic colorectal surgery is associated with lower rates of conversion than laparoscopy, but institutions and payers remain concerned about equipment and implementation costs. Recognizing that reimbursement reform and bundled payments expand perspectives on cost to include the entire surgical episode, we evaluated the role of minimally invasive conversion in total payments. This is an observational study from a linked data registry including clinical data from the Michigan Surgical Quality Collaborative and payment data from the Michigan Value Collaborative between July 2012 and April 2015. We evaluated colorectal resections initiated with open and minimally invasive approaches, and compared reported risk-adjusted and price-standardized 30-day episode payments and their components. We identified 1061 open, 1604 laparoscopic, and 275 robotic colorectal resections. Adjusted episode payments were significantly higher for open operations than for minimally invasive procedures completed without conversion ($19,489 vs. $15,518, p < 0.001). The conversion rate was significantly higher with laparoscopic than robotic operations (15.1 vs. 7.6%, p < 0.001). Adjusted episode payments for minimally invasive operations converted to open were significantly higher than for those completed by minimally invasive approaches ($18,098 vs. $15,518, p < 0.001). Payments for operations completed robotically were greater than those completed laparoscopically ($16,949 vs. $15,250, p < 0.001), but the difference was substantially decreased when conversion to open cases was included ($16,939 vs. $15,699, p = 0.041). Episode payments for open colorectal surgery exceed both laparoscopic and robotic minimally invasive options. Conversion to open surgery significantly increases the payments associated with minimally invasive colorectal surgery. Because conversion rates in robotic colorectal operations are half of those in laparoscopy, the excess expenditures attributable to robotics are attenuated by consideration of the cost of conversions.

Direct digital conversion detector technology

NASA Astrophysics Data System (ADS)

Mandl, William J.; Fedors, Richard

1995-06-01

Future imaging sensors for the aerospace and commercial video markets will depend on low cost, high speed analog-to-digital (A/D) conversion to efficiently process optical detector signals. Current A/D methods place a heavy burden on system resources, increase noise, and limit the throughput. This paper describes a unique method for incorporating A/D conversion right on the focal plane array. This concept is based on Sigma-Delta sampling, and makes optimum use of the active detector real estate. Combined with modern digital signal processors, such devices will significantly increase data rates off the focal plane. Early conversion to digital format will also decrease the signal susceptibility to noise, lowering the communications bit error rate. Computer modeling of this concept is described, along with results from several simulation runs. A potential application for direct digital conversion is also reviewed. Future uses for this technology could range from scientific instruments to remote sensors, telecommunications gear, medical diagnostic tools, and consumer products.

Geographic Differences in Time to Culture Conversion in Liquid Media: Tuberculosis Trials Consortium Study 28. Culture Conversion Is Delayed in Africa

PubMed Central

Mac Kenzie, William R.; Heilig, Charles M.; Bozeman, Lorna; Johnson, John L.; Muzanye, Grace; Dunbar, Denise; Jost, Kenneth C.; Diem, Lois; Metchock, Beverly; Eisenach, Kathleen; Dorman, Susan; Goldberg, Stefan

2011-01-01

Background Tuberculosis Trials Consortium Study 28, was a double blind, randomized, placebo-controlled, phase 2 clinical trial examining smear positive pulmonary Mycobacterium tuberculosis. Over the course of intensive phase therapy, patients from African sites had substantially delayed and lower rates of culture conversion to negative in liquid media compared to non-African patients. We explored potential explanations of this finding. Methods In TBTC Study 28, protocol-correct patients (n = 328) provided spot sputum specimens for M. tuberculosis culture in liquid media, at baseline and weeks 2, 4, 6 and 8 of study therapy. We compared sputum culture conversion for African and non-African patients stratified by four baseline measures of disease severity: AFB smear quantification, extent of disease on chest radiograph, cavity size and the number of days to detection of M. tuberculosis in liquid media using the Kaplan-Meier product-limit method. We evaluated specimen processing and culture procedures used at 29 study laboratories serving 27 sites. Results African TB patients had more extensive disease at enrollment than non-African patients. However, African patients with the least disease by the 4 measures of disease severity had conversion rates on liquid media that were substantially lower than conversion rates in non-African patients with the greatest extent of disease. HIV infection, smoking and diabetes did not explain delayed conversion in Africa. Some inter-site variation in laboratory processing and culture procedures within accepted practice for clinical diagnostic laboratories was found. Conclusions Compared with patients from non-African sites, African patients being treated for TB had delayed sputum culture conversion and lower sputum conversion rates in liquid media that were not explained by baseline severity of disease, HIV status, age, smoking, diabetes or race. Further investigation is warranted into whether modest variation in laboratory processes substantially influences the efficacy outcomes of phase 2 TB treatment trials or if other factors (e.g., nutrition, host response) are involved. Trial Registration ClinicalTrials.gov NCT00144417 PMID:21494548

Promoting Effect of Layered Titanium Phosphate on the Electrochemical and Photovoltaic Performance of Dye-Sensitized Solar Cells

PubMed Central

2010-01-01

We reported a composite electrolyte prepared by incorporating layered α-titanium phosphate (α-TiP) into an iodide-based electrolyte using 1-ethyl-3-methylimidazolium tetrafluoroborate(EmimBF4) ionic liquid as solvent. The obtained composite electrolyte exhibited excellent electrochemical and photovoltaic properties compared to pure ionic liquid electrolyte. Both the diffusion coefficient of triiodide (I3−) in the electrolyte and the charge-transfer reaction at the electrode/electrolyte interface were improved markedly. The mechanism for the enhanced electrochemical properties of the composite electrolyte was discussed. The highest conversion efficiency of dye-sensitized solar cell (DSSC) was obtained for the composite electrolyte containing 1wt% α-TiP, with an improvement of 58% in the conversion efficiency than the blank one, which offered a broad prospect for the fabrication of stable DSSCs with a high conversion efficiency. PMID:20676195

Piezoelectric ribbons printed onto rubber for flexible energy conversion.

PubMed

Qi, Yi; Jafferis, Noah T; Lyons, Kenneth; Lee, Christine M; Ahmad, Habib; McAlpine, Michael C

2010-02-10

The development of a method for integrating highly efficient energy conversion materials onto stretchable, biocompatible rubbers could yield breakthroughs in implantable or wearable energy harvesting systems. Being electromechanically coupled, piezoelectric crystals represent a particularly interesting subset of smart materials that function as sensors/actuators, bioMEMS devices, and energy converters. Yet, the crystallization of these materials generally requires high temperatures for maximally efficient performance, rendering them incompatible with temperature-sensitive plastics and rubbers. Here, we overcome these limitations by presenting a scalable and parallel process for transferring crystalline piezoelectric nanothick ribbons of lead zirconate titanate from host substrates onto flexible rubbers over macroscopic areas. Fundamental characterization of the ribbons by piezo-force microscopy indicates that their electromechanical energy conversion metrics are among the highest reported on a flexible medium. The excellent performance of the piezo-ribbon assemblies coupled with stretchable, biocompatible rubber may enable a host of exciting avenues in fundamental research and novel applications.

Efficient diode-end-pumped actively Q-switched Nd:YAG/SrWO4/KTP yellow laser.

PubMed

Cong, Zhenhua; Zhang, Xingyu; Wang, Qingpu; Liu, Zhaojun; Li, Shutao; Chen, Xiaohan; Zhang, Xiaolei; Fan, Shuzhen; Zhang, Huaijin; Tao, Xutang

2009-09-01

An efficient intracavity frequency-doubled Raman laser was obtained by using an SrWO(4) Raman medium, an Nd:YAG ceramic gain medium, and a KTP frequency-doubling medium. Three laser cavities, including a two-mirror cavity, a three-mirror coupled cavity, and a folded cavity, were investigated. With the coupled cavity, a 2.93 W, 590 nm laser was obtained at an incident pump power of 16.2 W and a pulse repetition frequency of 20 kHz; the corresponding conversion efficiency was 18.1%. The highest conversion efficiency of 19.2% was obtained at an incident pump power of 14.1 W and a pulse repetition frequency of 15 kHz. The obtained maximum output power and conversion efficiency were much higher than the results previously obtained with intracavity frequency-doubled solid-state Raman lasers.

Error free all optical wavelength conversion in highly nonlinear As-Se chalcogenide glass fiber.

PubMed

Ta'eed, Vahid G; Fu, Libin; Pelusi, Mark; Rochette, Martin; Littler, Ian C; Moss, David J; Eggleton, Benjamin J

2006-10-30

We present the first demonstration of all optical wavelength conversion in chalcogenide glass fiber including system penalty measurements at 10 Gb/s. Our device is based on As2Se3 chalcogenide glass fiber which has the highest Kerr nonlinearity (n(2)) of any fiber to date for which either advanced all optical signal processing functions or system penalty measurements have been demonstrated. We achieve wavelength conversion via cross phase modulation over a 10 nm wavelength range near 1550 nm with 7 ps pulses at 2.1 W peak pump power in 1 meter of fiber, achieving only 1.4 dB excess system penalty. Analysis and comparison of the fundamental fiber parameters, including nonlinear coefficient, two-photon absorption coefficient and dispersion parameter with other nonlinear glasses shows that As(2)Se(3) based devices show considerable promise for radically integrated nonlinear signal processing devices.

High thermoelectric power factor in two-dimensional crystals of Mo S2

NASA Astrophysics Data System (ADS)

Hippalgaonkar, Kedar; Wang, Ying; Ye, Yu; Qiu, Diana Y.; Zhu, Hanyu; Wang, Yuan; Moore, Joel; Louie, Steven G.; Zhang, Xiang

2017-03-01

The quest for high-efficiency heat-to-electricity conversion has been one of the major driving forces toward renewable energy production for the future. Efficient thermoelectric devices require high voltage generation from a temperature gradient and a large electrical conductivity while maintaining a low thermal conductivity. For a given thermal conductivity and temperature, the thermoelectric power factor is determined by the electronic structure of the material. Low dimensionality (1D and 2D) opens new routes to a high power factor due to the unique density of states (DOS) of confined electrons and holes. The 2D transition metal dichalcogenide (TMDC) semiconductors represent a new class of thermoelectric materials not only due to such confinement effects but especially due to their large effective masses and valley degeneracies. Here, we report a power factor of Mo S2 as large as 8.5 mW m-1K-2 at room temperature, which is among the highest measured in traditional, gapped thermoelectric materials. To obtain these high power factors, we perform thermoelectric measurements on few-layer Mo S2 in the metallic regime, which allows us to access the 2D DOS near the conduction band edge and exploit the effect of 2D confinement on electron scattering rates, resulting in a large Seebeck coefficient. The demonstrated high, electronically modulated power factor in 2D TMDCs holds promise for efficient thermoelectric energy conversion.

Climate and Land Use Controls on Soil Organic Carbon in the Loess Plateau Region of China

PubMed Central

Tao, Bo; Chen, Guangsheng; Lu, Chaoqun; Yang, Jia; Pan, Shufen; Wang, Guodong; Li, Shiqing; Tian, Hanqin

2014-01-01

The Loess Plateau of China has the highest soil erosion rate in the world where billion tons of soil is annually washed into Yellow River. In recent decades this region has experienced significant climate change and policy-driven land conversion. However, it has not yet been well investigated how these changes in climate and land use have affected soil organic carbon (SOC) storage on the Loess Plateau. By using the Dynamic Land Ecosystem Model (DLEM), we quantified the effects of climate and land use on SOC storage on the Loess Plateau in the context of multiple environmental factors during the period of 1961–2005. Our results show that SOC storage increased by 0.27 Pg C on the Loess Plateau as a result of multiple environmental factors during the study period. About 55% (0.14 Pg C) of the SOC increase was caused by land conversion from cropland to grassland/forest owing to the government efforts to reduce soil erosion and improve the ecological conditions in the region. Historical climate change reduced SOC by 0.05 Pg C (approximately 19% of the total change) primarily due to a significant climate warming and a slight reduction in precipitation. Our results imply that the implementation of “Grain for Green” policy may effectively enhance regional soil carbon storage and hence starve off further soil erosion on the Loess Plateau. PMID:24788559

Climate and land use controls on soil organic carbon in the loess plateau region of China.

PubMed

Dang, Yaai; Ren, Wei; Tao, Bo; Chen, Guangsheng; Lu, Chaoqun; Yang, Jia; Pan, Shufen; Wang, Guodong; Li, Shiqing; Tian, Hanqin

2014-01-01

The Loess Plateau of China has the highest soil erosion rate in the world where billion tons of soil is annually washed into Yellow River. In recent decades this region has experienced significant climate change and policy-driven land conversion. However, it has not yet been well investigated how these changes in climate and land use have affected soil organic carbon (SOC) storage on the Loess Plateau. By using the Dynamic Land Ecosystem Model (DLEM), we quantified the effects of climate and land use on SOC storage on the Loess Plateau in the context of multiple environmental factors during the period of 1961-2005. Our results show that SOC storage increased by 0.27 Pg C on the Loess Plateau as a result of multiple environmental factors during the study period. About 55% (0.14 Pg C) of the SOC increase was caused by land conversion from cropland to grassland/forest owing to the government efforts to reduce soil erosion and improve the ecological conditions in the region. Historical climate change reduced SOC by 0.05 Pg C (approximately 19% of the total change) primarily due to a significant climate warming and a slight reduction in precipitation. Our results imply that the implementation of "Grain for Green" policy may effectively enhance regional soil carbon storage and hence starve off further soil erosion on the Loess Plateau.

Enhancement of Power Conversion Efficiency of TiO₂-Based Dye-Sensitized Solar Cells on Various Acid Treatment.

PubMed

Sireesha, Pedaballi; Sun, Wei-Gang; Su, Chaochin; Kathirvel, Sasipriya; Lekphet, Woranan; Akula, Suri Babu; Li, Wen-Ri

2017-01-01

The surface modification of the TiO2 photoelectrode film is one of the promising ways to improve the photovoltaic performance of dye-sensitized solar cell (DSSC). In this work for the acid treatment of TiO2 powder, fluorine containing compounds such as trifluoroacetic acid was carried out to enhance the properties of photoanode. In order to investigate the effect of trifluoroacetyl group, the TiO2 nanopowders were also treated with different acids such as acetic acid, nitric acid, hydrochloric acid, and sulfuric acid and their properties were compared. The TiO2 powders treated with both acetic acid and TFA have possessed smooth surface morphologies as well as enhanced particle dispersions with reduced particle sizes. Photoelectrodes prepared for these two kinds of TiO2 powders accommodated high amounts of dye loading and exhibited excellent light transmittance (wavelength region of 400–600 nm). Electrochemical impedance spectroscopy analysis showed the smallest radius of the semicircle which indicates the enhanced rate of electron transport for the cell based photoelectrode with trifluoroacetic acid treated TiO2 powder. The solar cell from the untreated TiO2 film showed the power conversion efficiency of 8.86% and the highest efficiency of 9.51% was achieved by the cell fabricated from trifluoroacetic acid treated TiO2 film.

Furaldehyde substrate specificity and kinetics of Saccharomyces cerevisiae alcohol dehydrogenase 1 variants.

PubMed

Laadan, Boaz; Wallace-Salinas, Valeria; Carlsson, Åsa Janfalk; Almeida, João Rm; Rådström, Peter; Gorwa-Grauslund, Marie F

2014-08-09

A previously discovered mutant of Saccharomyces cerevisiae alcohol dehydrogenase 1 (Adh1p) was shown to enable a unique NADH-dependent reduction of 5-hydroxymethylfurfural (HMF), a well-known inhibitor of yeast fermentation. In the present study, site-directed mutagenesis of both native and mutated ADH1 genes was performed in order to identify the key amino acids involved in this substrate shift, resulting in Adh1p-variants with different substrate specificities. In vitro activities of the Adh1p-variants using two furaldehydes, HMF and furfural, revealed that HMF reduction ability could be acquired after a single amino acid substitution (Y295C). The highest activity, however, was reached with the double mutation S110P Y295C. Kinetic characterization with both aldehydes and the in vivo primary substrate acetaldehyde also enabled to correlate the alterations in substrate affinity with the different amino acid substitutions. We demonstrated the key role of Y295C mutation in HMF reduction by Adh1p. We generated and kinetically characterized a group of protein variants using two furaldehyde compounds of industrial relevance. Also, we showed that there is a threshold after which higher in vitro HMF reduction activities do not correlate any more with faster in vivo rates of HMF conversion, indicating other cell limitations in the conversion of HMF.

CuY zeolite catalysts prepared by ultrasonication-assisted ion-exchange for oxidative carbonylation of methanol to dimethyl carbonate.

PubMed

Woo, Je-Min; Seo, Jung Yoon; Kim, Hyunuk; Lee, Dong-Ho; Park, Young Cheol; Yi, Chang-Keun; Park, Yeong Seong; Moon, Jong-Ho

2018-06-01

The influence of ultrasonication treatment on the catalytic performance of CuY zeolite catalysts was investigated for the liquid-phase oxidative carbonylation of methanol to dimethyl carbonate (DMC). The deammoniation method of NH 4 Y into HY zeolites was optimized and characterized by elemental analyzer, derivative thermogravimetry, Brunauer-Emmett-Teller (BET) analyzer, and powder X-ray diffractometry, revealing that the HY zeolite deammoniated at 400 °C presented the highest surface area, complete ammonium/proton ion exchange, and no structure collapse, rendering it the best support from all the prepared zeolites. CuY zeolites were prepared via aqueous phase ion exchange with the aid of ultrasonication. Upon ultrasonication, the Cu + active centers were uniformly dispersed in the Y zeolites, penetrating the core of the zeolite particles in a very short time. In addition to enhancing the Cu dispersity, the ultrasonication treatment influenced the BET surface area, acid amount, Cu + /Cu 2+ ratio, and also had a relatively small impact on the Cu loading. Consequently, adequate exposure to ultrasonication was able to increase the conversion rate of methanol into dimethyl carbonate up to 11.4% with a comparable DMC selectivity of 23.7%. This methanol conversion is 2.65 times higher than that obtained without the ultrasonication treatment. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of cosubstrate concentration on xylose conversion by recombinant, XYL1-expressing Saccharomyces cerevisiae: a comparison of different sugars and ethanol as cosubstrates.

PubMed Central

Meinander, N Q; Hahn-Hägerdal, B

1997-01-01

Conversion of xylose to xylitol by recombinant Saccharomyces cerevisiae expressing the XYL1 gene, encoding xylose reductase, was investigated by using different cosubstrates as generators of reduced cofactors. The effect of a pulse addition of the cosubstrate on xylose conversion in cosubstrate-limited fed-batch cultivation was studied. Glucose, mannose, and fructose, which are transported with high affinity by the same transport system as is xylose, inhibited xylose conversion by 99, 77, and 78%, respectively, reflecting competitive inhibition of xylose transport. Pulse addition of maltose, which is transported by a specific transport system, did not inhibit xylose conversion. Pulse addition of galactose, which is also transported by a specific transporter, inhibited xylose conversion by 51%, in accordance with noncompetitive inhibition between the galactose and glucose/ xylose transport systems. Pulse addition of ethanol inhibited xylose conversion by 15%, explained by inhibition of xylose transport through interference with the hydrophobic regions of the cell membrane. The xylitol yields on the different cosubstrates varied widely. Galactose gave the highest xylitol yield, 5.6 times higher than that for glucose. The difference in redox metabolism of glucose and galactose was suggested to enhance the availability of reduced cofactors for xylose reduction with galactose. The differences in xylitol yield observed between some of the other sugars may also reflect differences in redox metabolism. With all cosubstrates, the xylitol yield was higher under cosubstrate limitation than with cosubstrate excess. PMID:9143128

VizieR Online Data Catalog: Flux conversion factors for the Swift/UVOT filters (Brown+, 2016)

NASA Astrophysics Data System (ADS)

Brown, P. J.; Breeveld, A.; Roming, P. W. A.; Siegel, M.

2016-10-01

The conversion of observed magnitudes (or the actual observed photon or electron count rates) to a flux density is one of the most fundamental calculations. The flux conversions factors for the six Swift/UVOT filters are tabulated in Table1. (1 data file).

Parametric Raman crystalline anti-Stokes laser at 503 nm with collinear beam interaction at tangential phase matching

NASA Astrophysics Data System (ADS)

Smetanin, S. N.; Jelínek, M.; Kubeček, V.

2017-07-01

Stimulated-Raman-scattering in crystals can be used for the single-pass frequency-conversion to the Stokes-shifted wavelengths. The anti-Stokes shift can also be achieved but the phase-matching condition has to be fulfilled because of the parametric four-wave mixing process. To widen the angular-tolerance of four-wave mixing and to obtain high-conversion-efficiency into the anti-Stokes, we developed a new scheme of the parametric Raman anti-Stokes laser at 503 nm with phase-matched collinear beam interaction of orthogonally-polarized Raman components in calcite oriented at the phase-matched angle under 532 nm 20 ps laser excitation. The excitation laser beam was split into two orthogonally-polarized components entering the calcite at the certain incidence angles to fulfill the nearly collinear phase-matching and also to compensate walk-off of extraordinary waves for collinear beam interaction. The phase matching of parametric Raman interaction is tangential and insensitive to the angular mismatch if the Poynting vectors of the biharmonic pump and parametrically generated (anti-Stokes) waves are collinear. For the first time it allows to achieve experimentally the highest conversion efficiency into the anti-Stokes wave (503 nm) up to 30% from the probe wave and up to 3.5% from both pump and probe waves in the single-pass picosecond parametric calcite Raman laser. The highest anti-Stokes pulse energy was 1.4 μJ.

Potential of sustainable hierarchical zeolites in the valorization of α-pinene.

PubMed

Nuttens, Nicolas; Verboekend, Danny; Deneyer, Aron; Van Aelst, Joost; Sels, Bert F

2015-04-13

In the valorization of α-pinene, which is an important biomass intermediate derived from turpentine oil, hierarchical (mesoporous) zeolites represent a superior class of catalysts. Hierarchical USY, ZSM-5, and beta zeolites have been prepared, characterized, and catalytically evaluated, with the aim of combining the highest catalytic performance with the most sustainable synthetic protocol. These zeolites are prepared by alkaline treatment in aqueous solutions of NH4 OH, NaOH, diethylamine, and NaOH complemented with tetrapropylammonium bromide. The hierarchical USY zeolite is the most attractive catalyst of the tested series, and is able to combine an overall organic-free synthesis with an up to sixfold activity enhancement and comparable selectivity over the conventional USY zeolite. This superior performance relates to a threefold greater activity than that of the commercial standard, namely, H2 SO4 /TiO2 . Correlation of the obtained benefits to the amount of solid lost during the postsynthetic modifications highlights that the highest activity gains are obtained with minor leaching. Furthermore, a highly zeolitic character, as determined by bulk XRD, is beneficial, but not crucial, in the conversion of α-pinene. The alkaline treatments not only result in a higher overall activity, but also a more functional external surface area, attaining up to four times the pinene conversions per square nanometer. The efficiency of the hierarchical USY zeolite is concomitantly demonstrated in the conversion of limonene and turpentine oil, which emphasizes its industrial potential. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hard templating ultrathin polycrystalline hematite nanosheets: effect of nano-dimension on CO2 to CO conversion via the reverse water-gas shift reaction.

PubMed

Fishman, Zachary S; He, Yulian; Yang, Ke R; Lounsbury, Amanda W; Zhu, Junqing; Tran, Thanh Minh; Zimmerman, Julie B; Batista, Victor S; Pfefferle, Lisa D

2017-09-14

Understanding how nano-dimensionality impacts iron oxide based catalysis is central to a wide range of applications. Here, we focus on hematite nanosheets, nanowires and nanoparticles as applied to catalyze the reverse water gas shift (RWGS) probe reaction. We introduce a novel approach to synthesize ultrathin (4-7 nm) hematite nanosheets using copper oxide nanosheets as a hard template and propose a reaction mechanism based on density functional theory (DFT) calculations. Hematite nanowires and nanoparticles were also synthesized and characterized. H 2 temperature programmed reduction (H 2 -TPR) and RWGS reactions were performed to glean insights into the mechanism of CO 2 conversion to CO over the iron oxide nanomaterials and were compared to H 2 binding energy calculations based on density functional theory. While the nanosheets did exhibit high CO 2 conversion, 28% at 510 °C, we found that the iron oxide nanowires had the highest CO 2 conversion, reaching 50% at 750 °C under atmospheric pressure. No products besides CO and H 2 O were detected.

External validation of the Cairns Prediction Model (CPM) to predict conversion from laparoscopic to open cholecystectomy.

PubMed

Hu, Alan Shiun Yew; Donohue, Peter O'; Gunnarsson, Ronny K; de Costa, Alan

2018-03-14

Valid and user-friendly prediction models for conversion to open cholecystectomy allow for proper planning prior to surgery. The Cairns Prediction Model (CPM) has been in use clinically in the original study site for the past three years, but has not been tested at other sites. A retrospective, single-centred study collected ultrasonic measurements and clinical variables alongside with conversion status from consecutive patients who underwent laparoscopic cholecystectomy from 2013 to 2016 in The Townsville Hospital, North Queensland, Australia. An area under the curve (AUC) was calculated to externally validate of the CPM. Conversion was necessary in 43 (4.2%) out of 1035 patients. External validation showed an area under the curve of 0.87 (95% CI 0.82-0.93, p = 1.1 × 10 -14 ). In comparison with most previously published models, which have an AUC of approximately 0.80 or less, the CPM has the highest AUC of all published prediction models both for internal and external validation. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

Prevalence and conversion to dementia of Mild Cognitive Impairment in an elderly Italian population.

PubMed

Limongi, Federica; Siviero, Paola; Noale, Marianna; Gesmundo, Antonella; Crepaldi, Gaetano; Maggi, Stefania

2017-06-01

Mild Cognitive Impairment (MCI) represents a significant risk factor for dementia but there are only a few Italian population studies on its prevalence and its rate of conversion to dementia. Aim of this study was to assess the prevalence of MCI, its subtypes, and rates of conversion to dementia 1 year later in an elderly Italian population. The data are based on an Italian multicenter population-based cohort study with both cross-sectional and longitudinal components. Two thousand three hundred thirty-seven individuals over 65 underwent screening, clinical confirmation and 1-year follow-up. The prevalence of MCI was 21.6% and the amnestic multiple domain was the most frequent subtype (63.2%). The conversion rate to dementia was 4.1% and was found only in the amnestic multiple domain and in the unclassifiable subjects, persons with cognitive deficit but neither demented nor with MCI. The prevalence of MCI in this population sample was similar to that found in other population studies using Petersen's modified MCI criteria as well as his original criteria. With regard to conversion to dementia, our results emphasize the importance to better classify the unclassifiable subjects at high risk of progression to dementia and also at risk of being undiagnosed and untreated. MCI is characterized by extreme variability and instability. Data on the prevalence and the rate of conversion from MCI to dementia are difficult to compare given the important differences from study to study especially with regard to the diagnostic criteria utilized and their operationalization.

Evolutionary Stasis in Cycad Plastomes and the First Case of Plastome GC-Biased Gene Conversion

PubMed Central

Wu, Chung-Shien; Chaw, Shu-Miaw

2015-01-01

In angiosperms, gene conversion has been known to reduce the mutational load of plastid genomes (the plastomes). Particularly, more frequent gene conversions in inverted repeat (IR) than in single copy (SC) regions result in contrasting substitution rates between these two regions. However, little has been known about the effect of gene conversion in the evolution of gymnosperm plastomes. Cycads (Cycadophyta) are the second largest gymnosperm group. Evolutionary study of their plastomes is limited to the basal cycad genus, Cycas. In this study, we addressed three questions. 1) Do the plastomes of other cycad genera evolve slowly as previously observed in the plastome of Cycas taitungensis? 2) Do substitution rates differ between their SC and IR regions? And 3) Does gene conversion occur in the cycad plastomes? If yes, is it AT-biased or GC-biased? Plastomes of eight species from other eight genera of cycads were sequenced. These plastomes are highly conserved in genome organization. Excluding ginkgo, cycad plastomes have significantly lower synonymous and nonsynonymous substitution rates than other gymnosperms, reflecting their evolutionary stasis in nucleotide mutations. In the IRs of cycad plastomes, the reduced substitution rates and GC-biased mutations are associated with a GC-biased gene conversion (gBGC) mechanism. Further investigations suggest that in cycads, gBGC is able to rectify plastome-wide mutations. Therefore, this study is the first to uncover the plastomic gBGC in seed plants. We also propose a gBGC model to interpret the dissimilar evolutionary patterns as well as the compositionally biased mutations in the SC and IR regions of cycad plastomes. PMID:26116919

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

Guardia, A. de, E-mail: amaury.de-guardia@cemagref.f; Universite Europeenne de Bretagne, F-35000 Rennes; Mallard, P.

This paper aimed to compare household waste, separated pig solids, food waste, pig slaughterhouse sludge and green algae regarding processes ruling nitrogen dynamic during composting. For each waste, three composting simulations were performed in parallel in three similar reactors (300 L), each one under a constant aeration rate. The aeration flows applied were comprised between 100 and 1100 L/h. The initial waste and the compost were characterized through the measurements of their contents in dry matter, total carbon, Kjeldahl and total ammoniacal nitrogen, nitrite and nitrate. Kjeldahl and total ammoniacal nitrogen and nitrite and nitrate were measured in leachates andmore » in condensates too. Ammonia and nitrous oxide emissions were monitored in continue. The cumulated emissions in ammonia and in nitrous oxide were given for each waste and at each aeration rate. The paper focused on process of ammonification and on transformations and transfer of total ammoniacal nitrogen. The parameters of nitrous oxide emissions were not investigated. The removal rate of total Kjeldahl nitrogen was shown being closely tied to the ammonification rate. Ammonification was modelled thanks to the calculation of the ratio of biodegradable carbon to organic nitrogen content of the biodegradable fraction. The wastes were shown to differ significantly regarding their ammonification ability. Nitrogen balances were calculated by subtracting nitrogen losses from nitrogen removed from material. Defaults in nitrogen balances were assumed to correspond to conversion of nitrate even nitrite into molecular nitrogen and then to the previous conversion by nitrification of total ammoniacal nitrogen. The pool of total ammoniacal nitrogen, i.e. total ammoniacal nitrogen initially contained in waste plus total ammoniacal nitrogen released by ammonification, was calculated for each experiment. Then, this pool was used as the referring amount in the calculation of the rates of accumulation, stripping and nitrification of total ammoniacal nitrogen. Separated pig solids were characterised by a high ability to accumulate total ammoniacal nitrogen. Whatever the waste, the striping rate depended mostly on the aeration rate and on the pool concentration in biofilm. The nitrification rate was observed as all the higher as the concentration in total ammoniacal nitrogen in the initial waste was low. Thus, household waste and green algae exhibited the highest nitrification rates. This result could mean that in case of low concentrations in total ammoniacal nitrogen, a nitrifying biomass was already developed and that this biomass consumed it. In contrast, in case of high concentrations, this could traduce some difficulties for nitrifying microorganisms to develop.« less

Conversational Behaviors in Youth with High-Functioning ASD and Asperger Syndrome

ERIC Educational Resources Information Center

Paul, Rhea; Orlovski, Stephanie Miles; Marcinko, Hillary Chuba; Volkmar, Fred

2009-01-01

Twenty-nine youth with autism spectrum disorders and 26 with typical development between 12 and 18 years of age were engaged in structured interviews (ADOS). The interviews were videotaped and rated for atypical conversational behaviors by trained raters, using the Pragmatic Rating Scale (Landa et al. "Psychol Med" 22:245-254, 1992). The ASD group…

Sex Steroid Metabolism in Benign and Malignant Intact Prostate Biopsies: Individual Profiling of Prostate Intracrinology

PubMed Central

Gianfrilli, Daniele; Pierotti, Silvia; Leonardo, Costantino; Ciccariello, Mauro

2014-01-01

In vitro studies reveal that androgens, oestrogens, and their metabolites play a crucial role in prostate homeostasis. Most of the studies evaluated intraprostatic hormone metabolism using cell lines or preprocessed specimens. Using an ex vivo model of intact tissue cultures with preserved architecture, we characterized the enzymatic profile of biopsies from patients with benign prostatic hyperplasia (BPH) or cancer (PC), focusing on 17β-hydroxy-steroid-dehydrogenases (17β-HSDs) and aromatase activities. Samples from 26 men who underwent prostate needle core biopsies (BPH n = 14; PC n = 12) were incubated with radiolabeled 3H-testosterone or 3H-androstenedione. Conversion was evaluated by TLC separation and beta-scanning of extracted supernatants. We identified three major patterns of conversion. The majority of BPHs revealed no active testosterone/oestradiol conversion as opposed to prostate cancer. Conversion correlated with histology and PSA, but not circulating hormones. Highest Gleason scores had a higher androstenedion-to-testosterone conversion and expression of 17β-HSD-isoenzymes-3/5. Conclusions. We developed an easy tool to profile individual intraprostatic enzymatic activity by characterizing conversion pathways in an intact tissue environment. In fresh biopsies we found that 17β-HSD-isoenzymes and aromatase activities correlate with biological behaviour allowing for morphofunctional phenotyping of pathology specimens and clinical monitoring of novel enzyme-targeting drugs. PMID:25184140

Effects of Appropriate Prolonged Sacral Neuromodulation Testing in Improving Implantation Rate of a Permanent Implantable Pulse Generator in Patients with Refractory Lower Urinary Tract Dysfunctions in Mainland China.

PubMed

Zhang, Peng; Zhang, Jian-Zhong; Wu, Li-Yang; Zhang, Xiao-Dong

2017-02-20

Sacral neuromodulation (SNM) has become an effective method for treating lower urinary tract voiding dysfunction during the past 20 years. Because of the expensive cost, the number of implantable pulse generator (IPG) implantations per year in China is far lower than that in Western developed countries since 2012. This study was to summarize the effects of the appropriate prolonged SNM testing time in improving the implantation rate of a permanent IPG in patients with refractory lower urinary tract symptoms (LUTS) in mainland China. From January 2013 to June 2016, 51 patients with refractory LUTS received SNM therapy. In this study, we compared the conversion rate 2 weeks after the Stage I test and final actual conversion rate. We also observed the complications (such as pain, infection, and electrode displacement) and effectiveness. We tried to improve an appropriate prolonged test time which was favorable for improving the SNM conversion rate while ensuring safety and effectiveness. Among 51 patients receiving SNM therapy, 19 patients (mean age 45.0 ± 16.9 years) had poor Stage I test results, and on an average, the electrode was removed 27.4 ± 9.6 days after the surgery. In one patient, the electrode was removed within 2 weeks; when the remaining 18 patients were questioned 2 weeks after testing, none of the patients wanted to terminate the test, and all the 18 patients desired to prolong the testing time to further observe the treatment effect. The remaining 32 patients (mean age 46.7 ± 15.3 years) received Stage II permanent implantation at 19.6 ± 10.4 days after the surgery. The overall Stage I-II conversion was 62.7% (32/51) in this study. Within 2 weeks after the surgery, only eight patients received Stage II permanent implantation, and the conversion rate was only 15.7% (8/51), which was much lower than the overall conversion rate of 62.7%. Nearly 84.4% (27/32) of the patients received Stage II implantation within 4 weeks. None of the patients had incision infections. In one patient, the entire system was removed 1 month after Stage II implantation due to pain in the implantation site. Appropriate extension of the Stage I testing time of an SNM-barbed electrode could significantly improve the Stage II permanent implantation rate in Chinese refractory LUTS patients; there were no wound infections, and the postoperative complication rate was low. This study recommended that Stage I period of SNM therapy should be 4 weeks according to safety and successful conversion rate.

The clinical efficacy of a clarithromycin-based regimen for Mycobacterium avium complex disease: A nationwide post-marketing study.

PubMed

Kadota, Jun-Ichi; Kurashima, Atsuyuki; Suzuki, Katsuhiro

2017-05-01

The revised 2007 American Thoracic Society/Infectious Diseases Society of America statement recommend clarithromycin-based combination therapy for treatment of Mycobacterium avium complex lung disease and stipulates approximately 1 year of continuous treatment after bacilli negative conversion. However, supporting data are insufficient. Our objective was to obtain data on the clinical outcome of clarithromycin-based daily regimens by conducting a nationwide retrospective post-marketing study of M. avium complex lung disease. In accordance with the Japanese guidelines, patients were enrolled in this survey according to their chest radiographic findings and microbiologic test results. They were treated with a multidrug regimen including clarithromycin, rifampicin, and ethambutol (clarithromycin-based regimen) until bacilli negative conversion, and the treatment was continued for approximately 1 year after the initial conversion. Data were collected before administration, at the time of bacilli negative conversion, at the end of treatment, and at 6 months after the end of treatment. Of the 466 subjects enrolled in the study, 271 patients who received clarithromycin at 800 mg/day underwent evaluation for M. avium complex disease. The final bacilli negative conversion rate in those patients was 94.7%. The bacteriological relapse rate was 5.0% (5/100 patients). Bacteriological relapse was noted in patients treated for less than 15 months after conversion. No life-threatening or serious adverse drug reactions were observed. This study demonstrated that a clarithromycin-based daily regimen can yield a high bacteriological conversion rate in M. avium complex disease. After conversion, treatment for less than 15 months might be insufficient to prevent bacteriological relapse. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Multi-keV x-ray sources from metal-lined cylindrical hohlraums

NASA Astrophysics Data System (ADS)

Jacquet, L.; Girard, F.; Primout, M.; Villette, B.; Stemmler, Ph.

2012-08-01

As multi-keV x-ray sources, plastic hohlraums with inner walls coated with titanium, copper, and germanium have been fired on Omega in September 2009. For all the targets, the measured and calculated multi-keV x-ray power time histories are in a good qualitative agreement. In the same irradiation conditions, measured multi-keV x-ray conversion rates are ˜6%-8% for titanium, ˜2% for copper, and ˜0.5% for germanium. For titanium and copper hohlraums, the measured conversion rates are about two times higher than those given by hydroradiative computations. Conversely, for the germanium hohlraum, a rather good agreement is found between measured and computed conversion rates. To explain these findings, multi-keV integrated emissivities calculated with RADIOM [M. Busquet, Phys. Fluids 85, 4191 (1993)], the nonlocal-thermal-equilibrium atomic physics model used in our computations, have been compared to emissivities obtained from different other models. These comparisons provide an attractive way to explain the discrepancies between experimental and calculated quantitative results.

[Effect of biological pretreatment with Trametes vesicolor on the enzymatic hydrolysis of softwood and hardwood].

PubMed

Yu, Hongbo; Zhang, Xiaoyu

2009-07-01

We evaluated the effect of biological pretreatment with white rot fungus Trametes vesicolor on the enzymatic hydrolysis of two wood species, Chinese willow (Salix babylonica, hardwood) and China-fir (Cunninghamia lanceolata, softwood). The result indicated that the pretreated woods showed significant increases in the final conversion ratios of enzymatic hydrolysis (4.78-fold for hardwood and 4.02-fold for softwood). In order to understand the role of biological pretreatment we investigated the enzyme-substrate interactions. Biological pretreatment enhanced the substrate accessibility to cellulase but not always correlated with the initial conversion rate. However, the change of the conversion rate decreased dramatically with increased desorption values after biological pretreatment. Thus, the biological pretreatment slowed down the declines in conversion rates during enzymatic hydrolysis by reducing the irreversible adsorption of cellulase and then improved the enzymatic hydrolysis. Moreover, the decreases of the irreversible adsorption may be attributed to the partial lignin degradation and alteration in lignin structure after biological pretreatment.

Continuous production of lipase-catalyzed biodiesel in a packed-bed reactor: optimization and enzyme reuse study.

PubMed

Chen, Hsiao-Ching; Ju, Hen-Yi; Wu, Tsung-Ta; Liu, Yung-Chuan; Lee, Chih-Chen; Chang, Cheng; Chung, Yi-Lin; Shieh, Chwen-Jen

2011-01-01

An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in a tert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of molar conversion. On the basis of ridge max analysis, the optimum conditions were as follows: flow rate 0.1 mL/min, temperature 52.1°C, and substrate molar ratio 1 : 4. The predicted and experimental values of molar conversion were 83.31 ± 2.07% and 82.81 ± .98%, respectively. Furthermore, the continuous process over 30 days showed no appreciable decrease in the molar conversion. The paper demonstrates the applicability of using immobilized lipase and a packed-bed reactor for continuous biodiesel synthesis.

Process relevant screening of cellulolytic organisms for consolidated bioprocessing.

PubMed

Antonov, Elena; Schlembach, Ivan; Regestein, Lars; Rosenbaum, Miriam A; Büchs, Jochen

2017-01-01

Although the biocatalytic conversion of cellulosic biomass could replace fossil oil for the production of various compounds, it is often not economically viable due to the high costs of cellulolytic enzymes. One possibility to reduce costs is consolidated bioprocessing (CBP), integrating cellulase production, hydrolysis of cellulose, and the fermentation of the released sugars to the desired product into one process step. To establish such a process, the most suitable cellulase-producing organism has to be identified. Thereby, it is crucial to evaluate the candidates under target process conditions. In this work, the chosen model process was the conversion of cellulose to the platform chemical itaconic acid by a mixed culture of a cellulolytic fungus with Aspergillus terreus as itaconic acid producer. Various cellulase producers were analyzed by the introduced freeze assay that measures the initial carbon release rate, quantifying initial cellulase activity under target process conditions. Promising candidates were then characterized online by monitoring their respiration activity metabolizing cellulose to assess the growth and enzyme production dynamics. The screening of five different cellulase producers with the freeze assay identified Trichoderma   reesei and Penicillium   verruculosum as most promising. The measurement of the respiration activity revealed a retarded induction of cellulase production for P.   verruculosum but a similar cellulase production rate afterwards, compared to T.   reesei . The freeze assay measurement depicted that P.   verruculosum reaches the highest initial carbon release rate among all investigated cellulase producers. After a modification of the cultivation procedure, these results were confirmed by the respiration activity measurement. To compare both methods, a correlation between the measured respiration activity and the initial carbon release rate of the freeze assay was introduced. The analysis revealed that the different initial enzyme/cellulose ratios as well as a discrepancy in cellulose digestibility are the main differences between the two approaches. With two complementary methods to quantify cellulase activity and the dynamics of cellulase production for CBP applications, T.   reesei and P.   verruculosum were identified as compatible candidates for the chosen model process. The presented methods can easily be adapted to screen for suitable cellulose degrading organisms for various other applications.

Conversion of rainforest into agroforestry and monoculture plantation in China: Consequences for soil phosphorus forms and microbial community.

PubMed

Wang, Jinchuang; Ren, Changqi; Cheng, Hanting; Zou, Yukun; Bughio, Mansoor Ahmed; Li, Qinfen

2017-10-01

Microbial communities and their associated enzyme activities affect quantity and quality of phosphorus (P) in soils. Land use change is likely to alter microbial community structure and feedback on ecosystem structure and function. This study presents a novel assessment of mechanistic links between microbial responses to land use and shifts in the amount and quality of soil phosphorus (P). We investigated effects of the conversion of rainforests into rubber agroforests (AF), young rubber (YR), and mature rubber (MR) plantations on soil P fractions (i.e., labile P, moderately labile P, occluded P, Ca P, and residual P) in Hainan Island, Southern China. Microbial community composition and microbial enzyme were assayed to assess microbial community response to forest conversion. In addition, we also identified soil P fractions that were closely related to soil microbial and chemical properties in these forests. Conversion of forest to pure rubber plantations and agroforestry system caused a negative response in soil microorganisms and activity. The bacteria phospholipid fatty acid (PLFAs) levels in young rubber, mature rubber and rubber agroforests decreased after forest conversion, while the fungal PLFAs levels did not change. Arbuscular mycorrhizal fungi (AMF) (16:1w5c) had the highest value of 0.246μmol(gOC) -1 in natural forest, followed by rubber agroforests, mature rubber and young rubber. Level of soil acid phosphatase activity declined soon (5 years) after forest conversion compared to natural forest, but it improved in mature rubber and agroforestry system. Labile P, moderately labile P, occluded P and residual P were highest in young rubber stands, while moderately labile, occluded and residual P were lowest in rubber agroforestry system. Soil P fractions such as labile P, moderately labile P, and Ca P were the most important contributors to the variation in soil microbial community composition. We also found that soil P factions differ significantly among the four transformation systems. Soil labile P faction and its potential sources (moderately labile P, occluded P, and residual P) were positively correlated with NO 3 - , but negatively correlated with AMF, suggesting that these properties play key roles in P transformation. Our study indicated that land use had an impact on microbial community composition and functions, which consequently influenced soil phosphorus availability and cycling. Copyright © 2017 Elsevier B.V. All rights reserved.

AN ACTIVE INTRODUCTION TO SWAHILI. GENERAL CONVERSATION.

ERIC Educational Resources Information Center

STEVICK, EARL; AND OTHERS

THIS TEXT, BASED ON AN "EXPERIMENTAL COURSE IN SWAHILI" (FSI 1965), WAS PREPARED FOR THE PEACE CORPS. THE STUDENT IS INTRODUCED TO THE RUDIMENTS OF SWAHILI GRAMMAR AS WELL AS TO A NUMBER OF THE HIGHEST FREQUENCY PATTERNS AND CLICHES WHICH HE WILL NEED IMMEDIATELY UPON ARRIVAL IN EAST AFRICA. THE DISTINCTIVE FEATURE OF THIS COURSE IS ITS…

Pharmacologic Conversion during Dofetilide Treatment for Persistent Atrial Fibrillation.

PubMed

Steinberg, Jonathan S; Shah, Yash; Szepietowska, Barbara

2017-06-01

Dofetilide is a pure I Kr blocker and is one of the few drugs specifically studied and approved in the United States for the management of persistent atrial fibrillation (AF). Dofetilide has been noted to have a high rate of pharmacologic conversion during initial dosing in prior smaller studies. The intent of the study was to examine the safety of an inpatient loading strategy, and the incidence and patterns of pharmacologic conversion by dofetilide during the treatment of persistent AF in a large consecutive cohort. This is a retrospective analysis of 308 consecutive patients with persistent AF electively admitted for inpatient dofetilide loading. The initiation dose of dofetilide was determined by the creatinine clearance. Overall, 88% (n = 271) successfully completed initiation of dofetilide and were discharged in sinus rhythm. The most common reason for failure to complete initiation of dofetilide loading was QTc prolongation in 24 patients (7.8%), and torsade de pointes occurred in three patients (1%). Pharmacologic conversion was observed in 56% (n = 151) after a median of two doses. The rate of pharmacologic conversion based on the final dose was 75%, 9%, and 0% for 500 mcg, 250 mcg, and 125 mcg, respectively (P < 0.05). Dofetilide is a well-tolerated antiarrhythmic drug with a low incidence of proarrhythmia and an especially high rate of pharmacologic conversion in patients with persistent AF. © 2017 Wiley Periodicals, Inc.

Development of Mesoporous Nanocatalysts for Production of Hydrogen and Fisher Tropsch Studies

NASA Astrophysics Data System (ADS)

Abrokwah, Richard Yeboah

The primary aim of this study was to develop mesoporous nanocatalysts for (i) hydrogen production via steam reforming of methanol (SRM) in a tubular reactor, and (ii) syngas conversion to hydrocarbons via Fisher-Tropsch synthesis using silicon microchannel microreactors. The mesoporous catalysts for SRM were prepared by an optimized one-pot hydrothermal synthesis procedure. The catalysts were investigated for SRM activity in a packed bed tubular reactor using metals, namely, Cu, Co, Ni, Pd, Zn, and Sn. The metals were incorporated in different supports -MCM-41, SBA-15, CeO2, TiO2, and ZrO2 to investigate the influence of support on catalyst properties. A sharp contrast in catalyst performance was noticed depending on the type of support employed. For example, in SRM at 250 °C, Cu supported on amorphous silica SBA-15 and MCM-41 produced significantly less CO (< 7%) compared to other crystalline supports Cu-TiO2 and Cu/ZrO2 that showed high CO selectivity of ˜56% and ˜37%, respectively. Amongst all the metals studied for SRM activity using 1:3 methanol:water mole ratio at 250 °C, 10%Cu-MCM-41 showed the best performance with 68% methanol conversion, 100% H2 , ˜6 % CO, 94% CO2 selectivities, and no methane formation. Furthermore, 10%Cu-CeO2 yielded the lowest CO selectivity of 1.84% and the highest CO2 selectivity of ˜98% at 250 °C. Stability studies of the catalysts conducted for time-on-stream of 40 h at 300 °C revealed that Cu-MCM41 was the most stable and displayed consistent steady state conversion of ˜74%. Our results indicate that, although coking played an influential role in deactivation of most catalysts, thermal sintering and changes in MCM-41 structure can be responsible for the catalyst deactivation. For monomtetallic systems, the MCM-41 supported catalysts especially Pd and Sn showed appreciable hydrothermal stability under the synthesis and reaction conditions. While bimetallic Pd-Co-MCM-41 and Cu-Ni-MCM-41 catalysts produced more CO, Cu-Zn-MCM-41 and Cu-Sn-MCM-41exhibited better SRM activity, and produced much less CO and CH4. In spite of the improved the stability and dispersion of the monometallic active sites in the support, no noticeable synergistic activity was observed in terms of H2 and CO selectivities in the multimetallic catalysts. For the Fisher-Tropsch (F-T) studies, Co-TiO 2, Fe-TiO2 and Ru-TiO2 catalysts were prepared by the sol-gel method and coated on 116 microchannels (50mum wide x 100mum deep) of a Si-microreactor. The F-T process parameters such as temperature, pressure and flow rates were controlled by an in-house setup programmed by LabVIEWRTM. The effect of temperature on F-T activity in the range of 150 to 300°C was investigated at 1 atm, a flow rate of 6 ml/min and a constant H2:CO molar ratio of 2:1. In our initial studies at 220 °C, 12%Ru-TiO2 showed higher CO conversion of 74% and produced the highest C2-C4 hydrocarbon selectivity-of ˜11% ethane, 22% propane and ˜17% butane. The overall catalyst stability and performance was in the order of 12%Ru-TiO2>> 12%Fe-TiO2 > 12%Co-TiO2.

Retrospective Conversion at a Two-Year College.

ERIC Educational Resources Information Center

Krieger, Michael T.

1982-01-01

Findings of a project to convert a single LC class from cards to machine readable tapes at a two-year college suggest that an in-house retrospective conversion is feasible for academic libraries. A high conversion hit rate, implying minimal original cataloging, will keep project costs and duration low. There are five references. (RAA)

5 CFR 531.217 - Special conversion rules for certain non-GS employees.

Code of Federal Regulations, 2012 CFR

2012-01-01

... be converted to GS-equivalent rates immediately before leaving the non-GS system, the employee is... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Special conversion rules for certain non... Appointment Or Position Changes § 531.217 Special conversion rules for certain non-GS employees. When an...

5 CFR 531.217 - Special conversion rules for certain non-GS employees.

Code of Federal Regulations, 2014 CFR

2014-01-01

... be converted to GS-equivalent rates immediately before leaving the non-GS system, the employee is... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Special conversion rules for certain non... Appointment Or Position Changes § 531.217 Special conversion rules for certain non-GS employees. When an...

5 CFR 531.217 - Special conversion rules for certain non-GS employees.

Code of Federal Regulations, 2011 CFR

2011-01-01

... be converted to GS-equivalent rates immediately before leaving the non-GS system, the employee is... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Special conversion rules for certain non... Appointment Or Position Changes § 531.217 Special conversion rules for certain non-GS employees. When an...

5 CFR 531.217 - Special conversion rules for certain non-GS employees.

Code of Federal Regulations, 2013 CFR

2013-01-01

... be converted to GS-equivalent rates immediately before leaving the non-GS system, the employee is... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Special conversion rules for certain non... Appointment Or Position Changes § 531.217 Special conversion rules for certain non-GS employees. When an...

5 CFR 531.217 - Special conversion rules for certain non-GS employees.

Code of Federal Regulations, 2010 CFR

2010-01-01

... be converted to GS-equivalent rates immediately before leaving the non-GS system, the employee is... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Special conversion rules for certain non... Appointment Or Position Changes § 531.217 Special conversion rules for certain non-GS employees. When an...

Mechanism of nuclear spin initiated para-H2 to ortho-H2 conversion.

PubMed

Buntkowsky, G; Walaszek, B; Adamczyk, A; Xu, Y; Limbach, H-H; Chaudret, B

2006-04-28

In this paper a quantitative explanation for a diamagnetic ortho/para H2 conversion is given. The description is based on the quantum-mechanical density matrix formalism originally developed by Alexander and Binsch for studies of exchange processes in NMR spectra. Only the nuclear spin system is treated quantum-mechanically. Employing the model of a three spin system, the reactions of the hydrogen gas with the catalysts are treated as a phenomenological rate process, described by a rate constant. Numerical calculations reveal that for nearly all possible geometrical arrangements of the three spin system an efficient spin conversion is obtained. Only in the chemically improbable case of a linear group H-X-H no spin conversion is obtained. The efficiency of the spin conversion depends strongly on the lifetime of the H-X-H complex and on the presence of exchange interactions between the two hydrogens. Even moderate exchange couplings cause a quench of the spin conversion. Thus a sufficiently strong binding of the dihydrogen to the S spin is necessary to render the quenching by the exchange interaction ineffective.

Performance assessment of U.S. residential cooking exhaust hoods.

PubMed

Delp, William W; Singer, Brett C

2012-06-05

This study assessed the performance of seven new residential cooking exhaust hoods representing common U.S. designs. Laboratory tests were conducted to determine fan curves relating airflow to duct static pressure, sound levels, and exhaust gas capture efficiency for front and back cooktop burners and the oven. Airflow rate sensitivity to duct flow resistance was higher for axial fan devices than for centrifugal fan devices. Pollutant capture efficiency (CE) ranged from <15% to >98%, varying across hoods and with airflow and burner position for each hood. CE was higher for back burners relative to front burners, presumably because most hoods covered only part of the front burners. Open hoods had higher CE than those with grease screen and metal-covered bottoms. The device with the highest CE--exceeding 80% for oven and front burners--had a large, open hood that covered most of the front burners. The airflow rate for this hood surpassed the industry-recommended level of 118 L·s(-1) (250 cfm) and produced sound levels too high for normal conversation. For hoods meeting the sound and fan efficacy criteria for Energy Star, CE was <30% for front and oven burners.

Detection of keyboard vibrations and effects on perceived piano quality.

PubMed

Fontana, Federico; Papetti, Stefano; Järveläinen, Hanna; Avanzini, Federico

2017-11-01

Two experiments were conducted on an upright and a grand piano, both either producing string vibrations or conversely being silent after the initial keypress, while pianists were listening to the feedback from a synthesizer through insulating headphones. In a quality experiment, participants unaware of the silent mode were asked to play freely and then rate the instrument according to a set of attributes and general preference. Participants preferred the vibrating over the silent setup, and preference ratings were associated to auditory attributes of richness and naturalness in the low and middle ranges. Another experiment on the same setup measured the detection of vibrations at the keyboard, while pianists played notes and chords of varying dynamics and duration. Sensitivity to string vibrations was highest in the lowest register and gradually decreased up to note D5. After the percussive transient, the tactile stimuli exhibited spectral peaks of acceleration whose perceptibility was demonstrated by tests conducted in active touch conditions. The two experiments confirm that piano performers perceive vibratory cues of strings mediated by spectral and spatial summations occurring in the Pacinian system in their fingertips, and suggest that such cues play a role in the evaluation of quality of the musical instrument.

Effect of nutrient supplements addition on ethanol production from cheese whey using Candida psuedotropicalis under batch condition

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

Ghaly, A.E.; El-Taweel, A.A.

1995-05-01

Candida psuedotropicalis ATCC 8619 was selected among nine strains of lactose fermenting yeast for the production of ethanol from cheese whey. The effects of three nutrients (ammonium sulfate (NH{sub 4}){sub 2}SO{sub 4}, dipotassium hydrogen phosphate K{sub 2}HPO{sub 4}, yeast extract, and combination of them) on the ethanol yield from cheese whey were investigated. The results indicated that no addition of nutrient supplement is necessary to achieve complete lactose utilization during the cheese whey ethanol fermentation. However, addition of a small concentration (0.005% w/v) of these supplements reduced the lag period and the total fermentation time and increased the specific growthmore » rate of the yeast. Higher concentrations (0.01 and 0.015% w/v) of ammonium sulfate and dipotassium hydrogen phosphate inhibited the cell growth rate of the yeast. The highest ethanol (21.7% g/L) was achieved using yeast extract at a concentration of 0.01% w/v, given a conversion efficiency of 98.3%. No indication of alcohol inhibition was observed in this study. 60 refs., 9 figs., 3 tabs.« less

Effect of prolonged exercise on oxidative damage and susceptibility to oxidants of rat tissues in severe hyperthyroidism.

PubMed

Venditti, P; De Rosa, R; Caldarone, G; Di Meo, S

2005-10-15

We investigated effects of prolonged aerobic exercise and severe hyperthyroidism on indices of oxidative damage, susceptibility to oxidants, and respiratory capacity of homogenates from rat liver, heart and skeletal muscle. Both treatments induced increases in hydroperoxide and protein-bound carbonyl levels. Moreover, the highest increases were found when hyperthyroid animals were subjected to exercise. These changes, which were associated to reduced exercise endurance capacity, were in part due to higher susceptibility to oxidants of hyperthyroid tissues. Levels of oxidative damage indices were scarcely related to changes in antioxidant enzyme activities and lipid-soluble antioxidant concentrations. However, the finding that, following exercise the scavenger levels generally decreased in liver homogenates and increased in heart and muscles ones, suggested a net shuttle of antioxidants from liver to other tissues under need. Aerobic capacity, evaluated by cytochrome oxidase activity, was not modified by exercise, which, conversely, affected the rates of oxygen consumption of hyperthyroid preparations. These results seem to confirm the higher susceptibility of hyperthyroid tissues to oxidative challenge, because the mechanisms underlying the opposite changes in respiration rates during State 4 and State 3 likely involve oxidative modifications of components of mitochondrial respiratory chain, different from cytochrome aa3.

Mother-child conversations about safety: implications for socializing safety values in children.

PubMed

O'Neal, Elizabeth E; Plumert, Jodie M

2014-05-01

This study examined how mothers socialize their children about safety through conversations about potentially unsafe activities. Mothers and their 8- and 10-year-old children discussed and rated the safety of 12 photographs depicting another same-gender child engaged in potentially dangerous activities. Conversations usually unfolded with children giving the first rating or rationale, followed by additional discussion between the mother and child. Mothers and children relied on 2 main types of rationales to justify their ratings: potential outcomes of the activity and specific features of the situation (dangerous and nondangerous). Mothers (but not children) used dangerous feature rationales more often than dangerous outcome rationales. When disagreements arose, mothers typically guided children to adopt their own rating rather than the child's rating. Additionally, children who used more nondangerous feature and outcome rationales had experienced more injuries requiring medical attention. Mothers' focus on dangerous features appears to reflect their efforts to help children make causal connections between dangerous elements of the situation and adverse outcomes that might result.

CO2 conversion in non-thermal plasma and plasma/g-C3N4 catalyst hybrid processes

NASA Astrophysics Data System (ADS)

Lu, Na; Sun, Danfeng; Zhang, Chuke; Jiang, Nan; Shang, Kefeng; Bao, Xiaoding; Li, Jie; Wu, Yan

2018-03-01

Carbon dioxide conversion at atmosphere pressure and low temperature has been studied in a cylindrical dielectric barrier discharge (DBD) reactor. Pure CO2 feed flows to the discharge zone and typical filamentary discharges were obtained in each half-cycle of the applied voltage. The gas temperature increased with discharge time and discharge power, which was found to affect the CO2 decomposition deeply. As the DBD reactor was cooled to ambient temperature, both the conversion of CO2 and the CO yield were enhanced. Especially the energy efficiencies changed slightly with the increase of discharge power and were much higher in cooling condition comparing to those without cooling. At a discharge power of 40 W, the energy efficiency under cooling condition was approximately six times more than that without cooling. Gas flow rate was observed to affect CO2 conversion and 0.1 L min-1 was obtained as optimum gas flow rate under cooling condition. In addition, the CO2 conversion rate in plasma/g-C3N4 catalyst hybrid system was twice times as that in plasma-alone system. In case of cooling, the existence of g-C3N4 catalyst contributed to a 47% increase of CO2 conversion compared to the sole plasma process. The maximum energy-efficiency with g-C3N4 was 0.26 mmol kJ-1 at 20 W, which increased by 157% compared to that without g-C3N4. The synergistic effect of DBD plasma with g-C3N4 on pure CO2 conversion was verified.

Application of an enthalpy balance model of the relation between growth and respiration to temperature acclimation of Eucalyptus globulus seedlings.

PubMed Central

Macfarlane, Craig; Adams, Mark A; Hansen, Lee D

2002-01-01

The enthalpy balance model of growth uses measurements of the rates of heat and CO(2) production to quantify rates of decarboxylation, oxidative phosphorylation and net anabolism. Enthalpy conversion efficiency (eta(H)) and the net rate of conservation of enthalpy in reduced biosynthetic products (R(SG)DeltaH(B)) can be calculated from metabolic heat rate (q) and CO(2) rate (R(CO2)). eta(H) is closely related to carbon conversion efficiency and the efficiency of conservation of available electrons in biosynthetic products. R(SG)DeltaH(B) and eta(H) can be used, together with biomass composition, to describe the rate and efficiency of growth of plant tissues. q is directly related to the rate of O(2) consumption and the ratio q:R(CO2) is inversely related to the respiratory quotient. We grew seedlings of Eucalyptus globulus at 16 and 28 degrees C for four to six weeks, then measured q and R(CO2) using isothermal calorimetry. Respiratory rate at a given temperature was increased by a lower growth temperature but eta(H) was unaffected. Enthalpy conversion efficiency - and, therefore, carbon conversion efficiency - decreased with increasing temperature from 15 to 35 degrees C. The ratio of oxidative phosphorylation to oxygen consumption (P/O ratio) was inferred in vivo from eta(H) and by assuming a constant ratio of growth to maintenance respiration with changing temperature. The P/O ratio decreased from 2.1 at 10-15 degrees C to less than 0.3 at 35 degrees C, suggesting that decreased efficiency was not only due to activity of the alternative oxidase pathway. In agreement with predictions from non-equilibrium thermodynamics, growth rate was maximal near 25 degrees C, where the calculated P/O ratio was about half maximum. We propose that less efficient pathways, such as the alternative oxidase pathway, are necessary to satisfy the condition of conductance matching whilst maintaining a near constant phosphorylation potential. These conditions minimize entropy production and maximize the efficiency of mitochondrial energy conversions as growing conditions change, while maintaining adequate finite rates of energy processing. PMID:12137581

Thermoelectric Oxide Modules (TOMs) for the Direct Conversion of Simulated Solar Radiation into Electrical Energy

PubMed Central

Tomeš, Petr; Trottmann, Matthias; Suter, Clemens; Aguirre, Myriam Heidi; Steinfeld, Aldo; Haueter, Philipp; Weidenkaff, Anke

2010-01-01

The direct conversion of concentrated high temperature solar heat into electrical energy was demonstrated with a series of four–leg thermoelectric oxide modules (TOM). These temperature stable modules were not yet optimized for high efficiency conversion, but served as proof-of-principle for high temperature conversion. They were constructed by connecting two p- (La1.98Sr0.02CuO4) and two n-type (CaMn0.98Nb0.02O3) thermoelements electrically in series and thermally in parallel. The temperature gradient ΔT was applied by a High–Flux Solar Simulator source (HFSS) which generates a spectrum similar to solar radiation. The influence of the graphite layer coated on the hot side of the Al2O3 substrate compared to the uncoated surface on ΔT, Pmax and η was studied in detail. The measurements show an almost linear temperature profile along the thermoelectric legs. The maximum output power of 88.8 mW was reached for a TOM with leg length of 5 mm at ΔT = 622 K. The highest conversion efficiency η was found for a heat flux of 4–8 W cm-2 and the dependence of η on the leg length was investigated.

Potential natural sensitizers extracted from the skin of Canarium odontophyllum fruits for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Lim, Andery; Kumara, N. T. R. N.; Tan, Ai Ling; Mirza, Aminul Huq; Chandrakanthi, R. L. N.; Petra, Mohammad Iskandar; Ming, Lim Chee; Senadeera, G. K. R.; Ekanayake, Piyasiri

2015-03-01

Possibility of use of dye extract from skin samples of a seasonal, indigenous fruit from Borneo, namely Canarium odontophyllum, in dye sensitized solar cells (DSSCs) are explored. Three main groups of flavonoid pigments are detected and these pigments exhibit different UV-vis absorption properties, and hence showing different light harvesting capabilities. When applied in DSSCs. The detected pigment constituents of the extract consist of aurone (maritimein), anthocyanidin (pelargonidin) and anthocyanidin (cyanidin derivatives). When tested in DSSC, the highest conversion efficiency of 1.43% is exhibited by cyanidin derivatives, and this is followed by conversion efficiencies of 0.51% and 0.79% for aurone and pelargonidin, respectively. It is shown that individual pigments, like cyanidin derivatives and pelargonidin, exhibit higher power conversion efficiency when compared to that of C.odontophyllum skin pigment mixture (with a conversion efficiency of only 0.68%). The results indicate a possibility of masking effects of the pigments when used as a mixture. The acidification of C.odontophyllum skin pigments with concentrated hydrochloric acid improves the conversion efficiency of the mixture from 0.68% to 0.99%. The discussion in this paper will draw data and observations from the variation in absorption and adsorption properties, the HOMO-LUMO levels, the energy band gaps and the functional group compositions of the detected flavonoids.

Evaluation of a microwave high-power reception-conversion array for wireless power transmission

NASA Technical Reports Server (NTRS)

Dickinson, R. M.

1975-01-01

Initial performance tests of a 24-sq m area array of rectenna elements are presented. The array is used as the receiving portion of a wireless microwave power transmission engineering verification test system. The transmitting antenna was located at a range of 1.54 km. Output dc voltage and power, input RF power, efficiency, and operating temperatures were obtained for a variety of dc load and RF incident power levels at 2388 MHz. Incident peak RF intensities of up to 170 mW/sq cm yielded up to 30.4 kW of dc output power. The highest derived collection-conversion efficiency of the array was greater than 80 percent.

Fabrication and photovoltaic properties of ZnO nanorods/perovskite solar cells

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

Shirahata, Yasuhiro; Tanaike, Kohei; Akiyama, Tsuyoshi

2016-02-01

ZnO nanorods/perovskite solar cells with different lengths of ZnO nanorods were fabricated. The ZnO nanorods were prepared by chemical bath deposition and directly confirmed to be hexagon-shaped nanorods. The lengths of the ZnO nanorads were controlled by deposition condition of ZnO seed layer. Photovoltaic properties of the ZnO nanorods/CH{sub 3}NH{sub 3}PbI{sub 3} solar cells were investigated by measuring current density-voltage characteristics and incident photon to current conversion efficiency. The highest conversion efficiency was obtained in ZnO nanorods/CH{sub 3}NH{sub 3}PbI{sub 3} with the longest ZnO nanorods.

Highly efficient continuous-wave Nd:YAG ceramic lasers at 946 nm

NASA Astrophysics Data System (ADS)

Zhu, H. Y.; Xu, C. W.; Zhang, J.; Tang, D. Y.; Luo, D. W.; Duan, Y. M.

2013-07-01

Highly efficient CW operation of diode-end-pumped Nd:YAG ceramic lasers at 946 nm is experimentally demonstrated. When a 5 mm long in-house fabricated Nd:YAG ceramic was used as the gain medium, a maximum output power of 10.5 W was obtained under an incident pump power of 35 W, corresponding to an optical conversion efficiency of 30%, while, when a 3 mm long ceramic sample was used, a maximum output power of 8.7 W was generated with a slope efficiency of 65% with respect to the absorbed pump power. Both the optical conversion efficiency and slope efficiency are the highest results reported so far for the diode-pumped 946 nm lasers.

High-efficiency second harmonic generation from a single hybrid ZnO nanowire/Au plasmonic nano-oligomer.

PubMed

Grinblat, Gustavo; Rahmani, Mohsen; Cortés, Emiliano; Caldarola, Martín; Comedi, David; Maier, Stefan A; Bragas, Andrea V

2014-11-12

We introduce a plasmonic-semiconductor hybrid nanosystem, consisting of a ZnO nanowire coupled to a gold pentamer oligomer by crossing the hot-spot. It is demonstrated that the hybrid system exhibits a second harmonic (SH) conversion efficiency of ∼3 × 10(-5)%, which is among the highest values for a nanoscale object at optical frequencies reported so far. The SH intensity was found to be ∼1700 times larger than that from the same nanowire excited outside the hot-spot. Placing high nonlinear susceptibility materials precisely in plasmonic confined-field regions to enhance SH generation opens new perspectives for highly efficient light frequency up-conversion on the nanoscale.

Acoustic and Perceptual Measurement of Expressive Prosody in High-Functioning Autism: Increased Pitch Range and What it Means to Listeners

ERIC Educational Resources Information Center

Nadig, Aparna; Shaw, Holly

2012-01-01

Are there consistent markers of atypical prosody in speakers with high functioning autism (HFA) compared to typically-developing speakers? We examined: (1) acoustic measurements of pitch range, mean pitch and speech rate in conversation, (2) perceptual ratings of conversation for these features and overall prosody, and (3) acoustic measurements of…

12 CFR Appendix B to Subpart A of... - Conversion of Scorecard Measures into Score

Code of Federal Regulations, 2014 CFR

2014-01-01

... 327—Conversion of Scorecard Measures into Score 1. Weighted Average CAMELS Rating Weighted average CAMELS ratings between 1 and 3.5 are assigned a score between 25 and 100 according to the following equation: S = 25 + [(20/3) * (C 2 −1)], where: S = the weighted average CAMELS score; and C = the weighted...

12 CFR Appendix B to Subpart A of... - Conversion of Scorecard Measures into Score

Code of Federal Regulations, 2013 CFR

2013-01-01

... 327—Conversion of Scorecard Measures into Score 1. Weighted Average CAMELS Rating Weighted average CAMELS ratings between 1 and 3.5 are assigned a score between 25 and 100 according to the following equation: S = 25 + [(20/3) * (C 2 −1)], where: S = the weighted average CAMELS score; and C = the weighted...

12 CFR Appendix B to Subpart A of... - Conversion of Scorecard Measures into Score

Code of Federal Regulations, 2012 CFR

2012-01-01

... 327—Conversion of Scorecard Measures into Score 1. Weighted Average CAMELS Rating Weighted average CAMELS ratings between 1 and 3.5 are assigned a score between 25 and 100 according to the following equation: S = 25 + [(20/3) * (C 2 −1)], where: S = the weighted average CAMELS score; and C = the weighted...

Negotiation of Meaning as a Tool for Evaluating Conversational Skills in the OPI

ERIC Educational Resources Information Center

Kitajima, Ryu

2009-01-01

Though the oral proficiency interview (OPI) rates the examinee's overall language proficiency in face-to-face interaction, the rating is based solely upon the evaluation of the examinee's contribution in isolation. No attempt is made to evaluate conversational skills in interaction. A criticism that has been made of the OPI is that the format is…

Effect of impact stress on microbial recovery on an agar surface.

PubMed Central

Stewart, S L; Grinshpun, S A; Willeke, K; Terzieva, S; Ulevicius, V; Donnelly, J

1995-01-01

Microbial stress due to the impaction of microorganisms onto an agar collection surface was studied experimentally. The relative recovery rates of aerosolized Pseudomonas fluorescens and Micrococcus luteus were determined as a function of the impaction velocity by using a moving agar slide impactor operating over a flow rate range from 3.8 to 40 liters/min yielding impaction velocities from 24 to 250 m/s. As a reference, the sixth stage of the Andersen Six-Stage Viable Particle Sizing Sampler was used at its operating flow rate of 28.3 liters/min (24 m/s). At a collection efficiency of close to 100% for the agar slide impactor, an increase in sampling flow rate and, therefore, in impaction velocity produced a significant decline in the percentage of microorganisms recovered. Conversely, when the collection efficiency was less than 100%, greater recovery and lower injury rates occurred. The highest relative rate of recovery (approximately 51% for P. fluorescens and approximately 62% for M. luteus) was obtained on the complete (Trypticase soy agar) medium at 40 and 24 m/s (6.4 and 3.8 liters/min), respectively. M. luteus demonstrated less damage than P. fluorescens, suggesting the hardy nature of the gram-positive strain versus that of the gram-negative microorganism. Comparison of results from the agar slide and Andersen impactors at the same sampling velocity showed that recovery and injury due to collection depends not only on the magnitude of the impaction velocity but also on the degree to which the microorganisms may be embedded in the collection medium.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7747946

Influence of stocking density on growth, body composition and energy budget of Atlantic salmon Salmo salar L. in recirculating aquaculture systems

NASA Astrophysics Data System (ADS)

Liu, Baoliang; Liu, Ying; Liu, Ziyi; Qiu, Denggao; Sun, Guoxiang; Li, Xian

2014-09-01

Atlantic salmon Salmo salar were reared at four stocking densities—high density D 1 (final density ˜39 kg/m3), medium densities D 2 (˜29 kg/m3) and D 3 (˜19 kg/m3), and low density D 4 (˜12 kg/m3)—for 40 days to investigate the effect of stocking density on their growth performance, body composition and energy budgets. Stocking density did not significantly affect specific growth rate in terms of weight (SGRw) but did affect specific growth rate in terms of energy (SGRe). Stocking density significantly influenced the ration level (RLw and RLe), feed conversion ratio (FCRw and FCRe) and apparent digestibility rate (ADR). Ration level and FCRw tended to increase with increasing density. Fish at the highest density D 1 and lowest density D 4 showed lower FCRe and higher ADR than at medium densities. Stocking density significantly affected protein and energy contents of the body but did not affect its moisture, lipid, or ash contents. The expenditure of energy for metabolism in the low-density and high-density groups was lower than that in the medium-density groups. Stocking density affected energy utilization from the feces but had no effect on excretion rate. The greater energy allocation to growth at high density and low density may be attributed to reduced metabolic rate and increased apparent digestibility rate. These findings provide information that will assist selection of suitable stocking densities in the Atlantic-salmon-farming industry.

Longitudinal relationships between college education and patterns of heavy drinking: a comparison between Caucasians and African-Americans.

PubMed

Chen, Pan; Jacobson, Kristen C

2013-09-01

The current study compared longitudinal relationships between college education and patterns of heavy drinking from early adolescence to adulthood for Caucasians and African-Americans. We analyzed data from 9,988 non-Hispanic Caucasian and African-American participants from all four waves of the National Longitudinal Study of Adolescent Health. Growth curve modeling tested differences in rates of change and levels of heavy drinking from ages 13 to 31 years among non-college youth, college withdrawers, 2-year college graduates, and 4-year college graduates, and compared these differences for Caucasians and African-Americans. There were significant racial differences in relationships between college education with both changes in and levels of heavy drinking. Rates of change of heavy drinking differed significantly across the college education groups examined for Caucasians but not for African-Americans. In addition, Caucasians who graduated from 4-year colleges showed the highest levels of heavy drinking after age 20 years, although differences among the four groups diminished by the early 30s. In contrast, for African-Americans, graduates from 2- or 4-year colleges did not show higher levels of heavy drinking from ages 20 to 31 years than the non-college group. Instead, African-American participants who withdrew from college without an associate's, bachelor's, or professional degree consistently exhibited the highest levels of heavy drinking from ages 26 to 31 years. The relationship between college education and increased levels of heavy drinking in young adulthood is significant for Caucasians but not African-Americans. Conversely, African-Americans are likely to be more adversely affected than are Caucasians by college withdrawal. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Longitudinal relationships between college education and patterns of heavy drinking: A comparison between Caucasians and African Americans

PubMed Central

Chen, Pan; Jacobson, Kristen C.

2013-01-01

Purpose The current study compared longitudinal relationships between college education and patterns of heavy drinking from early adolescence to adulthood for Caucasians and African Americans. Methods Data were collected from N=9,988 non-Hispanic Caucasian and African American participants from all four waves of the National Longitudinal Study of Adolescent Health. Growth curve modeling tested differences in rates of change and levels of heavy drinking from ages 13–31 among non-college youth, college withdrawers, 2-year-college graduates, and 4-year-college graduates, and compared these differences for Caucasians and African Americans. Results There were significant racial differences in relationships between college education with both changes in and levels of heavy drinking. Rates of change of heavy drinking differed significantly across the college education groups examined for Caucasians but not for African Americans. In addition, Caucasians who graduated from 4-year colleges showed the highest levels of heavy drinking after age 20, although differences between the four groups diminished by the early 30s. In contrast, for African Americans, graduates from 2- or 4-year colleges did not show higher levels of heavy drinking from ages 20–31 than the non-college group. Instead, African American participants who withdrew from college without an associate’s, bachelor’s, or professional degree consistently exhibited the highest levels of heavy drinking from ages 26–31. Conclusions The relationship between college education and increased levels of heavy drinking in young adulthood is significant for Caucasians but not African Americans. Conversely, African Americans are likely to be more adversely affected than Caucasians by college withdrawal. PMID:23707401

Evaluation of optimal parameters for using low-dose computed tomography to diagnose urolithiasis

NASA Astrophysics Data System (ADS)

Chen, Hui-Hsien; Yu, Cheng-Ching; Hsu, Fang-Yuh

2017-11-01

Urolithiasis is a common disease; patients suspected of suffering from urolithiasis will be examined by abdomen x-ray, Sono, Intraudio Videonous Urography (IVU) and Computed Tomography (CT). The detection rates for calculus in above examinations are respectively: 50-70% (x-ray), 50-60% (Sono), 70-90% (IVU) and 97% (CT). In addition, the effective doses are respectively: 0.63 mSv (x-ray), no radiation dose (Sono), 2.6 mSv (IVU) and 8-16 mSv (CT). Although CT has the highest detection rate for calculus, it also has the highest radiation dose. This research sought to lower the radiation dose by using CT scans with different dose conditions of standard dose (SD), 50% SD, 25% SD, and 15% SD to diagnose patients who suffer from urolithiasis and thus explore the feasibility of examining urolithiasis via CT with lower dose conditions. This research simulated the examination of patients with RANDO phantom, collocating PMMA slice phantom and pig's kidney. Fake calculuses made of five different materials of different sizes were put into the phantom and scanned individually. The results of the scanned images were given to two physicians who had many years of diagnostic experience to interpret the urolithiasis images. This study explored the different image qualities of CT with different dose conditions. In addition, this research used thermoluminescent dosimeters (TLD) to measure the radiation doses and compared the results with the dose values shown on the screen of the CT scanner to estimate the dose conversion factor (k). The research results showed that a low-dose CT was able to provide good image quality and thus have a lower radiation dose. Therefore, a low-dose CT is suggested the main examination method to diagnose patients with urolithiasis.

Direct 1H NMR evidence of spin-rotation coupling as a source of para → ortho-H2 conversion in diamagnetic solvents

NASA Astrophysics Data System (ADS)

Terenzi, Camilla; Bouguet-Bonnet, Sabine; Canet, Daniel

2017-04-01

At ambient temperature, conversion from 100% enriched para-hydrogen (p-H2; singlet state) to ortho-hydrogen (o-H2; triplet state) leads necessarily to the thermodynamic equilibrium proportions: 75% of o-H2 and 25% of p-H2. When p-H2 is dissolved in a diamagnetic organic solvent, conversion is very slow and can be considered as arising from nuclear spin relaxation phenomena. A first relaxation mechanism, specific to the singlet state and involving a combination of auto-correlation and cross correlation spectral densities, can be retained: randomly fluctuating magnetic fields due to inter-molecular dipolar interactions. We demonstrate here that (i) this dipolar mechanism is not sufficient for accounting for the p a r a →o r t h o conversion rate, (ii) spin-rotation interaction, an intra-molecular mechanism, behaves similarly to random-field interaction and, thus, may be involved in the singlet relaxation rate. Also, as the p a r a →o r t h o conversion is monitored by proton nuclear magnetic resonance (NMR) of dissolved o-H2 (p-H2 is NMR-silent), one has to account for H2 exchange between the liquid phase and the gas phase within the NMR tube, as well as for dissolution effects. Experimental evidence of the above statements is brought here in the case of two organic solvents: acetone-d6 and carbon disulfide. The observed temperature dependence of the p a r a →o r t h o conversion rate shows that spin-rotation can be the dominant contribution to the p-H2 relaxation rate in the absence of tangible dipolar interactions. Our findings shed new light on the "mysterious" mechanism of the p a r a →o r t h o conversion which has been searched for several decades.

Talking Less during Social Interactions Predicts Enjoyment: A Mobile Sensing Pilot Study

PubMed Central

Sandstrom, Gillian M.; Tseng, Vincent Wen-Sheng; Costa, Jean; Okeke, Fabian; Choudhury, Tanzeem; Dunn, Elizabeth W.

2016-01-01

Can we predict which conversations are enjoyable without hearing the words that are spoken? A total of 36 participants used a mobile app, My Social Ties, which collected data about 473 conversations that the participants engaged in as they went about their daily lives. We tested whether conversational properties (conversation length, rate of turn taking, proportion of speaking time) and acoustical properties (volume, pitch) could predict enjoyment of a conversation. Surprisingly, people enjoyed their conversations more when they spoke a smaller proportion of the time. This pilot study demonstrates how conversational properties of social interactions can predict psychologically meaningful outcomes, such as how much a person enjoys the conversation. It also illustrates how mobile phones can provide a window into everyday social experiences and well-being. PMID:27438475

Comparison of reconnection in magnetosphere and solar corona

NASA Astrophysics Data System (ADS)

Imada, Shinsuke; Hirai, Mariko; Isobe, Hiroaki; Oka, Mitsuo; Watanabe, Kyoko; Minoshima, Takashi

One of the most famous rapid energy conversion mechanisms in space is a magnetic reconnec-tion. The general concept of a magnetic reconnection is that the rapid energy conversion from magnetic field energy to thermal energy, kinetic energy or non-thermal particle energy. The understanding of rapid energy conversion rates from magnetic field energy to other energy is the fundamental and essential problem in the space physics. One of the important goals for studying magnetic reconnection is to answer what plasma condition/parameter controls the energy conversion rates. Earth's magnetotail has been paid much attention to discuss a mag-netic reconnection, because we can discuss magnetic reconnection characteristics in detail with direct in-situ observation. Recently, solar atmosphere has been focused as a space laboratory for magnetic reconnection because of its variety in plasma condition. So far considerable effort has been devoted toward understanding the energy conversion rates of magnetic reconnection, and various typical features associated with magnetic reconnection have been observed in the Earth's magnetotail and the solar corona. In this talk, we first introduce the variety of plasma condition/parameter in solar corona and Earth's magnetotail. Later, we discuss what plasma condition/parameter controls the energy conversion from magnetic field to especially non-thermal particle. To compare non-thermal electron and ion acceleration in magnetic reconnection, we used Hard X-ray (electron) /Neu-tron monitor (ion) for solar corona and Geotail in-situ measurement (electron and ion) for magnetoatil. We found both of electron and ion accelerations are roughly controlled by re-connection electric field (reconnection rate). However, some detail points are different in ion and electron acceleration. Further, we will discuss what is the major difference between solar corona and Earth's magnetotail for particle acceleration.

Evolutionary Stasis in Cycad Plastomes and the First Case of Plastome GC-Biased Gene Conversion.

PubMed

Wu, Chung-Shien; Chaw, Shu-Miaw

2015-06-27

In angiosperms, gene conversion has been known to reduce the mutational load of plastid genomes (the plastomes). Particularly, more frequent gene conversions in inverted repeat (IR) than in single copy (SC) regions result in contrasting substitution rates between these two regions. However, little has been known about the effect of gene conversion in the evolution of gymnosperm plastomes. Cycads (Cycadophyta) are the second largest gymnosperm group. Evolutionary study of their plastomes is limited to the basal cycad genus, Cycas. In this study, we addressed three questions. 1) Do the plastomes of other cycad genera evolve slowly as previously observed in the plastome of Cycas taitungensis? 2) Do substitution rates differ between their SC and IR regions? And 3) Does gene conversion occur in the cycad plastomes? If yes, is it AT-biased or GC-biased? Plastomes of eight species from other eight genera of cycads were sequenced. These plastomes are highly conserved in genome organization. Excluding ginkgo, cycad plastomes have significantly lower synonymous and nonsynonymous substitution rates than other gymnosperms, reflecting their evolutionary stasis in nucleotide mutations. In the IRs of cycad plastomes, the reduced substitution rates and GC-biased mutations are associated with a GC-biased gene conversion (gBGC) mechanism. Further investigations suggest that in cycads, gBGC is able to rectify plastome-wide mutations. Therefore, this study is the first to uncover the plastomic gBGC in seed plants. We also propose a gBGC model to interpret the dissimilar evolutionary patterns as well as the compositionally biased mutations in the SC and IR regions of cycad plastomes. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Risk factors influencing the early outcome results after laparoscopic repair of perforated duodenal ulcer and their predictive value.

PubMed

Lunevicius, Raimundas; Morkevicius, Matas

2005-09-01

Clear patient selection criteria and indications for laparoscopic repair of perforated duodenal ulcers are necessary. The aims of our study are to report the early outcome results after operation and to define the predictive values of risk factors influencing conversion rate and genesis of suture leakage. Sixty nonrandomly selected patients operated on laparoscopically in a tertiary care academic center between October 1996 and May 2004 for perforated duodenal ulcers were retrospectively analyzed. The primary outcome measures included the duration of symptoms, shock, underlying medical illness, ulcer size, age, Boey score, and the collective predictive value of these variables for conversion and suture leakage rates. Laparoscopic repair was completed in 46 patients (76.7%). Fourteen patients (23.3%) underwent conversion to open repair. Eight patients (13.3%) had postoperative complications. Suture leakage was confirmed in four patients (6.7%). Hospital stay was 7.8+/-5.3 days. There was no mortality. Patients with an ulcer perforation size of >8 mm had a significantly increased risk for conversion to open repair (p<0.05): positive predictive value (PPV) 75%, sensitivity 27%, specificity 98%, and negative predictive value (NPV) 85%. The significance of ulcer perforation size was confirmed by a stepwise logistic regression test (p=0.0201). All patients who developed suture leakage had acute symptoms for >9 h preoperatively (p<0.001): PPV 31%, specificity 84%, sensitivity 100%, and NPV 100%. Conversions happened with surgeons whose previous experience involved 1.8+/-2.3 cases compared to 3.9+/-2.9 cases in successful laparoscopic repair (p=0.039, t test). Ulcer perforation size of >8 mm is a significant risk factor influencing the conversion rate. An increase in the suture leakage rate is predicted by delayed presentation of >9 h.

Efficient co-conversion process of chicken manure into protein feed and organic fertilizer by Hermetia illucens L. (Diptera: Stratiomyidae) larvae and functional bacteria.

PubMed

Xiao, Xiaopeng; Mazza, Lorenzo; Yu, Yongqiang; Cai, Minmin; Zheng, Longyu; Tomberlin, Jeffery K; Yu, Jeffrey; van Huis, Arnold; Yu, Ziniu; Fasulo, Salvatore; Zhang, Jibin

2018-07-01

A chicken manure management process was carried out through co-conversion of Hermetia illucens L. larvae (BSFL) with functional bacteria for producing larvae as feed stuff and organic fertilizer. Thirteen days co-conversion of 1000 kg of chicken manure inoculated with one million 6-day-old BSFL and 10 9  CFU Bacillus subtilis BSF-CL produced aging larvae, followed by eleven days of aerobic fermentation inoculated with the decomposing agent to maturity. 93.2 kg of fresh larvae were harvested from the B. subtilis BSF-CL-inoculated group, while the control group only harvested 80.4 kg of fresh larvae. Chicken manure reduction rate of the B. subtilis BSF-CL-inoculated group was 40.5%, while chicken manure reduction rate of the control group was 35.8%. The weight of BSFL increased by 15.9%, BSFL conversion rate increased by 12.7%, and chicken manure reduction rate increased by 13.4% compared to the control (no B. subtilis BSF-CL). The residue inoculated with decomposing agent had higher maturity (germination index >92%), compared with the no decomposing agent group (germination index ∼86%). The activity patterns of different enzymes further indicated that its production was more mature and stable than that of the no decomposing agent group. Physical and chemical production parameters showed that the residue inoculated with the decomposing agent was more suitable for organic fertilizer than the no decomposing agent group. Both, the co-conversion of chicken manure by BSFL with its synergistic bacteria and the aerobic fermentation with the decomposing agent required only 24 days. The results demonstrate that co-conversion process could shorten the processing time of chicken manure compared to traditional compost process. Gut bacteria could enhance manure conversion and manure reduction. We established efficient manure co-conversion process by black soldier fly and bacteria and harvest high value-added larvae mass and biofertilizer. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assessment of anaerobic biodegradability of five different solid organic wastes

NASA Astrophysics Data System (ADS)

Kristanto, Gabriel Andari; Asaloei, Huinny

2017-03-01

The concept of waste to energy emerges as an alternative solution to increasing waste generation and energy crisis. In the waste to energy concept, waste will be used to produce renewable energy through thermochemical, biochemical, and physiochemical processes. In an anaerobic digester, organic matter brake-down due to anaerobic bacteria produces methane gas as energy source. The organic waste break-down is affected by various characteristics of waste components, such as organic matter content (C, N, O, H, P), solid contents (TS and VS), nutrients ratio (C/N), and pH. This research aims to analyze biodegradability and potential methane production (CH4) from organic waste largely available in Indonesia. Five solid wastes comprised of fecal sludge, cow rumen, goat farm waste, traditional market waste, and tofu dregs were analyzed which showed tofu dregs as waste with the highest rate of biodegradability compared to others since the tofu dregs do not contain any inhibitor which is lignin, have 2.7%VS, 14 C/N ratios and 97.3% organic matter. The highest cumulative methane production known as Biochemical Methane Potential was achieved by tofu dregs with volume of 77 ml during 30-day experiment which then followed by cow rumen, goat farm waste, and traditional market waste. Subsequently, methane productions were calculated through percentage of COD reduction, which showed the efficiency of 99.1% that indicates complete conversion of the high organic matter into methane.

The shadow of dichloroacetonitrile (DCAN), a typical nitrogenous disinfection by-product (N-DBP), in the waterworks and its backwash water reuse.

PubMed

Tan, Yiwen; Lin, Tao; Jiang, Fuchun; Dong, Jian; Chen, Wei; Zhou, Dongju

2017-08-01

Dichloroacetonitrile (DCAN) is one of nitrogenous disinfection by-products (N-DBPs) with strong cytotoxicity and genotoxicity. In this study, the formation potential (FP) of DCAN was investigated in the samples of six important water sources located in the Yangtze River Delta. The highest formation concentration of DCAN was 9.05 μg/L in the water sample taken from Taihu Lake with the lowest SUVA value. After the NOM fractionation, the conversion rate of hydrophilic fraction to DCAN was found the highest. Subsequently, a waterworks using Taihu Lake as water source was chosen to research the FP variations of DCAN in the treatment process and backwash water. The results showed that, compared to the conventional treatment process, O/biological activated carbon (BAC) process increased the removal efficiency of DCAN from 21.89% to 50.58% by removing aromatic protein and soluble biological by-products as main precursors of DCAN. The DCAN FP in the effluent of BAC filters using old granular activated carbon was higher than that in the influent and the DCAN FP of its backwash water was lower than that in raw water. In the backwash water of sand filters, the DCAN FP higher than raw water required the recycle ratio less than 5% to avoid the accumulation of DCAN. Copyright © 2017 Elsevier Ltd. All rights reserved.

5 CFR 9901.372 - Conversion or movement out of NSPS pay system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... worksite, and pay as of the day immediately before the date of conversion or movement out of NSPS. An... employee's pay band. If the employee's adjusted salary equals or exceeds the step 4 rate of the second... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Conversion or movement out of NSPS pay...

Adding moxifloxacin is associated with a shorter time to culture conversion in pulmonary tuberculosis.

PubMed

Wang, J-Y; Wang, J-T; Tsai, T-H; Hsu, C-L; Yu, C-J; Hsueh, P-R; Lee, L-N; Yang, P-C

2010-01-01

To investigate whether adding moxifloxacin (MXF) to the standard anti-tuberculosis regimen can shorten the time to sputum culture conversion in pulmonary tuberculosis (PTB). Adults with culture-positive PTB were divided into two treatment groups by their choice: standard regimen alone (HERZ group) and standard regimen plus daily 400 mg MXF in the first 2 months (MXF group). Sputum samples were collected thrice weekly in the first 8 weeks. The propensity score was calculated to estimate the conditional probability of entering the MXF group. Factors influencing time to culture conversion were investigated using Cox proportional hazards regression analysis stratified by propensity score. Sixty-two patients were enrolled in the MXF group and 88 in the HERZ group; respectively 51 and 72 completed the study. The regimen was modified before culture conversion in respectively 6 (12%) and 12 (16%; P = 0.47) patients, due to adverse effects. The time to culture conversion was shorter in the MXF group (HR 2.1, 95%CI 1.4-3.2). The culture conversion rate after 6 weeks of treatment was respectively 82% and 61% (P = 0.011, <0.05/4, calculated using the modified Bonferroni method). Adding MXF to the standard anti-tuberculosis regimen in the first 2 months was associated with a shorter time to culture conversion, a higher 6-week culture conversion rate and reduced transmission of tuberculosis.

Sequestration of flue gas CO₂ by direct gas-solid carbonation of air pollution control system residues.

PubMed

Tian, Sicong; Jiang, Jianguo

2012-12-18

Direct gas-solid carbonation reactions of residues from an air pollution control system (APCr) were conducted using different combinations of simulated flue gas to study the impact on CO₂ sequestration. X-ray diffraction analysis of APCr determined the existence of CaClOH, whose maximum theoretical CO₂ sequestration potential of 58.13 g CO₂/kg APCr was calculated by the reference intensity ratio method. The reaction mechanism obeyed a model of a fast kinetics-controlled process followed by a slow product layer diffusion-controlled process. Temperature is the key factor in direct gas-solid carbonation and had a notable influence on both the carbonation conversion and the CO₂ sequestration rate. The optimal CO₂ sequestrating temperature of 395 °C was easily obtained for APCr using a continuous heating experiment. CO₂ content in the flue gas had a definite influence on the CO₂ sequestration rate of the kinetics-controlled process, but almost no influence on the final carbonation conversion. Typical concentrations of SO₂ in the flue gas could not only accelerate the carbonation reaction rate of the product layer diffusion-controlled process, but also could improve the final carbonation conversion. Maximum carbonation conversions of between 68.6% and 77.1% were achieved in a typical flue gas. Features of rapid CO₂ sequestration rate, strong impurities resistance, and high capture conversion for direct gas-solid carbonation were proved in this study, which presents a theoretical foundation for the applied use of this encouraging technology on carbon capture and storage.

Land use effects on soil organic carbon sequestration in calcareous leptosols in former pastureland - a case study from the Tatra Mountains (Poland)

NASA Astrophysics Data System (ADS)

Wasak, K.; Drewnik, M.

2015-05-01

The purpose of the paper is to show SOC sequestration rates in calcareous shallow soils in reforested areas in Tatra Mts. with a particular focus on the different forms of organic matter (OM) storage. Three plant communities creating a mosaic on the slopes of the valley were taken into account. After 50 years since the conversion of pastureland to grassland, dwarf pine shrub, and larch forest on soils, the development of genetic soil horizons as well as SOC sequestration in soil occur despite the steepness of slopes. SOC stock is the highest in soils under larch forest (63.5 mg ha-1, SD 16.3), while in soil under grassland and under dwarf pine shrub, this value is smaller (47.5 mg ha-1, SD 13.3 and 42.9 mg ha-1, SD 22.0 respectively). The highest amount of mineral-associated OM inside stable microaggregates (MOM FF3) is found in grassland soil (21.9-27.1% of SOC), less under dwarf pine shrub (16.3-19.3% of SOC) and larch forest (15.3-17.7% of SOC). The pool of mineral-associated OM inside transitional macroaggregates (MOM FF2) is found in soil under dwarf pine shrub (39.2-59.2% of SOC), with less under larch forest (43.8-44.7% of SOC) and the least in grassland soil (37.9-41.6% of SOC). The highest amount of the free light particulate fraction (POM LF1) is found in soil under dwarf pine shrub (6.6-10.3% of SOC), with less under larch forest (2.6-6.2% of SOC) and the least in grassland soil (1.7-4.8% of SOC).

Land use effects on soil organic carbon sequestration in calcareous Leptosols in former pastureland - a case study from the Tatra Mountains (Poland)

NASA Astrophysics Data System (ADS)

Wasak, K.; Drewnik, M.

2015-10-01

The purpose of the paper is to describe soil organic carbon (SOC) sequestration rates in calcareous shallow soils in reforested areas in the Tatra Mountains with a particular focus on different forms of organic matter (OM) storage. Three plant communities creating a mosaic on the slopes of the studied valley were taken into account. Fifty years since the conversion of pastureland to unused grassland, dwarf pine shrub and larch forest have emerged in the study area, along with the development of genetic soil horizons as well as SOC sequestration in the soil despite the steepness of slopes. SOC stock was measured to be the highest in soils under larch forest (63.5 Mg ha-1), while in soil under grassland and under dwarf pine shrub, this value was found to be smaller (47.5 and 42.9 Mg ha-1, respectively). The highest amount of mineral-associated OM inside stable microaggregates (MOM FF3) was found in grassland soil (21.9-27.1 % of SOC) and less under dwarf pine shrub (16.3-19.3 % of SOC) and larch forest (15.3-17.7 % of SOC). A pool of mineral-associated OM inside transitional macroaggregates (MOM FF2) was found in soil under dwarf pine shrub (39.2-59.2 % of SOC), with less under larch forest (43.8-44.7 % of SOC) and the least in grassland soil (37.9-41.6 % of SOC). The highest amount of the free light particulate fraction (POM LF1) was found in soil under dwarf pine shrub (6.6-10.3 % of SOC), with less under larch forest (2.6-6.2 % of SOC) and the least in grassland soil (1.7-4.8 % of SOC).

40 CFR 63.626 - Performance tests and compliance provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... affected facility. P = equivalent P2O5 feed rate, metric ton/hr (ton/hr). K = conversion factor, 1000 mg/g... P2O5 stored, metric tons (tons). K = conversion factor, 1000 mg/g (453,600 mg/lb). (ii) Method 13A or... Where: E = emission rate of total fluorides, g/metric ton (lb/ton) of equivalent P2O5 feed. Csi...

40 CFR 63.626 - Performance tests and compliance provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... affected facility. P = equivalent P2O5 feed rate, metric ton/hr (ton/hr). K = conversion factor, 1000 mg/g... P2O5 stored, metric tons (tons). K = conversion factor, 1000 mg/g (453,600 mg/lb). (ii) Method 13A or... Where: E = emission rate of total fluorides, g/metric ton (lb/ton) of equivalent P2O5 feed. Csi...

40 CFR 63.626 - Performance tests and compliance provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... affected facility. P = equivalent P2O5 feed rate, metric ton/hr (ton/hr). K = conversion factor, 1000 mg/g... P2O5 stored, metric tons (tons). K = conversion factor, 1000 mg/g (453,600 mg/lb). (ii) Method 13A or... Where: E = emission rate of total fluorides, g/metric ton (lb/ton) of equivalent P2O5 feed. Csi...

Expanding Learning and Social Interaction through Intelligent Systems Design: Implementing a Reputation and Recommender System for the Claremont Conversation Online

ERIC Educational Resources Information Center

Thoms, Brian

2009-01-01

In this dissertation I examine the design, construction and implementation of an online blog ratings and user recommender system for the Claremont Conversation Online (CCO). In line with constructivist learning models and practical information systems (IS) design, I implemented a blog ratings system (a system that can be extended to allow for…

Talker Differences in Clear and Conversational Speech: Perceived Sentence Clarity for Young Adults with Normal Hearing and Older Adults with Hearing Loss

ERIC Educational Resources Information Center

Ferguson, Sarah Hargus; Morgan, Shae D.

2018-01-01

Purpose: The purpose of this study is to examine talker differences for subjectively rated speech clarity in clear versus conversational speech, to determine whether ratings differ for young adults with normal hearing (YNH listeners) and older adults with hearing impairment (OHI listeners), and to explore effects of certain talker characteristics…

Glass Cliffs, Queen Bees, and the Snow-Woman Effect: Persistent Barriers to Women's Leadership in the Academy

ERIC Educational Resources Information Center

Pasquerella, Lynn; Clauss-Ehlers, Caroline S.

2017-01-01

By outlining some of the familiar and persistent barriers to women's leadership at the highest administrative levels within colleges and universities, the authors want to open a conversation about how to accelerate the type of change embodied by Ronald Takaki's notion of a "different mirror." Developing this notion, Takaki asks,…

Efficient generation of far-infrared radiation in the vicinity of polariton resonance of lithium niobate.

PubMed

Lin, Xiaomu; Wang, Lei; Ding, Yujie J

2012-09-01

We efficiently generated far-infrared radiation at the wavelengths centered at 20.8 μm in the vicinity of one of the polariton resonances of lithium niobate. Such an efficient nonlinear conversion is made possible by exploiting phase matching for difference-frequency generation in lithium niobate. The highest peak power reached 233 W.

Hip Arthroscopy in Patients Age 40 or Older: A Systematic Review.

PubMed

Horner, Nolan S; Ekhtiari, Seper; Simunovic, Nicole; Safran, Marc R; Philippon, Marc J; Ayeni, Olufemi R

2017-02-01

To (1) report clinical outcomes, complication rates, and total hip arthroplasty (THA) conversion rates for patients age 40 or older who underwent hip arthroscopy, and (2) report any age-related predictors of outcome identified in the literature. MEDLINE, EMBASE, and PubMed were searched for relevant studies and pertinent data were abstracted from eligible studies. No meta-analysis was performed because of heterogeneity amongst studies. Seventeen studies were included in this review comprising 16,327 patients, including 9,954 patients age 40 or older. All studies reported statistically significant improvements in outcomes after hip arthroscopy for femoral osteochondroplasty, labral repair, or unspecified indications. In patients 40 or older who underwent labral debridement, these improvements were not clinically significant. Obesity and osteoarthritic changes predicted poorer outcomes. Only 1 of 3 studies directly comparing the 2 groups found that patients 40 or older had a significantly less improvement in a standardized hip outcome score than patients under 40 after hip arthroscopy, but all found that patients 40 or older had significantly higher rates of THA conversion. The rate of conversion to THA was 18.1% for patients 40 or older, 23.1% for patients over 50, and 25.2% for patients over 60 with a mean of 25.0 months to THA. Indications for hip arthroscopy including femoral osteochondroplasty and labral repair resulted in clinically significant improvements in patients 40 or older in most research studies examined in this review, whereas labral debridement did not produce clinically significant improvements postoperatively in the same studies. In these studies, the rate of conversion to THA is higher than in patients under 40 and increases with each decade of life, with many individual studies showing a significant increase in the rate of THA conversion. Hip arthroscopy may be suitable for some patients 40 or older, but patient selection is key and patients should be informed of the higher risk of conversion to THA. Level IV, systematic review of Level III and IV studies. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

A positive take on schizophrenia negative symptom scales: Converting scores between the SANS, NSA and SDS.

PubMed

Preda, Adrian; Nguyen, Dana D; Bustillo, Juan R; Belger, Aysenil; O'Leary, Daniel S; McEwen, Sarah; Ling, Shichun; Faziola, Lawrence; Mathalon, Daniel H; Ford, Judith M; Potkin, Steven G; van Erp, Theo G M

2018-06-20

To provide quantitative conversions between commonly used scales for the assessment of negative symptoms in schizophrenia. Linear regression analyses generated conversion equations between symptom scores from the Scale for the Assessment of Negative Symptoms (SANS), the Schedule for the Deficit Syndrome (SDS), the Positive and Negative Syndrome Scale (PANSS), or the Negative Symptoms Assessment (NSA) based on a cross sectional sample of 176 individuals with schizophrenia. Intraclass correlations assessed the rating conversion accuracy based on a separate sub-sample of 29 patients who took part in the initial study as well as an independent sample of 28 additional subjects with schizophrenia. Between-scale negative symptom ratings were moderately to highly correlated (r = 0.73-0.91). Intraclass correlations between the original negative symptom rating scores and those obtained via using the conversion equations were in the range of 0.61-0.79. While there is a degree of non-overlap, several negative symptoms scores reflect measures of similar constructs and may be reliably converted between some scales. The conversion equations are provided at http://www.converteasy.org and may be used for meta- and mega-analyses that examine negative symptoms. Copyright © 2018 Elsevier B.V. All rights reserved.

Catalytic Ethanol Dehydration over Different Acid-activated Montmorillonite Clays.

PubMed

Krutpijit, Chadaporn; Jongsomjit, Bunjerd

2016-01-01

In the present study, the catalytic dehydration of ethanol to obtain ethylene over montmorillonite clays (MMT) with mineral acid activation including H2SO4 (SA-MMT), HCl (HA-MMT) and HNO3 (NA-MMT) was investigated at temperature range of 200 to 400°C. It revealed that HA-MMT exhibited the highest catalytic activity. Ethanol conversion and ethylene selectivity were found to increase with increased reaction temperature. At 400°C, the HA-MMT yielded 82% of ethanol conversion having 78% of ethylene yield. At lower temperature (i.e. 200 to 300°C), diethyl ether (DEE) was a major product. The highest activity obtained from HA-MMT can be attributed to an increase of weak acid sites and acid density by the activation of MMT with HCl. It can be also proven by various characterization techniques that in most case, the main structure of MMT did not alter by acid activation (excepted for NA-MMT). Upon the stability test for 72 h during the reaction, the MMT and HA-MMT showed only slight deactivation due to carbon deposition. Hence, the acid activation of MMT by HCl is promising to enhance the catalytic dehydration of ethanol.

A solar photovoltaic system with ideal efficiency close to the theoretical limit.

PubMed

Zhao, Yuan; Sheng, Ming-Yu; Zhou, Wei-Xi; Shen, Yan; Hu, Er-Tao; Chen, Jian-Bo; Xu, Min; Zheng, Yu-Xiang; Lee, Young-Pak; Lynch, David W; Chen, Liang-Yao

2012-01-02

In order to overcome some physical limits, a solar system consisting of five single-junction photocells with four optical filters is studied. The four filters divide the solar spectrum into five spectral regions. Each single-junction photocell with the highest photovoltaic efficiency in a narrower spectral region is chosen to optimally fit into the bandwidth of that spectral region. Under the condition of solar radiation ranging from 2.4 SUN to 3.8 SUN (AM1.5G), the measured peak efficiency under 2.8 SUN radiation reaches about 35.6%, corresponding to an ideal efficiency of about 42.7%, achieved for the photocell system with a perfect diode structure. Based on the detailed-balance model, the calculated theoretical efficiency limit for the system consisting of 5 single-junction photocells can be about 52.9% under 2.8 SUN (AM1.5G) radiation, implying that the ratio of the highest photovoltaic conversion efficiency for the ideal photodiode structure to the theoretical efficiency limit can reach about 80.7%. The results of this work will provide a way to further enhance the photovoltaic conversion efficiency for solar cell systems in future applications.

POSS-Based Electrolyte for Efficient Solid-State Dye-Sensitized Solar Cells at Sub-Zero Temperatures.

PubMed

Lv, Kai; Zhang, Wei; Zhang, Lu; Wang, Zhong-Sheng

2016-03-02

To expand the application of solid-state dye-sensitized solar cells (ssDSSCs) to low temperatures, it is necessary to develop new solid electrolytes with low glass transition temperature (Tg). The Tg is regulated by varying the length of alkyl chain that is connected with the nitrogen atom in the imidazolium ring linked to the polyhedral oligomeric silsesquioxane (POSS). The Tg as low as -8.8 °C is achieved with the POSS grafted with methyl-substituted imidazolium. The effect of alkyl group on the conductivity, Tg, and photovoltaic performance has also been investigated. The conductivity and power conversion efficiency increase with the alkyl length, while the Tg first increases and then decreases with the alkyl length. Among the synthesized POSS-based ionic conductors, the POSS grafted with the methyl-substituted imidazolium yields the highest power conversion efficiency of 6.98% at RT due to its highest conductivity, and the efficiency (6.52%) is still good at -4 °C, as its Tg (-8.8 °C) is lower than the working temperature (-4 °C). This finding suggests that the POSS-based solid electrolyte is promising for subzero-temperature applications of ssDSSCs.

Waste Conversion into n-Caprylate and n-Caproate: Resource Recovery from Wine Lees Using Anaerobic Reactor Microbiomes and In-line Extraction

PubMed Central

Kucek, Leo A.; Xu, Jiajie; Nguyen, Mytien; Angenent, Largus T.

2016-01-01

To convert wastes into sustainable liquid fuels and chemicals, new resource recovery technologies are required. Chain elongation is a carboxylate-platform bioprocess that converts short-chain carboxylates (SCCs) (e.g., acetate [C2] and n-butyrate [C4]) into medium-chain carboxylates (MCCs) (e.g., n-caprylate [C8] and n-caproate [C6]) with hydrogen gas as a side product. Ethanol or another electron donor (e.g., lactate, carbohydrate) is required. Competitive MCC productivities, yields (product vs. substrate fed), and specificities (product vs. all products) were only achieved previously from an organic waste material when exogenous ethanol had been added. Here, we converted a real organic waste, which inherently contains ethanol, into MCCs with n-caprylate as the target product. We used wine lees, which consisted primarily of settled yeast cells and ethanol from wine fermentation, and produced MCCs with a reactor microbiome. We operated the bioreactor at a pH of 5.2 and with continuous in-line extraction and achieved a MCC productivity of 3.9 g COD/L-d at an organic loading rate of 5.8 g COD/L-d, resulting in a promising MCC yield of 67% and specificities of 36% for each n-caprylate and n-caproate (72% for both). Compared to all other studies that used complex organic substrates, we achieved the highest n-caprylate-to-ncaproate product ratio of 1.0 (COD basis), because we used increased broth-recycle rates through the forward membrane contactor, which improved in-line extraction rates. Increased recycle rates also allowed us to achieve the highest reported MCC production flux per membrane surface area thus far (20.1 g COD/m2-d). Through microbial community analyses, we determined that an operational taxonomic unit (OTU) for Bacteroides spp. was dominant and was positively correlated with increased MCC productivities. Our data also suggested that the microbiome may have been shaped for improved MCC production by the high broth-recycle rates. Comparable abiotic studies suggest that further increases in the broth-recycle rates could improve the overall mass transfer coefficient and its corresponding MCC production flux by almost 30 times beyond the maximum that we achieved. With improved in-line extraction, the chain-elongation biotechnology production platform offers new opportunities for resource recovery and sustainable production of liquid fuels and chemicals. PMID:27933053

Quantifying above- and belowground biomass carbon loss with forest conversion in tropical lowlands of Sumatra (Indonesia).

PubMed

Kotowska, Martyna M; Leuschner, Christoph; Triadiati, Triadiati; Meriem, Selis; Hertel, Dietrich

2015-10-01

Natural forests in South-East Asia have been extensively converted into other land-use systems in the past decades and still show high deforestation rates. Historically, lowland forests have been converted into rubber forests, but more recently, the dominant conversion is into oil palm plantations. While it is expected that the large-scale conversion has strong effects on the carbon cycle, detailed studies quantifying carbon pools and total net primary production (NPPtotal ) in above- and belowground tree biomass in land-use systems replacing rainforest (incl. oil palm plantations) are rare so far. We measured above- and belowground carbon pools in tree biomass together with NPPtotal in natural old-growth forests, 'jungle rubber' agroforests under natural tree cover, and rubber and oil palm monocultures in Sumatra. In total, 32 stands (eight plot replicates per land-use system) were studied in two different regions. Total tree biomass in the natural forest (mean: 384 Mg ha(-1) ) was more than two times higher than in jungle rubber stands (147 Mg ha(-1) ) and >four times higher than in monoculture rubber and oil palm plantations (78 and 50 Mg ha(-1) ). NPPtotal was higher in the natural forest (24 Mg ha(-1)  yr(-1) ) than in the rubber systems (20 and 15 Mg ha(-1)  yr(-1) ), but was highest in the oil palm system (33 Mg ha(-1)  yr(-1) ) due to very high fruit production (15-20 Mg ha(-1)  yr(-1) ). NPPtotal was dominated in all systems by aboveground production, but belowground productivity was significantly higher in the natural forest and jungle rubber than in plantations. We conclude that conversion of natural lowland forest into different agricultural systems leads to a strong reduction not only in the biomass carbon pool (up to 166 Mg C ha(-1) ) but also in carbon sequestration as carbon residence time (i.e. biomass-C:NPP-C) was 3-10 times higher in the natural forest than in rubber and oil palm plantations. © 2015 John Wiley & Sons Ltd.

Predictive Factors for Visual Field Conversion: Comparison of Scanning Laser Polarimetry and Optical Coherence Tomography.

PubMed

Diekmann, Theresa; Schrems-Hoesl, Laura M; Mardin, Christian Y; Laemmer, Robert; Horn, Folkert K; Kruse, Friedrich E; Schrems, Wolfgang A

2018-02-01

The purpose of this study was to compare the ability of scanning laser polarimetry (SLP) and spectral-domain optical coherence tomography (SD-OCT) to predict future visual field conversion of subjects with ocular hypertension and early glaucoma. All patients were recruited from the Erlangen glaucoma registry and examined using standard automated perimetry, 24-hour intraocular pressure profile, and optic disc photography. Peripapillary retinal nerve fiber layer thickness (RNFL) measurements were obtained by SLP (GDx-VCC) and SD-OCT (Spectralis OCT). Positive and negative predictive values (PPV, NPV) were calculated for morphologic parameters of SLP and SD-OCT. Kaplan-Meier survival curves were plotted and log-rank tests were performed to compare the survival distributions. Contingency tables and Venn-diagrams were calculated to compare the predictive ability. The study included 207 patients-75 with ocular hypertension, 85 with early glaucoma, and 47 controls. Median follow-up was 4.5 years. A total of 29 patients (14.0%) developed visual field conversion during follow-up. SLP temporal-inferior RNFL [0.667; 95% confidence interval (CI), 0.281-0.935] and SD-OCT temporal-inferior RNFL (0.571; 95% CI, 0.317-0.802) achieved the highest PPV; nerve fiber indicator (0.923; 95% CI, 0.876-0.957) and SD-OCT mean (0.898; 95% CI, 0.847-0.937) achieved the highest NPV of all investigated parameters. The Kaplan-Meier curves confirmed significantly higher survival for subjects within normal limits of measurements of both devices (P<0.001). Venn diagrams tested with McNemar test statistics showed no significant difference for PPV (P=0.219) or NPV (P=0.678). Both GDx-VCC and SD-OCT demonstrate comparable results in predicting future visual field conversion if taking typical scans for GDx-VCC. In addition, the likelihood ratios suggest that GDx-VCC's nerve fiber indicator<30 may be the most useful parameter to confirm future nonconversion. (http://www.ClinicalTrials.gov number, NTC00494923; Erlangen Glaucoma Registry).

Effects of conversation interference on annoyance due to aircraft noise

NASA Technical Reports Server (NTRS)

Key, K. F.; Powell, C. A.

1980-01-01

The annoyance and interference effects of aircraft flyover noise on face to face conversation were investigated. Twenty 5 minute sessions, each composed of three flyovers, were presented to each of 20 pairs of female subjects in a simulated living room. Flyovers varied in peak noise level (55-79 dB, A-weighted) and spectrum (low or high frequency components). Subjects engaged in conversation for 10 sessions and in reverie for the other 10 sessions, and completed subjective ratings following every session. Annoyance was affected by noise level, but was not significantly different for the two activities of reverie and conversation. A noise level of 77 db was found unacceptable for conversation by 50 percent of the subjects. Conversation interference was assessed by incidence of increased vocal effort and/or interruption of conversation during flyovers. Although conversation interference increased with noise level, the conversation interference measures did not improve prediction of individual annoyance judgments.

1.5- μm single photon counting using polarization-independent up-conversion detector

NASA Astrophysics Data System (ADS)

Takesue, Hiroki; Diamanti, Eleni; Langrock, Carsten; Fejer, M. M.; Yamamoto, Yoshihisa

2006-12-01

We report a 1.5- μm band polarization independent single photon detector based on frequency up-conversion in periodically poled lithium niobate (PPLN) waveguides. To overcome the polarization dependence of the PPLN waveguides, we employed a polarization diversity configuration composed of two up-conversion detectors connected with a polarization beam splitter. We experimentally confirmed polarization independent single photon counting using our detector. We undertook a proof-of-principle differential phase shift quantum key distribution experiment using the detector, and confirmed that the sifted key rate and error rate remained stable when the polarization state was changed during single photon transmission.

Comparing the Daily Versus the Intermittent Regimens of the Anti-Tubercular Chemotherapy in the Initial Intensive Phase in Non-HIV, Sputum Positive, Pulmonary Tuberculosis Patients.

PubMed

Mandal, Pranab Kumar; Mandal, Abhijit; Bhattacharyya, Sujit Kumar

2013-02-01

Tuberculosis (TB) is a major health problem in the universe and India is no longer exempted from this crisis .The emergence of HIV and MDRTB (Multi Drug Resistant Tuberculosis) have further made the situation critical. Our aim was to compare the efficacy of the daily and the intermittent doses of the Anti Tubercular Drug (ATD) therapy which is under the Revised National Tuberculosis Control Programme, amongst the sputum positive pulmonary tuberculosis in terms of the sputum conversion rate at the end of the initial phase , the default rate and the adverse drug reactions. This was an observational prospective study. Eighty three patients were selected from the out patient and the inpatient departments of a tertiary medical centre in India. Forty three cases received an intermittent regimen, where the major age group belonged to the under 40 years age group, the default rate to the therapy was 9.3%, the sputum conversion rate was 94.87% and adverse drug reactions were found in 25.58% of the patients. In the daily regimen, there was an equal proportion of the age group of the patients, both above and below 40 yrs, the sputum conversion rate was 94.74%, a default rate was found in 5% cases and adverse reactions were found in 35% of the cases. Both the intermittent and the daily regimens showed equal sputum conversion rates and the drug default cases were found more in the intermittent group. However, the adverse reactions were found more in the daily regimen category.

Biodiesel production using waste frying oil

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

Charpe, Trupti W.; Rathod, Virendra K., E-mail: vk.rathod@ictmumbai.edu.in

2011-01-15

Research highlights: {yields} Waste sunflower frying oil is successfully converted to biodiesel using lipase as catalyst. {yields} Various process parameters that affects the conversion of transesterification reaction such as temperature, enzyme concentration, methanol: oil ratio and solvent are optimized. {yields} Inhibitory effect of methanol on lipase is reduced by adding methanol in three stages. {yields} Polar solvents like n-hexane and n-heptane increases the conversion of tranesterification reaction. - Abstract: Waste sunflower frying oil is used in biodiesel production by transesterification using an enzyme as a catalyst in a batch reactor. Various microbial lipases have been used in transesterification reaction tomore » select an optimum lipase. The effects of various parameters such as temperature, methanol:oil ratio, enzyme concentration and solvent on the conversion of methyl ester have been studied. The Pseudomonas fluorescens enzyme yielded the highest conversion. Using the P. fluorescens enzyme, the optimum conditions included a temperature of 45 deg. C, an enzyme concentration of 5% and a methanol:oil molar ratio 3:1. To avoid an inhibitory effect, the addition of methanol was performed in three stages. The conversion obtained after 24 h of reaction increased from 55.8% to 63.84% because of the stage-wise addition of methanol. The addition of a non-polar solvent result in a higher conversion compared to polar solvents. Transesterification of waste sunflower frying oil under the optimum conditions and single-stage methanol addition was compared to the refined sunflower oil.« less

Two-Stage Variable Sample-Rate Conversion System

NASA Technical Reports Server (NTRS)

Tkacenko, Andre

2009-01-01

A two-stage variable sample-rate conversion (SRC) system has been pro posed as part of a digital signal-processing system in a digital com munication radio receiver that utilizes a variety of data rates. The proposed system would be used as an interface between (1) an analog- todigital converter used in the front end of the receiver to sample an intermediatefrequency signal at a fixed input rate and (2) digita lly implemented tracking loops in subsequent stages that operate at v arious sample rates that are generally lower than the input sample r ate. This Two-Stage System would be capable of converting from an input sample rate to a desired lower output sample rate that could be var iable and not necessarily a rational fraction of the input rate.

Enhancing conversation skills in patients with Alzheimer's disease using a prosthetic memory aid.

PubMed

Bourgeois, M S

1990-01-01

The effectiveness of teaching Alzheimer's disease subjects to use a prosthetic memory aid when conversing with familiar partners was evaluated. Effects of the training of three topics by caregivers was assessed in daily probes with the experimenter and twice weekly probes with a familiar conversational partner. All 3 subjects learned to use the memory aid with both conversational partners and improved the quality of their conversational content. Subjects made significantly more statements of fact and fewer ambiguous utterances after training on each topic according to a multiple baseline design. All subjects also generated novel, untrained statements in conversations with both partners. Treatment effects were maintained at high levels throughout training and at 3- and 6-week follow-up sessions. Naive judges rated baseline and posttreatment conversational samples as significantly improved on all eight conversational dimensions.

LifeChanger: A Pilot Study of a Game-Based Curriculum for Sexuality Education.

PubMed

Gilliam, Melissa; Jagoda, Patrick; Heathcock, Stephen; Orzalli, Sarah; Saper, Carolyn; Dudley, Jessyca; Wilson, Claire

2016-04-01

To assess the feasibility and acceptability of a game-based sexuality education curriculum. Curriculum evaluation used descriptive statistics, observation, and qualitative and quantitative data collection. The study was conducted in eighth grade classrooms in Chicago, Illinois. Students from 3 eighth grade classrooms from a school using a game-based curriculum. The intervention had 11 modules and used an ecological model informed by the extant literature. The intervention was developed by the Game Changer Chicago Design Lab and featured a card game designed with youth participation. The study outcomes of interest included learning, feasibility, and acceptability of the curriculum. Students highly rated frank conversation via "Ask the Doctor" sessions and role-playing. Students raised concerns about the breadth of activities, preferring to explore fewer topics in greater depth. A game-based curriculum was feasible, yet students placed the highest value on frank discussion about sexuality. Copyright © 2016 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.