Neutron Decay with PERC: a Progress Report

NASA Astrophysics Data System (ADS)

Konrad, G.; Abele, H.; Beck, M.; Drescher, C.; Dubbers, D.; Erhart, J.; Fillunger, H.; Gösselsberger, C.; Heil, W.; Horvath, M.; Jericha, E.; Klauser, C.; Klenke, J.; Märkisch, B.; Maix, R. K.; Mest, H.; Nowak, S.; Rebrova, N.; Roick, C.; Sauerzopf, C.; Schmidt, U.; Soldner, T.; Wang, X.; Zimmer, O.; Perc Collaboration

2012-02-01

The PERC collaboration will perform high-precision measurements of angular correlations in neutron beta decay at the beam facility MEPHISTO of the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Munich, Germany. The new beam station PERC, a clean, bright, and versatile source of neutron decay products, is designed to improve the sensitivity of neutron decay studies by one order of magnitude. The charged decay products are collected by a strong longitudinal magnetic field directly from inside a neutron guide. This combination provides the highest phase space density of decay products. A magnetic mirror serves to perform precise cuts in phase space, reducing related systematic errors. The new instrument PERC is under development by an international collaboration. The physics motivation, sensitivity, and applications of PERC as well as the status of the design and preliminary results on uncertainties in proton spectroscopy are presented in this paper.

CERT tribal internship program. Final intern report: D`Lisa Penney, 1994

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

NONE

1998-09-01

The purpose of this intern`s project was to: education the Nez Perce people of the Hanford situation; begin researching into past and present health effects from the Hanford site; and inform and educate the Nez Perce people of the Hanford site and past exposures. The specific objectives were to begin researching the history of Nez Perce people and Hanford; create an understanding for the importance of this research; define the radiation and risks and how they occur; inform the Nez Perce people of the issue; and write the paper so it is easy to understand. This intern report contains amore » copy of the final paper written for the Nez Perce people. Because the dose reconstruction for Hanford is not complete, the health effects section is informative, but not definitive.« less

Comparison of Retrograde Intrarenal Surgery and Micro-Percutaneous Nephrolithotomy in Moderately Sized Pediatric Kidney Stones.

PubMed

Baş, Okan; Dede, Onur; Aydogmus, Yasin; Utangaç, Mazhar; Yikilmaz, Taha Numan; Damar, Erman; Nalbant, İsmail; Bozkurt, Ömer Faruk

2016-07-01

To compare the effectiveness and reliability of retrograde intrarenal surgery (RIRS) and micro-percutaneous nephrolithotomy (micro-perc) for the management of kidney stones in pediatric patients. A retrospective analysis was made of pediatric patients aged <18 years with kidney stones that ranged from 10 to 20 mm in size, who underwent RIRS (n = 36) or micro-perc (n = 45) in referral centers. In the RIRS group, the mean age of patients was 8.39 ± 4.72 years and in the micro-perc group, it was 5.62 ± 4.50 years (p = 0.01). The mean stone size was 12.80 ± 3.03 mm in the RIRS group and 13.97 ± 3.46 mm in the micro-perc group (p = 0.189). The success rate was 86.2% (n = 31) in the RIRS group and 80.0% (n = 36) in the micro-perc group (p = 0.47). The mean complication rate was 16.6% and 13.3% in the RIRS and micro-perc groups, respectively (p = 0.675). Hospital stay and radiation exposure were significantly lower in the RIRS group (all p < 0.001). The mean anesthesia session was 1.94 in the RIRS group and 1.26 in the micro-perc group (p < 0.001). The mean hemoglobin drop was 0.53 ± 0.87 g/dL in the micro-perc group, and none of the cases required blood transfusion. The results of this study suggested that micro-perc and RIRS were highly effective methods for the treatment of moderately sized renal stones in children, with comparable success and complication rates. Patients and their parents should be informed about the currently available treatment options, and of their efficacy and safety. However, further clinical trials are needed to support these results.

Effect of the Pulmonary Embolism Rule-Out Criteria on Subsequent Thromboembolic Events Among Low-Risk Emergency Department Patients: The PROPER Randomized Clinical Trial.

PubMed

Freund, Yonathan; Cachanado, Marine; Aubry, Adeline; Orsini, Charlotte; Raynal, Pierre-Alexis; Féral-Pierssens, Anne-Laure; Charpentier, Sandrine; Dumas, Florence; Baarir, Nacera; Truchot, Jennifer; Desmettre, Thibaut; Tazarourte, Karim; Beaune, Sebastien; Leleu, Agathe; Khellaf, Mehdi; Wargon, Mathias; Bloom, Ben; Rousseau, Alexandra; Simon, Tabassome; Riou, Bruno

2018-02-13

The safety of the pulmonary embolism rule-out criteria (PERC), an 8-item block of clinical criteria aimed at ruling out pulmonary embolism (PE), has not been assessed in a randomized clinical trial. To prospectively validate the safety of a PERC-based strategy to rule out PE. A crossover cluster-randomized clinical noninferiority trial in 14 emergency departments in France. Patients with a low gestalt clinical probability of PE were included from August 2015 to September 2016, and followed up until December 2016. Each center was randomized for the sequence of intervention periods. In the PERC period, the diagnosis of PE was excluded with no further testing if all 8 items of the PERC rule were negative. The primary end point was the occurrence of a thromboembolic event during the 3-month follow-up period that was not initially diagnosed. The noninferiority margin was set at 1.5%. Secondary end points included the rate of computed tomographic pulmonary angiography (CTPA), median length of stay in the emergency department, and rate of hospital admission. Among 1916 patients who were cluster-randomized (mean age 44 years, 980 [51%] women), 962 were assigned to the PERC group and 954 were assigned to the control group. A total of 1749 patients completed the trial. A PE was diagnosed at initial presentation in 26 patients in the control group (2.7%) vs 14 (1.5%) in the PERC group (difference, 1.3% [95% CI, -0.1% to 2.7%]; P = .052). One PE (0.1%) was diagnosed during follow-up in the PERC group vs none in the control group (difference, 0.1% [95% CI, -∞ to 0.8%]). The proportion of patients undergoing CTPA in the PERC group vs control group was 13% vs 23% (difference, -10% [95% CI, -13% to -6%]; P < .001). In the PERC group, rates were significantly reduced for the median length of emergency department stay (mean reduction, 36 minutes [95% CI, 4 to 68]) and hospital admission (difference, 3.3% [95% CI, 0.1% to 6.6%]). Among very low-risk patients with suspected PE, randomization to a PERC strategy vs conventional strategy did not result in an inferior rate of thromboembolic events over 3 months. These findings support the safety of PERC for very low-risk patients presenting to the emergency department. clinicaltrials.gov Identifier: NCT02375919.

Numerical simulation of transport and sequential biodegradation of chlorinated aliphatic hydrocarbons using CHAIN_2D

NASA Astrophysics Data System (ADS)

Schaerlaekens, J.; Mallants, D.; Imûnek, J.; van Genuchten, M. Th.; Feyen, J.

1999-12-01

Microbiological degradation of perchloroethylene (PCE) under anaerobic conditions follows a series of chain reactions, in which, sequentially, trichloroethylene (TCE), cis-dichloroethylene (c-DCE), vinylchloride (VC) and ethene are generated. First-order degradation rate constants, partitioning coefficients and mass exchange rates for PCE, TCE, c-DCE and VC were compiled from the literature. The parameters were used in a case study of pump-and-treat remediation of a PCE-contaminated site near Tilburg, The Netherlands. Transport, non-equilibrium sorption and biodegradation chain processes at the site were simulated using the CHAIN_2D code without further calibration. The modelled PCE compared reasonably well with observed PCE concentrations in the pumped water. We also performed a scenario analysis by applying several increased reductive dechlorination rates, reflecting different degradation conditions (e.g. addition of yeast extract and citrate). The scenario analysis predicted considerably higher concentrations of the degradation products as a result of enhanced reductive dechlorination of PCE. The predicted levels of the very toxic compound VC were now an order of magnitude above the maximum permissible concentration levels.

Effect of methyl groups on conformational properties of small ionized comb-like polyelectrolytes at the atomic level.

PubMed

Zhao, Hongxia; Liu, Jiaping; Ran, Qianping; Yang, Yong; Shu, Xin

2017-03-01

Comb-like polycarboxylate ether (PCE) molecules with different content of methyl groups substituted on backbone and different location of methyl groups substituted on the side chains, respectively, were designed and were studied in explicit salt solutions by all-atom molecular dynamics simulations. Methyl groups substituted on the backbone of PCE have a great effect on the conformation of PCE. Stiffness of charged backbone was not only affected by the rotational freedom but also the electrostatic repulsion between the charged COO - groups. The interaction of counterions (Na + ) with COO - groups for PCE3 (with part of AA substituted by MAA on the backbone) was stronger and the screen effect was great, which decided the smaller size of PCE3. The interaction between water and COO - groups was strong regardless of the content of AA substituted by MAA on the backbone. The effect of methyl groups substituted on the different location of side chains on the conformation of PCE was less than that of methyl groups substituted on the backbone. The equilibrium sizes of the four PCE molecules with methyl groups substituted on the side chains were similar. Graphical Abstract Effect of methyl groups on conformational properties of small ionized comb-like polyelectrolytes at the atomic level.

Improving couples' quality of life through a Web-based prostate cancer education intervention.

PubMed

Song, Lixin; Rini, Christine; Deal, Allison M; Nielsen, Matthew E; Chang, Hao; Kinneer, Patty; Teal, Randall; Johnson, David C; Dunn, Mary W; Mark, Barbara; Palmer, Mary H

2015-03-01

To evaluate the feasibility and acceptability of a newly developed web-based, couple-oriented intervention called Prostate Cancer Education and Resources for Couples (PERC). Quantitative, qualitative, mixed-methods approach. Oncology outpatient clinics at the University of North Carolina (UNC) Lineberger Comprehensive Cancer Center at UNC–Chapel Hill. 26 patients with localized prostate cancer (PCa) and their partners. Pre- and postpilot quantitative assessments and a postpilot qualitative interview were conducted. General and PCa-specific symptoms, quality of life, psychosocial factors, PERC’s ease of use, and web activities. Improvement was shown in some PCa-specific and general symptoms (small effect sizes for patients and small-to-medium effect sizes for partners), overall quality of life, and physical and social domains of quality of life for patients (small effect sizes). Web activity data indicated high PERC use. Qualitative and quantitative analyses indicated that participants found PERC easy to use and understand,as well as engaging, of high quality, and relevant. Overall, participants were satisfied with PERC and reported that PERC improved their knowledge about symptom management and communication as a couple. PERC was a feasible, acceptable method of reducing the side effects of PCa treatment–related symptoms and improving quality of life. PERC has the potential to reduce the negative impacts of symptoms and enhance quality of life for patients with localized PCa and their partners, particularly for those who live in rural areas and have limited access to post-treatment supportive care.

Staggered transverse tripoles with quadripolar lateral anodes using percutaneous and surgical leads in spinal cord stimulation.

PubMed

Sankarasubramanian, Vishwanath; Buitenweg, Jan R; Holsheimer, Jan; Veltink, Peter H

2013-03-01

In spinal cord stimulation for low-back pain, the use of electrode arrays with both low-power requirements and selective activation of target dorsal column (DC) fibers is desired. The aligned transverse tripolar lead configuration offers the best DC selectivity. Electrode alignment of the same configuration using 3 parallel percutaneous leads is possible, but compromised by longitudinal migration, resulting in loss of DC selectivity. This loss might be repaired by using the adjacent anodal contacts on the lateral leads. To investigate if stimulation using adjacent anodal contacts on the lateral percutaneous leads of a staggered transverse tripole can restore DC selectivity. Staggered transverse tripoles with quadripolar lateral anodes were modeled on the low-thoracic vertebral region (T10-T12) of the spinal cord using (a) percutaneous lead with staggered quadripolar lateral anodal configuration (PERC QD) and (b) laminotomy lead with staggered quadripolar lateral anodal configuration (LAM QD), of the same contact dimensions. The commercially available LAM 565 surgical lead with 16 widely spaced contacts was also modeled. For comparison with PERC QD, staggered transverse tripoles with dual lateral anodes were modeled by using percutaneous lead with staggered dual lateral anodal configuration (PERC ST). The PERC QD improved the depth of DC penetration and enabled selective recruitment of DCs in comparison with PERC ST. Mediolateral selectivity of DCs could not be achieved with the LAM 565. Stimulation using PERC QD improves anodal shielding of dorsal roots and restores DC selectivity. Based on our modeling study, we hypothesize that, in clinical practice, LAM QD can provide an improved performance compared with the PERC QD. Our model also predicts that the same configuration realized on the commercial LAM 565 surgical lead with widely spaced contacts cannot selectively stimulate DCs essential in treating low-back pain.

Genetic analyses of Per.C6 cell clones producing a therapeutic monoclonal antibody regarding productivity and long-term stability.

PubMed

Tsuruta, Lilian Rumi; Lopes Dos Santos, Mariana; Yeda, Fernanda Perez; Okamoto, Oswaldo Keith; Moro, Ana Maria

2016-12-01

Genetic characterization of protein-producing clones represents additional value to cell line development. In the present study, ten Per.C6 clones producing a Rebmab100 monoclonal antibody were selected using two cloning methods: six clones originated from limiting dilution cloning and four by the automated colony picker ClonePix FL. A stability program was performed for 50 generations, including 4 batches distributed along the timeframe to determine specific productivity (Qp) maintenance. Four stable clones (two from limiting dilution and two from ClonePix FL) were further evaluated. The relative mRNA expression levels of both heavy chain (HC) and light chain (LC) genes were verified at generations 0, 30-35, and 50-55 of the stability program. At generations 0 and 30-35, LC gene expression level was higher than HC gene, whereas at generation 50-55, the opposite prevailed. A high correlation was observed between Qp and HC or LC mRNA expression level for all clones at each generation analyzed along the continuous culture. The mRNA stability study was performed at steady-state culture. The LC gene displayed a higher half-life and lower decay constant than HC gene, accounting for the higher observed expression level of LC mRNA in comparison to HC mRNA. Clone R6 was highlighted due its high Qp, mRNA expression levels, and mRNA stability. Besides the benefits of applying genetic characterization for the selection of stable and high-producing clones, the present study shows for the first time the correlation between Qp and HC or LC expression levels and also mRNA stability in clones derived from human cell line Per.C6(®).

Optimization of Controllable Factors in the Aluminum Silicon Eutectic Paste and Rear Silicon Nitride Mono-Passivation Layer of PERC Solar Cells

NASA Astrophysics Data System (ADS)

Park, Sungeun; Park, Hyomin; Kim, Dongseop; Yang, JungYup; Lee, Dongho; Kim, Young-Su; Kim, Hyun-Jong; Suh, Dongchul; Min, Byoung Koun; Kim, Kyung Nam; Park, Se Jin; Kim, Donghwan; Lee, Hae-Seok; Nam, Junggyu; Kang, Yoonmook

2018-05-01

Passivated emitter and rear contact (PERC) is a promising technology owing to high efficiency can be achieved with p-type wafer and their easily applicable to existing lines. In case of using p-type mono wafer, 0.5-1% efficiency increase is expected with PERC technologies compared to existing Al BSF solar cells, while for multi-wafer solar cells it is 0.5-0.8%. We addressed the optimization of PERC solar cells using the Al paste. The paste was prepared from the aluminum-silicon alloy with eutectic composition to avoid the formation of voids that degrade the open-circuit voltage. The glass frit of the paste was changed to improve adhesion. Scanning electron microscopy revealed voids and local back surface field between the aluminum electrode and silicon base. We confirmed the conditions on the SiNx passivation layer for achieving higher efficiency and better adhesion for long-term stability. The cell characteristics were compared across cells containing different pastes. PERC solar cells with the Al/Si eutectic paste exhibited the efficiency of 19.6%.

Gender-specific increase in susceptibility to metabolic syndrome of offspring rats after prenatal caffeine exposure with post-weaning high-fat diet

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

Li, Jing; Luo, Hanwen; Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071

Prenatal caffeine exposure (PCE) alters the hypothalamic–pituitary–adrenocortical (HPA) axis-associated neuroendocrine metabolic programming and induces an increased susceptibility to metabolic syndrome (MS) in intrauterine growth retardation (IUGR) offspring rats. High-fat diet (HFD) is one of the main environmental factors accounting for the incidence of MS. In this study, we aimed to clarify the gender-specific increase in susceptibility to MS in offspring rats after PCE with post-weaning HFD. Maternal Wistar rats were administered with caffeine (120 mg/kg·d) from gestational day 11 until delivery. The offspring rats with normal diet or HFD were euthanized at postnatal week 24, and blood samples were collected.more » Results showed that PCE not only reduced serum adrenocorticotropic hormone (ACTH) and corticosterone levels, but also enhanced serum glucose, triglyceride and total cholesterol (TCH) concentrations in the offspring rats. Moreover, several interactions among PCE, HFD and gender were observed by a three-way ANOVA analysis. In PCE offspring, HFD could aggravate the degree of increased serum triglyceride level. Meanwhile, serum corticosterone levels of females were decreased more obviously than those of males in PCE offspring. The results also revealed interactions between HFD and gender in the levels of serum ACTH, triglyceride and TCH, which were changed more evidently in female HFD offspring. These results indicate that HFD could exacerbate the dysfunction of lipid metabolism and the susceptibility to MS induced by PCE, and the female offspring are more sensitive to HFD-induced neuroendocrine metabolic dysfunction than their male counterparts. - Highlights: • Caffeine induced HPA axis dysfunction in offspring rats fed by high-fat diet (HFD). • Caffeine induced an increased susceptibility to metabolic syndrome. • HFD aggravated susceptibility to metabolic syndrome induced by caffeine. • Female was more sensitive to HFD-induced neuroendocrine metabolic dysfunction than male. • There were interactions among caffeine, high-fat diet and gender.« less

Industrial-hygiene report, perchloroethylene, Carman's Classic Cleaners, Richmond, California, July 28, 1978

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

Ludwig, H.R.

1978-03-01

The survey was part of an industrywide mortality and industrial hygiene study of dry cleaning workers exposure to perchlorethylene. To gather data for this larger study, an on site visit was made to the Carman's Classic Cleaners located in Richmond, California. Carman's Classic Cleaners has been using PCE since the present owner had the building constructed in 1954. About 621 kilograms of clothing were dry cleaned each week, with about 129 liters of PCE consumed monthly. The workforce of six includes two pressers, a full time employee who works at the counter and also sews, a part time maintenance man,more » the owner, and his wife. The owner did all the dry cleaning and spotting while his wife marked clothing and worked the counter. Air samples were collected using battery operated pumps and charcoal tubes. The time weighted average exposure to PCE during the 5 hours of operation was 25 parts per million (ppm) for the dry cleaner and 2ppm for the presser. Samples collected in the vicinity of the front counter, washer, and spotting table indicated PCE levels of 3, 29, and 21ppm, respectively. Five minute peak samples during clothing transfer indicated PCE levels of 22, 38, and 17ppm. These exposures were well within the current standards. However, as PCE is a suspected carcinogen, it is necessary that levels be lowered as much as possible. The author recommends measures to help bring this about.« less

A Novel Role for C5a in B-1 Cell Homeostasis

PubMed Central

Bröker, Katharina; Figge, Julia; Magnusen, Albert F.; Manz, Rudolf A.; Köhl, Jörg; Karsten, Christian M.

2018-01-01

B-1 cells constitute a unique subpopulation of lymphocytes residing mainly in body cavities like the peritoneal cavity (PerC) but are also found in spleen and bone marrow (BM). As innate-like B cells, they mediate first line immune defense through low-affinity natural IgM (nIgM) antibodies. PerC B-1 cells can egress to the spleen and differentiate into nIgM antibody-secreting plasma cells that recognize conserved exogenous and endogenous cellular structures. Homing to and homeostasis within the PerC are regulated by the chemokine CXCL13 released by PerC macrophages and stroma cells. However, the exact mechanisms underlying the regulation of CXCL13 and B-1 homeostasis are not fully explored. B-1 cells play important roles in the inflammatory response to infection, autoimmunity, ischemia/reperfusion injury, obesity, and atherosclerosis. Remarkably, this list of inflammatory entities has a strong overlap with diseases that are regulated by complement suggesting a link between B-1 cells and the complement system. Interestingly, up to now, no data exist regarding the role of complement in B-1 cell biology. Here, we demonstrate for the first time that C5a regulates B-1 cell steady-state dynamics within the peritoneum, the spleen, and the BM. We found decreased B-1a cell numbers in the peritoneum and the spleen of C5aR1−/− mice associated with increased B1-a and B1-b numbers in the spleen and high serum titers of nIgM antibodies directed against phosphorylcholine and several pneumococcal polysaccharides. Similarly, peritoneal B-1a cells were decreased in the peritoneum and splenic B-1a and B-1b cells were increased in C5aR2−/− mice. The decrease in peritoneal B-1 cell numbers was associated with decreased peritoneal CXCL13 levels in C5aR1−/− and C5aR2−/− mice. In search for mechanisms, we found that combined TLR2 and IL-10 receptor activation in PerC macrophages induced strong CXCL13 production, which was significantly reduced in cells from C5aR1- and C5aR2-deficient mice and after combined C5aR-targeting. Such stimulation also induced marked local C5 production by PerC macrophages and C5a generation. Importantly, peritoneal in vivo administration of C5a increased CXCL13 production. Taken together, our findings suggest that local non-canonical C5 activation in PerC macrophages fuels CXCL13 production as a novel mechanism to control B-1 cell homeostasis. PMID:29520270

Low functional programming of renal AT2R mediates the developmental origin of glomerulosclerosis in adult offspring induced by prenatal caffeine exposure.

PubMed

Ao, Ying; Sun, Zhaoxia; Hu, Shuangshuang; Zuo, Na; Li, Bin; Yang, Shuailong; Xia, Liping; Wu, Yong; Wang, Linlong; He, Zheng; Wang, Hui

2015-09-01

Our previous study has indicated that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR) of offspring. Recent research suggested that IUGR is a risk factor for glomerulosclerosis. However, whether PCE could induce glomerulosclerosis and its underlying mechanisms remain unknown. This study aimed to demonstrate the induction to glomerulosclerosis in adult offspring by PCE and its intrauterine programming mechanisms. A rat model of IUGR was established by PCE, male fetuses and adult offspring at the age of postnatal week 24 were euthanized. The results revealed that the adult offspring kidneys in the PCE group exhibited glomerulosclerosis as well as interstitial fibrosis, accompanied by elevated levels of serum creatinine and urine protein. Renal angiotensin II receptor type 2 (AT2R) gene expression in adult offspring was reduced by PCE, whereas the renal angiotensin II receptor type 1a (AT1aR)/AT2R expression ratio was increased. The fetal kidneys in the PCE group displayed an enlarged Bowman's space and a shrunken glomerular tuft, accompanied by a reduced cortex width and an increase in the nephrogenic zone/cortical zone ratio. Observation by electronic microscope revealed structural damage of podocytes; the reduced expression level of podocyte marker genes, nephrin and podocin, was also detected by q-PCR. Moreover, AT2R gene and protein expressions in fetal kidneys were inhibited by PCE, associated with the repression of the gene expression of glial-cell-line-derived neurotrophic factor (GDNF)/tyrosine kinase receptor (c-Ret) signaling pathway. These results demonstrated that PCE could induce dysplasia of fetal kidneys as well as glomerulosclerosis of adult offspring, and the low functional programming of renal AT2R might mediate the developmental origin of adult glomerulosclerosis. Copyright © 2015. Published by Elsevier Inc.

The association of prenatal cocaine exposure, externalizing behavior and adolescent substance use

PubMed Central

Minnes, Sonia; Min, Meeyoung O.; Kim, June-Yung; Francis, Meredith W.; Lang, Adelaide; Wu, Miaoping; Singer, Lynn T.

2017-01-01

Prenatal cocaine exposure (PCE) may increase adolescent substance use through alterations of neurotransmitter systems affecting fetal brain development. The relationship between PCE and substance use at 15 and 17 years was examined. Subjects (365: 186 PCE; 179 non-cocaine exposed (NCE)) supplied biologic and self-report data using the Youth Risk Behavior Surveillance System (YRBSS) and Computerized Diagnostic Interview Schedule for Children (C-DISC 4) at ages 15 and 17. The relationship between PCE and substance use was assessed using General Estimating Equation (GEE) analyses controlling for confounding factors including violence exposure and preschool lead level. Teens with PCE vs. NCE teens were 2 times more likely to use tobacco (OR = 2.1; 95% CI 1.21–3.63; p < .001) and marijuana (OR = 1.85; CI 1.18–2.91; p < .001) and have a substance use disorder at age 17 (OR = 2.51; CI 1.00–6.28; p < .05). Evaluation of PCE status by gender revealed an association between PCE and marijuana use that was more pronounced for boys than girls at 17 years. Violence exposure was also a significant predictor of alcohol (p < .001), tobacco (p < .05), and marijuana (p < .0006) use and substance abuse/dependence (p < .01). Externalizing behavior at age 12 fully mediated the effects of PCE on substance use disorder at age 17 and partially mediated effects of PCE on tobacco use, but did not mediate effects on marijuana use. The percentage of substance use reported increased between 15 and 17 years, with no differences between the PCE and NCE groups. Data suggest specialized drug use prevention measures for children with PCE may benefit this high risk group. PMID:28514694

Restore McComas Watershed; Meadow Creek Watershed, 2002-2003 Annual Report.

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

McRoberts, Heidi

2004-01-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing. During years 2000-2003, trees were planted in riparian areas within the meadow and its tributaries. Culverts have been prioritized for replacement to accommodate fish passage throughoutmore » the watershed. Designs for replacement are being coordinated with the Nez Perce National Forest. Twenty miles of road were contracted for decommissioning. Tribal crews completed maintenance to the previously built fence.« less

Restore McComas Meadows; Meadow Creek Watershed, 2003-2004 Annual Report.

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

McRoberts, Heidi

2006-08-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated and cost shared with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing, planting trees in riparian areas within the meadow and its tributaries, prioritizing culverts for replacement to accommodate fish passage, and decommissioning roads tomore » reduce sediment input. Designs for culvert replacements are being coordinated with the Nez Perce National Forest. 20 miles of roads were decommissioned. Tribal crews completed maintenance to the previously built fence.« less

Experimental Results and Issues on Equalization for Nonlinear Memory Channel: Pre-Cursor Enhanced Ram-DFE Canceler

NASA Technical Reports Server (NTRS)

Yuan, Lu; LeBlanc, James

1998-01-01

This thesis investigates the effects of the High Power Amplifier (HPA) and the filters over a satellite or telemetry channel. The Volterra series expression is presented for the nonlinear channel with memory, and the algorithm is based on the finite-state machine model. A RAM-based algorithm operating on the receiver side, Pre-cursor Enhanced RAM-FSE Canceler (PERC) is developed. A high order modulation scheme , 16-QAM is used for simulation, the results show that PERC provides an efficient and reliable method to transmit data on the bandlimited nonlinear channel. The contribution of PERC algorithm is that it includes both pre-cursors and post-cursors as the RAM address lines, and suggests a new way to make decision on the pre-addresses. Compared with the RAM-DFE structure that only includes post- addresses, the BER versus Eb/NO performance of PERC is substantially enhanced. Experiments are performed for PERC algorithms with different parameters on AWGN channels, and the results are compared and analyzed. The investigation of this thesis includes software simulation and hardware verification. Hardware is setup to collect actual TWT data. Simulation on both the software-generated data and the real-world data are performed. Practical limitations are considered for the hardware collected data. Simulation results verified the reliability of the PERC algorithm. This work was conducted at NMSU in the Center for Space Telemetering and Telecommunications Systems in the Klipsch School of Electrical and Computer Engineering Department.

Parental Perceptions of the Social Environment Are Inversely Related to Constraint of Adolescents’ Neighborhood Physical Activity

PubMed Central

Kepper, Maura; Broyles, Stephanie; Scribner, Richard; Tseng, Tung-Sung; Zabaleta, Jovanny; Griffiths, Lauren; Sothern, Melinda

2016-01-01

Background: The current study examined relationships between the neighborhood social environment (parental perceived collective efficacy (PCE)), constrained behaviors (e.g., avoidance or defensive behaviors) and adolescent offspring neighborhood physical activity in low- versus high-incivility neighborhoods. Methods: Adolescents (n = 71; 11–18 years (14.2, SD ± 1.6); male = 37 (52%); non-white = 24 (33.8%); low-income = 20 (29%); overweight/obese = 40 (56%)) and their parents/guardians enrolled in the Molecular and Social Determinants of Obesity in Developing Youth study were included in the current study. Questionnaires measured parents’/guardians’ PCE, constrained outdoor play practices and offspring neighborhood physical activity. Systematic social observation performed at the parcel-level using Google Street View assessed neighborhood incivilities. t-tests and chi-square tests determined differences by incivilities. Multilevel regression models examined relationships between PCE and: (1) constrained behaviors; and (2) neighborhood physical activity. The Hayes (2013) macro determined the mediating role of constrained behaviors. Results: Parents who had higher PCE reported lower levels of avoidance (p = 0.04) and defensive (p = 0.05) behaviors. However, demographic variables (i.e., gender, race and annual household income) limited these results. The direct relationship between PCE and parent-reported neighborhood physical activity was statistically significant in high-incivility neighborhoods only. Neither avoidance nor defensive behavior mediated the relationship between PCE and neighborhood physical activity. Conclusions: PCE influences parenting behaviors related to youth physical activity. Community-based programs that seek to facilitate social cohesion and control may be needed to increase adolescents’ physical activity. PMID:28009839

The Nez Perce Flight to Canada: An Analysis of the Nez Perce-US Cavalry Conflicts: Applying Historical Lessons Learned to Modern Counterinsurgency and Global War on Terrorism Operations

DTIC Science & Technology

2006-06-16

COUNTERINSURGENCY AND GLOBAL WAR ON TERRORISM OPERATIONS A thesis presented to the Faculty of the US Army Command and General Staff College in partial... Terrorism and counterinsurgency operations in Iraq and Afghanistan. The US Cavalry’s clash with the Nez Perce provides an excellent case study. Their...LESSONS LEARNED TO MODERN COUNTERINSURGENCY AND GLOBAL WAR ON TERRORISM OPERATIONS, by MAJ Scott E. Pfau, 81 pages. This study details the Nez

The Precision Expandable Radar Calibration Sphere (PERCS) With Applications for Laser Imaging and Ranging

NASA Astrophysics Data System (ADS)

Bernhardt, P.; Nicholas, A.; Thomas, L.; Davis, M.; Hoberman, C.; Davis, M.

The Naval Research Laboratory will provide an orbiting calibration sphere to be used with ground-based laser imaging telescopes and HF radio systems. The Precision Expandable Radar Calibration Sphere (PERCS) is a practical, reliable, high-performance HF calibration sphere and laser imaging target to orbit at about 600 km altitude. The sphere will be made of a spherical wire frame with aspect independent radar cross section in the 3 to 35 MHz frequency range. The necessary launch vehicle to place the PERCS in orbit will be provided by the Department of Defense Space Test Program. The expandable calibration target has a stowed diameter of 1 meter and a fully deployed diameter of 10.2 meters. A separate deployment mechanism is provided for the sphere. After deployment, the Precision Expandable Radar Calibration Sphere (PERCS) with 180 vertices will be in a high inclination orbit to scatter radio pulses from a number of ground systems, including (1) over-the-horizon (OTH) radars operated by the United States and Australia; (2) high power HF facilities such as HAARP in Alaska, EISCAT in Norway, and Arecibo in Puerto Rico; (3) the chain of high latitude SuperDARN radars used for auroral region mapping; and (4) HF direction finding for Navy ships. With the PERCS satellite, the accuracy of HF radars can be periodically checked for range, elevation, and azimuth errors. In addition, each of the 360 vertices on the PERCS sphere will support an optical retro-reflector for operations with ground laser facilities used to track satellites. The ground laser systems will be used to measure the precise location of the sphere within one cm accuracy and will provide the spatial orientation of the sphere as well as the rotation rate. The Department of Defense facilities that can use the corner-cube reflectors on the PERCS include (1) the Air Force Maui Optical Site (AMOS), (2) the Starfire Optical Range (SOR), and (3) the NRL Optical Test Facility (OTF).

78 FR 76389 - Notice of Passenger Facility Charge (PFC) Approvals and Disapprovals

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-17

... Perce and City of Lewiston, Lewiston, Idaho. Application Number: 13-04-C-00-LWS. Application Type... aircraft with a seating capacity of less than 20 passengers operating at Lewiston--Nez Perce County...

Innovative manufacturing technologies for low-cost, high efficiency PERC-based PV modules

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

Yelundur, Vijay

2017-04-19

The goal this project was to accelerate the deployment of innovative solar cell and module technologies that reduce the cost of PERC-based modules to best-in-class. New module integration technology was to be used to reduce the cost and reliance on conventional silver bus bar pastes and enhance cell efficiency. On the cell manufacturing front, the cost of PERC solar cells was to be reduced by introducing advanced metallization approaches to increase cell efficiency. These advancements will be combined with process optimization to target cell efficiencies in the range of 21 to 21.5%. This project will also explore the viability ofmore » a bifacial PERC solar cell design to enable cost savings through the use of thin silicon wafers. This project was terminated on 4/30/17 after four months of activity due financial challenges facing the recipient.« less

Association of Prenatal and Early Life Exposure to Tetrachloroethylene (PCE) with Polycystic Ovary Syndrome and Other Reproductive Disorders in the Cape Cod Health Study: A Retrospective Cohort Study

PubMed Central

Mahalingaiah, Shruthi; Winter, Michael R.; Aschengrau, Ann

2016-01-01

Background Tetrachloroethylene (PCE) is an organic lipophilic solvent with possible neuroendocrine toxicity. The objective of this study was to determine the association of prenatal and early childhood exposure to PCE-contaminated drinking water and development of adult-onset Polycystic Ovary Syndrome (PCOS), endometriosis, difficulty conceiving and miscarriage. Methods Five-hundred exposed and 331 unexposed female participants born between 1969 and 1983 completed questionnaires on demographic and lifestyle characteristics, and reproductive disorders. Residential locations from the prenatal period through five years of age were used to estimate early life PCE exposure with water modeling software. Results For any early life exposure to PCE, the adjusted risk ratio for PCOS was 0.9 (95% CI: 0.5–1.6). No statistically significant associations were observed for increasing levels of exposure with PCOS or the other reproductive disorders. Conclusion No meaningful associations were found among adult women with early life exposure to PCE-contaminated drinking water and adult-onset reproductive disorders. PMID:27412368

NEUROTOXICITY OF TETRACHLOROETHYLENE (PERCHLOROETHYLENE): DISCUSSION PAPER

EPA Science Inventory

This paper is a background document for a meeting of neurotoxicity experts to discuss the central nervous system effects of exposure to perchloroethylene (perc). The document reviews the literature on neurological testing of people exposed to perc occupationally in dry cleanin...

Low functional programming of renal AT{sub 2}R mediates the developmental origin of glomerulosclerosis in adult offspring induced by prenatal caffeine exposure

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

Ao, Ying; Hubei Provincial Key Laboratory of Developmentally Originated Disorder, Wuhan 430071; Sun, Zhaoxia

Our previous study has indicated that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR) of offspring. Recent research suggested that IUGR is a risk factor for glomerulosclerosis. However, whether PCE could induce glomerulosclerosis and its underlying mechanisms remain unknown. This study aimed to demonstrate the induction to glomerulosclerosis in adult offspring by PCE and its intrauterine programming mechanisms. A rat model of IUGR was established by PCE, male fetuses and adult offspring at the age of postnatal week 24 were euthanized. The results revealed that the adult offspring kidneys in the PCE group exhibited glomerulosclerosis as well asmore » interstitial fibrosis, accompanied by elevated levels of serum creatinine and urine protein. Renal angiotensin II receptor type 2 (AT{sub 2}R) gene expression in adult offspring was reduced by PCE, whereas the renal angiotensin II receptor type 1a (AT{sub 1a}R)/AT{sub 2}R expression ratio was increased. The fetal kidneys in the PCE group displayed an enlarged Bowman's space and a shrunken glomerular tuft, accompanied by a reduced cortex width and an increase in the nephrogenic zone/cortical zone ratio. Observation by electronic microscope revealed structural damage of podocytes; the reduced expression level of podocyte marker genes, nephrin and podocin, was also detected by q-PCR. Moreover, AT{sub 2}R gene and protein expressions in fetal kidneys were inhibited by PCE, associated with the repression of the gene expression of glial-cell-line-derived neurotrophic factor (GDNF)/tyrosine kinase receptor (c-Ret) signaling pathway. These results demonstrated that PCE could induce dysplasia of fetal kidneys as well as glomerulosclerosis of adult offspring, and the low functional programming of renal AT{sub 2}R might mediate the developmental origin of adult glomerulosclerosis. - Highlights: • Prenatal caffeine exposure induces glomerulosclerosis in adult offspring. • Prenatal caffeine exposure inhibits fetal kidney development. • Prenatal caffeine exposure causes low functional programming of renal AT{sub 2}R.« less

Truck travel characteristics as an indicator of system condition and performance.

DOT National Transportation Integrated Search

2011-07-01

The effect of trucks on the level of service is determined by considering passenger car equivalents (PCE) of trucks. The : Highway Capacity Manual (HCM) uses a single PCE value for all tucks combined. However, the composition of truck traffic : varie...

Impact of the Primary Care Exception on Family Medicine Resident Coding.

PubMed

Cawse-Lucas, Jeanne; Evans, David V; Ruiz, David R; Allcut, Elizabeth A; Andrilla, C Holly A; Thompson, Matthew; Norris, Thomas E

2016-03-01

The Medicare Primary Care Exception (PCE) allows residents to see and bill for less-complex patients independently in the primary care setting, requiring attending physicians only to see patients for higher-level visits and complete physical exams in order to bill for them as such. Primary care residencies apply the PCE in various ways. We investigated the impact of the PCE on resident coding practices. Family medicine residency directors in a five-state region completed a survey regarding interpretation and application of the PCE, including the number of established patient evaluation and management codes entered by residents and attending faculty at their institution. The percentage of high-level codes was compared between residencies using chi-square tests. We analyzed coding data for 125,016 visits from 337 residents and 172 faculty physicians in 15 of 18 eligible family medicine residencies. Among programs applying the PCE criteria to all patients, residents billed 86.7% low-mid complexity and 13.3% high-complexity visits. In programs that only applied the PCE to Medicare patients, residents billed 74.9% low-mid complexity visits and 25.2% high-complexity visits. Attending physicians coded more high-complexity visits at both types of programs. The estimated revenue loss over the 1,650 RRC-required outpatient visits was $2,558.66 per resident and $57,569.85 per year for the average residency in our sample. Residents at family medicine programs that apply the PCE to all patients bill significantly fewer high-complexity visits. This finding leads to compliance and regulatory concerns and suggests significant revenue loss. Further study is required to determine whether this discrepancy also reflects inaccuracy in coding.

A cascaded QSAR model for efficient prediction of overall power conversion efficiency of all-organic dye-sensitized solar cells.

PubMed

Li, Hongzhi; Zhong, Ziyan; Li, Lin; Gao, Rui; Cui, Jingxia; Gao, Ting; Hu, Li Hong; Lu, Yinghua; Su, Zhong-Min; Li, Hui

2015-05-30

A cascaded model is proposed to establish the quantitative structure-activity relationship (QSAR) between the overall power conversion efficiency (PCE) and quantum chemical molecular descriptors of all-organic dye sensitizers. The cascaded model is a two-level network in which the outputs of the first level (JSC, VOC, and FF) are the inputs of the second level, and the ultimate end-point is the overall PCE of dye-sensitized solar cells (DSSCs). The model combines quantum chemical methods and machine learning methods, further including quantum chemical calculations, data division, feature selection, regression, and validation steps. To improve the efficiency of the model and reduce the redundancy and noise of the molecular descriptors, six feature selection methods (multiple linear regression, genetic algorithms, mean impact value, forward selection, backward elimination, and +n-m algorithm) are used with the support vector machine. The best established cascaded model predicts the PCE values of DSSCs with a MAE of 0.57 (%), which is about 10% of the mean value PCE (5.62%). The validation parameters according to the OECD principles are R(2) (0.75), Q(2) (0.77), and Qcv2 (0.76), which demonstrate the great goodness-of-fit, predictivity, and robustness of the model. Additionally, the applicability domain of the cascaded QSAR model is defined for further application. This study demonstrates that the established cascaded model is able to effectively predict the PCE for organic dye sensitizers with very low cost and relatively high accuracy, providing a useful tool for the design of dye sensitizers with high PCE. © 2015 Wiley Periodicals, Inc.

Bridge 232, view looking east in Rock Creek Canyon at ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Bridge 23-2, view looking east in Rock Creek Canyon at Milepost 23.23 - Camas Prairie Railroad, Second Subdivision, From Spalding in Nez Perce County, through Lewis County, to Grangeville in Idaho County, Spalding, Nez Perce County, ID

Comparison of PCE and TCE disappearance in heated volatile organic analysis vials and flame-sealed ampules.

PubMed

Costanza, Jed; Pennell, Kurt D

2008-02-01

The rates of hydrolysis reported for tetrachloroethylene (PCE) and trichloroethylene (TCE) at elevated temperatures range over two orders-of-magnitude, where some of the variability may be due to the presence of a gas phase. Recent studies suggest that volatile organic analysis (VOA) vials provide a low-cost and readily available zero headspace system for measuring aqueous-phase hydrolysis rates. This work involved measuring rates of PCE and TCE disappearance and the corresponding appearance of dechlorination products in water-filled VOA vials and flame-sealed ampules incubated at 21 and 55 degrees C for up to 95.5 days. While PCE and TCE concentrations readily decreased in the VOA vials to yield first-order half lives of 11.2 days for PCE and 21.1 days for TCE at 55 degrees C, concentrations of anticipated dechlorination products, including chloride, remained constant or were not detected. The rate of PCE disappearance was 34 times faster in VOA vials at 55 degrees C compared to values obtained with flame-sealed ampules containing PCE-contaminated water. In addition, the concentration of TCE increased slightly in flame-sealed ampules incubated at 55 degrees C, while a decrease in TCE levels was observed in the VOA vials. The observed losses of PCE and TCE in the VOA vials were attributed to diffusion and sorption in the septa, rather than to dechlorination. These findings demonstrate that VOA vials are not suitable for measuring rates of volatile organic compound hydrolysis at elevated temperatures.

Bridge 231, view looking east at tunnel 5 in Rock ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Bridge 23-1, view looking east at tunnel 5 in Rock Creek Canyon at Milepost 23.1 - Camas Prairie Railroad, Second Subdivision, From Spalding in Nez Perce County, through Lewis County, to Grangeville in Idaho County, Spalding, Nez Perce County, ID

A view over Rock Creek Canyon off Bridge 232 looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A view over Rock Creek Canyon off Bridge 23-2 looking north at Milepost 23.26 - Camas Prairie Railroad, Second Subdivision, From Spalding in Nez Perce County, through Lewis County, to Grangeville in Idaho County, Spalding, Nez Perce County, ID

INHIBITORY EFFECTS OF PERCHLOROETHYLENE ON HUMAN NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS.

EPA Science Inventory

Perchloroethylene (PERC) is a volatile organic solvent with a variety of industrial uses. PERC exposure has been shown to cause adverse neurological effects including deficits in vision and memory in exposed individuals. Despite knowledge of these effects, the mechanisms by whi...

A control technology evaluation of state-of-the-art, perchloroethylene dry-cleaning machines.

PubMed

Earnest, G Scott

2002-05-01

NIOSH researchers evaluated the ability of fifth-generation dry-cleaning machines to control occupational exposure to perchloroethylene (PERC). Use of these machines is mandated in some countries; however, less than 1 percent of all U.S. shops have them. A study was conducted at a U.S. dry-cleaning shop where two fifth-generation machines were used. Both machines had a refrigerated condenser as a primary control and a carbon adsorber as a secondary control to recover PERC vapors during the dry cycle. These machines were designed to lower the PERC concentration in the cylinder at the end of the dry cycle to below 290 ppm. A single-beam infrared photometer continuously monitors the PERC concentration in the machine cylinder, and a door interlock prevents opening until the concentration is below 290 ppm. Personal breathing zone air samples were measured for the machine operator and presser. The operator had time-weighted average (TWA) PERC exposures that were less than 2 ppm. Highest exposures occurred during loading and unloading the machine and when performing routine machine maintenance. All presser samples were below the limit of detection. Real-time video exposure monitoring showed that the operator had peak exposures near 160 ppm during loading and unloading the machine (below the OSHA maximum of 300 ppm). This exposure (160 ppm) is an order of magnitude lower than exposures with more traditional machines that are widely used in the United States. The evaluated machines were very effective at reducing TWA PERC exposures as well as peak exposures that occur during machine loading and unloading. State-of-the-art dry-cleaning machines equipped with refrigerated condensers, carbon adsorbers, drum monitors, and door interlocks can provide substantially better protection than more traditional machines that are widely used in the United States.

Truck travel characteristics as an indicator of system condition and performance : [technical summary].

DOT National Transportation Integrated Search

2011-01-01

Truck traffic has significantly increased in past decades. The effect of trucks on the level of service is determined by considering passenger car equivalents (PCE) of trucks. The Highway Capacity Manual (HCM) uses a single PCE value for all tucks co...

Stratification of chlorinated ethenes natural attenuation in an alluvial aquifer assessed by hydrochemical and biomolecular tools.

PubMed

Němeček, Jan; Dolinová, Iva; Macháčková, Jiřina; Špánek, Roman; Ševců, Alena; Lederer, Tomáš; Černík, Miroslav

2017-10-01

Biomolecular and hydrochemical tools were used to evaluate natural attenuation of chlorinated ethenes in a Quaternary alluvial aquifer located close to a historical source of large-scale tetrachloroethylene (PCE) contamination. Distinct stratification of redox zones was observed, despite the aquifer's small thickness (2.8 m). The uppermost zone of the target aquifer was characterised by oxygen- and nitrate-reducing conditions, with mixed iron- to sulphate-reducing conditions dominant in the lower zone, along with indications of methanogenesis. Natural attenuation of PCE was strongly influenced by redox heterogeneity, while higher levels of PCE degradation coincided with iron- to sulphate reducing conditions. Next generation sequencing of the middle and/or lower zones identified anaerobic bacteria (Firmicutes, Chloroflexi, Actinobacteria and Bacteroidetes) associated with reductive dechlorination. The relative abundance of dechlorinators (Dehalococcoides mccartyi, Dehalobacter sp.) identified by real-time PCR in soil from the lower levels supports the hypothesis that there is a significant potential for reductive dechlorination of PCE. Local conditions were insufficiently reducing for rapid complete dechlorination of PCE to harmless ethene. For reliable assessment of natural attenuation, or when designing monitoring or remedial systems, vertical stratification of key biological and hydrochemical markers should be analysed as standard, even in shallow aquifers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tunnel 5, a view looking west at the east portal ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Tunnel 5, a view looking west at the east portal from Bridge 23-2 at Milepost 23.26 - Camas Prairie Railroad, Second Subdivision, From Spalding in Nez Perce County, through Lewis County, to Grangeville in Idaho County, Spalding, Nez Perce County, ID

Protect and Restore Mill Creek Watershed; Annual Report 2004-2005.

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

McRoberts, Heidi

2005-12-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe and the Nez Perce National Forest (NPNF) have formed a partnership in completing watershed restoration activities, and through this partnership, more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. Starting in FY 2002, continuing intomore » 2004, trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-stream crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed, and one high priority culvert was replaced in 2004. Maintenance to the previously built fence was also completed.« less

Protect and Restore Mill Creek Watershed; Annual Report 2003-2004.

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

McRoberts, Heidi

2004-06-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe and the Nez Perce National Forest have formed a partnership in completing watershed restoration activities, and through this partnership, more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. Starting in FY 2002, continuing into 2004,more » trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-stream crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed, and designs completed on two of the high priority culverts. Maintenance to the previously built fence was also completed.« less

Protect and Restore Mill Creek Watershed : Annual Report CY 2005.

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

McRoberts, Heidi

2006-03-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe and the Nez Perce National Forest (NPNF) have formed a partnership in completing watershed restoration activities, and through this partnership, more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. Starting in FY 2002, continuing intomore » 2004, trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-stream crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed, and one high priority culvert was replaced in 2004. Maintenance to the previously built fence was also completed.« less

76 FR 31388 - Idaho Disaster #ID-00014

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-31

... SMALL BUSINESS ADMINISTRATION [Disaster Declaration 12603 and 12604] Idaho Disaster ID-00014... declaration of a major disaster for Public Assistance Only for the State of Idaho (FEMA-- 1987--DR), dated 05..., Clearwater, Idaho, Nez Perce, Shoshone, Nez Perce Tribe. The Interest Rates are: Percent For Physical Damage...

Pinto common bean cultivars Blackfoot, Nez Perce, and Twin Falls

USDA-ARS?s Scientific Manuscript database

Pinto common bean cultivars Blackfoot (Reg. No. -----,), Nez Perce (Reg. No. -----, PI), and Twin Falls (Reg. No. -----,) were developed at the University of Idaho-Kimberly Research and Extension Center in collaboration with researchers in Colorado, Nebraska, and Washington State. Twin Falls is a fu...

A Fish Consumption Survey of the Nez Perce Tribe

EPA Science Inventory

This report culminates two years of work—preceded by years of discussion—to characterize the current and heritage fish consumption rates and fishing-related activities of the Nez Perce Tribe. The report contains three volumes in one document. Volume I is concerned with heritage r...

Monitoring and evaluation plan for the Nez Perce Tribal Hatchery

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

Steward, C.R.

1996-08-01

The Nez Perce Tribe has proposed to build and operate the Nez Perce Tribal Hatchery (NPTH) in the Clearwater River subbasin of Idaho for the purpose of restoring self-sustaining populations of spring, summer, and fall chinook salmon to their native habitats. The project comprises a combination of incubation and rearing facilities, satellite rearing facilities, juvenile and adult collection sites, and associated production and harvest management activities. As currently conceived, the NPTH program will produce approximately 768,000 spring chinook parr, 800,000 summer chinook fry, and 2,000,000 fall chinook fry on an annual basis. Hatchery fish would be spawned, reared, and releasedmore » under conditions that promote wild-type characteristics, minimize genetic changes in both hatchery and wild chinook populations, and minimize undesirable ecological interactions. The primary objective is to enable hatchery-produced fish to return to reproduce naturally in the streams in which they are released. These and other characteristics of the project are described in further detail in the Nez Perce Tribal Hatchery Master Plan, the 1995 Supplement to the Master Plan, and the Nez Perce Tribal Hatchery Program Environmental Impact Statement. The report in hand is referred to in project literature as the NPTH Monitoring and Evaluation (M&E) Plan. This report describes monitoring and evaluation activities that will help NPTH managers determine whether they were successful in restoring chinook salmon populations and avoiding adverse ecological impacts.« less

Prenatal caffeine exposure induced a lower level of fetal blood leptin mainly via placental mechanism

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

Wu, Yi-meng; Luo, Han-wen; Kou, Hao

It's known that blood leptin level is reduced in intrauterine growth retardation (IUGR) fetus, and placental leptin is the major source of fetal blood leptin. This study aimed to investigate the decreased fetal blood leptin level by prenatal caffeine exposure (PCE) and its underlying placental mechanisms. Pregnant Wistar rats were intragastrically administered caffeine (30–120 mg/kg day) from gestational day 9 to 20. The level of fetal serum leptin and the expression of placental leptin-related genes were analyzed. Furthermore, we investigated the molecular mechanism of the reduced placental leptin's expression by treatment with caffeine (0.8–20 μM) in the BeWo cells. Inmore » vivo, PCE significantly decreased fetal serum leptin level in caffeine dose-dependent manner. Meanwhile, placental mRNA expression of adenosine A2a receptor (Adora2a), cAMP-response element binding protein (CREB), a short-type leptin receptor (Ob-Ra) and leptin was reduced in the PCE groups. In vitro, caffeine significantly decreased the mRNA expression of leptin, CREB and ADORA2A in concentration and time-dependent manners. The addition of ADORA2A agonist or adenylyl cyclase (AC) agonist reversed the inhibition of leptin expression induced by caffeine. PCE induced a lower level of fetal blood leptin, which the primary mechanism is that caffeine inhibited antagonized Adora2a and AC activities to decreased cAMP synthesis, thus inhibited the expression of the transcription factor CREB and target gene leptin in the placenta. Meantime, the reduced transportation of maternal leptin by placental Ob-Ra also contributed to the reduced fetal blood leptin. Together, PCE decreased fetal blood leptin mainly via reducing the expression and transportation of leptin in the placenta. - Highlights: • Caffeine reduced fetal blood leptin level. • Caffeine inhibited placental leptin production and transport. • Caffeine down-regulated placental leptin expression via antagonizing ADORA2. • Caffeine inhibited placental leptin transport via decreased OB-Ra expression.« less

Property Changes in Aqueous Solutions due to Surfactant Treatment of PCE: Implications to Geophysical Measurements

NASA Astrophysics Data System (ADS)

Werkema, D. D.

2007-12-01

Select physicochemical properties of aqueous solutions composed of surfactants, dye, and perchloroethylene (PCE) were evaluated through a response surface quadratic design model of experiment. Nine surfactants, which are conventionally used in the remediation of PCE, were evaluated with varying concentrations of PCE and indicator dyes in aqueous solutions. Two hundred forty experiments were performed using PCE as a numerical factor (coded A) from 0 to 200 parts per million (ppm), dye type (coded B) as a 3-level categorical factor, and surfactant type (coded C) as a 10-level categorical factor. Five responses were measured: temperature (°C), pH, conductivity (μS/cm), dissolved oxygen (DO, mg/L), and density (g/mL). Diagnostics proved a normally distributed predictable response for all measured responses except pH. The Box-Cox plot for transforms recommended a power transform for the conductivity response with lambda (λ) = 0.50, and for the DO response, λ =2.2. The overall mean of the temperature response proved to be a better predictor than the linear model. The conductivity response is best fitted with a linear model using significant coded terms B and C. Both DO and density also showed a linear model with coded terms A, B, and C for DO; and terms A and C for density. Some of the surfactant treatments of PCE significantly alter the conductivity, DO, and density of the aqueous solution. However, the magnitude of the density response is so small that it does not exceed the instrument tolerance. Results for the conductivity and DO responses provide predictive models for the surfactant treatment of PCE and may be useful in determining the potential for geophysically monitoring surfactant enhanced aquifer remediation (SEAR) of PCE. As the aqueous physicochemical properties change due to surfactant remediation efforts, so will the properties of the subsurface pore water which are influential factors in geophysical measurements. Geoelectrical methods are potentially the best suited to measure SEAR alterations in the subsurface because the conductivity of the pore fluid has the largest relative change. This research has provided predictive models for alterations in the physicochemical properties of the pore fluid to SEAR of PCE. Future investigations should address the contribution of the solid matrix in the subsurface and the solid-fluid interaction during SEAR of PCE contamination. Notice: Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. Mention of trade names or commercial products does not constitute endorsement or recommendation by EPA for use.

Factors of Predicted Learning Disorders and their Interaction with Attentional and Perceptual Training Procedures.

ERIC Educational Resources Information Center

Friar, John T.

Two factors of predicted learning disorders were investigated: (1) inability to maintain appropriate classroom behavior (BEH), (2) perceptual discrimination deficit (PERC). Three groups of first-graders (BEH, PERC, normal control) were administered measures of impulse control, distractability, auditory discrimination, and visual discrimination.…

Simultaneous Transformation of Commingled Trichloroethylene, Tetrachloroethylene, and 1,4-Dioxane by a Microbially Driven Fenton Reaction in Batch Liquid Cultures.

PubMed

Sekar, Ramanan; Taillefert, Martial; DiChristina, Thomas J

2016-11-01

Improper disposal of 1,4-dioxane and the chlorinated organic solvents trichloroethylene (TCE) and tetrachloroethylene (also known as perchloroethylene [PCE]) has resulted in widespread contamination of soil and groundwater. In the present study, a previously designed microbially driven Fenton reaction system was reconfigured to generate hydroxyl (HO˙) radicals for simultaneous transformation of source zone levels of single, binary, and ternary mixtures of TCE, PCE, and 1,4-dioxane. The reconfigured Fenton reaction system was driven by fed batch cultures of the Fe(III)-reducing facultative anaerobe Shewanella oneidensis amended with lactate, Fe(III), and contaminants and exposed to alternating anaerobic and aerobic conditions. To avoid contaminant loss due to volatility, the Fe(II)-generating, hydrogen peroxide-generating, and contaminant transformation phases of the microbially driven Fenton reaction system were separated. The reconfigured Fenton reaction system transformed TCE, PCE, and 1,4-dioxane either as single contaminants or as binary and ternary mixtures. In the presence of equimolar concentrations of PCE and TCE, the ratio of the experimentally derived rates of PCE and TCE transformation was nearly identical to the ratio of the corresponding HO˙ radical reaction rate constants. The reconfigured Fenton reaction system may be applied as an ex situ platform for simultaneous degradation of commingled TCE, PCE, and 1,4-dioxane and provides valuable information for future development of in situ remediation technologies. A microbially driven Fenton reaction system [driven by the Fe(III)-reducing facultative anaerobe S. oneidensis] was reconfigured to transform source zone levels of TCE, PCE, and 1,4-dioxane as single contaminants or as binary and ternary mixtures. The microbially driven Fenton reaction may thus be applied as an ex situ platform for simultaneous degradation of at least three (and potentially more) commingled contaminants. Additional targets for ex situ and in situ degradation by the microbially driven Fenton reaction developed in the present study include multiple combinations of environmental contaminants susceptible to attack by Fenton reaction-generated HO˙ radicals, including commingled plumes of 1,4-dioxane, pentachlorophenol (PCP), PCE, TCE, 1,1,2-trichloroethane (TCA), and perfluoroalkylated substances (PFAS). Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Simultaneous Transformation of Commingled Trichloroethylene, Tetrachloroethylene, and 1,4-Dioxane by a Microbially Driven Fenton Reaction in Batch Liquid Cultures

PubMed Central

Sekar, Ramanan; Taillefert, Martial

2016-01-01

ABSTRACT Improper disposal of 1,4-dioxane and the chlorinated organic solvents trichloroethylene (TCE) and tetrachloroethylene (also known as perchloroethylene [PCE]) has resulted in widespread contamination of soil and groundwater. In the present study, a previously designed microbially driven Fenton reaction system was reconfigured to generate hydroxyl (HO˙) radicals for simultaneous transformation of source zone levels of single, binary, and ternary mixtures of TCE, PCE, and 1,4-dioxane. The reconfigured Fenton reaction system was driven by fed batch cultures of the Fe(III)-reducing facultative anaerobe Shewanella oneidensis amended with lactate, Fe(III), and contaminants and exposed to alternating anaerobic and aerobic conditions. To avoid contaminant loss due to volatility, the Fe(II)-generating, hydrogen peroxide-generating, and contaminant transformation phases of the microbially driven Fenton reaction system were separated. The reconfigured Fenton reaction system transformed TCE, PCE, and 1,4-dioxane either as single contaminants or as binary and ternary mixtures. In the presence of equimolar concentrations of PCE and TCE, the ratio of the experimentally derived rates of PCE and TCE transformation was nearly identical to the ratio of the corresponding HO˙ radical reaction rate constants. The reconfigured Fenton reaction system may be applied as an ex situ platform for simultaneous degradation of commingled TCE, PCE, and 1,4-dioxane and provides valuable information for future development of in situ remediation technologies. IMPORTANCE A microbially driven Fenton reaction system [driven by the Fe(III)-reducing facultative anaerobe S. oneidensis] was reconfigured to transform source zone levels of TCE, PCE, and 1,4-dioxane as single contaminants or as binary and ternary mixtures. The microbially driven Fenton reaction may thus be applied as an ex situ platform for simultaneous degradation of at least three (and potentially more) commingled contaminants. Additional targets for ex situ and in situ degradation by the microbially driven Fenton reaction developed in the present study include multiple combinations of environmental contaminants susceptible to attack by Fenton reaction-generated HO˙ radicals, including commingled plumes of 1,4-dioxane, pentachlorophenol (PCP), PCE, TCE, 1,1,2-trichloroethane (TCA), and perfluoroalkylated substances (PFAS). PMID:27542932

Exposure to Tetrachloroethylene-Contaminated Drinking Water and the Risk of Pregnancy Loss

PubMed Central

Aschengrau, Ann; Weinberg, Janice M.; Gallagher, Lisa G.; Winter, Michael R.; Vieira, Veronica M.; Webster, Thomas F.; Ozonoff, David M.

2010-01-01

There is little information on the impact of solvent-contaminated drinking water on pregnancy outcomes. This retrospective cohort study examined whether maternal exposure to tetrachloroethylene (PCE) - contaminated drinking water in the Cape Cod region of Massachusetts influenced the risk of clinically recognized pregnancy loss. The study identified exposed (n=959) and unexposed (1,087) women who completed a questionnaire on their residential and pregnancy histories, and confounding variables. Exposure was estimated using water distribution system modeling software. No meaningful associations were seen between PCE exposure level and the risk of clinically recognized pregnancy loss at the exposure levels experienced by the study population. Because PCE remains a common water contaminant, it is important to continue monitoring its impact on women and their pregnancies. PMID:20613966

78 FR 41782 - Nez Perce-Clearwater National Forests; Idaho; Notice To Proceed With Forest Plan Revision

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-11

... DEPARTMENT OF AGRICULTURE Forest Service Nez Perce-Clearwater National Forests; Idaho; Notice To... worked with University of Idaho staff to develop a strategy on how to engage the public in the Forest... orientation meetings, cohosted by County Commissioners and facilitated by University of Idaho staff, were held...

Forest resources of the Nez Perce National Forest

Treesearch

Michele Disney

2010-01-01

As part of a National Forest System cooperative inventory, the Interior West Forest Inventory and Analysis (IWFIA) Program of the USDA Forest Service conducted a forest resource inventory on the Nez Perce National Forest using a nationally standardized mapped-plot design (for more details see the section "Inventory methods"). This report presents highlights...

Transformation efficiency and formation of transformation products during photochemical degradation of TCE and PCE at micromolar concentrations

PubMed Central

2014-01-01

Background Trichloroethene and tetrachloroethene are the most common pollutants in groundwater and two of the priority pollutants listed by the U.S. Environmental Protection Agency. In previous studies on TCE and PCE photolysis and photochemical degradation, concentration ranges exceeding environmental levels by far with millimolar concentrations of TCE and PCE have been used, and it is not clear if the obtained results can be used to explain the degradation of these contaminants at more realistic environmental concentration levels. Methods Experiments with micromolar concentrations of TCE and PCE in aqueous solution using direct photolysis and UV/H2O2 have been conducted and product formation as well as transformation efficiency have been investigated. SPME/GC/MS, HPLC/UV and ion chromatography with conductivity detection have been used to determine intermediates of degradation. Results The results showed that chloride was a major end product in both TCE and PCE photodegradation. Several intermediates such as formic acid, dichloroacetic acid, dichloroacetaldehyede, chloroform, formaldehyde and glyoxylic acid were formed during both, UV and UV/H2O2 treatment of TCE. However chloroacetaldehyde and chloroacetic acid were only detected during direct UV photolysis of TCE and oxalic acid was only formed during the UV/H2O2 process. For PCE photodegradation, formic acid, di- and trichloroacetic acids were detected in both UV and UV/H2O2 systems, but formaldehyde and glyoxylic acid were only detected during direct UV photolysis. Conclusions For water treatment UV/H2O2 seems to be favorable over direct UV photolysis because of its higher degradation efficiency and lower risk for the formation of harmful intermediates. PMID:24401763

Transformation efficiency and formation of transformation products during photochemical degradation of TCE and PCE at micromolar concentrations.

PubMed

Dobaradaran, Sina; Lutze, Holger; Mahvi, Amir Hossein; Schmidt, Torsten C

2014-01-08

Trichloroethene and tetrachloroethene are the most common pollutants in groundwater and two of the priority pollutants listed by the U.S. Environmental Protection Agency. In previous studies on TCE and PCE photolysis and photochemical degradation, concentration ranges exceeding environmental levels by far with millimolar concentrations of TCE and PCE have been used, and it is not clear if the obtained results can be used to explain the degradation of these contaminants at more realistic environmental concentration levels. Experiments with micromolar concentrations of TCE and PCE in aqueous solution using direct photolysis and UV/H2O2 have been conducted and product formation as well as transformation efficiency have been investigated. SPME/GC/MS, HPLC/UV and ion chromatography with conductivity detection have been used to determine intermediates of degradation. The results showed that chloride was a major end product in both TCE and PCE photodegradation. Several intermediates such as formic acid, dichloroacetic acid, dichloroacetaldehyede, chloroform, formaldehyde and glyoxylic acid were formed during both, UV and UV/H2O2 treatment of TCE. However chloroacetaldehyde and chloroacetic acid were only detected during direct UV photolysis of TCE and oxalic acid was only formed during the UV/H2O2 process. For PCE photodegradation, formic acid, di- and trichloroacetic acids were detected in both UV and UV/H2O2 systems, but formaldehyde and glyoxylic acid were only detected during direct UV photolysis. For water treatment UV/H2O2 seems to be favorable over direct UV photolysis because of its higher degradation efficiency and lower risk for the formation of harmful intermediates.

Adding a purple corn extract in rats supplemented with chia oil decreases gene expression of SREBP-1c and retains Δ5 and Δ6 hepatic desaturase activity, unmodified the hepatic lipid profile.

PubMed

Reyna Gallegos, Sixto; Torres Arrunátegui, Génesis; Valenzuela, Rodrigo; Rincón-Cervera, Miguel Ángel; Villanueva Espinoza, María Elena

2018-05-01

Flavonoids upregulate gene expression of PPAR-α and underregulate the gene expression of SREBP-1c, and their intake increases the plasmatic concentration of n-3 LC-PUFAs. However, the biological mechanisms underlying these effects have not been elucidated. In this work, the effect of oral supplementation of ALA from chia (Salvia hispanica L.) seed oil and anthocyanins from a purple corn extract (PCE) on gene expression of SREBP-1c, PPAR-α and Δ5 and Δ6 desaturases (Δ5D and Δ6D), the activity of these enzymes in the liver as well as the hepatic lipid profile were evaluated in thirty-six female Sprague Dawley rats whose diet was supplemented with olive oil (OL), chia oil (CH), olive oil and PCE (OL + PCE) or chia oil and PCE (CH + PCE). Gene expression of PPAR-α was significantly higher when supplemented with CH and CH + PCE, SREBP-1c gene expression was higher when supplemented with chia oil. CH supplementation enhanced Δ5D expression whereas no significant differences between treatments were observed concerning Δ6D gene expression. Activities of both desaturases were increased by including olive oil (OL + PCE and OL), and they were found to be higher in CH + PCE respect to CH for both enzymes. The ALA and n-3 LCPUFAs hepatic content was higher with CH, decreasing the levels of AA and n-6 LCPUFAs. It is concluded that the joint action of flavonoids such as anthocyanins and ALA show an anti-adipogenic effect. Desaturase activity was inhibited by ALA and kept by the anthocyanins from PCE, thus anthocyanins would exert a protective effect on the desaturase activity but they would not affect on its gene expression, however, high doses of ALA increased the production of its metabolites, masking the effect of PCE. Copyright © 2018 Elsevier Ltd. All rights reserved.

Production of high titer attenuated poliovirus strains on the serum-free PER.C6(®) cell culture platform for the generation of safe and affordable next generation IPV.

PubMed

Sanders, Barbara P; Oakes, Isabel de los Rios; van Hoek, Vladimir; Liu, Ying; Marissen, Wilfred; Minor, Philip D; Wimmer, Eckard; Schuitemaker, Hanneke; Custers, Jerome H H V; Macadam, Andrew; Cello, Jeronimo; Edo-Matas, Diana

2015-11-27

As poliovirus eradication draws closer, alternative Inactivated Poliovirus Vaccines (IPV) are needed to overcome the risks associated with continued use of the Oral Poliovirus Vaccine and of neurovirulent strains used during manufacture of conventional (c) IPV. We have previously demonstrated the susceptibility of the PER.C6(®) cell line to cIPV strains; here we investigated the suspension cell culture platform for growth of attenuated poliovirus strains. We examined attenuated Sabin strain productivity on the PER.C6(®) cell platform compared to the conventional Vero cell platform. The suitability of the suspension cell platform for propagation of rationally-attenuated poliovirus strains (stabilized Sabin type 3 S19 derivatives and genetically attenuated and stabilized MonoCre(X) strains), was also assessed. Yields were quantified by infectious titer determination and D-antigen ELISA using either serotype-specific polyclonal rabbit sera for Sabin strains or monoclonal cIPV-strain-specific antibodies for cIPV, S19 and MonoCre(X) strains. PER.C6(®) cells supported the replication of Sabin strains to yields of infectious titers that were in the range of cIPV strains at 32.5°C. Sabin strains achieved 30-fold higher yields (p<0.0001) on the PER.C6(®) cell platform as compared to the Vero cell platform in infectious titer and D-antigen content. Furthermore, Sabin strain productivity on the PER.C6(®) cell platform was maintained at 10l scale. Yields of infectious titers of S19 and MonoCre(X) strains were 0.5-1 log10 lower than seen for cIPV strains, whereas D-antigen yield and productivities in doses/ml using rationally-attenuated strains were in line with yields reported for cIPV strains. Sabin and rationally-attenuated polioviruses can be grown to high infectious titers and D-antigen yields. Sabin strain infection shows increased productivity on the PER.C6(®) cell platform as compared to the conventional Vero cell platform. Novel cell platforms with the potential for higher yields could contribute to increased affordability of a next generation of IPV vaccines needed for achieving and maintaining poliovirus eradication. Copyright © 2015 Elsevier Ltd. All rights reserved.

77 FR 775 - Nez Perce-Clearwater National Forests; Idaho; Clear Creek Integrated Restoration Project

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-06

... species distributions habitat complexity (diversity) and landscape pattern across the forested portions of..., improve long term resistance and resilience at the landscape level; restore natural fire regimes and... landscape that is more highly fragmented than what would be expected through natural disturbance. Ladder...

77 FR 9621 - Nez Perce-Clearwater National Forests; Idaho; Clear Creek Integrated Restoration Project

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

..., vegetative species distributions, habitat complexity (diversity) and landscape patterns across the forested... resistance and resilience at the landscape level; reduce fuels; improve watershed conditions; improve elk... practices and fire suppression have created a landscape that is more highly fragmented than would be...

Nez Perce Tribe Welcomes Wolves Back to Idaho.

ERIC Educational Resources Information Center

Grossman, Elizabeth

2002-01-01

The Nez Perce Tribe is working with the U.S. Fish and Wildlife Service to reintroduce the gray wolf to central Idaho. The tribe does all the fieldwork with the wolves and shares their work with the public at the Wolf Education and Research Center, Winchester, Idaho. Despite opposition from ranchers and legislators, the wolf population is…

Blended Learning: Lessons from Best Practice Sites and the Philadelphia Context. PERC Research Brief

ERIC Educational Resources Information Center

Beaver, Jessica K.; Hallar, Brittan; Westmaas, Lucas; Englander, Katie

2015-01-01

The Philadelphia Education Research Consortium--or PERC--was launched in August 2014 as an innovative partnership designed to provide research and analyses on some of the city's most pressing education issues. This partnership was forged among the School District of Philadelphia, Philadelphia's charter school sector, and Research for Action (RFA).…

Assessment of subsurface chlorinated solvent contamination using tree cores at the front street site and a former dry cleaning facility at the Riverfront Superfund site, New Haven, Missouri, 1999-2003

USGS Publications Warehouse

Schumacher, John G.; Struckhoff, Garrett C.; Burken, Joel G.

2004-01-01

Tree-core sampling has been a reliable and inexpensive tool to quickly assess the presence of shallow (less than about 30 feet deep) tetrachloroethene (PCE) and trichloroethene (TCE) contamination in soils and ground water at the Riverfront Superfund Site. This report presents the results of tree-core sampling that was successfully used to determine the presence and extent of chlorinated solvent contamination at two sites, the Front Street site (operable unit OU1) and the former dry cleaning facility, that are part of the overall Riverfront Superfund Site. Traditional soil and ground-water sampling at these two sites later confirmed the results from the tree-core sampling. Results obtained from the tree-core sampling were used to design and focus subsequent soil and ground-water investigations, resulting in substantial savings in time and site assessment costs. The Front Street site is a small (less than 1-acre) site located on the Missouri River alluvium in downtown New Haven, Missouri, about 500 feet from the south bank of the Missouri River. Tree-core sampling detected the presence of subsurface PCE contamination at the Front Street site and beneath residential property downgradient from the site. Core samples from trees at the site contained PCE concentrations as large as 3,850 mg-h/kg (micrograms in headspace per kilogram of wet core) and TCE concentrations as large as 249 mg-h/kg. Soils at the Front Street site contained PCE concentrations as large as 6,200,000 mg/kg (micrograms per kilogram) and ground-water samples contained PCE concentrations as large as 11,000 mg/L (micrograms per liter). The former dry cleaning facility is located at the base of the upland that forms the south bank of the Missouri River alluvial valley. Tree-core sampling did not indicate the presence of PCE or TCE contamination at the former dry cleaning facility, a finding that was later confirmed by the analyses of soil samples collected from the site. The lateral extent of PCE contamination in trees was in close agreement with the extent of subsurface PCE contamination determined using traditional soil and ground-water sampling methods. Trees growing in soils containing PCE concentrations of 60 to 5,700 mg/kg or larger or overlying ground water containing PCE concentrations from 5 to 11,000 mg/L generally contained detectable concentrations of PCE. The depth to contaminated ground water was about 20 to 25 feet below the land surface. Significant quantitative relations [probability (p) values of less than 0.05 and correlation coefficient (r2) values of 0.88 to 0.90] were found between PCE concentrations in trees and subsurface soils between 4 and 16 feet deep. The relation between PCE concentrations in trees and underlying ground water was less apparent (r2 value of 0.17) and the poor relation is thought to be the result of equilibrium with PCE concentrations in soil and vapor in the unsaturated zone. Based on PCE concentrations detected in trees at the Front Street site and trees growing along contaminated tributaries in other operable units, and from field hydroponic experiments using hybrid poplar cuttings, analysis of tree-core samples appears to be able to detect subsurface PCE contamination in soils at levels of several hundred micrograms per liter or less and PCE concentrations in the range of 8 to 30 mg/L in ground water in direct contact with the roots. Loss of PCE from tree trunks by diffusion resulted in an exponential decrease in PCE concentrations with increasing height above the land surface in most trees. The rate of loss also appeared to be a function of the size and growth characteristics of the tree as some trees exhibited a linear loss with increasing height. Diffusional loss of PCE in small (0.5-inch diameter) trees was observed to occur at a rate more than 10 times larger than in trees 6.5 inches in diameter. Concentrations of PCE also exhibited directional variability around the tree trunks and concentration differe

Survey of hazardous organic compounds in the groundwater, air and wastewater effluents near the Tehran automobile industry.

PubMed

Kargar, Mahdi; Nadafi, Kazem; Nabizadeh, Ramin; Nasseri, Simin; Mesdaghinia, Alireza; Mahvi, Amir Hossein; Alimohammadi, Mahmood; Nazmara, Shahrokh; Rastkari, Noushin

2013-02-01

Potential of wastewater treatment in car industry and groundwater contamination by volatile organic compounds include perchloroethylene (PCE), trichloroethylene (TCE) and dichloromethane (DCM) near car industry was conducted in this study. Samples were collected in September through December 2011 from automobile industry. Head-space Gas chromatography with FID detector is used for analysis. Mean PCE levels in groundwater ranged from 0 to 63.56 μg L(-1) with maximum level of 89.1 μg L(-1). Mean TCE from 0 to 76.63 μg L(-1) with maximum level of 112 μg L(-1). Due to the data obtained from pre treatment of car staining site and conventional wastewater treatment in car factory, the most of TCE, PCE and DCM removed by pre aeration. Therefor this materials entry from liquid phase to air phase and by precipitation leak out to the groundwater. As a consequence these pollutants have a many negative health effect on the workers by air and groundwater.

Leveraging the Power of Peer-Led Learning: Investigating Effects on STEM Performance in Urban High Schools

ERIC Educational Resources Information Center

Thomas, Ally S.; Bonner, Sarah M.; Everson, Howard T.; Somers, Jennifer A.

2015-01-01

The Peer Enabled Restructured Classroom (PERC) is an instructional innovation developed to address gaps in science, technology, engineering, and math (STEM) in urban high schools. The PERC model changes instruction from teacher led to peer led by bringing peer students into the classroom to lead small-group work. Our study sought to provide…

The Launch of the Philadelphia Education Research Consortium: Lessons Learned from the First Year of Implementation

ERIC Educational Resources Information Center

Shaw, Kate

2016-01-01

The Philadelphia Education Research Consortium (PERC) was launched in July 2014 as an innovative place-based consortium of educational research partners from multiple sectors. Its primary objective is to provide research and analyses on some of the city's most pressing education issues. As such, PERC's research agenda is driven by both traditional…

Leader and Spokesman for a People in Exile: Chief Joseph and the Nez Perce

ERIC Educational Resources Information Center

Jain, Samvit

2009-01-01

This article discusses Chief Joseph's surrender that marked the beginning of his diplomatic stand for justice in Indian Territory, where his tribe was forcibly exiled in accordance with American Indian policy of the time. Joseph battled for the repatriation of the Nez Perce through protests and other legal means, winning the support of the growing…

Nez Perce Tribal Hatchery Program : Draft Environmental Impact Statement.

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

United States. Bonneville Power Administration; Nez Perce Tribal Hatchery

1996-06-01

Bonneville Power Administration, the Bureau of Indian Affairs, the Nez Perce Tribe propose a supplementation program to restore chinook salmon to the Clearwater River Subbasin in Idaho. The Clearwater River is a tributary to the Snake River, which empties into the Columbia River. The Nez Perce Tribe would build and operate two central incubation and rearing hatcheries and six satellite facilities. Spring, summer and fall chinook salmon would be reared and acclimated to different areas in the Subbasin and released at the hatchery and satellite sites or in other watercourses throughout the Subbasin. The supplementation program differs from other hatcherymore » programs because the fish would be released at different sizes and would return to reproduce naturally in the areas where they are released. Several environmental issues were identified during scoping: the possibility that the project would fail if mainstem Columbia River juvenile and adult passage problems are not solved; genetic risks to fish listed as endangered or threatened; potential impacts to wild and resident fish stocks because of increase competition for food and space; and water quality. The Proposed Action would affect several important aspects of Nez Perce tribal life, primarily salmon harvest, employment, and fisheries management.« less

Rehabilitate Newsome Creek Watershed, 2007-2008 Annual Report.

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

Bransford, Stephanie

2009-05-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridgetop approach. The Nez Perce Tribe (NPT) and the Nez Perce National Forest (NPNF) have formed a partnership in completing watershed restoration activities, and through this partnership more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Newsome Creek watershed of the South Fork Clearwater River in 1997. Progress has been made in restoring the watershed through road decommissioning and culvert replacement. Starting in FY 2001 and continuing into themore » present, a major stream restoration effort on the mainstem of Newsome Creek has been pursued. From completing a watershed assessment to a feasibility study of 4 miles of mainstem rehabilitation to carrying that forward into NEPA and a final design, we will begin the effort of restoring the mainstem channel of Newsome Creek to provide spawning and rearing habitat for anadromous and resident fish species. Roads have been surveyed and prioritized for removal or improvement as well as culverts being prioritized for replacement to accommodate fish passage throughout the watershed.« less

Clearwater Focus Watershed; Nez Perce Tribe, 2002-2003 Annual Report.

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

Jones, Ira

2004-01-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division, approaches watershed restoration with a goal to protect, restore, and enhance a connected network of functioning habitat types capable of supporting all fish life stages. Its goal is also to re-establish normal patters of production, dispersal, and exchange of genetic information within the 1855 Treaty Area. The Nez Perce Tribe began watershed restoration projects within the Clearwater River Subbasin in 1996. Progress has been made in restoring the sub-basin by excluding cattle from critical riparian areas through fencing, stabilizing streambanks, decommissioning roads, and upgrading culverts. Coordination of these projectsmore » is critical to the success of the restoration of the sub-basin. Coordination includes: within department coordination, sub-basin assessment and planning, and treaty area coordination.« less

Protect and Restore Mill Creek Watershed; Annual Report 2002-2003.

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

McRoberts, Heidi

2004-01-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Mill Creek watershed are coordinated with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. During the FY 2002, trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-streammore » crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed. Maintenance to the previously built fence was also completed.« less

Evaluation of the Webler-Brown model for estimating tetrachloroethylene exposure from vinyl-lined asbestos-cement pipes

PubMed Central

Spence, Lisa A; Aschengrau, Ann; Gallagher, Lisa E; Webster, Thomas F; Heeren, Timothy C; Ozonoff, David M

2008-01-01

Background From May 1968 through March 1980, vinyl-lined asbestos-cement (VL/AC) water distribution pipes were installed in New England to avoid taste and odor problems associated with asbestos-cement pipes. The vinyl resin was applied to the inner pipe surface in a solution of tetrachloroethylene (perchloroethylene, PCE). Substantial amounts of PCE remained in the liner and subsequently leached into public drinking water supplies. Methods Once aware of the leaching problem and prior to remediation (April-November 1980), Massachusetts regulators collected drinking water samples from VL/AC pipes to determine the extent and severity of the PCE contamination. This study compares newly obtained historical records of PCE concentrations in water samples (n = 88) with concentrations estimated using an exposure model employed in epidemiologic studies on the cancer risk associated with PCE-contaminated drinking water. The exposure model was developed by Webler and Brown to estimate the mass of PCE delivered to subjects' residences. Results The mean and median measured PCE concentrations in the water samples were 66 and 0.5 μg/L, respectively, and the range extended from non-detectable to 2432 μg/L. The model-generated concentration estimates and water sample concentrations were moderately correlated (Spearman rank correlation coefficient = 0.48, p < 0.0001). Correlations were higher in samples taken at taps and spigots vs. hydrants (ρ = 0.84 vs. 0.34), in areas with simple vs. complex geometry (ρ = 0.51 vs. 0.38), and near pipes installed in 1973–1976 vs. other years (ρ = 0.56 vs. 0.42 for 1968–1972 and 0.37 for 1977–1980). Overall, 24% of the variance in measured PCE concentrations was explained by the model-generated concentration estimates (p < 0.0001). Almost half of the water samples had undetectable concentrations of PCE. Undetectable levels were more common in areas with the earliest installed VL/AC pipes, at the beginning and middle of VL/AC pipes, at hydrants, and in complex pipe configurations. Conclusion PCE concentration estimates generated using the Webler-Brown model were moderately correlated with measured water concentrations. The present analysis suggests that the exposure assessment process used in prior epidemiological studies could be improved with more accurate characterization of water flow. This study illustrates one method of validating an exposure model in an epidemiological study when historical measurements are not available. PMID:18518975

Evaluation of the Webler-Brown model for estimating tetrachloroethylene exposure from vinyl-lined asbestos-cement pipes.

PubMed

Spence, Lisa A; Aschengrau, Ann; Gallagher, Lisa E; Webster, Thomas F; Heeren, Timothy C; Ozonoff, David M

2008-06-02

From May 1968 through March 1980, vinyl-lined asbestos-cement (VL/AC) water distribution pipes were installed in New England to avoid taste and odor problems associated with asbestos-cement pipes. The vinyl resin was applied to the inner pipe surface in a solution of tetrachloroethylene (perchloroethylene, PCE). Substantial amounts of PCE remained in the liner and subsequently leached into public drinking water supplies. Once aware of the leaching problem and prior to remediation (April-November 1980), Massachusetts regulators collected drinking water samples from VL/AC pipes to determine the extent and severity of the PCE contamination. This study compares newly obtained historical records of PCE concentrations in water samples (n = 88) with concentrations estimated using an exposure model employed in epidemiologic studies on the cancer risk associated with PCE-contaminated drinking water. The exposure model was developed by Webler and Brown to estimate the mass of PCE delivered to subjects' residences. The mean and median measured PCE concentrations in the water samples were 66 and 0.5 microg/L, respectively, and the range extended from non-detectable to 2432 microg/L. The model-generated concentration estimates and water sample concentrations were moderately correlated (Spearman rank correlation coefficient = 0.48, p < 0.0001). Correlations were higher in samples taken at taps and spigots vs. hydrants (rho = 0.84 vs. 0.34), in areas with simple vs. complex geometry (rho = 0.51 vs. 0.38), and near pipes installed in 1973-1976 vs. other years (rho = 0.56 vs. 0.42 for 1968-1972 and 0.37 for 1977-1980). Overall, 24% of the variance in measured PCE concentrations was explained by the model-generated concentration estimates (p < 0.0001). Almost half of the water samples had undetectable concentrations of PCE. Undetectable levels were more common in areas with the earliest installed VL/AC pipes, at the beginning and middle of VL/AC pipes, at hydrants, and in complex pipe configurations. PCE concentration estimates generated using the Webler-Brown model were moderately correlated with measured water concentrations. The present analysis suggests that the exposure assessment process used in prior epidemiological studies could be improved with more accurate characterization of water flow. This study illustrates one method of validating an exposure model in an epidemiological study when historical measurements are not available.

Spring Chinook Salmon Oncorhynchus tshawytscha Supplementation in the Clearwater Subbasin ; Nez Perce Tribal Hatchery Monitoring and Evaluation Project, 2007 Annual Report.

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

Backman, Thomas; Sprague, Sherman; Bretz, Justin

The Nez Perce Tribal Hatchery (NPTH) program has the following goals (BPA, et al., 1997): (1) Protect, mitigate, and enhance Clearwater Subbasin anadromous fish resources; (2) Develop, reintroduce, and increase natural spawning populations of salmon within the Clearwater Subbasin; (3) Provide long-term harvest opportunities for Tribal and non-Tribal anglers within Nez Perce Treaty lands within four generations (20 years) following project initiation; (4) Sustain long-term fitness and genetic integrity of targeted fish populations; (5) Keep ecological and genetic impacts to non-target populations within acceptable limits; and (6) Promote Nez Perce Tribal management of Nez Perce Tribal Hatchery Facilities and productionmore » areas within Nez Perce Treaty lands. The NPTH program was designed to rear and release 1.4 million fall and 625,000 spring Chinook salmon. Construction of the central incubation and rearing facility NPTH and spring Chinook salmon acclimation facilities were completed in 2003 and the first full term NPTH releases occurred in 2004 (Brood Year 03). Monitoring and evaluation plans (Steward, 1996; Hesse and Cramer, 2000) were established to determine whether the Nez Perce Tribal Hatchery program is achieving its stated goals. The monitoring and evaluation action plan identifies the need for annual data collection and annual reporting. In addition, recurring 5-year program reviews will evaluate emerging trends and aid in the determination of the effectiveness of the NPTH program with recommendations to improve the program's implementation. This report covers the Migratory Year (MY) 2007 period of the NPTH Monitoring & Evaluation (M&E) program. There are three NPTH spring Chinook salmon treatment streams: Lolo Creek, Newsome Creek, and Meadow Creek. In 2007, Lolo Creek received 140,284 Brood Year (BY) 2006 acclimated pre-smolts at an average weight of 34.9 grams per fish, Newsome Creek received 77,317 BY 2006 acclimated pre-smolts at an average of 24.9 grams per fish, and Meadow Creek received 53,425 BY 2006 direct stream release parr at an average of 4.7 grams per fish. Natural and hatchery origin spring Chinook salmon pre-smolt emigrants were monitored from September - November 2006 and smolts from March-June 2007. Data on adult returns were collected from May-September. A suite of performance measures were calculated including total adult and spawner escapement, juvenile production, and survival probabilities. These measures were used to evaluate the effectiveness of supplementation and provide information on the capacity of the natural environment to assimilate and support supplemented salmon populations.« less

Affinity for risky behaviors following prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water: a retrospective cohort study.

PubMed

Aschengrau, Ann; Weinberg, Janice M; Janulewicz, Patricia A; Romano, Megan E; Gallagher, Lisa G; Winter, Michael R; Martin, Brett R; Vieira, Veronica M; Webster, Thomas F; White, Roberta F; Ozonoff, David M

2011-12-02

Many studies of adults with acute and chronic solvent exposure have shown adverse effects on cognition, behavior and mood. No prior study has investigated the long-term impact of prenatal and early childhood exposure to the solvent tetrachloroethylene (PCE) on the affinity for risky behaviors, defined as smoking, drinking or drug use as a teen or adult. This retrospective cohort study examined whether early life exposure to PCE-contaminated drinking water influenced the occurrence of cigarette smoking, alcohol consumption, and drug use among adults from Cape Cod, Massachusetts. Eight hundred and thirty-one subjects with prenatal and early childhood PCE exposure and 547 unexposed subjects were studied. Participants completed questionnaires to gather information on risky behaviors as a teenager and young adult, demographic characteristics, other sources of solvent exposure, and residences from birth through 1990. PCE exposure was estimated using the U.S. EPA's water distribution system modeling software (EPANET) that was modified to incorporate a leaching and transport model to estimate PCE exposures from pipe linings. Individuals who were highly exposed to PCE-contaminated drinking water during gestation and early childhood experienced 50-60% increases in the risk of using two or more major illicit drugs as a teenager or as an adult (Relative Risk (RR) for teen use = 1.6, 95% CI: 1.2-2.2; and RR for adult use = 1.5, 95% CI: 1.2-1.9). Specific drugs for which increased risks were observed included crack/cocaine, psychedelics/hallucinogens, club/designer drugs, Ritalin without a prescription, and heroin (RRs:1.4-2.1). Thirty to 60% increases in the risk of certain smoking and drinking behaviors were also seen among highly exposed subjects. The results of this study suggest that risky behaviors, particularly drug use, are more frequent among adults with high PCE exposure levels during gestation and early childhood. These findings should be confirmed in follow-up investigations of other exposed populations.

Effects of Prenatal Cocaine Exposure on Early Sexual Behavior: Gender Difference in Externalizing Behavior as a Mediator

PubMed Central

Min, Meeyoung O.; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T.

2015-01-01

Background Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Methods Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year old adolescents participated in a prospective longitudinal study. Adolescents’ sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Results Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI= 1.2 – 4.1, p < .01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4 – 4.7, p < .002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. Conclusions PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. PMID:26088698

Prenatal cocaine exposure, illicit-substance use and stress and craving processes during adolescence.

PubMed

Yip, Sarah W; Lacadie, Cheryl M; Sinha, Rajita; Mayes, Linda C; Potenza, Marc N

2016-01-01

Prenatal cocaine exposure (PCE) is associated with increased rates of illicit-substance use during adolescence. In addition, both PCE and illicit-substance use are associated with alterations in cortico-striato-limbic neurocircuitry, development of which is ongoing throughout adolescence. However, the relationship between illicit-substance use, PCE and functional neural responses has not previously been assessed concurrently. Sixty-eight adolescents were recruited from an ongoing longitudinal study of childhood and adolescent development. All participants had been followed since birth. Functional magnetic resonance imaging (fMRI) data were acquired during presentation of personalized stressful, favorite-food and neutral/relaxing imagery scripts and compared between 46 PCE and 22 non-prenatally-drug-exposed (NDE) adolescents with and without lifetime illicit-substance use initiation. Data were analyzed using multi-level ANOVAs (pFWE<.05). There was a significant three-way interaction between illicit-substance use, PCE status and cue condition on neural responses within primarily cortical brain regions, including regions of the left and right insula. Among PCE versus NDE adolescents, illicit-substance use was associated with decreased subcortical and increased cortical activity during the favorite-food condition, whereas the opposite pattern of activation was observed during the neutral/relaxing condition. Among PCE versus NDE adolescents, illicit-substance use during stress processing was associated with decreased activity in cortical and subcortical regions including amygdala, hippocampus and prefrontal cortex. Neural activity within cortico-striato-limbic regions was significantly negatively associated with subjective ratings of anxiety and craving among illicit-substance users, but not among non-users. These findings suggest different neural substrates of experimentation with illicit drugs between adolescents with and without in utero cocaine exposure. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effects of prenatal cocaine exposure on early sexual behavior: Gender difference in externalizing behavior as a mediator.

PubMed

Min, Meeyoung O; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T

2015-08-01

Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year-old adolescents participated in a prospective longitudinal study. Adolescents' sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI=1.2-4.1, p<.01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4-4.7, p<.002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The Needs of Tribal Men and the Social Service Providers on or Near the Nez Perce Indian Nation.

ERIC Educational Resources Information Center

High Eagle, Gordon; And Others

This report results from an action research project of the Nee Mee Poom Ha Hum (Men's Coalition), investigating the needs of tribal men in the Nez Perce Indian Nation, as part of planning to improve men's development. Research was directed toward interviewing a stratified random sample of tribal men and interviewing the directors and employees of…

Consumers' environmental and ethical consciousness and the use of the related food products information: The role of perceived consumer effectiveness.

PubMed

Ghvanidze, Sophie; Velikova, Natalia; Dodd, Tim H; Oldewage-Theron, Wilna

2016-12-01

Consumers can be important active contributors to a sustainable society by selecting food choices that are both healthy and produced respecting environmental and socially ethical standards. The current study investigates five consumer behavioural factors - namely, perceived consumer effectiveness (PCE); environmental conscious behaviour; concerns for ethical food production; health conscious lifestyle; and healthy dietary patterns. The key interest of the study lies in exploring the moderating role of PCE - the extent to which the consumer believes that his/her own efforts can make a difference - in these interrelationships. The empirical analysis was conducted through an online survey of food consumers implemented in three markets - the US, the UK and Germany. Findings indicate that for individuals with higher levels of PCE, who are environmental conscious and ethically concerned, information on food labels relating to environmental and social issues represents value by itself. Interestingly, health and nutrition information on food labels was not perceived valuable by consumers with high PCE. The predictive effects of various socio-demographic variables on PCE, consumer environmental and health consciousness are discussed. Cross-cultural differences are also outlined. The results of this research may contribute to the development of environmental policies and communication strategies of the food industry to enhance perceived consumer effectiveness among consumers. Improved PCE, in turn, may catalyze consumers' environmental behaviour and ethical concerns in relation to consumption of food products with environmental and social information. Copyright © 2016 Elsevier Ltd. All rights reserved.

Commemoration and Preservation: An Administrative History of Big Hole National Battlefield.

ERIC Educational Resources Information Center

Catton, Theodore; Hubber, Ann

Few places in the west are as evocative of the tragic story of the Indian Wars as Big Hole (Montana) National Battlefield. The site memorializes the bravery of the Nez Perce and U.S. soldiers and volunteers who fought there during the epic flight of the Nez Perce in 1877. Big Hole preserves the scene of one of the most famous battles of the Indian…

`Iceyeeye Comes to School: Niimiipuu Cultural Competence and Use of Traditional Niimiipuu `Iceyeeye Stories to Construct Indigenous Knowledge with Classroom Teachers for Our Children

ERIC Educational Resources Information Center

Taylor, Arthur Maxwell Teewispelu

2013-01-01

From time immemorial, the Niimiipuu (Nez Perce) were very successful in passing on the traditions, languages, religions, and practices of the tribal people. Once created by `Iceyeeye (Coyote), the Children of the Coyote (Nez Perce) began to build and create their own society. The Niimiipuu built a system based upon economics, medicine, science,…

Protect and Restore Red River Watershed, 2007-2008 Annual Report.

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

Bransford, Stephanie

2009-05-04

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe (NPT) and the Nez Perce National Forest (NPNF) have formed a partnership in completing watershed restoration activities, and through this partnership more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Red River Watershed of the South Fork Clearwater River in 2001. Progress has been made in restoring the watershed through road decommissioning and culvert replacement. From completing a watershed assessment to two NEPAmore » efforts and a final stream restoration design, we will begin the effort of restoring the mainstem channel of Red River to provide spawning and rearing habitat for anadromous and resident fish species. Roads have been surveyed and prioritized for removal or improvement as well as culverts being prioritized for replacement to accommodate fish passage throughout the watershed. Another major, and extremely, important component of this project is the Red River Meadow Conservation Easement. We have begun the process of pursuing a conservation easement on approximately 270 acres of prime meadow habitat (Red River runs through this meadow and is prime spawning and rearing habitat).« less

Proteomics of the organohalide-respiring Epsilonproteobacterium Sulfurospirillum multivorans adapted to tetrachloroethene and other energy substrates

PubMed Central

Goris, Tobias; Schiffmann, Christian L.; Gadkari, Jennifer; Schubert, Torsten; Seifert, Jana; Jehmlich, Nico; von Bergen, Martin; Diekert, Gabriele

2015-01-01

Organohalide respiration is an environmentally important but poorly characterized type of anaerobic respiration. We compared the global proteome of the versatile organohalide-respiring Epsilonproteobacterium Sulfurospirillum multivorans grown with different electron acceptors (fumarate, nitrate, or tetrachloroethene [PCE]). The most significant differences in protein abundance were found for gene products of the organohalide respiration region. This genomic region encodes the corrinoid and FeS cluster containing PCE reductive dehalogenase PceA and other proteins putatively involved in PCE metabolism such as those involved in corrinoid biosynthesis. The latter gene products as well as PceA and a putative quinol dehydrogenase were almost exclusively detected in cells grown with PCE. This finding suggests an electron flow from the electron donor such as formate or pyruvate via the quinone pool and a quinol dehydrogenase to PceA and the terminal electron acceptor PCE. Two putative accessory proteins, an IscU-like protein and a peroxidase-like protein, were detected with PCE only and might be involved in PceA maturation. The proteome of cells grown with pyruvate instead of formate as electron donor indicates a route of electrons from reduced ferredoxin via an Epsilonproteobacterial complex I and the quinone pool to PCE. PMID:26387727

Impact of sorption processes on PCE concentrations in organohalide-respiring aquifer sediment samples.

PubMed

Leitner, Simon; Reichenauer, Thomas G; Watzinger, Andrea

2018-02-15

The evaluation of groundwater contaminant e.g. tetrachloroethene (PCE) degradation processes requires complete quantification of and pathway analysis of the groundwater contaminant under investigation. For example the reduction of PCE concentrations in the groundwater by unknown dissolution and/or sorption processes will impede interpretation of the fate and behaviour of such contaminants. In the present study PCE dissolution and sorption processes during anaerobic microbial degradation of chlorinated ethenes were investigated. For this purpose, microcosms were prepared using sediment samples from a PCE-contaminated aquifer, which in previous studies had demonstrated anaerobic organohalide respiration of PCE. Solid/water distribution coefficients (k d ) of PCE were determined and validated by loss-on-ignition (LOI) and PCE sorption experiments. The determined k d magnitudes indicated methodological congruency, yielding values for sediment samples within a range of 1.15±0.02 to 5.93±0.34L·kg -1 . The microcosm experiment showed lower PCE concentrations than expected, based on spiked PCE and observed anaerobic microbial degradation processes. Nevertheless the amount of PCE spike added was completely recovered albeit in the form of lower chlorinated metabolites. A delay due to dissolution processes was not responsible for this phenomenon. Sorption to sediments could only partially explain the reduction of PCE in the water phase. Accordingly, the results point to reversible sorption processes of PCE, possibly onto bacterial cell compartments and/or exopolymeric substances. Copyright © 2017 Elsevier B.V. All rights reserved.

Prenatal Cocaine Exposure Impacts Language and Reading Into Late Adolescence: Behavioral and ERP Evidence.

PubMed

Landi, Nicole; Avery, Trey; Crowley, Michael J; Wu, Jia; Mayes, Linda

2017-01-01

Extant research documents impaired language among children with prenatal cocaine exposure (PCE) relative to nondrug exposed (NDE) children, suggesting that cocaine alters development of neurobiological systems that support language. The current study examines behavioral and neural (electrophysiological) indices of language function in older adolescents. Specifically, we compare performance of PCE (N = 59) and NDE (N = 51) adolescents on a battery of cognitive and linguistic assessments that tap word reading, reading comprehension, semantic and grammatical processing, and IQ. In addition, we examine event related potential (ERP) responses in in a subset of these children across three experimental tasks that examine word level phonological processing (rhyme priming), word level semantic processing (semantic priming), and sentence level semantic processing (semantic anomaly). Findings reveal deficits across a number of reading and language assessments, after controlling for socioeconomic status and exposure to other substances. Additionally, ERP data reveal atypical orthography to phonology mapping (reduced N1/P2 response) and atypical rhyme and semantic processing (N400 response). These findings suggest that PCE continues to impact language and reading skills into the late teenage years.

Clearwater Focus Watershed; Nez Perce Tribe, 2003-2004 Annual Report.

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

Jones, Ira

2004-06-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division, approaches watershed restoration with a goal to protect, restore, and enhance a connected network of functioning habitat types capable of supporting all fish life stages. Its goal is also to re-establish normal patterns of production, dispersal, and exchange of genetic information within the 1855 Treaty Area. The Nez Perce Tribe began watershed restoration projects within the Clearwater River Subbasin in 1996. Progress has been made in restoring the sub-basin by excluding cattle from critical riparian areas through fencing, stabilizing stream banks, decommissioning roads, and upgrading culverts. Coordination of thesemore » projects is critical to the success of the restoration of the sub-basin. Coordination activities also includes: inter and intra-department coordination, sub-basin assessment and planning, involving government and private organizations, and treaty area coordination.« less

FDNS CFD Code Benchmark for RBCC Ejector Mode Operation

NASA Technical Reports Server (NTRS)

Holt, James B.; Ruf, Joe

1999-01-01

Computational Fluid Dynamics (CFD) analysis results are compared with benchmark quality test data from the Propulsion Engineering Research Center's (PERC) Rocket Based Combined Cycle (RBCC) experiments to verify fluid dynamic code and application procedures. RBCC engine flowpath development will rely on CFD applications to capture the multi-dimensional fluid dynamic interactions and to quantify their effect on the RBCC system performance. Therefore, the accuracy of these CFD codes must be determined through detailed comparisons with test data. The PERC experiments build upon the well-known 1968 rocket-ejector experiments of Odegaard and Stroup by employing advanced optical and laser based diagnostics to evaluate mixing and secondary combustion. The Finite Difference Navier Stokes (FDNS) code was used to model the fluid dynamics of the PERC RBCC ejector mode configuration. Analyses were performed for both Diffusion and Afterburning (DAB) and Simultaneous Mixing and Combustion (SMC) test conditions. Results from both the 2D and the 3D models are presented.

Planetary geology and terrestrial analogs in Asia

NASA Astrophysics Data System (ADS)

Komatsu, Goro; Namiki, Noriyuki

2012-04-01

2011 PERC Planetary Geology Field Symposium;Kitakyushu City, Japan, 5-6 November 2011 In spite of the extremely diverse geological settings that exist in Asia, relatively little attention has previously been paid to this region in terms of terrestrial analog studies for planetary application. Asia is emerging as a major center of studies in planetary geology, but no attempt had been made in the past to organize a broadly based meeting that would allow planetary geologists in Asia to meet with ones from more advanced centers, such as the United States and Europe, and that would include the participation of many geologists working primarily on terrestrial research. The Planetary Exploration Research Center (PERC) of the Chiba Institute of Technology hosted the first planetary geology field symposium in Asia to present results from recent planetary geology studies and to exchange ideas regarding terrestrial analogs (http://www.perc.it-chiba.ac.jp/meetings/pgfs2011/index.html).

Towards sustainable and safe apparel cleaning methods: A review.

PubMed

Troynikov, Olga; Watson, Christopher; Jadhav, Amit; Nawaz, Nazia; Kettlewell, Roy

2016-11-01

Perchloroethylene (PERC) is a compound commonly used as a solvent in dry cleaning, despite its severe health and environmental impacts. In recent times chemicals such as hydrocarbons, GreenEarth(®), acetal and liquid carbon dioxide have emerged as less damaging substitutes for PERC, and an even more sustainable water-based wet cleaning process has been developed. We employed a systematic review approach to provide a comprehensive overview of the existing research evidence in the area of sustainable and safe apparel cleaning methods and care. Our review describes traditional professional dry cleaning methods, as well as those that utilise solvents other than PERC, and their ecological attributes. In addition, the new professional wet cleaning process is discussed. Finally, we address the health hazards of the various solvents used in dry cleaning and state-of-the-art solvent residue trace analysis techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modeling field-scale cosolvent flooding for DNAPL source zone remediation

NASA Astrophysics Data System (ADS)

Liang, Hailian; Falta, Ronald W.

2008-02-01

A three-dimensional, compositional, multiphase flow simulator was used to model a field-scale test of DNAPL removal by cosolvent flooding. The DNAPL at this site was tetrachloroethylene (PCE), and the flooding solution was an ethanol/water mixture, with up to 95% ethanol. The numerical model, UTCHEM accounts for the equilibrium phase behavior and multiphase flow of a ternary ethanol-PCE-water system. Simulations of enhanced cosolvent flooding using a kinetic interphase mass transfer approach show that when a very high concentration of alcohol is injected, the DNAPL/water/alcohol mixture forms a single phase and local mass transfer limitations become irrelevant. The field simulations were carried out in three steps. At the first level, a simple uncalibrated layered model is developed. This model is capable of roughly reproducing the production well concentrations of alcohol, but not of PCE. A more refined (but uncalibrated) permeability model is able to accurately simulate the breakthrough concentrations of injected alcohol from the production wells, but is unable to accurately predict the PCE removal. The final model uses a calibration of the initial PCE distribution to get good matches with the PCE effluent curves from the extraction wells. It is evident that the effectiveness of DNAPL source zone remediation is mainly affected by characteristics of the spatial heterogeneity of porous media and the variable (and unknown) DNAPL distribution. The inherent uncertainty in the DNAPL distribution at real field sites means that some form of calibration of the initial contaminant distribution will almost always be required to match contaminant effluent breakthrough curves.

Modeling field-scale cosolvent flooding for DNAPL source zone remediation.

PubMed

Liang, Hailian; Falta, Ronald W

2008-02-19

A three-dimensional, compositional, multiphase flow simulator was used to model a field-scale test of DNAPL removal by cosolvent flooding. The DNAPL at this site was tetrachloroethylene (PCE), and the flooding solution was an ethanol/water mixture, with up to 95% ethanol. The numerical model, UTCHEM accounts for the equilibrium phase behavior and multiphase flow of a ternary ethanol-PCE-water system. Simulations of enhanced cosolvent flooding using a kinetic interphase mass transfer approach show that when a very high concentration of alcohol is injected, the DNAPL/water/alcohol mixture forms a single phase and local mass transfer limitations become irrelevant. The field simulations were carried out in three steps. At the first level, a simple uncalibrated layered model is developed. This model is capable of roughly reproducing the production well concentrations of alcohol, but not of PCE. A more refined (but uncalibrated) permeability model is able to accurately simulate the breakthrough concentrations of injected alcohol from the production wells, but is unable to accurately predict the PCE removal. The final model uses a calibration of the initial PCE distribution to get good matches with the PCE effluent curves from the extraction wells. It is evident that the effectiveness of DNAPL source zone remediation is mainly affected by characteristics of the spatial heterogeneity of porous media and the variable (and unknown) DNAPL distribution. The inherent uncertainty in the DNAPL distribution at real field sites means that some form of calibration of the initial contaminant distribution will almost always be required to match contaminant effluent breakthrough curves.

High-efficiency and high-reliability 9xx-nm bars and fiber-coupled devices at Coherent

NASA Astrophysics Data System (ADS)

Zhou, Hailong; Kennedy, Keith; Weiss, Eli; Li, Jun; Anikitchev, Serguei; Reichert, Patrick; Du, Jihua; Schleuning, David; Nabors, David; Reed, Murray; Toivonen, Mika; Lehkonen, Sami; Haapamaa, Jouko

2006-02-01

Ongoing optimization of epitaxial design within Coherent device engineering has led to a family of high power-conversion-efficiency (PCE) products on conductively cooled packages (CCP) and fiber array packages (FAP). At a 25°C heat sink temperature, the PCE was measured at 71.5% with 75W CW output power on 30% fill-factor (FF) bars with passive cooling. At heat sink temperatures as high as 60°C the PCE of these bars is still maintained above 60%. Powered by such high efficiency 9xx nm diodes, Coherent FAP products have consistently exceeded 55% PCE up to 50W power levels, with 62% PCE demonstrated out of the fiber. High linear-power-density (LPD) operation of 100μm x 7-emitter bars at LPD = 80 mW/μm was also demonstrated. Bars with 7-emitter were measured up to 140W QCW power before catastrophic optical mirror damage (COMD) occurred, which corresponds to a COMD value of 200mW/μm or 2D facet power density of 29.4 MW/cm2. Leveraging these improvements has enabled high power FAPs with >90W CW from an 800μm-diameter fiber bundle. Extensive reliability testing has already accumulated 400,000 total real-time device hours at a variety of accelerated and non-accelerated operating conditions. A random failure rate <0.5% per kilo-hours and gradual degradation rate <0.4% per kilo-hours have been observed. For a 30% FF 50W CW 9xx nm bar, this equates to >30,000 hours of median lifetime at a 90% confidence level. More optimized 30% FF 9xx nm bars are under development for power outputs up to 80W CW with extrapolated median lifetimes greater than 20,000 hours.

Affinity for risky behaviors following prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water: a retrospective cohort study

PubMed Central

2011-01-01

Background Many studies of adults with acute and chronic solvent exposure have shown adverse effects on cognition, behavior and mood. No prior study has investigated the long-term impact of prenatal and early childhood exposure to the solvent tetrachloroethylene (PCE) on the affinity for risky behaviors, defined as smoking, drinking or drug use as a teen or adult. Objectives This retrospective cohort study examined whether early life exposure to PCE-contaminated drinking water influenced the occurrence of cigarette smoking, alcohol consumption, and drug use among adults from Cape Cod, Massachusetts. Methods Eight hundred and thirty-one subjects with prenatal and early childhood PCE exposure and 547 unexposed subjects were studied. Participants completed questionnaires to gather information on risky behaviors as a teenager and young adult, demographic characteristics, other sources of solvent exposure, and residences from birth through 1990. PCE exposure was estimated using the U.S. EPA's water distribution system modeling software (EPANET) that was modified to incorporate a leaching and transport model to estimate PCE exposures from pipe linings. Results Individuals who were highly exposed to PCE-contaminated drinking water during gestation and early childhood experienced 50-60% increases in the risk of using two or more major illicit drugs as a teenager or as an adult (Relative Risk (RR) for teen use = 1.6, 95% CI: 1.2-2.2; and RR for adult use = 1.5, 95% CI: 1.2-1.9). Specific drugs for which increased risks were observed included crack/cocaine, psychedelics/hallucinogens, club/designer drugs, Ritalin without a prescription, and heroin (RRs:1.4-2.1). Thirty to 60% increases in the risk of certain smoking and drinking behaviors were also seen among highly exposed subjects. Conclusions The results of this study suggest that risky behaviors, particularly drug use, are more frequent among adults with high PCE exposure levels during gestation and early childhood. These findings should be confirmed in follow-up investigations of other exposed populations. PMID:22136431

Update of the Body Armour Purchase and Replacement Protocol

DTIC Science & Technology

2014-10-01

marized by t ty level (RQ escribes wha h a 95% perc ing plan rout ptance. For t 125 items a of 5.2%. T ts that are 5 es accepted a Typical Oper e OC...58 4.3.3 Operating Characteristic (OC) Curve...s Introduced ves for Sque rmour Purch breviations/a ed Armour T nsiderations ..................... ..................... with NIJ-010 glia C

Lessons Learned from Creating the Public Earthquake Resource Center at CERI

NASA Astrophysics Data System (ADS)

Patterson, G. L.; Michelle, D.; Johnston, A.

2004-12-01

The Center for Earthquake Research and Information (CERI) at the University of Memphis opened the Public Earthquake Resource Center (PERC) in May 2004. The PERC is an interactive display area that was designed to increase awareness of seismology, Earth Science, earthquake hazards, and earthquake engineering among the general public and K-12 teachers and students. Funding for the PERC is provided by the US Geological Survey, The NSF-funded Mid America Earthquake Center, and the University of Memphis, with input from the Incorporated Research Institutions for Seismology. Additional space at the facility houses local offices of the US Geological Survey. PERC exhibits are housed in a remodeled residential structure at CERI that was donated by the University of Memphis and the State of Tennessee. Exhibits were designed and built by CERI and US Geological Survey staff and faculty with the help of experienced museum display subcontractors. The 600 square foot display area interactively introduces the basic concepts of seismology, real-time seismic information, seismic network operations, paleoseismology, building response, and historical earthquakes. Display components include three 22" flat screen monitors, a touch sensitive monitor, 3 helicorder elements, oscilloscope, AS-1 seismometer, life-sized liquefaction trench, liquefaction shake table, and building response shake table. All displays include custom graphics, text, and handouts. The PERC website at www.ceri.memphis.edu/perc also provides useful information such as tour scheduling, ask a geologist, links to other institutions, and will soon include a virtual tour of the facility. Special consideration was given to address State science standards for teaching and learning in the design of the displays and handouts. We feel this consideration is pivotal to the success of any grass roots Earth Science education and outreach program and represents a valuable lesson that has been learned at CERI over the last several years. Another critical lesson that has been learned is to employ K-12 education professionals and utilize undergrad and graduate student workers in the University's Department of Education. Such staff members are keenly aware of the pressures and needs in diverse communities such as Shelby County, Tennessee and are uniquely suited to design and implement new and innovative programs that provide substantive short-term user benefits and promote long-term relationships with the K-12 teachers, students, and teacher's organizations.

Response of ponderosa pine stands to pre-commercial thinning on Nez Perce and Spokane Tribal forests in the Inland Northwest, USA

Treesearch

Dennis E. Ferguson; John C. Byrne; William R. Wykoff; Brian Kummet; Ted Hensold

2011-01-01

Stands of dense, natural ponderosa pine (Pinus ponderosa var. ponderosa) regeneration were operationally, precommercially thinned at seven sites - four on Nez Perce Tribal lands in northern Idaho and three on Spokane Tribal lands in eastern Washington. Five spacing treatments were studied - control (no thinning), 5x5 ft, 7x7 ft, 10x10 ft, and 14x14 ft. Sample trees...

Pharmaceutical Cognitive Enhancement in Greek University Students: Differences Between Users and Non-Users in Social Cognitive Variables, Burnout, and Engagement.

PubMed

Lazuras, Lambros; Ypsilanti, Antonia; Lamprou, Efthymios; Kontogiorgis, Christos

2017-06-07

Pharmaceutical cognitive enhancement (PCE) represents the non-medical use of prescribed medication for the improvement of cognitive functioning and academic performance. Although there are some studies about PCE prevalence, it is less clear how users and non-users of PCE substances differ with respect to their positive and negative student experiences (e.g. academic burnout and engagement with studies) and in social cognitive variables that relate to decision-making and self-regulation of PCE use. The present study assessed whether students with different experiences of PCE substance use displayed differences in academic burnout, study engagement, and social cognitive variables relevant to PCE use. Three hundred and forty-seven university students (mean age (M) = 22.15 years, SD = 1.69; 54% females) completed a battery of anonymous questionnaires on academic burnout, engagement with studies, social cognitive variables relevant to PCE use, and self-reported use of PCE substances and non-prescribed nutritional supplements. Three user groups emerged, namely non-users (51.9%, n = 180), single users of non-prescribed dietary supplements (25.4%, n = 88), and dual users of both non-prescribed dietary supplements and PCE (22.8%, n = 79). Multivariate analysis of variance indicated significant differences among the three user groups in intentions, attitudes, social norms, and anticipated regret toward PCE use. No significant differences were observed with respect to academic burnout and work engagement. The findings show that university students may engage in PCE use independent of their student experiences. Rather, a chemically assisted performance enhancement mindset seems to differentiate users from non-users of PCE substances.

Swiss University Students' Attitudes toward Pharmacological Cognitive Enhancement.

PubMed

Maier, Larissa J; Liakoni, Evangelia; Schildmann, Jan; Schaub, Michael P; Liechti, Matthias E

2015-01-01

Pharmacological cognitive enhancement (PCE) refers to the nonmedical use of prescription or recreational drugs to enhance cognitive performance. Several concerns about PCE have been raised in the public. The aim of the present study was to investigate students' attitudes toward PCE. Students at three Swiss universities were invited by e-mail to participate in a web-based survey. Of the 29,282 students who were contacted, 3,056 participated. Of these students, 22% indicated that they had used prescription drugs (12%) or recreational substances including alcohol (14%) at least once for PCE. The use of prescription drugs or recreational substances including alcohol prior to the last exam was reported by 16%. Users of pharmacological cognitive enhancers were more likely to consider PCE fair (24%) compared with nonusers (11%). Only a minority of the participants agreed with the nonmedical use of prescription drugs by fellow students when assuming weak (7%) or hypothetically strong efficacy and availability to everyone (14%). Two-thirds (68%) considered performance that is obtained with PCE less worthy of recognition. Additionally, 80% disagreed that PCE is acceptable in a competitive environment. More than half (64%) agreed that PCE in academia is similar to doping in sports. Nearly half (48%) claimed that unregulated access to pharmacological cognitive enhancers increases the pressure to engage in PCE and educational inequality (55%). In conclusion, Swiss students' main concerns regarding PCE were related to coercion and fairness. As expected, these concerns were more prevalent among nonusers than among users of pharmacological cognitive enhancers. More balanced information on PCE should be shared with students, and future monitoring of PCE is recommended.

Swiss University Students’ Attitudes toward Pharmacological Cognitive Enhancement

PubMed Central

Maier, Larissa J.; Liakoni, Evangelia; Schildmann, Jan; Schaub, Michael P.; Liechti, Matthias E.

2015-01-01

Pharmacological cognitive enhancement (PCE) refers to the nonmedical use of prescription or recreational drugs to enhance cognitive performance. Several concerns about PCE have been raised in the public. The aim of the present study was to investigate students’ attitudes toward PCE. Students at three Swiss universities were invited by e-mail to participate in a web-based survey. Of the 29,282 students who were contacted, 3,056 participated. Of these students, 22% indicated that they had used prescription drugs (12%) or recreational substances including alcohol (14%) at least once for PCE. The use of prescription drugs or recreational substances including alcohol prior to the last exam was reported by 16%. Users of pharmacological cognitive enhancers were more likely to consider PCE fair (24%) compared with nonusers (11%). Only a minority of the participants agreed with the nonmedical use of prescription drugs by fellow students when assuming weak (7%) or hypothetically strong efficacy and availability to everyone (14%). Two-thirds (68%) considered performance that is obtained with PCE less worthy of recognition. Additionally, 80% disagreed that PCE is acceptable in a competitive environment. More than half (64%) agreed that PCE in academia is similar to doping in sports. Nearly half (48%) claimed that unregulated access to pharmacological cognitive enhancers increases the pressure to engage in PCE and educational inequality (55%). In conclusion, Swiss students’ main concerns regarding PCE were related to coercion and fairness. As expected, these concerns were more prevalent among nonusers than among users of pharmacological cognitive enhancers. More balanced information on PCE should be shared with students, and future monitoring of PCE is recommended. PMID:26657300

Reductive tetrachloroethene dehalogenation in the presence of oxygen by Sulfurospirillum multivorans: physiological studies and proteome analysis.

PubMed

Gadkari, Jennifer; Goris, Tobias; Schiffmann, Christian L; Rubick, Raffael; Adrian, Lorenz; Schubert, Torsten; Diekert, Gabriele

2018-01-01

Reductive dehalogenation of organohalides is carried out by organohalide-respiring bacteria (OHRB) in anoxic environments. The tetrachloroethene (PCE)-respiring Epsilonproteobacterium Sulfurospirillum multivorans is one of few OHRB able to respire oxygen. Therefore, we investigated the organism's capacity to dehalogenate PCE in the presence of oxygen, which would broaden the applicability to use S. multivorans, unlike other commonly oxygen-sensitive OHRB, for bioremediation, e.g. at oxic/anoxic interphases. Additionally, this has an impact on our understanding of the global halogen cycle. Sulfurospirillum multivorans performs dehalogenation of PCE to cis-1,2-dichloroethene at oxygen concentrations below 0.19 mg/L. The redox potential of the medium electrochemically adjusted up to +400 mV had no influence on reductive dehalogenation by S. multivorans in our experiments, suggesting that higher levels of oxygen impair PCE dechlorination by inhibiting or inactivating involved enzymes. The PCE reductive dehalogenase remained active in cell extracts of S. multivorans exposed to 0.37 mg/L oxygen for more than 96 h. Analysis of the proteome revealed that superoxide reductase and cytochrome peroxidase amounts increased with 5% oxygen in the gas phase, while the response to atmospheric oxygen concentrations involved catalase and hydrogen peroxide reductase. Taken together, our results demonstrate that reductive dehalogenation by OHRB is not limited to anoxic conditions. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Prenatal and Early Childhood Exposure to Tetrachloroethylene and Adult Vision

PubMed Central

Getz, Kelly D.; Janulewicz, Patricia A.; Rowe, Susannah; Weinberg, Janice M.; Winter, Michael R.; Martin, Brett R.; Vieira, Veronica M.; White, Roberta F.

2012-01-01

Background: Tetrachloroethylene (PCE; or perchloroethylene) has been implicated in visual impairments among adults with occupational and environmental exposures as well as children born to women with occupational exposure during pregnancy. Objectives: Using a population-based retrospective cohort study, we examined the association between prenatal and early childhood exposure to PCE-contaminated drinking water on Cape Cod, Massachusetts, and deficits in adult color vision and contrast sensitivity. Methods: We estimated the amount of PCE that was delivered to the family residence from participants’ gestation through 5 years of age. We administered to this now adult study population vision tests to assess acuity, contrast sensitivity, and color discrimination. Results: Participants exposed to higher PCE levels exhibited lower contrast sensitivity at intermediate and high spatial frequencies compared with unexposed participants, although the differences were generally not statistically significant. Exposed participants also exhibited poorer color discrimination than unexposed participants. The difference in mean color confusion indices (CCI) was statistically significant for the Farnsworth test but not Lanthony’s D-15d test [Farnsworth CCI mean difference = 0.05, 95% confidence interval (CI): 0.003, 0.10; Lanthony CCI mean difference = 0.07, 95% CI: –0.02, 0.15]. Conclusions: Prenatal and early childhood exposure to PCE-contaminated drinking water may be associated with long-term subclinical visual dysfunction in adulthood, particularly with respect to color discrimination. Further investigation of this association in similarly exposed populations is necessary. PMID:22784657

Monitoring and Evaluation Plan for the Nez Perce Tribal Hatchery, 1996 Technical Report.

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

Steward, Cleveland R.

1996-08-01

The Nez Perce Tribe has proposed to build and operate the Nez Perce Tribal Hatchery (NPTH) in the Clearwater River subbasin of Idaho for the purpose of restoring self-sustaining populations of spring, summer, and fall chinook salmon to their native habitats. The project comprises a combination of incubation and rearing facilities, satellite rearing facilities, juvenile and adult collection sites, and associated production and harvest management activities. As currently conceived, the NPTH program will produce approximately 768,000 spring chinook parr, 800,000 summer chinook fry, and 2,000,000 fall chinook fry on an annual basis. Hatchery fish would be spawned, reared, and releasedmore » under conditions that promote wild-type characteristics, minimize genetic changes in both hatchery and wild chinook populations, and minimize undesirable ecological interactions. The primary objective is to enable hatchery-produced fish to return to reproduce naturally in the streams in which they are released. These and other characteristics of the project are described in further detail in the Nez Perce Tribal Hatchery Master Plan (Larson and Mobrand 1992), the 1995 Supplement to the Master Plan (Johnson et al. 1995), and the Nez Perce Tribal Hatchery Program Environmental Impact Statement (Bonneville Power Administration et al. 1996). The report in hand is referred to in project literature as the NPTH Monitoring and Evaluation (M&E) Plan. This report describes monitoring and evaluation activities that will help NPTH managers determine. whether they were successful in restoring chinook salmon populations and avoiding adverse ecological impacts. Program success will be gauged primarily by changes in the abundance and distribution of supplemented chinook populations. The evaluation of project-related impacts will focus on the biological effects of constructing and operating NPTH hatchery facilities, introducing hatchery fish into the natural environment, and removing or displacing wild fish, including targeted chinook, non-targeted chinook, and resident species.« less

Non-steady state partitioning of dry cleaning surfactants between tetrachloroethylene (PCE) and water in porous media.

PubMed

Hoggan, James L; Bae, Keonbeom; Kibbey, Tohren C G

2007-08-15

Trapped organic solvents, in both the vadose zone and below the water table, are frequent sources of environmental contamination. A common source of organic solvent contamination is spills, leaks, and improper solvent disposal associated with dry cleaning processes. Dry cleaning solvents, such as tetrachloroethylene (PCE), are typically enhanced with the addition of surfactants to improve cleaning performance. The objective of this work was to examine the partitioning behavior of surfactants from PCE in contact with water. The relative rates of surfactants partitioning and PCE dissolution are important for modeling the behavior of waste PCE in the subsurface, in that they influence the interfacial tension of the PCE, and how (or if) interfacial tension changes over time in the subsurface. The work described here uses a flow-through system to examine simultaneous partitioning and PCE dissolution in a porous medium. Results indicate that both nonylphenol ethoxylate nonionic surfactants and a sulfosuccinate anionic surfactant partition out of residual PCE much more rapidly than the PCE dissolves, suggesting that in many cases interfacial tension changes caused by partitioning may influence infiltration and distribution of PCE in the subsurface. Non-steady-state partitioning is found to be well-described by a linear driving force model incorporating measured surfactant partition coefficients.

A small amount of tetrachloroethylene ingestion from drinking water accelerates antigen-stimulated allergic responses.

PubMed

Seo, Makoto; Yamagiwa, Takeo; Kobayashi, Ryo; Ikeda, Koji; Satoh, Masahiko; Inagaki, Naoki; Nagai, Hiroichi; Nagase, Hisamitsu

2008-01-01

Previously, we observed that tetrachloroethylene (perchloroethylene, PCE) increased histamine release and inflammatory mediator production from antigen-stimulated mast cells. In this study, we examined the enhancing effect of low concentrations of PCE in drinking water on antigen-stimulated allergic responses. After exposure of Wistar rats to PCE in drinking water for 2 or 4 weeks, we performed a passive cutaneous anaphylaxis (PCA) reaction. PCE exposure for 4 weeks enhanced PCA reaction in a dose-dependent manner. In pathological studies, PCE exposure for 2 weeks exacerbated inflammation characterized by infiltration of lymphocytes and accumulation of mast cells around the vessel. Non-purified mast cells (NPMCs) from rats treated with 1mg/L PCE in drinking water for 2 weeks increased antigen-stimulated histamine release. Furthermore, the leukocytes of rats treated with PCE in drinking water for 4 weeks showed increased interleukin (IL)-4 expression. The mechanism of enhancing the PCA reaction is assumed to be that PCE increases IL-4 production and PCE causes T helper (Th) 1/Th2-type helper T-cell imbalance and increases histamine release from excessively accumulated mast cells. The results suggest that the intake of PCE in drinking water, even at a low concentration, leads to the initiation and acceleration of allergic diseases.

Prenatal Exposure to Tetrachloroethylene-Contaminated Drinking Water and the Risk of Adverse Birth Outcomes

PubMed Central

Aschengrau, Ann; Weinberg, Janice; Rogers, Sarah; Gallagher, Lisa; Winter, Michael; Vieira, Veronica; Webster, Thomas; Ozonoff, David

2008-01-01

Background Prior studies of prenatal exposure to tetrachloroethylene (PCE) have shown mixed results regarding its effect on birth weight and gestational age. Objectives In this retrospective cohort study we examined whether PCE contamination of public drinking-water supplies in Massachusetts influenced the birth weight and gestational duration of children whose mothers were exposed before the child’s delivery. Methods The study included 1,353 children whose mothers were exposed to PCE-contaminated drinking water and a comparable group of 772 children of unexposed mothers. Birth records were used to identify subjects and provide information on the outcomes. Mothers completed a questionnaire to gather information on residential histories and confounding variables. PCE exposure was estimated using EPANET water distribution system modeling software that incorporated a fate and transport model. Results We found no meaningful associations between PCE exposure and birth weight or gestational duration. Compared with children whose mothers were unexposed during the year of the last menstrual period (LMP), adjusted mean differences in birth weight were 20.9, 6.2, 30.1, and 15.2 g for children whose mothers’ average monthly exposure during the LMP year ranged from the lowest to highest quartile. Similarly, compared with unexposed children, adjusted mean differences in gestational age were −0.2, 0.1, −0.1, and −0.2 weeks for children whose mothers’ average monthly exposure ranged from the lowest to highest quartile. Similar results were observed for two other measures of prenatal exposure. Conclusions These results suggest that prenatal PCE exposure does not have an adverse effect on these birth outcomes at the exposure levels experienced by this population. PMID:18560539

Contamination of ground water by PCE - A national perspective

USGS Publications Warehouse

Moran, M.J.; Delzer, G.C.

2006-01-01

Perchloroethylene (PCE) has physical and chemical properties that make it likely to persist in groundwater if released to the environment. The US Geological Survey has collected or compiled data on the occurrence of PCE in groundwater from major aquifers around the US. These data represent the occurrence of PCE in the groundwater resource as a whole and not occurrence at specific release sites. PCE was detected at measurable concentrations in nearly one in 10 wells in major aquifers throughout the country. Trichloroethylene was found most commonly with PCE and its presence may be due, in part, to reductive dechlorination of PCE. This is an abstract of a paper presented at the Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention, Assessment, and Remediation Conference (Houston, TX 11/6-7/2006).

Surfactant enhanced remediation of soil columns contaminated by residual tetrachloroethylene

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

Pennell, K.D.; Jin, M.; Abriola, L.M.

1994-01-01

The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting (14)C-labeled PCE into water-saturated soil columns and displacing the free product with water. Miscible displacement experiments were conducted before and after PCE entrapment to determine the influence or residual PCE on column dispersivities. The first two column studies involved the injection of a 4% solution of polyoxyethylene (POE) (20) sorbitan monooleate, resulting in the removal of 90% and 97% of the residual PCE from 20-30- and 40-120-mesh Ottawa sand, respectively. Although micellar solubilization ofmore » PCE was the primary mode of recovery in these experiments, this process was shown to be rate-limited.« less

A low band-gap polymer based on unsubstituted benzo[1,2-b:4,5-b']dithiophene for high performance organic photovoltaics

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

Woong Jung, Jae; Woong Jo, Jea; Liu, Feng

2012-01-01

A low band-gap conjugated polymer, PBDTDPP, composed of unsubstituted benzo[1,2-b:4,5-b']dithiophene and diketopyrrolo[3,4-c]pyrrole was synthesized. The deep HOMO level of PBDTDPP enhances the VOC of a PSC up to 0.82 V and exhibits a PCE of 5.16%, while alkoxy substituted PBDTDPP-OR yields a PCE of 2.24% with a VOC of 0.61 V.

Restore McComas Meadows; Meadow Creek Watershed, 2005-2006 Annual Report.

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

McRoberts, Heidi

2006-07-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated and cost shared with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing, planting trees in riparian areas within the meadow and its tributaries, prioritizing culverts for replacement to accommodate fish passage, and decommissioning roads tomore » reduce sediment input. During this contract period work was completed on two culvert replacement projects; Doe Creek and a tributary to Meadow Creek. Additionally construction was also completed for the ditch restoration project within McComas Meadows. Monitoring for project effectiveness and trends in watershed conditions was also completed. Road decommissioning monitoring, as well as stream temperature, sediment, and discharge were completed.« less

From event analysis to global lessons: disaster forensics for building resilience

NASA Astrophysics Data System (ADS)

Keating, Adriana; Venkateswaran, Kanmani; Szoenyi, Michael; MacClune, Karen; Mechler, Reinhard

2016-04-01

With unprecedented growth in disaster risk, there is an urgent need for enhanced learning about and understanding disasters, particularly in relation to the trends in the drivers of increasing risk. Building on the disaster forensics field, we introduce the Post Event Review Capability (PERC) methodology for systematically and holistically analyzing disaster events, and identifying actionable recommendations. PERC responds to a need for learning about the successes and failures in disaster risk management and resilience, and uncovers the underlying drivers of increasing risk. We draw generalizable insights identified from seven applications of the methodology to date, where we find that across the globe policy makers and practitioners in disaster risk management face strikingly similar challenges despite variations in context, indicating encouraging potential for mutual learning. These lessons highlight the importance of integrated risk reduction strategies. We invite others to utilize the freely available PERC approach and contribute to building a repository of learnings on disaster risk management and resilience.

From event analysis to global lessons: disaster forensics for building resilience

NASA Astrophysics Data System (ADS)

Keating, Adriana; Venkateswaran, Kanmani; Szoenyi, Michael; MacClune, Karen; Mechler, Reinhard

2016-07-01

With unprecedented growth in disaster risk, there is an urgent need for enhanced learning and understanding of disasters, particularly in relation to the trends in drivers of increasing risk. Building on the disaster forensics field, we introduce the post-event review capability (PERC) methodology for systematically and holistically analysing disaster events, and identifying actionable recommendations. PERC responds to a need for learning about the successes and failures in disaster risk management and resilience, and uncovers the underlying drivers of increasing risk. We draw generalisable insights identified from seven applications of the methodology to date, where we find that across the globe policy makers and practitioners in disaster risk management face strikingly similar challenges despite variations in context, indicating encouraging potential for mutual learning. These lessons highlight the importance of integrated risk reduction strategies. We invite others to utilise the freely available PERC approach and contribute to building a repository of learning on disaster risk management and resilience.

FDNS CFD Code Benchmark for RBCC Ejector Mode Operation: Continuing Toward Dual Rocket Effects

NASA Technical Reports Server (NTRS)

West, Jeff; Ruf, Joseph H.; Turner, James E. (Technical Monitor)

2000-01-01

Computational Fluid Dynamics (CFD) analysis results are compared with benchmark quality test data from the Propulsion Engineering Research Center's (PERC) Rocket Based Combined Cycle (RBCC) experiments to verify fluid dynamic code and application procedures. RBCC engine flowpath development will rely on CFD applications to capture the multi -dimensional fluid dynamic interactions and to quantify their effect on the RBCC system performance. Therefore, the accuracy of these CFD codes must be determined through detailed comparisons with test data. The PERC experiments build upon the well-known 1968 rocket-ejector experiments of Odegaard and Stroup by employing advanced optical and laser based diagnostics to evaluate mixing and secondary combustion. The Finite Difference Navier Stokes (FDNS) code [2] was used to model the fluid dynamics of the PERC RBCC ejector mode configuration. Analyses were performed for the Diffusion and Afterburning (DAB) test conditions at the 200-psia thruster operation point, Results with and without downstream fuel injection are presented.

Characterization of uranium surfaces machined with aqueous propylene glycol-borax or perchloroethylene-mineral oil coolants

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

Cristy, S.S.; Bennett, R.K. Jr.; Dillon, J.J.

1986-12-31

The use of perchloroethylene (perc) as an ingredient in coolants for machining enriched uranium at the Oak Ridge Y-12 Plant has been discontinued because of environmental concerns. A new coolant was substituted in December 1985, which consists of an aqueous solution of propylene glycol with borax (sodium tetraborate) added as a nuclear poison and with a nitrite added as a corrosion inhibitor. Uranium surfaces machined using the two coolants were compared with respects to residual contamination, corrosion or corrosion potential, and with the aqueous propylene glycol-borax coolant was found to be better than that of enriched uranium machined with themore » perc-mineral oil coolant. The boron residues on the final-finished parts machined with the borax-containing coolant were not sufficient to cause problems in further processing. All evidence indicated that the enriched uranium surfaces machined with the borax-containing coolant will be as satisfactory as those machined with the perc coolant.« less

A Comparative Review of Waivers Granted in Pediatric Drug Development by FDA and EMA from 2007-2013.

PubMed

Egger, Gunter F; Wharton, Gerold T; Malli, Suzanne; Temeck, Jean; Murphy, M Dianne; Tomasi, Paolo

2016-09-01

The European Union and the United States have different legal frameworks in place for pediatric drug development, which can potentially lead to different pediatric research requirements for the pharmaceutical industry. This manuscript compares pediatric clinical trial waivers granted by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA). This is a retrospective review comparing EMA's Paediatric Committee (PDCO) decisions with FDA's Pediatric Review Committee (PeRC) recommendations for all product-specific pediatric full waiver applications submitted to EMA from January 2007 through December 2013. Using baseline data from EMA, we matched product-specific waivers with their FDA equivalents during the study period. For single active substance products, PDCO and PeRC adopted similar opinions in 42 of 49 indications (86%). For fixed-dose combinations, PDCO and PeRC adopted similar opinions in 24 of 31 indications (77%). Despite the different legal frameworks, criteria, and processes of determination, the waiver decisions of the 2 agencies were similar in the majority of cases.

PCE DNAPL degradation using ferrous iron solid mixture (ISM).

PubMed

Lee, Hong-Kyun; Do, Si-Hyun; Batchelor, Bill; Jo, Young-Hoon; Kong, Sung-Ho

2009-08-01

Ferrous iron solid mixture (ISM) containing Fe(II), Fe(III), and Cl was synthesized for degradation of tetrachloroethene (PCE) as a dense non-aqueous phase liquid (DNAPL), and an extraction procedure was developed to measure concentrations of PCE in both the aqueous and non-aqueous phases. This procedure included adding methanol along with hexane in order to achieve the high extraction efficiency, particularly when solids were present. When PCE was present as DNAPL, dechlorination of PCE was observed to decrease linearly with respect to the total PCE concentration (aqueous and non-aqueous phases) and the concentration of PCE in the aqueous phase was observed to be approximately constant. In the absence of DNAPL, the rate of PCE degradation was observed to be the first-order with respect to the concentration in the aqueous phase. A kinetic model was developed to describe these observations and it was able to fit experimental data well. Increasing the concentration of Fe(II) in ISM increased the values of rate constants, while increasing the concentration of PCE DNAPL did not affect the value of the rate constant. The reactivity of ISM for PCE dechlorination might be close to that of Friedel's salt, and the accumulation of trichloroethylene (TCE) might imply the lower reactivity of ISM for degradation of TCE or the necessity of large amount of Fe(II) in ISM. TCE (the major chlorinated intermediate), ethene (the major non-chlorinated compound), acetylene and ethane were detected, which implied that both hydrogenolysis and beta-elimination were pathways of PCE DNAPL degradation on ISM.

Estimated effects of in utero cocaine exposure on language development through early adolescence.

PubMed

Bandstra, Emmalee S; Morrow, Connie E; Accornero, Veronica H; Mansoor, Elana; Xue, Lihua; Anthony, James C

2011-01-01

The potential longitudinal effects of prenatal cocaine exposure (PCE) on language functioning were estimated from early childhood through early adolescence in a large, well-retained urban sample of 451 full-term children (242 cocaine-exposed, 209 non-cocaine-exposed) participating in the Miami Prenatal Cocaine Study (MPCS). The sample was enrolled prospectively at birth, with documentation of prenatal drug exposure status through maternal interview, and toxicology assays of maternal and infant urine, and infant meconium. Age-appropriate versions of the Clinical Evaluation of Language Fundamentals (CELF) were used to measure total, expressive, and receptive language at ages 3, 5, and 12years. Longitudinal latent growth curve (LLGC) modeling of the data revealed an association between PCE (measured dichotomously as yes/no) and lower functioning in expressive and total language scores, after considering other sources of variation including child's age at testing, sex, prenatal exposure to alcohol, marijuana, and tobacco, and additional medical and social-demographic covariates. Analyses of level of PCE showed a gradient, i.e. dose-dependent, relationship between PCE level and expressive, receptive, and total language scores in the models controlling for age, child's sex, and other prenatal drug exposures. With additional covariate control these findings were most stable for the total language score. The evidence supports an inference about an enduring stable cocaine-specific effect on children's language abilities, with no effect on language growth over time in the longitudinal trajectory of language development. Copyright © 2010 Elsevier Inc. All rights reserved.

Perchloroethylene-contaminated drinking water and the risk of breast cancer: additional results from Cape Cod, Massachusetts, USA.

PubMed Central

Aschengrau, Ann; Rogers, Sarah; Ozonoff, David

2003-01-01

In 1998 we published the results of a study suggesting an association between breast cancer and perchloroethylene (PCE; also called tetrachloroethylene) exposure from public drinking water. The present case-control study was undertaken to evaluate this association further. The cases were composed of female residents of eight towns in the Cape Cod region of Massachusetts who had been diagnosed with breast cancer from 1987 through 1993 (n = 672). Controls were composed of demographically similar women from the same towns (n = 616). Women were exposed to PCE when it leached from the vinyl lining of water distribution pipes from the late 1960s through the early 1980s. A relative delivered dose of PCE that entered a home was estimated using an algorithm that took into account residential history, water flow, and pipe characteristics. Small to moderate elevations in risk were seen among women whose exposure levels were above the 75th and 90th percentiles when 0-15 years of latency were considered (adjusted odds ratios, 1.5-1.9 for > 75th percentile, 1.3-2.8 for > 90th percentile). When data from the present and prior studies were combined, small to moderate increases in risk were also seen among women whose exposure levels were above the 75th and 90th percentiles when 0-15 years of latency were considered (adjusted odds ratios, 1.6-1.9 for > 75th percentile, 1.3-1.9 for > 90th percentile). The results of the present study confirm those of the previous one and suggest that women with the highest PCE exposure levels have a small to moderate increased risk of breast cancer. PMID:12573900

Phytoscreening for chlorinated solvents using rapid in vitro SPME sampling: Application to urban plume in Verl, Germany

USGS Publications Warehouse

Limmer, M.A.; Balouet, J.-C.; Karg, F.; Vroblesky, D.A.; Burken, J.G.

2011-01-01

Rapid detection and delineation of contaminants in urban settings is critically important in protecting human health. Cores from trees growing above a plume of contaminated groundwater in Verl, Germany, were collected in 1 day, with subsequent analysis and plume mapping completed over several days. Solid-phase microextraction (SPME) analysis was applied to detect tetrachloroethene (PCE) and trichloroethene (TCE) to below nanogram/liter levels in the transpiration stream of the trees. The tree core concentrations showed a clear areal correlation to the distribution of PCE and TCE in the groundwater. Concentrations in tree cores were lower than the underlying groundwater, as anticipated; however, the tree core water retained the PCE:TCE signature of the underlying groundwater in the urban, populated area. The PCE:TCE ratio can indicate areas of differing degradation activity. Therefore, the phytoscreening analysis was capable not only of mapping the spatial distribution of groundwater contamination but also of delineating zones of potentially differing contaminant sources and degradation. The simplicity of tree coring and the ability to collect a large number of samples in a day with minimal disruption or property damage in the urban setting demonstrates that phytoscreening can be a powerful tool for gaining reconnaissance-level information on groundwater contaminated by chlorinated solvents. The use of SPME decreases the detection level considerably and increases the sensitivity of phytoscreening as an assessment, monitoring, and phytoforensic tool. With rapid, inexpensive, and noninvasive methods of detecting and delineating contaminants underlying homes, as in this case, human health can be better protected through screening of broader areas and with far faster response times. ?? 2011 American Chemical Society.

Influencing factors, underlying mechanism and interactions affecting hypercholesterolemia in adult offspring with caffeine exposure during pregnancy.

PubMed

Guo, Yitian; Luo, Hanwen; Wu, Yimeng; Magdalou, Jacques; Chen, Liaobin; Wang, Hui

2018-05-22

Epidemiological surveys suggest that adult hypercholesterolemia has an intrauterine origin and exhibits gender differences. Our previous study demonstrated that adult rats with intrauterine growth retardation (IUGR) offspring rats induced by prenatal caffeine exposure (PCE) had a higher serum total cholesterol (TCH) level. In this study, we aimed to analyze the influencing factors, underlying mechanism and interactions affecting hypercholesterolemia in adult offspring with caffeine exposure during pregnancy. Pregnant rats were administered caffeine (120 mg/kg d) from gestational day 11 until delivery. Offspring rats fed a normal diet or a high-fat diet (HFD) were euthanized at postnatal week 24, and blood and liver samples were collected. The results showed that PCE could increase the serum levels of TCH and low-density lipoprotein-cholesterol (LDL-C), and the hepatic expression of HMG CoA reductase (HMGCR) and apolipoprotein B (ApoB), but decreased the high-density lipoprotein-cholesterol (HDL-C) level and the hepatic expression of scavenger receptor B1 (SR-B1) and LDL receptor (LDLR). Furthermore, PCE, HFD and gender interact with each other to influence the serum cholesterol phenotype and expression of hepatic cholesterol metabolic genes. These results suggest that the hypercholesterolemia in adult offspring rats induced by PCE mainly resulted from enhanced synthesis and the weakened reverse transport of cholesterol in the liver, furthermore HFD could aggravate this effect, which is caused by hepatic cholesterol metabolic disorders. Moreover, cholesterol metabolism in female rats was more sensitive to neuroendocrine changes and HFD than that in males. This study confirmed the influencing factors (such as a HFD and female gender) of hypercholesterolemia in IUGR offspring providing theoretical and experimental bases for the effective prevention of fetal-originated hypercholesterolemia. Copyright © 2018 Elsevier Inc. All rights reserved.

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

Wei Xiong; Liu, H. Helen; Tucker, Susan L.

Purpose: To identify clinical and dosimetric factors influencing the risk of pericardial effusion (PCE) in patients with inoperable esophageal cancer treated with definitive concurrent chemotherapy and radiation therapy (RT). Methods and Materials: Data for 101 patients with inoperable esophageal cancer treated with concurrent chemotherapy and RT from 2000 to 2003 at our institution were analyzed. The PCE was confirmed from follow-up chest computed tomography scans and radiologic reports, with freedom from PCE computed from the end of RT. Log-rank tests were used to identify clinical and dosimetric factors influencing freedom from PCE. Dosimetric factors were calculated from the dose-volume histogrammore » for the whole heart and pericardium. Results: The crude rate of PCE was 27.7% (28 of 101). Median time to onset of PCE was 5.3 months (range, 1.0-16.7 months) after RT. None of the clinical factors investigated was found to significantly influence the risk of PCE. In univariate analysis, a wide range of dose-volume histogram parameters of the pericardium and heart were associated with risk of PCE, including mean dose to the pericardium, volume of pericardium receiving a dose greater than 3 Gy (V3) to greater than 50 Gy (V50), and heart volume treated to greater than 32-38 Gy. Multivariate analysis selected V30 as the only parameter significantly associated with risk of PCE. Conclusions: High-dose radiation to the pericardium may strongly increase the risk of PCE. Such a risk may be reduced by minimizing the dose-volume of the irradiated pericardium and heart.« less

Effect of polycarboxylate ether comb-type polymer on viscosity and interfacial properties of kaolinite clay suspensions.

PubMed

Zhang, Ling; Lu, Qingye; Xu, Zhenghe; Liu, Qingxia; Zeng, Hongbo

2012-07-15

The interactions between kaolinite clay particles and a comb-type polymer (polycarboxylate ether or PCE), so-called PCE super-plasticizer, were investigated through viscosity and surface forces measurements by a rheometer and a Surface Forces Apparatus (SFA). The addition of PCE shows a strong impact on the viscosity of concentrated kaolinite suspensions in alkaline solutions (pH=8.3) but a weak effect under acidic conditions (pH=3.4). In acidic solutions, the high viscosity measured is attributed to the strong electrostatic interaction between negatively charged basal planes and positively charged edge surfaces of clay particles. Under the alkaline condition, the suspension viscosity was found to first increase significantly and then decrease with increasing PCE dosages. The results from surface forces measurement show that PCE molecules at low dosages can bridge the kaolinite particles in the concentrated suspensions via hydrogen bonding, leading to the formation of a kaolinite-PCE "network" and hence an increased suspension viscosity. At high PCE dosages, clay particles are fully covered by PCE molecules, leading to a more dispersed kaolinite suspensions and hence lower suspension viscosity due to steric repulsion between the adsorbed PCE molecules. The insights derived from measuring viscosity and interfacial properties of kaolinite suspensions containing varying amount of comb-type super-plasticizer PCE at different pH provide the foundation for many engineering applications and optimizing industrial processes. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of Ca2+ ion concentration on adsorption of poly(carboxylate ether)-based (PCE) superplasticizer on mica.

PubMed

Wu, Bo; Chun, Byong-Wa; Gu, Le; Kuhl, Tonya L

2018-05-09

Poly(carboxylate ether)-based (PCE) superplasticizers consist of a carboxylic acid backbone and grafted poly(ethylene glycol) (PEG) side chains. Ca 2+ ion bridging mechanism is commonly purported to control PCE's adsorption on negatively charged cement particle surfaces in cement suspension, thus PCE was expected to adsorb on negatively charged surfaces in synthetic pore solutions via Ca 2+ /COO - interactions. Adsorption behaviors of a commercial PCE on negatively charged mica were studied in aqueous electrolyte solutions by a surface forces apparatus. Direct force measurements indicated that the PCE adsorbed onto mica from 0.1 M K 2 SO 4 due to K + ion chelation by the ether oxygen units CH 2 CH 2 O on the PEG chains, but surprisingly did not adsorb from either 0.1 M K 2 SO 4 with saturated Ca(OH) 2 or 0.1 M Ca(NO 3 ) 2 . The adsorption in K 2 SO 4 was weak, enabling the adsorbed PCE layers to be squeezed out under modest compression. Upon separating the surfaces, the PCE immediately achieved an identical re-adsorption. In high-calcium conditions, the PCE was highly positively charged due to Ca 2+ ion chelation by PEG chains and backbone carboxylic groups COO - , and mica also underwent charge reversal due to electrostatic adsorption/binding of Ca 2+ ions. Consequently, the interaction between mica and PCE was electrostatically repulsive and no PCE adsorption occurred. These findings can be explained by the complex interplay of ion chelation by PEG chains, electrostatic binding and screening interactions with charged surfaces in the presence of monovalent and divalent counterions, and ultimately charge reversal of both the charged surfaces and polyelectrolyte in high divalent ion conditions. Copyright © 2018 Elsevier Inc. All rights reserved.

Pharmacological cognitive enhancement among non-ADHD individuals-A cross-sectional study in 15 countries.

PubMed

Maier, Larissa J; Ferris, Jason A; Winstock, Adam R

2018-06-11

Psychoactive substance use aiming at increased performance at work or while studying, usually referred to as pharmacological cognitive enhancement (PCE), has been extensively researched in recent years. While large scale national studies have tried to assess the prevalence of PCE among the general population, cross-cultural comparisons have been hampered by the different definitions and designs included. In addition, the non-medical use of prescription drugs indicated to treat the symptoms of the Attention Deficit Hyperactivity Disorder (ADHD) has been the focus of discussion, yet no study has addressed the association between ADHD rates, prescribing behaviour and PCE yet. The Global Drug Survey is an annually conducted anonymous web survey on substance use. Two data sets from male and female Global Drug Survey (GDS) participants aged 16 to 65 years with no previous ADHD diagnosis were analysed to assess12-month PCE in 15 countries. GDS2015 (n = 79,640) examined the patterns of and motives for stimulant PCE, while GDS2017 (n = 29,758) focused on both the use of stimulant and sedative drugs for PCE RESULTS: When comparing the study samples 2015 and 2017, PCE with prescription and illegal stimulants and modafinil increased across all countries. People who used stimulant drugs and modafinil for PCE rated the perceived effect on cognitive performance most beneficial, while alcohol was the substance with the most adverse effect. The analysis of data on stimulant use for PCE in the largest global sample highlights relatively low-risk PCE use patterns except for participants with illegal stimulant use for PCE. The globalisation of ADHD, physicians' prescribing behaviour and changes in drug policy are likely to influence the country-specific rate of PCE among non-ADHD individuals what calls for further investigation. Copyright © 2018 Elsevier B.V. All rights reserved.

Experimental and numerical investigation of DNAPL infiltration and spreading in a 2-D sandbox by means of light transmission method

NASA Astrophysics Data System (ADS)

Zheng, F.; Shi, X.; Wu, J.; Gao, Y. W.

2013-12-01

Chlorinated solvents such as trichloroethene (TCE) and tetrachloroethene (PCE) are widespread groundwater contaminants often referred to as dense non-aqueous phase liquids (DNAPLs). Accuracy description of the spreading behavior and configuration for subsurface DNAPL migration is important, especially favourable for design effective remediation strategies. In this study, a 2-D experiment was conducted to investigate the infiltration behavior and spatial distribution of PCE in saturated porous media. Accusand 20/30 mesh sand (Unimin, Le Sueur, MN) was used as the background medium with two 70/80 and 60/70 mesh lenses embedded to simulate heterogeneous conditions. Dyed PCE of 100 ml was released into the flow cell at a constant rate of 2ml/min using a Harvard Apparatus syringe pump with a 50 ml glass syringe for two times, and 5 ml/min water was continuously injected through the inlet at the left side of the sandbox, while kept the same effluent rate at right side to create hydrodynamic condition. A light transmission (LT) system was used to record the migration of PCE and determine the saturation distribution of PCE in the sandbox experiment with a thermoelectrically air-cooled charged-coupled device (CCD) camera. All images were processed using MATLAB to calculate thickness-averaged PCE saturation for each pixel. Mass balance was checked through comparing injected known mounts of PCE with that calculated from LT analysis. Results showed that LT method is effective to delineate PCE migration pathways and quantify the saturation distribution. The relative errors of total PCE volumes calculated by LT analysis at different times were within 15% of the injected PCE volumes. The simulation are conducted using the multiphase modeling software T2VOC, which calibrated by the LT analysis results of three recorded time steps to fit with the complete spatial-temporal distribution of the PCE saturation. Model verification was then performed using the other eight recorded time steps. Simulated results showed that the model could successfully reproduce the migration pathways and distribution configuration observed from the laboratory experiment and LT analysis, excepted for a smaller pool height on the lenses, and a lower saturation values in PCE accumulation area due to local heterogeneities. Due to the influence of water flow, the PCE distribution was asymmetrical, and the PCE distribution area, pool height as well as PCE saturation in the accumulation region at right side was much greater. Acknowledge: This work is financially supported by the National Nature Science Foundation of China grants No. 41030746 and 41172206.

Characterization of the Corrinoid Iron-Sulfur Protein Tetrachloroethene Reductive Dehalogenase of Dehalobacter restrictus

PubMed Central

Maillard, Julien; Schumacher, Wolfram; Vazquez, Francisco; Regeard, Christophe; Hagen, Wilfred R.; Holliger, Christof

2003-01-01

The membrane-bound tetrachloroethene reductive dehalogenase (PCE-RDase) (PceA; EC 1.97.1.8), the terminal component of the respiratory chain of Dehalobacter restrictus, was purified 25-fold to apparent electrophoretic homogeneity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a single band with an apparent molecular mass of 60 ± 1 kDa, whereas the native molecular mass was 71 ± 8 kDa according to size exclusion chromatography in the presence of the detergent octyl-β-d-glucopyranoside. The monomeric enzyme contained (per mol of the 60-kDa subunit) 1.0 ± 0.1 mol of cobalamin, 0.6 ± 0.02 mol of cobalt, 7.1 ± 0.6 mol of iron, and 5.8 ± 0.5 mol of acid-labile sulfur. Purified PceA catalyzed the reductive dechlorination of tetrachloroethene and trichloroethene to cis-1,2-dichloroethene with a specific activity of 250 ± 12 nkat/mg of protein. In addition, several chloroethanes and tetrachloromethane caused methyl viologen oxidation in the presence of PceA. The Km values for tetrachloroethene, trichloroethene, and methyl viologen were 20.4 ± 3.2, 23.7 ± 5.2, and 47 ± 10 μM, respectively. The PceA exhibited the highest activity at pH 8.1 and was oxygen sensitive, with a half-life of activity of 280 min upon exposure to air. Based on the almost identical N-terminal amino acid sequences of PceA of Dehalobacter restrictus, Desulfitobacterium hafniense strain TCE1 (formerly Desulfitobacterium frappieri strain TCE1), and Desulfitobacterium hafniense strain PCE-S (formerly Desulfitobacterium frappieri strain PCE-S), the pceA genes of the first two organisms were cloned and sequenced. Together with the pceA genes of Desulfitobacterium hafniense strains PCE-S and Y51, the pceA genes of Desulfitobacterium hafniense strain TCE1 and Dehalobacter restrictus form a coherent group of reductive dehalogenases with almost 100% sequence identity. Also, the pceB genes, which may code for a membrane anchor protein of PceA, and the intergenic regions of Dehalobacter restrictus and the three desulfitobacteria had identical sequences. Whereas the cprB (chlorophenol reductive dehalogenase) genes of chlorophenol-dehalorespiring bacteria are always located upstream of cprA, all pceB genes known so far are located downstream of pceA. The possible consequences of this feature for the annotation of putative reductive dehalogenase genes are discussed, as are the sequence around the iron-sulfur cluster binding motifs and the type of iron-sulfur clusters of the reductive dehalogenases of Dehalobacter restrictus and Desulfitobacterium dehalogenans identified by electron paramagnetic resonance spectroscopy. PMID:12902251

Anaerobic reductive dechlorination of tetrachloroethene: how can dual Carbon-Chlorine isotopic measurements help elucidating the underlying reaction mechanism?

NASA Astrophysics Data System (ADS)

Badin, Alice; Buttet, Géraldine; Maillard, Julien; Holliger, Christof; Hunkeler, Daniel

2014-05-01

Chlorinated ethenes (CEs) such as tetrachloroethene (PCE) are common persistent groundwater contaminants. Among clean-up strategies applied to sites affected by such pollution, bioremediation has been considered with a growing interest as it represents a cost-effective, environmental friendly approach. This technique however sometimes leads to an incomplete and slow biodegradation of CEs resulting in an accumulation of toxic metabolites. Understanding the reaction mechanisms underlying anaerobic reductive dechlorination would thus help assessing PCE biodegradation in polluted sites. Stable isotope analysis can provide insight into reaction mechanisms. For chlorinated hydrocarbons, carbon (C) and chlorine (Cl) isotope data (δ13C and δ37Cl) tend to show a linear correlation with a slope (m ≡ ɛC/ɛCl) characteristic of the reaction mechanism [1]. This study hence aims at exploring the potential of a dual C-Cl isotope approach in the determination of the reaction mechanisms involved in PCE reductive dechlorination. C and Cl isotope fractionation were investigated during anaerobic PCE dechlorination by two bacterial consortia containing members of the Sulfurospirillum genus. The specificity in these consortia resides in the fact that they each conduct PCE reductive dechlorination catalysed by one different reductive dehalogenase, i.e. PceADCE which yields trichloroethene (TCE) and cis-dichloroethene (cDCE), and PceATCE which yields TCE only. The bulk C isotope enrichment factors were -3.6±0.3 o for PceATCE and -0.7±0.1o for PceADCE. The bulk Cl isotope enrichment factors were -1.3±0.2 o for PceATCE and -0.9±0.1 o for PceADCE. When applying the dual isotope approach, two m values of 2.7±0.1 and 0.7±0.2 were obtained for the reductive dehalogenases PceATCE and PceADCE, respectively. These results suggest that PCE can be degraded according to two different mechanisms. Furthermore, despite their highly similar protein sequences, each reductive dehalogenase seems to catalyse PCE reductive dechlorination according to a different mechanism. In another study, an m value of 2.5±0.8 was found for PCE anaerobic dechlorination by a bacterial consortium dominated by species closely related to Desulfitobacterium aromaticivorans strain UKTL (consortia A) [2]. This value is indistinguishable from the one found for PceATCE within a 95% confidence interval although the reductive dehalogenase protein sequence of consortia A is distinctly different from the sequences of our two cultures. This suggests that the reaction mechanism is not related to the similarities between reductive dehalogenases. References 1. Abe, Y., et al., Carbon and Chlorine Isotope Fractionation during Aerobic Oxidation and Reductive Dechlorination of Vinyl Chloride and cis-1,2-Dichloroethene. Environmental Science & Technology, 2009. 43(1): p. 101-107. 2. Wiegert, C., et al., Carbon and Chlorine Isotope Fractionation During Microbial Degradation of Tetra- and Trichloroethene. Environmental Science & Technology, 2013. 47(12): p. 6449-6456.

Boosting the power conversion efficiency of perovskite solar cells using self-organized polymeric hole extraction layers with high work function.

PubMed

Lim, Kyung-Geun; Kim, Hak-Beom; Jeong, Jaeki; Kim, Hobeom; Kim, Jin Young; Lee, Tae-Woo

2014-10-08

A self-organized hole extraction layer (SOHEL) with high work function (WF) is designed for energy level alignment with the ionization potential level of CH3 NH3 PbI3 . The SOHEL increases the built-in potential, photocurrent, and power conversion efficiency (PCE) of CH3 NH3 PbI3 perovskite solar cells. Thus, interface engineering of the positive electrode of solution-processed planar heterojunction solar cells using a high-WF SOHEL is a very effective way to achieve high device efficiency (PCE = 11.7% on glass). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prenatal exposure to tetrachloroethylene-contaminated drinking water and the risk of congenital anomalies: a retrospective cohort study

PubMed Central

2009-01-01

Background Prior animal and human studies of prenatal exposure to solvents including tetrachloroethylene (PCE) have shown increases in the risk of certain congenital anomalies among exposed offspring. Objectives This retrospective cohort study examined whether PCE contamination of public drinking water supplies in Massachusetts influenced the occurrence of congenital anomalies among children whose mothers were exposed around the time of conception. Methods The study included 1,658 children whose mothers were exposed to PCE-contaminated drinking water and a comparable group of 2,999 children of unexposed mothers. Mothers completed a self-administered questionnaire to gather information on all of their prior births, including the presence of anomalies, residential histories and confounding variables. PCE exposure was estimated using EPANET water distribution system modeling software that incorporated a fate and transport model. Results Children whose mothers had high exposure levels around the time of conception had an increased risk of congenital anomalies. The adjusted odds ratio of all anomalies combined among children with prenatal exposure in the uppermost quartile was 1.5 (95% CI: 0.9, 2.5). No meaningful increases in the risk were seen for lower exposure levels. Increases were also observed in the risk of neural tube defects (OR: 3.5, 95% CI: 0.8, 14.0) and oral clefts (OR 3.2, 95% CI: 0.7, 15.0) among offspring with any prenatal exposure. Conclusion The results of this study suggest that the risk of certain congenital anomalies is increased among the offspring of women who were exposed to PCE-contaminated drinking water around the time of conception. Because these results are limited by the small number of children with congenital anomalies that were based on maternal reports, a follow-up investigation should be conducted with a larger number of affected children who are identified by independent records. PMID:19778411

Acute oral and percutaneous toxicity of pesticides to mallards: Correlations with mammalian toxicity data

USGS Publications Warehouse

Hudson, R.H.; Haegele, M.A.; Tucker, R.K.

1979-01-01

Acute oral (po) and 24-hr percutaneous (perc) LD50 values for 21 common pesticides (19 anticholinesterases, of which 18 were organophosphates, and one was a carbamate; one was an organochlorine central nervous system stimulant; and one was an organonitrogen pneumotoxicant) were determined in mallards (Anas platyrhynchos). Three of the pesticides tested were more toxic percutaneously than orally. An index to the percutaneous hazard of a pesticide, the dermal toxicity index (DTI = po LD50/perc LD50 ? 100), was also calculated for each pesticide. These toxicity values in mallards were compared with toxicity data for rats from the literature. Significant positive correlations were found between log po and log percutaneous LD50 values in mallards (r = 0.65, p 0.10). Variations in percutaneous methodologies are discussed with reference to interspecies variation in toxicity values. It is recommended that a mammalian DTI value approaching 30 be used as a guideline for the initiation of percutaneous toxicity studies in birds, when the po LD50 and/or projected percutaneous LD50 are less than expected field exposure levels.

Intrauterine programming mechanism for hypercholesterolemia in prenatal caffeine-exposed female adult rat offspring.

PubMed

Xu, Dan; Luo, Hanwen W; Hu, Wen; Hu, Shuwei W; Yuan, Chao; Wang, Guihua H; Zhang, Li; Yu, Hong; Magdalou, Jacques; Chen, Liaobin B; Wang, Hui

2018-05-02

Clinical and animal studies have indicated that hypercholesterolemia and its associated diseases have intrauterine developmental origins. Our previous studies showed that prenatal caffeine exposure (PCE) led to fetal overexposure to maternal glucocorticoids (GCs) and increased serum total cholesterol levels in adult rat offspring. This study further confirms the intrauterine programming of PCE-induced hypercholesterolemia in female adult rat offspring. Pregnant Wistar rats were intragastrically administered caffeine (30, 60, and 120 mg/kg/d) from gestational day (GD)9 to 20. Female rat offspring were euthanized at GD20 and postnatal wk 12; several adult rat offspring were additionally subjected to ice-water swimming stimulation to induce chronic stress prior to death. The effects of GCs on cholesterol metabolism and epigenetic regulation were verified using the L02 cell line. The results showed that PCE induced hypercholesterolemia in adult offspring, which manifested as significantly higher levels of serum total cholesterol and LDL cholesterol (LDL-C) as well as higher ratios of LDL-C/HDL cholesterol. We further found that the cholesterol levels were increased in fetal livers but were decreased in fetal blood, accompanied by increased maternal blood cholesterol levels and reduced placental cholesterol transport. Furthermore, analysis of PCE offspring in the uterus and in a postnatal basal/chronic stress state and the results of in vitro experiments showed that hepatic cholesterol metabolism underwent GC-dependent changes and was associated with cholesterol synthase via abnormalities in 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) histone acetylation. We concluded that, to compensate for intrauterine placentally derived decreases in fetal blood cholesterol levels, high intrauterine GC levels activated fetal hepatic CCAAT enhancer binding protein α signaling and down-regulated Sirtuin1 expression, which mediated the high levels of histone acetylation ( via H3K9ac and H3K14ac) and expression of HMGCR. This GC-dependent cholesterol metabolism programming effect was sustained through adulthood, leading to the occurrence of hypercholesterolemia.-Xu, D., Luo, H. W., Hu, W., Hu, S. W., Yuan, C., Wang, G. H., Zhang, L., Yu, H., Magdalou, J., Chen, L. B., Wang, H. Intrauterine programming mechanism for hypercholesterolemia in prenatal caffeine-exposed female adult rat offspring.

Indian Wars: Failings of the United States Army to Achieve Decisive Victory During the NEZ Perce War of 1877

DTIC Science & Technology

2005-06-17

Walla Ft. Walsh Ft. Missoula IDAHO TERRITORY OREGON Bozeman Butte Deer Lodge Helena Virginia City Cooke City Salmon Mis sour i R. Lewiston Sn ak e R...the US Government’s treaty demands aimed at removing their tribe from the Wallowa Valley to a small reservation in Idaho . This band of Nez Perce...who ruled the West; in the areas now know as Oregon, Idaho , Montana, and Wyoming.9 After putting up many valiant fights, and inflicting a great

A place for agent-based models. Comment on "Statistical physics of crime: A review" by M.R. D'Orsogna and M. Perc

NASA Astrophysics Data System (ADS)

Barbaro, Alethea

2015-03-01

Agent-based models have been widely applied in theoretical ecology to explain migrations and other collective animal movements [2,5,8]. As D'Orsogna and Perc have expertly highlighted in [6], the recent emergence of crime modeling has opened another interesting avenue for mathematical investigation. The area of crime modeling is particularly suited to agent-based models, because these models offer a great deal of flexibility within the model and also ease of communication among criminologist, law enforcement and modelers.

Towards a Moral Ecology of Pharmacological Cognitive Enhancement in British Universities.

PubMed

Vagwala, Meghana Kasturi; Bicquelet, Aude; Didziokaite, Gabija; Coomber, Ross; Corrigan, Oonagh; Singh, Ilina

2017-01-01

Few empirical studies in the UK have examined the complex social patterns and values behind quantitative estimates of the prevalence of pharmacological cognitive enhancement (PCE). We conducted a qualitative investigation of the social dynamics and moral attitudes that shape PCE practices among university students in two major metropolitan areas in the UK. Our thematic analysis of eight focus groups ( n  = 66) suggests a moral ecology that operates within the social infrastructure of the university. We find that PCE resilience among UK university students is mediated by normative and cultural judgments disfavoring competitiveness and prescription drug taking. PCE risk can be augmented by social factors such as soft peer pressure and normalization of enhancement within social and institutional networks. We suggest that moral ecological dynamics should be viewed as key mechanisms of PCE risk and resilience in universities. Effective PCE governance within universities should therefore attend to developing further understanding of the moral ecologies of PCE.

Development and characterization of cell culture systems from Puntius (Tor) chelynoides (McClelland).

PubMed

Goswami, M; Sharma, B S; Tripathi, A K; Yadav, Kamalendra; Bahuguna, S N; Nagpure, N S; Lakra, W S; Jena, J K

2012-05-25

Puntius (Tor) chelynoides, commonly known as dark mahseer, is a commercially important coldwater fish species which inhabits fast-flowing hill-streams of India and Nepal. Cell culture systems were developed from eye, fin, heart and swim bladder tissues of P. chelynoides using explant method. The cell culture system developed from eye has been maintained towards a continuous cell line designated as PCE. The cells were grown in 25cm(2) tissue culture flasks with Leibovitz' L-15 media supplemented with 20 % fetal bovine serum (FBS) at 24°C. The PCE cell line consists of predominantly fibroblast-like cells and showed high plating efficiency. The monolayer formed from the fin and heart explants were comprised of epithelial as well as fibroblast-like cells, a prominent and rhythmic heartbeat was also observed in heart explants. Monolayer formed from swim bladder explants showed the morphology of fibroblast-like cells. All the cells from different tissues are able to grow at an optimum temperature of 24°C and growth rate increased as the FBS concentration increased. The PCE cell line was characterized using amplification of mitochondrial cytochrome oxidase subunit I (COI) & 16S rRNA genes which confirmed that the cell line originated from P. chelynoides. Cytogenetic analysis of PCE cell line and cells from fin revealed a diploid count of 100 chromosomes. Upon transfection with pEGFP-C1 plasmid, bright fluorescent signals were observed, suggesting that this cell line can be used for transgenic and genetic manipulation studies. Further, genotoxicity assessment of PCE cells illustrated the utility of this cell line as an in vitro model for aquatic toxicological studies. The PCE cell line was successfully cryopreserved and revived at different passage levels. The cell line and culture systems are being maintained to develop continuous cell lines for further studies. Copyright © 2012 Elsevier B.V. All rights reserved.

Modulation of hexavalent chromium-induced genotoxic damage in peripheral blood of mice by epigallocatechin-3-gallate (EGCG) and its relationship to the apoptotic activity.

PubMed

García-Rodríguez, María Del Carmen; Montaño-Rodríguez, Ana Rosa; Altamirano-Lozano, Mario Agustín

2016-01-01

This study was conducted to investigate the relationship between modulation of genotoxic damage and apoptotic activity in Hsd:ICR male mice treated with (-)-epigallocatechin-3-gallate (EGCG) and hexavalent chromium [Cr(VI)]. Four groups of 5 mice each were treated with (i) control vehicle only, (ii) EGCG (10 mg/kg) by gavage, (iii) Cr(VI) (20 mg/kg of CrO3) intraperitoneally (ip), and (iv) EGCG in addition to CrO3 (EGCG-CrO3). Genotoxic damage was evaluated by examining presence of micronucleated polychromatic erythrocytes (MN-PCE) obtained from peripheral blood of the caudal vein at 0, 24, 48, and 72 h after treatment. Induction of apoptosis and cell viability were assessed by differential acridine orange/ethidium bromide (AO/EB) staining. EGCG treatment produced no significant changes in frequency of MN-PCE. However, CrO3 treatment significantly increased number of MN-PCE at 24 and 48 h post injection. Treatment with EGCG prior to CrO3 injection decreased number of MN-PCE compared to CrO3 alone. The MN-PCE reduction was greater than when EGCG was administered ip. The frequency of early apoptotic cells was elevated at 48 h following EGCG, CrO3, or EGCG-CrO3 exposure, with highest levels observed in the combined treatment group, while the frequencies of late apoptotic cells and necrotic cells were increased only in EGCG-CrO3 exposure. Our findings support the view that EGCG is protective against genotoxic damage induced by Cr(VI) and that apoptosis may contribute to elimination of DNA-damaged cells (MN-PCE) when EGCG was administered prior to CrO3. Further, it was found that the route of administration of EGCG plays an important role in protection against CrO3-induced genotoxic damage.

Synthetic virus seeds for improved vaccine safety: Genetic reconstruction of poliovirus seeds for a PER.C6 cell based inactivated poliovirus vaccine.

PubMed

Sanders, Barbara P; Edo-Matas, Diana; Papic, Natasa; Schuitemaker, Hanneke; Custers, Jerome H H V

2015-10-13

Safety of vaccines can be compromised by contamination with adventitious agents. One potential source of adventitious agents is a vaccine seed, typically derived from historic clinical isolates with poorly defined origins. Here we generated synthetic poliovirus seeds derived from chemically synthesized DNA plasmids encoding the sequence of wild-type poliovirus strains used in marketed inactivated poliovirus vaccines. The synthetic strains were phenotypically identical to wild-type polioviruses as shown by equivalent infectious titers in culture supernatant and antigenic content, even when infection cultures are scaled up to 10-25L bioreactors. Moreover, the synthetic seeds were genetically stable upon extended passaging on the PER.C6 cell culture platform. Use of synthetic seeds produced on the serum-free PER.C6 cell platform ensures a perfectly documented seed history and maximum control over starting materials. It provides an opportunity to maximize vaccine safety which increases the prospect of a vaccine end product that is free from adventitious agents. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Comparative Review of Waivers Granted in Pediatric Drug Development by FDA and EMA from 2007-2013

PubMed Central

Egger, Gunter F.; Wharton, Gerold T.; Malli, Suzanne; Temeck, Jean; Murphy, M. Dianne; Tomasi, Paolo

2016-01-01

Background The European Union and the United States have different legal frameworks in place for pediatric drug development, which can potentially lead to different pediatric research requirements for the pharmaceutical industry. This manuscript compares pediatric clinical trial waivers granted by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA). Methods This is a retrospective review comparing EMA’s Paediatric Committee (PDCO) decisions with FDA’s Pediatric Review Committee (PeRC) recommendations for all product-specific pediatric full waiver applications submitted to EMA from January 2007 through December 2013. Using baseline data from EMA, we matched product-specific waivers with their FDA equivalents during the study period. Results For single active substance products, PDCO and PeRC adopted similar opinions in 42 of 49 indications (86%). For fixed-dose combinations, PDCO and PeRC adopted similar opinions in 24 of 31 indications (77%). Conclusion Despite the different legal frameworks, criteria, and processes of determination, the waiver decisions of the 2 agencies were similar in the majority of cases. PMID:27274951

The role of mathematical modelling in modern criminology. Comment on "Statistical physics of crime: A review" by M.R. D'Orsogna and M. Perc

NASA Astrophysics Data System (ADS)

Primicerio, Mario

2015-03-01

Criminality is a big challenge at several different levels. This is particularly evident - even for microcriminality - in urban areas (in Europe and North America the percent of population living in urban areas is around 85%). It is considered by sociologists among the most important indexes affecting the (perception of the) quality of life in a given place.

Anaerobic bacteria that dechlorinate perchloroethene.

PubMed Central

Fathepure, B Z; Nengu, J P; Boyd, S A

1987-01-01

In this study, we identified specific cultures of anaerobic bacteria that dechlorinate perchlorethene (PCE). The bacteria that significantly dechlorinated PCE were strain DCB-1, an obligate anaerobe previously shown to dechlorinate chlorobenzoate, and two strains of Methanosarcina. The rate of PCE dechlorination by DCB-1 compared favorably with reported rates of trichloroethene bio-oxidation by methanotrophs. Even higher PCE dechlorination rates were achieved when DCB-1 was grown in a methanogenic consortium. PMID:3426224

The Effects of Petroselinum Crispum on Estrogen Receptor-positive Benign and Malignant Mammary Cells (MCF12A/MCF7).

PubMed

Schröder, Lennard; Koch, Julian; Mahner, Sven; Kost, Bernd P; Hofmann, Simone; Jeschke, Udo; Haumann, Jens; Schmedt, Julian; Richter, Dagmar Ulrike

2017-01-01

Phytoestrogens have controversial effects on hormone-dependent tumors. Herein we investigated the effects of parsley root extract (PCE) on DNA synthesis performance, metabolic activity and cytotoxicity in malignant and benign breast cells. The PCE was prepared and analyzed by mass spectrometry. MCF7 and MCF12A cells were incubated with various concentrations of PCE and analyzed for DNA synthesis performance, metabolic activity and cytotoxicity by BrdU proliferation, MTT and LDH assays, respectively. PCE was found to contain a substantial ratio of lignans. At a concentration range of 0.01 μg/ml-100 μg/ml the LDH assay analysis showed no significant cytotoxicity of PCE in both cell lines. However, at 500 μg/ml PCE's cytotoxicity was well over 70% of total cell population in both cell lines. According to the BrdU proliferation assay analysis, PCE demonstrated significant DNA synthesis inhibition of up to 80% at concentrations of 10, 50, 100 and 500 μg/ml in both cell lines. Based on the MTT assay analysis, only at a concentration of 500 μg/ml, PCE demonstrated a statistically significant inhibition of cellular metabolic activity of 63% in MCF7 and 75% in MCF12A of their respective normal capacity. PCE showed antiproliferative effects in MCF7 and MCF12A cells. Further investigation is required to determine whether this effect can be solely attributed to its phytoestrogens. Copyright© 2017 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Applicability of the polynomial chaos expansion method for personalization of a cardiovascular pulse wave propagation model.

PubMed

Huberts, W; Donders, W P; Delhaas, T; van de Vosse, F N

2014-12-01

Patient-specific modeling requires model personalization, which can be achieved in an efficient manner by parameter fixing and parameter prioritization. An efficient variance-based method is using generalized polynomial chaos expansion (gPCE), but it has not been applied in the context of model personalization, nor has it ever been compared with standard variance-based methods for models with many parameters. In this work, we apply the gPCE method to a previously reported pulse wave propagation model and compare the conclusions for model personalization with that of a reference analysis performed with Saltelli's efficient Monte Carlo method. We furthermore differentiate two approaches for obtaining the expansion coefficients: one based on spectral projection (gPCE-P) and one based on least squares regression (gPCE-R). It was found that in general the gPCE yields similar conclusions as the reference analysis but at much lower cost, as long as the polynomial metamodel does not contain unnecessary high order terms. Furthermore, the gPCE-R approach generally yielded better results than gPCE-P. The weak performance of the gPCE-P can be attributed to the assessment of the expansion coefficients using the Smolyak algorithm, which might be hampered by the high number of model parameters and/or by possible non-smoothness in the output space. Copyright © 2014 John Wiley & Sons, Ltd.

Continuous-flow column study of reductive dehalogenation of PCE upon bioaugmentation with the Evanite enrichment culture

NASA Astrophysics Data System (ADS)

Azizian, Mohammad F.; Behrens, Sebastian; Sabalowsky, Andrew; Dolan, Mark E.; Spormann, Alfred M.; Semprini, Lewis

2008-08-01

A continuous-flow anaerobic column experiment was conducted to evaluate the reductive dechlorination of tetrachloroethene (PCE) in Hanford aquifer material after bioaugmentation with the Evanite (EV) culture. An influent PCE concentration of 0.09 mM was transformed to vinyl chloride (VC) and ethene (ETH) within a hydraulic residence time of 1.3 days. The experimental breakthrough curves were described by the one-dimensional two-site-nonequilibrium transport model. PCE dechlorination was observed after bioaugmentation and after the lactate concentration was increased from 0.35 to 0.67 mM. At the onset of reductive dehalogenation, cis-dichloroethene (c-DCE) concentrations in the column effluent exceeded the influent PCE concentration indicating enhanced PCE desorption and transformation. When the lactate concentration was increased to 1.34 mM, c-DCE reduction to vinyl chloride (VC) and ethene (ETH) occurred. Spatial rates of PCE and VC transformation were determined in batch-incubated microcosms constructed with aquifer samples obtained from the column. PCE transformation rates were highest in the first 5 cm from the column inlet and decreased towards the column effluent. Dehalococcoides cell numbers dropped from ˜ 73.5% of the total Bacterial population in the original inocula, to about 0.5% to 4% throughout the column. The results were consistent with estimates of electron donor utilization, with 4% going towards dehalogenation reactions.

Target Organ Metabolism, Toxicity, and Mechanisms of Trichloroethylene and Perchloroethylene: Key Similarities, Differences, and Data Gaps

PubMed Central

Cichocki, Joseph A.; Guyton, Kathryn Z.; Guha, Neela; Chiu, Weihsueh A.

2016-01-01

Trichloroethylene (TCE) and perchloroethylene or tetrachloroethylene (PCE) are high–production volume chemicals with numerous industrial applications. As a consequence of their widespread use, these chemicals are ubiquitous environmental contaminants to which the general population is commonly exposed. It is widely assumed that TCE and PCE are toxicologically similar; both are simple olefins with three (TCE) or four (PCE) chlorines. Nonetheless, despite decades of research on the adverse health effects of TCE or PCE, few studies have directly compared these two toxicants. Although the metabolic pathways are qualitatively similar, quantitative differences in the flux and yield of metabolites exist. Recent human health assessments have uncovered some overlap in target organs that are affected by exposure to TCE or PCE, and divergent species- and sex-specificity with regard to cancer and noncancer hazards. The objective of this minireview is to highlight key similarities, differences, and data gaps in target organ metabolism and mechanism of toxicity. The main anticipated outcome of this review is to encourage research to 1) directly compare the responses to TCE and PCE using more sensitive biochemical techniques and robust statistical comparisons; 2) more closely examine interindividual variability in the relationship between toxicokinetics and toxicodynamics for TCE and PCE; 3) elucidate the effect of coexposure to these two toxicants; and 4) explore new mechanisms for target organ toxicity associated with TCE and/or PCE exposure. PMID:27511820

Occupational blood exposure among health care workers: I. Frequency and reporting.

PubMed

Nelsing, S; Nielsen, T L; Nielsen, J O

1993-01-01

The frequency and reporting rate concerning occupational blood exposure were investigated among former and currently employed medical staff at a Department of Infectious Diseases (DID) having a high prevalence of HIV-positive patients. Subjects were asked to complete an anonymous questionnaire describing occupational percutaneous exposure (PCE) and mucocutaneous exposure (MCE) to blood, experienced during their employment at the DID. 135 out of 168 (80%) subjects responded. 45 subjects described 37 incidents of PCE and 15 of MCE. 44 of the exposures (85%) involved HIV-positive blood and 6 (11.5%) involved blood from a patient with hepatitis B. Annual incidence rates of PCE and MCE were: for A) interns and residents, 0.51 PCE/year and 0.17 MCE/year; B) for senior residents and senior physicians, 0.13 PCE/year and 0.21 MCE/year; C) for registered nurses, 0.11 PCE/year and 0.03 MCE/year; D) for auxiliary nurses, 0.09 PCE/year and 0.11 MCE/year. 35% of PCE and 87% of MCE were not reported to the security representative, the major reason being that the subject felt it to be unnecessary. We conclude that medical employment, especially as interns and residents at clinics for infectious diseases, carries a real and serious risk of contracting infectious diseases due to occupational exposure to blood. The importance of reporting needs to be emphasized.

Grande Ronde Basin Supplementation Program; Lostine River, 2000 Annual Report.

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

Onjukka, Sam T.; Harbeck, Jim

2003-03-01

The Northwest Power Planning Council (NPPC) identified supplementation as a high priority to achieve its goal of increasing runs of anadromous fish in the Columbia Basin. Supplementation activities in the Lostine River and associated monitoring and evaluation conducted by the Nez Perce Tribe relate directly to the needs addressed in the Columbia River Basin Fish and Wildlife Program (NPPC 1994). Measure 7.4L.1 of the Program mandates that appropriate research accompany any proposed supplementation. In addition, measure 7.3B.2 of the Program stresses the need for evaluating supplementation projects to assess their ability to increase production. Finally, Section 7.4D.3 encourages the studymore » of hatchery rearing and release strategies to improve survival and adaptation of cultured fish. In 1997, Oregon Department of Fisheries and Wildlife (ODFW) requested a modification of Permit 1011 to allow the take of adult spring chinook salmon. In 1998, the Nez Perce Tribe also requested a permit specific to activities on Lostine River. The permit was issued in 2000. A special condition in the permits required the development of a long term management plan for the spring chinook salmon of the Grande Ronde Basin. The Nez Perce Tribe, ODFW, and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) completed a formal long range plan entitled ''Grande Ronde Basin Endemic Spring Chinook Salmon Supplementation Program''. The program proposes to increase the survival of spring chinook salmon in the Grand Ronde Basin through hatchery intervention. Adult salmon from the Lostine River, Catherine Creek, and the Upper Grande Ronde River are used for a conventional supplementation program in the basin. The Nez Perce program currently operates under the ESA Section 10 Permit 1149.« less

Grande Ronde Basin Supplementation Program; Lostine River, 2001 Annual Report.

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

Onjukka, Sam T.; Harbeck, Jim

2003-03-01

The Northwest Power Planning Council (NPPC) identified supplementation as a high priority to achieve its goal of increasing runs of anadromous fish in the Columbia Basin. Supplementation activities in the Lostine River and associated monitoring and evaluation conducted by the Nez Perce Tribe relate directly to the needs addressed in the Columbia River Basin Fish and Wildlife Program (NPPC 1994). Measure 7.4L.1 of the Program mandates that appropriate research accompany any proposed supplementation. In addition, measure 7.3B.2 of the Program stresses the need for evaluating supplementation projects to assess their ability to increase production. Finally, Section 7.4D.3 encourages the studymore » of hatchery rearing and release strategies to improve survival and adaptation of cultured fish. In 1997, Oregon Department of Fisheries and Wildlife (ODFW) requested a modification of Permit 1011 to allow the take of adult spring chinook salmon. In 1998, the Nez Perce Tribe also requested a permit specific to activities on Lostine River. The permit was issued in 2000. A special condition in the permits required the development of a long term management plan for the spring chinook salmon of the Grande Ronde Basin. The Nez Perce Tribe, ODFW, and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) completed a formal long range plan entitled ''Grande Ronde Basin Endemic Spring Chinook Salmon Supplementation Program''. The program proposes to increase the survival of spring chinook salmon in the Grand Ronde Basin through hatchery intervention. Adult salmon from the Lostine River, Catherine Creek, and the Upper Grande Ronde River are used for a conventional supplementation program in the basin. The Nez Perce program currently operates under the ESA Section 10 Permit 1149.« less

Degradation of Perchloroethene by zero-valent iron evaluated by carbon isotope fractionation

NASA Astrophysics Data System (ADS)

Leitner, Simon; Watzinger, Andrea; Reichenauer, Thomas G.

2014-05-01

Perchloroethene (PCE) is a widely spread groundwater contaminant in formally used industrial sites. Zero valent iron (ZVI) is used for in situ chemical reduction (ISCR) of PCE contaminants in the groundwater. A key factor in the application of in situ remediation technologies is a proper monitoring of contaminant reduction. The measurement of the stable isotope ratio is a promising method that is already used for quantifying microbial degradation of chlorinated contaminants. The carbon isotope ratio of PCE, measured by - isotope ratio mass spectrometry coupled to a gas chromatograph via a combustion interface (GC-C-IRMS), increases during degradation of PCE and can be directly related to the degree of degradation. It can be used to directly quantify chemical degradation and thus serves as a useful monitoring tool for groundwater remediation. An experiment to determine the carbon isotopic fractionation factor was performed as a lab experiment using Nanofer Star (NANOIRON). Two different PCE concentrations (c1: 220mgL-1, c2: 110mgL-1) mixed with 0.5 g of ZVI were sealed under deoxygenated conditions in 250 ml glas bottles locked with mininert caps. The bottles were incubated on a shaker for 865 h. Samples were taken weekly to measure the change in the carbon isotopic ratio of PCE as well as its concentration. Results showed a strong increase in the carbon isotope ratio (δ-value) of PCE (start: -27 o end: -4 ), which indicates a significant dechlorination process of PCE. Beside PCE also one degradation product (Trichloroethylene - TCE) was measured. TCE was further dechlorinated as indicated by the δ-value change of TCE from -26 o to -4 oȦn unexpected intermediate value of -45 o for TCE was observed in the experiment. This fluctuation could be induced by the time depending concentration due to degradation and conversation processes. Furthermore, it seems that the progress of the δ-value is affected by the starting concentration of PCE (δ-value of c1 < c2) as there is a higher ratio of PCE to ZVI.

D-A-D-Typed Hole Transport Materials for Efficient Perovskite Solar Cells: Tuning Photovoltaic Properties via the Acceptor Group.

PubMed

Xu, Peng; Liu, Peng; Li, Yuanyuan; Xu, Bo; Kloo, Lars; Sun, Licheng; Hua, Yong

2018-06-13

Two D-A-D-structured hole-transport materials (YN1 and YN2) have been synthesized and used in perovskite solar cells. The two HTMs have low-lying HOMO levels and impressive mobility. Perovskite-based solar cells (PSCs) fabricated with YN2 showed a power conversion efficiency (PCE) value of 19.27% in ambient air, which is significantly higher than that of Spiro-OMeTAD (17.80%). PSCs based on YN1 showed an inferior PCE of 16.03%. We found that the incorporation of the stronger electron-withdrawing group in the HTM YN2 improves the PCE of PSCs. Furthermore, the YN2-based PSCs exhibit good long-term stability retaining 91.3% of its initial efficiency, whereas PSCs based on Spiro-OMeTAD retained only 42.2% after 1000 h lifetime (dark conditions). These promising results can provide a new strategy for the design of D-A-D HTMs for PSC applications in future.

A quantitative and spatially resolved analysis of the performance-bottleneck in high efficiency, planar hybrid perovskite solar cells

DOE PAGES

Draguta, Sergiu; Christians, Jeffrey A.; Morozov, Yurii V.; ...

2018-01-01

Hybrid perovskites represent a potential paradigm shift for the creation of low-cost solar cells. Current power conversion efficiencies (PCEs) exceed 22%. However, despite this, record PCEs are still far from their theoretical Shockley–Queisser limit of 31%. To increase these PCE values, there is a pressing need to understand, quantify and microscopically model charge recombination processes in full working devices. Here, we present a complete microscopic account of charge recombination processes in high efficiency (18–19% PCE) hybrid perovskite (mixed cation and methylammonium lead iodide) solar cells. We employ diffraction-limited optical measurements along with relevant kinetic modeling to establish, for the firstmore » time, local photoluminescence quantum yields, trap densities, trapping efficiencies, charge extraction efficiencies, quasi-Fermi-level splitting, and effective PCE estimates. Correlations between these spatially resolved parameters, in turn, allow us to conclude that intrinsic electron traps in the perovskite active layers limit the performance of these state-of-the-art hybrid perovskite solar cells.« less

A quantitative and spatially resolved analysis of the performance-bottleneck in high efficiency, planar hybrid perovskite solar cells

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

Draguta, Sergiu; Christians, Jeffrey A.; Morozov, Yurii V.

Hybrid perovskites represent a potential paradigm shift for the creation of low-cost solar cells. Current power conversion efficiencies (PCEs) exceed 22%. However, despite this, record PCEs are still far from their theoretical Shockley–Queisser limit of 31%. To increase these PCE values, there is a pressing need to understand, quantify and microscopically model charge recombination processes in full working devices. Here, we present a complete microscopic account of charge recombination processes in high efficiency (18–19% PCE) hybrid perovskite (mixed cation and methylammonium lead iodide) solar cells. We employ diffraction-limited optical measurements along with relevant kinetic modeling to establish, for the firstmore » time, local photoluminescence quantum yields, trap densities, trapping efficiencies, charge extraction efficiencies, quasi-Fermi-level splitting, and effective PCE estimates. Correlations between these spatially resolved parameters, in turn, allow us to conclude that intrinsic electron traps in the perovskite active layers limit the performance of these state-of-the-art hybrid perovskite solar cells.« less

Simultaneous anaerobic transformation of carbon tetrachloride to carbon dioxide and tetrachloroethene to ethene in a continuous flow column.

PubMed

Azizian, Mohammad F; Semprini, Lewis

2017-08-01

The simultaneous anaerobic transformation of tetrachloroethene (PCE) and carbon tetrachloride (CT) was evaluated in a continuous flow column. The column was packed with quartz sand and bioaugmented with the Evanite culture (EV) that is capable of transforming PCE to ethene. Azizian and Semprini (2016) reported that PCE and CT could be simultaneously transformed in the column, with PCE (0.1mM) transformed mainly to ethene and CT (0.015mM) to chloroform (CF) (20%) and an unknown transformation product, likely carbon dioxide (CO 2 ). The fermentation of propionate, formed from lactate fermentation, was inhibited after the transformation of CT, likely from the exposure to CF. Reported here is the second phase of that study where a second bioaugmentation of the EV culture was made to reintroduce a lactate and propionate fermenting population to the column. Effective lactate and propionate fermentation were restored with a H 2 concentration of ~25nM maintained in the column effluent. PCE (0.1mM) was effectively transformed to ethene (~98%) and vinyl chloride (VC) (~2%). Unlabeled CT (0.015 to 0.03mM) was completely transformed with a transient build-up of CF and chloromethane (CM), which were subsequently removed below their detection limits. A series of transient tests were initiated through the addition of carbon-13 labeled CT ( 13 CT), with concentrations gradually increased from 0.03 to 0.10mM. GC-MS analysis of the column effluent showed that 13 C labeled CO 2 ( 13 CO 2 ) was formed, ranging from 82 to 93% of the 13 CT transformed, with the transient increases in 13 CO 2 associated with the increased concentration of 13 CT. A modified COD analysis indicated a lesser amount of 13 CT (18%) was transformed to soluble products, while 13 CO 2 represented 82% the 13 CT transformed. In a final transient test, the influent lactate concentration was decreased from 1.1 to 0.67mM. The transformation of both CT and PCE changed dramatically. Only 59% of the 13 CT was transformed, primarily to CF. 13 CO 2 concentrations gradually decreased to background levels, indicating CO 2 was no longer a transformation product. PCE transformation resulted in the following percentage of products formed: cDCE (60%), VC (36%), and ethene (4%). Incomplete propionate fermentation was also observed, consistent with the build-up of CF and the decrease in H 2 concentrations to approximately 2nM. The results clearly demonstrate that high concentrations of CT were transformed to CO 2 , and effective PCE dehalogenation to ethene was maintained when excess lactate was fed and propionate was effectively fermented. However, when the lactate concentration was reduced, both PCE and CT transformation and propionate fermentation were negatively impacted. Published by Elsevier B.V.

Simultaneous anaerobic transformation of carbon tetrachloride to carbon dioxide and tetrachloroethene to ethene in a continuous flow column

NASA Astrophysics Data System (ADS)

Azizian, Mohammad F.; Semprini, Lewis

2017-08-01

The simultaneous anaerobic transformation of tetrachloroethene (PCE) and carbon tetrachloride (CT) was evaluated in a continuous flow column. The column was packed with quartz sand and bioaugmented with the Evanite culture (EV) that is capable of transforming PCE to ethene. Azizian and Semprini (2016) reported that PCE and CT could be simultaneously transformed in the column, with PCE (0.1 mM) transformed mainly to ethene and CT (0.015 mM) to chloroform (CF) (20%) and an unknown transformation product, likely carbon dioxide (CO2). The fermentation of propionate, formed from lactate fermentation, was inhibited after the transformation of CT, likely from the exposure to CF. Reported here is the second phase of that study where a second bioaugmentation of the EV culture was made to reintroduce a lactate and propionate fermenting population to the column. Effective lactate and propionate fermentation were restored with a H2 concentration of 25 nM maintained in the column effluent. PCE (0.1 mM) was effectively transformed to ethene ( 98%) and vinyl chloride (VC) ( 2%). Unlabeled CT (0.015 to 0.03 mM) was completely transformed with a transient build-up of CF and chloromethane (CM), which were subsequently removed below their detection limits. A series of transient tests were initiated through the addition of carbon-13 labeled CT (13CT), with concentrations gradually increased from 0.03 to 0.10 mM. GC-MS analysis of the column effluent showed that 13C labeled CO2 (13CO2) was formed, ranging from 82 to 93% of the 13CT transformed, with the transient increases in 13CO2 associated with the increased concentration of 13CT. A modified COD analysis indicated a lesser amount of 13CT (18%) was transformed to soluble products, while 13CO2 represented 82% the 13CT transformed. In a final transient test, the influent lactate concentration was decreased from 1.1 to 0.67 mM. The transformation of both CT and PCE changed dramatically. Only 59% of the 13CT was transformed, primarily to CF. 13CO2 concentrations gradually decreased to background levels, indicating CO2 was no longer a transformation product. PCE transformation resulted in the following percentage of products formed: cDCE (60%), VC (36%), and ethene (4%). Incomplete propionate fermentation was also observed, consistent with the build-up of CF and the decrease in H2 concentrations to approximately 2 nM. The results clearly demonstrate that high concentrations of CT were transformed to CO2, and effective PCE dehalogenation to ethene was maintained when excess lactate was fed and propionate was effectively fermented. However, when the lactate concentration was reduced, both PCE and CT transformation and propionate fermentation were negatively impacted.

Perylene-Diimide Based Donor-Acceptor-Donor Type Small-Molecule Acceptors for Solution-Processable Organic Solar Cells

NASA Astrophysics Data System (ADS)

Ganesamoorthy, Ramasamy; Vijayaraghavan, Rajagopalan; Sakthivel, Pachagounder

2017-12-01

Development of nonfullerene acceptors plays an important role in the commercial availability of plastic solar cells. We report herein synthesis of bay-substituted donor-acceptor-donor (D-A-D)-type perylene diimide (PDI)-based small molecules (SM-1 to SM-4) by Suzuki coupling method and their use as acceptors in bulk heterojunction organic solar cells (BHJ-OSCs) with poly(3-hexylthiophene) (P3HT) polymer donor. We varied the number of electron-rich thiophene units and the solubilizing side chains and also evaluated the optical and electrochemical properties of the small molecules. The synthesized small molecules were confirmed by Fourier-transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and high-resolution mass spectroscopy (HR-MS). The small molecules showed extensive and strong absorption in the ultraviolet-visible (UV-Vis) region up to 750 nm, with bandgap (E_{{g}}^{{opt}} ) reduced below <2 eV. The energy levels of small molecules SM-1 to SM-4 were suitable for use as electron-accepting materials. The small molecules showed good thermal stability up to 300°C. BHJ-OSCs with SM-1 and P3HT polymer donor showed maximum power conversion efficiency (PCE) of 0.19% with V oc of 0.30 V, J sc of 1.72 mA cm-2, and fill factor (FF) of 37%. The PCE decreased with the number of thiophene units. The PCE of SM-2 was lower than that of SM-1. This difference in PCE can be explained by the higher aggregation tendency of the bithiophene compared with the thiophene unit. Introduction of the solubilizing group in the bay position increased the aggregation property, leading to much lower PCE than for the small molecules without solubilizing group.

Who Are the High-Cost Users? A Method for Person-Centred Attribution of Health Care Spending.

PubMed

Guilcher, Sara J T; Bronskill, Susan E; Guan, Jun; Wodchis, Walter P

2016-01-01

To develop person-centered episodes of care (PCE) for community-dwelling individuals in the top fifth percentile of Ontario health care expenditures in order to: (1) describe the main clinical groupings for spending; and (2) identify patterns of spending by health sector (e.g. acute care, home care, physician billings) within and across PCE. Data were drawn from population-based administrative databases for all publicly funded health care in Ontario, Canada in 2010/11. This study is a retrospective cohort study. A total of 587,982 community-dwelling individuals were identified among those accounting for the top 5% of provincial health care expenditures between April 1, 2010 and March 31, 2011. PCE were defined as starting with an acute care admission and persisting through subsequent care settings and providers until individuals were without health system contact for 30 days. PCE were classified according to the clinical grouping for the initial admission. PCE and non-PCE costs were calculated and compared to provide a comprehensive measurement of total health system costs for the year. Among this community cohort, 697,059 PCE accounted for nearly 70% ($11,815.3 million (CAD)) of total annual publicly-funded expenditures on high-cost community-dwelling individuals. The most common clinical groupings to start a PCE were Acute Planned Surgical (35.2%), Acute Unplanned Medical (21.0%) and Post-Admission Events (10.8%). Median PCE costs ranged from $3,865 (IQR = $1,712-$10,919) for Acute Planned Surgical to $20,687 ($12,207-$39,579) for Post-Admission Events. Inpatient acute ($8,194.5 million) and inpatient rehabilitation ($434.6 million) health sectors accounted for the largest proportions of allocated PCE spending over the year. Our study provides a novel methodological approach to categorize high-cost health system users into meaningful person-centered episodes. This approach helps to explain how costs are attributable within individuals across sectors and has applications in episode-based payment formulas and quality monitoring.

Three layers multi-granularity OCDM switching system based on learning-stateful PCE

NASA Astrophysics Data System (ADS)

Wang, Yubao; Liu, Yanfei; Sun, Hao

2017-10-01

In the existing three layers multi-granularity OCDM switching system (TLMG-OCDMSS), F-LSP, L-LSP and OC-LSP can be bundled as switching granularity. For CPU-intensive network, the node not only needs to compute the path but also needs to bundle the switching granularity so that the load of single node is heavy. The node will paralyze when the traffic of the node is too heavy, which will impact the performance of the whole network seriously. The introduction of stateful PCE(S-PCE) will effectively solve these problems. PCE is composed of two parts, namely, the path computation element and the database (TED and LSPDB), and returns the result of path computation to PCC (path computation clients) after PCC sends the path computation request to it. In this way, the pressure of the distributed path computation in each node is reduced. In this paper, we propose the concept of Learning PCE (L-PCE), which uses the existing LSPDB as the data source of PCE's learning. By this means, we can simplify the path computation and reduce the network delay, as a result, improving the performance of network.

P3HT:PCBM-based organic solar cells : Optimisation of active layer nanostructure and interface properties

NASA Astrophysics Data System (ADS)

Kadem, Burak Yahya

Organic solar cells (OSCs) have attracted a significant attention during the last decade due to their simple processability on a flexible substrate as well as scope for large-scale production using role to role technique. Improving the performance of the organic solar cells and their lifetime stability are one of the main challenges faced by researchers in this field. In this thesis, work has been carried out using a blend of Poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-Phenyl C[61] butyric acid methyl ester (PCBM) as an active layer in the ratio of (1:1) (P3HT:PCBM). The efficiency and stability of P3HT:PCBM-based solar cells have been examined using different methods and employing novel materials such as1-[N-(2-ethoxyethyl) pent-4-ynamide] -8 (11), 15 (18), 22 (25) -tris-{2-[2-(2-ethoxyethoxy) ethoxy]-1-[2-((2- ethoxyethoxy) - ethoxy) methyl] ethyloxy} phthalocyaninato zinc (II) (ZnPc) to construct a ternary hybrid as the active layer. Controlling the morphology and crystallinity of P3HT:PCBM active layer was carried out using different solvents including chloroform (CF), chlorobenzene (CB) and dichlorobenzene (DCB) and their co-solvents in the ratio of (1:1) to dissolve the P3HT:PCBM blend. Optimum morphology and crystallinity were achieved using a co-solvent made of CB:CF with the obtained solar cell exhibiting the highest performance with PCE reaching 2.73% among other devices prepared using different solvents. Further device performance improvement was observed through optimization of active layer thickness with studied thickness falling in range 65-266 nm. Measurements of the PV characteristics of the investigated OSC devices have revealed optimum performance when active layer thickness was 95 nm with PCE=3.846%. The stability of the P3HT:PCBM-based devices on optimisation of the active layer thickness has shown a decrease in PCE of about 71% over a period of 41 days. Furthermore, P3HT has been blended with different fullerene derivatives (PC[60]BM, PC[61]BM, PC[70]BM and PC[71]BM) and the active layers were processed using the optimum solvent as well as optimum film's thickness.These PCBM derivatives have different lower unoccupied molecular level (LUMO) and different higher occupied molecular level (HOMO) positions, which subsequently influence the PV parameters of the OSCs such as the device open circuit voltage (V[oc]) and its built-in potential (V[bi]). P3HT:PC61BM-based blend has exhibited the highest device performance with PCE reaching 4.2%. Using the above mentioned optimum parameters, the P3HT:PCBM-based devices have been subjected to post-deposition annealing at different temperatures in the range 100-180°C. Efficient device performance was ascribed to P3HT:PCBM layers being subjected to post-deposition heat treatment at 140°C with PCE=5.5%. Device stability as a result of post-deposition heat treatment has also been shown to improve with PCE degrading by about 38% after 55 days.The use of interfacial layer is found to play a key part in modifying the solar cell performance; using electron transport layer (ETL) such as aluminium tris(8-hydroxyquinoline) (Alq3) as a solution processable layer has contributed in increasing PCE to 4.25%, while, using PEDOT:PSS as a hole transport layer (HTL) doped with metal salts has significantly contributed in increasing PCE to reach 6.82% in device when PEDOT:PSS was doped with LiCl aqueous solution. Stability study for the device based on HTL has shown degradation in the PCE from 6.82% to around 1% over 96 days. Using ETL and HTL simultaneously in a complete device has shown a further enhanced PCE reaching 7%. In a further study, doping the P3HT:PCBM with the novel ZnPc hybrids (SWCNTs and reduced graphene oxide (rGO) are covalently and non-covalently functionalised to ZnPc) with the weight ratio of (1:0.01) has significantly altered the solar cell device properties. The best performance is based on P3HT:PCBM blended with ZnPc-SWCNTs-co bonded as a ternary active layer demonstrating device PCE of 5.3% compared to a reference device based on bare P3HT:PCBM blend with PCE of 3.46%.

Coupling Post-Event and Prospective Analyses for El Niño-related Risk Reduction in Peru

NASA Astrophysics Data System (ADS)

French, Adam; Keating, Adriana; Mechler, Reinhard; Szoenyi, Michael; Cisneros, Abel; Chuquisengo, Orlando; Etienne, Emilie; Ferradas, Pedro

2017-04-01

Analyses in the wake of natural disasters play an important role in identifying how ex ante risk reduction and ex post hazard response activities have both succeeded and fallen short in specific contexts, thereby contributing to recommendations for improving such measures in the future. Event analyses have particular relevance in settings where disasters are likely to reoccur, and especially where recurrence intervals are short. This paper applies the Post Event Review Capability (PERC) methodology to the context of frequently reoccurring El Niño Southern Oscillation (ENSO) events in the country of Peru, where over the last several decades ENSO impacts have generated high levels of damage and economic loss. Rather than analyzing the impacts of a single event, this study builds upon the existing PERC methodology by combining empirical event analysis with a critical examination of risk reduction and adaptation measures implemented both prior to and following several ENSO events in the late 20th and early 21st centuries. Additionally, the paper explores linking the empirical findings regarding the uptake and outcomes of particular risk reduction and adaptation strategies to a prospective, scenario-based approach for projecting risk several decades into the future.

Prenatal cocaine effects on brain structure in early infancy.

PubMed

Grewen, Karen; Burchinal, Margaret; Vachet, Clement; Gouttard, Sylvain; Gilmore, John H; Lin, Weili; Johns, Josephine; Elam, Mala; Gerig, Guido

2014-11-01

Prenatal cocaine exposure (PCE) is related to subtle deficits in cognitive and behavioral function in infancy, childhood and adolescence. Very little is known about the effects of in utero PCE on early brain development that may contribute to these impairments. The purpose of this study was to examine brain structural differences in infants with and without PCE. We conducted MRI scans of newborns (mean age = 5 weeks) to determine cocaine's impact on early brain structural development. Subjects were three groups of infants: 33 with PCE co-morbid with other drugs, 46 drug-free controls and 40 with prenatal exposure to other drugs (nicotine, alcohol, marijuana, opiates, SSRIs) but without cocaine. Infants with PCE exhibited lesser total gray matter (GM) volume and greater total cerebral spinal fluid (CSF) volume compared with controls and infants with non-cocaine drug exposure. Analysis of regional volumes revealed that whole brain GM differences were driven primarily by lesser GM in prefrontal and frontal brain regions in infants with PCE, while more posterior regions (parietal, occipital) did not differ across groups. Greater CSF volumes in PCE infants were present in prefrontal, frontal and parietal but not occipital regions. Greatest differences (GM reduction, CSF enlargement) in PCE infants were observed in dorsal prefrontal cortex. Results suggest that PCE is associated with structural deficits in neonatal cortical gray matter, specifically in prefrontal and frontal regions involved in executive function and inhibitory control. Longitudinal study is required to determine whether these early differences persist and contribute to deficits in cognitive functions and enhanced risk for drug abuse seen at school age and in later life. Copyright © 2014 Elsevier Inc. All rights reserved.

Altered functional connectivity to stressful stimuli in prenatally cocaine-exposed adolescents.

PubMed

Zakiniaeiz, Yasmin; Yip, Sarah W; Balodis, Iris M; Lacadie, Cheryl M; Scheinost, Dustin; Constable, R Todd; Mayes, Linda C; Sinha, Rajita; Potenza, Marc N

2017-11-01

Prenatal cocaine exposure (PCE) is linked to addiction and obesity vulnerability. Neural responses to stressful and appetitive cues in adolescents with PCE versus those without have been differentially linked to substance-use initiation. However, no prior studies have assessed cue-reactivity responses among PCE adolescents using a connectivity-based approach. Twenty-two PCE and 22 non-prenatally drug-exposed (NDE) age-, sex-, IQ- and BMI-matched adolescents participated in individualized guided imagery with appetitive (favorite-food), stressful and neutral-relaxing cue scripts during functional magnetic resonance imaging. Subjective favorite-food craving scores were collected before and after script exposure. A data-driven voxel-wise intrinsic connectivity distribution analysis was used to identify between-group differences and examine relationships with craving scores. A group-by-cue interaction effect identified a parietal lobe cluster where PCE versus NDE adolescents showed less connectivity during stressful and more connectivity during neutral-relaxing conditions. Follow-up seed-based connectivity analyses revealed that, among PCE adolescents, the parietal seed was positively connected to inferior parietal and sensory areas and negatively connected to corticolimbic during both stress and neutral-relaxing conditions. For NDE, greater parietal connectivity to parietal, cingulate and sensory areas and lesser parietal connectivity to medial prefrontal areas were found during stress compared to neutral-relaxing cueing. Craving scores inversely correlated with corticolimbic connectivity in PCE, but not NDE adolescents, during the favorite-food condition. Findings from this first data-driven intrinsic connectivity analysis of PCE influences on adolescent brain function indicate differences relating to PCE status and craving. These findings provide insight into the developmental impact of in utero drug exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

Predictive factors for pericardial effusion identified by heart dose-volume histogram analysis in oesophageal cancer patients treated with chemoradiotherapy.

PubMed

Hayashi, K; Fujiwara, Y; Nomura, M; Kamata, M; Kojima, H; Kohzai, M; Sumita, K; Tanigawa, N

2015-02-01

To identify predictive factors for the development of pericardial effusion (PCE) in patients with oesophageal cancer treated with chemotherapy and radiotherapy (RT). From March 2006 to November 2012, patients with oesophageal cancer treated with chemoradiotherapy (CRT) using the following criteria were evaluated: radiation dose >50 Gy; heart included in the radiation field; dose-volume histogram (DVH) data available for analysis; no previous thoracic surgery; and no PCE before treatment. The diagnosis of PCE was independently determined by two radiologists. Clinical factors, the percentage of heart volume receiving >5-60 Gy in increments of 5 Gy (V5-60, respectively), maximum heart dose and mean heart dose were analysed. A total of 143 patients with oesophageal cancer were reviewed retrospectively. The median follow-up by CT was 15 months (range, 2.1-72.6 months) after RT. PCE developed in 55 patients (38.5%) after RT, and the median time to develop PCE was 3.5 months (range, 0.2-9.9 months). On univariate analysis, DVH parameters except for V60 were significantly associated with the development of PCE (p < 0.001). No clinical factor was significantly related to the development of PCE. Recursive partitioning analysis including all DVH parameters as variables showed a V10 cut-off value of 72.8% to be the most influential factor. The present results showed that DVH parameters are strong independent predictive factors for the development of PCE in patients with oesophageal cancer treated with CRT. A heart dosage was associated with the development of PCE with radiation and without prophylactic nodal irradiation.

Effects of Arbutin on Radiation-Induced Micronuclei in Mice Bone Marrow Cells and Its Definite Dose Reduction Factor

PubMed Central

Nadi, Saba; Monfared, Ali Shabestani; Mozdarani, Hossein; Mahmodzade, Aziz; Pouramir, Mahdi

2016-01-01

Background: Interactions of free radicals from ionizing radiation with DNA can induce DNA damage and lead to mutagenesis and carsinogenesis. With respect to radiation damage to human, it is important to protect humans from side effects induced by ionizing radiation. In the present study, the effects of arbutin were investigated by using the micronucleus test for anti-clastogenic activity, to calculate the ratio of polychromatic erythrocyte to polychromatic erythrocyte plus normochromatic erythrocyte (PCE/PCE+NCE) in order to show cell proliferation activity. Methods: Arbutin (50, 100, and 200 mg/kg) was intraperitoneally (ip)administered to NMRI mice two hours before gamma radiation at 2 and 4 gray (Gy). The frequency of micronuclei in 1000 PCEs (MnPCEs) and the ratio of PCE/PCE+NCE were calculated for each sample. Data were statistically evaluated using one-way ANOVA, Tukey HSD test, and t-test. Results: The findings indicated that gamma radiation at 2 and 4 Gy extremely increased the frequencies of MnPCE (P<0.001) while reducing PCE/PCE+NCE (P<0.001) compared to the control group. All three doses of arbutin before irradiation significantly reduced the frequencies of MnPCEs and increased the ratio of PCE/PCE+NCE in mice bone marrow compared to the non-drug-treated irradiated control (P<0.001). All three doses of arbutin had no toxicity effect on bone marrow cells. The calculated dose reduction factor (DRF) showed DRF=1.93 for 2Gy and DRF=2.22 for 4 Gy. Conclusion: Our results demonstrated that arbutin gives significant protection to rat bone against the clastogenic and cytotoxic effects of gamma irradiation. PMID:27217601

Risk of breast cancer following exposure to tetrachloroethylene-contaminated drinking water in Cape Cod, Massachusetts: reanalysis of a case-control study using a modified exposure assessment

PubMed Central

2011-01-01

Background Tetrachloroethylene (PCE) is an important occupational chemical used in metal degreasing and drycleaning and a prevalent drinking water contaminant. Exposure often occurs with other chemicals but it occurred alone in a pattern that reduced the likelihood of confounding in a unique scenario on Cape Cod, Massachusetts. We previously found a small to moderate increased risk of breast cancer among women with the highest exposures using a simple exposure model. We have taken advantage of technical improvements in publically available software to incorporate a more sophisticated determination of water flow and direction to see if previous results were robust to more accurate exposure assessment. Methods The current analysis used PCE exposure estimates generated with the addition of water distribution modeling software (EPANET 2.0) to test model assumptions, compare exposure distributions to prior methods, and re-examine the risk of breast cancer. In addition, we applied data smoothing to examine nonlinear relationships between breast cancer and exposure. We also compared a set of measured PCE concentrations in water samples collected in 1980 to modeled estimates. Results Thirty-nine percent of individuals considered unexposed in prior epidemiological analyses were considered exposed using the current method, but mostly at low exposure levels. As a result, the exposure distribution was shifted downward resulting in a lower value for the 90th percentile, the definition of "high exposure" in prior analyses. The current analyses confirmed a modest increase in the risk of breast cancer for women with high PCE exposure levels defined by either the 90th percentile (adjusted ORs 1.0-1.5 for 0-19 year latency assumptions) or smoothing analysis cut point (adjusted ORs 1.3-2.0 for 0-15 year latency assumptions). Current exposure estimates had a higher correlation with PCE concentrations in water samples (Spearman correlation coefficient = 0.65, p < 0.0001) than estimates generated using the prior method (0.54, p < 0.0001). Conclusions The incorporation of sophisticated flow estimates in the exposure assessment method shifted the PCE exposure distribution downward, but did not meaningfully affect the exposure ranking of subjects or the strength of the association with the risk of breast cancer found in earlier analyses. Thus, the current analyses show a slightly elevated breast cancer risk for highly exposed women, with strengthened exposure assessment and minimization of misclassification by using the latest technology. PMID:21600013

COMPLETE NATURAL ATTENUATION OF PCE AND TCE WITHOUT VINYL CHLORIDE AND ETHENE ACCUMULATION

EPA Science Inventory

A shallow aquifer at the Twin Cities Army Ammunition Plant (TCAAP) was contaminated with tetrachloroethylene (PCE) and trichloroethylene (TCE). Cisdichloroethylene (cis-DCE) is found in ground water at the site, indicating that reductive dehalogenation of PCE and TCE is occurrin...

EMERGING TECHNOLOGY BULLETIN: TWO-ZONE PCE BIOREMEDIATION SYSTEM - ABB ENVIRONMENTAL SERVICES, INC. - U.S. ENVIRONMENTAL PROTECTION AGENCY

EPA Science Inventory

ABB Environmental Services, Inc.'s (ABB-ES), research has demonstrated that sequential anaerobic/aerobic biodegradation of tetrachloroethylene (PCE) is feasible if the proper conditions can be established. The anaerobic process can potentially completely dechlorinate PCE. Howeve...

SURFACTANT ENHANCED REMEDIATION OF SOIL COLUMNS CONTAMINATED BY RESIDUAL TETRACHLOROETHYLENE

EPA Science Inventory

The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting ¹⁴C-labeled PCE into water-saturated soil columns and displacing the free product ...

Pulmonary Embolism from Cement Augmentation of the Vertebral Body.

PubMed

Ignacio, Jose Manuel Fernando; Ignacio, Katrina Hannah Dizon

2018-04-01

Pulmonary cement embolism (PCE) can follow cement augmentation procedures for spine fractures due to osteoporosis, traumatic injuries, and painful metastatic lesions. PCE is underreported and it is likely that many cases remain undiagnosed. Risk factors for PCE have been identified, which can help alert clinicians to patients likely to develop the condition, and there are recommended techniques to reduce its incidence. Most patients with PCE are asymptomatic or only develop transient symptoms, although a few may exhibit florid cardiorespiratory manifestations which can ultimately be fatal. Diagnosis is mainly by radiographic means, commonly using simple radiographs and computed tomography scans of the chest with ancillary tests that assess the patient's cardiorespiratory condition. Management depends on the location and size of the emboli as well as the patient's symptomatology. The aim of this review is to raise awareness of the not uncommon complications of PCE following vertebral cement augmentation and the possibility of serious sequelae. Recommendations for the diagnosis and management of PCE are presented, based on the most recent literature.

Nez Perce Tribal Hatchery Project : Combined-Planning & Design and Operations & Maintenance Reports, 2000 Annual Report.

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

Larson, Roy Edward; Walker, Grant W.

2002-12-31

Nez Perce Tribal Hatchery (NPTH) Year-2000 Combined Maintenance and Operations (O&M) and Planning and Design (P&D) contract is hereby completed based on this annual report patterned after the Statement of Work (SOW) for the project as contracted with Bonneville Power Administration. Primary project activities focused on completion of the Northwest Power Planning Council Step-3 process that: (1) Accepted final design, (2) Authorized a capital construction amount of $16,050,000, and (3) Authorized contractor selection, and (4) Provided construction site dedication, and (5) Implemented construction activities over an anticipated 2-year period of July 2000 through October 2002.

Restore McComas Meadows; Meadow Creek Watershed, 2004-2005 Annual Report.

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

McRoberts, Heidi

2005-12-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated and cost shared with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing, planting trees in riparian areas within the meadow and its tributaries, prioritizing culverts for replacement to accommodate fish passage, and decommissioning roads tomore » reduce sediment input. During this contract period, bids were solicited and awarded for two culvert replacement projects on Doe Creek, and a tributary to Meadow Creek. Additionally, NEPA and permits were completed for the ditch restoration project within McComas Meadows. Due to delays in cultural resource surveys, the contract was not awarded for the performance of the ditch restoration. It will occur in 2005. Monitoring for project effectiveness and trends in watershed conditions was also completed. Road decommissioning monitoring, as well as stream temperature, sediment, and discharge were completed.« less

Different behavioral effect dose–response profiles in mice exposed to two-carbon chlorinated hydrocarbons: Influence of structural and physical properties

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

Umezu, Toyoshi, E-mail: umechan2@nies.go.jp; Shibata, Yasuyuki, E-mail: yshibata@nies.go.jp

2014-09-01

The present study aimed to clarify whether dose–response profiles of acute behavioral effects of 1,2-dichloroethane (DCE), 1,1,1-trichloroethane (TCE), trichloroethylene (TRIC), and tetrachloroethylene (PERC) differ. A test battery involving 6 behavioral endpoints was applied to evaluate the effects of DCE, TCE, TRIC, and PERC in male ICR strain mice under the same experimental conditions. The behavioral effect dose–response profiles of these compounds differed. Regression analysis was used to evaluate the relationship between the dose–response profiles and structural and physical properties of the compounds. Dose–response profile differences correlated significantly with differences in specific structural and physical properties. These results suggest that differencesmore » in specific structural and physical properties of DCE, TCE, TRIC, and PERC are responsible for differences in behavioral effects that lead to a variety of dose–response profiles. - Highlights: • We examine effects of 4 chlorinated hydrocarbons on 6 behavioral endpoints in mice. • The behavioral effect dose–response profiles for the 4 compounds are different. • We utilize regression analysis to clarify probable causes of the different profiles. • The compound's physicochemical properties probably produce the different profiles.« less

RNA helicase A modulates translation of HIV-1 and infectivity of progeny virions

PubMed Central

Bolinger, Cheryl; Sharma, Amit; Singh, Deepali; Yu, Lianbo; Boris-Lawrie, Kathleen

2010-01-01

Retroviruses rely on host RNA-binding proteins to modulate various steps in their replication. Previously several animal retroviruses were determined to mediate Dhx9/RNA helicase A (RHA) interaction with a 5′ terminal post-transcriptional control element (PCE) for efficient translation. Herein PCE reporter assays determined HTLV-1 and HIV-1 RU5 confer orientation-dependent PCE activity. The effect of Dhx9/RHA down-regulation and rescue with siRNA-resistant RHA on expression of HIV-1NL4–3 provirus determined that RHA is necessary for efficient HIV-1 RNA translation and requires ATPase-dependent helicase function. Quantitative analysis determined HIV-1 RNA steady-state and cytoplasmic accumulation were not reduced; rather the translational activity of viral RNA was reduced. Western blotting determined that RHA-deficient virions assemble with Lys-tRNA synthetase, exhibit processed reverse transcriptase and contain similar level of viral RNA, but they are poorly infectious on primary lymphocytes and HeLa cells. The results demonstrate RHA is an important host factor within the virus-producer cell and within the viral particle. The identification of RHA-dependent PCE activity in cellular junD RNA and in six of seven genera of Retroviridae suggests conservation of this translational control mechanism among vertebrates, and convergent evolution of Retroviridae to utilize this host mechanism. PMID:20007598

Effect of emplaced nZVI mass and groundwater velocity on PCE dechlorination and hydrogen evolution in water-saturated sand.

PubMed

Kim, Hye-Jin; Leitch, Megan; Naknakorn, Bhanuphong; Tilton, Robert D; Lowry, Gregory V

2017-01-15

The effect of nZVI mass loading and groundwater velocity on the tetrachloroethylene (PCE) dechlorination rate and the hydrogen evolution rate for poly(maleic acid-co-olefin) (MW=12K) coated nZVI was examined. In batch reactors, the PCE reaction rate constant (3.7×10 -4 Lhr -1 m -2 ) and hydrogen evolution rate constant (1.4 nanomolLhr -1 m -2 ) were independent of nZVI concentration above 10g/L, but the PCE dechlorination rate decreased and the hydrogen evolution rate increased for nZVI concentration below 10g/L. The nonlinearity between nZVI mass loading and PCE dechlorination and H 2 evolution was explained by differences in pH and E h at each nZVI mass loading; PCE reactivity increased when solution E h decreased, and the H 2 evolution rate increased with decreasing pH. Thus, nZVI mass loading of <5g/L yields lower reactivity with PCE and lower efficiency of Fe° utilization than for higher nZVI mass loading. The PCE dechlorination rate increased with increasing pore-water velocity, suggesting that mass transfer limits the reaction at low porewater velocity. Overall, this work suggests that design of nZVI-based reactive barriers for groundwater treatment should consider the non-linear effects of both mass loading and flow velocity on performance and expected reactive lifetime. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison between acetate and hydrogen as electron donors and implications for the reductive dehalogenation of PCE and TCE.

PubMed

Lee, Il-Su; Bae, Jae-Ho; McCarty, Perry L

2007-10-30

Bioremediation by reductive dehalogenation of groundwater contaminated with tetrachloroethene (PCE) or trichloroethene (TCE) is generally carried out through the addition of a fermentable electron donor such as lactate, benzoate, carbohydrates or vegetable oil. These fermentable donors are converted by fermenting organisms into acetate and hydrogen, either of which might be used by dehalogenating microorganisms. Comparisons were made between H2 and acetate on the rate and extent of reductive dehalogenation of PCE. PCE dehalogenation with H2 alone was complete to ethene, but with acetate alone it generally proceeded only about half as fast and only to cis-1,2-dichloroethene (cDCE). Additionally, acetate was not used as an electron donor in the presence of H2. These findings suggest the fermentable electron donor requirement for PCE dehalogenation to ethene can be reduced up to 50% by separating PCE dehalogenation into two stages, the first of which uses acetate for the conversion of PCE to cDCE, and the second uses H2 for the conversion of cDCE to ethene. This can be implemented with a recycle system in which the fermentable substrate is added down-gradient, where the hydrogen being produced by fermentation effects cDCE conversion into ethene. The acetate produced is recycled up-gradient to achieve PCE conversion into cDCE. With the lower electron donor usage required, potential problems of aquifer clogging, excess methane production, and high groundwater chemical oxygen demand (COD) can be greatly reduced.

Comparison between acetate and hydrogen as electron donors and implications for the reductive dehalogenation of PCE and TCE

NASA Astrophysics Data System (ADS)

Lee, Il-Su; Bae, Jae-Ho; McCarty, Perry L.

2007-10-01

Bioremediation by reductive dehalogenation of groundwater contaminated with tetrachloroethene (PCE) or trichloroethene (TCE) is generally carried out through the addition of a fermentable electron donor such as lactate, benzoate, carbohydrates or vegetable oil. These fermentable donors are converted by fermenting organisms into acetate and hydrogen, either of which might be used by dehalogenating microorganisms. Comparisons were made between H 2 and acetate on the rate and extent of reductive dehalogenation of PCE. PCE dehalogenation with H 2 alone was complete to ethene, but with acetate alone it generally proceeded only about half as fast and only to cis-1,2-dichloroethene (cDCE). Additionally, acetate was not used as an electron donor in the presence of H 2. These findings suggest the fermentable electron donor requirement for PCE dehalogenation to ethene can be reduced up to 50% by separating PCE dehalogenation into two stages, the first of which uses acetate for the conversion of PCE to cDCE, and the second uses H 2 for the conversion of cDCE to ethene. This can be implemented with a recycle system in which the fermentable substrate is added down-gradient, where the hydrogen being produced by fermentation effects cDCE conversion into ethene. The acetate produced is recycled up-gradient to achieve PCE conversion into cDCE. With the lower electron donor usage required, potential problems of aquifer clogging, excess methane production, and high groundwater chemical oxygen demand (COD) can be greatly reduced.

Target Organ Metabolism, Toxicity, and Mechanisms of Trichloroethylene and Perchloroethylene: Key Similarities, Differences, and Data Gaps.

PubMed

Cichocki, Joseph A; Guyton, Kathryn Z; Guha, Neela; Chiu, Weihsueh A; Rusyn, Ivan; Lash, Lawrence H

2016-10-01

Trichloroethylene (TCE) and perchloroethylene or tetrachloroethylene (PCE) are high-production volume chemicals with numerous industrial applications. As a consequence of their widespread use, these chemicals are ubiquitous environmental contaminants to which the general population is commonly exposed. It is widely assumed that TCE and PCE are toxicologically similar; both are simple olefins with three (TCE) or four (PCE) chlorines. Nonetheless, despite decades of research on the adverse health effects of TCE or PCE, few studies have directly compared these two toxicants. Although the metabolic pathways are qualitatively similar, quantitative differences in the flux and yield of metabolites exist. Recent human health assessments have uncovered some overlap in target organs that are affected by exposure to TCE or PCE, and divergent species- and sex-specificity with regard to cancer and noncancer hazards. The objective of this minireview is to highlight key similarities, differences, and data gaps in target organ metabolism and mechanism of toxicity. The main anticipated outcome of this review is to encourage research to 1) directly compare the responses to TCE and PCE using more sensitive biochemical techniques and robust statistical comparisons; 2) more closely examine interindividual variability in the relationship between toxicokinetics and toxicodynamics for TCE and PCE; 3) elucidate the effect of coexposure to these two toxicants; and 4) explore new mechanisms for target organ toxicity associated with TCE and/or PCE exposure. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Effects of prenatal caffeine exposure on glucose homeostasis of adult offspring rats

NASA Astrophysics Data System (ADS)

Kou, Hao; Wang, Gui-hua; Pei, Lin-guo; Zhang, Li; Shi, Chai; Guo, Yu; Wu, Dong-fang; Wang, Hui

2017-12-01

Epidemiological evidences show that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR). The IUGR offspring also present glucose intolerance and type 2 diabetes mellitus after maturity. We have previously demonstrated that PCE induced IUGR and increased susceptibility to adult metabolic syndrome in rats. This study aimed to further investigate the effects of PCE on glucose homeostasis in adult offspring rats. Pregnant rats were administered caffeine (120 mg/kg/day, intragastrically) from gestational days 11 to 20. PCE offspring presented partial catch-up growth pattern after birth, characterizing by the increased body weight gain rates. Meanwhile, PCE had no significant influences on the basal blood glucose and insulin phenotypes of adult offspring but increased the glucose tolerance, glucose-stimulated insulin section and β cell sensitivity to glucose in female progeny. The insulin sensitivity of both male and female PCE offspring were enhanced accompanied with reduced β cell fraction and mass. Western blotting results revealed that significant augmentation in protein expression of hepatic insulin signaling elements of PCE females, including insulin receptor (INSR), insulin receptor substrate 1 (IRS-1) and the phosphorylation of serine-threonine protein kinase (Akt), was also potentiated. In conclusion, we demonstrated that PCE reduced the pancreatic β mass but increased the glucose tolerance in adult offspring rats, especially for females. The adaptive compensatory enhancement of β cell responsiveness to glucose and elevated insulin sensitivity mainly mediated by upregulated hepatic insulin signaling might coordinately contribute to the increased glucose tolerance.

Effects of Direct-fed Microbial and Pine Cone Extract on Carcass Traits and Meat Quality of Hanwoo (Korean Native Cattle)

PubMed Central

Muhlisin; Song, Chang Soo; Rhee, Yong Joon; Song, Young Han; Lee, Sung Ki

2016-01-01

The carcass traits and meat quality of Hanwoo (Korean native cattle) whose diets were supplemented with direct-fed microbial (DFM) and pine cone extract (PCE) were evaluated. Twenty head of Hanwoo steers were divided equally into four groups and for a period of 6 months were given different diets: One group was fed a basal diet as control (CON), the other three groups were fed a basal diet supplemented with DFM-1%, DFM+PCE-1% and DFM+PEC-3%, respectively. DFM+PCE3% diet resulted the lowest carcass quality grade. The loins of DFM-1% contained higher moisture and lower fat than did the loins from the CON group. The crude protein content of DFM+PCE-3% group was significantly higher than that of the other groups. The water holding capacity and Warner-Bratzler shear force of the DFM+PCE-1% and 3% groups were lower than those of the CON and DFM-1% groups. The DFM-1% and 3% groups contained lower saturated fatty acid, higher unsaturated fatty acid, mono-unsaturated fatty acid, and poly-unsaturated fatty acid than did CON and DFM+PCE 1% group. Moreover, the n6:n3 ratios of DFM-1% and DFM+PCE-1% and 3% groups were slightly lower than that of the CON group. Thus we concluded that DFM and PCE supplementation resulted healthier Hanwoo beef with lower fat content and n6:n3 ratio. PMID:26954123

Long-Term Neurotoxic Effects of Early Life Exposure to Tetrachloroethylene-contaminated Drinking Water

PubMed Central

Aschengrau, Ann; Janulewicz, Patricia A.; White, Roberta F.; Vieira, Veronica M.; Gallagher, Lisa G.; Getz, Kelly D.; Webster, Thomas F.; Ozonoff, David M.

2016-01-01

Background Tetrachloroethene (PCE) is a common environmental and occupational contaminant and an acknowledged neurotoxicant. From 1968 through 1983 widespread contamination of public drinking water supplies with PCE occurred in the Cape Cod region of Massachusetts. The source of the contamination was a vinyl liner applied to the inner surface of water distribution pipes. Objectives A retrospective cohort study (“the Cape Cod Health Study”) was undertaken to examine possible health consequences of early life exposure to PCE-contaminated drinking water. This review describes the study methods and findings regarding the impact of prenatal and childhood exposure on neurological outcomes during early adulthood, including vision, neuropsychological functioning, brain structure, risky behaviors, and mental illness. The review also describes the strengths and challenges of conducting population-based epidemiological research in this unique setting. Methods Subjects were identified by cross-matching birth certificate and water system data. Information on health outcomes and confounding variables was collected from self-administered surveys (N= 1,689), neuropsychological tests (N=63), vision exam (N=63), and magnetic resonance imaging (N=42). Early life exposure to PCE was estimated using a leaching and transport model. The data analysis compared the occurrence of each health outcome among subjects with prenatal and early childhood PCE exposure to unexposed subjects while considering the impact of confounding variables. Results The study found evidence that early life exposure to PCE-contaminated drinking water has long-term neurotoxic effects. The strongest associations were seen with illicit drug use, bipolar disorder, and post-traumatic stress disorder. Key strengths of the study were availability of historical data on affected water systems, a relatively high exposure prevalence and wide range of exposure levels, and little confounding. Challenges arose mainly from the historical nature of the exposure assessments. Conclusions The Cape Cod Health Study demonstrates how scientists can take advantage of unique “natural experiments” to learn about the health effects of environmental pollution. This body of work has improved our understanding of the long-term health effects of early life exposure to this common environmental contaminant and will help risk assessors and policy makers ensure that U.S. drinking water supplies are safe for vulnerable populations. PMID:27325074

DEPENDENCE OF A HIGH-RATE, PCE-DECHLORINATING ENRICHMENT CULTURE ON METHANOGENIC ACTIVITY. (R825549C053)

EPA Science Inventory

The role served by the presence of methanogenic activity within a tetrachloroethene (PCE)-dechlorinating culture was investigated through a series of supplementation experiments. An acclimated lactate-enrichment culture (LEC 1) capable of rapidly converting PCE to ethene was s...

EVALUATION OF GEOPHYSICAL METHODS FOR THE DETECTION OF SUBSURFACE TETRACHLOROETHYLENE (PCE) IN CONTROLLED SPILL EXPERIMENTS

EPA Science Inventory

Tetrachloroethylene (PCE), typically used as a dry cleaning solvent, is a predominant contaminant in the subsurface at Superfund Sites. PCE is a dense non-aqueous phase liquid (DNAPL) that migrates downward into the earth, leaving behind areas of residual saturation and free prod...

Effects of chlorinated solvents on four species of North American amphibians.

PubMed

McDaniel, T V; Martin, P A; Ross, N; Brown, S; Lesage, S; Pauli, B D

2004-07-01

Tetrachloroethylene (PCE), a dry cleaning and degreasing solvent, can enter groundwater through accidental leaks or spills, and concentrations as high as 75 mg/L have been reported in Canadian aquifers. Amphibians in wetlands receiving contaminated groundwater may be exposed to PCE and its degradation products, but little information is available on the impacts of these compounds on indigenous amphibian species. Acute (96-h static renewal) exposures to PCE and its major degradation products, trichloroethylene (TCE) and cisand trans-dichloroethylene, were conducted on embryos of four North American amphibian species: wood frogs (Rana sylvatica), green frogs (R. clamitans), American toads (Bufo americanus), and spotted salamanders (Ambystoma maculatum). Subsequently, chronic exposures to PCE and TCE were conducted with the larvae of American toads. Both PCE and TCE were teratogenic to amphibian embryos; median effective concentrations (EC50s) for developmental deformities produced by PCE and TCE exposure for wood frogs and green frogs were 12 and 40 mg/L, respectively. Embryonic survivorship, however, was not compromised at these concentrations. American toads were less sensitive; the EC50 for developmental abnormalities was not attained at the highest test concentrations, 45 and 85 mg/L PCE and TCE, respectively. These results are pertinent in assessing the impact of groundwater pollution on an aquifer-fed wetland.

Field Applicable Method to Reduce Dental Emergencies.

DTIC Science & Technology

1982-04-15

removed from a lower right 2nd molar and an orthodontic band was cemented and the tooth restored with the 70 percEnt SnF 2-polycarboxylate cement. 51 dAK...Martens & Mpqkin (1972) using only the buccal surfaces of 20 teeth (from 2nd premolars to 2nd pre - molars of both maxillary and mandibular arches). The...34 effect (Table 1, Fig. 3). Salivary and Urinary Fluoride Levels The pre -experimental baseline for salivary and urinary fluoride were 0.039 + 0.015 and

Simulation of solute transport of tetrachloroethylene in ground water of the glacial-drift aquifer at the Savage Municipal Well Superfund Site, Milford, New Hampshire, 1960-2000

USGS Publications Warehouse

Harte, Philip T.

2004-01-01

The Savage Municipal Well Superfund site, named after the former municipal water-supply well for the town of Milford, is underlain by a 0.5-square mile plume of volatile organic compounds (VOCs), primarily tetrachloroethylene (PCE). The plume occurs mostly within a highly transmissive sand-and-gravel unit, but also extends to an underlying till and bedrock unit. The plume logistically is divided into two areas termed Operable Unit No. 1 (OU1), which contains the primary source area, and Operable Unit No. 2 (OU2), which is the extended plume area. PCE concentrations in excess of 100,000 parts per billion (ppb) had been detected in the OU1 area in 1995, indicating a likely Dense Non-Aqueous Phase Liquid (DNAPL) source. In the fall of 1998, the New Hampshire Department of Environmental Services (NHDES) and the U.S. Environmental Protection Agency (USEPA) installed a remedial system in OU1. The OU1 remedial system includes a low-permeability barrier that encircles the highest detected concentrations of PCE, and a series of injection and extraction wells. The barrier primarily sits atop bedrock and penetrates the full thickness of the sand and gravel; and in some places, the full thickness of the underlying basal till. The sand and gravel unit and the till comprise the aquifer termed the Milford-Souhegan glacial-drift aquifer (MSGD). Two-dimensional and three-dimensional finite-difference solute-transport models of the unconsolidated sediments (MSGD aquifer) were constructed to help evaluate solute-transport processes, assess the effectiveness of remedial activities in OU1, and to help design remedial strategies in OU2. The solute-transport models simulate PCE concentrations, and model results were compared to observed concentrations of PCE. Simulations were grouped into the following three time periods: an historical calibration of the distribution of PCE from the initial input (circa 1960) of PCE into the subsurface to the 1990s, a pre-remedial calibration from 1995 to 1998, and a remedial (post-barrier wall) calibration from 1998 to 1999. Model results also were checked against observed PCE concentrations from May and June 2000 as a post-audit of model performance. Results of the simulations of the two-dimensional model for the historical calibration indicate that the model-computed length of the plume is affected by the retardation factor (retardation). Values of retardation greater than 3 caused the longitudinal length of the computed plume to be too short compared to the observed plume. A retardation of 2-2.5 produced a reasonable comparison between computed and observed PCE concentrations. Testing of different starting times and rates of mass input of PCE indicated that the plume reaches a quasi steady-state distribution in about 20 years regardless of the rate of mass input or values of the solute-transport parameters (retardation, dispersion, and irreversible reaction) assigned the model. Results of the simulations of the three-dimensional model for the pre-remedial (1995-98) calibration of PCE for the OU2 area identified some spatial biases in computed concentrations that generally were unaffected by changes in retardation. The computed PCE concentrations exceeded observed concentrations along the northern part of the plume in OU2, where PCE increases were observed in a bedrock well. These results indicate that some PCE in this area may be entering the bedrock, which is not simulated in the model. Conversely, computed PCE concentrations were less than observed concentrations along the southern part of the plume in OU2. Because testing of high (above 4) values of retardation did little to reduce residuals, it is concluded that the low computed PCE concentrations along the southern flank are likely the result of an underestimation of the initial PCE mass in this area or an unaccounted source of PCE. Results of the simulations of the three-dimensional model for the remedial calibration period (1998-99) and po

Who Are the High-Cost Users? A Method for Person-Centred Attribution of Health Care Spending

PubMed Central

Guilcher, Sara J. T.; Bronskill, Susan E.; Guan, Jun; Wodchis, Walter P.

2016-01-01

Objective To develop person-centered episodes of care (PCE) for community-dwelling individuals in the top fifth percentile of Ontario health care expenditures in order to: (1) describe the main clinical groupings for spending; and (2) identify patterns of spending by health sector (e.g. acute care, home care, physician billings) within and across PCE. Data sources Data were drawn from population-based administrative databases for all publicly funded health care in Ontario, Canada in 2010/11. Study design This study is a retrospective cohort study. Data collection/extraction methods A total of 587,982 community-dwelling individuals were identified among those accounting for the top 5% of provincial health care expenditures between April 1, 2010 and March 31, 2011. PCE were defined as starting with an acute care admission and persisting through subsequent care settings and providers until individuals were without health system contact for 30 days. PCE were classified according to the clinical grouping for the initial admission. PCE and non-PCE costs were calculated and compared to provide a comprehensive measurement of total health system costs for the year. Principal findings Among this community cohort, 697,059 PCE accounted for nearly 70% ($11,815.3 million (CAD)) of total annual publicly-funded expenditures on high-cost community-dwelling individuals. The most common clinical groupings to start a PCE were Acute Planned Surgical (35.2%), Acute Unplanned Medical (21.0%) and Post-Admission Events (10.8%). Median PCE costs ranged from $3,865 (IQR = $1,712-$10,919) for Acute Planned Surgical to $20,687 ($12,207-$39,579) for Post-Admission Events. Inpatient acute ($8,194.5 million) and inpatient rehabilitation ($434.6 million) health sectors accounted for the largest proportions of allocated PCE spending over the year. Conclusions Our study provides a novel methodological approach to categorize high-cost health system users into meaningful person-centered episodes. This approach helps to explain how costs are attributable within individuals across sectors and has applications in episode-based payment formulas and quality monitoring. PMID:26937955

Combined C and Cl isotope effects indicate differences between corrinoids and enzyme (Sulfurospirillum multivorans PceA) in reductive dehalogenation of tetrachloroethene, but not trichloroethene.

PubMed

Renpenning, Julian; Keller, Sebastian; Cretnik, Stefan; Shouakar-Stash, Orfan; Elsner, Martin; Schubert, Torsten; Nijenhuis, Ivonne

2014-10-21

The role of the corrinoid cofactor in reductive dehalogenation catalysis by tetrachloroethene reductive dehalogenase (PceA) of Sulfurospirillum multivorans was investigated using isotope analysis of carbon and chlorine. Crude extracts containing PceA--harboring either a native norpseudo-B12 or the alternative nor-B12 cofactor--were applied for dehalogenation of tetrachloroethene (PCE) or trichloroethene (TCE), and compared to abiotic dehalogenation with the respective purified corrinoids (norpseudovitamin B12 and norvitamin B12), as well as several commercially available cobalamins and cobinamide. Dehalogenation of TCE resulted in a similar extent of C and Cl isotope fractionation, and in similar dual-element isotope slopes (εC/εCl) of 5.0-5.3 for PceA enzyme and 3.7-4.5 for the corrinoids. Both observations support an identical reaction mechanism. For PCE, in contrast, observed C and Cl isotope fractionation was smaller in enzymatic dehalogenation, and dual-element isotope slopes (2.2-2.8) were distinctly different compared to dehalogenation mediated by corrinoids (4.6-7.0). Remarkably, εC/εCl of PCE depended in addition on the corrinoid type: εC/εCl values of 4.6 and 5.0 for vitamin B12 and norvitamin B12 were significantly different compared to values of 6.9 and 7.0 for norpseudovitamin B12 and dicyanocobinamide. Our results therefore suggest mechanistic and/or kinetic differences in catalytic PCE dehalogenation by enzymes and different corrinoids, whereas such differences were not observed for TCE.

Bayesian regression analyses of radiation modality effects on pericardial and pleural effusion and survival in esophageal cancer.

PubMed

He, Liru; Chapple, Andrew; Liao, Zhongxing; Komaki, Ritsuko; Thall, Peter F; Lin, Steven H

2016-10-01

To evaluate radiation modality effects on pericardial effusion (PCE), pleural effusion (PE) and survival in esophageal cancer (EC) patients. We analyzed data from 470 EC patients treated with definitive concurrent chemoradiotherapy (CRT). Bayesian semi-competing risks (SCR) regression models were fit to assess effects of radiation modality and prognostic covariates on the risks of PCE and PE, and death either with or without these preceding events. Bayesian piecewise exponential regression models were fit for overall survival, the time to PCE or death, and the time to PE or death. All models included propensity score as a covariate to correct for potential selection bias. Median times to onset of PCE and PE after RT were 7.1 and 6.1months for IMRT, and 6.5 and 5.4months for 3DCRT, respectively. Compared to 3DCRT, the IMRT group had significantly lower risks of PE, PCE, and death. The respective probabilities of a patient being alive without either PCE or PE at 3-years and 5-years were 0.29 and 0.21 for IMRT compared to 0.13 and 0.08 for 3DCRT. In the SCR regression analyses, IMRT was associated with significantly lower risks of PCE (HR=0.26) and PE (HR=0.49), and greater overall survival (probability of beneficial effect (pbe)>0.99), after controlling for known clinical prognostic factors. IMRT reduces the incidence and postpones the onset of PCE and PE, and increases survival probability, compared to 3DCRT. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Thermocatalytic Destruction of Gas-Phase Perchloroethylene Using Propane as a Hydrogen Source

PubMed Central

Willinger, Marty; Rupp, Erik; Barbaris, Brian; Gao, Song; Arnolda, Robert; Betterton, Eric; Sáez, A. Eduardo

2009-01-01

The use of propane in combination with oxygen to promote the destruction of perchloroethylene (PCE) over a platinum (Pt)/rhodium (Rh) catalyst on a cerium/zirconium oxide washcoat supported on an alumina monolith was explored. Conversions of PCE were measured in a continuous flow reactor with residence times less than 0.5 s and temperatures ranging from 200 to 600°C. The presence of propane was shown to increase significantly the conversion of PCE over oxygen-only conditions. Conversions close to 100% were observed at temperatures lower than 450°C with 20% oxygen and 2% propane in the feed, which makes this process attractive from a practical standpoint. In the absence of oxygen, PCE conversion is even higher, but the catalyst suffers significant deactivation in less than an hour. Even though results show that oxygen competes with reactants for active sites on the catalyst, the long-term stability that oxygen confers to the catalyst makes the process an efficient alternative to PCE oxidation. A Langmuir-Hinshelwood competitive adsorption model is proposed to quantify PCE conversion. PMID:19217713

Risk factors for pericardial effusion in patients with stage I esophageal cancer treated with chemoradiotherapy.

PubMed

Tamari, Keisuke; Isohashi, Fumiaki; Akino, Yuichi; Suzuki, Osamu; Seo, Yuji; Yoshioka, Yasuo; Hayashi, Yoshito; Nishida, Tsutomu; Takehara, Tetsuo; Mori, Masaki; Doki, Yuichiro; Ogawa, Kazuhiko

2014-12-01

We investigated clinical and dosimetric factors influencing the risk of developing pericardial effusion (PCE) in patients with Stage I esophageal cancer undergoing definitive chemoradiotherapy. Sixty-nine patients with Stage I esophageal cancer who underwent definitive chemoradiotherapy were retrospectively analyzed. Treatment comprised of three-dimensional conformal radiotherapy (60 Gy in 30 fractions) with concurrent chemotherapy. Clinical and dosimetric factors associated with PCE development were analyzed. The median follow-up was 37 months (range=8-111 months); the crude PCE incidence rate was 52.2%. Grade 2 and 3 incidence rate was 47.8% and 4.3%, respectively. The median time to PCE onset was 5.7 months after radiotherapy. In multivariate analysis, pericardial V30 ≥ 41.6%, age ≥ 66 years, body mass index (BMI) ≥ 19 and diabetes mellitus (DM) were significant predictors of developing PCE. The present study suggests that higher pericardial V30, advanced age, high BMI and DM are risk factors for developing PCE. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Different Effects of NSF and PCE Superplasticizer on Adsorption, Dynamic Yield Stress and Thixotropy of Cement Pastes

PubMed Central

2018-01-01

This study compares the differences and similarities of two types of superplasticizers—NSF (Naphthalene Sulfonate Formaldehyde) and PCE (PolyCarboxylate Ester)—in fresh cement paste systems, in terms of adsorption, dynamic yield stress, and thixotropic index. Results show that with either NSF or PCE addition, the more superplasticizer is added, the more it is adsorbed and the more it remains in the interstitial pore solution. The dynamic yield stress and thixotropic index also decrease with increasing addition the amount of either superplasticizer. However, NSF is less efficient in decreasing the dynamic yield stress than PCE. More importantly, the decreasing patterns of dynamic yield stress and thixotropic index are different with NSF and PCE additions; this is tied to the adsorption and dispersing mechanisms of these two types of superplasticizers. PMID:29710782

Regulation of palmitoyl-CoA chain elongation by clofibric acid in the liver of Zucker fa/fa rats.

PubMed

Toyama, Tomoaki; Kudo, Naomi; Mitsumoto, Atsushi; Kawashima, Yoichi

2005-05-01

The regulation of palmitoyl-CoA chain elongation (PCE) by clofibric acid [2-(4-chlorophenoxy)-2-methylpropionic acid] was investigated in comparison with stearoyl-CoA desaturase (SCD) in the liver of obese Zucker fa/fa rats. The proportion of oleic acid in the hepatic lipids of Zucker obese rats is 2.7 times higher than that of lean littermates. The activities of PCE and SCD in the liver of Zucker obese rats were markedly higher than in lean rats, and the hepatic uptake of 2-deoxyglucose (2-DG) was also higher in Zucker obese rats compared with lean rats. The increased activities of SCD and PCE in Zucker obese rats were due to the enhanced expression of mRNA of both SCD1 and rat FA elongase 2 (rELO2), but not SCD2 or rELO1. The proportion of oleic acid in the liver was significantly increased by the administration of clofibric acid to Zucker obese rats, and the hepatic PCE activity and rELO2 mRNA expression, but not the SCD activity or SCD1 mRNA expression, were increased in response to clofibric acid treatment. By contrast, the activities of both PCE and SCD and the mRNA expression of SCD1 and rELO2 in the liver were increased by the treatment of Zucker lean rats with clofibric acid. Multiple regression analysis, which was performed to determine the relationships involving PCE activity, SCD activity, and the proportion of oleic acid, revealed that the three parameters were significantly correlated and that the standardized partial regression coefficient of PCE was higher than that of SCD. These results indicate that oleic acid is synthesized by the concerted action of PCE and SCD and that PCE plays a crucial role in the formation of oleic acid when Zucker fa/fa rats are given clofibric acid.

Identification of active dehalorespiring microbial populations in anoxic river sediment by RNA-based stable isotope probing

NASA Astrophysics Data System (ADS)

Kittelmann, S.; Friedrich, M. W.

2005-12-01

Tetrachloroethene (perchloroethylene, PCE), a persistent contaminant in aquifers, soils and sediments, can be reductively dechlorinated by anaerobic microorganisms in a process referred to as dehalorespiration. However, the biodiversity of dehalorespiring microorganisms and their distribution especially in pristine environments is largely unexplored. Therefore, the aim of this study was to detect potentially novel PCE-dehalorespiring microorganisms by using stable isotope probing (SIP), a technique that allows to directly identify the function of uncultivated microbial populations. We simulated a PCE contamination by incubating pristine river sediment in the presence of PCE at a steady, low aqueous concentration (20 μM). Dehalogenation activity in microcosms (20 nmol cis-dichloroethene per ml slurry per day formed) was detected already after 4 weeks at 20°C with sediment indigenous electron donors. The microbial community in sediment incubations was probed with 13C-labelled acetate (0.5 mM) as electron donor and carbon source at 15°C for 3 days. After RNA extraction, "heavy" 13C-rRNA and light 12C-rRNA were separated by isopycnic centrifugation, and Bacteria-related populations in gradient fractions were characterised by terminal restriction fragment length polymorphism analysis and cloning. In heavy gradient fractions from the microcosm with PCE, we detected a prominent 506-bp terminal restriction fragment (T-RF) and a few minor T-RFs only. In contrast, in the control without PCE, Bacteria-specific rRNA was restricted to light gradient fractions, and the prominent T-RFs found in the PCE-dechlorinating microcosm were of minor importance. Apparently, 13C-acetate was incorporated into bacterial rRNA more effectively in PCE-respiring microcosms. Thus, rRNA-SIP provides strong evidence for the presence of PCE-dehalorespiring, 13C-acetate-utilising populations in river sediment microcosms. Cloning/sequencing analysis identified the prominent members of the heavy gradient fractions as members of the phylum Chloroflexi only distantly related to cultivated dechlorinating Dehalococcides spp.

Nonthermal Photocoercivity Effect in a Low-Doped (Ga,Mn)As Ferromagnetic Semiconductor

NASA Astrophysics Data System (ADS)

Astakhov, G. V.; Hoffmann, H.; Korenev, V. L.; Kiessling, T.; Schwittek, J.; Schott, G. M.; Gould, C.; Ossau, W.; Brunner, K.; Molenkamp, L. W.

2009-05-01

We report a photoinduced change of the coercive field, i.e., a photocoercivity effect (PCE), under very low intensity illumination of a low-doped (Ga,Mn)As ferromagnetic semiconductor. We find a strong correlation between the PCE and the sample resistivity. Spatially resolved dynamics of the magnetization reversal rule out any role of thermal heating in the origin of this PCE, and we propose a mechanism based on the light-induced lowering of the domain wall pinning energy. The PCE is local and reversible, allowing writing and erasing of magnetic images using light.

Nonthermal photocoercivity effect in a low-doped (Ga,Mn)As ferromagnetic semiconductor.

PubMed

Astakhov, G V; Hoffmann, H; Korenev, V L; Kiessling, T; Schwittek, J; Schott, G M; Gould, C; Ossau, W; Brunner, K; Molenkamp, L W

2009-05-08

We report a photoinduced change of the coercive field, i.e., a photocoercivity effect (PCE), under very low intensity illumination of a low-doped (Ga,Mn)As ferromagnetic semiconductor. We find a strong correlation between the PCE and the sample resistivity. Spatially resolved dynamics of the magnetization reversal rule out any role of thermal heating in the origin of this PCE, and we propose a mechanism based on the light-induced lowering of the domain wall pinning energy. The PCE is local and reversible, allowing writing and erasing of magnetic images using light.

2D black phosphorous nanosheets as a hole transporting material in perovskite solar cells

NASA Astrophysics Data System (ADS)

Muduli, Subas Kumar; Varrla, Eswaraiah; Kulkarni, Sneha Avinash; Han, Guifang; Thirumal, Krishnamoorthy; Lev, Ovadia; Mhaisalkar, Subodh; Mathews, Nripan

2017-12-01

We demonstrate for the first-time liquid exfoliated few layers of 2D Black phosphorus (BP) nanosheets as a hole transporting material (HTM) for perovskite based solar cells. The photoelectron spectroscopy in air (PESA) measurements confirm the low laying valence band level of BP nanosheets (-5.2 eV) favourable for hole injection from CH3NH3PbI3 (MAPbI3). Our results show that ∼25% improvement in power conversion efficiency (PCE) of η = 16.4% for BP nanosheets + Spiro-OMeTAD as an HTM as compared to spiro-OMeTAD (η = 13.1%). When BP nanosheets are exclusively utilised as an HTM, a PCE of η = 7.88% is noted, an improvement over the 4% PCE values observed for HTM free devices. Photoluminescence (PL) quenching of MAPbI3 and impedance measurements further confirm the charge extraction ability of BP nanosheets. The structural and optical characterization of liquid exfoliated BP nanosheets is discussed in detail with the aid of transmission electron microscopy, Raman spectroscopy, absorption spectroscopy and photo-electron spectroscopy.

INFLUENCE OF HYDRAULIC RETENTION TIME ON EXTENT OF PCE DECHLORINATION AND PRELIMINARY CHARACTERIZATION OF THE ENRICHMENT CULTURE. (R826694C703)

EPA Science Inventory

The extent of tetrachloroethene (PCE) dechlorination in two chemostats was evaluated as a function of hydraulic retention time (HRT). The inoculum of these chemostats was from an upflow anaerobic sludge blanket (UASB) reactor that rapidly converts PCE to vinyl chloride (VC) an...

REPORT ON THE GEOELECTRICAL DETECTION OF SURFACTANT ENHANCED AQUIFER REMEDIATION OF PCE: PROPERTY CHANGES IN AQUEOUS SOLUTIONS DUE TO SURFACTANT TREATMENT OF PERCHLOROETHYLENE: IMPLICATIONS TO GEOPHYSICAL MEASUREMENTS

EPA Science Inventory

Select physicochemical properties of nine surfactants which are conventionally used in the remediation of perchloroethylene (PCE, a.k.a. tetrachloroethene) were evaluated with varying concentrations of PCE and indicator dyes in aqueous solutions using a response surface quadrati...

75 FR 19575 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for Navarretia fossalis

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-15

... (PCE 2), and the topography and soils that support ponding during winter and spring months (PCE 3). The... and upland habitats that act as the local watershed (PCE 2), and the topography and soils that support... businesses (13 CFR 121.201). Small businesses include manufacturing and mining concerns with fewer than 500...

CH3 NH3 PbI3 and HC(NH2 )2 PbI3 Powders Synthesized from Low-Grade PbI2 : Single Precursor for High-Efficiency Perovskite Solar Cells.

PubMed

Zhang, Yong; Kim, Seul-Gi; Lee, Do-Kyoung; Park, Nam-Gyu

2018-05-09

High-efficiency perovskite solar cells are generally fabricated by using highly pure (>99.99 %) PbI 2 mixed with an organic iodide in polar aprotic solvents. However, the use of such an expensive chemical may impede progress toward large-scale industrial applications. Here, we report on the synthesis of perovskite powders by using inexpensive low-grade (99 %) PbI 2 and on the photovoltaic performance of perovskite solar cells prepared from a powder-based single precursor. Pure APbI 3 [A=methylammonium (MA) or formamidinium (FA)] perovskite powders were synthesized by treating low-grade PbI 2 with MAI or FAI in acetonitrile at ambient temperature. The structural phase purity was confirmed by X-ray diffraction. The solar cell with a MAPbI 3 film prepared from the synthesized perovskite powder demonstrated a power conversion efficiency (PCE) of 17.14 %, which is higher than the PCE of MAPbI 3 films prepared by using both MAI and PbI 2 as precursors (PCE=13.09 % for 99 % pure PbI 2 and PCE=16.39 % for 99.9985 % pure PbI 2 ). The synthesized powder showed better absorption and photoluminescence, which were responsible for the better photovoltaic performance. For the FAPbI 3 powder, a solution with a yellow non-perovskite δ-FAPbI 3 powder synthesized at room temperature was found to lead to a black perovskite film, whereas a solution with the black perovskite α-FAPbI 3 powder synthesized at 150 °C was not transformed into a black perovskite film. The α↔δ transition between the powder and film was assumed to correlate with the difference in the iodoplumbates in the powder-dissolved solution. An average PCE of 17.21 % along with a smaller hysteresis [ΔPCE=PCE reverse -PCE forward )=1.53 %] was demonstrated from the perovskite solar cell prepared by using δ-FAPbI 3 powder; this PCE is higher than the average PCE of 17.05 % with a larger hysteresis (ΔPCE=2.71 %) for a device based on a conventional precursor solution dissolving MAI with high-purity PbI 2 . The smaller hysteresis was indicative of fewer defects in the resulting FAPbI 3 film prepared by using the δ-FAPbI 3 powder. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Predictive value of preoperative electrocardiography for perioperative cardiovascular outcomes in patients undergoing noncardiac, nonvascular surgery.

PubMed

Biteker, Murat; Duman, Dursun; Tekkeşin, Ahmet Ilker

2012-08-01

The utility of routine preoperative electrocardiography (ECG) for assessing perioperative cardiovascular risk in patients undergoing noncardiac, nonvascular surgery (NCNVS) is unclear. There would be an association between preoperative ECG and perioperative cardiovascular outcomes in patients undergoing NCNVS. A total of 660 patients undergoing NCNVS were prospectively evaluated. Patients age >18 years who underwent an elective, nonday case, open surgical procedure were enrolled. Troponin I concentrations and 12-lead ECG were evaluated the day before surgery, immediately after surgery, and on the first 5 postoperative days. Preoperative ECG showing atrial fibrillation, left or right bundle branch block, left ventricular hypertrophy, frequent premature ventricular complexes, pacemaker rhythm, Q-wave, ST-segment changes, or sinus tachycardia or bradycardia were classified as abnormal. The patients were followed up during hospitalization and were evaluated for the presence of perioperative cardiovascular events (PCE). Eighty patients (12.1%) experienced PCE. Patients with abnormal ECG findings had a greater incidence of PCE than those with normal ECG results (16% vs 6.4%; P < 0.001). Mean QTc interval was significantly longer in the patients who had PCE (436.6 ± 31.4 vs 413.3 ± 16.7 ms; P < 0.001). Univariate analysis showed a significant association between preoperative atrial fibrillation, pacemaker rhythm, ST-segment changes, QTc prolongation, and in-hospital PCE. However, only QTc prolongation (odds ratio: 1.15, 95% confidence interval: 1.06-1.2, P < 0.001) was an independent predictor of PCE according to the multivariate analysis. Every 10-ms increase in QTc interval was related to a 13% increase for PCE. Prolongation of the QTc interval on the preoperative ECG was related with PCE in patients undergoing NCNVS. © 2011 Wiley Periodicals, Inc.

Palliative Care for Hospitalized Patients With Stroke: Results From the 2010 to 2012 National Inpatient Sample.

PubMed

Singh, Tarvinder; Peters, Steven R; Tirschwell, David L; Creutzfeldt, Claire J

2017-09-01

Substantial variability exists in the use of life-prolonging treatments for patients with stroke, especially near the end of life. This study explores patterns of palliative care utilization and death in hospitalized patients with stroke across the United States. Using the 2010 to 2012 nationwide inpatient sample databases, we included all patients discharged with stroke identified by International Classification of Diseases-Ninth Revision codes. Strokes were subclassified as ischemic, intracerebral, and subarachnoid hemorrhage. We compared demographics, comorbidities, procedures, and outcomes between patients with and without a palliative care encounter (PCE) as defined by the International Classification of Diseases-Ninth Revision code V66.7. Pearson χ 2 test was used for categorical variables. Multivariate logistic regression was used to account for hospital, regional, payer, and medical severity factors to predict PCE use and death. Among 395 411 patients with stroke, PCE was used in 6.2% with an increasing trend over time ( P <0.05). We found a wide range in PCE use with higher rates in patients with older age, hemorrhagic stroke types, women, and white race (all P <0.001). Smaller and for-profit hospitals saw lower rates. Overall, 9.2% of hospitalized patients with stroke died, and PCE was significantly associated with death. Length of stay in decedents was shorter for patients who received PCE. Palliative care use is increasing nationally for patients with stroke, especially in larger hospitals. Persistent disparities in PCE use and mortality exist in regards to age, sex, race, region, and hospital characteristics. Given the variations in PCE use, especially at the end of life, the use of mortality rates as a hospital quality measure is questioned. © 2017 The Authors.

Relation of water chemistry of the Edwards aquifer to hydrogeology and land use, San Antonio Region, Texas

USGS Publications Warehouse

Buszka, Paul M.

1987-01-01

In general, the quality of ground water in the freshwater parts of the aquifer (north of the "bad-water" line) is suitable for all uses including human consumption. Two areas that are exceptions are: (1) Northeast of Garner Field in Uvalde, Texas, where PCE (tetrachloroethylene) has been detected in groundwater samples, and (2) north-central Bexar County near the former West Avenue landfill where PCE and benzene have been detected in ground-water samples. Concentrations of these organic compounds in water from many wells in the two areas exceed the maximum contaminant level for human consumption set by the U.S. Environmental Protection Agency.

Daily insulin requirement of children and adolescents with type 1 diabetes: effect of age, gender, body mass index and mode of therapy.

PubMed

Wiegand, Susanna; Raile, Klemens; Reinehr, Thomas; Hofer, Sabine; Näke, Andrea; Rabl, Wolfgang; Holl, Reinhard W

2008-04-01

The purpose of this study was to generate insulin dose (ID) percentiles for children and adolescents with type 1 diabetes mellitus (DM1) having the opportunity to assess this important parameter in relation to age and sex. Daily IDs per weight (ID/kg) were recorded in 22,177 patients with DM1 (3-25 years of age, DM1 duration of more than 2 years, 48% female) and ID percentiles (ID-Perc) were created statistically. The ID-Perc were compared between male and female, and between multiple insulin injection therapy (MIT) and continuous s.c. insulin infusion (CSII). A multivariate regression analysis was performed for ID in the third year of DM1 with ID/kg, body weight, age, gender, and insulin delivery regimen as variables. The 50th ID-Perc (P50) varied among 0.67 IU/kg (age 3 years), 0.93 IU/kg (13 years), and 0.70 IU/kg (23 years) increasing from early childhood to adolescence and decreasing toward adulthood. Highest P50 ID was found at 12 years in females (0.94 IU/kg) and at 14 years in males (0.92 IU/kg). Using ICT, the ID was significantly higher compared with CSII (P50: 0.94 IU/kg versus 0.79 IU/kg at 13 years). In multivariate regression analysis, ID was significantly (P>0.001) associated with age, gender, and insulin delivery regime. The ID-Perc were significantly different during various periods of childhood and were influenced by gender, body weight, and insulin injection regimes. Therefore, the presented data 1) provide evidence to interpret individual ID in children and adolescents with DM1 and 2) more specifically identify children with unusually high (insulin resistance and non-compliance) or low (MODY and persistent remission) insulin requirement.

Comparison of biophysical factors influencing on emphysema quantification with low-dose CT

NASA Astrophysics Data System (ADS)

Heo, Chang Yong; Kim, Jong Hyo

2014-03-01

Emphysema Index(EI) measurements in MDCT is known to be influenced by various biophysical factors such as total lung volume, and body size. We investigated the association of the four biophysical factors with emphysema index in low-dose MDCT. In particular, we attempted to identify a potentially stronger biophysical factor than total lung volume. A total of 400 low-dose MDCT volumes taken at 120kVp, 40mAs, 1mm thickness, and B30f reconstruction kernel were used. The lungs, airways, and pulmonary vessels were automatically segmented, and two Emphysema Indices, relative area below -950HU(RA950) and 15th percentile(Perc15), were extracted from the segmented lungs. The biophysical factors such as total lung volume(TLV), mode of lung attenuation(ModLA), effective body diameter(EBD), and the water equivalent body diameter(WBD) were estimated from the segmented lung and body area. The association of biophysical factors with emphysema indices were evaluated by correlation coefficients. The mean emphysema indices were 8.3±5.5(%) in RA950, and -930±18(HU) in Perc15. The estimates of biophysical factors were 4.7±1.0(L) in TLV, -901±21(HU) in ModLA, 26.9±2.2(cm) in EBD, and 25.9±2.6(cm) in WBD. The correlation coefficients of biophysical factors with RA950 were 0.73 in TLV, 0.94 in ModLA, 0.31 in EBD, and 0.18 WBD, the ones with Perc15 were 0.74 in TLV, 0.98 in ModLA, 0.29 in EBD, and 0.15 WBD. Study results revealed that two biophysical factors, TLV and ModLA, mostly affects the emphysema indices. In particular, the ModLA exhibited strongest correlation of 0.98 with Perc15, which indicating the ModLA is the most significant confounding biophysical factor in emphysema indices measurement.

Large impacted upper ureteral calculi: A comparative study between retrograde ureterolithotripsy and percutaneous antegrade ureterolithotripsy in the modified lateral position

PubMed Central

Moufid, Kamal; Abbaka, Najib; Touiti, Driss; Adermouch, Latifa; Amine, Mohamed; Lezrek, Mohammed

2013-01-01

Context: The treatment for patients with large impacted proximal ureteral stone remains controversial, especially at institutions with limited resources. Aim: The aim of this study is to compare and to evaluate the outcome and complications of two main treatment procedures for impacted proximal ureteral calculi, retrograde ureterolithotripsy (URS), and percutaneous antegrade ureterolithotripsy (Perc-URS). Settings and Design: Our inclusion criteria were solitary, radiopaque calculi, >15 mm in size in a functioning renal unit. Only those patients in whom the attempt at passing a guidewire or catheter beyond the calculus failed were included in this study. Patients and Methods: Between January 2007 and July 2011, a total of 52 patients (13 women and 39 men) with large impacted upper-ureteral calculi >15 mm and meeting the inclusion criteria were selected. Of these, Perc-URS was done in 22 patients (group 1) while retrograde ureteroscopy was performed in 30 patients (group 2). We analyzed operative time, incidence of complications during and after surgery, the number of postoperative recovery days, median total costs associated per patient per procedure, and the stone-free rate immediately after 5 days and after 1 month. Statistical Analysis Used: Bivariate analysis used the Student t-test and the Mann-Whitney test to compare two means and Chi-square and Fisher's exact tests to compare two percentages. The significance level was set at 0.05. Results: The mean age was 42.3 years (range 22-69). The mean stone sizes (mm) were 34 ± 1.2 and 29.3 ± 1.8 mm in group 1 and 2, respectively. In the Perc-URS group, 21 patients (95.45%) had complete calculus clearance through a single tract in one session of percutaneous surgery, whereas in the URS group, only 20 patients (66.7%) had complete stone clearance (P = 0.007). The mean operative time was higher in the Perc-URS group compared to group 2 (66.5 ± 21.7 vs. 52.13 ± 17.3 min, respectively; P = 0.013). Complications encountered in group 1 included transient postoperative fever (2 pts) and simple urine outflow (2 pts). Ten patients (33%) of group 2 experienced failure: Migration to the kidney (3 pts), ureteral perforation (2 pts), tortuosity of the ureter (2 pts), and epithelial polyps (2 patients). Group 1 patients had an average visual analog (VAS) pain score of 47 mm compared with 31 mm in group 2 patients. The mean hospital stay (days) in group 1 was higher than the group 2 (2.27 ± 0.8 vs. 1.67 ± 0.6, respectively; P = 0.01). The mean analgesia requirement for group 1 (paracetamol chlorhydrate + codeine 12 ± 3 g) was significantly more compared with group B (6.8 ± 2 g) (P < 0.01). The difference in average blood loss between the two groups was not statistically significant. Total costs was slightly higher in group 1 but the difference was not statistically significant between the two groups (15000 vs. 13400 MDH respectively; P > 0.05). After 1 month, the stone free-rate remained higher in group 1 (95.5% vs. 66.7%, respectively; P = 0.012). Conclusions: In our series, Perc-URS is a safe and efficient treatment option for proximal ureteral stone, especially when the stone size is superior to 15 mm with the presence of moderate or severe hydronephrosis. PMID:24049373

Quantum-classical transition of photon-Carnot engine induced by quantum decoherence

NASA Astrophysics Data System (ADS)

Quan, H. T.; Zhang, P.; Sun, C. P.

2006-03-01

We study the physical implementation of the photon-Carnot engine (PCE) based on the cavity quantum electrodynamics system [M. O. Scully, M. Suhail Zubairy, G. S. Agarwal, and H. Walther, Science 299, 862 (2003)]. Here we analyze two decoherence mechanisms for the more practical systems of PCE, the dissipation of photon field, and the pure dephasing of the input atoms. As a result we find that (i) the PCE can work well to some extent even in the existence of the cavity loss (photon dissipation) and (ii) the short-time atomic dephasing, which can destroy the PCE, is a fatal problem to be overcome.

Insights into dechlorination of PCE and TCE from carbon isotope fractionation by vitamin B12

NASA Astrophysics Data System (ADS)

Slater, G.; Sherwood Lollar, B.; Lesage, S.; Brown, S.

2003-04-01

Reductive dechlorination of perchloroethylene (PCE) and trichloroethylene (TCE) by vitamin B12 is both a potential remediation technique and an analogue of the microbial reductive dechlorination reaction. Stable carbon isotopic analysis, an effective and powerful tool for the investigation and monitoring of contaminant remediation, was used to characterize the isotopic effects of reductive dechlorination of PCE and TCE by vitamin B12 in laboratory microcosms. 10 mg/L vitamin B12 degraded greater than 90% of an initial concentration of PCE of 20 mg/L. TCE, the primary product of PCE degradation, accounted for between 64 - 72% of the PCE degraded. In experiments with TCE, 147 mg/L vitamin B12 degraded greater than 90% of an initial concentration of TCE of 20 mg/L. Cis-dichloroethene (cDCE), the primary product of TCE degradation, accounted for between 30 - 35% of the TCE degraded. Degradation of both PCE and TCE exhibited first order kinetics. Strong isotopic fractionation of the reactant PCE and of the reactant TCE was observed over the course of degradation. This fractionation could be described by a Rayleigh model with enrichment factors between -16.5 ppm and -15.8 ppm for PCE, and -17.2 ppm and -16.6 ppm for TCE. Fractionation was similar in all four experiments, with a mean enrichment factor of -16.5 +/- 0.6 ppm. These large enrichment factors indicate that isotopic analysis can be used to assess the occurrence of dechlorination of PCE and TCE by vitamin B12 in remediation situations. Significantly, the Rayleigh model could be used to predict the isotopic compositions of the major products of the reaction as well as the reactant, notwithstanding the lack of complete mass balance observed between product and reactant. This evidence suggests that isotopic fractionation is taking place during complexation of the chlorinated ethenes to vitamin B12, as has been suggested for reductive dechlorination by zero valent iron. The differences between e for this reaction and those observed for microbial biodegradation of the chlorinated ethenes suggest that there may be differences in the rate determining step for these two processes. Determining which steps are rate determining during degradation may allow optimization of contaminant remediation.

The Physiological Opportunism of Desulfitobacterium hafniense Strain TCE1 towards Organohalide Respiration with Tetrachloroethene

PubMed Central

Duret, Aurélie; Holliger, Christof

2012-01-01

Desulfitobacterium hafniense strain TCE1 is capable of metabolically reducing tetra- and trichloroethenes by organohalide respiration. A previous study revealed that the pce gene cluster responsible for this process is located on an active composite transposon, Tn-Dha1. In the present work, we investigated the effects on the stability of the transposon during successive subcultivations of strain TCE1 in a medium depleted of tetrachloroethene. At the physiological level, an increased fitness of the population was observed after 9 successive transfers and was correlated with a decrease in the level of production of the PceA enzyme. The latter observation was a result of the gradual loss of the pce genes in the population of strain TCE1 and not of a regulation mechanism, as was postulated previously for a similar phenomenon described for Sulfurospirillum multivorans. A detailed molecular analysis of genetic rearrangements occurring around Tn-Dha1 showed two independent but concomitant events, namely, the transposition of the first insertion sequence, ISDha1-a, and homologous recombination across identical copies of ISDha1 flanking the transposon. A new model is proposed for the genetic heterogeneity around Tn-Dha1 in D. hafniense strain TCE1, along with some considerations for the cleavage mechanism mediated by the transposase TnpA1 encoded by ISDha1. PMID:22729540

Does cataract surgery alleviate poverty? Evidence from a multi-centre intervention study conducted in Kenya, the Philippines and Bangladesh.

PubMed

Kuper, Hannah; Polack, Sarah; Mathenge, Wanjiku; Eusebio, Cristina; Wadud, Zakia; Rashid, Mamunur; Foster, Allen

2010-11-09

Poverty and blindness are believed to be intimately linked, but empirical data supporting this purported relationship are sparse. The objective of this study is to assess whether there is a reduction in poverty after cataract surgery among visually impaired cases. A multi-centre intervention study was conducted in three countries (Kenya, Philippines, Bangladesh). Poverty data (household per capita expenditure--PCE, asset ownership and self-rated wealth) were collected from cases aged ≥50 years who were visually impaired due to cataract (visual acuity<6/24 in the better eye) and age-sex matched controls with normal vision. Cases were offered free/subsidised cataract surgery. Approximately one year later participants were re-interviewed about poverty. 466 cases and 436 controls were examined at both baseline and follow-up (Follow up rate: 78% for cases, 81% for controls), of which 263 cases had undergone cataract surgery ("operated cases"). At baseline, operated cases were poorer compared to controls in terms of PCE (Kenya: $22 versus £35 p = 0.02, Bangladesh: $16 vs $24 p = 0.004, Philippines: $24 vs 32 p = 0.0007), assets and self-rated wealth. By follow-up PCE had increased significantly among operated cases in each of the three settings to the level of controls (Kenya: $30 versus £36 p = 0.49, Bangladesh: $23 vs $23 p = 0.20, Philippines: $45 vs $36 p = 0.68). There were smaller increases in self-rated wealth and no changes in assets. Changes in PCE were apparent in different socio-demographic and ocular groups. The largest PCE increases were apparent among the cases that were poorest at baseline. This study showed that cataract surgery can contribute to poverty alleviation, particularly among the most vulnerable members of society. This study highlights the need for increased provision of cataract surgery to poor people and shows that a focus on blindness may help to alleviate poverty and achieve the Millennium Development Goals.

Regulation by carbohydrate and clofibric acid of palmitoyl-CoA chain elongation in the liver of rats.

PubMed

Kudo, Naomi; Toyama, Tomoaki; Mitsumoto, Atsushi; Kawashima, Yoichi

2003-05-01

Regulation of palmitoyl-CoA chain elongation (PCE) and its contribution to oleic acid formation were investigated in rat liver in comparison with stearoyl-CoA desaturase (SCD). Hepatic PCE activity was induced by the administration of 20% wt/vol glucose or fructose in the drinking water of normal rats. In streptozotocin-induced diabetic rats, the activities of both PCE and SCD were suppressed, and fructose, but not glucose, feeding caused an increase in the activities of both enzymes. Treatment of normal rats with clofibric acid in combination with carbohydrate further increased PCE, but not SCD, activity. FA analysis of hepatic lipids revealed that the proportion of oleic acid (18:1 n-9) increased upon administration of carbohydrate or clofibric acid. The treatment of rats with clofibric acid in combination with carbohydrate greatly increased the proportion of 18:1 n-9. A significant correlation was observed between PCE activity and the hepatic proportion of 18:1 n-9 (r2 = 0.874, P < 0.01), whereas the relationship between SCD activity and the proportion of 18:1 n-9 was not significant (r2 = 0.552, P > 0.05). Taken together, these results suggest that carbohydrate induces PCE as well as SCD activity to increase the hepatic 18:1 content in rat liver, and the increased PCE activity seems to be responsible for the further increase in 18:1 n-9 when carbohydrate is administered in combination with clofibric acid.

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion.

PubMed

Wilson, Jordan L; Samaranayake, V A; Limmer, Matt A; Burken, Joel G

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman's correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with minimal equipment at the PCE Southeast Contamination Site was sufficient to delineate vapor intrusion potential in the study area and offered comparable delineation to traditional sub-slab sampling performed at 140 properties over a period of approximately 2 years.

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion

USGS Publications Warehouse

Wilson, Jordan L.; Samaranayake, V.A.; Limmer, Matthew A.; Burken, Joel G.

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman’s correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with minimal equipment at the PCE Southeast Contamination Site was sufficient to delineate vapor intrusion potential in the study area and offered comparable delineation to traditional sub-slab sampling performed at 140 properties over a period of approximately 2 years.

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion

PubMed Central

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman’s correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with minimal equipment at the PCE Southeast Contamination Site was sufficient to delineate vapor intrusion potential in the study area and offered comparable delineation to traditional sub-slab sampling performed at 140 properties over a period of approximately 2 years. PMID:29451904

Why interdisciplinary research enriches the study of crime. Comment on "Statistical physics of crime: A review" by M.R. D'Orsogna and M. Perc

NASA Astrophysics Data System (ADS)

Donnay, Karsten

2015-03-01

The past several years have seen a rapidly growing interest in the use of advanced quantitative methodologies and formalisms adapted from the natural sciences to study a broad range of social phenomena. The research field of computational social science [1,2], for example, uses digital artifacts of human online activity to cast a new light on social dynamics. Similarly, the studies reviewed by D'Orsogna and Perc showcase a diverse set of advanced quantitative techniques to study the dynamics of crime. Methods used range from partial differential equations and self-exciting point processes to agent-based models, evolutionary game theory and network science [3].

Long-term Neurotoxic Effects of Early-life Exposure to Tetrachloroethylene-contaminated Drinking Water.

PubMed

Aschengrau, Ann; Janulewicz, Patricia A; White, Roberta F; Vieira, Veronica M; Gallagher, Lisa G; Getz, Kelly D; Webster, Thomas F; Ozonoff, David M

2016-01-01

Tetrachloroethene (PCE) is a common environmental and occupational contaminant and an acknowledged neurotoxicant. From 1968 through 1983, widespread contamination of public drinking water supplies with PCE occurred in the Cape Cod region of Massachusetts. The source of the contamination was a vinyl liner applied to the inner surface of water distribution pipes. A retrospective cohort study (the Cape Cod Health Study) was undertaken to examine possible health consequences of early-life exposure to PCE-contaminated drinking water. This review describes the study methods and findings regarding the effects of prenatal and childhood exposure on neurologic outcomes during early adulthood, including vision, neuropsychological functioning, brain structure, risky behaviors, and mental illness. The review also describes the strengths and challenges of conducting population-based epidemiologic research in this unique setting. Participants were identified by cross-matching birth certificates and water system data. Information on health outcomes and confounding variables was collected from self-administered surveys (n = 1689), neuropsychological tests (n = 63), vision examinations (n = 63), and magnetic resonance imaging (n = 42). Early-life exposure to PCE was estimated using a leaching and transport model. The data analysis compared the occurrence of each health outcome among individuals with prenatal and early childhood PCE exposure to unexposed individuals while considering the effect of confounding variables. The study found evidence that early-life exposure to PCE-contaminated drinking water has long-term neurotoxic effects. The strongest associations were seen with illicit drug use, bipolar disorder, and post-traumatic stress disorder. Key strengths of the study were availability of historical data on affected water systems, a relatively high exposure prevalence and wide range of exposure levels, and little confounding. Challenges arose mainly from the historical nature of the exposure assessments. The Cape Cod Health Study demonstrates how scientists can take advantage of unique "natural experiments" to learn about the health effects of environmental pollution. This body of work has improved our understanding of the long-term health effects of early-life exposure to this common environmental contaminant and will help risk assessors and policymakers ensure that drinking water supplies in the United States are safe for vulnerable populations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Exploring associations between prenatal solvent exposures and teenage drug and alcohol use: a retrospective cohort study.

PubMed

Gallagher, Lisa G; Webster, Thomas F; Aschengrau, Ann

2017-03-11

Investigating the effects of prenatal and childhood exposures on behavioral health outcomes in adolescence is challenging given the lengthy period between the exposure and outcomes. We conducted a retrospective cohort study in Cape Cod, Massachusetts to evaluate the impact of prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water on the occurrence of risk-taking behaviors as a teenager. An increased occurrence of risk-taking behaviors, particularly illicit drug use, was observed in those highly exposed to PCE. We hypothesized that there may be other sources of prenatal solvent exposure such as maternal consumption of alcoholic beverages during pregnancy which might modify the previously observed associations between PCE and risk-taking behaviors and so we conducted an exploratory analysis using available cohort data. The current report presents the results of these analyses and describes the difficulties in conducting research on long-term behavioral effects of early life exposures. The exploratory analysis compared a referent group of subjects with no early life exposure to PCE or alcohol (n = 242) to subjects with only alcohol exposure (n = 201), subjects with only PCE exposure (n = 361), and subjects with exposure to both PCE and alcohol (n = 302). Surveys completed by the subject's mother included questions on prenatal alcoholic beverage consumption and available confounding variables such as cigarette smoking and marijuana use. Surveys completed by the subjects included questions on risk-taking behaviors such as alcoholic beverage consumption and illicit drug use as a teenager and available confounding variables. PCE exposure was modeled using a leaching and transport algorithm embedded in water distribution system modeling software that estimated the amount of PCE delivered to a subject's residence during gestation and early childhood. Subjects with early life exposure to both PCE and alcohol had an increased risk of using two or more major drugs as a teen (RR = 1.9 (95% CI 1.2, 3.0)) compared to unexposed subjects. Increased risks for only PCE exposure (RR = 1.6 (95% CI 1.0, 2.4) and only alcohol exposure (RR = 1.3 (95% CI 0.7, 2.1)) were also evident but were smaller than the increased risk associated with both exposures. While available confounding variables were controlled, many relevant social risk factors were not obtained due to limitations in the retrospective study design. This exploratory analysis found evidence for an additive effect of early life exposure to PCE and alcohol on the risk of use of multiple illicit drugs as a teenager. Because of numerous limitations in this retrospective study, further research is needed to examine longstanding behavioral effects of early life exposures. To be most informative, this research should involve long-term prospective data collection.

Using mixed solvent and changing spin-coating parameters to increase the efficiency and lifetime of organic solar cells.

PubMed

Tsai, Yu Sheng; Chu, Wei-Ping; Tang, Rong-Ming; Juang, Fuh-Shyang; Chang, Ming-Hua; Liu, Mark O; Hsieh, Tsung-Eong

2008-10-01

The derivative of C60, i.e., PCBM, and P3HT (3-hexylthiophene) were dissolved in chloroform:dichlorobenzene mixed solvent, then spin-coated as the active layer for organic solar cells (OSC). The experimental parameters were studied carefully to obtain the optimum power conversion efficiency (PCE), including the solvent mixing ratio, spin-coating speed, annealing conditions for the active layer, etc. The OSC devices were packaged with glass and a newly developed UV-glue to improve the lifetime and PCE. Dichlorobenzene solvent has great effect upon the PCE. Changing the spin-coating speed and increasing the number of steps increased the PCE apparently to 1.4%.

Transformation of mackinawite to greigite by trichloroethylene and tetrachloroethylene.

PubMed

Lan, Ying; Elwood Madden, Andrew S; Butler, Elizabeth C

2016-10-12

Trichloroethylene (TCE) and tetrachloroethylene (PCE) are common ground water contaminants susceptible to reductive dechlorination by FeS (mackinawite) in anaerobic environments. The objective of this study was to characterize the mineral-associated products that form when mackinawite reacts with TCE and PCE. The dissolved products of the reaction included Cl - and Fe 2+ , and trace amounts of cis 1,2-dichloroethylene (for TCE) and TCE (for PCE). Selected area electron diffraction (SAED) analysis identified greigite as a mackinawite oxidation product formed after reaction between TCE or PCE and FeS over seven weeks. Release of Fe 2+ is consistent with the solid state transformation of mackinawite to greigite, resulting in depletion of the solid with Fe. X-ray photoelectron spectroscopy of the sulfur 2p peak showed a shift to a higher binding energy after FeS reacted with TCE or PCE, also observed in other studies of mackinawite oxidation to greigite. The results may help efforts to maintain the reactivity of FeS generated to remediate chlorinated aliphatic contaminants in ground water.

Transformation rules and degradation of CAHs by Fentonlike oxidation in growth ring of water distribution network-A review

NASA Astrophysics Data System (ADS)

Zhong, D.; Ma, W. C.; Jiang, X. Q.; Yuan, Y. X.; Yuan, Y.; Wang, Z. Q.; Fang, T. T.; Huang, W. Y.

2017-08-01

Chlorinated hydrocarbons are widely used as organic solvent and chemical raw materials. After treatment, water polluted with trichloroethylene (TCE)/tetrachloroethylene (PCE) can reach the water quality requirements, while water with trace amounts of TCE/PCE is still harmful to humans, which will cause cancers. Water distribution network is an extremely complicated system, in which adsorption, desorption, flocculation, movement, transformation and reduction will occur, leading to changes of TCE/PCE concentrations and products. Therefore, it is important to investigate the transformation rules of TCE/PCE in water distribution network. What’s more, growth-ring, including drinking water pipes deposits, can act as catalysts in Fenton-like reagent (H2O2). This review summarizes the status of transformation rules of CAHs in water distribution network. It also evaluates the effectiveness and fruit of CAHs degradation by Fenton-like reagent based on growth-ring. This review is important in solving the potential safety problems caused by TCE/PCE in water distribution network.

Numerical Modeling Analysis of Hydrodynamic and Microbial Controls on DNAPL Pool Dissolution and Detoxification: Dehalorespirers in Co-culture

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

Wesseldyke, Eric S.; Becker, Jennifer G.; Seagren, Eric A.

Dissolution of dense non-aqueous phase liquid (DNAPL) contaminants like tetrachloroethene (PCE) can be “bioenhanced” via biodegradation, which increases the concentration gradient at the DNAPL–water interface. Model simulations were used to evaluate the impact of ecological interactions between different dehalorespiring strains and hydrodynamics on the bioenhancement effect and the extent of PCE dechlorination. Simulations were performed using a two-dimensional coupled flow-transport model, with a DNAPL pool source and two microbial species, Dehalococcoides mccartyi 195 and Desulfuromonas michiganensis, which compete for electron acceptors (e.g., PCE), but not for their electron donors. Under biostimulation, low vx conditions, D. michiganensis alone significantly enhanced dissolutionmore » by rapidly utilizing aqueous-phase PCE. In co-culture under these conditions, D. mccartyi 195 increased this bioenhancement modestly and greatly increased the extent of PCE transformation. Although D. michiganensis was the dominant population under low velocity conditions, D. mccartyi 195 dominated under high velocity conditions due to bioclogging effects.« less

Sub-ppb, Autonomous, Real-time Detection of VOCs with iCRDS

NASA Astrophysics Data System (ADS)

Leen, J.; Gupta, M.; Baer, D. S.

2013-12-01

The continuous, real-time detection of sub-parts-per-billion (ppb) concentrations of volatile organic compounds (VOCs) such as trichloroethylene (TCE) and tetrachloroethylene (PCE) remains difficult, time consuming and expensive. In particular, short term exposure spikes and diurnal variations are difficult or impossible to detect with traditional TO-15 measurements. We present laboratory and field performance data from an instrument based on incoherent cavity ringdown spectroscopy (iCRDS) that operates in the mid-infrared (bands from 860-1060 cm-1 or 970-1280 cm-1) and is capable of detecting a broad range of VOCs, in situ, continuously and autonomously. We have demonstrated the measurement of TCE in zero air with a precision of 0.17 ppb (1σ in 4 minutes). PCE was measured with a precision of 0.15 ppb (1σ in 4 minutes). Both of these measured precisions exceed the EPA's commercial building action limit, which for TCE is 0.92 ppb (5 μg/m3) and for PCE is 0.29 ppb (2 μg/m3). Additionally, the instrument is capable of precisely measuring and quantifying BTEX compounds (benzene, toluene, ethylbenzene, xylene), including differentiation of xylene isomers. We have demonstrated the accurate, interference free measurement of Mountain View, California air doped with TCE concentrations ranging from 4.22 ppb (22.8 μg/m3) to 17.74 ppb (96 μg/m3) with a precision of 1.42 ppb (1σ in 4 minutes). Mountain View, California air doped with 10.83 ppb of PCE (74.0 μg/m3) was measured with a precision of 0.54 ppb (1σ in 4 minutes). Finally, the instrument was deployed to the Superfund site at Moffett Naval Air Station in Mountain View, California where contaminated ground water results in vapor intrusion of TCE and PCE. For two weeks, the instrument operated continuously and autonomously, successfully measuring TCE and PCE concentrations in both the breathing zone and steam tunnel air. TCE concentrations in the breathing zone averaged 0.186 × 0.669 ppb while tunnel air averaged 17.38 × 4.96 ppb, in excellent agreement with previous TO-15 8 hr averages. PCE concentrations in the breathing zone averaged 0.063 × 0.270 ppb while tunnel air averaged 0.755 × 0.359 ppb, again, in excellent agreement with previous TO-15 8 hr averages. The iCRDS instrument has shown the ability to continuously and autonomously measure sub-ppb levels of toxic VOCs in the field, offering an unprecedented picture of the short term dynamics associated with vapor intrusion and ground water pollution.

Predictors of Appropriate Pharmacotherapy Management of COPD Exacerbations and Impact on 6-Month Readmission.

PubMed

Tran, Melody; Xiang, Pin; Rascati, Karen L; Stock, Eileen M; Godley, Paul J; Coleman, Amber; Bogart, Michael R; Stanford, Richard H

2016-10-01

Suboptimal treatment of exacerbations is a major concern in management of chronic obstructive pulmonary disease (COPD). The Pharmacotherapy Management of COPD Exacerbation (PCE) Healthcare Effectiveness Data and Information Set (HEDIS) measure is a quality measure included by the National Committee for Quality Assurance that focuses on appropriate use of steroids and bronchodilators during an acute COPD exacerbation. There is limited evidence evaluating predictors of this quality measure, as well as its association with hospital readmission and cost outcomes. To (a) describe characteristics of patients hospitalized for COPD, (b) evaluate factors associated with appropriate receipt of pharmacotherapy upon discharge, and (c) evaluate factors associated with the rate of readmission. In this retrospective, observational, event-based study of COPD-related hospital and ED visits, events were identified between 2007 and 2013 from a Central Texas health plan using administrative claims data. The index date was defined as the date of admission. Subjects were included if they were aged ≥ 40 years and had a medical claim with a primary diagnosis for COPD or a pharmacy claim for a COPD maintenance medication during the 1-year pre-index period. Study groups were identified based on the receipt of PCE within the time frame specified by HEDIS: (a) a systemic corticosteroid within 14 days of discharge (PCE-C) or (b) a bronchodilator within 30 days of discharge (PCE-D). Bivariate analyses of potential factors associated with the receipt of PCE were performed using t-tests for continuous data and chi-square tests for categorical data. Generalized estimating equations, including significant predictors from the bivariate analyses, were used to determine factors associated with receipt of PCE-C and/or PCE-D, as well association with COPD-related and all-cause readmission within 6 months of discharge. Of 375 identified index admissions, 254 (68%) patients received PCE-C; 299 (80%) received PCE-D; and 229 (61%) received both. Patients were more likely to receive PCE with an index inpatient visit as compared with an ED visit (PCE-C: RR = 2.25, 95% CI = 1.21-4.17, P = 0.010; PCE-D: RR = 1.90, 95% CI = 1.01-3.58, P = 0.048). Those with previous use of rescue medication were also more likely to receive PCE (PCE-C: RR = 1.88, 95% CI = 1.12-3.17, P = 0.018; PCE-D: RR = 2.11, 95% CI = 1.16-3.83, P = 0.014). Patients with greater adherence (proportion of days covered [PDC] ≥ 75%) to COPD maintenance medication before admission (RR = 8.67, 95% CI = 1.60-46.78, P = 0.012) were also more likely to receive PCE-D. Older patients were more likely to have a COPD-related readmission (RR = 1.07, 95% CI = 1.01-1.13, P = 0.028), while use of maintenance medication before admission was associated with lower risk of an all-cause readmission (RR = 0.49, 95% CI = 0.30-0.79, P = 0.004). In addition, patients with higher medical and pharmacy costs before the index event were more likely to have all-cause readmission (RR = 1.01, 95% CI = 1.00-1.02, P = 0.013). Receipt of PCE was not shown to be a significant predictor of all-cause or COPD-related readmission. The use of bronchodilators and systemic corticosteroids after a COPD-related inpatient or ED visit may be related to the severity of the index COPD exacerbation or patients' previous pattern of bronchodilator use. However, the use of maintenance medication before the index event was associated with a significant reduction in all-cause readmission, so proper treatment of the underlying disease may be an effective strategy in reducing readmission. Funding for this study was provided by GlaxoSmithKline (HO-14-15081). Tran was a Fellow at Scott & White Health Plan (SWHP) during year 1 of this study and a Fellow at Novartis during year 2 of this study. Novartis did not have any input in this study nor did it contribute any funding or support for this research. Tran, Xiang, Godley, and Stock were employed by SWHP at the time of this study. Rascati is employed by the University of Texas at Austin and also by the Journal of Managed Care & Specialty Pharmacy and has received consulting fees from GlaxoSmithKline. Coleman, Bogart, and Stanford are GlaxoSmithKline employees and shareholders. Study design was created by Rascati, Tran, and Godley, with assistance from Stock, Coleman, Bogart, and Stanford. Tran and Xiang collected the data, with data analysis and interpretation performed by Stock and Rascati. The manuscript was written by Tran, Rascati, and Xiang and revised by Godley, Stock, Coleman, Bogart, and Stanford.

Low-Volume Pulsed Hydrogen Biosparging

DTIC Science & Technology

2003-10-07

Groundwater Services, Inc. Houston, TX deioinzed water with 2 mM of ferric iron and 0.01 mM of vinyl...6.5.3 Results a. VOC Effluent Data To simulate a PCE dissolved groundwater plume, PCE was metered into the influent water to achieve a mean PCE...SERDP Arlington, VA October 7, 2003 Groundwater Services, Inc. 2211 Norfolk, Suite 1000, Houston, Texas 77098-4044 G-2535 2003 FINAL REPORT Low

Partition behavior of surfactants, butanol, and salt during application of density-modified displacement of dense non-aqueous phase liquids.

PubMed

Damrongsiri, S; Tongcumpou, C; Sabatini, D A

2013-03-15

Density-modified displacement (DMD) is a recent approach for removal of trapped dense NAPL (DNAPL). In this study, butanol and surfactant are contacted with the DNAPL to both reduce the density as well as release the trapped DNAPL (perchloroethylene: PCE). The objective of the study was to determine the distribution of each component (e.g., butanol, surfactant, water, PCE) between the original aqueous and PCE phases during the application of DMD. The results indicated that the presence of the surfactant increased the amount of n-butanol required to make the NAPL phase reach its desired density. In addition, water and anionic surfactant were found to partition along with the BuOH into the PCE phase. The water also found partitioned to reverse micelles in the modified phase. Addition of salt was seen to increase partitioning of surfactant to BuOH containing PCE phase. Subsequently, a large amount of water was solubilized into reverse micelles which lead to significantly increase in volume of the PCE phase. This work thus demonstrates the role of each component and the implications for the operation design of an aquifer treatment using the DMD technique. Copyright © 2013 Elsevier B.V. All rights reserved.

Identification of TCE and PCE sorption and biodegradation parameters in a sandy aquifer for fate and transport modelling: batch and column studies.

PubMed

Kret, E; Kiecak, A; Malina, G; Nijenhuis, I; Postawa, A

2015-07-01

The main aim of this study was to determine the sorption and biodegradation parameters of trichloroethene (TCE) and tetrachloroethene (PCE) as input data required for their fate and transport modelling in a Quaternary sandy aquifer. Sorption was determined based on batch and column experiments, while biodegradation was investigated using the compound-specific isotope analysis (CSIA). The aquifer materials medium (soil 1) to fine (soil 2) sands and groundwater samples came from the representative profile of the contaminated site (south-east Poland). The sorption isotherms were approximately linear (TCE, soil 1, K d = 0.0016; PCE, soil 1, K d = 0.0051; PCE, soil 2, K d = 0.0069) except for one case in which the best fitting was for the Langmuir isotherm (TCE, soil 2, K f = 0.6493 and S max = 0.0145). The results indicate low retardation coefficients (R) of TCE and PCE; however, somewhat lower values were obtained in batch compared to column experiments. In the column experiments with the presence of both contaminants, TCE influenced sorption of PCE, so that the R values for both compounds were almost two times higher. Non-significant differences in isotope compositions of TCE and PCE measured in the observation points (δ(13)C values within the range of -23.6 ÷ -24.3‰ and -26.3 ÷-27.7‰, respectively) indicate that biodegradation apparently is not an important process contributing to the natural attenuation of these contaminants in the studied sandy aquifer.

Simultaneous anaerobic transformation of tetrachloroethene and carbon tetrachloride in a continuous flow column

NASA Astrophysics Data System (ADS)

Azizian, Mohammad F.; Semprini, Lewis

2016-07-01

Tetrachloroethene (PCE) and carbon tetrachloride (CT) were simultaneously transformed in a packed column that was bioaugmented with the Evanite culture (EV). The data presented here have been obtained over a period of 1930 days. Initially the column was continuously fed synthetic groundwater with PCE (0.1 mM), sulfate (SO42 -) (0.2 mM) and formate (2.1 mM) or lactate (1.1 mM), but not CT. In these early stages of the study the effluent H2 concentrations ranged from 7 to 19 nM, and PCE was transformed to ethene (ETH) (81 to 85%) and vinyl chloride (VC) (11 to 17%), and SO42 - was completely reduced when using either lactate or formate as electron donors. SO42 - reduction occurred concurrently with cis-DCE and VC dehalogenation. Formate was a more effective substrate for promoting dehalogenation based on electron donor utilization efficiency. Simultaneous PCE and CT tests found CT (0.015 mM) was completely transformed with 20% observed as chloroform (CF) and trace amounts of chloromethane (CM) and dichloromethane (DCM), but no methane (CH4) or carbon disulfide (CS2). PCE transformation to ETH improved with CT addition in response to increases in H2 concentrations to 160 nM that resulted from acetate formation being inhibited by either CT or CF. Lactate fermentation was negatively impacted after CT transformation tests, with propionate accumulating, and H2 concentrations being reduced to below 1 nM. Under these conditions both SO42 - reduction and dehalogenation were negatively impacted, with sulfate reduction not occurring and PCE being transformed to cis-dichloroethene (c-DCE) (52%) and VC (41%). Upon switching to formate, H2 concentrations increased to 40 nM, and complete SO42 - reduction was achieved, while PCE was transformed to ETH (98%) and VC (1%), with no acetate detected. Throughout the study PCE dehalogenation to ethene was positively correlated with the effluent H2 concentrations.

Rescue of the mouse DDK syndrome by parent-of-origin-dependent modifiers.

PubMed

Ideraabdullah, Folami Y; Kim, Kuikwon; Pomp, Daniel; Moran, Jennifer L; Beier, David; de Villena, Fernando Pardo-Manuel

2007-02-01

When females of the DDK inbred mouse strain are mated to males of other strains, 90-100% of the resulting embryos die during early embryonic development. This DDK syndrome lethality results from incompatibility between an ooplasmic DDK factor and a non-DDK paternal gene, which map to closely linked loci on chromosome 11. It has been proposed that the expression of the gene that encodes the ooplasmic factor is subject to allelic exclusion in oocytes. Previous studies have demonstrated the existence of recessive modifiers that increase lethality in the C57BL/6 and BALB/c strains. These modifiers are thought to skew the choice of allele undergoing allelic exclusion in the oocytes of heterozygous females. In the present study, we demonstrate the presence of modifiers in three Mus musculus domesticus wild-derived strains, PERA, PERC, and RBA. These modifiers completely rescued DDK syndrome lethality. We mapped the major locus that is responsible for rescue in PERA and PERC crosses to proximal chromosome 13 and named this locus Rmod1 (Rescue Modifier of the DDK Syndrome 1). Our experiments demonstrate that PERA or PERC alleles at Rmod1 rescue lethality independently of allelic exclusion. In addition, rescue of the lethal phenotype depends on the parental origin of the Rmod1 alleles; transmission through the dam leads to rescue, while transmission through the sire has no effect.

Superfund Record of Decision (EPA Region 2): Garden State Cleaners, Buena Borough, Atlantic County, NJ. (First remedial action), September 1991. Final report

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

Not Available

1991-09-26

The 3,000-square-foot Garden State Cleaners (GSC) site is an active dry cleaning operation in Minotola, Bueno Borough, Atlantic County, New Jersey. Land use in the area is residential and commercial, and local residents obtain drinking water from the Borough municipal water supply system. From 1966 to the present, dry cleaning activities using PCE were conducted at the GSC site, and until 1985, wastes were discharged through pipes directly into the ground. In 1984, State investigations showed elevated levels of PCE in ground water adjacent to and downgradient from the GSC and SJCC facilities, and elevated levels of PCE and TCEmore » in onsite soil. The selected remedial action for the site includes treating onsite approximately 1,600 cubic yards of contaminated soil using in-situ vapor extraction; treating the contaminated wastewater from the vapor extraction processes onsite using an air stripping column; treating air emissions using carbon adsorption units; pumping and onsite treatment of contaminated ground water using air stripping and carbon adsorption; reinjecting the treated ground water upgradient from the site; regenerating spent activated carbon from both treatment processes offsite; conducting long-term ground water monitoring; and implementing temporary institutional controls. The estimated present worth cost for the remedial action at the GSC site is $5,451,000, which includes an estimated annual O and M cost of $249,500 for 70 years.« less

Dry Cleaning Sector (NAICS 8123)

EPA Pesticide Factsheets

The dry cleaning sector includes establishments engaged in providing laundry services and industrial launderers. Find environmental regulatory information for perchloroethylene (PERC) cleaners as well as hazardous waste regulations for dry cleaners.

Protect and Restore Lolo Creek Watershed : Annual Report CY 2005.

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

McRoberts, Heidi

2006-03-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Lolo Creek watershed are coordinated with the Clearwater National Forest and Potlatch Corporation. The Nez Perce Tribe began watershed restoration projects within the Lolo Creek watershed of the Clearwater River in 1996. Fencing to exclude cattle for stream banks, stream bank stabilization, decommissioning roads, and upgrading culverts are the primary focuses of this effort. The successful completion of the replacement and removal of several passage blocking culverts represent a major improvement to the watershed. Thesemore » projects, coupled with other recently completed projects and those anticipated in the future, are a significant step in improving habitat conditions in Lolo Creek.« less

Benchmark of FDNS CFD Code For Direct Connect RBCC Test Data

NASA Technical Reports Server (NTRS)

Ruf, J. H.

2000-01-01

Computational Fluid Dynamics (CFD) analysis results are compared with experimental data from the Pennsylvania State University's (PSU) Propulsion Engineering Research Center (PERC) rocket based combined cycle (RBCC) rocket-ejector experiments. The PERC RBCC experimental hardware was in a direct-connect configuration in diffusion and afterburning (DAB) operation. The objective of the present work was to validate the Finite Difference Navier Stokes (FDNS) CFD code for the rocket-ejector mode internal fluid mechanics and combustion phenomena. A second objective was determine the best application procedures to use FDNS as a predictive/engineering tool. Three-dimensional CFD analysis was performed. Solution methodology and grid requirements are discussed. CFD results are compared to experimental data for static pressure, Raman Spectroscopy species distribution data and RBCC net thrust and specified impulse.

NASA Propulsion Engineering Research Center, volume 2

NASA Technical Reports Server (NTRS)

1993-01-01

On 8-9 Sep. 1993, the Propulsion Engineering Research Center (PERC) at The Pennsylvania State University held its Fifth Annual Symposium. PERC was initiated in 1988 by a grant from the NASA Office of Aeronautics and Space Technology as a part of the University Space Engineering Research Center (USERC) program; the purpose of the USERC program is to replenish and enhance the capabilities of our Nation's engineering community to meet its future space technology needs. The Centers are designed to advance the state-of-the-art in key space-related engineering disciplines and to promote and support engineering education for the next generation of engineers for the national space program and related commercial space endeavors. Research on the following areas was initiated: liquid, solid, and hybrid chemical propulsion, nuclear propulsion, electrical propulsion, and advanced propulsion concepts.

Evaluation of a new amplified enzyme immunoassay (EIA) for the detection of Chlamydia trachomatis in male urine, female endocervical swab, and patient obtained vaginal swab specimens

PubMed Central

Tanaka, M.; Nakayama, H.; Sagiyama, K.; Haraoka, M.; Yoshida, H.; Hagiwara, T.; Akazawa, K.; Naito, S.

2000-01-01

Aims—To compare the performance of a new generation dual amplified enzyme immunoassay (EIA) with a molecular method for the diagnosis of Chlamydia trachomatis, using a range of urogenital samples, and to assess the reliability of testing self collected vaginal specimens compared with clinician collected vaginal specimens. Methods—Two population groups were tested. For the first population group, first void urine samples were collected from 193 male patients with urethritis, and endocervical swabs were collected from 187 high risk commercial sex workers. All urine and endocervical specimens were tested by a conventional assay (IDEIA chlamydia), a new generation amplified immunoassay (IDEIA PCE chlamydia), and the Amplicor polymerase chain reaction (PCR). Discrepant results obtained among the three sample types were confirmed using a nested PCR test with a different plasmid target region. For the second population group, four swab specimens, including one patient obtained vaginal swab, two clinician obtained endocervical swabs, and one clinician obtained vaginal swab, were collected from 91 high risk sex workers. Self collected and clinician collected vaginal swabs were tested by IDEIA PCE chlamydia. Clinician obtained endocervical swabs were assayed by IDEIA PCE chlamydia and Amplicor PCR. Results—The performance of the IDEIA PCE chlamydia test was comparable to that of the Amplicor PCR test when male urine and female endocervical swab specimens were analysed. The relative sensitivities of IDEIA, IDEIA PCE, and Amplicor PCR on male first void urine specimens were 79.3%, 91.4%, and 100%, respectively. The relative sensitivities of the three tests on female endocervical specimens were 85.0%, 95.0%, and 100%, respectively. The positivity rates for patient collected vaginal specimens and clinician collected vaginal specimens by IDEIA PCE were 25.2% and 23.1%, respectively, whereas those for clinician collected endocervical swabs by PCR and IDEIA PCE were both 27.5%. Conclusions—IDEIA PCE chlamydia is a lower cost but sensitive alternative test to PCR for testing male urine samples and female endocervical swabs. In addition, self collected or clinician collected vaginal specimens tested by IDEIA PCE chlamydia are a reliable alternative to analysing endocervical specimens. Key Words: Chlamydia trachomatis • enzyme immunoassay • clinical specimens PMID:10889816

Detecting event-related changes of multivariate phase coupling in dynamic brain networks.

PubMed

Canolty, Ryan T; Cadieu, Charles F; Koepsell, Kilian; Ganguly, Karunesh; Knight, Robert T; Carmena, Jose M

2012-04-01

Oscillatory phase coupling within large-scale brain networks is a topic of increasing interest within systems, cognitive, and theoretical neuroscience. Evidence shows that brain rhythms play a role in controlling neuronal excitability and response modulation (Haider B, McCormick D. Neuron 62: 171-189, 2009) and regulate the efficacy of communication between cortical regions (Fries P. Trends Cogn Sci 9: 474-480, 2005) and distinct spatiotemporal scales (Canolty RT, Knight RT. Trends Cogn Sci 14: 506-515, 2010). In this view, anatomically connected brain areas form the scaffolding upon which neuronal oscillations rapidly create and dissolve transient functional networks (Lakatos P, Karmos G, Mehta A, Ulbert I, Schroeder C. Science 320: 110-113, 2008). Importantly, testing these hypotheses requires methods designed to accurately reflect dynamic changes in multivariate phase coupling within brain networks. Unfortunately, phase coupling between neurophysiological signals is commonly investigated using suboptimal techniques. Here we describe how a recently developed probabilistic model, phase coupling estimation (PCE; Cadieu C, Koepsell K Neural Comput 44: 3107-3126, 2010), can be used to investigate changes in multivariate phase coupling, and we detail the advantages of this model over the commonly employed phase-locking value (PLV; Lachaux JP, Rodriguez E, Martinerie J, Varela F. Human Brain Map 8: 194-208, 1999). We show that the N-dimensional PCE is a natural generalization of the inherently bivariate PLV. Using simulations, we show that PCE accurately captures both direct and indirect (network mediated) coupling between network elements in situations where PLV produces erroneous results. We present empirical results on recordings from humans and nonhuman primates and show that the PCE-estimated coupling values are different from those using the bivariate PLV. Critically on these empirical recordings, PCE output tends to be sparser than the PLVs, indicating fewer significant interactions and perhaps a more parsimonious description of the data. Finally, the physical interpretation of PCE parameters is straightforward: the PCE parameters correspond to interaction terms in a network of coupled oscillators. Forward modeling of a network of coupled oscillators with parameters estimated by PCE generates synthetic data with statistical characteristics identical to empirical signals. Given these advantages over the PLV, PCE is a useful tool for investigating multivariate phase coupling in distributed brain networks.

Assessment of an aqueous seed extract of Parkia clappertoniana on reproductive performance and toxicity in rodents.

PubMed

Boye, Alex; Boampong, Victor Addai; Takyi, Nutifafa; Martey, Orleans

2016-06-05

The seeds of Parkia clappertoniana Keay (Family: Fabaceae) are extensively used in food in the form of a local condiment called 'Dawadawa' in Ghana and consumed by all class of people including sensitive groups such as pregnant women and children. Also, crudely pounded preparations of P. clappertoniana seeds are used as labor inducing agent in farm animals by local farmers across northern Ghana where nomadism is the livelihood of most indigenes. Ecologically, P. clappertoniana is extensively distributed across the savannah ecological zone of many African countries where just like Ghana it enjoys ethnobotanical usage. Although, many studies have investigated some aspects of the pharmacological activity of P. clappertoniana, none of these studies focused on the reproductive system, particularly its effects on reproductive performance and toxicity. To contribute, this study assessed the effect of aqueous seed extract of P. clappertoniana (PCE) on reproductive performance and toxicity in Sprague-Dawley rats and ICR mice. After preparation of PCE, it was then tested on rodents at different gestational and developmental windows (1-7, 8-14, and 15-term gestational days) to assess the following: mating behavior, implantation rate, maternal and developmental toxicities. Generally, animals were randomly grouped into five and treated as follows: normal saline group (5ml/kg po), cytotec (misoprostol) group (200mg/kg po), folic acid group (5mg/kg po), and PCE groups (100, 200, and 500mg/kg po), however, these groupings were varied to suit the specific requirements of some parameters. For acute toxicity, animals were orally administered PCE (3 and 5g/kg for mice and rats respectively). PCE-treated rats showed improved mating behavior compared to control rats. PCE improved implantation rate compared to misoprostol-treated rats. On the average, PCE-treated rats delivered termed live pubs at 21 days compared to that of folic acid-treated rats at 23 days. Also, PCE-treated rats showed no observable maternal and developmental toxicities compared to folic acid and control rats. PCE (3-5g/kg po) was orally tolerated in rodents. Oral administration of Parkia clappertoniana seed extract improves reproductive performance in rodents with no observable maternal and developmental toxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Characteristics and influencing factors of tetrachloroethylene sorption-desorption on soil and its components.

PubMed

Qiu, Zhaofu; Yang, Weiwei; He, Long; Zhao, Zhexuan; Lu, Shuguang; Sui, Qian

2016-02-01

To investigate the effects of soil structure, soil organic carbon (SOC), minerals, initial tetrachloroethylene (PCE) concentration (C0), and ionic strength (Ci) on PCE sorption-desorption, six types of soil were adopted as adsorbents, including two types of natural soil and four types of soil with most of the "soft carbon" pre-treated by H2O2 or with all SOC removed from the original soil by 600 °C ignition. The results showed that all of the sorption-desorption isotherms of PCE were non-linear within the experimental range, and the H2O2-treated samples exhibited higher non-linear sorption isotherms than those of the original soils. The hysteresis index of PCE sorption to original soil is less pronounced than that of the H2O2-treated and 600 °C-heated samples due to the entrapment of sorbate molecules in the "hard carbon" domain, together with the meso- and microporous structures within the 600 °C-heated samples. Both SOC and minerals have impacts on the sorption-desorption of PCE, and the sorption-desorption contribution rate of minerals increased with decreasing SOC content. C0 has almost no influence on the sorption to minerals of the soils, but the contribution rate of minerals decreased with increasing C0 in the desorption stage. As a result of the salting-out effect, PCE sorption capacity was increased by increasing Ci, especially when Ci ≥ 0.1 M. Moreover, desorption increased and hysteresis weakened with increasing Ci, except for the 600 °C-heated samples. In addition, no significant effect of Ci on desorption of PCE and no hysteresis was observed in this experimental range for the 600 °C-heated samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tetrachloroethene degradation by reducing-agent enhanced Fe(II)/Fe(III) catalyzed percarbonate

NASA Astrophysics Data System (ADS)

Miao, Z.; Brusseau, M. L.; Lu, S.; Gu, X.; Yan, N.; Qiu, Z.; Sui, Q.

2015-12-01

This project investigated the effect of reducing agents on the degradation of tetrachloroethene(PCE) by Fe(II)/Fe(III) catalyzed sodium percarbonate (SPC). SPC possesses similar function as liquid H2O2, such that free H2O2 is released into solution when percarbonate is mixed with water. The addition of reducing agents, including hydroxylamine hydrochloride, sodium sulfite, ascorbic acid and sodium ascorbate, accelerated the Fe(III)/Fe(II) redoxcycle, leading to a relatively steady Fe(II) concentration and higher production of free radicals. This, in turn, resulted in enhanced PCE oxidation by SPC, with almost complete PCE removal obtained for appropriate Fe and SPC concentrations.The results of chemical probe tests, using nitrobenzene and carbon tetrachloride, demonstrated that HO● was the predominant radical in the system and that O2●-played a minor role. This was further confirmed by the results of electron paramagnetic resonance measurements and salicylic acid hydroxylationanalysis by high performance liquid chromatography(HPLC). PCE degradation decreased significantly with the addition of isopropanol, a strong HO● scavenger, supporting the hypothesis that HO● was primarily responsible for PCE degradation. It should be noted that the release of Cl- was slightly delayed in the first 20 mins, indicating that intermediate products were produced. However, gas chromatography mass spectrometry (GC/MS) analysis did not detect any chlorinated organic compound except PCE, indicating these intermediates were quickly degraded, which resulted in the complete conversion of PCE to CO2. In conclusion, the use of reducing agents to enhance Fe(II)/Fe(III) catalyzed SPC oxidation appears to be a promising approach for the rapid degradation of organic contaminants in groundwater.

Impacts of Residual Surfactant on Tetrachloroethene (PCE) Degradation Following Pilot-Scale SEAR Treatment at a Chloroethene-Impacted Site

NASA Astrophysics Data System (ADS)

Ramsburg, C. A.; Abriola, L. M.; Pennell, K. D.; Löffler, F. E.; Gamache, M.; Petrovskis, E. A.

2003-04-01

A pilot-scale surfactant-enhanced aquifer remediation (SEAR) demonstration was completed during the summer of 2000 at the Bachman Road site (Oscoda, MI USA). For this test, an aqueous solution of 60 g/L Tween 80 (polyoxyethylene (20) sorbitan monooleate) was used to recover tetrachloroethene (PCE) from a suspected source zone, located underneath a former dry-cleaning facility. Tween 80 was selected for use based upon its demonstrated capacity to solubilize PCE, “food-grade” status, and biodegradative potential. Hydraulic control was maintained throughout the test, with 95% of the injected surfactant mass recovered by a single extraction well. Source-zone monitoring conducted 15 months after SEAR treatment revealed the presence of previously undetected volatile fatty acids (acetate and formate) and PCE degradation products (trichloroethene, cis-1,2-dichloroethene, trans-1,2-dichlorethene, and vinyl chloride), in conjunction with PCE concentration reductions of approximately two orders-of-magnitude. The detection of volatile fatty acids is relevant, as they are likely fermentation products of residual Tween 80. Microbial reductive dechlorination is limited by available electron donors, and microcosm studies demonstrated that both acetate and formate support reductively dechlorinating populations present at the oligotrophic Bachman Road site aquifer. Surfactant transport simulations, using a regional flow model developed for the site, were employed to determine appropriate down-gradient monitoring locations. Drive point samples taken 15 months post-treatment in the vicinity of the simulated residual surfactant plume, contained elevated concentrations of acetate and PCE daughter products. Ongoing efforts include continued site-monitoring, and microcosm studies to corroborate a causal relationship between Tween 80 fermentation and PCE dechlorination.

Organohalide Respiration with Chlorinated Ethenes under Low pH Conditions

DOE PAGES

Yang, Yi; Cápiro, Natalie L.; Marcet, Tyler F.; ...

2017-06-30

Bioremediation at chlorinated solvent sites often leads to groundwater acidification due to electron donor fermentation and enhanced dechlorination activity. The microbial reductive dechlorination process is robust at circumneutral pH, but activity declines at groundwater pH values below 6.0. Consistent with this observation, the activity of tetrachloroethene (PCE) dechlorinating cultures declined at pH 6.0 and was not sustained in pH 5.5 medium, with one notable exception. Sulf urospirillum multivorans dechlorinated PCE to cis-1,2-dichloroethene (cDCE) in pH 5.5 medium and maintained this activity upon repeated transfers. Microcosms established with soil and aquifer materials from five distinct locations dechlorinated PCE-to-ethene at pH 5.5more » and pH 7.2. Dechlorination to ethene was maintained following repeated transfers at pH 7.2, but no ethene was produced at pH 5.5, and only the transfer cultures derived from the Axton Cross Superfund (ACS) microcosms sustained PCE dechlorination to cDCE as a final product. 16S rRNA gene amplicon sequencing of pH 7.2 and pH 5.5 ACS enrichments revealed distinct microbial communities, with the dominant dechlorinator being Dehalococcoides in pH 7.2 and Sulf urospirillum in pH 5.5 cultures. PCE-to-trichloroethene- (TCE-) and PCE-to-cDCEdechlorinating isolates obtained from the ACS pH 5.5 enrichment shared 98.6%, and 98.5% 16S rRNA gene sequence similarities to Sulf urospirillum multivorans. Lastly, these findings imply that sustained Dehalococcoides activity cannot be expected in low pH (i.e., ≤ 5.5) groundwater, and organohalide-respiring Sulf urospirillum spp. are key contributors to in situ PCE reductive dechlorination under low pH conditions.« less

Organohalide Respiration with Chlorinated Ethenes under Low pH Conditions

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

Yang, Yi; Cápiro, Natalie L.; Marcet, Tyler F.

Bioremediation at chlorinated solvent sites often leads to groundwater acidification due to electron donor fermentation and enhanced dechlorination activity. The microbial reductive dechlorination process is robust at circumneutral pH, but activity declines at groundwater pH values below 6.0. Consistent with this observation, the activity of tetrachloroethene (PCE) dechlorinating cultures declined at pH 6.0 and was not sustained in pH 5.5 medium, with one notable exception. Sulf urospirillum multivorans dechlorinated PCE to cis-1,2-dichloroethene (cDCE) in pH 5.5 medium and maintained this activity upon repeated transfers. Microcosms established with soil and aquifer materials from five distinct locations dechlorinated PCE-to-ethene at pH 5.5more » and pH 7.2. Dechlorination to ethene was maintained following repeated transfers at pH 7.2, but no ethene was produced at pH 5.5, and only the transfer cultures derived from the Axton Cross Superfund (ACS) microcosms sustained PCE dechlorination to cDCE as a final product. 16S rRNA gene amplicon sequencing of pH 7.2 and pH 5.5 ACS enrichments revealed distinct microbial communities, with the dominant dechlorinator being Dehalococcoides in pH 7.2 and Sulf urospirillum in pH 5.5 cultures. PCE-to-trichloroethene- (TCE-) and PCE-to-cDCEdechlorinating isolates obtained from the ACS pH 5.5 enrichment shared 98.6%, and 98.5% 16S rRNA gene sequence similarities to Sulf urospirillum multivorans. Lastly, these findings imply that sustained Dehalococcoides activity cannot be expected in low pH (i.e., ≤ 5.5) groundwater, and organohalide-respiring Sulf urospirillum spp. are key contributors to in situ PCE reductive dechlorination under low pH conditions.« less

Coexistence of two distinct Sulfurospirillum populations respiring tetrachloroethene-genomic and kinetic considerations.

PubMed

Buttet, Géraldine Florence; Murray, Alexandra Marie; Goris, Tobias; Burion, Mélissa; Jin, Biao; Rolle, Massimo; Holliger, Christof; Maillard, Julien

2018-05-01

Two anaerobic bacterial consortia, each harboring a distinct Sulfurospirillum population, were derived from a 10 year old consortium, SL2, previously characterized for the stepwise dechlorination of tetrachloroethene (PCE) to cis-dichloroethene (cis-DCE) via accumulation of trichloroethene (TCE). Population SL2-1 dechlorinated PCE to TCE exclusively, while SL2-2 produced cis-DCE from PCE without substantial TCE accumulation. The reasons explaining the long-term coexistence of the populations were investigated. Genome sequencing revealed a novel Sulfurospirillum species, designated 'Candidatus Sulfurospirillum diekertiae', whose genome differed significantly from other Sulfurospirillum spp. (78%-83% ANI). Genome-wise, SL2-1 and SL2-2 populations are almost identical, but differences in their tetrachloroethene reductive dehalogenase sequences explain the distinct dechlorination patterns. An extended series of batch cultures were performed at PCE concentrations of 2-200 μM. A model was developed to determine their dechlorination kinetic parameters. The affinity constant and maximal growth rate differ between the populations: the affinity is 6- to 8-fold higher and the growth rate 5-fold lower for SL2-1 than SL2-2. Mixed cultivation of the enriched populations at 6 and 30 μM PCE showed that a low PCE concentration could be the driving force for both functional diversity of reductive dehalogenases and niche specialization of organohalide-respiring bacteria with overlapping substrate ranges.

Language outcomes at 12 years for children exposed prenatally to cocaine.

PubMed

Lewis, Barbara A; Minnes, Sonia; Short, Elizabeth J; Min, Meeyoung O; Wu, Miaoping; Lang, Adelaide; Weishampel, Paul; Singer, Lynn T

2013-10-01

In this study, the authors aimed to examine the long-term effects of prenatal cocaine exposure (PCE) on the language development of 12-year-old children using a prospective design, controlling for confounding prenatal drug exposure and environmental factors. Children who were exposed to cocaine in utero (PCE; n = 183) and children who were not exposed to cocaine (i.e., no cocaine exposure [NCE]; n = 181) were followed prospectively from birth to 12 years of age and were compared on language subtests of the Test of Language Development-Intermediate, Third Edition ( Hammill & Newcomer, 1997b), and phonological processing as measured by the Comprehensive Test of Phonological Processing ( Wagner & Torgesen, 1999). The authors evaluated the relationship of PCE to language development through a multivariate analysis of covariance and regression analyses while controlling for confounders. Results show that PCE has small effects on specific aspects of language, including syntax and phonological processing. The caregiver variables of lower maternal vocabulary, more psychological symptoms, and a poorer home environment also had consistent effects on language and phonological processing scores. These findings suggest that PCE continues to have small, subtle effects on specific aspects of language at age 12 years. Phonological processing skills were significantly related to the reading outcomes of letter-word identification, reading fluency, and reading comprehension, indicating that PCE also has small but lasting effects on the language skills that are related to later literacy skills.

A study on radiation technological degradation of organic chloride wastewater--exemplified by TCE and PCE.

PubMed

Huang, Sheng-Kai; Hsieh, Ling-Ling; Chen, Chia-Chieh; Lee, Po-Hsiu; Hsieh, Bor-Tsung

2009-01-01

This paper describes the potential of using gamma radiation technology to degrade trichloroethylene (TCE) and perchloroethylene (PCE) wastewater. The experimental method is divided into two parts: (1) using the gamma-ray to irradiate the TCE and PCE solution, the dose-rate is 10Gy/minute, the irradiation dosage is 0-2.5kGy and (2) self-making the UV irradiation system, the tube specification is 254nm and 6W, and turning on 8 tubes at the same time to make the irradiation. The efficiency of degradation ratio for gamma-ray is better than UV in the range of 0.1-250ppm; for example, as for the concentration of 0.1ppm, when TCE is degraded to D(90) and T(90), the gamma-ray only needed 46.7Gy and took about 4.67 minutes, but UV needed to take about 28.1 minutes. The dose-concentration equations of TCE and PCE are: TCE: y=44.58+8.832x, R(2)=0.999; and PCE: y=81.33+12.81x, R(2)=0.997. We verified that the radiation technology is able to effectively degrade the organic chlorine wastewater without yielding the secondary pollution, and the TCE and PCE that degraded by using gamma-ray will be reached US-EPA and Taiwan Effluent Standard (5ppb).

Enhancement effects of chelating agents on the degradation of tetrachloroethene in Fe(III) catalyzed percarbonate system

PubMed Central

Miao, Zhouwei; Gu, Xiaogang; Lu, Shuguang; Brusseau, Mark L.; Zhang, Xiang; Fu, Xiaori; Danish, Muhammad; Qiu, Zhaofu; Sui, Qian

2015-01-01

The performance of Fe(III)-based catalyzed sodium percarbonate (SPC) for stimulating the oxidation of tetrachloroethene (PCE) for groundwater remediation applications was investigated. The chelating agents citric acid monohydrate (CIT), oxalic acid (OA), and Glutamic acid (Glu) significantly enhanced the degradation of PCE. Conversely, ethylenediaminetetraacetic acid (EDTA) had a negative impact on PCE degradation, which may due to its strong Fe chelation and HO• scavenging abilities. However, excessive SPC or chelating agent will retard PCE degradation. In addition, investigations using free radical probe compounds and radical scavengers revealed that PCE was primarily degraded by HO• radical oxidation in both the chelated and non-chelated systems, while O2•− also participated in the non-chelated system and the OA and Glu modified systems. According to the electron paramagnetic resonance (EPR) studies, the presence of HO• in the Fe(III)/SPC system was maintained much longer than that in the Fe(II)/SPC system. The results indicated that the addition of CIT, OA or Glu indeed enhanced the generation of HO• in the first 10 min and promoted degradation efficiency by increasing the amount of Fe(III) and maintaining the concentration of HO• radicals in solution. In conclusion, chelated Fe(III)-based catalyzed SPC oxidation is a promising method for the remediation of PCE-contaminated groundwater. PMID:26549979

Solvent-Assisted Preparation of High-Performance Mesoporous CH₃NH₃Pbl₃ Perovskite Solar Cells.

PubMed

Li, Zhi-Hua; Liu, Jie; Ma, Jing-Yuan; Jiang, Yan; Ge, Qian-Qing; Ding, Jie; Hu, Jin-Song; Wan, Li-Jun

2016-01-01

Organometal trihalide perovskite based solar cells have attracted great attention worldwide since their power conversion efficiency (PCE) have risen to over 15% within only 3 years of development. Comparing with other types of perovskite solar cells, mesostructured perovskite solar cells based on CH₃NH₃Pbl₃ as light harvesting material have already demonstrated remarkable advance in performance and reproducibility. Here, we reported a mesoscopic TiO₂/CH₃NH₃Pbl₃ heterojunction solar cell with uniform perovskite thin film prepared via solvent-assisted solution processing method. The best performing device delivered photocurrent density of 20.11 mA cm⁻², open-circuit voltage of 1.02 V, and fill factor of 0.70, leading to a PCE of 14.41%. A small anomalous hysteresis in the J-V curves was observed, where the PCE at forward scan was measured to be 84% of the PCE at reverse scan. Based on a statistical analysis, the perovskite solar cells prepared by the reported method exhibited reproducible and high PCE, indicating its promising application in the fabrication of low-cost and high-efficiency perovskite solar cells.

Air purification from TCE and PCE contamination in a hybrid bioreactors and biofilter integrated system.

PubMed

Tabernacka, Agnieszka; Zborowska, Ewa; Lebkowska, Maria; Borawski, Maciej

2014-01-15

A two-stage waste air treatment system, consisting of hybrid bioreactors (modified bioscrubbers) and a biofilter, was used to treat waste air containing chlorinated ethenes - trichloroethylene (TCE) and tetrachloroethylene (PCE). The bioreactor was operated with loadings in the range 0.46-5.50gm(-3)h(-1) for TCE and 2.16-9.02gm(-3)h(-1) for PCE. The biofilter loadings were in the range 0.1-0.97gm(-3)h(-1) for TCE and 0.2-2.12gm(-3)h(-1) for PCE. Under low pollutant loadings, the efficiency of TCE elimination was 23-25% in the bioreactor and 54-70% in the biofilter. The efficiency of PCE elimination was 44-60% in the bioreactor and 50-75% in the biofilter. The best results for the bioreactor were observed one week after the pollutant loading was increased. However, the process did not stabilize. In the next seven days contaminant removal efficiency, enzymatic activity and biomass content were all diminished. Copyright © 2013 Elsevier B.V. All rights reserved.

Adult Neuropsychological Performance Following Prenatal and Early Postnatal Exposure to Tetrachloroethylene (PCE)-contaminated Drinking Water

PubMed Central

Janulewicz, Patricia A; White, Roberta F; Martin, Brett M; Winter, Michael R; Weinberg, Janice M; Vieira, Veronica; Aschengrau, Ann

2012-01-01

This population-based retrospective cohort study examined adult performance on a battery of neuropsychological tests in relation to prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using pipe network information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and a Geographic Information System (GIS). Results of crude and multivariate analyses among 35 exposed and 28 unexposed subjects showed no association between prenatal and early postnatal exposure and decrements on tests that assess abilities in the domains of omnibus intelligence, academic achievement or language. The results were suggestive of an association between prenatal and early postnatal PCE exposure and diminished performance on tests that assessed abilities in the domains of visuospatial functioning, learning and memory, motor, attention and mood. Because the sample size was small, most findings were not statistically significant. Future studies with larger sample sizes should be conducted to further define the neuropsychological consequences of early developmental PCE exposure. PMID:22522125

PCE: web tools to compute protein continuum electrostatics

PubMed Central

Miteva, Maria A.; Tufféry, Pierre; Villoutreix, Bruno O.

2005-01-01

PCE (protein continuum electrostatics) is an online service for protein electrostatic computations presently based on the MEAD (macroscopic electrostatics with atomic detail) package initially developed by D. Bashford [(2004) Front Biosci., 9, 1082–1099]. This computer method uses a macroscopic electrostatic model for the calculation of protein electrostatic properties, such as pKa values of titratable groups and electrostatic potentials. The MEAD package generates electrostatic energies via finite difference solution to the Poisson–Boltzmann equation. Users submit a PDB file and PCE returns potentials and pKa values as well as color (static or animated) figures displaying electrostatic potentials mapped on the molecular surface. This service is intended to facilitate electrostatics analyses of proteins and thereby broaden the accessibility to continuum electrostatics to the biological community. PCE can be accessed at . PMID:15980492

Effects of a remedial system and its operation on volatile organic compound-contaminated ground water, Operable Unit 1, Savage Municipal Well Superfund Site, Milford, New Hampshire, 1998-2004

USGS Publications Warehouse

Harte, Philip T.

2006-01-01

The Savage Municipal Well Superfund site in the Town of Milford, N.H., is underlain by a 0.5-square mile plume of volatile organic compounds (VOCs), mostly tetrachloroethylene (PCE). The plume occurs mostly within a highly transmissive sand and gravel layer, but also extends into underlying till and bedrock. The plume has been divided into two areas called Operable Unit 1 (OU1), which contains the primary source area, and Operable Unit 2 (OU2), which is defined as the extended plume area. PCE concentrations in excess of 100,000 parts per billion (ppb) had been detected in the OU1 area in 1995, indicating a likely Dense Non-Aqueous Phase Liquid (DNAPL) source. In the fall of 1998, the New Hampshire Department of Environmental Services (NHDES) and the U.S. Environmental Protection Agency (USEPA) installed a remedial system in OU1 to contain and capture the dissolved VOC plume. The OU1 remedial system includes a low-permeability barrier wall that encircles the highest detected concentrations of PCE, and a series of injection and extraction wells to contain and remove contaminants. The barrier wall likely penetrates the full thickness of the sand and gravel; in most places, it also penetrates the full thickness of the underlying basal till and sits atop bedrock. Remedial injection and extraction wells have been operating since the spring of 1999 and include a series of interior (inside the barrier wall) injection and extractions wells and exterior (outside the barrier wall) injection and extraction wells. A recharge gallery outside the barrier wall receives the bulk of the treated water and reinjects it into the shallow aquifer. From 1998 to 2004, PCE concentrations decreased by an average of 80 percent at most wells outside the barrier wall. This decrease indicates (1) the barrier wall and interior extraction effectively contained high PCE concentrations inside the wall, (2) other sources of PCE did not appear to be outside of the wall, and (3) ambient ground-water flow in conjunction with the exterior remedial wells effectively remediated most of the dissolved PCE plume outside the wall. The overburden at middle depths (40 to 70 ft below land surface) downgradient from exterior extraction wells showed relatively slow decreases in PCE concentrations compared to other areas outside the barrier wall. Numerical simulation shows extraction caused the formation of a small downgradient slow-velocity zone. Because the ambient ground-water velocities are high (approximately 1 foot per day), temporary termination of extraction at the exterior wells may increase dilution downgradient from the exterior extraction wells. Extraction can also be optimized on the basis of seasonal hydrologic conditions to facilitate exterior well capture from upgradient areas outside of the barrier wall where PCE concentrations are highest. Reductions in concentrations of PCE inside the barrier wall from 1998 to 2003 were minimal near suspected source areas, indicating that the operation of interior remedial wells had not been effective in remediating dissolved PCE or the DNAPL source. Capture of the dissolved PCE plume within the barrier wall by interior extraction wells could be enhanced if operation (injection rates) increased at underutilized interior injection wells, thereby increasing hydraulic gradients.

Dye-Incorporated Polynaphthalenediimide Acceptor for Additive-Free High-Performance All-Polymer Solar Cells.

PubMed

Chen, Dong; Yao, Jia; Chen, Lie; Yin, Jingping; Lv, Ruizhi; Huang, Bin; Liu, Siqi; Zhang, Zhi-Guo; Yang, Chunhe; Chen, Yiwang; Li, Yongfang

2018-04-16

All-polymer solar cells (all-PSCs) can offer unique advantages for applications in flexible devices, and naphthalene diimide (NDI)-based polymer acceptors are the widely used polymer acceptors. However, their power conversion efficiency (PCE) still lags behind that of state-of-the-art polymer solar cells, due to low light absorption, suboptimal energy levels and the strong aggregation of the NDI-based polymer acceptor. Herein, a rhodanine-based dye molecule was introduced into the NDI-based polymer acceptor by simple random copolymerization and showed an improved light absorption coefficient, an up-shifted lowest unoccupied molecular orbital level and reduced crystallization. Consequently, additive-free all-PSCs demonstrated a high PCE of 8.13 %, which is one of the highest performance characteristics reported for all-PSCs to date. These results indicate that incorporating a dye into the n-type polymer gives insight into the precise design of high-performance polymer acceptors for all-PSCs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Impact of Replacing the Pooled Cohort Equation With Other Cardiovascular Disease Risk Scores on Atherosclerotic Cardiovascular Disease Risk Assessment (from the Multi-Ethnic Study of Atherosclerosis [MESA]).

PubMed

Qureshi, Waqas T; Michos, Erin D; Flueckiger, Peter; Blaha, Michael; Sandfort, Veit; Herrington, David M; Burke, Gregory; Yeboah, Joseph

2016-09-01

The increase in statin eligibility by the new cholesterol guidelines is mostly driven by the Pooled Cohort Equation (PCE) criterion (≥7.5% 10-year PCE). The impact of replacing the PCE with either the modified Framingham Risk Score (FRS) or the Systematic Coronary Risk Evaluation (SCORE) on assessment of atherosclerotic cardiovascular disease (ASCVD) risk assessment and statin eligibility remains unknown. We assessed the comparative benefits of using the PCE, FRS, and SCORE for ASCVD risk assessment in the Multi-Ethnic Study of Atherosclerosis. Of 6,815 participants, 654 (mean age 61.4 ± 10.3; 47.1% men; 37.1% whites; 27.2% blacks; 22.3% Hispanics; 12.0% Chinese-Americans) were included in analysis. Area under the curve (AUC) and decision curve analysis were used to compare the 3 risk scores. Decision curve analysis is the plot of net benefit versus probability thresholds; net benefit = true positive rate - (false positive rate × weighting factor). Weighting factor = Threshold probability/1 - threshold probability. After a median of 8.6 years, 342 (6.0%) ASCVD events (myocardial infarction, coronary heart disease death, fatal or nonfatal stroke) occurred. All 4 risk scores had acceptable discriminative ability for incident ASCVD events; (AUC [95% CI] PCE: 0.737 [0.713 to 0.762]; FRS: 0.717 [0.691 to 0.743], SCORE (high risk) 0.722 [0.696 to 0.747], and SCORE (low risk): 0.721 [0.696 to 0.746]. At the ASCVD risk threshold recommended for statin eligibility for primary prevention (≥7.5%), the PCE provides the best net benefit. Replacing the PCE with the SCORE (high), SCORE (low) and FRS results in a 2.9%, 8.9%, and 17.1% further increase in statin eligibility. The PCE has the best discrimination and net benefit for primary ASCVD risk assessment in a US-based multiethnic cohort compared with the SCORE or the FRS. Copyright © 2016 Elsevier Inc. All rights reserved.

A Continuous Flow Column Study of Anaerobic PCE Transformation With the Evanite Culture and Hanford Aquifer Solids

NASA Astrophysics Data System (ADS)

Semprini, L.; Behrens, S.; Azizian, M.; Sabalowsky, A.; Dolan, M.; Ruiz-Hass, P.; Ingle, J.; Spormann, A.

2005-12-01

Anaerobic reductive dehalogenation of tetrachloroethene (PCE) and trichoroethene (TCE) is a promising technology for the in situ treatment of high concentration source zones in contaminated aquifers. Continuous flow column studies were performed where a mixed dehalogenating culture (Evanite culture) that contains Dehalococcides-like microorganisms was bioaugmented into aquifer solids from the Hanford DOE site. Studies conducted prior to bioaugmentation showed PCE transport was retarded due to sorption onto the aquifer solids. Upon bioaugmentation and with continuous lactate addition, PCE (10 mg/L) was transformed to cis-dichloroethene ( cis-DCE), and enhanced transformation of sorbed PCE was observed. Prolonged production of cis-DCE was associated with iron reducing conditions, while eventual vinyl chloride (VC) reduction to ethene was associated with sulfate reducing conditions. Microbial processes included lactate fermentation to acetate and propionate, iron reduction, sulfate reduction, and reductive dehalogenation, with reductive dehalogenation utilizing 2 to 3% of the electron donor addition. PCE was completely transformed to ethene within a hydraulic residence time of one day. Upon competition of the column tests spatial samples of aquifer solids were analyzed using molecular methods and solids were used in batch microcosm activity tests. Dehalococcoides sp. 16S rRNA gene copy numbers dropped from ~ 74% of total Eubacterial 16S rRNA genes in the original inoculum, to about 0.5 to 4% through out the column, consistent with the estimates of electron donor utilization for dehalogenation reactions. Microcosm tests showed most of PCE transformation activity at the entrance of the column, consistent with the Dehalococcoides sp. 16S rRNA gene copy numbers being highest in that area. Roughly 20% of the Dehalococcoides sp. population in the column possessed a vcrA gene for the respiration of VC to ethene. The vcrA-positive subpopulation decreases to about 5% towards the column outflow, while VC microcosm activity tests show fairly constant rates of VC transformation across the column. The column studies demonstrated that complete transformation of PCE to ethene can be obtained over short spatial and temporal scales.

Examination of overall treatment effect and the proportion attributable to contextual effect in osteoarthritis: meta-analysis of randomised controlled trials.

PubMed

Zou, Kun; Wong, Jean; Abdullah, Natasya; Chen, Xi; Smith, Toby; Doherty, Michael; Zhang, Weiya

2016-11-01

To examine the overall treatment effect and the proportion attributable to contextual effect (PCE) in randomised controlled trials (RCTs) of diverse treatments for osteoarthritis (OA). We searched Medline, Embase, Central, Science Citation Index, AMED and CINAHL through October 2014, supplemented with manual search of reference lists, published meta-analyses and systematic reviews. Included were RCTs in OA comparing placebo with representative complementary, pharmacological, non-pharmacological and surgical treatments. The primary outcome was pain. Secondary outcomes were function and stiffness. The effect size (ES) of overall treatment effect and the PCE were pooled using random-effects model. Subgroup analyses and meta-regression were conducted to examine determinants of the PCE. In total, 215 trials (41 392 participants) were included. The overall treatment effect for pain ranged from the smallest with lavage (ES=0.46, 95% CI 0.24 to 0.68) to the largest with topical non-steroidal anti-inflammatory drugs (ES=1.37, 95% CI 1.19 to 1.55). On average, 75% (PCE=0.75, 95% CI 0.72 to 0.79) of pain reduction was attributable to contextual effect. It varied by treatment from 47% (PCE=0.47, 95% CI 0.32 to 0.70) for intra-articular corticosteroid to 91% (PCE=0.91, 95% CI 0.60 to 1.37) for joint lavage. Similar results were observed for function and stiffness. Treatment delivered by needle/injection and other means than oral medication, longer duration of treatment, large sample size (≥100 per arm) and public funding source were associated with increased PCE for pain reduction. The majority (75%) of the overall treatment effect in OA RCTs is attributable to contextual effects rather than the specific effect of treatments. Reporting overall treatment effect and PCE, in addition to traditional ES, permits a more balanced, clinically meaningful interpretation of RCT results. This would help dispel the frequent discordance between conclusions from RCT evidence and clinical experience-the 'efficacy paradox'. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Use of 13C Labeled Carbon Tetrachloride to Demonstrate the Transformation to Carbon Dioxide under Anaerobic Conditions in a Continuous Flow Column

NASA Astrophysics Data System (ADS)

Semprini, L.; Azizian, M.

2012-12-01

The demonstration of transformation of chlorinated aliphatic compounds (CAHs) in the subsurface is a challenge, especially when the products are carbon dioxide (CO2) and chloride ion. The groundwater contaminant carbon tetrachloride (CT) is of particular interest since a broad range of transformation products can be potentially formed under anaerobic conditions. The ability to demonstrate the transformation of CT to CO2 as a non toxic endproduct, is also of great interest. Results will be presented from a continuous flow column study where 13C labeled CT was used to demonstrate its transformation to CO2. The column was packed with a quartz sand and bioaugmented the Evanite Culture (EV) that is capable of transforming tetrachloroethene (PCE) to ethene. The column was continously fed a synthetic groundwater that was amended with PCE (0.10 mM) and either formate (1.5 mM) or lactate (1.1 mM), which ferments to produce hydrogen (H2) as the ultimate electron donor. Earlier CT transformation studies with the column, in the absence of sulfate reduction, and with formate added as a donor found CT (0.015 mM) was over 98% transformed with about 20% converted to chloroform (CF) (0.003 mM) and with a transient detection of chloromethane (CM). Methane and carbon disulfide, as potential products, were not detected. Neither CT nor CF inhibited the reductive dehalogenation of PCE to ethene. A series of transient studies conducted after these initial CT transformation tests, but in the absence of CT, showed formate remained an effective substrate for maintaining sulfate reduction and PCE transformation. Lactate, which was effectively fermented prior to CT addition, was not effectively fermented, with propionate accumulating as a fermentation product. When lactate was added, PCE was mainly transformed to cis-dichloroethene (cis-DCE) and VC, and sulfate reduction did not occur. In order to restore effective lactate fermentation the column was then bioaugmented with an EV culture that was capable of lactate fermentation. After bioaugmentation, effective lactate fermentation, sulfate reduction and PCE transformation to ethene was achieved. Unlabeled CT (0.015 mM) addition was then started and complete transformation was achieved with a transient build-up of CF and chloromethane, which were subsequently removed below their detection limits. CT continued to be completely transformed after the influent concentration was increased to 0.03 mM. 13C labeled CT (0.03 mM) was then added to the column. GC-MS analysis showed that 13C labeled CO2 was formed at near stoichiometric levels to the CT that was transformed. The results clearly demonstrate that CT can being transformed to CO2 at high CT concentrations, while maintaining effective PCE dehalogenation, sulfate reduction and lactate fermentation. The results also illustrate the great potential of using 13C labeled compounds in subsurface investigations.

Utility of Nontraditional Risk Markers in Individuals Ineligible for Statin Therapy According to the 2013 American College of Cardiology/American Heart Association Cholesterol Guidelines.

PubMed

Yeboah, Joseph; Polonsky, Tamar S; Young, Rebekah; McClelland, Robyn L; Delaney, Joseph C; Dawood, Farah; Blaha, Michael J; Miedema, Michael D; Sibley, Christopher T; Carr, J Jeffrey; Burke, Gregory L; Goff, David C; Psaty, Bruce M; Greenland, Philip; Herrington, David M

2015-09-08

In the general population, the majority of cardiovascular events occur in people at the low to moderate end of population risk distribution. The 2013 American College of Cardiology/American Heart Association guideline on the treatment of blood cholesterol recommends consideration of statin therapy for adults with an estimated 10-year atherosclerotic cardiovascular disease (ASCVD) risk ≥7.5% based on traditional risk factors. Whether use of nontraditional risk markers can improve risk assessment in those below this threshold for statin therapy is unclear. Using data from the Multi-Ethnic Study of Atherosclerosis (MESA), a population sample free of clinical CVD at baseline, we calibrated the Pooled Cohort Equations (cPCE). ASCVD was defined as myocardial infarction, coronary heart disease death, or fatal or nonfatal stroke. Adults with an initial cPCE <7.5% and elevated levels of additional risk markers (abnormal test) whose new calculated risk was ≥7.5% were considered statin eligible: low-density lipoprotein cholesterol ≥160 mg/dL; family history of ASCVD; high-sensitivity C-reactive protein ≥2 mg/dL; coronary artery calcium score ≥300 Agatston units or ≥75th percentile for age, sex, and ethnicity; and ankle-brachial index <0.9. We compared the absolute and relative ASCVD risks among those with versus without elevated posttest estimated risk. We calculated the number needed to screen to identify 1 person with abnormal test for each risk marker, defined as the number of participants with baseline cPCE risk <7.5% divided by the number with an abnormal test reclassified as statin eligible. Of 5185 participants not taking statins with complete data (age, 45-84 years), 4185 had a cPCE risk <7.5%. During 10 years of follow-up, 57% of the ASCVD events (183 of 320) occurred among adults with a cPCE risk <7.5%. When people with diabetes mellitus were excluded, the coronary artery calcium criterion reclassified 6.8% upward, with an event rate of 13.3%, absolute risk of 10%, relative risk of 4.0 (95% confidence interval [CI], 2.8-5.7), and number needed to screen of 14.7. The corresponding numbers for family history of ASCVD were 4.6%, 15.1%, 12%, 4.3 (95% CI, 3.0-6.4), and 21.8; for high-sensitivity C-reactive protein criteria, 2.6%, 10%, 6%, 2.6 (95% CI, 1.4-4.8), and 39.2; for ankle-brachial index criteria, 0.6%, 9%, 5%, 2.3 (95% CI, 0.6-8.6), and 176.5; and for low-density lipoprotein cholesterol criteria, 0.5%, 5%, 1%, 1.2 (95% CI, 0.2-8.4), and 193.3, respectively. Of the 3882 with <7.5% cPCE risk, 431 (11.1%) were reclassified to ≥7.5% (statin eligible) by at least 1 of the additional risk marker criteria. In this generally low-risk population sample, a large proportion of ASCVD events occurred among adults with a 10-year cPCE risk <7.5%. We found that the coronary artery calcium score, high-sensitivity C-reactive protein, family history of ASCVD, and ankle-brachial index recommendations by the American College of Cardiology/American Heart Association cholesterol guidelines (Class IIB) identify small subgroups of asymptomatic population with a 10-year cPCE risk <7.5% but with observed ASCVD event rates >7.5% who may warrant statin therapy considerations. © 2015 American Heart Association, Inc.

Language Outcomes at 12 Years for Children Exposed Prenatally to Cocaine

PubMed Central

Lewis, Barbara A.; Minnes, Sonia; Short, Elizabeth J.; Min, Meeyoung O.; Wu, Miaoping; Lang, Adelaide; Weishampel, Paul; Singer, Lynn T.

2014-01-01

Purpose In this study, the authors aimed to examine the long-term effects of prenatal cocaine exposure (PCE) on the language development of 12-year-old children using a prospective design, controlling for confounding prenatal drug exposure and environmental factors. Method Children who were exposed to cocaine in utero (PCE; n = 183) and children who were not exposed to cocaine (i.e., no cocaine exposure [NCE]; n = 181) were followed prospectively from birth to 12 years of age and were compared on language subtests of the Test of Language Development—Intermediate, Third Edition (Hammill & Newcomer, 1997b), and phonological processing as measured by the Comprehensive Test of Phonological Processing (Wagner & Torgesen, 1999). The authors evaluated the relationship of PCE to language development through a multivariate analysis of covariance and regression analyses while controlling for confounders. Results Results show that PCE has small effects on specific aspects of language, including syntax and phonological processing. The caregiver variables of lower maternal vocabulary, more psychological symptoms, and a poorer home environment also had consistent effects on language and phonological processing scores. Conclusions These findings suggest that PCE continues to have small, subtle effects on specific aspects of language at age 12 years. Phonological processing skills were significantly related to the reading outcomes of letter–word identification, reading fluency, and reading comprehension, indicating that PCE also has small but lasting effects on the language skills that are related to later literacy skills. PMID:24149136

Understanding pH Effects on Trichloroethylene and Perchloroethylene Adsorption to Iron in Permeable Reactive Barriers for Groundwater Remediation.

PubMed

Luo, Jing; Farrell, James

2013-01-01

Metallic iron filings are becoming increasing used in permeable reactive barriers for remediating groundwater contaminated by chlorinated solvents. Understanding solution pH effects on rates of reductive dechlorination in permeable reactive barriers is essential for designing remediation systems that can meet treatment objectives under conditions of varying groundwater properties. The objective of this research was to investigate how the solution pH value affects adsorption of trichloroethylene (TCE) and perchloroethylene (PCE) on metallic iron surfaces. Because adsorption is first required before reductive dechlorination can occur, pH effects on halocarbon adsorption energies may explain pH effects on dechlorination rates. Adsorption energies for TCE and PCE were calculated via molecular mechanics simulations using the Universal force field and a self-consistent reaction field charge equilibration scheme. A range in solution pH values was simulated by varying the amount of atomic hydrogen adsorbed on the iron. The potential energies associated TCE and PCE complexes were dominated by electrostatic interactions, and complex formation with the surface was found to result in significant electron transfer from the iron to the adsorbed halocarbons. Adsorbed atomic hydrogen was found to lower the energies of TCE complexes more than those for PCE. Attractions between atomic hydrogen and iron atoms were more favorable when TCE versus PCE was adsorbed to the iron surface. These two findings are consistent with the experimental observation that changes in solution pH affect TCE reaction rates more than those for PCE.

Application Forms for Forestry and Silvicultural Burning Tribal Permits Under the FARR

EPA Pesticide Factsheets

Application form for forestry and silvicultural burning on the Nez Perce Indian Reservation and the Confederated Tribes of the Umatilla Indian Reservation under EPA's Federal Air Rules for Reservations.

Protect and Restore Lolo Creek Watershed, 2003-2004 Annual Report.

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

McRoberts, Heidi

2004-06-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Lolo Creek watershed are coordinated with the Clearwater National Forest and Potlatch Corporation. The Nez Perce Tribe began watershed restoration projects within the Lolo Creek watershed of the Clearwater River in 1996. Fencing to exclude cattle for stream banks, stream bank stabilization, decommissioning roads, and upgrading culverts are the primary focuses of this project. Riparian enhancement through planning of riparian trees continues. Culvert inventory is on-going and will be completed in 2004 for the entiremore » Lolo Creek drainage. High priority culverts are being replaced and passage blocking log culverts are being removed. Tribal crews completed maintenance to the previously built fence.« less

Knowledge Translation of the PERC Rule for Suspected Pulmonary Embolism: A Blueprint for Reducing the Number of CT Pulmonary Angiograms.

PubMed

Drescher, Michael J; Fried, Jeremy; Brass, Ryan; Medoro, Amanda; Murphy, Timothy; Delgado, João

2017-10-01

Computerized decision support decreases the number of computed tomography pulmonary angiograms (CTPA) for pulmonary embolism (PE) ordered in emergency departments, but it is not always well accepted by emergency physicians. We studied a department-endorsed, evidence-based clinical protocol that included the PE rule-out criteria (PERC) rule, multi-modal education using principles of knowledge translation (KT), and clinical decision support embedded in our order entry system, to decrease the number of unnecessary CTPA ordered. We performed a historically controlled observational before-after study for one year pre- and post-implementation of a departmentally-endorsed protocol. We included patients > 18 in whom providers suspected PE and who did not have a contraindication to CTPA. Providers entered clinical information into a diagnostic pathway via computerized order entry. Prior to protocol implementation, we provided education to ordering providers. The primary outcome measure was the number of CTPA ordered per 1,000 visits one year before vs. after implementation. CTPA declined from 1,033 scans for 98,028 annual visits (10.53 per 1,000 patient visits (95% CI [9.9-11.2]) to 892 scans for 101,172 annual visits (8.81 per 1,000 patient visits (95% CI [8.3-9.4]) p<0.001. The absolute reduction in PACT ordered was 1.72 per 1,000 visits (a 16% reduction). Patient characteristics were similar for both periods. Knowledge translation clinical decision support using the PERC rule significantly reduced the number of CTPA ordered.

Effect of sudden addition of PCE and bioreactor coupling to ZVI filters on performance of fluidized bed bioreactors operated in simultaneous electron acceptor modes.

PubMed

Moreno-Medina, C U; Poggi-Varaldo, Hector M; Breton-Deval, L; Rinderknecht-Seijas, N

2017-11-01

The present work evaluated the effects of (i) feeding a water contaminated with 80 mg/L PCE to bioreactors seeded with inoculum not acclimated to PCE, (ii) coupling ZVI side filters to bioreactors, and (iii) working in different biological regimes, i.e., simultaneous methanogenic aeration and simultaneous methanogenic-denitrifying regimes, on fluidized bed bioreactor performance. Simultaneous electron acceptors refer to the simultaneous presence of two compounds operating as final electron acceptors in the biological respiratory chain (e.g., use of either O 2 or NO 3 - in combination with a methanogenic environment) in a bioreactor or environmental niche. Four lab-scale, mesophilic, fluidized bed bioreactors (bioreactors) were implemented. Two bioreactors were operated as simultaneous methanogenic-denitrifying (MD) units, whereas the other two were operated in partially aerated methanogenic (PAM) mode. In the first period, all bioreactors received a wastewater with 1 g chemical oxygen demand of methanol per liter (COD-methanol/L). In a second period, all the bioreactors received the wastewater plus 80 mg perchloroethylene (PCE)/L; at the start of period 2, one MD and one PAM were coupled to side sand-zero valent iron filters (ZVI). All bioreactors were inoculated with a microbial consortium not acclimated to PCE. In this work, the performance of the full period 1 and the first 60 days of period 2 is reported and discussed. The COD removal efficiency and the nitrate removal efficiency of the bioreactors essentially did not change between period 1 and period 2, i.e., upon PCE addition. On the contrary, specific methanogenic activity in PAM bioreactors (both with and without coupled ZVI filter) significantly decreased. This was consistent with a sharp fall of methane productivity in those bioreactors in period 2. During period 2, PCE removals in the range 86 to 97 % were generally observed; the highest removal corresponded to PAM bioreactors along with the highest dehalogenation efficiency (94 %). Principal component analysis as well as cluster analysis confirmed the trends mentioned above, i.e., the better performance of PAM over MD, and the unexpected no effect of the ZVI side filters on PCE removal and dehalogenation efficiencies. To the best of our knowledge, this is the first report on the combined treatment ZVI-biological of a water polluted with PCE, where the biological operation relied on simultaneous electron acceptors.

Australian University Students’ Coping Strategies and Use of Pharmaceutical Stimulants as Cognitive Enhancers

PubMed Central

Jensen, Charmaine; Forlini, Cynthia; Partridge, Brad; Hall, Wayne

2016-01-01

Background: There are reports that some university students are using prescription stimulants for non-medical ‘pharmaceutical cognitive enhancement (PCE)’ to improve alertness, focus, memory, and mood in an attempt to manage the demands of study at university. Purported demand for PCEs in academic contexts have been based on incomplete understandings of student motivations, and often based on untested assumptions about the context within which stimulants are used. They may represent attempts to cope with biopsychosocial stressors in university life by offsetting students’ inadequate coping responses, which in turn may affect their cognitive performance. This study aimed to identify (a) what strategies students adopted to cope with the stress of university life and, (b) to assess whether students who have used stimulants for PCE exhibit particular stress or coping patterns. Methods: We interviewed 38 university students (with and without PCE experience) about their experience of managing student life, specifically their: educational values; study habits; achievement; stress management; getting assistance; competing activities and demands; health habits; and cognitive enhancement practices. All interview transcripts were coded into themes and analyzed. Results: Our thematic analysis revealed that, generally, self-rated coping ability decreased as students’ self-rated stress level increased. Students used emotion- and problem-focused coping for the most part and adjustment-focused coping to a lesser extent. Avoidance, an emotion-focused coping strategy, was the most common, followed by problem-focused coping strategies, the use of cognition on enhancing substances, and planning and monitoring of workload. PCE users predominantly used avoidant emotion-focused coping strategies until they no longer mitigated the distress of approaching deadlines resulting in the use of prescription stimulants as a substance-based problem-focused coping strategy. Conclusion: Our study suggests that students who choose coping responses that do not moderate stress where possible, may cause themselves additional distress and avoid learning more effective coping responses. Helping students to understand stress and coping, and develop realistic stress appraisal techniques, may assist students in general to maintain manageable distress levels and functioning. Furthermore, assisting students who may be inclined to use prescription stimulants for cognitive enhancement may reduce possible drug-related harms. PMID:26973573

Australian University Students' Coping Strategies and Use of Pharmaceutical Stimulants as Cognitive Enhancers.

PubMed

Jensen, Charmaine; Forlini, Cynthia; Partridge, Brad; Hall, Wayne

2016-01-01

There are reports that some university students are using prescription stimulants for non-medical 'pharmaceutical cognitive enhancement (PCE)' to improve alertness, focus, memory, and mood in an attempt to manage the demands of study at university. Purported demand for PCEs in academic contexts have been based on incomplete understandings of student motivations, and often based on untested assumptions about the context within which stimulants are used. They may represent attempts to cope with biopsychosocial stressors in university life by offsetting students' inadequate coping responses, which in turn may affect their cognitive performance. This study aimed to identify (a) what strategies students adopted to cope with the stress of university life and, (b) to assess whether students who have used stimulants for PCE exhibit particular stress or coping patterns. We interviewed 38 university students (with and without PCE experience) about their experience of managing student life, specifically their: educational values; study habits; achievement; stress management; getting assistance; competing activities and demands; health habits; and cognitive enhancement practices. All interview transcripts were coded into themes and analyzed. Our thematic analysis revealed that, generally, self-rated coping ability decreased as students' self-rated stress level increased. Students used emotion- and problem-focused coping for the most part and adjustment-focused coping to a lesser extent. Avoidance, an emotion-focused coping strategy, was the most common, followed by problem-focused coping strategies, the use of cognition on enhancing substances, and planning and monitoring of workload. PCE users predominantly used avoidant emotion-focused coping strategies until they no longer mitigated the distress of approaching deadlines resulting in the use of prescription stimulants as a substance-based problem-focused coping strategy. Our study suggests that students who choose coping responses that do not moderate stress where possible, may cause themselves additional distress and avoid learning more effective coping responses. Helping students to understand stress and coping, and develop realistic stress appraisal techniques, may assist students in general to maintain manageable distress levels and functioning. Furthermore, assisting students who may be inclined to use prescription stimulants for cognitive enhancement may reduce possible drug-related harms.

Can we calibrate simultaneously groundwater recharge and aquifer hydrodynamic parameters ?

NASA Astrophysics Data System (ADS)

Hassane Maina, Fadji; Ackerer, Philippe; Bildstein, Olivier

2017-04-01

By groundwater model calibration, we consider here fitting the measured piezometric heads by estimating the hydrodynamic parameters (storage term and hydraulic conductivity) and the recharge. It is traditionally recommended to avoid simultaneous calibration of groundwater recharge and flow parameters because of correlation between recharge and the flow parameters. From a physical point of view, little recharge associated with low hydraulic conductivity can provide very similar piezometric changes than higher recharge and higher hydraulic conductivity. If this correlation is true under steady state conditions, we assume that this correlation is much weaker under transient conditions because recharge varies in time and the parameters do not. Moreover, the recharge is negligible during summer time for many climatic conditions due to reduced precipitation, increased evaporation and transpiration by vegetation cover. We analyze our hypothesis through global sensitivity analysis (GSA) in conjunction with the polynomial chaos expansion (PCE) methodology. We perform GSA by calculating the Sobol indices, which provide a variance-based 'measure' of the effects of uncertain parameters (storage and hydraulic conductivity) and recharge on the piezometric heads computed by the flow model. The choice of PCE has the following two benefits: (i) it provides the global sensitivity indices in a straightforward manner, and (ii) PCE can serve as a surrogate model for the calibration of parameters. The coefficients of the PCE are computed by probabilistic collocation. We perform the GSA on simplified real conditions coming from an already built groundwater model dedicated to a subdomain of the Upper-Rhine aquifer (geometry, boundary conditions, climatic data). GSA shows that the simultaneous calibration of recharge and flow parameters is possible if the calibration is performed over at least one year. It provides also the valuable information of the sensitivity versus time, depending on the aquifer inertia and climatic conditions. The groundwater levels variations during recharge (increase) are sensitive to the storage coefficient whereas the groundwater levels variations after recharge (decrease) are sensitive to the hydraulic conductivity. The performed model calibration on synthetic data sets shows that the parameters and recharge are estimated quite accurately.

Natural attenuation of chlorinated solvents at Area 6, Dover Air Force Base: Groundwater biogeochemistry

USGS Publications Warehouse

Witt, M.E.; Klecka, G.M.; Lutz, E.J.; Ei, T.A.; Grosso, N.R.; Chapelle, F.H.

2002-01-01

Monitored natural attenuation (MNA) has recently emerged as a viable groundwater remediation technology in the United States. Area 6 at Dover Air Force Base (Dover, DE) was chosen as a test site to examine the potential for MNA of tetrachloroethene (PCE) and trichloroethene (TCE) in groundwater and aquifer sediments. A "lines of evidence" approach was used to document the occurrence of natural attenuation. Chlorinated hydrocarbon and biogeochemical data were used to develop a site-specific conceptual model where both anaerobic and aerobic biological processes are responsible for the destruction of PCE, TCE, and daughter metabolites. An examination of groundwater biogeochemical data showed a region of depleted dissolved oxygen with elevated dissolved methane and hydrogen concentrations. Reductive dechlorination likely dominated in the anaerobic portion of the aquifer where PCE and TCE levels were observed to decrease with a simultaneous increase in cis-1,2-dichloroethene (cis-DCE), vinyl chloride (VC), ethene, and dissolved chloride. Near the anaerobic/aerobic interface, concentrations of cis-DCE and VC decreased to below detection limits, presumably due to aerobic biotransformation processes. Therefore, the contaminant and daughter product plumes present at the site appear to have been naturally attenuated by a combination of active anaerobic and aerobic biotransformation processes. ?? 2002 Elsevier Science B.V. All rights reserved.

PCE solubilization and mobilization by commercial humic acid

NASA Astrophysics Data System (ADS)

Johnson, William P.; John, W. Wynn

1999-01-01

In this paper, comparison is made of terms describing solubilization of hydrophobic organic compounds (HOC) by dissolved humic substances (DHS) and commercial non-ionic surfactants. This paper examines the ability of a commercial humic acid (Aldrich humic acid) to solubilize and mobilize tetrachlorothene (PCE) residual in porous media. The constant for solubilization of PCE by Aldrich humic acid is shown to be a factor of two to thirty times less than that published for dodecyl alcohol ethoxylate surfactants, showing that Aldrich humic acid is less capable than some non-ionic surfactants at solubilizing residual PCE. The depression of PCE-water interfacial tension in the presence of DHS is shown to be significantly less than published values for a non-ionic surfactant, and surfactant mixtures, indicating that the DHS used in this study is less prone to cause mobilization of non-aqueous phase liquids relative to surfactants. Several possible advantages of DHS use in the remediation of subsurface media contaminated with HOC are described, including the ability of DHS to solubilize HOC irrespective of the DHS concentration, and potential lesser tendency of DHS to depress the interfacial tension between non-aqueous phases and water relative to surfactants (an advantage when mobilization is undesired).

How Often Do They Have Sex? A Comparative Analysis of the Population Structure of Seven Eukaryotic Microbial Pathogens

PubMed Central

Tomasini, Nicolás; Lauthier, Juan José; Ayala, Francisco José; Tibayrenc, Michel; Diosque, Patricio

2014-01-01

The model of predominant clonal evolution (PCE) proposed for micropathogens does not state that genetic exchange is totally absent, but rather, that it is too rare to break the prevalent PCE pattern. However, the actual impact of this “residual” genetic exchange should be evaluated. Multilocus Sequence Typing (MLST) is an excellent tool to explore the problem. Here, we compared online available MLST datasets for seven eukaryotic microbial pathogens: Trypanosoma cruzi, the Fusarium solani complex, Aspergillus fumigatus, Blastocystis subtype 3, the Leishmania donovani complex, Candida albicans and Candida glabrata. We first analyzed phylogenetic relationships among genotypes within each dataset. Then, we examined different measures of branch support and incongruence among loci as signs of genetic structure and levels of past recombination. The analyses allow us to identify three types of genetic structure. The first was characterized by trees with well-supported branches and low levels of incongruence suggesting well-structured populations and PCE. This was the case for the T. cruzi and F. solani datasets. The second genetic structure, represented by Blastocystis spp., A. fumigatus and the L. donovani complex datasets, showed trees with weakly-supported branches but low levels of incongruence among loci, whereby genetic structuration was not clearly defined by MLST. Finally, trees showing weakly-supported branches and high levels of incongruence among loci were observed for Candida species, suggesting that genetic exchange has a higher evolutionary impact in these mainly clonal yeast species. Furthermore, simulations showed that MLST may fail to show right clustering in population datasets even in the absence of genetic exchange. In conclusion, these results make it possible to infer variable impacts of genetic exchange in populations of predominantly clonal micro-pathogens. Moreover, our results reveal different problems of MLST to determine the genetic structure in these organisms that should be considered. PMID:25054834

Accomplishment of Multifunctional π-Conjugated Polymers by Regulating the Degree of Side-Chain Fluorination for Efficient Dopant-Free Ambient-Stable Perovskite Solar Cells and Organic Solar Cells.

PubMed

Kranthiraja, Kakaraparthi; Park, Sang Ho; Kim, Hyunji; Gunasekar, Kumarasamy; Han, Gibok; Kim, Bumjoon J; Kim, Chang Su; Kim, Soohyun; Lee, Hyunjung; Nishikubo, Ryosuke; Saeki, Akinori; Jin, Sung-Ho; Song, Myungkwan

2017-10-18

We present an efficient approach to develop a series of multifunctional π-conjugated polymers (P1-P3) by controlling the degree of fluorination (0F, 2F, and 4F) on the side chain linked to the benzodithiophene unit of the π-conjugated polymer. The most promising changes were noticed in optical, electrochemical, and morphological properties upon varying the degree of fluorine atoms on the side chain. The properly aligned energy levels with respect to the perovskite and PCBM prompted us to use them in perovskite solar cells (PSCs) as hole-transporting materials (HTMs) and in bulk heterojunction organic solar cells (BHJ OSCs) as photoactive donors. Interestingly, P2 (2F) and P3 (4F) showed an enhanced power conversion efficiency (PCE) of 14.94%, 10.35% compared to P1 (0F) (9.80%) in dopant-free PSCs. Similarly, P2 (2F) and P3 (4F) also showed improved PCE of 7.93% and 7.43%, respectively, compared to P1 (0F) (PCE of 4.35%) in BHJ OSCs. The high photvoltaic performance of the P2 and P3 based photovotaic devices over P1 are well correlated with their energy level alignment, charge transporting, morphological and packing properties, and hole transfer yields. In addition, the P1-P3 based dopant-free PSCs and BHJ OSCs showed an excellent ambient stability up to 30 days without a significant drop in their initial performance.

Risk Assessment: Perchloroethylene Dry Cleaners Refined Human Health Risk Characterization

EPA Pesticide Factsheets

This November 2005 memo and appendices describe the methods by which EPA conducted its refined risk assessment of the Major Source and Area Source facilities within the perchloroethylene (perc) dry cleaners source category.

75 FR 28612 - Environmental Impact Statements; Notice of Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-21

... Counties, OR and Adams and Nez Perce Counties, ID, Wait Period Ends: 06/21/2010, Contact: Robert W. Rock.... EIS No. 20100181, Final EIS, DOE, MS, Kemper County Integrated Gasification Combined-Cycle (IGCC...

An adaptive ANOVA-based PCKF for high-dimensional nonlinear inverse modeling

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

Li, Weixuan, E-mail: weixuan.li@usc.edu; Lin, Guang, E-mail: guang.lin@pnnl.gov; Zhang, Dongxiao, E-mail: dxz@pku.edu.cn

2014-02-01

The probabilistic collocation-based Kalman filter (PCKF) is a recently developed approach for solving inverse problems. It resembles the ensemble Kalman filter (EnKF) in every aspect—except that it represents and propagates model uncertainty by polynomial chaos expansion (PCE) instead of an ensemble of model realizations. Previous studies have shown PCKF is a more efficient alternative to EnKF for many data assimilation problems. However, the accuracy and efficiency of PCKF depends on an appropriate truncation of the PCE series. Having more polynomial chaos basis functions in the expansion helps to capture uncertainty more accurately but increases computational cost. Selection of basis functionsmore » is particularly important for high-dimensional stochastic problems because the number of polynomial chaos basis functions required to represent model uncertainty grows dramatically as the number of input parameters (random dimensions) increases. In classic PCKF algorithms, the PCE basis functions are pre-set based on users' experience. Also, for sequential data assimilation problems, the basis functions kept in PCE expression remain unchanged in different Kalman filter loops, which could limit the accuracy and computational efficiency of classic PCKF algorithms. To address this issue, we present a new algorithm that adaptively selects PCE basis functions for different problems and automatically adjusts the number of basis functions in different Kalman filter loops. The algorithm is based on adaptive functional ANOVA (analysis of variance) decomposition, which approximates a high-dimensional function with the summation of a set of low-dimensional functions. Thus, instead of expanding the original model into PCE, we implement the PCE expansion on these low-dimensional functions, which is much less costly. We also propose a new adaptive criterion for ANOVA that is more suited for solving inverse problems. The new algorithm was tested with different examples and demonstrated great effectiveness in comparison with non-adaptive PCKF and EnKF algorithms.« less

An Adaptive ANOVA-based PCKF for High-Dimensional Nonlinear Inverse Modeling

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

LI, Weixuan; Lin, Guang; Zhang, Dongxiao

2014-02-01

The probabilistic collocation-based Kalman filter (PCKF) is a recently developed approach for solving inverse problems. It resembles the ensemble Kalman filter (EnKF) in every aspect—except that it represents and propagates model uncertainty by polynomial chaos expansion (PCE) instead of an ensemble of model realizations. Previous studies have shown PCKF is a more efficient alternative to EnKF for many data assimilation problems. However, the accuracy and efficiency of PCKF depends on an appropriate truncation of the PCE series. Having more polynomial chaos bases in the expansion helps to capture uncertainty more accurately but increases computational cost. Bases selection is particularly importantmore » for high-dimensional stochastic problems because the number of polynomial chaos bases required to represent model uncertainty grows dramatically as the number of input parameters (random dimensions) increases. In classic PCKF algorithms, the PCE bases are pre-set based on users’ experience. Also, for sequential data assimilation problems, the bases kept in PCE expression remain unchanged in different Kalman filter loops, which could limit the accuracy and computational efficiency of classic PCKF algorithms. To address this issue, we present a new algorithm that adaptively selects PCE bases for different problems and automatically adjusts the number of bases in different Kalman filter loops. The algorithm is based on adaptive functional ANOVA (analysis of variance) decomposition, which approximates a high-dimensional function with the summation of a set of low-dimensional functions. Thus, instead of expanding the original model into PCE, we implement the PCE expansion on these low-dimensional functions, which is much less costly. We also propose a new adaptive criterion for ANOVA that is more suited for solving inverse problems. The new algorithm is tested with different examples and demonstrated great effectiveness in comparison with non-adaptive PCKF and EnKF algorithms.« less

Influence of Different Electron Donors and Acceptors on Dehalorespiration of Tetrachloroethene by Desulfitobacterium frappieri TCE1

PubMed Central

Gerritse, Jan; Drzyzga, Oliver; Kloetstra, Geert; Keijmel, Mischa; Wiersum, Luit P.; Hutson, Roger; Collins, Matthew D.; Gottschal, Jan C.

1999-01-01

Strain TCE1, a strictly anaerobic bacterium that can grow by reductive dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE), was isolated by selective enrichment from a PCE-dechlorinating chemostat mixed culture. Strain TCE1 is a gram-positive, motile, curved rod-shaped organism that is 2 to 4 by 0.6 to 0.8 μm and has approximately six lateral flagella. The pH and temperature optima for growth are 7.2 and 35°C, respectively. On the basis of a comparative 16S rRNA sequence analysis, this bacterium was identified as a new strain of Desulfitobacterium frappieri, because it exhibited 99.7% relatedness to the D. frappieri type strain, strain PCP-1. Growth with H2, formate, l-lactate, butyrate, crotonate, or ethanol as the electron donor depends on the availability of an external electron acceptor. Pyruvate and serine can also be used fermentatively. Electron donors (except formate and H2) are oxidized to acetate and CO2. When l-lactate is the growth substrate, strain TCE1 can use the following electron acceptors: PCE and TCE (to produce cis-1,2-dichloroethene), sulfite and thiosulfate (to produce sulfide), nitrate (to produce nitrite), and fumarate (to produce succinate). Strain TCE1 is not able to reductively dechlorinate 3-chloro-4-hydroxyphenylacetate. The growth yields of the newly isolated bacterium when PCE is the electron acceptor are similar to those obtained for other dehalorespiring anaerobes (e.g., Desulfitobacterium sp. strain PCE1 and Desulfitobacterium hafniense) and the maximum specific reductive dechlorination rates are 4 to 16 times higher (up to 1.4 μmol of chloride released · min−1 · mg of protein−1). Dechlorination of PCE and TCE is an inducible process. In PCE-limited chemostat cultures of strain TCE1, dechlorination is strongly inhibited by sulfite but not by other alternative electron acceptors, such as fumarate or nitrate. PMID:10583967

COMPARISON OF HYDROGEN CONCENTRATIONS IN PCE-DEHALOGENATING AND SULFATE-REDUCING ESTUARINE SEDIMENTS

EPA Science Inventory

The primary transformation pathway for PCE in anoxic environments is through sequential reductive dehalogenation, and information concerning dehalogenation processes that occur in environments containing alternative electron acceptors (sulfate) is limited. Hydrogen is postulated ...

Morphology Development During Deposition in OPV Low Band Gap Polymer:Bis-Fullerene Heterojunctions: Effect of a Second Solvent

NASA Astrophysics Data System (ADS)

Chen, Huipeng; Hsiao, Yu-Che; Hu, Bin; Dadmun, Mark

2014-03-01

Polymer based bulk-heterojunction solar cells, based on blends of conjugated polymers and fullerenes are one potential option for low cost renewable power generation. One way to improve power conversion efficiency (PCE) of this cell is to increase the open-circuit voltage (Voc) . It has been reported that replacing PCBM with bis-adduct fullerenes (i.e. ICBA) significantly improves Voc and PCE in P3HT device. However, for the most promising low band-gap polymer (LBP) system, replacing PCBM with ICBA gives very poor short-circuit current (Jsc) and PCE although Voc is significantly improved. As Jsc and PCE strongly depend on the morphology, we therefore tried to optimize the morphology of as-cast LBP/ICBA mixture by adding a second solvent with varying solubility to LBP and ICBA to the deposition solution. The results show that there is no change of LBP ordering by adding the second solvent regardless of its solubility. The morphology of all the as-cast samples is then determined by neutron scattering. A homogenous dispersion of ICBA in LBP is found in the sample where the second solvent is selective to LBP, giving poor PCE. Aggregates of ICBA are formed in those samples where the second solvent is selective to ICBA. The resultant morphology improves PCE by up to 246%. A quantitative analysis of neutron data shows that the interfacial area between ICBA aggregates and LBP/ICBA mixed phase is improved in these samples, which appears to facilitate charge transport and reduce the recombination of free charge carriers.

Transfer of methyl chloroform, trichloroethylene and tetrachloroethylene to milk, tissues and expired air following intraruminal or oral administration in lactating goats and milk-fed kids.

PubMed

Hamada, T; Tanaka, H

1995-01-01

The distribution of methyl chloroform was determined (MCF), trichloroethylene (TRI) and tetrachloroethylene (PCE) in milk, tissues and expired air by intraruminally administering 0.625 ml kg(-0.75) of an equal-volume mixture of the three compounds to lactating goats. The milk secreted during 24 h after the intraruminal administration contained 1.42 mg of MCF, 1.87 mg of TRI, 6.43 mg of PCE and 0.33 mg of trichloroethanol (TCE). MCF, TRI and PCE appeared in the blood less than 30 min after administration. Oral administration of these chemicals to milk-fed kids showed that at 3.5 h post-administration, the liver contained these chemicals in greatest abundance. The adaptation of milk-fed kids to 3 weeks administration of small amounts of propylene glycol stimulated the metabolic conversion of TRI to TCE. There were linear relationships between the blood concentrations of these chemicals and the expiration rates after oral administration of 0.4 ml kg(-1) of each chemical to milk-fed kids. The expiration rates of MCF, TRI and PCE were 605, 122 and 46 microg min(-1) kg(-1) at 2 microg ml(-1) blood concentrations of MCF, TRI and PCE, respectively. These results suggested that MCF is little metabolized, being most readily exhaled in expired air, while PCE demonstrates the greatest tissue-partitioning, being largely secreted into the milk or retained in the liver. TRI can be extensively metabolized to other compounds such as TCE in milk-fed kids.

Numerical simulation of surfactant-enhanced remediation using UTCHEM

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

Freeze, G.A.; Fountain, J.C.; Pope, G.A.

1995-12-31

The UTCHEM multiphase compositional simulator was used to model the migration and surfactant-enhanced remediation of perchloroethylene (PCE) in a test cell at Canadian Forces Base Borden, Ontario. A line of five injection wells was installed on one side of the test cell and a line of five withdrawal wells was installed on the opposite side of the cell. The injection and withdrawal wells penetrated the entire depth of the sand aquifer. A total of 231 liters of PCE was injected into a shallow well in the center of the test cell. Prior to surfactant flushing, 47 liters of free-phase PCE,more » which flowed into the injection and withdrawal wells over a two week period, was removed using a small-diameter plastic tube and a peristaltic pump. One to two months of water flooding (pump-and-treat), using the injection-withdrawal well system, flushed an additional 12 liters of PCE. Following the water flooding, an aqueous surfactant solution of 1% nonyl phenol ethoxylate and 1% phosphate ester of the nonyl phenol ethoxylate was circulated through the test cell via the injection-withdrawal wells. Between November 11, 1990 and May 29, 1991, a total of 130,000 liters of surfactant solution were recirculated through the test cell, during which time 62 liters of PCE were recovered. This paper describes preliminary scoping simulations of the surfactant flushing process at the Borden test site to demonstrate the capability of UTCHEM to model surfactant-enhanced remediation of a non-aqueous-phase liquid (NAPL). A discussion of efforts to simulate PCE migration is also presented.« less

77 FR 68065 - Amendment of Class D and Class E Airspace; Lewiston, ID

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-15

... Measuring Equipment (VOR/ DME), and the Lewiston-Nez Perce Instrument Landing System (ILS) Localizer... feet or more above the surface of the earth. * * * * * ANM ID E5 Lewiston, ID [Modified] Lewiston-Nez...

Protect and Restore Lolo Creek Watershed, 2004-2005 Annual Report.

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

McRoberts, Heidi

2005-12-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Lolo Creek watershed are coordinated with the Clearwater National Forest and Potlatch Corporation. The Nez Perce Tribe began watershed restoration projects within the Lolo Creek watershed of the Clearwater River in 1996. Fencing to exclude cattle for stream banks, stream bank stabilization, decommissioning roads, and upgrading culverts are the primary focuses of this project. Riparian enhancement through planting of riparian trees and streambank bioengineering was completed. Culvert inventory was completed in 2004 on US Forestmore » Service and Potlatch Corporation lands in the Lolo Creek drainage. Two high priority culverts were replaced, and are now accessible for fish species. Four miles of road was decommissioned. Tribal crews completed maintenance to the previously built fence.« less

Protect and Restore Lolo Creek Watershed, 2002-2003 Annual Report.

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

McRoberts, Heidi

2004-01-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Lolo Creek watershed are coordinated with the Clearwater National Forest and Potlatch Corporation. The Nez Perce Tribe began watershed restoration projects within the Lolo Creek watershed of the Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing, stabilizing streambanks, decommissioning roads, and upgrading culverts. During the years 2000-2003, trees were planted in riparian areas of headwater streams to Lolo Creek. Inventory of culvertsmore » is an on-going practice, being completed by sub-drainage, and are being prioritized for replacement to accommodate fish passage and 100-year flow events throughout the watershed. Tribal crews completed maintenance to the previously built fence.« less

Suppressive effect of wasabi (pungent Japanese spice) on gastric carcinogenesis induced by MNNG in rats.

PubMed

Tanida, N; Kawaura, A; Takahashi, A; Sawada, K; Shimoyama, T

1991-01-01

Dietary habits have been causally implicated in gastric carcinogenesis, whereas minor dietary items may also play a part. Wasabi is a popular pungent spice in Japanese meals. In this study the effect of wasabi on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis was studied in rats. Wistar WKY male rats received drinking water containing 50 micrograms/ml of MNNG or tap water alone and a basal diet (PCE-2) or PCE-2 containing 10% (wt/wt) of wasabi powder for 40 weeks. Thus, three groups were completed as MNNG + PCE-2 (n = 30), MNNG + wasabi (n = 30), and tap water + wasabi (n = 30). At autopsy, nine rats (30%) had seven glandular stomach tumors (2 adenocarcinomas, 2 adenomatous polyps, and 3 adenomatous glandular hyperplasias) and three duodenal adenocarcinomas in the MNNG + PCE-2 group, whereas in the MNNG + wasabi group, two rats (7%) had one forestomach epidermoid cyst and one duodenal carcinosarcoma (corrected chi 2 = 4.63, p less than 0.05 for incidences of glandular stomach tumors between 2 groups). In addition, two rats had microscopic atypical glands in the MNNG + PCE-2 group. There was no tumor in the tap water + wasabi group. These results indicated that glandular stomach carcinogenesis induced by MNNG was suppressed by the administration of wasabi.

Analysis of actuator delay and its effect on uncertainty quantification for real-time hybrid simulation

NASA Astrophysics Data System (ADS)

Chen, Cheng; Xu, Weijie; Guo, Tong; Chen, Kai

2017-10-01

Uncertainties in structure properties can result in different responses in hybrid simulations. Quantification of the effect of these uncertainties would enable researchers to estimate the variances of structural responses observed from experiments. This poses challenges for real-time hybrid simulation (RTHS) due to the existence of actuator delay. Polynomial chaos expansion (PCE) projects the model outputs on a basis of orthogonal stochastic polynomials to account for influences of model uncertainties. In this paper, PCE is utilized to evaluate effect of actuator delay on the maximum displacement from real-time hybrid simulation of a single degree of freedom (SDOF) structure when accounting for uncertainties in structural properties. The PCE is first applied for RTHS without delay to determine the order of PCE, the number of sample points as well as the method for coefficients calculation. The PCE is then applied to RTHS with actuator delay. The mean, variance and Sobol indices are compared and discussed to evaluate the effects of actuator delay on uncertainty quantification for RTHS. Results show that the mean and the variance of the maximum displacement increase linearly and exponentially with respect to actuator delay, respectively. Sensitivity analysis through Sobol indices also indicates the influence of the single random variable decreases while the coupling effect increases with the increase of actuator delay.

Serum-free suspension cultivation of PER.C6(R) cells and recombinant adenovirus production under different pH conditions.

PubMed

Xie, Liangzhi; Pilbrough, Warren; Metallo, Christian; Zhong, Tanya; Pikus, Lana; Leung, John; Auniņs, John G; Zhou, Weichang

2002-12-05

PER.C6(R) cell growth, metabolism, and adenovirus production were studied in head-to-head comparisons in stirred bioreactors under different pH conditions. Cell growth rate was found to be similar in the pH range of 7.1-7.6, while a long lag phase and a slower growth rate were observed at pH 6.8. The specific consumption rates of glucose and glutamine decreased rapidly over time during batch cell growth, as did the specific lactate and ammonium production rates. Cell metabolism in both infected and uninfected cultures was very sensitive to culture pH, resulting in dramatic differences in glucose/glutamine consumption and lactate/ammonium production under different pH conditions. It appeared that glucose metabolism was suppressed at low pH but the efficiency of energy production from glucose was enhanced. Adenovirus infection resulted in profound changes in cell growth and metabolism. Cell growth was largely arrested under all pH conditions, while glucose consumption and lactate production were elevated post virus infection. Virus infection induced a reduction in glutamine consumption at low pH but an increase at high pH. The optimal pH for adenovirus production was found to be 7.3 under the experimental conditions used in the study. Deviations from this optimum resulted in significant reductions of virus productivity. The results indicate that culture pH is a very critical process parameter in PER.C6(R) cell culture and adenovirus production. Copyright 2002 Wiley Periodicals, Inc.

Acute Exposure to Perchlorethylene alters Rat Visual Evoked Potentials in Relation to Brain Concentration

EPA Science Inventory

These experiments sought to establish a dose-effect relationship between the concentration of perchloroethylene (PCE) in brain tissue and concurrent changes in visual function. A physiologically-based pharmacokinetic (PBPK) model was implemented to predict concentrations of PCE ...

REDUCTIVE BIOTRANSFORMATION OF TETRACHLOROETHENE TO ETHENE DURING ANAEROBIC DEGRADATION OF TOLUENE: EXPERIMENTAL EVIDENCE AND KINETICS

EPA Science Inventory

Reductive biotransformation of tetrachloroethene (PCE) to ethene occurred during anaerobic degradation of toluene in an enrichment culture. Ethene was detected as a dominant daughter product of PCE dechlorination with negligible accumulation of other partially chlorinated ethenes...

75 FR 14131 - Effect on Propane Consumers of the Propane Education and Research Council's Operations, Market...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

... Education and Research Council (PERC), in conjunction with the cumulative effects of market changes and... the Secretary of Energy a report examining whether operation of the Council, in conjunction with the...

Occurrence of mental illness following prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water: a retrospective cohort study

PubMed Central

2012-01-01

Background While many studies of adults with solvent exposure have shown increased risks of anxiety and depressive disorders, there is little information on the impact of prenatal and early childhood exposure on the subsequent risk of mental illness. This retrospective cohort study examined whether early life exposure to tetrachloroethylene (PCE)-contaminated drinking water influenced the occurrence of depression, bipolar disorder, post-traumatic stress disorder, and schizophrenia among adults from Cape Cod, Massachusetts. Methods A total of 1,512 subjects born between 1969 and 1983 were studied, including 831 subjects with both prenatal and early childhood PCE exposure and 547 unexposed subjects. Participants completed questionnaires to gather information on mental illnesses, demographic and medical characteristics, other sources of solvent exposure, and residences from birth through 1990. PCE exposure originating from the vinyl-liner of water distribution pipes was assessed using water distribution system modeling software that incorporated a leaching and transport algorithm. Results No meaningful increases in risk ratios (RR) for depression were observed among subjects with prenatal and early childhood exposure (RR: 1.1, 95% CI: 0.9-1.4). However, subjects with prenatal and early childhood exposure had a 1.8-fold increased risk of bipolar disorder (N = 36 exposed cases, 95% CI: 0.9-1.4), a 1.5-fold increased risk post-traumatic stress disorder (N = 47 exposed cases, 95% CI: 0.9-2.5), and a 2.1-fold increased risk of schizophrenia (N = 3 exposed cases, 95% CI: 0.2-20.0). Further increases in the risk ratio were observed for bipolar disorder (N = 18 exposed cases, RR; 2.7, 95% CI: 1.3-5.6) and post-traumatic stress disorder (N = 18 exposed cases, RR: 1.7, 95% CI: 0.9-3.2) among subjects with the highest exposure levels. Conclusions The results of this study provide evidence against an impact of early life exposure to PCE on the risk of depression. In contrast, the results provide support for an impact of early life exposure on the risk of bipolar disorder and post-traumatic stress disorder. The number of schizophrenia cases was too small to draw reliable conclusions. These findings should be confirmed in investigations of other similarly exposed populations. PMID:22264316

Occurrence of mental illness following prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water: a retrospective cohort study.

PubMed

Aschengrau, Ann; Weinberg, Janice M; Janulewicz, Patricia A; Romano, Megan E; Gallagher, Lisa G; Winter, Michael R; Martin, Brett R; Vieira, Veronica M; Webster, Thomas F; White, Roberta F; Ozonoff, David M

2012-01-20

While many studies of adults with solvent exposure have shown increased risks of anxiety and depressive disorders, there is little information on the impact of prenatal and early childhood exposure on the subsequent risk of mental illness. This retrospective cohort study examined whether early life exposure to tetrachloroethylene (PCE)-contaminated drinking water influenced the occurrence of depression, bipolar disorder, post-traumatic stress disorder, and schizophrenia among adults from Cape Cod, Massachusetts. A total of 1,512 subjects born between 1969 and 1983 were studied, including 831 subjects with both prenatal and early childhood PCE exposure and 547 unexposed subjects. Participants completed questionnaires to gather information on mental illnesses, demographic and medical characteristics, other sources of solvent exposure, and residences from birth through 1990. PCE exposure originating from the vinyl-liner of water distribution pipes was assessed using water distribution system modeling software that incorporated a leaching and transport algorithm. No meaningful increases in risk ratios (RR) for depression were observed among subjects with prenatal and early childhood exposure (RR: 1.1, 95% CI: 0.9-1.4). However, subjects with prenatal and early childhood exposure had a 1.8-fold increased risk of bipolar disorder (N = 36 exposed cases, 95% CI: 0.9-1.4), a 1.5-fold increased risk post-traumatic stress disorder (N = 47 exposed cases, 95% CI: 0.9-2.5), and a 2.1-fold increased risk of schizophrenia (N = 3 exposed cases, 95% CI: 0.2-20.0). Further increases in the risk ratio were observed for bipolar disorder (N = 18 exposed cases, RR; 2.7, 95% CI: 1.3-5.6) and post-traumatic stress disorder (N = 18 exposed cases, RR: 1.7, 95% CI: 0.9-3.2) among subjects with the highest exposure levels. The results of this study provide evidence against an impact of early life exposure to PCE on the risk of depression. In contrast, the results provide support for an impact of early life exposure on the risk of bipolar disorder and post-traumatic stress disorder. The number of schizophrenia cases was too small to draw reliable conclusions. These findings should be confirmed in investigations of other similarly exposed populations.

The importance of stress, self-efficacy, and self-medication for pharmacological neuroenhancement among employees and students.

PubMed

Maier, Larissa J; Haug, Severin; Schaub, Michael P

2015-11-01

This study examined the relationship between stress, self-efficacy, self-medication, and pharmacological neuroenhancement (PNE) in the Swiss general population. Using the largest Swiss Internet panel, a sample of 10,171 employees and students (unweighted N=10,084) aged 15-74 years was recruited and asked to complete a self-administered online survey. The data were weighted for age, sex, and language region to provide results that were representative of the Swiss population. Multinomial logistic regression models were conducted to identify predictors of pharmacological cognitive enhancement (PCE) and pharmacological mood enhancement (PME) over the past year. Two self-medication models and an overall model were determined. Current medical treatment for a mental disorder was the best predictor of both PCE and PME use as serious self-medication. The overall model revealed that cannabis use, frequent stress, and long-term stress were predictors of both PCE and PME, whereas negative stressors and time pressure at work did not remain in the final model. Furthermore, past-year PCE with and without PME was associated with being male, being a student, and using illegal drugs other than cannabis, whereas being female and having low self-efficacy predicted past-year PME only. Consideration of the predictor variables identified in this study may help to identify the potential PCE and PME users for whom measures to prevent drug abuse and manage stress are most appropriate. More specifically, the use of PCE and PME as self-medication to enhance performance at work or while studying needs further consideration in the neuroenhancement debate. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Insights into the use of time-lapse GPR data as observations for inverse multiphase flow simulations of DNAPL migration

USGS Publications Warehouse

Johnson, R.H.; Poeter, E.P.

2007-01-01

Perchloroethylene (PCE) saturations determined from GPR surveys were used as observations for inversion of multiphase flow simulations of a PCE injection experiment (Borden 9??m cell), allowing for the estimation of optimal bulk intrinsic permeability values. The resulting fit statistics and analysis of residuals (observed minus simulated PCE saturations) were used to improve the conceptual model. These improvements included adjustment of the elevation of a permeability contrast, use of the van Genuchten versus Brooks-Corey capillary pressure-saturation curve, and a weighting scheme to account for greater measurement error with larger saturation values. A limitation in determining PCE saturations through one-dimensional GPR modeling is non-uniqueness when multiple GPR parameters are unknown (i.e., permittivity, depth, and gain function). Site knowledge, fixing the gain function, and multiphase flow simulations assisted in evaluating non-unique conceptual models of PCE saturation, where depth and layering were reinterpreted to provide alternate conceptual models. Remaining bias in the residuals is attributed to the violation of assumptions in the one-dimensional GPR interpretation (which assumes flat, infinite, horizontal layering) resulting from multidimensional influences that were not included in the conceptual model. While the limitations and errors in using GPR data as observations for inverse multiphase flow simulations are frustrating and difficult to quantify, simulation results indicate that the error and bias in the PCE saturation values are small enough to still provide reasonable optimal permeability values. The effort to improve model fit and reduce residual bias decreases simulation error even for an inversion based on biased observations and provides insight into alternate GPR data interpretations. Thus, this effort is warranted and provides information on bias in the observation data when this bias is otherwise difficult to assess. ?? 2006 Elsevier B.V. All rights reserved.

Teens With Heavy Prenatal Cocaine Exposure Respond to Experimental Social Provocation with Escape Not Aggression

PubMed Central

Greenwald, M.K.; Chiodo, L.M.; Hannigan, J.H.; Sokol, R.J.; Janisse, J.; Delaney-Black, V.

2010-01-01

Preclinical data show that, compared to no exposure, prenatal cocaine exposure (PCE) has age-dependent effects on social interaction and aggression. The aim of this clinical study was to determine how heavy/persistent PCE – after controlling for other prenatal drug exposures, sex and postnatal factors – predicts behavioral sensitivity to provocation (i.e., reactive aggression) using a well-validated human laboratory model of aggression. African American teens (mean = 14.2 yrs old) with histories of heavy/persistent PCE (maternal cocaine use ≥ 2 times/week during pregnancy, or positive maternal or infant urine/meconium test at delivery; n = 86) or none/some exposure (NON: maternal cocaine use < 2 times/week during pregnancy; n = 330) completed the Point Subtraction Aggression Paradigm. In this task, teens competed in a computer game against a fictitious opponent. There were three possible responses: (a) earn points, to exchange for money later; or (b) “aggress” against the fictitious opponent by subtracting their points; or (c) escape temporarily from point subtraction perpetrated by the fictitious opponent. The PCE group responded significantly more frequently on the escape option than the NON group, but did not differ in aggressive or money-earning responses. These data indicate that PCE-teens provoked with a social stressor exhibit a behavioral preference for escape (negative reinforcement) more than for aggressive (retaliatory) or appetitive (point- or money-reinforced) responses. These findings are consistent with preclinical data showing that social provocation of adolescent or young adult offspring after PCE is associated with greater escape behavior, inferring greater submission, social withdrawal, or anxiety, as opposed to aggressive behavior. PMID:20600841

Synergistic effects of chlorination and a fully two-dimensional side-chain design on molecular energy level modulation toward non-fullerene photovoltaics

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

Chao, Pengjie; Wang, Huan; Mo, Daize

By taking the advantage of chlorination and fully conjugated side chains,2D-PBTClshows a PCE of up to 8.81% in non-fullerene solar cells, which corresponds to an approximately 28% improvement compared to that ofPTB7-Th-based devices.

Synergistic effects of chlorination and a fully two-dimensional side-chain design on molecular energy level modulation toward non-fullerene photovoltaics

DOE PAGES

Chao, Pengjie; Wang, Huan; Mo, Daize; ...

2017-12-18

By taking the advantage of chlorination and fully conjugated side chains,2D-PBTClshows a PCE of up to 8.81% in non-fullerene solar cells, which corresponds to an approximately 28% improvement compared to that ofPTB7-Th-based devices.

Interfacial engineering of electron transport layer using Caesium Iodide for efficient and stable organic solar cells

NASA Astrophysics Data System (ADS)

Upama, Mushfika Baishakhi; Elumalai, Naveen Kumar; Mahmud, Md Arafat; Wright, Matthew; Wang, Dian; Xu, Cheng; Haque, Faiazul; Chan, Kah Howe; Uddin, Ashraf

2017-09-01

Polymer solar cells (PSCs) have gained immense research interest in the recent years predominantly due to low-cost, solution process-ability, and facile device fabrication. However, achieving high stability without compromising the power conversion efficiency (PCE) serves to be an important trade-off for commercialization. In line with this, we demonstrate the significance of incorporating a CsI/ZnO bilayer as electron transport layer (ETL) in the bulk heterojunction PSCs employing low band gap polymer (PTB7) and fullerene (PC71BM) as the photo-active layer. The devices with CsI/ZnO interlayer exhibited substantial enhancement of 800% and 12% in PCE when compared to the devices with pristine CsI and pristine ZnO as ETL, respectively. Furthermore, the UV and UV-ozone induced degradation studies revealed that the devices incorporating CsI/ZnO bilayer possess excellent decomposition stability (∼23% higher) over the devices with pristine ZnO counterparts. The incorporation of CsI between ITO and ZnO was found to favorably modify the energy-level alignment at the interface, contributing to the charge collection efficiency as well as protecting the adjacent light absorbing polymer layers from degradation. The mechanism behind the improvement in PCE and stability is analyzed using the electrochemical impedance spectroscopy and dark I-V characteristics.

Comparative analysis of risk-based cleanup levels and associated remediation costs using linearized multistage model (cancer slope factor) vs. threshold approach (reference dose) for three chlorinated alkenes

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

Lawton, L.J.; Mihalich, J.P.

1995-12-31

The chlorinated alkenes 1,1-dichloroethene (1,1-DCE), tetrachloroethene (PCE), and trichloroethene (TCE) are common environmental contaminants found in soil and groundwater at hazardous waste sites. Recent assessment of data from epidemiology and mechanistic studies indicates that although exposure to 1,1-DCE, PCE, and TCE causes tumor formation in rodents, it is unlikely that these chemicals are carcinogenic to humans. Nevertheless, many state and federal agencies continue to regulate these compounds as carcinogens through the use of the linearized multistage model and resulting cancer slope factor (CSF). The available data indicate that 1,1-DCE, PCE, and TCE should be assessed using a threshold (i.e., referencemore » dose [RfD]) approach rather than a CSF. This paper summarizes the available metabolic, toxicologic, and epidemiologic data that question the use of the linear multistage model (and CSF) for extrapolation from rodents to humans. A comparative analysis of potential risk-based cleanup goals (RBGs) for these three compounds in soil is presented for a hazardous waste site. Goals were calculated using the USEPA CSFs and using a threshold (i.e., RfD) approach. Costs associated with remediation activities required to meet each set of these cleanup goals are presented and compared.« less

Kinetics of micronucleus induction and cytotoxicity caused by distinct antineoplastics and alkylating agents in vivo.

PubMed

Morales-Ramírez, Pedro; Vallarino-Kelly, Teresita; Cruz-Vallejo, Virginia

2014-01-30

This mini-review aims to compare the differences in the kinetics of the induction of micronucleated polychromatic erythrocytes (MN-PCE) and cytotoxicity by distinct antineoplastic and genotoxic agents in murine peripheral blood in vivo and to correlate these kinetics with the underlying processes. Comparisons were carried out using our previously obtained data with nominal doses causing similar levels of cytotoxicity, as measured in terms reduction of PCE. The aneuploidogens caused the most rapid induction of MN-PCEs and had the highest rates of cytotoxicity and genotoxicity. The promutagens cyclophosphamide and dimethylnitrosamine showed the most delayed responses and had the lowest genotoxic and cytotoxic efficiencies. DNA crosslinking agents had a similar delay of 4-5 h, greater than those of aneuploidogens, but differed in their cytotoxic and genotoxic efficiencies. Methylnitrosourea and 5-aza-cytidine caused greater delays than crosslinking agents. These delays can be due to the methylnitrosourea-mediated induction of formation of mono alkyl adducts which are interpreted as mismatches during DNA duplication, whereas 5-aza-cytidine requires incorporation into the DNA to induce breakage. This review allows us to conclude that the requirement for metabolic activation and the mechanisms of DNA breakage and of micronucleus induction are the main factors that affect the time of maximal MN-PCE induction. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Benzothiadiazole Versus Thiophene: Influence of the Auxiliary Acceptor on the Photovoltaic Properties of Donor-Acceptor-Based Copolymers.

PubMed

Li, Zongbo; Weng, Kangkang; Chen, Aihua; Sun, Xiaobo; Wei, Donghui; Yu, Mingming; Huo, Lijun; Sun, Yanming

2018-01-01

Two donor-acceptor (D-A) type conjugated copolymers, P1 and P2, are designed and synthesized. A classical benzothiadiazole acceptor is used to replace a thiophene unit in the polymer chain of P1 to obtain P2 terpolymer. Compared with P1, P2 exhibits broader absorption spectra, higher absorption coefficient, deeper lowest unoccupied molecular orbital level, and a relatively lower band gap. As a result, the P2-based solar cell exhibits a high power conversion efficiency (PCE) of 6.60%, with a short-circuit current (J sc ) of 12.43 mA cm -2 , and a fill factor (FF) of 73.1%, which are higher than those of the P1-based device with a PCE of 4.70%, a J sc of 9.43 mA cm -2 , and an FF of 61.6%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Incorporation of quaternary ammonium salts containing different counterions to improve the performance of inverted perovskite solar cells

NASA Astrophysics Data System (ADS)

Yan, Po-Ruei; Huang, Wei-Jie; Yang, Sheng-Hsiung

2017-02-01

In this research, three quaternary ammonium salts containing different counterions, including tetrabutylammonium bromide (TBABr), tetrabutylammonium tetrafluoroborate (TBABF4), and tetrabutylammonium hexafluorophosphate (TBAPF6), were incorporated into [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) as electron transporting layer (ETL). These salts-doped PCBM films revealed higher electron mobility and Fermi levels compared with the un-doped one. Better charge transfer at the interface between perovskite and salts-doped PCBM was also obtained from PL quenching experiments. Inverted perovskite solar cells with the configuration of ITO/PEDOT:PSS/CH3NH3PbI3/PCBM + salts/Ag were fabricated, and the JSC and FF of devices were significantly enhanced using salts-doped PCBM as ETL. The best device based on TBABF4-doped PCBM delivered a power conversion efficiency (PCE) up to 13.41%, which was superior to the one with undoped PCBM layer (PCE = 8.77%).

Synergistic degradation of chlorinated hydrocarbons with microorganisms and zero valent iron

NASA Astrophysics Data System (ADS)

Schöftner, Philipp; Summer, Dorothea; Leitner, Simon; Watzinger, Andrea; Wimmer, Bernhard; Reichenauer, Thomas

2016-04-01

Sites contaminated with chlorinated hydrocarbons (CHC) are located mainly within build-up regions. Therefore in most cases only in-situ technologies without excavation of soil material can be used for remediation. This project examines a novel in-situ remediation method, in which the biotic degradation via bacteria is combined with abiotic degradation via zero-valent iron particles (ZVI). ZVI particles are injected into the aquifer where CHC-molecules are reductively dechlorinated. However Fe0 is also oxidized by reaction with water leading to generation of H2 without any CHC degradation. To achieve biotic degradation often strictly anaerobic strains of the bacteria Dehalococcoides are used. These bacteria can dechlorinate CHC by utilizing H2. By combining these processes the H2, produced during the anaerobic corrosion of Fe0, could be used by bacteria for further CHC degradation. Therefore the amount of used Fe0 and as a consequence also remediation costs could be reduced. Additionally the continuous supply of H2 could make the bacterial degradation more controllable. Different Fe0 particles (nano- and micro-scale) were tested for their perchloroethene (PCE) degradation rate and H2 production rate in microcosms. PCE-degradation rate by different bacterial cultures was investigated in the same microcosm system. In course of these experiments the 13C enrichment factors of the PCE degradation of the different particles and cultures were determined to enable the differentiation of biotic and abiotic degradation. Preliminary results showed, that the nano-scale particles reacted faster with PCE and water than their micro-scaled counterparts. The PCE degradation via micro-scaled particles lead to 13C enrichment factors in the range of -3,6 ‰ ± 0,6 to -9,5 ‰ ± 0,2. With one of the examined bacterial cultures a fast reduction of PCE to ethene was observed. Although PCE and TCE were completely degraded by this culture the metabolites DCE and VC could still be detected. Further microcosm experiments will be implemented by the time of the EGU General Assembly 2016. In the framework of these experiments other bacterial cultures and ZVI particles as well as the combination of biotic and abiotic dehalogenation will be investigated.

Graphene oxide as a p-dopant and an anti-reflection coating layer, in graphene/silicon solar cells

NASA Astrophysics Data System (ADS)

Yavuz, S.; Kuru, C.; Choi, D.; Kargar, A.; Jin, S.; Bandaru, P. R.

2016-03-01

It is shown that coating graphene-silicon (Gr/Si) Schottky junction based solar cells with graphene oxide (GO) improves the power conversion efficiency (PCE) of the cells, while demonstrating unprecedented device stability. The PCE has been shown to be increased to 10.6% (at incident radiation of 100 mW cm-2) for the Gr/Si solar cell with an optimal GO coating thickness compared to 3.6% for a bare/uncoated Gr/Si solar cell. The p-doping of graphene by the GO, which also serves as an antireflection coating (ARC) has been shown to be a main contributing factor to the enhanced PCE. A simple spin coating process has been used to apply GO with thickness commensurate with an anti-refection coating (ARC) and indicates the suitability of the developed methodology for large-scale solar cell assembly.It is shown that coating graphene-silicon (Gr/Si) Schottky junction based solar cells with graphene oxide (GO) improves the power conversion efficiency (PCE) of the cells, while demonstrating unprecedented device stability. The PCE has been shown to be increased to 10.6% (at incident radiation of 100 mW cm-2) for the Gr/Si solar cell with an optimal GO coating thickness compared to 3.6% for a bare/uncoated Gr/Si solar cell. The p-doping of graphene by the GO, which also serves as an antireflection coating (ARC) has been shown to be a main contributing factor to the enhanced PCE. A simple spin coating process has been used to apply GO with thickness commensurate with an anti-refection coating (ARC) and indicates the suitability of the developed methodology for large-scale solar cell assembly. Electronic supplementary information (ESI) available: (i) Experimental methods, (ii) optical images of devices with and without graphene oxide (GO), (iii) comparison of the power conversion efficiency (PCE) due to the GO coating and nitric acid doping, (iv) specular and diffuse reflectance measurements, (v) stability data of pristine graphene/silicon (Gr/Si) solar cells. See DOI: 10.1039/c5nr09143h

The Membrane-Bound C Subunit of Reductive Dehalogenases: Topology Analysis and Reconstitution of the FMN-Binding Domain of PceC

PubMed Central

Buttet, Géraldine F.; Willemin, Mathilde S.; Hamelin, Romain; Rupakula, Aamani; Maillard, Julien

2018-01-01

Organohalide respiration (OHR) is the energy metabolism of anaerobic bacteria able to use halogenated organic compounds as terminal electron acceptors. While the terminal enzymes in OHR, so-called reductive dehalogenases, are well-characterized, the identity of proteins potentially involved in electron transfer to the terminal enzymes remains elusive. Among the accessory genes identified in OHR gene clusters, the C subunit (rdhC) could well code for the missing redox protein between the quinol pool and the reductive dehalogenase, although it was initially proposed to act as transcriptional regulator. RdhC sequences are characterized by the presence of multiple transmembrane segments, a flavin mononucleotide (FMN) binding motif and two conserved CX3CP motifs. Based on these features, we propose a curated selection of RdhC proteins identified in general sequence databases. Beside the Firmicutes from which RdhC sequences were initially identified, the identified sequences belong to three additional phyla, the Chloroflexi, the Proteobacteria, and the Bacteriodetes. The diversity of RdhC sequences mostly respects the phylogenetic distribution, suggesting that rdhC genes emerged relatively early in the evolution of the OHR metabolism. PceC, the C subunit of the tetrachloroethene (PCE) reductive dehalogenase is encoded by the conserved pceABCT gene cluster identified in Dehalobacter restrictus PER-K23 and in several strains of Desulfitobacterium hafniense. Surfaceome analysis of D. restrictus cells confirmed the predicted topology of the FMN-binding domain (FBD) of PceC that is the exocytoplasmic face of the membrane. Starting from inclusion bodies of a recombinant FBD protein, strategies for successful assembly of the FMN cofactor and refolding were achieved with the use of the flavin-trafficking protein from D. hafniense TCE1. Mass spectrometry analysis and site-directed mutagenesis of rFBD revealed that threonine-168 of PceC is binding FMN covalently. Our results suggest that PceC, and more generally RdhC proteins, may play a role in electron transfer in the metabolism of OHR. PMID:29740408

Static Force-Deflection Properties of Automobile Steering Components

DOT National Transportation Integrated Search

1987-06-01

This report provides the static force-deflection test results for 28 steering columns and 24 steering wheels used in domestic and import passener cars from model year 1975 to 1985. The steering columns and wheels tested include approzimately 90 perce...

Speed limits set lower than engineering recommendations : project summary report.

DOT National Transportation Integrated Search

2016-08-01

The Montana Department of Transportation (MDT) generally ensures that posted speed limits are set in accordance with engineering recommendations, which means that speed limits are typically set such that they are about equal to the observed 85th-perc...

2005 survey of seat belt wearing rates

DOT National Transportation Integrated Search

2005-01-01

The 2005 seat belt survey showed a minor improvement in driver wearing : rates. Over the 2003 2005 period, estimated wearing rates for male drivers : increased by one percentage point to 83 per cent, and for female drivers : increased by two perc...

PROPERTY CHANGES IN AQUEOUS SOLUTIONS DUE TO SURFACTANT TREATMENT OF PCE: IMPLICATIONS TO GEOPHYSICAL MEASUREMENTS

EPA Science Inventory

Select physicochemical properties of aqueous solutions composed of surfactants, dye, and

perchloroethylene (PCE) were evaluated through a response surface quadratic design

model of experiment. Nine surfactants, which are conventionally used in the

remediation...

Peak Communication Experiences: Concept, Structure, and Sex Differences.

ERIC Educational Resources Information Center

Gordon, Ron; Dulaney, Earl

A study was conducted to test a "peak communication experience" (PCE) scale developed from Abraham Maslow's theory of PCE's, a model of one's highest interpersonal communication moments in terms of perceived mutual understanding, happiness, and personal fulfillment. Nineteen items, extrapolated from Maslow's model but rendered more…

Geochemical, isotopic, and dissolved gas characteristics of groundwater in a fractured crystalline-rock aquifer, Savage Municipal Well Superfund site, Milford, New Hampshire, 2011

USGS Publications Warehouse

Harte, Philip T.

2013-01-01

Tetrachloroethylene (PCE), a volatile organic compound, was detected in groundwater from deep (more than (>) 300 feet (ft) below land surface) fractures in monitoring wells tapping a crystalline-rock aquifer beneath operable unit 1 (OU1) of the Savage Municipal Well Superfund site (Weston, Inc., 2010). Operable units define remedial areas of contaminant concern. PCE contamination within the fractured-rock aquifer has been designated as a separate operable unit, operable unit 3 (OU3; Weston, Inc., 2010). PCE contamination was previously detected in the overlying glacial sand and gravel deposits and basal till, hereafter termed the Milford-Souhegan glacial-drift (MSGD) aquifer (Harte, 2004, 2006). Operable units 1 and 2 encompass areas within the MSGD aquifer, whereas the extent of the underlying OU3 has yet to be defined. The primary original source of contamination has been identified as a former manufacturing facility—the OK Tool manufacturing facility; hence OU1 sometimes has been referred to as the OK Tool Source Area (New Hampshire Department of Environmental Services, undated). A residential neighborhood of 30 to 40 houses is located in close proximity (one-quarter of a mile) from the PCE-contaminated monitoring wells. Each house has its own water-supply well installed in similar rocks as those of the monitoring wells, as indicated by the New Hampshire State geologic map (Lyons and others, 1997). An investigation was initiated in 2010 by the U.S. Environmental Protection Agency (USEPA) region 1, and the New Hampshire Department of Environmental Services (NHDES) to assess the potential for PCE transport from known contaminant locations (monitoring wells) to the residential wells. The U.S. Geological Survey (USGS) and the NHDES entered into a cooperative agreement in 2011 to assist in the evaluation of PCE transport in the fractured-rock aquifer. Periodic sampling over the last decade by the USEPA and NHDES has yet to detect PCE in groundwater from the residential-supply wells (as of 2012). However, part of assessing the potential for PCE transport involves understanding the origin of the groundwater in the monitoring and residential wells. One of the tools in delineating the movement of groundwater to wells, particularly in complex, highly heterogeneous fractured-rock aquifers, is the understanding of the geochemical and isotopic composition of groundwater (Lipfert and Reeve, 2004; Harte and others, 2012). This report summarizes findings from analyses of geochemical, isotopic, and dissolved gas characteristics of groundwater. Samples of groundwater were collected in 2011 from monitoring wells and nearby residential-supply wells in proximity to OU1.

Effects of prenatal cocaine exposure on social development in mice.

PubMed

Kabir, Zeeba D; Kennedy, Bruce; Katzman, Aaron; Lahvis, Garet P; Kosofsky, Barry E

2014-01-01

Prenatal cocaine exposure (PCE) in humans and animals has been shown to impair social development. Molecules that mediate synaptic plasticity and learning in the medial prefrontal cortex (mPFC), specifically brain-derived neurotrophic factor (BDNF) and its downstream signaling molecule, early growth response protein 1 (egr1), have been shown to affect the regulation of social interactions (SI). In this study we determined the effects of PCE on SI and the corresponding ultrasonic vocalizations (USVs) in developing mice. Furthermore, we studied the PCE-induced changes in the constitutive expression of BDNF, egr1 and their transcriptional regulators in the mPFC as a possible molecular mechanism mediating the altered SI. In prenatal cocaine-exposed (PCOC) mice we identified increased SI and USV production at postnatal day (PD) 25, and increased SI but not USVs at PD35. By PD45 the expression of both social behaviors normalized in PCOC mice. At the molecular level, we found increased BDNF exon IV and egr1 mRNA in the mPFC of PCOC mice at PD30 that normalized by PD45. This was concurrent with increased EGR1 protein in the mPFC of PCOC mice at PD30, suggesting a role of egr1 in the enhanced SI observed in juvenile PCOC mice. Additionally, by measuring the association of acetylation of histone 3 at lysine residues 9 and 14 (acH3K9,14) and MeCP2 at the promoters of BDNF exons I and IV and egr1, our results provide evidence of promoter-specific alterations in the mPFC of PCOC juvenile mice, with increased association of acH3K9,14 only at the BDNF exon IV promoter. These results identify a potential PCE-induced molecular alteration as the underlying neurobiological mechanism mediating the altered social development in juvenile mice. © 2014 S. Karger AG, Basel.

Detection of new VOC compounds with iCRDS

NASA Astrophysics Data System (ADS)

Huang, H.; Leen, J. B.; Gardner, A.; Gupta, M.; Baer, D. S.

2015-12-01

The instrument at Los Gatos Research (a member of ABB Inc.) which is based on incoherent cavity ringdown spectroscopy (iCRDS) that operates in the mid-infrared (bands from 860-1060 cm-1 or 970-1280 cm-1) is capable of detecting a broad range of VOCs, in situ, continuously and autonomously, for example, BTEX compounds (benzene, toluene, ethylbenzene, xylene), including differentiation of xylene isomers. Previously, we have demonstrated the measurement of trichloroethylene (TCE) in zero air with a precision of 0.17 ppb (1σ in 4 minutes), and the measurement of tetrachloroethylene (PCE) with a precision of 0.15 ppb (1σ in 4 minutes). Both of these measured precisions exceed the EPA's commercial building action limit, which for TCE is 0.92 ppb (5 µg/m3) and for PCE is 0.29 ppb (2 µg/m3). This ability has been fully demonstrated by the deployment of the instrument to the Superfund site at Moffett Naval Air Station in Mountain View, California where contaminated ground water results in vapor intrusion of TCE and PCE. For two weeks, the instrument operated continuously and autonomously, successfully measuring TCE and PCE concentrations in both the breathing zone and steam tunnel air, in excellent agreement with previous TO-15 data. In this poster, we present laboratory performance data targeting new toxic molecules with the same instrument. We have demonstrated the measurement of trichlorofluolomethane (Freon 11) in zero air with a precision of 1 ppb (3σ at 1075cm-1), and hexafluoropropene in zero air with a precision of about 0.3 ppb (3σ per spectrum). The iCRDS instrument has shown the ability to continuously and autonomously measure sub-ppb levels of toxic VOCs in the lab/field, offering an unprecedented picture of the short term dynamics associated with vapor intrusion and ground water pollution.

A material combination principle for highly efficient polymer solar cells investigated by mesoscopic phase heterogeneity

NASA Astrophysics Data System (ADS)

Yan, Han; Li, Denghua; He, Chang; Wei, Zhixiang; Yang, Yanlian; Li, Yongfang

2013-11-01

Organic solar cells have become a promising energy conversion candidate because of their unique advantages. Novel fullerene derivatives, as a common acceptor, can increase power conversion efficiency (PCE) by increasing the open-circuit voltage. As a representative acceptor, Indene-C60 bisadduct (ICBA) can reach high efficiency with poly(3-hexylthiophene) (P3HT). On the other hand, the novel synthesized polymers mainly aimed to broaden the optical absorption range have steadily promoted efficiency to higher than 9%. However, it is challenging to obtain the desired result by simply combining ICBA with other high-efficiency donors. Thus, P3HT or a high-efficiency polymer PBDTTT-C-T (copolymer of thienyl-substituted BDT with substituted TT) is used as donor and PCBM or ICBA as acceptor in this article to clarify the mechanism behind these materials. The optical and photovoltaic properties of the materials are studied for pair-wise combination. Among these four material groups, the highest PCE of 6.2% is obtained for the PBDTTT-C-T/PCBM combination while the lowest PCE of 3.5% is obtained for the PBDTTT-C-T/ICBA combination. The impact of the mesoscopic heterogeneity on the local mesoscopic photoelectric properties is identified by photo-conductive AFM (pc-AFM), and the consistence between the mesoscopic properties and the macroscopic device performances is also observed. Based on these results, an interface combined model is proposed based on the mesoscopic phase heterogeneity. This study provides a new view on the rational selection of photovoltaic materials, where, aside from the traditional energy level and absorption spectrum matching, the matching of mesoscopic heterogeneity must also be considered.Organic solar cells have become a promising energy conversion candidate because of their unique advantages. Novel fullerene derivatives, as a common acceptor, can increase power conversion efficiency (PCE) by increasing the open-circuit voltage. As a representative acceptor, Indene-C60 bisadduct (ICBA) can reach high efficiency with poly(3-hexylthiophene) (P3HT). On the other hand, the novel synthesized polymers mainly aimed to broaden the optical absorption range have steadily promoted efficiency to higher than 9%. However, it is challenging to obtain the desired result by simply combining ICBA with other high-efficiency donors. Thus, P3HT or a high-efficiency polymer PBDTTT-C-T (copolymer of thienyl-substituted BDT with substituted TT) is used as donor and PCBM or ICBA as acceptor in this article to clarify the mechanism behind these materials. The optical and photovoltaic properties of the materials are studied for pair-wise combination. Among these four material groups, the highest PCE of 6.2% is obtained for the PBDTTT-C-T/PCBM combination while the lowest PCE of 3.5% is obtained for the PBDTTT-C-T/ICBA combination. The impact of the mesoscopic heterogeneity on the local mesoscopic photoelectric properties is identified by photo-conductive AFM (pc-AFM), and the consistence between the mesoscopic properties and the macroscopic device performances is also observed. Based on these results, an interface combined model is proposed based on the mesoscopic phase heterogeneity. This study provides a new view on the rational selection of photovoltaic materials, where, aside from the traditional energy level and absorption spectrum matching, the matching of mesoscopic heterogeneity must also be considered. Electronic Supplementary Information (ESI) available. See DOI: 10.1039/c3nr03165a

Highly Efficient LiYF4:Yb(3+), Er(3+) Upconversion Single Crystal under Solar Cell Spectrum Excitation and Photovoltaic Application.

PubMed

Chen, Xu; Xu, Wen; Song, Hongwei; Chen, Cong; Xia, Haiping; Zhu, Yongsheng; Zhou, Donglei; Cui, Shaobo; Dai, Qilin; Zhang, Jiazhong

2016-04-13

Luminescent upconversion is a promising way to harvest near-infrared (NIR) sunlight and transforms it into visible light that can be directly absorbed by active materials of solar cells and improve their power conversion efficiency (PCE). However, it is still a great challenge to effectively improve the PCE of solar cells with the assistance of upconversion. In this work, we demonstrate the application of the transparent LiYF4:Yb(3+), Er(3+) single crystal as an independent luminescent upconverter to improve the PCE of perovskite solar cells. The LiYF4:Yb(3+), Er(3+) single crystal is prepared by an improved Bridgman method, and its internal quantum efficiency approached to 5.72% under 6.2 W cm(-2) 980 nm excitation. The power-dependent upconversion luminescence indicated that under the excitation of simulated sunlight the (4)F(9/2)-(4)I(15/2) red emission originally results from the cooperation of a 1540 nm photon and a 980 nm photon. Furthermore, when the single crystal is placed in front of the perovskite solar cells, the PCE is enhanced by 7.9% under the irradiation of simulated sunlight by 7-8 solar constants. This work implies the upconverter not only can serve as proof of principle for improving PCE of solar cells but also is helpful to practical application.

Uncertainty Quantification in CO 2 Sequestration Using Surrogate Models from Polynomial Chaos Expansion

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

Zhang, Yan; Sahinidis, Nikolaos V.

2013-03-06

In this paper, surrogate models are iteratively built using polynomial chaos expansion (PCE) and detailed numerical simulations of a carbon sequestration system. Output variables from a numerical simulator are approximated as polynomial functions of uncertain parameters. Once generated, PCE representations can be used in place of the numerical simulator and often decrease simulation times by several orders of magnitude. However, PCE models are expensive to derive unless the number of terms in the expansion is moderate, which requires a relatively small number of uncertain variables and a low degree of expansion. To cope with this limitation, instead of using amore » classical full expansion at each step of an iterative PCE construction method, we introduce a mixed-integer programming (MIP) formulation to identify the best subset of basis terms in the expansion. This approach makes it possible to keep the number of terms small in the expansion. Monte Carlo (MC) simulation is then performed by substituting the values of the uncertain parameters into the closed-form polynomial functions. Based on the results of MC simulation, the uncertainties of injecting CO{sub 2} underground are quantified for a saline aquifer. Moreover, based on the PCE model, we formulate an optimization problem to determine the optimal CO{sub 2} injection rate so as to maximize the gas saturation (residual trapping) during injection, and thereby minimize the chance of leakage.« less

Effect of biosurfactants on the aqueous solubility of PCE and TCE.

PubMed

Albino, John D; Nambi, Indumathi M

2009-12-01

The effect of biosurfactants on the solubility of tetrachloroethylene (PCE) and trichloroethylene (TCE) was studied in batch experiments pertaining to their use for solubilization and mobilization of such contaminants in surfactant enhanced aquifer remediation. Biosurfactants, rhamnolipid and surfactin used in solubility studies were synthesized in our laboratory by Pseudomonas aeruginosa (MTCC 2297) and Bacillus subtilis (MTCC 2423), respectively. The efficiency of the biosurfactants in solubilizing the chlorinated solvents was compared to that of synthetic surfactants. The Weight Solubilization Ratio (WSR) values for solubilization of PCE and TCE by biosurfactants were very high compared to the values obtained for synthetic surfactants. Surfactin proved to be a better surfactant over rhamnolipid. The WSR of surfactin on solubilization of PCE and TCE were 3.83 and 12.5, respectively, whereas the values obtained for rhamnolipid were 2.06 and 8.36. The solubility of the chlorinated solvents by biosurfactants was considerably affected by the changes in pH. The aqueous solubility of PCE and TCE increased tremendously with decrease in pH. The solubility of biosurfactants was observed to decrease with the pH, favoring partitioning of surfactants into the chlorinated solvents in significant amounts at lower pH. The excessive accumulation of biosurfactants at the interface facilitated interfacial tension reductions resulting in higher solubility of the chlorinated solvents at pH less than 7.

A Continuous Flow Column Study of the Anaerobic Transformation of a CAH Mixture of Tetrachloroethene and Carbon Tetrachloride Using Formate as an Electron Donor

NASA Astrophysics Data System (ADS)

Semprini, L.; Azizian, M. F.; Kim, Y.

2011-12-01

Many groundwater sites are contaminated with mixtures of chlorinated aliphatic hydrocarbons (CAHs) that represent a challenge when biological remediation processes are being considered. This is especially challenging when high concentrations of CAHs are present.Trichloromethane (CF), for example, has been observed to inhibit and potentially exert toxicity on reductive dehalogenation of tetrachloroethene (PCE) and trichloroethene (TCE). Results will be presented from a continuous flow column study where the simultaneous transformation of PCE and carbon tetrachloride (CT) was achieved. The column was packed with a quartz sand and bioaugmented with the Evanite Culture (EV) that is capable of transforming PCE to ethene. The column was fed a synthetic groundwater that was amended with PCE to achieve an influent concentration near its solubility limit (0.10 mM) and formate (1.5 mM) that reacts to produce hydrogen as the ultimate electron donor. The column was operated for over 1600 days prior to the addition of CT. During this period PCE was transformed mainly to vinyl chloride (VC) and ethene (ETH) and minor amounts of cis-dichloroethene (cis-DCE) and TCE. The transformation extent achieved based on the column effluent concentrations ranged from about 50% ETH, 30% VC, and 20 cis-DCE up to 80% ETH and 20% VC. When the column was fed sulfate, it was completely transformed via sulfate reduction. Ferrous iron production from ferric iron reduction was observed early in the study. Acetate was also formed as a result of homoacetogenesis from hydrogen utilization. CT addition (0.015 mM) was started at 1600 days while PCE addition was continued. During the first 25 days of CT addition, CT concentrations gradually increased to 50% of the injection concentration and chloromethane (CM) and CF were observed as transformation products. CT concentrations then decreased with over 98% transformation achieved.CM was removed to below the detection limit and CF concentration decreases to about 0.003 mM, representing 20% of the CT transformed. Other transformation products have not been identified. Neither methane nor carbon monoxide have been detected as transformation products. The transformation of PCE to ethene actually improved after the addition of CT. Thus, neither CT nor CF are inhibiting the reductive dehalogenation of PCE. The improvement in PCE transformation extent coincided with an increase in the aqueous hydrogen concentration from 5 nM, prior to CT addition, to 150 nM after CT addition. This increase in hydrogen was associated with the inhibition in acetate production and the increase in formate concentrations from below detection to 1.0 mM after CT addition. The results indicate that there are likely benefits in adding formate to produce hydrogen when contaminants are present that can inhibit fermentation. The results from the column study are consistent with our observations in batch reactors using the EV culture.

Evaluation of contaminated drinking water and preterm birth, small for gestational age, and birth weight at Marine Corps Base Camp Lejeune, North Carolina: a cross-sectional study.

PubMed

Ruckart, Perri Zeitz; Bove, Frank J; Maslia, Morris

2014-11-20

Births during 1968-1985 at Camp Lejeune were exposed to drinking water contaminated with trichloroethylene (TCE), tetrachloroethylene (PCE), and benzene. We conducted a cross-sectional study to evaluate associations between residential prenatal exposure to contaminated drinking water at Camp Lejeune during 1968-1985 and preterm birth, small for gestational age (SGA), term low birth weight (TLBW), and mean birth weight (MBW) deficit. Birth certificates identified mothers residing at Camp Lejeune at delivery. We analyzed exposure data for the entire pregnancy and individual trimesters. For each period examined, births were categorized as unexposed if mothers did not reside at Camp Lejeune or if their residence on base received uncontaminated drinking water. Ground water contaminant fate/transport and distribution system models provided monthly estimated contaminant levels at residences. For PCE and TCE, the exposed group was divided into four levels: < median value, ≥ median value, ≥75th percentile, and ≥90th percentile. For benzene, the exposed group was categorized as <1 part per billion (ppb) versus ≥1 ppb because of sparse data. Magnitude of effect estimates and exposure response relationships were used to assess associations. Confidence intervals (CIs) indicated precision of estimates. For the highest TCE exposure category during the entire pregnancy, odds ratios (ORs) were 1.5 (95% CI: 1.2, 1.9) and 1.3 (95% CI: 0.8, 2.2) for SGA and TLBW, respectively, and reduced MBW β = -78.3 g (95% CI: -115.0, -41.7). The OR =1.3 (95% CI: 1.0, 1.6) for preterm birth and the highest PCE exposure category during the entire pregnancy. Monotonic exposure-response relationships were observed for benzene exposure during the entire pregnancy and TLBW (highest category OR =1.5, 85% CI: 0.9, 2.3). Although a monotonic association between benzene and adjusted MBW difference was also observed (highest category β = -36.2 g, 95% CI: -72.3, -0.1), the association disappeared when TCE was also added to the model. We found no evidence suggesting any other associations between outcomes and exposures. Findings suggested associations between in utero exposures to TCE and SGA, TLBW and reduced MBW; benzene and TLBW; and PCE and preterm birth.

CHARACTERIZATION OF THE EFFECTS OF INHALED PERCHLOROETHYLENE ON SUSTAINED ATTENTION IN RATS PERFORMING A VISUAL SIGNAL DETECTION TASK

EPA Science Inventory

The aliphatic hydrocarbon perchloroethyelene (PCE) has been associated with neurobehavioral dysfunction including reduced attention in humans. The current study sought to assess the effects of inhaled PCE on sustained attention in rats performing a visual signal detection task (S...

EVALUATION OF GEOPHYSICAL METHODS FOR THE DETECTION OF SUBSURFACE TETRACHLOROETHYLENE IN CONTROLLED SPILL EXPERIMENTS

EPA Science Inventory

The purpose of the work was to determine the capability of various geophysical methods to detect PCE in the subsurface. Measurements were made with ten different geophysical techniques before, during, and after the PCE injection. This approach provided a clear identification of a...

FIELD MEASUREMENT OF VAPOR INTRUSION RATES AT A PCE SITE (ABSTRACT ONLY)

EPA Science Inventory

A field study was performed to evaluate vapor intrusion (VI) of tetrachloroethylene (PCE) and other chlorinated solvents at a commercial retail site in Dallas, TX. The building is approximately 40 years old and once housed a dry cleaning operation. Results from an initial site ch...

COMPLETE NATURAL ATTENUATION OF A PCE AND TCE PLUME AFTER SOURCE REMOVAL

EPA Science Inventory

Disposal of the chlorinated solvents PCE and TCE at the Twin Cities Army Ammunition Plant (TCAAP) resulted in the contamination of groundwater in a shallow, unconsolidated sand aquifer. The resulting plume had moved over 1000 feet from the disposal source area and had impacted p...

Effectiveness of rumble stripes on roadway safety in Mississippi.

DOT National Transportation Integrated Search

2009-12-01

Although traffic deaths are caused by an array of factors, in the United States more than half of all roadway : fatalities are caused by roadway departures [FHWA 2006]. In 2003, there were 25,562 roadway departure : fatalities, accounting for 55 perc...

The Way of Sweat.

ERIC Educational Resources Information Center

Leonhardy, Galen

2001-01-01

Presents a narrative description of experiences shared by the author, his father, and a Nez Perce man named Larry Greene. Explores those experiences in relation to institutionalized education in order to provide insight into not only subjugated ways of knowing but also alternative places of learning. (SG)

78 FR 1832 - Nez Perce-Clearwater National Forests; Id; Crooked River Valley Rehabilitation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-09

... the thirty-fourth through thirty-sixth lines, `` http://www.fs.fed.usinepa/fs-usda-pop.php/?project=40648 '' should read `` http://www.fs.fed.us/nepa/fs-usda-pop.php/?project=40648 ''. [FR Doc. C1-2012...

40 CFR 49.10404 - Source surveillance. [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Source surveillance. [Reserved] 49.10404 Section 49.10404 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER... Plan for the Nez Perce Tribe of Idaho § 49.10404 Source surveillance. [Reserved] ...

Priority chemical pollutants of drinking water in the city of Kazan: approach based on risk assessment

NASA Astrophysics Data System (ADS)

Stepanova, N. V.; Arkhipova, N. S.; Fomina, S. F.

2018-01-01

Assessment of non-carcinogenic risks from chemical substances ingested with drinking water included peroral, skin and inhalation routes of contact with water. The study was carried out for children aged 3-6 years living in 4 districts (zones) of the city of Kazan. Regional exposure factors (REF) at the median (Me) and the 95-th Percentile (95P) levels were identified according to the results of the questionnaire survey. The value of total hazard indices (THI) calculated with application of REF at the median (Me) and the 95-th Percentile (95P) levels made THIMe = 14.2 and 17.1, and THI 95perc = 13.03 and 16.3 in zones with a combined type of water supply. The ingestion of chemical substances with drinking water in different zones of the city of Kazan implies, alert and high levels of non-carcinogenic health risk for the child population.

Treatment of moderate hallux valgus by percutaneous, extra-articular reverse-L Chevron (PERC) osteotomy.

PubMed

Lucas y Hernandez, J; Golanó, P; Roshan-Zamir, S; Darcel, V; Chauveaux, D; Laffenêtre, O

2016-03-01

The aim of this study was to report a single surgeon series of consecutive patients with moderate hallux valgus managed with a percutaneous extra-articular reverse-L chevron (PERC) osteotomy. A total of 38 patients underwent 45 procedures. There were 35 women and three men. The mean age of the patients was 48 years (17 to 69). An additional percutaneous Akin osteotomy was performed in 37 feet and percutaneous lateral capsular release was performed in 22 feet. Clinical and radiological assessments included the type of forefoot, range of movement, the American Orthopedic Foot and Ankle (AOFAS) score, a subjective rating and radiological parameters. The mean follow-up was 59.1 months (45.9 to 75.2). No patients were lost to follow-up. The mean AOFAS score increased from 62.5 (30 to 80) pre-operatively to 97.1 (75 to 100) post-operatively. A total of 37 patients (97%) were satisfied. At the last follow up there was a statistically significant decrease in the hallux valgus angle, the intermetatarsal angle and the proximal articular set angle. The range of movement of the first metatarsophalangeal joint improved significantly.. There was more improvement in the range of movement in patients who had fixation of the osteotomy of the proximal phalanx. Preliminary results of this percutaneous approach are promising. This technique is reliable and reproducible. Its main asset is that it maintains an excellent range of movement. The PERC osteotomy procedure is an effective approach for surgical management of moderate hallux valgus which combines the benefits of percutaneous surgery with the versatility of the chevron osteotomy whilst maintaining excellent first MTPJ range of motion. ©2016 The British Editorial Society of Bone & Joint Surgery.

Training for percutaneous renal access on a virtual reality simulator.

PubMed

Zhang, Yi; Yu, Cheng-fan; Liu, Jin-shun; Wang, Gang; Zhu, He; Na, Yan-qun

2013-01-01

The need to develop new methods of surgical training combined with advances in computing has led to the development of virtual reality surgical simulators. The PERC Mentor(TM) is designed to train the user in percutaneous renal collecting system access puncture. This study aimed to validate the use of this kind of simulator, in percutaneous renal access training. Twenty-one urologists were enrolled as trainees to learn a fluoroscopy-guided percutaneous renal accessing technique. An assigned percutaneous renal access procedure was immediately performed on the PERC Mentor(TM) after watching instruction video and an analog operation. Objective parameters were recorded by the simulator and subjective global rating scale (GRS) score were determined. Simulation training followed and consisted of 2 hours daily training sessions for 2 consecutive days. Twenty-four hours after the training session, trainees were evaluated performing the same procedure. The post-training evaluation was compared to the evaluation of the initial attempt. During the initial attempt, none of the trainees could complete the appointed procedure due to the lack of experience in fluoroscopy-guided percutaneous renal access. After the short-term training, all trainees were able to independently complete the procedure. Of the 21 trainees, 10 had primitive experience in ultrasound-guided percutaneous nephrolithotomy. Trainees were thus categorized into the group of primitive experience and inexperience. The total operating time and amount of contrast material used were significantly lower in the group of primitive experience versus the inexperience group (P = 0.03 and 0.02, respectively). The training on the virtual reality simulator, PERC Mentor(TM), can help trainees with no previous experience of fluoroscopy-guided percutaneous renal access to complete the virtual manipulation of the procedure independently. This virtual reality simulator may become an important training and evaluation tool in teaching fluoroscopy-guided percutaneous renal access.

Origin of the ornamented bâton percé from the Gołębiewo site 47 as a trigger of discussion on long-distance exchange among Early Mesolithic communities of Central Poland and Northern Europe

PubMed Central

Witas, Henryk; Lisowska-Gaczorek, Aleksandra; Reitsema, Laurie; Szostek, Krzysztof; Płoszaj, Tomasz; Kuriga, Justyna; Makowiecki, Daniel; Jędrychowska-Dańska, Krystyna; Cienkosz-Stepańczak, Beata

2017-01-01

This article describes evidence for contact and exchange among Mesolithic communities in Poland and Scandinavia, based on the interdisciplinary analysis of an ornamented bâton percé from Gołębiewo site 47 (Central Poland). Typological and chronological-cultural analyses show the artefact to be most likely produced in the North European Plain, during the Boreal period. Carbon-14 dating confirms the antiquity of the artefact. Ancient DNA analysis shows the artefact to be of Rangifer tarandus antler. Following this species designation, a dispersion analysis of Early-Holocene reindeer remains in Europe was conducted, showing this species to exist only in northern Scandinavia and north-western Russia in this period. Therefore, the bâton from Gołębiewo constitutes the youngest reindeer remains in the European Plain and south-western Scandinavia known to date. An attempt was made to determine the biogeographic region from which the antler used to produce the artefact originates from. To this end, comprehensive δ18O, δ13C and δ15N isotope analyses were performed. North Karelia and South Lapland were determined as the most probable regions in terms of isotopic data, results which correspond to the known distribution range of Rangifer tarandus at this time. In light of these finds, the likelihood of contact between Scandinavia and Central Europe in Early Holocene is evaluated. The bâton percé from Gołębiewo is likely key evidence for long-distance exchange during the Boreal period. PMID:28977014

Origin of the ornamented bâton percé from the Gołębiewo site 47 as a trigger of discussion on long-distance exchange among Early Mesolithic communities of Central Poland and Northern Europe.

PubMed

Osipowicz, Grzegorz; Witas, Henryk; Lisowska-Gaczorek, Aleksandra; Reitsema, Laurie; Szostek, Krzysztof; Płoszaj, Tomasz; Kuriga, Justyna; Makowiecki, Daniel; Jędrychowska-Dańska, Krystyna; Cienkosz-Stepańczak, Beata

2017-01-01

This article describes evidence for contact and exchange among Mesolithic communities in Poland and Scandinavia, based on the interdisciplinary analysis of an ornamented bâton percé from Gołębiewo site 47 (Central Poland). Typological and chronological-cultural analyses show the artefact to be most likely produced in the North European Plain, during the Boreal period. Carbon-14 dating confirms the antiquity of the artefact. Ancient DNA analysis shows the artefact to be of Rangifer tarandus antler. Following this species designation, a dispersion analysis of Early-Holocene reindeer remains in Europe was conducted, showing this species to exist only in northern Scandinavia and north-western Russia in this period. Therefore, the bâton from Gołębiewo constitutes the youngest reindeer remains in the European Plain and south-western Scandinavia known to date. An attempt was made to determine the biogeographic region from which the antler used to produce the artefact originates from. To this end, comprehensive δ18O, δ13C and δ15N isotope analyses were performed. North Karelia and South Lapland were determined as the most probable regions in terms of isotopic data, results which correspond to the known distribution range of Rangifer tarandus at this time. In light of these finds, the likelihood of contact between Scandinavia and Central Europe in Early Holocene is evaluated. The bâton percé from Gołębiewo is likely key evidence for long-distance exchange during the Boreal period.

SORPTION OF NONIONIC SURFACTANT OLIGOMERS TO SEDIMENT AND PCE DNAPL: EFFECTS ON PCE DISTRIBUTION BETWEEN WATER AND SEDIMENT. (R826650)

EPA Science Inventory

Introduction of surfactant mixtures to the subsurface for the purpose of
surfactant-enhanced aquifer remediation requires consideration of the effects of
surfactant sorption to sediment and nonaqueous phase liquids. These effects
include alteration of the solubiliz...

Adolescent Initiation of Drug Use: Effects of Prenatal Cocaine Exposure

ERIC Educational Resources Information Center

Richardson, Gale A.; Larkby, Cynthia; Goldschmidt, Lidush; Day, Nancy L.

2013-01-01

Objective: To investigate the direct effects of prenatal cocaine exposure (PCE) on adolescent drug use, while controlling for other predictors of adolescent use. Method: Data are from a longitudinal study of PCE in which women and their offspring were assessed throughout childhood. Adolescents were interviewed at 15 years about their age at…

Complete biological reductive transformation of tetrachloroethene to ethane.

PubMed Central

de Bruin, W P; Kotterman, M J; Posthumus, M A; Schraa, G; Zehnder, A J

1992-01-01

Reductive dechlorination of tetrachloroethene (perchloroethylene; PCE) was observed at 20 degrees C in a fixed-bed column, filled with a mixture (3:1) of anaerobic sediment from the Rhine river and anaerobic granular sludge. In the presence of lactate (1 mM) as an electron donor, 9 microM PCE was dechlorinated to ethene. Ethene was further reduced to ethane. Mass balances demonstrated an almost complete conversion (95 to 98%), with no chlorinated compounds remaining (less than 0.5 micrograms/liter). When the temperature was lowered to 10 degrees C, an adaptation of 2 weeks was necessary to obtain the same performance as at 20 degrees C. Dechlorination by column material to ethene, followed by a slow ethane production, could also be achieved in batch cultures. Ethane was not formed in the presence of bromoethanesulfonic acid, an inhibitor of methanogenesis. The high dechlorination rate (3.7 mumol.l-1.h-1), even at low temperatures and considerable PCE concentrations, together with the absence of chlorinated end products, makes reductive dechlorination an attractive method for removal of PCE in bioremediation processes. PMID:1622277

Flexible inverted polymer solar cells fabricated in air at low temperatures

NASA Astrophysics Data System (ADS)

Kuwabara, Takayuki; Wang, Xiaofan; Kusumi, Takuji; Yamaguchi, Takahiro; Taima, Tetsuya; Takahashi, Kohshin

2016-08-01

A series of modified indium tin oxide (ITO) materials, including sol-gel zinc-oxide-coated ITO (ITO/ZnO), ZnO nanoparticle-coated ITO (ITO/ZnO-NP), 1,4-bis(3-aminopropyl)piperazine (BAP)-modified ITO, and polyethylenimine ethoxylated (PEIE)-modified ITO, were used for electron-collection electrodes in inverted polymer solar cells (PSCs). The modified ITO electrodes were prepared in air at temperatures below 100 °C, using various ITO films on flexible poly(ethylene terephthalate) substrates (PET-ITO) with sheet resistances ranging from 12 to 60 Ω sq-1. The PET-ITO (12 Ω sq-1)/ZnO-NP PSC exhibited an improved power conversion efficiency (PCE) (2.93%), and this PCE was ˜90% of that observed for a cell using glass-ITO/ZnO-NP (sheet resistance = 10 Ω sq-1 PCE = 3.28%). Additionally, we fabricated a flexible inverted ZnO-NP PSC using an indene-C60 bisadduct (ICBA) as the acceptor material in place of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and obtained a PCE of 4.18%.

PC_Eyewitness: a computerized framework for the administration and practical application of research in eyewitness psychology.

PubMed

MacLin, Otto H; Meissner, Christian A; Zimmerman, Laura A

2005-05-01

Eyewitness identification evidence is an important aspect of our legal system. Society relies on witnesses to identify suspects whom they have observed during the commission of a crime. Because a witness has only a mental representation of the individual he or she observed, law enforcement must rely on verbal descriptions and identification procedures to document eyewitness evidence. The present article introduces and details a computer program, referred to as PC_Eyewitness (PCE), which can be used in laboratories to conduct research on eyewitness memory. PCE is a modular program written in Visual Basic 6.0 that allows a researcher to present stimuli to a participant, to conduct distractor tasks, to elicit verbal descriptors regarding a target individual, and to present a lineup for the participant to provide an identification response. To illustrate the versatility of the program, several classic studies in the eyewitness literature are recreated in the context of PCE. The program is also shown to have applications in the conduct of field research and for use by law enforcement to administer lineups in everyday practice. PCE is distributed at no cost.

Vapor-phase exchange of perchloroethene between soil and plants

USGS Publications Warehouse

Struckhoff, G.C.; Burken, J.G.; Schumacher, J.G.

2005-01-01

Tree core concentrations of tetrachloroethylene (perchloroethene, PCE) at the Riverfront Superfund Site in New Haven, MO, were found to mimic the profile of soil phase concentrations. The observed soil-tree core relationship was stronger than that of groundwater PCE to tree core concentrations at the same site. Earlier research has shown a direct, linear relationship between tree core and groundwater concentrations of chlorinated solvents and other organics. Laboratory-scale experiments were performed to elucidate this phenomenon, including determining partitioning coefficients of PCE between plant tissues and air and between plant tissues and water, measured to be 8.1 and 49 L/kg, respectively. The direct relationship of soil to tree core PCE concentrations was hypothesized to be caused by diffusion between tree roots and the soil vapor phase in the subsurface. The central findings of this research are discovering the importance of subsurface vapor-phase transfer for VOCs and uncovering a direct relationship between soil vapor-phase chlorinated solvents and uptake rates that impact contaminant translocation from the subsurface and transfer into the atmosphere. ?? 2005 American Chemical Society.

Effects of trichloroethylene and perchloroethylene on wild rodents at Edwards Air Force Base, California, USA

USGS Publications Warehouse

Spring, Sarah E.; Miles, A. Keith; Anderson, Michael J.

2004-01-01

Effects of inhalation of volatilized trichloroethylene (TCE) or perchloroethylene (PCE) were assessed based on the health and population size of wild, burrowing mammals at Edwards Air Force Base (CA, USA). Organic soil-vapor concentrations were measured at three sites with aquifer contamination of TCE or PCE of 5.5 to 77 mg/L and at two uncontaminated reference sites. Population estimates of kangaroo rats (Dipodomys merriami and D. panamintinus) as well as hematology, blood chemistry, and histopathology of kangaroo rats and deer mice (Peromyscus maniculatus) were compared between contaminated and uncontaminated populations. Maximum soil-gas concentrations associated with groundwater contamination were less than 1.5 μl/L of TCE and 0.07 μl/L of PCE. Population estimates of kangaroo rats were similar at contaminated and reference sites. Hematology, blood chemistry, and histopathology of kangaroo rats and deer mice indicated no evidence of health effects caused by exposure. Trichloroethylene or PCE in groundwater and in related soil gas did not appear to reduce the size of small mammal populations or impair the health of individuals.

Plug cluster engine concept for in-space missions

NASA Technical Reports Server (NTRS)

Obrien, C. J.; Aukerman, C. A.

1979-01-01

The development of a suitable orbital transfer vehicle (OTV) engine is discussed. The OTV's dimensions are limited by those of the Space Shuttle payload bay on which it will be carried. An approach to utilize the available diameter to achieve high area ratio and thus high engine performance, is presented. Unconventional nozzles, such as clusters of small thrusters around a large diameter contoured plug, are investigated to arrive at engine designs which feature lower chamber pressures, with attendant lower heat flux, lower wall temperature, longer fatigue life, and less critical turbomachinery. Attention is also given to plug nozzle technology, high area ratio module- and scarfed bell- Plug Cluster Engine (PCE) concepts, as well as PCE performance, weight, and assessment. A conceptual design of a PCE formed from a cluster of high area ratio, scarfed, bell nozzles proved to be competitive with bell and spike nozzle engines. PCE advantages cited include increased payload length due to shorter engine length, ability to increase or decrease the number of modules and thereby the thrust, and low cost due to utilization of off-the-shelf technology.

Preparation, Characterization and Performances of Powdered Polycarboxylate Superplasticizer with Bulk Polymerization.

PubMed

Liu, Xiao; Wang, Ziming; Zheng, Yunsheng; Cui, Suping; Lan, Mingzhang; Li, Huiqun; Zhu, Jie; Liang, Xu

2014-08-29

A polycarboxylate superplasticizer (PCE) was synthesized in a non-solvent system with bulk polymerization and then was pulverized into powdered form to achieve a rapid transportation and convenient preparation. PCE synthesized by using isopentenyl polyethylene glycol (TPEG) or isobutenyl polyethylene glycol (IPEG) as a macromonomer exhibited the best fluidities and retaining properties at 80 °C and 75 °C, respectively. Besides, azobisisobutyronitrile (AIBN) was suitable as an initiator, and the fumaric acid was suitable as the third monomer. The test results of ¹H nuclear magnetic resonance (¹H NMR) confirmed the occurrences of polymerization, and the measurement results of molecular weight and distribution showed that PCE molecular weight characteristics were in accordance with their fluidity properties in cement paste. The application performances in cement showed that PCEs with the best paste fluidity retentions had the longest final setting time and the shortest setting time interval, and the PCEs with good fluidity properties can obviously delay the hydration process and lower the hydration heat. Accordingly, this is a novel, energy-saving and economical method to prepare powdered PCE in the field of concrete admixtures.

Preparation, Characterization and Performances of Powdered Polycarboxylate Superplasticizer with Bulk Polymerization

PubMed Central

Liu, Xiao; Wang, Ziming; Zheng, Yunsheng; Cui, Suping; Lan, Mingzhang; Li, Huiqun; Zhu, Jie; Liang, Xu

2014-01-01

A polycarboxylate superplasticizer (PCE) was synthesized in a non-solvent system with bulk polymerization and then was pulverized into powdered form to achieve a rapid transportation and convenient preparation. PCE synthesized by using isopentenyl polyethylene glycol (TPEG) or isobutenyl polyethylene glycol (IPEG) as a macromonomer exhibited the best fluidities and retaining properties at 80 °C and 75 °C, respectively. Besides, azobisisobutyronitrile (AIBN) was suitable as an initiator, and the fumaric acid was suitable as the third monomer. The test results of 1H nuclear magnetic resonance (1H NMR) confirmed the occurrences of polymerization, and the measurement results of molecular weight and distribution showed that PCE molecular weight characteristics were in accordance with their fluidity properties in cement paste. The application performances in cement showed that PCEs with the best paste fluidity retentions had the longest final setting time and the shortest setting time interval, and the PCEs with good fluidity properties can obviously delay the hydration process and lower the hydration heat. Accordingly, this is a novel, energy-saving and economical method to prepare powdered PCE in the field of concrete admixtures. PMID:28788184

40 CFR 49.10403 - Legal authority. [Reserved

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Legal authority. [Reserved] 49.10403 Section 49.10403 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... Implementation Plan for the Nez Perce Tribe of Idaho § 49.10403 Legal authority. [Reserved] ...

40 CFR 49.10403 - Legal authority. [Reserved

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Legal authority. [Reserved] 49.10403 Section 49.10403 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... Implementation Plan for the Nez Perce Tribe of Idaho § 49.10403 Legal authority. [Reserved] ...

Driver response to the TetraStar Navigation Assistance System by age and sex

DOT National Transportation Integrated Search

1997-07-01

This study is part of the evaluation of the FAST-TRAC operational test of an Intelligent Transportation System (ITS) in Michigan and is concerned with user perceptions and behaviors with Advanced Traveler Information Systems (ATIS). The use and perce...

77 FR 51967 - North Central Idaho Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-28

... DEPARTMENT OF AGRICULTURE Forest Service North Central Idaho Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The North Central Idaho RAC will be meeting via... held at the Nez Perce National Forest Supervisors Office, 104 Airport Road, Grangeville, Idaho. Written...

U.S. Department of Transportation : FY 1998 budget in brief

DOT National Transportation Integrated Search

1998-01-01

The fiscal year (FY) 1998 budget request for DOT makes a down payment on meeting the : transportation challenges of the 21st century. A total of $38.4 billion is proposed to support : transportation programs in FY 1998. This is approximately one perc...

40 CFR 49.10404 - Source surveillance. [Reserved

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Source surveillance. [Reserved] 49.10404 Section 49.10404 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER...-Region X Implementation Plan for the Nez Perce Tribe of Idaho § 49.10404 Source surveillance. [Reserved] ...

40 CFR 49.10404 - Source surveillance. [Reserved

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Source surveillance. [Reserved] 49.10404 Section 49.10404 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER...-Region X Implementation Plan for the Nez Perce Tribe of Idaho § 49.10404 Source surveillance. [Reserved] ...

40 CFR 49.10404 - Source surveillance. [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Source surveillance. [Reserved] 49.10404 Section 49.10404 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER...-Region X Implementation Plan for the Nez Perce Tribe of Idaho § 49.10404 Source surveillance. [Reserved] ...

40 CFR 49.10404 - Source surveillance. [Reserved

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Source surveillance. [Reserved] 49.10404 Section 49.10404 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER...-Region X Implementation Plan for the Nez Perce Tribe of Idaho § 49.10404 Source surveillance. [Reserved] ...

Mixed Redox Catalytic Destruction of Chlorinated Solvents in Soils and Groundwater: From the Laboratory to the Field

PubMed Central

Gao, Song; Rupp, Erik; Bell, Suzanne; Willinger, Martin; Foley, Theresa; Barbaris, Brian; Sáez, A. Eduardo; Arnold, Robert G.; Betterton, Eric

2010-01-01

A new thermocatalytic method to destroy chlorinated solvents has been developed in the laboratory and tested in a pilot field study. The method employs a conventional Pt/Rh catalyst on a ceramic honeycomb. Reactions proceed at moderate temperatures in the simultaneous presence of oxygen and a reductant (mixed redox conditions) to minimize catalyst deactivation. In the laboratory, stable operation with high conversions (above 90% at residence times shorter than 1 s) for perchloroethylene (PCE) is achieved using hydrogen as the reductant. A molar ratio of H2/O2 = 2 yields maximum conversions; the temperature required to produce maximum conversions is sensitive to influent PCE concentration. When a homologous series of aliphatic alkanes is used to replace hydrogen as the reductant, the resultant mixed redox conditions also produce high PCE conversions. It appears that the dissociation energy of the C–H bond in the respective alkane molecule is a strong determinant of the activation energy, and therefore the reaction rate, for PCE conversion. This new method was employed in a pilot field study in Tucson, Arizona. The mixed redox system was operated semicontinuously for 240 days with no degradation of catalyst performance and complete destruction of PCE and trichloroethylene in a soil vapor extraction gas stream. Use of propane as the reductant significantly reduced operating costs. Mixed redox destruction of chlorinated solvents provides a potentially viable alternative to current soil and groundwater remediation technologies. PMID:18991945

Vertical TiO2 Nanorods as a Medium for Stable and High-Efficiency Perovskite Solar Modules.

PubMed

Fakharuddin, Azhar; Di Giacomo, Francesco; Palma, Alessandro L; Matteocci, Fabio; Ahmed, Irfan; Razza, Stefano; D'Epifanio, Alessandra; Licoccia, Silvia; Ismail, Jamil; Di Carlo, Aldo; Brown, Thomas M; Jose, Rajan

2015-08-25

Perovskite solar cells employing CH3NH3PbI3-xClx active layers show power conversion efficiency (PCE) as high as 20% in single cells and 13% in large area modules. However, their operational stability has often been limited due to degradation of the CH3NH3PbI3-xClx active layer. Here, we report a perovskite solar module (PSM, best and av. PCE 10.5 and 8.1%), employing solution-grown TiO2 nanorods (NRs) as the electron transport layer, which showed an increase in performance (∼5%) even after shelf-life investigation for 2500 h. A crucial issue on the module fabrication was the patterning of the TiO2 NRs, which was solved by interfacial engineering during the growth process and using an optimized laser pulse for patterning. A shelf-life comparison with PSMs built on TiO2 nanoparticles (NPs, best and av. PCE 7.9 and 5.5%) of similar thickness and on a compact TiO2 layer (CL, best and av. PCE 5.8 and 4.9%) shows, in contrast to that observed for NR PSMs, that PCE in NPs and CL PSMs dropped by ∼50 and ∼90%, respectively. This is due to the fact that the CH3NH3PbI3-xClx active layer shows superior phase stability when incorporated in devices with TiO2 NR scaffolds.

Effects of surface active agents on DNAPL migration and distribution in saturated porous media.

PubMed

Cheng, Zhou; Gao, Bin; Xu, Hongxia; Sun, Yuanyuan; Shi, Xiaoqing; Wu, Jichun

2016-11-15

Dissolved surface active agents such as surfactant and natural organic matter can affect the distribution and fate of dense nonaqueous liquids (DNAPLs) in soil and groundwater systems. This work investigated how two common groundwater surface active agents, humic acid (HA) and Tween 80, affected tetrachloroethylene (PCE) migration and source zone architecture in saturated porous media under environmentally relevant conditions. Batch experiments were first conducted to measure the contact angles and interfacial tensions (IFT) between PCE and quartz surface in water containing different amount of surface active agents. Results showed that the contact angle increased and IFT decreased with concentration of surface active agent increasing, and Tween 80 was much more effective than HA. Five 2-D flow cell experiments were then conducted. Correspondingly, Tween 80 showed strong effects on the migration and distribution of PCE in the porous media due to its ability to change the medium wettability from water-wet into intermediate/NAPL-wet. The downward migration velocities of the PCE in three Tween 80 cells were slower than those in the other two cells. In addition, the final saturation of the PCE in the cells containing surface active agents was higher than that in the water-only cell. Results from this work indicate that the presence of surface active agents in groundwater may strongly affect the fate and distribution of DNAPL through altering porous medium wettability. Copyright © 2016 Elsevier B.V. All rights reserved.

Volatile halocarbons in butter: elevated tetrachloroethylene levels in samples obtained in close proximity to dry-cleaning establishments

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

Miller, L.J.; Uhler, A.D.

1988-09-01

In recent years materials not directly associated with food production, such as polychlorinated and brominated biphenyls, have been found in foods. According to the criteria to evaluate the likelihood for a chemical to contaminate food, the volatile halocarbons (VHCs) were selected as target compounds in an examination for potential contaminants in selected foods. The technique of multiple headspace extraction (MHE) was used in this study to minimize sample handling, and thereby reduce the potential for laboratory contamination and maximize throughput. Recently this laboratory reported findings of several VHCs in margarine, including PCE in four samples at levels above the usualmore » background findings. Those samples had been obtained from a food store located immediately next to a dry-cleaning establishment. Follow-up investigation was conducted to determine the frequency of occurrence and levels of PCE that may be present in fatty foods purchased from stores located both near and distant from dry cleaners. Butter was chosen as a model food because it is a highly uniform product of very high fat content, which would be expected to act as a good absorber of the lipophilic VHCs. This paper presents results of these analyses and correlations between level of VHCs in butter and the proximity to dry cleaners of the food store where the butter was purchased.« less

Enhanced reductive dechlorination in columns treated with edible oil emulsion

NASA Astrophysics Data System (ADS)

Long, Cameron M.; Borden, Robert C.

2006-09-01

The effect of edible oil emulsion treatment on enhanced reductive dechlorination was evaluated in a 14 month laboratory column study. Experimental treatments included: (1) emulsified soybean oil and dilute HCl to inhibit biological activity; (2) emulsified oil only; (3) emulsified oil and anaerobic digester sludge; and (4) continuously feeding soluble substrate. A single application of emulsified oil was effective in generating strongly reducing, anaerobic conditions for over 14 months. PCE was rapidly reduced to cis-DCE in all three live columns. Bioaugmentation with a halorespiring enrichment culture resulted in complete dechlorination of PCE to ethene in the soluble substrate column (yeast extract and lactate). However, an additional treatment with a pulse of yeast extract and bioaugmentation culture was required to stimulate complete dechlorination in the emulsion treated columns. Once the dechlorinating population was established, the emulsion only column degraded PCE from 90-120 μM to below detection with concurrent ethene production in a 33 day contact time. The lower biodegradation rates in the emulsion treated columns compared to the soluble substrate column suggest that emulsified oil barriers may require a somewhat longer contact time for effective treatment. In the HCl inhibited column, partitioning of PCE to the retained oil substantially delayed PCE breakthrough. However, reduction of PCE to more soluble degradation products ( cis-DCE, VC and ethene) greatly reduced the impact of oil-water partitioning in live columns. There was only a small decline in the hydraulic conductivity ( K) of column #1 (low pH + emulsion, Kfinal/ Kinitial = 0.57) and column #2 (live + emulsion, Kfinal/ Kinitial = 0.73) indicating emulsion injection did not result in appreciable clogging of the clayey sand. However, K loss was greater in column #3 (sludge +emulsion, Kfinal/ Kinitial = 0.12) and column #4 (soluble substrate, Kfinal/ Kinitial = 0.03) indicating clogging due to biomass and/or gas production can be significant.

PceRBase: a database of plant competing endogenous RNA.

PubMed

Yuan, Chunhui; Meng, Xianwen; Li, Xue; Illing, Nicola; Ingle, Robert A; Wang, Jingjing; Chen, Ming

2017-01-04

Competition for microRNA (miRNA) binding between RNA molecules has emerged as a novel mechanism for the regulation of eukaryotic gene expression. Competing endogenous RNA (ceRNA) can act as decoys for miRNA binding, thereby forming a ceRNA network by regulating the abundance of other RNA transcripts which share the same or similar microRNA response elements. Although this type of RNA cross talk was first described in Arabidopsis, and was subsequently shown to be active in animal models, there is no database collecting potential ceRNA data for plants. We have developed a Plant ceRNA database (PceRBase, http://bis.zju.edu.cn/pcernadb/index.jsp) which contains potential ceRNA target-target, and ceRNA target-mimic pairs from 26 plant species. For example, in Arabidopsis lyrata, 311 candidate ceRNAs are identified which could affect 2646 target-miRNA-target interactions. Predicted pairing structure between miRNAs and their target mRNA transcripts, expression levels of ceRNA pairs and associated GO annotations are also stored in the database. A web interface provides convenient browsing and searching for specific genes of interest. Tools are available for the visualization and enrichment analysis of genes in the ceRNA networks. Moreover, users can use PceRBase to predict novel competing mimic-target and target-target interactions from their own data. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Interaction of planar and nonplanar organic contaminants with coal fly ash: effects of polar and nonpolar solvent solutions.

PubMed

Burgess, Robert M; Ryba, Stephan A; Cantwell, Mark G; Gundersen, Jennifer L; Tien, Rex; Perron, Monique M

2006-08-01

Coal fly ash has a very high sorption capacity for a variety of anthropogenic contaminants and has been used to cleanse wastewater of pollutants for approximately 40 years. Like other black carbons, the planar structure of the residual carbon in fly ash results in elevated affinities for planar organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and some polychlorinated biphenyls (PCBs). The present study was performed to understand better the mechanisms affecting the strong interaction between planar contaminants and coal fly ash. The removal of 10 PCBs and 10 PAHs by several fly ashes and other sorbents was evaluated under different experimental conditions to highlight the intermolecular forces influencing adsorption. Varying fly ash concentration and solvent system composition indicated that dispersive interactions were most prevalent. For the PCBs, empirical results also were compared to molecular modeling estimates of the energy necessary for the PCB molecule to assume a planar conformation (PCe). The PCe levels ranged from 8 to 25 kcal/mol, depending on the degree of ortho-substituted chlorination of the PCB. A significant correlation between PCe and PCB removal from solution was observed for the fly ashes and activated carbon, whereas the nonplanar sorbent octadecyl (C18) indicated no relationship. These findings demonstrate the strong interaction between black carbon fly ash and planar organic contaminants. Furthermore, as exemplified by the PCBs, these results show how this interaction is a function of a contaminant's ability to assume a planar conformation.

Behavior of a chlorinated ethene plume following source-area treatment with Fenton's reagent

USGS Publications Warehouse

Chapelle, F.H.; Bradley, P.M.; Casey, C.C.

2005-01-01

Monitoring data collected over a 6-year period show that a plume of chlorinated ethene-contaminated ground water has contracted significantly following treatment of the contaminant source area using in situ oxidation. Prior to treatment (1998), concentrations of perchloroethene (PCE) exceeded 4500 ??g/L in a contaminant source area associated with a municipal landfill in Kings Bay, Georgia. The plume emanating from this source area was characterized by vinyl chloride (VC) concentrations exceeding 800 ??g/L. In situ oxidation using Fenton's reagent lowered PCE concentrations in the source area below 100 ??g/L, and PCE concentrations have not rebounded above this level since treatment. In the 6 years following treatment, VC concentrations in the plume have decreased significantly. These concentration declines can be attributed to the movement of Fenton's reagent-treated water downgradient through the system, the cessation of a previously installed pump-and-treat system, and the significant natural attenuation capacity of this anoxic aquifer. While in situ oxidation briefly decreased the abundance and activity of microorganisms in the source area, this activity rebounded in <6 months. Nevertheless, the shift from sulfate-reducing to Fe(III)-reducing conditions induced by Fenton's treatment may have decreased the efficiency of reductive dechlorination in the injection zone. The results of this study indicate that source-area removal actions, particularly when applied to ground water systems that have significant natural attenuation capacity, can be effective in decreasing the areal extent and contaminant concentrations of chlorinated ethene plumes. Copyright ?? 2005 National Ground Water Association.

Long-term perchloroethylene exposure: a limited meta-analysis of neurobehavorial deficits in occupationally and residentially exposed groups

EPA Science Inventory

The literature concerning the neurobehavioral and neurophysiological effects of long-term exposure to perchloroethylene (PERC) in humans was meta-analyzed to provide a quantitative review and synthesis. The useable data base from this literature comprised studies reporting effec...

Confidence Interval Coverage for Cohen's Effect Size Statistic

ERIC Educational Resources Information Center

Algina, James; Keselman, H. J.; Penfield, Randall D.

2006-01-01

Kelley compared three methods for setting a confidence interval (CI) around Cohen's standardized mean difference statistic: the noncentral-"t"-based, percentile (PERC) bootstrap, and biased-corrected and accelerated (BCA) bootstrap methods under three conditions of nonnormality, eight cases of sample size, and six cases of population…

Hexaazatrinaphthylene derivatives: Efficient electron-transporting materials with tunable energy levels for inverted perovskite solar cells

DOE PAGES

Zhao, Dongbing; Zhu, Zonglong; Kuo, Ming -Yu; ...

2016-06-08

Hexaazatrinaphthylene (HATNA) derivatives have been successfully shown to function as efficient electron-transporting materials (ETMs) for perovskite solar cells (PVSCs). The cells demonstrate a superior power conversion efficiency (PCE) of 17.6% with negligible hysteresis. Furthermore, this study provides one of the first nonfullerene small-moleculebased ETMs for high-performance p–i–n PVSCs.

Simultaneous improvement in short circuit current, open circuit voltage, and fill factor of polymer solar cells through ternary strategy.

PubMed

An, Qiaoshi; Zhang, Fujun; Li, Lingliang; Wang, Jian; Sun, Qianqian; Zhang, Jian; Tang, Weihua; Deng, Zhenbo

2015-02-18

We present a smart strategy to simultaneously increase the short circuit current (Jsc), the open circuit voltage (Voc), and the fill factor (FF) of polymer solar cells (PSCs). A two-dimensional conjugated small molecule photovoltaic material (SMPV1), as the second electron donor, was doped into the blend system of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C71-butyric acid methyl (PC71BM) to form ternary PSCs. The ternary PSCs with 5 wt % SMPV1 doping ratio in donors achieve 4.06% champion power conversion efficiency (PCE), corresponding to about 21.2% enhancement compared with the 3.35% PCE of P3HT:PC71BM-based PSCs. The underlying mechanism on performance improvement of ternary PSCs can be summarized as (i) harvesting more photons in the longer wavelength region to increase Jsc; (ii) obtaining the lower mixed highest occupied molecular orbital (HOMO) energy level by incorporating SMPV1 to increase Voc; (iii) forming the better charge carrier transport channels through the cascade energy level structure and optimizing phase separation of donor/acceptor materials to increase Jsc and FF.

The effect of strontium and barium doping on perovskite-structured energy materials for photovoltaic applications

NASA Astrophysics Data System (ADS)

Wu, Ming-Chung; Chen, Wei-Cheng; Chan, Shun-Hsiang; Su, Wei-Fang

2018-01-01

Perovskite solar cell is a novel photovoltaic technology with the superior progress in efficiency and the simple solution processes. Develop lead-free or lead-reduced perovskite materials is a significant concern for high-performance perovskite solar cell. Among the alkaline earth metals, the Sr2+ and Ba2+ are suitable for Pb2+ replacement in perovskite film due to fitting Goldschmidt's tolerance factor. In this study, we adopted Ba-doped and Sr-doped perovskite structured materials with different doping levels, including 1.0, 5.0, and 10.0 mol%, to prepare perovskite solar cells. Both Ba-doped and Sr-doped perovskite structured materials have a related tendency in absorption behavior and surface morphology. At 10.0 mol% doping level, the power conversion efficiency (PCE) of Sr-doped perovskite solar cells is only ∼0.5%, but the PCE of Ba-doped perovskite solar cells can be achieved to ∼9.7%. Ba-doped perovskite solar cells showed the acceptable photovoltaic characteristics than Sr-doped perovskite solar cells. Ba dopant can partially replace the amount of lead in the perovskite solar cells, and it could be a potential candidate in the field of lead-free or lead-reduced perovskite energy materials.

Fullerene-bisadduct acceptors for polymer solar cells.

PubMed

Li, Yongfang

2013-10-01

Polymer solar cells (PSCs) have drawn great attention in recent years for their simple device structure, light weight, and low-cost fabrication in comparison with inorganic semiconductor solar cells. However, the power-conversion efficiency (PCE) of PSCs needs to be increased for their future application. The key issue for improving the PCE of PSCs is the design and synthesis of high-efficiency conjugated polymer donors and fullerene acceptors for the photovoltaic materials. For the acceptor materials, several fullerene-bisadduct acceptors with high LUMO energy levels have demonstrated excellent photovoltaic performance in PSCs with P3HT as a donor. In this Focus Review, recent progress in high-efficiency fullerene-bisadduct acceptors is discussed, including the bisadduct of PCBM, indene-C60 bisadduct (ICBA), indene-C70 bisadduct (IC70BA), DMPCBA, NCBA, and bisTOQC. The LUMO levels and photovoltaic performance of these bisadduct acceptors with P3HT as a donor are summarized and compared. In addition, the applications of an ICBA acceptor in new device structures and with other conjugated polymer donors than P3HT are also introduced and discussed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Are reactive transport models reliable tools for reconstructing historical contamination scenarios?

NASA Astrophysics Data System (ADS)

Clement, P.

2009-12-01

This presentation will be based on a recent project effort that I completed while serving as a member of National Academy of Sciences and Engineering panel. The primary goal of this congressionally-mandated project effort was to review scientific evidence on the association between adverse health effect s and exposure to a contaminated water supply system at the U.S. Marine Corps Base Camp Lejeune (CLJ) in North Carolina. The detailed NRC study report was released in June 2009, and is available at this NRC weblink: http://www.nap.edu/catalog.php?record_id=12618. Multiple water supply systems at this Marine Base were contaminated with harmful chemicals, such as PCE, TCE and other waste products, since the early 50s. In 1982, a routine water quality survey completed at the site indicated the presence of several volatile organic compounds including PCE and TCE. Further investigations revealed that there are several waste disposal facilities located on-site that have discharged TCE and other waste products into groundwater systems. In addition, there was also an off-site dry cleaning facility located close to the Tarawa Terrace in-take well locations that disposed PCE into the subsurface environment. The dry cleaner has been using PCE since 1953 and disposed various forms of PCE-contaminated wastes in a septic tank and in several shallow pits. Therefore, the residents who lived in Tarawa Terrace on-site family housing units had the potential to be exposed to these harmful environmental contaminants through the drinking water source. In late 1980s, the concerns raised by CLJ public lead to an epidemiological study to evaluate the potential associations of utero and infant exposures to the VOCs and childhood cancers and birth defects. The study included births occurring during the period of 1968-1985 to women who were pregnant while they resided at the base. Since there was no monitoring data available for the study period (1968-1982), researchers used reactive transport models to reconstruct the historical concentration levels. In this presentation, I will first briefly review the details of the contamination problem and the modeling results. Later I will use the field study to answer the following questions: 1) Are reactive transport modeling tools sufficiently reliable for reconstructing historical VOC contamination at field sites? 2) What are the benefits of using reactive transport models for resolving policy problems related to a groundwater risk/exposure assessment problem? Finally, we will use this example to answer a rhetorical question—-how much complexity is too much complexity?

Deviant ERP Response to Spoken Non-Words among Adolescents Exposed to Cocaine in Utero

ERIC Educational Resources Information Center

Landi, Nicole; Crowley, Michael J.; Wu, Jia; Bailey, Christopher A.; Mayes, Linda C.

2012-01-01

Concern for the impact of prenatal cocaine exposure (PCE) on human language development is based on observations of impaired performance on assessments of language skills in these children relative to non-exposed children. We investigated the effects of PCE on speech processing ability using event-related potentials (ERPs) among a sample of…

Language Outcomes at 12 Years for Children Exposed Prenatally to Cocaine

ERIC Educational Resources Information Center

Lewis, Barbara A.; Minnes, Sonia; Short, Elizabeth J.; Min, Meeyoung O.; Wu, Miaoping; Lang, Adelaide; Weishampel, Paul; Singer, Lynn T.

2013-01-01

Purpose: In this study, the authors aimed to examine the long-term effects of prenatal cocaine exposure (PCE) on the language development of 12-year-old children using a prospective design, controlling for confounding prenatal drug exposure and environmental factors. Method: Children who were exposed to cocaine in utero (PCE; "n" = 183)…

Biodegradation of Dense Non-Aqueous Phase Liquids (DNAPL) Through Bioaugmentation of Source Areas - Dover National Test Site, Dover, Delaware

DTIC Science & Technology

2008-08-01

the distribution of DNAPL. The OSU research team evaluated the use of radon as a partitioning groundwater tracer. The DNAPL release fulfilled one...close to the source area generated more PCE equivalent mass over time. The exponential decay from the fitted line (predicted PCE, orange line in each

Novel Semiconducting Polymers for Highly Efficient Solar Energy Harvesting

DTIC Science & Technology

2014-03-11

pyrrole -4,6-dione, a well known electron-deficient monomer, to obtain the new copolymer PTTATPD-1 for comparison in physical properties. The number...bulk side chain showed a PCE about 0.6%; PTTATT-4 with 2- ethyldedocyl side chain showed a PCE about 3.0% and the copolymer with thieno[3,4-c] pyrrol

PCE/K-10 Activities for Career Education, Grades 4-6.

ERIC Educational Resources Information Center

Portland Public Schools, OR. Area II Office.

The Portland (Oregon) Public School Project Career Education (PCE) Activities for grades 4-6 is based on the city's overall Area 2 program goals for career education which proposed that children completing school should have sufficient knowledge and competencies to enter into a field of employment or an advanced training program in that field.…

Reversible structural transformation and enhanced performance of PEDOT:PSS-based hybrid solar cells driven by light intensity.

PubMed

Thomas, Joseph Palathinkal; Srivastava, Saurabh; Zhao, Liyan; Abd-Ellah, Marwa; McGillivray, Donald; Kang, Jung Soo; Rahman, Md Anisur; Moghimi, Nafiseh; Heinig, Nina F; Leung, Kam Tong

2015-04-15

Hybrid solar cells made of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) and appropriate amounts of a cosolvent and a fluorosurfactant on planar n-type silicon substrates showed a photoconversion efficiency (PCE) of above 13%. These cells also exhibited stable, reproducible, and high external quantum efficiency (EQE) that was not sensitive to light-bias intensity (LBI). In contrast, solar cells made of pristine PSS showed low PCE and high EQE only under certain measurement conditions. The EQE was found to degrade with increasing LBI. Here we report that the LBI-sensitive variation of EQE of the low-PCE cells is related to a reversible structural transformation from a quinoid to a benzoid structure of PEDOT.

Light engineering for bifacial transparent perovskite solar cells with high performance

NASA Astrophysics Data System (ADS)

Gao, Liguo; Zhao, Erling; Yang, Shuzhang; Wang, Likun; Li, Yanqiang; Zhao, Yingyuan; Ma, Tingli

2017-11-01

Bifacial transparent perovskite solar cells (BTPSCs) were designed to harvest more solar energy and ensure higher efficiency than conventional PSCs. A series of BTPSCs was successfully prepared using transparent ultrathin Au electrodes with different thicknesses. The transmittance and resistance of Au electrodes played a major role in achieving photo-to-electricity conversion efficiency (PCE). Engineering the light-harvesting ability of the fabricated BTPSCs led to the highest PCE of 14.74%. Reflecting-light intensity and illumination angle were further observed to be the key factors affecting PCE. These BTPSCs could be applied on building integration of photovoltaics (PVs), such as semitransparent PV windows or venetian blinds. Another alternative application is to use these BTPSCs as the wings of unmanned aerial vehicles.

Radio protective effect of black mulberry extract on radiation-induced damage in bone marrow cells and liver in the rat

NASA Astrophysics Data System (ADS)

Ghasemnezhad Targhi, Reza; Homayoun, Mansour; Mansouri, Somaieh; Soukhtanloo, Mohammad; Soleymanifard, Shokouhozaman; Seghatoleslam, Masoumeh

2017-01-01

Ionizing radiation by producing free radicals induces tissue oxidative stress and has clastogenic and cytotoxic effects. The radio protective effect of black mulberry extract (BME) has been investigated on liver tissue and bone marrow cells in the rat. Intraperitoneal (ip) administration of 200 mg/kg BME three days before and three days after 3 Gy and 6 Gy gamma irradiation significantly reduced the frequencies of micro nucleated polychromatic erythrocytes (MnPCEs) and micro nucleated norm chromatic erythrocyte (MnNCEs) and increased PCE/PCE+NCE ratio in rat bone marrow compared to the non-treated irradiated groups. Moreover, this concentration of BME extract decreased the level of malondialdehyde (MDA) and superoxide dismutase (SOD), as well as enhanced the total thiol content and catalase activity in rat's liver compared to the non-treated irradiated groups. It seems that BME extract with antioxidant activity reduced the genotoxicity and cytotoxicity induced by gamma irradiation in bone marrow cells and liver in the rat.

Energy Level Tuning of Poly(phenylene-alt-dithienobenzothiadiazole)s for Low Photon Energy Loss Solar Cells.

PubMed

Heuvel, Ruurd; van Franeker, Jacobus J; Janssen, René A J

2017-03-01

Six poly(phenylene- alt -dithienobenzothiadiazole)-based polymers have been synthesized for application in polymer-fullerene solar cells. Hydrogen, fluorine, or nitrile substitution on benzo-thiadiazole and alkoxy or ester substitution on the phenylene moiety are investigated to reduce the energy loss per converted photon. Power conversion efficiencies (PCEs) up to 6.6% have been obtained. The best performance is found for the polymer-fullerene combination with distinct phase separation and crystalline domains. This improves the maximum external quantum efficiency for charge formation and collection to 66%. The resulting higher photocurrent compensates for the relatively large energy loss per photon ( E loss = 0.97 eV) in achieving a high PCE. By contrast, the poly-mer that provides a reduced energy loss ( E loss = 0.49 eV) gives a lower photocurrent and a reduced PCE of 1.8% because the external quantum efficiency of 17% is limited by a suboptimal morphology and a reduced driving force for charge transfer.

Functional Genotyping of Sulfurospirillum spp. in Mixed Cultures Allowed the Identification of a New Tetrachloroethene Reductive Dehalogenase

PubMed Central

Buttet, Géraldine F.; Holliger, Christof

2013-01-01

Reductive dehalogenases are the key enzymes involved in the anaerobic respiration of organohalides such as the widespread groundwater pollutant tetrachloroethene. The increasing number of available bacterial genomes and metagenomes gives access to hundreds of new putative reductive dehalogenase genes that display a high level of sequence diversity and for which substrate prediction remains very challenging. In this study, we present the development of a functional genotyping method targeting the diverse reductive dehalogenases present in Sulfurospirillum spp., which allowed us to unambiguously identify a new reductive dehalogenase from our tetrachloroethene-dechlorinating SL2 bacterial consortia. The new enzyme, named PceATCE, shows 92% sequence identity with the well-characterized PceA enzyme of Sulfurospirillum multivorans, but in contrast to the latter, it is restricted to tetrachloroethene as a substrate. Its apparent higher dechlorinating activity with tetrachloroethene likely allowed its selection and maintenance in the bacterial consortia among other enzymes showing broader substrate ranges. The sequence-substrate relationships within tetrachloroethene reductive dehalogenases are also discussed. PMID:23995945

78 FR 24718 - Nez Perce-Clearwater National Forests; Idaho; Lolo Insect & Disease Project

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-26

... portions of the project area. Road decommissioning, culvert replacements, road improvements, and soils... to be cost-effective and provide maximum protection of soil and water quality. Big game, primarily... watershed restoration in the Lolo Creek drainage is associated with roads and soil improvement. Existing...

Sensitivity analysis of bridge health index to element failure and element conditions.

DOT National Transportation Integrated Search

2009-11-01

Bridge Health Index (BHI) is a bridge performance measure based on the condition of the bridge elements. It : is computed as the ratio of remaining value of the bridge structure to the initial value of the structure. Since it : is expressed as a perc...

Overview of the health properties of blueberries

USDA-ARS?s Scientific Manuscript database

The blueberry (Vaccinium spp.) is one of the few fruits that is native to eastern North America, but have recently gained popularity as a food in other countries. As evidence of the increased interest in this fruit, North American blueberry production has undergone a growth of greater than 300 perc...

RISK ASSESSMENT FOR CRYPTOSPORIDIUM: A HIERARCHICAL BAYESIAN ANALYSIS OF HUMAN DOSE-RESPONSE DATA. (R828035)

EPA Science Inventory

Three dose_¯response studies were conducted with healthy volunteers using different Cryptosporidium parvum isolates (IOWA, TAMU, and UCP). The study data were previously analyzed for median infectious dose (ID₅₀) using a simple cumulative perce...

Application of the a posteriori granddaughter design to the Holstein genome

USDA-ARS?s Scientific Manuscript database

An a posteriori granddaughter design was applied to determine haplotype effects for the Holstein genome. A total of 52 grandsire families, each with >=100 genotyped sons with genetic evaluations based on progeny tests, were analyzed for 33 traits (milk, fat, and protein yields; fat and protein perce...

Alternative Fuels Data Center

Science.gov Websites

Propane Education, Research, and Training The Propane Education and Research Act of 1996 established the Propane Education and Research Council (PERC) to develop programs education and training efforts to promote the use of propane as an alternative fuel. The Propane Education and Research

Working Together to Support English Language Learners: School-Family-Community Engagement. PERC Research Brief

ERIC Educational Resources Information Center

Hughes, Rosemary; Reumann-Moore, Rebecca; Rowland, Jeannette; Lin, Joshua

2016-01-01

When schools, families, and communities work together, student outcomes are better. This brief focuses on the ways family and community engagement can enhance schools' efforts to improve outcomes for ELLs and highlights specific strategies schools can use to more effectively engage families and communities.

Modeling Emissions and Vertical Plume Transport of Crop Residue Burning Experiments in the Pacific Northwest

EPA Science Inventory

A study in eastern Washington (Walla Walla) and north Idaho (Nez Perce) in August 2013 consisted of multiple burns of well characterized fuels with nearby surface and aerial measurements including trace species concentrations, plume rise height and boundary layer structure. Detai...

Systematic Review of Prenatal Cocaine Exposure and Adolescent Development

PubMed Central

Buckingham-Howes, Stacy; Berger, Sarah Shafer; Scaletti, Laura A.

2013-01-01

BACKGROUND AND OBJECTIVE: Previous research found that prenatal cocaine exposure (PCE) may increase children's vulnerability to behavior and cognition problems. Maturational changes in brain and social development make adolescence an ideal time to reexamine associations. The objective was to conduct a systematic review of published studies examining associations between PCE and adolescent development (behavior, cognition/school outcomes, physiologic responses, and brain morphology/functioning). METHODS: Articles were obtained from PubMed, PsycInfo, Web of Science, and CINAHL databases through July 2012 with search terms: prenatal drug, substance, or cocaine exposure; adolescence/adolescent; and in utero substance/drug exposure. Criteria for inclusion were nonexposed comparison group, human adolescents aged 11 to 19, peer-reviewed, English-language, and adolescent outcomes. RESULTS: Twenty-seven studies representing 9 cohorts met the criteria. Four outcome categories were identified: behavior, cognition/school performance, brain structure/function, and physiologic responses. Eleven examined behavior; 7 found small but significant differences favoring nonexposed adolescents, with small effect sizes. Eight examined cognition/school performance; 6 reported significantly lower scores on language and memory tasks among adolescents with PCE, with varying effect sizes varied. Eight examined brain structure/function and reported morphologic differences with few functional differences. Three examined physiologic responses with discordant findings. Most studies controlled for other prenatal exposures, caregiving environment, and violence exposure; few examined mechanisms. CONCLUSIONS: Consistent with findings among younger children, PCE increases the risk for small but significantly less favorable adolescent functioning. Although the clinical importance of differences is often unknown, the caregiving environment and violence exposure pose additional threats. Future research should investigate mechanisms linking PCE with adolescent functioning. PMID:23713107

Lactate Injection by Electric Currents for Bioremediation of Tetrachloroethylene in Clay

PubMed Central

Wu, Xingzhi; Gent, David B.; Davis, Jeffrey L.; Alshawabkeh, Akram N.

2012-01-01

Biological transformation of tetrachloroethylene (PCE) in silty clay samples by ionic injection of lactate under electric fields is evaluated. To prepare contaminated samples, a silty clay slurry was mixed with PCE, inoculated with KB-1® dechlorinators and was consolidated in a 40 cm long cell. A current density between 5.3 and 13.3 A m−2 was applied across treated soil samples while circulating electrolytes containing 10 mg L−1 lactate concentration between the anode and cathode compartments to maintain neutral pH and chemically reducing boundary conditions. The total adsorbed and aqueous PCE was degraded in the soil to trichloroethylene (TCE), cis-1,2-dichloroethene (cis-DCE), vinyl chloride (VC) and ethene in 120 d, which is about double the time expected for transformation. Lactate was delivered into the soil by a reactive transport rate of 3.7 cm2 d−1 V−1. PCE degradation in the clay samples followed zero order transformation rates ranging from 1.5 to 5 mg L−1 d−1 without any significant formation of TCE. cis-DCE transformation followed first order transformation rates of 0.06 to 0.10 per day. A control experiment conducted with KB-1 and lactate, but without electricity did not show any significant lactate buildup or cis-DCE transformation because the soil was practically impermeable (hydraulic conductivity of 2×10−7 cm s−1). It is concluded that ionic migration will deliver organic additives and induce biological activity and complete PCE transformation in clay, even though the transformation occurs under slower rates compared to ideal conditions. PMID:23264697

Effects of microarrangement of solid particles on PCE migration and its remediation in porous media

NASA Astrophysics Data System (ADS)

Wu, Ming; Wu, Jianfeng; Wu, Jichun; Hu, Bill X.

2018-02-01

Groundwater can be stored abundantly in granula-composed aquifers with high permeability. The microstructure of granular materials has important effect on the permeability of aquifers and the contaminant migration and remediation in aquifers is also influenced by the characteristics of porous media. In this study, two different microscale arrangements of sand particles are compared to reveal the effects of microstructure on the contaminant migration and remediation. With the help of fractal theory, the mathematical expressions of permeability and entry pressure are conducted to delineate granular materials with regular triangle arrangement (RTA) and square pitch arrangement (SPA) at microscale. Using a sequential Gaussian simulation (SGS) method, a synthetic heterogeneous site contaminated by perchloroethylene (PCE) is then used to investigate the migration and remediation affected by the two different microscale arrangements. PCE is released from an underground storage tank into the aquifer and the surfactant is used to clean up the subsurface contamination. Results suggest that RTA can not only cause more groundwater contamination, but also make remediation become more difficult. The PCE remediation efficiency of 60.01-99.78 % with a mean of 92.52 and 65.53-99.74 % with a mean of 95.83 % is achieved for 200 individual heterogeneous realizations based on the RTA and SPA, respectively, indicating that the cleanup of PCE in aquifer with SPA is significantly easier. This study leads to a new understanding of the microstructures of porous media and demonstrates how microscale arrangements control contaminant migration in aquifers, which is helpful to design successful remediation scheme for underground storage tank spill.

Repeatability and validity of a field kit for estimation of cholinesterase in whole blood.

PubMed Central

London, L; Thompson, M L; Sacks, S; Fuller, B; Bachmann, O M; Myers, J E

1995-01-01

OBJECTIVES--To evaluate a spectrophotometric field kit (Test-Mate-OP) for repeatability and validity in comparison with reference laboratory methods and to model its anticipated sensitivity and specificity based on these findings. METHODS--76 farm workers between the age of 20 and 55, of whom 30 were pesticide applicators exposed to a range of organophosphates in the preceding 10 days, had blood taken for plasma cholinesterase (PCE) and erythrocyte cholinesterase (ECE) measurement by field kit or laboratory methods. Paired blinded duplicate samples were taken from subgroups in the sample to assess repeatability of laboratory and field kit methods. Field kits were also used to test venous blood in one subgroup. The variance obtained for the field kit tests was then applied to two hypothetical scenarios that used published action guidelines to model the kit's sensitivity and specificity. RESULTS--Repeatability for PCE was much poorer and for ECE slightly poorer than that of laboratory measures. A substantial upward bias for field kit ECE relative to laboratory measurements was found. Sensitivity of the kit to a 40% drop in PCE was 67%, whereas that for ECE was 89%. Specificity of the kit with no change in mean of the population was 100% for ECE and 91% for PCE. CONCLUSION--Field kit ECE estimation seems to be sufficiently repeatable for surveillance activities, whereas PCE does not. Repeatability of both tests seems to be too low for use in epidemiological dose-response investigations. Further research is indicated to characterise the upward bias in ECE estimation on the kit. PMID:7697143

Estimation of representative elementary volume for DNAPL saturation and DNAPL-water interfacial areas in 2D heterogeneous porous media

NASA Astrophysics Data System (ADS)

Wu, Ming; Cheng, Zhou; Wu, Jianfeng; Wu, Jichun

2017-06-01

Representative elementary volume (REV) is important to determine properties of porous media and those involved in migration of contaminants especially dense nonaqueous phase liquids (DNAPLs) in subsurface environment. In this study, an experiment of long-term migration of the commonly used DNAPL, perchloroethylene (PCE), is performed in a two dimensional (2D) sandbox where several system variables including porosity, PCE saturation (Soil) and PCE-water interfacial area (AOW) are accurately quantified by light transmission techniques over the entire PCE migration process. Moreover, the REVs for these system variables are estimated by a criterion of relative gradient error (εgi) and results indicate that the frequency of minimum porosity-REV size closely follows a Gaussian distribution in the range of 2.0 mm and 8.0 mm. As experiment proceeds in PCE infiltration process, the frequency and cumulative frequency of both minimum Soil-REV and minimum AOW-REV sizes change their shapes from the irregular and random to the regular and smooth. When experiment comes into redistribution process, the cumulative frequency of minimum Soil-REV size reveals a linear positive correlation, while frequency of minimum AOW-REV size tends to a Gaussian distribution in the range of 2.0 mm-7.0 mm and appears a peak value in 13.0 mm-14.0 mm. Undoubtedly, this study will facilitate the quantification of REVs for materials and fluid properties in a rapid, handy and economical manner, which helps enhance our understanding of porous media and DNAPL properties at micro scale, as well as the accuracy of DNAPL contamination modeling at field-scale.

Distinguishing the importance of fullerene phase separation from polymer ordering in the performance of low band gap polymer: Bis-fullerene heterojunctions

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

Chen, Huipeng; Hsiao, Yu -Che; Chen, Jihua

2014-09-16

It is known, one way to improve power conversion efficiency (PCE) of polymer based bulk-heterojunction (BHJ) photovoltaic cells is to increase the open circuit voltage (V oc). Replacing PCBM with bis-adduct fullerenes significantly improves V oc and the PCE in devices based on the conjugated polymer poly(3-hexyl thiophene) (P3HT). However, for the most promising low band-gap polymer (LBP) system, replacing PCBM with ICBA results in poor short-circuit current (J sc) and PCE although V oc is significantly improved. The optimization of the morphology of as-cast LBP/bis-fullerene BHJ photovoltaics is attempted by adding a co-solvent to the polymer/fullerene solution prior tomore » film deposition. Varying the solubility of polymer and fullerene in the co-solvent, bulk heterojunctions are fabricated with no change of polymer ordering, but with changes in fullerene phase separation. The morphologies of the as-cast samples are characterized by small angle neutron scattering and neutron reflectometry. A homogenous dispersion of ICBA in LBP is found in the samples where the co-solvent is selective to the polymer, giving poor device performance. Aggregates of ICBA are formed in samples where the co-solvent is selective to ICBA. Furthermore, the resultant morphology improves PCE by up to 246%. Finally, a quantitative analysis of the neutron data shows that the interfacial area between ICBA aggregates and its surrounding matrix is improved, facilitating charge transport and improving the PCE.« less

DNAPL MAPPING AND WATER SATURATION MEASUREMENTS IN 2-D MODELS USING LIGHT TRANSMISSION VISUALIZATION (LTV) TECHNIQUE

EPA Science Inventory

• LTV can be used to characterize free phase PCE architecture in 2-D flow chambers without using a dye. • Results to date suggest that error in PCE detection using LTV can be less than 10% if the imaging system is optimized. • Mass balance calculations show a maximum error of 9...

Structure and transcriptional impact of divergent repetitive elements inserted within Phanerochaete chrysosporium strain RP-78 genes

Treesearch

Luis F. Larrondo; Paulo Canessa; Rafael Vicuna; Philip Stewart; Amber Vanden Wymelenberg; Dan Cullen

2007-01-01

We describe the structure, organization, and transcriptional impact of repetitive elements within the lignin-degrading basidiomycete, Phanerochaete chrysosporium. Searches of the P. chrysosporium genome revealed five copies of pce1, a 1,750-nt non-autonomous, class II element. Alleles encoding a putative glucosyltransferase and a cytochrome P450 harbor pce insertions...

Passenger car equivalents of becak bermotor at road segment in Medan

NASA Astrophysics Data System (ADS)

Surbakti, M. S.; Sembiring, I.

2018-02-01

The road traffic systems, travel patterns and other traffic characteristics are different for each country due to differences in the geometric patterns, available transport facilities for commuters, proportional and type of the vehicle itself and so on. In Indonesia, the standard of pce (Passenger Car Equivalent) value found on IHCM (Indonesian Highway Capacity Manual) published in 1997. IHCM stated that the value of pce for heavy vehicles and motorcycles are 1.3 and 0.5 respectively. On these day, regarding Medan as a third biggest city in Indonesia, there have been lot of changes with regarding to the composition of the vehicle, as well as variations of the type of the vehicle itself. Becak bermotor (motorized tricycles) is a vehicle which is widely available in the city of Medan. Data from Medan City Transportation Department stated that there are more than 20,000 motorized motorized tricycles vehicles operating in the city at these day. Pce value of these rickshaws will be calculated based on observations at road and intersections in Medan. The calculation result shows that the pce value of motorized rickshaw is more than 1. This value will make the calculations regarding the performance of the traffic can be performed more accurately.

Perovskite solar cells: from materials to devices.

PubMed

Jung, Hyun Suk; Park, Nam-Gyu

2015-01-07

Perovskite solar cells based on organometal halide light absorbers have been considered a promising photovoltaic technology due to their superb power conversion efficiency (PCE) along with very low material costs. Since the first report on a long-term durable solid-state perovskite solar cell with a PCE of 9.7% in 2012, a PCE as high as 19.3% was demonstrated in 2014, and a certified PCE of 17.9% was shown in 2014. Such a high photovoltaic performance is attributed to optically high absorption characteristics and balanced charge transport properties with long diffusion lengths. Nevertheless, there are lots of puzzles to unravel the basis for such high photovoltaic performances. The working principle of perovskite solar cells has not been well established by far, which is the most important thing for understanding perovksite solar cells. In this review, basic fundamentals of perovskite materials including opto-electronic and dielectric properties are described to give a better understanding and insight into high-performing perovskite solar cells. In addition, various fabrication techniques and device structures are described toward the further improvement of perovskite solar cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chloroethene degradation and expression of Dehalococcoides dehalogenase genes in cultures originating from Yangtze sediments.

PubMed

Kranzioch, Irene; Ganz, Selina; Tiehm, Andreas

2015-02-01

The anaerobic Dehalococcoides spp. is the only microorganism known to completely dechlorinate the hazardous compounds tetrachloroethene (PCE) or trichloroethene (TCE) via dichloroethene (DCE) and vinyl chloride (VC) to the terminal product, ethene. In this study, growth of Dehalococcoides spp. (DHC) and the expression of DHC dehalogenase genes were demonstrated for Yangtze enrichment cultures. Reductive dechlorination of chloroethenes occurred in Yangtze sediment without the addition of any external auxiliary substrates. All Yangtze enrichment cultures completely dechlorinated PCE and cis-DCE to ethene. To investigate expression of the dehalogenase genes pceA, tceA, vcrA, and bvcA, a protocol for messenger RNA (mRNA) extraction followed by reverse transcription and quantitative PCR analysis was established. During dechlorination, an increase in gene copy numbers of pceA, tceA, and vcrA was observed. However, temporary formation of mRNA was only measured in the case of the dehalogenase genes tceA and vcrA. Comparison of DHC dehalogenase patterns indicated that the Yangtze DHC community does not match any of the previously published enrichment cultures that were obtained from contaminated areas in the USA or Europe.

An Integrated Power-Efficient Active Rectifier With Offset-Controlled High Speed Comparators for Inductively Powered Applications

PubMed Central

Lee, Hyung-Min; Ghovanloo, Maysam

2011-01-01

We present an active full-wave rectifier with offset-controlled high speed comparators in standard CMOS that provides high power conversion efficiency (PCE) in high frequency (HF) range for inductively powered devices. This rectifier provides much lower dropout voltage and far better PCE compared to the passive on-chip or off-chip rectifiers. The built-in offset-control functions in the comparators compensate for both turn-on and turn-off delays in the main rectifying switches, thus maximizing the forward current delivered to the load and minimizing the back current to improve the PCE. We have fabricated this active rectifier in a 0.5-μm 3M2P standard CMOS process, occupying 0.18 mm2 of chip area. With 3.8 V peak ac input at 13.56 MHz, the rectifier provides 3.12 V dc output to a 500 Ω load, resulting in the PCE of 80.2%, which is the highest measured at this frequency. In addition, overvoltage protection (OVP) as safety measure and built-in back telemetry capabilities have been incorporated in our design using detuning and load shift keying (LSK) techniques, respectively, and tested. PMID:22174666

Robust High-performance Dye-sensitized Solar Cells Based on Ionic Liquid-sulfolane Composite Electrolytes.

PubMed

Lau, Genevieve P S; Décoppet, Jean-David; Moehl, Thomas; Zakeeruddin, Shaik M; Grätzel, Michael; Dyson, Paul J

2015-12-16

Novel ionic liquid-sulfolane composite electrolytes based on the 1,2,3-triazolium family of ionic liquids were developed for dye-sensitized solar cells. The best performing device exhibited a short-circuit current density of 13.4 mA cm(-2), an open-circuit voltage of 713 mV and a fill factor of 0.65, corresponding to an overall power conversion efficiency (PCE) of 6.3%. In addition, these devices are highly stable, retaining more than 95% of the initial device PCE after 1000 hours of light- and heat-stress. These composite electrolytes show great promise for industrial application as they allow for a 14.5% improvement in PCE, compared to the solvent-free eutectic ionic liquid electrolyte system, without compromising device stability.

Comparison of temporal trends in VOCs as measured with PDB samplers and low-flow sampling methods

USGS Publications Warehouse

Harte, P.T.

2002-01-01

Analysis of temporal trends in tetrachloroethylene (PCE) concentration determined by two sample techniques showed that passive diffusion bag (pdb) samplers adequately sample the large variation in PCE concentrations at the site. The slopes of the temporal trends in concentrations were comparable between the two techniques, and the pdb sample concentration generally reflected the instantaneous concentration sampled by the low-flow technique. Thus, the pdb samplers provided an appropriate sampling technique for PCE at these wells. One or two wells did not make the case for widespread application of pdb samples at all sites. However, application of pdb samples in some circumstances was appropriate for evaluating temporal and spatial variations in VOC concentrations, thus, should be considered as a useful tool in hydrogeology.

Solvent control of the morphology of the hole transport layer for high-performance perovskite solar cells

NASA Astrophysics Data System (ADS)

Xie, Xiaoyin; Liu, Guanchen; Chen, Li; Li, Shuangcui; Liu, Zhihai

2017-11-01

We investigated the effect of the morphology of 2,2‧,7,7‧-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9‧-spirobifluorene (spiro-OMeTAD) prepared using chlorobenzene (CB) and 1,2-dichlorobenzene (DCB) on the performance of perovskite solar cells (PSCs). We find that a more uniform and smoother spiro-OMeTAD layer was obtained using DCB than CB. The PSCs prepared using DCB exhibited a higher power conversion efficiency (PCE = 16.2%) than those obtained using CB (PCE = 14.5%). The hysteresis was reduced from 4.8% to 0.6%, with improved stability. The highest PCE of PSCs prepared using DCB was 16.6%, indicating that the use of DCB for spiro-OMeTAD processing enables the fabrication of high-performance PSCs.

Hydrostratigraphic mapping of the Milford-Souhegan glacial drift aquifer, and effects of hydrostratigraphy on transport of PCE, Operable Unit 1, Savage Superfund Site, Milford, New Hampshire

USGS Publications Warehouse

Harte, Philip T.

2010-01-01

The Savage Municipal Well Superfund site in the Town of Milford, New Hampshire, was underlain by a 0.5-square mile plume (as mapped in 1994) of volatile organic compounds (VOCs), most of which consisted of tetrachloroethylene (PCE). The plume occurs mostly within highly transmissive stratified-drift deposits but also extends into underlying till and bedrock. The plume has been divided into two areas called Operable Unit 1 (OU1), which contains the primary source area, and Operable Unit 2 (OU2), which is defined as the extended plume area outside of OU1. The OU1 remedial system includes a low-permeability barrier wall that encircles the highest detected concentrations of PCE and a series of injection and extraction wells to contain and remove contaminants. The barrier wall likely penetrates the full thickness of the sand and gravel; in many places, it also penetrates the full thickness of the underlying basal till and sits atop bedrock.From 1998 to 2004, PCE concentrations decreased by an average of 80 percent at most wells outside the barrier wall. However, inside the barrier, PCE concentrations greater than 10,000 micrograms per liter (μg/L) still exist (2008). The remediation of these areas of recalcitrant PCE presents challenges to successful remediation.The U.S. Geological Survey (USGS), in cooperation with the New Hampshire Department of Environmental Services (NHDES) and the U.S. Environmental Protection Agency (USEPA), Region 1, is studying the solute transport of VOCs (primarily PCE) in contaminated groundwater in the unconsolidated sediments (overburden) of the Savage site and specifically assisting in the evaluation of the effectiveness of remedial operations in the OU1 area. As part of this effort, the USGS analyzed the subsurface stratigraphy to help understand hydrostratigraphic controls on remediation.A combination of lithologic, borehole natural gamma-ray and electromagnetic (EM) induction logging, and test drilling has identified 11 primary hydrostratigraphic units in OU1. These 11 units consist of several well-sorted sandy layers with some gravel that are separated by poorly sorted cobble layers with a fine-grained matrix. Collectively these units represent glacial sediments deposited by localized ice-margin fluctuations. For the most part, the units are semi-planar, particularly the cobble units, and truncated by an undulating bedrock surface. The lowermost unit is a basal till that ranges in thickness from zero to greater than 10 feet and mantles the bedrock surface.The 11 units have different lithologic and hydraulic characteristics. The hydraulic conductivity of the well-sorted sand and gravel units is typically greater than the conductivity of the poorly sorted cobble units and the basal till. The hydraulic conductivity ranges from 5 to greater than 500 feet per day. Lateral and vertical variation in lithology and hydraulic conductivity are inferred by variations in borehole natural gamma-ray counts and estimates of hydraulic conductivity.The comparison of hydrostratigraphic units with the spatial distribution of PCE concentrations suggests that solute transport away from source areas is primarily lateral within the permeable sandy units in the middle to lower parts of the aquifer. Along the centerline of the interior barrier area, highest PCE concentrations are in the sandy units to the east of suspected source areas.

Installing the new PCE (Proximity Communications Equipment) hardware

NASA Image and Video Library

2005-06-29

ISS011-E-09799 (27 June 2005) --- Cosmonaut Sergei K. Krikalev, Expedition 11 commander representing Russia's Federal Space Agency, works with the new Proximity Communications Equipment (PCE) hardware of the ASN-M satellite navigation system for the European Automated Transfer Vehicle (ATV) “Jules Verne” in the Zvezda Service Module of the International Space Station. The ATV is scheduled to arrive at the Station next year.

Modification of back electrode with WO3 layer and its effect on Cu2ZnSn(S,Se)4-based solar cells

NASA Astrophysics Data System (ADS)

Shi, Kun; Yao, Bin; Li, Yongfeng; Ding, Zhanhui; Deng, Rui; Sui, Yingrui; Zhang, Zhenzhong; Zhao, Haifeng; Zhang, Ligong

2018-01-01

In the present work, we designed and prepared Cu2ZnSn(S,Se)4 (CZTSSe)-based solar cells with a new structure of Al/ITO/ZnO/CdS/CZTSSe/WO3/Mo/SLG (S1-5) by depositing about 5-nm-thick WO3 layer with monoclinic structure on the back electrode Mo/SLG of solar cells with the convention structure of Al/ITO/ZnO/CdS/CZTSSe/Mo/SLG (S2), with the aim of improving the power conversion efficiency (PCE) of CZTSSe-based solar cells. It is found that the average open circuit voltage (Voc) increases from 346.7 mV of the S2 cells to 400.9 mV of the S1-5 cells, the average short circuit current density (Jsc) from 26.4 mA/cm2 to 32.1 mA/cm2 and the filling factor (FF) from 33.8 to 40.0 by addition of the WO3 layer, which results in that the average PCE increases from 3.10% of the S2 cells to 5.14% of the S1-5 cells. The average increasing percent of the PCE is 65.8%. The increase in Voc, Jsc and FF of the S1-5 cells compared to the S2 cells is attributed to that the WO3 layer prevent the Se coming from Se ambient and CZTSSe to react with the Mo to form MoSe2 and other second phases, which makes the shunt resistance (Rsh) of the S1-5 increase and the series resistance (Rs) and reverse saturation current density (J0) decrease compared to the S2 cells. The decreased J0 is main factor of improvement of the PCE. A mechanism of influence of the Rsh, Rs and J0 on the PCE is also revealed. Our result demonstrates that addition of the WO3 layer with a reasonable thickness can be a promising technical route of improving the PCE of the CZTSSe-based solar cell.

Spatial and temporal dynamics of organohalide-respiring bacteria in a heterogeneous PCE-DNAPL source zone

NASA Astrophysics Data System (ADS)

Cápiro, Natalie L.; Löffler, Frank E.; Pennell, Kurt D.

2015-11-01

Effective treatment of sites contaminated with dense non-aqueous phase liquids (DNAPLs) requires detailed understanding of the microbial community responses to changes in source zone strength and architecture. Changes in the spatial and temporal distributions of the organohalide-respiring Dehalococcoides mccartyi (Dhc) strains and Geobacter lovleyi strain SZ (GeoSZ) were examined in a heterogeneous tetrachloroethene- (PCE-) DNAPL source zone within a two-dimensional laboratory-scale aquifer flow cell. As part of a combined remedy approach, flushing with 2.3 pore volumes (PVs) of 4% (w/w) solution of the nonionic, biodegradable surfactant Tween® 80 removed 55% of the initial contaminant mass, and resulted in a PCE-DNAPL distribution that contained 51% discrete ganglia and 49% pools (ganglia-to-pool ratio of 1.06). Subsequent bioaugmentation with the PCE-to-ethene-dechlorinating consortium BDI-SZ resulted in cis-1,2-dichloroethene (cis-DCE) formation after 1 PV (ca. 7 days), while vinyl chloride (VC) and ethene were detected 10 PVs after bioaugmentation. Maximum ethene yields (ca. 90 μM) within DNAPL pool and ganglia regions coincided with the detection of the vcrA reductive dehalogenase (RDase) gene that exceeded the Dhc 16S rRNA genes by 2.0 ± 1.3 and 4.0 ± 1.7 fold in the pool and ganglia regions, respectively. Dhc and GeoSZ cell abundance increased by up to 4 orders-of-magnitude after 28 PVs of steady-state operation, with 1 to 2 orders-of-magnitude increases observed in close proximity to residual PCE-DNAPL. These observations suggest the involvement of these dechlorinators the in observed PCE dissolution enhancements of up to 2.3 and 6.0-fold within pool and ganglia regions, respectively. Analysis of the solid and aqueous samples at the conclusion of the experiment revealed that the highest VC (≥ 155 μM) and ethene (≥ 65 μM) concentrations were measured in zones where Dhc and GeoSZ were predominately attached to the solids. These findings demonstrate dynamic responses of organohalide-respiring bacteria in a heterogeneous DNAPL source zone, and emphasize the influence of source zone architecture on bioremediation performance.

Engineering Interface Structure to Improve Efficiency and Stability of Organometal Halide Perovskite Solar Cells.

PubMed

Qiu, Longbin; Ono, Luis K; Jiang, Yan; Leyden, Matthew R; Raga, Sonia R; Wang, Shenghao; Qi, Yabing

2018-01-18

The rapid rise of power conversion efficiency (PCE) of low cost organometal halide perovskite solar cells suggests that these cells are a promising alternative to conventional photovoltaic technology. However, anomalous hysteresis and unsatisfactory stability hinder the industrialization of perovskite solar cells. Interface engineering is of importance for the fabrication of highly stable and hysteresis free perovskite solar cells. Here we report that a surface modification of the widely used TiO 2 compact layer can give insight into interface interaction in perovskite solar cells. A highest PCE of 18.5% is obtained using anatase TiO 2 , but the device is not stable and degrades rapidly. With an amorphous TiO 2 compact layer, the devices show a prolonged lifetime but a lower PCE and more pronounced hysteresis. To achieve a high PCE and long lifetime simultaneously, an insulating polymer interface layer is deposited on top of TiO 2 . Three polymers, each with a different functional group (hydroxyl, amino, or aromatic group), are investigated to further understand the relation of interface structure and device PCE as well as stability. We show that it is necessary to consider not only the band alignment at the interface, but also interface chemical interactions between the thin interface layer and the perovskite film. The hydroxyl and amino groups interact with CH 3 NH 3 PbI 3 leading to poor PCEs. In contrast, deposition of a thin layer of polymer consisting of an aromatic group to prevent the direct contact of TiO 2 and CH 3 NH 3 PbI 3 can significantly enhance the device stability, while the same time maintaining a high PCE. The fact that a polymer interface layer on top of TiO 2 can enhance device stability, strongly suggests that the interface interaction between TiO 2 and CH 3 NH 3 PbI 3 plays a crucial role. Our work highlights the importance of interface structure and paves the way for further optimization of PCEs and stability of perovskite solar cells.

Polynomial meta-models with canonical low-rank approximations: Numerical insights and comparison to sparse polynomial chaos expansions

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

Konakli, Katerina, E-mail: konakli@ibk.baug.ethz.ch; Sudret, Bruno

2016-09-15

The growing need for uncertainty analysis of complex computational models has led to an expanding use of meta-models across engineering and sciences. The efficiency of meta-modeling techniques relies on their ability to provide statistically-equivalent analytical representations based on relatively few evaluations of the original model. Polynomial chaos expansions (PCE) have proven a powerful tool for developing meta-models in a wide range of applications; the key idea thereof is to expand the model response onto a basis made of multivariate polynomials obtained as tensor products of appropriate univariate polynomials. The classical PCE approach nevertheless faces the “curse of dimensionality”, namely themore » exponential increase of the basis size with increasing input dimension. To address this limitation, the sparse PCE technique has been proposed, in which the expansion is carried out on only a few relevant basis terms that are automatically selected by a suitable algorithm. An alternative for developing meta-models with polynomial functions in high-dimensional problems is offered by the newly emerged low-rank approximations (LRA) approach. By exploiting the tensor–product structure of the multivariate basis, LRA can provide polynomial representations in highly compressed formats. Through extensive numerical investigations, we herein first shed light on issues relating to the construction of canonical LRA with a particular greedy algorithm involving a sequential updating of the polynomial coefficients along separate dimensions. Specifically, we examine the selection of optimal rank, stopping criteria in the updating of the polynomial coefficients and error estimation. In the sequel, we confront canonical LRA to sparse PCE in structural-mechanics and heat-conduction applications based on finite-element solutions. Canonical LRA exhibit smaller errors than sparse PCE in cases when the number of available model evaluations is small with respect to the input dimension, a situation that is often encountered in real-life problems. By introducing the conditional generalization error, we further demonstrate that canonical LRA tend to outperform sparse PCE in the prediction of extreme model responses, which is critical in reliability analysis.« less

Effect of Rubidium Incorporation on the Structural, Electrical, and Photovoltaic Properties of Methylammonium Lead Iodide-Based Perovskite Solar Cells.

PubMed

Park, Ik Jae; Seo, Seongrok; Park, Min Ah; Lee, Sangwook; Kim, Dong Hoe; Zhu, Kai; Shin, Hyunjung; Kim, Jin Young

2017-12-06

We report the electrical properties of rubidium-incorporated methylammonium lead iodide ((Rb x MA 1-x )PbI 3 ) films and the photovoltaic performance of (Rb x MA 1-x )PbI 3 film-based p-i-n-type perovskite solar cells (PSCs). The incorporation of a small amount of Rb + (x = 0.05) increases both the open circuit voltage (V oc ) and the short circuit photocurrent density (J sc ) of the PSCs, leading to an improved power conversion efficiency (PCE). However, a high fraction of Rb + incorporation (x = 0.1 and 0.2) decreases the J sc and thus the PCE, which is attributed to the phase segregation of the single tetragonal perovskite phase to a MA-rich tetragonal perovskite phase and a RbPbI 3 orthorhombic phase at high Rb fractions. Conductive atomic force microscopic and admittance spectroscopic analyses reveal that the single-phase (Rb 0.05 MA 0.95 )PbI 3 film has a high electrical conductivity because of a reduced deep-level trap density. We also found that Rb substitution enhances the diode characteristics of the PSC, as evidenced by the reduced reverse saturation current (J 0 ). The optimized (Rb x MA 1-x )PbI 3 PSCs exhibited a PCE of 18.8% with negligible hysteresis in the photocurrent-voltage curve. The results from this work enhance the understanding of the effect of Rb incorporation into organic-inorganic hybrid halide perovskites and enable the exploration of Rb-incorporated mixed perovskites for various applications, such as solar cells, photodetectors, and light-emitting diodes.

77 FR 73976 - Nez Perce-Clearwater National Forests; Idaho; Crooked River Valley Rehabilitation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-12

... maintenance of the road. Proposed Action The proposed action is to rehabilitate the lower two miles of the... from the road, improve forest visitor safety, and provide easier maintenance of the road. The proposed... the effects to cultural resources, public access, and future road maintenance costs. Permits or...

40 CFR 49.10407 - EPA-approved Tribal rules and plans. [Reserved

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 1 2012-07-01 2012-07-01 false EPA-approved Tribal rules and plans. [Reserved] 49.10407 Section 49.10407 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND... Tribes-Region X Implementation Plan for the Nez Perce Tribe of Idaho § 49.10407 EPA-approved Tribal rules...

Maternal overweight predicts infant caloric intake from complimentary foods and weight-for-length at age 6 months

USDA-ARS?s Scientific Manuscript database

We assessed the role of maternal overweight on infant dietary intake and body size during the first 6 months of life. Participants were from the Beginnings study, an on-going, longitudinal cohort. Trained research assistants measured infant weight and length; weight-for-length percentiles (WL perc...

Relationships between water table and model simulated ET

Treesearch

Prem B. Parajuli; Gretchen F. Sassenrath; Ying Ouyang

2013-01-01

This research was conducted to develop relationships among evapotranspiration (ET), percolation (PERC), groundwater discharge to the stream (GWQ), and water table fluctuations through a modeling approach. The Soil and Water Assessment Tool (SWAT) hydrologic and crop models were applied in the Big Sunflower River watershed (BSRW; 7660 km2) within the Yazoo River Basin...

Educating English Language Learners: Instructional Approaches and Teacher Collaboration in Philadelphia Public Schools. PERC Research Brief

ERIC Educational Resources Information Center

Reumann-Moore, Rebecca; Rowland, Jeannette; Hughes, Rosemary; Lin, Joshua

2016-01-01

Districts, charter management organizations, and individual schools can learn a great deal from each other about strategies for creating robust and supportive learning environments for English Language Learners (ELLS). This brief highlights key findings about how Philadelphia public schools were crafting instructional approaches to serve their…

Alternative Fuels Data Center: Alternative Fuels Help Ensure America's

Science.gov Websites

key players from the start. For example, a strategic partnership with Black Bear Solar Institute led is replacing its fleet vehicles with efficient and alternative fuel vehicles. For example, in recent deploying seven propane mowers, thanks to a donation from the Propane Education & Research Council (PERC

Semiconductors: In Situ Processing of Photovoltaic Devices

NASA Technical Reports Server (NTRS)

Curreri, Peter A.

1998-01-01

The possible processing of semiconductor photovoltaic devices is discussed. The requirements for lunar PV cells is reviewed, and the key challenges involved in their manufacturing are investigated. A schematic diagram of a passivated emitter and rear cell (PERC) is presented. The possible fabrication of large photovoltaic arrays in space from lunar materials is also discussed.

Effects of road obliteration on stream water quality

Treesearch

Randy B. Foltz; Kristina A. Yanosek

2005-01-01

The Nez Perce National Forest and the Rocky Mountain Research Station are conducting a long-term study of road obliteration that includes measurements of sediment generated during obliteration activities. Three culvert locations in the Horse Creek drainage of Idaho were monitored during road obliteration activity. Sediment yields varied from 2 to 170 kg. Yields...

Educating English Language Learners: Opportunities for Improved Infrastructure. PERC Research Brief

ERIC Educational Resources Information Center

Rowland, Jeannette; Reumann-Moore, Rebecca; Hughes, Rosemary; Lin, Joshua

2016-01-01

Academic success for ELLs depends on high quality instruction and the infrastructure needed to support it (e.g., staff, curricular materials, collaboration, professional development). This brief examines the challenges schools face in these areas and the strategies they use to mediate them. The purpose of this brief is to share these strategies…

Potlatch and Powwow: Dynamics of Culture through Lives Lived Dancing

ERIC Educational Resources Information Center

Andrews, Tracy J.; Olney, Jon

2007-01-01

In collaboration with the Kwakwaka'wakw First Nations' U'mista Cultural Centre and the Nez Perce Tribe's Cultural Resources Program, this study addresses aspects of the recent history and contemporary roles of dance in their societies from the dancers' perspectives. The social science literature commonly documents the cultural history of dances…

Two World Walkers: The Eagles in Aerospace Program.

ERIC Educational Resources Information Center

Stark, Jason

1997-01-01

The Nez Perce council, NASA, and the University of Idaho initiated a program that enables Native American students to identify and correspond with Native American professionals in aeronautical careers who are willing to mentor these students. The goal is to move academia and academic programs into the realm of Native American identity, ideology,…

Transportation Services, Utilization and Needs of the Elderly in Non-Urban Areas; Patterns in Two Kentucky Communities

DOT National Transportation Integrated Search

1994-12-01

It is now axiomatic that America's population is growing older. Primary : indicators of this aging are the number of individuals age 65 years and over : (which increased from about 26 million in 1980 to over 33 million by 1990) and : the elderly perc...

Static Thrust and Power Characteristics of Six Full-Scale Propellers

DTIC Science & Technology

1940-01-01

8217 v’arri’a’t aaINt Ilio- adasigns tip) speed’a by 1ii1) ,i vinag .10 perce’ant aI’a’aita’n Itiliil tha’ thar’ist a’auaflia’i’iit o’’~af n faictaoi

Salmon and the Adaptive Capacity of Nimiipuu (Nez Perce) Culture to Cope with Change

ERIC Educational Resources Information Center

Colombi, Benedict J.

2012-01-01

Change due to natural disturbances and disasters, population growth and decline, economic crises, and environmental and climate change creates significant cultural challenges. Rapid change and the transformation it brings also involve complex relationships between sovereign tribes, resources, and the global system. This article explores how salmon…

Effects of ethanol addition on micellar solubilization and plume migration during surfactant enhanced recovery of tetrachloroethene.

PubMed

Taylor, Tammy P; Rathfelder, Klaus M; Pennell, Kurt D; Abriola, Linda M

2004-03-01

Alcohol addition has been suggested for use in combination with surfactant flushing to enhance solubilization kinetics and permit density control of dense non-aqueous phase liquid (DNAPL)-laden surfactant plumes. This study examined the effects of adding ethanol (EtOH) to a 4% Tween 80 (polyoxyethylene (20) sorbitan monooleate) solution used to flush tetrachloroethene (PCE)-contaminated porous media. The influence of EtOH concentration, subsurface layering and scale on flushing solution delivery and PCE recovery was investigated through a combination of experimental and mathematical modeling studies. Results of batch experiments demonstrated that the addition of 2.5%, 5% and 10% (wt.) EtOH incrementally increased the PCE solubilization capacity and viscosity of the surfactant solution, while reducing solution density from 1.002 to 0.986 g/cm3. Effluent concentration data obtained from one-dimensional (1-D) column experiments were used to characterize rate-limited micellar solubilization of residual PCE, which was strongly dependent upon flow velocity and weakly dependent upon EtOH concentration. Two-dimensional (2-D) box studies illustrated that minor differences (0.008 g/cm3) between flushing and resident solution density can strongly influence surfactant front propagation. A two-dimensional multiphase simulator, MISER, was used to model the influence of EtOH composition on the aqueous flow field and PCE mass recovery. The ability of the numerical simulator to predict effluent concentrations and front propagation was demonstrated for both 1-D columns and 2-D boxes flushed with EtOH-amended Tween 80 solutions. Results of this study quantify the potential influence of alcohol addition on surfactant solution properties and solubilization capacity, and demonstrate the importance of considering small density variations in remedial design.

In Vivo Effects of Vanadium Pentoxide and Antioxidants (Ascorbic Acid and Alpha-Tocopherol) on Apoptotic, Cytotoxic, and Genotoxic Damage in Peripheral Blood of Mice

PubMed Central

García-Rodríguez, María del Carmen; Hernández-Cortés, Lourdes Montserrat; Altamirano-Lozano, Mario Agustín

2016-01-01

This study was conducted to investigate the effects of vanadium pentoxide (V2O5), ascorbic acid (AA), and alpha-tocopherol (α-TOH) on apoptotic, cytotoxic, and genotoxic activity. Groups of five Hsd:ICR mice were treated with the following: (a) vehicle, distilled water; (b) vehicle, corn oil; (c) AA, 100 mg/kg intraperitoneally (ip); (d) α-TOH, 20 mg/kg by gavage; (e) V2O5, 40 mg/kg by ip injection; (f) AA + V2O5; and (g) α-TOH + V2O5. Genotoxic damage was evaluated by examining micronucleated polychromatic erythrocytes (MN-PCE) obtained from the caudal vein at 0, 24, 48, and 72 h after treatments. Induction of apoptosis and cell viability were assessed at 48 h after treatment in nucleated cells of peripheral blood. Treatment with AA alone reduced basal MN-PCE, while V2O5 treatment marginally increased MN-PCE at all times after injection. Antioxidants treatments prior to V2O5 administration decreased MN-PCE compared to the V2O5 group, with the most significant effect in the AA + V2O5 group. The apoptotic cells increased with all treatments, suggesting that this process may contribute to the elimination of the cells with V2O5-induced DNA damage (MN-PCE). The necrotic cells only increased in the V2O5 group. Therefore, antioxidants such as AA and α-TOH can be used effectively to protect or reduce the genotoxic effects induced by vanadium compounds like V2O5. PMID:27413422

Phasegram Analysis of Vocal Fold Vibration Documented With Laryngeal High-speed Video Endoscopy.

PubMed

Herbst, Christian T; Unger, Jakob; Herzel, Hanspeter; Švec, Jan G; Lohscheller, Jörg

2016-11-01

In a recent publication, the phasegram, a bifurcation diagram over time, has been introduced as an intuitive visualization tool for assessing the vibratory states of oscillating systems. Here, this nonlinear dynamics approach is augmented with quantitative analysis parameters, and it is applied to clinical laryngeal high-speed video (HSV) endoscopic recordings of healthy and pathological phonations. HSV data from a total of 73 females diagnosed as healthy (n = 42), or with functional dysphonia (n = 15) or with unilateral vocal fold paralysis (n = 16), were quantitatively analyzed. Glottal area waveforms (GAW) and left and right hemi-GAWs (hGAW) were extracted from the HSV recordings. Based on Poincaré sections through phase space-embedded signals, two novel quantitative parameters were computed: the phasegram entropy (PE) and the phasegram complexity estimate (PCE), inspired by signal entropy and correlation dimension computation, respectively. Both PE and PCE assumed higher average values (suggesting more irregular vibrations) for the pathological as compared with the healthy participants, thus significantly discriminating healthy group from the paralysis group (P = 0.02 for both PE and PCE). Comparisons of individual PE or PCE data for the left and the right hGAW within each subject resulted in asymmetry measures for the regularity of vocal fold vibration. The PCE-based asymmetry measure revealed significant differences between the healthy group and the paralysis group (P = 0.03). Quantitative phasegram analysis of GAW and hGAW data is a promising tool for the automated processing of HSV data in research and in clinical practice. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Effects of initial saturation on properties modification and displacement of tetrachloroethene with aqueous isobutanol.

PubMed

Boyd, Glen R; Ocampo-Gómez, Ana M; Li, Minghua; Husserl, Johana

2006-11-20

Packed column experiments were conducted to study effects of initial saturation of tetrachloroethene (PCE) in the range of 1.0-14% pore volume (PV) on mobilization and downward migration of the non-aqueous phase liquid (NAPL) product upon contact with aqueous isobutanol ( approximately 10 vol.%). This study focused on the consequences of swelling beyond residual saturation. Columns were packed with mixtures of neat PCE, water and glass beads and waterflooded to establish a desired homogeneous residual saturation, and then flooded with aqueous isobutanol under controlled hydraulic conditions. Results showed a critical saturation of approximately 8% PV for these packed column experimental conditions. At low initial PCE saturations (<8% PV), experimental results showed reduced risk of NAPL-product migration upon contact with aqueous isobutanol. At higher initial PCE saturations (>8% PV), results showed NAPL-product mobilization and downward migration which was attributed to interfacial tension (IFT) reduction, swelling of the NAPL-product, and reduced density modification. Packed column results were compared with good agreement to theoretical predictions of NAPL-product mobilization using the total trapping number, N(T). In addition to the packed column study, preliminary batch experiments were conducted to study the effects of PCE volumetric fraction in the range of 0.5-20% on density, viscosity, and IFT modification as a function of time following contact with aqueous isobutanol ( approximately 10 vol.%). Modified NAPL-product fluid properties approached equilibrium within approximately 2 h of contact for density and viscosity. IFT reduction occurred immediately as expected. Measured fluid properties were compared with good agreement to theoretical equilibrium predictions based on UNIQUAC. Overall, this study demonstrates the importance of initial DNAPL saturation, and the associated risk of downward NAPL-product migration, in applying alcohol flooding for remediation of DNAPL contaminated ground water sites.

A convenient method for the quantitative determination of elemental sulfur in coal by HPLC analysis of perchloroethylene extracts

USGS Publications Warehouse

Buchanan, D.H.; Coombs, K.J.; Murphy, P.M.; Chaven, C.

1993-01-01

A convenient method for the quantitative determination of elemental sulfur in coal is described. Elemental sulfur is extracted from the coal with hot perchloroethylene (PCE) (tetrachloroethene, C2Cl4) and quantitatively determined by HPLC analysis on a C18 reverse-phase column using UV detection. Calibration solutions were prepared from sublimed sulfur. Results of quantitative HPLC analyses agreed with those of a chemical/spectroscopic analysis. The HPLC method was found to be linear over the concentration range of 6 ?? 10-4 to 2 ?? 10-2 g/L. The lower detection limit was 4 ?? 10-4 g/L, which for a coal sample of 20 g is equivalent to 0.0006% by weight of coal. Since elemental sulfur is known to react slowly with hydrocarbons at the temperature of boiling PCE, standard solutions of sulfur in PCE were heated with coals from the Argonne Premium Coal Sample program. Pseudo-first-order uptake of sulfur by the coals was observed over several weeks of heating. For the Illinois No. 6 premium coal, the rate constant for sulfur uptake was 9.7 ?? 10-7 s-1, too small for retrograde reactions between solubilized sulfur and coal to cause a significant loss in elemental sulfur isolated during the analytical extraction. No elemental sulfur was produced when the following pure compounds were heated to reflux in PCE for up to 1 week: benzyl sulfide, octyl sulfide, thiane, thiophene, benzothiophene, dibenzothiophene, sulfuric acid, or ferrous sulfate. A sluury of mineral pyrite in PCE contained elemental sulfur which increased in concentration with heating time. ?? 1993 American Chemical Society.

Pathways to adolescent sexual risk behaviors: Effects of prenatal cocaine exposure.

PubMed

Min, Meeyoung O; Minnes, Sonia; Lang, Adelaide; Albert, Jeffrey M; Kim, June-Yung; Singer, Lynn T

2016-04-01

To assess the impact of prenatal cocaine exposure (PCE) on adolescent sexual risk behaviors. Externalizing behavior, teen substance use, and early sexual intercourse were examined as pathways mediating the effects of PCE on sexual risk behaviors. Adolescents (N=364; 185 PCE, 179 non-cocaine exposure (NCE); 205 girls, 159 boys), primarily African-American and of low socioeconomic status, were prospectively enrolled in a longitudinal study at birth. Risky sexual behaviors were assessed at ages 15 and 17. Externalizing behavior at 12 years was assessed with the Youth Self-Report. Substance use, via self-report and biologic assays, and early (before age 15) sexual intercourse were assessed at age 15. Path analyses with the weighted least squares estimator with mean and variance adjustments were performed. The final structural equation model-based path model, χ(2)=31.97 (df=27), p=.23, CFI=.99, TLI=.99, RMSEA=.021, WRMR=.695, indicated a direct effect of PCE on sexual risk behavior (β=.16, p=.02). Although PCE was related to greater externalizing behavior (β=.14, p=.009), which in turn, predicted early sexual intercourse (β=.16, p=.03), leading to sexual risk behavior (β=.44, p<.001), bootstrapping indicated a non-significant indirect effect (β=.01, p>.10). Substance use was correlated with early sexual intercourse (r=.60, p<.001) and predicted sexual risk behavior by age 17 (β=.31, p=.01). Prenatal cocaine exposure was related to more engagement in sexual risk behaviors, suggesting the importance of reducing substance use among pregnant women as a means of prevention of offspring substance use and sexual risk behavior. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Use and Customization of Risk Scores for Predicting Cardiovascular Events Using Electronic Health Record Data.

PubMed

Wolfson, Julian; Vock, David M; Bandyopadhyay, Sunayan; Kottke, Thomas; Vazquez-Benitez, Gabriela; Johnson, Paul; Adomavicius, Gediminas; O'Connor, Patrick J

2017-04-24

Clinicians who are using the Framingham Risk Score (FRS) or the American College of Cardiology/American Heart Association Pooled Cohort Equations (PCE) to estimate risk for their patients based on electronic health data (EHD) face 4 questions. (1) Do published risk scores applied to EHD yield accurate estimates of cardiovascular risk? (2) Are FRS risk estimates, which are based on data that are up to 45 years old, valid for a contemporary patient population seeking routine care? (3) Do the PCE make the FRS obsolete? (4) Does refitting the risk score using EHD improve the accuracy of risk estimates? Data were extracted from the EHD of 84 116 adults aged 40 to 79 years who received care at a large healthcare delivery and insurance organization between 2001 and 2011. We assessed calibration and discrimination for 4 risk scores: published versions of FRS and PCE and versions obtained by refitting models using a subset of the available EHD. The published FRS was well calibrated (calibration statistic K=9.1, miscalibration ranging from 0% to 17% across risk groups), but the PCE displayed modest evidence of miscalibration (calibration statistic K=43.7, miscalibration from 9% to 31%). Discrimination was similar in both models (C-index=0.740 for FRS, 0.747 for PCE). Refitting the published models using EHD did not substantially improve calibration or discrimination. We conclude that published cardiovascular risk models can be successfully applied to EHD to estimate cardiovascular risk; the FRS remains valid and is not obsolete; and model refitting does not meaningfully improve the accuracy of risk estimates. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Field-scale Prediction of Enhanced DNAPL Dissolution Using Partitioning Tracers and Flow Pattern Effects

NASA Astrophysics Data System (ADS)

Wang, F.; Annable, M. D.; Jawitz, J. W.

2012-12-01

The equilibrium streamtube model (EST) has demonstrated the ability to accurately predict dense nonaqueous phase liquid (DNAPL) dissolution in laboratory experiments and numerical simulations. Here the model is applied to predict DNAPL dissolution at a PCE-contaminated dry cleaner site, located in Jacksonville, Florida. The EST is an analytical solution with field-measurable input parameters. Here, measured data from a field-scale partitioning tracer test were used to parameterize the EST model and the predicted PCE dissolution was compared to measured data from an in-situ alcohol (ethanol) flood. In addition, a simulated partitioning tracer test from a calibrated spatially explicit multiphase flow model (UTCHEM) was also used to parameterize the EST analytical solution. The ethanol prediction based on both the field partitioning tracer test and the UTCHEM tracer test simulation closely matched the field data. The PCE EST prediction showed a peak shift to an earlier arrival time that was concluded to be caused by well screen interval differences between the field tracer test and alcohol flood. This observation was based on a modeling assessment of potential factors that may influence predictions by using UTCHEM simulations. The imposed injection and pumping flow pattern at this site for both the partitioning tracer test and alcohol flood was more complex than the natural gradient flow pattern (NGFP). Both the EST model and UTCHEM were also used to predict PCE dissolution under natural gradient conditions, with much simpler flow patterns than the forced-gradient double five spot of the alcohol flood. The NGFP predictions based on parameters determined from tracer tests conducted with complex flow patterns underestimated PCE concentrations and total mass removal. This suggests that the flow patterns influence aqueous dissolution and that the aqueous dissolution under the NGFP is more efficient than dissolution under complex flow patterns.

Lifetime excess cancer risk due to carcinogens in food and beverages: Urban versus rural differences in Canada.

PubMed

Cheasley, Roslyn; Keller, C Peter; Setton, Eleanor

2017-09-14

To explore differences in urban versus rural lifetime excess risk of cancer from five specific contaminants found in food and beverages. Probable contaminant intake is estimated using Monte Carlo simulations of contaminant concentrations in combination with dietary patterns. Contaminant concentrations for arsenic, benzene, lead, polychlorinated biphenyls (PCBs) and tetrachloroethylene (PERC) were derived from government dietary studies. The dietary patterns of 34 944 Canadians from 10 provinces were available from Health Canada's Canadian Community Health Survey, Cycle 2.2, Nutrition (2004). Associated lifetime excess cancer risk (LECR) was subsequently calculated from the results of the simulations. In the calculation of LECR from food and beverages for the five selected substances, two (lead and PERC) were shown to have excess risk below 10 per million; whereas for the remaining three (arsenic, benzene and PCBs), it was shown that at least 50% of the population were above 10 per million excess cancers. Arsenic residues, ingested via rice and rice cereal, registered the greatest disparity between urban and rural intake, with LECR per million levels well above 1000 per million at the upper bound. The majority of PCBs ingestion comes from meat, with values slightly higher for urban populations and LECR per million estimates between 50 and 400. Drinking water is the primary contributor of benzene intake in both urban and rural populations, with LECR per million estimates of 35 extra cancers in the top 1% of sampled population. Overall, there are few disparities between urban and rural lifetime excess cancer risk from contaminants found in food and beverages. Estimates could be improved with more complete Canadian dietary intake and concentration data in support of detailed exposure assessments in estimating LECR.

Ionic liquid-functionalized carbon nanoparticles-modified cathode for efficiency enhancement in polymer solar cells

NASA Astrophysics Data System (ADS)

Chen, Xiaohong; Yang, Jiaxiang; Lu, Jiong; Manga, Kiran Kumar; Loh, Kian Ping; Zhu, Furong

2009-09-01

The power conversion efficiency (PCE) of regioregular poly(3-hexylthiophene) (P3HT) and {6,6}-phenyl C61-butyric acid methylester (PCBM)-based polymer solar cells was increased using an ionic liquid-functionalized carbon nanoparticles (ILCNs) thin film-modified cathode. The PCE of P3HT:PCBM based-polymer solar cells with a conventional aluminum (Al)-only cathode was increased by 20%-30% when the identical devices were made with an ILCNs-modified Al cathode, but its PCE was 10% lower than that of devices with LiF/Al cathode, measured under AM1.5G illumination of 100 mW/cm2. The ILCN interlayer approach, however, offers practical advantages to LiF in terms of its solution-processability, which is compatible with low cost, large area, and flexible solar cell fabrication.

Polynomial chaos representation of databases on manifolds

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

Soize, C., E-mail: christian.soize@univ-paris-est.fr; Ghanem, R., E-mail: ghanem@usc.edu

2017-04-15

Characterizing the polynomial chaos expansion (PCE) of a vector-valued random variable with probability distribution concentrated on a manifold is a relevant problem in data-driven settings. The probability distribution of such random vectors is multimodal in general, leading to potentially very slow convergence of the PCE. In this paper, we build on a recent development for estimating and sampling from probabilities concentrated on a diffusion manifold. The proposed methodology constructs a PCE of the random vector together with an associated generator that samples from the target probability distribution which is estimated from data concentrated in the neighborhood of the manifold. Themore » method is robust and remains efficient for high dimension and large datasets. The resulting polynomial chaos construction on manifolds permits the adaptation of many uncertainty quantification and statistical tools to emerging questions motivated by data-driven queries.« less

Comparative analysis between different font types and letter styles using a nonlinear invariant digital correlation

NASA Astrophysics Data System (ADS)

Coronel-Beltrán, Ángel; Álvarez-Borrego, Josué

2010-01-01

We present, in this paper, a comparative analysis of the letters in Times New Roman (TNR), Courier New (CN) and Arial (Ar) font types in plain and italic style and the effects of five foreground/background color combinations using an invariant digital correlation system with a nonlinear filter with k = 0.3. The evaluation of the output plane with this filter is given by the peak-to-correlation energy (PCE) metric. The results show that the letters in TNR font have a better mean PCE value when compared with the CN and Ar fonts. This result is in agreement with some studies on text legibility and for readability where the reaction time (RT) of some participant individuals reading a text is measured. We conclude that the PCE metric is proportional to 1/RT.

Efficient inverted polymer solar cells based on conjugated polyelectrolyte and zinc oxide modified ITO electrode

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

Yuan, Tao; Zhu, Xiaoguang; Tu, Guoli, E-mail: tgl@hust.edu.cn

Efficient inverted polymer solar cells (PSCs) were constructed by utilizing a conjugated polyelectrolyte PF{sub EO}SO{sub 3}Na and zinc oxide to modify the indium tin oxide (ITO) electrode. The ITO electrode modified by PF{sub EO}SO{sub 3}Na and zinc oxide possesses high transparency, increased electron mobility, smoothened surface, and lower work function. PTB7:PC{sub 71}BM inverted PSCs containing the modified ITO electrode achieved a high power conversion efficiency (PCE) of 8.49%, exceeding that of the control device containing a ZnO modified ITO electrode (7.48%). Especially, PCE-10:PC{sub 71}BM inverted polymer solar cells achieved a high PCE up to 9.4%. These results demonstrate a usefulmore » approach to improve the performance of inverted polymer solar cells.« less

Co-functionalized organic/inorganic hybrid ZnO nanorods as electron transporting layers for inverted organic solar cells

NASA Astrophysics Data System (ADS)

Ambade, Swapnil B.; Ambade, Rohan B.; Eom, Seung Hun; Baek, Myung-Jin; Bagde, Sushil S.; Mane, Rajaram S.; Lee, Soo-Hyoung

2016-02-01

In an unprecedented attempt, we present an interesting approach of coupling solution processed ZnO planar nanorods (NRs) by an organic small molecule (SM) with a strong electron withdrawing cyano moiety and the carboxylic group as binding sites by a facile co-functionalization approach. Direct functionalization by SMs (SM-ZnO NRs) leads to higher aggregation owing to the weaker solubility of SMs in solutions of ZnO NRs dispersed in chlorobenzene (CB). A prior addition of organic 2-(2-methoxyethoxy)acetic acid (MEA) over ZnO NRs not only inhibits aggregation of SMs over ZnO NRs, but also provides enough sites for the SM to strongly couple with the ZnO NRs to yield transparent SM-MEA-ZnO NRs hybrids that exhibited excellent capability as electron transporting layers (ETLs) in inverted organic solar cells (iOSCs) of P3HT:PC60BM bulk-heterojunction (BHJ) photoactive layers. A strongly coupled SM-MEA-ZnO NR hybrid reduces the series resistance by enhancing the interfacial area and tunes the energy level alignment at the interface between the (indium-doped tin oxide, ITO) cathode and BHJ photoactive layers. A significant enhancement in power conversion efficiency (PCE) was achieved for iOSCs comprising ETLs of SM-MEA-ZnO NRs (3.64%) advancing from 0.9% for pristine ZnO NRs, while the iOSCs of aggregated SM-ZnO NRs ETL exhibited a much lower PCE of 2.6%, thus demonstrating the potential of the co-functionalization approach. The superiority of the co-functionalized SM-MEA-ZnO NRs ETL is also evident from the highest PCE of 7.38% obtained for the iOSCs comprising BHJ of PTB7-Th:PC60BM compared with extremely poor 0.05% for non-functionalized ZnO NRs.In an unprecedented attempt, we present an interesting approach of coupling solution processed ZnO planar nanorods (NRs) by an organic small molecule (SM) with a strong electron withdrawing cyano moiety and the carboxylic group as binding sites by a facile co-functionalization approach. Direct functionalization by SMs (SM-ZnO NRs) leads to higher aggregation owing to the weaker solubility of SMs in solutions of ZnO NRs dispersed in chlorobenzene (CB). A prior addition of organic 2-(2-methoxyethoxy)acetic acid (MEA) over ZnO NRs not only inhibits aggregation of SMs over ZnO NRs, but also provides enough sites for the SM to strongly couple with the ZnO NRs to yield transparent SM-MEA-ZnO NRs hybrids that exhibited excellent capability as electron transporting layers (ETLs) in inverted organic solar cells (iOSCs) of P3HT:PC60BM bulk-heterojunction (BHJ) photoactive layers. A strongly coupled SM-MEA-ZnO NR hybrid reduces the series resistance by enhancing the interfacial area and tunes the energy level alignment at the interface between the (indium-doped tin oxide, ITO) cathode and BHJ photoactive layers. A significant enhancement in power conversion efficiency (PCE) was achieved for iOSCs comprising ETLs of SM-MEA-ZnO NRs (3.64%) advancing from 0.9% for pristine ZnO NRs, while the iOSCs of aggregated SM-ZnO NRs ETL exhibited a much lower PCE of 2.6%, thus demonstrating the potential of the co-functionalization approach. The superiority of the co-functionalized SM-MEA-ZnO NRs ETL is also evident from the highest PCE of 7.38% obtained for the iOSCs comprising BHJ of PTB7-Th:PC60BM compared with extremely poor 0.05% for non-functionalized ZnO NRs. Electronic supplementary information (ESI) available: Fig. S1-S3 and Table S1. See DOI: 10.1039/c5nr08849f

Testing the newly installed PCE (Proximity Communications Equipment) hardware

NASA Image and Video Library

2005-06-29

ISS011-E-09816 (28 June 2005) --- Cosmonaut Sergei K. Krikalev, Expedition 11 commander representing Russia's Federal Space Agency, tests the newly installed Proximity Communications Equipment (PCE) hardware of the ASN-M satellite navigation system for the European Automated Transfer Vehicle (ATV) “Jules Verne” in the Zvezda Service Module of the International Space Station. The ATV is scheduled to arrive at the Station next year.

Testing the newly installed PCE (Proximity Communications Equipment) hardware

NASA Image and Video Library

2005-06-28

ISS011-E-09812 (28 June 2005) --- Cosmonaut Sergei K. Krikalev, Expedition 11 commander representing Russia's Federal Space Agency, tests the newly installed Proximity Communications Equipment (PCE) hardware of the ASN-M satellite navigation system for the European Automated Transfer Vehicle (ATV) “Jules Verne” in the Zvezda Service Module of the international space station. The ATV is scheduled to arrive at the station next year.

Testing of stack-unit/aquifer sensitivity analysis using contaminant plume distribution in the subsurface of Savannah River Site, South Carolina, USA

USGS Publications Warehouse

Rine, J.M.; Shafer, J.M.; Covington, E.; Berg, R.C.

2006-01-01

Published information on the correlation and field-testing of the technique of stack-unit/aquifer sensitivity mapping with documented subsurface contaminant plumes is rare. The inherent characteristic of stack-unit mapping, which makes it a superior technique to other analyses that amalgamate data, is the ability to deconstruct the sensitivity analysis on a unit-by-unit basis. An aquifer sensitivity map, delineating the relative sensitivity of the Crouch Branch aquifer of the Administrative/Manufacturing Area (A/M) at the Savannah River Site (SRS) in South Carolina, USA, incorporates six hydrostratigraphic units, surface soil units, and relevant hydrologic data. When this sensitivity map is compared with the distribution of the contaminant tetrachloroethylene (PCE), PCE is present within the Crouch Branch aquifer within an area classified as highly sensitive, even though the PCE was primarily released on the ground surface within areas classified with low aquifer sensitivity. This phenomenon is explained through analysis of the aquifer sensitivity map, the groundwater potentiometric surface maps, and the plume distributions within the area on a unit-by- unit basis. The results of this correlation show how the paths of the PCE plume are influenced by both the geology and the groundwater flow. ?? Springer-Verlag 2006.

Mesoporous multi-shelled ZnO microspheres for the scattering layer of dye sensitized solar cell with a high efficiency

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

Xia, Weiwei; Mei, Chao; Zeng, Xianghua, E-mail: xhzeng@yzu.edu.cn

2016-03-14

Both light scattering and dye adsorbing are important for the power conversion efficiency PCE performance of dye sensitized solar cell (DSSC). Nanostructured scattering layers with a large specific surface area are regarded as an efficient way to improve the PCE by increasing dye adsorbing, but excess adsorbed dye will hinder light scattering and light penetration. Thus, how to balance the dye adsorbing and light penetration is a key problem to improve the PCE performance. Here, multiple-shelled ZnO microspheres with a mesoporous surface are fabricated by a hydrothermal method and are used as scattering layers on the TiO{sub 2} photoanode ofmore » the DSSC in the presence of N719 dye and iodine–based electrolyte, and the results reveal that the DSSCs based on triple shelled ZnO microsphere with a mesoporous surface exhibit an enhanced PCE of 7.66%, which is 13.0% higher than those without the scattering layers (6.78%), indicating that multiple-shelled microspheres with a mesoporous surface can ensure enough light scattering between the shells, and a favorable concentration of the adsorbed dye can improve the light penetration. These results may provide a promising pathway to obtain the high efficient DSSCs.« less

Three-tier multi-granularity switching system based on PCE

NASA Astrophysics Data System (ADS)

Wang, Yubao; Sun, Hao; Liu, Yanfei

2017-10-01

With the growing demand for business communications, electrical signal processing optical path switching can't meet the demand. The multi-granularity switch system that can improve node routing and switching capabilities came into being. In the traditional network, each node is responsible for calculating the path; synchronize the whole network state, which will increase the burden on the network, so the concept of path calculation element (PCE) is proposed. The PCE is responsible for routing and allocating resources in the network1. In the traditional band-switched optical network, the wavelength is used as the basic routing unit, resulting in relatively low wavelength utilization. Due to the limitation of wavelength continuity, the routing design of the band technology becomes complicated, which directly affects the utilization of the system. In this paper, optical code granularity is adopted. There is no continuity of the optical code, and the number of optical codes is more flexible than the wavelength. For the introduction of optical code switching, we propose a Code Group Routing Entity (CGRE) algorithm. In short, the combination of three-tier multi-granularity optical switching system and PCE can simplify the network structure, reduce the node load, and enhance the network scalability and survivability. Realize the intelligentization of optical network.

Tree Sampling as a Method to Assess Vapor Intrusion Potential at a Site Characterized by VOC-Contaminated Groundwater and Soil.

PubMed

Wilson, Jordan L; Limmer, Matthew A; Samaranayake, V A; Schumacher, John G; Burken, Joel G

2017-09-19

Vapor intrusion (VI) by volatile organic compounds (VOCs) in the built environment presents a threat to human health. Traditional VI assessments are often time-, cost-, and labor-intensive; whereas traditional subsurface methods sample a relatively small volume in the subsurface and are difficult to collect within and near structures. Trees could provide a similar subsurface sample where roots act as the "sampler' and are already onsite. Regression models were developed to assess the relation between PCE concentrations in over 500 tree-core samples with PCE concentrations in over 50 groundwater and 1000 soil samples collected from a tetrachloroethylene- (PCE-) contaminated Superfund site and analyzed using gas chromatography. Results indicate that in planta concentrations are significantly and positively related to PCE concentrations in groundwater samples collected at depths less than 20 m (adjusted R 2 values greater than 0.80) and in soil samples (adjusted R 2 values greater than 0.90). Results indicate that a 30 cm diameter tree characterizes soil concentrations at depths less than 6 m over an area of 700-1600 m 2 , the volume of a typical basement. These findings indicate that tree sampling may be an appropriate method to detect contamination at shallow depths at sites with VI.

Polymer-fullerene miscibility: a metric for screening new materials for high-performance organic solar cells.

PubMed

Treat, Neil D; Varotto, Alessandro; Takacs, Christopher J; Batara, Nicolas; Al-Hashimi, Mohammed; Heeney, Martin J; Heeger, Alan J; Wudl, Fred; Hawker, Craig J; Chabinyc, Michael L

2012-09-26

The improvement of the power conversion efficiency (PCE) of polymer bulk heterojunction (BHJ) solar cells has generally been achieved through synthetic design to control frontier molecular orbital energies and molecular ordering of the electron-donating polymer. An alternate approach to control the PCE of a BHJ is to tune the miscibility of the fullerene and a semiconducting polymer by varying the structure of the fullerene. The miscibility of a series of 1,4-fullerene adducts in the semiconducting polymer, poly(3-hexylselenophene), P3HS, was measured by dynamic secondary ion mass spectrometry using a model bilayer structure. The microstructure of the bilayer was investigated using high-angle annular dark-field scanning transmission microscopy and linked to the polymer-fullerene miscibility. Finally, P3HS:fullerene BHJ solar cells were fabricated from each fullerene derivative, enabling the correlation of the active layer microstructure to the charge collection efficiency and resulting PCE of each system. The volume fraction of polymer-rich, fullerene-rich, and polymer-fullerene mixed domains can be tuned using the miscibility leading to improvement in the charge collection efficiency and PCE in P3HS:fullerene BHJ solar cells. These results suggest a rational approach to the design of fullerenes for improved BHJ solar cells.

Multi-Shaped Ag Nanoparticles in the Plasmonic Layer of Dye-Sensitized Solar Cells for Increased Power Conversion Efficiency.

PubMed

Song, Da Hyun; Kim, Ho-Sub; Suh, Jung Sang; Jun, Bong-Hyun; Rho, Won-Yeop

2017-06-04

The use of dye-sensitized solar cells (DSSCs) is widespread owing to their high power conversion efficiency (PCE) and low cost of manufacturing. We prepared multi-shaped Ag nanoparticles (NPs) and introduced them into DSSCs to further enhance their PCE. The maximum absorption wavelength of the multi-shaped Ag NPs is 420 nm, including the shoulder with a full width at half maximum (FWHM) of 121 nm. This is a broad absorption wavelength compared to spherical Ag NPs, which have a maximum absorption wavelength of 400 nm without the shoulder of 61 nm FWHM. Therefore, when multi-shaped Ag NPs with a broader plasmon-enhanced absorption were coated on a mesoporous TiO₂ layer on a layer-by-layer structure in DSSCs, the PCE increased from 8.44% to 10.22%, equivalent to an improvement of 21.09% compared to DSSCs without a plasmonic layer. To confirm the plasmon-enhanced effect on the composite film structure in DSSCs, the PCE of DSSCs based on the composite film structure with multi-shaped Ag NPs increased from 8.58% to 10.34%, equivalent to an improvement of 20.51% compared to DSSCs without a plasmonic layer. This concept can be applied to perovskite solar cells, hybrid solar cells, and other solar cells devices.

Attitudes toward pharmacological cognitive enhancement—a review

PubMed Central

Schelle, Kimberly J.; Faulmüller, Nadira; Caviola, Lucius; Hewstone, Miles

2014-01-01

A primary means for the augmentation of cognitive brain functions is “pharmacological cognitive enhancement” (PCE). The term usually refers to the off-label use of medical substances to improve mental performance in healthy individuals. With the final aim to advance the normative debate taking place on that topic, several empirical studies have been conducted to assess the attitudes toward PCE in the public, i.e., in groups outside of the academic debate. In this review, we provide an overview of the 40 empirical studies published so far, reporting both their methodology and results. Overall, we find that several concerns about the use of PCE are prevalent in the public. These concerns largely match those discussed in the normative academic debate. We present our findings structured around the three most common concerns: medical safety, coercion, and fairness. Fairness is divided into three subthemes: equality of opportunity, honesty, and authenticity. Attitudes regarding some concerns are coherent across studies (e.g., coercion), whereas for others we find mixed results (e.g., authenticity). Moreover, we find differences in how specific groups—such as users, nonusers, students, parents, and health care providers—perceive PCE: a coherent finding is that nonusers display more concerns regarding medical safety and fairness than users. We discuss potential psychological explanations for these differences. PMID:24860438

High performance planar p-i-n perovskite solar cells with crown-ether functionalized fullerene and LiF as double cathode buffer layers

NASA Astrophysics Data System (ADS)

Liu, Xiaodong; Lei, Ming; Zhou, Yi; Song, Bo; Li, Yongfang

2015-08-01

Double cathode buffer layers (CBLs) composed of fullerene derivative functionalized with a crown-ether end group in its side chain (denoted as PCBC) and a LiF layer were introduced between the PCBM acceptor layer and the top cathode in planar p-i-n perovskite solar cells (pero-SCs) based on CH3NH3PbI3-XClX. The devices with the PCBC/LiF double CBLs showed significant improvements in power conversion efficiency (PCE) and long-term stability when compared to the device with LiF single CBL. Through optimizing the spin-coating speed of PCBC, a maximum PCE of 15.53% has been achieved, which is approximately 15% higher than that of the device with single LiF CBL. The remarkable improvement in PCE can be attributed to the formation of a better ohmic contact in the CBL between PCBC and LiF/Al electrode arising from the dipole moment of PCBC, leading to the enhanced fill factor and short-circuit current density (Jsc). Besides the PCE, the long-term stability of the devices with PCBC interlayer is also superior to that of the device with LiF single CBL, which is due to the more effective protection for the perovskite/PCBM interface.

Cyclodextrin-enhanced solubilization and removal of residual-phase chlorinated solvents from porous media

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

Boving, T.B.; Wang, X.; Brusseau, M.L.

1999-03-01

The development of improved methods for remediation of contaminated aquifers has emerged as a significant environmental priority. One technology that appears to have considerable promise involves the use of solubilization agents such as surfactants and cosolvents for enhancing the removal of residual phase immiscible liquids. The authors examined the use of cyclodextrin, a glucose-based molecule, for solubilizing and removing residual-phase immiscible liquid from porous media. Batch experiments were conducted to measure the degree of trichloroethene (TCE) and tetrachloroethene (PCE) solubilization induced by hydroxypropyl-{beta}-cyclodextrin (HPCD) and methyl-{beta}-cyclodextrin (MCD). These studies revealed that the solubilities of TCE and PCE were enhanced bymore » up to 9.5 and 36.0 times, respectively. Column experiments were conducted to compare water and cyclodextrin-enhanced flushing of Borden sand containing residual saturations of TCE and PCE. The results indicate that solubilization and mass removal were enhanced substantially with the use of cyclodextrins. The effluent concentrations during the steady-state phase of the HPCD and MCD flushing experiments were close to the apparent solubilities measured with the batch experiments, indicating equilibrium concentrations were maintained during the initial phase of cyclodextrin flushing. Mobilization was observed for only the TCE-MCD and PCE-5%MCD experiments.« less

Protective effect of hawthorn extract against genotoxicity induced by cyclophosphamide in mouse bone marrow cells.

PubMed

Hosseinimehr, Seyed Jalal; Azadbakht, Mohammad; Abadi, Atefeh Jahan

2008-01-01

The preventive effect of hawthorn (Crataegus microphylla) fruit extract was investigated in mouse bone marrow cells against genotoxicity induced by cyclophosphamide. Mice were orally (gavages) pretreated with solutions of hawthorn extract which was prepared at five different doses (25, 50, 100, 200 and 400mg/kg b.w.) for seven consecutive days. Mice were injected intraperitoneally on the seventh day with cyclophosphamide (50mg/kg b.w.) and killed after 24h for the evaluation of micronucleated polychromatic erythrocytes (MnPCEs) and the ratio of PCE/(PCE+NCE) (polychromatic erythrocyte/polychromatic erythrocyte+normochromatic erythrocyte). All of five doses of extract significantly reduced MnPCEs induced by cyclophosphamide (P<0.0001). Hawthorn extract at dose 100mg/kg b.w. reduced MnPCEs 2.5 time and also completely normalized PCE/(PCE+NCE) ratio. Hawthorn extract exhibited concentration-dependent antioxidant activity on 1,1-diphenyl-2-picryl hydrazyl free radical. Hawthorn contains high amounts of phenolic compounds; the HPLC analysis showed that it contained chlorogenic acid, epicatechin and hyperoside. It is obvious that hawthorn, particularly flavonoids constituents with antioxidative activity, reduced the oxidative stress and genotoxicity induced by cyclophosphamide in mouse bone marrow cells. Copyright © 2007 Elsevier B.V. All rights reserved.

Direct Correlation of Excitonics with Efficiency in a Core-Shell Quantum Dot Solar Cell.

PubMed

Dana, Jayanta; Maiti, Sourav; Tripathi, Vaidehi S; Ghosh, Hirendra N

2018-02-16

Shell thickness dependent band-gap engineering of quasi type II core-shell material with higher carrier cooling time, lower interfacial defect states, and longer charge carrier recombination time can be a promising candidate for both photocatalysis and solar cell. In the present investigation, colloidal CdSe@CdS core-shells with different shell thickness (2, 4 and 6 monolayer CdS) were synthesized through hot injection method and have been characterized by high resolution transmission electron microscope (HRTEM) followed by steady state absorption and luminescence techniques. Ultrafast transient absorption (TA) studies suggest longer carrier cooling, lower interfacial surface states, and slower carrier recombination time in CdSe@CdS core-shell with increasing shell thickness. By TA spectroscopy, the role of CdS shell in power conversion efficiency (PCE) has been explained in detail. The measured PCE was found to initially increase and then decrease with increasing shell thickness. Shell thickness has been optimized to maximize the efficiency after correlating the shell controlled carrier cooling and recombination with PCE values and a maximum PCE of 3.88 % was obtained with 4 monolayers of CdS shell, which is found to be 57 % higher than compared to bare CdSe QDs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tree sampling as a method to assess vapor intrusion potential at a site characterized by VOC-contaminated groundwater and soil

USGS Publications Warehouse

Wilson, Jordan L.; Limmer, Matthew A.; Samaranayake, V. A.; Schumacher, John G.; Burken, Joel G.

2017-01-01

Vapor intrusion (VI) by volatile organic compounds (VOCs) in the built environment presents a threat to human health. Traditional VI assessments are often time-, cost-, and labor-intensive; whereas traditional subsurface methods sample a relatively small volume in the subsurface and are difficult to collect within and near structures. Trees could provide a similar subsurface sample where roots act as the “sampler’ and are already onsite. Regression models were developed to assess the relation between PCE concentrations in over 500 tree-core samples with PCE concentrations in over 50 groundwater and 1000 soil samples collected from a tetrachloroethylene- (PCE-) contaminated Superfund site and analyzed using gas chromatography. Results indicate that in planta concentrations are significantly and positively related to PCE concentrations in groundwater samples collected at depths less than 20 m (adjusted R2 values greater than 0.80) and in soil samples (adjusted R2 values greater than 0.90). Results indicate that a 30 cm diameter tree characterizes soil concentrations at depths less than 6 m over an area of 700–1600 m2, the volume of a typical basement. These findings indicate that tree sampling may be an appropriate method to detect contamination at shallow depths at sites with VI.

Nonthermal Photocoercivity Effect in Low-Doped (Ga,Mn)As Ferromagnetic Semiconductor

NASA Astrophysics Data System (ADS)

Kiessling, T.; Astakhov, G. V.; Hoffmann, H.; Korenev, V. L.; Schwittek, J.; Schott, G. M.; Gould, C.; Ossau, W.; Brunner, K.; Molenkamp, L. W.

2011-12-01

We report a photoinduced change of the coercive field of a low doped Ga1-xMnxAs ferromagnetic semiconductor under very low intensity illumination. This photocoercivity effect (PCE) is local and reversible, which enables the controlled formation of localized magnetization domains. The PCE arises from a light induced lowering of the domain wall pinning energy as confirmed by test experiments on high doped, fully metallic ferromagnetic Ga1-xMnxAs.

Fabrication of flexible indium tin oxide-free polymer solar cells with silver nanowire transparent electrode

NASA Astrophysics Data System (ADS)

Lin, Ming-Yi; Chen, Tsun-Jui; Xu, Wei-Feng; Hsiao, Li-Jen; Budiawan, Widhya; Tu, Wei-Chen; Chen, Shih-Lun; Chu, Chih-Wei; Wei, Pei-Kuen

2018-03-01

Flexible indium tin oxide (ITO)-free poly(3-hexylthiophene):[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PC61BM) solar cells with a spin-coated silver nanowire transparent electrode are demonstrated. The solution-processed silver nanowire thin film not only exhibits high transmission (∼87%), but also shows low sheet resistance R s (∼25 Ω/sq). For solar cells with a conventional structure, the power conversion efficiency (PCE) of devices based on silver nanowires can reach around 2.29%. For the inverted structure, the PCE of devices can reach 3.39%. Conventional and inverted flexible ITO-based P3HT:PC61BM solar cells are also fabricated as a reference for comparison. For both types of solar cells, the PCE of ITO-free devices is very close that of an ITO-based polymer solar cell.

A vacuum flash-assisted solution process for high-efficiency large-area perovskite solar cells

NASA Astrophysics Data System (ADS)

Li, Xiong; Bi, Dongqin; Yi, Chenyi; Décoppet, Jean-David; Luo, Jingshan; Zakeeruddin, Shaik Mohammed; Hagfeldt, Anders; Grätzel, Michael

2016-07-01

Metal halide perovskite solar cells (PSCs) currently attract enormous research interest because of their high solar-to-electric power conversion efficiency (PCE) and low fabrication costs, but their practical development is hampered by difficulties in achieving high performance with large-size devices. We devised a simple vacuum flash-assisted solution processing method to obtain shiny, smooth, crystalline perovskite films of high electronic quality over large areas. This enabled us to fabricate solar cells with an aperture area exceeding 1 square centimeter, a maximum efficiency of 20.5%, and a certified PCE of 19.6%. By contrast, the best certified PCE to date is 15.6% for PSCs of similar size. We demonstrate that the reproducibility of the method is excellent and that the cells show virtually no hysteresis. Our approach enables the realization of highly efficient large-area PSCs for practical deployment.

Graphene/Si solar cells employing triethylenetetramine dopant and polymethylmethacrylate antireflection layer

NASA Astrophysics Data System (ADS)

Shin, Dong Hee; Jang, Chan Wook; Lee, Ha Seung; Seo, Sang Woo; Kim, Sung; Choi, Suk-Ho

2018-03-01

We report the use of triethylenetetramine (TETA) as a dopant of graphene transparent conducting electrodes (TCEs) for Si heterojunction solar cells. The molar concentration (nD) of TETA is varied from 0.05 to 0.3 mM to optimize the graphene TCEs. The TETA-doped graphene/Si Schottky solar cells show a maximum power-conversion efficiency (PCE) of 4.32% at nD = 0.2 mM, resulting from the enhanced electrical and optical properties, as proved from the nD-dependent behaviors of sheet resistance, transmittance, reflectance, series resistance, and external quantum efficiency. In addition, polymethylmethacrylate is employed as an antireflection layer to enhance the light-trapping effect on graphene/Si solar cells, resulting in further enhancement of the maximum PCE from 4.32 to 5.48%. The loss of the PCE is only within 2% of its original value during 10 days in air.

High Performance Perovskite Solar Cells

PubMed Central

Tong, Xin; Lin, Feng; Wu, Jiang

2015-01-01

Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long‐term stable all‐solid‐state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost‐effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole‐transporting materials (HTMs) and electron‐transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction. PMID:27774402

Effect of Different CH3NH3PbI3 Morphologies on Photovoltaic Properties of Perovskite Solar Cells

NASA Astrophysics Data System (ADS)

Chen, Lung-Chien; Lee, Kuan-Lin; Wu, Wen-Ti; Hsu, Chien-Feng; Tseng, Zong-Liang; Sun, Xiao Hong; Kao, Yu-Ting

2018-05-01

In this study, the perovskite layers were prepared by two-step wet process with different CH3NH3I (MAI) concentrations. The cell structure was glass/FTO/TiO2-mesoporous/CH3NH3PbI3 (MAPbI3)/spiro-OMeTAD/Ag. The MAPbI3 perovskite films were prepared using high and low MAI concentrations in a two-step process. The perovskite films were optimized at different spin coating speed and different annealing temperatures to enhance the power conversion efficiency (PCE) of perovskite solar cells. The PCE of the resulting device based on the different perovskite morphologies was discussed. The PCE of the best cell was up to 17.42%, open circuit voltage of 0.97 V, short current density of 24.06 mA/cm2, and fill factor of 0.747.

Effect of Different CH3NH3PbI3 Morphologies on Photovoltaic Properties of Perovskite Solar Cells.

PubMed

Chen, Lung-Chien; Lee, Kuan-Lin; Wu, Wen-Ti; Hsu, Chien-Feng; Tseng, Zong-Liang; Sun, Xiao Hong; Kao, Yu-Ting

2018-05-08

In this study, the perovskite layers were prepared by two-step wet process with different CH 3 NH 3 I (MAI) concentrations. The cell structure was glass/FTO/TiO 2 -mesoporous/CH 3 NH 3 PbI 3 (MAPbI 3 )/spiro-OMeTAD/Ag. The MAPbI 3 perovskite films were prepared using high and low MAI concentrations in a two-step process. The perovskite films were optimized at different spin coating speed and different annealing temperatures to enhance the power conversion efficiency (PCE) of perovskite solar cells. The PCE of the resulting device based on the different perovskite morphologies was discussed. The PCE of the best cell was up to 17.42%, open circuit voltage of 0.97 V, short current density of 24.06 mA/cm 2 , and fill factor of 0.747.

Polynomial chaos expansion with random and fuzzy variables

NASA Astrophysics Data System (ADS)

Jacquelin, E.; Friswell, M. I.; Adhikari, S.; Dessombz, O.; Sinou, J.-J.

2016-06-01

A dynamical uncertain system is studied in this paper. Two kinds of uncertainties are addressed, where the uncertain parameters are described through random variables and/or fuzzy variables. A general framework is proposed to deal with both kinds of uncertainty using a polynomial chaos expansion (PCE). It is shown that fuzzy variables may be expanded in terms of polynomial chaos when Legendre polynomials are used. The components of the PCE are a solution of an equation that does not depend on the nature of uncertainty. Once this equation is solved, the post-processing of the data gives the moments of the random response when the uncertainties are random or gives the response interval when the variables are fuzzy. With the PCE approach, it is also possible to deal with mixed uncertainty, when some parameters are random and others are fuzzy. The results provide a fuzzy description of the response statistical moments.

Panchromatic polymer-polymer ternary solar cells enhanced by Forster resonance energy transfer and solvent vapor annealing

DOE PAGES

Goh, Tenghooi; Sfeir, Matthew Y.; Huang, Jing -Shun; ...

2015-08-04

Thanks to the bulk-heterojunction (BHJ) feature of polymer solar cells (PSC), additional light active components can be added with ease to form ternary solar cells. This strategy has achieved great success largely due to expanded spectral response range and improved power conversion efficiency (PCE) without incurring excessive processing costs. Here, we report ternary blend polymer–polymer solar cells comprised of PTB7, P3HT, and PC71BM with PCE as high as 8.2%. Analyses of femtosecond time resolved photoluminescence and transient absorption spectroscopy data confirm that P3HT is effective in transferring energy non-radiatively by inducing excitons and prolonging their overall lifetime in PTB7. Asmore » a result, solvent vapor annealing (SVA) treatment was employed to rectify the overly-coarse morphology, thus enhancing the fill factor, reducing interfacial recombination, and boosting the PCE to 8.7%.« less

Smart photovoltaics based on dye-sensitized solar cells using photochromic spiropyran derivatives as photosensitizers

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

Ma, Shengbo; Ting, Hungkit; Ma, Yingzhuang

2015-05-15

In this paper, smart photovoltaic (SPV) devices, integrating both functions of solar cells and smart windows, was fabricated based on dye-sensitized solar cells using photochromic spiropyran derivatives SIBT as photosensitizers. SPV devices have self-regulated power conversion efficiency (PCE) and light transmission responding to the incident spectra due to the photoisomerization of SIBT. SIBT isomerize from closed-ring form to open-ring form under UV illumination, accompanied with enhanced visible light absorption and electron delocalization. Therefore, increased PCE and absorption in SPV devices were observed under UV treatment and the devices can be restored gradually to the initial status when kept in dark.more » The SPV devices have self-regulation of PCE and sunlight transmission responding to the changing sun spectra in different times of a day, providing a proper energy usage and a better sun-shading.« less

Diagnostic analysis of two-dimensional monthly average ozone balance with Chapman chemistry

NASA Technical Reports Server (NTRS)

Stolarski, Richard S.; Jackman, Charles H.; Kaye, Jack A.

1986-01-01

Chapman chemistry has been used in a two-dimensional model to simulate ozone balance phenomenology. The similarity between regions of ozone production and loss calculated using Chapman chemistry and those computed using LIMS and SAMS data with a photochemical equilibrium model indicate that such simplified chemistry is useful in studying gross features in stratospheric ozone balance. Net ozone production or loss rates are brought about by departures from the photochemical equilibrium (PCE) condition. If transport drives ozone above its PCE condition, then photochemical loss dominates production. If transport drives ozone below its PCE condition, then photochemical production dominates loss. Gross features of ozone loss/production (L/P) inferred for the real atmosphere from data are also simulated using only eddy diffusion. This indicates that one must be careful in assigning a transport scheme for a two-dimensional model that mimics only behavior of the observed ozone L/P.

Self-perceived lactose intolerance results in lower intakes of calcium and dairy foods and is associated with hypertension and diabetes in adults

USDA-ARS?s Scientific Manuscript database

Self-perceived lactose intolerance may result in adverse dietary modifications; thus, more studies are needed to understand the prevalence of self-perceived lactose intolerance and how it relates to calcium intake and selected health conditions. The objective was to examine the effects of self-perce...

The Native American Persistence in Higher Education: A Journey through Story to Identify the Family Support to Native American Graduates

ERIC Educational Resources Information Center

Bisbee, Yolanda J. Guzman

2013-01-01

This Indigenous Framed Research will utilize counter-storytelling through shared collaborator stories provided by Nez Perce Native American Graduates. The methodology is shaped by an Indigenous Framework as this form of research promotes and develops a culturally resonant environment for constructing, analyzing and sharing information. The…

Cryopreservation of Adult Male Spring and Summer Chinook Salmon Gametes in the Snake River Basin, 1997 Annual Report.

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

Faurot, Dave; Kucera, Paul A.; Armstrong, Robyn D.

1998-06-01

Chinook salmon populations in the Northwest are decreasing in number. The Nez Perce Tribe was funded in 1997 by the Bonneville Power Administration to coordinate and initiate gene banking of adult male gametes from Endangered Species Act (ESA) listed spring and summer chinook salmon in the Snake River basin.

A Superintendent in Cultural Transition: An Autoethnography

ERIC Educational Resources Information Center

Aiken, David

2013-01-01

This research illustrates a personalized account of the unique transition from a third grade classroom directly to a superintendency in a public school located on the Nez Perce Indian Reservation. This self-study is about me as the subject as well as the researcher in the cultural context of a school district with an 89% Native American student…

Universal Prevention Program Outcomes: Safe Schools Healthy Students in a Rural, Multicultural Setting

ERIC Educational Resources Information Center

Harris, Elizabeth; McFarland, Joyce; Siebold, Wendi; Aguilar, Rafael; Sarmiento, Ana

2007-01-01

The Idaho Consortium for Safe Schools Healthy Students consists of three school districts in rural North Central Idaho and the Nez Perce Tribe's Students for Success Program. Universal prevention programs implemented in the elementary schools include Second Step and the middle schools implemented the Life Skills program. Each of the three…

STRONTIUM AS AN EFFICIENT PROMOTER FOR SUPPORTED PALLADIUM HYDROGENATION CATALYSTS

EPA Science Inventory

The effect of strontium promotion is studied for a series of supported palladium catalysts such as Pd/zeolite-β, Pd/Al₂O₃, Pd/SiO₂, Pd/hydrotalcite and Pd/MgO. Strontium is found to be an effective promoter for enhancing the metal area, perce...

Howard’s Command and Control of Idaho’s Nez Perce War

DTIC Science & Technology

1993-06-04

Valencia Boise, ID S;5(:)7 Josie Spellman 60:7 17th Street Coeur D’Alene, ID 83814 Ray Stark 3=5S Agate Court Boise, ID 8Z705 Criag Stremel 5215 Tarre Heights Manhattan, KS 66502 0 129 1 • •• 0 0 06 0 0 A

Characteristics of English Language Learners in the School District of Philadelphia. PERC Research Brief

ERIC Educational Resources Information Center

Lin, Joshua; Hughes, Rosemary; Long, Daniel; Kim, Dae

2016-01-01

As a group, English Language Learners (ELLs) are diverse and come from a variety of home languages, cultures, educational backgrounds, and educational needs. This brief focuses on descriptive characteristics of the ELL students served by the School District of Philadelphia in 2014-2015. Specifically, this brief highlights the diversity of the ELL…

77 FR 6778 - Nez Perce-Clearwater National Forests; Idaho; Clear Creek Integrated Restoration Project

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-09

... Environmental Policy Act (NEPA) analysis and decision making process on the proposal so interested and affected members of the public may participate and contribute to the final decision. DATES: Comments concerning the...Forest Supervisor. 12730 Highway 12, Orofinio, ID 83544. The Decision To Be Made is whether to adopt the...

Examining the Need for a Code of Conduct in New Jersey Teacher Union Contracts

ERIC Educational Resources Information Center

Guarneri, Cristina M.

2009-01-01

The purpose of this cross-sectional, comparison study attempted to investigate if a code of conduct existed in New Jersey teacher union contracts to nursing/hospital union contracts. Archived data of public school district and nursing/hospital union contracts held with the New Jersey Public Employment Relations Committee (NJ PERC) and Health…

Restoring youth: Restoring relationships to wildlife and wild places

Treesearch

Linda Moon Stumpff

2007-01-01

American Indian tribes recognize the most important resource for protecting the values of wild places is within youth. The Nez Perce Tribe, the San Carlos Apache Tribes and the Warm Springs Tribe are among many who have long emphasized the importance of initiating youth by providing experiences, activities and education in remote locations and carried that practice...

Enhanced Light Absorption in Fluorinated Ternary Small-Molecule Photovoltaics

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

Eastham, Nicholas D.; Dudnik, Alexander S.; Harutyunyan, Boris

2017-06-14

Using small-molecule donor (SMD) semiconductors in organic photovoltaics (OPVs) has historically afforded lower power conversion efficiencies (PCEs) than their polymeric counterparts. The PCE difference is attributed to shorter conjugated backbones, resulting in reduced intermolecular interactions. Here, a new pair of SMDs is synthesized based on the diketopyrrolopyrrole-benzodithiophene-diketopyrrolopyrrole (BDT-DPP2) skeleton but having fluorinated and fluorinefree aromatic side-chain substituents. Ternary OPVs having varied ratios of the two SMDs with PC61BM as the acceptor exhibit tunable open-circuit voltages (Vocs) between 0.833 and 0.944 V due to a fluorination-induced shift in energy levels and the electronic “alloy” formed from the miscibility of the twomore » SMDs. A 15% increase in PCE is observed at the optimal ternary SMD ratio, with the short-circuit current density (Jsc) significantly increased to 9.18 mA/cm2. The origin of Jsc enhancement is analyzed via charge generation, transport, and diffuse reflectance measurements, and is attributed to increased optical absorption arising from a maximum in film crystallinity at this SMD ratio, observed by grazing incidence wide-angle X-ray scattering.« less

Effect of thermal annealing treatment with titanium chelate on buffer layer in inverted polymer solar cells

NASA Astrophysics Data System (ADS)

Liu, Zhiyong; Wang, Ning; Fu, Yan

2016-12-01

The solution processable electron extraction layer (EEL) is crucial for polymer solar cells (PSCs). Here, we investigated titanium (diisopropoxide) bis(2,4-pentanedionate) (TIPD) as an EEL and fabricated inverted PSCs with a blend of poly(3-hexylthiophene) (P3HT) and indene-C60 bisadduct (ICBA) acting as the photoactive layer, with a structure of ITO/TIPD/P3HT:ICBA/MoO3/Ag. After thermal annealing treatment at 150 °C for 15 min, the PSC performances increased from 3.85% to 6.84% and they achieve stable power conversion efficiency (PCE), with a similar PCE compared with TiO2 as an EEL by the vacuum evaporated method. Fourier transform infrared spectroscopy (FTIR) and ultraviolet photoelectron spectroscopy (UPS) confirmed that the TIPD decomposed and formed the Tidbnd O bond, and the energy level of the lowest unoccupied molecular orbital and the highest occupied molecular orbital increased. The space charge limited current (SCLC) measurements further confirmed the improvement in electron collection and the transport ability using TIPD as the EEL and thermal annealing.

Polymer/Polymer Blend Solar Cells Using Tetraazabenzodifluoranthene Diimide Conjugated Polymers as Electron Acceptors

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

Li, Haiyan; Hwang, Ye-Jin; Earmme, Taeshik

2015-03-02

Two n-type semiconducting polymers with alternating arylene (thiophene or selenophene)–tetraazabenzodifluoranthene diimide (BFI) donor–acceptor architecture have been investigated as new electron acceptors in polymer/polymer blend solar cells. The new selenophene-linked polymer, PBFI-S, has a significantly smaller optical band gap (1.13 eV) than the thiophene-linked PBFI-T (1.38 eV); however, both polymers have similar HOMO/LUMO energy levels determined from cyclic voltammetry. Blends of PBFI-T with the thiazolothiazole–dithienylsilole donor polymer (PSEHTT) gave a 2.60% power conversion efficiency (PCE) with a 7.34 mA/cm2 short-circuit current. In contrast, PBFI-S:PSEHTT blends had a 0.75% PCE with similarly reduced photocurrent and external quantum efficiency. Reduced free energy formore » charge transfer and reduced bulk electron mobility in PBFI-S:PSEHTT blends compared to PBFI-T:PSEHTT blends as well as significant differences in bulk film morphology are among the reasons for the large loss in efficiency in PBFI-S:PSEHTT blend solar cells.« less

Simultaneous Increase in Open-Circuit Voltage and Efficiency of Fullerene-Free Solar Cells through Chlorinated Thieno[3,4-b]thiophene Polymer Donor

DOE PAGES

Wang, Huan; Chao, Pengjie; Chen, Hui; ...

2017-08-01

Here, the chlorinated polymer, PBTCl, have been found to be an efficient donor in non-fullerene PSCs, which showed a blue-shifted absorbance compared to that of its fluorine analog (PTB7-th), and resulted in a more complementary light absorption with non-fullerene acceptor, such as ITIC. Meanwhile, chlorine substitution lowered the HOMO level of PBTCl, which increased the open-circuit voltage of the corresponding polymer-based devices. The 2D GIWAXS analysis illustrated that the PBTCl/ITIC blend film exhibited a “face-on” orientation and scattering features of both PBTCl and ITIC, suggesting that the blend of PBTCl and ITIC was phase separated and formed individual crystalline domainsmore » of the donor and acceptor, which promoted charge transfer in the bi-continuous film and eventually elevated the solar energy conversion efficiency. The PBTCl-based non-fullerene PSC exhibited a maximum PCE of 7.57% with a Voc of 0.91 V, which was an approximately 13% increasing in the PCE compared to the fluorine-analog-based device.« less

Achieving over 9.8% Efficiency in Nonfullerene Polymer Solar Cells by Environmentally Friendly Solvent Processing.

PubMed

Wu, Yue; Zou, Yan; Yang, Hang; Li, Yaowen; Li, Hongkun; Cui, Chaohua; Li, Yongfang

2017-10-25

Nowadays, most of the solution-processed high-efficiency polymer solar cell (PSC) devices are fabricated by halogenated solvents (such as chlorobenzene, 1,2-dichlorobenzene, chloroform, etc.) which are harmful to people and the environment. Therefore, it is essential to develop high-efficiency PSC devices processed by environmentally friendly solvent processing for their industrialization. In this regard, we report a new alkylthio chain-based conjugated polymer PBDB-TS as donor material for environmentally friendly solvent-processed PSCs. PBDB-TS possesses a low-lying HOMO energy level at -5.42 eV and a good solubility in toluene and o-xylene. By using o-xylene and 1% N-methylpyrrolidone as processing solvent, following by the thermal annealing treatment for PBDB-TS:ITIC blend films, well-developed morphological features, and balanced charge transport properties are observed, leading to a high power conversion efficiency (PCE) of 9.85%, higher than that of the device cast from halogenated solvent (PCE = 9.65%). The results suggest that PBDB-TS is an attractive donor material for nonhalogen solvents-processing PSCs.

Simultaneous Increase in Open-Circuit Voltage and Efficiency of Fullerene-Free Solar Cells through Chlorinated Thieno[3,4- b ]thiophene Polymer Donor

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

Wang, Huan; Chao, Pengjie; Chen, Hui

The chlorinated polymer, PBTCl, has been found to be an efficient donor in nonfullerene polymer solar cells (PSCs), which showed a blue-shifted absorbance compared to that of its fluorine analogue (PTB7-th) and resulted in more complementary light absorption with a nonfullerene acceptor, such as ITIC. Meanwhile, chlorine substitution lowered the HOMO level of PBTCl, which increased the open-circuit voltage of the corresponding polymer-based devices. The 2D GIWAXS analysis illustrated that the PBTCl/ITIC blend film exhibited a “face-on” orientation and scattering features of both PBTCl and ITIC, suggesting that the blend of PBTCl and ITIC was phase-separated and formed individual crystallinemore » domains of the donor and acceptor, which promoted charge transfer in the bicontinuous film and eventually elevated the solar energy conversion efficiency. The PBTCl-based nonfullerene PSC exhibited a maximum PCE of 7.57% with a Voc of 0.91 V, which was an approximately 13% increasing in the PCE compared to that of the fluorine-analogue-based device.« less

Simultaneous Increase in Open-Circuit Voltage and Efficiency of Fullerene-Free Solar Cells through Chlorinated Thieno[3,4-b]thiophene Polymer Donor

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

Wang, Huan; Chao, Pengjie; Chen, Hui

Here, the chlorinated polymer, PBTCl, have been found to be an efficient donor in non-fullerene PSCs, which showed a blue-shifted absorbance compared to that of its fluorine analog (PTB7-th), and resulted in a more complementary light absorption with non-fullerene acceptor, such as ITIC. Meanwhile, chlorine substitution lowered the HOMO level of PBTCl, which increased the open-circuit voltage of the corresponding polymer-based devices. The 2D GIWAXS analysis illustrated that the PBTCl/ITIC blend film exhibited a “face-on” orientation and scattering features of both PBTCl and ITIC, suggesting that the blend of PBTCl and ITIC was phase separated and formed individual crystalline domainsmore » of the donor and acceptor, which promoted charge transfer in the bi-continuous film and eventually elevated the solar energy conversion efficiency. The PBTCl-based non-fullerene PSC exhibited a maximum PCE of 7.57% with a Voc of 0.91 V, which was an approximately 13% increasing in the PCE compared to the fluorine-analog-based device.« less

Probing photo-carrier collection efficiencies of individual silicon nanowire diodes on a wafer substrate.

PubMed

Schmitt, S W; Brönstrup, G; Shalev, G; Srivastava, S K; Bashouti, M Y; Döhler, G H; Christiansen, S H

2014-07-21

Vertically aligned silicon nanowire (SiNW) diodes are promising candidates for the integration into various opto-electronic device concepts for e.g. sensing or solar energy conversion. Individual SiNW p-n diodes have intensively been studied, but to date an assessment of their device performance once integrated on a silicon substrate has not been made. We show that using a scanning electron microscope (SEM) equipped with a nano-manipulator and an optical fiber feed-through for tunable (wavelength, power using a tunable laser source) sample illumination, the dark and illuminated current-voltage (I-V) curve of individual SiNW diodes on the substrate wafer can be measured. Surprisingly, the I-V-curve of the serially coupled system composed of SiNW/wafers is accurately described by an equivalent circuit model of a single diode and diode parameters like series and shunting resistivity, diode ideality factor and photocurrent can be retrieved from a fit. We show that the photo-carrier collection efficiency (PCE) of the integrated diode illuminated with variable wavelength and intensity light directly gives insight into the quality of the device design at the nanoscale. We find that the PCE decreases for high light intensities and photocurrent densities, due to the fact that considerable amounts of photo-excited carriers generated within the substrate lead to a decrease in shunting resistivity of the SiNW diode and deteriorate its rectification. The PCE decreases systematically for smaller wavelengths of visible light, showing the possibility of monitoring the effectiveness of the SiNW device surface passivation using the shown measurement technique. The integrated device was pre-characterized using secondary ion mass spectrometry (SIMS), TCAD simulations and electron beam induced current (EBIC) measurements to validate the properties of the characterized material at the single SiNW diode level.

Effect of Rubidium Incorporation on the Structural, Electrical, and Photovoltaic Properties of Methylammonium Lead Iodide-Based Perovskite Solar Cells

DOE PAGES

Park, Ik Jae; Seo, Seongrok; Park, Min Ah; ...

2017-11-10

We report the electrical properties of rubidium-incorporated methylammonium lead iodide ((Rb xMA 1-x)PbI 3) films and the photovoltaic performance of (Rb xMA 1-x)PbI 3 film-based p-i-n-type perovskite solar cells (PSCs). The incorporation of a small amount of Rb + (x = 0.05) increases both the open circuit voltage (V oc) and the short circuit photocurrent density (J sc) of the PSCs, leading to an improved power conversion efficiency (PCE). However, a high fraction of Rb + incorporation (x = 0.1 and 0.2) decreases the J sc and thus the PCE, which is attributed to the phase segregation of the singlemore » tetragonal perovskite phase to a MA-rich tetragonal perovskite phase and a RbPbI 3 orthorhombic phase at high Rb fractions. Conductive atomic force microscopic and admittance spectroscopic analyses reveal that the single-phase (Rb 0.05MA 0.95)PbI 3 film has a high electrical conductivity because of a reduced deep-level trap density. We also found that Rb substitution enhances the diode characteristics of the PSC, as evidenced by the reduced reverse saturation current (J 0). The optimized (Rb xMA 1-x)PbI 3 PSCs exhibited a PCE of 18.8% with negligible hysteresis in the photocurrent-voltage curve. The results from this work enhance the understanding of the effect of Rb incorporation into organic-inorganic hybrid halide perovskites and enable the exploration of Rb-incorporated mixed perovskites for various applications, such as solar cells, photodetectors, and light-emitting diodes.« less

Effect of Rubidium Incorporation on the Structural, Electrical, and Photovoltaic Properties of Methylammonium Lead Iodide-Based Perovskite Solar Cells

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

Park, Ik Jae; Seo, Seongrok; Park, Min Ah

We report the electrical properties of rubidium-incorporated methylammonium lead iodide ((Rb xMA 1-x)PbI 3) films and the photovoltaic performance of (Rb xMA 1-x)PbI 3 film-based p-i-n-type perovskite solar cells (PSCs). The incorporation of a small amount of Rb + (x = 0.05) increases both the open circuit voltage (V oc) and the short circuit photocurrent density (J sc) of the PSCs, leading to an improved power conversion efficiency (PCE). However, a high fraction of Rb + incorporation (x = 0.1 and 0.2) decreases the J sc and thus the PCE, which is attributed to the phase segregation of the singlemore » tetragonal perovskite phase to a MA-rich tetragonal perovskite phase and a RbPbI 3 orthorhombic phase at high Rb fractions. Conductive atomic force microscopic and admittance spectroscopic analyses reveal that the single-phase (Rb 0.05MA 0.95)PbI 3 film has a high electrical conductivity because of a reduced deep-level trap density. We also found that Rb substitution enhances the diode characteristics of the PSC, as evidenced by the reduced reverse saturation current (J 0). The optimized (Rb xMA 1-x)PbI 3 PSCs exhibited a PCE of 18.8% with negligible hysteresis in the photocurrent-voltage curve. The results from this work enhance the understanding of the effect of Rb incorporation into organic-inorganic hybrid halide perovskites and enable the exploration of Rb-incorporated mixed perovskites for various applications, such as solar cells, photodetectors, and light-emitting diodes.« less

Spinel Co3O4 nanomaterials for efficient and stable large area carbon-based printed perovskite solar cells.

PubMed

Bashir, Amna; Shukla, Sudhanshu; Lew, Jia Haur; Shukla, Shashwat; Bruno, Annalisa; Gupta, Disha; Baikie, Tom; Patidar, Rahul; Akhter, Zareen; Priyadarshi, Anish; Mathews, Nripan; Mhaisalkar, Subodh G

2018-02-01

Carbon based perovskite solar cells (PSCs) are fabricated through easily scalable screen printing techniques, using abundant and cheap carbon to replace the hole transport material (HTM) and the gold electrode further reduces costs, and carbon acts as a moisture repellent that helps in maintaining the stability of the underlying perovskite active layer. An inorganic interlayer of spinel cobaltite oxides (Co 3 O 4 ) can greatly enhance the carbon based PSC performance by suppressing charge recombination and extracting holes efficiently. The main focus of this research work is to investigate the effectiveness of Co 3 O 4 spinel oxide as the hole transporting interlayer for carbon based perovskite solar cells (PSCs). In these types of PSCs, the power conversion efficiency (PCE) is restricted by the charge carrier transport and recombination processes at the carbon-perovskite interface. The spinel Co 3 O 4 nanoparticles are synthesized using the chemical precipitation method, and characterized by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and UV-Vis spectroscopy. A screen printed thin layer of p-type inorganic spinel Co 3 O 4 in carbon PSCs provides a better-energy level matching, superior efficiency, and stability. Compared to standard carbon PSCs (PCE of 11.25%) an improved PCE of 13.27% with long-term stability, up to 2500 hours under ambient conditions, is achieved. Finally, the fabrication of a monolithic perovskite module is demonstrated, having an active area of 70 cm 2 and showing a power conversion efficiency of >11% with virtually no hysteresis. This indicates that Co 3 O 4 is a promising interlayer for efficient and stable large area carbon PSCs.

Non-Fullerene Polymer Solar Cells Based on Alkylthio and Fluorine Substituted 2D-Conjugated Polymers Reach 9.5% Efficiency.

PubMed

Bin, Haijun; Zhang, Zhi-Guo; Gao, Liang; Chen, Shanshan; Zhong, Lian; Xue, Lingwei; Yang, Changduk; Li, Yongfang

2016-04-06

Non-fullerene polymer solar cells (PSCs) with solution-processable n-type organic semiconductor (n-OS) as acceptor have seen rapid progress recently owing to the synthesis of new low bandgap n-OS, such as ITIC. To further increase power conversion efficiency (PCE) of the devices, it is of a great challenge to develop suitable polymer donor material that matches well with the low bandgap n-OS acceptors thus providing complementary absorption and nanoscaled blend morphology, as well as suppressed recombination and minimized energy loss. To address this challenge, we synthesized three medium bandgap 2D-conjugated bithienyl-benzodithiophene-alt-fluorobenzotriazole copolymers J52, J60, and J61 for the application as donor in the PSCs with low bandgap n-OS ITIC as acceptor. The three polymers were designed with branched alkyl (J52), branched alkylthio (J60), and linear alkylthio (J61) substituent on the thiophene conjugated side chain of the benzodithiophene (BDT) units for studying effect of the substituents on the photovoltaic performance of the polymers. The alkylthio side chain, red-shifted absorption down-shifted the highest occupied molecular orbital (HOMO) level and improved crystallinity of the 2D conjugated polymers. With linear alkylthio side chain, the tailored polymer J61 exhibits an enhanced JSC of 17.43 mA/cm(2), a high VOC of 0.89 V, and a PCE of 9.53% in the best non-fullerene PSCs with the polymer as donor and ITIC as acceptor. To the best of our knowledge, the PCE of 9.53% is one of the highest values reported in literature to date for the non-fullerene PSCs. The results indicate that J61 is a promising medium bandgap polymer donor in non-fullerene PSCs.

Spatial and temporal dynamics of organohalide-respiring bacteria in a heterogeneous PCE-DNAPL source zone.

PubMed

Cápiro, Natalie L; Löffler, Frank E; Pennell, Kurt D

2015-11-01

Effective treatment of sites contaminated with dense non-aqueous phase liquids (DNAPLs) requires detailed understanding of the microbial community responses to changes in source zone strength and architecture. Changes in the spatial and temporal distributions of the organohalide-respiring Dehalococcoides mccartyi (Dhc) strains and Geobacter lovleyi strain SZ (GeoSZ) were examined in a heterogeneous tetrachloroethene- (PCE-) DNAPL source zone within a two-dimensional laboratory-scale aquifer flow cell. As part of a combined remedy approach, flushing with 2.3 pore volumes (PVs) of 4% (w/w) solution of the nonionic, biodegradable surfactant Tween® 80 removed 55% of the initial contaminant mass, and resulted in a PCE-DNAPL distribution that contained 51% discrete ganglia and 49% pools (ganglia-to-pool ratio of 1.06). Subsequent bioaugmentation with the PCE-to-ethene-dechlorinating consortium BDI-SZ resulted in cis-1,2-dichloroethene (cis-DCE) formation after 1 PV (ca. 7 days), while vinyl chloride (VC) and ethene were detected 10 PVs after bioaugmentation. Maximum ethene yields (ca. 90 μM) within DNAPL pool and ganglia regions coincided with the detection of the vcrA reductive dehalogenase (RDase) gene that exceeded the Dhc 16S rRNA genes by 2.0±1.3 and 4.0±1.7 fold in the pool and ganglia regions, respectively. Dhc and GeoSZ cell abundance increased by up to 4 orders-of-magnitude after 28 PVs of steady-state operation, with 1 to 2 orders-of-magnitude increases observed in close proximity to residual PCE-DNAPL. These observations suggest the involvement of these dechlorinators the in observed PCE dissolution enhancements of up to 2.3 and 6.0-fold within pool and ganglia regions, respectively. Analysis of the solid and aqueous samples at the conclusion of the experiment revealed that the highest VC (≥155 μM) and ethene (≥65 μM) concentrations were measured in zones where Dhc and GeoSZ were predominately attached to the solids. These findings demonstrate dynamic responses of organohalide-respiring bacteria in a heterogeneous DNAPL source zone, and emphasize the influence of source zone architecture on bioremediation performance. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution of potentially bioavailable natural organic carbon in aquifer sediments at a chloroethene-contaminated site

USGS Publications Warehouse

Thomas, L.K.; Widdowson, M.A.; Chapelle, F.H.; Novak, J.T.; Boncal, J.E.; Lebrón, C. A.

2012-01-01

The distribution of natural organic carbon was investigated at a chloroethene-contaminated site where complete reductive dechlorination of tetrachloroethene (PCE) to vinyl chloride and ethene was observed. In this study, operationally defined potentially bioavailable organic carbon (PBOC) was measured in surficial aquifer sediment samples collected at varying depths and locations in the vicinity of a dense nonaqueous phase liquid (DNAPL) source and aqueous phase plume. The relationship between chloroethene concentrations and PBOC levels was examined by comparing differences in extractable organic carbon in aquifer sediments with minimal chloroethene exposure relative to samples collected in the source zone. Using performance-monitoring data, direct correlations with PBOC were also developed with chloroethene concentrations in groundwater. Results show a logarithm-normal distribution for PBOC in aquifer sediments with a mean concentration of 187  mg/kg. PBOC levels in sediments obtained from the underlying confining unit were generally greater when compared to sediments collected in the sandy surficial aquifer. Results demonstrated a statistically significant inverse correlation (p=0.007) between PBOC levels in aquifer sediments and chloroethene concentrations for selected monitoring wells in which chloroethene exposure was the highest. Results from laboratory exposure assays also demonstrated that sediment samples exhibited a reduction in PBOC levels of 35% and 73%, respectively, after a 72-h exposure period to PCE (20,000  μg/L). These results support the notion that PBOC depletion in sediments may be expected in chloroethene-contaminated aquifers, which has potential implications for the long-term sustainability of monitored natural attenuation.

Sustainable Energy Solutions for Rural Alaska

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

Allen, Riley; Brutkoski, Donna; Farnsworth, David

2016-04-22

The state of Alaska recognizes the challenges these rural communities face and provides financial support via the Power Cost Equalization (PCE) program. The PCE subsidizes the electricity prices paid by customers of these high-cost utilities. The PCE program is designed to spread the benefits of Alaska’s natural resources more evenly throughout the state. Yet even with this subsidy, electricity is still much more expensive for these rural customers. And beyond the PCE, other forms of assistance to rural utilities are becoming scarce given the state’s current fiscal environment. Nearly 90 percent of Alaska’s unrestricted budget funds in recent years havemore » been tied to oil royalties—a sector experiencing significant declines in production and oil prices. Consequently, as Alaska looks to tighten budgets, the challenge of lowering rural utility costs, while encouraging self-sufficiency, has become more urgent.This study examines reliability, capital and strategic planning, management, workforce development, governance, financial performance and system efficiency in the various communities visited by the research team. Using those attributes, a tier system was developed to categorize rural Alaska utilities into Leading and Innovating Systems (Tier I), Advanced Diesel Systems (Tier II), Basic Systems (Tier III), and Underperforming Systems (Tier IV). The tier approach is not meant to label specific utilities, but rather to provide a general set of benchmarks and guideposts for improvement.« less

High performance planar p-i-n perovskite solar cells with crown-ether functionalized fullerene and LiF as double cathode buffer layers

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

Liu, Xiaodong; Zhou, Yi, E-mail: yizhou@suda.edu.cn, E-mail: songbo@suda.edu.cn, E-mail: liyf@iccas.ac.cn; Song, Bo, E-mail: yizhou@suda.edu.cn, E-mail: songbo@suda.edu.cn, E-mail: liyf@iccas.ac.cn

2015-08-10

Double cathode buffer layers (CBLs) composed of fullerene derivative functionalized with a crown-ether end group in its side chain (denoted as PCBC) and a LiF layer were introduced between the PCBM acceptor layer and the top cathode in planar p-i-n perovskite solar cells (pero-SCs) based on CH{sub 3}NH{sub 3}PbI{sub 3−X}Cl{sub X}. The devices with the PCBC/LiF double CBLs showed significant improvements in power conversion efficiency (PCE) and long-term stability when compared to the device with LiF single CBL. Through optimizing the spin-coating speed of PCBC, a maximum PCE of 15.53% has been achieved, which is approximately 15% higher than thatmore » of the device with single LiF CBL. The remarkable improvement in PCE can be attributed to the formation of a better ohmic contact in the CBL between PCBC and LiF/Al electrode arising from the dipole moment of PCBC, leading to the enhanced fill factor and short-circuit current density (J{sub sc}). Besides the PCE, the long-term stability of the devices with PCBC interlayer is also superior to that of the device with LiF single CBL, which is due to the more effective protection for the perovskite/PCBM interface.« less