MaRAP2-4, a waterlogging-responsive ERF from Mentha, regulates bidirectional sugar transporter AtSWEET10 to modulate stress response in Arabidopsis.

PubMed

Phukan, Ujjal J; Jeena, Gajendra Singh; Tripathi, Vineeta; Shukla, Rakesh Kumar

2018-01-01

As waterlogging and successive events severely influence growth and development of economically important plants, we attempted to characterize the role of a waterlogging-responsive group I (A-6) ethylene response factor (MaRAP2-4) from Mentha arvensis. Waterlogging, ethylene and methyl jasmonate rapidly induced the expression of MaRAP2-4. MaRAP2-4 interacted with multiple cis-elements like dehydration response elements (DRE1/2), anoxia/jasmonic acid response element (JARE) and GCC box showing its involvement in multiple responses. MaRAP2-4 localizes in the nucleus and acts as a transcriptional activator. Truncation and internal deletion identified a 20 amino acids potential transactivation domain (PLPSSVDAKLEAICQSLAIN) in MaRAP2-4. MaRAP2-4 transgenic Arabidopsis showed enhanced waterlogging and subsequent oxidative stress tolerance. Microarray analysis revealed that within up-regulated genes 483, 212 and 132 promoters carry either single or multiple copies of DRE, JARE and GCC cis-element/s, respectively. Within these promoters, a large section belongs to carbohydrate metabolism/transport, including many SWEET transporters. Further analysis showed MaRAP2-4 specifically targets two positions in AtSWEEET10 promoter carrying DRE and/or GCC box that might regulate carbohydrate availability and waterlogging tolerance. These results demonstrate that MaRAP2-4 is a positive regulator of waterlogging tolerance, and as energy-consuming processes such as carbohydrate biosynthesis are reduced under waterlogging-induced hypoxia, sugar transport through SWEETs may be the primary option to make sugar available to the required tissue. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Digital rectal examination in Indian graduates.

PubMed

Beena, Aishwarya; Jagadisan, Barath

2018-02-12

Digital rectal examination (DRE) is an important component of physical examination and an essential skill for medical graduates. DRE is often underutilised in clinical practice. The lack of confidence and expertise and also underutilization of DRE have been associated with inadequate training of medical students during their undergraduate studies. The training of Indian undergraduates in DRE has not been studied. A questionnaire on undergraduate training in DRE was administered to students from various medical colleges joining specialty postgraduate courses in Jawaharlal Institute of Postgraduate Medical Education and Research. A total of 101 out of 131 students participated in the survey. Ninety-one percent of students were taught DRE as undergraduates but only three-quarters had performed DRE on patients. Among the respondents who had performed DRE, two-thirds had performed fewer than five DREs before the completion of their medical education. Respondents who had performed fewer DREs were less confident about performing DRE (p < 0.05). Only 8% had performed DRE with manikins. Patients declining DRE and the need to minimise DRE influenced the decisions to perform DRE during training. DRE was never taught in paediatrics. DREs were most often performed only in the final year of the Bachelor of Medicine and Bachelor of Surgery (MBBS) degree, and mostly without supervision (49.3%); 61.4% were unsatisfied with their training in DRE and would like to be trained better. A lack of confidence, expertise and use of DRE are associated with inadequate training of medical students CONCLUSION: The survey indicates a lack of importance given to DRE training of undergraduate students and huge gaps in imparting this clinical skill. Training may be improved by introducing manikins, changing attitudes to DRE by incorporating it in clinical problem solving, and with more frequent opportunities to practise under supervision. © 2018 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

Cross-talk between abscisic acid-dependent and abscisic acid-independent pathways during abiotic stress.

PubMed

Roychoudhury, Aryadeep; Paul, Saikat; Basu, Supratim

2013-07-01

Salinity, drought and low temperature are the common forms of abiotic stress encountered by land plants. To cope with these adverse environmental factors, plants execute several physiological and metabolic responses. Both osmotic stress (elicited by water deficit or high salt) and cold stress increase the endogenous level of the phytohormone abscisic acid (ABA). ABA-dependent stomatal closure to reduce water loss is associated with small signaling molecules like nitric oxide, reactive oxygen species and cytosolic free calcium, and mediated by rapidly altering ion fluxes in guard cells. ABA also triggers the expression of osmotic stress-responsive (OR) genes, which usually contain single/multiple copies of cis-acting sequence called abscisic acid-responsive element (ABRE) in their upstream regions, mostly recognized by the basic leucine zipper-transcription factors (TFs), namely, ABA-responsive element-binding protein/ABA-binding factor. Another conserved sequence called the dehydration-responsive element (DRE)/C-repeat, responding to cold or osmotic stress, but not to ABA, occurs in some OR promoters, to which the DRE-binding protein/C-repeat-binding factor binds. In contrast, there are genes or TFs containing both DRE/CRT and ABRE, which can integrate input stimuli from salinity, drought, cold and ABA signaling pathways, thereby enabling cross-tolerance to multiple stresses. A strong candidate that mediates such cross-talk is calcium, which serves as a common second messenger for abiotic stress conditions and ABA. The present review highlights the involvement of both ABA-dependent and ABA-independent signaling components and their interaction or convergence in activating the stress genes. We restrict our discussion to salinity, drought and cold stress.

ACTIVATION OF DIOXIN RESPONSE ELEMENT (DRE)-ASSOCIATED GENES BY BENZO(A)PYRENE 3,6-QUINONE AND BENZO(A)PYRENE 1,6-QUINONE IN MCF-10A HUMAN MAMMARY EPITHELIAL CELLS

PubMed Central

Burchiel, Scott W.; Thompson, Todd A.; Lauer, Fredine T.; Oprea, Tudor I.

2007-01-01

Benzo(a)pyrene (BaP) is a known human carcinogen and a suspected breast cancer complete carcinogen. BaP is metabolized by several metabolic pathways, some having bioactivation and others detoxification properties. BaP-quinones (BPQs) are formed via cytochrome P450 and peroxidase dependent pathways. Previous studies by our laboratory have shown that BPQs have significant growth promoting and anti-apoptotic activities in human MCF-10A mammary epithelial cells examined in vitro. Previous results suggest that BPQs act via redox-cycling and oxidative stress. However, because two specific BPQs (1,6-BPQ and 3,6-BPQ) differed in their ability to produce reactive oxygen species (ROS) and yet both had strong proliferative and EGF receptor activating activity, we utilized mRNA expression arrays and qRT-PCR to determine potential pathways and mechanisms of gene activation. The results of the present studies demonstrated that 1,6-BPQ and 3,6-BPQ activate dioxin response elements (DRE, also known as xenobiotic response elements, XRE) and anti-oxidant response elements (ARE, also known and electrophile response elements, EpRE). 3,6-BPQ had greater DRE activity than 1,6-BPQ, whereas the opposite was true for the activation of ARE. Both 3,6-BPQ and 1,6-BPQ induced oxidative stress associated genes (HMOX1, GCLC, GCLM, and SLC7A11), phase 2 enzyme genes (NQO1, NQO2, ALDH3A1) PAH metabolizing genes (CYP1B1, EPHX1, AKR1C1), and certain EGF receptor associated genes (EGFR, IER3, ING1, SQSTM1 and TRIM16). The results of these studies demonstrate that BPQs activate numerous pathways in human mammary epithelial cells associated with increased cell growth and survival that may play important roles in tumor promotion. PMID:17466351

Measurement-based climatology of aerosol direct radiative effect, its sensitivities, and uncertainties from a background southeast US site

NASA Astrophysics Data System (ADS)

Sherman, James P.; McComiskey, Allison

2018-03-01

Aerosol optical properties measured at Appalachian State University's co-located NASA AERONET and NOAA ESRL aerosol network monitoring sites over a nearly four-year period (June 2012-Feb 2016) are used, along with satellite-based surface reflectance measurements, to study the seasonal variability of diurnally averaged clear sky aerosol direct radiative effect (DRE) and radiative efficiency (RE) at the top-of-atmosphere (TOA) and at the surface. Aerosol chemistry and loading at the Appalachian State site are likely representative of the background southeast US (SE US), home to high summertime aerosol loading and one of only a few regions not to have warmed during the 20th century. This study is the first multi-year ground truth DRE study in the SE US, using aerosol network data products that are often used to validate satellite-based aerosol retrievals. The study is also the first in the SE US to quantify DRE uncertainties and sensitivities to aerosol optical properties and surface reflectance, including their seasonal dependence.Median DRE for the study period is -2.9 W m-2 at the TOA and -6.1 W m-2 at the surface. Monthly median and monthly mean DRE at the TOA (surface) are -1 to -2 W m-2 (-2 to -3 W m-2) during winter months and -5 to -6 W m-2 (-10 W m-2) during summer months. The DRE cycles follow the annual cycle of aerosol optical depth (AOD), which is 9 to 10 times larger in summer than in winter. Aerosol RE is anti-correlated with DRE, with winter values 1.5 to 2 times more negative than summer values. Due to the large seasonal dependence of aerosol DRE and RE, we quantify the sensitivity of DRE to aerosol optical properties and surface reflectance, using a calendar day representative of each season (21 December for winter; 21 March for spring, 21 June for summer, and 21 September for fall). We use these sensitivities along with measurement uncertainties of aerosol optical properties and surface reflectance to calculate DRE uncertainties. We also estimate uncertainty in calculated diurnally-averaged DRE due to diurnal aerosol variability. Aerosol DRE at both the TOA and surface is most sensitive to changes in AOD, followed by single-scattering albedo (ω0). One exception is under the high summertime aerosol loading conditions (AOD ≥ 0.15 at 550 nm), when sensitivity of TOA DRE to ω0 is comparable to that of AOD. Aerosol DRE is less sensitive to changes in scattering asymmetry parameter (g) and surface reflectance (R). While DRE sensitivity to AOD varies by only ˜ 25 to 30 % with season, DRE sensitivity to ω0, g, and R largely follow the annual AOD cycle at APP, varying by factors of 8 to 15 with season. Since the measurement uncertainties of AOD, ω0, g, and R are comparable at Appalachian State, their relative contributions to DRE uncertainty are largely influenced by their (seasonally dependent) DRE sensitivity values, which suggests that the seasonal dependence of DRE uncertainty must be accounted for. Clear sky aerosol DRE uncertainty at the TOA (surface) due to measurement uncertainties ranges from 0.45 (0.75 W m-2) for December to 1.1 (1.6 W m-2) for June. Expressed as a fraction of DRE computed using monthly median aerosol optical properties and surface reflectance, the DRE uncertainties at TOA (surface) are 20 to 24 % (15 to 22 %) for March, June, and September and 49 (50 %) for DEC. The relatively low DRE uncertainties are largely due to the low uncertainty in AOD measured by AERONET. Use of satellite-based AOD measurements by MODIS in the DRE calculations increases DRE uncertainties by a factor of 2 to 5 and DRE uncertainties are dominated by AOD uncertainty for all seasons. Diurnal variability in AOD (and to a lesser extent g) contributes to uncertainties in DRE calculated using daily-averaged aerosol optical properties that are slightly larger (by ˜ 20 to 30 %) than DRE uncertainties due to measurement uncertainties during summer and fall, with comparable uncertainties during winter and spring.

A novel method to decompose two potent greenhouse gases: photoreduction of SF6 and SF5CF3 in the presence of propene.

PubMed

Huang, Li; Shen, Yan; Dong, Wenbo; Zhang, Renxi; Zhang, Jianliang; Hou, Huiqi

2008-03-01

SF5CF3 and SF6 are the most effective greenhouse gases on a per molecule basis in the atmosphere. Original laboratory trial for photoreduction of them by use of propene as a reactant was performed to develop a novel technique to destroy them. The highly reductive radicals produced during the photolysis of propene at 184.9 nm, such as .CH3, .C2H3, and .C3H5, could efficiently decompose SF6 and SF5CF3 to CH4, elemental sulfur and trace amounts of fluorinated organic compounds. It was further demonstrated that the destruction and removal efficiency (DRE) of SF5X (X represented F or CF3) was highly dependent on the initial propene-to-SF5X ratio. The addition of certain amounts of oxygen and water vapor not only enhanced the DRE but avoided the generation of deposits. In both systems, employment nitrogen as dilution gas lessened the DRE slightly. Given the advantage of less toxic products, the technique might contribute to SF5X remediation.

High-Speed Boundary-Layer Transition: Study of Stationary Crossflow Using Spectral Analysis

NASA Astrophysics Data System (ADS)

McGuire, Patrick Joseph

Crossflow instability is primary cause of boundary-layer transition on swept wings used in high-speed applications. Delaying the downstream location of transition would drastically reduce the viscous drag over the wing surface, and subsequently improves the overall aircraft efficiency. By studying the development of instability growth rates and how they interact with the surroundings, researchers can control the crossflow transition location. Experiments on the 35° swept-wing model were performed in the NASA Langley 20-Inch Supersonic Wind Tunnel with Mach 2.0 flow conditions and 20 μm tall discrete roughness elements (DRE) with varying spacing placed along the leading edge. Fluorene was used as the sublimating chemical in the surface flow visualization technique to observe the transition front and stationary crossflow vortex patterns in the laminar flow region. Spatial spectral decomposition was completed on high-resolution images of sublimating chemical runs using a newly developed image processing technique. Streamwise evolution of the vortex track wavelengths within the laminar boundary-layer region was observed. The spectral information was averaged to produce dominant modes present throughout the laminar region.

Isolation and characterization of a water stress-specific genomic gene, pwsi 18, from rice.

PubMed

Joshee, N; Kisaka, H; Kitagawa, Y

1998-01-01

One of the water stress-specific cDNA clones of rice characterised previously, wsi18, was selected for further study. The wsi18 gene can be induced by water stress conditions such as mannitol, NaCl, and dryness, but not by ABA, cold, or heat. A genomic clone for wsi18, pwsi18, contained about 1.7 kbp of the 5' upstream sequence, two introns, and the full coding sequence. The 5'-upstream sequence of pwsi18 contained putative cis-acting elements, namely an ABA-responsive element (ABRE), three G-boxes, three E-boxes, a MEF-2 sequence, four direct and two inverted repeats, and four sequences similar to DRE, which is involved in the dehydration response of Arabidopsis genes. The gusA reporter gene under the control of the pwsi18 promoter showed transient expression in response to water stress. Deletion of the downstream DRE-like sequence between the distal G-boxes-2 and -3 resulted in rather low GUS expression.

Screening for prostate cancer: are digital rectal examinations being performed?

PubMed

Federman, Daniel G; Pitkin, Patricia; Carbone, Vera; Concato, John; Kravetz, Jeffrey D

2014-04-01

Prostate cancer is common and prostate cancer screening is controversial; this retrospective observational study was conducted to determine the prevalence of digital rectal examination (DRE) in those in whom a prostate-specific antigen (PSA) test was performed. A manual review was performed of the electronic medical record for male veterans in the VA Connecticut Healthcare System without a history of known prostate cancer aged between 50 and 74 years who underwent PSA testing. Documentation of DRE (or refusal) within 12 months before or after the performance of a PSA test. Less than half (47.6%) of patients underwent DRE. An additional 6.9% were offered DRE and refused. Although the provider gender was not associated with DRE, resident physicians were less likely to perform DRE than nonresidents; P = 0.01. Patients whose PSA was > 4.0 ng/mL were more likely to undergo DRE than those whose PSA was ≤ 4.0 ng/mL; P = 0.002. Those with body mass index (BMI) > 40 kg/m 2 were less likely to undergo DRE than those with BMI < 30 kg/m 2 ; P = 0.04. Screening for prostate cancer remains controversial. We found a low rate of DRE among veterans in whom prostate cancer screening was entertained. Although the provider gender does not seem to influence DRE, resident physicians were less likely to perform DRE than other providers. Our finding that BMI > 40 kg/m 2 is associated with a lower rate of DRE than those with BMI < 30 kg/m 2 is consistent with screening for other cancers and should be explored further.

An ABRE promoter sequence is involved in osmotic stress-responsive expression of the DREB2A gene, which encodes a transcription factor regulating drought-inducible genes in Arabidopsis.

PubMed

Kim, June-Sik; Mizoi, Junya; Yoshida, Takuya; Fujita, Yasunari; Nakajima, Jun; Ohori, Teppei; Todaka, Daisuke; Nakashima, Kazuo; Hirayama, Takashi; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2011-12-01

In plants, osmotic stress-responsive transcriptional regulation depends mainly on two major classes of cis-acting elements found in the promoter regions of stress-inducible genes: ABA-responsive elements (ABREs) and dehydration-responsive elements (DREs). ABRE has been shown to perceive ABA-mediated osmotic stress signals, whereas DRE is known to be involved in an ABA-independent pathway. Previously, we reported that the transcription factor DRE-BINDING PROTEIN 2A (DREB2A) regulates DRE-mediated transcription of target genes under osmotic stress conditions in Arabidopsis (Arabidopsis thaliana). However, the transcriptional regulation of DREB2A itself remains largely uncharacterized. To elucidate the transcriptional mechanism associated with the DREB2A gene under osmotic stress conditions, we generated a series of truncated and base-substituted variants of the DREB2A promoter and evaluated their transcriptional activities individually. We found that both ABRE and coupling element 3 (CE3)-like sequences located approximately -100 bp from the transcriptional initiation site are necessary for the dehydration-responsive expression of DREB2A. Coupling our transient expression analyses with yeast one-hybrid and chromatin immunoprecipitation (ChIP) assays indicated that the ABRE-BINDING PROTEIN 1 (AREB1), AREB2 and ABRE-BINDING FACTOR 3 (ABF3) bZIP transcription factors can bind to and activate the DREB2A promoter in an ABRE-dependent manner. Exogenous ABA application induced only a modest accumulation of the DREB2A transcript when compared with the osmotic stress treatment. However, the osmotic stress-induced DREB2A expression was found to be markedly impaired in several ABA-deficient and ABA-insensitive mutants. These results suggest that in addition to an ABA-independent pathway, the ABA-dependent pathway plays a positive role in the osmotic stress-responsive expression of DREB2A.

The transcriptional repressor DREAM is involved in thyroid gene expression

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

D'Andrea, Barbara; Di Palma, Tina; Mascia, Anna

2005-04-15

Downstream regulatory element antagonistic modulator (DREAM) was originally identified in neuroendocrine cells as a calcium-binding protein that specifically binds to downstream regulatory elements (DRE) on DNA, and represses transcription of its target genes. To explore the possibility that DREAM may regulate the endocrine activity of the thyroid gland, we analyzed its mRNA expression in undifferentiated and differentiated thyroid cells. We demonstrated that DREAM is expressed in the normal thyroid tissue as well as in differentiated thyroid cells in culture while it is absent in FRT poorly differentiated cells. In the present work, we also show that DREAM specifically binds tomore » DRE sites identified in the 5' untranslated region (UTR) of the thyroid-specific transcription factors Pax8 and TTF-2/FoxE1 in a calcium-dependent manner. By gel retardation assays we demonstrated that thapsigargin treatment increases the binding of DREAM to the DRE sequences present in Pax8 and TTF-2/Foxe1 5' UTRs, and this correlates with a significant reduction of the expression of these genes. Interestingly, in poorly differentiated thyroid cells overexpression of exogenous DREAM strongly inhibits Pax8 expression. Moreover, we provide evidence that a mutated form of DREAM unable to bind Ca{sup 2+} interferes with thyroid cell proliferation. Therefore, we propose that in thyroid cells DREAM is a mediator of the calcium-signaling pathway and it is involved in the regulation of thyroid cell function.« less

OsDREB2A, a Rice Transcription Factor, Significantly Affects Salt Tolerance in Transgenic Soybean

PubMed Central

Ma, Qi-bin; Yang, Cun-yi; Mu, Ying-hui; Suo, Hai-cui; Luo, Lai-hui; Nian, Hai

2013-01-01

The dehydration responsive element binding (DREB) transcription factors play an important role in regulating stress-related genes. OsDREB2A, a member of the DREBP subfamily of AP2/ERF transcription factors in rice (Oryza sativa), is involved in the abiotic stress response. OsDREB2A expression is induced by drought, low-temperature and salt stresses. Here, we report the ability of OsDREB2A to regulate high-salt response in transgenic soybean. Overexpressing OsDREB2A in soybeans enhanced salt tolerance by accumulating osmolytes, such as soluble sugars and free proline, and improving the expression levels of some stress-responsive transcription factors and key genes. The phenotypic characterization of transgenic soybean were significantly better than those of wild-type (WT). Electrophoresis mobility shift assay (EMSA) revealed that the OsDREB2A can bind to the DRE core element in vitro. These results indicate that OsDREB2A may participate in abiotic stress by directly binding with DRE element to regulate the expression of downstream genes. Overexpression of OsDREB2A in soybean might be used to improve tolerance to salt stress. PMID:24376625

NCEA Handbook for DREs.

ERIC Educational Resources Information Center

National Catholic Educational Association, Washington, DC.

In five sections, this handbook provides information for directors of religious education (DRE's) in Catholic schools covering the catechetical ministry and the DRE, the functions of the DRE, hiring procedures, compensation and benefits, and evaluation. Section 1 discusses catechesis in the Church today, the DRE as minister of the Word, and…

A comparison of uncertainties in the aerosol direct radiative effect in the SE U.S. calculated using satellite-based and ground-based aerosol properties

NASA Astrophysics Data System (ADS)

Sherman, J. P.

2017-12-01

Satellite-retrieved aerosol optical depth is typically used for measurement-based estimates of the aerosol direct radiative effect (DRE) on solar radiation, on both global and regional scales. The SE U.S. is one of only a few regions not to have warmed during the 20th century and is home to some of the highest summertime levels of biogenic and sulfate aerosols in the U.S. While decreases in aerosol optical depth over the past few decades have likely reduced the cooling effect of aerosols in the region, satellite-derived estimates of aerosol DRE alone may not be sufficient to study long-term DRE trends and the roles played by changing AOD and aerosol optical properties. Appalachian State University (APP) in Boone, NC is home to the only co-located NASA AERONET, NOAA ESRL, and (active) NASA MPLNET sites in the U.S. and is well-positioned to validate satellite-based aerosol retrievals and better constrain background aerosol DRE in regional climate models. As part of the first multi-year `ground truth' DRE study in the SE U.S., Sherman and McComiskey (2017) applied nearly four years of spectral AOD from the APP AERONET site, along with single-scattering albedo(SSA) and asymmetry parameter from the APP NOAA ESRL site, as inputs to the SBDART Radiative Transfer model to calculate seasonal dependence of aerosol DRE and DRE uncertainties at the top-of-atmosphere and at the surface. Clear sky aerosol DRE uncertainty at the TOA (surface) above APP ranges from 0.44 Wm-2 (0.73 Wm-2) for DEC to 0.90 Wm-2 (1.3 Wm-2) for JUN. Expressed as a fraction of seasonal-mean DRE, these uncertainties are 12-20% for all seasons except winter, when they are close to 50%. Use of MODIS or MISR AOD in place of AERONET increases these uncertainties by factors of 2.5 to 5 and DRE uncertainties are dominated by AOD uncertainty for all seasons. The use of SSA from OMI or MISR further increases the DRE uncertainties, especially during the higher AOD summer months, when DRE sensitivity to aerosol type (SSA, g) is highest. Seasonally-dependent sensitivities of aerosol DRE to AOD, SSA, and g above the regionally-representative APP site will be presented, along with current measurement uncertainties from MODIS, MISR, and OMI, to estimate uncertainties in satellite-based estimates of DRE and the degree to which they must be reduced if DRE uncertainty of 1 Wm-2 is to be achieved.

A population-based study of active and drug-resistant epilepsies in Northern Italy.

PubMed

Giussani, Giorgia; Canelli, Valentina; Bianchi, Elisa; Franchi, Carlotta; Nobili, Alessandro; Erba, Giuseppe; Beghi, Ettore

2016-02-01

Drug-resistant epilepsy (DRE) is defined by the International League Against Epilepsy as a failure of adequate trials of two tolerated, appropriately chosen, and used antiepileptic drugs to achieve sustained seizure freedom. Our aim was to calculate the following: (1) the prevalence of active epilepsy and DRE in a well-defined population of Northern Italy and (2) the proportion of incident cases developing DRE. The study population (146,506; year 2008) resided in the province of Lecco, Northern Italy. The medical records of 123 general practitioners were reviewed to identify patients with epilepsy, diagnosed by a neurologist during the period 2000-2008. The point prevalence of active epilepsy and DRE was calculated on December 31, 2008. A total of 747 prevalent patients with epilepsy, 684 patients with active epilepsy, and 342 incident cases were identified. The frequency of DRE was 15.6% (107/684) of all active epilepsies and 10.5% (36/342) of incident cases. The point prevalence was 0.73 per 1000. The standardized prevalence of DRE was 0.7 per 1000 (Italian population) and 0.8 per 1000 (world population). Our data indicate that 1/6 patients with active epilepsy in the general population has DRE, and 1/10 patients with newly diagnosed epilepsy will develop DRE within nine years from the diagnosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Prostate health index (PHI) and prostate-specific antigen (PSA) predictive models for prostate cancer in the Chinese population and the role of digital rectal examination-estimated prostate volume.

PubMed

Chiu, Peter K F; Roobol, Monique J; Teoh, Jeremy Y; Lee, Wai-Man; Yip, Siu-Ying; Hou, See-Ming; Bangma, Chris H; Ng, Chi-Fai

2016-10-01

To investigate PSA- and PHI (prostate health index)-based models for prediction of prostate cancer (PCa) and the feasibility of using DRE-estimated prostate volume (DRE-PV) in the models. This study included 569 Chinese men with PSA 4-10 ng/mL and non-suspicious DRE with transrectal ultrasound (TRUS) 10-core prostate biopsies performed between April 2008 and July 2015. DRE-PV was estimated using 3 pre-defined classes: 25, 40, or 60 ml. The performance of PSA-based and PHI-based predictive models including age, DRE-PV, and TRUS prostate volume (TRUS-PV) was analyzed using logistic regression and area under the receiver operating curves (AUC), in both the whole cohort and the screening age group of 55-75. PCa and high-grade PCa (HGPCa) was diagnosed in 10.9 % (62/569) and 2.8 % (16/569) men, respectively. The performance of DRE-PV-based models was similar to TRUS-PV-based models. In the age group 55-75, the AUCs for PCa of PSA alone, PSA with DRE-PV and age, PHI alone, PHI with DRE-PV and age, and PHI with TRUS-PV and age were 0.54, 0.71, 0.76, 0.78, and 0.78, respectively. The corresponding AUCs for HGPCa were higher (0.60, 0.70, 0.85, 0.83, and 0.83). At 10 and 20 % risk threshold for PCa, 38.4 and 55.4 % biopsies could be avoided in the PHI-based model, respectively. PHI had better performance over PSA-based models and could reduce unnecessary biopsies. A DRE-assessed PV can replace TRUS-assessed PV in multivariate prediction models to facilitate clinical use.

Microarray-based bioinformatics analysis of the combined effects of SiNPs and PbAc on cardiovascular system in zebrafish.

PubMed

Hu, Hejing; Zhang, Yannan; Shi, Yanfeng; Feng, Lin; Duan, Junchao; Sun, Zhiwei

2017-10-01

With rapid development of nanotechnology and growing environmental pollution, the combined toxic effects of SiNPs and pollutants of heavy metals like lead have received global attentions. The aim of this study was to explore the cardiovascular effects of the co-exposure of SiNPs and lead acetate (PbAc) in zebrafish using microarray and bioinformatics analysis. Although there was no other obvious cardiovascular malformation except bleeding phenotype, bradycardia, angiogenesis inhibition and declined cardiac output in zebrafish co-exposed of SiNPs and PbAc at NOAEL level, significant changes were observed in mRNA and microRNA (miRNA) expression patterns. STC-GO analysis indicated that the co-exposure might have more toxic effects on cardiovascular system than that exposure alone. Key differentially expressed genes were discerned out based on the Dynamic-gene-network, including stxbp1a, ndfip2, celf4 and gsk3b. Furthermore, several miRNAs obtained from the miRNA-Gene-Network might play crucial roles in cardiovascular disease, such as dre-miR-93, dre-miR-34a, dre-miR-181c, dre-miR-7145, dre-miR-730, dre-miR-129-5p, dre-miR-19d, dre-miR-218b, dre-miR-221. Besides, the analysis of miRNA-pathway-network indicated that the zebrafish were stimulated by the co-exposure of SiNPs and PbAc, which might cause the disturbance of calcium homeostasis and endoplasmic reticulum stress. As a result, cardiac muscle contraction might be deteriorated. In general, our data provide abundant fundamental research clues to the combined toxicity of environmental pollutants and further in-depth verifications are needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

The diagnostic test accuracy of rectal examination for prostate cancer diagnosis in symptomatic patients: a systematic review.

PubMed

Jones, Daniel; Friend, Charlotte; Dreher, Andreas; Allgar, Victoria; Macleod, Una

2018-06-02

Prostate cancer is the most common cancer in men in the UK. NICE guidelines on recognition and referral of suspected cancer, recommend performing digital rectal examination (DRE) on patients with urinary symptoms and urgently referring if the prostate feels malignant. However, this is based on the results of one case control study, so it is not known if DRE performed in primary care is an accurate method of detecting prostate cancer. The aim of this review is to ascertain the sensitivity, specificity, positive and negative predictive value of DRE for the detection of prostate cancer in symptomatic patients in primary care. CENTRAL, MEDLINE, EMBASE and CINAHL databases were searched in august 2015 for studies in which a DRE was performed in primary care on symptomatic patients and compared against a reference diagnostic procedure. Four studies were included with a total of 3225 patients. The sensitivity and specificity for DRE as a predictor of prostate cancer in symptomatic patients was 28.6 and 90.7%, respectively. The positive and negative predictive values were 42.3 and 84.2%, respectively. This review found that DRE performed in general practice is accurate, and supports the UK NICE guidelines that patients with a malignant prostate on examination are referred urgently for suspected prostate cancer. Abnormal DRE carried a 42.3% chance of malignancy, above the 3% risk threshold which NICE guidance suggests warrants an urgent referral. However this review questions the benefit of performing a DRE in primary care in the first instance, suggesting that a patient's risk of prostate cancer based on symptoms alone would warrant urgent referral even if the DRE feels normal.

An ABA-responsive DRE-binding protein gene from Setaria italica, SiARDP, the target gene of SiAREB, plays a critical role under drought stress.

PubMed

Li, Cong; Yue, Jing; Wu, Xiaowei; Xu, Cong; Yu, Jingjuan

2014-10-01

The DREB (dehydration-responsive element binding)-type transcription factors regulate the expression of stress-inducible genes by binding the DRE/CRT cis-elements in promoter regions. The upstream transcription factors that regulate the transcription of DREB transcription factors have not been clearly defined, although the function of DREB transcription factors in abiotic stress is known. In this study, an abscisic acid (ABA)-responsive DREB-binding protein gene (SiARDP) was cloned from foxtail millet (Setaria italica). The transcript level of SiARDP increased not only after drought, high salt, and low temperature stresses, but also after an ABA treatment in foxtail millet seedlings. Two ABA-responsive elements (ABRE1: ACGTGTC; ABRE2: ACGTGGC) exist in the promoter of SiARDP. Further analyses showed that two ABA-responsive element binding (AREB)-type transcription factors, SiAREB1 and SiAREB2, could physically bind to the ABRE core element in vitro and in vivo. The constitutive expression of SiARDP in Arabidopsis thaliana enhanced drought and salt tolerance during seed germination and seedling development, and overexpression of SiARDP in foxtail millet improved drought tolerance. The expression levels of target genes of SiARDP were upregulated in transgenic Arabidopsis and foxtail millet. These results reveal that SiARDP, one of the target genes of SiAREB, is involved in ABA-dependent signal pathways and plays a critical role in the abiotic stress response in plants. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

The DRE-Principal Partnership: Making It Work.

ERIC Educational Resources Information Center

Davis, Barbara; Elliott, Karen

1995-01-01

Discusses the roles of the director of religious education (DRE) and the school principal at Catholic schools, viewing them as complimentary rather than competitive. Provides examples of positive cooperation between the principal and DRE at Most Pure Heart of Mary Parish, in Shelby, Ohio. (KP)

Explaining the disease phenotype of intergenic SNP through predicted long range regulation

PubMed Central

Chen, Jingqi; Tian, Weidong

2016-01-01

Thousands of disease-associated SNPs (daSNPs) are located in intergenic regions (IGR), making it difficult to understand their association with disease phenotypes. Recent analysis found that non-coding daSNPs were frequently located in or approximate to regulatory elements, inspiring us to try to explain the disease phenotypes of IGR daSNPs through nearby regulatory sequences. Hence, after locating the nearest distal regulatory element (DRE) to a given IGR daSNP, we applied a computational method named INTREPID to predict the target genes regulated by the DRE, and then investigated their functional relevance to the IGR daSNP's disease phenotypes. 36.8% of all IGR daSNP-disease phenotype associations investigated were possibly explainable through the predicted target genes, which were enriched with, were functionally relevant to, or consisted of the corresponding disease genes. This proportion could be further increased to 60.5% if the LD SNPs of daSNPs were also considered. Furthermore, the predicted SNP-target gene pairs were enriched with known eQTL/mQTL SNP-gene relationships. Overall, it's likely that IGR daSNPs may contribute to disease phenotypes by interfering with the regulatory function of their nearby DREs and causing abnormal expression of disease genes. PMID:27280978

Organization of cis-acting regulatory elements in osmotic- and cold-stress-responsive promoters.

PubMed

Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo

2005-02-01

cis-Acting regulatory elements are important molecular switches involved in the transcriptional regulation of a dynamic network of gene activities controlling various biological processes, including abiotic stress responses, hormone responses and developmental processes. In particular, understanding regulatory gene networks in stress response cascades depends on successful functional analyses of cis-acting elements. The ever-improving accuracy of transcriptome expression profiling has led to the identification of various combinations of cis-acting elements in the promoter regions of stress-inducible genes involved in stress and hormone responses. Here we discuss major cis-acting elements, such as the ABA-responsive element (ABRE) and the dehydration-responsive element/C-repeat (DRE/CRT), that are a vital part of ABA-dependent and ABA-independent gene expression in osmotic and cold stress responses.

Transition Induced by a Streamwise Array of Roughness Elements on a Supersonic Flat Plate

NASA Technical Reports Server (NTRS)

Chou, Amanda; Kegerise, Michael A.

2017-01-01

Roughness is unavoidable on practical high-speed vehicles, so it is critical to determine its impact on boundary layer transition. The flow field downstream of a streamwise array of cylindrical roughness elements is probed with hot-wire anemometry in this experiment. Mean flow distortion is examined in several measurement planes in the wake of the cylindrical roughness using the streak strength profiles and contour plots of the mass flux and total temperature. The roughness element heights and spacings were varied and their instability modes were examined. Cylindrical roughness elements approximately 140 micron tall produce an odd instability mode that grows weakly with downstream distance in the measurement range of this experiment. Cylindrical roughness elements approximately 280 micron tall produce an even instability mode that grows, becomes nonlinear, and then breaks down. Transition onset remains constant relative to the most downstream roughness in the streamwise array when the 280 micron roughness elements are spaced 2 diameters apart. Transition onset occurs at an earlier upstream location relative to the most downstream roughness in the streamwise array when the roughness elements are spaced 4 diameters appear to recover before the next downstream roughness element, so the location of transition shifts with the location of the most downstream roughness element in the array. When the rough- apart. The wake behind roughness elements spaced 2 diameters apart do not ness elements are spaced 4 diameters apart, the flow behind the first roughness element has enough space to recover before feeding into the second roughness element, and thus, moves transition forward.

Direct Radiative Effects of Aerosols Over South Asia From Observations and Modeling

NASA Technical Reports Server (NTRS)

Nair, Vijayakumar S.; Babu, S. Suresh; Manoj, M. R.; Moorthy, Krishna K.; Chin, Mian

2016-01-01

Quantitative assessment of the seasonal variations in the direct radiative effect (DRE) of composite aerosols as well as the constituent species over the Indian sub continent has been carried out using a synergy of observations from a dense network of ground based aerosol observatories and modeling based on chemical transport model simulations. Seasonal variation of aerosol constituents depict significant influence of anthropogenic aerosol sources in winter and the dominance of natural sources in spring, even though the aerosol optical depth doesn't change significantly between these two seasons. A significant increase in the surface cooling and atmospheric warming has been observed as season changes from winter DRE(sub SUR) = -28 +/- 12 W m(exp -2) and DRE(sub ATM) = +19.6 +/- 9 W m(exp -2) to spring DRE(sub SUR) = -33.7 +/- 12 W m(exp -2) and DRE(sub ATM) = +27 +/- 9 W m(exp-2). Interestingly, springtime aerosols are more absorptive in nature compared to winter and consequently the aerosol induced diabatic heating of the atmosphere goes as high as approximately 1 K day(exp -1) during spring, especially over eastern India. The atmospheric DRE due to dust aerosols (+14 +/- 7 W m(exp 2) during spring overwhelms that of black carbon DRE (+11.8 +/- 6 W m(exp -2) during winter. The DRE at the top of the atmosphere is mostly governed by the anthropogenic aerosols during all the seasons. The columnar aerosol loading, its anthropogenic fraction and radiative effects shows a steady increase with latitude across Indian mainland leading to a larger aerosol-induced atmospheric warming during spring than in winter.

Cocaine Modulates the Expression of Opioid Receptors and miR-let-7d in Zebrafish Embryos

PubMed Central

López-Bellido, Roger; Barreto-Valer, Katherine; Sánchez-Simón, Fátima Macho; Rodríguez, Raquel E.

2012-01-01

Prenatal exposure to cocaine, in mammals, has been shown to interfere with the expression of opioid receptors, which can have repercussions in its activity. Likewise, microRNAs, such as let-7, have been shown to regulate the expression of opioid receptors and hence their functions in mammals and in vitro experiments. In light of this, using the zebrafish embryos as a model our aim here was to evaluate the actions of cocaine in the expression of opioid receptors and let-7d miRNA during embryogenesis. In order to determine the effects produced by cocaine on the opioid receptors (zfmor, zfdor1 and zfdor2) and let-7d miRNA (dre-let-7d) and its precursors (dre-let-7d-1 and dre-let-7d-2), embryos were exposed to 1.5 µM cocaine hydrochloride (HCl). Our results revealed that cocaine upregulated dre-let-7d and its precursors, and also increased the expression of zfmor, zfdor1 and zfdor2 during early developmental stages and decreased them in late embryonic stages. The changes observed in the expression of opioid receptors might occur through dre-let-7d, since DNA sequences and the morpholinos of opioid receptors microinjections altered the expression of dre-let-7d and its precursors. Likewise, opioid receptors and dre-let-7d showed similar distributions in the central nervous system (CNS) and at the periphery, pointing to a possible interrelationship between them. In conclusion, the silencing and overexpression of opioid receptors altered the expression of dre-let-7d, which points to the notion that cocaine via dre-let-7 can modulate the expression of opioid receptors. Our study provides new insights into the actions of cocaine during zebrafish embryogenesis, indicating a role of miRNAs, let-7d, in development and its relationship with gene expression of opioid receptors, related to pain and addiction process. PMID:23226419

Dandelion root extract affects colorectal cancer proliferation and survival through the activation of multiple death signalling pathways

PubMed Central

Ovadje, Pamela; Ammar, Saleem; Guerrero, Jose-Antonio; Arnason, John Thor; Pandey, Siyaram

2016-01-01

Dandelion extracts have been studied extensively in recent years for its anti-depressant and anti-inflammatory activity. Recent work from our lab, with in-vitro systems, shows the anti-cancer potential of an aqueous dandelion root extract (DRE) in several cancer cell models, with no toxicity to non-cancer cells. In this study, we examined the cancer cell-killing effectiveness of an aqueous DRE in colon cancer cell models. Aqueous DRE induced programmed cell death (PCD) selectively in > 95% of colon cancer cells, irrespective of their p53 status, by 48 hours of treatment. The anti-cancer efficacy of this extract was confirmed in in-vivo studies, as the oral administration of DRE retarded the growth of human colon xenograft models by more than 90%. We found the activation of multiple death pathways in cancer cells by DRE treatment, as revealed by gene expression analyses showing the expression of genes implicated in programmed cell death. Phytochemical analyses of the extract showed complex multi-component composition of the DRE, including some known bioactive phytochemicals such as α-amyrin, β-amyrin, lupeol and taraxasterol. This suggested that this natural extract could engage and effectively target multiple vulnerabilities of cancer cells. Therefore, DRE could be a non-toxic and effective anti-cancer alternative, instrumental for reducing the occurrence of cancer cells drug-resistance. PMID:27564258

Barriers and Facilitators to Digital Rectal Examination Screening among African-American and Afro-Caribbean Men

PubMed Central

Lee, Daniel J; Consedine, Nathan S; Spencer, Benjamin A

2011-01-01

Objective To examine the effect of race/ethnicity and fear characteristics on the initiation and maintenance of DRE screening. Methods 533 men from Brooklyn, NY, aged 45–70, were classified into four race/ethnic groups: US-born whites, US-born African-American, Jamaican, and Trinidadian/Tobagonian. Participants recorded the number of DRE’s in the past 10 years. Demographics and structural variables, as well as prostate cancer worry and screening fear were measured with validated tools. Results Overall, 30% of subjects reported never having a DRE and 24% reported annual DRE’s. African-American, Jamaican, and Trinidadian/Tobagonian men have higher prostate cancer worry and screening fear scores than white men (all p<0.05). African-American, Jamaican, and Trinidadian/Tobagonian men were less likely to maintain annual DRE’s than white males (ORs = 0.17, 0.26, and 0.16, respectively, all p<0.05). Men with low screening fear were more likely to have an initial DRE (OR=2.3, p<0.05 vs. high screening fear), but no more or less likely to have annual DRE’s. Having a regular physician, comprehensive physician discussion, and annual visits were also associated with undergoing DRE. Conclusion We identified several ethnically-varying barriers and facilitators to DRE screening. African-American and Afro-Caribbean men undergo DRE less often and have higher prostate cancer worry and screening fear scores than white men. Screening fear predicts the likelihood of undergoing an initial, but not annual, DRE screen. Access to a physician and annual visits facilitate DRE screening. Interventions that include both culturally-sensitive education and patient navigation, and consider whether patients should be initiating or maintaining screening, may facilitate guideline-consistent screening. PMID:21477716

Improving the sensory and oxidative stability of cooked and chill-stored lamb using dietary rosemary diterpenes.

PubMed

Serrano, Rafael; Ortuño, Jordi; Bañón, Sancho

2014-09-01

Two dietary rosemary extracts (DREs) containing diterpenes (carnosic acid and carnosol at 1:1 and 2:1 w:w) were tested in fattening lambs to stabilize the sensory quality of cooked and chill-stored patties. A total of 63 lambs were fed freely for 80 ± 5 d with a basal diet supplemented or not with DRE. Minced leg meat from each lamb was used to make patty batches. The patties were cooked at 72 ºC for 2 min, aerobically packed, kept at 2 ºC for up to 4 d and then reheated. Sensory traits (color, odor, flavor, and texture), CIELab color, and lipid oxidation (assessed as TBARS) were determined. In a first experiment, the lamb diet was supplemented with 600 mg of 1:1-DRE or 2:1-DRE kg(-1) feed. The 1:1-DRE diet delayed discoloration, flavor deterioration, and rancidity, while the 2:1-DRE diet was ineffective in this respect. In a second experiment, 4 supplementation levels of 1:1-DRE (0, 200, 400, and 600 mg kg(-1) feed) were compared. Flavor deterioration was delayed when the lamb diet was supplemented with at least 400 mg 1:1-DRE kg(-1) feed. The effects of the diet on the odor, flavor, and color were corroborated by differences in TBARS and CIELab. The results obtained suggest that rosemary diterpenes and/or their active secondary compounds deposited in muscle can act as endogenous antioxidants in cooked lamb. The carnosol intake seems crucial in the antioxidant actions achieved through DRE. The use of rosemary antioxidants in animal feeding would allow meat-based dishes to be preserved longer without adding preservatives. © 2014 Institute of Food Technologists®

CALIPSO-Inferred Aerosol Direct Radiative Effects: Bias Estimates Using Ground-Based Raman Lidars

NASA Technical Reports Server (NTRS)

Thorsen, Tyler; Fu, Qiang

2016-01-01

Observational constraints on the change in the radiative energy budget caused by the presence of aerosols, i.e. the aerosol direct radiative effect (DRE), have recently been made using observations from the Cloud- Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO). CALIPSO observations have the potential to provide improved global estimates of aerosol DRE compared to passive sensor-derived estimates due to CALIPSO's ability to perform vertically-resolved aerosol retrievals over all surface types and over cloud. In this study we estimate the uncertainties in CALIPSO-inferred aerosol DRE using multiple years of observations from the Atmospheric Radiation Measurement (ARM) program's Raman lidars (RL) at midlatitude and tropical sites. Examined are assumptions about the ratio of extinction-to-backscatter (i.e. the lidar ratio) made by the CALIPSO retrievals, which are needed to retrieve the aerosol extinction profile. The lidar ratio is shown to introduce minimal error in the mean aerosol DRE at the top-of-atmosphere and surface. It is also shown that CALIPSO is unable to detect all radiatively-significant aerosol, resulting in an underestimate in the magnitude of the aerosol DRE by 30-50%. Therefore, global estimates of the aerosol DRE inferred from CALIPSO observations are likely too weak.

Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013

PubMed Central

Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

2014-01-01

We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ. PMID:25359919

Explaining the disease phenotype of intergenic SNP through predicted long range regulation.

PubMed

Chen, Jingqi; Tian, Weidong

2016-10-14

Thousands of disease-associated SNPs (daSNPs) are located in intergenic regions (IGR), making it difficult to understand their association with disease phenotypes. Recent analysis found that non-coding daSNPs were frequently located in or approximate to regulatory elements, inspiring us to try to explain the disease phenotypes of IGR daSNPs through nearby regulatory sequences. Hence, after locating the nearest distal regulatory element (DRE) to a given IGR daSNP, we applied a computational method named INTREPID to predict the target genes regulated by the DRE, and then investigated their functional relevance to the IGR daSNP's disease phenotypes. 36.8% of all IGR daSNP-disease phenotype associations investigated were possibly explainable through the predicted target genes, which were enriched with, were functionally relevant to, or consisted of the corresponding disease genes. This proportion could be further increased to 60.5% if the LD SNPs of daSNPs were also considered. Furthermore, the predicted SNP-target gene pairs were enriched with known eQTL/mQTL SNP-gene relationships. Overall, it's likely that IGR daSNPs may contribute to disease phenotypes by interfering with the regulatory function of their nearby DREs and causing abnormal expression of disease genes. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

A remorin gene SiREM6, the target gene of SiARDP, from foxtail millet (Setaria italica) promotes high salt tolerance in transgenic Arabidopsis.

PubMed

Yue, Jing; Li, Cong; Liu, Yuwei; Yu, Jingjuan

2014-01-01

Remorin proteins (REMs) form a plant-specific protein family, with some REMs being responsive to abiotic stress. However, the precise functions of REMs in abiotic stress tolerance are not clear. In this study, we identified 11 remorin genes from foxtail millet (Setaria italica) and cloned a remorin gene, SiREM6, for further investigation. The transcript level of SiREM6 was increased by high salt stress, low temperature stress and abscisic acid (ABA) treatment, but not by drought stress. The potential oligomerization of SiREM6 was examined by negative staining electron microscopy. The overexpression of SiREM6 improved high salt stress tolerance in transgenic Arabidopsis at the germination and seedling stages as revealed by germination rate, survival rate, relative electrolyte leakage and proline content. The SiREM6 promoter contains two dehydration responsive elements (DRE) and one ABA responsive element (ABRE). An ABA responsive DRE-binding transcription factor, SiARDP, and an ABRE-binding transcription factor, SiAREB1, were cloned from foxtail millet. SiARDP could physically bind to the DREs, but SiAREB1 could not. These results revealed that SiREM6 is a target gene of SiARDP and plays a critical role in high salt stress tolerance.

Meeting the Challenge of Distributed Real-Time & Embedded (DRE) Systems

DTIC Science & Technology

2012-05-10

IP RTOS Middleware Middleware Services DRE Applications Operating Sys & Protocols Hardware & Networks Middleware Middleware Services DRE...Services COTS & standards-based middleware, language, OS , network, & hardware platforms • Real-time CORBA (TAO) middleware • ADAPTIVE Communication...SPLs) F-15 product variant A/V 8-B product variant F/A 18 product variant UCAV product variant Software Produce-Line Hardware (CPU, Memory, I/O) OS

MarDRe: efficient MapReduce-based removal of duplicate DNA reads in the cloud.

PubMed

Expósito, Roberto R; Veiga, Jorge; González-Domínguez, Jorge; Touriño, Juan

2017-09-01

This article presents MarDRe, a de novo cloud-ready duplicate and near-duplicate removal tool that can process single- and paired-end reads from FASTQ/FASTA datasets. MarDRe takes advantage of the widely adopted MapReduce programming model to fully exploit Big Data technologies on cloud-based infrastructures. Written in Java to maximize cross-platform compatibility, MarDRe is built upon the open-source Apache Hadoop project, the most popular distributed computing framework for scalable Big Data processing. On a 16-node cluster deployed on the Amazon EC2 cloud platform, MarDRe is up to 8.52 times faster than a representative state-of-the-art tool. Source code in Java and Hadoop as well as a user's guide are freely available under the GNU GPLv3 license at http://mardre.des.udc.es . rreye@udc.es. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

CALIPSO-Inferred Aerosol Direct Radiative Effects: Bias Estimates Using Ground-Based Raman Lidars

NASA Technical Reports Server (NTRS)

Thorsen, Tyler; Fu, Qiang

2015-01-01

Observational constraints on the change in the radiative energy budget caused by the presence of aerosols, i.e. the aerosol direct radiative effect (DRE), have recently been made using observations from the Cloud- Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO). CALIPSO observations have the potential to provide improved global estimates of aerosol DRE compared to passive sensor-derived estimates due to CALIPSO's ability to perform vertically-resolved aerosol retrievals over all surface types and over cloud. In this study we estimate the uncertainties in CALIPSO-inferred aerosol DRE using multiple years of observations from the Atmospheric Radiation Measurement (ARM) program's Raman lidars (RL) at mid-latitude and tropical sites. Examined are assumptions about the ratio of extinction-to-backscatter (i.e. the lidar ratio) made by the CALIPSO retrievals, which are needed to retrieve the aerosol extinction profile. The lidar ratio is shown to introduce minimal error in the mean aerosol DRE at the top-of-atmosphere and surface. It is also shown that CALIPSO is unable to detect all radiatively-significant aerosol, resulting in an underestimate in the magnitude of the aerosol DRE by 30â€"50%. Therefore, global estimates of the aerosol DRE inferred from CALIPSO observations are likely too weak.

Barriers to prostate cancer screening: psychological aspects and descriptive variables---is there a correlation?

PubMed

Naccarato, Angela Maria Elizabeth Piccolotto; Reis, Leonardo Oliveira; Matheus, Wagner Eduardo; Ferreira, Ubirajara; Denardi, Fernandes

2011-03-01

To evaluate psychological and demographic aspects of men who received DRE during the PCa screening in an outpatient clinical setting. Patients (345) who underwent DRE for the first time from February 2006 to December 2007 were evaluated for their psychological reactions and feelings after the examination. The average age of the patients was 52.8 years (25 - 85 years); 40.94% had felt fear (examination fear 15.94%, and diagnosis fear 25%), 26.45% shame and 48.26% indicated they were not thinking about anything. There was no correlation between age, educational level and emotional reactions. Most patients (96.8%) would undergo a DRE again and 52.35% had considered it better than they had imagined. Of these patients, 41.81% were illiterate/incomplete elementary school. Only 4.12% described having a negative experience. The factors that persuaded the patients to book an appointment were: 50.1% made their own decision, 26.67% were recommended by a physician, 18.55% family/friends and 6.67% were influenced by the media. Wives booked 24.06% of the consultations. Although 85.47% of patients had some previous knowledge about the examination, 80.81% felt they had further clarification afterward. Lower educational level was related to lack of information about DRE, while 52.38% who made their own decision had previous knowledge of the importance of DRE. The majority of the patients found DRE less awkward than they had imagined it to be and would repeat the examination in the future. Fear and shame before the examination are present and are barriers to the DRE.

Lack of evidence to support routine digital rectal examination in pediatric trauma patients.

PubMed

Shlamovitz, Gil Z; Mower, William R; Bergman, Jonathan; Crisp, Jonathan; DeVore, Heather K; Hardy, David; Sargent, Martine; Shroff, Sunil D; Snyder, Eric; Morgan, Marshall T

2007-08-01

Current advanced trauma life support guidelines recommend that a digital rectal examination (DRE) should be performed as part of the initial evaluation of all trauma patients. Our primary goal was to estimate the test characteristics of the DRE in pediatric patients for the following injuries: (1) spinal cord injuries, (2) bowel injuries, (3) rectal injuries, (4) pelvic fractures, and (5) urethral disruptions. We conducted a nonconcurrent, observational, chart review study of a consecutive series of pediatric trauma patients. We enrolled all patients younger than 18 years seen in our ED from January 2003 to February 2005, for whom the trauma team was activated and who had a documented DRE. For each patient, we reviewed all available clinical documents in a computerized medical record system to identify the DRE findings followed by review of radiological reports, operative reports, and discharge summaries to identify specific injuries. Two hundred thirteen patients met our selection criteria and were included in the analysis. We identified 3 patients with spinal cord injury (1% prevalence), 13 patients with bowel injury (6%), 5 patients with rectal injury (2%), 12 patients with a pelvic fracture (6%), and 1 patient with urethral disruption (0.5%). The DRE failed to diagnose (false-negative rate) 66% of spinal cord injuries, 100% of bowel injuries, 100% of rectal wall injuries, 100% of pelvic fractures, and 100% of urethral disruption injuries. The DRE has poor sensitivity for the diagnosis of spinal cord, bowel, rectal, bony pelvis, and urethral injuries. Our findings suggest that the DRE should not be routinely used in pediatric trauma patients.

Consensus-recommended diagnostic and therapeutic guidelines for drug-resistant epilepsy in Spain (Consenso RATE-España).

PubMed

Sánchez-Álvarez, J C; Mauri-Llerda, J A; Gil-Nagel, A; Casas-Fernández, C; Salas-Puig, J; Lahuerta, J; Sancho-Rieger, J

2012-10-01

To ascertain the opinions of an Epilepsy Expert Group and prepare a consensus document on the definition of drug-resistant epilepsy (DRE) according to the International League Against Epilepsy (ILAE) and the different healthcare levels for the patient with epilepsy in Spain. The study was conducted using the Delphi method, by means of successive rounds of questionnaires. A scientific committee prepared a preliminary document and fourteen associated questions, which were sent by e-mail to the panel of experts. They included items related to the concept of DRE, health care levels and the route between these levels for patients with DRE. A total of 41 experts answered the questionnaire. They agreed regarding the necessity and applicability of the DRE definition according to the ILAE, the need for an expert panel on epilepsy, specialist epilepsy clinics, and clinical epilepsy units stratified depending on the level of activities they carried out. There was moderate consensus on the resources and activity of the clinical units of reference and there was no consensus on the referral of patients who have suffered an epileptic seizure to an epilepsy clinic. The expert panel agreed with the definition of DRE according to the ILAE and on referring patients with DRE for a detailed study in an epilepsy clinic or epilepsy clinical unit. They highlighted the need for video-EEG monitoring in the study of patients with DRE and the need to propose other forms of treatment in selected patients. Copyright © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Digital Rectal Examination and Balloon Expulsion Test in the Study of Defecatory Disorders: Are They Suitable as Screening or Excluding Tests?

PubMed

Caetano, Ana C; Santa-Cruz, André; Rolanda, Carla

2016-01-01

Background . Rome III criteria add physiological criteria to symptom-based criteria of chronic constipation (CC) for the diagnosis of defecatory disorders (DD). However, a gold-standard test is still lacking and physiological examination is expensive and time-consuming. Aim . Evaluate the usefulness of two low-cost tests-digital rectal examination (DRE) and balloon expulsion test (BET)-as screening or excluding tests of DD. Methods . We performed a systematic search in PUBMED and MEDLINE. We selected studies where constipated patients were evaluated by DRE or BET. Heterogeneity was assessed and random effect models were used to calculate the sensitivity, specificity, and negative predictive value (NPV) of the DRE and the BET. Results . Thirteen studies evaluating BET and four studies evaluating DRE (2329 patients) were selected. High heterogeneity ( I 2 > 80%) among studies was demonstrated. The studies evaluating the BET showed a sensitivity and specificity of 67% and 80%, respectively. Regarding the DRE, a sensitivity of 80% and specificity of 84% were calculated. NPV of 72% for the BET and NPV of 64% for the DRE were estimated. The sensitivity and specificity were similar when we restrict the analysis to studies using Rome criteria to define CC. The BET seems to perform better when a cut-off time of 2 minutes is used and when it is compared with a combination of physiological tests. Considering the DRE, strict criteria seem to improve the sensitivity but not the specificity of the test. Conclusion . Neither of the low-cost tests seems suitable for screening or excluding DD.

The effect of digital rectal exam on the 4Kscore for aggressive prostate cancer.

PubMed

Maccini, Michael A; Westfall, Nicholas J; Van Bokhoven, Adrie; Lucia, Marshall Scott; Poage, Wendy; Maroni, Paul D; Wilson, Shandra S; Glodé, Leonard Michael; Arangua, Paul; Newmark, Jay; Steiner, Mitchell; Werahera, Priya N; Crawford, Elward David

2018-05-01

The 4Kscore is a new commercially available blood-based diagnostic test which predicts risk for aggressive, clinically significant prostate cancer on prostate biopsy. The 4Kscore is currently restricted to patients who have not had a digital rectal exam (DRE) in the previous 96 h, owing to prior mixed data suggesting that prostate specific antigen (PSA) isoforms may increase by a statistically significant-if not necessarily clinically significant-amount shortly after DRE. Our primary objective was to determine if 4Kscore test results are affected by a preceding DRE. Participants at a Prostate Cancer Awareness Week screening event sponsored by the Prostate Conditions Education Council filled out clinical history questionnaires and had blood samples for 4Kscore testing drawn prior to DRE, then 15-45 min following DRE. Patients with prior cancer diagnosis, 5-alpha reductase inhibitor medication use, or lower urinary tract procedures in the prior 6 months were excluded, resulting in a population of 162 participants for analysis. Values were then compared to determine if there was a significant difference in 4Kscore following DRE. A statistically significant increase was seen in levels of 3 kallikreins measured (total PSA, free PSA, and intact PSA; median <0.03 ng/mL for all). This resulted in a small but statistically significant decrease in post-DRE 4Kscore (median absolute score decrease 0.43%). Using a 4Kscore cutoff of 7.5% resulted in reclassification of 10 patients (6.2%), nine of whom were "downgraded" from above the cutoff to below. If the blood draw for the 4 K score is performed after a screening DRE, there is a statistically significant difference in the 4 K score results, but in the vast majority of cases it would not affect clinical decision making. © 2018 Wiley Periodicals, Inc.

Genome-wide identification of galactinol synthase (GolS) genes in Solanum lycopersicum and Brachypodium distachyon.

PubMed

Filiz, Ertugrul; Ozyigit, Ibrahim Ilker; Vatansever, Recep

2015-10-01

GolS genes stand as potential candidate genes for molecular breeding and/or engineering programs in order for improving abiotic stress tolerance in plant species. In this study, a total of six galactinol synthase (GolS) genes/proteins were retrieved for Solanum lycopersicum and Brachypodium distachyon. GolS protein sequences were identified to include glyco_transf_8 (PF01501) domain structure, and to have a close molecular weight (36.40-39.59kDa) and amino acid length (318-347 aa) with a slightly acidic pI (5.35-6.40). The sub-cellular location was mainly predicted as cytoplasmic. S. lycopersicum genes located on chr 1 and 2, and included one segmental duplication while genes of B. distachyon were only on chr 1 with one tandem duplication. GolS sequences were found to have well conserved motif structures. Cis-acting analysis was performed for three abiotic stress responsive elements, including ABA responsive element (ABRE), dehydration and cold responsive elements (DRE/CRT) and low-temperature responsive element (LTRE). ABRE elements were found in all GolS genes, except for SlGolS4; DRE/CRT was not detected in any GolS genes and LTRE element found in SlGolS1 and BdGolS1 genes. AU analysis in UTR and ORF regions indicated that SlGolS and BdGolS mRNAs may have a short half-life. SlGolS3 and SlGolS4 genes may generate more stable transcripts since they included AATTAAA motif for polyadenylation signal POLASIG2. Seconder structures of SlGolS proteins were well conserved than that of BdGolS. Some structural divergences were detected in 3D structures and predicted binding sites exhibited various patterns in GolS proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.

Shear Stress Partitioning in Large Patches of Roughness in the Atmospheric Inertial Sublayer

NASA Technical Reports Server (NTRS)

Gillies, John A.; Nickling, William G.; King, James

2007-01-01

Drag partition measurements were made in the atmospheric inertial sublayer for six roughness configurations made up of solid elements in staggered arrays of different roughness densities. The roughness was in the form of a patch within a large open area and in the shape of an equilateral triangle with 60 m long sides. Measurements were obtained of the total shear stress (tau) acting on the surfaces, the surface shear stress on the ground between the elements (tau(sub S)) and the drag force on the elements for each roughness array. The measurements indicated that tau(sub S) quickly reduced near the leading edge of the roughness compared with tau, and a tau(sub S) minimum occurs at a normalized distance (x/h, where h is element height) of approx. -42 (downwind of the roughness leading edge is negative), then recovers to a relatively stable value. The location of the minimum appears to scale with element height and not roughness density. The force on the elements decreases exponentially with normalized downwind distance and this rate of change scales with the roughness density, with the rate of change increasing as roughness density increases. Average tau(sub S): tau values for the six roughness surfaces scale predictably as a function of roughness density and in accordance with a shear stress partitioning model. The shear stress partitioning model performed very well in predicting the amount of surface shear stress, given knowledge of the stated input parameters for these patches of roughness. As the shear stress partitioning relationship within the roughness appears to come into equilibrium faster for smaller roughness element sizes it would also appear the shear stress partitioning model can be applied with confidence for smaller patches of smaller roughness elements than those used in this experiment.

Postencephalitic epilepsy and drug-resistant epilepsy after infectious and antibody-associated encephalitis in childhood: Clinical and etiologic risk factors.

PubMed

Pillai, Sekhar C; Mohammad, Shekeeb S; Hacohen, Yael; Tantsis, Esther; Prelog, Kristina; Barnes, Elizabeth H; Gill, Deepak; Lim, Ming J; Brilot, Fabienne; Vincent, Angela; Dale, Russell C

2016-01-01

To define the risk factors for postencephalitic epilepsy (PE) and drug-resistant epilepsy (DRE) in childhood following infectious and autoimmune encephalitis, we included 147 acute encephalitis patients with a median follow-up of 7.3 years (range 2-15.8 years). PE was defined as the use of antiepileptic drugs (AEDs) for ≥24 months, and DRE was defined as the persistence of seizures despite ≥2 appropriate AEDs at final follow-up. PE and DRE were diagnosed in 31 (21%) and 15 (10%) of patients, respectively. The features during acute encephalitis predictive of DRE (presented as odds ratio [OR] with confidence intervals [CIs]) were status epilepticus (OR 10.8, CI 3.4-34.3), visual disturbance (6.4, 1.4-29.9), focal seizures (6.2, 1.9-20.6), magnetic resonance imaging (MRI) hippocampal/amygdala involvement (5.0, 1.7-15.4), intensive care admission (4.7, 1.4-15.4), use of >3 AEDs (4.5, 1.2-16.1), MRI gadolinium enhancement (4.1, 1.2-14.2), any seizure (3.9, 1.1-14.4), and electroencephalography (EEG) epileptiform discharges (3.9, 1.3-12.0). On multivariable regression analysis, only status epilepticus remained predictive of DRE in all models. DRE was common in herpes simplex virus (3/9, 33%) and unknown (8/40, 20%) encephalitis, but absent in acute disseminated encephalomyelitis (ADEM) (0/32, 0%), enterovirus (0/18), and anti-N-methyl-d-aspartate receptor-NMDAR encephalitis (0/9). We have identified risk factors for DRE and demonstrated "high-risk," and "low-risk" etiologies. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

In Vitro Drug Transfer Due to Drug Retention in Human Epidermis Pretreated with Application of Marketed Estradiol Transdermal Systems.

PubMed

Krishnaiah, Yellela S R; Pavurala, Naresh; Yang, Yang; Manda, Prashanth; Katragadda, Usha; Yang, Yongsheng; Shah, Rakhi; Fang, Guodong; Khan, Mansoor A

2017-08-01

Study objective was to assess skin-to-skin drug transfer potential that may occur due to drug retention in human epidermis (DRE) pretreated with application of estradiol transdermal drug delivery systems (TDDS) and other estradiol transdermal dosage forms (gels and sprays). TDDS (products-A, B, and C) with varying formulation design and composition, and other estradiol transdermal products (gel and spray) were applied to heat separated human epidermis (HSE) and subjected to in vitro drug permeation study. Amounts of DRE were quantified after 24 h. The DRE with product-B was significantly (P < 0.001) higher than that with product-C, product-A, gel, and spray. However, products-A and C, gel, and spray showed almost the same (P > 0.05) amounts of DRE. A separate in vitro permeation study was carried out to determine amounts of drug transferred from drug-retaining epidermis to untreated HSE. The amounts of drug transferred, due to DRE after 8 h, with product-C were significantly (P < 0.001) higher than those with products-A and B, gel, and spray. The in vitro study results indicate a high potential of skin-to-skin drug transfer due to the DRE after labeled period of using estradiol TDDS, though the clinical relevance of these findings is yet to be determined.

Identification, occurrence, and validation of DRE and ABRE Cis-regulatory motifs in the promoter regions of genes of Arabidopsis thaliana.

PubMed

Mishra, Sonal; Shukla, Aparna; Upadhyay, Swati; Sanchita; Sharma, Pooja; Singh, Seema; Phukan, Ujjal J; Meena, Abha; Khan, Feroz; Tripathi, Vineeta; Shukla, Rakesh Kumar; Shrama, Ashok

2014-04-01

Plants posses a complex co-regulatory network which helps them to elicit a response under diverse adverse conditions. We used an in silico approach to identify the genes with both DRE and ABRE motifs in their promoter regions in Arabidopsis thaliana. Our results showed that Arabidopsis contains a set of 2,052 genes with ABRE and DRE motifs in their promoter regions. Approximately 72% or more of the total predicted 2,052 genes had a gap distance of less than 400 bp between DRE and ABRE motifs. For positional orientation of the DRE and ABRE motifs, we found that the DR form (one in direct and the other one in reverse orientation) was more prevalent than other forms. These predicted 2,052 genes include 155 transcription factors. Using microarray data from The Arabidopsis Information Resource (TAIR) database, we present 44 transcription factors out of 155 which are upregulated by more than twofold in response to osmotic stress and ABA treatment. Fifty-one transcripts from the one predicted above were validated using semiquantitative expression analysis to support the microarray data in TAIR. Taken together, we report a set of genes containing both DRE and ABRE motifs in their promoter regions in A. thaliana, which can be useful to understand the role of ABA under osmotic stress condition. © 2013 Institute of Botany, Chinese Academy of Sciences.

DReAM: Demand Response Architecture for Multi-level District Heating and Cooling Networks

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

Bhattacharya, Saptarshi; Chandan, Vikas; Arya, Vijay

In this paper, we exploit the inherent hierarchy of heat exchangers in District Heating and Cooling (DHC) networks and propose DReAM, a novel Demand Response (DR) architecture for Multi-level DHC networks. DReAM serves to economize system operation while still respecting comfort requirements of individual consumers. Contrary to many present day DR schemes that work on a consumer level granularity, DReAM works at a level of hierarchy above buildings, i.e. substations that supply heat to a group of buildings. This improves the overall DR scalability and reduce the computational complexity. In the first step of the proposed approach, mathematical models ofmore » individual substations and their downstream networks are abstracted into appropriately constructed low-complexity structural forms. In the second step, this abstracted information is employed by the utility to perform DR optimization that determines the optimal heat inflow to individual substations rather than buildings, in order to achieve the targeted objectives across the network. We validate the proposed DReAM framework through experimental results under different scenarios on a test network.« less

Shelf life of meat from lambs given essential oil-free rosemary extract containing carnosic acid plus carnosol at 200 or 400 mg kg⁻¹.

PubMed

Ortuño, Jordi; Serrano, Rafael; Jordán, María José; Bañón, Sancho

2014-04-01

The use of dietary rosemary extract (DRE) at low doses is proposed as a nutritional strategy to improve meat preservation. Lamb diet was supplemented with 0, 200 or 400mg DRE (containing carnosic acid and carnosol at 1:1 w:w) per kg feed during the fattening stage. Meat quality was evaluated in lamb fillets packed under protective atmosphere and kept in retail conditions for up to 14 days. The effects of diet and storage time were determined on different physical-chemical (L*a*b* color, pH, TBARS, protein oxidation and volatiles from lipid oxidation), microbial (total viable and psychrophilic bacteria, Enterobacteriaceae, molds and yeasts) and sensory (appearance and odor) characteristics of the meat. The antioxidant and antimicrobial effects of DRE on meat were demonstrated. DRE delayed lean and fat discoloration, lipid oxidation, odor deterioration and microbial spoilage, extending the shelf life time of fillets from around 9 to 13 days. Both DRE doses provided similar shelf life extension. Copyright © 2013 Elsevier Ltd. All rights reserved.

Laminar-Turbulent Transition Behind Discrete Roughness Elements in a High-Speed Boundary Layer

NASA Technical Reports Server (NTRS)

Choudhari, Meelan M.; Li, Fei; Wu, Minwei; Chang, Chau-Lyan; Edwards, Jack R., Jr.; Kegerise, Michael; King, Rudolph

2010-01-01

Computations are performed to study the flow past an isolated roughness element in a Mach 3.5, laminar, flat plate boundary layer. To determine the effects of the roughness element on the location of laminar-turbulent transition inside the boundary layer, the instability characteristics of the stationary wake behind the roughness element are investigated over a range of roughness heights. The wake flow adjacent to the spanwise plane of symmetry is characterized by a narrow region of increased boundary layer thickness. Beyond the near wake region, the centerline streak is surrounded by a pair of high-speed streaks with reduced boundary layer thickness and a secondary, outer pair of lower-speed streaks. Similar to the spanwise periodic pattern of streaks behind an array of regularly spaced roughness elements, the above wake structure persists over large distances and can sustain strong enough convective instabilities to cause an earlier onset of transition when the roughness height is sufficiently large. Time accurate computations are performed to clarify additional issues such as the role of the nearfield of the roughness element during the generation of streak instabilities, as well as to reveal selected details of their nonlinear evolution. Effects of roughness element shape on the streak amplitudes and the interactions between multiple roughness elements aligned along the flow direction are also investigated.

Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013.

PubMed

Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

2014-10-30

We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ. Copyright © 2014 Díaz-Quiñonez et al.

Stages of Anal Cancer

MedlinePlus

... past illnesses and treatments will also be taken. Digital rectal examination (DRE) : An exam of the anus ... lumps or anything else that seems unusual. Enlarge Digital rectal exam (DRE). The doctor inserts a gloved, ...

Drosophila nuclear factor DREF regulates the expression of the mitochondrial DNA helicase and mitochondrial transcription factor B2 but not the mitochondrial translation factor B1

PubMed Central

Fernández-Moreno, Miguel A.; Hernández, Rosana; Adán, Cristina; Roberti, Marina; Bruni, Francesco; Polosa, Paola Loguercio; Cantatore, Palmiro; Matsushima, Yuichi; Kaguni, Laurie S.; Garesse, Rafael

2016-01-01

DREF [DRE (DNA replication-related element)-binding factor] controls the transcription of numerous genes in Drosophila, many involved in nuclear DNA (nDNA) replication and cell proliferation, three in mitochondrial DNA (mtDNA) replication and two in mtDNA transcription termination. In this work, we have analysed the involvement of DREF in the expression of the known remaining genes engaged in the minimal mtDNA replication (d-mtDNA helicase) and transcription (the activator d-mtTFB2) machineries and of a gene involved in mitochondrial mRNA translation (d-mtTFB1). We have identified their transcriptional initiation sites and DRE sequences in their promoter regions. Gel-shift and chromatin immunoprecipitation assays demonstrate that DREF interacts in vitro and in vivo with the d-mtDNA helicase and d-mtTFB2, but not with the d-mtTFB1 promoters. Transient transfection assays in Drosophila S2 cells with mutated DRE motifs and truncated promoter regions show that DREF controls the transcription of d-mtDNA helicase and d-mtTFB2, but not that of d-mtTFB1. RNA interference of DREF in S2 cells reinforces these results showing a decrease in the mRNA levels of d-mtDNA helicase and d-mtTFB2 and no changes in those of the d-mtTFB1. These results link the genetic regulation of nuclear DNA replication with the genetic control of mtDNA replication and transcriptional activation in Drosophila. PMID:23916463

Treatment Option Overview (Anal Cancer)

MedlinePlus

... past illnesses and treatments will also be taken. Digital rectal examination (DRE) : An exam of the anus ... lumps or anything else that seems unusual. Enlarge Digital rectal exam (DRE). The doctor inserts a gloved, ...

Dandelion Root Extract Induces Intracellular Ca2+ Increases in HEK293 Cells.

PubMed

Gerbino, Andrea; Russo, Daniela; Colella, Matilde; Procino, Giuseppe; Svelto, Maria; Milella, Luigi; Carmosino, Monica

2018-04-07

Dandelion (Taraxacum officinale Weber ex F.H.Wigg.) has been used for centuries as an ethnomedical remedy. Nonetheless, the extensive use of different kinds of dandelion extracts and preparations is based on empirical findings. Some of the tissue-specific effects reported for diverse dandelion extracts may result from their action on intracellular signaling cascades. Therefore, the aim of this study was to evaluate the effects of an ethanolic dandelion root extract (DRE) on Ca 2+ signaling in human embryonic kidney (HEK) 293 cells. The cytotoxicity of increasing doses of crude DRE was determined by the Calcein viability assay. Fura-2 and the fluorescence resonance energy transfer (FRET)-based probe ERD1 were used to measure cytoplasmic and intraluminal endoplasmic reticulum (ER) Ca 2+ levels, respectively. Furthermore, a green fluorescent protein (GFP)-based probe was used to monitor phospholipase C (PLC) activation (pleckstrin homology [PH]-PLCδ-GFP). DRE (10-400 µg/mL) exposure, in the presence of external Ca 2+ , dose-dependently increased intracellular Ca 2+ levels. The DRE-induced Ca 2+ increase was significantly reduced in the absence of extracellular Ca 2+ . In addition, DRE caused a significant Ca 2+ release from the ER of intact cells and a concomitant translocation of PH-PLCδ-GFP. In conclusion, DRE directly activates both the release of Ca 2+ from internal stores and a significant Ca 2+ influx at the plasma membrane. The resulting high Ca 2+ levels within the cell seem to directly stimulate PLC activity.

Sensitivity of inorganic aerosol radiative effects to U.S. emissions

NASA Astrophysics Data System (ADS)

Holt, J. I.; Solomon, S.; Selin, N. E.

2017-06-01

Between 2005 and 2012, U.S. emissions of nitrogen oxides (NOx) and sulfur dioxide (SO2) decreased by 42% and 62%, respectively. These species, as well as ammonia (NH3), are precursors of inorganic fine aerosols, which scatter incoming shortwave radiation and thus affect climate. Scaling aerosol concentrations to emissions, as might be done for near-term climate projections, neglects nonlinear chemical interactions. To estimate the magnitude of these nonlinearities, we conduct a suite of simulations with a chemical transport model and an off-line radiative transfer model. We find that the direct radiative effect (DRE) over the North American domain decreases by 59 and 160 mW m-2 in winter and summer, respectively, between 2005 and 2012. The sensitivities of DRE to NOx and SO2 emissions increase, by 11% and 21% in summer, while sensitivity to NH3 emissions decreases. The wintertime sensitivity of DRE to NOx emissions is small in 2005 but is 5 times as large in 2012. Scaling radiative effects from 2005 to 2012 based on 2005 sensitivities overestimates the magnitude of the DRE of 7% and 6% of the U.S. attributable DRE in January and July, respectively. The difference between the changes in DRE and the changes in sensitivity suggests that scaling to SO2 emissions alone has so far been an accurate approximation, but it may not be in the near future. These values represent the level of accuracy that can be expected in adjusting aerosol radiative effects in climate models without chemistry.

Dandelion Root Extract Induces Intracellular Ca2+ Increases in HEK293 Cells

PubMed Central

Russo, Daniela; Svelto, Maria; Carmosino, Monica

2018-01-01

Dandelion (Taraxacum officinale Weber ex F.H.Wigg.) has been used for centuries as an ethnomedical remedy. Nonetheless, the extensive use of different kinds of dandelion extracts and preparations is based on empirical findings. Some of the tissue-specific effects reported for diverse dandelion extracts may result from their action on intracellular signaling cascades. Therefore, the aim of this study was to evaluate the effects of an ethanolic dandelion root extract (DRE) on Ca2+ signaling in human embryonic kidney (HEK) 293 cells. The cytotoxicity of increasing doses of crude DRE was determined by the Calcein viability assay. Fura-2 and the fluorescence resonance energy transfer (FRET)-based probe ERD1 were used to measure cytoplasmic and intraluminal endoplasmic reticulum (ER) Ca2+ levels, respectively. Furthermore, a green fluorescent protein (GFP)-based probe was used to monitor phospholipase C (PLC) activation (pleckstrin homology [PH]–PLCδ–GFP). DRE (10–400 µg/mL) exposure, in the presence of external Ca2+, dose-dependently increased intracellular Ca2+ levels. The DRE-induced Ca2+ increase was significantly reduced in the absence of extracellular Ca2+. In addition, DRE caused a significant Ca2+ release from the ER of intact cells and a concomitant translocation of PH–PLCδ–GFP. In conclusion, DRE directly activates both the release of Ca2+ from internal stores and a significant Ca2+ influx at the plasma membrane. The resulting high Ca2+ levels within the cell seem to directly stimulate PLC activity. PMID:29642457

Investigation of wall-bounded turbulence over sparsely distributed roughness

NASA Astrophysics Data System (ADS)

Placidi, Marco; Ganapathisubramani, Bharath

2011-11-01

The effects of sparsely distributed roughness elements on the structure of a turbulent boundary layer are examined by performing a series of Particle Image Velocimetry (PIV) experiments in a wind tunnel. From the literature, the best way to characterise a rough wall, especially one where the density of roughness elements is sparse, is unclear. In this study, rough surfaces consisting of sparsely and uniformly distributed LEGO® blocks are used. Five different patterns are adopted in order to examine the effects of frontal solidity (λf, frontal area of the roughness elements per unit wall-parallel area), plan solidity (λp, plan area of roughness elements per unit wall-parallel area) and the geometry of the roughness element (square and cylindrical elements), on the turbulence structure. The Karman number, Reτ , has been matched, at the value of approximately 2300, in order to compare across the different cases. In the talk, we will present detailed analysis of mean and rms velocity profiles, Reynolds stresses and quadrant decomposition.

Effect of truncated cone roughness element density on hydrodynamic drag

NASA Astrophysics Data System (ADS)

Womack, Kristofer; Schultz, Michael; Meneveau, Charles

2017-11-01

An experimental study was conducted on rough-wall, turbulent boundary layer flow with roughness elements whose idealized shape model barnacles that cause hydrodynamic drag in many applications. Varying planform densities of truncated cone roughness elements were investigated. Element densities studied ranged from 10% to 79%. Detailed turbulent boundary layer velocity statistics were recorded with a two-component LDV system on a three-axis traverse. Hydrodynamic roughness length (z0) and skin-friction coefficient (Cf) were determined and compared with the estimates from existing roughness element drag prediction models including Macdonald et al. (1998) and other recent models. The roughness elements used in this work model idealized barnacles, so implications of this data set for ship powering are considered. This research was supported by the Office of Naval Research and by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.

A Novel Method for Estimating Shortwave Direct Radiative Effect of Above-cloud Aerosols over Ocean Using CALIOP and MODIS Data

NASA Technical Reports Server (NTRS)

Zhang, Z.; Meyer, K.; Platnick, S.; Oreopoulos, L.; Lee, D.; Yu, H.

2013-01-01

This paper describes an efficient and unique method for computing the shortwave direct radiative effect (DRE) of aerosol residing above low-level liquid-phase clouds using CALIOP and MODIS data. It accounts for the overlapping of aerosol and cloud rigorously by utilizing the joint histogram of cloud optical depth and cloud top pressure. Effects of sub-grid scale cloud and aerosol variations on DRE are accounted for. It is computationally efficient through using grid-level cloud and aerosol statistics, instead of pixel-level products, and a pre-computed look-up table in radiative transfer calculations. We verified that for smoke over the southeast Atlantic Ocean the method yields a seasonal mean instantaneous shortwave DRE that generally agrees with more rigorous pixel-level computation within 4%. We have also computed the annual mean instantaneous shortwave DRE of light-absorbing aerosols (i.e., smoke and polluted dust) over global ocean based on 4 yr of CALIOP and MODIS data. We found that the variability of the annual mean shortwave DRE of above-cloud light-absorbing aerosol is mainly driven by the optical depth of the underlying clouds.

A Novel Method for Estimating Shortwave Direct Radiative Effect of Above-Cloud Aerosols Using CALIOP and MODIS Data

NASA Technical Reports Server (NTRS)

Zhang, Z.; Meyer, K.; Platnick, S.; Oreopoulos, L.; Lee, D.; Yu, H.

2014-01-01

This paper describes an efficient and unique method for computing the shortwave direct radiative effect (DRE) of aerosol residing above low-level liquid-phase clouds using CALIOP and MODIS data. It accounts for the overlapping of aerosol and cloud rigorously by utilizing the joint histogram of cloud optical depth and cloud top pressure. Effects of sub-grid scale cloud and aerosol variations on DRE are accounted for. It is computationally efficient through using grid-level cloud and aerosol statistics, instead of pixel-level products, and a pre-computed look-up table in radiative transfer calculations. We verified that for smoke over the southeast Atlantic Ocean the method yields a seasonal mean instantaneous shortwave DRE that generally agrees with more rigorous pixel-level computation within 4. We have also computed the annual mean instantaneous shortwave DRE of light-absorbing aerosols (i.e., smoke and polluted dust) over global ocean based on 4 yr of CALIOP and MODIS data. We found that the variability of the annual mean shortwave DRE of above-cloud light-absorbing aerosol is mainly driven by the optical depth of the underlying clouds.

Prostate Mechanical Imaging: A New Method For Prostate Assessment

PubMed Central

Weiss, Robert E; Egorov, Vladimir; Ayrapetyan, Suren; Sarvazyan, Noune; Sarvazyan, Armen

2008-01-01

Objectives To evaluate the ability of Prostate Mechanical Imaging (PMI) technology to provide an objective and reproducible image and to assess the prostate nodularity. Methods The PMI device developed by Artann Laboratories was evaluated in a pilot clinical study. For the 168 patients (ages 44 to 94) presented to an urologist for prostate evaluation, PMI-produced images and assessment of prostate size, shape, consistency/hardness, mobility, nodularity, and was compared with digital rectal examination (DRE) findings. The PMI and DRE results were further tested for correlation against a transrectal ultrasound of the prostate (TRUS) guided biopsy for a sub-group of 21 patients with an elevated PSA level. Results In 84% of the cases the PMI device was able to reconstruct 3-D and 2-D cross-sectional images of the prostate. The PMI System and DRE pre-tests were able to determine malignant nodules in 10 and 6 patients, respectively, of the 13 patients with biopsy-confirmed malignant inclusions. The PMI System findings were consistent with all 8 biopsy negative cases, while the DRE had 1 abnormal reading for this group. The correlation between PMI and DRE detection of palpable nodularity was 81%, as indicated by the area under the receiver operating characteristic (ROC) curve. Estimates of the prostate size provided by PMI and DRE were found to be statistically significantly correlated. Conclusions The PMI has the potential to enable a physician to obtain, examine and store a three dimensional image of the prostate based on mechanical and geometrical characteristics of the gland and its internal structures. PMID:18342178

Computations of Disturbance Amplification Behind Isolated Roughness Elements and Comparison with Measurements

NASA Technical Reports Server (NTRS)

Choudhari, Meelan; Li, Fei; Bynum, Michael; Kegerise, Michael; King, Rudolph

2015-01-01

Computations are performed to study laminar-turbulent transition due to isolated roughness elements in boundary layers at Mach 3.5 and 5.95, with an emphasis on flow configurations for which experimental measurements from low disturbance wind tunnels are available. The Mach 3.5 case corresponds to a roughness element with right-triangle planform with hypotenuse that is inclined at 45 degrees with respect to the oncoming stream, presenting an obstacle with spanwise asymmetry. The Mach 5.95 case corresponds to a circular roughness element along the nozzle wall of the Purdue BAMQT wind tunnel facility. In both cases, the mean flow distortion due to the roughness element is characterized by long-lived streamwise streaks in the roughness wake, which can support instability modes that did not exist in the absence of the roughness element. The linear amplification characteristics of the wake flow are examined towards the eventual goal of developing linear growth correlations for the onset of transition.

The Efficacy of Dandelion Root Extract in Inducing Apoptosis in Drug-Resistant Human Melanoma Cells

PubMed Central

Chatterjee, S. J.; Ovadje, P.; Mousa, M.; Hamm, C.; Pandey, S.

2011-01-01

Notoriously chemoresistant melanoma has become the most prevalent form of cancer for the 25–29 North American age demographic. Standard treatment after early detection involves surgical excision (recurrence is possible), and metastatic melanoma is refractory to immuno-, radio-, and most harmful chemotherapies. Various natural compounds have shown efficacy in killing different cancers, albeit not always specifically. In this study, we show that dandelion root extract (DRE) specifically and effectively induces apoptosis in human melanoma cells without inducing toxicity in noncancerous cells. Characteristic apoptotic morphology of nuclear condensation and phosphatidylserine flipping to the outer leaflet of the plasma membrane of A375 human melanoma cells was observed within 48 hours. DRE-induced apoptosis activates caspase-8 in A375 cells early on, demonstrating employment of an extrinsic apoptotic pathway to kill A375 cells. Reactive Oxygen Species (ROS) generated from DRE-treated isolated mitochondria indicates that natural compounds in DRE can also directly target mitochondria. Interestingly, the relatively resistant G361 human melanoma cell line responded to DRE when combined with the metabolism interfering antitype II diabetic drug metformin. Therefore, treatment with this common, yet potent extract of natural compounds has proven novel in specifically inducing apoptosis in chemoresistant melanoma, without toxicity to healthy cells. PMID:21234313

Eddy current compensation for delta relaxation enhanced MR by dynamic reference phase modulation.

PubMed

Hoelscher, Uvo Christoph; Jakob, Peter M

2013-04-01

Eddy current compensation by dynamic reference phase modulation (eDREAM) is a compensation method for eddy current fields induced by B 0 field-cycling which occur in delta relaxation enhanced MR (dreMR) imaging. The presented method is based on a dynamic frequency adjustment and prevents eddy current related artifacts. It is easy to implement and can be completely realized in software for any imaging sequence. In this paper, the theory of eDREAM is derived and two applications are demonstrated. The theory describes how to model the behavior of the eddy currents and how to implement the compensation. Phantom and in vivo measurements are carried out and demonstrate the benefits of eDREAM. A comparison of images acquired with and without eDREAM shows a significant improvement in dreMR image quality. Images without eDREAM suffer from severe artifacts and do not allow proper interpretation while images with eDREAM are artifact free. In vivo experiments demonstrate that dreMR imaging without eDREAM is not feasible as artifacts completely change the image contrast. eDREAM is a flexible eddy current compensation for dreMR. It is capable of completely removing the influence of eddy currents such that the dreMR images do not suffer from artifacts.

Aryl Hydrocarbon Receptor-Dependent Retention of Nuclear HuR Suppresses Cigarette Smoke-Induced Cyclooxygenase-2 Expression Independent of DNA-Binding

PubMed Central

Zago, Michela; Sheridan, Jared A.; Nair, Parameswaran; Rico de Souza, Angela; Gallouzi, Imed-Eddine; Rousseau, Simon; Di Marco, Sergio; Hamid, Qutayba; Eidelman, David H.; Baglole, Carolyn J.

2013-01-01

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that responds to man-made environmental toxicants, has emerged as an endogenous regulator of cyclooxygenase-2 (Cox-2) by a mechanism that is poorly understood. In this study, we first used AhR-deficient (AhR−/−) primary pulmonary cells, together with pharmacological tools to inhibit new RNA synthesis, to show that the AhR is a prominent factor in the destabilization of Cox-2 mRNA. The destabilization of Cox-2 mRNA and subsequent suppression of cigarette smoke-induced COX-2 protein expression by the AhR was independent of its ability to bind the dioxin response element (DRE), thereby differentiating the DRE-driven toxicological AhR pathway from its anti-inflammatory abilities. We further describe that the AhR destabilizes Cox-2 mRNA by sequestering HuR within the nucleus. The role of HuR in AhR stabilization of Cox-2 mRNA was confirmed by knockdown of HuR, which resulted in rapid Cox-2 mRNA degradation. Finally, in the lungs of AhR−/− mice exposed to cigarette smoke, there was little Cox-2 mRNA despite robust COX-2 protein expression, a finding that correlates with almost exclusive cytoplasmic HuR within the lungs of AhR−/− mice. Therefore, we propose that the AhR plays an important role in suppressing the expression of inflammatory proteins, a function that extends beyond the ability of the AhR to respond to man-made toxicants. These findings open the possibility that a DRE-independent AhR pathway may be exploited therapeutically as an anti-inflammatory target. PMID:24086407

Aryl hydrocarbon receptor-dependent retention of nuclear HuR suppresses cigarette smoke-induced cyclooxygenase-2 expression independent of DNA-binding.

PubMed

Zago, Michela; Sheridan, Jared A; Nair, Parameswaran; Rico de Souza, Angela; Gallouzi, Imed-Eddine; Rousseau, Simon; Di Marco, Sergio; Hamid, Qutayba; Eidelman, David H; Baglole, Carolyn J

2013-01-01

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that responds to man-made environmental toxicants, has emerged as an endogenous regulator of cyclooxygenase-2 (Cox-2) by a mechanism that is poorly understood. In this study, we first used AhR-deficient (AhR(-/-) ) primary pulmonary cells, together with pharmacological tools to inhibit new RNA synthesis, to show that the AhR is a prominent factor in the destabilization of Cox-2 mRNA. The destabilization of Cox-2 mRNA and subsequent suppression of cigarette smoke-induced COX-2 protein expression by the AhR was independent of its ability to bind the dioxin response element (DRE), thereby differentiating the DRE-driven toxicological AhR pathway from its anti-inflammatory abilities. We further describe that the AhR destabilizes Cox-2 mRNA by sequestering HuR within the nucleus. The role of HuR in AhR stabilization of Cox-2 mRNA was confirmed by knockdown of HuR, which resulted in rapid Cox-2 mRNA degradation. Finally, in the lungs of AhR(-/-) mice exposed to cigarette smoke, there was little Cox-2 mRNA despite robust COX-2 protein expression, a finding that correlates with almost exclusive cytoplasmic HuR within the lungs of AhR(-/-) mice. Therefore, we propose that the AhR plays an important role in suppressing the expression of inflammatory proteins, a function that extends beyond the ability of the AhR to respond to man-made toxicants. These findings open the possibility that a DRE-independent AhR pathway may be exploited therapeutically as an anti-inflammatory target.

A potential endogenous ligand for the aryl hydrocarbon receptor has potent agonist activity in vitro and in vivo.

PubMed

Henry, E C; Bemis, J C; Henry, O; Kende, A S; Gasiewicz, T A

2006-06-01

The aryl hydrocarbon receptor (AhR) is best known as a mediator of toxicity of a diverse family of xenobiotic chemicals such as dioxins and PCBs. However, many naturally occurring compounds also activate AhR. One such compound, 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), was isolated from tissue and found to be potent in preliminary tests [J. Song, M. Clagett-Dame, R.E. Peterson, M.E. Hahn, W.M. Westler, R.R. Sicinski, H.F. DeLuca, Proc. Natl. Acad. Sci. USA 99 (2002) 14694-14699]. We have synthesized ITE and [(3)H]ITE and further evaluated its AhR activity in several in vitro and in vivo assays in comparison with the toxic ligand, TCDD. AhR in Hepa1c1c7 cell cytosol bound [(3)H]ITE with high affinity and the AhR.ITE complex formed in vitro bound dioxin response element (DRE) oligonucleotide as potently as TCDD.AhR. In cells treated with ITE, nuclear translocation of AhR, and induction of CYP1A1 protein and of a DRE-dependent luciferase reporter gene were observed. ITE administered to pregnant DRE-LacZ transgenic mice activated fetal AhR, observed as X-gal staining in the same sites as in TCDD-treated mice. However, unlike TCDD, ITE did not induce cleft palate or hydronephrosis. TCDD but not ITE induced thymic atrophy in young adult mice, but both ITE and TCDD caused similar loss of cells and alterations of cell profiles in cultured fetal thymi. These data demonstrate that ITE is a potent AhR agonist in cell extracts, cultured cells, and intact animals, but does not cause the toxicity associated with the more stable xenobiotic ligand, TCDD.

Deciphering the Role of CBF/DREB Transcription Factors and Dehydrins in Maintaining the Quality of Table Grapes cv. Autumn Royal Treated with High CO2 Levels and Stored at 0°C

PubMed Central

Vazquez-Hernandez, Maria; Romero, Irene; Escribano, M. I.; Merodio, Carmen; Sanchez-Ballesta, M. T.

2017-01-01

C-repeat/dehydration-responsive element binding factors (CBF/DREB) are transcription factors which play a role in improving plant cold stress resistance and recognize the DRE/CRT element in the promoter of a set of cold regulated genes. Dehydrins (DHNs) are proteins that accumulate in plants in response to cold stress, which present, in some cases, CBF/DREB recognition sequences in their promoters and are activated by members of this transcription factor family. The application of a 3-day gaseous treatment with 20 kPa CO2 at 0°C to table grapes cv. Autumn Royal maintained the quality of the bunches during postharvest storage at 0°C, reducing weight loss and rachis browning. In order to determine the role of CBF/DREB genes in the beneficial effect of the gaseous treatment by regulating DHNs, we have analyzed the gene expression pattern of three VviDREBA1s (VviDREBA1-1, VviDREBA1-6, and VviDREBA1-7) as well as three VviDHNs (VviDHN1a, VviDHN2, and VviDHN4), in both alternative splicing forms. Results showed that the differences in VviDREBA1s expression were tissue and atmosphere composition dependent, although the application of high levels of CO2 caused a greater increase of VviDREBA1-1 in the skin, VviDREBA1-6 in the pulp and VviDREBA1-7 in the skin and pulp. Likewise, the application of high levels of CO2 regulated the retention of introns in the transcripts of the dehydrins studied in the different tissues analyzed. The DHNs promoter analysis showed that VviDHN2 presented the cis-acting DRE and CRT elements, whereas VviDHN1a presented only the DRE motif. Our electrophoretic mobility shift assays (EMSA) showed that VviDREBA1-1 was the only transcription factor that had in vitro binding capacity to the CRT element of the VviDHN2 promoter region, indicating that the transcriptional regulation of VviDHN1a and VviDHN4 would be carried out by activating other independent routes of these transcription factors. Our results suggest that the application of high CO2 levels to maintain table grape quality during storage at 0°C, leads to an activation of CBF/DREBs transcription factors. Among these factors, VviDREBA1-1 seems to participate in the transcriptional activation of VviDHN2 via CRT binding, with the unspliced form of this DHN being activated by high CO2 levels in all the tissues analyzed. PMID:28970842

[On the role of selective silencer Freud-1 in the regulation of the brain 5-HT(1A) receptor gene expression].

PubMed

Naumenko, V S; Osipova, D V; Tsybko, A S

2010-01-01

Selective 5-HT(1A) receptor silencer (Freud-1) is known to be one of the main factors for transcriptional regulation of brain serotonin 5-HT(1A) receptor. However, there is a lack of data on implication of Freud-1 in the mechanisms underlying genetically determined and experimentally altered 5-HT(1A) receptor system state in vivo. In the present study we have found a difference in the 5-HT(1A) gene expression in the midbrain of AKR and CBA inbred mouse strains. At the same time no distinction in Freud-1 expression was observed. We have revealed 90.3% of homology between mouse and rat 5-HT(1A) receptor DRE-element, whereas there was no difference in DRE-element sequence between AKR and CBA mice. This indicates the absence of differences in Freud-1 binding site in these mouse strains. In the model of 5-HT(1A) receptor desensitization produced by chronic 5-HT(1A) receptor agonist administration, a significant reduction of 5-HT(1A) receptor gene expression together with considerable increase of Freud-1 expression were found. These data allow us to conclude that the selective silencer of 5-HT(1A) receptor, Freud-1, is involved in the compensatory mechanisms that modulate the functional state of brain serotonin system, although it is not the only factor for 5-HT(1A) receptor transcriptional regulation.

The DEK oncogene activates VEGF expression and promotes tumor angiogenesis and growth in HIF-1α-dependent and -independent manners

PubMed Central

Li, Yang; Lv, Zhaohui; Zhu, Jie; Lin, Jing; Ding, Lihua; Ye, Qinong

2016-01-01

The DEK oncogene is overexpressed in various cancers and overexpression of DEK correlates with poor clinical outcome. Vascular endothelial growth factor (VEGF) is the most important regulator of tumor angiogenesis, a process essential for tumor growth and metastasis. However, whether DEK enhances tumor angiogenesis remains unclear. Here, we show that DEK is a key regulator of VEGF expression and tumor angiogenesis. Using chromatin immunoprecipitation assay, we found that DEK promoted VEGF transcription in breast cancer cells (MCF7, ZR75-1 and MDA-MB-231) by directly binding to putative DEK-responsive element (DRE) of the VEGF promoter and indirectly binding to hypoxia response element (HRE) upstream of the DRE through its interaction with the transcription factor hypoxia-inducible factor 1α (HIF-1α), a master regulator of tumor angiogenesis and growth. DEK is responsible for recruitment of HIF-1α and the histone acetyltransferase p300 to the VEGF promoter. DEK-enhanced VEGF increases vascular endothelial cell proliferation, migration and tube formation as well as angiogenesis in the chick chorioallantoic membrane. DEK promotes tumor angiogenesis and growth in nude mice in HIF-1α-dependent and -independent manners. Immunohistochemical staining showed that DEK expression positively correlates with the expression of VEGF and microvessel number in 58 breast cancer patients. Our data establish DEK as a sequence-specific binding transcription factor, a novel coactivator for HIF-1α in regulation of VEGF transcription and a novel promoter of angiogenesis. PMID:26988756

Ectopic Overexpression of SsCBF1, a CRT/DRE-Binding Factor from the Nightshade Plant Solanum lycopersicoides, Confers Freezing and Salt Tolerance in Transgenic Arabidopsis

PubMed Central

Zhang, Lili; Li, Zhenjun; Li, Jingfu; Wang, Aoxue

2013-01-01

The C-repeat (CRT)/dehydration-responsive element (DRE) binding factor (CBF/DREB1) transcription factors play a key role in cold response. However, the detailed roles of many plant CBFs are far from fully understood. A CBF gene (SsCBF1) was isolated from the cold-hardy plant Solanum lycopersicoides. A subcellular localization study using GFP fusion protein indicated that SsCBF1 is localized in the nucleus. We delimited the SsCBF1 transcriptional activation domain to the C-terminal segment comprising amino acid residues 193–228 (SsCBF1193–228). The expression of SsCBF1 could be dramatically induced by cold, drought and high salinity. Transactivation assays in tobacco leaves revealed that SsCBF1 could specifically bind to the CRT cis-elements in vivo to activate the expression of downstream reporter genes. The ectopic overexpression of SsCBF1 conferred increased freezing and high-salinity tolerance and late flowering phenotype to transgenic Arabidopsis. RNA-sequencing data exhibited that a set of cold and salt stress responsive genes were up-regulated in transgenic Arabidopsis. Our results suggest that SsCBF1 behaves as a typical CBF to contribute to plant freezing tolerance. Increased resistance to high-salinity and late flowering phenotype derived from SsCBF1 OE lines lend more credence to the hypothesis that plant CBFs participate in diverse physiological and biochemical processes related to adverse conditions. PMID:23755095

Transition Experiments on Blunt Bodies with Isolated Roughness Elements in Hypersonic Free Flight

NASA Technical Reports Server (NTRS)

Reda, Daniel C.; Wilder, Michael C.; Prabhu, Dinesh K.

2010-01-01

Smooth titanium hemispheres with isolated three-dimensional (3D) surface roughness elements were flown in the NASA Ames hypersonic ballistic range through quiescent CO2 and air environments. Global surface intensity (temperature) distributions were optically measured and thermal wakes behind individual roughness elements were analyzed to define tripping effectiveness. Real-gas Navier-Stokes calculations of model flowfields, including laminar boundary layer development in these flowfields, were conducted predict key dimensionless parameters used to correlate transition on blunt bodies in hypersonic flow. For isolated roughness elements totally immersed within the laminar boundary layer, critical roughness Reynolds numbers for flights in air were found to be higher than those measured for flights in CO2, i.e., it was easier to trip the CO2 boundary layer to turbulence. Tripping effectiveness was found to be dependent on trip location within the subsonic region of the blunt body flowfield, with effective tripping being most difficult to achieve for elements positioned closest to the stagnation point. Direct comparisons of critical roughness Reynolds numbers for 3D isolated versus 3D distributed roughness elements for flights in air showed that distributed roughness patterns were significantly more effective at tripping the blunt body laminar boundary layer to turbulence.

An Assessment of the Surface Longwave Direct Radiative Effect of Airborne Saharan Dust During the NAMMA Field Campaign

NASA Technical Reports Server (NTRS)

Hansell, R. A.; Tsay, S. C.; Ji, Q.; Hsu, N. C.; Jeong, M. J.; Wang, S. H.; Reid, J. S.; Liou, K. N.; Ou, S. C.

2010-01-01

In September 2006, NASA Goddard s mobile ground-based laboratories were deployed to Sal Island in Cape Verde (16.73degN, 22.93degW) to support the NASA African Monsoon Multidisciplinary Analysis (NAMMA) field study. The Atmospheric Emitted Radiance Interferometer (AERI), a key instrument for spectrally characterizing the thermal IR, was used to retrieve the dust IR aerosol optical depths (AOTs) in order to examine the diurnal variability of airborne dust with emphasis on three separate dust events. AERI retrievals of dust AOT are compared with those from the coincident/collocated multifilter rotating shadow-band radiometer (MFRSR), micropulse lidar (MPL), and NASA Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) sensors. The retrieved AOTs are then inputted into the Fu-Liou 1D radiative transfer model to evaluate local instantaneous direct longwave radiative effects (DRE(sub LW)) of dust at the surface in cloud-free atmospheres and its sensitivity to dust microphysical parameters. The top-of-atmosphere DRE(sub LW) and longwave heating rate profiles are also evaluated. Instantaneous surface DRE(sub LW) ranges from 2 to 10 W/sq m and exhibits a strong linear dependence with dust AOT yielding a DRE(sub LW) of 16 W/sq m per unit dust AOT. The DRE(sub LW) is estimated to be approx.42% of the diurnally averaged direct shortwave radiative effect at the surface but of opposite sign, partly compensating for the shortwave losses. Certainly nonnegligible, the authors conclude that DRE(sub LW) can significantly impact the atmospheric energetics, representing an important component in the study of regional climate variation.

Simulated-microgravity induced G2/M arrest in zebrafish embryonic cell is regulated by dre-miR-22a and its target cep135

NASA Astrophysics Data System (ADS)

Hang, Xiaoming; Sun, Yeqing; Wu, Di; Li, Yixiao; Wang, Ruonan

2016-07-01

Microgravity has been recognized as a major environmental factor that can induce a number of adverse effects such as bone loss, skeletal muscle atrophy, cardiovascular problems and immune system dysregulation, etc. The underlying mechanisms are not absolutely identified yet. Our previous study demonstrated centrosomal protein of 135 kDa (CEP135) might be a microgravity sensitive molecule. In this study, the expression and regulation of CEP135 and its possible roles in cell cycle regulation under simulated microgravity (SMG) condition were investigated. SMG can induce significant increasing of cep135 in zebrafish embryos, detected by both in situ hybridization and RT-qPCR, while CEP135 protein level was significantly decreased, tested by western blot. The similar results were also obtained in zebrafish embryonic cells (ZF4) exposed to SMG. Accordingly, the expression level of dre-miR-22a, which might be the potential miRNA for targeting cep135, was significantly increased in SMG exposed ZF4 cells. By combining the results obtained from transfection and dual luciferase reporter assay, we firstly confirmed that dre-miR-22a regulated the expression of cep135 in ZF4 cells. Further investigation on cell cycle demonstrated SMG induced a significant arrest in G2/M phase. Transfection of dre-miR-22a also induced G2/M arrest in ZF4 cells. These results suggest that SMG induced G2/M arrest in ZF4 cells is via cep135, while dre-miR-22a plays a key role in modulating this effect. Key Words: Simulated-microgravity; cep135; dre-miR-22a; G2/M arrest; zebrafish embryonic cell

Soybean DREB1/CBF-type transcription factors function in heat and drought as well as cold stress-responsive gene expression.

PubMed

Kidokoro, Satoshi; Watanabe, Keitaro; Ohori, Teppei; Moriwaki, Takashi; Maruyama, Kyonoshin; Mizoi, Junya; Myint Phyu Sin Htwe, Nang; Fujita, Yasunari; Sekita, Sachiko; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2015-02-01

Soybean (Glycine max) is a globally important crop, and its growth and yield are severely reduced by abiotic stresses, such as drought, heat, and cold. The cis-acting element DRE (dehydration-responsive element)/CRT plays an important role in activating gene expression in response to these stresses. The Arabidopsis DREB1/CBF genes that encode DRE-binding proteins function as transcriptional activators in the cold stress responsive gene expression. In this study, we identified 14 DREB1-type transcription factors (GmDREB1s) from a soybean genome database. The expression of most GmDREB1 genes in soybean was strongly induced by a variety of abiotic stresses, such as cold, drought, high salt, and heat. The GmDREB1 proteins activated transcription via DREs (dehydration-responsive element) in Arabidopsis and soybean protoplasts. Transcriptome analyses using transgenic Arabidopsis plants overexpressing GmDREB1s indicated that many of the downstream genes are cold-inducible and overlap with those of Arabidopsis DREB1A. We then comprehensively analyzed the downstream genes of GmDREB1B;1, which is closely related to DREB1A, using a transient expression system in soybean protoplasts. The expression of numerous genes induced by various abiotic stresses were increased by overexpressing GmDREB1B;1 in soybean, and DREs were the most conserved element in the promoters of these genes. The downstream genes of GmDREB1B;1 included numerous soybean-specific stress-inducible genes that encode an ABA receptor family protein, GmPYL21, and translation-related genes, such as ribosomal proteins. We confirmed that GmDREB1B;1 directly activates GmPYL21 expression and enhances ABRE-mediated gene expression in an ABA-independent manner. These results suggest that GmDREB1 proteins activate the expression of numerous soybean-specific stress-responsive genes under diverse abiotic stress conditions. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Wake Instabilities Behind Discrete Roughness Elements in High Speed Boundary Layers

NASA Technical Reports Server (NTRS)

Choudhari, Meelan; Li, Fei; Chang, Chau-Lyan; Norris, Andrew; Edwards, Jack

2013-01-01

Computations are performed to study the flow past an isolated, spanwise symmetric roughness element in zero pressure gradient boundary layers at Mach 3.5 and 5.9, with an emphasis on roughness heights of less than 55 percent of the local boundary layer thickness. The Mach 5.9 cases include flow conditions that are relevant to both ground facility experiments and high altitude flight ("cold wall" case). Regardless of the Mach number, the mean flow distortion due to the roughness element is characterized by long-lived streamwise streaks in the roughness wake, which can support instability modes that did not exist in the absence of the roughness element. The higher Mach number cases reveal a variety of instability mode shapes with velocity fluctuations concentrated in different localized regions of high base flow shear. The high shear regions vary from the top of a mushroom shaped structure characterizing the centerline streak to regions that are concentrated on the sides of the mushroom. Unlike the Mach 3.5 case with nearly same values of scaled roughness height k/delta and roughness height Reynolds number Re(sub kk), the odd wake modes in both Mach 5.9 cases are significantly more unstable than the even modes of instability. Additional computations for a Mach 3.5 boundary layer indicate that the presence of a roughness element can also enhance the amplification of first mode instabilities incident from upstream. Interactions between multiple roughness elements aligned along the flow direction are also explored.

Direct radiative effect of carbonaceous aerosols from crop residue burning during the summer harvest season in East China

NASA Astrophysics Data System (ADS)

Yao, Huan; Song, Yu; Liu, Mingxu; Archer-Nicholls, Scott; Lowe, Douglas; McFiggans, Gordon; Xu, Tingting; Du, Pin; Li, Jianfeng; Wu, Yusheng; Hu, Min; Zhao, Chun; Zhu, Tong

2017-04-01

East China experiences extensive crop residue burnings in fields during harvest season. The direct radiative effect (DRE) of carbonaceous aerosols from crop residue burning in June 2013 in East China was investigated using the Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem). Absorption of organic aerosol (OA) in the presence of brown carbon was considered using the parameterization of Saleh et al. (2014), in which the imaginary part of the OA refractive index is a function of wavelength and the ratio of black carbon (BC) and OA. The carbonaceous emissions from crop fires were estimated using the Moderate Resolution Imaging Spectroradiometer (MODIS) fire radiative power (FRP) product with a localized crop-burning-sourced BC-to-organic carbon (OC) ratio emission ratio of 0.27. Evaluation of the model results with in situ measurements of particulate matter with aerodynamic diameter less than 2.5 µm (PM2. 5) chemical composition, MODIS aerosol optical depth (AOD) detections and meteorological observations showed that this model was able to reproduce the magnitude, spatial variation and optical characteristics of carbonaceous aerosol pollution. The observed BC and OC peak concentrations at the site in Suixi, Anhui province, during the 2013 wheat burning season reached 55.3 µg m-3 and 157.9 µg m-3. WRF-Chem simulations reproduced these trends with a correlation coefficient of 0.74, estimating that crop residue burning contributed 86 and 90 % of peak BC and OC, respectively. The simulated hourly DRE from crop residue burning at the top of atmosphere (TOA) reached a maximum of +22.66 W m-2 at the Suixi site. On average, the simulations showed that the crop residue burning introduced a net positive DRE of +0.14 W m-2 at TOA throughout East China, with BC from this source as the main heating contributor (+0.79 W m-2). The OA DRE from crop burning (-0.22 W m-2) was a combined effect of the positive DRE of absorption (+0.21 W m-2) and a stronger negative DRE of scattering (-0.43 W m-2). Sensitivity tests showed that the DRE of OA absorption strongly depended on the imaginary part of the OA refractive index, the BC-to-OA emission ratio from crop residue burning and the assumed mixing state of the aerosol, whereby the volume mixing treatment resulted in a higher positive DRE compared to the core-shell treatment. The BC mixing state and associated absorption enhancement during BC aging processes will be investigated in detail in future research.

Significance of serum total prostate specific antigen and digital rectal examination in the diagnosis of prostate cancer.

PubMed

Abdrabo, Abdelkarim A; Fadlalla, Adil I; Fadl-Elmula, Imad M

2011-11-01

To assess the significance of serum total prostate specific antigen (tPSA) and digital rectal examination (DRE) in the diagnosis of prostate cancer (PC). One hundred and eighteen patients with serum tPSA ranging between 2.5 and 10 ng/ml with lower urinary tract symptoms presented at the Urology Clinic of Soba University Hospital, Khartoum, Sudan from August 2008 and January 2010 were included in the study. Serum tPSA was measured using enzyme immunoassay method, and accordingly, the patients were classified into 2 groups: patients that had tPSA between 2.5-4.0 ng/ml; and patients that had tPSA between 4.1-10 ng/ml. The DRE was performed on all patients by a qualified urologist, and were recorded as a group with suspicion of PC, and a group with no suspicion of PC. All patients underwent transrectal sextant prostate biopsy. The DRE alone showed 63.8% sensitivity and 68% specificity with 46.9% positive predictive value (PPV) for the diagnosis of PC. The tPSA test revealed 91.6% sensitivity and 24% specificity with PPV of 34%. However, when combining DRE and tPSA, the sensitivity reached 100% and the specificity increased to 92% with PPV of 49%. Combining DRE and tPSA test increases the sensitivity, specificity, and PPV of PC detection.

Quantifying palpation techniques in relation to performance in a clinical prostate exam.

PubMed

Wang, Ninghuan; Gerling, Gregory J; Childress, Reba Moyer; Martin, Marcus L

2010-07-01

This paper seeks to quantify finger palpation techniques in the prostate clinical exam, determine their relationship with performance in detecting abnormalities, and differentiate the tendencies of nurse practitioner students and resident physicians. One issue with the digital rectal examination (DRE) is that performance in detecting abnormalities varies greatly and agreement between examiners is low. The utilization of particular palpation techniques may be one way to improve clinician ability. Based on past qualitative instruction, this paper algorithmically defines a set of palpation techniques for the DRE, i.e., global finger movement (GFM), local finger movement (LFM), and average intentional finger pressure, and utilizes a custom-built simulator to analyze finger movements in an experiment with two groups: 18 nurse practitioner students and 16 resident physicians. Although technique utilization varied, some elements clearly impacted performance. For example, those utilizing the LFM of vibration were significantly better at detecting abnormalities. Also, the V GFM led to greater success, but finger pressure played a lesser role. Interestingly, while the residents were clearly the superior performers, their techniques differed only subtly from the students. In summary, the quantified palpation techniques appear to account for examination ability at some level, but not entirely for differences between groups.

Numerical investigation of hypersonic flat-plate boundary layer transition mechanism induced by different roughness shapes

NASA Astrophysics Data System (ADS)

Zhou, Yunlong; Zhao, Yunfei; Xu, Dan; Chai, Zhenxia; Liu, Wei

2016-10-01

The roughness-induced laminar-turbulent boundary layer transition is significant for high-speed aerospace applications. The transition mechanism is closely related to the roughness shape. In this paper, high-order numerical method is used to investigate the effect of roughness shape on the flat-plate laminar-to-turbulent boundary layer transition. Computations are performed in both the supersonic and hypersonic regimes (free-stream Mach number from 3.37 up to 6.63) for the square, cylinder, diamond and hemisphere roughness elements. It is observed that the square and diamond roughness elements are more effective in inducing transition compared with the cylinder and hemisphere ones. The square roughness element has the longest separated region in which strong unsteadiness exists and the absolute instability is formed, thus resulting in the earliest transition. The diamond roughness element has a maximum width of the separated region leading to the widest turbulent wake region far downstream. Furthermore, transition location moves backward as the Mach number increases, which indicates that the compressibility significantly suppresses the roughness-induced boundary layer transition.

A Numerical Study of 2-D Surface Roughness Effects on the Growth of Wave Modes in Hypersonic Boundary Layers

NASA Astrophysics Data System (ADS)

Fong, Kahei Danny

The current understanding and research efforts on surface roughness effects in hypersonic boundary-layer flows focus, almost exclusively, on how roughness elements trip a hypersonic boundary layer to turbulence. However, there were a few reports in the literature suggesting that roughness elements in hypersonic boundary-layer flows could sometimes suppress the transition process and delay the formation of turbulent flow. These reports were not common and had not attracted much attention from the research community. Furthermore, the mechanisms of how the delay and stabilization happened were unknown. A recent study by Duan et al. showed that when 2-D roughness elements were placed downstream of the so-called synchronization point, the unstable second-mode wave in a hypersonic boundary layer was damped. Since the second-mode wave is typically the most dangerous and dominant unstable mode in a hypersonic boundary layer for sharp geometries at a zero angle of attack, this result has pointed to an explanation on how roughness elements delay transition in a hypersonic boundary layer. Such an understanding can potentially have significant practical applications for the development of passive flow control techniques to suppress hypersonic boundary-layer transition, for the purpose of aero-heating reduction. Nevertheless, the previous study was preliminary because only one particular flow condition with one fixed roughness parameter was considered. The study also lacked an examination on the mechanism of the damping effect of the second mode by roughness. Hence, the objective of the current research is to conduct an extensive investigation of the effects of 2-D roughness elements on the growth of instability waves in a hypersonic boundary layer. The goal is to provide a full physical picture of how and when 2-D roughness elements stabilize a hypersonic boundary layer. Rigorous parametric studies using numerical simulation, linear stability theory (LST), and parabolized stability equation (PSE) are performed to ensure the fidelity of the data and to study the relevant flow physics. All results unanimously confirm the conclusion that the relative location of the synchronization point with respect to the roughness element determines the roughness effect on the second mode. Namely, a roughness placed upstream of the synchronization point amplifies the unstable waves while placing a roughness downstream of the synchronization point damps the second-mode waves. The parametric study also shows that a tall roughness element within the local boundary-layer thickness results in a stronger damping effect, while the effect of the roughness width is relatively insignificant compared with the other roughness parameters. On the other hand, the fact that both LST and PSE successfully predict the damping effect only by analyzing the meanflow suggests the mechanism of the damping is by the meanflow alteration due to the existence of roughness elements, rather than new mode generation. In addition to studying the unstable waves, the drag force and heating with and without roughness have been investigated by comparing the numerical simulation data with experimental correlations. It is shown that the increase in drag force generated by the Mach wave around a roughness element in a hypersonic boundary layer is insignificant compared to the reduction of drag force by suppressing turbulent flow. The study also shows that, for a cold wall flow which is the case for practical flight applications, the Stanton number decreases as roughness elements smooth out the temperature gradient in the wall-normal direction. Based on the knowledge of roughness elements damping the second mode gained from the current study, a novel passive transition control method using judiciously placed roughness elements has been developed, and patented, during the course of this research. The main idea of the control method is that, with a given geometry and flow condition, it is possible to find the most unstable second-mode frequency that can lead to transition. And by doing a theoretical analysis such as LST, the synchronization location for the most unstable frequency can be found. Roughness elements are then strategically placed downstream of the synchronization point to damp out this dangerous second-mode wave, thus stabilizing the boundary layer and suppressing the transition process. This method is later experimentally validated in Purdue's Mach 6 quiet wind tunnel. Overall, this research has not only provided details of when and how 2-D roughness stabilizes a hypersonic boundary layer, it also has led to a successful application of numerical simulation data to the development of a new roughness-based transition delay method, which could potentially have significant contributions to the design of future generation hypersonic vehicles.

Using Large-Scale Roughness Elements to Control Sand and Dust Flux at the Keeler Dunes, Keeler, CA

NASA Astrophysics Data System (ADS)

Gillies, John; McCarley-Holder, Grace

2014-05-01

Controlling dust emission from areas that subsequently degrade air quality and threaten human and animal health and reduce the quality of life for people residing in proximity to such sources is necessary, but also challenging. Recent research has indicated that arrays of large roughness elements (height >0.3 m) can be used effectively to modulate sand transport and the associated dust emissions. Prediction of the rate of sand flux reduction as a function of downwind distance upon entering an array of roughness elements, and the equilibrium flux reduction in the interior of the array is possible using the known geometric properties of the roughness elements, their number, and published relationships. Air quality in the town of Keeler, CA (36 deg 29' 17.92" N, 117 deg 52' 24.62" W) is degraded by levels of particulate matter <10 µm aerodynamic diameter (PM10) during periods of elevated wind speeds due to sand transport and dust emissions in the nearby Keeler Dunes. A demonstration project was designed to evaluate the effectiveness of an array of roughness elements composed of solid elements and managed vegetation to meet sand and dust flux reduction criteria. This project has two major goals: 1) to demonstrate that solid roughness elements placed on areas of the Keeler Dunes immediately arrest sand movement to specified levels (target of 85% reduction), and 2) to assess whether native plant species, planted in the sheltered area of the solid roughness elements can effectively thrive and subsequently replace the solid roughness to achieve the desired sand flux reduction control efficiency. This poster describes the results related mostly to objective one, as considerable time has to pass before sufficient data will be obtained to evaluate the success of the planted and managed vegetation to achieve a control level provided by the solid element roughness array.

Fear, knowledge, and efficacy beliefs differentially predict the frequency of digital rectal examination versus prostate specific antigen screening in ethnically diverse samples of older men.

PubMed

Consedine, Nathan S; Horton, David; Ungar, Tracey; Joe, Andrew K; Ramirez, Paul; Borrell, Luisa

2007-03-01

Emotional and cognitive characteristics have been studied in the context of women's cancer screening but have received scant attention in the study of men's screening behavior. Researchers know little about how such factors interact to predict screening or whether digital rectal examination (DRE) and prostate specific antigen (PSA) screens are predicted by the same characteristics. This study examines the relevance of emotional and cognitive characteristics to DRE and PSA screening among 180 U.S.-born African American, U.S.- born European American, and immigrant Jamaican men. The study identifies the expected effects in which fear is negatively related and efficacy beliefs positively related to DRE and PSA screening. Greater efficacy and (marginally) knowledge appear to "offset" the negative impact of fear on screening, and fear appears particularly relevant to DRE frequency. Results are discussed in terms of their implications for the development of health belief and self-regulatory models in the context of prostate cancer screening among minority men.

Prevalence of BPH and lower urinary tract symptoms in West Africans.

PubMed

Chokkalingam, A P; Yeboah, E D; Demarzo, A; Netto, G; Yu, K; Biritwum, R B; Tettey, Y; Adjei, A; Jadallah, S; Li, Y; Chu, L W; Chia, D; Niwa, S; Partin, A; Thompson, I M; Roehrborn, C; Hoover, R N; Hsing, A W

2012-06-01

BPH and lower urinary tract symptoms (LUTS) are very common among older men in Western countries. However, the prevalence of these two conditions in the developing countries is less clear. We assessed the age-standardized prevalence of BPH and/or LUTS among West Africans in a probability sample of 950 men aged 50-74 in Accra, Ghana, with no evidence of biopsy-confirmed prostate cancer after screening with PSA and digital rectal examination (DRE). Information on LUTS was based on self-reports of the International Prostate Symptom Score (IPSS). BPH was estimated using DRE, PSA levels and imputed prostate volume. The prevalence of DRE-detected enlarged prostate was 62.3%, while that of PSA≥1.5 ng ml(-1) (an estimate of prostate volume ≥ 30 cm(3)) was 35.3%. The prevalence of moderate-to-severe LUTS (IPSS≥8) was 19.9%. The prevalence of IPSS≥8 and an enlarged prostate on DRE was 13.3%. Although there is no universally agreed-upon definition of BPH/LUTS, making comparisons across populations difficult, BPH and/or LUTS appear to be quite common among older Ghanaian men. We found that after age standardization, the prevalence of DRE-detected enlarged prostate in Ghanaian men is higher than previously reported for American men, but the prevalence of LUTS was lower than previously reported for African Americans. Further studies are needed to confirm these findings and identify the risk factors for BPH in both Africans and African Americans.

Direct radiative effect due to brownness in organic carbon aerosols generated from biomass combustion

NASA Astrophysics Data System (ADS)

Rathod, T. D.; Sahu, S. K.; Tiwari, M.; Pandit, G. G.

2016-12-01

We report the enhancement in the direct radiative effect due the presence of Brown carbon (BrC) as a part of organic carbon aerosols. The optical properties of organic carbon aerosols generated from pyrolytic combustion of mango tree wood (Magnifera Indica) and dung cake at different temperatures were considered. Mie codes were used to calculate absorption and scattering coefficients coupled with experimentally derived imaginary complex refractive index. The direct radiative effect (DRE) for sampled organic carbon aerosols was estimated using a wavelength dependent radiative transfer equation. The BrC DRE was estimated taking virtually non absorbing organic aerosols as reference. The BrC DRE from wood and dung cake was compared at different combustion temperatures and conditions. The BrC contributed positively to the direct top of the atmosphere radiative effect. Dung cake generated BrC aerosols were found to be strongly light absorbing as compared to BrC from wood combustion. It was noted that radiative effects of BrC from wood depended on its generation temperature and conditions. For BrC aerosols from dung cake such strong dependence was not observed. The average BrC aerosol DRE values were 1.53±0.76 W g-1 and 17.84±6.45 W g-1 for wood and dung cake respectively. The DRE contribution of BrC aerosols came mainly (67-90%) from visible light absorption though they exhibited strong absorption in shorter wavelengths of the UV-visible spectrum.

Near-field flow structures about subcritical surface roughness

NASA Astrophysics Data System (ADS)

Doolittle, Charles J.; Drews, Scott D.; Goldstein, David B.

2014-12-01

Laminar flow over a periodic array of cylindrical surface roughness elements is simulated with an immersed boundary spectral method both to validate the method for subsequent studies and to examine how persistent streamwise vortices are introduced by a low Reynolds number roughness element. Direct comparisons are made with prior studies at a roughness-based Reynolds number Rek (=U(k) k/ν) of 205 and a diameter to spanwise spacing ratio d/λ of 1/3. Downstream velocity contours match present and past experiments very well. The shear layer developed over the top of the roughness element produces the downstream velocity deficit. Upstream of the roughness element, the vortex topology is found to be consistent with juncture flow experiments, creating three cores along the recirculation line. Streamtraces stemming from these upstream cores, however, have unexpectedly little effect on the downstream flowfield as lateral divergence of the boundary layer quickly dissipates their vorticity. Long physical relaxation time of the recirculating wake behind the roughness remains a prominent issue for simulating this type of flowfield.

Need for and relevance of prostate cancer screening in Nigeria.

PubMed

Akinremi, To; Adeniyi, A; Olutunde, A; Oduniyi, A; Ogo, Cn

2014-01-01

Prostate cancer (PCa) has become the most prevalent cancer among males in Nigeria, and similar to other black populations, Nigerian men present with more advanced disease at an earlier age than in several other ethnic groups. In this unscreened, high-risk group, the reference range for early detection and diagnosis as well as risk factors need to be determined through large-scale screening. Over 4 years, 1124 previously unscreened men between 40 and 85 years of age were screened at free community health programmes for PCa, using the common parameters of prostate-specific antigen (PSA) plus digital rectal examination (DRE). We thereby assessed the practicality and importance of screening. Consent was obtained, demographic data obtained, PSA measured using qualitative laboratory kits, and DRE performed by surgeons. We found that the number of men attending and consenting to screening increases from year to year. Of 40-85-year-old men, 85.4% consented, of whom 33.3% (a third) and 60% were 51-60 years old and 51-65 years, respectively. While 11.5% of men had PSA >4 ng/ml, 31.45% showed abnormal DRE. Of the men who took the PSA test, 79.2% also consented to the DRE, of whom 5.8% had combined abnormal DRE and PSA >4 ng/ml. Our findings suggest that Nigerian men are a willing group for screening by both the PSA and DRE with the positive response to calls for health screening and interest in prostate health. The finding of PSA >4 ng/ml in 11.15% of this population reveals the need for greater awareness and measures to increase early detection. However, the value and validity of established PSA reference ranges and cutoff of 'normal' still need to be established. Screening is very important to better define the PCa prevalence and characteristics in our population; otherwise political and economic circumstances will ensure that men still present late with aggressive PCa.

Influence of the three-dimensional heterogeneous roughness on electrokinetic transport in microchannels.

PubMed

Hu, Yandong; Werner, Carsten; Li, Dongqing

2004-12-15

Surface roughness has been considered as a passive means of enhancing species mixing in electroosmotic flow through microfluidic systems. It is highly desirable to understand the synergetic effect of three-dimensional (3D) roughness and surface heterogeneity on the electrokinetic flow through microchannels. In this study, we developed a three-dimensional finite-volume-based numerical model to simulate electroosmotic transport in a slit microchannel (formed between two parallel plates) with numerous heterogeneous prismatic roughness elements arranged symmetrically and asymmetrically on the microchannel walls. We consider that all 3D prismatic rough elements have the same surface charge or zeta potential, the substrate (the microchannel wall) surface has a different zeta potential. The results showed that the rough channel's geometry and the electroosmotic mobility ratio of the roughness elements' surface to that of the substrate, epsilon(mu), have a dramatic influence on the induced-pressure field, the electroosmotic flow patterns, and the electroosmotic flow rate in the heterogeneous rough microchannels. The associated sample-species transport presents a tidal-wave-like concentration field at the intersection between four neighboring rough elements under low epsilon(mu) values and has a concentration field similar to that of the smooth channels under high epsilon(mu) values.

The Long Range Persistence of Wakes Behind a Row of Roughness Elements

NASA Technical Reports Server (NTRS)

Goldstein, M. E.; Sescu, Adrian; Duck, Peter W.; Choudhari, Meelan

2010-01-01

We consider a periodic array of relatively small roughness elements whose spanwise separation is of the order of the local boundary-layer thickness and construct a local asymptotic high-Reynolds-number solution that is valid in the vicinity of the roughness. The resulting flow decays on the very short streamwise length scale of the roughness, but the solution eventually becomes invalid at large downstream distances and a new solution has to be constructed in the downstream region. This latter result shows that the roughness-generated wakes can persist over very long streamwise distances, which are much longer than the distance between the roughness elements and the leading edge. Detailed numerical results are given for the far wake structure.

The violent Strombolian eruption of 10 ka Pelado shield volcano, Sierra Chichinautzin, Central Mexico

NASA Astrophysics Data System (ADS)

Lorenzo-Merino, A.; Guilbaud, M.-N.; Roberge, J.

2018-03-01

Pelado volcano is a typical example of an andesitic Mexican shield with a summital scoria cone. It erupted ca. 10 ka in the central part of an elevated plateau in what is today the southern part of Mexico City. The volcano forms a roughly circular, 10-km wide lava shield with two summital cones, surrounded by up to 2.7-m thick tephra deposits preserved up to a distance of 3 km beyond the shield. New cartographic, stratigraphic, granulometric, and componentry data indicate that Pelado volcano was the product of a single, continuous eruption marked by three stages. In the early stage, a > 1.5-km long fissure opened and was active with mild explosive activity. Intermediate and late stages were mostly effusive and associated with the formation of a 250-m high lava shield. Nevertheless, during these stages, the emission of lava alternated and/or coexisted with highly explosive events that deposited a widespread tephra blanket. In the intermediate stage, multiple vents were active along the fissure, but activity was centered at the main cone during the late stage. The final activity was purely effusive. The volcano emitted > 0.9 km3 dense-rock equivalent (DRE) of tephra and up to 5.6 km3 DRE of lavas. Pelado shares various features with documented "violent Strombolian" eruptions, including a high fragmentation index, large dispersal area, occurrence of plate tephra, high eruptive column, and simultaneous explosive and effusive activity. Our results suggest that the associated hazards (mostly tephra fallout and emplacement of lava) would seriously affect areas located up to 25 km from the vent for fallout and 5 km from the vent for lava, an important issue for large cities built near or on potentially active zones, such as Mexico City.

Simultaneously inferring above-cloud absorbing aerosol optical thickness and underlying liquid phase cloud optical and microphysical properties using MODIS

NASA Astrophysics Data System (ADS)

Meyer, Kerry; Platnick, Steven; Zhang, Zhibo

2015-06-01

The regional haze over the southeast (SE) Atlantic Ocean induced by biomass burning in southern Africa can be problematic for passive imager-based retrievals of the underlying quasi-permanent marine boundary layer (MBL) clouds and for estimates of top-of-atmosphere (TOA) aerosol direct radiative effect (DRE). Here an algorithm is introduced to simultaneously retrieve above-cloud aerosol optical thickness (AOT), the cloud optical thickness (COT), and cloud effective particle radius (CER) of the underlying MBL clouds while also providing pixel-level estimates of retrieval uncertainty. This approach utilizes reflectance measurements at six Moderate Resolution Imaging Spectroradiometer (MODIS) channels from the visible to the shortwave infrared. Retrievals are run under two aerosol model assumptions on 8 years (2006-2013) of June-October Aqua MODIS data over the SE Atlantic, from which a regional cloud and above-cloud aerosol climatology is produced. The cloud retrieval methodology is shown to yield COT and CER consistent with those from the MODIS operational cloud product (MOD06) when forcing AOT to zero, while the full COT-CER-AOT retrievals that account for the above-cloud aerosol attenuation increase regional monthly mean COT and CER by up to 9% and 2%, respectively. Retrieved AOT is roughly 3 to 5 times larger than the collocated 532 nm Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) retrievals, though closer agreement is observed with the CALIOP 1064 nm retrievals, a result consistent with previous case study analyses. Regional cloudy-sky above-cloud aerosol DRE calculations are also performed that illustrate the importance of the aerosol model assumption and underlying cloud retrievals.

Sulfate Aerosol in the Arctic: Source Attribution and Radiative Forcing

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

Yang, Yang; Wang, Hailong; Smith, Steven J.

Source attributions of Arctic sulfate and its direct radiative effect for 2010–2014 are quantified in this study using the Community Earth System Model (CESM) equipped with an explicit sulfur source-tagging technique. Regions that have high emissions and/or are near/within the Arctic present relatively large contributions to Arctic sulfate burden, with the largest contribution from sources in East Asia (27%). East Asia and South Asia together have the largest contributions to Arctic sulfate concentrations at 9–12 km, whereas sources within or near the Arctic account largely below 2 km. For remote sources with strong emissions, their contributions to Arctic sulfate burdenmore » are primarily driven by meteorology, while contributions of sources within or near the Arctic are dominated by their emission strength. The sulfate direct radiative effect (DRE) is –0.080 W m-2 at the Arctic surface, offsetting the net warming effect from the combination of in-snow heating and DRE cooling from black carbon. East Asia, Arctic local and Russia/Belarus/Ukraine sources contribute –0.017, –0.016 and –0.014 W m-2, respectively, to Arctic sulfate DRE. A 20% reduction in anthropogenic SO2 emissions leads to a net increase of +0.013 W m-2 forcing at the Arctic surface. These results indicate that a joint reduction in BC emissions could prevent possible Arctic warming from future reductions in SO2 emissions. Sulfate DRE efficiency calculations suggest that short transport pathways together with meteorology favoring long sulfate lifetimes make certain sources more efficient in influencing the Arctic sulfate DRE.« less

Detection of prostate cancer-specific transcripts in extracellular vesicles isolated from post-DRE urine

PubMed Central

Pellegrini, Kathryn L.; Patil, Dattatraya; Douglas, Kristen J.S.; Lee, Grace; Wehrmeyer, Kathryn; Torlak, Mersiha; Clark, Jeremy; Cooper, Colin S.; Moreno, Carlos S.; Sanda, Martin G.

2018-01-01

Background The measurement of gene expression in post-digital rectal examination (DRE) urine specimens provides a non-invasive method to determine a patient’s risk of prostate cancer. Many currently available assays use whole urine or cell pellets for the analysis of prostate cancer-associated genes, although the use of extracellular vesicles (EVs) has also recently been of interest. We investigated the expression of prostate-, kidney-, and bladder-specific transcripts and known prostate cancer biomarkers in urine EVs. Methods Cell pellets and EVs were recovered from post-DRE urine specimens, with the total RNA yield and quality determined by Bioanalyzer. The levels of prostate, kidney, and bladder-associated transcripts in EVs were assessed by TaqMan qPCR and targeted sequencing. Results RNA was more consistently recovered from the urine EV specimens, with over 80% of the patients demonstrating higher RNA yields in the EV fraction as compared to urine cell pellets. The median EV RNA yield of 36.4 ng was significantly higher than the median urine cell pellet RNA yield of 4.8 ng. Analysis of the post-DRE urine EVs indicated that prostate-specific transcripts were more abundant than kidney- or bladder-specific transcripts. Additionally, patients with prostate cancer had significantly higher levels of the prostate cancer-associated genes PCA3 and ERG. Conclusions Post-DRE urine EVs are a viable source of prostate-derived RNAs for biomarker discovery and prostate cancer status can be distinguished from analysis of these specimens. Continued analysis of urine EVs offers the potential discovery of novel biomarkers for pre-biopsy prostate cancer detection. PMID:28419548

Detection of prostate cancer-specific transcripts in extracellular vesicles isolated from post-DRE urine.

PubMed

Pellegrini, Kathryn L; Patil, Dattatraya; Douglas, Kristen J S; Lee, Grace; Wehrmeyer, Kathryn; Torlak, Mersiha; Clark, Jeremy; Cooper, Colin S; Moreno, Carlos S; Sanda, Martin G

2017-06-01

The measurement of gene expression in post-digital rectal examination (DRE) urine specimens provides a non-invasive method to determine a patient's risk of prostate cancer. Many currently available assays use whole urine or cell pellets for the analysis of prostate cancer-associated genes, although the use of extracellular vesicles (EVs) has also recently been of interest. We investigated the expression of prostate-, kidney-, and bladder-specific transcripts and known prostate cancer biomarkers in urine EVs. Cell pellets and EVs were recovered from post-DRE urine specimens, with the total RNA yield and quality determined by Bioanalyzer. The levels of prostate, kidney, and bladder-associated transcripts in EVs were assessed by TaqMan qPCR and targeted sequencing. RNA was more consistently recovered from the urine EV specimens, with over 80% of the patients demonstrating higher RNA yields in the EV fraction as compared to urine cell pellets. The median EV RNA yield of 36.4 ng was significantly higher than the median urine cell pellet RNA yield of 4.8 ng. Analysis of the post-DRE urine EVs indicated that prostate-specific transcripts were more abundant than kidney- or bladder-specific transcripts. Additionally, patients with prostate cancer had significantly higher levels of the prostate cancer-associated genes PCA3 and ERG. Post-DRE urine EVs are a viable source of prostate-derived RNAs for biomarker discovery and prostate cancer status can be distinguished from analysis of these specimens. Continued analysis of urine EVs offers the potential discovery of novel biomarkers for pre-biopsy prostate cancer detection. © 2017 Wiley Periodicals, Inc.

Direct radiative effect by multicomponent aerosol over China

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

Huang, Xin; Song, Yu; Zhao, Chun

The direct radiative effect (DRE) of multiple aerosol species (sulfate, nitrate, ammonium, black carbon (BC), organic carbon (OC), and mineral aerosol) and their spatiotemporal variations over China were investigated using a fully coupled meteorology–chemistry model (WRF-Chem) for the entire year of 2006. We made modifications to improve model performance, including updating land surface parameters, improving the calculation of transition metal-catalyzed oxidation of SO 2, and adding in heterogeneous reactions between mineral aerosol and acid gases. The modified model well reproduced the magnitude, seasonal pattern, and spatial distribution of the measured meteorological conditions, concentrations of PM 10 and its components, andmore » aerosol optical depth (AOD). A diagnostic iteration method was used to estimate the overall DRE of aerosols and contributions from different components. At the land surface, all kinds of aerosol species reduced the incident net radiation flux with a total DRE of 10.2 W m -2 over China. Aerosols significantly warm the atmosphere with the national mean DRE of +10.8 W m -2. BC was the leading radiative-heating component (+8.7 W m -2), followed by mineral aerosol (+1.1 W m -2). At the top of the atmosphere (TOA), BC introduced the largest radiative perturbation (+4.5 W m -2), followed by sulfate (-1.4 W m -2). The overall perturbation of aerosols on radiation transfer is quite small over China, demonstrating the counterbalancing effect between scattering and adsorbing aerosols. Aerosol DRE at the TOA had distinct seasonality, generally with a summer maximum and winter minimum, mainly determined by mass loadings, hygroscopic growth, and incident radiation flux.« less

Effect of surface morphology on drag and roughness sublayer in flows over regular roughness elements

NASA Astrophysics Data System (ADS)

Placidi, Marco; Ganapathisubramani, Bharathram

2014-11-01

The effects of systematically varied roughness morphology on bulk drag and on the spatial structure of turbulent boundary layers are examined by performing a series of wind tunnel experiments. In this study, rough surfaces consisting of regularly and uniformly distributed LEGO™ bricks are employed. Twelve different patterns are adopted in order to methodically examine the individual effects of frontal solidity (λF, frontal area of the roughness elements per unit wall-parallel area) and plan solidity (λP, plan area of roughness elements per unit wall-parallel area), on both the bulk drag and the turbulence structure. A floating element friction balance based on Krogstad & Efros (2010) was designed and manufactured to measure the drag generated by the different surfaces. In parallel, high resolution planar and stereoscopic Particle Image Velocimetry (PIV) was applied to investigate the flow features. This talk will focus on the effects of each solidity parameter on the bulk drag and attempt to relate the observed trends to the flow structures in the roughness sublayer. Currently at City University London.

Direct numerical simulation of instabilities in parallel flow with spherical roughness elements

NASA Technical Reports Server (NTRS)

Deanna, R. G.

1992-01-01

Results from a direct numerical simulation of laminar flow over a flat surface with spherical roughness elements using a spectral-element method are given. The numerical simulation approximates roughness as a cellular pattern of identical spheres protruding from a smooth wall. Periodic boundary conditions on the domain's horizontal faces simulate an infinite array of roughness elements extending in the streamwise and spanwise directions, which implies the parallel-flow assumption, and results in a closed domain. A body force, designed to yield the horizontal Blasius velocity in the absence of roughness, sustains the flow. Instabilities above a critical Reynolds number reveal negligible oscillations in the recirculation regions behind each sphere and in the free stream, high-amplitude oscillations in the layer directly above the spheres, and a mean profile with an inflection point near the sphere's crest. The inflection point yields an unstable layer above the roughness (where U''(y) is less than 0) and a stable region within the roughness (where U''(y) is greater than 0). Evidently, the instability begins when the low-momentum or wake region behind an element, being the region most affected by disturbances (purely numerical in this case), goes unstable and moves. In compressible flow with periodic boundaries, this motion sends disturbances to all regions of the domain. In the unstable layer just above the inflection point, the disturbances grow while being carried downstream with a propagation speed equal to the local mean velocity; they do not grow amid the low energy region near the roughness patch. The most amplified disturbance eventually arrives at the next roughness element downstream, perturbing its wake and inducing a global response at a frequency governed by the streamwise spacing between spheres and the mean velocity of the most amplified layer.

Receptivity of Hypersonic Boundary Layers to Distributed Roughness and Acoustic Disturbances

NASA Technical Reports Server (NTRS)

Balakumar, P.

2013-01-01

Boundary-layer receptivity and stability of Mach 6 flows over smooth and rough seven-degree half-angle sharp-tipped cones are numerically investigated. The receptivity of the boundary layer to slow acoustic disturbances, fast acoustic disturbances, and vortical disturbances is considered. The effects of three-dimensional isolated roughness on the receptivity and stability are also simulated. The results for the smooth cone show that the instability waves are generated in the leading edge region and that the boundary layer is much more receptive to slow acoustic waves than to the fast acoustic waves. Vortical disturbances also generate unstable second modes, however the receptivity coefficients are smaller than that of the slow acoustic wave. Distributed roughness elements located near the nose region decreased the receptivity of the second mode generated by the slow acoustic wave by a small amount. Roughness elements distributed across the continuous spectrum increased the receptivity of the second mode generated by the slow and fast acoustic waves and the vorticity wave. The largest increase occurred for the vorticity wave. Roughness elements distributed across the synchronization point did not change the receptivity of the second modes generated by the acoustic waves. The receptivity of the second mode generated by the vorticity wave increased in this case, but the increase is lower than that occurred with the roughness elements located across the continuous spectrum. The simulations with an isolated roughness element showed that the second mode waves generated by the acoustic disturbances are not influenced by the small roughness element. Due to the interaction, a three-dimensional wave is generated. However, the amplitude is orders of magnitude smaller than the two-dimensional wave.

Integrative Analysis of Desert Dust Size and Abundance Suggests Less Dust Climate Cooling

NASA Technical Reports Server (NTRS)

Kok, Jasper F.; Ridley, David A.; Zhou, Qing; Miller, Ron L.; Zhao, Chun; Heald, Colette L.; Ward, Daniel S.; Albani, Samuel; Haustein, Karsten

2017-01-01

Desert dust aerosols affect Earths global energy balance through interactions with radiation, clouds, and ecosystems. But the magnitudes of these effects are so uncertain that it remains unclear whether atmospheric dust has a net warming or cooling effect on global climate. Consequently, it is still uncertain whether large changes in atmospheric dust loading over the past century have slowed or accelerated anthropogenic climate change, and the climate impact of possible future alterations in dust loading is similarly disputed. Here we use an integrative analysis of dust aerosol sizes and abundance to constrain the climatic impact of dust through direct interactions with radiation. Using a combination of observational, experimental, and model data, we find that atmospheric dust is substantially coarser than represented in current climate models. Since coarse dust warms global climate, the dust direct radiative effect (DRE) is likely less cooling than the 0.4 W m superscript 2 estimated by models in a current ensemble. We constrain the dust DRE to -0.20 (-0.48 to +0.20) W m superscript 2, which suggests that the dust DRE produces only about half the cooling that current models estimate, and raises the possibility that dust DRE is actually net warming the planet.

Human Freud-2/CC2D1B: a novel repressor of postsynaptic serotonin-1A receptor expression.

PubMed

Hadjighassem, Mahmoud R; Austin, Mark C; Szewczyk, Bernadeta; Daigle, Mireille; Stockmeier, Craig A; Albert, Paul R

2009-08-01

Altered expression of serotonin-1A (5-HT1A) receptors, both presynaptic in the raphe nuclei and post-synaptic in limbic and cortical target areas, has been implicated in mood disorders such as major depression and anxiety. Within the 5-HT1A receptor gene, a powerful dual repressor element (DRE) is regulated by two protein complexes: Freud-1/CC2D1A and a second, unknown repressor. Here we identify human Freud-2/CC2D1B, a Freud-1 homologue, as the second repressor. Freud-2 distribution was examined with Northern and Western blot, reverse transcriptase polymerase chain reaction, and immunohistochemistry/immunofluorescence; Freud-2 function was examined by electrophoretic mobility shift, reporter assay, and Western blot. Freud-2 RNA was widely distributed in brain and peripheral tissues. Freud-2 protein was enriched in the nuclear fraction of human prefrontal cortex and hippocampus but was weakly expressed in the dorsal raphe nucleus. Freud-2 immunostaining was co-localized with 5-HT1A receptors, neuronal and glial markers. In prefrontal cortex, Freud-2 was expressed at similar levels in control and depressed male subjects. Recombinant hFreud-2 protein bound specifically to 5' or 3' human DRE adjacent to the Freud-1 site. Human Freud-2 showed strong repressor activity at the human 5-HT1A or heterologous promoter in human HEK-293 5-HT1A-negative cells and neuronal SK-N-SH cells, a model of postsynaptic 5-HT1A receptor-positive cells. Furthermore, small interfering RNA knockdown of endogenous hFreud-2 expression de-repressed 5-HT1A promoter activity and increased levels of 5-HT1A receptor protein in SK-N-SH cells. Human Freud-2 binds to the 5-HT1A DRE and represses the human 5-HT1A receptor gene to regulate its expression in non-serotonergic cells and neurons.

High clustering rates of multidrug-resistant Mycobacterium tuberculosis genotypes in Panama

PubMed Central

2013-01-01

Background Tuberculosis continues to be one of the leading causes of death worldwide and in the American region. Although multidrug-resistant tuberculosis (MDR-TB) remains a threat to TB control in Panama, few studies have focused in typing MDR-TB strains. The aim of our study was to characterize MDR Mycobacterium tuberculosis clinical isolates using PCR-based genetic markers. Methods From 2002 to 2004, a total of 231 Mycobacterium tuberculosis isolates from TB cases country-wide were screened for antibiotic resistance, and MDR-TB isolates were further genotyped by double repetitive element PCR (DRE-PCR), (GTG)5-PCR and spoligotyping. Results A total of 37 isolates (0.85%) were resistant to both isoniazid (INH) and rifampicin (RIF). Among these 37 isolates, only two (5.4%) were resistant to all five drugs tested. Dual genotyping using DRE-PCR and (GTG)5-PCR of MDR Mycobacterium tuberculosis isolates revealed eight clusters comprising 82.9% of the MDR-TB strain collection, and six isolates (17.1%) showed unique fingerprints. The spoligotyping of MDR-TB clinical isolates identified 68% as members of the 42 (LAM9) family genotype. Conclusion Our findings suggest that MDR Mycobacterium tuberculosis is highly clustered in Panama’s metropolitan area corresponding to Panama City and Colon City, and our study reveals the genotype distribution across the country. PMID:24053690

Investigation of secondary flows in turbulent pipe flows with three-dimensional sinusoidal walls

NASA Astrophysics Data System (ADS)

Chan, Leon; MacDonald, Michael; Chung, Daniel; Hutchins, Nicholas; Ooi, Andrew

2017-11-01

The occurrence of secondary flows is systematically investigated via Direct Numerical Simulations (DNS) of turbulent flow in a rough wall pipe at friction Reynolds numbers of 540. In this study, the peak-to-trough height of the roughness elements, which consist of three-dimensional sinusoidal roughness, is fixed at 120 viscous units while the wavelength of the roughness elements is varied. The solidity or effective slope (ES) of the roughness ranges from the sparse regime (ES = 0.18) to the closely packed roughness/dense regime (ES = 0.72). The time-independent dispersive stresses, which arise due to the stationary features of the flow, are analysed and are found to increase with increasing roughness wavelength. These dispersive stresses are related to the occurrence of secondary flows and are maximum within the roughness canopy. Above the crest of the roughness elements, the dispersive stresses reduce to zero at wall-normal heights greater than half of the roughness wavelength. This study has found that the size and wall-normal extent of the secondary flows scales with the roughness wavelength and can reach wall-normal heights of almost half of the pipe radius.

Variation in bed level shear stress on surfaces sheltered by nonerodible roughness elements

NASA Astrophysics Data System (ADS)

Sutton, Stephen L. F.; McKenna-Neuman, Cheryl

2008-09-01

Direct bed level observations of surface shear stress, pressure gradient variability, turbulence intensity, and fluid flow patterns were carried out in the vicinity of cylindrical roughness elements mounted in a boundary layer wind tunnel. Paired corkscrew vortices shed from each of the elements result in elevated shear stress and increased potential for the initiation of particle transport within the far wake. While the size and shape of these trailing vortices change with the element spacing, they persist even for large roughness densities. Wake interference coincides with the impingement of the upwind horseshoe vortices upon one another at a point when their diameter approaches half the distance between the roughness elements. While the erosive capability of the horseshoe vortex has been suggested for a variety of settings, the present study shows that the fluid stress immediately beneath this coherent structure is actually small in comparison to that caused by compression of the incident flow as it is deflected around the element and attached vortex. Observations such as these are required for further refinement of models of stress partitioning on rough surfaces.

A Novel Method for Estimating Shortwave Direct Radiative Effect of Above-Cloud Aerosols Using CALIOP and MODIS Data

NASA Technical Reports Server (NTRS)

Zhang, Zhibo; Meyer, Kerry G.; Platnick, Steven; Oreopoulos, Lazaros; Lee, Dongmin; Yu, Hongbin

2014-01-01

This paper describes an efficient and unique method for computing the shortwave direct radiative effect (DRE) of aerosol residing above low-level liquid-phase clouds using CALIOP and MODIS data. It addresses the overlap of aerosol and cloud rigorously by utilizing the joint histogram of cloud optical depth and cloud top pressure while also accounting for subgrid-scale variations of aerosols. The method is computationally efficient because of its use of grid-level cloud and aerosol statistics, instead of pixel-level products, and a pre-computed look-up table based on radiative transfer calculations. We verify that for smoke over the southeast Atlantic Ocean the method yields a seasonal mean instantaneous (approximately 1:30PM local time) shortwave DRE of above cloud aerosol (ACA) that generally agrees with more rigorous pixel-level computation within 4 percent. We also estimate the impact of potential CALIOP aerosol optical depth (AOD) retrieval bias of ACA on DRE. We find that the regional and seasonal mean instantaneous DRE of ACA over southeast Atlantic Ocean would increase, from the original value of 6.4 W m(-2) based on operational CALIOP AOD to 9.6 W m(-2) if CALIOP AOD retrieval are biased low by a factor of 1.5 (Meyer et al., 2013) and further to 30.9 W m(-2) if CALIOP AOD retrieval are biased low by a factor of 5 as suggested in (Jethva et al., 2014). In contrast, the instantaneous ACA radiative forcing efficiency (RFE) remains relatively invariant in all cases at about 53 W m(-2) AOD(-1), suggesting a near linear relation between the instantaneous RFE and AOD. We also compute the annual mean instantaneous shortwave DRE of light-absorbing aerosols (i.e., smoke and polluted dust) over global oceans based on 4 years of CALIOP and MODIS data. We find that the variability of the annual mean shortwave DRE of above-cloud light-absorbing aerosol is mainly driven by the optical depth of the underlying clouds. While we demonstrate our method using CALIOP and MODIS data, it can also be extended to other satellite data sets, as well as climate model outputs.

Chalcophile element partitioning in highly oxidised and highly reduced bodies.

NASA Astrophysics Data System (ADS)

Kiseeva, K.; Wood, B. J.

2015-12-01

In our recent studies [1-3] we showed that partitioning of many chalcophile elements could be described by a simple relationship as a function of the FeO content of the silicate liquid. LogDi ~= A-0.5nlog[FeO] where A is a constant, n is the constant related to the valency of element i and [FeO] is the concentration of FeO in the silicate melt. For many chalcophile and moderately chalcophile elements (e.g., Zn, Cr, Pb, Sb, In), the fitted slope n depends only on the valency of the element. More lithophile elements (e.g., Ti, Nb, Ce, Ga) exhibit concave upwards behavior on a plot of logD versus log[FeO] due to their strong interaction with oxygen in sulphide, which increases with the increasing FeO content of the silicate liquid. Strongly chalcophile elements, like Cu, Ag and Ni have the opposite trend (concave downwards) and their D decreases both at high (> 10-12wt %) and very low (< 1wt%) FeO contents of the silicate melt. These changes correlate with increasing S content of the silicate melt (up to 11 wt%) as the FeO content of the silicate melt declines to ~0.3wt%. An experiment at 1.5 GPa/1420oC having 4 wt% S and 0.28 wt% FeO in the silicate melt has DCu (sulf/sil) ~ 84, which is about 6 times lower than the DCu(sulf/sil) at identical p-T conditions but at 8 wt% FeO in the silicate melt. Our new experimental data on Re partitioning between sulphide and silicate melt in the CMAS+FeO system show that Re behaves similarly to the highly chalcophile elements and exhibits concave downwards behaviour on the LogD/LogFeO diagram. With the highest DRe (sulf/sil) at around 1.5-2.0x104 at 1.5-6.0 wt% FeO in the silicate melt, DRe (sulf/sil) declines to the values of 50-150 at ~0.5 wt% and > ~15 wt% FeO in the silicate melt, respectively. This means that at highly reducing conditions Re is similarly or less chalcophile than some of the highly lithophile elements, like Ta (D ≈ 9), Nb (D ≈ 600), Ti (D ≈ 6) [3]. The results mean that in oxidised bodies like Mars and reduced bodies like Mercury, most "lithophile" elements partition more strongly into sulphide than Re and Cu. [1] Kiseeva E. S., Wood B. J. (2013). EPSL 383, p. 68-81. [2] Kiseeva E. S., Wood B. J. (2015). EPSL 424, p. 280-294. [3] Wood B. J., Kiseeva E. S. (2015). AmMin (in press).

Convection from Hemispherical and Conical Model Ice Roughness Elements in Stagnation Region Flows

NASA Technical Reports Server (NTRS)

Hughes, Michael T.; Shannon, Timothy A.; McClain, Stephen T.; Vargas, Mario; Broeren, Andy

2016-01-01

To improve ice accretion prediction codes, more data regarding ice roughness and its effects on convective heat transfer are required. The Vertical Icing Studies Tunnel (VIST) at NASA Glenn Research was used to model realistic ice roughness in the stagnation region of a NACA 0012 airfoil. In the VIST, a test plate representing the leading 2% chord of the airfoil was subjected to flows of 7.62 m/s (25 ft/s), 12.19 m/s (40 ft/s), and 16.76 m/s (55 ft/s). The test plate was fitted with multiple surfaces or sets of roughness panels, each with a different representation of ice roughness. The sets of roughness panels were constructed using two element distribution patterns that were created based on a laser scan of an iced airfoil acquired in the Icing Research Tunnel at NASA Glenn. For both roughness patterns, surfaces were constructed using plastic hemispherical elements, plastic conical elements, and aluminum conical elements. Infrared surface thermometry data from tests run in the VIST were used to calculate area averaged heat transfer coefficient values. The values from the roughness surfaces were compared to the smooth control surface, showing convective enhancement as high as 400% in some cases. The data gathered during this study will ultimately be used to improve the physical modeling in LEWICE or other ice accretion codes and produce predictions of in-flight ice accretion on aircraft surfaces with greater confidence.

Seizure frequency reduction after posteromedial hypothalamus deep brain stimulation in drug-resistant epilepsy associated with intractable aggressive behavior.

PubMed

Benedetti-Isaac, Juan C; Torres-Zambrano, Martin; Vargas-Toscano, Andres; Perea-Castro, Esther; Alcalá-Cerra, Gabriel; Furlanetti, Luciano L; Reithmeier, Thomas; Tierney, Travis S; Anastasopoulos, Constantin; Fonoff, Erich T; Contreras Lopez, William Omar

2015-07-01

The aim of this study was to analyze the impact of deep brain stimulation (DBS) of the posteromedial hypothalamus (pHyp) on seizure frequency in patients with drug-resistant epilepsy (DRE) associated with intractable aggressive behavior (IAB). Data were collected retrospectively from nine patients, who received bilateral stereotactic pHyp-DBS for the treatment of medically intractable aggressive behavior, focusing on five patients who also had DRE. All patients were treated at the Colombian Center and Foundation of Epilepsy and Neurological Diseases-FIRE (Chapter of the International Bureau for Epilepsy), in Cartagena de Indias, Colombia from 2010 to 2014. Each case was evaluated previously by the institutional ethical committee, assessing the impact of aggressive behavior on the patient's family and social life, the humanitarian aspects of preserving the safety and physical integrity of caregivers, and the need to prevent self-harm. Epilepsy improvement was measured by a monthly seizure reduction percentage, comparing preoperative state and outcome. Additional response to epilepsy was defined by reduction of the antiepileptic drugs (AEDs). Aggressive behavior response was measured using the Overt Aggression Scale (OAS). All the patients with DRE associated with IAB presented a significant decrease of the rate of epileptic seizures after up to 4 years follow-up, achieving a general 89.6% average seizure reduction from the state before the surgery. Aggressiveness was significantly controlled, with evident improvement in the OAS, enhancing the quality of life of patients and families. In well-selected patients, DBS of the pHyp seems to be a safe and effective procedure for treatment of DRE associated with refractory aggressive behavior. Larger and prospective series are needed to define the pHyp as a target for DRE in different contexts. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Seasonal variation in non-structural carbohydrates, sucrolytic activity and secondary metabolites in deciduous and perennial Diospyros species sampled in Western Mexico

PubMed Central

Ramírez-Briones, Ernesto; Rodríguez-Macías, Ramón; Salcedo-Pérez, Eduardo; Martínez-Gallardo, Norma; Tiessen, Axel; Molina-Torres, Jorge; Délano-Frier, John P.; Zañudo-Hernández, Julia

2017-01-01

This study was performed to test the working hypothesis that the primary determinants influencing seasonal driven modifications in carbon mobilization and other key biochemical parameters in leaves of poorly known Diospyros digyna (Ddg; semi-domesticated; perennial) and D. rekoi (Dre; undomesticated; deciduous) trees are determined by environmental growing conditions, agronomic management and physiological plasticity. Thus, biochemical changes in leaves of both trees were recorded seasonally during two successive fruiting years. Trees were randomly sampled in Western Mexico habitats with differing soil quality, climatic conditions, luminosity, and cultivation practices. Leaves of Ddg had consistently higher total chlorophyll contents (CT) that, unexpectedly, peaked in the winter of 2015. In Dre, the highest leaf CT values recorded in the summer of 2015 inversely correlated with low average luminosity and high Chl a/ Chlb ratios. The seasonal CT variations in Dre were congruent with varying luminosity, whereas those in Ddg were probably affected by other factors, such as fluctuating leaf protein contents and the funneling of light energy to foliar non-structural carbohydrates (NSCs) accumulation, which were consistently higher than those detected in Dre leaves. Seasonal foliar NSC fluctuations in both species were in agreement with the carbon (C) demands of flowering, fruiting and/ or leaf regrowth. Seasonal changes in foliar hexose to sucrose (Hex/ Suc) ratios coincided with cell wall invertase activity in both species. In Dre, high Hex/ Suc ratios in spring leaves possibly allowed an accumulation of phenolic acids, not observed in Ddg. The above results supported the hypothesis proposed by showing that leaf responses to changing environmental conditions differ in perennial and deciduous Diospyros trees, including a dynamic adjustment of NSCs to supply the C demands imposed by reproduction, leaf regrowth and, possibly, stress. PMID:29073239

Etiological associations and outcome predictors of acute electroencephalography in childhood encephalitis.

PubMed

Mohammad, Shekeeb S; Soe, Samantha M; Pillai, Sekhar C; Nosadini, Margherita; Barnes, Elizabeth H; Gill, Deepak; Dale, Russell C

2016-10-01

To examine EEG features in a retrospective 13-year cohort of children with encephalitis. 354 EEGs from 119 patients during their admission were rated blind using a proforma with demonstrated inter-rater reliability (mean k=0.78). Patients belonged to 12 etiological groups that could be grouped into infectious and infection-associated (n=47), immune-mediated (n=36) and unknown (n=33). EEG features were analyzed between groups and for risk of abnormal Liverpool Outcome Score and drug resistant epilepsy (DRE) at last follow up. 86% children had an abnormal first EEG and 89% had at least one abnormal EEG. 55% had an abnormal outcome, and 13% had DRE after median follow-up of 7.3years (2.0-15.8years). Reactive background on first EEGs (9/11, p=0.04) and extreme spindles (4/11, p<0.001) distinguished patients with anti-N-Methyl-d-Aspartate Receptor encephalitis. Non-reactive EEG background (48% first EEGs) predicted abnormal outcome (OR 3.8, p<0.001). A shifting focal seizure pattern, seen in FIRES (4/5), anti-voltage gated potassium channel (2/3), Mycoplasma (1/10), other viral (1/10) and other unknown (1/28) encephalitis, was most predictive of DRE after multivariable analysis (OR 11.9, p<0.001). Non-reactive EEG background and the presence of shifting focal seizures resembling migrating partial seizures of infancy are predictors of abnormal outcome and DRE respectively in childhood encephalitis. EEG is a sensitive but non-discriminatory marker of childhood encephalitis. We highlight the EEG features that predict abnormal outcome and DRE. Copyright © 2016 International Federation of Clinical Neurophysiology. All rights reserved.

Exploring the observational constraints on the simulation of brown carbon

NASA Astrophysics Data System (ADS)

Wang, X.; Heald, C. L.; Liu, J.; Weber, R. J.; Campuzano-Jost, P.; Jimenez, J. L.; Schwarz, J. P.; Perring, A. E.

2017-12-01

Brown carbon (BrC) is the component of organic aerosols (OA) which strongly absorbs solar radiation in the near-UV range of the spectrum. However the sources, evolution, and optical properties of BrC remain highly uncertain, and therefore constitute a large source of uncertainty in estimating the global direct radiative effect (DRE) of aerosols. Previous modeling studies of BrC optical properties and DRE have been unable to fully evaluate the skill of their simulations, given the lack of direct measurements of organic aerosol absorption. In this study, we develop a global model simulation (GEOS-Chem) of BrC and test it against BrC absorption measurements from two aircraft campaigns in the U.S. (SEAC4RS and DC3). To our knowledge, this is the first study to compare simulated BrC absorption with direct, continuous ambient measurements. We show that the laboratory-based BrC absorption properties from biomass burning overestimate the aircraft measurements of ambient BrC. In addition, applying a photochemical whitening scheme to simulated BrC is better able to represent the observed BrC absorption. These observations are consistent with a mass absorption coefficient (MAC) of freshly emitted biomass burning OA of 0.57m2g-1. Using the RRTMG model integrated with GEOS-Chem, we estimate that the all-sky top-of-atmosphere direct radiative effect (DRE) of OA is -0.350 Wm-2, 10% higher than that without consideration of BrC absorption. Therefore, our best estimate of the absorption DRE of BrC is +0.042 Wm-2. We suggest that the DRE of BrC has been overestimated previously due to the lack of observational constraints from direct measurements as well as neglect of the effects of photochemical whitening.

Investigation of wall-bounded turbulence over regularly distributed roughness

NASA Astrophysics Data System (ADS)

Placidi, Marco; Ganapathisubramani, Bharathram

2012-11-01

The effects of regularly distributed roughness elements on the structure of a turbulent boundary layer are examined by performing a series of Planar (high resolution l+ ~ 30) and Stereoscopic Particle Image Velocimetry (PIV) experiments in a wind tunnel. An adequate description of how to best characterise a rough wall, especially one where the density of roughness elements is sparse, is yet to be developed. In this study, rough surfaces consisting of regularly and uniformly distributed LEGO® blocks are used. Twelve different patterns are adopted in order to systematically examine the effects of frontal solidity (λf, frontal area of the roughness elements per unit wall-parallel area) and plan solidity (λp, plan area of roughness elements per unit wall-parallel area), on the turbulence structure. The Karman number, Reτ , is approximately 4000 across the different cases. Spanwise 3D vector fields at two different wall-normal locations (top of the canopy and within the log-region) are also compared to examine the spanwise homogeneity of the flow across different surfaces. In the talk, a detailed analysis of mean and rms velocity profiles, Reynolds stresses, and quadrant decomposition for the different patterns will be presented.

Photomask CD and LER characterization using Mueller matrix spectroscopic ellipsometry

NASA Astrophysics Data System (ADS)

Heinrich, A.; Dirnstorfer, I.; Bischoff, J.; Meiner, K.; Ketelsen, H.; Richter, U.; Mikolajick, T.

2014-10-01

Critical dimension and line edge roughness on photomask arrays are determined with Mueller matrix spectroscopic ellipsometry. Arrays with large sinusoidal perturbations are measured for different azimuth angels and compared with simulations based on rigorous coupled wave analysis. Experiment and simulation show that line edge roughness leads to characteristic changes in the different Mueller matrix elements. The influence of line edge roughness is interpreted as an increase of isotropic character of the sample. The changes in the Mueller matrix elements are very similar when the arrays are statistically perturbed with rms roughness values in the nanometer range suggesting that the results on the sinusoidal test structures are also relevant for "real" mask errors. Critical dimension errors and line edge roughness have similar impact on the SE MM measurement. To distinguish between both deviations, a strategy based on the calculation of sensitivities and correlation coefficients for all Mueller matrix elements is shown. The Mueller matrix elements M13/M31 and M34/M43 are the most suitable elements due to their high sensitivities to critical dimension errors and line edge roughness and, at the same time, to a low correlation coefficient between both influences. From the simulated sensitivities, it is estimated that the measurement accuracy has to be in the order of 0.01 and 0.001 for the detection of 1 nm critical dimension error and 1 nm line edge roughness, respectively.

Comparison of aerodynamically and model-derived roughness lengths (zo) over diverse surfaces, central Mojave Desert, California, USA

USGS Publications Warehouse

MacKinnon, D.J.; Clow, G.D.; Tigges, R.K.; Reynolds, R.L.; Chavez, P.S.

2004-01-01

The vulnerability of dryland surfaces to wind erosion depends importantly on the absence or the presence and character of surface roughness elements, such as plants, clasts, and topographic irregularities that diminish wind speed near the surface. A model for the friction velocity ratio has been developed to account for wind sheltering by many different types of co-existing roughness elements. Such conditions typify a monitored area in the central Mojave Desert, California, that experiences frequent sand movement and dust emission. Two additional models are used to convert the friction velocity ratio to the surface roughness length (zo) for momentum. To calculate roughness lengths from these models, measurements were made at 11 sites within the monitored area to characterize the surface roughness element. Measurements included (1) the number of roughness species (e.g., plants, small-scale topography, clasts), and their associated heights and widths, (2) spacing among species, and (3) vegetation porosity (a measurement of the spatial distribution of woody elements of a plant). Documented or estimated values of drag coefficients for different species were included in the modeling. At these sites, wind-speed profiles were measured during periods of neutral atmospheric stability using three 9-m towers with three or four calibrated anemometers on each. Modeled roughness lengths show a close correspondence (correlation coefficient, 0.84-0.86) to the aerodynamically determined values at the field sites. The geometric properties of the roughness elements in the model are amenable to measurement at much higher temporal and spatial resolutions using remote-sensing techniques than can be accomplished through laborious ground-based methods. A remote-sensing approach to acquire values of the modeled roughness length is particularly important for the development of linked surface/atmosphere wind-erosion models sensitive to climate variability and land-use changes in areas such as the southwestern United States, where surface roughness has large spatial and temporal variations. ?? 2004 Elsevier B.V. All rights reserved.

Modelling turbulent boundary layer flow over fractal-like multiscale terrain using large-eddy simulations and analytical tools.

PubMed

Yang, X I A; Meneveau, C

2017-04-13

In recent years, there has been growing interest in large-eddy simulation (LES) modelling of atmospheric boundary layers interacting with arrays of wind turbines on complex terrain. However, such terrain typically contains geometric features and roughness elements reaching down to small scales that typically cannot be resolved numerically. Thus subgrid-scale models for the unresolved features of the bottom roughness are needed for LES. Such knowledge is also required to model the effects of the ground surface 'underneath' a wind farm. Here we adapt a dynamic approach to determine subgrid-scale roughness parametrizations and apply it for the case of rough surfaces composed of cuboidal elements with broad size distributions, containing many scales. We first investigate the flow response to ground roughness of a few scales. LES with the dynamic roughness model which accounts for the drag of unresolved roughness is shown to provide resolution-independent results for the mean velocity distribution. Moreover, we develop an analytical roughness model that accounts for the sheltering effects of large-scale on small-scale roughness elements. Taking into account the shading effect, constraints from fundamental conservation laws, and assumptions of geometric self-similarity, the analytical roughness model is shown to provide analytical predictions that agree well with roughness parameters determined from LES.This article is part of the themed issue 'Wind energy in complex terrains'. © 2017 The Author(s).

Discrete-Roughness-Element-Enhanced Swept-Wing Natural Laminar Flow at High Reynolds Numbers

NASA Technical Reports Server (NTRS)

Malik, Mujeeb; Liao, Wei; Li, Fei; Choudhari, Meelan

2015-01-01

Nonlinear parabolized stability equations and secondary-instability analyses are used to provide a computational assessment of the potential use of the discrete-roughness-element technology for extending swept-wing natural laminar flow at chord Reynolds numbers relevant to transport aircraft. Computations performed for the boundary layer on a natural-laminar-flow airfoil with a leading-edge sweep angle of 34.6 deg, freestream Mach number of 0.75, and chord Reynolds numbers of 17 × 10(exp 6), 24 × 10(exp 6), and 30 × 10(exp 6) suggest that discrete roughness elements could delay laminar-turbulent transition by about 20% when transition is caused by stationary crossflow disturbances. Computations show that the introduction of small-wavelength stationary crossflow disturbances (i.e., discrete roughness element) also suppresses the growth of most amplified traveling crossflow disturbances.

Hypersonic Viscous Flow Over Large Roughness Elements

NASA Technical Reports Server (NTRS)

Chang, Chau-Lyan; Choudhari, Meelan M.

2009-01-01

Viscous flow over discrete or distributed surface roughness has great implications for hypersonic flight due to aerothermodynamic considerations related to laminar-turbulent transition. Current prediction capability is greatly hampered by the limited knowledge base for such flows. To help fill that gap, numerical computations are used to investigate the intricate flow physics involved. An unstructured mesh, compressible Navier-Stokes code based on the space-time conservation element, solution element (CESE) method is used to perform time-accurate Navier-Stokes calculations for two roughness shapes investigated in wind tunnel experiments at NASA Langley Research Center. It was found through 2D parametric study that at subcritical Reynolds numbers, spontaneous absolute instability accompanying by sustained vortex shedding downstream of the roughness is likely to take place at subsonic free-stream conditions. On the other hand, convective instability may be the dominant mechanism for supersonic boundary layers. Three-dimensional calculations for both a rectangular and a cylindrical roughness element at post-shock Mach numbers of 4.1 and 6.5 also confirm that no self-sustained vortex generation from the top face of the roughness is observed, despite the presence of flow unsteadiness for the smaller post-shock Mach number case.

Numerical Simulation of Roughness-Induced Transient Growth in a Laminar Boundary Layer

NASA Technical Reports Server (NTRS)

Fischer, Paul; Choudhari, Meelan

2004-01-01

Numerical simulations are used to examine the roughness-induced transient growth in a laminar boundary-layer flow. Based on the spectral element method, these simulations model the stationary disturbance field associated with a nonsmooth roughness geometry, such as the spanwise periodic array of circular disks used by White and co-workers during a series of wind tunnel experiments at Case Western Reserve University. Besides capturing the major trends from the recent measurements by White and Ergin, the simulations provide additional information concerning the relative accuracy of the experimental findings derived from two separate wall-finding procedures. The paper also explores the dependence of transient growth on geometric characteristics of the roughness distribution, including the height and planform shape of the roughness element and the ratio of roughness due to spacing between an adjacent pair of elements. Results are used for a preliminary assessment of the differences between recently reported theoretical results of Tumin and Reshotko and the measurements by White and Ergin.

Representation of Vegetation and Other Nonerodible Elements in Aeolian Shear Stress Partitioning Models for Predicting Transport Threshold

NASA Technical Reports Server (NTRS)

King, James; Nickling, William G.; Gillies, John A.

2005-01-01

The presence of nonerodible elements is well understood to be a reducing factor for soil erosion by wind, but the limits of its protection of the surface and erosion threshold prediction are complicated by the varying geometry, spatial organization, and density of the elements. The predictive capabilities of the most recent models for estimating wind driven particle fluxes are reduced because of the poor representation of the effectiveness of vegetation to reduce wind erosion. Two approaches have been taken to account for roughness effects on sediment transport thresholds. Marticorena and Bergametti (1995) in their dust emission model parameterize the effect of roughness on threshold with the assumption that there is a relationship between roughness density and the aerodynamic roughness length of a surface. Raupach et al. (1993) offer a different approach based on physical modeling of wake development behind individual roughness elements and the partition of the surface stress and the total stress over a roughened surface. A comparison between the models shows the partitioning approach to be a good framework to explain the effect of roughness on entrainment of sediment by wind. Both models provided very good agreement for wind tunnel experiments using solid objects on a nonerodible surface. However, the Marticorena and Bergametti (1995) approach displays a scaling dependency when the difference between the roughness length of the surface and the overall roughness length is too great, while the Raupach et al. (1993) model's predictions perform better owing to the incorporation of the roughness geometry and the alterations to the flow they can cause.

Prostate cancer diagnosis in a resource-poor setting: the changing role of digital rectal examination.

PubMed

Ahmed, Muhammed

2011-07-01

We undertook this study in order to determine the current role of digital rectal examination (DRE) in the diagnosis of prostate cancer in a resource-poor setting. The diagnosis of prostate cancer has been revolutionized by the introduction of prostate-specific antigen (PSA), transrectal ultrasound (TRUS) for biopsy guidance and more efficient biopsy equipment, but they are not readily available in most developing countries. This is a prospective study of 131 patients with suspected prostate cancer based on clinical presentation, DRE and elevated PSA. The presence or absence of cancer was confirmed by biopsy and histologic examination. Patients with screen- or incidentally-detected prostate cancer were excluded. The most common symptom was the development of lower urinary tract symptoms (LUTS). All patients had abnormal DRE and indurated prostate was the most frequent finding (50%). The mean PSA was 33.9 ng/mL: of the 131 patients, 80 (61.1%) had a malignant histology following biopsy, 47 (35.9%) were benign and four (3.0%) were prostate intraepithelial neoplasia (PIN). The low specificity of DRE in the diagnosis of prostate cancer requires that it should be combined with other diagnostic modalities such as PSA and TRUS-guided prostate biopsy. Thus government and health-care providers in resource-poor countries must strive to make these facilities available in order to improve prostate cancer diagnosis.

Spatial characteristics of secondary flow in a turbulent boundary layer over longitudinal surface roughness

NASA Astrophysics Data System (ADS)

Hwang, Hyeon Gyu; Lee, Jae Hwa

2017-11-01

Direct numerical simulations of turbulent boundary layers (TBLs) over spanwise heterogeneous surface roughness are performed to investigate the characteristics of secondary flow. The longitudinal surface roughness, which features lateral change in bed elevation, is described by immersed boundary method. The Reynolds number based on the momentum thickness is varied in the range of Reθ = 300-900. As the TBLs over the roughness elements spatially develop in the streamwise direction, a secondary flow emerges in a form of counter-rotating vortex pair. As the spanwise spacing between the roughness elements and roughness width vary, it is shown that the size of the secondary flow is determined by the valley width between the roughness elements. In addition, the strength of the secondary flow is mostly affected by the spanwise distance between the cores of the secondary flow. Analysis of the Reynolds-averaged turbulent kinetic energy transport equation reveals that the energy redistribution terms in the TBLs over-the ridge type roughness play an important role to derive low-momentum pathways with upward motion over the roughness crest, contrary to the previous observation with the strip-type roughness. This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A1A09000537) and the Ministry of Science, ICT & Future Planning (NRF-2017R1A5A1015311).

Ten-core versus 16-core transrectal ultrasonography guided prostate biopsy for detection of prostatic carcinoma: a prospective comparative study in Indian population

PubMed Central

Prakash, V. Surya; Mohan, G. Chandra; Krishnaiah, S. Venkata; Vijaykumar, V.; Babu, G. Ramesh; Reddy, G. Vijaya Bhaskar; Mahaboob, V. S.

2013-01-01

Purpose: To compare the cancer detection rate in patients with raised serum prostate-specific antigen (PSA) or abnormal digital rectal examination (DRE) results between the 10-core and the 16-core biopsy techniques in an Indian population. Methods: Between November 2010 and November 2012, 95 men aged >50 years who presented to the Urology Department with lower urinary tract symptoms, elevated serum PSA, and/or abnormal DRE findings underwent transrectal ultrasonography (TRUS)-guided prostate biopsy. A total of 53 patients underwent 10-core biopsy and 42 patients underwent 16-core biopsy. Results: Of the 53 men in the 10-core group, 8 had cancer, whereas in the 16-core biopsy group, 23 of 42 men had cancer. Detection of prostate cancer was significantly higher in patients who underwent 16-core biopsy than in those who underwent 10-core biopsy (P<0.001). Among the 95 men, 44 men had abnormal DRE findings (46.3%), of whom 23 showed cancer (52.27%). Of 51 men with normal DRE findings and elevated PSA, 8 men had malignancy with a cancer detection rate of 15.68%. Among 20 men with PSA between 4.1 and 10 ng/mL, 2 (10%) had cancer. In 31 men with PSA between 10.1 and 20 ng/mL, 3 cancers (9.67%) were detected, and in 44 men with PSA >20 ng/mL, 26 cancers were detected (59.09%). Conclusions: The cancer detection rate with 16-core TRUS-guided biopsy is significantly higher than that with 10-core biopsy (54.76% vs. 15.09%, P<0.001). In patients with both normal and abnormal DRE findings, 16-core biopsy has a better detection rate than the 10-core biopsy protocol. With increasing PSA, there is a high rate of detection of prostate cancer in both 10-core and 16-core biopsy patients. PMID:24392441

Ten-core versus 16-core transrectal ultrasonography guided prostate biopsy for detection of prostatic carcinoma: a prospective comparative study in Indian population.

PubMed

Prakash, V Surya; Mohan, G Chandra; Krishnaiah, S Venkata; Vijaykumar, V; Babu, G Ramesh; Reddy, G Vijaya Bhaskar; Mahaboob, V S

2013-01-01

To compare the cancer detection rate in patients with raised serum prostate-specific antigen (PSA) or abnormal digital rectal examination (DRE) results between the 10-core and the 16-core biopsy techniques in an Indian population. Between November 2010 and November 2012, 95 men aged >50 years who presented to the Urology Department with lower urinary tract symptoms, elevated serum PSA, and/or abnormal DRE findings underwent transrectal ultrasonography (TRUS)-guided prostate biopsy. A total of 53 patients underwent 10-core biopsy and 42 patients underwent 16-core biopsy. Of the 53 men in the 10-core group, 8 had cancer, whereas in the 16-core biopsy group, 23 of 42 men had cancer. Detection of prostate cancer was significantly higher in patients who underwent 16-core biopsy than in those who underwent 10-core biopsy (P<0.001). Among the 95 men, 44 men had abnormal DRE findings (46.3%), of whom 23 showed cancer (52.27%). Of 51 men with normal DRE findings and elevated PSA, 8 men had malignancy with a cancer detection rate of 15.68%. Among 20 men with PSA between 4.1 and 10 ng/mL, 2 (10%) had cancer. In 31 men with PSA between 10.1 and 20 ng/mL, 3 cancers (9.67%) were detected, and in 44 men with PSA >20 ng/mL, 26 cancers were detected (59.09%). The cancer detection rate with 16-core TRUS-guided biopsy is significantly higher than that with 10-core biopsy (54.76% vs. 15.09%, P<0.001). In patients with both normal and abnormal DRE findings, 16-core biopsy has a better detection rate than the 10-core biopsy protocol. With increasing PSA, there is a high rate of detection of prostate cancer in both 10-core and 16-core biopsy patients.

Exploring the observational constraints on the simulation of brown carbon

NASA Astrophysics Data System (ADS)

Wang, Xuan; Heald, Colette L.; Liu, Jiumeng; Weber, Rodney J.; Campuzano-Jost, Pedro; Jimenez, Jose L.; Schwarz, Joshua P.; Perring, Anne E.

2018-01-01

Organic aerosols (OA) that strongly absorb solar radiation in the near-UV are referred to as brown carbon (BrC). The sources, evolution, and optical properties of BrC remain highly uncertain and contribute significantly to uncertainty in the estimate of the global direct radiative effect (DRE) of aerosols. Previous modeling studies of BrC optical properties and DRE have been unable to fully evaluate model performance due to the lack of direct measurements of BrC absorption. In this study, we develop a global model simulation (GEOS-Chem) of BrC and test it against BrC absorption measurements from two aircraft campaigns in the continental US (SEAC4RS and DC3). To the best of our knowledge, this is the first study to compare simulated BrC absorption with direct aircraft measurements. We show that BrC absorption properties estimated based on previous laboratory measurements agree with the aircraft measurements of freshly emitted BrC absorption but overestimate aged BrC absorption. In addition, applying a photochemical scheme to simulate bleaching/degradation of BrC improves model skill. The airborne observations are therefore consistent with a mass absorption coefficient (MAC) of freshly emitted biomass burning OA of 1.33 m2 g-1 at 365 nm coupled with a 1-day whitening e-folding time. Using the GEOS-Chem chemical transport model integrated with the RRTMG radiative transfer model, we estimate that the top-of-the-atmosphere all-sky direct radiative effect (DRE) of OA is -0.344 Wm-2, 10 % higher than that without consideration of BrC absorption. Therefore, our best estimate of the absorption DRE of BrC is +0.048 Wm-2. We suggest that the DRE of BrC has been overestimated previously due to the lack of observational constraints from direct measurements and omission of the effects of photochemical whitening.

2013 Annual National Digital Rectal Exam Day: impact on prostate health awareness and disease detection.

PubMed

Chua, Michael E; Lapitan, Marie Carmela M; Morales, Marcelino L; Roque, Aristotle Bernard Maniego; Domingo, John Kenneth

2014-03-01

"Mag-paDRE" is a yearly prostate health public awareness program initiated by the Philippine Urological Association. This study aimed to describe the demographic and clinical data of the participants in the 2013 "Mag-paDRE" program and to identify factors that will further improve prostate health public awareness. A descriptive cross-sectional study undertaken to collect and assess the demographic data, International Prostate Symptom Score (IPSS) and digital rectal examination findings of the participants in the "Mag-paDRE" conducted in the 10 Philippine Board of Urology (PBU) different accredited training institutions. Descriptive statistics was used to report the proportion of Filipino men aged 40 or older who presented for their first prostate health evaluation. Clinical profile were reviewed and summarized. The study protocol was registered in the Clinicaltrial.gov under Identifier NCT01886547. A total of 925 participants from the 10 PBU accredited training institutions were assessed. Among the 10 training institutions the large tertiary government owned medical center had the highest number of participants and target participants recruited; while the private sectors owned tertiary hospitals have the highest proportion of target participants and cases. According to the predetermined definition of this study, 614 (66%) were considered the target population for the "Mag-paDRE" program. The mean age of the target participants was 58.9±9.9. Only 360 of 614 (59%) were new case, 118 (32.7%) had severe lower urinary tract symptoms (LUTS), 223 (62%) had moderate LUTS, 19 (5.3%) were asymptomatic but with hard prostates, palpable prostate nodules or prostate tenderness. The most bothersome symptoms were incomplete bladder emptying (30.2%), and frequency (22.9%). Overall, the 2013 "Mag-paDRE" among the 10 training institutions was effective in promoting prostate health awareness. A need to modify the preactivity information dissemination by these institutions can be done to further increase the attendance of targeted population of the prostate health awareness program.

Flow transition with 2-D roughness elements in a 3-D channel

NASA Technical Reports Server (NTRS)

Liu, Zhining; Liu, Chaoquin; Mccormick, Stephen F.

1993-01-01

We develop a new numerical approach to study the spatially evolving instability of the streamwise dominant flow in the presence of roughness elements. The difficulty in handling the flow over the boundary surface with general geometry is removed by using a new conservative form of the governing equations and an analytical mapping. The numerical scheme uses second-order backward Euler in time, fourth-order central differences in all three spatial directions, and boundary-fitted staggered grids. A three-dimensional channel with multiple two-dimensional-type roughness elements is employed as the test case. Fourier analysis is used to decompose different Fourier modes of the disturbance. The results show that surface roughness leads to transition at lower Reynolds number than for smooth channels.

On the receptivity problem for Goertler vortices: Vortex motions induced by wall roughness

NASA Technical Reports Server (NTRS)

Denier, James P.; Hall, Philip; Seddougui, Sharon

1990-01-01

The receptivity problem for Goertler vortices induced by wall roughness is investigated. The roughness is modelled by small amplitude perturbations to the curved wall over which the flow takes place. The amplitude of these perturbations is taken to be sufficiently small for the induced Goertler vortices to be described by linear theory. The roughness is assumed to vary in the spanwise direction on the boundary layer lengthscale, while in the flow direction the corresponding variation is on the lengthscale over which the wall curvature varies. In fact the latter condition can be relaxed to allow for a faster streamwise roughness variation so long as the variation does not become as fast as that in the spanwise direction. The function which describes the roughness is assumed to be such that its spanwise and streamwise dependences can be separated; this enables progress by taking Fourier or Laplace transforms where appropriate. The cases of isolated and distributed roughness elements are investigated and the coupling coefficient which relates the amplitude of the forcing and the induced vortex amplitude is found asymptotically in the small wavelength limit. It is shown that this coefficient is exponentially small in the latter limit so that it is unlikely that this mode can be stimulated directly by wall roughness. The situation at 0(1) wavelengths is quite different and this is investigated numerically for different forcing functions. It is found that an isolated roughness element induces a vortex field which grows within a wedge at a finite distance downstream of the element. However, immediately downstream of the obstacle the disturbed flow produced by the element decays in amplitude. The receptivity problem at larger Goertler numbers appropriate to relatively large wall curvature is discussed in detail.

Recycling inflow method for simulations of spatially evolving turbulent boundary layers over rough surfaces

NASA Astrophysics Data System (ADS)

Yang, Xiang I. A.; Meneveau, Charles

2016-01-01

The technique by Lund et al. to generate turbulent inflow for simulations of developing boundary layers over smooth flat plates is extended to the case of surfaces with roughness elements. In the Lund et al. method, turbulent velocities on a sampling plane are rescaled and recycled back to the inlet as inflow boundary condition. To rescale mean and fluctuating velocities, appropriate length scales need be identified and for smooth surfaces, the viscous scale lν = ν/uτ (where ν is the kinematic viscosity and uτ is the friction velocity) is employed for the inner layer. Different from smooth surfaces, in rough wall boundary layers the length scale of the inner layer, i.e. the roughness sub-layer scale ld, must be determined by the geometric details of the surface roughness elements and the flow around them. In the proposed approach, it is determined by diagnosing dispersive stresses that quantify the spatial inhomogeneity caused by the roughness elements in the flow. The scale ld is used for rescaling in the inner layer, and the boundary layer thickness δ is used in the outer region. Both parts are then combined for recycling using a blending function. Unlike the blending function proposed by Lund et al. which transitions from the inner layer to the outer layer at approximately 0.2δ, here the location of blending is shifted upwards to enable simulations of very rough surfaces in which the roughness length may exceed the height of 0.2δ assumed in the traditional method. The extended rescaling-recycling method is tested in large eddy simulation of flow over surfaces with various types of roughness element shapes.

Add-on perampanel and aggressive behaviour in severe drug-resistant focal epilepsies.

PubMed

Juhl, S; Rubboli, G

This study aimed to investigate the incidence of aggressiveness in patients with severe drug-refractory focal epilepsy (DRE) who started perampanel (PER) as add-on treatment, and to identify possible predisposing factors. Data on 49 consecutive patients with severe DRE who initiated PER were retrospectively collected. Twelve of the 49 patients experienced aggressiveness as adverse event related to PER treatment, one third of them on low (2-4 mg/day) PER dosages. PER was discontinued in 10/12 patients because of aggressive behaviors. Aggressiveness could appear after several months or even more than one year of PER treatment. One third of patients with PER-related aggressiveness had intellectual disabilities and 5/12 patients took levetiracetam as a concomitant antiepileptic drug. Our study suggests that the occurrence of aggressive behaviors in patients with severe DRE is not uncommon during PER treatment and that it may occur after months or even years of treatment with a stable dosage, requiring PER discontinuation in the great majority of patients.

An Agent-Based Modeling Framework and Application for the Generic Nuclear Fuel Cycle

NASA Astrophysics Data System (ADS)

Gidden, Matthew J.

Key components of a novel methodology and implementation of an agent-based, dynamic nuclear fuel cycle simulator, Cyclus , are presented. The nuclear fuel cycle is a complex, physics-dependent supply chain. To date, existing dynamic simulators have not treated constrained fuel supply, time-dependent, isotopic-quality based demand, or fuel fungibility particularly well. Utilizing an agent-based methodology that incorporates sophisticated graph theory and operations research techniques can overcome these deficiencies. This work describes a simulation kernel and agents that interact with it, highlighting the Dynamic Resource Exchange (DRE), the supply-demand framework at the heart of the kernel. The key agent-DRE interaction mechanisms are described, which enable complex entity interaction through the use of physics and socio-economic models. The translation of an exchange instance to a variant of the Multicommodity Transportation Problem, which can be solved feasibly or optimally, follows. An extensive investigation of solution performance and fidelity is then presented. Finally, recommendations for future users of Cyclus and the DRE are provided.

Numerical analysis of the effect of surface roughness on mechanical fields in polycrystalline aggregates

NASA Astrophysics Data System (ADS)

Guilhem, Yoann; Basseville, Stéphanie; Curtit, François; Stéphan, Jean-Michel; Cailletaud, Georges

2018-06-01

This paper is dedicated to the study of the influence of surface roughness on local stress and strain fields in polycrystalline aggregates. Finite element computations are performed with a crystal plasticity model on a 316L stainless steel polycrystalline material element with different roughness states on its free surface. The subsequent analysis of the plastic strain localization patterns shows that surface roughness strongly affects the plastic strain localization induced by crystallography. Nevertheless, this effect mainly takes place at the surface and vanishes under the first layer of grains, which implies the existence of a critical perturbed depth. A statistical analysis based on the plastic strain distribution obtained for different roughness levels provides a simple rule to define the size of the affected zone depending on the rough surface parameters.

High-Speed Boundary-Layer Transition Induced by an Isolated Roughness Element

NASA Technical Reports Server (NTRS)

Kegerise, Michael A.; Owens, Lewis R.; King, Rudolph A.

2010-01-01

Progress on an experimental effort to quantify the instability mechanisms associated with roughness-induced transition in a high-speed boundary layer is reported in this paper. To simulate the low-disturbance environment encountered during high-altitude flight, the experimental study was performed in the NASA-Langley Mach 3.5 Supersonic Low-Disturbance Tunnel. A flat plate trip sizing study was performed first to identify the roughness height required to force transition. That study, which included transition onset measurements under both quiet and noisy freestream conditions, confirmed the sensitivity of roughness-induced transition to freestream disturbance levels. Surveys of the laminar boundary layer on a 7deg half-angle sharp-tipped cone were performed via hot-wire anemometry and pitot-pressure measurements. The measured mean mass-flux and Mach-number profiles agreed very well with computed mean-flow profiles. Finally, surveys of the boundary layer developing downstream of an isolated roughness element on the cone were performed. The measurements revealed an instability in the far wake of the roughness element that grows exponentially and has peak frequencies in the 150 to 250 kHz range.

Effect of sound on boundary layer stability

NASA Technical Reports Server (NTRS)

Saric, William S. (Principal Investigator); Spencer, Shelly Anne

1993-01-01

Experiments are conducted in the Arizona State University Unsteady Wind Tunnel with a zero-pressure-gradient flat-plate model that has a 67:1 elliptical leading edge. Boundary-layer measurements are made of the streamwise fluctuating-velocity component in order to identify the amplified T-S waves that are forced by downstream-travelling, sound waves. Measurements are taken with circular 3-D roughness elements placed at the Branch 1 neutral stability point for the frequency under consideration, and then with the roughness element downstream of Branch 1. These roughness elements have a principal chord dimension equal to 2(lambda)(sub TS)/pi, of the T-S waves under study and are 'stacked' in order to resemble a Gaussian height distribution. Measurements taken just downstream of the roughness (with leading-edge T-S waves, surface roughness T-S waves, instrumentation sting vibrations and the Stokes wave subtracted) show the generation of 3-D-T-S waves, but not in the characteristic heart-shaped disturbance field predicted by 3-D asymptotic theory. Maximum disturbance amplitudes are found on the roughness centerline. However, some near-field characteristics predicted by numerical modelling are observed.

Effect of sound on boundary layer stability

NASA Technical Reports Server (NTRS)

Saric, William S.; Spencer, Shelly Anne

1993-01-01

Experiments are conducted in the Arizona State University Unsteady Wind Tunnel with a zero-pressure-gradient flat-plate model that has a 67:1 elliptical leading edge. Boundary-layer measurements are made of the streamwise fluctuating-velocity component in order to identify the amplified T-S waves that are forced by downstream-traveling sound waves. Measurements are taken with circular 3-D roughness elements placed at the Branch 1 neutral stability point for the frequency under consideration, and then with the roughness element downstream of Branch 1. These roughness elements have a principal chord dimension equal to 2 lambda(sub TS)/pi of the T-S waves under study and are 'stacked' in order to resemble a Gaussian height distribution. Measurements taken just downstream of the roughness (with leading-edge T-S waves, surface roughness T-S waves, instrumentation sting vibrations, and the Stokes wave subtracted) show the generation of 3-D T-S waves, but not in the characteristic heart-shaped disturbance field predicted by 3-D asymptotic theory. Maximum disturbance amplitudes are found on the roughness centerline. However, some near-field characteristics predicted by numerical modeling are observed.

Assessment of removal efficiency of perfluorocompounds (PFCs) in a semiconductor fabrication plant by gas chromatography.

PubMed

Ou Yang, Chang-Feng; Kam, Seak-Hong; Liu, Chia-Hung; Tzou, Jiren; Wang, Jia-Lin

2009-08-01

This study investigated a gas chromatographic (GC) method to assess the destruction or removal efficiency (DRE) of local scrubbers on five perfluorocompounds (PFCs), i.e., SF(6), NF(3), CF(4), C(2)F(6), and C(3)F(8), which are very potent greenhouse gases used in a semiconductor fabrication plant. Air samples taken at inlets and outlets of local scrubbers were analyzed by a self-constructed multi-column GC system equipped with thermal conductivity detection. Three packed columns were integrated into the heart-cut GC system to allow simultaneous analysis of the five target PFCs. The Porapak Q pre-column performs rough separation and cuts eluent groups to two analytical columns for optimal separation. The Molecular Sieve - 5A column separated NF(3), CF(4), and C(3)F(8) and the second Porapak Q separated SF(6) and C(2)F(6). Linearity was greater than 0.995 (R(2)) for the five PFCs, and the reproducibility was about 4% (relative standard deviation) for NF(3), and better than 0.5% for the other four PFCs. DRE for the combustion (CB) and electric-thermal types of local scrubbers was evaluated by taking into account the in-line dilution from air and fuel gases. Both flow and tracer methods were employed to deduce the dilution factors (DFs). For the tracer method, helium was employed as the tracer and injected upstream of the scrubbers and thus mixed with the exhaust gas. With this method, the DFs were determined to be in the range from 4.8 to 5.9 for the CB unit, significantly higher than the value of 3.3 based on the flow method. The DREs for the CB unit for C(3)F(8) were greater than 90% and between 40% and 50% for CF(4).

A validation of the new definition of drug-resistant epilepsy by the International League Against Epilepsy.

PubMed

Téllez-Zenteno, Jose F; Hernández-Ronquillo, Lizbeth; Buckley, Samantha; Zahagun, Ricardo; Rizvi, Syed

2014-06-01

To establish applicability, the recently proposed International League Against Epilepsy (ILAE) consensus on drug-resistant epilepsy (DRE) requires testing in clinical and research settings. This study evaluates the reliability and validity of these criteria in a clinical population. In phase I, two independent evaluators reviewed 97 randomly selected medical records of patients with epilepsy at two separate intervals. Both ILEA consensus and standard diagnostic criteria were employed. Kappa, weighted kappa, and intraclass correlation coefficient (ICC) were used to determine interobserver and intraobserver variability. In phase II, ILAE consensus criteria were applied to 250 patients with epilepsy to determine risk factors associated with development of DRE and to calculate point prevalence. The interobserver agreement of the four definitions was as follows: Berg (0.56), Kwan and Brodie (0.58), Camfield and Camfield (0.69), and ILAE (0.77). The intraobserver agreement of the four definition was as follows: Berg (0.81), Kwan and Brodie (0.82), Camfield and Camfield (0.72), and ILAE (0.82). The prevalence of DRE was the following: with the Berg's definition was 28.4%, Kwan and Brodie 34%, Camfield and Camfield 37%, and with ILAE was 33%. This is first study to establish reliability and validity of ILAE criteria for the diagnosis of DRE. This new definition compares favorably with previously established constructs, which continue to retain clinical significance. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

Effects of Roof-Edge Roughness on Air Temperature and Pollutant Concentration in Urban Canyons

NASA Astrophysics Data System (ADS)

Aliabadi, Amir A.; Krayenhoff, E. Scott; Nazarian, Negin; Chew, Lup Wai; Armstrong, Peter R.; Afshari, Afshin; Norford, Leslie K.

2017-08-01

The influence of roof-edge roughness elements on airflow, heat transfer, and street-level pollutant transport inside and above a two-dimensional urban canyon is analyzed using an urban energy balance model coupled to a large-eddy simulation model. Simulations are performed for cold (early morning) and hot (mid afternoon) periods during the hottest month of the year (August) for the climate of Abu Dhabi, United Arab Emirates. The analysis suggests that early in the morning, and when the tallest roughness elements are implemented, the temperature above the street level increases on average by 0.5 K, while the pollutant concentration decreases by 2% of the street-level concentration. For the same conditions in mid afternoon, the temperature decreases conservatively by 1 K, while the pollutant concentration increases by 7% of the street-level concentration. As a passive or active architectural solution, the roof roughness element shows promise for improving thermal comfort and air quality in the canyon for specific times, but this should be further verified experimentally. The results also warrant a closer look at the effects of mid-range roughness elements in the urban morphology on atmospheric dynamics so as to improve parametrizations in mesoscale modelling.

Hypersonic Viscous Flow Over Large Roughness Elements

NASA Technical Reports Server (NTRS)

Chang, Chau-Lyan; Choudhari, Meelan M.

2009-01-01

Viscous flow over discrete or distributed surface roughness has great implications for hypersonic flight due to aerothermodynamic considerations related to laminar-turbulent transition. Current prediction capability is greatly hampered by the limited knowledge base for such flows. To help fill that gap, numerical computations are used to investigate the intricate flow physics involved. An unstructured mesh, compressible Navier-Stokes code based on the space-time conservation element, solution element (CESE) method is used to perform time-accurate Navier-Stokes calculations for two roughness shapes investigated in wind tunnel experiments at NASA Langley Research Center. It was found through 2D parametric study that at subcritical Reynolds numbers of the boundary layers, absolute instability resulting in vortex shedding downstream, is likely to weaken at supersonic free-stream conditions. On the other hand, convective instability may be the dominant mechanism for supersonic boundary layers. Three-dimensional calculations for a rectangular or cylindrical roughness element at post-shock Mach numbers of 4.1 and 6.5 also confirm that no self-sustained vortex generation is present.

Form drag in rivers due to small-scale natural topographic features: 1. Regular sequences

USGS Publications Warehouse

Kean, J.W.; Smith, J.D.

2006-01-01

Small-scale topographic features are commonly found on the boundaries of natural rivers, streams, and floodplains. A simple method for determining the form drag on these features is presented, and the results of this model are compared to laboratory measurements. The roughness elements are modeled as Gaussian-shaped features defined in terms of three parameters: a protrusion height, H; a streamwise length scale, ??; and a spacing between crests, ??. This shape is shown to be a good approximation to a wide variety of natural topographic bank features. The form drag on an individual roughness element embedded in a series of identical elements is determined using the drag coefficient of the individual element and a reference velocity that includes the effects of roughness elements further upstream. In addition to calculating the drag on each element, the model determines the spatially averaged total stress, skin friction stress, and roughness height of the boundary. The effects of bank roughness on patterns of velocity and boundary shear stress are determined by combining the form drag model with a channel flow model. The combined model shows that drag on small-scale topographic features substantially alters the near-bank flow field. These methods can be used to improve predictions of flow resistance in rivers and to form the basis for fully predictive (no empirically adjusted parameters) channel flow models. They also provide a foundation for calculating the near-bank boundary shear stress fields necessary for determining rates of sediment transport and lateral erosion.

Constitutive expression of DaCBF7, an Antarctic vascular plant Deschampsia antarctica CBF homolog, resulted in improved cold tolerance in transgenic rice plants.

PubMed

Byun, Mi Young; Lee, Jungeun; Cui, Li Hua; Kang, Yoonjee; Oh, Tae Kyung; Park, Hyun; Lee, Hyoungseok; Kim, Woo Taek

2015-07-01

Deschampsia antarctica is an Antarctic hairgrass that grows on the west coast of the Antarctic peninsula. In this report, we have identified and characterized a transcription factor, D. antarctica C-repeat binding factor 7 (DaCBF7), that is a member of the monocot group V CBF homologs. The protein contains a single AP2 domain, a putative nuclear localization signal, and the typical CBF signature. DaCBF7, like other monocot group V homologs, contains a distinct polypeptide stretch composed of 43 amino acids in front of the AP2 motif. DaCBF7 was predominantly localized to nuclei and interacted with the C-repeat/dehydration responsive element (CRT/DRE) core sequence (ACCGAC) in vitro. DaCBF7 was induced by abiotic stresses, including drought, cold, and salinity. To investigate its possible cellular role in cold tolerance, a transgenic rice system was employed. DaCBF7-overexpressing transgenic rice plants (Ubi:DaCBF7) exhibited markedly increased tolerance to cold stress compared to wild-type plants without growth defects; however, overexpression of DaCBF7 exerted little effect on tolerance to drought or salt stress. Transcriptome analysis of a Ubi:DaCBF7 transgenic line revealed 13 genes that were up-regulated in DaCBF7-overexpressing plants compared to wild-type plants in the absence of cold stress and in short- or long-term cold stress. Five of these genes, dehydrin, remorin, Os03g63870, Os11g34790, and Os10g22630, contained putative CRT/DRE or low-temperature responsive elements in their promoter regions. These results suggest that overexpression of DaCBF7 directly and indirectly induces diverse genes in transgenic rice plants and confers enhanced tolerance to cold stress. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Drosophila myeloid leukemia factor acts with DREF to activate the JNK signaling pathway

PubMed Central

Yanai, H; Yoshioka, Y; Yoshida, H; Nakao, Y; Plessis, A; Yamaguchi, M

2014-01-01

Drosophila myelodysplasia/myeloid leukemia factor (dMLF), a homolog of human MLF1, oncogene was first identified by yeast two-hybrid screen using the DNA replication-related element-binding factor (DREF) as bait. DREF is a transcription factor that regulates proliferation-related genes in Drosophila. It is known that overexpression of dMLF in the wing imaginal discs through the engrailed-GAL4 driver causes an atrophied wing phenotype associated with the induction of apoptosis. However, the precise mechanisms involved have yet to be clarified. Here, we found the atrophied phenotype to be suppressed by loss-of-function mutation of Drosophila Jun N-terminal kinase (JNK), basket (bsk). Overexpression of dMLF induced ectopic JNK activation in the wing disc monitored with the puckered-lacZ reporter line, resulting in induction of apoptosis. The DREF-binding consensus DRE sequence could be shown to exist in the bsk promoter. Chromatin immunoprecipitation assays in S2 cells with anti-dMLF IgG and quantitative real-time PCR revealed that dMLF binds specifically to the bsk promoter region containing the DRE sequence. Furthermore, using a transient luciferase expression assay, we provide evidence that knockdown of dMLF reduced bsk gene promoter activity in S2 cells. Finally, we show that dMLF interacts with DREF in vivo. Altogether, these data indicate that dMLF acts with DREF to stimulate the bsk promoter and consequently activates the JNK pathway to promote apoptosis. PMID:24752236

Drosophila myeloid leukemia factor acts with DREF to activate the JNK signaling pathway.

PubMed

Yanai, H; Yoshioka, Y; Yoshida, H; Nakao, Y; Plessis, A; Yamaguchi, M

2014-04-21

Drosophila myelodysplasia/myeloid leukemia factor (dMLF), a homolog of human MLF1, oncogene was first identified by yeast two-hybrid screen using the DNA replication-related element-binding factor (DREF) as bait. DREF is a transcription factor that regulates proliferation-related genes in Drosophila. It is known that overexpression of dMLF in the wing imaginal discs through the engrailed-GAL4 driver causes an atrophied wing phenotype associated with the induction of apoptosis. However, the precise mechanisms involved have yet to be clarified. Here, we found the atrophied phenotype to be suppressed by loss-of-function mutation of Drosophila Jun N-terminal kinase (JNK), basket (bsk). Overexpression of dMLF induced ectopic JNK activation in the wing disc monitored with the puckered-lacZ reporter line, resulting in induction of apoptosis. The DREF-binding consensus DRE sequence could be shown to exist in the bsk promoter. Chromatin immunoprecipitation assays in S2 cells with anti-dMLF IgG and quantitative real-time PCR revealed that dMLF binds specifically to the bsk promoter region containing the DRE sequence. Furthermore, using a transient luciferase expression assay, we provide evidence that knockdown of dMLF reduced bsk gene promoter activity in S2 cells. Finally, we show that dMLF interacts with DREF in vivo. Altogether, these data indicate that dMLF acts with DREF to stimulate the bsk promoter and consequently activates the JNK pathway to promote apoptosis.

Discrete surface roughness effects on a blunt hypersonic cone in a quiet tunnel

NASA Astrophysics Data System (ADS)

Sharp, Nicole; White, Edward

2013-11-01

The mechanisms by which surface roughness creates boundary-layer disturbances in hypersonic flow are little understood. Work by Reshotko (AIAA 2008-4294) and others suggests that transient growth, resulting from the superposition of decaying non-orthogonal modes, may be responsible. The present study examines transient growth experimentally using a smooth 5-degree half-angle conic frustum paired with blunted nosetips with and without an azimuthal array of discrete roughness elements. A combination of hotwire anemometry and Pitot measurements in the low-disturbance Mach 6 Quiet Tunnel are used for boundary layer profiles downstream of the ring of roughness elements as well as azimuthal measurements to examine the high- and low-speed streaks characteristic of transient growth of stationary roughness-induced disturbances.

Tomographic PIV investigation of roughness-induced transition in a hypersonic boundary layer

NASA Astrophysics Data System (ADS)

Avallone, F.; Ye, Q.; Schrijer, F. F. J.; Scarano, F.; Cardone, G.

2014-11-01

The disturbance generated by roughness elements in a hypersonic laminar boundary layer is investigated, with attention to its three-dimensional properties. The transition of the boundary layer is inspected with tomographic particle image velocimetry that is applied for the first time at Mach 7.5 inside a short duration hypersonic wind tunnel. A low aspect ratio cylindrical roughness element is installed on a flat plate, and experiments are conducted downstream of the element describing the mean velocity field and the turbulent fluctuations. Details of the experimental procedure needed to realize these measurements are discussed, along with the fluid dynamic behaviour of the perturbed hypersonic boundary layer.

Prostate cancer marker panel with single cell sensitivity in urine.

PubMed

Nickens, Kristen P; Ali, Amina; Scoggin, Tatiana; Tan, Shyh-Han; Ravindranath, Lakshmi; McLeod, David G; Dobi, Albert; Tacha, David; Sesterhenn, Isabell A; Srivastava, Shiv; Petrovics, Gyorgy

2015-06-15

Over one million men undergo prostate biopsies annually in the United States, a majority of whom due to elevated serum PSA. More than half of the biopsies turn out to be negative for prostate cancer (CaP). The limitations of both the PSA test and the biopsy procedure have led to the development for more precise CaP detection assays in urine (e.g., PCA3, TMPRSS2-ERG) or blood (e.g., PHI, 4K). Here, we describe the development and evaluation of the Urine CaP Marker Panel (UCMP) assay for sensitive and reproducible detection of CaP cells in post-digital rectal examination (post-DRE) urine. The cellular content of the post-DRE urine was captured on a translucent filter membrane, which is placed on Cytoclear slides for direct evaluation by microscopy and immuno-cytochemistry (ICC). Cells captured on the membrane were assayed for PSA and Prostein expression to identify prostate epithelial cells, and for ERG and AMACR to identify prostate tumor cells. Immunostained cells were analyzed for quantitative and qualitative features and correlated with biopsy positive and negative status for malignancy. The assay was optimized for single cell capture sensitivity and downstream evaluations by spiking a known number of cells from established CaP cell lines, LNCaP and VCaP, into pre-cleared control urine. The cells captured from the post-DRE urine of subjects, obtained prior to biopsy procedure, were co-stained for ERG, AMACR (CaP specific), and Prostein or PSA (prostate epithelium specific) rendering a whole cell based analysis and characterization. A feasibility cohort of 63 post-DRE urine specimens was assessed. Comparison of the UCMP results with blinded biopsy results showed an assay sensitivity of 64% (16 of 25) and a specificity of 68.8% (22 of 32) for CaP detection by biopsy. This pilot study assessing a minimally invasive CaP detection assay with single cell sensitivity cell-capture and characterization from the post-DRE urine holds promise for further development of this novel assay platform. Prostate 75: 969-975, 2015. © 2015 The Authors. The Prostate, published by Wiley Periodicals, Inc. © 2015 The Authors. The Prostate, published by Wiley Periodicals, Inc.

Characterization of hypersonic roughness-induced boundary-layer transition

NASA Astrophysics Data System (ADS)

Tirtey, S. C.; Chazot, O.; Walpot, L.

2011-02-01

The flow-field structure in the vicinity and in the wake of an isolated 3D roughness element has been studied. Different experimental techniques have been coupled and supported by CFD simulation for a good understanding of the flow-field topology. The results have shown strong flow-field similarities for different roughness elements. A model describing the flow structure and interaction mechanisms has been proposed. This model is in good agreement with experimental and CFD results as well as the literature.

Direct radiative effects of aerosols over South Asia from observations and modeling

NASA Astrophysics Data System (ADS)

Nair, Vijayakumar S.; Babu, S. Suresh; Manoj, M. R.; Moorthy, K. Krishna; Chin, Mian

2017-08-01

Quantitative assessment of the seasonal variations in the direct radiative effect (DRE) of composite aerosols as well as the constituent species over the Indian sub continent has been carried out using a synergy of observations from a dense network of ground based aerosol observatories and modeling based on chemical transport model simulations. Seasonal variation of aerosol constituents depict significant influence of anthropogenic aerosol sources in winter and the dominance of natural sources in spring, even though the aerosol optical depth doesn't change significantly between these two seasons. A significant increase in the surface cooling and atmospheric warming has been observed as season changes from winter (DRESUR = -28 ± 12 W m-2 and DREATM = +19.6 ± 9 W m-2) to spring (DRESUR = -33.7 ± 12 W m-2 and DREATM = +27 ± 9 W m-2). Interestingly, springtime aerosols are more absorptive in nature compared to winter and consequently the aerosol induced diabatic heating of the atmosphere goes as high as 1 K day-1 during spring, especially over eastern India. The atmospheric DRE due to dust aerosols (+14 ± 7 W m-2) during spring overwhelms that of black carbon DRE (+11.8 ± 6 W m-2) during winter. The DRE at the top of the atmosphere is mostly governed by the anthropogenic aerosols during all the seasons. The columnar aerosol loading, its anthropogenic fraction and radiative effects shows a steady increase with latitude across Indian mainland leading to a larger aerosol-induced atmospheric warming during spring than in winter.

Epigenetic role for the conserved Fe-S cluster biogenesis protein AtDRE2 in Arabidopsis thaliana.

PubMed

Buzas, Diana Mihaela; Nakamura, Miyuki; Kinoshita, Tetsu

2014-09-16

On fertilization in Arabidopsis thaliana, one maternal gamete, the central cell, forms a placenta-like tissue, the endosperm. The DNA glycosylase DEMETER (DME) excises 5-methylcytosine via the base excision repair pathway in the central cell before fertilization, creating patterns of asymmetric DNA methylation and maternal gene expression across DNA replications in the endosperm lineage (EDL). Active DNA demethylation in the central cell is essential for transcriptional activity in the EDL of a set of genes, including FLOWERING WAGENINGEN (FWA). A DME-binding motif for iron-sulfur (Fe-S) cluster cofactors is indispensable for its catalytic activity. We used an FWA-GFP reporter to find mutants defective in maternal activation of FWA-GFP in the EDL, and isolated an allele of the yeast Dre2/human antiapoptotic factor CIAPIN1 homolog, encoding an enzyme previously implicated in the cytosolic Fe-S biogenesis pathway (CIA), which we named atdre2-2. We found that AtDRE2 acts in the central cell to regulate genes maternally activated in the EDL by DME. Furthermore, the FWA-GFP expression defect in atdre2-2 was partially suppressed genetically by a mutation in the maintenance DNA methyltransferase MET1; the DNA methylation levels at four DME targets increased in atdre2-2 seeds relative to WT. Although atdre2-2 shares zygotic seed defects with CIA mutants, it also uniquely manifests dme phenotypic hallmarks. These results demonstrate a previously unidentified epigenetic function of AtDRE2 that may be separate from the CIA pathway.

On the Effects of Surface Roughness on Boundary Layer Transition

NASA Technical Reports Server (NTRS)

Choudhari, Meelan M.; Li, Fei; Chang, Chau-Lyan; Edwards, Jack

2009-01-01

Surface roughness can influence laminar-turbulent transition in many different ways. This paper outlines selected analyses performed at the NASA Langley Research Center, ranging in speed from subsonic to hypersonic Mach numbers and highlighting the beneficial as well as adverse roles of the surface roughness in technological applications. The first theme pertains to boundary-layer tripping on the forebody of a hypersonic airbreathing configuration via a spanwise periodic array of trip elements, with the goal of understanding the physical mechanisms underlying roughness-induced transition in a high-speed boundary layer. The effect of an isolated, finite amplitude roughness element on a supersonic boundary layer is considered next. The other set of flow configurations examined herein corresponds to roughness based laminar flow control in subsonic and supersonic swept wing boundary layers. A common theme to all of the above configurations is the need to apply higher fidelity, physics based techniques to develop reliable predictions of roughness effects on laminar-turbulent transition.

ParDRe: faster parallel duplicated reads removal tool for sequencing studies.

PubMed

González-Domínguez, Jorge; Schmidt, Bertil

2016-05-15

Current next generation sequencing technologies often generate duplicated or near-duplicated reads that (depending on the application scenario) do not provide any interesting biological information but can increase memory requirements and computational time of downstream analysis. In this work we present ParDRe, a de novo parallel tool to remove duplicated and near-duplicated reads through the clustering of Single-End or Paired-End sequences from fasta or fastq files. It uses a novel bitwise approach to compare the suffixes of DNA strings and employs hybrid MPI/multithreading to reduce runtime on multicore systems. We show that ParDRe is up to 27.29 times faster than Fulcrum (a representative state-of-the-art tool) on a platform with two 8-core Sandy-Bridge processors. Source code in C ++ and MPI running on Linux systems as well as a reference manual are available at https://sourceforge.net/projects/pardre/ jgonzalezd@udc.es. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Electrochemical machining process for forming surface roughness elements on a gas turbine shroud

DOEpatents

Lee, Ching-Pang; Johnson, Robert Alan; Wei, Bin; Wang, Hsin-Pang

2002-01-01

The back side recessed cooling surface of a shroud defining in part the hot gas path of a turbine is electrochemically machined to provide surface roughness elements and spaces therebetween to increase the heat transfer coefficient. To accomplish this, an electrode with insulating dielectric portions and non-insulating portions is disposed in opposition to the cooling surface. By passing an electrolyte between the cooling surface and electrode and applying an electrical current between the electrode and a shroud, roughness elements and spaces therebetween are formed in the cooling surface in opposition to the insulating and non-insulating portions of the electrode, hence increasing the surface area and heat transfer coefficient of the shroud.

Three Dimensional Plenoptic PIV Measurements of a Turbulent Boundary Layer Overlying a Hemispherical Roughness Element

NASA Astrophysics Data System (ADS)

Johnson, Kyle; Thurow, Brian; Kim, Taehoon; Blois, Gianluca; Christensen, Kenneth

2016-11-01

Three-dimensional, three-component (3D-3C) measurements were made using a plenoptic camera on the flow around a roughness element immersed in a turbulent boundary layer. A refractive index matched approach allowed whole-field optical access from a single camera to a measurement volume that includes transparent solid geometries. In particular, this experiment measures the flow over a single hemispherical roughness element made of acrylic and immersed in a working fluid consisting of Sodium Iodide solution. Our results demonstrate that plenoptic particle image velocimetry (PIV) is a viable technique to obtaining statistically-significant volumetric velocity measurements even in a complex separated flow. The boundary layer to roughness height-ratio of the flow was 4.97 and the Reynolds number (based on roughness height) was 4.57×103. Our measurements reveal key flow features such as spiraling legs of the shear layer, a recirculation region, and shed arch vortices. Proper orthogonal decomposition (POD) analysis was applied to the instantaneous velocity and vorticity data to extract these features. Supported by the National Science Foundation Grant No. 1235726.

PCA3 Reference Set Application: T2-Erg-Martin Sanda-Emory (2014) — EDRN Public Portal

Cancer.gov

We hypothesize that combining T2:erg (T2:erg) fusion and PCA3 detection in urine collected after digital rectal exam can improve the specificity of identifying clinically significant prostate cancer presence over the standard PSA and DRE. To address this hypothesis we propose to validate the performance of the urinary T2:erg in a multiplex model predicting the diagnosis of clinically significant prostate cancer on subsequent prostate biopsy using post-DRE pre biopsy urine specimens from a cohort of 900 men on the EDRN’s PCA3 trial.

On the role of acoustic feedback in boundary-layer instability.

PubMed

Wu, Xuesong

2014-07-28

In this paper, the classical triple-deck formalism is employed to investigate two instability problems in which an acoustic feedback loop plays an essential role. The first concerns a subsonic boundary layer over a flat plate on which two well-separated roughness elements are present. A spatially amplifying Tollmien-Schlichting (T-S) wave between the roughness elements is scattered by the downstream roughness to emit a sound wave that propagates upstream and impinges on the upstream roughness to regenerate the T-S wave, thereby forming a closed feedback loop in the streamwise direction. Numerical calculations suggest that, at high Reynolds numbers and for moderate roughness heights, the long-range acoustic coupling may lead to absolute instability, which is characterized by self-sustained oscillations at discrete frequencies. The dominant peak frequency may jump from one value to another as the Reynolds number, or the distance between the roughness elements, is varied gradually. The second problem concerns the supersonic 'twin boundary layers' that develop along two well-separated parallel flat plates. The two boundary layers are in mutual interaction through the impinging and reflected acoustic waves. It is found that the interaction leads to a new instability that is absent in the unconfined boundary layer. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Convective Enhancement of Icing Roughness Elements in Stagnation Region Flows

NASA Technical Reports Server (NTRS)

Hughes, Michael T.; McClain, Stephen T.; Vargas, Mario; Broeren, Andy

2015-01-01

To improve existing ice accretion simulation codes, more data regarding ice roughness and its effects on convective heat transfer are required. To build on existing research on this topic, this study used the Vertical Icing Studies Tunnel (VIST) at NASA Glenn Research to model realistic ice roughness in the stagnation region of a NACA 0012 airfoil. Using the VIST, a test plate representing the leading 2% chord of the airfoil was subjected to flows of 7.62 m/s (25 ft/s), 12.19 m/s (40 ft/s), and 16.76 m/s (55 ft/s). The test plate was fitted with 3 surfaces, each with a different representation of ice roughness: 1) a control surface with no ice roughness, 2) a surface with ice roughness with element height scaled by 10x and streamwise rough zone width from the stagnation point scaled by 10x, and 3) a surface with ice roughness with element height scaled by 10x and streamwise rough zone width from the stagnation point scaled by 25x. Temperature data from the tests were recorded using an infrared camera and thermocouples imbedded in the test plate. From the temperature data, a convective heat transfer coefficient map was created for each case. Additional testing was also performed to validate the VIST's flow quality. These tests included five-hole probe and hot-wire probe velocity traces to provide flow visualization and to study boundary layer formation on the various test surfaces. The knowledge gained during the experiments will help improve ice accretion codes by providing heat transfer coefficient validation data and by providing flow visualization data helping understand current and future experiments performed in the VIST.

Heat Transfer Measurements on Surfaces with Natural Ice Castings and Modeled Roughness

NASA Technical Reports Server (NTRS)

Breuer, Kenneth S.; Torres, Benjamin E.; Orr, D. J.; Hansman, R. John

1997-01-01

An experimental method is described to measure and compare the convective heat transfer coefficient of natural and simulated ice accretion roughness and to provide a rational means for determining accretion-related enhanced heat transfer coefficients. The natural ice accretion roughness was a sample casting made from accretions at the NASA Lewis Icing Research Tunnel (IRT). One of these castings was modeled using a Spectral Estimation Technique (SET) to produce three roughness elements patterns that simulate the actual accretion. All four samples were tested in a flat-plate boundary layer at angle of attack in a "dry" wind tunnel test. The convective heat transfer coefficient was measured using infrared thermography. It is shown that, dispite some problems in the current data set, the method does show considerable promise in determining roughness-induced heat transfer coefficients, and that, in addition to the roughness height and spacing in the flow direction, the concentration and spacing of elements in the spanwise direction are important parameters.

Optimal frequency-response sensitivity of compressible flow over roughness elements

NASA Astrophysics Data System (ADS)

Fosas de Pando, Miguel; Schmid, Peter J.

2017-04-01

Compressible flow over a flat plate with two localised and well-separated roughness elements is analysed by global frequency-response analysis. This analysis reveals a sustained feedback loop consisting of a convectively unstable shear-layer instability, triggered at the upstream roughness, and an upstream-propagating acoustic wave, originating at the downstream roughness and regenerating the shear-layer instability at the upstream protrusion. A typical multi-peaked frequency response is recovered from the numerical simulations. In addition, the optimal forcing and response clearly extract the components of this feedback loop and isolate flow regions of pronounced sensitivity and amplification. An efficient parametric-sensitivity framework is introduced and applied to the reference case which shows that first-order increases in Reynolds number and roughness height act destabilising on the flow, while changes in Mach number or roughness separation cause corresponding shifts in the peak frequencies. This information is gained with negligible effort beyond the reference case and can easily be applied to more complex flows.

Kcnip1 a Ca²⁺-dependent transcriptional repressor regulates the size of the neural plate in Xenopus.

PubMed

Néant, Isabelle; Mellström, Britt; Gonzalez, Paz; Naranjo, Jose R; Moreau, Marc; Leclerc, Catherine

2015-09-01

In amphibian embryos, our previous work has demonstrated that calcium transients occurring in the dorsal ectoderm at the onset of gastrulation are necessary and sufficient to engage the ectodermal cells into a neural fate by inducing neural specific genes. Some of these genes are direct targets of calcium. Here we search for a direct transcriptional mechanism by which calcium signals are acting. The only known mechanism responsible for a direct action of calcium on gene transcription involves an EF-hand Ca²⁺ binding protein which belongs to a group of four proteins (Kcnip1 to 4). Kcnip protein can act in a Ca²⁺-dependent manner as a transcriptional repressor by binding to a specific DNA sequence, the Downstream Regulatory Element (DRE) site. In Xenopus, among the four kcnips, we show that only kcnip1 is timely and spatially present in the presumptive neural territories and is able to bind DRE sites in a Ca²⁺-dependent manner. The loss of function of kcnip1 results in the expansion of the neural plate through an increased proliferation of neural progenitors. Later on, this leads to an impairment in the development of anterior neural structures. We propose that, in the embryo, at the onset of neurogenesis Kcnip1 is the Ca²⁺-dependent transcriptional repressor that controls the size of the neural plate. This article is part of a Special Issue entitled: 13th European Symposium on Calcium. Copyright © 2014. Published by Elsevier B.V.

Ca2+–calmodulin-dependent protein kinase II represses cardiac transcription of the L-type calcium channel α1C-subunit gene (Cacna1c) by DREAM translocation

PubMed Central

Ronkainen, Jarkko J; Hänninen, Sandra L; Korhonen, Topi; Koivumäki, Jussi T; Skoumal, Reka; Rautio, Sini; Ronkainen, Veli-Pekka; Tavi, Pasi

2011-01-01

Abstract Recent studies have demonstrated that changes in the activity of calcium–calmodulin-dependent protein kinase II (CaMKII) induce a unique cardiomyocyte phenotype through the regulation of specific genes involved in excitation–contraction (E–C)-coupling. To explain the transcriptional effects of CaMKII we identified a novel CaMKII-dependent pathway for controlling the expression of the pore-forming α-subunit (Cav1.2) of the L-type calcium channel (LTCC) in cardiac myocytes. We show that overexpression of either cytosolic (δC) or nuclear (δB) CaMKII isoforms selectively downregulate the expression of the Cav1.2. Pharmacological inhibition of CaMKII activity induced measurable changes in LTCC current density and subsequent changes in cardiomyocyte calcium signalling in less than 24 h. The effect of CaMKII on the α1C-subunit gene (Cacna1c) promoter was abolished by deletion of the downstream regulatory element (DRE), which binds transcriptional repressor DREAM/calsenilin/KChIP3. Imaging DREAM–GFP (green fluorescent protein)-expressing cardiomyocytes showed that CaMKII potentiates the calcium-induced nuclear translocation of DREAM. Thereby CaMKII increases DREAM binding to the DRE consensus sequence of the endogenous Cacna1c gene. By mathematical modelling we demonstrate that the LTCC downregulation through the Ca2+–CaMKII–DREAM cascade constitutes a physiological feedback mechanism enabling cardiomyocytes to adjust the calcium intrusion through LTCCs to the amount of intracellular calcium detected by CaMKII. PMID:21486818

Comparing DNS and Experiments of Subcritical Flow Past an Isolated Surface Roughness Element

NASA Astrophysics Data System (ADS)

Doolittle, Charles; Goldstein, David

2009-11-01

Results are presented from computational and experimental studies of subcritical roughness within a Blasius boundary layer. This work stems from discrepancies presented by Stephani and Goldstein (AIAA Paper 2009-585) where DNS results did not agree with hot-wire measurements. The near wake regions of cylindrical surface roughness elements corresponding to roughness-based Reynolds numbers Rek of about 202 are of specific concern. Laser-Doppler anemometry and flow visualization in water, as well as the same spectral DNS code used by Stephani and Goldstein are used to obtain both quantitative and qualitative comparisons with previous results. Conclusions regarding previous studies will be presented alongside discussion of current work including grid resolution studies and an examination of vorticity dynamics.

Development and optimization of hardware for delta relaxation enhanced MRI.

PubMed

Harris, Chad T; Handler, William B; Araya, Yonathan; Martínez-Santiesteban, Francisco; Alford, Jamu K; Dalrymple, Brian; Van Sas, Frank; Chronik, Blaine A; Scholl, Timothy J

2014-10-01

Delta relaxation enhanced magnetic resonance (dreMR) imaging requires an auxiliary B0 electromagnet capable of shifting the main magnetic field within a clinical 1.5 Tesla (T) MR system. In this work, the main causes of interaction between an actively shielded, insertable resistive B0 electromagnet and a 1.5T superconducting system are systematically identified and mitigated. The effects of nonideal fabrication of the field-shifting magnet are taken into consideration through careful measurement during winding and improved accuracy in the design of the associated active shield. The shielding performance of the resultant electromagnet is compared against a previously built system in which the shield design was based on an ideal primary coil model. Hardware and software approaches implemented to eliminate residual image artifacts are presented in detail. The eddy currents produced by the newly constructed dreMR system are shown to have a significantly smaller "long-time-constant" component, consistent with the hypothesis that less energy is deposited into the cryostat of the MR system. With active compensation, the dreMR imaging system is capable of 0.22T field shifts within a clinical 1.5T MRI with no significant residual eddy-current fields. Copyright © 2013 Wiley Periodicals, Inc.

Regulatory mechanism of the flavoprotein Tah18-dependent nitric oxide synthesis and cell death in yeast.

PubMed

Yoshikawa, Yuki; Nasuno, Ryo; Kawahara, Nobuhiro; Nishimura, Akira; Watanabe, Daisuke; Takagi, Hiroshi

2016-07-01

Nitric oxide (NO) is a ubiquitous signaling molecule involved in the regulation of a large number of cellular functions. The regulatory mechanism of NO generation in unicellular eukaryotic yeast cells is poorly understood due to the lack of mammalian and bacterial NO synthase (NOS) orthologues, even though yeast produces NO under oxidative stress conditions. Recently, we reported that the flavoprotein Tah18, which was previously shown to transfer electrons to the iron-sulfur cluster protein Dre2, is involved in NOS-like activity in the yeast Saccharomyces cerevisiae. On the other hand, Tah18 was reported to promote apoptotic cell death after exposure to hydrogen peroxide (H2O2). Here, we showed that NOS-like activity requiring Tah18 induced cell death upon treatment with H2O2. Our experimental results also indicate that Tah18-dependent NO production and cell death are suppressed by enhancement of the interaction between Tah18 and its molecular partner Dre2. Our findings indicate that the Tah18-Dre2 complex regulates cell death as a molecular switch via Tah18-dependent NOS-like activity in response to environmental changes. Copyright © 2016 Elsevier Inc. All rights reserved.

Debate: the per rectal/digital rectal examination exam in the emergency department, still best practice?

PubMed

Quinn, John; Zeleny, Tomas; Rajaratnam, Venu; Ghiurluc, Dan-Lucian; Bencko, Vladimir

2018-03-27

Emergency medicine practice in the UK and Ireland offers a junior and middle grade doctor great learning opportunities that force engagement with multiple specialties, life-saving procedures, exposure to a myriad of patient presentations, and opportunities for best practices in medicine. The emergency department (ED) can be a hectic and dynamic environment; communication from the ED to specialists is essential to ensure best clinical outcomes for patients. The "per rectal" (PR) or "digital rectal exam" (DRE) can be a very difficult diagnostic test for even the most skilled operator to discern pathological versus normal; we propose this is especially the case in the emergency department patient population. Some specialists require this exam performed by an unskilled junior doctor with varying results prior to reviewing a referred and sick patient. The PR/DRE benefits may be limited in the ED setting for some pathologies, and the result of the exam may have limited impact in the overall treatment plan in the ED. This short paper reviews the indications, benefits, shortfalls, and limitations of the PR/DRE in the emergency department setting and offers novel alternatives to maximize best practice, ensure best clinical outcomes for patients, and, to first, do no harm.

In silico analysis of cis-acting regulatory elements in 5' regulatory regions of sucrose transporter gene families in rice (Oryza sativa Japonica) and Arabidopsis thaliana.

PubMed

Ibraheem, Omodele; Botha, Christiaan E J; Bradley, Graeme

2010-12-01

The regulation of gene expression involves a multifarious regulatory system. Each gene contains a unique combination of cis-acting regulatory sequence elements in the 5' regulatory region that determines its temporal and spatial expression. Cis-acting regulatory elements are essential transcriptional gene regulatory units; they control many biological processes and stress responses. Thus a full understanding of the transcriptional gene regulation system will depend on successful functional analyses of cis-acting elements. Cis-acting regulatory elements present within the 5' regulatory region of the sucrose transporter gene families in rice (Oryza sativa Japonica cultivar-group) and Arabidopsis thaliana, were identified using a bioinformatics approach. The possible cis-acting regulatory elements were predicted by scanning 1.5kbp of 5' regulatory regions of the sucrose transporter genes translational start sites, using Plant CARE, PLACE and Genomatix Matinspector professional databases. Several cis-acting regulatory elements that are associated with plant development, plant hormonal regulation and stress response were identified, and were present in varying frequencies within the 1.5kbp of 5' regulatory region, among which are; A-box, RY, CAT, Pyrimidine-box, Sucrose-box, ABRE, ARF, ERE, GARE, Me-JA, ARE, DRE, GA-motif, GATA, GT-1, MYC, MYB, W-box, and I-box. This result reveals the probable cis-acting regulatory elements that possibly are involved in the expression and regulation of sucrose transporter gene families in rice and Arabidopsis thaliana during cellular development or environmental stress conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

A re-appraisal of the stratigraphy and volcanology of the Cerro Galán volcanic system, NW Argentina

USGS Publications Warehouse

Folkes, Christopher B.; Wright, Heather M.; Cas, Ray A.F.; de Silva, Shanaka L.; Lesti, Chiara; Viramonte, Jose G.

2011-01-01

From detailed fieldwork and biotite 40Ar/39Ar dating correlated with paleomagnetic analyses of lithic clasts, we present a revision of the stratigraphy, areal extent and volume estimates of ignimbrites in the Cerro Galán volcanic complex. We find evidence for nine distinct outflow ignimbrites, including two newly identified ignimbrites in the Toconquis Group (the Pitas and Vega Ignimbrites). Toconquis Group Ignimbrites (~5.60–4.51 Ma biotite ages) have been discovered to the southwest and north of the caldera, increasing their spatial extents from previous estimates. Previously thought to be contemporaneous, we distinguish the Real Grande Ignimbrite (4.68 ± 0.07 Ma biotite age) from the Cueva Negra Ignimbrite (3.77 ± 0.08 Ma biotite age). The form and collapse processes of the Cerro Galán caldera are also reassessed. Based on re-interpretation of the margins of the caldera, we find evidence for a fault-bounded trapdoor collapse hinged along a regional N-S fault on the eastern side of the caldera and accommodated on a N-S fault on the western caldera margin. The collapsed area defines a roughly isosceles trapezoid shape elongated E-W and with maximum dimensions 27 × 16 km. The Cerro Galán Ignimbrite (CGI; 2.08 ± 0.02 Ma sanidine age) outflow sheet extends to 40 km in all directions from the inferred structural margins, with a maximum runout distance of ~80 km to the north of the caldera. New deposit volume estimates confirm an increase in eruptive volume through time, wherein the Toconquis Group Ignimbrites increase in volume from the ~10 km3 Lower Merihuaca Ignimbrite to a maximum of ~390 km3 (Dense Rock Equivalent; DRE) with the Real Grande Ignimbrite. The climactic CGI has a revised volume of ~630 km3 (DRE), approximately two thirds of the commonly quoted value.

A comparison of finite element and analytic models of acoustic scattering from rough poroelastic interfaces.

PubMed

Bonomo, Anthony L; Isakson, Marcia J; Chotiros, Nicholas P

2015-04-01

The finite element method is used to model acoustic scattering from rough poroelastic surfaces. Both monostatic and bistatic scattering strengths are calculated and compared with three analytic models: Perturbation theory, the Kirchhoff approximation, and the small-slope approximation. It is found that the small-slope approximation is in very close agreement with the finite element results for all cases studied and that perturbation theory and the Kirchhoff approximation can be considered valid in those instances where their predictions match those given by the small-slope approximation.

Micro PIV measurements of turbulent flow over 2D structured roughness

NASA Astrophysics Data System (ADS)

Hartenberger, Joel; Perlin, Marc

2015-11-01

We investigate the turbulent boundary layer over surfaces with 2D spanwise square and triangular protrusions having nominal heights of 100 - 300 microns for Reynolds numbers ranging from Reτ ~ 1500 through Reτ ~ 4500 using a high speed, high magnification imaging system. Micro PIV analysis gives finely resolved velocity fields of the flow (on the order of 10 microns between vectors) enabling a detailed look at the inner region as well as the flow in the immediate vicinity of the roughness elements. Additionally, planar PIV with lower resolution is performed to capture the remainder of the boundary layer to the freestream flow. Varying the streamwise distance between individual roughness elements from one to ten times the nominal heights allows investigation of k-type and d-type roughness in both the transitionally rough and fully rough regimes. Preliminary results show a shift in the mean velocity profile similar to the results of previous studies. Turbulent statistics will be presented also. The authors would like to acknowledge the support of NAVSEA which funded this project through the Naval Engineering Education Center (NEEC).

Flow formed by spanwise gaps between roughness elements

NASA Technical Reports Server (NTRS)

Logan, E.; Lin, S. H.; Islam, O.

1985-01-01

Measurements of the three mean velocity components and the three Reynolds shear stresses were made in the region downstream of gaps between wall-mounted roughness elements of square cross section and high aspect ratio in a thick turbulent boundary layer. The effect of small and large gaps was studied in a wind tunnel at a Reynolds number of 3600, based on obstacle height and free-stream velocity. The small gap produces retardation of the gap flow as with a two-dimensional roughness element, but a definite interaction between gap and wake flows is observed. The interaction is more intense for the large gap than for the small. Both gaps generate a secondary crossflow which moves fluid away from the centerline in the wall region and toward the centerline in the outer (y greater than 1.5H) region.

Study on light scattering characterization for polishing surface of optical elements

NASA Astrophysics Data System (ADS)

Zhang, Yingge; Tian, Ailing; Wang, Chunhui; Wang, Dasen; Liu, Weiguo

2017-02-01

Based on the principle of bidirectional reflectance distribution function (BRDF), the relationship between the surface roughness and the spatial scattering distribution of the optical elements were studied. First, a series of optical components with different surface roughness was obtained by the traditional polishing processing, and measured by Talysurf CCI 3000. Secondly, the influences of different factors on the scattering characteristics were simulated and analyzed, such as different surface roughness, incident wavelength and incident angle. Finally, the experimental device was built, and the spatial distribution of scattered light was measured with the different conditions, and then the data curve variation was analyzed. It was shown that the experimental method was reliable by comparing the simulation and experimental results. Base on this to know, many studies on light scattering characteristics for optical element polishing surface can try later.

An integral wall model for Large Eddy Simulation (iWMLES) and applications to developing boundary layers over smooth and rough plates

NASA Astrophysics Data System (ADS)

Yang, Xiang; Sadique, Jasim; Mittal, Rajat; Meneveau, Charles

2014-11-01

A new wall model for Large-Eddy-Simulations is proposed. It is based on an integral boundary layer method that assumes a functional form for the local mean velocity profile. The method, iWMLES, evaluates required unsteady and advective terms in the vertically integrated boundary layer equations analytically. The assumed profile contains a viscous or roughness sublayer, and a logarithmic layer with an additional linear term accounting for inertial and pressure gradient effects. The iWMLES method is tested in the context of a finite difference LES code. Test cases include developing turbulent boundary layers on a smooth flat plate at various Reynolds numbers, over flat plates with unresolved roughness, and a sample application to boundary layer flow over a plate that includes resolved roughness elements. The elements are truncated cones acting as idealized barnacle-like roughness elements that often occur in biofouling of marine surfaces. Comparisons with data show that iWMLES provides accurate predictions of near-wall velocity profiles in LES while, similarly to equilibrium wall models, its cost remains independent of Reynolds number and is thus significantly lower compared to standard zonal or hybrid wall models. This work is funded by ONR Grant N00014-12-1-0582 (Dr. R. Joslin, program manager).

Fingerprinting the type of line edge roughness

NASA Astrophysics Data System (ADS)

Fernández Herrero, A.; Pflüger, M.; Scholze, F.; Soltwisch, V.

2017-06-01

Lamellar gratings are widely used diffractive optical elements and are prototypes of structural elements in integrated electronic circuits. EUV scatterometry is very sensitive to structure details and imperfections, which makes it suitable for the characterization of nanostructured surfaces. As compared to X-ray methods, EUV scattering allows for steeper angles of incidence, which is highly preferable for the investigation of small measurement fields on semiconductor wafers. For the control of the lithographic manufacturing process, a rapid in-line characterization of nanostructures is indispensable. Numerous studies on the determination of regular geometry parameters of lamellar gratings from optical and Extreme Ultraviolet (EUV) scattering also investigated the impact of roughness on the respective results. The challenge is to appropriately model the influence of structure roughness on the diffraction intensities used for the reconstruction of the surface profile. The impact of roughness was already studied analytically but for gratings with a periodic pseudoroughness, because of practical restrictions of the computational domain. Our investigation aims at a better understanding of the scattering caused by line roughness. We designed a set of nine lamellar Si-gratings to be studied by EUV scatterometry. It includes one reference grating with no artificial roughness added, four gratings with a periodic roughness distribution, two with a prevailing line edge roughness (LER) and another two with line width roughness (LWR), and four gratings with a stochastic roughness distribution (two with LER and two with LWR). We show that the type of line roughness has a strong impact on the diffuse scatter angular distribution. Our experimental results are not described well by the present modelling approach based on small, periodically repeated domains.

Characterization of Ice Roughness From Simulated Icing Encounters

NASA Technical Reports Server (NTRS)

Anderson, David N.; Shin, Jaiwon

1997-01-01

Detailed measurements of the size of roughness elements on ice accreted on models in the NASA Lewis Icing Research Tunnel (IRT) were made in a previous study. Only limited data from that study have been published, but included were the roughness element height, diameter and spacing. In the present study, the height and spacing data were found to correlate with the element diameter, and the diameter was found to be a function primarily of the non-dimensional parameters freezing fraction and accumulation parameter. The width of the smooth zone which forms at the leading edge of the model was found to decrease with increasing accumulation parameter. Although preliminary, the success of these correlations suggests that it may be possible to develop simple relationships between ice roughness and icing conditions for use in ice-accretion-prediction codes. These codes now require an ice-roughness estimate to determine convective heat transfer. Studies using a 7.6-cm-diameter cylinder and a 53.3-cm-chord NACA 0012 airfoil were also performed in which a 1/2-min icing spray at an initial set of conditions was followed by a 9-1/2-min spray at a second set of conditions. The resulting ice shape was compared with that from a full 10-min spray at the second set of conditions. The initial ice accumulation appeared to have no effect on the final ice shape. From this result, it would appear the accreting ice is affected very little by the initial roughness or shape features.

Pollutant Plume Dispersion in the Atmospheric Boundary Layer over Idealized Urban Roughness

NASA Astrophysics Data System (ADS)

Wong, Colman C. C.; Liu, Chun-Ho

2013-05-01

The Gaussian model of plume dispersion is commonly used for pollutant concentration estimates. However, its major parameters, dispersion coefficients, barely account for terrain configuration and surface roughness. Large-scale roughness elements (e.g. buildings in urban areas) can substantially modify the ground features together with the pollutant transport in the atmospheric boundary layer over urban roughness (also known as the urban boundary layer, UBL). This study is thus conceived to investigate how urban roughness affects the flow structure and vertical dispersion coefficient in the UBL. Large-eddy simulation (LES) is carried out to examine the plume dispersion from a ground-level pollutant (area) source over idealized street canyons for cross flows in neutral stratification. A range of building-height-to-street-width (aspect) ratios, covering the regimes of skimming flow, wake interference, and isolated roughness, is employed to control the surface roughness. Apart from the widely used aerodynamic resistance or roughness function, the friction factor is another suitable parameter that measures the drag imposed by urban roughness quantitatively. Previous results from laboratory experiments and mathematical modelling also support the aforementioned approach for both two- and three-dimensional roughness elements. Comparing the UBL plume behaviour, the LES results show that the pollutant dispersion strongly depends on the friction factor. Empirical studies reveal that the vertical dispersion coefficient increases with increasing friction factor in the skimming flow regime (lower resistance) but is more uniform in the regimes of wake interference and isolated roughness (higher resistance). Hence, it is proposed that the friction factor and flow regimes could be adopted concurrently for pollutant concentration estimate in the UBL over urban street canyons of different roughness.

Direct numerical simulation of flow over dissimilar, randomly distributed roughness elements: A systematic study on the effect of surface morphology on turbulence

NASA Astrophysics Data System (ADS)

Forooghi, Pourya; Stroh, Alexander; Schlatter, Philipp; Frohnapfel, Bettina

2018-04-01

Direct numerical simulations are used to investigate turbulent flow in rough channels, in which topographical parameters of the rough wall are systematically varied at a fixed friction Reynolds number of 500, based on a mean channel half-height h and friction velocity. The utilized roughness generation approach allows independent variation of moments of the surface height probability distribution function [thus root-mean-square (rms) surface height, skewness, and kurtosis], surface mean slope, and standard deviation of the roughness peak sizes. Particular attention is paid to the effect of the parameter Δ defined as the normalized height difference between the highest and lowest roughness peaks. This parameter is used to understand the trends of the investigated flow variables with departure from the idealized case where all roughness elements have the same height (Δ =0 ). All calculations are done in the fully rough regime and for surfaces with high slope (effective slope equal to 0.6-0.9). The rms roughness height is fixed for all cases at 0.045 h and the skewness and kurtosis of the surface height probability density function vary in the ranges -0.33 to 0.67 and 1.9 to 2.6, respectively. The goal of the paper is twofold: first, to investigate the possible effect of topographical parameters on the mean turbulent flow, Reynolds, and dispersive stresses particularly in the vicinity of the roughness crest, and second, to investigate the possibility of using the wall-normal turbulence intensity as a physical parameter for parametrization of the flow. Such a possibility, already suggested for regular roughness in the literature, is here extended to irregular roughness.

Towards predictive models for transitionally rough surfaces

NASA Astrophysics Data System (ADS)

Abderrahaman-Elena, Nabil; Garcia-Mayoral, Ricardo

2017-11-01

We analyze and model the previously presented decomposition for flow variables in DNS of turbulence over transitionally rough surfaces. The flow is decomposed into two contributions: one produced by the overlying turbulence, which has no footprint of the surface texture, and one induced by the roughness, which is essentially the time-averaged flow around the surface obstacles, but modulated in amplitude by the first component. The roughness-induced component closely resembles the laminar steady flow around the roughness elements at the same non-dimensional roughness size. For small - yet transitionally rough - textures, the roughness-free component is essentially the same as over a smooth wall. Based on these findings, we propose predictive models for the onset of the transitionally rough regime. Project supported by the Engineering and Physical Sciences Research Council (EPSRC).

Endocrine activity in an urban river system and the biodegradation of estrogen-like endocrine disrupting chemicals through a bio-analytical approach using DRE- and ERE-CALUX bioassays.

PubMed

Vandermarken, T; Croes, K; Van Langenhove, K; Boonen, I; Servais, P; Garcia-Armisen, T; Brion, N; Denison, M S; Goeyens, L; Elskens, M

2018-06-01

The Zenne River, crossing the Brussels region (Belgium) is an extremely urbanized river impacted by both domestic and industrial effluents. The objective of this study was to monitor the occurrence and activity of Endocrine Active Substances (EAS) in river water and sediments in the framework of the Environmental Quality Standards Directive (2008/105/EC and 2013/39/EU). Activities were determined using Estrogen and Dioxin Responsive Elements (ERE and DRE) Chemical Activated Luciferase Gene Expression (CALUX) bioassays. A potential contamination source of estrogen active compounds was identified in the river at an industrial area downstream from Brussels with a peak value of 938 pg E2 eq./L water (above the EQS of 0.4 ng/L) and 195 pg E2 eq./g sediment. Estrogens are more abundantly present in the sediments than in the dissolved phase. Principal Component Analysis (PCA) showed high correlations between Suspended Particulate Matter (SPM), Particulate (POC) and Dissolved Organic Carbon (DOC) and estrogenic EAS. The dioxin fractions comply with previous data and all were above the United States Environmental Protection Agency (US EPA) low-level risk, with one (42 pg TCDD eq./g sediment) exceeding the high-level risk value for mammals. The self-purifying ability of the Zenne River regarding estrogens was examined with an in vitro biodegradation experiment using the bacterial community naturally present in the river. Hill coefficient and EC 50 values (Effective Concentration at 50%) revealed a process of biodegradation in particulate and dissolved phase. The estrogenic activity was decreased by 80%, demonstrating the ability of self-purification of estrogenic compounds in the Zenne River. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dioxin mediates downregulation of the reduced folate carrier transport activity via the arylhydrocarbon receptor signalling pathway

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

Halwachs, Sandra, E-mail: halwachs@vetmed.uni-leipzig.d; Lakoma, Cathleen; Gebhardt, Rolf

2010-07-15

Dioxins such as 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD) are common environmental contaminants known to regulate several genes via activation of the transcription factor aryl hydrocarbon receptor (AhR) associated with the development of numerous adverse biological effects. However, comparatively little is known about the molecular mechanisms by which dioxins display their toxic effects in vertebrates. The 5' untranslated region of the hepatocellular Reduced folate carrier (Rfc1; Slc19a1) exhibits AhR binding sites termed dioxin responsive elements (DRE) that have as yet only been found in the promoter region of prototypical TCDD target genes. Rfc1 mediated transport of reduced folates and antifolate drugs such as methotrexatemore » (MTX) plays an essential role in physiological folate homeostasis and MTX cancer chemotherapy. In order to determine whether this carrier represents a target gene of dioxins we have investigated the influence of TCDD on functional Rfc1 activity in rat liver. Pre-treatment of rats with TCDD significantly diminished hepatocellular Rfc1 uptake activity in a time- and dose-dependent manner. In further mechanistic studies we demonstrated that this reduction was due to TCDD-dependent activation of the AhR signalling pathway. We additionally showed that binding of the activated receptor to DRE motifs in the Rfc1 promoter resulted in downregulation of Rfc1 gene expression and reduced carrier protein levels. As downregulation of pivotal Rfc1 activity results in functional folate deficiency associated with an elevated risk of cardiovascular diseases or carcinogenesis, our results indicate that deregulation of this essential transport pathway represents a novel regulatory mechanism how dioxins display their toxic effects through the Ah receptor.« less

SiASR4, the Target Gene of SiARDP from Setaria italica, Improves Abiotic Stress Adaption in Plants.

PubMed

Li, Jianrui; Dong, Yang; Li, Cong; Pan, Yanlin; Yu, Jingjuan

2016-01-01

Drought and other types of abiotic stresses negatively affect plant growth and crop yields. The abscisic acid-, stress-, and ripening-induced (ASR) proteins play important roles in the protection of plants against abiotic stress. However, the regulatory pathway of the gene encoding this protein remains to be elucidated. In this study, the foxtail millet ( Setaria italica ) ASR gene, SiASR4 , was cloned and characterized. SiASR4 localized to the cell nucleus, cytoplasm and cytomembrane, and the protein contained 102 amino acids, including an ABA/WDS (abscisic acid/water-deficit stress) domain, with a molecular mass of 11.5 kDa. The abundance of SiASR4 transcripts increased after treatment with ABA, NaCl, and PEG in foxtail millet seedlings. It has been reported that the S. italica ABA-responsive DRE-binding protein (SiARDP) binds to a DNA sequence with a CCGAC core and that there are five dehydration-responsive element (DRE) motifs within the SiASR4 promoter. Our analyses demonstrated that the SiARDP protein could bind to the SiASR4 promoter in vitro and in vivo . The expression of SiASR4 increased in SiARDP -overexpressing plants. SiASR4 -transgenic Arabidopsis and SiASR4 -overexpressing foxtail millet exhibited enhanced tolerance to drought and salt stress. Furthermore, the transcription of stress-responsive and reactive oxygen species (ROS) scavenger-associated genes was activated in SiASR4 transgenic plants. Together, these findings show that SiASR4 functions in the adaption to drought and salt stress and is regulated by SiARDP via an ABA-dependent pathway.

Disaster Risk Education of Final Year High School Students Requires a Partnership with Families and Charity Organizations: An International Cross-sectional Survey.

PubMed

Codreanu, Tudor A; Celenza, Antonio; Ngo, Hanh

2016-06-01

Introduction The aim of disaster reduction education (DRE) is to achieve behavioral change. Over the past two decades, many efforts have been directed towards this goal, but educational activities have been developed based on unverified assumptions. Further, the literature has not identified any significant change towards disaster preparedness at the individual level. In addition, previous research suggests that change is dependent on multiple independent predictors. It is difficult to determine what specific actions DRE might result in; therefore, the preamble of such an action, which is to have discussions about it, has been chosen as the surrogate outcome measure for DRE success. This study describes the relationship of the perceived entity responsible for disaster education, disaster education per se, sex, and country-specific characteristics, with students discussing disasters with friends and family as a measure of proactive behavioral change in disaster preparedness. A total of 3,829 final year high school students participated in an international, multi-center prospective, cross-sectional study using a validated questionnaire. Nine countries with different levels of disaster exposure risk and economic development were surveyed. Regression analyses examined the relationship between the likelihood of discussing disasters with friends and family (dependent variable) and a series of independent variables. There was no statistically significant relationship between a single entity responsible for disaster education and discussions about potential hazards and risks with friends and/or family. While several independent predictors showed a significant main effect, DRE through school lessons in interaction with Family & Charity Organizations had the highest predictive value. Disaster reduction education might require different delivery channels and methods and should engage with the entities with which the teenagers are more likely to collaborate. Codreanu TA , Celenza A , Ngo H . Disaster risk education of final year high school students requires a partnership with families and charity organizations: an international cross-sectional survey. Prehosp Disaster Med. 2016;31(3):242-254.

Clinical correlates of enlarged prostate size in subjects with sexual dysfunction

PubMed Central

Corona, Giovanni; Gacci, Mauro; Maseroli, Elisa; Rastrelli, Giulia; Vignozzi, Linda; Sforza, Alessandra; Forti, Gianni; Mannucci, Edoardo; Maggi, Mario

2014-01-01

Digito-rectal examination (DRE) of the prostate provides useful information on the state of prostate growth and on the presence of suspected peripheral nodules. The aim of this study is to describe the clinical and biochemical correlates of finding an enlarged prostate size at DRE in subjects with sexual dysfunction (SD). A consecutive series of 2379 patients was retrospectively studied. The analysis was focused on a subset of subjects (n = 1823; mean age 54.7 ± 11.4) selected for being free from overt prostatic diseases. Several parameters were investigated. After adjusting for confounders, the presence of an enlarged prostate size at DRE was associated with a higher risk of metabolic syndrome (HR = 1.346 (1.129–1.759); P = 0.030), type 2 diabetes mellitus (HR = 1.489 (1.120–1.980); P = 0.006), increased LDL cholesterol (>100 mg dl−1; HR = 1.354 (1.018–1.801); P = 0.037) and increased mean blood pressure (BP) values (HR = 1.017 (1.007–1.027) for each mmHg increment; P = 0.001). Accordingly, enlarged prostate size was also associated with a higher risk of arteriogenic erectile dysfunction (ED), as well as with other andrological conditions, such as varicocele and premature ejaculation (PE). PSA levels were significantly higher in subjects with enlarged prostate size when compared to the rest of the sample (HR = 3.318 (2.304; 4.799) for each log unit increment in PSA levels; P < 0.0001). Arteriogenic ED, according to different criteria, was also associated with increased PSA levels. In conclusion, our data support the need to examine prostate size either by clinical (DRE) or biochemical (PSA) inspection in subjects with SD, in order to have insights into the nature of the SD and the metabolic and cardiovascular (CV) background of the patient. PMID:24830688

Left lobe of the prostate during clinical prostate cancer screening: the dark side of the gland for right-handed examiners.

PubMed

Ploussard, G; Nicolaiew, N; Mongiat-Artus, P; Terry, S; Allory, Y; Vacherot, F; Abbou, C-C; Desgrandchamps, F; Salomon, L; de la Taille, A

2014-06-01

The predictive value of the abnormality side during digital rectal examination (DRE) has never been studied, suggesting that physicians examined the left lobe of the gland as well as the right lobe. We aimed to assess the predictive value of the side of DRE abnormality for prostate cancer (PCa) detection and aggressiveness in right-handed urologists. An analysis of a prospective database was carried out that included all consecutive men undergoing prostate biopsies between 2001 and 2012. The main end point was the predictive value of the abnormality side during DRE for cancer detection in clinically suspicious unilateral T2 disease. The diagnostic performance of left- versus right-sided abnormality was also assessed in terms of sensitivity, specificity and negative/positive predictive values. Overall, 308 patients had a suspicious unilateral clinical disease (detection rate 57.5%). The cancer detection rate was significantly higher in case of left-sided compared with right-sided clinical T2 stage (odds ratio 2.1). In case of left-sided disease, the number of positive cores, the rate of perineural invasion, the rate of primary grade 4 pattern and the percentage of cancer involvement per core were significantly higher compared with those reported for right-sided disease. The predictive value of abnormality laterality for cancer detection and aggressiveness remained statistically independent in multivariate models. The positive predictive value for cancer detection was 64.6 in case of suspicious left-sided disease versus 46.9 in case of right-sided disease. The risks of detecting PCa and aggressive disease on biopsy are significantly higher when DRE reveals a suspicious left-sided clinical disease as compared with right-sided disease. Right-handed physicians should be aware of this variance in diagnostic performance and potential underdetection of left-sided clinical disease, and should improve their examination of the left lobe of the gland by conducting longer exams or changing the patient's position.

Comparing Experiment and Computation of Hypersonic Laminar Boundary Layers with Isolated Roughness

NASA Technical Reports Server (NTRS)

Bathel, Brett F.; Iyer, Prahladh S.; Mahesh, Krishnan; Danehy, Paul M.; Inman, Jennifer A.; Jones, Stephen B.; Johansen, Craig T.

2014-01-01

Streamwise velocity profile behavior in a hypersonic laminar boundary layer in the presence of an isolated roughness element is presented for an edge Mach number of 8.2. Two different roughness element types are considered: a 2-mm tall, 4-mm diameter cylinder, and a 2-mm radius hemisphere. Measurements of the streamwise velocity behavior using nitric oxide (NO) planar laser-induced fluorescence (PLIF) molecular tagging velocimetry (MTV) have been performed on a 20-degree wedge model. The top surface of this model acts as a flat-plate and is oriented at 5 degrees with respect to the freestream flow. Computations using direct numerical simulation (DNS) of these flows have been performed and are compared to the measured velocity profiles. Particular attention is given to the characteristics of velocity profiles immediately upstream and downstream of the roughness elements. In these regions, the streamwise flow can experience strong deceleration or acceleration. An analysis in which experimentally measured MTV profile displacements are compared with DNS particle displacements is performed to determine if the assumption of constant velocity over the duration of the MTV measurement is valid. This assumption is typically made when reporting MTV-measured velocity profiles, and may result in significant errors when comparing MTV measurements to computations in regions with strong deceleration or acceleration. The DNS computations with the cylindrical roughness element presented in this paper were performed with and without air injection from a rectangular slot upstream of the cylinder. This was done to determine the extent to which gas seeding in the MTV measurements perturbs the boundary layer flowfield.

Trace element analysis of rough diamond by LA-ICP-MS: a case of source discrimination?

PubMed

Dalpé, Claude; Hudon, Pierre; Ballantyne, David J; Williams, Darrell; Marcotte, Denis

2010-11-01

Current profiling of rough diamond source is performed using different physical and/or morphological techniques that require strong knowledge and experience in the field. More recently, chemical impurities have been used to discriminate diamond source and with the advance of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) empirical profiling of rough diamonds is possible to some extent. In this study, we present a LA-ICP-MS methodology that we developed for analyzing ultra-trace element impurities in rough diamond for origin determination ("profiling"). Diamonds from two sources were analyzed by LA-ICP-MS and were statistically classified by accepted methods. For the two diamond populations analyzed in this study, binomial logistic regression produced a better overall correct classification than linear discriminant analysis. The results suggest that an anticipated matrix match reference material would improve the robustness of our methodology for forensic applications. © 2010 American Academy of Forensic Sciences.

A novel cold-inducible zinc finger protein from soybean, SCOF-1, enhances cold tolerance in transgenic plants.

PubMed

Kim, J C; Lee, S H; Cheong, Y H; Yoo, C M; Lee, S I; Chun, H J; Yun, D J; Hong, J C; Lee, S Y; Lim, C O; Cho, M J

2001-02-01

Cold stress on plants induces changes in the transcription of cold response genes. A cDNA clone encoding C2H2-type zinc finger protein, SCOF-1, was isolated from soybean. The transcription of SCOF-1 is specifically induced by low temperature and abscisic acid (ABA) but not by dehydration or high salinity. Constitutive overexpression of SCOF-1 induced cold-regulated (COR) gene expression and enhanced cold tolerance of non-acclimated transgenic Arabidopsis and tobacco plants. SCOF-1 localized to the nucleus but did not bind directly to either C-repeat/dehydration (CRT/DRE) or ABA responsive element (ABRE), cis-acting DNA regulatory elements present in COR gene promoters. However, SCOF-1 greatly enhanced the DNA binding activity of SGBF-1, a soybean G-box binding bZIP transcription factor, to ABRE in vitro. SCOF-1 also interacted with SGBF-1 in a yeast two-hybrid system. The SGBF-1 transactivated the beta-glucuronidase reporter gene driven by the ABRE element in Arabidopsis leaf protoplasts. Furthermore, the SCOF-1 enhanced ABRE-dependent gene expression mediated by SGBF-1. These results suggest that SCOF-1 may function as a positive regulator of COR gene expression mediated by ABRE via protein-protein interaction, which in turn enhances cold tolerance of plants.

Numerical Computations of Hypersonic Boundary-Layer over Surface Irregularities

NASA Technical Reports Server (NTRS)

Chang, Chau-Lyan; Choudhari, Meelan M.; Li, Fei

2010-01-01

Surface irregularities such as protuberances inside a hypersonic boundary layer may lead to premature transition on the vehicle surface. Early transition in turn causes large localized surface heating that could damage the thermal protection system. Experimental measurements as well as numerical computations aimed at building a knowledge base for transition Reynolds numbers with respect to different protuberance sizes and locations have been actively pursued in recent years. This paper computationally investigates the unsteady wake development behind large isolated cylindrical roughness elements and the scaled wind-tunnel model of the trip used in a recent flight measurement during the reentry of space shuttle Discovery. An unstructured mesh, compressible flow solver based on the space-time conservation element, solution element (CESE) method is used to perform time-accurate Navier-Stokes calculations for the flow past a roughness element under several wind-tunnel conditions. For a cylindrical roughness element with a height to the boundary-layer thickness ratio from 0.8 to 2.5, the wake flow is characterized by a mushroom-shaped centerline streak and horse-shoe vortices. While time-accurate solutions converged to a steady-state for a ratio of 0.8, strong flow unsteadiness is present for a ratio of 1.3 and 2.5. Instability waves marked by distinct disturbance frequencies were found in the latter two cases. Both the centerline streak and the horse-shoe vortices become unstable downstream. The oscillatory vortices eventually reach an early breakdown stage for the largest roughness element. Spectral analyses in conjunction with the computed root mean square variations suggest that the source of the unsteadiness and instability waves in the wake region may be traced back to possible absolute instability in the front-side separation region.

Comparison of different rubber stoppers; the effect of sterilization on the number of particles released.

PubMed

Mannermaa, J P; Muttonen, E; Yliruusi, J; Juppo, A

1992-01-01

The effect of sterilization on the number of particles released from five different types of rubber stoppers, as well as on their surface roughness and elemental composition before and after sterilization is described. The stoppers were immersed in 200 ml of 0.9% sodium chloride solution in conical flasks. The number of particles released into the sodium chloride solution was measured by Coulter Counter. The surface roughness and the elemental composition of the stoppers were determined by SEM/EDX. All measurements were made both before and after sterilization at 121 degrees C to F0 15 mins. The number of particles released from a stopper during sterilization varies considerably between different stoppers and even between different batches of the same stopper. The only non-siliconized stopper in this study performed well. The absence of surface siliconization may have contributed to this performance. The scanning electron micrographs revealed well the differences in the surface roughness of the stoppers. The sterilization generally increases the surface roughness of the samples. The x-ray microanalysis revealed that the elemental composition of the stoppers may vary not only between different types of stoppers but also between different batches of the same stopper.

Prostate cancer screening

MedlinePlus

Prostate cancer screening - PSA; Prostate cancer screening - digital rectal exam; Prostate cancer screening - DRE ... level of PSA could mean you have prostate cancer. But other conditions can also cause a high ...

Aeroheating Measurement of Apollo Shaped Capsule with Boundary Layer Trip in the Free-piston Shock Tunnel HIEST

NASA Technical Reports Server (NTRS)

Hideyuki, TANNO; Tomoyuki, KOMURO; Kazuo, SATO; Katsuhiro, ITOH; Lillard, Randolph P.; Olejniczak, Joseph

2013-01-01

An aeroheating measurement test campaign of an Apollo capsule model with laminar and turbulent boundary layer was performed in the free-piston shock tunnel HIEST at JAXA Kakuda Space Center. A 250mm-diameter 6.4%-scaled Apollo CM capsule model made of SUS-304 stainless steel was applied in this study. To measure heat flux distribution, the model was equipped with 88 miniature co-axial Chromel-Constantan thermocouples on the heat shield surface of the model. In order to promote boundary layer transition, a boundary layer trip insert with 13 "pizza-box" isolated roughness elements, which have 1.27mm square, were placed at 17mm below of the model geometric center. Three boundary layer trip inserts with roughness height of k=0.3mm, 0.6mm and 0.8mm were used to identify the appropriate height to induce transition. Heat flux records with or without roughness elements were obtained for model angles of attack 28º under stagnation enthalpy between H(sub 0)=3.5MJ/kg to 21MJ/kg and stagnation pressure between P(sub 0)=14MPa to 60MPa. Under the condition above, Reynolds number based on the model diameter was varied from 0.2 to 1.3 million. With roughness elements, boundary layer became fully turbulent less than H(sub 0)=9MJ/kg condition. However, boundary layer was still laminar over H(sub 0)=13MJ/kg condition even with the highest roughness elements. An additional experiment was also performed to correct unexpected heat flux augmentation observed over H(sub 0)=9MJ/kg condition.

Rough set classification based on quantum logic

NASA Astrophysics Data System (ADS)

Hassan, Yasser F.

2017-11-01

By combining the advantages of quantum computing and soft computing, the paper shows that rough sets can be used with quantum logic for classification and recognition systems. We suggest the new definition of rough set theory as quantum logic theory. Rough approximations are essential elements in rough set theory, the quantum rough set model for set-valued data directly construct set approximation based on a kind of quantum similarity relation which is presented here. Theoretical analyses demonstrate that the new model for quantum rough sets has new type of decision rule with less redundancy which can be used to give accurate classification using principles of quantum superposition and non-linear quantum relations. To our knowledge, this is the first attempt aiming to define rough sets in representation of a quantum rather than logic or sets. The experiments on data-sets have demonstrated that the proposed model is more accuracy than the traditional rough sets in terms of finding optimal classifications.

Examination of Surface Roughness on Light Scattering by Long Ice Columns by Use of a Two-Dimensional Finite-Difference Time-Domain Algorithm

NASA Technical Reports Server (NTRS)

Sun, W.; Loeb, N. G.; Videen, G.; Fu, Q.

2004-01-01

Natural particles such as ice crystals in cirrus clouds generally are not pristine but have additional micro-roughness on their surfaces. A two-dimensional finite-difference time-domain (FDTD) program with a perfectly matched layer absorbing boundary condition is developed to calculate the effect of surface roughness on light scattering by long ice columns. When we use a spatial cell size of 1/120 incident wavelength for ice circular cylinders with size parameters of 6 and 24 at wavelengths of 0.55 and 10.8 mum, respectively, the errors in the FDTD results in the extinction, scattering, and absorption efficiencies are smaller than similar to 0.5%. The errors in the FDTD results in the asymmetry factor are smaller than similar to 0.05%. The errors in the FDTD results in the phase-matrix elements are smaller than similar to 5%. By adding a pseudorandom change as great as 10% of the radius of a cylinder, we calculate the scattering properties of randomly oriented rough-surfaced ice columns. We conclude that, although the effect of small surface roughness on light scattering is negligible, the scattering phase-matrix elements change significantly for particles with large surface roughness. The roughness on the particle surface can make the conventional phase function smooth. The most significant effect of the surface roughness is the decay of polarization of the scattered light.

Slip and accommodation coefficients from rarefaction and roughness in rotating microscale disk flows

NASA Astrophysics Data System (ADS)

Blanchard, Danny; Ligrani, Phil

2007-06-01

Accommodation coefficients are determined from experimental results and analysis based on the Navier-Stokes equations for rotation-induced flows in C-shaped fluid chamber passages formed between a rotating disk and a stationary surface. A first-order boundary condition is used to model the slip flow. The fluid chamber passage height ranges from 6.85to29.2μm to give Knudsen numbers from 0.0025 to 0.031 for air and helium. In all cases, roughness size is large compared to molecular mean free path. The unique method presented for deducing tangential momentum accommodation coefficients gives values with less uncertainty compared to procedures that rely on flows in stationary tubes and channels. When channel height is defined at the tops of the roughness elements, slip velocity magnitudes and associated accommodation coefficients are a result of rarefaction at solid-gas interfaces and shear at the gas-gas interfaces. With this arrangement, tangential accommodation coefficients obtained with this approach decrease, and slip velocity magnitudes increase, at a particular value of Knudsen number, as the level of surface roughness increases. At values of the mean roughness height greater than 500nm, accommodation coefficients then appear to be lower in air flows than in helium flows, when compared for a particular roughness configuration. When channel height is defined midway between the crests and troughs of the roughness elements, nondimensional pressure rise data show little or no dependence on the level of disk surface roughness and working fluid. With this arrangement, slip is largely independent of surface roughness magnitude and mostly due to rarefaction, provided the appropriate channel height is chosen to define the roughness height.

[Not Available].

PubMed

Ballesteros-Pomar, María; Villar-Taibo, Rocío; Calleja-Fernández, Alicia; Pintor-de-la-Maza, Begoña; Álvarez-Del-Campo, Cecilia; Vidal-Casariego, Alfonso; Cano-Rodríguez, Isidoro

2016-06-03

Los datos del estudio PREDYCES® nos revelaron que en España la desnutrición relacionada con la enfermedad (DRE) afecta a uno de cada cuatro pacientes hospitalizados. Esta cifra aumenta hasta el 36,8% en los pacientes hematológicos. Se calcula que un 20% de los pacientes oncológicos muere por complicaciones relacionadas con la DRE. Nuestro grupo se planteó en 2011 comenzar la implantación de un cribado nutricional en los servicios con mayor riesgo de DRE. La presente revisión trata de describir todo el proceso que hemos seguido para mejorar la situación nutricional en los pacientes ingresados en el Servicio de Hematología del Complejo Asistencial Universitario de León (CAULE), mayoritariamente con diagnóstico de neoplasias hematológicas. En un primer estudio piloto, detectamos una alta prevalencia de desnutrición, que tendió a aumentar durante la hospitalización. Además, solo el 8,3% los enfermos valorados recibieron algún tipo de soporte nutricional y no se estaban cubriendo sus necesidades ni calóricas ni proteicas, lo que se asociaba a un peor pronóstico. Por este motivo, nos decidimos a implantar de manera sistemática un cribado y una intervención nutricional adecuada, que comenzó en 2011 y que ha recibido el reconocimiento como Buena Práctica del Sistema Nacional de Salud.

Abatement of fluorinated compounds using a 2.45GHz microwave plasma torch with a reverse vortex plasma reactor.

PubMed

Kim, J H; Cho, C H; Shin, D H; Hong, Y C; Shin, Y W

2015-08-30

Abatement of fluorinated compounds (FCs) used in semiconductor and display industries has received an attention due to the increasingly stricter regulation on their emission. We have developed a 2.45GHz microwave plasma torch with reverse vortex reactor (RVR). In order to design a reverse vortex plasma reactor, we calculated a volume fraction and temperature distribution of discharge gas and waste gas in RVR by ANSYS CFX of computational fluid dynamics (CFD) simulation code. Abatement experiments have been performed with respect to SF6, NF3 by varying plasma power and N2 flow rates, and FCs concentration. Detailed experiments were conducted on the abatement of NF3 and SF6 in terms of destruction and removal efficiency (DRE) using Fourier transform infrared (FTIR). The DRE of 99.9% for NF3 was achieved without an additive gas at the N2 flow rate of 150 liter per minute (L/min) by applying a microwave power of 6kW with RVR. Also, a DRE of SF6 was 99.99% at the N2 flow rate of 60 L/min using an applied microwave power of 6kW. The performance of reverse vortex reactor increased about 43% of NF3 and 29% of SF6 abatements results definition by decomposition energy per liter more than conventional vortex reactor. Copyright © 2015 Elsevier B.V. All rights reserved.

Towards quantifying global aerosol radiative effects using lidar

NASA Astrophysics Data System (ADS)

Thorsen, T. J.

2017-12-01

Spaceborne lidar observations alleviate many of the limitations of passivesensors and have great potential to provide accurate global all-sky estimatesof the aerosol direct radiative effect (DRE). However, analysis of CALIPSOlidar observations show that CALIPSO does not detect allradiatively-significant aerosol, i.e. aerosol that directly modifies theEarth's radiation budget. We estimated that using CALIPSO observationsresults in an underestimate of the magnitude of the global mean aerosol DREby up to 54%. The CATS lidar on-board the ISS is shown to have a poorersensitivity than CALIPSO and the expected sensitivity of the upcoming ATLIDlidar on EarthCARE indicates that calculations of the aerosol DRE willcontinue to be significantly biased. Improvements to our knowledge of aerosol forcing, which contributes thelargest uncertainty to climate sensitivity, could be achieved by a futurespace-based HSRL mission. To this end, high-accuracy ground-based andairborne lidar datasets have been used to compute the detection sensitivityrequired to accurately resolve the aerosol DRE. Multiwavelength HSRLmeasurements also can retrieve vertically-resolved aerosol optical propertiesneeded for radiative transfer calculations which are not provided by currentsatellite observations. Current satellite observations also do not provideall the quantities needed to compute the aerosol direct radiative forcing,i.e. the radiative effect of just anthropogenic aerosols. A multiwavelengthHSRL allows for a more refined aerosol classification to be made enablingboth calculations of anthropogenic aerosol radiative effects and betterconstraints on global models.

Predictors of participation in prostate cancer screening at worksites.

PubMed

Weinrich, S P; Greiner, E; Reis-Starr, C; Yoon, S; Weinrich, M

1998-01-01

Unfortunately, African American men have a higher incidence of and a higher mortality rate for prostate cancer than White men but are less likely to participate in prostate cancer screening. This correlational survey research identifies predictors for participation in a free prostate cancer screening in 179 men, 64% of whom are African American. Each man was invited to see his personal physician for a free prostate cancer screening following a prostate cancer educational program given at his worksite. Forty-seven percent of the African American men went to their personal physician following the educational program and received a digital rectal examination (DRE) and a prostate specific antigen (PSA) screening. In the original cohort of educational program attendees, only 16% of the African Americans had obtained a DRE in the previous 12 months. However, 44% subsequently did participate in free DRE screening. Similarly, only 6% of the African American men had received a PSA screening in the previous 12 months, yet 42% obtained a PSA screening after the educational program, a sevenfold increase. Implications for allocating limited resources for education and screening to the high-risk group of African American men are discussed. This study's model of a prostate cancer educational program at worksites followed by attendees visiting their personal physician for screening could be replicated throughout the United States to increase African American men's participation in prostate cancer screening.

Gene silencing in Tribolium castaneum as a tool for the targeted identification of candidate RNAi targets in crop pests.

PubMed

Knorr, Eileen; Fishilevich, Elane; Tenbusch, Linda; Frey, Meghan L F; Rangasamy, Murugesan; Billion, Andre; Worden, Sarah E; Gandra, Premchand; Arora, Kanika; Lo, Wendy; Schulenberg, Greg; Valverde-Garcia, Pablo; Vilcinskas, Andreas; Narva, Kenneth E

2018-02-01

RNAi shows potential as an agricultural technology for insect control, yet, a relatively low number of robust lethal RNAi targets have been demonstrated to control insects of agricultural interest. In the current study, a selection of lethal RNAi target genes from the iBeetle (Tribolium castaneum) screen were used to demonstrate efficacy of orthologous targets in the economically important coleopteran pests Diabrotica virgifera virgifera and Meligethes aeneus. Transcript orthologs of 50 selected genes were analyzed in D. v. virgifera diet-based RNAi bioassays; 21 of these RNAi targets showed mortality and 36 showed growth inhibition. Low dose injection- and diet-based dsRNA assays in T. castaneum and D. v. virgifera, respectively, enabled the identification of the four highly potent RNAi target genes: Rop, dre4, ncm, and RpII140. Maize was genetically engineered to express dsRNA directed against these prioritized candidate target genes. T 0 plants expressing Rop, dre4, or RpII140 RNA hairpins showed protection from D. v. virgifera larval feeding damage. dsRNA targeting Rop, dre4, ncm, and RpII140 in M. aeneus also caused high levels of mortality both by injection and feeding. In summary, high throughput systems for model organisms can be successfully used to identify potent RNA targets for difficult-to-work with agricultural insect pests.

Secondary flows in turbulent boundary layers over longitudinal surface roughness

NASA Astrophysics Data System (ADS)

Hwang, Hyeon Gyu; Lee, Jae Hwa

2018-01-01

Direct numerical simulations of turbulent boundary layers over longitudinal surface roughness are performed to investigate the impact of the surface roughness on the mean flow characteristics related to counter-rotating large-scale secondary flows. By systematically changing the two parameters of the pitch (P) and width (S) for roughness elements in the ranges of 0.57 ≤P /δ ≤2.39 and 0.15 ≤S /δ ≤1.12 , where δ is the boundary layer thickness, we find that the size of the secondary flow in each case is mostly determined by the value of P - S, i.e., the valley width, over the ridge-type roughness. However, the strength of the secondary flows on the cross-stream plane relative to the flow is increased when the value of P increases or when the value of S decreases. In addition to the secondary flows, additional tertiary and quaternary flows are observed both above the roughness crest and in the valley as the values of P and S increase further. Based on an analysis using the turbulent kinetic energy transport equation, it is shown that the secondary flow over the ridge-type roughness is both driven and sustained by the anisotropy of turbulence, consistent with previous observations of a turbulent boundary layer over strip-type roughness [Anderson et al., J. Fluid Mech. 768, 316 (2015), 10.1017/jfm.2015.91]. Careful inspection of the turbulent kinetic energy budget reveals that the opposite rotational sense of the secondary flow between the ridge- and strip-type roughness elements is primarily attributed to the local imbalance of energy budget created by the strong turbulent transport term over the ridge-type roughness. The active transport of the kinetic energy over the ridge-type roughness is closely associated with the upward deflection of spanwise motions in the valley, mostly due to the roughness edge.

Numerical investigation of roughness effects in aircraft icing calculations

NASA Astrophysics Data System (ADS)

Matheis, Brian Daniel

2008-10-01

Icing codes are playing a role of increasing significance in the design and certification of ice protected aircraft surfaces. However, in the interest of computational efficiency certain small scale physics of the icing problem are grossly approximated by the codes. One such small scale phenomena is the effect of ice roughness on the development of the surface water film and on the convective heat transfer. This study uses computational methods to study the potential effect of ice roughness on both of these small scale phenomena. First, a two-dimensional condensed layer code is used to examine the effect of roughness on surface water development. It is found that the Couette approximation within the film breaks down as the wall shear goes to zero, depending on the film thickness. Roughness elements with initial flow separation in the air induce flow separation in the water layer at steady state, causing a trapping of the film. The amount of trapping for different roughness configurations is examined. Second, a three-dimensional incompressible Navier-Stokes code is developed to examine large scale ice roughness on the leading edge. The effect on the convective heat transfer and potential effect on the surface water dynamics is examined for a number of distributed roughness parameters including Reynolds number, roughness height, streamwise extent, roughness spacing and roughness shape. In most cases the roughness field increases the net average convective heat transfer on the leading edge while narrowing surface shear lines, indicating a choking of the surface water flow. Both effects show significant variation on the scale of the ice roughness. Both the change in heat transfer as well as the potential change in surface water dynamics are presented in terms of the development of singularities in the surface shear pattern. Of particular interest is the effect of the smooth zone upstream of the roughness which shows both a relatively large increase in convective heat transfer as well as excessive choking of the surface shear lines at the upstream end of the roughness field. A summary of the heat transfer results is presented for both the averaged heat transfer as well as the maximum heat transfer over each roughness element, indicating that the roughness Reynolds number is the primary parameter which characterizes the behavior of the roughness for the problem of interest.

Characterization and prediction of monomer-based dose rate effects in electron-beam polymerization

NASA Astrophysics Data System (ADS)

Schissel, Sage M.; Lapin, Stephen C.; Jessop, Julie L. P.

2017-12-01

Properties of some materials produced by electron-beam (EB) induced polymerization appear dependent upon the rate at which the initiating dose was delivered. However, the magnitude of these dose rate effects (DREs) can vary greatly with different monomer formulations, suggesting DREs are dependent on chemical structure. The relationship among dose, dose rate, conversion, and the glass transition temperature (Tg) of the cured material was explored for an acrylate monomer series. A strong correlation was determined between the DRE magnitude and monomer size, and this correlation may be attributed to chain transfer. Using the Tg shift caused by changes in dose, a preliminary predictive relationship was developed to estimate the magnitude of the Tg DRE, enabling scale-up of process variables for polymers prone to dose rate effects.

Near-memory data reorganization engine

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

Gokhale, Maya; Lloyd, G. Scott

A memory subsystem package is provided that has processing logic for data reorganization within the memory subsystem package. The processing logic is adapted to reorganize data stored within the memory subsystem package. In some embodiments, the memory subsystem package includes memory units, a memory interconnect, and a data reorganization engine ("DRE"). The data reorganization engine includes a stream interconnect and DRE units including a control processor and a load-store unit. The control processor is adapted to execute instructions to control a data reorganization. The load-store unit is adapted to process data move commands received from the control processor via themore » stream interconnect for loading data from a load memory address of a memory unit and storing data to a store memory address of a memory unit.« less

Boundary-layer receptivity of sound with roughness

NASA Technical Reports Server (NTRS)

Saric, William S.; Hoos, Jon A.; Radeztsky, Ronald H.

1991-01-01

An experimental study of receptivity was carried out using an acoustical disturbance in the freestream. The receptivity was enhanced by using a uniform two-dimensional roughness strip (tape). The roughness strip generated the local adjustment in the flow needed to couple the long-wavelength sound wave with the short-wavelength T-S wave. The method proved to be highly sensitive, with slight changes in the forcing frequency or in the height of the 2D roughness element having a strong effect on the amplitude of the observed T-S wave.

Time Resolved Tomographic PIV Measurements of Rough-Wall Turbulent Channel Flow

NASA Astrophysics Data System (ADS)

Miorini, Rinaldo; Zhang, Cao; Katz, Joseph

2013-11-01

Time resolved tomographic PIV is used to study flow structures in the outer region of a rough-wall turbulent boundary layer, focusing on imprints of the roughness on the outer layer. Measurements are performed in a transparent channel installed in the JHU optically index matched facility. The roughness consists of pyramids with height, k = 0.46 mm, and wavelength, λ = 3.2 mm, satisfying h/k = 55 (h = 25.4 mm is the channel half-height), k + = 64 and Re = 40000. The TPIV setup consists of four high-speed cameras operating at 3 kHz, which view the sample volume through acrylic prisms. The flow field is illuminated by an Nd:YLF laser. Following enhancement, calibration, and reconstruction, 643 voxels interrogation volumes with 0.75 overlap provide 3D velocity fields with spacing of 0.5883 mm3. Formation and transport of near-wall 3D U-shaped vortex structures, with base in front of the pyramids, and quasi-streamwise legs extending between pyramid crest lines are evident from the data. Extended streamwise regions of high wall-normal vorticity appear ``latched'' to the roughness elements close to the wall, but are transported downstream at higher elevations. Also evident are traveling streamwise low velocity streaks, which cover many roughness elements. Sponsored by NSF CBET and ONR.

Modelling NDE pulse-echo inspection of misorientated planar rough defects using an elastic finite element method

NASA Astrophysics Data System (ADS)

Pettit, J. R.; Walker, A. E.; Lowe, M. J. S.

2015-03-01

Pulse-echo ultrasonic NDE examination of large pressure vessel forgings is a design and construction code requirement in the power generation industry. Such inspections aim to size and characterise potential defects that may have formed during the forging process. Typically these defects have a range of orientations and surface roughnesses which can greatly affect ultrasonic wave scattering behaviour. Ultrasonic modelling techniques can provide insight into defect response and therefore aid in characterisation. However, analytical approaches to solving these scattering problems can become inaccurate, especially when applied to increasingly complex defect geometries. To overcome these limitations a elastic Finite Element (FE) method has been developed to simulate pulse-echo inspections of embedded planar defects. The FE model comprises a significantly reduced spatial domain allowing for a Monte-Carlo based approach to consider multiple realisations of defect orientation and surface roughness. The results confirm that defects aligned perpendicular to the path of beam propagation attenuate ultrasonic signals according to the level of surface roughness. However, for defects orientated away from this plane, surface roughness can increase the magnitude of the scattered component propagating back along the path of the incident beam. This study therefore highlights instances where defect roughness increases the magnitude of ultrasonic scattered signals, as opposed to attenuation which is more often assumed.

The transcription factor DREAM represses A20 and mediates inflammation

PubMed Central

Tiruppathi, Chinnaswamy; Soni, Dheeraj; Wang, Dong-Mei; Xue, Jiaping; Singh, Vandana; Thippegowda, Prabhakar B.; Cheppudira, Bopaiah P.; Mishra, Rakesh K.; DebRoy, Auditi; Qian, Zhijian; Bachmaier, Kurt; Zhao, Youyang; Christman, John W.; Vogel, Stephen M.; Ma, Averil; Malik, Asrar B.

2014-01-01

Here we show that the transcription-repressor DREAM binds to the A20 promoter to repress the expression of A20, the deubiquitinase suppressing inflammatory NF-κB signaling. DREAM-deficient (Dream−/−) mice displayed persistent and unchecked A20 expression in response to endotoxin. DREAM functioned by transcriptionally repressing A20 through binding to downstream regulatory elements (DREs). In contrast, USF1 binding to the DRE-associated E-box domain activated A20 expression in response to inflammatory stimuli. These studies define the critical opposing functions of DREAM and USF1 in inhibiting and inducing A20 expression, respectively, and thereby the strength of NF-κB signaling. Targeting of DREAM to induce USF1-mediated A20 expression is therefore a potential anti-inflammatory strategy in diseases such as acute lung injury associated with unconstrained NF-κB activity. PMID:24487321

Characteristics of surface roughness associated with leading edge ice accretion

NASA Technical Reports Server (NTRS)

Shin, Jaiwon

1994-01-01

Detailed size measurements of surface roughness associated with leading edge ice accretions are presented to provide information on characteristics of roughness and trends of roughness development with various icing parameters. Data was obtained from icing tests conducted in the Icing Research Tunnel (IRT) at NASA Lewis Research Center (LeRC) using a NACA 0012 airfoil. Measurements include diameters, heights, and spacing of roughness elements along with chordwise icing limits. Results confirm the existence of smooth and rough ice zones and that the boundary between the two zones (surface roughness transition region) moves upstream towards stagnation region with time. The height of roughness grows as the air temperature and the liquid water content increase, however, the airspeed has little effect on the roughness height. Results also show that the roughness in the surface roughness transition region grows during a very early stage of accretion but reaches a critical height and then remains fairly constant. Results also indicate that a uniformly distributed roughness model is only valid at a very initial stage of the ice accretion process.

Radiative characteristics of aerosol during extreme fire event over Siberia in summer 2012

NASA Astrophysics Data System (ADS)

Zhuravleva, Tatiana B.; Kabanov, Dmitriy M.; Nasrtdinov, Ilmir M.; Russkova, Tatiana V.; Sakerin, Sergey M.; Smirnov, Alexander; Holben, Brent N.

2017-01-01

Microphysical and optical properties of aerosol were studied during a mega-fire event in summer 2012 over Siberia using ground-based measurements of spectral solar radiation at the AERONET site in Tomsk and satellite observations. The data were analysed using multi-year (2003-2013) measurements of aerosol characteristics under background conditions and for less intense fires, differing in burning biomass type, stage of fire, remoteness from observation site, etc. (ordinary smoke). In June-August 2012, the average aerosol optical depth (AOD, 500 nm) had been 0.95 ± 0.86, about a factor of 6 larger than background values (0.16 ± 0.08), and a factor of 2.5 larger than in ordinary smoke. The AOD values were extremely high on 24-28 July and reached 3-5. A comparison with satellite observations showed that ground-based measurements in the region of Tomsk not only reflect the local AOD features, but are also characteristic for the territory of Western Siberia as a whole. Single scattering albedo (SSA, 440 nm) in this period ranged from 0.91 to 0.99 with an average of ˜ 0.96 in the entire wavelength range of 440-1020 nm. The increase in absorptance of aerosol particles (SSA(440 nm) = 0.92) and decrease in SSA with wavelength observed in ordinary smoke agree with the data from multi-year observations in analogous situations in the boreal zone of USA and Canada. Volume aerosol size distribution in extreme and ordinary smoke had a bimodal character with significant prevalence of fine-mode particles, but in summer 2012 the mean median radius and the width of the fine-mode distribution somewhat increased. In contrast to data from multi-year observations, in summer 2012 an increase in the volume concentration and median radius of the coarse mode was observed with growing AOD. The calculations of the average radiative effects of smoke and background aerosol are presented. Compared to background conditions and ordinary smoke, under the extreme smoke conditions the cooling effect of aerosol considerably intensifies: direct radiative effects (DRE) at the bottom (BOA) and at the top of the atmosphere (TOA) are -13, -35, and -60 W m-2 and -5, -14, and -35 W m-2 respectively. The maximal values of DRE were observed on 27 July (AOD(500 nm) = 3.5), when DRE(BOA) reached -150 W m-2, while DRE(TOA) and DRE of the atmosphere were -75 W m-2. During the fire event in summer 2012 the direct radiative effect efficiency varied in range: at the BOA it was -80-40 W m-2, at the TOA it was -50-20 W m-2 and in the atmosphere it was -35-20 W m-2.

Roughness Induced Transition in a Supersonic Boundary Layer

NASA Technical Reports Server (NTRS)

Balakumar, Ponnampalam; Kergerise, Michael A.

2013-01-01

Direct numerical simulation is used to investigate the transition induced by threedimensional isolated roughness elements in a supersonic boundary layer at a free stream Mach number of 3.5. Simulations are performed for two different configurations: one is a square planform roughness and the other is a diamond planform roughness. The mean-flow calculations show that the roughness induces counter rotating streamwise vortices downstream of the roughness. These vortices persist for a long distance downstream and lift the low momentum fluid from the near wall region and place it near the outer part of the boundary layer. This forms highly inflectional boundary layer profiles. These observations agree with recent experimental observations. The receptivity calculations showed that the amplitudes of the mass-flux fluctuations near the neutral point for the diamond shape roughness are the same as the amplitude of the acoustic disturbances. They are three times smaller for the square shape roughness.

Analysis of the coherent and turbulent stresses of a numerically simulated rough wall pipe

NASA Astrophysics Data System (ADS)

Chan, L.; MacDonald, M.; Chung, D.; Hutchins, N.; Ooi, A.

2017-04-01

A turbulent rough wall flow in a pipe is simulated using direct numerical simulation (DNS) where the roughness elements consist of explicitly gridded three-dimensional sinusoids. Two groups of simulations were conducted where the roughness semi-amplitude h+ and the roughness wavelength λ+ are systematically varied. The triple decomposition is applied to the velocity to separate the coherent and turbulent components. The coherent or dispersive component arises due to the roughness and depends on the topological features of the surface. The turbulent stress on the other hand, scales with the friction Reynolds number. For the case with the largest roughness wavelength, large secondary flows are observed which are similar to that of duct flows. The occurrence of these large secondary flows is due to the spanwise heterogeneity of the roughness which has a spacing approximately equal to the boundary layer thickness δ.

Numerical Solution of Light Scattered from and Transmitted through a Rough Dielectric Surface with Applications to Periodic Roughness and Isolated Structures

NASA Technical Reports Server (NTRS)

Sun, Wenbo; Videnn, Gorden; Lin, Bing; Hu, Yongxiang

2007-01-01

Light scattering and transmission by rough surfaces are of considerable interest in a variety of applications including remote sensing and characterization of surfaces. In this work, the finite-difference time domain technique is applied to calculate the scattered and transmitted electromagnetic fields of an infinite periodic rough surface. The elements of Mueller matrix for scattered light are calculated by an integral of the near fields over a significant number of periods of the surface. The normalized Mueller matrix elements of the scattered light and the spatial distribution of the transmitted flux for a monolayer of micron-sized dielectric spheres on a silicon substrate are presented. The numerical results show that the nonzero Mueller matrix elements of the system of the monolayer of dielectric spheres on a silicon substrate have specific maxima at some scattering angles. These maxima may be used in characterization of the feature of the system. For light transmitted through the monolayer of spheres, our results show that the transmitted energy focuses around the ray passing through centers of the spheres. At other locations, the transmitted flux is very small. The technique also may be used to calculate the perturbance of the electromagnetic field due to the presence of an isolated structure on the substrate.

Shortwave direct radiative effects of above cloud aerosols over global oceans derived from eight years of CALIOP and MODIS observations

NASA Astrophysics Data System (ADS)

Zhang, Z.; Meyer, K.; Yu, H.; Platnick, S.; Colarco, P.; Liu, Z.; Oreopoulos, L.

2015-09-01

In this paper, we studied the frequency of occurrence and shortwave direct radiative effects (DRE) of above-cloud aerosols (ACAs) over global oceans using eight years of collocated CALIOP and MODIS observations. Similar to previous work, we found high ACA occurrence in four regions: Southeast (SE) Atlantic region where ACAs are mostly light-absorbing aerosols, i.e., smoke and polluted dust according to CALIOP classification, originating from biomass burning over African Savanna; Tropical Northeast Atlantic and Arabian Sea where ACAs are predominantly windblown dust from the Sahara and Arabian desert, respectively; and Northwest Pacific where ACAs are mostly transported smoke and polluted dusts from Asian. From radiative transfer simulations based on CALIOP-MODIS observations and a set of the preselected aerosol optical models, we found the DREs of ACAs at the top of atmosphere (TOA) to be positive (i.e., warming) in the SE Atlantic and NW Pacific regions, but negative (i.e., cooling) in TNE Atlantic and Arabian Sea. The cancellation of positive and negative regional DREs results in a global ocean annual mean diurnally averaged cloudy-sky DRE of 0.015 W m-2 (range of -0.03 to 0.06 W m-2) at TOA. The DREs at surface and within atmosphere are -0.15 W m-2 (range of -0.09 to -0.21 W m-2), and 0.17 W m-2 (range of 0.11 to 0.24 W m-2), respectively. The regional and seasonal mean DREs are much stronger. For example, in the SE Atlantic region the JJA (July ~ August) seasonal mean cloudy-sky DRE is about 0.7 W m-2 (range of 0.2 to 1.2 W m-2) at TOA. The uncertainty in our DRE computations is mainly cause by the uncertainties in the aerosol optical properties, in particular aerosol absorption, and uncertainties in the CALIOP operational aerosol optical thickness retrieval. In situ and remotely sensed measurements of ACA from future field campaigns and satellite missions, and improved lidar retrieval algorithm, in particular vertical feature masking, would help reduce the uncertainty.

Application of a roughness-length representation to parameterize energy loss in 3-D numerical simulations of large rivers

NASA Astrophysics Data System (ADS)

Sandbach, S. D.; Lane, S. N.; Hardy, R. J.; Amsler, M. L.; Ashworth, P. J.; Best, J. L.; Nicholas, A. P.; Orfeo, O.; Parsons, D. R.; Reesink, A. J. H.; Szupiany, R. N.

2012-12-01

Recent technological advances in remote sensing have enabled investigation of the morphodynamics and hydrodynamics of large rivers. However, measuring topography and flow in these very large rivers is time consuming and thus often constrains the spatial resolution and reach-length scales that can be monitored. Similar constraints exist for computational fluid dynamics (CFD) studies of large rivers, requiring maximization of mesh- or grid-cell dimensions and implying a reduction in the representation of bedform-roughness elements that are of the order of a model grid cell or less, even if they are represented in available topographic data. These "subgrid" elements must be parameterized, and this paper applies and considers the impact of roughness-length treatments that include the effect of bed roughness due to "unmeasured" topography. CFD predictions were found to be sensitive to the roughness-length specification. Model optimization was based on acoustic Doppler current profiler measurements and estimates of the water surface slope for a variety of roughness lengths. This proved difficult as the metrics used to assess optimal model performance diverged due to the effects of large bedforms that are not well parameterized in roughness-length treatments. However, the general spatial flow patterns are effectively predicted by the model. Changes in roughness length were shown to have a major impact upon flow routing at the channel scale. The results also indicate an absence of secondary flow circulation cells in the reached studied, and suggest simpler two-dimensional models may have great utility in the investigation of flow within large rivers.

Simulation of leakage through mechanical sealing device

NASA Astrophysics Data System (ADS)

Tikhomorov, V. P.; Gorlenko, O. A.; Izmerov, M. A.

2018-03-01

The procedure of mathematical modeling of leakage through the mechanical seal taking into account waviness and roughness is considered. The percolation process is represented as the sum of leakages through a gap between wavy surfaces and percolation through gaps formed by fractal roughness, i.e. the total leakage is determined by the slot model and filtration leakage. Dependences of leaks on the contact pressure of corrugated and rough surfaces of the mechanical seal elements are presented.

Instability of a Supersonic Boundary-Layer with Localized Roughness

NASA Technical Reports Server (NTRS)

Marxen, Olaf; Iaccarino, Gianluca; Shaqfeh, Eric S. G.

2010-01-01

A localized 3-D roughness causes boundary-layer separation and (weak) shocks. Most importantly, streamwise vortices occur which induce streamwise (low U, high T) streaks. Immersed boundary method (volume force) suitable to represent roughness element in DNS. Favorable comparison between bi-global stability theory and DNS for a "y-mode" Outlook: Understand the flow physics (investigate "z-modes" in DNS through sinuous spanwise forcing, study origin of the beat in DNS).

An Experimental and Numerical Study of Roughness-Induced Instabilities in a Mach 3.5 Boundary Layer

NASA Technical Reports Server (NTRS)

Kegerise, Michael A.; King, Rudolph A.; Owens, Lewis R.; Choudhari, Meelan M.; Norris, Andrew T.; Li, Fei; Chang, Chau-Layn

2012-01-01

Progress on a joint experimental and numerical study of laminar-to-turbulent transition induced by an isolated roughness element in a high-speed laminar boundary layer is reported in this paper. The numerical analysis suggests that transition is driven by the instability of high- and low-speed streaks embedded in the wake of the isolated roughness element. In addition, spatial stability analysis revealed that the wake flow supports multiple modes (even and odd) of convective instabilities that experience strong enough growth to cause transition. The experimental measurements, which included hot-wire and pitot-probe surveys, confirmed the existence of embedded high- and low-speed streaks in the roughness wake. Furthermore, the measurements indicate the presence of both even and odd modes of instability, although their relative magnitude depends on the specifics of the roughness geometry and flow conditions (e.g., the value of Re(sub kk) or k/delta. For the two test cases considered in the measurements (Re(sub kk) values of 462 and 319), the even mode and the odd mode were respectively dominant and appear to play a primary role in the transition process.

Understanding Prostate Changes

Cancer.gov

Prostate changes and symptoms that are not cancer. Learn about symptoms, risk factors, and treatment for prostatitis, enlarged prostate (BPH), prostate cancer. Talk with doctor about prostate cancer screening tests (DRE, PSA), biopsy, and Gleason score.

Non-linear boundary-layer receptivity due to distributed surface roughness

NASA Technical Reports Server (NTRS)

Amer, Tahani Reffet

1995-01-01

The process by which a laminar boundary layer internalizes the external disturbances in the form of instability waves is known as boundary-layer receptivity. The objective of the present research was to determine the effect of acoustic excitation on boundary-layer receptivity for a flat plate with distributed variable-amplitude surface roughness through measurements with a hot-wire probe. Tollmien-Schlichting mode shapes due to surface roughness receptivity have also been determined, analyzed, and shown to be in agreement with theory and other experimental work. It has been shown that there is a linear relationship between the surface roughness and receptivity for certain roughness configurations with constant roughness wavelength. In addition, strong non-linear receptivity effects exist for certain surface roughness configurations over a band where the surface roughness and T-S wavelength are matched. The results from the present experiment follow the trends predicted by theory and other experimental work for linear receptivity. In addition, the results show the existence of non-linear receptivity effects for certain combinations of surface roughness elements.

Biological half-life of gaseous elemental iodine deposited onto rice grains

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

Uchida, S.; Muramatsu, Y.; Sumiya, M.

In order to obtain the biological half-life (Tb) of iodine deposited on rough rice grains, rice plants of four different growing stages--heading, milky, dough, and yellow ripe--were exposed to elemental gaseous iodine. After the exposure, the rough rice samples were collected at different intervals and analyzed for iodine to estimate the value of Tb. The average value of Tb obtained by the experiments at the dough and yellow ripe stages was about 200 d. This value is considerably larger than those for pasture grass and leafy vegetables.

Cancer Today

MedlinePlus

... your doctor if you are considering having a prostate-specific antigen (PSA) test or digital rectal examination (DRE). Skin ... regular colonoscopy for cancer of the colon, serum prostatic-specific antigen (PSA) for prostate cancer, mammography for breast cancer, ...

EDRN Pre-Validation of Multiplex Biomarker in Urine — EDRN Public Portal

Cancer.gov

The goal of this proposal is to begin to establish an EDRN “pre-validation” trial of a multiplex set of transcripts, including the ETS gene fusions, in post-DRE urine sediments. As can be evidenced by our preliminary data, we have established the utility of this multiplex urine test (which includes TMPRSS-ERG, SPINK1, PCA3 and GOLPH2) in a cohort of prospectively collected urine sediments from the University of Michigan EDRN CEVC site (collected by co-I, Dr. John Wei). In this proposal, we will run this multiplex assay on prospectively collected post-DRE urines collected from other EDRN sites. The idea is to couple this “pre-validation” study with an EDRN validation trial under consideration for the Gen-Probe PCA3 urine test (directed by Drs. John Wei and Harry Rittenhouse).

Event processing in X-IFU detector onboard Athena.

NASA Astrophysics Data System (ADS)

Ceballos, M. T.; Cobos, B.; van der Kuurs, J.; Fraga-Encinas, R.

2015-05-01

The X-ray Observatory ATHENA was proposed in April 2014 as the mission to implement the science theme "The Hot and Energetic Universe" selected by ESA for L2 (the second Large-class mission in ESA's Cosmic Vision science programme). One of the two X-ray detectors designed to be onboard ATHENA is X-IFU, a cryogenic microcalorimeter based on Transition Edge Sensor (TES) technology that will provide spatially resolved high-resolution spectroscopy. X-IFU will be developed by a consortium of European research institutions currently from France (leadership), Italy, The Netherlands, Belgium, UK, Germany and Spain. From Spain, IFCA (CSIC-UC) is involved in the Digital Readout Electronics (DRE) unit of the X-IFU detector, in particular in the Event Processor Subsytem. We at IFCA are in charge of the development and implementation in the DRE unit of the Event Processing algorithms, designed to recognize, from a noisy signal, the intensity pulses generated by the absorption of the X-ray photons, and lately extract their main parameters (coordinates, energy, arrival time, grade, etc.) Here we will present the design and performance of the algorithms developed for the event recognition (adjusted derivative), and pulse grading/qualification as well as the progress in the algorithms designed to extract the energy content of the pulses (pulse optimal filtering). IFCA will finally have the responsibility of the implementation on board in the (TBD) FPGAs or micro-processors of the DRE unit, where this Event Processing part will take place, to fit into the limited telemetry of the instrument.

Comprehensive gene and microRNA expression profiling on cardiovascular system in zebrafish co-exposured of SiNPs and MeHg.

PubMed

Hu, Hejing; Shi, Yanfeng; Zhang, Yannan; Wu, Jing; Asweto, Collins Otieno; Feng, Lin; Yang, Xiaozhe; Duan, Junchao; Sun, Zhiwei

2017-12-31

Air pollution has been shown to increase cardiovascular diseases. However, little attention has been paid to the combined effects of PM and air pollutants on the cardiovascular system. To explore this, a high-throughput sequencing technology was used to determine combined effects of silica nanoparticles (SiNPs) and MeHg in zebrafish. Our study demonstrated that SiNPs and MeHg co-exposure could cause significant changes in mRNA and miRNA expression patterns in zebrafish. The differentially expressed (DE) genes in profiles 17 and 26 of STC analysis suggest that SiNPs and MeHg co-exposure had more proinflammatory and cardiovascular toxicity in zebrafish than single exposure. Major gene functions associated with cardiovascular system in the co-exposed zebrafish were discerned from the dynamic-gene-network, including stxbp1a, celf4, ahr1b and bai2. In addition, the prominently expressed pathway of cardiac muscle contraction was targeted by 3 DE miRNAs identified by the miRNA-pathway-network (dre-miR-7147, dre-miR-26a and dre-miR-375), which included 23 DE genes. This study presents a global view of the combined SiNPs and MeHg toxicity on the dynamic expression of both mRNAs and miRNAs in zebrafish, and could serve as fundamental research clues for future studies, especially on cardiovascular system toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling Integrated Cave Drip Recharge Data using DReAM (Daily Recharge Assessment Model) in a Dry Eastern Mediterranean Area, Sif Cave - Israel

NASA Astrophysics Data System (ADS)

Anker, Y.; Sheffer, N. A.; Scanlon, B. R.; Gimburg, A.; Morin, E.

2010-12-01

Understanding recharge mechanisms and controls in karst regions is extremely important for managing water resources because of the dynamic nature of the system. To better understand this mechanism, a cave in the recharge area of the karstic Western Mountain Aquifer (WMA) of Israel was equipped to measure precipitation infiltration (2006-2008) by collecting integrated water drips from three areas in the cave (14, 46, and 52 m2 areas). Barrels equipped with pressure transducers record drip rate and volume for each of the three areas and enable estimation of recharge. A water budget model - DReAM (Daily Recharge Assessment Model) was used to quantify and predict infiltration behavior at the cave. DReAM includes calculations of all water cycle components - precipitation, evapotranspiration, runoff and recharge. The model was calibrated and validated using two independent sets of values, providing good agreement between calculated and observed data. Modeling results agree with previous studies that show: 1) three distinct flow paths (slow, intermediate, and fast flows) of water infiltrating at the cave; 2) a threshold of ~100 mm rain at the beginning of the rainy season for infiltration to begin; and 3) a decrease in lag time between rain events and infiltration response throughout the rainy season. This modeling tool and analysis approach can translate precipitation to groundwater recharge which will be very important for projecting future water resources in response to climate variability.

Expression analysis and functional characterization of a novel cold-responsive gene CbCOR15a from Capsella bursa-pastoris.

PubMed

Zhou, Mingqi; Wu, Lihua; Liang, Jing; Shen, Chen; Lin, Juan

2012-05-01

The cold-responsive (COR) genes involved in C-repeat binding factor signaling pathway function essentially in cold acclimation of higher plants. A novel COR gene CbCOR15a from shepherd's purse (Capsella bursa-pastoris) was predicted to be a homolog of COR15 in Arabidopsis. The analysis of tissue specific expression pattern as well as characterization of the CbCOR15a promoter revealed that the expression of CbCOR15a was induced by coldness not only in leaves and stem but also in roots. Sequence analysis showed that a 909 bp promoter region of CbCOR15a contained two CRT/DRE elements, two ABRE elements, one auxin-responsive TGA-element and one MeJA-responsive CGTCA-motif. In young seedlings the expression of CbCOR15a could be apparently increased by SA, ABA, MeJA and IAA, and transiently increased by GA(3) accompanied by obvious feedback suppression. According to the altered physiological index values in tobacco under cold treatments, the overexpression of CbCOR15a significantly increased the cold tolerance of transgenic tobacco plants. It can be suggested that CbCOR15a was involved in cold response of Capsella bursa-pastoris associated with SA, ABA, MeJA, IAA and GA(3) regulation and confers enhanced cold acclimation in transgenic plants.

Radar-aeolian roughness project

NASA Technical Reports Server (NTRS)

Greeley, Ronald; Dobrovolskis, A.; Gaddis, L.; Iversen, J. D.; Lancaster, N.; Leach, Rodman N.; Rasnussen, K.; Saunders, S.; Vanzyl, J.; Wall, S.

1991-01-01

The objective is to establish an empirical relationship between measurements of radar, aeolian, and surface roughness on a variety of natural surfaces and to understand the underlying physical causes. This relationship will form the basis for developing a predictive equation to derive aeolian roughness from radar backscatter. Results are given from investigations carried out in 1989 on the principal elements of the project, with separate sections on field studies, radar data analysis, laboratory simulations, and development of theory for planetary applications.

Modelling NDE pulse-echo inspection of misorientated planar rough defects using an elastic finite element method

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

Pettit, J. R.; Lowe, M. J. S.; Walker, A. E.

2015-03-31

Pulse-echo ultrasonic NDE examination of large pressure vessel forgings is a design and construction code requirement in the power generation industry. Such inspections aim to size and characterise potential defects that may have formed during the forging process. Typically these defects have a range of orientations and surface roughnesses which can greatly affect ultrasonic wave scattering behaviour. Ultrasonic modelling techniques can provide insight into defect response and therefore aid in characterisation. However, analytical approaches to solving these scattering problems can become inaccurate, especially when applied to increasingly complex defect geometries. To overcome these limitations a elastic Finite Element (FE) methodmore » has been developed to simulate pulse-echo inspections of embedded planar defects. The FE model comprises a significantly reduced spatial domain allowing for a Monte-Carlo based approach to consider multiple realisations of defect orientation and surface roughness. The results confirm that defects aligned perpendicular to the path of beam propagation attenuate ultrasonic signals according to the level of surface roughness. However, for defects orientated away from this plane, surface roughness can increase the magnitude of the scattered component propagating back along the path of the incident beam. This study therefore highlights instances where defect roughness increases the magnitude of ultrasonic scattered signals, as opposed to attenuation which is more often assumed.« less

Mixed convection of nanofluids in a lid-driven rough cavity

NASA Astrophysics Data System (ADS)

Guo, Zhimeng; Wang, Jinyu; Mozumder, Aloke K.; Das, Prodip K.

2017-06-01

Mixed convection heat transfer and fluid flow of air, water or oil in enclosures have been studied extensively using experimental and numerical means for many years due to their ever-increasing applications in many engineering fields. In comparison, little effort has been given to the problem of mixed convection of nanofluids in spite of several applications in solar collectors, electronic cooling, lubrication technologies, food processing, and nuclear reactors. Mixed convection of nanofluids is a challenging problem due to the complex interactions among inertia, viscous, and buoyancy forces. In this study, mixed convection of nanofluids in a lid-driven square cavity with sinusoidal roughness elements at the bottom is studied numerically using the Navier-Stokes equations with the Boussinesq approximation. The numerical model is developed using commercial finite volume software ANSYS-FLUENT for Al2O3-water and CuO-water nanofluids inside a square cavity with various roughness elements. The effects of number and amplitude of roughness elements on the heat transfer and fluid flow are analysed for various volume concentrations of Al2O3 and CuO nanoparticles. The flow fields, temperature fields, and heat transfer rates are examined for different values of Rayleigh and Reynolds numbers. The outcome of this study provides some important insight into the heat transfer behaviour of Al2O3-water and CuO-water nanofluids inside a lid-driven rough cavity. This knowledge can be further used in developing novel geometries with enhanced and controlled heat transfer for solar collectors, electronic cooling, and food processing industries.

Digital Rectal Exam (DRE)

MedlinePlus

... Considerations How Cancer is Treated Side Effects Dating, Sex, and Reproduction Advanced Cancer For Children For Teens For Young Adults For Older Adults Prevention and Healthy Living Cancer.Net Videos Coping With Cancer Research and Advocacy Survivorship Blog ...

Influence of wall roughness and thermal coductivity on turbulent natural convection

NASA Astrophysics Data System (ADS)

Orlandi, Paolo; Pirozzoli, Sergio; Bernardini, Matteo

2015-11-01

We study turbulent natural convection in enclosures with conjugate heat transfer. The simplest way to increase the heat transfer in this flow is through rough surfaces. In numerical simulations often constant temperatures are assigned on the walls, but this is an unrealistic condition in laboratory experiments. Therefore, in the DNS, to be of help to experimentalists, it is necessary to solve the heat conduction in the solid walls together with the turbulent flow between the hot and the cold walls. Here the cold wall, 0 . 5 h tick is smooth, and the hot wall has 2D and 3D rough elements of thickness 0 . 2 h above a solid layer 0 . 3 h tick. The simulation is performed in a bi-periodic domain 4 h wide. The Rayleigh number varies from 106 to 108. Two values of the thermal conductivity, one corresponding to copper and the other ten times higher were assumed. It has been found that the Nusselt number behaves as Nu = αRaγ , with α increasing with the solid conductivity and depending of the roughness shape. 3D elements produce a heat transfer greater than 2D elements. An imprinting of the flow structures on the thermal field inside the walls is observed. The one-dimensional spectra at the center, one decade wide, agree with those of forced isotropic turbulence.

The Effect of Volumetric Porosity on Roughness Element Drag

NASA Astrophysics Data System (ADS)

Gillies, John; Nickling, William; Nikolich, George; Etyemezian, Vicken

2016-04-01

Much attention has been given to understanding how the porosity of two dimensional structures affects the drag force exerted by boundary-layer flow on these flow obstructions. Porous structures such as wind breaks and fences are typically used to control the sedimentation of sand and snow particles or create micro-habitats in their lee. Vegetation in drylands also exerts control on sediment transport by wind due to aerodynamic effects and interaction with particles in transport. Recent research has also demonstrated that large spatial arrays of solid three dimensional roughness elements can be used to reduce sand transport to specified targets for control of wind erosion through the effect of drag partitioning and interaction of the moving sand with the large (>0.3 m high) roughness elements, but porous elements may improve the effectiveness of this approach. A thorough understanding of the role porosity plays in affecting the drag force on three-dimensional forms is lacking. To provide basic understanding of the relationship between the porosity of roughness elements and the force of drag exerted on them by fluid flow, we undertook a wind tunnel study that systematically altered the porosity of roughness elements of defined geometry (cubes, rectangular cylinders, and round cylinders) and measured the associated change in the drag force on the elements under similar Reynolds number conditions. The elements tested were of four basic forms: 1) same sized cubes with tubes of known diameter milled through them creating three volumetric porosity values and increasing connectivity between the tubes, 2) cubes and rectangular cylinders constructed of brass screen that nested within each other, and 3) round cylinders constructed of brass screen that nested within each other. The two-dimensional porosity, defined as the ratio of total surface area of the empty space to the solid surface area of the side of the element presented to the fluid flow was conserved at 0.519 for the cubes and 0.525 for the mesh forms. Results from the study indicate that as volumetric porosity increases, the force of drag on an element increases although the 2-dimensional porosity remains unchanged for the case of the cube forms. The mesh forms show a similar result that with increasing number of internal forms present, drag increases, but the drag curves are different, suggesting the kind of porosity has an effect on drag. An important scaling parameter that controls drag on the cubes is the permeability (K) of the element, which is a function of the diameter of the tubes and the porosity. K seems to be of lesser importance for controlling drag on the mesh forms. We hypothesize that the drag force data do not universally collapse as a function of permeability due to Reynolds number dependency on flow conditions within the elements that can be laminar, transitional, or turbulent even though flow exterior to the forms is fully turbulent. For the mesh forms, the greatest effect on drag occurs with the addition of the first internal form with subsequent additions showing very little additional effect.

Smoothed Two-Dimensional Edges for Laminar Flow

NASA Technical Reports Server (NTRS)

Holmes, B. J.; Liu, C. H.; Martin, G. L.; Domack, C. S.; Obara, C. J.; Hassan, A.; Gunzburger, M. D.; Nicolaides, R. A.

1986-01-01

New concept allows passive method for installing flaps, slats, iceprotection equipment, and other leading-edge devices on natural-laminar-flow (NLF) wings without causing loss of laminar flow. Two-dimensional roughness elements in laminar boundary layers strategically shaped to increase critical (allowable) height of roughness. Facilitates installation of leading-edge devices by practical manufacturing methods.

Assessment of dioxin-like activity in PM10 air samples from an industrial location in Algeria, using the DRE-CALUX bioassay.

PubMed

Khedidji, Sidali; Croes, Kim; Yassaa, Noureddine; Ladji, Riad; Denison, Michael S; Baeyens, Willy; Elskens, Marc

2017-05-01

When compared to the European guidelines, PM 10 (particulate matter up to 10-μm size) concentrations in Algeria are often exceeding the maximum limits, and in general, no information exists on the compounds bound on its surface. The objective of this study was to measure the dioxin-like activity of polychlorinated dibenzodioxines and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) in the PM 10 fraction at the Sour El Ghozlane cement plant in Algeria. PM 10 samples (n = 23) were taken between 24 March and 15 April 2013, using a medium volume sampler and 47-mm PTFE filters. The 24-h samples were dried to determine the PM 10 content and afterward extracted, cleaned up, and analyzed with the dioxin-responsive element-chemical-activated luciferase gene expression (DRE-CALUX) bioassay. Our results showed that the measured bioanalytical equivalents (BEQs) were similar to those in other international industrial sites worldwide. The PCDD/Fs and dioxin-like PCBs (dl-PCBs) were positively correlated (rho = 0.6, p = 0.002), indicating that they have similar sources. Furthermore, samples from March showed higher PCDD/F and dl-PCB BEQs and humidity but lower temperatures compared to samples from April, while there was no difference in the PM 10 concentrations between the two months. These results reveal that PM 10 alone is not a good proxy and that meteorological conditions are an important factor in assessing dioxin-like pollution in the atmosphere. It seems that, at present, there is no health hazard through direct airborne human exposure to dioxin-like pollutants in PM 10 from this site. However, it is important to monitor these POPs for a longer period of time and also to gain more insight in their distribution between the particulate and gas phase in relation to meteorological conditions.

Turbulent Flow Over Large Roughness Elements: Effect of Frontal and Plan Solidity on Turbulence Statistics and Structure

NASA Astrophysics Data System (ADS)

Placidi, M.; Ganapathisubramani, B.

2018-04-01

Wind-tunnel experiments were carried out on fully-rough boundary layers with large roughness (δ /h ≈ 10, where h is the height of the roughness elements and δ is the boundary-layer thickness). Twelve different surface conditions were created by using LEGO™ bricks of uniform height. Six cases are tested for a fixed plan solidity (λ _P) with variations in frontal density (λ _F), while the other six cases have varying λ _P for fixed λ _F. Particle image velocimetry and floating-element drag-balance measurements were performed. The current results complement those contained in Placidi and Ganapathisubramani (J Fluid Mech 782:541-566, 2015), extending the previous analysis to the turbulence statistics and spatial structure. Results indicate that mean velocity profiles in defect form agree with Townsend's similarity hypothesis with varying λ _F, however, the agreement is worse for cases with varying λ _P. The streamwise and wall-normal turbulent stresses, as well as the Reynolds shear stresses, show a lack of similarity across most examined cases. This suggests that the critical height of the roughness for which outer-layer similarity holds depends not only on the height of the roughness, but also on the local wall morphology. A new criterion based on shelter solidity, defined as the sheltered plan area per unit wall-parallel area, which is similar to the `effective shelter area' in Raupach and Shaw (Boundary-Layer Meteorol 22:79-90, 1982), is found to capture the departure of the turbulence statistics from outer-layer similarity. Despite this lack of similarity reported in the turbulence statistics, proper orthogonal decomposition analysis, as well as two-point spatial correlations, show that some form of universal flow structure is present, as all cases exhibit virtually identical proper orthogonal decomposition mode shapes and correlation fields. Finally, reduced models based on proper orthogonal decomposition reveal that the small scales of the turbulence play a significant role in assessing outer-layer similarity.

Form drag in rivers due to small-scale natural topographic features: 2. Irregular sequences

USGS Publications Warehouse

Kean, J.W.; Smith, J.D.

2006-01-01

The size, shape, and spacing of small-scale topographic features found on the boundaries of natural streams, rivers, and floodplains can be quite variable. Consequently, a procedure for determining the form drag on irregular sequences of different-sized topographic features is essential for calculating near-boundary flows and sediment transport. A method for carrying out such calculations is developed in this paper. This method builds on the work of Kean and Smith (2006), which describes the flow field for the simpler case of a regular sequence of identical topographic features. Both approaches model topographic features as two-dimensional elements with Gaussian-shaped cross sections defined in terms of three parameters. Field measurements of bank topography are used to show that (1) the magnitude of these shape parameters can vary greatly between adjacent topographic features and (2) the variability of these shape parameters follows a lognormal distribution. Simulations using an irregular set of topographic roughness elements show that the drag on an individual element is primarily controlled by the size and shape of the feature immediately upstream and that the spatial average of the boundary shear stress over a large set of randomly ordered elements is relatively insensitive to the sequence of the elements. In addition, a method to transform the topography of irregular surfaces into an equivalently rough surface of regularly spaced, identical topographic elements also is given. The methods described in this paper can be used to improve predictions of flow resistance in rivers as well as quantify bank roughness.

Dynamic mortar finite element method for modeling of shear rupture on frictional rough surfaces

NASA Astrophysics Data System (ADS)

Tal, Yuval; Hager, Bradford H.

2017-09-01

This paper presents a mortar-based finite element formulation for modeling the dynamics of shear rupture on rough interfaces governed by slip-weakening and rate and state (RS) friction laws, focusing on the dynamics of earthquakes. The method utilizes the dual Lagrange multipliers and the primal-dual active set strategy concepts, together with a consistent discretization and linearization of the contact forces and constraints, and the friction laws to obtain a semi-smooth Newton method. The discretization of the RS friction law involves a procedure to condense out the state variables, thus eliminating the addition of another set of unknowns into the system. Several numerical examples of shear rupture on frictional rough interfaces demonstrate the efficiency of the method and examine the effects of the different time discretization schemes on the convergence, energy conservation, and the time evolution of shear traction and slip rate.

Full Wave Analysis of RF Signal Attenuation in a Lossy Rough Surface Cave using a High Order Time Domain Vector Finite Element Method

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

Pingenot, J; Rieben, R; White, D

2005-10-31

We present a computational study of signal propagation and attenuation of a 200 MHz planar loop antenna in a cave environment. The cave is modeled as a straight and lossy random rough wall. To simulate a broad frequency band, the full wave Maxwell equations are solved directly in the time domain via a high order vector finite element discretization using the massively parallel CEM code EMSolve. The numerical technique is first verified against theoretical results for a planar loop antenna in a smooth lossy cave. The simulation is then performed for a series of random rough surface meshes in ordermore » to generate statistical data for the propagation and attenuation properties of the antenna in a cave environment. Results for the mean and variance of the power spectral density of the electric field are presented and discussed.« less

Transcriptional regulation of ABI3- and ABA-responsive genes including RD29B and RD29A in seeds, germinating embryos, and seedlings of Arabidopsis.

PubMed

Nakashima, Kazuo; Fujita, Yasunari; Katsura, Koji; Maruyama, Kyonoshin; Narusaka, Yoshihiro; Seki, Motoaki; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2006-01-01

ABA-responsive elements (ABREs) are cis-acting elements and basic leucine zipper (bZIP)-type ABRE-binding proteins (AREBs) are transcriptional activators that function in the expression of RD29B in vegetative tissue of Arabidopsis in response to abscisic acid (ABA) treatment. Dehydration-responsive elements (DREs) function as coupling elements of ABRE in the expression of RD29A in response to ABA. Expression analysis using abi3 and abi5 mutants showed that ABI3 and ABI5 play important roles in the expression of RD29B in seeds. Base-substitution analysis showed that two ABREs function strongly and one ABRE coupled with DRE functions weakly in the expression of RD29A in embryos. In a transient transactivation experiment, ABI3, ABI5 and AREB1 activated transcription of a GUS reporter gene driven by the RD29B promoter strongly but these proteins activated the transcription driven by the RD29A promoter weakly. In 35S::ABI3 Arabidopsis plants, the expression of RD29B was up-regulated strongly, but that of RD29A was up-regulated weakly. These results indicate that the expression of RD29B having ABREs in the promoter is up-regulated strongly by ABI3, whereas that of RD29A having one ABRE coupled with DREs in the promoter is up-regulated weakly by ABI3. We compared the expression of 7000 Arabidopsis genes in response to ABA treatment during germination and in the vegetative growth stage, and that in 35S::ABI3 plants using a full-length cDNA microarray. The expression of ABI3- and/or ABA-responsive genes and cis-elements in the promoters are discussed.

Static and sliding contact of rough surfaces: Effect of asperity-scale properties and long-range elastic interactions

NASA Astrophysics Data System (ADS)

Hulikal, Srivatsan; Lapusta, Nadia; Bhattacharya, Kaushik

2018-07-01

Friction in static and sliding contact of rough surfaces is important in numerous physical phenomena. We seek to understand macroscopically observed static and sliding contact behavior as the collective response of a large number of microscopic asperities. To that end, we build on Hulikal et al. (2015) and develop an efficient numerical framework that can be used to investigate how the macroscopic response of multiple frictional contacts depends on long-range elastic interactions, different constitutive assumptions about the deforming contacts and their local shear resistance, and surface roughness. We approximate the contact between two rough surfaces as that between a regular array of discrete deformable elements attached to a elastic block and a rigid rough surface. The deformable elements are viscoelastic or elasto/viscoplastic with a range of relaxation times, and the elastic interaction between contacts is long-range. We find that the model reproduces the main macroscopic features of evolution of contact and friction for a range of constitutive models of the elements, suggesting that macroscopic frictional response is robust with respect to the microscopic behavior. Viscoelasticity/viscoplasticity contributes to the increase of friction with contact time and leads to a subtle history dependence. Interestingly, long-range elastic interactions only change the results quantitatively compared to the meanfield response. The developed numerical framework can be used to study how specific observed macroscopic behavior depends on the microscale assumptions. For example, we find that sustained increase in the static friction coefficient during long hold times suggests viscoelastic response of the underlying material with multiple relaxation time scales. We also find that the experimentally observed proportionality of the direct effect in velocity jump experiments to the logarithm of the velocity jump points to a complex material-dependent shear resistance at the microscale.

Direct Numerical Simulation of Flow Over Passive Geometric Disturbances

NASA Astrophysics Data System (ADS)

Vizard, Alexander

It is well understood that delaying flow separation on a bluff body allows significant drag reduction, which is attractive in many applications. With this in mind, many separation control mechanisms, both active and passive, have been developed and tested to optimize the effects of this phenomenon. Although this idea is generally accepted, the physical occurrences in the near-wall region during transition that lead to separation delay are not well understood. The current study evaluates the impact of both spherical dimples, and sandgrain style roughness on downstream flow by performing direct numerical simulations over such geometries on a zero pressure gradient flat plate. It is shown that although dimples and random roughness of similar characteristic length scales exhibit similar boundary layer characteristics, dimples are more successful in developing high momentum in the vicinity of the wall. Additionally it is shown that increasing the relative size of the rough elements does not increase the near-wall momentum, and is undesirable in controlling separation. Finally, it is shown that the impact of roughness elements on the flow is more immediate, and that, for the case of one row of dimples and an equivalent area of roughness, the roughness patch is more successful in transitioning the near-wall region to a non-laminar state. It can be concluded from variation in the span of the flowfield for a single row of dimples that the size and orientation of the disturbance region is significant to the results.

Roughness Based Crossflow Transition Control for a Swept Airfoil Design Relevant to Subsonic Transports

NASA Technical Reports Server (NTRS)

Li, Fei; Choudhari, Meelan M.; Carpenter, Mark H.; Malik, Mujeeb R.; Eppink, Jenna; Chang, Chau-Lyan; Streett, Craig L.

2010-01-01

A high fidelity transition prediction methodology has been applied to a swept airfoil design at a Mach number of 0.75 and chord Reynolds number of approximately 17 million, with the dual goal of an assessment of the design for the implementation and testing of roughness based crossflow transition control and continued maturation of such methodology in the context of realistic aerodynamic configurations. Roughness based transition control involves controlled seeding of suitable, subdominant crossflow modes in order to weaken the growth of naturally occurring, linearly more unstable instability modes via a nonlinear modification of the mean boundary layer profiles. Therefore, a synthesis of receptivity, linear and nonlinear growth of crossflow disturbances, and high-frequency secondary instabilities becomes desirable to model this form of control. Because experimental data is currently unavailable for passive crossflow transition control for such high Reynolds number configurations, a holistic computational approach is used to assess the feasibility of roughness based control methodology. Potential challenges inherent to this control application as well as associated difficulties in modeling this form of control in a computational setting are highlighted. At high Reynolds numbers, a broad spectrum of stationary crossflow disturbances amplify and, while it may be possible to control a specific target mode using Discrete Roughness Elements (DREs), nonlinear interaction between the control and target modes may yield strong amplification of the difference mode that could have an adverse impact on the transition delay using spanwise periodic roughness elements.

Water soluble contrast enema examination of the integrity of the rectal anastomosis prior to loop ileostomy reversal may be superfluous.

PubMed

Larsson, Anna; Lindmark, Gudrun; Syk, Ingvar; Buchwald, Pamela

2015-03-01

Defunctioning loop ileostomy in low anterior resection (LAR) is routinely used to reduce consequences of anastomotic leakage. The purpose of this study was to analyze which examination technique is optimal for evaluating the integrity of the anastomosis prior to loop ileostomy reversal. Retrospective analysis of 95 patients who had been subjected to LAR at Helsingborg Hospital and Skåne University Hospital, Sweden, was undertaken between January 2007 and June 2009. The examination techniques of the rectal anastomosis prior to reversal and the clinical outcome after reversal were studied. Radiologic anastomosis control using water soluble contrast enema, digital rectal examination (DRE), and rectoscopy were performed in 53 % (50/95), 98 % (93/95), and 69 % (66/95), respectively. In two patients, no control of the anastomosis was performed before reversal. Fifty-two percent (49/95) of the patients were examined using all techniques. Six patients demonstrated leakage detected before reversal of which two were only radiological leakages. These two patients underwent loop ileostomy reversal after delay without complications. They were the only ones where the three examination techniques did not prove coherence. Four patients had symptomatic leakage; these were detected with rectoscopy and DRE and verified with enema. Three patients developed anastomotic leakage after loop ileostomy reversal despite normal preoperative examinations. Two of these patients had rectovaginal fistulas (AVFs). This retrospective study indicates that contrast enema does not provide additional information if rectoscopy and DRE are normal. Despite negative examinations, three of nine leakages were diagnosed after loop ileostomy reversal. Especially, AVFs seem difficult to diagnose.

Prostate cancer screening behavior in men from seven ethnic groups: the fear factor.

PubMed

Consedine, Nathan S; Morgenstern, Amy H; Kudadjie-Gyamfi, Elizabeth; Magai, Carol; Neugut, Alfred I

2006-02-01

Rates of prostate cancer screening are known to vary among the major ethnic groups. However, likely variations in screening behavior among ethnic subpopulations and the likely role of psychological characteristics remain understudied. We examined differences in prostate cancer screening among samples of 44 men from each of seven ethnic groups (N = 308; U.S.-born European Americans, U.S.-born African Americans, men from the English-speaking Caribbean, Haitians, Dominicans, Puerto Ricans, and Eastern Europeans) and the associations among trait fear, emotion regulatory characteristics, and screening. As expected, there were differences in the frequency of both digital rectal exam (DRE) and prostate-specific antigen (PSA) tests among the groups, even when demographic factors and access were controlled. Haitian men reported fewer DRE and PSA tests than either U.S.-born European American or Dominican men, and immigrant Eastern European men reported fewer tests than U.S.-born European Americans; consistent with prior research, U.S.-born African Americans differed from U.S.-born European Americans for DRE but not PSA frequency. Second, the addition of trait fear significantly improved model fit, as did the inclusion of a quadratic, inverted U, trait fear term, even where demographics, access, and ethnicity were controlled. Trait fear did not interact with ethnicity, suggesting its effect may operate equally across groups, and adding patterns of information processing and emotion regulation to the model did not improve model fit. Overall, our data suggest that fear is among the key psychological determinants of male screening behavior and would be usefully considered in models designed to increase male screening frequency.

Site remediation using photocatalytic VOC destruction of chlorinated hydrocarbons

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

Brunet, R.A.H.; Pearcey, R.; Kittrell, J.R.

1999-07-01

An innovative environmental technology has been developed and demonstrated for cost-effective control of toxic air emissions, such as trichloroethylene (TCE) and perchloroethylene (PCE), found in soil and groundwater at hazardous waste sites and in industrial effluents. The technology uses UV light and a proprietary photocatalyst to adsorb and destroy pollutants at ambient conditions, even with high humidity. Air stripping and soil vapor extraction efficiently transfer the pollutants to the gas phase, where they can be economically treated by photocatalysis without the risk of hazardous by-product formation. The AIR2000 photocatalytic technology was successfully installed at the Stamina Mills Superfund site inmore » Rhode Island, where a commercial scale unit is treating 700 cfm of up to 1,000 ppm TCE, mixed with PCE, dichloroethylene (DCE), trichloroethane (TCA), and vinyl chloride (VC) produced through a combination of soil vapor extraction (SVE) and air stripping. As part of the EPA SITE program, the system was monitored for overall destruction removal efficiency (DRE) and hazardous by-product formation. A DRE in excess of 99% was reported over the first four months of operation, with greater than 99.99% DRE achieved, without production of hazardous by-products. The operating cost of the system is approximately 20% of activated carbon adsorption, which provides approximately $1,500,000 in cost savings over the life of the Stamina Mills project. The Adsorption Integrated Reaction (AIR) process is the recipient of the 1997 SBIR Technology of the Year award, the 1998 EPA Environmental Technology Innovator Award, and the 1998 R and D 100 Award.« less

Finite Element Simulation of Shot Peening: Prediction of Residual Stresses and Surface Roughness

NASA Astrophysics Data System (ADS)

Gariépy, Alexandre; Perron, Claude; Bocher, Philippe; Lévesque, Martin

Shot peening is a surface treatment that consists of bombarding a ductile surface with numerous small and hard particles. Each impact creates localized plastic strains that permanently stretch the surface. Since the underlying material constrains this stretching, compressive residual stresses are generated near the surface. This process is commonly used in the automotive and aerospace industries to improve fatigue life. Finite element analyses can be used to predict residual stress profiles and surface roughness created by shot peening. This study investigates further the parameters and capabilities of a random impact model by evaluating the representative volume element and the calculated stress distribution. Using an isotropic-kinematic hardening constitutive law to describe the behaviour of AA2024-T351 aluminium alloy, promising results were achieved in terms of residual stresses.

Health Screening: What Tests You Need and When

MedlinePlus

... cancer screening if you are considering having a prostate-specific antigen (PSA) test or digital rectal examination (DRE). Sexually ... regular colonoscopy for cancer of the colon, serum prostatic-specific antigen (PSA) for prostate cancer, mammography for breast cancer, ...

The Canopy Horizontal Array Turbulence Study (CHATS)

Treesearch

Edward G. Patton; Thomas W. Horst; Donald H. Lenschow; Peter P. Sullivan; Steven Oncley; Sean Burns; Alex Guenther; Andreas Held; Thomas Karl; Shane Mayor; Luciana Rizzo; Scott Spuler; Jielun Sun; Andrew Turnipseed; Eugene Allwine; Steven Edburg; Brian Lamb; Roni Avissar; Heidi E. Holder; Ron Calhoun; Jan Kleissl; William Massman; Kyaw Tha Paw U; Jeffrey C. Weil

2008-01-01

Turbulence in the planetary boundary layer (PBL) well above the surface has been shown to be independent of the details of the surface roughness. In this region well-quantified similarity relationships work well when characterizing turbulent fluxes (e.g., Raupach, 1979). However, in the near-surface layer which is directly influenced by roughness elements, i.e., the...

Reprogramming of a defense signaling pathway in rough lemon and sweet orange is a critical element of the early response to ‘Candidatus Liberibacter asiaticus’

USDA-ARS?s Scientific Manuscript database

Huanglongbing (HLB) in citrus infected by Candidatus Liberibacter asiaticus (CLas) has caused tremendous losses to the citrus industry. No resistant genotypes have been identified in citrus species or close relatives. Among citrus varieties, rough lemon (Citrus jambhiri) has been considered tolerant...

Shortwave direct radiative effects of above-cloud aerosols over global oceans derived from 8 years of CALIOP and MODIS observations

NASA Astrophysics Data System (ADS)

Zhang, Zhibo; Meyer, Kerry; Yu, Hongbin; Platnick, Steven; Colarco, Peter; Liu, Zhaoyan; Oreopoulos, Lazaros

2016-03-01

In this paper, we studied the frequency of occurrence and shortwave direct radiative effects (DREs) of above-cloud aerosols (ACAs) over global oceans using 8 years (2007-2014) of collocated CALIOP and MODIS observations. Similar to previous work, we found high ACA occurrence in four regions: southeastern (SE) Atlantic region, where ACAs are mostly light-absorbing aerosols, i.e., smoke and polluted dust according to CALIOP classification, originating from biomass burning over the African Savanna; tropical northeastern (TNE) Atlantic and the Arabian Sea, where ACAs are predominantly windblown dust from the Sahara and Arabian deserts, respectively; and the northwestern (NW) Pacific, where ACAs are mostly transported smoke and polluted dusts from Asian. From radiative transfer simulations based on CALIOP-MODIS observations and a set of the preselected aerosol optical models, we found the DREs of ACAs at the top of atmosphere (TOA) to be positive (i.e., warming) in the SE Atlantic and NW Pacific regions, but negative (i.e., cooling) in the TNE Atlantic Ocean and the Arabian Sea. The cancellation of positive and negative regional DREs results in a global ocean annual mean diurnally averaged cloudy-sky DRE of 0.015 W m-2 (range of -0.03 to 0.06 W m-2) at TOA. The DREs at surface and within the atmosphere are -0.15 W m-2 (range of -0.09 to -0.21 W m-2), and 0.17 W m-2 (range of 0.11 to 0.24 W m-2), respectively. The regional and seasonal mean DREs are much stronger. For example, in the SE Atlantic region, the JJA (July-August) seasonal mean cloudy-sky DRE is about 0.7 W m-2 (range of 0.2 to 1.2 W m-2) at TOA. All our DRE computations are publicly available1. The uncertainty in our DRE computations is mainly caused by the uncertainties in the aerosol optical properties, in particular aerosol absorption, the uncertainties in the CALIOP operational aerosol optical thickness retrieval, and the ignorance of cloud and potential aerosol diurnal cycle. In situ and remotely sensed measurements of ACA from future field campaigns and satellite missions and improved lidar retrieval algorithm, in particular vertical feature masking, would help reduce the uncertainty.

Shortwave Direct Radiative Effects of Above-Cloud Aerosols Over Global Oceans Derived From 8 Years of CALIOP and MODIS Observations

NASA Technical Reports Server (NTRS)

Zhang, Zhibo; Meyer, Kerry; Yu, Hongbin; Platnick, Steven; Colarco, Peter; Liu, Zhaoyan; Oraiopoulos, Lazaros

2016-01-01

In this paper, we studied the frequency of occurrence and shortwave direct radiative effects (DREs) of above-cloud aerosols (ACAs) over global oceans using 8 years (2007-2014) of collocated CALIOP and MODIS observations. Similar to previous work, we found high ACA occurrence in four regions: southeastern (SE) Atlantic region, where ACAs are mostly light-absorbing aerosols, i.e., smoke and polluted dust according to CALIOP classification, originating from biomass burning over the African Savanna; tropical northeastern (TNE) Atlantic and the Arabian Sea, where ACAs are predominantly windblown dust from the Sahara and Arabian deserts, respectively; and the northwestern (NW) Pacific, where ACAs are mostly transported smoke and polluted dusts from Asia. From radiative transfer simulations based on CALIOP-MODIS observations and a set of the preselected aerosol optical models, we found the DREs of ACAs at the top of atmosphere (TOA) to be positive (i.e., warming) in the SE Atlantic and NW Pacific regions, but negative (i.e., cooling) in the TNE Atlantic Ocean and the Arabian Sea. The cancellation of positive and negative regional DREs results in a global ocean annual mean diurnally averaged cloudy-sky DRE of 0.015 W m(exp. -2) [range of -0.03 to 0.06 W m (exp. -2)] at TOA. The DREs at surface and within the atmosphere are -0.015 W m(exp. -2) [range of -0.09 to -0.21 W m(exp. -2)], and 0.17 W m(exp. -2) [range of 0.11 to 0.24 W m(exp. -2)], respectively. The regional and seasonal mean DREs are much stronger. For example, in the SE Atlantic region, the JJA (July-August) seasonal mean cloudy-sky DRE is about 0.7 W m(exp. -2) [range of 0.2 to 1.2 W m(exp. -2)] at TOA. All our DRE computations are publicly available. The uncertainty in our DRE computations is mainly caused by the uncertainties in the aerosol optical properties, in particular aerosol absorption, the uncertainties in the CALIOP operational aerosol optical thickness retrieval, and the ignorance of cloud and potential aerosol diurnal cycle. In situ and remotely sensed measurements of ACA from future field campaigns and satellite missions and improved lidar retrieval algorithm, in particular vertical feature masking, would help reduce the uncertainty.

Roughness effects on thermal-infrared emissivities estimated from remotely sensed images

NASA Astrophysics Data System (ADS)

Mushkin, Amit; Danilina, Iryna; Gillespie, Alan R.; Balick, Lee K.; McCabe, Matthew F.

2007-10-01

Multispectral thermal-infrared images from the Mauna Loa caldera in Hawaii, USA are examined to study the effects of surface roughness on remotely retrieved emissivities. We find up to a 3% decrease in spectral contrast in ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) 90-m/pixel emissivities due to sub-pixel surface roughness variations on the caldera floor. A similar decrease in spectral contrast of emissivities extracted from MASTER (MODIS/ASTER Airborne Simulator) ~12.5-m/pixel data can be described as a function of increasing surface roughness, which was measured remotely from ASTER 15-m/pixel stereo images. The ratio between ASTER stereo images provides a measure of sub-pixel surface-roughness variations across the scene. These independent roughness estimates complement a radiosity model designed to quantify the unresolved effects of multiple scattering and differential solar heating due to sub-pixel roughness elements and to compensate for both sub-pixel temperature dispersion and cavity radiation on TIR measurements.

Membrane fouling in a submerged membrane bioreactor: An unified approach to construct topography and to evaluate interaction energy between two randomly rough surfaces.

PubMed

Cai, Xiang; Shen, Liguo; Zhang, Meijia; Chen, Jianrong; Hong, Huachang; Lin, Hongjun

2017-11-01

Quantitatively evaluating interaction energy between two randomly rough surfaces is the prerequisite to quantitatively understand and control membrane fouling in membrane bioreactors (MBRs). In this study, a new unified approach to construct rough topographies and to quantify interaction energy between a randomly rough particle and a randomly rough membrane was proposed. It was found that, natural rough topographies of both foulants and membrane could be well constructed by a modified two-variable Weierstrass-Mandelbrot (WM) function included in fractal theory. Spatial differential relationships between two constructed surfaces were accordingly established. Thereafter, a new approach combining these relationships, surface element integration (SEI) approach and composite Simpson's rule was deduced to calculate the interaction energy between two randomly rough surfaces in a submerged MBR. The obtained results indicate the profound effects of surface morphology on interaction energy and membrane fouling. This study provided a basic approach to investigate membrane fouling and interface behaviors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Roughness-induced generation of crossflow vortices in three-dimensional boundary layers

NASA Technical Reports Server (NTRS)

Choudhari, Meelan

1993-01-01

The receptivity theory of Goldstein and Ruban is extended within the nonasymptotic (quasi-parallel) framework of Zavol'skii et al to predict the roughness-induced generation of stationary and nonstationary instability waves in three-dimensional, incompressible boundary layers. The influence of acoustic-wave orientation, as well as that of different types of roughness geometries, including isolated roughness elements, periodic arrays, and two-dimensional lattices of compact roughness shapes, as well as random, but spatially homogeneous roughness distributions, is examined. The parametric study for the Falkner-Skan-Cooke family of boundary layers supports our earlier conjecture that the initial amplitudes of roughness-induced stationary vortices are likely to be significantly larger than the amplitudes of similarly induced nonstationary vortices in the presence of acoustic disturbances in the free stream. Maximum unsteady receptivity occurs when the acoustic velocity fluctuation is aligned with the wavenumber vector of the unsteady vortex mode. On the other hand, roughness arrays that are oriented somewhere close to the group velocity direction are likely to produce higher instability amplitudes. Limitations of the nonasymptotic theory are discussed, and future work is suggested.

Estimation of effective aerodynamic roughness with altimeter measurements

NASA Technical Reports Server (NTRS)

Menenti, M.; Ritchie, J. C.

1992-01-01

A new method is presented for estimating the aerodynamic roughness length of heterogeneous land surfaces and complex landscapes using elevation measurements performed with an airborne laser altimeter and the Seasat radar altimeter. Land surface structure is characterized at increasing length scales by considering three basic landscape elements: (1) partial to complete canopies of herbaceous vegetation; (2) sparse obstacles (e.g., shrubs and trees); and (3) local relief. Measured parameters of land surface geometry are combined to obtain an effective aerodynamic roughness length which parameterizes the total atmosphere-land surface stress.

Global instability in a laminar boundary layer perturbed by an isolated roughness element

NASA Astrophysics Data System (ADS)

Puckert, Dominik K.; Rist, Ulrich

2018-03-01

Roughness-induced boundary-layer instabilities are investigated by means of hot-film anemometry in a water channel to provide experimental evidence of a global instability. It is shown that the roughness wake dynamics depends on extrinsic disturbances (amplifier) at subcritical Reynolds numbers, whereas intrinsic, self-sustained oscillations (wavemaker) are suspected at supercritical Reynolds numbers. The critical Reynolds number, therefore, separates between two different instability mechanisms. Furthermore, the critical Reynolds number from recent theoretical results is successfully confirmed in this experiment, supporting the physical relevance of 3-d global stability theory.

An efficient finite element method for simulation of droplet spreading on a topologically rough surface

NASA Astrophysics Data System (ADS)

Luo, Li; Wang, Xiao-Ping; Cai, Xiao-Chuan

2017-11-01

We study numerically the dynamics of a three-dimensional droplet spreading on a rough solid surface using a phase-field model consisting of the coupled Cahn-Hilliard and Navier-Stokes equations with a generalized Navier boundary condition (GNBC). An efficient finite element method on unstructured meshes is introduced to cope with the complex geometry of the solid surfaces. We extend the GNBC to surfaces with complex geometry by including its weak form along different normal and tangential directions in the finite element formulation. The semi-implicit time discretization scheme results in a decoupled system for the phase function, the velocity, and the pressure. In addition, a mass compensation algorithm is introduced to preserve the mass of the droplet. To efficiently solve the decoupled systems, we present a highly parallel solution strategy based on domain decomposition techniques. We validate the newly developed solution method through extensive numerical experiments, particularly for those phenomena that can not be achieved by two-dimensional simulations. On a surface with circular posts, we study how wettability of the rough surface depends on the geometry of the posts. The contact line motion for a droplet spreading over some periodic rough surfaces are also efficiently computed. Moreover, we study the spreading process of an impacting droplet on a microstructured surface, a qualitative agreement is achieved between the numerical and experimental results. The parallel performance suggests that the proposed solution algorithm is scalable with over 4,000 processors cores with tens of millions of unknowns.

Investigation of turbulent wedges generated by different single surface roughness elements

NASA Astrophysics Data System (ADS)

Traphan, Dominik; Meinlschmidt, Peter; Lutz, Otto; Peinke, Joachim; Gülker, Gerd

2013-11-01

It is known that small faults on rotor blades of wind turbines can cause significant power loss. In order to better understand the governing physical effects, in this experimental study, the formation of a turbulent wedge over a flat plate induced by single surface roughness elements is under investigation. The experiments are performed at different ambient pressure gradients, thus allowing conclusions about the formation of a turbulent wedge over an airfoil. With respect to typical initial faults on operating airfoils, the roughness elements are modified in both size and shape (raised or recessed). None intrusive experimental methods, such as stereoscopic PIV and LDA, enable investigations based on temporally and spatially highly resolved velocity measurements. In this way, a spectral analysis of the turbulent boundary layer is performed and differences in coherent structures within the wedge are identified. These findings are correlated with global measurements of the wedge carried out by infrared thermography. This correlation aims to enable distinguishing the cause and main properties of a turbulent wedge by the easy applicable method of infrared thermography, which is of practical relevance in the field of condition monitoring of wind turbines.

Healthy Family 2009: Practicing Healthy Adult Living

MedlinePlus

... doctor the pros and cons of having a prostate-specific antigen (PSA) test or digital rectal examination (DRE) to ... colonoscopies for cancer of the colon, serum prostatin-specific antigen (PSA) tests for prostate cancer, and mammograms for breast cancer. Work out ...

The flow field around a pair of cubic roughness elements with different spacings immersed in turbulent boundary layer

NASA Astrophysics Data System (ADS)

Agarwal, Karuna; Gao, Jian; Katz, Joseph

2017-11-01

The shape, size, and spacing between roughness elements in turbulent boundary layers affect the associated drag and noise. Understanding them require data on the flow structure around these elements. Dual-view tomographic holography is used to study the 3D 3-component velocity field around a pair of cubic roughness elements immersed in a turbulent boundary layer at Reτ = 2500 . These a = 1 mm high cubes correspond to 4% of the half channel height and 90 wall units (δν = 11 μ m). Tests are performed for spanwise spacings of a, 1.5 a and 2.5 a. The sample volume is 385δν × 250δν × 190δν and the vector spacing is 5.4δν. Conversed statistics is obtained by recording 1500 realizations in volumes centered upstream, downstream and around a cube. The boundary layer separating upstream of the cube does not reattach until the wake region, resulting in formation of a vortical ``canopy'' that engulfs each cube. It is dominated by spanwise vorticity above the cube and separated region, bounded by vertical vorticity on the sides. Flow channeling in the space between cubes causes asymmetry in the vorticity distributions along the inner and outer walls. The legs of horseshoe vortices remain near the wall between cubes, but grow and expand in the wake region. Funded by NSF and ONR.

Observations on the Growth of Roughness Elements Into Icing Feathers

NASA Technical Reports Server (NTRS)

Vargas, Mario; Tsao, Jen, Ching

2007-01-01

This work presents the results of an experiment conducted in the Icing Research Tunnel at NASA Glenn Research Center to understand the process by which icing feathers are formed in the initial stages of ice accretion formation on swept wings. Close-up photographic data were taken on an aluminum NACA 0012 swept wing tip airfoil. Two types of photographic data were obtained: time sequence close-up photographic data during the run and close-up photographic data of the ice accretion at the end of each run. Icing runs were conducted for short ice accretion times from 10 to 180 sec. The time sequence close-up photographic data was used to study the process frame by frame and to create movies of how the process developed. The movies confirmed that at glaze icing conditions in the attachment line area icing feathers develop from roughness elements. The close-up photographic data at the end of each run showed that roughness elements change into a pointed shape with an upstream facet and join on the side with other elements having the same change to form ridges with pointed shape and upstream facet. The ridges develop into feathers when the upstream facet grows away to form the stem of the feather. The ridges and their growth into feathers were observed to form the initial scallop tips present in complete scallops.

Arabidopsis DREB2C modulates ABA biosynthesis during germination.

PubMed

Je, Jihyun; Chen, Huan; Song, Chieun; Lim, Chae Oh

2014-09-12

Plant dehydration-responsive element binding factors (DREBs) are transcriptional regulators of the APETELA2/Ethylene Responsive element-binding Factor (AP2/ERF) family that control expression of abiotic stress-related genes. We show here that under conditions of mild heat stress, constitutive overexpression seeds of transgenic DREB2C overexpression Arabidopsis exhibit delayed germination and increased abscisic acid (ABA) content compared to untransformed wild-type (WT). Treatment with fluridone, an inhibitor of the ABA biosynthesis abrogated these effects. Expression of an ABA biosynthesis-related gene, 9-cis-epoxycarotenoid dioxygenase 9 (NCED9) was up-regulated in the DREB2C overexpression lines compared to WT. DREB2C was able to trans-activate expression of NCED9 in Arabidopsis leaf protoplasts in vitro. Direct and specific binding of DREB2C to a complete DRE on the NCED9 promoter was observed in electrophoretic mobility shift assays. Exogenous ABA treatment induced DREB2C expression in germinating seeds of WT. Vegetative growth of transgenic DREB2C overexpression lines was more strongly inhibited by exogenous ABA compared to WT. These results suggest that DREB2C is a stress- and ABA-inducible gene that acts as a positive regulator of ABA biosynthesis in germinating seeds through activating NCED9 expression. Copyright © 2014 Elsevier Inc. All rights reserved.

DEAR1, a transcriptional repressor of DREB protein that mediates plant defense and freezing stress responses in Arabidopsis.

PubMed

Tsutsui, Tomokazu; Kato, Wataru; Asada, Yutaka; Sako, Kaori; Sato, Takeo; Sonoda, Yutaka; Kidokoro, Satoshi; Yamaguchi-Shinozaki, Kazuko; Tamaoki, Masanori; Arakawa, Keita; Ichikawa, Takanari; Nakazawa, Miki; Seki, Motoaki; Shinozaki, Kazuo; Matsui, Minami; Ikeda, Akira; Yamaguchi, Junji

2009-11-01

Plants have evolved intricate mechanisms to respond and adapt to a wide variety of biotic and abiotic stresses in their environment. The Arabidopsis DEAR1 (DREB and EAR motif protein 1; At3g50260) gene encodes a protein containing significant homology to the DREB1/CBF (dehydration-responsive element binding protein 1/C-repeat binding factor) domain and the EAR (ethylene response factor-associated amphiphilic repression) motif. We show here that DEAR1 mRNA accumulates in response to both pathogen infection and cold treatment. Transgenic Arabidopsis overexpressing DEAR1 (DEAR1ox) showed a dwarf phenotype and lesion-like cell death, together with constitutive expression of PR genes and accumulation of salicylic acid. DEAR1ox also showed more limited P. syringae pathogen growth compared to wild-type, consistent with an activated defense phenotype. In addition, transient expression experiments revealed that the DEAR1 protein represses DRE/CRT (dehydration-responsive element/C-repeat)-dependent transcription, which is regulated by low temperature. Furthermore, the induction of DREB1/CBF family genes by cold treatment was suppressed in DEAR1ox, leading to a reduction in freezing tolerance. These results suggest that DEAR1 has an upstream regulatory role in mediating crosstalk between signaling pathways for biotic and abiotic stress responses.

Boundary-Layer Instability Measurements in a Mach-6 Quiet Tunnel

NASA Technical Reports Server (NTRS)

Berridge, Dennis C.; Ward, Christopher, A. C.; Luersen, Ryan P. K.; Chou, Amanda; Abney, Andrew D.; Schneider, Steven P.

2012-01-01

Several experiments have been performed in the Boeing/AFOSR Mach-6 Quiet Tunnel at Purdue University. A 7 degree half angle cone at 6 degree angle of attack with temperature-sensitive paint (TSP) and PCB pressure transducers was tested under quiet flow. The stationary crossflow vortices appear to break down to turbulence near the lee ray for sufficiently high Reynolds numbers. Attempts to use roughness elements to control the spacing of hot streaks on a flared cone in quiet flow did not succeed. Roughness was observed to damp the second-mode waves in areas influenced by the roughness, and wide roughness spacing allowed hot streaks to form between the roughness elements. A forward-facing cavity was used for proof-of-concept studies for a laser perturber. The lowest density at which the freestream laser perturbations could be detected was 1.07 x 10(exp -2) kilograms per cubic meter. Experiments were conducted to determine the transition characteristics of a streamwise corner flow at hypersonic velocities. Quiet flow resulted in a delayed onset of hot streak spreading. Under low Reynolds number flow hot streak spreading did not occur along the model. A new shock tube has been built at Purdue. The shock tube is designed to create weak shocks suitable for calibrating sensors, particularly PCB-132 sensors. PCB-132 measurements in another shock tube show the shock response and a linear calibration over a moderate pressure range.

Influence of foundation mass and surface roughness on dynamic response of beam on dynamic foundation subjected to the moving load

NASA Astrophysics Data System (ADS)

Tran Quoc, Tinh; Khong Trong, Toan; Luong Van, Hai

2018-04-01

In this paper, Improved Moving Element Method (IMEM) is used to analyze the dynamic response of Euler-Bernoulli beam structures on the dynamic foundation model subjected to the moving load. The effects of characteristic foundation model parameters such as Winkler stiffness, shear layer based on the Pasternak model, viscoelastic dashpot and characteristic parameter of mass on foundation. Beams are modeled by moving elements while the load is fixed. Based on the principle of the publicly virtual balancing and the theory of moving element method, the motion differential equation of the system is established and solved by means of the numerical integration based on the Newmark algorithm. The influence of mass on foundation and the roughness of the beam surface on the dynamic response of beam are examined in details.

Excitation of Crossflow Instabilities in a Swept Wing Boundary Layer

NASA Technical Reports Server (NTRS)

Carpenter, Mark H.; Choudhari, Meelan; Li, Fei; Streett, Craig L.; Chang, Chau-Lyan

2010-01-01

The problem of crossflow receptivity is considered in the context of a canonical 3D boundary layer (viz., the swept Hiemenz boundary layer) and a swept airfoil used recently in the SWIFT flight experiment performed at Texas A&M University. First, Hiemenz flow is used to analyze localized receptivity due to a spanwise periodic array of small amplitude roughness elements, with the goal of quantifying the effects of array size and location. Excitation of crossflow modes via nonlocalized but deterministic distribution of surface nonuniformity is also considered and contrasted with roughness induced acoustic excitation of Tollmien-Schlichting waves. Finally, roughness measurements on the SWIFT model are used to model the effects of random, spatially distributed roughness of sufficiently small amplitude with the eventual goal of enabling predictions of initial crossflow disturbance amplitudes as functions of surface roughness parameters.

Wave and setup dynamics on steeply-sloping reefs with large bottom roughness

NASA Astrophysics Data System (ADS)

Buckley, M. L.; Hansen, J.; Lowe, R.

2016-12-01

High-resolution observations from a wave flume were used to investigate the dynamics of wave setup over a steeply-sloping fringing reef profile with the effect of bottom roughness modeled using roughness elements scaled to mimic a coral reef. Results with roughness were compared with smooth bottom runs across sixteen offshore wave and still water level conditions. The time-averaged and depth-integrated force balance was evaluated from observations collected at seventeen locations across the flume, which was found to consist of cross-shore pressure and radiation stress gradients whose sum was balanced by mean quadratic bottom stresses. We found that when radiation stress gradients were calculated from observations of the radiation stress derived from linear wave theory, both wave setdown and setup were under predicted for the majority of wave and water level conditions tested. Inaccuracies in the predicted setdown and setup were improved by including a wave roller model, which provides a correction to the kinetic energy predicted by linear wave theory for breaking waves and produces a spatial delay in the wave forcing that was consistent with the observations. The introduction of roughness had two primary effects. First, the amount of wave energy dissipated during wave breaking was reduced due to frictional wave dissipation that occurred on the reef slope offshore of the breakpoint. Second, offshore directed mean bottom stresses were generated by the interaction of the combined wave-current velocity field with the roughness elements. These two mechanisms acted counter to one another. As a result, setup on the reef flat was comparable (7% mean difference) between corresponding rough and smooth runs. These findings are used to assess prior results from numerical modelling studies of reefs, and also to discuss the broader implications for how steep slopes and large roughness influences setup dynamics for general nearshore systems.

40 CFR 266.110 - Waiver of DRE trial burn for boilers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... percent of fuel fired to the device shall be fossil fuel, fuels derived from fossil fuel, tall oil, or, if... comparable to fossil fuel. Such fuels are termed “primary fuel” for purposes of this section. (Tall oil is a...

40 CFR 266.110 - Waiver of DRE trial burn for boilers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... percent of fuel fired to the device shall be fossil fuel, fuels derived from fossil fuel, tall oil, or, if... comparable to fossil fuel. Such fuels are termed “primary fuel” for purposes of this section. (Tall oil is a...

40 CFR 266.110 - Waiver of DRE trial burn for boilers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... percent of fuel fired to the device shall be fossil fuel, fuels derived from fossil fuel, tall oil, or, if... comparable to fossil fuel. Such fuels are termed “primary fuel” for purposes of this section. (Tall oil is a...

40 CFR 266.110 - Waiver of DRE trial burn for boilers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... percent of fuel fired to the device shall be fossil fuel, fuels derived from fossil fuel, tall oil, or, if... comparable to fossil fuel. Such fuels are termed “primary fuel” for purposes of this section. (Tall oil is a...

40 CFR 266.110 - Waiver of DRE trial burn for boilers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... percent of fuel fired to the device shall be fossil fuel, fuels derived from fossil fuel, tall oil, or, if... comparable to fossil fuel. Such fuels are termed “primary fuel” for purposes of this section. (Tall oil is a...

2006 evaluation of the Las Vegas Metropolitan Area Express (MAX) bus rapid transit project : December 1, 2006

DOT National Transportation Integrated Search

2006-12-01

The surface transportation system plays a crucial role in responding to natural disasters, terrorist acts, and other catastrophic events. The Disaster Response and Evacuation (DRE) User Service uses intelligent transportation systems (ITS) to enhance...

TRIAL BURN RESULTS AND FUTURE ACTIVITES OF THE EPA MOBILE INCINERATOR

EPA Science Inventory

The EPA Mobile Incinerator has demonstrated its ability to successfully destroy dioxin. A trial burn conducted in 1987 demonstrated the incinerator's ability to destroy a wide variety of compounds. The destruction and removal efficiency (DRE) of carbon tetrachloride, hexachloro...

Holistic care for pediatric organ transplant recipients and their families during their dark postoperative recovery stage in the hospital.

PubMed

Yang, F C; Shih, F Jong; Tseng, P H; Wang, S S; Shih, F Jin

2014-05-01

This study explored the difficulties in caring for pediatric organ transplant recipients (POTR) and their families during dark recovery experiences (DRE) in the hospital from the perspectives of Taiwan organ transplant health professionals (OTHP). A qualitative design was used, with a purposive sample of OTHP including OT surgeons (OTS) and nursing groups. Data were collected by thorough face-to-face interviews and were analyzed using content analysis. Fifty-five subjects (39 female, 16 male) participated in this project. They included 15 OTS and 40 nurses. The nurses included registered nurses (n = 27), nurse practitioners (n = 5), and assistant or head nurses (n = 8). Their ages ranged from 25 to 66 (mean = 38.4) years old. Thirty-eight (69%) had college education, and 17 (31%) had graduate education. Their OT careers ranged from between 3 to 40 (mean = 23.8) years for OTS, and 0.5 to 15 (mean = 4.10) years for the OT nursing group. Five types of caring difficulties were reported: (1) threat of OT failure, (2) work overload, (3) insufficient collaboration within interdisciplinary teams due to incongruent surgical and nursing opinions, (4) poor communication between OTHP and POTR, and (5) lack of competent professional OT care. The following suggestions were made to help relieve the OTHPs' stress in providing holistic care for POTR and their families during DRE: (1) increasing the amount of experienced OT manpower and professional communication liaisons, (2) providing systematic on-the-job interdisciplinary case seminars and OT workshops, and (3) enhancing the POTR's mental health care and helping manage their distress of DRE. Copyright © 2014 Elsevier Inc. All rights reserved.

Stereo-EEG: Diagnostic and therapeutic tool for periventricular nodular heterotopia epilepsies.

PubMed

Mirandola, Laura; Mai, Roberto F; Francione, Stefano; Pelliccia, Veronica; Gozzo, Francesca; Sartori, Ivana; Nobili, Lino; Cardinale, Francesco; Cossu, Massimo; Meletti, Stefano; Tassi, Laura

2017-11-01

Periventricular nodular heterotopias (PNHs) are malformations of cortical development related to neuronal migration disorders, frequently associated with drug-resistant epilepsy (DRE). Stereo-electroencephalography (SEEG) is considered a very effective step of the presurgical evaluation, providing the recognition of the epileptogenic zone (EZ). At the same time, via the intracerebral electrodes it is possible to perform radiofrequency thermocoagulation (SEEG-guided RF-TC) with the aim of ablating and/or disrupting the EZ. The purpose of this study was to evaluate both the relationships between PNH and the EZ, and the efficacy of SEEG-guided RF-TC. Twenty patients with DRE related to PNHs were studied. Inclusion criteria were the following: (1) patients with epilepsy and PNHs (unilateral or bilateral, single or multiple nodules) diagnosed on brain magnetic resonance imaging (MRI); (2) SEEG recordings available as part of the presurgical investigations, with at least one intracerebral electrode inside the heterotopia; (3) complete surgical workup with SEEG-guided RF-TC and/or with traditional neurosurgery, with a follow-up of at least 12 months. Complex and heterogenic epileptic networks were found in these patients. SEEG-guided RF-TC both into the nodules and/or the cortex was efficacious in the 76% of patients. Single or multiple, unilateral or bilateral PNHs are the most suitable for this procedure, whereas patients with PNHs associated with complex cortical malformations obtained excellent outcome only with traditional resective surgery. Each patient had a specific epileptogenic network, independent from the number, size, or location of nodules and from the cortical malformation associated with. SEEG-guided RF-TC appears as a new and very effective diagnostic and therapeutic approach for DRE related to PNHs. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Constraints for recently discovered ignimbrites in the Altiplano-Puna Volcanic Complex (APVC), northern Chile

NASA Astrophysics Data System (ADS)

Layana, S.; Aguilera, F.

2014-12-01

One of most voluminous ignimbrite provinces in the world (>30.000 km3) is located in the Central Andean Volcanic Zone (CAVZ), which has been continuously active since Upper Oligocene. Altiplano-Puna Volcanic Complex (APVC), located between 21 and 24ºS, is a volcano-tectonic province constituted by diverse caldera complexes and ignimbrite deposits (Upper Miocene - Lower Pleistocene) that covers an area ~50.000 km2. In this work, we present data from three new ignimbrites discovered in a portion of APVC (22°-22,4°S), with the objective to establish its origin and provenance. Were identified 3 new ignimbrites: 1) Cabana ignimbrite (>7.5 Ma), constituted by 3 pyroclastic flow and 1 pyroclastic surge units of crystal-glass rich dacitic tuffs, 80 m maximum thick, 0.18 km3 volume and 0.14 km3 DRE; 2) Inacaliri ignimbrite (7.5 Ma) constituted by two members, corresponding to glassy dacitic (basal member) and basaltic andesites (upper member) tuffs, the total thick reach up 20 m, 0.003 km3 volume and 0.002 km3 DRE; 3) Tolar ignimbrite (>1.3 Ma), constituted by a single pyroclastic flow and a basal fall glassy dacitic deposits, 50 m maximum thick, 0.04 km3 volume and 0.03 km3 DRE. Cabana ignimbrite seems to have been originated from a single caldera complex, whose cannot be recognized in the field. Inacaliri ignimbrite could be related to initial phases of building of Inacaliri and Apacheta-Aguilucho volcanic complexes, or originated to a buried caldera located below both volcanic complexes. Finally, Tolar ignimbrite corresponds to initial building stage of Toconce volcano, located 2 km at NE from these deposits.

A functional polymorphism of the microRNA-146a gene is associated with susceptibility to drug-resistant epilepsy and seizures frequency.

PubMed

Cui, Lili; Tao, Hua; Wang, Yan; Liu, Zhou; Xu, Zhien; Zhou, Haihong; Cai, Yujie; Yao, Lifen; Chen, Beichu; Liang, Wandong; Liu, Yu; Cheng, Wanwen; Liu, Tingting; Ma, Guoda; Li, You; Zhao, Bin; Li, Keshen

2015-04-01

Epilepsy is the third most common chronic brain disorder and is characterized by an enduring predisposition for seizures. Recently, a growing body of evidence has suggested that microRNA-146a (miR-146a) is upregulated in the brains of epilepsy patients and of mouse models; furthermore, miR-146a may be involved in the development and progression of seizures through the regulation of inflammation and immune responses. In this report, we performed a case-control study to analyze the relationship between the two potentially functional single nucleotide polymorphisms (SNPs) of the miR-146a gene (rs2910464 and rs57095329) and the risk of epilepsy in a Chinese population comprising 249 cases and 249 healthy controls. Our study comprised 249 epilepsy patients and 249 healthy controls in two regions of China. The DNA was genotyped using the ABI PRISM SNapShot method. The statistical analysis was estimated using the chi-square test or Fisher's exact test. Our results indicated a significant association between the rs57095329 SNP of the miR-146a gene and the risk of drug resistant epilepsy (DRE) (genotypes, p = 0.0258 and alleles, p = 0.0108). Moreover, the rs57095329 A allele was found to be associated with a reduced risk of seizures frequency in DRE patients (all p < 0.001). However, the rs2910164 variant was not associated with epilepsy. Our data indicate that the rs57095329 polymorphism in the promoter region of miR-146a is involved in the genetic susceptibility to DRE and the seizures frequency. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Diagnostic approach to constipation impacts pediatric emergency department disposition.

PubMed

Chumpitazi, Corrie E; Rees, Chris A; Camp, Elizabeth A; Henkel, Erin B; Valdez, Karina L; Chumpitazi, Bruno P

2017-10-01

Constipation is a common cause of abdominal pain in children presenting to the emergency department (ED). The objectives of this study were to determine the diagnostic evaluation undertaken for constipation and to assess the association of the evaluation with final ED disposition. A retrospective chart review of children presenting to the pediatric ED of a quaternary care children's hospital with abdominal pain that received a soap suds enema therapy. A total of 512 children were included, 270 (52.7%) were female, and the median age was 8.0 (IQR: 4.0-11.0). One hundred and thirty eight patients (27%) had a digital rectal exam (DRE), 120 (22.8%) had bloodwork performed, 218 (43%) had urinalysis obtained, 397 (77.5%) had abdominal radiographs, 120 (23.4%) had abdominal ultrasounds, and 18 (3.5%) had computed tomography scans. Children who had a DRE had a younger median age (6.0, IQR: 3.0-9.25 vs. 8.0, IQR: 4.0-12.0; p<0.001) and were significantly less likely to have radiologic imaging (OR=0.50, 95% CI 0.32-0.78; p=0.002), but did not have an increased odds of being discharged home. After adjusting for gender, ethnicity, and significant past medical history those with an abdominal radiograph were less likely to be discharged to home (aOR=0.56, 95% CI 0.31-1.01; p=0.05). The diagnostic evaluation of children diagnosed with fecal impaction in the ED varied. Abdominal imaging may be avoided if children receive a DRE. When children presenting to the ED with abdominal pain had an abdominal radiograph, they were more likely to be admitted. Copyright © 2017 Elsevier Inc. All rights reserved.

Prevalence and characteristics of prostate cancer among participants of a community-based screening in Nigeria using serum prostate specific antigen and digital rectal examination.

PubMed

Ikuerowo, Stephen Odunayo; Omisanjo, Olufunmilade Adefolarin; Bioku, Muftau Jimoh; Ajala, Michael Olawale; Mordi, Victor Patrick Nonyelim; Esho, Julius Olusanmi

2013-01-01

Prostate cancer (CaP) is the most commonly diagnosed cancer among Nigerian men but CaP screening is not a common practice. The true burden of the disease in Nigeria is not known. The study was aimed at studying the community burden of CaP in Lagos. During a community-based prostate cancer awareness program in 13 local government areas of Lagos, men aged >40 years had serum total PSA (tPSA) test and digital rectal examination (DRE). Those with abnormal DRE or tPSA >95th percentile of the cohort or both were selected for prostate biopsy (TRPB). 4172 men were screened and complete data was available for 4110 (98.5%). The mean age was 60.8 years. DRE was abnormal in 410 men and was significantly correlated with the age of the patient and tPSA (p<0.001). The tPSA ranged from 0 to 438.3 ng/ml with a median, mean and 95th percentile of 1.5, 2.5 and 10.0 ng/ml respectively. 341 out of the 438 (78%) men selected were subjected to TRBP. Forty-three men had histological diagnosis of CaP, giving an estimated prevalence rate of at least 1.046% or 1046 per 100,000 men of age ≥40. Only 11 (26%) had organ-confined disease while 17 (40%) had locally advanced disease and 15 (35%) men had metastatic disease. The majority of the men, 32 (74%) were reported to have Gleason's score of ≥7. The prevalence rate of CaP among men aged ≥40 years in Lagos is higher than previously reported in hospital-based study. Majority have advanced and high-grade disease.

Next-generation sequencing improves treatment efficacy and reduces hospitalization in children with drug-resistant epilepsy.

PubMed

Peng, Jing; Pang, Nan; Wang, Ying; Wang, Xiao-Le; Chen, Jian; Xiong, Juan; Peng, Pan; Zhu, Can-Hui; Kessi, Miriam Barakael; He, Fang; Yin, Fei

2018-06-22

The purposes of this study were three-fold: (i) to determine the contribution of known genes to the causation of a broad-spectrum of pediatric drug-resistant epilepsy (DRE), (ii) to compare the diagnostic yield and cost among different next-generation sequencing (NGS) approaches, and especially (iii) to assess how NGS approaches can benefit patients by improving diagnosis and treatment efficiency. This study enrolled 273 pediatric DRE patients with no obvious acquired etiology. Seventy-four patients underwent whole-exome sequencing (WES), 141 patients had epilepsy-related gene panel testing, and another 58 patients had clinical WES gene panel testing. We obtained these patients' seizure and hospitalization frequency by periodic follow-up phone calls and outpatient visits. Genetic diagnosis was achieved in 86 patients (31.5%) and involved 93 likely disease-causing mutations in 33 genes. In this study, the detection rates of the epilepsy-related gene panel, the clinical WES gene panel, and WES were 32.6% (46/141), 44.8% (26/58), and 17.3% (13/74), respectively. Moreover, 34 patients accepted corrective therapy according to their mutant genes, after which 52.9% (18/34) became seizure-free and 38.2% (13/34) achieved seizure reduction. In the end, patients with either positive or negative genetic results had significantly fewer hospitalization incidents (times/half year) than before (positive genetic results group 0.58 ± 1.14 vs 0.10 ± 0.26; negative genetic results group 0.72 ± 1.65 vs 0.12 ± 0.33). These results offer further proof that NGS approaches represent powerful tools for establishing a definitive diagnosis. Moreover, this study indicated how NGS can improve treatment efficacy and reduce hospitalization in children with DRE. © 2018 John Wiley & Sons Ltd.

Surface smoothening of the inherent roughness of micro-lenses fabricated with 2-photon lithography

NASA Astrophysics Data System (ADS)

Schift, Helmut; Kirchner, Robert; Chidambaram, Nachiappan; Altana, Mirco

2018-01-01

Two-photon polymerization by direct laser writing enables to write refractive micro-optical elements with sub-μm precision. The trajectories and layering during the direct writing process often result in roughness in the range of the writing increment, which has adverse effects for optical applications. Instead of increasing overlap between adjacent voxels, roughness in the range of 100 nm can be smoothed out by post-processing. For this a method known as TASTE was developed, which allows polishing of surfaces without changing the structural details or the overall shape. It works particularly well with thermoplastic polymers and enables sub-10 nm roughness. The optical quality was confirmed for an array with several 100 microlenses.

Experiments on Hypersonic Roughness Induced Transition by Means of Infrared Thermography

NASA Astrophysics Data System (ADS)

Schrijer, F. F. J.; Scarano, F.; van Oudheusden, B. W.; Bannink, W. J.

2005-02-01

Roughness induced boundary layer transition is experimentally investigated in the hypersonic flow regime at M = 9. The primary interest is the possible effect of stepwise geometry imperfections (2D isolated roughness) on (boundary layer) transition which may be caused on the EXPERT vehicle by the difference in thermal expansion due to the different materials used in the vehicle-nose construction. Also 3D isolated and 3D distributed roughness configurations were studied. Quantitative Infra-Red Thermography (QIRT) is used as primary diagnostic technique to measure the surface convective heat transfer and to detect boundary layer laminar-to-turbulent transition. The investigation shows that for a given height of the roughness element, the boundary layer is least sensitive to a step-like disturbance, whereas distributed 3D roughness was found to be effective in triggering transition. The experimental results have been compared to existing hypersonic transition correlations (PANT and Shuttle). Finally a transition criterion is evaluated which is based on the critical roughness height Reynolds number. Usage of this criterion enables a straightforward extrapolation to flight. Key words: hypersonic flow, boundary layer transition.

Direct numerical simulation of a compressible boundary-layer flow past an isolated three-dimensional hump in a high-speed subsonic regime

NASA Astrophysics Data System (ADS)

De Grazia, D.; Moxey, D.; Sherwin, S. J.; Kravtsova, M. A.; Ruban, A. I.

2018-02-01

In this paper we study the boundary-layer separation produced in a high-speed subsonic boundary layer by a small wall roughness. Specifically, we present a direct numerical simulation (DNS) of a two-dimensional boundary-layer flow over a flat plate encountering a three-dimensional Gaussian-shaped hump. This work was motivated by the lack of DNS data of boundary-layer flows past roughness elements in a similar regime which is typical of civil aviation. The Mach and Reynolds numbers are chosen to be relevant for aeronautical applications when considering small imperfections at the leading edge of wings. We analyze different heights of the hump: The smaller heights result in a weakly nonlinear regime, while the larger result in a fully nonlinear regime with an increasing laminar separation bubble arising downstream of the roughness element and the formation of a pair of streamwise counterrotating vortices which appear to support themselves.

Automated high-speed Mueller matrix scatterometer.

PubMed

Delplancke, F

1997-08-01

A new scatterometer-polarimeter is described. It measures the angular distribution of intensity and of the complete Mueller matrix of light scattered by rough surfaces and particle suspensions. The measurement time is 1 s/scattering angle in the present configuration but can be reduced to a few milliseconds with modified electronics. The instrument uses polarization modulation and a Fourier analysis of four detected signals to obtain the 16 Mueller matrix elements. This method is particularly well suited to online, real time, industrial process control involving rough surfaces and large particle suspensions (an arithmetic roughness or particle diameter of >1 microm). Some results are given.

Surface Roughness Relief

NASA Astrophysics Data System (ADS)

Marras, L.; Fontana, R.; Gambino, M. C.; Greco, M.; Materazzi, M.; Pampaloni, E.; Pezzati, L.; Poggi, P.

The knowledge of the shape of an artwork is an important element for its study and conservation. When dealing with a stone statue, roughness measurement is a very useful contribution to document its surface conditions, to assess either changes due to restoration intervention or surface decays due to weathering agents, and to monitor its time-evolution in terms of shape variations. In this work we present the preliminary results of the statistical analysis carried out on acquired data relative to six areas of the Michelangelo's David marble statue, representative of differently degraded surfaces. Determination of the roughness and its relative characteristic wavelength is shown.

DRE Directions: What Makes an Effective Catechetical Leader?

ERIC Educational Resources Information Center

Walters, Thomas P.; Walters, Rita Tyson

2003-01-01

Discusses the top ten characteristics of effective Catechetical leaders: (1) prayerful/spiritual people; (2) passion for Catechetical Ministry; (3) creativity; (4) cooperative behavior; (5) active in professional organizations; (6) learns continuously; (7) respected by peers; (8) possesses administrative skills and run creative programs; (9)…

Abatement of Perfluorinated Compounds Using Cylindrical Microwave Plasma Source at Low Pressure

NASA Astrophysics Data System (ADS)

Kim, Seong Bong; Park, S.; Park, Y.; Youn, S.; Yoo, S. J.

2016-10-01

Microwave plasma source with a cylindrical cavity has been proposed to abate the perfluorinated compounds (PFCs). This plasma source was designed to generate microwave plasma with the cylindrical shape and to be easily installed in existing exhaust line. The microwave frequency is 2.45 GHz and the operating pressure range is 0.1 Torr to 0.3 Torr. The plasma characteristic of the cylindrical microwave plasma source was measured using the optical spectrometer, and tunable diode laser absorption spectroscopy (TDLAS). The destruction and removal efficiency (DRE) of CF4 and CHF3 were measured by a quadrupole mass spectroscopy (QMS) with the various operation conditions. The effect of the addition of the oxygen gas were tested and also the correlation between the plasma parameters and the DRE are presented in this study. This work was supported by R&D Program of ``Plasma Advanced Technology for Agriculture and Food (Plasma Farming)'' through the National Fusion Research Institute of Korea (NFRI) funded by the Government funds.

The Effect of an Isogrid on Cryogenic Propellant Behavior and Thermal Stratification

NASA Technical Reports Server (NTRS)

Oliveira, Justin; Kirk, Daniel R.; Chintalapati, Sunil; Schallhorn, Paul A.; Piquero, Jorge L.; Campbell, Mike; Chase, Sukhdeep

2007-01-01

All models for thermal stratification available in the presentation are derived using smooth, flat plate laminar and turbulent boundary layer models. This study examines the effect of isogrid (roughness elements) on the surface of internal tank walls to mimic the effects of weight-saving isogrid, which is located on the inside of many rocket propellant tanks. Computational Fluid Dynamics (CFD) is used to study the momentum and thermal boundary layer thickness for free convection flows over a wall with generic roughness elements. This presentation makes no mention of actual isogrid sizes or of any specific tank geometry. The magnitude of thermal stratification is compared for smooth and isogrid-lined walls.

Wind erosion in semiarid landscapes: Predictive models and remote sensing methods for the influence of vegetation

NASA Technical Reports Server (NTRS)

Musick, H. Brad; Truman, C. Randall; Trujillo, Steven M.

1992-01-01

Wind erosion in semi-arid regions is a significant problem for which the sheltering effect of rangeland vegetation is poorly understood. Individual plants may be considered as porous roughness elements which absorb or redistribute the wind's momentum. The saltation threshold is the minimum wind velocity at which soil movement begins. The dependence of the saltation threshold on geometrical parameters of a uniform roughness array was studied in a wind tunnel. Both solid and porous elements were used to determine relationships between canopy structure and the threshold velocity for soil transport. The development of a predictive relation for the influence of vegetation canopy structure on wind erosion of soil is discussed.

Ice Roughness in Short Duration SLD Icing Events

NASA Technical Reports Server (NTRS)

McClain, Stephen T.; Reed, Dana; Vargas, Mario; Kreeger, Richard E.; Tsao, Jen-Ching

2014-01-01

Ice accretion codes depend on models of roughness parameters to account for the enhanced heat transfer during the ice accretion process. While mitigating supercooled large droplet (SLD or Appendix O) icing is a significant concern for manufacturers seeking future vehicle certification due to the pending regulation, historical ice roughness studies have been performed using Appendix C icing clouds which exhibit mean volumetric diameters (MVD) much smaller than SLD clouds. Further, the historical studies of roughness focused on extracting parametric representations of ice roughness using multiple images of roughness elements. In this study, the ice roughness developed on a 21-in. NACA 0012 at 0deg angle of attack exposed to short duration SLD icing events was measured in the Icing Research Tunnel at the NASA Glenn Research Center. The MVD's used in the study ranged from 100 micrometer to 200 micrometers, in a 67 m/s flow, with liquid water contents of either 0.6 gm/cubic meters or 0.75 gm/cubic meters. The ice surfaces were measured using a Romer Absolute Arm laser scanning system. The roughness associated with each surface point cloud was measured using the two-dimensional self-organizing map approach developed by McClain and Kreeger (2013) resulting in statistical descriptions of the ice roughness.

Experimental partitioning of Tc, Mo, Ru, and Re between solid and liquid during crystallization in Fe-Ni-S 1

NASA Astrophysics Data System (ADS)

Lazar, C.; Walker, D.; Walker, R. J.

2004-02-01

Technetium isotopes 97Tc, 98Tc and 99Tc decay to 97Mo, 98Ru and 99Ru, with half-lives of 2.6 My, 4.1 My, and 0.21 My respectively. If there were early solar system processes that resulted in significant fractionation of Tc from the daughter elements, decay of extant Tc could have led to the creation of Mo and Ru isotopic heterogeneities. To assess the potential of metallic core crystallization to fractionate these elements, we examine the partitioning behavior of Tc relative to Re, Mo and Ru in the Fe-Ni-S system between solid metal and liquid metal alloy. The experimental evidence shows that Tc behaves more like the modestly compatible siderophile element Ru than the more highly compatible siderophile element Re, and that Tc is substantially more compatible than Mo. We also demonstrate a pressure effect in the partitioning of Mo during the crystallization of Fe-Ni-S melts. For a sulfur concentration in the liquid fraction of the core of 10 wt% (16.3 at%), the Jones and Malvin (1990) parameter is -ln(1-2 × 1.09 × 0.163) ≅ 0.44, which yields: D(Re) ≅ 4.1; D(Ru) ≅ 2.3; D(Tc) ≅ 1.7; D(Mo) Lo-P ≅ 1.0;.and D(Mo) Hi-P ≅ 0.5. Our results suggest that detectable Tc-induced isotopic anomalies (≥0.1 ɛ unit) in Ru and Mo could only be produced by unrealistically extreme degrees of crystallization of metal during asteroidal core fractionation, regardless of the time scales and initial Tc abundances involved.

Watershed Complexity Impacts on Rainfall-Runoff Modeling

NASA Astrophysics Data System (ADS)

Goodrich, D. C.; Grayson, R.; Willgoose, G.; Palacios-Velez, O.; Bloeschl, G.

2002-12-01

Application of distributed hydrologic watershed models fundamentally requires watershed partitioning or discretization. In addition to partitioning the watershed into modeling elements, these elements typically represent a further abstraction of the actual watershed surface and its relevant hydrologic properties. A critical issue that must be addressed by any user of these models prior to their application is definition of an acceptable level of watershed discretization or geometric model complexity. A quantitative methodology to define a level of geometric model complexity commensurate with a specified level of model performance is developed for watershed rainfall-runoff modeling. In the case where watershed contributing areas are represented by overland flow planes, equilibrium discharge storage was used to define the transition from overland to channel dominated flow response. The methodology is tested on four subcatchments which cover a range of watershed scales of over three orders of magnitude in the USDA-ARS Walnut Gulch Experimental Watershed in Southeastern Arizona. It was found that distortion of the hydraulic roughness can compensate for a lower level of discretization (fewer channels) to a point. Beyond this point, hydraulic roughness distortion cannot compensate for topographic distortion of representing the watershed by fewer elements (e.g. less complex channel network). Similarly, differences in representation of topography by different model or digital elevation model (DEM) types (e.g. Triangular Irregular Elements - TINs; contour lines; and regular grid DEMs) also result in difference in runoff routing responses that can be largely compensated for by a distortion in hydraulic roughness.

Continuity and Change; the Need for Both.

ERIC Educational Resources Information Center

Benezet, Louis T.

Eighteen administrators, organization directors, and senior professors were asked to determine what elements had remained the most unchanged during their roughly 30 years in higher education, and what elements had changed the most and would, perhaps, continue to change. (To the outsider, among many transformations related to the increasing size…

UV Exposure, Vitamin D, and Prostate Cancer Risk in African Americans

DTIC Science & Technology

2006-08-01

positive DRE. They were recruited through Howard University Hospital. Nine age- and ethnicity-matched controls have been recruited through the free...screenings program at Howard University Cancer Center. For patients and controls, the authors have collected medical histories and blood samples for gene

Plume Dispersion over Idealized Urban-liked Roughness with Height Variation: an LES Approach

NASA Astrophysics Data System (ADS)

Wong, Colman Ching Chi; Liu, Chun-Ho

2013-04-01

Human activities (e.g. vehicular emission) are the primary pollutant sources affecting the health and living quality of stakeholders in modern compact cities. Gaussian plume dispersion model is commonly used for pollutant distribution estimate that works well over rural areas with flat terrain. However, its major parameters, dispersion coefficients, exclude the effect of surface roughness that unavoidably prone to error handling the pollutant transport in the urban boundary layer (UBL) over building roughness. Our recent large-eddy simulation (LES) has shown that urban surfaces affect significantly the pollutant dispersion over idealized, identical two-dimensional (2D) street canyons of uniform height. As an extension to our on-going effort, this study is conceived to investigate how rough urban surfaces, which are constructed by 2D street canyons of non-uniform height, modify the UBL pollutant dispersion . A series of LESs with idealized roughness elements of non-uniform heights were performed in neutral stratification. Building models with two different heights were placed alternatively in the computational domain to construct 2D street canyons in cross flows. The plume dispersion from a ground-level passive pollutant source over more realistic urban areas was then examined. Along with the existing building-height-to-street-width (aspect) ratio (AR), a new parameter, building-height variability (BHV), is used to measure the building height unevenness. Four ARs (1, 0.5, 0.25 and 0.125) and three BHVs (20%, 40% and 60%) were considered in this study. Preliminary results show that BHV greatly increases the aerodynamic roughness of the hypothetical urban surfaces for narrow street canyons. Analogous to our previous findings, the air exchange rate (ACH) of street canyons increases with increasing friction factor, implying that street-level ventilation could be improved by increasing building roughness via BHV. In addition, the parameters used in dispersion coefficient estimates are related to the friction factor in the way similar to that of uniform street canyons, i.e. they are linear functions of friction factor when the roughness is small and become insensitive to friction factor thereafter over very rough surfaces. It is thus suggested that aerodynamic resistance is the key factor affecting the air quality in urban areas. Moreover, the friction factor could be used to parameterize the dispersion coefficients over different roughness elements.

Boundary Layer Control for Hypersonic Airbreathing Vehicles

NASA Technical Reports Server (NTRS)

Berry, Scott A.; Nowak, Robert J.; Horvath, Thomas J.

2004-01-01

Active and passive methods for tripping hypersonic boundary layers have been examined in NASA Langley Research Center wind tunnels using a Hyper-X model. This investigation assessed several concepts for forcing transition, including passive discrete roughness elements and active mass addition (or blowing), in the 20-Inch Mach 6 Air and the 31-Inch Mach 10 Air Tunnels. Heat transfer distributions obtained via phosphor thermography, shock system details, and surface streamline patterns were measured on a 0.333-scale model of the Hyper-X forebody. The comparisons between the active and passive methods for boundary layer control were conducted at test conditions that nearly match the Hyper-X nominal Mach 7 flight test-point of an angle-of-attack of 2-deg and length Reynolds number of 5.6 million. For passive roughness, the primary parametric variation was a range of trip heights within the calculated boundary layer thickness for several trip concepts. The passive roughness study resulted in a swept ramp configuration, scaled to be roughly 0.6 of the calculated boundary layer thickness, being selected for the Mach 7 flight vehicle. For the active blowing study, the manifold pressure was systematically varied (while monitoring the mass flow) for each configuration to determine the jet penetration height, with schlieren, and transition movement, with the phosphor system, for comparison to the passive results. All the blowing concepts tested, which included various rows of sonic orifices (holes), two- and three-dimensional slots, and random porosity, provided transition onset near the trip location with manifold stagnation pressures on the order of 40 times the model surface static pressure, which is adequate to ensure sonic jets. The present results indicate that the jet penetration height for blowing was roughly half the height required with passive roughness elements for an equivalent amount of transition movement.

Dust Devils on Mars: Effects of Surface Roughness on Particle Threshold

NASA Technical Reports Server (NTRS)

Neakrase, Lynn D.; Greeley, Ronald; Iversen, James D.; Balme, Matthew L.; Foley, Daniel J.; Eddlemon, Eric E.

2005-01-01

Dust devils have been proposed as effective mechanisms for lofting large quantities of dust into the martian atmosphere. Previous work showed that vortices lift dust more easily than simple boundary layer winds. The aim of this study is to determine experimentally the effects of non-erodable roughness elements on vortex particle threshold through laboratory simulations of natural surfaces. Additional information is included in the original extended abstract.

Effects of surface roughness and electrokinetic heterogeneity on electroosmotic flow in microchannel

NASA Astrophysics Data System (ADS)

Masilamani, Kannan; Ganguly, Suvankar; Feichtinger, Christian; Bartuschat, Dominik; Rüde, Ulrich

2015-06-01

In this paper, a hybrid lattice-Boltzmann and finite-difference (LB-FD) model is applied to simulate the effects of three-dimensional surface roughness and electrokinetic heterogeneity on electroosmotic flow (EOF) in a microchannel. The lattice-Boltzmann (LB) method has been employed to obtain the flow field and a finite-difference (FD) method is used to solve the Poisson-Boltzmann (PB) equation for the electrostatic potential distribution. Numerical simulation of flow through a square cross-section microchannel with designed roughness is conducted and the results are critically analysed. The effects of surface heterogeneity on the electroosmotic transport are investigated for different roughness height, width, roughness interval spacing, and roughness surface potential. Numerical simulations reveal that the presence of surface roughness changes the nature of electroosmotic transport through the microchannel. It is found that the electroosmotic velocity decreases with the increase in roughness height and the velocity profile becomes asymmetric. For the same height of the roughness elements, the EOF velocity rises with the increase in roughness width. For the heterogeneously charged rough channel, the velocity profile shows a distinct deviation from the conventional plug-like flow pattern. The simulation results also indicate locally induced flow vortices which can be utilized to enhance the flow and mixing within the microchannel. The present study has important implications towards electrokinetic flow control in the microchannel, and can provide an efficient way to design a microfluidic system of practical interest.

Roughness Sensitivity Comparisons of Wind Turbine Blade Sections

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

Wilcox, Benjamin J.; White, Edward B.; Maniaci, David Charles

One explanation for wind turbine power degradation is insect roughness. Historical studies on insect-induced power degradation have used simulation methods which are either un- representative of actual insect roughness or too costly or time-consuming to be applied to wide-scale testing. Furthermore, the role of airfoil geometry in determining the relations between insect impingement locations and roughness sensitivity has not been studied. To link the effects of airfoil geometry, insect impingement locations, and roughness sensitivity, a simulation code was written to determine representative insect collection patterns for different airfoil shapes. Insect collection pattern data was then used to simulate roughness onmore » an NREL S814 airfoil that was tested in a wind tunnel at Reynolds numbers between 1.6 x 10 6 and 4.0 x 10 6. Results are compared to previous tests of a NACA 63 3 -418 airfoil. Increasing roughness height and density results in decreased maximum lift, lift curve slope, and lift-to-drag ratio. Increasing roughness height, density, or Reynolds number results in earlier bypass transition, with critical roughness Reynolds numbers lying within the historical range. Increased roughness sensitivity on the 25% thick NREL S814 is observed compared to the 18% thick NACA 63 3 -418. Blade-element-momentum analysis was used to calculate annual energy production losses of 4.9% and 6.8% for a NACA 63 3 -418 turbine and an NREL S814 turbine, respectively, operating with 200 μm roughness. These compare well to historical field measurements.« less

Roughness sensitivity comparisons of wind turbine blade sections

NASA Astrophysics Data System (ADS)

Wilcox, Benjamin Jacob

One explanation for wind turbine power degradation is insect roughness. Historical studies on insect-induced power degradation have used simulation methods which are either unrepresentative of actual insect roughness or too costly or time-consuming to be applied to wide-scale testing. Furthermore, the role of airfoil geometry in determining the relations between insect impingement locations and roughness sensitivity has not been studied. To link the effects of airfoil geometry, insect impingement locations, and roughness sensitivity, a simulation code was written to determine representative insect collection patterns for different airfoil shapes. Insect collection pattern data was then used to simulate roughness on an NREL S814 airfoil that was tested in a wind tunnel at Reynolds numbers between 1:6 x 106 and 4:0 x 106. Results are compared to previous tests of a NACA 633-418 airfoil. Increasing roughness height and density results in decreased maximum lift, lift curve slope, and lift-to-drag ratio. Increasing roughness height, density, or Reynolds number results in earlier bypass transition, with critical roughness Reynolds numbers lying within the historical range. Increased roughness sensitivity on the 25% thick NREL S814 is observed compared to the 18% thick NACA 633-418. Blade-element-momentum analysis was used to calculate annual energy production losses of 4.9% and 6.8% for a NACA 633-418 turbine and an NREL S814 turbine, respectively, operating with 200 microm roughness. These compare well to historical field measurements.

A finite-element model study of the impact of the proposed I-326 crossing on flood stages of the Congaree River near Columbia, South Carolina

USGS Publications Warehouse

Lee, J.K.; Bennett, C. S.

1981-01-01

A two-dimensional finite element surface water model was used to study the hydraulic impact of the proposed Interstate Route 326 crossing of the Congaree River near Columbia, SC. The finite element model was assessed as a potential operational tool for analyzing complex highway crossings and other modifications of river flood plains. Infrared aerial photography was used to define regions of homogeneous roughness in the flood plain. Finite element networks approximating flood plain topography were designed using elements of three roughness types. High water marks established during an 8-yr flood that occurred in October 1976 were used to calibrate the model. The maximum flood of record, an approximately 100-yr flood that occurred in August 1908, was modeled in three cases: dikes on the right bank, dikes on the left bank, and dikes on both banks. In each of the three cases, simulations were performed both without and with the proposed highway embankments in place. Detailed information was obtained about backwater effects upstream from the proposed highway embankments, changes in flow distribution resulting from the embankments, and local velocities in the bridge openings. On the basis of results from the model study, the South Carolina Department of Highways and Public Transportation changed the design of several bridge openings. A simulation incorporating the new design for the case with dikes on the left bank indicated that both velocities in the bridge openings and backwater were reduced. A major problem in applying the model was the difficulty in predicting the network detail necessary to avoid local errors caused by roughness discontinuities and large depth gradients. (Lantz-PTT)

DRE Directions: Determining Fair Compensation for Parish Catechetical Leaders.

ERIC Educational Resources Information Center

Almon, Sister Marianne

2001-01-01

Reports that those who work as professional directors of religious education and coordinators of religious education have often been compensated with a volunteers stipend only. States that the National Association of Parish Catechetical Directors met to share information on what can be done to better compensate these leaders. (CJW)

40 CFR 266.104 - Standards to control organic emissions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... DRE trial burn. (5) Low risk waste. Owners and operators of boilers or industrial furnaces that burn... HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.104...) of this section, a boiler or industrial furnace burning hazardous waste must achieve a destruction...

40 CFR 266.104 - Standards to control organic emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... DRE trial burn. (5) Low risk waste. Owners and operators of boilers or industrial furnaces that burn... HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.104...) of this section, a boiler or industrial furnace burning hazardous waste must achieve a destruction...

Teratogenic impact of dioxin-activated AHR in laboratory animals

EPA Science Inventory

AHR and ARNT are expressed in mouse and human palatal shelves and in the urinary tract of the mouse fetus. AHR expression, translocation to the nucleus, binding to DRE, and activation are required for mediation of TCDD-induction of CP and HN. Although the human palate requires a ...

40 CFR 266.104 - Standards to control organic emissions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.104...) of this section, a boiler or industrial furnace burning hazardous waste must achieve a destruction... demonstrate conformance with this requirement, 99.99% DRE must be demonstrated during a trial burn for each...

40 CFR 266.104 - Standards to control organic emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.104...) of this section, a boiler or industrial furnace burning hazardous waste must achieve a destruction... demonstrate conformance with this requirement, 99.99% DRE must be demonstrated during a trial burn for each...

40 CFR 266.104 - Standards to control organic emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.104...) of this section, a boiler or industrial furnace burning hazardous waste must achieve a destruction... demonstrate conformance with this requirement, 99.99% DRE must be demonstrated during a trial burn for each...

High-precision surface analysis of the roughness of Michelangelo's David

NASA Astrophysics Data System (ADS)

Fontana, Raffaella; Gambino, Maria Chiara; Greco, Marinella; Marras, Luciano; Materazzi, Marzia; Pampaloni, Enrico; Pezzati, Luca

2003-10-01

The knowledge of the shape of an artwork is an important element for its study and conservation. When dealing with a statue, roughness measurement is a very useful contribution to document its surface conditions, to assess either changes due to restoration intervention or surface decays due to wearing agents, and to monitor its time-evolution in terms of shape variations. In this work we present the preliminary results of the statistical analysis carried out on acquired data relative to six areas of the Michelangelo"s David marble statue, representative of differently degraded surfaces. Determination of the roughness and its relative characteristic wavelength is shown.

Influence of the Cutting Conditions in the Surface Finishing of Turned Pieces of Titanium Alloys

NASA Astrophysics Data System (ADS)

Huerta, M.; Arroyo, P.; Sánchez Carrilero, M.; Álvarez, M.; Salguero, J.; Marcos, M.

2009-11-01

Titanium is a material that, despite its high cost, is increasingly being introduced in the aerospace industry due to both, its weight, its mechanical properties and its corrosion potential, very close to that of carbon fiber based composite material. This fact allows using Ti to form Fiber Metal Laminates Machining operations are usually used in the manufacturing processes of Ti based aerospace structural elements. These elements must be machined under high surface finish requirements. Previous works have shown the relationship between the surface roughness and the tool changes in the first instants of turning processes. From these results, new tests have been performed in an aeronautical factory, in order to analyse roughness in final pieces.

Investigation of the influence of a step change in surface roughness on turbulent heat transfer

NASA Technical Reports Server (NTRS)

Taylor, Robert P.; Coleman, Hugh W.; Taylor, J. Keith; Hosni, M. H.

1991-01-01

The use is studied of smooth heat flux gages on the otherwise very rough SSME fuel pump turbine blades. To gain insights into behavior of such installations, fluid mechanics and heat transfer data were collected and are reported for a turbulent boundary layer over a surface with a step change from a rough surface to a smooth surface. The first 0.9 m length of the flat plate test surface was roughened with 1.27 mm hemispheres in a staggered, uniform array spaced 2 base diameters apart. The remaining 1.5 m length was smooth. The effect of the alignment of the smooth surface with respect to the rough surface was also studied by conducting experiments with the smooth surface aligned with the bases or alternatively with the crests of the roughness elements. Stanton number distributions, skin friction distributions, and boundary layer profiles of temperature and velocity are reported and are compared to previous data for both all rough and all smooth wall cases. The experiments show that the step change from rough to smooth has a dramatic effect on the convective heat transfer. It is concluded that use of smooth heat flux gages on otherwise rough surfaces could cause large errors.

Non-Contact Surface Roughness Measurement by Implementation of a Spatial Light Modulator

PubMed Central

Aulbach, Laura; Salazar Bloise, Félix; Lu, Min; Koch, Alexander W.

2017-01-01

The surface structure, especially the roughness, has a significant influence on numerous parameters, such as friction and wear, and therefore estimates the quality of technical systems. In the last decades, a broad variety of surface roughness measurement methods were developed. A destructive measurement procedure or the lack of feasibility of online monitoring are the crucial drawbacks of most of these methods. This article proposes a new non-contact method for measuring the surface roughness that is straightforward to implement and easy to extend to online monitoring processes. The key element is a liquid-crystal-based spatial light modulator, integrated in an interferometric setup. By varying the imprinted phase of the modulator, a correlation between the imprinted phase and the fringe visibility of an interferogram is measured, and the surface roughness can be derived. This paper presents the theoretical approach of the method and first simulation and experimental results for a set of surface roughnesses. The experimental results are compared with values obtained by an atomic force microscope and a stylus profiler. PMID:28294990

Fatigue Debonding of the Roughened Stem–Cement Interface: Effects of Surface Roughness and Stem Heating Conditions

PubMed Central

Damron, Leatha A.; Kim, Do-Gyoon; Mann, Kenneth A.

2007-01-01

The aim of this study was to determine the effects of cyclic loading on the debond process of a roughened stem– cement interface used in total hip arthroplasty. The specific goals were to assess the effects of two surgeon-controlled variables (stem heating and degree of stem surface roughness) and to determine if an independent finite element-based fracture mechanics model could be used to predict the debond response. A clamped cantilever beam geometry was used to determine the fatigue debond response of the stem– cement interface and was created using an experimental mold that simulated in vivo cementing conditions. A second experiment was performed using a torsion-loading model representative of the stem– cement–bone composite. For both experiments, two stem heating (room temperature and 50°C) and surface roughness conditions (grit blasted: Ra = 2.3 and 5.1 μm) were used. Finally, a finite element model of the torsion experiment with provision for crack growth was developed and compared with the experimental results. Results from both experiments revealed that neither stem preheating nor use of a stem with a greater surface roughness had a marked effect on the fatigue debond response. There was substantial variability in the debond response for all cases; this may be due to microscopic gaps at the interface for all interface conditions. The debond rate from the finite element simulation (10−7.31 m/cycle) had a magnitude similar to the experimental torsion model (10− (6.77 ± 1.25) m/cycle). This suggests that within the context of the experimental conditions studied here that the debond response could be assessed using a linear elastic fracture mechanics-type approach. PMID:16292769

The effect of catchment discretization on rainfall-runoff model predictions

NASA Astrophysics Data System (ADS)

Goodrich, D.; Grayson, R.; Willgoose, G.; Palacios-Valez, O.; Bloschl, G.

2003-04-01

Application of distributed hydrologic watershed models fundamentally requires watershed partitioning or discretization. In addition to partitioning the watershed into modelling elements, these elements typically represent a further abstraction of the actual watershed surface and its relevant hydrologic properties. A critical issue that must be addressed by any user of these models prior to their application is definition of an acceptable level and type of watershed discretization or geometric model complexity. A quantitative methodology to define a level of geometric model complexity commensurate with a specified level of model performance is developed for watershed rainfall-runoff modelling. The methodology is tested on four subcatchments which cover a range of watershed scales of over three orders of magnitude in the USDA-ARS Walnut Gulch Experimental Watershed in Southeastern Arizona. It was found that distortion of the hydraulic roughness can compensate for a lower level of discretization (fewer channels) to a point. Beyond this point, hydraulic roughness distortion cannot compensate for the topographic distortion of representing the watershed by fewer elements (e.g. less complex channel network). Similarly, differences in representation of topography by different model or digital elevation model (DEM) types (e.g. Triangular Irregular Elements - TINs; contour lines; and regular grid DEMs) also result in difference in runoff routing responses that can be largely compensated for by a distortion in hydraulic roughness or path length. To put the effect of these discretization models in context it will be shown that relatively small non-compliance with Peclet number restrictions on timestep size can overwhelm the relatively modest differences resulting from the type of representation of topography.

Comparison of different types of phacoemulsification tips. I. Quantitative analysis of elemental composition and tip surface microroughness.

PubMed

Tsaousis, Konstantinos T; Werner, Liliana; Perez, Jesus Paulo; Li, He J; Reiter, Nicholas; Guan, Jia J; Mamalis, Nick

2016-09-01

To evaluate the elemental composition of phacoemulsification tips and their surface roughness in the microscale. John A. Moran Eye Center and Utah Nanofab, College of Engineering, University of Utah, Salt Lake City, Utah, USA. Experimental study. Seven types of phacoemulsification tips were studied. The phaco tips were examined through energy-dispersive x-ray spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) for elemental composition. In addition, the roughness of the opening in all tips was assessed through 3-dimensional white-light interferometry. Elemental analysis showed considerable differences in the surface layers between manufacturers. Alcon tips had a thinner oxidized titanium (Ti) layer in their surface. Through XPS, vanadium was not detected in the superficial layers of any tip, but only in deeper levels. The microroughness surface analysis showed comparable results regarding their root-mean-square (RMS) metric. Maximum peak valley distance values varied and appeared to be dependent on the quality of material process rather than the material itself. Phacoemulsification tips are made of Ti alloys and showed differences between models, especially regarding their composition in the superficial layers. Their opening end roughness showed an overall appropriate RMS value of less than 1.0 μm in all cases. The existence of small defected areas highlights the importance of adequate quality control of these critical surgical instruments. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Development of channel organization and roughness following sediment pulses in single‐thread, gravel bed rivers

USGS Publications Warehouse

Madej, Mary Ann

2001-01-01

Large, episodic inputs of coarse sediment (sediment pulses) in forested, mountain streams may result in changes in the size and arrangement of bed forms and in channel roughness. A conceptual model of channel organization delineates trajectories of response to sediment pulses for many types of gravel bed channels. Channels exhibited self‐organizing behavior to various degrees based on channel gradient, presence of large in‐channel wood or other forcing elements, the size of the sediment pulse, and the number of bed‐mobilizing flows since disturbance. Typical channel changes following a sediment pulse were initial decreases in water depth, in variability of bed elevations, and in the regularity of bed form spacing. Trajectories of change subsequently showed increased average water depth, more variable and complex bed topography, and increased uniformity of bed form spacing. Bed form spacing in streams with abundant forcing elements developed at a shorter spatial scale (two to five channel widths) than in streams without such forcing mechanisms (five to 10 channel widths). Channel roughness increased as bed forms developed.

Effect of blade-surface-roughness on the pumping performance of a turbomolecular pump

NASA Astrophysics Data System (ADS)

Sawada, T.; Yabuki, M.; Sugiyama, W.; Watanabe, M.

2005-11-01

Turbomolecular pumps (TMPs) are widely used in the semiconductor and other thin film industries. Some semiconductor processes form corrosive gases such as HCl or HF as byproducts. The elements of a TMP are sometimes coated with ceramic (SiO2) film for the purpose of preventing corrosion of the TMP. The blades coated with SiO2 have relatively rough surfaces. The effect of the surface roughness of the blades on the pumping performance has been studied experimentally and theoretically. Experimental results for TMPs with two rotor disks and one stator disk show that the TMP coated with SiO2 film gives about 11% to 13% higher maximum-compression ratio than the noncoated TMP when the blade speed ratio is 0.47. The theory based on the conic peak/dimple-surface-roughness model that has been proposed by the authors explains the change in the compression ratio with the surface roughness shown in the experiment.

An Investigation of the Influence of Initial Roughness on the Friction and Wear Behavior of Ground Surfaces

PubMed Central

Liang, Guoxing; Schmauder, Siegfried; Lyu, Ming; Schneider, Yanling; Zhang, Cheng; Han, Yang

2018-01-01

Friction and wear tests were performed on AISI 1045 steel specimens with different initial roughness parameters, machined by a creep-feed dry grinding process, to study the friction and wear behavior on a pin-on-disc tester in dry sliding conditions. Average surface roughness (Ra), root mean square (Rq), skewness (Rsk) and kurtosis (Rku) were involved in order to analyse the influence of the friction and wear behavior. The observations reveal that a surface with initial roughness parameters of higher Ra, Rq and Rku will lead to a longer initial-steady transition period in the sliding tests. The plastic deformation mainly concentrates in the depth of 20–50 μm under the worn surface and the critical plastic deformation is generated on the rough surface. For surfaces with large Ra, Rq, low Rsk and high Rku values, it is easy to lose the C element in, the reciprocating extrusion. PMID:29401703

Determining Surface Roughness in Urban Areas Using Lidar Data

NASA Technical Reports Server (NTRS)

Holland, Donald

2009-01-01

An automated procedure has been developed to derive relevant factors, which can increase the ability to produce objective, repeatable methods for determining aerodynamic surface roughness. Aerodynamic surface roughness is used for many applications, like atmospheric dispersive models and wind-damage models. For this technique, existing lidar data was used that was originally collected for terrain analysis, and demonstrated that surface roughness values can be automatically derived, and then subsequently utilized in disaster-management and homeland security models. The developed lidar-processing algorithm effectively distinguishes buildings from trees and characterizes their size, density, orientation, and spacing (see figure); all of these variables are parameters that are required to calculate the estimated surface roughness for a specified area. By using this algorithm, aerodynamic surface roughness values in urban areas can then be extracted automatically. The user can also adjust the algorithm for local conditions and lidar characteristics, like summer/winter vegetation and dense/sparse lidar point spacing. Additionally, the user can also survey variations in surface roughness that occurs due to wind direction; for example, during a hurricane, when wind direction can change dramatically, this variable can be extremely significant. In its current state, the algorithm calculates an estimated surface roughness for a square kilometer area; techniques using the lidar data to calculate the surface roughness for a point, whereby only roughness elements that are upstream from the point of interest are used and the wind direction is a vital concern, are being investigated. This technological advancement will improve the reliability and accuracy of models that use and incorporate surface roughness.

Underwater sky image as remote sensing instrument of sea roughness parameters and its variability

NASA Astrophysics Data System (ADS)

Molkov, Alexander A.; Dolin, Lev S.; Kapustin, Ivan A.; Sergievskaya, Irina A.; Shomina, Olga V.

2016-10-01

At present a sufficient amount of methods is offered for determining the characteristics of sea roughness in accordance with optical images of wavy water surface obtained from different near-shore constructions, sea platforms, vessels, aircraft and satellites. The most informative elements in this case are solar path and peripheral areas of the image free from sun glitters. However, underwater images of the surface obtained with the help of optical receiver located at a certain depth contain apart from the mentioned elements one more informative element- Snell's window. It is an underwater sky image which distortions of border contain information on roughness characteristics and serve as the indicator of its variability. The research offers the method for determining energy spectra of wind waves in accordance with the second statistical moment of Snell's window image. The results of testing of the offered method are provided based on natural images registered in the course of trip to the Black Sea under conditions of different wind and wave environment for clear surface and surface covered by surfactant films. For both cases frequency spectra of surface slopes are recovered and their good coincidence to the spectra received by processing of signals from a string wave recorder is established. Efficiency of application of the offered method for tasks of remote monitoring and environmental control of natural reservoirs is shown.

Smoothed particle hydrodynamics study of the roughness effect on contact angle and droplet flow

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

Shigorina, Elena; Kordilla, Jannes; Tartakovsky, Alexandre M.

We employ a pairwise force Smoothed Particle Hydrodynamics (PF-SPH) model to simulate sessile and transient droplets on rough hydrophobic and hydrophilic surfaces. PF-SPH allows for modeling of free surface flow without discretizing the air phase, which is achieved by imposing the surface tension and dynamic contact angles with pairwise interaction forces. We use the PF-SPH model to study the effect of surface roughness and microscopic contact angle on the effective contact angle and droplet dynamics. In the first part of this work, we investigate static contact angles of sessile droplets on rough surfaces in a shape of a sinusoidal functionmore » and made of rectangular bars placed on top of a flat surface. We find that the effective static contact angles of Cassie and Wenzel droplets on a rough surface are greater than the corresponding microscale static contact angles. As a result, microscale hydrophobic rough surfaces also show effective hydrophobic behavior. On the other hand, microscale hydrophilic surfaces may be macroscopically hydrophilic or hydrophobic, depending on the type of roughness. Next, we study the impact of the roughness orientation (i.e., an anisotropic roughness) and surface inclination on droplet flow velocities. Simulations show that droplet flow velocities are lower if the surface roughness is oriented perpendicular to the flow direction. If the predominant elements of surface roughness are in alignment with the flow direction, the flow velocities increase compared to smooth surfaces, which can be attributed to the decrease in fluid-solid contact area similar to the classical lotus effect. We demonstrate that linear scaling relationships between Bond and capillary number for droplet flow on flat surfaces also hold for flow on rough surfaces.« less

FY2015 Analysis of the Teamwork USA Program. Memorandum

ERIC Educational Resources Information Center

Howard, Mark

2015-01-01

The Department of Research and Evaluation (DRE) has completed an analysis of the performance of students who participated in the Teamwork USA Program, administered in FY2014 at three District schools. Teamwork USA hopes to improve student achievement at select Title I elementary schools via its Instrumental Music Program grant. This memorandum to…

40 CFR 63.1221 - What are the replacement standards for hazardous waste burning lightweight aggregate kilns?

Code of Federal Regulations, 2013 CFR

2013-07-01

... hazardous waste burning lightweight aggregate kilns? 63.1221 Section 63.1221 Protection of Environment... hazardous waste burning lightweight aggregate kilns? (a) Emission and hazardous waste feed limits for... prior to release to the atmosphere. (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes...

40 CFR 63.1221 - What are the replacement standards for hazardous waste burning lightweight aggregate kilns?

Code of Federal Regulations, 2014 CFR

2014-07-01

... hazardous waste burning lightweight aggregate kilns? 63.1221 Section 63.1221 Protection of Environment... hazardous waste burning lightweight aggregate kilns? (a) Emission and hazardous waste feed limits for... prior to release to the atmosphere. (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes...

A Two-Year Study of Δ 9 Tetrahydrocannabinol Concentrations in Drivers; Part 2: Physiological Signs on Drug Recognition Expert (DRE) and non-DRE Examinations,.

PubMed

Declues, Kari; Perez, Shelli; Figueroa, Ariana

2018-03-01

Whole blood samples were examined for ∆ 9 -Tetrahydrocannabinol (THC) over 2 years in drivers suspected of driving under the influence. Part one of the study examined the link between [THC] and performance on field sobriety tests. This portion examined objective signs, eye examinations and physiological indicators; and their relationship to the presence of THC. Several objective signs were excellent indicators of the presence of THC: red eyes (94%), droopy eyelids (85.6%), affected speech (87.6%), tongue coating (96.2%), and odor of marijuana (82.4%). About 63.6% of THC positive subjects had dialted pupils (room light). THC positive subjects had either rebound dilation or hippus in 88.8% of cases. Pulse and blood pressure (BP) were evaluated to determine any correlation with [THC]. An increased pulse rate correlated well to the presence of THC (88.5%), but not [THC]. BP did not correlate to [THC] and was also a poor indicator of THC in the blood (50% high). © 2017 American Academy of Forensic Sciences.

Discovery of Nigri/nox and Panto/pox site-specific recombinase systems facilitates advanced genome engineering.

PubMed

Karimova, Madina; Splith, Victoria; Karpinski, Janet; Pisabarro, M Teresa; Buchholz, Frank

2016-07-22

Precise genome engineering is instrumental for biomedical research and holds great promise for future therapeutic applications. Site-specific recombinases (SSRs) are valuable tools for genome engineering due to their exceptional ability to mediate precise excision, integration and inversion of genomic DNA in living systems. The ever-increasing complexity of genome manipulations and the desire to understand the DNA-binding specificity of these enzymes are driving efforts to identify novel SSR systems with unique properties. Here, we describe two novel tyrosine site-specific recombination systems designated Nigri/nox and Panto/pox. Nigri originates from Vibrio nigripulchritudo (plasmid VIBNI_pA) and recombines its target site nox with high efficiency and high target-site selectivity, without recombining target sites of the well established SSRs Cre, Dre, Vika and VCre. Panto, derived from Pantoea sp. aB, is less specific and in addition to its native target site, pox also recombines the target site for Dre recombinase, called rox. This relaxed specificity allowed the identification of residues that are involved in target site selectivity, thereby advancing our understanding of how SSRs recognize their respective DNA targets.

The Impact of Aerosol Microphysical Representation in Models on the Direct Radiative Effect

NASA Astrophysics Data System (ADS)

Ridley, D. A.; Heald, C. L.

2017-12-01

Aerosol impacts the radiative balance of the atmosphere both directly and indirectly. There is considerable uncertainty remaining in the aerosol direct radiative effect (DRE), hampering understanding of the present magnitude of anthropogenic aerosol forcing and how future changes in aerosol loading will influence climate. Computationally expensive explicit aerosol microphysics are usually reserved for modelling of the aerosol indirect radiative effects that depend upon aerosol particle number. However, the direct radiative effects of aerosol are also strongly dependent upon the aerosol size distribution, especially particles between 0.2µm - 2µm diameter. In this work, we use a consistent model framework and consistent emissions to explore the impact of prescribed size distributions (bulk scheme) relative to explicit microphysics (sectional scheme) on the aerosol radiative properties. We consider the difference in aerosol burden, water uptake, and extinction efficiency resulting from the two representations, highlighting when and where the bulk and sectional schemes diverge significantly in their estimates of the DRE. Finally, we evaluate the modelled size distributions using in-situ measurements over a range of regimes to provide constraints on both the accumulation and coarse aerosol sizes.

Fine structure of the late Eocene Ir anomaly in marine sediments

NASA Technical Reports Server (NTRS)

Asaro, F.

1991-01-01

The Late Eocene Ir abundance profile in deep sea cores from Ocean Drilling Program Leg 113 Hole 689B on the Maude Rise off of Antarctica was studied with 410 samples continuously in 10 cm increments and measured with the Iridium Coincidence (ICS). The ICS was subsequently modified to measure 13 other elements simultaneously with the Ir. The abundance profiles of these elements were then determined in the Late Eocene Massignano section in central Italy with 250 samples (encompassing roughly 2 million years of accumulation) which were collected about every 5 cm in about 2 cm increments. These studies augmented a previous one (which included many elements) of deep sea cores from Deep Sea Drilling Project Site 592 on the Lord Howe Rise in the Tasman Sea between Australia and New Zealand. In the latter study, 50 samples (encompassing roughly 0.7 million years of accumulation) were collected continuously in 10 cm increments. The results from these studies are discussed.

Our Community -- Today and Yesterday. Book One (Nihil Hahoodzodoo -- Diijiidi doo Adaadaa. Naaltsoos T'aala'i Gone Yits'iligii). Fourth Grade Navajo Bilingual-Bicultural Social Studies Curriculum.

ERIC Educational Resources Information Center

Bia, Fred; And Others

Presented in five chapters, book 1 of the Rough Rock fourth grade Navajo social studies program text is written in Navajo and English. The first chapter is on the community of Rough Rock (Arizona) illustrated by photographs of the community and people. Chapter II discusses the four elements (air, water, earth, and fire) the community needs to…

Detection rate of prostate cancer following biopsy among the northern Han Chinese population: a single-center retrospective study of 1022 cases.

PubMed

Jia, Yong; Zhu, Lei-Yi; Xian, Yu-Xin; Sun, Xiao-Qing; Gao, Jian-Gang; Zhang, Xin-Hong; Hou, Si-Chuan; Zhang, Chang-Cun; Liu, Zhao-Xu

2017-08-29

Prostate cancer is known to have ethnic and regional differences. The study aimed to clinically evaluate the detection rate of prostate cancer on transrectal ultrasonography (TRUS)-guided prostate biopsy and analyze its characteristics among the northern Han Chinese population at a single center. Between October 2009 and September 2016, a total of 1027 Chinese men, who had undergone TRUS-guided prostate biopsy at Qingdao Municipal Hospital, were retrospectively analyzed. Prostate biopsies were performed in the case of an abnormally elevated serum PSA level, and/or abnormal digital rectal examination (DRE) findings, and/or suspicious prostatic imaging findings. Of the 1022 men enrolled in the analysis, 438 patients (42.8%) were diagnosed with prostate adenocarcinoma histologically. When serum PSA levels were divided into five subgroups (less than 4.0, 4.0 to 10.0, 10.0 to 20.0, 20.0 to 100.0, and ≥ 100.0 ng/ml), the detection rates of prostate cancer were 12.4, 15.9, 34.1, 66.2, and 93.8%, respectively. With serum PSA levels of 4.0 to 10.0 ng/ml, the cancer detection rates for a normal DRE and a suspect DRE finding were 13.5 and 58.2%, respectively. Accordingly, the cancer detection rates for a normal imaging and a suspect imaging finding were 13.5 and 58.2%, respectively. Besides, a large proportion of the patients were in the clinically advanced stage. The present study data reported a relatively higher prostate cancer detection rate of 42.8% and that the majority of the patients presented with clinically advanced prostate cancers within a local clinical urologic practice. An early detection and screening program for prostate cancer is of great need to reduce the burden from this disease among the northern Han Chinese population.

Dust layer effects on the atmospheric radiative budget and heating rate profiles

NASA Astrophysics Data System (ADS)

Perrone, Maria Rita; Tafuro, A. M.; Kinne, S.

2012-11-01

The effect of mineral aerosol optical properties and vertical distribution on clear-sky, instantaneous and daily-average aerosol direct radiative effects (DREs) and heating rates (HRs) is analyzed in the solar (S, 0.3-4 μm) and terrestrial (T, 4-80 μm) spectral domain, respectively. The used radiative transfer model is based on lidar, sun-sky photometer, and radiosonde measurements. The study focuses on the Sahara dust outbreak of July 16, 2009 which advected dust particles from north-western Africa over south-eastern Italy. Clear-sky, instantaneous aerosol DREs and HRs undergo large changes within few hours, for the variability of the dust aerosol properties and vertical distribution. The daily-average, clear-sky aerosol S-DRE is near -5 Wm-2 and -12 Wm-2 at the top of the atmosphere (ToA) and surface (sfc), respectively. The daily-average aerosol T-DRE offsets the S-DRE by about one third at the ToA and by about one half at the surface. The daily average aerosol HR integrated over the whole aerosol column is 0.5 and -0.3 K day-1 in the S and T domain, respectively. Thus, the all-wave integrated HR is 0.2 K day-1. These results highlight the importance of accounting for the interaction of dust particles with T and S radiation. Sensitivity tests indicate that the uncertainties of the aerosol refractive index, size distribution, and vertical distribution have on average a large impact on aerosol HRs in the S and T domain, respectively. Refractive index and aerosol size distribution uncertainties also have a large impact on S- and T-DREs. The aerosol vertical distribution that has a negligible impact on aerosol S-DREs, is important for aerosol T-DREs. It is also shown that aerosol HRs and DREs in the terrestrial domain are affected by the water vapour vertical distribution.

PCA3-based nomogram for predicting prostate cancer and high grade cancer on initial transrectal guided biopsy.

PubMed

Elshafei, Ahmed; Chevli, K Kent; Moussa, Ayman S; Kara, Onder; Chueh, Shih-Chieh; Walter, Peter; Hatem, Asmaa; Gao, Tianming; Jones, J Stephen; Duff, Michael

2015-12-01

To develop a validated prostate cancer antigen 3 (PCA3) based nomogram that predicts likelihood of overall prostate cancer (PCa) and intermediate/high grade prostate cancer (HGPCa) in men pursuing initial transrectal prostate biopsy (TRUS-PBx). Data were collected on 3,675 men with serum prostate specific antigen level (PSA) ≤ 20 ng/ml who underwent initial prostate biopsy with at least 10 cores sampling at time of the biopsy. Two logistic regression models were constructed to predict overall PCa and HGPCa incorporating age, race, family history (FH) of PCa, PSA at diagnosis, PCA3, total prostate volume (TPV), and digital rectal exam (DRE). One thousand six hundred twenty (44%) patients had biopsy confirmed PCa with 701 men (19.1%) showing HGPCa. Statistically significant predictors of overall PCa were age (P < 0.0001, OR. 1.51), PSA at diagnosis (P < 0.0001, OR.1.95), PCA3 (P < 0.0001, OR.3.06), TPV (P < 0.0001, OR.0.47), FH (P = 0.003, OR.1.32), and abnormal DRE (P = 0.001, OR. 1.32). While for HGPCa, predictors were age (P < 0.0001, OR.1.77), PSA (P < 0.0001, OR.2.73), PCA3 (P < 0.0001, OR.2.26), TPV (P < 0.0001, OR.0.4), and DRE (P < 0.0001, OR.1.53). Two nomograms were reconstructed for predicted overall PCa probability at time of initial biopsy with a concordance index of 0.742 (Fig. 1), and HGPCa with a concordance index of 0.768 (Fig. 2). Our internally validated initial biopsy PCA3 based nomogram is reconstructed based on a large dataset. The c-index indicates high predictive accuracy, especially for high grade PCa and improves the ability to predict biopsy outcomes. © 2015 Wiley Periodicals, Inc.

Modeling interface shear behavior of granular materials using micro-polar continuum approach

NASA Astrophysics Data System (ADS)

Ebrahimian, Babak; Noorzad, Ali; Alsaleh, Mustafa I.

2018-01-01

Recently, the authors have focused on the shear behavior of interface between granular soil body and very rough surface of moving bounding structure. For this purpose, they have used finite element method and a micro-polar elasto-plastic continuum model. They have shown that the boundary conditions assumed along the interface have strong influences on the soil behavior. While in the previous studies, only very rough bounding interfaces have been taken into account, the present investigation focuses on the rough, medium rough and relatively smooth interfaces. In this regard, plane monotonic shearing of an infinite extended narrow granular soil layer is simulated under constant vertical pressure and free dilatancy. The soil layer is located between two parallel rigid boundaries of different surface roughness values. Particular attention is paid to the effect of surface roughness of top and bottom boundaries on the shear behavior of granular soil layer. It is shown that the interaction between roughness of bounding structure surface and the rotation resistance of bounding grains can be modeled in a reasonable manner through considered Cosserat boundary conditions. The influence of surface roughness is investigated on the soil shear strength mobilized along the interface as well as on the location and evolution of shear localization formed within the layer. The obtained numerical results have been qualitatively compared with experimental observations as well as DEM simulations, and acceptable agreement is shown.

An Experimental Study of Roughness-Induced Instabilities in a Supersonic Boundary Layer

NASA Technical Reports Server (NTRS)

Kegerise, Michael A.; King, Rudolph A.; Choudhari, Meelan; Li, Fei; Norris, Andrew

2014-01-01

Progress on an experimental study of laminar-to-turbulent transition induced by an isolated roughness element in a supersonic laminar boundary layer is reported in this paper. Here, the primary focus is on the effects of roughness planform shape on the instability and transition characteristics. Four different roughness planform shapes were considered (a diamond, a circle, a right triangle, and a 45 degree fence) and the height and width of each one was held fixed so that a consistent frontal area was presented to the oncoming boundary layer. The nominal roughness Reynolds number was 462 and the ratio of the roughness height to the boundary layer thickness was 0.48. Detailed flow- field surveys in the wake of each geometry were performed via hot-wire anemometry. High- and low-speed streaks were observed in the wake of each roughness geometry, and the modified mean flow associated with these streak structures was found to support a single dominant convective instability mode. For the symmetric planform shapes - the diamond and circular planforms - the instability characteristics (mode shapes, growth rates, and frequencies) were found to be similar. For the asymmetric planform shapes - the right-triangle and 45 degree fence planforms - the mode shapes were asymmetrically distributed about the roughness-wake centerline. The instability growth rates for the asymmetric planforms were lower than those for the symmetric planforms and therefore, transition onset was delayed relative to the symmetric planforms.

Effects of surface roughness on an adverse-pressure-gradient separating turbulent boundary layer

NASA Astrophysics Data System (ADS)

Wu, Wen; Piomelli, Ugo; Turbulence Simulation; Modelling Laboratory Team

2017-11-01

Separating turbulent boundary layers over smooth and rough flat plates are investigated by large-eddy simulations. A suction-blowing velocity distribution is imposed at the top boundary to produce an adverse-to-favourable pressure gradient and a closed separation bubble. Sandgrain roughness in the fully-rough regime is modelled by an immersed boundary method. In the rough-wall case, streamline detachment occurs earlier and the separation region is substantially larger due to the momentum deficit caused by the roughness. The adverse pressure gradient decreases the form drag and causes a thin reversed-flow region below the roughness crest, so that Cf = 0 does not coincide with the detachment of the flow from the surface. The wake regions behind roughness elements affect the intermittency of the near-wall flow, so that upstream of the detachment point the flow can be reversed half of the time, but its average is positive. The separated shear layer exhibits higher turbulent kinetic energy (TKE); the growth of the TKE there begins earlier relative to the separation point, and the peak TKE occurs close to the separation point. The momentum deficit caused by the roughness, again, plays a critical role in these changes. The authors acknowledge the support from Hydro-Québec and the NSERC Collaborative Research & Development program (CRDPJ 418786-11). The simulations were performed at CAC Queen't site. UP also thanks the support of Canada Research Chair Program.

Addressing scale dependence in roughness and morphometric statistics derived from point cloud data.

NASA Astrophysics Data System (ADS)

Buscombe, D.; Wheaton, J. M.; Hensleigh, J.; Grams, P. E.; Welcker, C. W.; Anderson, K.; Kaplinski, M. A.

2015-12-01

The heights of natural surfaces can be measured with such spatial density that almost the entire spectrum of physical roughness scales can be characterized, down to the morphological form and grain scales. With an ability to measure 'microtopography' comes a demand for analytical/computational tools for spatially explicit statistical characterization of surface roughness. Detrended standard deviation of surface heights is a popular means to create continuous maps of roughness from point cloud data, using moving windows and reporting window-centered statistics of variations from a trend surface. If 'roughness' is the statistical variation in the distribution of relief of a surface, then 'texture' is the frequency of change and spatial arrangement of roughness. The variance in surface height as a function of frequency obeys a power law. In consequence, roughness is dependent on the window size through which it is examined, which has a number of potential disadvantages: 1) the choice of window size becomes crucial, and obstructs comparisons between data; 2) if windows are large relative to multiple roughness scales, it is harder to discriminate between those scales; 3) if roughness is not scaled by the texture length scale, information on the spacing and clustering of roughness `elements' can be lost; and 4) such practice is not amenable to models describing the scattering of light and sound from rough natural surfaces. We discuss the relationship between roughness and texture. Some useful parameters which scale vertical roughness to characteristic horizontal length scales are suggested, with examples of bathymetric point clouds obtained using multibeam from two contrasting riverbeds, namely those of the Colorado River in Grand Canyon, and the Snake River in Hells Canyon. Such work, aside from automated texture characterization and texture segmentation, roughness and grain size calculation, might also be useful for feature detection and classification from point clouds.

[In Process Citation].

PubMed

Cuerda, Cristina; Álvarez, Julia; Ramos, Primitivo; Abánades, Juan Carlos; García-de-Lorenzo, Abelardo; Gil, Pedro; De-la-Cruz, Juan José

2016-03-25

Introducción: la desnutrición relacionada con la enfermedad (DRE) es un problema sociosanitario frecuente que afecta preferentemente a los mayores de 65 años, que aumenta la morbimortalidad y disminuye la calidad de vida.  Objetivo: estudiar la prevalencia de DRE en mayores de 65 años en diferentes centros sociosanitarios del Servicio Regional de Bienestar Social de la Comunidad de Madrid. Métodos: estudio transversal en 33 centros sociosanitarios de Madrid (6 centros de atención primaria [AP], 9 centros de mayores [CM], 9 hospitales [H] y 9 residencias [R]) seleccionados mediante muestreo polietápico. Las variables estudiadas fueron edad, sexo, nivel de dependencia según la escala de incapacidad de la Cruz Roja, motivo de ingreso y enfermedad de base, hábitat (urbano-periurbano-rural) y distribución geográfica (norte centro-sur). Como herramienta de cribado nutricional se utilizó el Mini Nutritional Assessment (MNA-cribaje) en todos los centros. En los pacientes con cribado positivo (en riesgo-desnutrición) se realizó el MNA-evaluación. El estudio estadístico se realizó con el paquete SSS 21.0 e incluyó estadística descriptiva, test de Chi-cuadrado y prueba exacta de Fisher, ANOVA de un factor, Kruskal-Wallis y análisis de regresión logística (RL) binaria univariante y multivariante. Se consideró significación estadística p < 0,05. Resultados: se reclutaron 1.103 sujetos (275 AP, 278 CM, 281 H, 269 R), edad media de 79,5 ± 8,4 años (41,2% varones, 58,8% mujeres). Los sujetos procedentes de H y R tuvieron un mayor grado de incapacidad (p < 0,001). La prevalencia global de DRE fue del 10%, encontrándose un 23,3% en riesgo de desnutrición, con diferencias entre los cuatro tipos de centros sociosanitarios (p < 0,001). El análisis univariante de RL mostró diferencia significativas en la prevalencia de desnutrición según la edad, sexo, grado de dependencia, tipo de centro sociosanitario, hábitat y zona geográfica. Sin embargo, en el análisis multivariante solo el grado de dependencia, el tipo de centro y el hábitat tuvieron significación estadística. Conclusiones: la prevalencia de DRE en mayores de 65 años en la Comunidad de Madrid es del 10%, encontrándose además un 23,3% en riesgo de desnutrición. Las únicas variables que se relacionaron de forma independiente con la desnutrición en el análisis multivariante fueron el nivel de dependencia de los pacientes y el tipo y hábitat de centro sociosanitario.

Health Technology Assessment report on the presurgical evaluation and surgical treatment of drug-resistant epilepsy.

PubMed

Marras, Carlo Efisio; Canevini, Maria Paola; Colicchio, Gabriella; Guerrini, Renzo; Rubboli, Guido; Scerrati, Massimo; Spreafico, Roberto; Tassi, Laura; LoRusso, Giorgio; Tinuper, Paolo

2013-10-01

Epilepsy is a neurologic disorder with major social impact. Surgery is a valuable option in patients who are not responding to antiepileptic drugs. The literature reports demonstrate that a proportion ranging from 40 to 100% of patients with epilepsy achieve seizure remission after surgery. A presurgical evaluation (clinical and instrumental) must be performed in all patients with drug-resistant epilepsy to assess their suitability for surgical intervention. Health Technology Assessment (HTA) represents a modern approach to the analysis of technologies used for health care. HTA could be considered a bridge between science that produces evidence and the decisions that can be taken on the basis of that evidence at different levels of the health care system. The aim of this study is the HTA of epilepsy surgery including clinical, ethical, social, and economic features. The present study includes an analysis of the diagnostic and surgical workup performed at the Italian centers for the diagnosis and treatment of drug-resistant epilepsy (DRE). The study includes the following issues: (1) social, ethical impact, and costs of the disease; (2) clinical results, efficacy, and safety of surgery; (3) ethics and quality of life after surgery; and (4) economic impact and productivity regained after surgery. The cost of managing a patient with DRE included in the presurgical study was estimated by the bottom-up microcosting technique that starts from a detailed collection of data on consumption of resources and full costing. The phases analyzed were (1) noninvasive diagnostic workup; (2) neurosurgical intervention; and (3) follow-up. The literature reports indicate epilepsy surgery as an effective treatment both on clinical results and on ethical, social, and quality of life aspects. The workup including the noninvasive presurgical study followed by surgery has a total cost of €20,827. Management of short-term follow-up increases the overhead to €22,291 at the first year, and then to €23,571 after 5 years. According to the estimates made in this survey, funding based on diagnosis-related group (DRG) tariff for the noninvasive diagnostic stage involving hospital admission is not remunerative in Italy either at regional or national levels. Effectively the difference between full cost and DRG has a delta of €3,402 and €2,537 respectively. The total cost of the presurgical, surgical, and follow-up evaluation is not remunerative for €10,554 (national data). Economic surveys in Italy have shown that surgery for DRE is an advantageous treatment from the standpoint of third-party payers and is cost-effective for society. DRE presurgical evaluation and surgery are not remunerative either at regional or national levels. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

Discrete Roughness Effects on Shuttle Orbiter at Mach 6

NASA Technical Reports Server (NTRS)

Berry, Scott A.; Hamilton, H. Harris, II

2002-01-01

Discrete roughness boundary layer transition results on a Shuttle Orbiter model in the NASA Langley Research Center 20-Inch Mach 6 Air Tunnel have been reanalyzed with new boundary layer calculations to provide consistency for comparison to other published results. The experimental results were previously obtained utilizing the phosphor thermography system to monitor the status of the boundary layer via global heat transfer images of the Orbiter windward surface. The size and location of discrete roughness elements were systematically varied along the centerline of the 0.0075-scale model at an angle of attack of 40 deg and the boundary layer response recorded. Various correlative approaches were attempted, with the roughness transition correlations based on edge properties providing the most reliable results. When a consistent computational method is used to compute edge conditions, transition datasets for different configurations at several angles of attack have been shown to collapse to a well-behaved correlation.

Viscoelastic reciprocating contacts in presence of finite rough interfaces: A numerical investigation

NASA Astrophysics Data System (ADS)

Putignano, Carmine; Carbone, Giuseppe

2018-05-01

Viscoelastic reciprocating contacts are crucial in a number of systems, ranging from sealing components to viscoelastic dampers. Roughness plays in these conditions a central role, but no exhaustive assessment in terms of influence on area, separation and friction has been drawn so far. This is due to the huge number of time and space scales involved in the problem. By means of an innovative Boundary Element methodology, which treats the time as a parameter and then requires only to discretize the space domain, we investigate the viscoelastic reciprocating contact mechanics between rough solids. In particular, we consider the alternate contact of a rigid finite-size rough punch over a viscoelastic layer: the importance of the domain finiteness in the determination of the contact area and the contact solution anisotropy is enlightened. Implications on real system may be drawn on this basis. Finally, we focus on the hysteretic cycle related to the viscoelastic tangential forces.

A novel approach for quantitative evaluation of the physicochemical interactions between rough membrane surface and sludge foulants in a submerged membrane bioreactor.

PubMed

Lin, Hongjun; Zhang, Meijia; Mei, Rongwu; Chen, Jianrong; Hong, Huachang

2014-11-01

This study proposed a novel approach for quantitative evaluation of the physicochemical interactions between a particle and rough surface. The approach adopts the composite Simpson's rule to numerically calculate the double integrals in the surface element integration of these physicochemical interactions. The calculation could be achieved by a MATLAB program based on this approach. This approach was then applied to assess the physicochemical interactions between rough membrane surface and sludge foulants in a submerged membrane bioreactor (MBR). The results showed that, as compared with smooth membrane surface, rough membrane surface had a much lower strength of interactions with sludge foulants. Meanwhile, membrane surface morphology significantly affected the strength and properties of the interactions. This study showed that the newly developed approach was feasible, and could serve as a primary tool for investigating membrane fouling in MBRs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Distributed-Roughness Effects on Stability and Transition In Swept-Wing Boundary Layers

NASA Technical Reports Server (NTRS)

Carrillo, Ruben B., Jr.; Reibert, Mark S.; Saric, William S.

1997-01-01

Boundary-layer stability experiments are conducted in the Arizona State University Unsteady Wind Tunnel on a 45 deg swept airfoil. The pressure distribution and test conditions are designed to suppress Tollmien-Schlichting disturbances and provide crossflow-dominated transition. The surface of the airfoil is finely polished to a near mirror finish. Under these conditions, submicron surface irregularities cause the naturally occurring stationary crossflow waves to grow to nonuniform amplitudes. Spanwise-uniform stationary crossflow disturbances are generated through careful control of the initial conditions with full-span arrays of micron-high roughness elements near the attachment line. Detailed hot-wire measurements are taken to document the stationary crossflow structure and determine growth rates for the total and individual-mode disturbances. Naphthalene flow visualization provides transition location information. Roughness spacing and roughness height are varied to examine the effects on transition location and all amplified wavelengths. The measurements show that roughness spacings that do not contain harmonics equal to the most unstable wavelength as computed by linear stability theory effectively suppress the most unstable mode. Under certain conditions, subcritical roughness spacing delays transition past that of the corresponding smooth surface.

Transition Experiments on Large Bluntness Cones with Distributed Roughness in Hypersonic Flight

NASA Technical Reports Server (NTRS)

Reda, Daniel. C.; Wilder, Michael C.; Prabhu, Dinesh K.

2012-01-01

Large bluntness cones with smooth nosetips and roughened frusta were flown in the NASA Ames hypersonic ballistic range at a Mach number of 10 through quiescent air environments. Global surface intensity (temperature) distributions were optically measured and analyzed to determine transition onset and progression over the roughened surface. Real-gas Navier-Stokes calculations of model flowfields, including laminar boundary layer development in these flowfields, were conducted to predict values of key dimensionless parameters used to correlate transition on such configurations in hypersonic flow. For these large bluntness cases, predicted axial distributions of the roughness Reynolds number showed (for each specified freestream pressure) that this parameter was a maximum at the physical beginning of the roughened zone and decreased with increasing run length along the roughened surface. Roughness-induced transition occurred downstream of this maximum roughness Reynolds number location, and progressed upstream towards the beginning of the roughened zone as freestream pressure was systematically increased. Roughness elements encountered at the upstream edge of the roughened frusta thus acted like a finite-extent trip array, consistent with published results concerning the tripping effectiveness of roughness bands placed on otherwise smooth surfaces.

Transition Experiments on Blunt Bodies with Distributed Roughness in Hypersonic Free Flight in Carbon Dioxide

NASA Technical Reports Server (NTRS)

Wilder, Michael C.; Reda, Daniel C.; Prabhu, Dinesh K.

2015-01-01

Blunt-body geometries were flown through carbon dioxide in the NASA Ames Hypervelocity Free Flight Aerodynamic Facility to investigate the influence of distributed surface roughness on transition to turbulence in CO2-dominated atmospheres, such as those of Mars and Venus. Tests were also performed in air for direct comparison with archival results. Models of hemispherical and spherically-blunted large-angle conical geometries were flown at speeds between 2.8 km/s and 5.1 km/s and freestream pressures between 50 Torr and 228 Torr. Transition fronts were determined from global surface heat flux distributions measured using thermal imaging techniques. Distributed surface roughness was produced by grit-blasting the model surfaces. Real-gas Navier-Stokes solutions were used to calculate non-dimensional correlating parameters at the measured transition onset locations. Transition-onset locations correlated well with a constant roughness Reynolds number based on the mean roughness element height. The critical roughness Reynolds number for transition onset determined for flight in CO2 was 223 +/- 25%. This mean value is lower than the critical value of 250 +/- 20% previously-established from tests conducted in air, but within the bounds of the expected measurement uncertainty.

Evolution of the Campanian Ignimbrite Magmatic System II: Trace Element and Th Isotopic Evidence for Open-System Processes

NASA Astrophysics Data System (ADS)

Bohrson, W. A.; Spera, F. J.; Fowler, S.; Belkin, H.; de Vivo, B.

2005-12-01

The Campanian Ignimbrite, a large volume (~200 km3 DRE) trachytic to phonolitic ignimbrite was deposited at ~39.3 ka and represents the largest of a number of highly explosive volcanic events in the region near Naples, Italy. Thermodynamic modeling of the major element evolution using the MELTS algorithm (see companion contribution by Fowler et al.) provides detailed information about the identity of and changes in proportions of solids along the liquid line of descent during isobaric fractional crystallization. We have derived trace element mass balance equations that explicitly accommodate changing mineral-melt bulk distribution coefficients during crystallization and also simultaneously satisfy energy and major element mass conservation. Although major element patterns are reasonably modeled assuming closed system fractional crystallization, modeling of trace elements that represent a range of behaviors (e.g. Zr, Nb, Th, U, Rb, Sm, Sr) yields trends for closed system fractionation that are distinct from those observed. These results suggest open-system processes were also important in the evolution of the Campanian magmatic system. Th isotope data yield an apparent isochron that is ~20 kyr younger than the age of the deposit, and age-corrected Th isotope data indicate that the magma body was an open-system at the time of eruption. Because open-system processes can profoundly change isotopic characteristics of a magma body, these results illustrate that it is critical to understand the contribution that open-system processes make to silicic magma bodies prior to assigning relevance to age or timescale information derived from isotope systematics. Fluid-magma interaction has been proposed as a mechanism to change isotopic and elemental characteristics of magma bodies, but an evaluation of the mass and thermal constraints on such a process suggest large-scale fluid-melt interaction at liquidus temperatures is unlikely. In the case of the magma body associated with the Campanian Ignimbrite, the most likely source of open-system signatures is assimilation of partial melts of compositionally heterogeneous basement composed of older cumulates and intrusive equivalents of volcanic activity within the Campanian region. Additional trace element modeling, explicitly evaluating the mass and energy balance effects that fluid, solids, and melt have on trace element evolution, will further elucidate the contributions of open vs. closed system processes within the Campanian magma body.

Cross Flow Effects on Glaze Ice Roughness Formation

NASA Technical Reports Server (NTRS)

Tsao, Jen-Ching

2004-01-01

The present study examines the impact of large-scale cross flow on the creation of ice roughness elements on the leading edge of a swept wing under glaze icing conditions. A three-dimensional triple-deck structure is developed to describe the local interaction of a 3 D air boundary layer with ice sheets and liquid films. A linear stability analysis is presented here. It is found that, as the sweep angle increases, the local icing instabilities enhance and the most linearly unstable modes are strictly three dimensional.

Scattering of Acoustic Waves from Ocean Boundaries

DTIC Science & Technology

2015-09-30

of buried mines and improve SONAR performance in shallow water. OBJECTIVES 1) Determination of the correct physical model of acoustic propagation... acoustic parameters in the ocean. APPROACH 1) Finite Element Modeling for Range Dependent Waveguides: Finite element modeling is applied to a...roughness measurements for reverberation modeling . GLISTEN data provide insight into the role of biology on acoustic propagation and scattering

Scuffing Characteristics of High-Load Rolling/Sliding Contacts Operating in Liquid Oxygen: Effects of Materials and Surface Roughness

NASA Technical Reports Server (NTRS)

Chang, L.; Hall, P. B.; Thom, R.

1996-01-01

This research reports on an experimental study of the effects of materials and surface roughness on the scuffing characteristics of rolling/sliding contacts cooled and lubricated with liquid oxygen. Experiments were carried out under heavy loading with a Hertzian pressure in the range of 2.0 GPa to 3.0 GPa and with a high rolling velocity of up to 48 m/s. For contacts between AISI 440 C stainless-steel elements, the results showed that the scuffing behavior of the system was fairly consistent under a wide range of rolling velocity. Scuffing commenced at a small slide-to-roll ratio of around 0.02, and the scuffing behavior of the contact was not sensitive to surface roughness for the test-sample RMS roughness ranging from 0.02 microns to 0.10 microns. For contacts between 440 C and Si3N4 elements, on the other hand, the scuffing behavior of the system was not very consistent and somewhat unpredictable. The results were sensitive to surface roughness particularly that of the Si3N4 test sample. With well polished test samples, consistent results were obtained; the level of traction was lower than that with a 440 C toroid and scuffing did not take place up to a slide-to-roll ratio of near 0.03. The results strongly suggest that significant hydrodynamic effect can be generated by liquid oxygen under heavy loading and high velocity conditions. The results also suggest that the hydrodynamic action is likely generated by the conventional viscous mechanism as it can be largely destroyed by a narrow circumferential surface scratch running through the central region of the contact.

The effect of piezoelectric ultrasonic instrumentation on titanium discs: a microscopy and trace elemental analysis in vitro study.

PubMed

Tawse-Smith, A; Atieh, M A; Tompkins, G; Duncan, W J; Reid, M R; Stirling, C H

2016-08-01

To evaluate in vitro topographical and composition changes by piezoelectric ultrasonic instrumentation with metallic and plastic tips on machined and moderately roughened titanium surfaces. Twenty machined and moderately roughened laser-marked titanium discs were ultrasonically instrumented with metallic and plastic tips. Surface instrumentation was carried out with controlled pressure for 20 and 30 seconds at two power settings. For each time and power setting, instrumentation was repeated four times with one instrumentation per disc quadrant. Surface topography analysis was performed using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Surface roughness measurements were compared between instrumented and non-instrumented surfaces. Surface element composition and rinsing solutions were evaluated using energy-dispersive spectroscopy (EDS) and trace elemental analysis using inductively coupled plasma mass spectrometry (ICPMS), respectively. SEM photomicrographs and CLSM 3D surface plot images of instrumented machined and moderately roughened surfaces demonstrated severe surface topographical alterations with metallic tips and mild to moderate changes for plastic tip instrumented sites. ICPMS analysis of the rinsing solutions identified titanium and other metal traces with the use of metallic tips, and mainly titanium and carbon when plastic tips were used. Surface EDS analysis showed elemental traces of the ultrasonic tips. Ultrasonic instrumentation with metallic or plastic tips created surface topographical and compositional changes. Different changes in surface topography were noted between the surfaces, as the roughness of the machined surfaces increased while the extent of roughness of the moderately roughened surfaces decreased. The clinical relevance of these changes is yet to be determined. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Smoothed particle hydrodynamics study of the roughness effect on contact angle and droplet flow.

PubMed

Shigorina, Elena; Kordilla, Jannes; Tartakovsky, Alexandre M

2017-09-01

We employ a pairwise force smoothed particle hydrodynamics (PF-SPH) model to simulate sessile and transient droplets on rough hydrophobic and hydrophilic surfaces. PF-SPH allows modeling of free-surface flows without discretizing the air phase, which is achieved by imposing the surface tension and dynamic contact angles with pairwise interaction forces. We use the PF-SPH model to study the effect of surface roughness and microscopic contact angle on the effective contact angle and droplet dynamics. In the first part of this work, we investigate static contact angles of sessile droplets on different types of rough surfaces. We find that the effective static contact angles of Cassie and Wenzel droplets on a rough surface are greater than the corresponding microscale static contact angles. As a result, microscale hydrophobic rough surfaces also show effective hydrophobic behavior. On the other hand, microscale hydrophilic surfaces may be macroscopically hydrophilic or hydrophobic, depending on the type of roughness. We study the dependence of the transition between Cassie and Wenzel states on roughness and droplet size, which can be linked to the critical pressure for the given fluid-substrate combination. We observe good agreement between simulations and theoretical predictions. Finally, we study the impact of the roughness orientation (i.e., an anisotropic roughness) and surface inclination on droplet flow velocities. Simulations show that droplet flow velocities are lower if the surface roughness is oriented perpendicular to the flow direction. If the predominant elements of surface roughness are in alignment with the flow direction, the flow velocities increase compared to smooth surfaces, which can be attributed to the decrease in fluid-solid contact area similar to the lotus effect. We demonstrate that classical linear scaling relationships between Bond and capillary numbers for droplet flow on flat surfaces also hold for flow on rough surfaces.

Developing Coastal Surface Roughness Maps Using ASTER and QuickBird Data Sources

NASA Technical Reports Server (NTRS)

Spruce, Joe; Berglund, Judith; Davis, Bruce

2006-01-01

This viewgraph presentation regards one element of a larger project on the integration of NASA science models and data into the Hazards U.S. Multi-Hazard (HAZUS-MH) Hurricane module for hurricane damage and loss risk assessment. HAZUS-MH is a decision support tool being developed by the National Institute of Building Sciences for the Federal Emergency Management Agency (FEMA). It includes the Hurricane Module, which employs surface roughness maps made from National Land Cover Data (NLCD) maps to estimate coastal hurricane wind damage and loss. NLCD maps are produced and distributed by the U.S. Geological Survey. This presentation discusses an effort to improve upon current HAZUS surface roughness maps by employing ASTER multispectral classifications with QuickBird "ground reference" imagery.

Large eddy simulation study of spanwise spacing effects on secondary flows in turbulent channel flow

NASA Astrophysics Data System (ADS)

Aliakbarimiyanmahaleh, Mohammad; Anderson, William

2015-11-01

The structure of turbulent flow over a complex topography composed of streamwise-aligned rows of cones with varying spanwise spacing, s is studied with large-eddy simulation (LES). Similar to the experimental study of Vanderwel and Ganapathisubramani, 2015: J. Fluid Mech., we investigate the relationship between secondary flow and s, for 0 . 25 <= s / δ <= 5 . For cases with s / δ > 2 , domain-scale rollers freely exist. These had previously been called ``turbulent secondary flows'' (Willingham et al., 2014: Phys. Fluids; Barros and Christensen, 2014: J. Fluid Mech.; Anderson et al., 2015: J. Fluid Mech.), but closer inspection of the statistics indicates these are a turbulent tertiary flow: they only remain ``anchored'' to the conical roughness elements for s / δ > 2 . For s / δ < 2 , turbulent tertiary flows are prevented from occupying the domain by virtue of proximity to adjacent, counter-rotating tertiary flows. Turbulent secondary flows are associated with the conical roughness elements. These turbulent secondary flows emanate from individual conical topographic elements and set the roughness sublayer depth. The turbulent secondary flows remain intact for large and small spacing. For s / δ < 1 , a mean tertiary flow is not present. This work was supported by the Air Force Office of Sci. Research, Young Inv. Program (PM: Dr. R. Ponnoppan and Ms. E. Montomery) under Grant # FA9550-14-1-0394. Computational resources were provided by the Texas Adv. Comp. Center at the Univ. of Texas.

Reconstructing photorealistic 3D models from image sequence using domain decomposition method

NASA Astrophysics Data System (ADS)

Xiong, Hanwei; Pan, Ming; Zhang, Xiangwei

2009-11-01

In the fields of industrial design, artistic design and heritage conservation, physical objects are usually digitalized by reverse engineering through some 3D scanning methods. Structured light and photogrammetry are two main methods to acquire 3D information, and both are expensive. Even if these expensive instruments are used, photorealistic 3D models are seldom available. In this paper, a new method to reconstruction photorealistic 3D models using a single camera is proposed. A square plate glued with coded marks is used to place the objects, and a sequence of about 20 images is taken. From the coded marks, the images are calibrated, and a snake algorithm is used to segment object from the background. A rough 3d model is obtained using shape from silhouettes algorithm. The silhouettes are decomposed into a combination of convex curves, which are used to partition the rough 3d model into some convex mesh patches. For each patch, the multi-view photo consistency constraints and smooth regulations are expressed as a finite element formulation, which can be resolved locally, and the information can be exchanged along the patches boundaries. The rough model is deformed into a fine 3d model through such a domain decomposition finite element method. The textures are assigned to each element mesh, and a photorealistic 3D model is got finally. A toy pig is used to verify the algorithm, and the result is exciting.

Effects of ice crystal surface roughness and air bubble inclusions on cirrus cloud radiative properties from remote sensing perspective

NASA Astrophysics Data System (ADS)

Tang, Guanglin; Panetta, R. Lee; Yang, Ping; Kattawar, George W.; Zhai, Peng-Wang

2017-07-01

We study the combined effects of surface roughness and inhomogeneity on the optical scattering properties of ice crystals and explore the consequent implications to remote sensing of cirrus cloud properties. Specifically, surface roughness and inhomogeneity are added to the Moderate Resolution Imaging Spectroradiometer (MODIS) collection 6 (MC6) cirrus cloud particle habit model. Light scattering properties of the new habit model are simulated using a modified version of the Improved Geometric Optics Method (IGOM). Both inhomogeneity and surface roughness affect the single scattering properties significantly. In visible bands, inhomogeneity and surface roughness both tend to smooth the phase function and eliminate halos and the backscattering peak. The asymmetry parameter varies with the degree of surface roughness following a U shape - decreases and then increases - with a minimum at around 0.15, whereas it decreases monotonically with the air bubble volume fraction. Air bubble inclusions significantly increase phase matrix element -P12 for scattering angles between 20°-120°, whereas surface roughness has a much weaker effect, increasing -P12 slightly from 60°-120°. Radiative transfer simulations and cirrus cloud property retrievals are conducted by including both the factors. In terms of surface roughness and air bubble volume fraction, retrievals of cirrus cloud optical thickness or the asymmetry parameter using solar bands show similar patterns of variation. Polarimetric simulations using the MC6 cirrus cloud particle habit model are shown to be more consistent with observations when both surface roughness and inhomogeneity are simultaneously considered.

Flow resistance in open channels with fixed movable bed

USGS Publications Warehouse

Simoes, Francisco J.

2010-01-01

In spite of an increasingly large body of research by many investigators, accurate quantitative prediction of open channel flow resistance remains a challenge. In general, the relations between the elements influencing resistance (turbulence, boundary roughness, and channel shape features, such as discrete obstacles, bars, channel curvature, recirculation areas, secondary circulation, etc.) and mean flow variables are complex and poorly understood. This has resulted in numerous approaches to compute friction using many and diverse variables and equally diverse prescriptions for their use. In this paper, a new resistance law for surface (grain) resistance, the resistance due to the flow viscous effects on the channel boundary roughness elements, is presented for the cases of flow in the transition (5 < Re* <70) and fully rough (Re* ≥ 70) turbulent flow regimes, where Re* is the Reynolds number based on shear velocity and sediment particle mean diameter. It is shown that the new law is sensitive to bed movement without requiring previous knowledge of sediment transport conditions. Comparisons between computation and measurements, as well as comparisons with other well-known existing roughness predictors, are presented to demonstrate its accuracy and range of application. It is shown that the method accurately predicts total friction losses in channels and natural rivers with plane beds, regardless of sediment transport conditions. This work is useful to hydraulic engineers involved with the derivation of depth-discharge relations in open channel flow and with the estimation of sediment transport rates for the case of bedload transport.

Rough surface reconstruction for ultrasonic NDE simulation

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

Choi, Wonjae; Shi, Fan; Lowe, Michael J. S.

2014-02-18

The reflection of ultrasound from rough surfaces is an important topic for the NDE of safety-critical components, such as pressure-containing components in power stations. The specular reflection from a rough surface of a defect is normally lower than it would be from a flat surface, so it is typical to apply a safety factor in order that justification cases for inspection planning are conservative. The study of the statistics of the rough surfaces that might be expected in candidate defects according to materials and loading, and the reflections from them, can be useful to develop arguments for realistic safety factors.more » This paper presents a study of real rough crack surfaces that are representative of the potential defects in pressure-containing power plant. Two-dimensional (area) values of the height of the roughness have been measured and their statistics analysed. Then a means to reconstruct model cases with similar statistics, so as to enable the creation of multiple realistic realizations of the surfaces, has been investigated, using random field theory. Rough surfaces are reconstructed, based on a real surface, and results for these two-dimensional descriptions of the original surface have been compared with those from the conventional model based on a one-dimensional correlation coefficient function. In addition, ultrasonic reflections from them are simulated using a finite element method.« less

Modeling of surface roughness effects on glaze ice accretion

NASA Technical Reports Server (NTRS)

Hansman, R. John, Jr.; Yamaguchi, Keiko; Berkowitz, Brian M.; Potapczuk, Mark

1990-01-01

A series of experimental investigations focused on studying the cause and effect of roughness on accreting glaze ice surfaces were conducted. Detailed microvideo observations were made of glaze ice accretions on 1 to 4 inch diameter cylinders in three icing wind tunnels (the Data Products of New England six inch test facility, the NASA Lewis Icing Research Tunnel, and the B. F. Goodrich Ice Protection Research Facility). Infrared thermal video recordings were made of accreting ice surfaces in the Goodrich facility. Distinct zones of surface water behavior were observed; a smooth wet zone in the stagnation region with a uniform water film; a rough zone where surface tension effects caused coalescence of surface water into stationary beads; a horn zone where roughness elements grow into horn shapes; a runback zone where surface water ran back as rivulets; and a dry zone where rime feathers formed. The location of the transition from the smooth to the rough zone was found to migrate with time towards the stagnation point. The behavior of the transition appeared to be controlled by boundary layer transition and bead formation mechanisms at the interface between the smooth and rough zones. Regions of wet ice growth and enhanced heat transfer were clearly visible in the infrared video recordings of glaze ice surfaces. A simple multi-zone modification to the current glaze ice accretion model was proposed to include spatial variability in surface roughness.

High Resolution Anatomic and Elastographic Transrectal Ultrasound for Improved Diagnosis of Prostate Cancer

DTIC Science & Technology

2007-02-01

Elastographic Transrectal Ultrasound for Improved Diagnosis of Prostate Cancer PRINCIPAL INVESTIGATOR: John A. Hossack, Ph.D...Resolution Anatomic and Elastographic Transrectal Ultrasound for Improved 5a. CONTRACT NUMBER Diagnosis of Prostate Cancer 5b. GRANT NUMBER...improve upon conventional Digital Rectal Examination (DRE) and PSA blood test by using ultrasound elasticity imaging. A latex sheath over the transrectal

40 CFR 63.1216 - What are the standards for solid fuel boilers that burn hazardous waste?

Code of Federal Regulations, 2013 CFR

2013-07-01

... boilers that burn hazardous waste? 63.1216 Section 63.1216 Protection of Environment ENVIRONMENTAL... that burn hazardous waste? (a) Emission limits for existing sources. You must not discharge or cause...% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or F027 (see § 261...

40 CFR 63.1216 - What are the standards for solid fuel boilers that burn hazardous waste?

Code of Federal Regulations, 2011 CFR

2011-07-01

... boilers that burn hazardous waste? 63.1216 Section 63.1216 Protection of Environment ENVIRONMENTAL... burn hazardous waste? (a) Emission limits for existing sources. You must not discharge or cause...% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or F027 (see § 261...

40 CFR 63.1221 - What are the replacement standards for hazardous waste burning lightweight aggregate kilns?

Code of Federal Regulations, 2012 CFR

2012-07-01

... hazardous waste burning lightweight aggregate kilns? 63.1221 Section 63.1221 Protection of Environment... burning lightweight aggregate kilns? (a) Emission and hazardous waste feed limits for existing sources... atmosphere. (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or...

40 CFR 63.1216 - What are the standards for solid fuel boilers that burn hazardous waste?

Code of Federal Regulations, 2012 CFR

2012-07-01

... boilers that burn hazardous waste? 63.1216 Section 63.1216 Protection of Environment ENVIRONMENTAL... burn hazardous waste? (a) Emission limits for existing sources. You must not discharge or cause...% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or F027 (see § 261...

40 CFR 63.1221 - What are the replacement standards for hazardous waste burning lightweight aggregate kilns?

Code of Federal Regulations, 2011 CFR

2011-07-01

... hazardous waste burning lightweight aggregate kilns? 63.1221 Section 63.1221 Protection of Environment... burning lightweight aggregate kilns? (a) Emission and hazardous waste feed limits for existing sources... atmosphere. (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or...

40 CFR 63.1216 - What are the standards for solid fuel boilers that burn hazardous waste?

Code of Federal Regulations, 2014 CFR

2014-07-01

... boilers that burn hazardous waste? 63.1216 Section 63.1216 Protection of Environment ENVIRONMENTAL... that burn hazardous waste? (a) Emission limits for existing sources. You must not discharge or cause...% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or F027 (see § 261...

40 CFR 63.1221 - What are the replacement standards for hazardous waste burning lightweight aggregate kilns?

Code of Federal Regulations, 2010 CFR

2010-07-01

... hazardous waste burning lightweight aggregate kilns? 63.1221 Section 63.1221 Protection of Environment... burning lightweight aggregate kilns? (a) Emission and hazardous waste feed limits for existing sources... atmosphere. (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or...

40 CFR 63.1216 - What are the standards for solid fuel boilers that burn hazardous waste?

Code of Federal Regulations, 2010 CFR

2010-07-01

... boilers that burn hazardous waste? 63.1216 Section 63.1216 Protection of Environment ENVIRONMENTAL... burn hazardous waste? (a) Emission limits for existing sources. You must not discharge or cause...% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or F027 (see § 261...

Evaluation test on a landfill gas-fired internal-combustion-engine system at the City of Glendale No. 1 Scholl Canyon Power Plant. Air pollution test report

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

Not Available

1986-07-01

A cooperative test program was conducted from January 28 through January 31, 1986, by Air Resources Board (ARB) and South Coast Air Quality Management District (SCAQMD) staff to evaluate the gaseous constituents from untreated landfill gas used to fuel an internal combustion engine (ICE) and the emissions from that ICE located at the City of Glendale Scholl Canyon Power Plant. The ICE was fueled with gases generated by the anaerobic decomposition of buried refuse at the No. 1 Scholl Canyon Landfill operated by the City of Glendale, Public Service Department. The test was conducted as part of an ongoing programmore » by the SCAQMD to allow assessment of the inlet fuel gas (landfill gas) and exhaust gas characteristics from such devices as ICEs, gas turbines, and flares. Emissions of criteria pollutants as determined from test data are reported. Mass flow rates and destruction and removal efficiencies (DRE's) of non-criteria pollutants compounds determined from SCAQMD bag sample test data and mass flow rates and DRE's for chlorinated and aromatic compounds determined from data from ARB resin samples are presented.« less

Remediation of 1,2,3-trichlorobenzene contaminated soil using a combined thermal desorption-molten salt oxidation reactor system.

PubMed

Li, Jin-hui; Sun, Xiao-fei; Yao, Zhi-tong; Zhao, Xiang-yang

2014-02-01

A combined thermal desorption (TD)-molten salt oxidation (MSO) reactor system was applied to remediate the 1,2,3-trichlorobenzene (1,2,3-TCB) contaminated soil. The TD reactor was used to enrich the contaminant from soil, and its dechlorination of the contaminant was achieved in the MSO reactor. The optimum operating conditions of TD, and the effects of MSO reactor temperatures, additive amounts of the TCB on destruction and removal efficiency (DRE) of TCB and chlorine retention efficiency (CRE) were investigated. The reaction mechanism and pathway were proposed as well. The combined system could remediate the contaminated soil at a large scale of concentration from 5 to 25gkg(-1), and the DRE and CRE reached more than 99% and 95%, respectively, at temperatures above 850°C. The reaction emissions included C6H6, CH4, CO and CO2, and chlorinated species were not detected. It was found that a little increase in the temperature can considerably reduce the emission of C6H6, CH4, and CO, while the CO2 level increased. Copyright © 2014. Published by Elsevier Ltd.

Discovery of Nigri/nox and Panto/pox site-specific recombinase systems facilitates advanced genome engineering

PubMed Central

Karimova, Madina; Splith, Victoria; Karpinski, Janet; Pisabarro, M. Teresa; Buchholz, Frank

2016-01-01

Precise genome engineering is instrumental for biomedical research and holds great promise for future therapeutic applications. Site-specific recombinases (SSRs) are valuable tools for genome engineering due to their exceptional ability to mediate precise excision, integration and inversion of genomic DNA in living systems. The ever-increasing complexity of genome manipulations and the desire to understand the DNA-binding specificity of these enzymes are driving efforts to identify novel SSR systems with unique properties. Here, we describe two novel tyrosine site-specific recombination systems designated Nigri/nox and Panto/pox. Nigri originates from Vibrio nigripulchritudo (plasmid VIBNI_pA) and recombines its target site nox with high efficiency and high target-site selectivity, without recombining target sites of the well established SSRs Cre, Dre, Vika and VCre. Panto, derived from Pantoea sp. aB, is less specific and in addition to its native target site, pox also recombines the target site for Dre recombinase, called rox. This relaxed specificity allowed the identification of residues that are involved in target site selectivity, thereby advancing our understanding of how SSRs recognize their respective DNA targets. PMID:27444945

Physical modeling of the atmospheric boundary layer in the UNH Flow Physics Facility

NASA Astrophysics Data System (ADS)

Taylor-Power, Gregory; Gilooly, Stephanie; Wosnik, Martin; Klewicki, Joe; Turner, John

2016-11-01

The Flow Physics Facility (FPF) at UNH has test section dimensions W =6.0m, H =2.7m, L =72m. It can achieve high Reynolds number boundary layers, enabling turbulent boundary layer, wind energy and wind engineering research with exceptional spatial and temporal instrument resolution. We examined the FPF's ability to experimentally simulate different types of the atmospheric boundary layer (ABL) using upstream roughness arrays. The American Society for Civil Engineers defines standards for simulating ABLs for different terrain types, from open sea to dense city areas (ASCE 49-12). The standards require the boundary layer to match a power law shape, roughness height, and power spectral density criteria. Each boundary layer type has a corresponding power law exponent and roughness height. The exponent and roughness height both increase with increasing roughness. A suburban boundary layer was chosen for simulation and a roughness element fetch was created. Several fetch lengths were experimented with and the resulting boundary layers were measured and compared to standards in ASCE 49-12: Wind Tunnel Testing for Buildings and Other Structures. Pitot tube and hot wire anemometers were used to measure average and fluctuating flow characteristics. Velocity profiles, turbulence intensity and velocity spectra were found to compare favorably.

Flu Diagnosis System Using Jaccard Index and Rough Set Approaches

NASA Astrophysics Data System (ADS)

Efendi, Riswan; Azah Samsudin, Noor; Mat Deris, Mustafa; Guan Ting, Yip

2018-04-01

Jaccard index and rough set approaches have been frequently implemented in decision support systems with various domain applications. Both approaches are appropriate to be considered for categorical data analysis. This paper presents the applications of sets operations for flu diagnosis systems based on two different approaches, such as, Jaccard index and rough set. These two different approaches are established using set operations concept, namely intersection and subset. The step-by-step procedure is demonstrated from each approach in diagnosing flu system. The similarity and dissimilarity indexes between conditional symptoms and decision are measured using Jaccard approach. Additionally, the rough set is used to build decision support rules. Moreover, the decision support rules are established using redundant data analysis and elimination of unclassified elements. A number data sets is considered to attempt the step-by-step procedure from each approach. The result has shown that rough set can be used to support Jaccard approaches in establishing decision support rules. Additionally, Jaccard index is better approach for investigating the worst condition of patients. While, the definitely and possibly patients with or without flu can be determined using rough set approach. The rules may improve the performance of medical diagnosis systems. Therefore, inexperienced doctors and patients are easier in preliminary flu diagnosis.

Proceedings of the U.S. Air Force and The Federal Republic of Germany Data Exchange Agreement Meeting (9th), Viscous and Interacting Flow Field Effects Held at Silver Spring, Maryland on 9-10 May 1984,

DTIC Science & Technology

1984-08-01

found in References 1-3. 2. Modeling of Roughness Effects on Turbulent Flow In turbulent flow analysis , use of time-averaged equations leads to the...eddy viscosity and the mixing length which are important parameters used in current algebraic modeling of the turbulence shear term. Two different ...surfaces with three-dimensional (distributed) roughness elements. Calculations using the present model have been compared with experimental data from

A 2.5D finite element and boundary element model for the ground vibration from trains in tunnels and validation using measurement data

NASA Astrophysics Data System (ADS)

Jin, Qiyun; Thompson, David J.; Lurcock, Daniel E. J.; Toward, Martin G. R.; Ntotsios, Evangelos

2018-05-01

A numerical model is presented for the ground-borne vibration produced by trains running in tunnels. The model makes use of the assumption that the geometry and material properties are invariant in the axial direction. It is based on the so-called two-and-a-half dimensional (2.5D) coupled Finite Element and Boundary Element methodology, in which a two-dimensional cross-section is discretised into finite elements and boundary elements and the third dimension is represented by a Fourier transform over wavenumbers. The model is applied to a particular case of a metro line built with a cast-iron tunnel lining. An equivalent continuous model of the tunnel is developed to allow it to be readily implemented in the 2.5D framework. The tunnel structure and the track are modelled using solid and beam finite elements while the ground is modelled using boundary elements. The 2.5D track-tunnel-ground model is coupled with a train consisting of several vehicles, which are represented by multi-body models. The response caused by the passage of a train is calculated as the sum of the dynamic component, excited by the combined rail and wheel roughness, and the quasi-static component, induced by the constant moving axle loads. Field measurements have been carried out to provide experimental validation of the model. These include measurements of the vibration of the rail, the tunnel invert and the tunnel wall. In addition, simultaneous measurements were made on the ground surface above the tunnel. Rail roughness and track characterisation measurements were also made. The prediction results are compared with measured vibration obtained during train passages, with good agreement.

Snow snake performance monitoring.

DOT National Transportation Integrated Search

2008-12-01

A recent study, Three-Dimensional Roughness Elements for Snow Retention (FHWA-WY-06/04F) (Tabler 2006), demonstrated : positive evidence for the effectiveness of Snow Snakes, a new type of snow fence suitable for use within the highway right-of...

Culvert roughness elements for native Utah fish passage : phase II.

DOT National Transportation Integrated Search

2012-04-01

Native fishes have become an increasingly important concern when designing fish passable culverts. Many operational culverts constrict waterways which increase velocities and prevent upstream passage of small fish species. The current method to ensur...

The quantitative analysis of silicon carbide surface smoothing by Ar and Xe cluster ions

NASA Astrophysics Data System (ADS)

Ieshkin, A. E.; Kireev, D. S.; Ermakov, Yu. A.; Trifonov, A. S.; Presnov, D. E.; Garshev, A. V.; Anufriev, Yu. V.; Prokhorova, I. G.; Krupenin, V. A.; Chernysh, V. S.

2018-04-01

The gas cluster ion beam technique was used for the silicon carbide crystal surface smoothing. The effect of processing by two inert cluster ions, argon and xenon, was quantitatively compared. While argon is a standard element for GCIB, results for xenon clusters were not reported yet. Scanning probe microscopy and high resolution transmission electron microscopy techniques were used for the analysis of the surface roughness and surface crystal layer quality. The gas cluster ion beam processing results in surface relief smoothing down to average roughness about 1 nm for both elements. It was shown that xenon as the working gas is more effective: sputtering rate for xenon clusters is 2.5 times higher than for argon at the same beam energy. High resolution transmission electron microscopy analysis of the surface defect layer gives values of 7 ± 2 nm and 8 ± 2 nm for treatment with argon and xenon clusters.

The Effects of Surface Roughness on the NEAR XRS Elemental Results: Monte-Carlo Modeling

NASA Technical Reports Server (NTRS)

Lin, Lucy F.; Nittler, Larry R.

2011-01-01

The objective of the NEAR-Shoemaker X-ray Gamma-Ray Spec1roscopy ("XGRS") investigation was to determine the elemental composition of the near-Earth asteroid 433 Eros. The X-ray Spectrometer (XRS) system measured the characteristic fluorescence of six major elements (Mg, Al, Si, S, Ca, Fe) in the 1-10 keV energy range excited by the interaction of solar X-rays with the upper 100 microns of the surface of 433 Eros. Various investigators, using both laboratory experiments and computer simulations have established that X-ray fluorescent line ratios can be influenced by small-scale surface roughness at high incidence or emission angles. The effect on the line ratio is specific to the geometry, excitation spectrum, and composition involved, In general, however, the effect is only substantial for ratios of lines with a significant energy difference between them: Fe/Si and Ca/Si are much more likely to be affected than AI/Si or Mg/Si. We apply a Monte-Carlo code to the specific geometry and spectrum of a major NEAR XRS solar flare observation, using an H chondrite composition as the substrate. The seventeen most abundant elements were included in the composition model, from oxygen to titanium.

The impact of climate and composition on playa surface roughness: Investigation of atmospheric mineral dust emission mechanisms

NASA Astrophysics Data System (ADS)

Tollerud, H. J.; Fantle, M. S.

2011-12-01

Atmospheric mineral dust has a wide range of impacts, including the transport of elements in geochemical cycles, health hazards from small particles, and climate forcing via the reflection of sunlight from dust particles. In particular, the mineral dust component of climate forcing is one of the most uncertain elements in the IPCC climate forcing summary. Mineral dust is also an important component of geochemical cycles. For instance, dust inputs to the ocean potentially affect the iron cycle by stimulating natural iron fertilization, which could then modify climate via the biological pump. Also dust can transport nutrients over long distances and fertilize nutrient-poor regions, such as island ecosystems or the Amazon rain forest. However, there are still many uncertainties in quantifying dust emissions from source regions. One factor that influences dust emission is surface roughness and texture, since a weak, unconsolidated surface texture is more easily ablated by wind than a strong, hard crust. We are investigating the impact of processes such as precipitation, groundwater evaporation, and wind on surface roughness in a playa dust source region. We find that water has a significant influence on surface roughness. We utilize ESA's Advanced Synthetic Aperture Radar (ASAR) instrument to measure roughness in the playa. A map of roughness indicates where the playa surface is smooth (on the scale of centimeters) and potentially very strong, and where it is rough and might be more sensitive to disturbance. We have analyzed approximately 40 ASAR observations of the Black Rock Desert from 2007-2011. In general, the playa is smoother and more variable over time relative to nearby areas. There is also considerable variation within the playa. While the playa roughness maps changed significantly between summers and between observations during the winters, over the course of each summer, the playa surface maintained essentially the same roughness pattern. This suggests that there were no active processes during the summers that changed surface roughness. Images from NASA's MODIS instrument (1640 nm, band 6) delineate winter flooding on the playa. Areas of water in the winter tend to be smoother in the summer. In particular, a smooth area of the play in summer 2010 aligns very closely with ponded water in February 2010. This indicates that standing water disrupts the playa surface, reducing roughness. We also compared the distribution of surface roughness across the playa to playa composition. X-ray diffraction (XRD) of samples from the Black Rock Desert demonstrates that the playa surface is composed of approximately 30% quartz, 45% clays, 10% calcite, and 5% halite. Calcite and halite concentrations vary significantly between samples. We produced a map of calcite concentration in the Black Rock Desert based on hyperspectral data from NASA's EO-1 Hyperion instrument. We find that calcite concentrations are higher in smooth areas that have been inundated by water. Without an understanding of the surface processes associated with dust emission, it is difficult to model atmospheric dust, especially in the past or future when there is much less data for an empirical dust model.

Eggshell structure in Caiman latirostris eggs improves embryo survival during nest inundation.

PubMed

Cedillo-Leal, César; Simoncini, Melina S; Leiva, Pamela M L; Larriera, Alejandro; Lang, Jeffrey W; Piña, Carlos I

2017-05-17

Egg inundation often results in poor hatching success in crocodylians. However, how tolerant eggs are to submergence, and/or how eggshell ultrastructure may affect embryo survival when inundated, are not well understood. In this study, our objective was to determine if embryo survival in Caiman latirostris is affected by eggshell surface roughness, when eggs are submerged under water. Tolerance to inundation was tested early (day 30) versus late (day 60) in development, using eight clutches (four per time treatments), subdivided into four groups: ( N = 9 per clutch per treatment; 9 × 4 = 36 eggs per group). 'Rough' eggshell represented the natural, unmodified eggshell surface structure. 'Smooth' eggshell surface structure was created by mechanically sanding the natural rough surface to remove surface columnar elements and secondary layer features, e.g. irregularities that result in 'roughness'. When inundated by submerging eggs under water for 10 h at day 30, 'smooth' eggshell structure resulted in more than twice as many dead embryos (16 versus 6, smooth versus rough; N = 36), and fewer than half as many healthy embryos (6 versus 13, smooth versus rough, respectively; N = 36). By contrast, at day 60, inundation resulted in very low hatching success, regardless of eggshell surface structure. Only two hatchlings survived the inundation, notably in the untreated group with intact, rough eggshells. Inundation produced a high rate of malformations (58% at day 30), but did not affect hatchling size. Our results indicate that eggshell roughness enhances embryo survival when eggs are inundated early in development, but not late in development. Apparently, the natural surface 'roughness' entraps air bubbles at the eggshell surface during inundation, thereby facilitating gas exchange through the eggshell even when the egg is submerged under water. © 2017 The Author(s).

Modeling and forecasting tephra hazards at Redoubt Volcano, Alaska, during 2009 unrest and eruption

NASA Astrophysics Data System (ADS)

Mastin, L. G.; Denlinger, R. P.; Wallace, K. L.; Schaefer, J. R.

2009-12-01

In late 2008, Redoubt Volcano, on the west coast of Alaska’s Cook Inlet, began a period of unrest that culminated in more than 19 small tephra-producing events between March 19 and April 4, 2009, followed by growth of a lava dome whose volume now exceeds 70 million cubic meters. The explosive events lasted from <1 to 31 minutes, sent tephra columns to heights of 19 km asl, and emitted dense-rock (DRE) tephra volumes up to several million cubic meters. Tephra fall affected transportation and infrastructure throughout Cook Inlet, including the Anchorage metropolitan area. The months of unrest that preceded the first explosive event allowed us to develop tools to forecast tephra hazards. As described in an accompanying abstract, colleagues at the University of Pisa produced automated, daily tephra-fall forecast maps using the 3-D VOL-CALPUFF model with input scenarios that represented likely event sizes and durations. Tephra-fall forecast maps were also generated every six hours for hypothetical events of 10M m3 volume DRE using the 2-D model ASHFALL, and relationships between hypothetical plume height and eruption rate were evaluated four times daily under then-current atmospheric conditions using the program PLUMERIA. Eruptive deposits were mapped and isomass contours constructed for the two largest events, March 24 (0340-0355Z) and April 4 (1358-1429Z), which produced radar-determined plume heights of 18.3 and 15.2 km asl (~15.6 and 12.5 km above the vent), and tephra volumes (DRE) of 6.3M and 3.1M m3, respectively. For the volumetric eruption rates calculated from mapped erupted volume and seismic duration (V=6.2×103 and 1.7×103 m3/s DRE), measured plume heights H above the vent fall within 10% of the empirical best-fit curve H=1.67V0.259 published in the book Volcanic Plumes by Sparks et al. (1997, eq. 5.1). The plume heights are slightly higher than (but still within 13% of) the 14.6 and 11.1 km predicted by PLUMERIA under the existing atmospheric conditions. We have also modeled these two events using the 3-D transient model FALL3D, which considers topographic effects on wind and tephra dispersal. Using the eruption rates and plume heights constrained by deposit mapping, seismic data, and Doppler radar, and an archived wind field obtained from the NOAA GDAS model for these dates, modeled isomass contours from the April 4 event closely resemble measured values, but modeled contours from the March 24 event extend only about half to three fourths as far from the volcano as measured. This discrepancy may result from inaccuracies in the modeled wind pattern, the grain-size distribution, or turbulent entrainment algorithms. The deposit pattern may also have been affected by a lateral blast which is thought to have accompanied this event.

Advancing our understanding of the onshore propagation of tsunami bores over rough surfaces through numerical modeling

NASA Astrophysics Data System (ADS)

Marras, S.; Suckale, J.; Eguzkitza, B.; Houzeaux, G.; Vázquez, M.; Lesage, A. C.

2016-12-01

The propagation of tsunamis in the open ocean has been studied in detail with many excellent numerical approaches available to researchers. Our understanding of the processes that govern the onshore propagation of tsunamis is less advanced. Yet, the reach of tsunamis on land is an important predictor of the damage associated with a given event, highlighting the need to investigate the factors that govern tsunami propagation onshore. In this study, we specifically focus on understanding the effect of bottom roughness at a variety of scales. The term roughness is to be understood broadly, as it represents scales ranging from small features like rocks, to vegetation, up to the size of larger structures and topography. In this poster, we link applied mathematics, computational fluid dynamics, and tsunami physics to analyze the small scales features of coastal hydrodynamics and the effect of roughness on the motion of tsunamis as they run up a sloping beach and propagate inland. We solve the three-dimensional Navier-Stokes equations of incompressible flows with free surface, which is tracked by a level set function in combination with an accurate re-distancing scheme. We discretize the equations via linear finite elements for space approximation and fully implicit time integration. Stabilization is achieved via the variational multiscale method whereas the subgrid scales for our large eddy simulations are modeled using a dynamically adaptive Smagorinsky eddy viscosity. As the geometrical characteristics of roughness in this study vary greatly across different scales, we implement a scale-dependent representation of the roughness elements. We model the smallest sub-grid scale roughness features by the use of a properly defined law of the wall. Furthermore, we utilize a Manning formula to compute the shear stress at the boundary. As the geometrical scales become larger, we resolve the geometry explicitly and compute the effective volume drag introduced by large scale immersed bodies. This study is a necessary step to verify and validate our model before proceeding further into the simulation of sediment transport in turbulent free surface flows. The simulation of such problems requires a space and time-dependent viscosity to model the effect of solid bodies transported by the incoming flow on onshore tsunami propagation.

Culvert roughness elements for native Utah fish passage : phase I.

DOT National Transportation Integrated Search

2011-01-01

Laboratory flume testing of native Utah non-salmonid fish was performed to observe how : they use altered flow around obstacles to swim upstream. Three experimental setups included : a bare Plexiglas flume, vertical cylinders, and natural substrate p...

Institute for Aviation Research and Development Research Project

DTIC Science & Technology

1989-01-01

Symbolics Artificial Intelligence * Vision Systems * Finite Element Modeling ( NASTRAN ) * Aerodynamic Paneling (VSAERO) Projects: * Software...34Wall Functions for k and epsilon for Turbulent Flow Through Rough and Smooth Pipes," Eleventh International Symposium on Turbulence, October 17-19, 1988

AFRC2017-0037-01

NASA Image and Video Library

2017-02-17

The Swept Wing Laminar Flow test article, integrated to the underside of a NASA F-15, will examine the effectiveness of different configurations of small dots, called distributed roughness elements, to extend smooth, laminar airflow over a wing’s depth, reducing friction drag.

Flow Resistance Interactions on Hillslopes With Heterogeneous Attributes: Effects on Runoff Hydrograph Characteristics

NASA Astrophysics Data System (ADS)

Papanicolaou, Athanasios N.; Abban, Benjamin K. B.; Dermisis, Dimitrios C.; Giannopoulos, Christos P.; Flanagan, Dennis C.; Frankenberger, James R.; Wacha, Kenneth M.

2018-01-01

An improved modeling framework for capturing the effects of space and time-variant resistance to overland flow is developed for intensively managed landscapes. The framework builds on the WEPP model but it removes the limitations of the "equivalent" plane and time-invariant roughness assumption. The enhanced model therefore accounts for spatiotemporal changes in flow resistance along a hillslope due to changes in roughness, in profile curvature, and downslope variability. The model is used to quantify the degree of influence—from individual soil grains to aggregates, "isolated roughness elements," and vegetation—on overland flow characteristics under different storm magnitudes, downslope gradients, and profile curvatures. It was found that the net effects of land use change from vegetation to a bare surface resulted in hydrograph peaks that were up to 133% larger. Changes in hillslope profile curvature instead resulted in peak runoff rate changes that were only up to 16%. The stream power concept is utilized to develop a taxonomy that relates the influence of grains, isolated roughness elements, and vegetation, on overland flow under different storm magnitudes and hillslope gradients. Critical storm magnitudes and hillslope gradients were found beyond which the effects of these landscape attributes on the peak stream power were negligible. The results also highlight weaknesses of the space/time-invariant flow resistance assumption and demonstrate that assumptions on landscape terrain characteristics exert a strong control both on the shape and magnitude of hydrographs, with deviations reaching 65% in the peak runoff when space/time-variant resistance effects are ignored in some cases.

Simulation of thermal stress in Er2O3 and Al2O3 tritium penetration barriers by finite-element analysis

NASA Astrophysics Data System (ADS)

Ze, LIU; Guogang, YU; Anping, HE; Ling, WANG

2017-09-01

The physical vapor deposition method is an effective way to deposit Al2O3 and Er2O3 on 316L stainless steel substrates acting as tritium permeation barriers in a fusion reactor. The distribution of residual thermal stress is calculated both in Al2O3 and Er2O3 coating systems with planar and rough substrates using finite element analysis. The parameters influencing the thermal stress in the sputter process are analyzed, such as coating and substrate properties, temperature and Young’s modulus. This work shows that the thermal stress in Al2O3 and Er2O3 coating systems exhibit a linear relationship with substrate thickness, temperature and Young’s modulus. However, this relationship is inversed with coating thickness. In addition, the rough substrate surface can increase the thermal stress in the process of coating deposition. The adhesive strength between the coating and the substrate is evaluated by the shear stress. Due to the higher compressive shear stress, the Al2O3 coating has a better adhesive strength with a 316L stainless steel substrate than the Er2O3 coating. Furthermore, the analysis shows that it is a useful way to improve adhesive strength with increasing interface roughness.

Mass and charge transport in IPMC actuators with fractal interfaces

NASA Astrophysics Data System (ADS)

Chang, Longfei; Wu, Yucheng; Zhu, Zicai; Li, Heng

2016-04-01

Ionic Polymer-Metal Composite (IPMC) actuators have been attracting a growing interest in extensive applications, which consequently raises the demands on the accuracy of its theoretical modeling. For the last few years, rough landscape of the interface between the electrode and the ionic membrane of IPMC has been well-documented as one of the key elements to ensure a satisfied performance. However, in most of the available work, the interface morphology of IPMC was simplified with structural idealization, which lead to perplexity in the physical interpretation on its interface mechanism. In this paper, the quasi-random rough interface of IPMC was described with fractal dimension and scaling parameters. And the electro-chemical field was modeled by Poisson equation and a properly simplified Nernst-Planck equation set. Then, by simulation with Finite Element Method, a comprehensive analysis on he inner mass and charge transportation in IPMC actuators with different fractal interfaces was provided, which may be further adopted to instruct the performance-oriented interface design for ionic electro-active actuators. The results also verified that rough interface can impact the electrical and mechanical response of IPMC, not only from the respect of the real surface increase, but also from mass distribution difference caused by the complexity of the micro profile.

Grand Marais Harbor, Cook County, Minnesota, Operation and Maintenance Activities, Environment Assessment Report.

DTIC Science & Technology

1974-12-01

34 - . .. .. . . . . . . -.. 2.523 In rocky crevices along the shore walls there are a variety of sedges, rushes, grasses, mosses, lichens ...our dre~tinn anid d!’aonal planu ~ for 1rand ’N r~ls Hxariors ihe a1tcrrat.v.e deacrit’,ed In’ tti..i; le.tter ealicatn. dipoa plans for l𔃺tii pollato-4

40 CFR 63.1218 - What are the standards for hydrochloric acid production furnaces that burn hazardous waste?

Code of Federal Regulations, 2012 CFR

2012-07-01

... acid production furnaces that burn hazardous waste? 63.1218 Section 63.1218 Protection of Environment... production furnaces that burn hazardous waste? (a) Emission limits for existing sources. You must not...% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or F027 (see § 261...

Areal distribution, thickness, mass, volume, and grain size of tephra-fall deposits from the 1992 eruptions of Crater Peak vent, Mt. Spurr Volcano, Alaska

USGS Publications Warehouse

McGimsey, Robert G.; Neal, Christina A.; Riley, Colleen M.

2001-01-01

The Crater Peak flank vent of Mount Spurr volcano erupted June 27, August 18, and September 16-17, 1992. The three eruptions were similar in intensity (vulcanian to subplinian eruption columns reaching up to 14 km Above Sea Level) and duration (3.5 to 4.0 hours) and produced tephra-fall deposits (12, 14, 15 x 106 m3 Dense Rock Equivalent [DRE]) discernible up to 1,000 km downwind. The June 27 ash cloud traveled north over the rugged, ice- and snow-covered Alaska Range. The August 18 ash cloud was carried southeastward over Anchorage, across Prince William Sound, and down the southeastern shoreline of the Gulf of Alaska. The September 16-17 ash plume was directed eastward over the Talkeetna and Wrangell mountains and into the Yukon Territory of Canada. Over 50 mass-per-unit-area (MPUA) samples were collected for each of the latter two fall deposits at distances ranging from about 2 km to 370 km downwind from the volcano. Only 10 (mostly proximal) samples were collected for the June fall deposit due to inaccessible terrain and funding constraints. MPUA data were plotted and contoured (isomass lines) to graphically display the distribution of each fall deposit. For the August and September eruptions, fallout was concentrated along a narrow (30 to 50 km wide) belt. The fallout was most concentrated (100,000 to greater than 250,000 g/m2) within about 80 km of the volcano. Secondary maxima occur at 200 km (2,620 g/m2) and 300 km (4,659 g/m2), respectively, down axis for the August and September deposits. The maxima contain bimodal grain size distributions (with peaks at 88.4 and 22.1 microns) indicating aggregation within the ash cloud. Combined tephra-volume for the 1992 Mount Spurr eruptions (41 x 106 m3 DRE) is comparable to that (tephra-fall only) of the 1989-90 eruptions of nearby Redoubt volcano (31-49 x 106 m3 DRE).

Predictors of spontaneous transient seizure remission in patients of medically refractory epilepsy due to mesial temporal sclerosis (MTS).

PubMed

Dhiman, Vikas; Sinha, Sanjib; Arimappamagan, Arivazhagan; Mahadevan, Anita; Bharath, Rose Dawn; Saini, Jitender; Rajeswaran, Jamuna; Rao, Malla Bhaskar; Shankar, Susrala K; Satishchandra, Parathasarthy

2015-02-01

To analyze the predictors of spontaneous transient seizure remission for ≥1 year in patients with drug-resistant epilepsy (DRE) due to mesial temporal sclerosis (MTS). This analysis included 38 patients with DRE (M:F = 20:18, age: 31.7 ± 10.9 years) diagnosed with unilateral MTS (right:left = 16:22). Group I ('remission' group) comprised of patients with seizure remission (M:F = 10:8, age: 32.8 ± 12.3 years, mean seizure free period: 2.2 ± 1.1 years; median: 2.1 years). Group II ('non-remission' group) comprised of age and gender matched 20 patients (M:F = 10:10, age: 30.7 ± 9.7 years) with unilateral MTS who never had seizure remission and subsequently underwent epilepsy surgery. Groups I and II were compared to find the predictors associated with transient seizure remission. The age at onset of seizures in group I was 13.2 ± 11.8 years and in group II was 12.0 ± 7.6 years. The duration of seizure was: group I - 19.7 ± 12.5 years and group II - 19.3 ± 7.7 years. Past history of seizure remissions (p < 0.001), frequent periods of remissions (p < 0.001), first remission within a year of onset of seizures (p = 0.04) and normal EEG (p = 0.04) were the important clinical predictors associated with seizure remission in this cohort. Fifteen patients in group I (83.3%) experienced remission following either change in AED (p ≤ 0.001) or increase in AED dosages (p < 0.001). There was no difference between the two groups regarding the type of semiology (partial vs. secondarily generalized) (p = 0.50), family history of seizures (p = 1.0), side of the lesion (p = 0.34), history of febrile seizures (p = 1.0) and the number of AEDs used (p = 0.53). The present study unfolds, some of the clinically relevant predictors associated with transient seizure remission in patients with DRE and MTS. Future molecular and network studies are required to understand its mechanism. Copyright © 2014 Elsevier B.V. All rights reserved.

Crystal Structures of Two Bacterial 3-Hydroxy-3-methylglutaryl-CoA Lyases Suggest a Common Catalytic Mechanism among a Family of TIM Barrel Metalloenzymes Cleaving Carbon-Carbon Bonds

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

Forouhar,F.; Hussain, M.; Farid, R.

The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) lyase catalyzes the terminal steps in ketone body generation and leucine degradation. Mutations in this enzyme cause a human autosomal recessive disorder called primary metabolic aciduria, which typically kills victims because of an inability to tolerate hypoglycemia. Here we present crystal structures of the HMG-CoA lyases from Bacillus subtilis and Brucella melitensis at 2.7 and 2.3 {angstrom} resolution, respectively. These enzymes share greater than 45% sequence identity with the human orthologue. Although the enzyme has the anticipated triose-phosphate isomerase (TIM) barrel fold, the catalytic center contains a divalent cation-binding site formed by a cluster ofmore » invariant residues that cap the core of the barrel, contrary to the predictions of homology models. Surprisingly, the residues forming this cation-binding site and most of their interaction partners are shared with three other TIM barrel enzymes that catalyze diverse carbon-carbon bond cleavage reactions believed to proceed through enolate intermediates (4-hydroxy-2-ketovalerate aldolase, 2-isopropylmalate synthase, and transcarboxylase 5S). We propose the name 'DRE-TIM metallolyases' for this newly identified enzyme family likely to employ a common catalytic reaction mechanism involving an invariant Asp-Arg-Glu (DRE) triplet. The Asp ligates the divalent cation, while the Arg probably stabilizes charge accumulation in the enolate intermediate, and the Glu maintains the precise structural alignment of the Asp and Arg. We propose a detailed model for the catalytic reaction mechanism of HMG-CoA lyase based on the examination of previously reported product complexes of other DRE-TIM metallolyases and induced fit substrate docking studies conducted using the crystal structure of human HMG-CoA lyase (reported in the accompanying paper by Fu, et al. (2006) J. Biol. Chem. 281, 7526-7532). Our model is consistent with extensive mutagenesis results and can guide subsequent studies directed at definitive experimental elucidation of this enzyme's reaction mechanism.« less

Modeling Of Spontaneous Multiscale Roughening And Branching of Ruptures Propagating On A Slip-Weakening Frictional Fault

NASA Astrophysics Data System (ADS)

Elbanna, A. E.

2013-12-01

Numerous field and experimental observations suggest that faults surfaces are rough at multiple scales and tend to produce a wide range of branch sizes ranging from micro-branching to large scale secondary faults. The development and evolution of fault roughness and branching is believed to play an important role in rupture dynamics and energy partitioning. Previous work by several groups has succeeded in determining conditions under which a main rupture may branch into a secondary fault. Recently, there great progress has been made in investigating rupture propagation on rough faults with and without off-fault plasticity. Nonetheless, in most of these models the heterogeneity, whether the roughness profile or the secondary faults orientation, was built into the system from the beginning and consequently the final outcome depends strongly on the initial conditions. Here we introduce an adaptive mesh technique for modeling mode-II crack propagation on slip weakening frictional interfaces. We use a Finite Element Framework with random mesh topology that adapts to crack dynamics through element splitting and sequential insertion of frictional interfaces dictated by the failure criterion. This allows the crack path to explore non-planar paths and develop the roughness profile that is most compatible with the dynamical constraints. It also enables crack branching at different scales. We quantify energy dissipation due to the roughening process and small scale branching. We compare the results of our model to a reference case for propagation on a planar fault. We show that the small scale processes of roughening and branching influence many characteristics of the rupture propagation including the energy partitioning, rupture speed and peak slip rates. We also estimate the fracture energy required for propagating a crack on a planar fault that will be required to produce comparable results. We anticipate that this modeling approach provides an attractive methodology that complements the current efforts in modeling off-fault plasticity and damage.

Finite element analysis of the Wolf Creek multispan curved girder bridge.

DOT National Transportation Integrated Search

2008-01-01

The use of curved girder bridges in highway construction has grown steadily during the last 40 years. Today, roughly 25% of newly constructed bridges have a curved alignment. Curved girder bridges have numerous complicating geometric features that di...

Management Information in Tertiary Institutions.

ERIC Educational Resources Information Center

Findlay, A. W.

1981-01-01

A college or university's management information system corresponds roughly to the institution's structure, with these elements in descending order in the hierarchy: policy and planning, a planning system, control and coordination, and typical operating systems (payroll, exams, scheduling, library, facilities assignments, and accounting…

Modeling the Interactions Between Multiple Crack Closure Mechanisms at Threshold

NASA Technical Reports Server (NTRS)

Newman, John A.; Riddell, William T.; Piascik, Robert S.

2003-01-01

A fatigue crack closure model is developed that includes interactions between the three closure mechanisms most likely to occur at threshold; plasticity, roughness, and oxide. This model, herein referred to as the CROP model (for Closure, Roughness, Oxide, and Plasticity), also includes the effects of out-of plane cracking and multi-axial loading. These features make the CROP closure model uniquely suited for, but not limited to, threshold applications. Rough cracks are idealized here as two-dimensional sawtooths, whose geometry induces mixed-mode crack- tip stresses. Continuum mechanics and crack-tip dislocation concepts are combined to relate crack face displacements to crack-tip loads. Geometric criteria are used to determine closure loads from crack-face displacements. Finite element results, used to verify model predictions, provide critical information about the locations where crack closure occurs.

Characterization of surface roughness effects on pressure drop in single-phase flow in minichannels

NASA Astrophysics Data System (ADS)

Kandlikar, Satish G.; Schmitt, Derek; Carrano, Andres L.; Taylor, James B.

2005-10-01

Roughness features on the walls of a channel wall affect the pressure drop of a fluid flowing through that channel. This roughness effect can be described by (i) flow area constriction and (ii) increase in the wall shear stress. Replotting the Moody's friction factor chart with the constricted flow diameter results in a simplified plot and yields a single asymptotic value of friction factor for relative roughness values of ɛ /D>0.03 in the fully developed turbulent region. After reviewing the literature, three new roughness parameters are proposed (maximum profile peak height Rp, mean spacing of profile irregularities RSm, and floor distance to mean line Fp). Three additional parameters are presented to consider the localized hydraulic diameter variation (maximum, minimum, and average) in future work. The roughness ɛ is then defined as Rp+Fp. This definition yields the same value of roughness as obtained from the sand-grain roughness [H. Darcy, Recherches Experimentales Relatives au Mouvement de L'Eau dans les Tuyaux (Mallet-Bachelier, Paris, France, 1857); J. T. Fanning, A Practical Treatise on Hydraulic and Water Supply Engineering (Van Nostrand, New York, 1877, revised ed. 1886); J. Nikuradse, "Laws of flow in rough pipes" ["Stromungsgesetze in Rauen Rohren," VDI-Forschungsheft 361 (1933)]; Beilage zu "Forschung auf dem Gebiete des Ingenieurwesens," Ausgabe B Band 4, English translation NACA Tech. Mem. 1292 (1937)]. Specific experiments are conducted using parallel sawtooth ridge elements, placed normal to the flow direction, in aligned and offset configurations in a 10.03mm wide rectangular channel with variable gap (resulting hydraulic diameters of 325μm-1819μm with Reynolds numbers ranging from 200 to 7200 for air and 200 to 5700 for water). The use of constricted flow diameter extends the applicability of the laminar friction factor equations to relative roughness values (sawtooth height) up to 14%. In the turbulent region, the aligned and offset roughness arrangements yield different results indicating a need to further characterize the surface features. The laminar to turbulent transition is also seen to occur at lower Reynolds numbers with an increase in the relative roughness.

Reprogramming of a defense signaling pathway in rough lemon and sweet orange is a critical element of the early response to ‘Candidatus Liberibacter asiaticus’

PubMed Central

Yu, Qibin; Chen, Chunxian; Du, Dongliang; Huang, Ming; Yao, Jiqiang; Yu, Fahong; Brlansky, Ronald H; Gmitter, Frederick G.

2017-01-01

Huanglongbing (HLB) in citrus infected by Candidatus Liberibacter asiaticus (CLas) has caused tremendous losses to the citrus industry. No resistant genotypes have been identified in citrus species or close relatives. Among citrus varieties, rough lemon (Citrus jambhiri) has been considered tolerant due to its ability to produce a healthy flush of new growth after infection. The difference between tolerance and susceptibility is often defined by the speed and intensity of a plant’s response to a pathogen, especially early defense responses. RNA-seq data were collected from three biological replicates of CLas- and mock-inoculated rough lemon and sweet orange at week 0 and 7 following infection. Functional analysis of the differentially expressed genes (DEGs) indicated that genes involved in the mitogen activated protein kinase (MAPK) signaling pathway were highly upregulated in rough lemon. MAPK induces the transcription of WRKY and other transcription factors which potentially turn on multiple defense-related genes. A Subnetwork Enrichment Analysis further revealed different patterns of regulation of several functional categories, suggesting DEGs with different functions were subjected to reprogramming. In general, the amplitude of the expression of defense-related genes is much greater in rough lemon than in sweet orange. A quantitative disease resistance response may contribute to the durable tolerance level to HLB observed in rough lemon. PMID:29214028

A Study of the Mean Force Structure of Rough-Wall Turbulent Boundary Layers

NASA Astrophysics Data System (ADS)

Mehdi, Faraz; Klewicki, Joseph

2011-11-01

Analysis of existing data by Mehdi, Klewicki & White [Physica D 239(2010)] provides evidence that the traditional classifications do not fully account for the combined effects of roughness and Reynolds number. We continue to explore this further, and in the present talk report on experiments that used 24-grit sandpaper and pea gravel for roughness over an 8m fetch. Two-component LDV measurements are used to acquire well-resolved mean velocity and Reynolds stress profiles over a modest range of Reynolds numbers. These data are used to estimate the terms in the appropriate mean statement of dynamics, which directly reveals the operative time-averaged balance of forces. The present results further reinforce the previous observation that the mean viscous force retains dominant order above (and often well-above) the roughness elements. Force balance data are shown to be usefully organized relative to the length scale that defines the region from the wall to where the leading order mean dynamics are described by a balance between mean advection and the mean effect of turbulent inertia. In the smooth-wall flow, this length scale is only a function of Reynolds number. In rough-wall flows, the data indicate it to be a function of roughness and Reynolds number. The support of the ONR (N000140810836, grant monitor Ronald Joslin) is gratefully acknowledged.

Detecting surface roughness effects on the atmospheric boundary layer via AIRSAR data: A field experiment in Death Valley, California

NASA Technical Reports Server (NTRS)

Blumberg, Dan G.; Greeley, Ronald

1992-01-01

The part of the troposphere influenced by the surface of the earth is termed the atmospheric boundary layer. Flow within this layer is influenced by the roughness of the surface; rougher surfaces induce more turbulence than smoother surfaces and, hence, higher atmospheric transfer rates across the surface. Roughness elements also shield erodible particles, thus decreasing the transport of windblown particles. Therefore, the aerodynamic roughness length (z(sub 0)) is an important parameter in aeolian and atmospheric boundary layer processes as it describes the aerodynamic properties of the underlying surface. z(sub 0) is assumed to be independent of wind velocity or height, and dependent only on the surface topography. It is determined using in situ measurements of the wind speed distribution as a function of height. For dry, unvegetated soils the intensity of the radar backscatter (sigma(sup 0)) is affected primarily by surface roughness at a scale comparable with the radar wavelength. Thus, both wind and radar respond to surface roughness variations on a scale of a few meters or less. Greeley showed the existence of a correlation between z(sub 0) and sigma(sup 0). This correlation was based on measurements over lava flows, alluvial fans, and playas in the southwest deserts of the United States. It is shown that the two parameters behave similarly also when there are small changes over a relatively homogeneous surface.

Broadband gradient index microwave quasi-optical elements based on non-resonant metamaterials.

PubMed

Liu, Ruopeng; Cheng, Qiang; Chin, Jessie Y; Mock, Jack J; Cui, Tie Jun; Smith, David R

2009-11-09

Utilizing non-resonant metamaterial elements, we demonstrate that complex gradient index optics can be constructed exhibiting low material losses and large frequency bandwidth. Although the range of structures is limited to those having only electric response, with an electric permittivity always equal to or greater than unity, there are still numerous metamaterial design possibilities enabled by leveraging the non-resonant elements. For example, a gradient, impedance matching layer can be added that drastically reduces the return loss of the optical elements due to reflection. In microwave experiments, we demonstrate the broadband design concepts with a gradient index lens and a beam-steering element, both of which are confirmed to operate over the entire X-band (roughly 8-12 GHz) frequency spectrum.

Effects of plaque lengths on stent surface roughness.

PubMed

Syaifudin, Achmad; Takeda, Ryo; Sasaki, Katsuhiko

2015-01-01

The physical properties of the stent surface influence the effectiveness of vascular disease treatment after stent deployment. During the expanding process, the stent acquires high-level deformation that could alter either its microstructure or the magnitude of surface roughness. This paper constructed a finite element simulation to observe the changes in surface roughness during the stenting process. Structural transient dynamic analysis was performed using ANSYS, to identify the deformation after the stent is placed in a blood vessel. Two types of bare metal stents are studied: a Palmaz type and a Sinusoidal type. The relationship between plaque length and the changes in surface roughness was investigated by utilizing three different length of plaque; plaque length longer than the stent, shorter than the stent and the same length as the stent. In order to reduce computational time, 3D cyclical and translational symmetry was implemented into the FE model. The material models used was defined as a multilinear isotropic for stent and hyperelastic for the balloon, plaque and vessel wall. The correlation between the plastic deformation and the changes in surface roughness was obtained by intermittent pure tensile test using specimen whose chemical composition was similar to that of actual stent material. As the plastic strain is achieved from FE simulation, the surface roughness can be assessed thoroughly. The study found that the plaque size relative to stent length significantly influenced the critical changes in surface roughness. It was found that the length of stent which is equal to the plaque length was preferable due to the fact that it generated only moderate change in surface roughness. This effect was less influential to the Sinusoidal stent.

Bassett Creek Watershed, Hennepin County, Minnesota. Feasibility Report for Control. Appendixes.

DTIC Science & Technology

1976-03-01

maintenance of the creek corridor . The local interests objected to any plan that would impair the aesthetics of the creek. The needs of the watershed with...OPEN CHANNEL CORRIDOR TO THE MISSISSIPPI RIVR (Alternate 5-E) ...... .............. D-26 COMBINATIONS OF NONSTRUCTURAL AND STRUCTURAL ALTERNATIVES...AND DRE TURNEL (Alternate 6-D) . . ... . . . . . . . . . . D-30 FLOOD STORAGE AND FLOOD PROOFIM. WIT7 AN O(IUI SPACE-- OPEN CHANNEL CORRIDOR TO THE

Hand Anthropometry of U.S. Army Personnel

DTIC Science & Technology

1991-12-01

warrant extra attention . Dr. Parham has been extreme! y helpful in obtaining the necessary resources to keep the hand system running, and in listening to...ethnicjracial groups. A report by Wagner ( 1988) explored the anthropometry of 127· male arrl 111 female pianists . Wagner was able to show that the...harrls of professional pianists , as a specialized occupational group, are unique in their anthropometric characteristics when compared with nDre

Apparatus for high flux photocatalytic pollution control using a rotating fluidized bed reactor

DOEpatents

Tabatabaie-Raissi, Ali; Muradov, Nazim Z.; Martin, Eric

2003-06-24

An apparatus based on optimizing photoprocess energetics by decoupling of the process energy efficiency from the DRE for target contaminants. The technique is applicable to both low- and high-flux photoreactor design and scale-up. An apparatus for high-flux photocatalytic pollution control is based on the implementation of multifunctional metal oxide aerogels and other media in conjunction with a novel rotating fluidized particle bed reactor.

Comparing association of preoperative transrectal ultrasound prostate weight with prostate weight obtained after radical prostatectomy after adjustment for other prognostic factors in a subset of the Northwestern University Prostate SPORE database

NASA Astrophysics Data System (ADS)

Helenowski, Irene; Jovanovic, Borko; Gurley, Michael; Leikin, Robin; Catalona, William; Roston, Arden; Kuzel, Timothy

Transrectal ultrasound (TRUS) is a non-invasive approach to measure prostate size as a surrogate (density =1.0) for prostate weight with implications in prostate cancer prognosis. But the question is how reliable is this preoperative measurement compared to other measures of prostate weight. This work presents the correlations between preoperative TRUS prostate weight and prostate weight obtained after radical prostatectomy in 434 patients with mean TRUS weight 36g (range: 10g-120g) and the mean prostate weight obtained after radical prostatectomy 51g (range: 16g-180g) from the Northwestern University Prostate SPORE database. 311 patients with weight obtained by digital rectal exam (DRE) were also compared to the TRUS prostate weights with mean and range of DRE weights 33g (10g - 78g). Correlations were adjusted by age, BMI, an indicator variable for a pathological stage of III or greater, and for Gleason score greater than 7. Correlations were also computed for separately for European American and Other Race populations. Differences in means were evaluated via the paired t-test. Results indicate TRUS measures obtained via ultrasound as promising but improvement in the technology still appears needed.

Study on regional air quality impact from a chemical plant emergency shutdown.

PubMed

Ge, Sijie; Wang, Sujing; Xu, Qiang; Ho, Thomas

2018-06-01

Emergency shutdowns of chemical plants (ESCP) inevitably generate intensive and huge amounts of VOCs and NO x emissions through flaring that can cause highly localized and transient air pollution events with elevated ozone concentrations. However, quantitative studies of regional ozone impact due to ESCP, in terms of how ESCP would affect and to what extent ESCP could impact, are still lacking. This paper reports a systematic study on regional air quality impact from an olefin plant emergency shutdown due to the sudden failure of its cracked gas compressor (CGC). It demonstrates that emergency shutdown may cause significant ozone increment subject to different factors such as the starting time of emergency shutdown, flare destruction and removal efficiency (DRE) and plant location. In our studied case, the 8-hr ozone increment ranges from 0.4 to 3.3 ppb under different starting time, from 3.3 to 24.8 ppb under different DRE, and from 1.6 to 3.3 ppb under different locations. The results enable us to understand how and to what extent emergency operating activities of the chemical process will affect local air quality, which might be beneficial for decision makings on emergency air-quality response and control in the future. Copyright © 2018 Elsevier Ltd. All rights reserved.

Thinking Style as a Predictor of Men’s Participation in Cancer Screening

PubMed Central

McGuiness, Clare E.; Turnbull, Deborah; Wilson, Carlene; Duncan, Amy; Flight, Ingrid H.; Zajac, Ian

2016-01-01

Men’s participation in cancer screening may be influenced by their thinking style. Men’s need for cognition (NFC) and faith in intuition were measured to explore whether they varied by demographic variables or predicted screening behavior. Australian males (n = 585, aged 50-74 years) completed surveys about past screening and were subsequently offered mailed fecal occult blood tests (FOBTs). Demographic predictors included age, socioeconomic status, educational attainment, and language spoken at home. The screening behaviors were self-reported prostate cancer screening (prostate-specific antigen testing and digital rectal examinations [DREs]), and colorectal cancer screening (self-reported FOBT participation and recorded uptake of the FOBT offer). Analysis comprised principal component analysis and structural equation modelling. NFC was positively related to demographic variables education, socioeconomic status, and speaking English at home. Faith in intuition was negatively related to educational attainment. NFC predicted variance in self-reported DRE participation (r = .11, p = .016). No other relationships with thinking style were statistically significant. The relationship of NFC to DRE participation may reflect the way certain attributes of this screening method are processed, or alternatively, it may reflect willingness to report participation. The relationship of thinking style to a range of healthy behaviors should be further explored. PMID:27923966

Research experiences and mentoring practices in selected east Asian graduate programs: predictors of research productivity among doctoral students in molecular biology.

PubMed

Ynalvez, Ruby; Garza-Gongora, Claudia; Ynalvez, Marcus Antonius; Hara, Noriko

2014-01-01

Although doctoral mentors recognize the benefits of providing quality advisement and close guidance, those of sharing project management responsibilities with mentees are still not well recognized. We observed that mentees, who have the opportunity to co-manage projects, generate more written output. Here we examine the link between research productivity, doctoral mentoring practices (DMP), and doctoral research experiences (DRE) of mentees in programs in the non-West. Inspired by previous findings that early career productivity is a strong predictor of later productivity, we examine the research productivity of 210 molecular biology doctoral students in selected programs in Japan, Singapore, and Taiwan. Using principal component (PC) analysis, we derive two sets of PCs: one set from 15 DMP and another set from 16 DRE items. We model research productivity using Poisson and negative-binomial regression models with these sets as predictors. Our findings suggest a need to re-think extant practices and to allocate resources toward professional career development in training future scientists. We contend that doctoral science training must not only be an occasion for future scientists to learn scientific and technical skills, but it must also be the opportunity to experience, to acquire, and to hone research management skills. © 2014 The International Union of Biochemistry and Molecular Biology.

Characterisation of antimicrobial extracts from dandelion root (Taraxacum officinale) using LC-SPE-NMR.

PubMed

Kenny, O; Brunton, N P; Walsh, D; Hewage, C M; McLoughlin, P; Smyth, T J

2015-04-01

Plant extracts have traditionally been used as sources of natural antimicrobial compounds, although in many cases, the compounds responsible for their antimicrobial efficacy have not been identified. In this study, crude and dialysed extracts from dandelion root (Taraxacum officinale) were evaluated for their antimicrobial properties against Gram positive and Gram negative bacterial strains. The methanol hydrophobic crude extract (DRE3) demonstrated the strongest inhibition of microbial growth against Staphylococcus aureus, methicillin-resistant S. aureus and Bacillus cereus strains. Normal phase (NP) fractionation of DRE3 resulted in two fractions (NPF4 and NPF5) with enhanced antimicrobial activity. Further NP fractionation of NPF4 resulted in two fractions (NPF403 and NPF406) with increased antimicrobial activity. Further isolation and characterisation of compounds in NPF406 using liquid chromatography solid phase extraction nuclear magnetic resonance LC-SPE-NMR resulted in the identification of 9-hydroxyoctadecatrienoic acid and 9-hydroxyoctadecadienoic acid, while the phenolic compounds vanillin, coniferaldehyde and p-methoxyphenylglyoxylic acid were also identified respectively. The molecular mass of these compounds was confirmed by LC mass spectroscopy (MS)/MS. In summary, the antimicrobial efficacy of dandelion root extracts demonstrated in this study support the use of dandelion root as a source of natural antimicrobial compounds. Copyright © 2015 John Wiley & Sons, Ltd.

Initial dynamic load estimates during configuration design

NASA Technical Reports Server (NTRS)

Schiff, Daniel

1987-01-01

This analysis includes the structural response to shock and vibration and evaluates the maximum deflections and material stresses and the potential for the occurrence of elastic instability, fatigue and fracture. The required computations are often performed by means of finite element analysis (FEA) computer programs in which the structure is simulated by a finite element model which may contain thousands of elements. The formulation of a finite element model can be time consuming, and substantial additional modeling effort may be necessary if the structure requires significant changes after initial analysis. Rapid methods for obtaining rough estimates of the structural response to shock and vibration are presented for the purpose of providing guidance during the initial mechanical design configuration stage.

Stress inducible expression of the DREB1A transcription factor from xeric, Hordeum spontaneum L. in turf and forage grass (Paspalum notatum Flugge) enhances abiotic stress tolerance.

PubMed

James, Victoria A; Neibaur, Isaac; Altpeter, Fredy

2008-02-01

The dehydration-responsive element binding proteins (DREB1)/C-repeat (CRT) binding factors (CBF) function as transcription activators and bind to the DRE/CRT cis-acting element commonly present in the promoters of abiotic stress-regulated genes. A DREB1A transcription factor ortholog was isolated from a xeric, wild barley (Hordeum spontaneum L.) accession, originating from the Negev desert. Sequence comparison revealed a very high degree of sequence conservation of HsDREB1A to the published barley (Hordeum vulgare L.) DREB1A. Constitutive expression of the HsDREB1A gene was able to trans-activate a reporter gene under transcriptional control of the stress-inducible HVA1s and Dhn8 promoters. HsDREB1A was subcloned under transcriptional control of the stress-inducible barley HVA1s promoter and introduced into the apomictic bahiagrass (Paspalum notatum Flugge) cultivar 'Argentine'. HsDREB1A integration and stress inducible expression was detected in primary transgenic bahiagrass plants and apomictic seed progeny by Southern blot, RT-PCR and northern blot analysis respectively. Transgenic bahiagrass plants with stress-inducible expression of HsDREB1A survived severe salt stress and repeated cycles of severe dehydration stress under controlled environment conditions, in contrast to non-transgenic plants. The observed abiotic stress tolerance is very desirable in turf and forage grasses like bahiagrass, where seasonal droughts and irrigation restrictions affect establishment, persistence or productivity of this perennial crop.

Characterization of Conventional and High-Translucency Y-TZP Dental Ceramics Submitted to Air Abrasion.

PubMed

Tostes, Bhenya Ottoni; Guimarães, Renato Bastos; Noronha-Filho, Jaime Dutra; Botelho, Glauco Dos Santos; Guimarães, José Guilherme Antunes; Silva, Eduardo Moreira da

2017-01-01

This study evaluated the effect of air-abrasion on t®m phase transformation, roughness, topography and the elemental composition of three Y-TZP (Yttria-stabilized tetragonal zirconia polycrystal) dental ceramics: two conventional (Lava Frame and IPS ZirCad) and one with high-translucency (Lava Plus). Plates obtained from sintered blocks of each ceramic were divided into four groups: AS (as-sintered); 30 (air-abrasion with 30 mm Si-coated Al2O3 particles); 50 (air-abrasion with 50 mm Al2O3 particles) and 150 (air-abrasion with 150 mm Al2O3 particles). After the treatments, the plates were submitted to X-ray diffractometry; 3-D profilometry and SEM/EDS. The AS surfaces were composed of Zr and t phases. All treatments produced t®m phase transformation in the ceramics. The diameter of air-abrasion particles influenced the roughness (150>50>30>AS) and the topography. SEM analysis showed that the three treatments produced groove-shaped microretentions on the ceramic surfaces, which increased with the diameter of air-abrasion particles. EDS showed a decrease in Zr content along with the emergence of O and Al elements after air-abrasion. Presence of Si was also detected on the plates air-abraded with 30 mm Si-coated Al2O3 particles. It was concluded that irrespective of the type and diameter of the particles, air-abrasion produced t®m phase transformation, increased the roughness and changed the elemental composition of the three Y-TZP dental ceramics. Lava Plus also behaved similarly to the conventional Y-TZP ceramics, indicating that this high translucency ceramic could be more suitable to build monolithic ceramic restorations in the aesthetic restorative dentistry field.

Fabrication of transparent superhydrophobic polytetrafluoroethylene coating

NASA Astrophysics Data System (ADS)

Alawajji, Raad A.; Kannarpady, Ganesh K.; Biris, Alexandru S.

2018-06-01

Polytetrafluoroethylene (PTFE) thin films were successfully deposited on glass substrates using pulsed laser deposition, with deposition times ranging from 30 to 120 minutes (min). The surface roughness of the films increased as deposition time increased, with micro/nanoscale roughness developing when deposition time increased over 60 min. This roughness made the surface superhydrophobic, having a contact angle of about 151.6°±1. UV-vis spectroscopic analysis of the PTFE films revealed that they were highly transparent, up to ∼90% in visible and near-infrared ranges. Furthermore, when the deposition time was increased-which increased the films' thickness-the films were able to absorb 80-90% of ultraviolet light in the wavelength range <300 nm. The researchers used an x-ray photoelectron spectrometer to find the chemical and elemental composition of the films' surfaces. Atomic force microscopy was used to determine the effect of surface roughness on the films' hydrophobicity. The fabricated superhydrophobic films have many potential practical uses, from self-cleaning materials to solar cell panel coatings. Additionally, the low dielectric properties of PTFE make the films' ideal for communication antenna coatings and similar applications.

Observations of Seafloor Roughness in a Tidally Modulated Inlet

NASA Astrophysics Data System (ADS)

Lippmann, T. C.; Hunt, J.

2014-12-01

The vertical structure of shallow water flows are influenced by the presence of a bottom boundary layer, which spans the water column for long period waves or mean flows. The nature of the boundary is determined in part by the roughness elements that make up the seafloor, and includes sometimes complex undulations associated with regular and irregular shaped bedforms whose scales range several orders of magnitude from orbital wave ripples (10-1 m) to mega-ripples (100 m) and even larger features (101-103) such as sand waves, bars, and dunes. Modeling efforts often parameterize the effects of roughness elements on flow fields, depending on the complexity of the boundary layer formulations. The problem is exacerbated by the transient nature of bedforms and their large spatial extent and variability. This is particularly important in high flow areas with large sediment transport, such as tidally dominated sandy inlets like New River Inlet, NC. Quantification of small scale seafloor variability over large spatial areas requires the use of mobile platforms that can measure with fine scale (order cm) accuracy in wide swaths. The problem is difficult in shallow water where waves and currents are large, and water clarity is often limited. In this work, we present results from bathymetric surveys obtained with the Coastal Bathymetry Survey System, a personal watercraft equipped with a Imagenex multibeam acoustic echosounder and Applanix POS-MV 320 GPS-aided inertial measurement unit. This system is able to measure shallow water seafloor bathymetry and backscatter intensity with very fine scale (10-1 m) resolution and over relatively large scales (103 m) in the presence of high waves and currents. Wavenumber spectra show that the noise floor of the resolved multibeam bathymetry is on the order of 2.5 - 5 cm in amplitude, depending on water depths ranging 2 - 6 m, and about 30 cm in wavelength. Seafloor roughness elements are estimated from wavenumber spectra across the inlet from bathymetric maps of the seafloor obtained with 10-25 cm horizontal resolution. Implications of the effects of the bottom variability on the vertical structure of the currents will be discussed. This work was supported by ONR and NOAA.

A wind tunnel study of flows over idealised urban surfaces with roughness sublayer corrections

NASA Astrophysics Data System (ADS)

Ho, Yat-Kiu; Liu, Chun-Ho

2017-10-01

Dynamics in the roughness (RSLs) and inertial (ISLs) sublayers in the turbulent boundary layers (TBLs) over idealised urban surfaces are investigated analytically and experimentally. In this paper, we derive an analytical solution to the mean velocity profile, which is a continuous function applicable to both RSL and ISL, over rough surfaces in isothermal conditions. Afterwards, a modified mixing-length model for RSL/ISL transport is developed that elucidates how surface roughness affects the turbulence motions. A series of wind tunnel experiments are conducted to measure the vertical profiles of mean and fluctuating velocities, together with momentum flux over various configurations of surface-mounted ribs in cross flows using hot-wire anemometry (HWA). The analytical solution agrees well with the wind tunnel result that improves the estimate to mean velocity profile over urban surfaces and TBL dynamics as well. The thicknesses of RSL and ISL are calculated by monitoring the convergence/divergence between the temporally averaged and spatio-temporally averaged profiles of momentum flux. It is found that the height of RSL/ISL interface is a function of surface roughness. Examining the direct, physical influence of roughness elements on near-surface RSL flows reveals that the TBL flows over rough surfaces exhibit turbulence motions of two different length scales which are functions of the RSL and ISL structure. Conclusively, given a TBL, the rougher the surface, the higher is the RSL intruding upward that would thinner the ISL up to 50 %. Therefore, the conventional ISL log-law approximation to TBL flows over urban surfaces should be applied with caution.

The effect of roughness on the nucleation and propagation of shear rupture on small faults

NASA Astrophysics Data System (ADS)

Tal, Y.; Hager, B. H.

2016-12-01

Faults are rough at all scales and can be described as self-affine fractals. This deviation from planarity results in geometric asperities and a locally heterogeneous stress field, which affect the nucleation and propagation of shear rupture. We study this effect numerically and aim to understand the relative effects of different fault geometries, remote stresses, and medium and fault properties, focusing on small earthquakes, in which realistic geometry and friction law parameters can be incorporated in the model. Our numerical approach includes three main features. First, to enable slip that is large relative to the size of the elements near the fault, as well as the variation of normal stress during slip, we implement slip-weakening and rate-and state-friction laws into the Mortar Finite Element Method, in which non-matching meshes are allowed across the fault and the contacts are continuously updated. Second, we refine the mesh near the fault using hanging nodes, thereby enabling accurate representation of the fault geometry. Finally, using a variable time step size, we gradually increase the remote stress and let the rupture nucleate spontaneously. This procedure involves a quasi-static backward Euler scheme for the inter-seismic stages and a dynamic implicit Newmark scheme for the co-seismic stages. In general, under the same range of external loads, rougher faults experience more events but with smaller slips, stress drops, and slip rates, where the roughest faults experience only slow-slip aseismic events. Moreover, the roughness complicates the nucleation process, with asymmetric expansion of the rupture and larger nucleation length. In the propagation phase of the seismic events, the roughness results in larger breakdown zones.

The Effect of Interface Roughness and Oxide Film Thickness on the Inelastic Response of Thermal Barrier Coatings to Thermal Cycling

NASA Technical Reports Server (NTRS)

Pindera, Marek-Jerzy; Aboudi, Jacob; Arnold, Steven M.

1999-01-01

The effects of interfacial roughness and oxide film thickness on thermally-induced stresses in plasma-sprayed thermal barrier coatings subjected to thermal cycling are investigated using the recently developed higher-order theory for functionally graded materials. The higher-order theory is shown to be a viable alternative to the finite-element approach, capable of modeling different interfacial roughness architectures in the presence of an aluminum oxide layer and capturing the high stress gradients that occur at the top coat/bond coat interface. The oxide layer thickness is demonstrated to have a substantially greater effect on the evolution of residual stresses than local variations in interfacial roughness. Further, the location of delamination initiation in the top coat is predicted to change with increasing oxide layer thickness. This result can be used to optimize the thickness of a pre-oxidized layer introduced at the top coat/bond coat interface in order to enhance TBC durability as suggested by some researchers. The results of our investigation also support a recently proposed hypothesis regarding delamination initiation and propagation in the presence of an evolving bond coat oxidation, while pointing to the importance of interfacial roughness details and specimen geometry in modeling this phenomenon.

Simulation of RBS spectra with known 3D sample surface roughness

NASA Astrophysics Data System (ADS)

Malinský, Petr; Siegel, Jakub; Hnatowicz, Vladimir; Macková, Anna; Švorčík, Václav

2017-09-01

The Rutherford Backscattering Spectrometry (RBS) is a technique for elemental depth profiling with a nanometer depth resolution. Possible surface roughness of analysed samples can deteriorate the RBS spectra and makes their interpretation more difficult and ambiguous. This work describes the simulation of RBS spectra which takes into account real 3D morphology of the sample surface obtained by AFM method. The RBS spectrum is calculated as a sum of the many particular spectra obtained for randomly chosen particle trajectories over sample 3D landscape. The spectra, simulated for different ion beam incidence angles, are compared to the experimental ones measured with 2.0 MeV 4He+ ions. The main aim of this work is to obtain more definite information on how a particular surface morphology and measuring geometry affects the RBS spectra and derived elemental depth profiles. A reasonable agreement between the measured and simulated spectra was found and the results indicate that the AFM data on the sample surface can be used for the simulation of RBS spectra.

Morphological, elemental, and optical characterization of plasma polymerized n-butyl methacrylate thin films

NASA Astrophysics Data System (ADS)

Nasrin, Rahima; Hossain, Khandker S.; Bhuiyan, A. H.

2018-05-01

Plasma polymerized n-butyl methacrylate (PPnBMA) thin films of varying thicknesses were prepared at room temperature by AC plasma polymerization system using a capacitively coupled parallel plate reactor. Field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy-dispersive X-ray (EDX) analysis, and ultraviolet-visible (UV-Vis) spectroscopic investigation have been performed to study the morphological, elemental, and optical properties of the PPnBMA thin films, respectively. The flat and defect-free nature of thin films were confirmed by FESEM and AFM images. With declining plasma power, average roughness and root mean square roughness increase. Allowed direct transition ( E gd) and indirect transition ( E gi) energy gaps were found to be 3.64-3.80 and 3.38-3.45 eV, respectively, for PPnBMA thin films of different thicknesses. Values of E gd as well as E gi increase with the increase of thickness. The extinction coefficient, Urbach energy, and steepness parameter were also determined for these thin films.

Membrane fouling in a submerged membrane bioreactor: New method and its applications in interfacial interaction quantification.

PubMed

Hong, Huachang; Cai, Xiang; Shen, Liguo; Li, Renjie; Lin, Hongjun

2017-10-01

Quantification of interfacial interactions between two rough surfaces represents one of the most pressing requirements for membrane fouling prediction and control in membrane bioreactors (MBRs). This study firstly constructed regularly rough membrane and particle surfaces by using rigorous mathematical equations. Thereafter, a new method involving surface element integration (SEI) method, differential geometry and composite Simpson's rule was proposed to quantify the interfacial interactions between the two constructed rough surfaces. This new method were then applied to investigate interfacial interactions in a MBR with the data of surface properties of membrane and foulants experimentally measured. The feasibility of the new method was verified. It was found that asperity amplitude and period of the membrane surface exerted profound effects on the total interaction. The new method had broad potential application fields especially including guiding membrane surface design for membrane fouling mitigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of Flow Resistance Coefficient for Vegetation in Open Channel: Laboratory study

NASA Astrophysics Data System (ADS)

Aliza Ahmad, Noor; Ali, ZarinaMd; Arish, Nur Aini Mohd; Munirah Mat Daud, Azra; Fatin Amirah Alias, Nur

2018-04-01

This study focused on determination of flow resistances coefficient for grass in an open channel. Laboratory works were conducted to examine the effects of varying of roughness elements on the flume to determine flow resistance coefficient and also to determine the optimum flow resistance with five different flow rate, Q. Laboratory study with two type of vegetation which are Cow Grass and Pearl Grass were implementing to the bed of a flume. The roughness coefficient, n value is determine using Manning’s equation while Soil Conservation Services (SCS) method was used to determine the surface resistance. From the experiment, the flow resistance coefficient for Cow Grass in range 0.0008 - 0.0039 while Pearl Grass value for the flow resistance coefficient are in between 0.0013 - 0.0054. As a conclusion the vegetation roughness value in open channel are depends on density, distribution type of vegetation used and physical characteristic of the vegetation itself

A high-order multi-zone cut-stencil method for numerical simulations of high-speed flows over complex geometries

NASA Astrophysics Data System (ADS)

Greene, Patrick T.; Eldredge, Jeff D.; Zhong, Xiaolin; Kim, John

2016-07-01

In this paper, we present a method for performing uniformly high-order direct numerical simulations of high-speed flows over arbitrary geometries. The method was developed with the goal of simulating and studying the effects of complex isolated roughness elements on the stability of hypersonic boundary layers. The simulations are carried out on Cartesian grids with the geometries imposed by a third-order cut-stencil method. A fifth-order hybrid weighted essentially non-oscillatory scheme was implemented to capture any steep gradients in the flow created by the geometries and a third-order Runge-Kutta method is used for time advancement. A multi-zone refinement method was also utilized to provide extra resolution at locations with expected complex physics. The combination results in a globally fourth-order scheme in space and third order in time. Results confirming the method's high order of convergence are shown. Two-dimensional and three-dimensional test cases are presented and show good agreement with previous results. A simulation of Mach 3 flow over the logo of the Ubuntu Linux distribution is shown to demonstrate the method's capabilities for handling complex geometries. Results for Mach 6 wall-bounded flow over a three-dimensional cylindrical roughness element are also presented. The results demonstrate that the method is a promising tool for the study of hypersonic roughness-induced transition.

Multi-hybrid method for investigation of EM scattering from inhomogeneous object above a dielectric rough surface

NASA Astrophysics Data System (ADS)

Li, Jie; Guo, LiXin; He, Qiong; Wei, Bing

2012-10-01

An iterative strategy combining Kirchhoff approximation^(KA) with the hybrid finite element-boundary integral (FE-BI) method is presented in this paper to study the interactions between the inhomogeneous object and the underlying rough surface. KA is applied to study scattering from underlying rough surfaces, whereas FE-BI deals with scattering from the above target. Both two methods use updated excitation sources. Huygens equivalence principle and an iterative strategy are employed to consider the multi-scattering effects. This hybrid FE-BI-KA scheme is an improved and generalized version of previous hybrid Kirchhoff approximation-method of moments (KA-MoM). This newly presented hybrid method has the following advantages: (1) the feasibility of modeling multi-scale scattering problems (large scale underlying surface and small scale target); (2) low memory requirement as in hybrid KA-MoM; (3) the ability to deal with scattering from inhomogeneous (including coated or layered) scatterers above rough surfaces. The numerical results are given to evaluate the accuracy of the multi-hybrid technique; the computing time and memory requirements consumed in specific numerical simulation of FE-BI-KA are compared with those of MoM. The convergence performance is analyzed by studying the iteration number variation caused by related parameters. Then bistatic scattering from inhomogeneous object of different configurations above dielectric Gaussian rough surface is calculated and the influences of dielectric compositions and surface roughness on the scattering pattern are discussed.

Numerical study of transitional flow in fractures: the role of roughness on the road to turbulence

NASA Astrophysics Data System (ADS)

Linga, G.; Mathiesen, J.

2017-12-01

In aquifers and petroleum reservoirs, fractures are ubiquitous, and the majority of the fluid transport in such systems often occurs through fracture networks. Knowledge of the flow properties in the single fractures that together form the networks is hence necessary for safe operation downhole. Non-linear, high-velocity flow in such systems is of particular importance for geothermics, since turbulent mixing is known to increase heat conduction by several orders of magnitude. This is of importance both in terms of storing and recovering heat from aquifers. On the other hand, flow in rough fractures is interesting from a turbulence perspective. The onset of turbulence in pipes and channels is a phenomenon that historically has received broad attention since the early experiments by Reynolds, and only during the last decades, the phenomenon is beginning to be fully understood. However, in the presence of roughness, much less is known. In this work, we present comprehensive numerical simulations of flow in synthetic rough channels, representing single fracture joints. Using the finite element method, we solve the full-fledged, time-dependent Navier-Stokes equations for flow in the channels, from laminar flow, through transitional, to turbulent flow. We link the descriptions of microscopic to macroscopic properties, using geometric properties such as effective aperture, paying particular attention to the role of inertia and roughness for the transport properties of the channels. Finally, we discuss implications of our study for the transition to turbulence in the presence of roughness.

Influence of roughness bottom on the dynamics of a buoyant cloud : application to a powder avalanche

NASA Astrophysics Data System (ADS)

Brossard, D.; Naaim-Bouvet, F.; Naaim, M.; Caccamo, P.

2009-04-01

A powder avalanche is referred to as a turbulent flow of snow particles in air. In the past such avalanches have been modelled by buoyant cloud in a watertank: buoyant clouds flow along an inclined plane from a small immersed tank with a release gate (injection is of short duration). The powder avalanches are simulated by a heavy fluid (salt water + colorant or kaolin) which is dispersing in a lighter one. Such experiments allow studies for the influence of roughness bottoms on the dynamics of a buoyant clouds. The authors studied the flows of buoyant clouds on an uniform slope of 20° with different roughness: smooth PVC, abrasive paper, bottom covered with glued particles of PMMA or with glued glass beads of different sizes arranged in a compact way. The released volume varies between 2 to 4 liters and the density of salted water is 1.2. Two cameras are used to obtain the height together with the front velocity. Inside the study area the front velocity is approximately constant and the height of the clouds varies linearly with the distance from the released gate as usually observed in previous experiments. So for each roughness a front velocity and height growth can be defined. It was shown from the experiments that: As the bottom increases in roughness, the front speed increases and the height growth decreases. Nevertheless the height of glued elements does not seem to be the most appropriate parameter to characterize the roughness.

Optimization of Machining Process Parameters for Surface Roughness of Al-Composites

NASA Astrophysics Data System (ADS)

Sharma, S.

2013-10-01

Metal matrix composites (MMCs) have become a leading material among the various types of composite materials for different applications due to their excellent engineering properties. Among the various types of composites materials, aluminum MMCs have received considerable attention in automobile and aerospace applications. These materials are known as the difficult-to-machine materials because of the hardness and abrasive nature of reinforcement element-like silicon carbide particles. In the present investigation Al-SiC composite was produced by stir casting process. The Brinell hardness of the alloy after SiC addition had increased from 74 ± 2 to 95 ± 5 respectively. The composite was machined using CNC turning center under different machining parameters such as cutting speed (S), feed rate (F), depth of cut (D) and nose radius (R). The effect of machining parameters on surface roughness (Ra) was studied using response surface methodology. Face centered composite design with three levels of each factor was used for surface roughness study of the developed composite. A response surface model for surface roughness was developed in terms of main factors (S, F, D and R) and their significant interactions (SD, SR, FD and FR). The developed model was validated by conducting experiments under different conditions. Further the model was optimized for minimum surface roughness. An error of 3-7 % was observed in the modeled and experimental results. Further, it was fond that the surface roughness of Al-alloy at optimum conditions is lower than that of Al-SiC composite.

The velocity and composition of supernova ejecta

NASA Technical Reports Server (NTRS)

Colgate, S. A.

1971-01-01

In case of the Gum nebula, a pulsar - a presumed neutron star - is believed to be a relic of the supernova explosion. Regardless of the mechanism of the explosion, the velocity distribution and composition of the ejected matter will be roughly the same. The reimploding mass fraction is presumed to be neutron rich. The final composition is thought to be roughly 1/3 iron and 2/3 silicon, with many small fractions of elements from helium to iron. The termination of helium shell burning occurs because the shell is expanded and cooled by radiation stress. The mass fraction of the helium burning shell was calculated.

Photometry of icy satellites: How important is multiple scattering in diluting shadows?

NASA Technical Reports Server (NTRS)

Buratti, B.; Veverka, J.

1984-01-01

Voyager observations have shown that the photometric properties of icy satellites are influenced significantly by large-scale roughness elements on the surfaces. While recent progress was made in treating the photometric effects of macroscopic roughness, it is still the case that even the most complete models do not account for the effects of multiple scattering fully. Multiple scattering dilutes shadows caused by large-scale features, yet for any specific model it is difficult to calculate the amount of dilution as a function of albedo. Accordingly, laboratory measurements were undertaken using the Cornell Goniometer to evaluate the magnitude of the effect.

Effect of ultraprecision polishing techniques on coherence times of shallow nitrogen-vacancy centers in diamond

NASA Astrophysics Data System (ADS)

Braunbeck, G.; Mandal, S.; Touge, M.; Williams, O. A.; Reinhard, F.

2018-05-01

We investigate the correlation between surface roughness and corresponding $T_2$ times of nearsurface nitrogen-vacancy centers (~7 nm/ 5 keV implantation energy) in diamond. For this purpose we compare five different polishing techniques, including both purely mechanical as well as chemical mechanical approaches, two different substrate sources (Diam2tec and Element Six) and two different surface terminations (O- and H-termination) during nitrogen-vacancy forming. All coherence times are measured and compared before and after an oxygen surface treatment at 520 {\\deg}C. We find that the coherence times of shallow nitrogen-vacancy centers are surprisingly independent of surface roughness.

Breast Cancer Center Support Grant

DTIC Science & Technology

1999-09-01

indicator for the disease. Am J Epidemiol 1980 ; 111:301-8. (42) Dupont WD, Page DL. Breast cancer risk associated with proliferative disease, age...1993;187:75-9. (52) Burhenne HJ, Burhenne LW, Goldberg F, Hislop TG, Worth AJ, Rebbeck PM, et al. Interval breast cancers in the Screening Mammography...Basier, Ian M. Thompson Until the mid- 1980s , early detection for prostate cancer had only one tool—digital rectal examination (DRE). The tool is

Lateral ring metal elastic wheel absorbs shock loading

NASA Technical Reports Server (NTRS)

Galan, L.

1966-01-01

Lateral ring metal elastic wheel absorbs practically all shock loading when operated over extremely rough terrain and delivers only a negligible shock residue to associated suspension components. The wheel consists of a rigid aluminum assembly to which lateral titanium ring flexible elements with treads are attached.

Magma-Tectonic Interactions along the Central America Volcanic Arc: Insights from the August 1999 Magmatic and Tectonic Event at Cerro Negro, Nicaragua

NASA Astrophysics Data System (ADS)

La Femina, P.; Connor, C.; Strauch, W.

2002-12-01

Volcanic vent alignments form parallel to the direction of maximum horizontal stress, accommodating extensional strain via dike injection. Roughly east-west extension within the Central America Volcanic Arc is accommodated along north-northwest-trending basaltic vent alignments. In Nicaragua, these alignments are located in a northwest-trending zone of dextral shear, with shear accommodated along northeast trending bookshelf faults. The recent eruption of Cerro Negro volcano, Nicaragua and Marabios Range seismic swarm revealed the interaction of these fault systems. A low energy (VEI 1), small volume (0.001 km3 DRE) eruption of highly crystalline basalt occurred at Cerro Negro volcano, Nicaragua, August 5-7, 1999. This eruption followed three tectonic earthquakes (each Mw 5.2) in the vicinity of Cerro Negro hours before the onset of eruptive activity. The temporal and spatial pattern of microseismicity and focal mechanisms of the Mw 5.2 earthquakes suggests the activation of northeast-trending faults northwest and southeast of Cerro Negro within the Marabios Range. The eruption was confined to three new vents formed on the southern flank of Cerro Negro along a preexisting north-northwest trending alignment; the El Hoyo alignment of cinder cones, maars and explosion craters. Surface ruptures formed > 1 km south and southeast of the new vents suggest dike injection. Numerical simulations of conduit flow illustrate that the observed effusion rates (up to 65 ms-1) and fountain heights (50-300 m) can be achieved by eruption of magma with little or no excess fluid pressure, in response to tectonic strain. These observations and models suggest that 1999 Cerro Negro activity is an excellent example of tectonically induced small-volume eruptions in an arc setting.

Preliminary Determination of the Temperature Dependence of Siderophile Element Diffusion in Iron Meteorites at 1GPa

NASA Astrophysics Data System (ADS)

Watson, H. C.; Watson, B.

2002-05-01

Preliminary results for diffusion of siderophile elements (Cu, Pd, Re, Os, and Mo) in an iron meteorite analog were obtained at temperatures ranging from 1175° C to 1400° C and 1GPa from diffusion couple experiments in a piston-cylinder apparatus. Alloys were prepared by synthesizing mixtures of pure metal powders. The alloys were made from a 90 wt% Fe and 10 wt% Ni base mixture, and approximately 1wt% of the various siderophile elements was added (individually) to the same base mixture to make the doped alloys. The powders were packed in pre-drilled holes ( ~1 mm diameter by 8 mm deep) in MgO cylinders, and run in a piston cylinder apparatus at 1400° C and 1GPa for 48 hours. The resulting homogeneous alloys were then sectioned into wafers approximately 1mm thick, and the faces were polished to prepare for the diffusion experiments. A diffusion couple experiment was conducted by mating a pure alloy wafer and a doped wafer, and placing the couple into an MgO capsule for pressurization and heating in the piston cylinder. The duration of the diffusion experiments ranged from 12 hours to 100 hours. Upon run completion, the diffusion couples were extracted, sectioned lengthwise, and polished for analysis. Diffusion profiles were measured using standard electron microprobe techniques. Preliminary Arrhenius relations have been found as follows: DMo=2.12E-1+/-0.20 m2/s exp(390.86+/-40.46 kJ/mol/RT) DCu=1.37E-3+/-1.25E-3 m2/s exp(315.24+/-31.64 kJ/mol/RT) DPd=2.40E-5+/-2.40E-5 m2/s exp(269.64+/-87.49 kJ/mol/RT) Diffusion coefficients have also been found for Re and Os at 1325° C. They are: DRe=7.89E-15+/-6.70 m2/s and DOs=9.69E-15+/-8.24 m2/s

LMOOCs, Classifying Design: Survey Findings from LMOOC Providers

ERIC Educational Resources Information Center

Beirne, Elaine; Mhichíl, Mairéad Nic Giolla; Cleircín, Gearóid Ó

2017-01-01

Many of the major Massive Open Online Course (MOOC) platforms support learning approaches which can be roughly categorised as transmission-based and asynchronous (Morris & Lambe, 2014), with limited forms of interactive elements. Language learning is viewed within this study as an active process which includes knowledge, skills, and cultural…

A simple method to estimate threshold friction velocity of wind erosion in the field

USDA-ARS?s Scientific Manuscript database

Nearly all wind erosion models require the specification of threshold friction velocity (TFV). Yet determining TFV of wind erosion in field conditions is difficult as it depends on both soil characteristics and distribution of vegetation or other roughness elements. While several reliable methods ha...

Scattering of Acoustic Waves from Ocean Boundaries

DTIC Science & Technology

2014-09-30

of buried mines and improve SONAR performance in shallow water. OBJECTIVES 1) Determination of the correct physical model of acoustic propagation...Nicholas Chotiros, particularly for theoretical development of bulk acoustic /sediment modeling and laser roughness measurements. REFERENCES C...PUBLICATIONS 1. M. Isakson, and N. Chotiros. Finite Element Modeling of Acoustic

Title Sequences, Dress, Settings, and Such.

ERIC Educational Resources Information Center

Bell, John

Comparisons of television shows along genre lines suggest significant elements of aural/visual richness as well as valuable categories of comparison for future use in other comparisons. An examination of two sitcoms and two police shows produced roughly 25 years apart--"Make Room for Daddy" with "The Cosby Show" and "Naked…

Value of transrectal power Doppler sonography in the detection of low-risk prostate cancers.

PubMed

Sauvain, J-L; Sauvain, E; Rohmer, P; Louis, D; Nader, N; Papavero, R; Bremon, J-M; Jehl, J

2013-01-01

To evaluate the risk of low-risk prostate cancer or prostate cancer that may benefit from surveillance in patients with a PSA level less than 10 ng/ml, a normal digital rectal examination (DRE) and a transrectal power Doppler sonography (PDS) without anomaly. Two hundred and forty-three consecutive patients with a PSA level less than 10 ng/ml and a DRE without anomaly had PDS-guided biopsies: 12 to 15 samples were systematically taken and echo-guided in the suspect areas. The PDS results were rated from 1 to 4: 1: normal, 2: slightly hypoechogenic avascular area in which the hypo-echogenicity disappears after compression by probe, 3: hypoechogenic avascular area, 4: hypoechogenic vascularised area with power Doppler sonography. Patients rated 3 or 4 were considered to be pathological. D'Amico's criteria were used to assess the risk of a biological recurrence after treatment and those of Dall'Era were used to select the patients that could benefit from active surveillance (AS). The PDS was considered to be a true positive if at least one biopsy was positive in the same sextant as the suspect image. In a prospective manner, 106 cancers were diagnosed that could be qualified as low-risk in 84% of the cases (89% with a normal PDS and 79% with an abnormal PDS). Sixty-nine percent of the cases could be subject to AS (86% of the normal PDS cases and 47% of the abnormal PDS cases; P<0.001). The PDS was normal in 159 of the 243 patients (65%). With a normal PDS, there was a 96% probability of not having a high-risk cancer. With an abnormal PDS, at least one biopsy was positive in 57% of the cases and the probability of having a significant cancer was 30% according to the Dall'Era criteria. A significant reduction was noted with a normal PDS, to 36% and 5%, respectively (VPN=95%) (P=0.015). A normal PDS in patients presenting a PSA level less than 10 ng/ml and a DRE without anomaly may be used to put off the indication for a biopsy in order to reduce their number as well as the risks of overtreatment for a latent cancer. Copyright © 2012 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

A novel urinary long non-coding RNA transcript improves diagnostic accuracy in patients undergoing prostate biopsy.

PubMed

Zhang, Wei; Ren, Shan-Cheng; Shi, Xiao-Lei; Liu, Ya-Wei; Zhu, Ya-Sheng; Jing, Tai-Le; Wang, Fu-Bo; Chen, Rui; Xu, Chuan-Liang; Wang, Hui-Qing; Wang, Hai-Feng; Wang, Yan; Liu, Bing; Li, Yao-Ming; Fang, Zi-Yu; Guo, Fei; Lu, Xin; Shen, Dan; Gao, Xu; Hou, Jian-Guo; Sun, Ying-Hao

2015-05-01

Long non-coding RNA (LncRNA) PCA3 has been a well-established urine biomarker for the detection of prostate cancer (PCa). Our previous study showed a novel LncRNA FR0348383 is up-regulated in over 70% of PCa compared with matched benign tissues. The aim of this study was to evaluate the diagnostic value of urinary FR0348383 for men undergoing prostate biopsy due to elevated PSA (PSA > 4.0 ng/ml) and/or abnormal digital rectal examination (DRE). Post-DRE first-catch urine specimens prior to prostate biopsies were prospectively collected. After the whole transcriptome amplification, quantitative real time polymerase chain reaction was applied to quantify urine FR0348383 and PSA levels. The FR0348383 score was calculated as the ratio of PSA and FR0348383 mRNA (PSA mRNA/FR0348383 mRNA × 1000). The diagnostic value of FR0348383 score was evaluated by logistic regression and decision curve analysis. 213 cases with urine samples containing sufficient mRNA were included, 94 cases had serum PSA level 4.0-10.0 ng/ml. PCa was identified in 72 cases. An increasing FR0348383 score was correlated with an increasing probability of a positive biopsy (P < 0.001). Multivariable logistic analysis indicated FR0348383 score (P < 0.001), PSA (P = 0.004), age (P = 0.007), prostate volume (P < 0.001) were independent predictors of PCa. ROC analysis demonstrated FR0348383 score outperformed PSA, %free PSA, and PSA Density in the prediction of PCa in the subgroup of patients with grey area PSA (AUC: 0.815 vs. 0.562 vs. 0.599 vs. 0.645). When using a probability threshold of 30% in the grey zone cohort, The FR0348383 score would save 52.0% of avoidable biopsies without missing any high grade cancers. FR0348383 transcript in post-DRE urine may be a novel biomarker for detection of PCa with great diagnostic value, especially in the grey zone cohort. The application of FR0348383 score in clinical practice might avoid unnecessary prostate biopsies and increase the specificity of PCa diagnosis. © 2015 Wiley Periodicals, Inc.

A moderate decrease in temperature induces COR15a expression through the CBF signaling cascade and enhances freezing tolerance.

PubMed

Wang, Yi; Hua, Jian

2009-10-01

Temperature has a profound effect on plant growth and development. However, the molecular mechanisms underlying this regulation are not well understood. In particular, how moderate temperature variations are perceived and transduced inside the plant cells remains obscure. In this study, we analyzed transcriptional responses to a moderate decrease in temperature (cooling) in Arabidopsis thaliana. The cooling response involves a weaker and more transient induction of cold-induced genes, such as COR15a, than cold response. This induction probably accounts for the increase in freezing tolerance by cooling acclimation. Cooling also induces some defense response genes, and their induction, but not that of COR15a, requires the salicylic acid signaling pathway. Analysis of the regulation of COR15a reveals that cooling induction is mediated through the same C repeat/dehydration-responsive (CRT/DRE) element as cold induction. Furthermore, we identified a role for CBF1 and CBF4 in transducing signals of moderate decreases in temperature. It appears that variants of the CBF signaling cascade are utilized in cold and cooling responses, and a moderate decrease in temperature may invoke an adaptive response to prepare plants to cope with a more drastic decrease in temperature.

Abscisic Acid and abiotic stress signaling.

PubMed

Tuteja, Narendra

2007-05-01

Abiotic stress is severe environmental stress, which impairs crop production on irrigated land worldwide. Overall, the susceptibility or tolerance to the stress in plants is a coordinated action of multiple stress responsive genes, which also cross-talk with other components of stress signal transduction pathways. Plant responses to abiotic stress can be determined by the severity of the stress and by the metabolic status of the plant. Abscisic acid (ABA) is a phytohormone critical for plant growth and development and plays an important role in integrating various stress signals and controlling downstream stress responses. Plants have to adjust ABA levels constantly in responce to changing physiological and environmental conditions. To date, the mechanisms for fine-tuning of ABA levels remain elusive. The mechanisms by which plants respond to stress include both ABA-dependent and ABA-independent processes. Various transcription factors such as DREB2A/2B, AREB1, RD22BP1 and MYC/MYB are known to regulate the ABA-responsive gene expression through interacting with their corrosponding cis-acting elements such as DRE/CRT, ABRE and MYCRS/MYBRS, respectively. Understanding these mechanisms is important to improve stress tolerance in crops plants. This article first describes the general pathway for plant stress response followed by roles of ABA and transcription factors in stress tolerance including the regulation of ABA biosynthesis.

Abscisic Acid and Abiotic Stress Signaling

PubMed Central

2007-01-01

Abiotic stress is severe environmental stress, which impairs crop production on irrigated land worldwide. Overall, the susceptibility or tolerance to the stress in plants is a coordinated action of multiple stress responsive genes, which also cross-talk with other components of stress signal transduction pathways. Plant responses to abiotic stress can be determined by the severity of the stress and by the metabolic status of the plant. Abscisic acid (ABA) is a phytohormone critical for plant growth and development and plays an important role in integrating various stress signals and controlling downstream stress responses. Plants have to adjust ABA levels constantly in responce to changing physiological and environmental conditions. To date, the mechanisms for fine-tuning of ABA levels remain elusive. The mechanisms by which plants respond to stress include both ABA-dependent and ABA-independent processes. Various transcription factors such as DREB2A/2B, AREB1, RD22BP1 and MYC/MYB are known to regulate the ABA-responsive gene expression through interacting with their corrosponding cis-acting elements such as DRE/CRT, ABRE and MYCRS/MYBRS, respectively. Understanding these mechanisms is important to improve stress tolerance in crops plants. This article first describes the general pathway for plant stress response followed by roles of ABA and transcription factors in stress tolerance including the regulation of ABA biosynthesis. PMID:19516981

Heat Transfer Enhancement By Three-Dimensional Surface Roughness Technique In Nuclear Fuel Rod Bundles

NASA Astrophysics Data System (ADS)

Najeeb, Umair

This thesis experimentally investigates the enhancement of single-phase heat transfer, frictional loss and pressure drop characteristics in a Single Heater Element Loop Tester (SHELT). The heater element simulates a single fuel rod for Pressurized Nuclear reactor. In this experimental investigation, the effect of the outer surface roughness of a simulated nuclear rod bundle was studied. The outer surface of a simulated fuel rod was created with a three-dimensional (Diamond-shaped blocks) surface roughness. The angle of corrugation for each diamond was 45 degrees. The length of each side of a diamond block is 1 mm. The depth of each diamond block was 0.3 mm. The pitch of the pattern was 1.614 mm. The simulated fuel rod had an outside diameter of 9.5 mm and wall thickness of 1.5 mm and was placed in a test-section made of 38.1 mm inner diameter, wall thickness 6.35 mm aluminum pipe. The Simulated fuel rod was made of Nickel 200 and Inconel 625 materials. The fuel rod was connected to 10 KW DC power supply. The Inconel 625 material of the rod with an electrical resistance of 32.3 kO was used to generate heat inside the test-section. The heat energy dissipated from the Inconel tube due to the flow of electrical current flows into the working fluid across the rod at constant heat flux conditions. The DI water was employed as working fluid for this experimental investigation. The temperature and pressure readings for both smooth and rough regions of the fuel rod were recorded and compared later to find enhancement in heat transfer coefficient and increment in the pressure drops. Tests were conducted for Reynold's Numbers ranging from 10e4 to 10e5. Enhancement in heat transfer coefficient at all Re was recorded. The maximum heat transfer co-efficient enhancement recorded was 86% at Re = 4.18e5. It was also observed that the pressure drop and friction factor increased by 14.7% due to the increased surface roughness.

Experimental Investigation of Average Heat-Transfer and Friction Coefficients for Air Flowing in Circular Tubes Having Square-Thread-Type Roughness

NASA Technical Reports Server (NTRS)

Sams, E. W.

1952-01-01

An investigation of forced-convection heat transfer and associated pressure drops was conducted with air flowing through electrically heated Inconel tubes having various degrees of square-thread-type roughness, an inside diameter of 1/2 inch, and a length of 24 inches. were obtained for tubes having conventional roughness ratios (height of thread/radius of tube) of 0 (smooth tube), 0.016, 0.025, and 0.037 over ranges of bulk Reynolds numbers up to 350,000, average inside-tube-wall temperatures up to 1950deg R, and heat-flux densities up to 115,000 Btu per hour per square foot. Data The experimental data showed that both heat transfer and friction increased with increase in surface roughness, becoming more pronounced with increase in Reynolds number; for a given roughness, both heat transfer and friction were also influenced by the tube wall-to-bulk temperature ratio. Good correlation of the heat-transfer data for all the tubes investigated was obtained by use of a modification of the conventional Nusselt correlation parameters wherein the mass velocity in the Reynolds number was replaced by the product of air density evaluated at the average film temperature and the so-called friction velocity; in addition, the physical properties of air were evaluated at the average film temperature. The isothermal friction data for the rough tubes, when plotted in the conventional manner, resulted in curves similar to those obtained by other investigators; that is, the curve for a given roughness breaks away from the Blasius line (representing turbulent flow in smooth tubes) at some value of Reynolds number, which decreases with increase in surface roughness, and then becomes a horizontal line (friction coefficient independent of Reynolds number). A comparison of the friction data for the rough tubes used herein indicated that the conventional roughness ratio is not an adequate measure of relative roughness for tubes having a square-thread-type element. The present data, as well as those of other investigators, were used to isolate the influence of ratios of thread height to width, thread spacing to width, and the conventional roughness ratio on the friction coefficient. A fair correlation of the friction data was obtained for each tube with heat addition when the friction coefficient and Reynolds number were defined on the basis of film properties; however, the data for each tube retained the curve characteristic of that particular roughness. The friction data for all the rough tubes could be represented by a single line for the complete turbulence region by incorporating a roughness parameter in the film correlation. No correlation was obtained for the region of incomplete turbulence.

A dynamic subgrid-scale parameterization of the effective wall stress in atmospheric boundary layer flows over multiscale, fractal-like surfaces

NASA Astrophysics Data System (ADS)

Anderson, William; Meneveau, Charles

2010-05-01

A dynamic subgrid-scale (SGS) parameterization for hydrodynamic surface roughness is developed for large-eddy simulation (LES) of atmospheric boundary layer (ABL) flow over multiscale, fractal-like surfaces. The model consists of two parts. First, a baseline model represents surface roughness at horizontal length-scales that can be resolved in the LES. This model takes the form of a force using a prescribed drag coefficient. This approach is tested in LES of flow over cubes, wavy surfaces, and ellipsoidal roughness elements for which there are detailed experimental data available. Secondly, a dynamic roughness model is built, accounting for SGS surface details of finer resolution than the LES grid width. The SGS boundary condition is based on the logarithmic law of the wall, where the unresolved roughness of the surface is modeled as the product of local root-mean-square (RMS) of the unresolved surface height and an unknown dimensionless model coefficient. This coefficient is evaluated dynamically by comparing the plane-average hydrodynamic drag at two resolutions (grid- and test-filter scale, Germano et al., 1991). The new model is tested on surfaces generated through superposition of random-phase Fourier modes with prescribed, power-law surface-height spectra. The results show that the method yields convergent results and correct trends. Limitations and further challenges are highlighted. Supported by the US National Science Foundation (EAR-0609690).

Multigrid methods for flow transition in three-dimensional boundary layers with surface roughness

NASA Technical Reports Server (NTRS)

Liu, Chaoqun; Liu, Zhining; Mccormick, Steve

1993-01-01

The efficient multilevel adaptive method has been successfully applied to perform direct numerical simulations (DNS) of flow transition in 3-D channels and 3-D boundary layers with 2-D and 3-D isolated and distributed roughness in a curvilinear coordinate system. A fourth-order finite difference technique on stretched and staggered grids, a fully-implicit time marching scheme, a semi-coarsening multigrid method associated with line distributive relaxation scheme, and an improved outflow boundary-condition treatment, which needs only a very short buffer domain to damp all order-one wave reflections, are developed. These approaches make the multigrid DNS code very accurate and efficient. This allows us not only to be able to do spatial DNS for the 3-D channel and flat plate at low computational costs, but also to do spatial DNS for transition in the 3-D boundary layer with 3-D single and multiple roughness elements, which would have extremely high computational costs with conventional methods. Numerical results show good agreement with the linear stability theory, the secondary instability theory, and a number of laboratory experiments. The contribution of isolated and distributed roughness to transition is analyzed.

X-33 Hypersonic Boundary Layer Transition

NASA Technical Reports Server (NTRS)

Berry, Scott A.; Horvath, Thomas J.; Hollis, Brian R.; Thompson, Richard A.; Hamilton, H. Harris, II

1999-01-01

Boundary layer and aeroheating characteristics of several X-33 configurations have been experimentally examined in the Langley 20-Inch Mach 6 Air Tunnel. Global surface heat transfer distributions, surface streamline patterns, and shock shapes were measured on 0.013-scale models at Mach 6 in air. Parametric variations include angles-of-attack of 20-deg, 30-deg, and 40-deg; Reynolds numbers based on model length of 0.9 to 6.6 million; and body-flap deflections of 0, 10 and 20-deg. The effects of discrete and distributed roughness elements on boundary layer transition, which included trip height, size, location, and distribution, both on and off the windward centerline, were investigated. The discrete roughness results on centerline were used to provide a transition correlation for the X-33 flight vehicle that was applicable across the range of reentry angles of attack. The attachment line discrete roughness results were shown to be consistent with the centerline results, as no increased sensitivity to roughness along the attachment line was identified. The effect of bowed panels was qualitatively shown to be less effective than the discrete trips; however, the distributed nature of the bowed panels affected a larger percent of the aft-body windward surface than a single discrete trip.

Pilot Test of Hot Gas Decontamination of Explosives-Contaminated Equipment at Hawthorne Army Ammunition Plant (HWAAP), Hawthorne, Nevada

DTIC Science & Technology

1990-06-01

modifications be made to the system to increase the overall efficiency, these conditions will change. Stack test results indicate that the DRE for TNT...those whose values were not affected by test operations (e.g., ambient air temperature). No attempts were made to modify or control independent...attempts were made to change the initial contaminant concentration (those items that were grossly contaminated (e.g., clay pipe and motors) or

40 CFR Table I-16 to Subpart I of... - Default Emission Destruction or Removal Efficiency (DRE) Factors for Electronics Manufacturing

Code of Federal Regulations, 2014 CFR

2014-07-01

... Manufacturing: Plasma Etch/Wafer Clean Process Type: CF4 75 CH3F 97 CHF3 97 CH2F2 97 C2F6 97 C3F8 97 C4F6 97 C4F8 97 C5F8 97 SF6 97 NF3 96 All other carbon-based plasma etch/wafer clean fluorinated GHG 60 Chamber...

Estimating the eruptive volume of a large pyroclastic body: the Otowi Member of the Bandelier Tuff, Valles caldera, New Mexico

NASA Astrophysics Data System (ADS)

Cook, Geoffrey W.; Wolff, John A.; Self, Stephen

2016-02-01

The 1.60 Ma caldera-forming eruption of the Otowi Member of the Bandelier Tuff produced Plinian and coignimbrite fall deposits, outflow and intracaldera ignimbrite, all of it deposited on land. We present a detailed approach to estimating and reconstructing the original volume of the eroded, partly buried large ignimbrite and distal ash-fall deposits. Dense rock equivalent (DRE) volume estimates for the eruption are 89 + 33/-10 km3 of outflow ignimbrite and 144 ± 72 km3 of intracaldera ignimbrite. Also, there was at least 65 km3 (DRE) of Plinian fall when extrapolated distally, and 107 + 40/-12 km3 of coignimbrite ash was "lost" from the outflow sheet to form an unknown proportion of the distal ash fall. The minimum total volume is 216 km3 and the maximum is 550 km3; hence, the eruption overlaps the low end of the super-eruption spectrum (VEI ˜8.0). Despite an abundance of geological data for the Otowi Member, the errors attached to these estimates do not allow us to constrain the proportions of intracaldera (IC), outflow (O), and distal ash (A) to better than a factor of three. We advocate caution in applying the IC/O/A = 1:1:1 relation of Mason et al. (2004) to scaling up mapped volumes of imperfectly preserved caldera-forming ignimbrites.

Jasmonate Regulates the INDUCER OF CBF EXPRESSION–C-REPEAT BINDING FACTOR/DRE BINDING FACTOR1 Cascade and Freezing Tolerance in Arabidopsis[W

PubMed Central

Hu, Yanru; Jiang, Liqun; Wang, Fang; Yu, Diqiu

2013-01-01

The INDUCER OF CBF EXPRESSION (ICE)–C-REPEAT BINDING FACTOR/DRE BINDING FACTOR1 (CBF/DREB1) transcriptional pathway plays a critical role in modulating cold stress responses in Arabidopsis thaliana. Dissecting crucial upstream regulatory signals or components of the ICE-CBF/DREB1 cascade will enhance our understanding of plant cold-tolerance mechanisms. Here, we show that jasmonate positively regulates plant responses to freezing stress in Arabidopsis. Exogenous application of jasmonate significantly enhanced plant freezing tolerance with or without cold acclimation. By contrast, blocking endogenous jasmonate biosynthesis and signaling rendered plants hypersensitive to freezing stress. Consistent with the positive role of jasmonate in freezing stress, production of endogenous jasmonate was triggered by cold treatment. In addition, cold induction of genes acting in the CBF/DREB1 signaling pathway was upregulated by jasmonate. Further investigation revealed that several JASMONATE ZIM-DOMAIN (JAZ) proteins, the repressors of jasmonate signaling, physically interact with ICE1 and ICE2 transcription factors. JAZ1 and JAZ4 repress the transcriptional function of ICE1, thereby attenuating the expression of its regulon. Consistent with this, overexpression of JAZ1 or JAZ4 represses freezing stress responses of Arabidopsis. Taken together, our study provides evidence that jasmonate functions as a critical upstream signal of the ICE-CBF/DREB1 pathway to positively regulate Arabidopsis freezing tolerance. PMID:23933884

Jasmonate regulates the inducer of cbf expression-C-repeat binding factor/DRE binding factor1 cascade and freezing tolerance in Arabidopsis.

PubMed

Hu, Yanru; Jiang, Liqun; Wang, Fang; Yu, Diqiu

2013-08-01

The inducer of cbf expression (ICE)-C-repeat binding factor/DRE binding factor1 (CBF/DREB1) transcriptional pathway plays a critical role in modulating cold stress responses in Arabidopsis thaliana. Dissecting crucial upstream regulatory signals or components of the ICE-CBF/DREB1 cascade will enhance our understanding of plant cold-tolerance mechanisms. Here, we show that jasmonate positively regulates plant responses to freezing stress in Arabidopsis. Exogenous application of jasmonate significantly enhanced plant freezing tolerance with or without cold acclimation. By contrast, blocking endogenous jasmonate biosynthesis and signaling rendered plants hypersensitive to freezing stress. Consistent with the positive role of jasmonate in freezing stress, production of endogenous jasmonate was triggered by cold treatment. In addition, cold induction of genes acting in the CBF/DREB1 signaling pathway was upregulated by jasmonate. Further investigation revealed that several jasmonate ZIM-domain (JAZ) proteins, the repressors of jasmonate signaling, physically interact with ICE1 and ICE2 transcription factors. JAZ1 and JAZ4 repress the transcriptional function of ICE1, thereby attenuating the expression of its regulon. Consistent with this, overexpression of JAZ1 or JAZ4 represses freezing stress responses of Arabidopsis. Taken together, our study provides evidence that jasmonate functions as a critical upstream signal of the ICE-CBF/DREB1 pathway to positively regulate Arabidopsis freezing tolerance.

Effects and possible mechanisms of simulated-microgravity on zebrafish embryonic cell

NASA Astrophysics Data System (ADS)

Hang, Xiaoming; Sun, Yeqing; Wu, Di; Li, Yixiao; Wang, Ruonan

2016-07-01

Cellular level studies are helpful for revealing the underlying mechanisms of microgravity effects on living organisms. Many cell types, ranging from bacteria to mammalian cells, are sensitive to the microgravity environment. In this study, zebrafish embryonic cells (ZF4) were exposed to simulated-microgravity (SMG) for different times to investigate the effects and possible mechanisms of microgravity on fibroblasts. A significant arrest in G2/M phase was detected in ZF4 cells after 24 or 48 hour of SMG exposure, respectively. The mRNA levels of G2/M phase regulators cyclinB1 and cdc2 were significantly decreased, while wee1 was significantly increased. Additionally, CEP135, a core centrosome protein throughout the cell cycle, seems to play a key role in modulating this effect. Quantitative analysis showed that cep135 expression was significantly increased, while CEP135 protein expression level was significantly decreased two times after SMG. Further investigation demonstrated the transfection of dre-miR-22a, a miRNA for targeting cep135, also induced G2/M arrest in ZF4 cells. These results suggest that SMG induced G2/M arrest in ZF4 cells may due to the regulation of dre-miR-22a and its target cep135. Key Words: Simulated-microgravity; zebrafish embryonic cell; G2/M arrest; molecular mechanism

Analysis of urinary PSA glycosylation is not indicative of high-risk prostate cancer.

PubMed

Barrabés, Sílvia; Llop, Esther; Ferrer-Batallé, Montserrat; Ramírez, Manel; Aleixandre, Rosa N; Perry, Antoinette S; de Llorens, Rafael; Peracaula, Rosa

2017-07-01

The levels of core fucosylation and α2,3-linked sialic acid in serum Prostate Specific Antigen (PSA), using the lectins Pholiota squarrosa lectin (PhoSL) and Sambucus nigra agglutinin (SNA), can discriminate between Benign Prostatic Hyperplasia (BPH) and indolent prostate cancer (PCa) from aggressive PCa. In the present work we evaluated whether these glycosylation determinants could also be altered in urinary PSA obtained after digital rectal examination (DRE) and could also be useful for diagnosis determinations. For this purpose, α2,6-sialic acid and α1,6-fucose levels of urinary PSA from 53 patients, 18 biopsy-negative and 35 PCa patients of different aggressiveness degree, were analyzed by sandwich ELLA (Enzyme Linked Lectin Assay) using PhoSL and SNA. Changes in the levels of specific glycosylation determinants, that in serum PSA samples were indicative of PCa aggressiveness, were not found in PSA from DRE urine samples. Although urine is a simpler matrix for analyzing PSA glycosylation compared to serum, an immunopurification step was necessary to specifically detect the glycans on the PSA molecule. Those specific glycosylation determinants on urinary PSA were however not useful to improve PCa diagnosis. This could be probably due to the low proportion of PSA from the tumor in urine samples, which precludes the identification of aberrantly glycosylated PSA. Copyright © 2017 Elsevier B.V. All rights reserved.

Can Prostate-Specific Antigen Kinetics before Prostate Biopsy Predict the Malignant Potential of Prostate Cancer?

PubMed

Kim, Sang Jin; Jeong, Tae Yoong; Yoo, Dae Seon; Park, Jinsung; Cho, Seok; Kang, Seok Ho; Lee, Sang Hyub; Jeon, Seung Hyun; Lee, Tchun Yong; Park, Sung Yul

2015-11-01

To predict the malignant potential of prostate cancer (PCa) according to prostate-specific antigen velocity (PSAV), PSA density (PSAD), free/total PSA ratio (%fPSA), and digital rectal examination (DRE). From January 2009 to December 2012, 548 adult male patients were diagnosed with PCa by prostate biopsy at four hospitals in Korea. We retrospectively analyzed 155 adult male patients with an initial PSA level≤10 ng/mL and whose PSA levels had been checked more than two times at least 6 months before they had been diagnosed with PCa, with test intervals of more than 3 months. Patients with a urinary tract infection, and patients who had previously undergone cystoscopy or surgery of the prostate were excluded. We separated patients into two groups according to Gleason sum [Gleason sum≤7 (n=134) or Gleason sum≥8 (n=21)] and the presence of extracapsular invasion [organ confined (n=129) or extracapsular invasion (n=26)]. Differences between the groups were compared. The group with a Gleason sum≥8 or extracapsular invasion of PCa showed high PSAV and significantly lower %fPSA. There were no significant differences in PSAD and the presence of an abnormality on DRE between two groups. In PCa patients treated with other therapies besides prostatectomy, a high PSA velocity and a low %fPSA may predict high grade PCa with a Gleason sum≥8 or the presence of extracapsular invasion.

N-acetylglucosamine-Mediated Expression of nagA and nagB in Streptococcus pneumoniae.

PubMed

Afzal, Muhammad; Shafeeq, Sulman; Manzoor, Irfan; Henriques-Normark, Birgitta; Kuipers, Oscar P

2016-01-01

In this study, we have explored the transcriptomic response of Streptococcus pneumoniae D39 to N-acetylglucosamine (NAG). Transcriptome comparison of S. pneumoniae D39 wild-type grown in chemically defined medium (CDM) in the presence of 0.5% NAG to that grown in the presence of 0.5% glucose revealed elevated expression of many genes/operons, including nagA, nagB, manLMN , and nanP . We have further confirmed the NAG-dependent expression of nagA, nagB, manLMN , and nanP by β-galactosidase assays. nagA, nagB and glmS are putatively regulated by a transcriptional regulator NagR. We predicted the operator site of NagR ( dre site) in P nagA , P nagB , and P glmS , which was further confirmed by mutating the predicted dre site in the respective promoters ( nagA, nagB , and glmS ). Growth comparison of Δ nagA , Δ nagB , and Δ glmS with the D39 wild-type demonstrates that nagA and nagB are essential for S. pneumoniae D39 to grow in the presence of NAG as a sole carbon source. Furthermore, deletion of ccpA shows that CcpA has no effect on the expression of nagA, nagB , and glmS in the presence of NAG in S . pneumoniae .

N-acetylglucosamine-Mediated Expression of nagA and nagB in Streptococcus pneumoniae

PubMed Central

Afzal, Muhammad; Shafeeq, Sulman; Manzoor, Irfan; Henriques-Normark, Birgitta; Kuipers, Oscar P.

2016-01-01

In this study, we have explored the transcriptomic response of Streptococcus pneumoniae D39 to N-acetylglucosamine (NAG). Transcriptome comparison of S. pneumoniae D39 wild-type grown in chemically defined medium (CDM) in the presence of 0.5% NAG to that grown in the presence of 0.5% glucose revealed elevated expression of many genes/operons, including nagA, nagB, manLMN, and nanP. We have further confirmed the NAG-dependent expression of nagA, nagB, manLMN, and nanP by β-galactosidase assays. nagA, nagB and glmS are putatively regulated by a transcriptional regulator NagR. We predicted the operator site of NagR (dre site) in PnagA, PnagB, and PglmS, which was further confirmed by mutating the predicted dre site in the respective promoters (nagA, nagB, and glmS). Growth comparison of ΔnagA, ΔnagB, and ΔglmS with the D39 wild-type demonstrates that nagA and nagB are essential for S. pneumoniae D39 to grow in the presence of NAG as a sole carbon source. Furthermore, deletion of ccpA shows that CcpA has no effect on the expression of nagA, nagB, and glmS in the presence of NAG in S. pneumoniae. PMID:27900287

Feedback effect of base roughness on particle size segregation in bidisperse granular avalanche

NASA Astrophysics Data System (ADS)

Jing, L.; Kwok, F.

2017-12-01

Particle size segregation in a geophysical flow interplays with base roughness, leading to rich behaviors such as bouldery front formation and fingering instability. The interplay originates mainly from the fact that larger particles slip more easily on a slope, the slip affects the progress of segregation, and segregation changes the size of particles contacting the slope. Recent studies show that slip velocity scales with geometric roughness (which involves both the size and spacing of base particles), and the roughness becomes a function of time during segregation. However, at least two questions remain unanswered: 1) In addition to geometric roughness, what is the role of mechanical parameters at boundaries? 2) To what extent the findings from steady flows are valid in a transient system, which is more common in actual geophysical flows? Here we study two configurations using the discrete element method, the first being a steady flow with periodic boundaries, where we vary the size, spatial arrangement, and contact parameters of base particles. The second consists in dambreak-type bidisperse granular avalanches over inclined planes, where the degree of segregation, base roughness, flow thickness, and base velocity are measured locally as the flow evolves. We found that: 1) On a frictional plane in the absence of geometric roughness, the friction parameter μ controls the amount of basal slip. A lower μ leads to a slower segregation. 2) On a bumpy base with low geometric roughness (where slip still occurs), the effect of μ becomes marginal, while the coefficient of restitution e controls the slip velocity; this indicates the significance of normal collision in the working mechanism of a bumpy base. Upon sliding, large particles near the base may exhibit an ordered state where shear is poorly developed, which delays the onset of segregation. 3) Both μ and e have no influence when the geometric roughness is sufficient to sustain a nonslip condition. Our results suggest the feedback effect of base roughness on segregation, which has a theoretical significance in the boundary treatment when modeling geophysical flows. The study also shows the possibility to establish a universal scaling law correlating slip velocity, base roughness, and the degree of segregation in both steady and unsteady flows.

The improvement of laser induced damage resistance of optical workpiece surface by hydrodynamic effect polishing

NASA Astrophysics Data System (ADS)

Peng, Wenqiang; Guan, Chaoliang; Li, Shengyi; Wang, Zhuo

2016-10-01

Surface and subsurface damage in optical element will greatly decrease the laser induced damage threshold (LIDT) in the intense laser optical system. Processing damage on the workpiece surface can be inevitably caused when the material is removed in brittle or plastic mode. As a non-contact polishing technology, hydrodynamic effect polishing (HEP) shows very good performance on generating an ultra-smooth surface without damage. The material is removed by chemisorption between nanoparticle and workpiece surface in the elastic mode in HEP. The subsurface damage and surface scratches can be effectively removed after the polishing process. Meanwhile ultra-smooth surface with atomic level surface roughness can be achieved. To investigate the improvement of LIDT of optical workpiece, polishing experiment was conducted on a magnetorheological finishing (MRF) silica glass sample. AFM measurement results show that all the MRF directional plastic marks have been removed clearly and the root-mean-square (rms) surface roughness has decreased from 0.673nm to 0.177nm after HEP process. Laser induced damage experiment was conducted with laser pulse of 1064nm wavelength and 10ns time width. Compared with the original state, the LEDT of the silica glass sample polished by HEP has increased from 29.78J/cm2 to 45.47J/cm2. It demonstrates that LIDT of optical element treated by HEP can be greatly improved for ultra low surface roughness and nearly defect-free surface/subsurface.

Mapping urban porosity and roughness characteristics as a mean of defining urban ventilation corridors

NASA Astrophysics Data System (ADS)

Wicht, Marzena; Wicht, Andreas; Osińska-Skotak, Katarzyna

2017-10-01

Cities can be characterized with the roughest aerodynamic boundaries, which results in the enhanced turbulent motion and increased drag effect. This leads to reduced wind speeds and directly increases negative effects of living within urban areas. Urban Heat Island, decreased air quality or densely built-up residential/industrial areas occur in many cities, both in temperate and tropical regions, and are included in these negative effects. This case study investigates Warsaw, the capital of Poland, representing a dense, urban environment, located in the temperate zone. It suffers from immense air pollution levels, as well as Urban Heat Island, and the local government is seeking ways to resolve these issues. Among many mitigation techniques, air restoration and exchange system were suggested as appropriate measures, as they address many of the aforementioned issues. The essential elements of such system are ventilation corridors. This paper describes mapping these corridors utilizing the morphometric methods of urban roughness aided by remote sensing data. We focus especially on the terrain topology and texture of single elements, including high vegetation canopy layer. This study considers DSM and different porosity of obstacles, deriving a new outlook at the morphometric methods as a way to improve them. The mapped areas of low roughness characteristics might be appointed as ventilation corridors and play a crucial role in air restoration and exchange system. They may also be included in further planning processes by the local government as preservation areas.

Quality of water and sediment in streams affected by historical mining, and quality of Mine Tailings, in the Rio Grande/Rio Bravo Basin, Big Bend Area of the United States and Mexico, August 2002

USGS Publications Warehouse

Lambert, Rebecca B.; Kolbe, Christine M.; Belzer, Wayne

2008-01-01

The U.S. Geological Survey, in cooperation with the International Boundary and Water Commission - U.S. and Mexican Sections, the National Park Service, the Texas Commission on Environmental Quality, the Secretaria de Medio Ambiente y Recursos Naturales in Mexico, the Area de Proteccion de Flora y Fauna Canon de Santa Elena in Mexico, and the Area de Proteccion de Flora y Fauna Maderas del Carmen in Mexico, collected samples of stream water, streambed sediment, and mine tailings during August 2002 for a study to determine whether trace elements from abandoned mines in the area in and around Big Bend National Park have affected the water and sediment quality in the Rio Grande/Rio Bravo Basin of the United States and Mexico. Samples were collected from eight sites on the main stem of the Rio Grande/Rio Bravo, four Rio Grande/Rio Bravo tributary sites downstream from abandoned mines or mine-tailing sites, and 11 mine-tailing sites. Mines in the area were operated to produce fluorite, germanium, iron, lead, mercury, silver, and zinc during the late 1800s through at least the late 1970s. Moderate (relatively neutral) pHs in stream-water samples collected at the 12 Rio Grande/Rio Bravo main-stem and tributary sites indicate that water is well mixed, diluted, and buffered with respect to the solubility of trace elements. The highest sulfate concentrations were in water samples from tributaries draining the Terlingua mining district. Only the sample from the Rough Run Draw site exceeded the Texas Surface Water Quality Standards general-use protection criterion for sulfate. All chloride and dissolved solids concentrations in water samples were less than the general-use protection criteria. Aluminum, copper, mercury, nickel, selenium, and zinc were detected in all water samples for which each element was analyzed. Cadmium, chromium, and lead were detected in samples less frequently, and silver was not detected in any of the samples. None of the sample concentrations of aluminum, cadmium, chromium, nickel, selenium, and zinc exceeded the Texas Surface Water Quality Standards criteria for aquatic life-use protection or human health. The only trace elements detected in the water samples at concentrations exceeding the Texas Surface Water Quality Standards criterion for human health (fish consumption use) was lead at one site and mercury at 10 of 12 sites. Relatively high mercury concentrations distributed throughout the area might indicate sources of mercury in addition to abandoned mining areas. Streambed-sediment samples were collected from 12 sites and analyzed for 44 major and trace elements. In general, the trace elements detected in streambed-sediment samples were low in concentration, interpreted as consistent with background concentrations. Concentrations at two sites, however, were elevated compared to Texas Commission on Environmental Quality criteria. Concentrations of antimony, arsenic, cadmium, lead, silver, and zinc in the sample from San Carlos Creek downstream from La Esperanza (San Carlos) Mine exceeded the Texas Commission on Environmental Quality screening levels for sediment. The sample from Rough Run Draw, downstream from the Study Butte Mine, also showed elevated concentrations of arsenic, cadmium, and lead, but these concentrations were much lower than those in the San Carlos Creek sample and did not exceed screening levels. Elevated concentrations of multiple trace elements in streambed-sediment samples from San Carlos Creek and Rough Run Draw indicate that San Carlos Creek, and probably Rough Run Draw, have been adversely affected by mining activities. Fourteen mine-tailing samples from 11 mines were analyzed for 25 major and trace elements. All trace elements except selenium and thallium were detected in one or more samples. The highest lead concentrations were detected in tailings samples from the Boquillas, Puerto Rico, La Esperanza (San Carlos), and Tres Marias Mines, as might be expected because the tailings ar

Optical scattering from rough-rolled aluminum surfaces.

PubMed

Rönnelid, M; Adsten, M; Lindström, T; Nostell, P; Wäckelgård, E

2001-05-01

Bidirectional, angular resolved scatterometry was used to evaluate the feasibility of using rolled aluminum as reflectors in solar thermal collectors and solar cells. Two types of rolled aluminum with different surface roughnesses were investigated. The results show that the smoother of the two samples [rms height, (0.20 ? 0.02) mum] can be used as a nonimaging, concentrating reflector with moderate reflection losses compared with those of optically smooth aluminum reflectors. The sample with the rougher surface [rms height, (0.6 ? 0.1) mum] is not suitable as a concentrating element but can be used as planar reflectors. The orientation of the rolling grooves is then of importance for minimizing reflection losses in the system.

Nuclear localization and transactivation by Vitis CBF transcription factors are regulated by combinations of conserved amino acid domains.

PubMed

Carlow, Chevonne E; Faultless, J Trent; Lee, Christine; Siddiqua, Mahbuba; Edge, Alison; Nassuth, Annette

2017-09-01

The highly conserved CBF pathway is crucial in the regulation of plant responses to low temperatures. Extensive analysis of Arabidopsis CBF proteins revealed that their functions rely on several conserved amino acid domains although the exact function of each domain is disputed. The question was what functions similar domains have in CBFs from other, overwintering woody plants such as Vitis, which likely have a more involved regulation than the model plant Arabidopsis. A total of seven CBF genes were cloned and sequenced from V. riparia and the less frost tolerant V. vinifera. The deduced species-specific amino acid sequences differ in only a few amino acids, mostly in non-conserved regions. Amino acid sequence comparison and phylogenetic analysis showed two distinct groups of Vitis CBFs. One group contains CBF1, CBF2, CBF3 and CBF8 and the other group contains CBF4, CBF5 and CBF6. Transient transactivation assays showed that all Vitis CBFs except CBF5 activate via a CRT or DRE promoter element, whereby Vitis CBF3 and 4 prefer a CRT element. The hydrophobic domains in the C-terminal end of VrCBF6 were shown to be important for how well it activates. The putative nuclear localization domain of Vitis CBF1 was shown to be sufficient for nuclear localization, in contrast to previous reports for AtCBF1, and also important for transactivation. The latter highlights the value of careful analysis of domain functions instead of reliance on computer predictions and published data for other related proteins. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Functional and structural insights into novel DREB1A transcription factors in common wheat (Triticum aestivum L.): A molecular modeling approach.

PubMed

Kumar, Anuj; Kumar, Sanjay; Kumar, Upendra; Suravajhala, Prashanth; Gajula, M N V Prasad

2016-10-01

Triticum aestivum L. known as common wheat is one of the most important cereal crops feeding a large and growing population. Various environmental stress factors including drought, high salinity and heat etc. adversely affect wheat production in a significant manner. Dehydration-responsive element-binding (DREB1A) factors, a class of transcription factors (TF) play an important role in combating drought stress. It is known that DREB1A specifically interacts with the dehydration responsive elements (DRE/CRT) inducing expression of genes involved in environmental stress tolerance in plants. Despite its critical interplay in plants, the structural and functional aspects of DREB1A TF in wheat remain unresolved. Previous studies showed that wheat DREBs (DREB1 and DREB2) were isolated using various methods including yeast two-hybrid screens but no extensive structural models were reported. In this study, we made an extensive in silico study to gain insight into DREB1A TF and reported the location of novel DREB1A in wheat chromosomes. We inferred the three-dimensional structural model of DREB1A using homology modelling and further evaluated them using molecular dynamics(MD) simulations yielding refined modelled structures. Our biochemical function predictions suggested that the wheat DREB1A orthologs have similar biochemical functions and pathways to that of AtDREB1A. In conclusion, the current study presents a structural perspective of wheat DREB1A and helps in understanding the molecular basis for the mechanism of DREB1A in response to environmental stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

Aerodynamics and thermal physics of helicopter ice accretion

NASA Astrophysics Data System (ADS)

Han, Yiqiang

Ice accretion on aircraft introduces significant loss in airfoil performance. Reduced lift-to- drag ratio reduces the vehicle capability to maintain altitude and also limits its maneuverability. Current ice accretion performance degradation modeling approaches are calibrated only to a limited envelope of liquid water content, impact velocity, temperature, and water droplet size; consequently inaccurate aerodynamic performance degradations are estimated. The reduced ice accretion prediction capabilities in the glaze ice regime are primarily due to a lack of knowledge of surface roughness induced by ice accretion. A comprehensive understanding of the ice roughness effects on airfoil heat transfer, ice accretion shapes, and ultimately aerodynamics performance is critical for the design of ice protection systems. Surface roughness effects on both heat transfer and aerodynamic performance degradation on airfoils have been experimentally evaluated. Novel techniques, such as ice molding and casting methods and transient heat transfer measurement using non-intrusive thermal imaging methods, were developed at the Adverse Environment Rotor Test Stand (AERTS) facility at Penn State. A novel heat transfer scaling method specifically for turbulent flow regime was also conceived. A heat transfer scaling parameter, labeled as Coefficient of Stanton and Reynolds Number (CSR = Stx/Rex --0.2), has been validated against reference data found in the literature for rough flat plates with Reynolds number (Re) up to 1x107, for rough cylinders with Re ranging from 3x104 to 4x106, and for turbine blades with Re from 7.5x105 to 7x106. This is the first time that the effect of Reynolds number is shown to be successfully eliminated on heat transfer magnitudes measured on rough surfaces. Analytical models for ice roughness distribution, heat transfer prediction, and aerodynamics performance degradation due to ice accretion have also been developed. The ice roughness prediction model was developed based on a set of 82 experimental measurements and also compared to existing predictions tools. Two reference predictions found in the literature yielded 76% and 54% discrepancy with respect to experimental testing, whereas the proposed ice roughness prediction model resulted in a 31% minimum accuracy in prediction. It must be noted that the accuracy of the proposed model is within the ice shape reproduction uncertainty of icing facilities. Based on the new ice roughness prediction model and the CSR heat transfer scaling method, an icing heat transfer model was developed. The approach achieved high accuracy in heat transfer prediction compared to experiments conducted at the AERTS facility. The discrepancy between predictions and experimental results was within +/-15%, which was within the measurement uncertainty range of the facility. By combining both the ice roughness and heat transfer predictions, and incorporating the modules into an existing ice prediction tool (LEWICE), improved prediction capability was obtained, especially for the glaze regime. With the available ice shapes accreted at the AERTS facility and additional experiments found in the literature, 490 sets of experimental ice shapes and corresponding aerodynamics testing data were available. A physics-based performance degradation empirical tool was developed and achieved a mean absolute deviation of 33% when compared to the entire experimental dataset, whereas 60% to 243% discrepancies were observed using legacy drag penalty prediction tools. Rotor torque predictions coupling Blade Element Momentum Theory and the proposed drag performance degradation tool was conducted on a total of 17 validation cases. The coupled prediction tool achieved a 10% predicting error for clean rotor conditions, and 16% error for iced rotor conditions. It was shown that additional roughness element could affect the measured drag by up to 25% during experimental testing, emphasizing the need of realistic ice structures during aerodynamics modeling and testing for ice accretion.

A suggested periodic table up to Z≤ 172, based on Dirac-Fock calculations on atoms and ions.

PubMed

Pyykkö, Pekka

2011-01-07

Extended Average Level (EAL) Dirac-Fock calculations on atoms and ions agree with earlier work in that a rough shell-filling order for the elements 119-172 is 8s < 5g≤ 8p(1/2) < 6f < 7d < 9s < 9p(1/2) < 8p(3/2). The present Periodic Table develops further that of Fricke, Greiner and Waber [Theor. Chim. Acta 1971, 21, 235] by formally assigning the elements 121-164 to (nlj) slots on the basis of the electron configurations of their ions. Simple estimates are made for likely maximum oxidation states, i, of these elements M in their MX(i) compounds, such as i = 6 for UF(6). Particularly high i are predicted for the 6f elements.

Slip as the basic mechanism for formation of deformation relief structural elements

NASA Astrophysics Data System (ADS)

Lychagin, D. V.; Alfyorova, E. A.

2017-07-01

The experimental results of investigation of the nickel single crystal surface morphology after compression deformation are presented. The quasi-periodic character of the deformation profile, common for shear deformation of different types of relief structural elements, is found. It is demonstrated that the morphological manifestation of these structural elements is determined by local shear systems along octahedral planes. The regularities of the deformation structure in these regions defining the material extrusion and intrusion regions and the specific features of disorientation accumulation are established. If reorientation of local regions takes part in the relief element formation, along with octahedral slip, much stronger growth of the surface area is observed. The possibility of application of two-dimensional and three-dimensional surface roughness parameters for description of deformation relief is considered.

Supersonic turbulent boundary layers with periodic mechanical non-equilibrium

NASA Astrophysics Data System (ADS)

Ekoto, Isaac Wesley

Previous studies have shown that favorable pressure gradients reduce the turbulence levels and length scales in supersonic flow. Wall roughness has been shown to reduce the large-scales in wall bounded flow. Based on these previous observations new questions have been raised. The fundamental questions this dissertation addressed are: (1) What are the effects of wall topology with sharp versus blunt leading edges? and (2) Is it possible that a further reduction of turbulent scales can occur if surface roughness and favorable pressure gradients are combined? To answer these questions and to enhance the current experimental database, an experimental analysis was performed to provide high fidelity documentation of the mean and turbulent flow properties along with surface and flow visualizations of a high-speed (M = 2.86), high Reynolds number (Retheta ≈ 60,000) supersonic turbulent boundary layer distorted by curvature-induced favorable pressure gradients and large-scale ( k+s ≈ 300) uniform surface roughness. Nine models were tested at three separate locations. Three pressure gradient models strengths (a nominally zero, a weak, and a strong favorable pressure gradient) and three roughness topologies (aerodynamically smooth, square, and diamond shaped roughness elements) were used. Highly resolved planar measurements of mean and fluctuating velocity components were accomplished using particle image velocimetry. Stagnation pressure profiles were acquired with a traversing Pitot probe. Surface pressure distributions were characterized using pressure sensitive paint. Finally flow visualization was accomplished using schlieren photographs. Roughness topology had a significant effect on the boundary layer mean and turbulent properties due to shock boundary layer interactions. Favorable pressure gradients had the expected stabilizing effect on turbulent properties, but the improvements were less significant for models with surface roughness near the wall due to increased tendency towards flow separation. It was documented that proper roughness selection coupled with a sufficiently strong favorable pressure gradient produced regions of "negative" production in the transport of turbulent stress. This led to localized areas of significant turbulence stress reduction. With proper roughness selection and sufficient favorable pressure gradient strength, it is believed that localized relaminarization of the boundary layer is possible.

Simulation analysis of air flow and turbulence statistics in a rib grit roughened duct.

PubMed

Vogiatzis, I I; Denizopoulou, A C; Ntinas, G K; Fragos, V P

2014-01-01

The implementation of variable artificial roughness patterns on a surface is an effective technique to enhance the rate of heat transfer to fluid flow in the ducts of solar air heaters. Different geometries of roughness elements investigated have demonstrated the pivotal role that vortices and associated turbulence have on the heat transfer characteristics of solar air heater ducts by increasing the convective heat transfer coefficient. In this paper we investigate the two-dimensional, turbulent, unsteady flow around rectangular ribs of variable aspect ratios by directly solving the transient Navier-Stokes and continuity equations using the finite elements method. Flow characteristics and several aspects of turbulent flow are presented and discussed including velocity components and statistics of turbulence. The results reveal the impact that different rib lengths have on the computed mean quantities and turbulence statistics of the flow. The computed turbulence parameters show a clear tendency to diminish downstream with increasing rib length. Furthermore, the applied numerical method is capable of capturing small-scale flow structures resulting from the direct solution of Navier-Stokes and continuity equations.

Physical Mechanisms of Glaze Ice Scallop Formations on Swept Wings

NASA Technical Reports Server (NTRS)

Vargas, Mario; Reshotko, Eli

1998-01-01

An experiment was conducted to understand the physical mechanisms that lead to the formation of scallops on swept wings. Icing runs were performed on a NACA 0012 swept wing tip at 45 deg, 30 deg, and 15 deg sweep angles. A baseline case was chosen and direct measurements of scallop height and spacing, castings, video data and close-up photographic data were obtained. The results showed the scallops are made of glaze ice feathers that grow from roughness elements that have reached a minimum height and are located beyond a given distance from the attachment line. This distance depends on tunnel conditions and sweep angle, and is the critical parameter in the formation of scallops. It determines if complete scallops, incomplete scallops or no scallops are going to be formed. The mechanisms of growth for complete and incomplete scallops were identified. The effect of velocity, temperature and LWC on scallop formation was studied. The possibility that cross flow instability may be the physical mechanism that triggers the growth of roughness elements into glaze ice feathers is examined.

Effects of the interface roughness in metal-adhesive-metal structure on the propagation of shear horizontal waves.

PubMed

Ech Cherif El Kettani, Mounsif; Leduc, Damien; Potel, Catherine; Bruneau, Michel; Foze, Ludovic; Predoi, Mihai

2017-06-01

The influence of the interface roughness in a three-layer metal-adhesive-metal structure on the propagation of shear horizontal waves and more particularly on the transmission coefficient versus the frequency is studied in the particular case of a periodic grating of triangular grooves. For given phonon frequencies, the interaction of an incident shear horizontal mode with the periodical grating gives rise to a retro-converted mode. A numerical finite element simulation permits us to predict the existence of the phonon mode in the three-layer structure and to obtain the evolution of the transmission coefficient around the phonon frequency. An experimental study, based on a generation of waves by a piezocomposite contact transducer and a reception by a laser vibrometer, then confirms these predictions. Finally, a parametric numerical study is performed: the influence of the depth of the roughness and of the number of spatial periods of the grooves on the transmission coefficient is studied.

Effects of Suction on Swept-Wing Transition

NASA Technical Reports Server (NTRS)

Saric, William S.

1998-01-01

Stability experiments are conducted in the Arizona State University Unsteady Wind Tunnel on a 45 deg swept airfoil. The pressure gradient is designed to provide purely crossflow-dominated transition; that is, the boundary layer is subcritical to Tollmien-Schlichting disturbances. The airfoil surface is hand polished to a 0.25 microns rms finish. Under these conditions, stationary crossflow disturbances grow to nonuniform amplitude due to submicron surface irregularities near the leading edge. Uniform stationary crossflow waves are produced by controlling the initial conditions with spanwise arrays of micron-sized roughness elements near the attachment line. Hot-wire measurements provide detailed maps of the crossflow wave structure, and accurate spectral decompositions isolate individual-mode growth rates for the fundamental and harmonic disturbances. Roughness spacing, roughness height, and Reynolds number are varied to investigate the growth of all amplified wavelengths. The measurements show early nonlinear mode interaction causing amplitude saturation well before transition. Comparisons with nonlinear parabolized stability equations calculations show excellent agreement in both the disturbance amplitude and the mode-shape profiles.

Modification of the large-scale features of high Reynolds number wall turbulence by passive surface obtrusions

NASA Astrophysics Data System (ADS)

Monty, J. P.; Allen, J. J.; Lien, K.; Chong, M. S.

2011-12-01

A high Reynolds number boundary-layer wind-tunnel facility at New Mexico State University was fitted with a regularly distributed braille surface. The surface was such that braille dots were closely packed in the streamwise direction and sparsely spaced in the spanwise direction. This novel surface had an unexpected influence on the flow: the energy of the very large-scale features of wall turbulence (approximately six-times the boundary-layer thickness in length) became significantly attenuated, even into the logarithmic region. To the author's knowledge, this is the first experimental study to report a modification of `superstructures' in a rough-wall turbulent boundary layer. The result gives rise to the possibility that flow control through very small, passive surface roughness may be possible at high Reynolds numbers, without the prohibitive drag penalty anticipated heretofore. Evidence was also found for the uninhibited existence of the near-wall cycle, well known to smooth-wall-turbulence researchers, in the spanwise space between roughness elements.

Large-Eddy Simulations of Fully Developed Turbulent Channel and Pipe Flows with Smooth and Rough Walls

NASA Astrophysics Data System (ADS)

Saito, Namiko

Studies in turbulence often focus on two flow conditions, both of which occur frequently in real-world flows and are sought-after for their value in advancing turbulence theory. These are the high Reynolds number regime and the effect of wall surface roughness. In this dissertation, a Large-Eddy Simulation (LES) recreates both conditions over a wide range of Reynolds numbers Retau = O(102) - O(108) and accounts for roughness by locally modeling the statistical effects of near-wall anisotropic fine scales in a thin layer immediately above the rough surface. A subgrid, roughness-corrected wall model is introduced to dynamically transmit this modeled information from the wall to the outer LES, which uses a stretched-vortex subgrid-scale model operating in the bulk of the flow. Of primary interest is the Reynolds number and roughness dependence of these flows in terms of first and second order statistics. The LES is first applied to a fully turbulent uniformly-smooth/rough channel flow to capture the flow dynamics over smooth, transitionally rough and fully rough regimes. Results include a Moody-like diagram for the wall averaged friction factor, believed to be the first of its kind obtained from LES. Confirmation is found for experimentally observed logarithmic behavior in the normalized stream-wise turbulent intensities. Tight logarithmic collapse, scaled on the wall friction velocity, is found for smooth-wall flows when Re tau ≥ O(106) and in fully rough cases. Since the wall model operates locally and dynamically, the framework is used to investigate non-uniform roughness distribution cases in a channel, where the flow adjustments to sudden surface changes are investigated. Recovery of mean quantities and turbulent statistics after transitions are discussed qualitatively and quantitatively at various roughness and Reynolds number levels. The internal boundary layer, which is defined as the border between the flow affected by the new surface condition and the unaffected part, is computed, and a collapse of the profiles on a length scale containing the logarithm of friction Reynolds number is presented. Finally, we turn to the possibility of expanding the present framework to accommodate more general geometries. As a first step, the whole LES framework is modified for use in the curvilinear geometry of a fully-developed turbulent pipe flow, with implementation carried out in a spectral element solver capable of handling complex wall profiles. The friction factors have shown favorable agreement with the superpipe data, and the LES estimates of the Karman constant and additive constant of the log-law closely match values obtained from experiment.

Method and apparatus for decoupled thermo-catalytic pollution control

DOEpatents

Tabatabaie-Raissi, Ali; Muradov, Nazim Z.; Martin, Eric

2006-07-11

A new method for design and scale-up of thermocatalytic processes is disclosed. The method is based on optimizing process energetics by decoupling of the process energetics from the DRE for target contaminants. The technique is applicable to high temperature thermocatalytic reactor design and scale-up. The method is based on the implementation of polymeric and other low-pressure drop support for thermocatalytic media as well as the multifunctional catalytic media in conjunction with a novel rotating fluidized particle bed reactor.

Annual Progress Report, October 1, 1982 - September 15, 1983 on Contract N00014-79-C-0126,

DTIC Science & Technology

1983-09-15

bulk of bound Na+ (i.e., 77/) ar displaced by 300 rrM guar =dre. However, at 100 mrM concentration, the most effective displacement was not guanidine...polyvinylmethylether (PVME), and a counter and expressed as a ratio to thenumber of native gums , polysaccharides, etc.A labelled Na" concentration in...precipitation and deterioration of the organic components in the GIB medium. The GIB medium was obtained in sterile dry powder form from Grand Island

NASA Deputy Administrator Tours Sierra Nevada Space Systems' Dre

NASA Image and Video Library

2011-02-05

Director of Advanced Programs, Sierra Nevada Corporation, Jim Voss talks during a press conference with Sierra Nevada's Dream Chaser spacecraft in the background on Saturday, Feb. 5, 2011, at the University of Colorado at Boulder. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

NASA Deputy Administrator Tours Sierra Nevada Space Systems' Dre

NASA Image and Video Library

2011-02-05

Sierra Nevada Space Systems chairman Mark Sirangello talks during a press conference with Sierra Nevada's Dream Chaser spacecraft in the background on Saturday, Feb. 5, 2011, at the University of Colorado at Boulder. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

NASA Deputy Administrator Tours Sierra Nevada Space Systems' Dre

NASA Image and Video Library

2011-02-05

NASA Deputy Administrator Lori Garver talks during a press conference with Sierra Nevada's Dream Chaser spacecraft in the background on Saturday, Feb. 5, 2011, at the University of Colorado at Boulder. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

NASA Deputy Administrator Tours Sierra Nevada Space Systems' Dre

NASA Image and Video Library

2011-02-05

Sierra Nevada's Dream Chaser spacecraft is seen as NASA Deputy Administrator Lori Garver talks during a press conference on Saturday, Feb. 5, 2011, at the University of Colorado at Boulder. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

Dual Production Sources in the Procurement of Weapon Systems: A Policy Analysis

DTIC Science & Technology

1983-11-01

Competitive Aspects of the AIM-9B Seeker Assembly Procurement, memorandum to Carl Wilbourn , U.S. Navy OP-96D, December 16, 1977. 3 sARINC Report, p...Corporation, R-2706-DR&E, February 1981. Carroll, Frank, Competitive Aspects of the AIM-9B Seeker Assembly Procurement, Memorandum to Carl Wilbourn , U.S...David J., and Joseph P. Large, Estimated Costs of Extended Low Rate Airframe Production, The Rand Corporation, R-2243-AF, March 1978, Fisher, Gene H

AIS Data Base Generation.

DTIC Science & Technology

1981-04-01

intelligence and Reconnaissance Djvisi F~~THE COM&NADER: If your addres a"s cbagd (m If ymo wisn = be remwd f r t-e RAMC m Iins Liac, or if the adresme I...information content? 2. How reliable is the source? 3. How "credible" is the data? His evaluations of incoming information are based on his cognitive...therefC)re, dre 2-2 evaluated in the light of the needs and requirements of the particular intelligence activities they are to serve. The OSI approach

Effect of surface treatment on stress distribution in immediately loaded dental implants--a 3D finite element analysis.

PubMed

Bahrami, Babak; Shahrbaf, Shirin; Mirzakouchaki, Behnam; Ghalichi, Farzan; Ashtiani, Mohammed; Martin, Nicolas

2014-04-01

To investigate, by means of FE analysis, the effect of surface roughness treatments on the distribution of stresses at the bone-implant interface in immediately loaded mandibular implants. An accurate, high resolution, digital replica model of bone structure (cortical and trabecular components) supporting an implant was created using CT scan data and image processing software (Mimics 13.1; Materialize, Leuven, Belgium). An anatomically accurate 3D model of a mandibular-implant complex was created using a professional 3D-CAD modeller (SolidWorks, DassaultSystèmes Solid Works Corp; 2011). Finite element models were created with one of the four roughness treatments on the implant fixture surface. Of these, three were surface treated to create a uniform coating determined by the coefficient of friction (μ); these were either (1) plasma sprayed or porous-beaded (μ=1.0), (2) sandblasted (μ=0.68) or (3) polished (μ=0.4). The fourth implant had a novel two-part surface roughness consisting of a coronal polished component (μ=0.4) interfacing with the cortical bone, and a body plasma treated surface component (μ=1) interfacing with the trabecular bone. Finite element stress analysis was carried out under vertical and lateral forces. This investigation showed that the type of surface treatment on the implant fixture affects the stress at the bone-implant interface of an immediately loaded implant complex. Von Mises stress data showed that the two-part surface treatment created the better stress distribution at the implant-bone interface. The results from this FE computational analysis suggest that the proposed two-part surface treatment for IL implants creates lower stresses than single uniform treatments at the bone-implant interface, which might decrease peri-implant bone loss. Future investigations should focus on mechanical and clinical validation of these FE results. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.