WorldWideScience

Sample records for surface markedly impact

  1. Forensic surface metrology: tool mark evidence.

    Science.gov (United States)

    Gambino, Carol; McLaughlin, Patrick; Kuo, Loretta; Kammerman, Frani; Shenkin, Peter; Diaczuk, Peter; Petraco, Nicholas; Hamby, James; Petraco, Nicholas D K

    2011-01-01

    Over the last several decades, forensic examiners of impression evidence have come under scrutiny in the courtroom due to analysis methods that rely heavily on subjective morphological comparisons. Currently, there is no universally accepted system that generates numerical data to independently corroborate visual comparisons. Our research attempts to develop such a system for tool mark evidence, proposing a methodology that objectively evaluates the association of striated tool marks with the tools that generated them. In our study, 58 primer shear marks on 9 mm cartridge cases, fired from four Glock model 19 pistols, were collected using high-resolution white light confocal microscopy. The resulting three-dimensional surface topographies were filtered to extract all "waviness surfaces"-the essential "line" information that firearm and tool mark examiners view under a microscope. Extracted waviness profiles were processed with principal component analysis (PCA) for dimension reduction. Support vector machines (SVM) were used to make the profile-gun associations, and conformal prediction theory (CPT) for establishing confidence levels. At the 95% confidence level, CPT coupled with PCA-SVM yielded an empirical error rate of 3.5%. Complementary, bootstrap-based computations for estimated error rates were 0%, indicating that the error rate for the algorithmic procedure is likely to remain low on larger data sets. Finally, suggestions are made for practical courtroom application of CPT for assigning levels of confidence to SVM identifications of tool marks recorded with confocal microscopy. Copyright © 2011 Wiley Periodicals, Inc.

  2. Marked fatgraph complexes and surface automorphisms

    DEFF Research Database (Denmark)

    Kuno, Yusuke; Penner, Robert; Turaev, Vladimir

    2013-01-01

    Combinatorial aspects of the Torelli-Johnson-Morita theory of surface automorphisms are extended to certain subgroups of the mapping class groups. These subgroups are defined relative to a specified homomorphism from the fundamental group of the surface onto an arbitrary group $K$. For $K$ abelia...

  3. Surface laser marking optimization using an experimental design approach

    Science.gov (United States)

    Brihmat-Hamadi, F.; Amara, E. H.; Lavisse, L.; Jouvard, J. M.; Cicala, E.; Kellou, H.

    2017-04-01

    Laser surface marking is performed on a titanium substrate using a pulsed frequency doubled Nd:YAG laser ( λ= 532 nm, τ pulse=5 ns) to process the substrate surface under normal atmospheric conditions. The aim of the work is to investigate, following experimental and statistical approaches, the correlation between the process parameters and the response variables (output), using a Design of Experiment method (DOE): Taguchi methodology and a response surface methodology (RSM). A design is first created using MINTAB program, and then the laser marking process is performed according to the planned design. The response variables; surface roughness and surface reflectance were measured for each sample, and incorporated into the design matrix. The results are then analyzed and the RSM model is developed and verified for predicting the process output for the given set of process parameters values. The analysis shows that the laser beam scanning speed is the most influential operating factor followed by the laser pumping intensity during marking, while the other factors show complex influences on the objective functions.

  4. EcoMark: Evaluating Models of Vehicular Environmental Impact

    DEFF Research Database (Denmark)

    Guo, Chenjuan; Ma, Mike; Yang, Bin

    2012-01-01

    The reduction of greenhouse gas (GHG) emissions from transporta- tion is essential for achieving politically agreed upon emissions re- duction targets that aim to combat global climate change. So-called eco-routing and eco-driving are able to substantially reduce GHG emissions caused by vehicular...... the vehicle travels in. We develop an evaluation framework, called EcoMark, for such environmental impact models. In addition, we survey all eleven state-of-the-art impact models known to us. To gain insight into the capabilities of the models and to understand the effectiveness of the EcoMark, we apply...

  5. 16 CFR 1203.11 - Marking the impact test line.

    Science.gov (United States)

    2010-01-01

    ... Section 1203.11 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... (HPI), with the brow parallel to the basic plane. Place a 5-kg (11-lb) preload ballast on top of the... helmet coinciding with the intersection of the surface of the helmet with the impact line planes defined...

  6. Drop Impact on Superheated Surfaces

    NARCIS (Netherlands)

    Tran, Tuan; Staat, Erik-Jan; Prosperetti, Andrea; Sun, Chao; Lohse, Detlef

    2012-01-01

    At the impact of a liquid droplet on a smooth surface heated above the liquid’s boiling point, the droplet either immediately boils when it contacts the surface (“contact boiling”), or without any surface contact forms a Leidenfrost vapor layer towards the hot surface and bounces back (“gentle film

  7. HYDROLOGIC AND FEATURE-BASED SURFACE ANALYSIS FOR TOOL MARK INVESTIGATION ON ARCHAEOLOGICAL FINDS

    Directory of Open Access Journals (Sweden)

    K. Kovács

    2012-07-01

    Full Text Available The improvement of detailed surface documentation methods provides unique tool mark-study opportunities in the field of archaeological researches. One of these data collection techniques is short-range laser scanning, which creates a digital copy of the object’s morphological characteristics from high-resolution datasets. The aim of our work was the accurate documentation of a Bronze Age sluice box from Mitterberg, Austria with a spatial resolution of 0.2 mm. Furthermore, the investigation of the entirely preserved tool marks on the surface of this archaeological find was also accomplished by these datasets. The methodology of this tool mark-study can be summarized in the following way: At first, a local hydrologic analysis has been applied to separate the various patterns of tools on the finds’ surface. As a result, the XYZ coordinates of the special points, which represent the edge lines of the sliding tool marks, were calculated by buffer operations in a GIS environment. During the second part of the workflow, these edge points were utilized to manually clip the triangle meshes of these patterns in reverse engineering software. Finally, circle features were generated and analysed to determine the different sections along these sliding tool marks. In conclusion, the movement of the hand tool could be reproduced by the spatial analysis of the created features, since the horizontal and vertical position of the defined circle centre points indicated the various phases of the movements. This research shows an exact workflow to determine the fine morphological structures on the surface of the archaeological find.

  8. Radiochemical analyses of surface water from U.S. Geological Survey hydrologic bench-mark stations

    Science.gov (United States)

    Janzer, V.J.; Saindon, L.G.

    1972-01-01

    The U.S. Geological Survey's program for collecting and analyzing surface-water samples for radiochemical constituents at hydrologic bench-mark stations is described. Analytical methods used during the study are described briefly and data obtained from 55 of the network stations in the United States during the period from 1967 to 1971 are given in tabular form.Concentration values are reported for dissolved uranium, radium, gross alpha and gross beta radioactivity. Values are also given for suspended gross alpha radioactivity in terms of natural uranium. Suspended gross beta radioactivity is expressed both as the equilibrium mixture of strontium-90/yttrium-90 and as cesium-137.Other physical parameters reported which describe the samples include the concentrations of dissolved and suspended solids, the water temperature and stream discharge at the time of the sample collection.

  9. Generating Impact Maps from Automatically Detected Bomb Craters in Aerial Wartime Images Using Marked Point Processes

    Science.gov (United States)

    Kruse, Christian; Rottensteiner, Franz; Hoberg, Thorsten; Ziems, Marcel; Rebke, Julia; Heipke, Christian

    2018-04-01

    The aftermath of wartime attacks is often felt long after the war ended, as numerous unexploded bombs may still exist in the ground. Typically, such areas are documented in so-called impact maps which are based on the detection of bomb craters. This paper proposes a method for the automatic detection of bomb craters in aerial wartime images that were taken during the Second World War. The object model for the bomb craters is represented by ellipses. A probabilistic approach based on marked point processes determines the most likely configuration of objects within the scene. Adding and removing new objects to and from the current configuration, respectively, changing their positions and modifying the ellipse parameters randomly creates new object configurations. Each configuration is evaluated using an energy function. High gradient magnitudes along the border of the ellipse are favored and overlapping ellipses are penalized. Reversible Jump Markov Chain Monte Carlo sampling in combination with simulated annealing provides the global energy optimum, which describes the conformance with a predefined model. For generating the impact map a probability map is defined which is created from the automatic detections via kernel density estimation. By setting a threshold, areas around the detections are classified as contaminated or uncontaminated sites, respectively. Our results show the general potential of the method for the automatic detection of bomb craters and its automated generation of an impact map in a heterogeneous image stock.

  10. Localization of burn mark under an abnormal topography on MOSFET chip surface using liquid crystal and emission microscopy tools.

    Science.gov (United States)

    Lau, C K; Sim, K S; Tso, C P

    2011-01-01

    This article focuses on the localization of burn mark in MOSFET and the scanning electron microscope (SEM) inspection on the defect location. When a suspect abnormal topography is shown on the die surface, further methods to pin-point the defect location is necessary. Fault localization analysis becomes important because an abnormal spot on the chip surface may and may not have a defect underneath it. The chip surface topography can change due to the catastrophic damage occurred at layers under the chip surface, but it could also be due to inconsistency during metal deposition in the wafer fabrication process. Two localization techniques, liquid crystal thermography and emission microscopy, were performed to confirm that the abnormal topography spot is the actual defect location. The tiny burn mark was surfaced by performing a surface decoration at the defect location using hot hydrochloric acid. SEM imaging, which has the high magnification and three-dimensional capabilities, was used to capture the images of the burn mark. Copyright © 2011 Wiley Periodicals, Inc.

  11. A survey of some metallographic etching reagents for restoration of obliterated engraved marks on aluminium-silicon alloy surfaces.

    Science.gov (United States)

    Uli, Norjaidi; Kuppuswamy, R; Amran, Mohd Firdaus Che

    2011-05-20

    A brief survey to assess the sensitivity and efficacy of some common etching reagents for revealing obliterated engraved marks on Al-Si alloy surfaces is presented. Experimental observations have recommended use of alternate swabbing of 10% NaOH and 10% HNO(3) on the obliterated surfaces for obtaining the desired results. The NaOH etchant responsible for bringing back the original marks resulted in the deposition of some dark coating that has masked the recovered marks. The coating had been well removed by dissolving it in HNO(3) containing 10-20% acid. However, the above etching procedure was not effective on aluminium (99% purity) and Al-Zn-Mg-Cu alloy surfaces. Also the two reagents (i) immersion in 10% aq. phosphoric acid and (ii) alternate swabbing of 60% HCl and 40% NaOH suggested earlier for high strength Al-Zn-Mg-Cu alloys [23] were quite ineffective on Al-Si alloys. Thus different aluminium alloys needed different etching treatments for successfully restoring the obliterated marks. Al-Si alloys used in casting find wide applications especially in the manufacture of engine blocks of motor vehicles. Hence, the results presented in this paper are of much relevance in serial number restoration problems involving this alloy. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  12. Visibility of road markings on wet road surfaces : a literature study.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1981-01-01

    The English version of B 14153 is presented. Road markings, notably lane markers, are often only poorly visible when the road is wet. This is particularly a problem at night on unlit roads. A study is made of whether a solution for this problem can be found on the basis of the known, published

  13. Interpretation and significance of reverse chevron-shaped markings on fracture surfaces of API X100 pipeline steels

    International Nuclear Information System (INIS)

    Sowards, Jeffrey W.; McCowan, Chris N.; Drexler, Elizabeth S.

    2012-01-01

    Highlights: ► We investigated fractures of X100 steel linepine produced during fracture mechanics testing. ► Fractures exhibited a unique chevron pattern that points in the direction of crack propagation. ► A qualitative model is proposed to explain the fracture pattern formation. ► Findings indicate that careful interpretation of ductile material fractures is necessary. - Abstract: Fracture surfaces of X100 pipeline steels were examined with optical and electron microscopy after crack tip opening angle fracture testing. Some fracture surfaces exhibited chevron-shaped fracture patterns that are markedly different from classic chevron fracture. The chevron-shaped markings on the X100 fracture surfaces point in the direction of crack growth, rather than towards the location of fracture initiation, as observed in classic cases of chevron fracture. Existing models, predicting formation of chevron fracture patterns, do not explain the fracture behavior observed for X100 steel. A mechanism is proposed where reverse chevron-shaped patterns are developed due to the shape of the crack front itself. The chevron shape forms as a result of crack tunneling, and the overall pattern is developed on the fracture surface due to intermittent crack growth, resulting in alternating regions (bands) of fast fracture and slower, more ductile fracture. The contrast between these bands of alternating fracture defines the chevron. Care should be taken during interpretation of intermittent chevron markings on fractures of ductile materials, as they may point away from rather than towards the origin of fracture.

  14. Elimination or Minimization of Oscillation Marks: A Path To Improved Cast Surface Quality

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Alan W. Cramb

    2007-12-17

    Oscillation marks are the most recognizable feature of continuous casting and can be related to the subsurface defects that can be found on product rolled from continuous cast slabs. The purpose of this work was to develop strategies that can be used on industrial continuous casters to reduce oscillation mark depth and, in particular, to minimize the formation of hook type defects that are prevalent on ultra low carbon grades. The major focus of the work was on developing a technique to allow heat transfer in the meniscus region of the continuous caster to be measured and the effect of mold slag chemistry and chrystallization to be documented. A new experimental technique was developed that allowed the effect of mold flux chemistry and chrystallization on the radiation heat transfer rate to be measured dynamically.

  15. Social Impacts of the Marking Scheme in Public Housing in Hong Kong

    Science.gov (United States)

    Yau, Yung

    2012-01-01

    To improve environmental hygiene in public housing estates in Hong Kong, the Housing Department launched the Marking Scheme for Tenancy Enforcement in Public Housing Estates in 2003. The marking scheme operates as a penalty-point system where sitting tenants will be expelled from their public housing units if they receive penalty points up to a…

  16. Effect of impact surface in equestrian falls

    OpenAIRE

    Clark, J. Michio; Post, Andrew; Connor, Thomas A.; Hoshizaki, Thomas Blaine; Gilchrist, M. D.

    2016-01-01

    This study examines the effect of impact surface on head kinematic response and maximum principal strain (MPS) for equestrian falls. A helmeted Hybrid III headform was dropped unrestrained onto three impact surfaces of different stiffness (steel, turf and sand) and three locations. Peak resultant linear acceleration, rotational acceleration and duration of the impact events were measured. A finite element brain model was used to calculate MPS. The results revealed that drops onto steel produc...

  17. The impact of preoperative stoma site marking on the incidence of complications, quality of life, and patient's independence.

    Science.gov (United States)

    Person, Benjamin; Ifargan, Ruth; Lachter, Jesse; Duek, Simon D; Kluger, Yoram; Assalia, Ahmad

    2012-07-01

    Preoperative stoma site marking and counseling aim to improve patients' rehabilitation and adaptation to a new medical condition. Objective studies are needed to provide evidence of the impact of care by stoma therapists. Key quality indicators include patients' quality of life, independence, and complication rates as affected by the variable modes of stoma site marking and planning. The aim of this study was to evaluate the impact of preoperative stoma site marking on patients' quality of life, independence, and complication rates. : A validated stoma quality-of-life questionnaire was used as the main assessment tool. Complications were noted on regular postoperative visits. This is a single-center, clinical study. The study was conducted at the Rambam Health Care Campus in Haifa, Israel. Rambam Health Care Campus is a tertiary university hospital. All patients who underwent an elective stoma creation between 2006 and 2008 were included. Evaluated parameters included demographics, stoma type, marking status, complication rates, quality of life, and independence parameters. : One hundred five patients (60 men and 45 women) were included, of whom 52 (49.5%) were preoperatively marked and 53 (50.5%) were not marked. Sixty stomas (57%) were permanent, and 45 (43%) stomas were temporary. The quality of life of patients whose stoma sites were preoperatively marked was significantly better than that of the unmarked patients (p stoma type. Preoperative stoma site marking is crucial for improving patients' postoperative quality of life, promoting their independence, and reducing the rates of postoperative complications. The role of the enterostomal therapist is very important in the ostomates' pre- and postoperative care.

  18. Mucosal immunoglobulins at respiratory surfaces mark an ancient association that predates the emergence of tetrapods

    DEFF Research Database (Denmark)

    Xu, Zhen; Takizawa, Fumio; Parra, David

    2016-01-01

    the first example of locally induced immunoglobulin in the mucosa of a cold-blooded species. Moreover, we demonstrate that gill microbiota is predominantly coated with IgT, thus providing previously unappreciated evidence that the microbiota present at a respiratory surface of a vertebrate is recognized...

  19. Impact damage reduction by structured surface geometry

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Fedorov, Vladimir; McGugan, Malcolm

    2018-01-01

    performance was observed for polyurethane-coated fibre composites with structured geometries at the back surfaces. Repeated impacts by rubber balls on the coated side caused damage and delamination of the coating. The laminates with structured back surfaces showed longer durability than those with a flat back...

  20. Flash lamp annealing of tungsten surfaces marks a new way to optimized slow positron yields

    Science.gov (United States)

    Anwand, W.; Johnson, J. M.; Butterling, M.; Wagner, A.; Skorupa, W.; Brauer, G.

    2013-06-01

    Tungsten in the form of a mono-crystalline foil with an optimum thickness of about 2 μm is often used as a positron moderator in mono-energetic positron beams with 22Na positron sources. The efficiency of such a moderator strongly depends on its prior heat treatment, i.e. an annealing procedure with considerable difficulty at temperatures of about 2000 °C under vacuum conditions. Flash lamp annealing (FLA) has been tested as new method to quickly anneal W foils in order to produce easy manageable, low-cost moderators with a high efficiency. With FLA, just the surface of a W foil is heated above the melting point (3422°C) within 1 to 3 ms, i.e. without melting the whole foil volume. In this way, a surface cleaning is reached connected with a considerable increase in the positron diffusion length. Conventional polycrystalline W foils of 9 μm ± 25% thickness, heat treated by FLA, were characterized and tested as positron moderators. First promising tests result in a moderator efficiency of ~3*10-4 and clearly demonstrate that FLA is also applicable to tungsten meshes.

  1. Prediction of Outside Surface Aluminium Tank Corrosion on TRIGA Mark - IIResearch Reactor Bandung

    International Nuclear Information System (INIS)

    Soedardjo

    2000-01-01

    The prediction of outside surface aluminium tank corrosion on researchreactor design which coated by epoxy paint, has been assessed. The new TRIGAMark - II Bandung research reactor tank design separated by 3 section arebottom, middle and upper section then inserted into the existing old reactor.The separation carried out caused by the space constraint on top of old tank,so that the novel tank impossible inserted into old tank all at once. Thespace between novel and old tank is 10 mm. After bottom and middle section oftank welded then followed by epoxy painting and inserted partially into oldtank. From then on the middle and upper section welded and followed by epoxypainting then inserted into old tank. Based on prediction result, that theroot cause of corrosion would be took place on welding and on imperfectlyepoxy painting area. The outside surface novel tank would be generated by thereaction between imperfectly epoxy painting area and the highly basecondition on cement grout that available on novel and old tank gap. (author)

  2. Enteroendocrine cells are specifically marked by cell surface expression of claudin-4 in mouse small intestine.

    Directory of Open Access Journals (Sweden)

    Takahiro Nagatake

    Full Text Available Enteroendocrine cells are solitary epithelial cells scattered throughout the gastrointestinal tract and produce various types of hormones, constituting one of the largest endocrine systems in the body. The study of these rare epithelial cells has been hampered by the difficulty in isolating them because of the lack of specific cell surface markers. Here, we report that enteroendocrine cells selectively express a tight junction membrane protein, claudin-4 (Cld4, and are efficiently isolated with the use of an antibody specific for the Cld4 extracellular domain and flow cytometry. Sorted Cld4+ epithelial cells in the small intestine exclusively expressed a chromogranin A gene (Chga and other enteroendocrine cell-related genes (Ffar1, Ffar4, Gpr119, and the population was divided into two subpopulations based on the activity of binding to Ulex europaeus agglutinin-1 (UEA-1. A Cld4+UEA-1- cell population almost exclusively expressed glucose-dependent insulinotropic polypeptide gene (Gip, thus representing K cells, whereas a Cld4+UEA-1+ cell population expressed other gut hormone genes, including glucagon-like peptide 1 (Gcg, pancreatic polypeptide-like peptide with N-terminal tyrosine amide (Pyy, cholecystokinin (Cck, secretin (Sct, and tryptophan hydroxylase 1 (Tph1. In addition, we found that orally administered luminal antigens were taken up by the solitary Cld4+ cells in the small intestinal villi, raising the possibility that enteroendocrine cells might also play a role in initiation of mucosal immunity. Our results provide a useful tool for the cellular and functional characterization of enteroendocrine cells.

  3. Progressing quality control in environmental impact assessment beyond legislative compliance: An evaluation of the IEMA EIA Quality Mark certification scheme

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Alan, E-mail: alan.bond@uea.ac.uk [School of Environmental Sciences, University of East Anglia (United Kingdom); Research Unit for Environmental Sciences and Management, North-West University (South Africa); Fischer, Thomas B, E-mail: fischer@liverpool.ac.uk [School of Environmental Sciences, University of Liverpool (United Kingdom); Fothergill, Josh, E-mail: j.fothergill@iema.net [Institute of Environmental Management and Assessment, Lincoln (United Kingdom)

    2017-03-15

    The effectiveness of Environmental Impact Assessment (EIA) systems is contingent on a number of control mechanisms: procedural; judicial; evaluative; public and government agency; professional; and development aid agency. If we assume that procedural and judicial controls are guaranteed in developed EIA systems, then progressing effectiveness towards an acceptable level depends on improving the performance of other control mechanisms over time. These other control mechanisms are either absent, or are typically centrally controlled, requiring public finances; this we argue is an unpopular model in times of greater Government austerity. Here we evaluate a market-based mechanism for improving the performance of evaluative and professional control mechanisms, the UK Institute of Environmental Management and Assessments' EIA Quality Mark. We do this by defining dimensions of effectiveness for the purposes of our evaluation, and by identifying international examples of the approaches taken to delivering the other control measures to validate the approach taken in the EIA Quality Mark. We then evaluate the EIA Quality Mark, when used in combination with legal procedures and an active judiciary, against the effectiveness dimensions and use time-series analysis of registrant data to examine its ability to progress practice. We conclude that the EIA Quality Mark has merit as a model for a market-based mechanism, and may prove a more financially palatable approach for delivering effective EIA in mature systems in countries that lack centralised agency oversight. It may, therefore, be of particular interest to some Member States of the European Union for ensuring forthcoming certification requirements stemming from recent amendments to the EIA Directive. - Highlights: • Quality control mechanisms in EIA are identified. • Effectiveness of EIA is conceptualised for evaluation purposes. • The UK IEMA EIA Quality Mark is introduced as a market-based mechanism. • The

  4. Progressing quality control in environmental impact assessment beyond legislative compliance: An evaluation of the IEMA EIA Quality Mark certification scheme

    International Nuclear Information System (INIS)

    Bond, Alan; Fischer, Thomas B; Fothergill, Josh

    2017-01-01

    The effectiveness of Environmental Impact Assessment (EIA) systems is contingent on a number of control mechanisms: procedural; judicial; evaluative; public and government agency; professional; and development aid agency. If we assume that procedural and judicial controls are guaranteed in developed EIA systems, then progressing effectiveness towards an acceptable level depends on improving the performance of other control mechanisms over time. These other control mechanisms are either absent, or are typically centrally controlled, requiring public finances; this we argue is an unpopular model in times of greater Government austerity. Here we evaluate a market-based mechanism for improving the performance of evaluative and professional control mechanisms, the UK Institute of Environmental Management and Assessments' EIA Quality Mark. We do this by defining dimensions of effectiveness for the purposes of our evaluation, and by identifying international examples of the approaches taken to delivering the other control measures to validate the approach taken in the EIA Quality Mark. We then evaluate the EIA Quality Mark, when used in combination with legal procedures and an active judiciary, against the effectiveness dimensions and use time-series analysis of registrant data to examine its ability to progress practice. We conclude that the EIA Quality Mark has merit as a model for a market-based mechanism, and may prove a more financially palatable approach for delivering effective EIA in mature systems in countries that lack centralised agency oversight. It may, therefore, be of particular interest to some Member States of the European Union for ensuring forthcoming certification requirements stemming from recent amendments to the EIA Directive. - Highlights: • Quality control mechanisms in EIA are identified. • Effectiveness of EIA is conceptualised for evaluation purposes. • The UK IEMA EIA Quality Mark is introduced as a market-based mechanism. • The

  5. Dose of dialysis based on body surface area is markedly less in younger children than in older adolescents.

    Science.gov (United States)

    Daugirdas, John T; Hanna, Melisha G; Becker-Cohen, Rachel; Langman, Craig B

    2010-05-01

    BACKGROUND AND OBSERVATIONS: The current denominator for dosing dialysis is the urea distribution volume (V). Normalizing Kt/V to body surface area (S) has been proposed, but the implications of doing this in children have not been examined. Dialysis dose given to children and adolescents was calculated in terms of conventional V-based scaling and surface-area-normalized standard Kt/V (SAN-stdKt/V) calculated as stdKt/V x (Vant/S)/17.5, where Vant was an anthropometric estimate of V calculated using the Morgenstern equation. Formal 2-pool modeling was used to compute all dialysis adequacy outputs. In 34 children (11 girls, 23 boys) dialyzed 3 times a week, age range 1.4 to 18 years, the mean delivered equilibrated Kt/V (eKt/V) was 1.40, and the mean stdKt/V was 2.49, both of which tended to be higher in younger children. The ratio of Vant to S was 15.6 +/- 2.69 and was strongly associated with age between ages 2 and 16. SAN-stdKt/V averaged 2.21 and was strongly correlated with age between ages 2 and 16. If one considers a desired target for SAN-stdKt/V to be 2.45, all children less than 10 years of age were below target, despite having relatively high values of eKt/V and stdKt/V. If a surface-area-based denominator were to be adopted for dialysis dosing, most children under 10 years of age would receive markedly less dialysis than adolescent patients and would require 6- to 8-hour hemodialysis sessions or, for the youngest children, treatments given more frequently than 3 times/wk.

  6. Drop "impact" on an airfoil surface.

    Science.gov (United States)

    Wu, Zhenlong

    2018-05-17

    Drop impact on an airfoil surface takes place in drop-laden two-phase flow conditions such as rain and icing, which are encountered by wind turbines or airplanes. This phenomenon is characterized by complex nonlinear interactions that manifest rich flow physics and pose unique modeling challenges. In this article, the state of the art of the research about drop impact on airfoil surface in the natural drop-laden two-phase flow environment is presented. The potential flow physics, hazards, characteristic parameters, droplet trajectory calculation, drop impact dynamics and effects are discussed. The most key points in establishing the governing equations for a drop-laden flow lie in the modeling of raindrop splash and water film. The various factors affecting the drop impact dynamics and the effects of drop impact on airfoil aerodynamic performance are summarized. Finally, the principle challenges and future research directions in the field as well as some promising measures to deal with the adverse effects of drop-laden flows on airfoil performance are proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Impact of marked weight loss induced by bariatric surgery on bone mineral density and remodeling

    Directory of Open Access Journals (Sweden)

    F.A. Pereira

    2007-04-01

    Full Text Available Data about the impact of bariatric surgery (BS and subsequent weight loss on bone are limited. The objective of the present study was to determine bone mineral density (BMD, bone remodeling metabolites and hormones that influence bone trophism in premenopausal women submitted to BS 9.8 months, on average, before the study (OGg, N = 16. The data were compared to those obtained for women of normal weight (CG, N = 11 and for obese women (OG, N = 12. Eight patients in each group were monitored for one year, with the determination of BMD, of serum calcium, phosphorus, magnesium, parathyroid hormone, 25-hydroxyvitamin D, insulin-like growth factor-I (IGF-I and osteocalcin, and of urinary calcium and deoxypyridinoline. The biochemical determinations were repeated every three months in the longitudinal study and BMD was measured at the end of the study. Parathyroid hormone levels were similar in the three groups. IGF-I levels (CG = 332 ± 62 vs OG = 230 ± 37 vs OGg = 128 ± 19 ng/mL were significantly lower in the operated patients compared to the non-operated obese women. Only OGg patients presented a significant fall in BMD of 6.2% at L1-L4, of 10.2% in the femoral neck, and of 5.1% in the forearm. These results suggest that the weight loss induced by BS is associated with a significant loss of bone mass even at sites that are not influenced by weight overload, with hormonal factors such as IGF-I being associated with this process.

  8. Environmental impact assessment of Ar-41 released by the normal operation of TRIGA-Mark 2 research reactor

    International Nuclear Information System (INIS)

    Qassoud, D.; Soufi, I.; Ziagos, J.; Demir, Z

    2007-01-01

    Full text: In accordance with the international regulation of nuclear safety and radiological protection of the environment applicable to the basic nuclear installations, category in which the Triga-Mark 2 research reactor is considered, an assesment of the impact in to the environment of the Ar-41 radioelement is accomplished. This radioelement is released by the normal operation of this reactor. The assessment is based on the characteristics of a Moroccan site (where the reactor is installed). It is carried out using CEA Gaussian models and mathematical models developed in LLNL. Considering the assumptions of impact assessments of the radioactivity in the atmosphere, the most important exposure is relatively corresponding to 1 Km from the reactor. This exposure is approximately 0,07% of the lawful limit. Beyond this locality, the exposure becomes lower than 0,02% of this limit. Beyond 5 Km, it becomes lower than ten nono-Sivert. In the basis of the site radiological baseline, the environmental impact of Ar-41 released in normal operation of the reactor is negligible in the studied case. [fr

  9. A comparison of multi-metal deposition processes utilising gold nanoparticles and an evaluation of their application to 'low yield' surfaces for finger mark development.

    Science.gov (United States)

    Fairley, C; Bleay, S M; Sears, V G; NicDaeid, N

    2012-04-10

    This paper reports a comparison of the effectiveness and practicality of using different multi-metal deposition processes for finger mark development. The work investigates whether modifications can be made to improve the performance of the existing process published by Schnetz. Secondly, we compare the ability of different multi-metal deposition processes to develop finger marks on a range of surfaces with that of other currently used development processes. All published multi-metal deposition processes utilise an initial stage of colloidal gold deposition followed by enhancement of the marks with using a physical developer. All possible combinations of colloidal gold and physical developer stages were tested. The method proposed by Schnetz was shown to be the most effective process, however a modification which reduced the pH of the enhancement solution was revealed to provide the best combination of effectiveness and practicality. In trials comparing the modified formulation with vacuum metal deposition, superglue and powder suspensions on surfaces which typically give low finger mark yields (cling film, plasticised vinyl, leather and masking tape), the modified method produced significantly better results over existing processes for cling film and plasticised vinyl. The modified formulation was found to be ineffective on both masking tape and leather. It is recommended that further tests be carried out on the modified multi-metal deposition formulation to establish whether it could be introduced for operational work on cling film material in particular. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Stretch Marks

    Science.gov (United States)

    ... completely without the help of a dermatologist or plastic surgeon. These doctors may use one of many types of treatments — from actual surgery to techniques like microdermabrasion and laser treatment — to reduce the appearance of stretch marks. These techniques are ...

  11. Hydraulic "fracking": are surface water impacts an ecological concern?

    Science.gov (United States)

    Burton, G Allen; Basu, Niladri; Ellis, Brian R; Kapo, Katherine E; Entrekin, Sally; Nadelhoffer, Knute

    2014-08-01

    Use of high-volume hydraulic fracturing (HVHF) in unconventional reservoirs to recover previously inaccessible oil and natural gas is rapidly expanding in North America and elsewhere. Although hydraulic fracturing has been practiced for decades, the advent of more technologically advanced horizontal drilling coupled with improved slickwater chemical formulations has allowed extensive natural gas and oil deposits to be recovered from shale formations. Millions of liters of local groundwaters are utilized to generate extensive fracture networks within these low-permeability reservoirs, allowing extraction of the trapped hydrocarbons. Although the technology is relatively standardized, the geographies and related policies and regulations guiding these operations vary markedly. Some ecosystems are more at risk from these operations than others because of either their sensitivities or the manner in which the HVHF operations are conducted. Generally, the closer geographical proximity of the susceptible ecosystem to a drilling site or a location of related industrial processes, the higher the risk of that ecosystem being impacted by the operation. The associated construction of roads, power grids, pipelines, well pads, and water-extraction systems along with increased truck traffic are common to virtually all HVHF operations. These operations may result in increased erosion and sedimentation, increased risk to aquatic ecosystems from chemical spills or runoff, habitat fragmentation, loss of stream riparian zones, altered biogeochemical cycling, and reduction of available surface and hyporheic water volumes because of withdrawal-induced lowering of local groundwater levels. The potential risks to surface waters from HVHF operations are similar in many ways to those resulting from agriculture, silviculture, mining, and urban development. Indeed, groundwater extraction associated with agriculture is perhaps a larger concern in the long term in some regions. Understanding the

  12. Impact of high resolution land surface initialization in Indian summer ...

    Indian Academy of Sciences (India)

    The direct impact of high resolution land surface initialization on the forecast bias in a regional climate model in recent years ... surface initialization using a regional climate model. ...... ization of the snow field in a cloud model; J. Clim. Appl.

  13. Impact of surface nanostructure on ice nucleation.

    Science.gov (United States)

    Zhang, Xiang-Xiong; Chen, Min; Fu, Ming

    2014-09-28

    Nucleation of water on solid surface can be promoted noticeably when the lattice parameter of a surface matches well with the ice structure. However, the characteristic length of the surface lattice reported is generally less than 0.5 nm and is hardly tunable. In this paper, we show that a surface with nanoscale roughness can also remarkably promote ice nucleation if the characteristic length of the surface structure matches well with the ice crystal. A series of surfaces composed of periodic grooves with same depth but different widths are constructed in molecular dynamics simulations. Water cylinders are placed on the constructed surfaces and frozen at constant undercooling. The nucleation rates of the water cylinders are calculated in the simulation using the mean first-passage time method and then used to measure the nucleation promotion ability of the surfaces. Results suggest that the nucleation behavior of the supercooled water is significantly sensitive to the width of the groove. When the width of the groove matches well with the specific lengths of the ice crystal structure, the nucleation can be promoted remarkably. If the width does not match with the ice crystal, this kind of promotion disappears and the nucleation rate is even smaller than that on the smooth surface. Simulations also indicate that even when water molecules are adsorbed onto the surface structure in high-humidity environment, the solid surface can provide promising anti-icing ability as long as the characteristic length of the surface structure is carefully designed to avoid geometric match.

  14. Analysis of energy flow during playground surface impacts.

    Science.gov (United States)

    Davidson, Peter L; Wilson, Suzanne J; Chalmers, David J; Wilson, Barry D; Eager, David; McIntosh, Andrew S

    2013-10-01

    The amount of energy dissipated away from or returned to a child falling onto a surface will influence fracture risk but is not considered in current standards for playground impact-attenuating surfaces. A two-mass rheological computer simulation was used to model energy flow within the wrist and surface during hand impact with playground surfaces, and the potential of this approach to provide insights into such impacts and predict injury risk examined. Acceleration data collected on-site from typical playground surfaces and previously obtained data from children performing an exercise involving freefalling with a fully extended arm provided input. The model identified differences in energy flow properties between playground surfaces and two potentially harmful surface characteristics: more energy was absorbed by (work done on) the wrist during both impact and rebound on rubber surfaces than on bark, and rubber surfaces started to rebound (return energy to the wrist) while the upper limb was still moving downward. Energy flow analysis thus provides information on playground surface characteristics and the impact process, and has the potential to identify fracture risks, inform the development of safer impact-attenuating surfaces, and contribute to development of new energy-based arm fracture injury criteria and tests for use in conjunction with current methods.

  15. The Impact of Preoperative Stoma Marking on Health-Related Quality of Life: A Comparison Cohort Study.

    Science.gov (United States)

    McKenna, Linda S; Taggart, Elizabeth; Stoelting, Joyce; Kirkbride, Geri; Forbes, Gordon B

    2016-01-01

    The purpose of this study was to compare health-related quality of life (HRQOL) in patients receiving preoperative stoma marking by a certified wound, ostomy and continence nurse (CWOCN) to patients who did not receive preoperative marking. Quasi-experimental, nonrandomized comparison cohort study. The sample comprised 59 patients immediately following creation of a fecal stoma during an 18-month period between 2008 and 2010. The experimental group consisted of 35 patients with a mean age of 49.7 years who received preoperative stoma site marking by a CWOCN. Six of those 35 patients (17%) received preoperative ostomy education and stoma site marking. The control group consisted of 24 patients with a mean age of 60.1 years who did not receive preoperative stoma site marking or preoperative ostomy education. The study setting was a 500-bed Midwest Magnet-designated teaching hospital. Data collection occurred at 2 points: within 72 hours before hospital discharge and 8 weeks after discharge. The Stoma Quality of Life (Stoma-QOL) instrument was used to measure HRQOL. Two CWOCNs and 3 RNs, all members of Memorial's Ostomy & Wound Services, administered the Stoma QOL within 72 hours before hospital discharge. The 2 CWOCNs followed a scripted message to collect functional lifestyle factors and administer the Stoma-QOL, for the second time at 8 weeks after discharge. Groups were compared using analysis of covariance to control for age; analysis demonstrated significantly higher HOQOL in the marked group compared to the unmarked group (F = 4.9, P = .031). Findings demonstrated that patients who underwent stoma site marking reported higher HRQOL than those who did not.

  16. Statistical methods for the forensic analysis of striated tool marks

    Energy Technology Data Exchange (ETDEWEB)

    Hoeksema, Amy Beth [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    In forensics, fingerprints can be used to uniquely identify suspects in a crime. Similarly, a tool mark left at a crime scene can be used to identify the tool that was used. However, the current practice of identifying matching tool marks involves visual inspection of marks by forensic experts which can be a very subjective process. As a result, declared matches are often successfully challenged in court, so law enforcement agencies are particularly interested in encouraging research in more objective approaches. Our analysis is based on comparisons of profilometry data, essentially depth contours of a tool mark surface taken along a linear path. In current practice, for stronger support of a match or non-match, multiple marks are made in the lab under the same conditions by the suspect tool. We propose the use of a likelihood ratio test to analyze the difference between a sample of comparisons of lab tool marks to a field tool mark, against a sample of comparisons of two lab tool marks. Chumbley et al. (2010) point out that the angle of incidence between the tool and the marked surface can have a substantial impact on the tool mark and on the effectiveness of both manual and algorithmic matching procedures. To better address this problem, we describe how the analysis can be enhanced to model the effect of tool angle and allow for angle estimation for a tool mark left at a crime scene. With sufficient development, such methods may lead to more defensible forensic analyses.

  17. Prayer marks.

    Science.gov (United States)

    Abanmi, Abdullah A; Al Zouman, Abdulrahman Y; Al Hussaini, Husa; Al-Asmari, Abdulrahman

    2002-07-01

    Prayer marks (PMs) are asymptomatic, chronic skin changes that consist mainly of thickening, lichenification, and hyperpigmentation, and develop over a long period of time as a consequence of repeated, extended pressure on bony prominences during prayer. Three hundred and forty-nine Muslims and 24 non-Muslims were examined for the appearance of PMs at different body sites. The prospective study of 349 Muslims (both males and females) with regular praying habits showed the occurrence of PMs on specific locations, such as the forehead, knees, ankles, and dorsa of the feet, leading to dermatologic changes consisting of lichenification and hyperpigmentation. The incidence of PMs was significantly higher in males than in females. Older subjects (over 50 years of age) demonstrated a significantly higher frequency of lichenification and hyperpigmentation, suggesting that repeated pressure and friction for prolonged periods are the causative factors for the development of PMs. Histologic examination of skin biopsies from the affected sites showed compact orthokeratosis, hypergranulosis, dermal papillary fibrosis, and dermal vascularization. PMs were not associated with any risk of secondary complications, such as erythema, bullous formation, and infections. PMs are commonly occurring dermatologic changes in Muslims who pray for prolonged periods.

  18. Drop Impact on a Solid Surface

    KAUST Repository

    Josserand, C.

    2015-09-22

    © Copyright 2016 by Annual Reviews. All rights reserved. A drop hitting a solid surface can deposit, bounce, or splash. Splashing arises from the breakup of a fine liquid sheet that is ejected radially along the substrate. Bouncing and deposition depend crucially on the wetting properties of the substrate. In this review, we focus on recent experimental and theoretical studies, which aim at unraveling the underlying physics, characterized by the delicate interplay of not only liquid inertia, viscosity, and surface tension, but also the surrounding gas. The gas cushions the initial contact; it is entrapped in a central microbubble on the substrate; and it promotes the so-called corona splash, by lifting the lamella away from the solid. Particular attention is paid to the influence of surface roughness, natural or engineered to enhance repellency, relevant in many applications.

  19. Effects on energetic impact of atomic clusters with surfaces

    International Nuclear Information System (INIS)

    Popok, V.N.; Vuchkovich, S.; Abdela, A.; Campbell, E.E.B.

    2007-01-01

    A brief state-of-the-art review in the field of cluster ion interaction with surface is presented. Cluster beams are efficient tools for manipulating agglomerates of atoms providing control over the synthesis as well as modification of surfaces on the nm-scale. The application of cluster beams for technological purposes requires knowledge of the physics of cluster-surface impact. This has some significant differences compared to monomer ion - surface interactions. The main effects of cluster-surface collisions are discussed. Recent results obtained in experiments on silicon surface nanostructuring using keV-energy implantation of inert gas cluster ions are presented and compared with molecular dynamics simulations. (authors)

  20. Film Levitation of Droplet Impact on Heated Nanotube Surfaces

    Science.gov (United States)

    Duan, Fei; Tong, Wei; Qiu, Lu

    2017-11-01

    Contact boiling of an impacting droplet impacting on a heated surface can be observed when the surface temperature is able to activate the nucleation and growth of vapor bubbles, the phenomena are related to nature and industrial application. The dynamic boiling patterns us is investigated when a single falling water droplet impacts on a heated titanium (Ti) surface covered with titanium oxide (TiO2) nanotubes. In the experiments, the droplets were generated from a flat-tipped needle connected to a syringe mounted on a syringe pump. The droplet diameter and velocity before impacting on the heated surface are measured by a high-speed camera with the Weber number is varied from 45 to 220. The dynamic wetting length, spreading diameter, levitation distance, and the associated parameter are measured. Interesting film levitation on titanium (Ti) surface has been revealed. The comparison of the phase diagrams on the nanotube surface and bare Ti surface suggests that the dynamic Leidenfrost point of the surface with the TiO2 nanotubes has been significantly delayed as compared to that on a bare Ti surface. The delay is inferred to result from the increase in the surface wettability and the capillary effect by the nanoscale tube structure. The further relation is discussed.

  1. The Cell Surface Estrogen Receptor, G Protein- Coupled Receptor 30 (GPR30, is Markedly Down Regulated During Breast Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Indira Poola

    2008-01-01

    Full Text Available Background: GPR30 is a cell surface estrogen receptor that has been shown to mediate a number of non-genomic rapid effects of estrogen and appear to balance the signaling of estrogen and growth factors. In addition, progestins appear to use GPR30 for their actions. Therefore, GPR30 could play a critical role in hormonal regulation of breast epithelial cell integrity. Deregulation of the events mediated by GPR30 could contribute to tumorigenesis.Methods: To understand the role of GPR30 in the deregulation of estrogen signaling processes during breast carcinogenesis, we have undertaken this study to investigate its expression at mRNA levels in tumor tissues and their matched normal tissues. We compared its expression at mRNA levels by RT quantitative real-time PCR relative to GAPDH in ERα”—positive (n = 54 and ERα”—negative (n = 45 breast cancer tissues to their matched normal tissues.Results: We report here, for the first time, that GPR30 mRNA levels were significantly down-regulated in cancer tissues in comparison with their matched normal tissues (p 0.0001 by two sided paired t-test. The GPR30 expression levels were significantly lower in tumor tissues from patients (n = 29 who had lymph node metastasis in comparison with tumors from patients (n = 53 who were negative for lymph node metastasis (two sample t-test, p 0.02, but no association was found with ERα, PR and other tumor characteristics.Conclusions: Down-regulation of GPR30 could contribute to breast tumorigenesis and lymph node metastasis.

  2. Economic Impacts of Surface Mining on Household Drinking Water Supplies

    Science.gov (United States)

    This report provides information on the economic and social impacts of contaminated surface and ground water supplies on residents and households near surface mining operations. The focus is on coal slurry contamination of water supplies in Mingo County, West Virginia, and descr...

  3. Droplet impact on superheated micro-structured surfaces

    NARCIS (Netherlands)

    Tran, Tuan; Staat, Erik-Jan; Susarrey Arce, A.; Foertsch, T.C.; van Houselt, Arie; Gardeniers, Johannes G.E.; Prosperetti, Andrea; Lohse, Detlef; Sun, Chao

    2013-01-01

    When a droplet impacts upon a surface heated above the liquid's boiling point, the droplet either comes into contact with the surface and boils immediately (contact boiling), or is supported by a developing vapor layer and bounces back (film boiling, or Leidenfrost state). We study the transition

  4. Environmental impact of by pass channel of surface waters

    International Nuclear Information System (INIS)

    Vismara, R.; Renoldi, M.; Torretta, V.

    1996-01-01

    In this paper are analyzed the impacts generated by surface waters drawing on river course. This impacts are generated also by reduction of water flow. This effect is most important for the presence of biological community: algae, fiches, micro invertebrates. Are also reported regional laws, water master plan of Lombardia region

  5. Initial surface deformations during impact on a liquid pool

    NARCIS (Netherlands)

    Bouwhuis, W.; Hendrix, M.H.W.; van der Meer, Roger M.; Snoeijer, Jacobus Hendrikus

    2015-01-01

    A tiny air bubble can be entrapped at the bottom of a solid sphere that impacts onto a liquid pool. The bubble forms due to the deformation of the liquid surface by a local pressure buildup inside the surrounding gas, as also observed during the impact of a liquid drop on a solid wall. Here, we

  6. Bubble entrapment during sphere impact onto quiescent liquid surfaces

    KAUST Repository

    Marston, Jeremy; Vakarelski, Ivan Uriev; Thoroddsen, Sigurdur T

    2011-01-01

    We report observations of air bubble entrapment when a solid sphere impacts a quiescent liquid surface. Using high-speed imaging, we show that a small amount of air is entrapped at the bottom tip of the impacting sphere. This phenomenon is examined

  7. The impact of runoff and surface hydrology on Titan's climate

    Science.gov (United States)

    Faulk, Sean; Lora, Juan; Mitchell, Jonathan

    2017-10-01

    Titan’s surface liquid distribution has been shown by general circulation models (GCMs) to greatly influence the hydrological cycle. Simulations from the Titan Atmospheric Model (TAM) with imposed polar methane “wetlands” reservoirs realistically produce many observed features of Titan’s atmosphere, whereas “aquaplanet” simulations with a global methane ocean are not as successful. In addition, wetlands simulations, unlike aquaplanet simulations, demonstrate strong correlations between extreme rainfall behavior and observed geomorphic features, indicating the influential role of precipitation in shaping Titan’s surface. The wetlands configuration is, in part, motivated by Titan’s large-scale topography featuring low-latitude highlands and high-latitude lowlands, with the implication being that methane may concentrate in the high-latitude lowlands by way of runoff and subsurface flow. However, the extent to which topography controls the surface liquid distribution and thus impacts the global hydrological cycle by driving surface and subsurface flow is unclear. Here we present TAM simulations wherein the imposed wetlands reservoirs are replaced by a surface runoff scheme that allows surface liquid to self-consistently redistribute under the influence of topography. To isolate the singular impact of surface runoff on Titan’s climatology, we run simulations without parameterizations of subsurface flow and topography-atmosphere interactions. We discuss the impact of surface runoff on the surface liquid distribution over seasonal timescales and compare the resulting hydrological cycle to observed cloud and surface features, as well as to the hydrological cycles of the TAM wetlands and aquaplanet simulations. While still idealized, this more realistic representation of Titan’s hydrology provides new insight into the complex interaction between Titan’s atmosphere and surface, demonstrates the influence of surface runoff on Titan’s global climate

  8. Impact of lithospheric rheology on surface topography

    Science.gov (United States)

    Liao, K.; Becker, T. W.

    2017-12-01

    The expression of mantle flow such as due to a buoyant plume as surface topography is a classical problem, yet the role of rheological complexities could benefit from further exploration. Here, we investigate the topographic expressions of mantle flow by means of numerical and analytical approaches. In numerical modeling, both conventional, free-slip and more realistic, stress-free boundary conditions are applied. For purely viscous rheology, a high viscosity lithosphere will lead to slight overestimates of topography for certain settings, which can be understood by effectively modified boundary conditions. Under stress-free conditions, numerical and analytical results show that the magnitude of dynamic topography decreases with increasing lithosphere thickness (L) and viscosity (ηL), as L-1 and ηL-3. The wavelength of dynamic topography increases linearly with L and (ηL/ ηM) 1/3. We also explore the time-dependent interactions of a rising plume with the lithosphere. For a layered lithosphere with a decoupling weak lower crust embedded between stronger upper crust and lithospheric mantle, dynamic topography increases with a thinner and weaker lower crust. The dynamic topography saturates when the decoupling viscosity is 3-4 orders lower than the viscosity of upper crust and lithospheric mantle. We further explore the role of visco-elastic and visco-elasto-plastic rheologies.

  9. Stratospheric Impact of Varying Sea Surface Temperatures

    Science.gov (United States)

    Newman, Paul A.; Nash, Eric R.; Nielsen, Jon E.; Waugh, Darryn; Pawson, Steven

    2004-01-01

    The Finite-Volume General Circulation Model (FVGCM) has been run in 50 year simulations with the: 1) 1949-1999 Hadley Centre sea surface temperatures (SST), and 2) a fixed annual cycle of SSTs. In this presentation we first show that the 1949-1999 FVGCM simulation produces a very credible stratosphere in comparison to an NCEP/NCAR reanalysis climatology. In particular, the northern hemisphere has numerous major and minor stratospheric warming, while the southern hemisphere has only a few over the 50-year simulation. During the northern hemisphere winter, temperatures are both warmer in the lower stratosphere and the polar vortex is weaker than is found in the mid-winter southern hemisphere. Mean temperature differences in the lower stratosphere are shown to be small (less than 2 K), and planetary wave forcing is found to be very consistent with the climatology. We then will show the differences between our varying SST simulation and the fixed SST simulation in both the dynamics and in two parameterized trace gases (ozone and methane). In general, differences are found to be small, with subtle changes in planetary wave forcing that lead to reduced temperatures in the SH and increased temperatures in the NH.

  10. Marked augmentation of PLGA nanoparticle-induced metabolically beneficial impact of γ-oryzanol on fuel dyshomeostasis in genetically obese-diabetic ob/ob mice.

    Science.gov (United States)

    Kozuka, Chisayo; Shimizu-Okabe, Chigusa; Takayama, Chitoshi; Nakano, Kaku; Morinaga, Hidetaka; Kinjo, Ayano; Fukuda, Kotaro; Kamei, Asuka; Yasuoka, Akihito; Kondo, Takashi; Abe, Keiko; Egashira, Kensuke; Masuzaki, Hiroaki

    2017-11-01

    Our previous works demonstrated that brown rice-specific bioactive substance, γ-oryzanol acts as a chaperone, attenuates exaggerated endoplasmic reticulum (ER) stress in brain hypothalamus and pancreatic islets, thereby ameliorating metabolic derangement in high fat diet (HFD)-induced obese diabetic mice. However, extremely low absorption efficiency from intestine of γ-oryzanol is a tough obstacle for the clinical application. Therefore, in this study, to overcome extremely low bioavailability of γ-oryzanol with super-high lipophilicity, we encapsulated γ-oryzanol in polymer poly (DL-lactide-co-glycolide) (PLGA) nanoparticles (Nano-Orz), and evaluated its metabolically beneficial impact in genetically obese-diabetic ob/ob mice, the best-known severest diabetic model in mice. To our surprise, Nano-Orz markedly ameliorated fuel metabolism with an unexpected magnitude (∼1000-fold lower dose) compared with regular γ-oryzanol. Furthermore, such a conspicuous impact was achievable by its administration once every 2 weeks. Besides the excellent impact on dysfunction of hypothalamus and pancreatic islets, Nano-Orz markedly decreased ER stress and inflammation in liver and adipose tissue. Collectively, nanotechnology-based developments of functional foods oriented toward γ-oryzanol shed light on the novel approach for the treatment of a variety of metabolic diseases in humans.

  11. A patterned abrasion caused by the impact of a cartridge case may simulate an atypical muzzle imprint mark.

    Science.gov (United States)

    Kramer, Lena; Nadjem, Hadi; Glardon, Matthieu; Kneubuehl, Beat P; Pollak, Stefan; Große Perdekamp, Markus; Pircher, Rebecca

    2016-05-01

    In contact shots, the muzzle imprint is an informative finding associated with the entrance wound. It typically mirrors the constructional components being in line with the muzzle or just behind. Under special conditions, other patterned skin marks located near a gunshot entrance wound may give the impression to be part of the muzzle imprint. A potential mechanism causing a patterned pressure abrasion in close proximity to the bullet entrance site is demonstrated on the basis of a suicidal shot to the temple. The skin lesion in question appeared as a ring-shaped excoriation with a diameter corresponding to that of the cartridge case. Two hypotheses concerning the causative mechanism were investigated by test shots: - After being ejected, the cartridge case ricocheted inside a confined space (car cabin in the particular case) and secondarily hit the skin near the gunshot entrance wound. - The ejection of the cartridge case failed so that the case became stuck in the ejection port and its mouth contacted the skin when the body collapsed after being hit.

  12. Short-term hurricane impacts on a neotropical community of marked birds and implications for early-stage community resilience.

    Science.gov (United States)

    Johnson, Andrew B; Winker, Kevin

    2010-11-30

    Populations in fragmented ecosystems risk extirpation through natural disasters, which must be endured rather than avoided. Managing communities for resilience is thus critical, but details are sketchy about the capacity for resilience and its associated properties in vertebrate communities. We studied short-term resilience in a community of individually marked birds, following this community through the catastrophic destruction of its forest habitat by Hurricane Iris in Belize, Central America. We sampled for 58 d immediately before the storm, 28 d beginning 11 d after Hurricane Iris, and for 69 d approximately one year later. Our data showed that the initial capacity for resilience was strong. Many banded individuals remained after the storm, although lower post-hurricane recapture rates revealed increased turnover among individuals. Changes occurred in community dynamics and in abundances among species and guilds. Survivors and immigrants both were critical components of resilience, but in a heterogeneous, species-specific manner. Delayed effects, including higher fat storage and increased species losses, were evident one year later.

  13. Environmental impact assessment for surface coal mine - a case study

    International Nuclear Information System (INIS)

    Sen, P.; Chakraborty, K.

    1994-01-01

    Surface coal mines being the largest contributor to the national coal production, the study of environmental impacts due to this becomes mandatory as it will help in proper planning and safe operations of the mine in an environmentally compatible manner. Within the scope of this paper, a model for preparation of comprehensive environmental impact assessment (EIA) by utilising a new evaluation methodology leading to determination of Environmental Quality Designation an index has been developed and this model has been validated by using data from a running surface coal mine in Wardha Valley Coalfield. Based on this exercise, the overall impact of the surface coal mine under consideration on environment indicates a medium level and accordingly the control measures have to be planned. Thus repair to the environment has to be made a concurrent activity with mining i.e. to say we have to design with nature not against it

  14. The air bubble entrapped under a drop impacting on a solid surface

    Science.gov (United States)

    Thoroddsen, S. T.; Etoh, T. G.; Takehara, K.; Ootsuka, N.; Hatsuki, Y.

    2005-12-01

    We present experimental observations of the disk of air caught under a drop impacting onto a solid surface. By imaging the impact through an acrylic plate with an ultra-high-speed video camera, we can follow the evolution of the air disk as it contracts into a bubble under the centre of the drop. The initial size and contraction speed of the disk were measured for a range of impact Weber and Reynolds numbers. The size of the initial disk is related to the bottom curvature of the drop at the initial contact, as measured in free-fall. The initial contact often leaves behind a ring of micro-bubbles, marking its location. The air disk contracts at a speed comparable to the corresponding air disks caught under a drop impacting onto a liquid surface. This speed also seems independent of the wettability of the liquid, which only affects the azimuthal shape of the contact line. For some impact conditions, the dynamics of the contraction leaves a small droplet at the centre of the bubble. This arises from a capillary wave propagating from the edges of the contracting disk towards the centre. As the wave converges its amplitude grows until it touches the solid substrate, thereby pinching off the micro-droplet at the plate, in the centre of the bubble. The effect of increasing liquid viscosity is to slow down the contraction speed and to produce a more irregular contact line leaving more micro-bubbles along the initial ring.

  15. Underground coal mine subsidence impacts on surface water

    International Nuclear Information System (INIS)

    Stump, D.E. Jr.

    1992-01-01

    This paper reports that subsidence from underground coal mining alters surface water discharge and availability. The magnitude and areal extent of these impacts are dependent on many factors, including the amount of subsidence, topography, geology, climate, surface water - ground water interactions, and fractures in the overburden. There alterations may have positive and/or negative impacts. One of the most significant surface water impacts occurred in July 1957 near West Pittston, Pennsylvania. Subsidence in the Knox Mine under the Coxton Yards of the Lehigh Valley Railroad allowed part of the discharge in the Susquehanna River to flow into the mine and create a crater 200 feet in diameter and 300 feet deep. Fourteen railroad gondola cars fell into the hole which was eventually filled with rock, sand, and gravel. Other surface water impacts from subsidence may include the loss of water to the ground water system, the gaining of water from the ground water system, the creation of flooded subsidence troughs, the increasing of impoundment storage capacity, the relocation of water sources (springs), and the alteration of surface drainage patterns

  16. Numerical study of droplet impact and rebound on superhydrophobic surface

    Science.gov (United States)

    Cai, Xuan; Wu, Yanchen; Woerner, Martin; Frohnapfel, Bettina

    2017-11-01

    Droplet impact and rebound on superhydrophobic surface is an important process in many applications; among them are developing self-cleaning or anti-icing materials and limiting liquid film formation of Diesel Exhaust Fluid (DEF) in exhaust gas pipe. In the latter field, rebound of DEF droplet from wall is desired as an effective mean for avoiding or reducing unwanted solid deposition. Our goal is to numerically study influence of surface wettability on DEF droplet impact and rebound behavior. A phase-field method is chosen, which was implemented in OpenFOAM by us and validated for wetting-related interfacial flow problems. In the present contribution we first numerically reproduce relevant experimental studies in literature, to validate the code for droplet impact and rebound problem. There we study droplet-surface contact time, maximum/instantaneous spreading factor and droplet shape evolution. Our numerical results show good agreement with experimental data. Next we investigate for DEF droplets the effects of diameter, impact velocity and surface wettability on rebound behavior and jumping height. Based on Weber number and equilibrium contact angle, two regimes are identified. We show that surface wettability is a deciding factor for achieving rebound event. This work is supported by Foundation ``Friedrich-und-Elisabeth Boysen Stiftung fuer Forschung und Innovation'' (BOY-127-TP1).

  17. Experimental study of liquid drop impact onto a powder surface

    KAUST Repository

    Marston, Jeremy; Thoroddsen, Sigurdur T; Ng, Waikiong; Tan, Reginald

    2010-01-01

    The initial dynamics of liquid drop impact onto powder surfaces is studied experimentally using high-speed photography. For a range of bed packing fractions, φ, liquid physical properties and impact velocities, ui, we observe a variety of phenomena that can be representative of a hydrophobic surface, a rough surface or a porous medium. The solids packing fraction in the bed, 0.38≤φ≤0.65, and the impact Weber number, 3.5≤We=ρDui 2/φ≤750, (where ρ, D and φ are the drop density, diameter and surface tension respectively) are shown to be the critical parameters governing the outcome of an impact. For high packing fractions, φ≳0.5, we show that the observed spreading, rebound and splashing can be broadly characterised in terms of the Weber number while for looser packing fractions, φ≲0.5, we observe powder ejectas and provide a qualitative description of the granule nucleation at the centre of the impact sites. © 2010 Elsevier B.V.

  18. Experimental study of liquid drop impact onto a powder surface

    KAUST Repository

    Marston, Jeremy

    2010-11-01

    The initial dynamics of liquid drop impact onto powder surfaces is studied experimentally using high-speed photography. For a range of bed packing fractions, φ, liquid physical properties and impact velocities, ui, we observe a variety of phenomena that can be representative of a hydrophobic surface, a rough surface or a porous medium. The solids packing fraction in the bed, 0.38≤φ≤0.65, and the impact Weber number, 3.5≤We=ρDui 2/φ≤750, (where ρ, D and φ are the drop density, diameter and surface tension respectively) are shown to be the critical parameters governing the outcome of an impact. For high packing fractions, φ≳0.5, we show that the observed spreading, rebound and splashing can be broadly characterised in terms of the Weber number while for looser packing fractions, φ≲0.5, we observe powder ejectas and provide a qualitative description of the granule nucleation at the centre of the impact sites. © 2010 Elsevier B.V.

  19. Effects of pulsating water jet impact on aluminium surface

    Czech Academy of Sciences Publication Activity Database

    Foldyna, Josef; Sitek, Libor; Ščučka, Jiří; Martinec, Petr; Valíček, Jan; Páleníková, K.

    2009-01-01

    Roč. 2009, č. 20 (2009), s. 6174-6180 ISSN 0924-0136 R&D Projects: GA ČR GA101/07/1451; GA ČR GP101/07/P512 Institutional research plan: CEZ:AV0Z30860518 Keywords : pulsating water jet * jet impact * material erosion * surface characteristics Subject RIV: JQ - Machines ; Tools Impact factor: 1.420, year: 2009 http://www.sciencedirect.com/science

  20. Bubble entrapment during sphere impact onto quiescent liquid surfaces

    KAUST Repository

    Marston, Jeremy

    2011-06-20

    We report observations of air bubble entrapment when a solid sphere impacts a quiescent liquid surface. Using high-speed imaging, we show that a small amount of air is entrapped at the bottom tip of the impacting sphere. This phenomenon is examined across a broad range of impact Reynolds numbers, 0.2 a Re = (DU0/Il) a 1.2\\' 105. Initially, a thin air pocket is formed due to the lubrication pressure in the air layer between the sphere and the liquid surface. As the liquid surface deforms, the liquid contacts the sphere at a finite radius, producing a thin sheet of air which usually contracts to a nearly hemispherical bubble at the bottom tip of the sphere depending on the impact parameters and liquid properties. When a bubble is formed, the final bubble size increases slightly with the sphere diameter, decreases with impact speed but appears independent of liquid viscosity. In contrast, for the largest viscosities tested herein, the entrapped air remains in the form of a sheet, which subsequently deforms upon close approach to the base of the tank. The initial contact diameter is found to conform to scalings based on the gas Reynolds number whilst the initial thickness of the air pocket or adimplea scales with a Stokes\\' number incorporating the influence of the air viscosity, sphere diameter and impact speed and liquid density. © 2011 Cambridge University Press.

  1. Axisymmetric Lattice Boltzmann Model of Droplet Impact on Solid Surfaces

    Science.gov (United States)

    Dalgamoni, Hussein; Yong, Xin

    2017-11-01

    Droplet impact is a ubiquitous fluid phenomena encountered in scientific and engineering applications such as ink-jet printing, coating, electronics manufacturing, and many others. It is of great technological importance to understand the detailed dynamics of drop impact on various surfaces. The lattice Boltzmann method (LBM) emerges as an efficient method for modeling complex fluid systems involving rapidly evolving fluid-fluid and fluid-solid interfaces with complex geometries. In this work, we model droplet impact on flat solid substrates with well-defined wetting behavior using a two-phase axisymmetric LBM with high density and viscosity contrasts. We extend the two-dimensional Lee and Liu model to capture axisymmetric effect in the normal impact. First we compare the 2D axisymmetric results with the 2D and 3D results reported by Lee and Liu to probe the effect of axisymmetric terms. Then, we explore the effects of Weber number, Ohnesorge number, and droplet-surface equilibrium contact angle on the impact. The dynamic contact angle and spreading factor of the droplet during impact are investigated to qualitatively characterize the impact dynamics.

  2. Characteristics of Eurasian snowmelt and its impacts on the land surface and surface climate

    Science.gov (United States)

    Ye, Kunhui; Lau, Ngar-Cheung

    2018-03-01

    The local hydrological and climatic impacts of Eurasian snowmelt are studied using advanced land surface and atmospheric data. It is found that intense melting of snow is located at mid-high latitudes in April and May. Snowmelt plays an important role in determining the seasonal cycles of surface runoff and soil moisture (SM). Specifically, melting is accompanied by sharp responses in surface runoff and surface SM while the impacts are delayed for deeper-layer of soil. This is particularly significant in the western sector of Eurasia. On interannual timescales, the responses of various surface parameters to snowmelt in the same month are rather significant. However, the persistence of surface SM anomalies is weak due to the strong soil evaporation anomalies and surplus of surface energy for evaporation. Strong impacts on the sensible heat flux, planetary boundary layer height and precipitation in the next month following the melting of snow are identified in west Russia and Siberia. Downward propagation of surface SM anomalies is observed and a positive evaporation-convection feedback is identified in west Russia. However, the subsequent impacts on the local convective precipitation in late spring-summer and its contribution to the total precipitation are seemingly weak. The atmospheric water vapor convergence has strong control over the total precipitation anomalies. Overall, snowmelt-produced SM anomalies are not found to significantly impact the late spring-summer local climate anomalies in Northern Eurasia. Therefore, the delayed remote-responses of atmospheric circulation and climate to the melting of Eurasian snow may be only possible near the melting period.

  3. NotaMark industrial laser marking system: a new security marking technology

    Science.gov (United States)

    Moreau, Vincent G.

    2004-06-01

    Up until now, the only variable alphanumeric data which could be added to banknotes was the number, applied by means of impact typographical numbering boxes. As an additional process or an alternative to this mechanical method, a non-contact laser marking process can be used offering high quality and greater levels of flexibility. For this purpose KBA-GIORI propose an exclusive laser marking solution called NotaMark. The laser marking process NotaMark is the ideal solution for applying variable data and personalizing banknotes (or any other security documents) with a very high resolution, for extremely large production volumes. A completely integrated solution has been developed comprised of laser light sources, marking head units, and covers and extraction systems. NotaMark allows the marking of variable data by removing locally and selectively, specific printed materials leaving the substrate itself untouched. A wide range of materials has already been tested extensively. NotaMark is a new security feature which is easy to identify and difficult to counterfeit, and which complies with the standard mechanical and chemical resistance tests in the security printing industry as well as with other major soiling tests. The laser marking process opens up a whole new range of design possibilities and can be used to create a primary security feature such as numbering, or to enhance the value of existing features.

  4. The Impact Of Surface Shape Of Chip-Breaker On Machined Surface

    Science.gov (United States)

    Šajgalík, Michal; Czán, Andrej; Martinček, Juraj; Varga, Daniel; Hemžský, Pavel; Pitela, David

    2015-12-01

    Machined surface is one of the most used indicators of workpiece quality. But machined surface is influenced by several factors such as cutting parameters, cutting material, shape of cutting tool or cutting insert, micro-structure of machined material and other known as technological parameters. By improving of these parameters, we can improve machined surface. In the machining, there is important to identify the characteristics of main product of these processes - workpiece, but also the byproduct - the chip. Size and shape of chip has impact on lifetime of cutting tools and its inappropriate form can influence the machine functionality and lifetime, too. This article deals with elimination of long chip created when machining of shaft in automotive industry and with impact of shape of chip-breaker on shape of chip in various cutting conditions based on production requirements.

  5. Impact of initial surface parameters on the final quality of laser micro-polished surfaces

    Science.gov (United States)

    Chow, Michael; Bordatchev, Evgueni V.; Knopf, George K.

    2012-03-01

    Laser micro-polishing (LμP) is a new laser-based microfabrication technology for improving surface quality during a finishing operation and for producing parts and surfaces with near-optical surface quality. The LμP process uses low power laser energy to melt a thin layer of material on the previously machined surface. The polishing effect is achieved as the molten material in the laser-material interaction zone flows from the elevated regions to the local minimum due to surface tension. This flow of molten material then forms a thin ultra-smooth layer on the top surface. The LμP is a complex thermo-dynamic process where the melting, flow and redistribution of molten material is significantly influenced by a variety of process parameters related to the laser, the travel motions and the material. The goal of this study is to analyze the impact of initial surface parameters on the final surface quality. Ball-end micromilling was used for preparing initial surface of samples from H13 tool steel that were polished using a Q-switched Nd:YAG laser. The height and width of micromilled scallops (waviness) were identified as dominant parameter affecting the quality of the LμPed surface. By adjusting process parameters, the Ra value of a surface, having a waviness period of 33 μm and a peak-to-valley value of 5.9 μm, was reduced from 499 nm to 301 nm, improving the final surface quality by 39.7%.

  6. Impact of indoor surface material on perceived air quality.

    Science.gov (United States)

    Senitkova, I

    2014-03-01

    The material combination impact on perceived indoor air quality for various surface interior materials is presented in this paper. The chemical analysis and sensory assessments identifies health adverse of indoor air pollutants (TVOCs). In this study, emissions and odors from different common indoor surface materials were investigated in glass test chamber under standardized conditions. Chemical measurements (TVOC concentration) and sensory assessments (odor intensity, air acceptability) were done after building materials exposure to standardized conditions. The results of the chemical and sensory assessment of individual materials and their combinations are compared and discussed within the paper. The using possibility of individual material surface sorption ability was investigated. The knowledge of targeted sorption effects can be used in the interior design phase. The results demonstrate the various sorption abilities of various indoor materials as well as the various sorption abilities of the same indoor material in various combinations. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Drop Impact of Viscous Suspensions on Solid Surfaces

    Science.gov (United States)

    Bolleddula, Daniel; Aliseda, Alberto

    2009-11-01

    Droplet impact is a well studied subject with over a century of progress. Most studies are motivated by applications such as inkjet printing, agriculture spraying, or printed circuit boards. Pharmaceutically relevant fluids provide an experimental set that has received little attention. Medicinal tablets are coated by the impaction of micron sized droplets of aqueous suspensions and subsequently dried for various purposes such as brand recognition, mask unpleasant taste, or functionality. We will present a systematic study of micron sized drop impact of Newtonian and Non-Newtonian fluids used in pharmaceutical coating processes. In our experiments we extend the range of Ohnesorge numbers, O(1), of previous studies on surfaces of varying wettability and roughness.

  8. Communication: Methane dissociation on Ni(111) surface: Importance of azimuth and surface impact site

    International Nuclear Information System (INIS)

    Shen, Xiangjian; Zhang, Zhaojun; Zhang, Dong H.

    2016-01-01

    Understanding the role of reactant ro-vibrational degrees of freedom (DOFs) in reaction dynamics of polyatomic molecular dissociation on metal surfaces is of great importance to explore the complex chemical reaction mechanism. Here, we present an expensive quantum dynamics study of the dissociative chemisorption of CH 4 on a rigid Ni(111) surface by developing an accurate nine-dimensional quantum dynamical model including the DOF of azimuth. Based on a highly accurate fifteen-dimensional potential energy surface built from first principles, our simulations elucidate that the dissociation probability of CH 4 has the strong dependence on azimuth and surface impact site. Some improvements are suggested to obtain the accurate dissociation probability from quantum dynamics simulations.

  9. Ion Production by Laser Impact on a Silver Surface

    DEFF Research Database (Denmark)

    Christensen, Bo Toftmann; Schou, Jørgen

    Even at moderate fluence (0.6 -2.4 J/cm2) laser impact on metals in the UV regime results in a significant number of ions emitted from the surface. Even at this low fluence the particles ejected from a surface interact with each other in a so-called laser ablation plume. The ablated particles...... are largely neutrals at low fluence, but the fraction of ions increases strongly with fluence. We have irradiated silver in a vacuum chamber (~ 10-7 mbar) with a Nd:YAG laser at a wavelength of 355 nm. The ion flow in different directions has been measured with a hemispherical array of Langmuir probes...... range considered is also a typical range for pulsed laser deposition (PLD), by which the material is collected on a suitable substrate for thin film growth. PLD has the advantage compared with other film deposition methods, that even a complicated stoichiometry, e.g. metal oxides or alloys, can...

  10. Impacts of Cosmic Dust on Planetary Atmospheres and Surfaces

    Science.gov (United States)

    Plane, John M. C.; Flynn, George J.; Määttänen, Anni; Moores, John E.; Poppe, Andrew R.; Carrillo-Sanchez, Juan Diego; Listowski, Constantino

    2018-02-01

    Recent advances in interplanetary dust modelling provide much improved estimates of the fluxes of cosmic dust particles into planetary (and lunar) atmospheres throughout the solar system. Combining the dust particle size and velocity distributions with new chemical ablation models enables the injection rates of individual elements to be predicted as a function of location and time. This information is essential for understanding a variety of atmospheric impacts, including: the formation of layers of metal atoms and ions; meteoric smoke particles and ice cloud nucleation; perturbations to atmospheric gas-phase chemistry; and the effects of the surface deposition of micrometeorites and cosmic spherules. There is discussion of impacts on all the planets, as well as on Pluto, Triton and Titan.

  11. Laser marking method and device

    International Nuclear Information System (INIS)

    Okazaki, Yuki; Aoki, Nobutada; Mukai, Narihiko; Sano, Yuji; Yamamoto, Seiji.

    1997-01-01

    An object is disposed in laser beam permeating liquid or gaseous medium. Laser beams such as CW laser or pulse laser oscillated from a laser device are emitted to the object to apply laser markings with less degradation of identification and excellent corrosion resistance on the surface of the object simply and easily. Upon applying the laser markings, a liquid or gas as a laser beam permeating medium is blown onto the surface of the object, or the liquid or gas in the vicinity of the object is sucked, the laser beam-irradiated portion on the surface can be cooled positively. Accordingly, the laser marking can be formed on the surface of the object with less heat affection to the object. In addition, if the content of a nitrogen gas in the laser beam permeating liquid medium is reduced by degassing to lower than a predetermined value, or the laser beam permeating gaseous medium is formed by an inert gas, a laser marking having high corrosion resistance and reliability can be formed on the surface of the objective member. (N.H.)

  12. Impacts of thermal and chemical discharges to surface water

    International Nuclear Information System (INIS)

    Stober, Q.J.

    1974-01-01

    Various aspects of thermal and chemical discharges to surface water are outlined. The major impacts of nuclear power plants on aquatic resources are disruption during construction, intake of cooling water, discharge problems, and interactions with other water users. The following topics are included under the heading, assessment of aquatic ecology: identification of flora and fauna; abundance of aquatic organisms; species-environment relationships; and identification of pre-existing environmental stress. The following topics are included under the heading, environmental effects of plant operation: entrapment of fish by cooling water; passage of plankton through cooling system; discharge area and thermal plume; chemical effluents; and plant construction. (U.S.)

  13. Assessment of the impact of underground mining on ground surface

    International Nuclear Information System (INIS)

    Toomik, Arvi

    1999-01-01

    The mine able oil shale bed is located in horizontally lying Ordovician limestones at a depth of 10-60 meters from the ground surface. Limestones are covered with Quaternary sediments, mainly till and loam, sporadically seams of clay occur. The overburden rocks of oil shale bed are jointed limestones with weak contacts between layers. The upper part of limestones is weakened additionally due to weathering to depths of 10-20 metres. Ground movements caused by mining reach the ground surface easily due to the shallow location of workings. The size and nature of these movements depend on mining and roof control methods used. In this study the impact of geotechnical processes on the ground surface caused by four different mining methods is analysed. A new, artificial micro relief is formed on undermined areas, where the ground surface depressions are alternating with rising grounds. When the Quaternary cover contains loamy sediments, the surface (rain) water will accumulate in the depressions. The response of usable lands on undermined areas depends on the degree of changes in the relief and water regime. There exists a maximum degree (limit) of changes of ground movements in case of which the changes in land use are not yet considerable. The factor of land deterioration was developed for arable and forest lands taking into account the character and degree of negative impacts. When no one deterioration factor exceeds the limit, the value of arable land will be 1.0 (100%). When some factor exceeds the limit, then water logging in subsidence troughs will diminish the value to 0.7, slopes to 0.8 and the area of weathered basic rocks to 0.9. In case of a combined effect of all these factors the value of arable land will fall to 0.5. As the long-term character of ground movement after room and pillar mining is not yet established, the factor for quasi stable areas is taken preliminarily as 0.9. Using detailed plans of mined out areas and the proposed factors, it is possible

  14. Coil Tolerance Impact on Plasma Surface Quality for NCSX

    International Nuclear Information System (INIS)

    Brooks, Art; Reiersen, Wayne

    2003-01-01

    The successful operation of the National Compact Stellarator Experiment (NCSX) machine will require producing plasma configurations with good flux surfaces, with a minimum volume of the plasma lost to magnetic islands or stochastic regions. The project goal is to achieve good flux surfaces over 90% of the plasma volume. NCSX is a three period device designed to be operated with iota ranging from ∼0.4 on axis to ∼0.7 at the edge. The field errors of most concern are those that are resonant with 3/5 and 3/6 modes (for symmetry preserving field errors) and the 1/2 and 2/3 modes (for symmetry breaking field errors). In addition to losses inherent in the physics configuration itself, there will be losses from field errors arising from coil construction and assembly errors. Some of these losses can be recovered through the use of trim coils or correction coils. The impact of coil tolerances on plasma surface quality is evaluated herein for the NCSX design. The methods used in this evaluation are discussed. The ability of the NCSX trim coils to correct for field errors is also examined. The results are used to set coils tolerances for the various coil systems

  15. The hydrodynamics of bubble rise and impact with solid surfaces.

    Science.gov (United States)

    Manica, Rogerio; Klaseboer, Evert; Chan, Derek Y C

    2016-09-01

    A bubble smaller than 1mm in radius rises along a straight path in water and attains a constant speed due to the balance between buoyancy and drag force. Depending on the purity of the system, within the two extreme limits of tangentially immobile or mobile boundary conditions at the air-water interface considerably different terminal speeds are possible. When such a bubble impacts on a horizontal solid surface and bounces, interesting physics can be observed. We study this physical phenomenon in terms of forces, which can be of colloidal, inertial, elastic, surface tension and viscous origins. Recent advances in high-speed photography allow for the observation of phenomena on the millisecond scale. Simultaneous use of such cameras to visualize both rise/deformation and the dynamics of the thin film drainage through interferometry are now possible. These experiments confirm that the drainage process obeys lubrication theory for the spectrum of micrometre to millimetre-sized bubbles that are covered in this review. We aim to bridge the colloidal perspective at low Reynolds numbers where surface forces are important to high Reynolds number fluid dynamics where the effect of the surrounding flow becomes important. A model that combines a force balance with lubrication theory allows for the quantitative comparison with experimental data under different conditions without any fitting parameter. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. The impact of aminated surface ligands and silica shells on the stability, uptake, and toxicity of engineered silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bonventre, Josephine A.; Pryor, Joseph B.; Harper, Bryan J.; Harper, Stacey L., E-mail: stacey.harper@oregonstate.edu [Oregon State University, Department of Environmental and Molecular Toxicology (United States)

    2014-12-15

    Inherent nanomaterial characteristics, composition, surface chemistry, and primary particle size, are known to impact particle stability, uptake, and toxicity. Nanocomposites challenge our ability to predict nanoparticle reactivity in biological systems if they are composed of materials with contrasting relative toxicities. We hypothesized that toxicity would be dominated by the nanoparticle surface (shell vs core), and that modulating the surface ligands would have a direct impact on uptake. We exposed developing zebrafish (Danio rerio) to a series of ∼70 nm amine-terminated silver nanoparticles with silica shells (AgSi NPs) to investigate the relative influence of surface amination, composition, and size on toxicity. Like-sized aminated AgSi and Si NPs were more toxic than paired hydroxyl-terminated nanoparticles; however, both AgSi NPs were more toxic than the Si NPs, indicating a significant contribution of the silver core to the toxicity. Incremental increases in surface amination did not linearly increase uptake and toxicity, but did have a marked impact on dispersion stability. Mass-based exposure metrics initially supported the hypothesis that smaller nanoparticles (20 nm) would be more toxic than larger particles (70 nm). However, surface area-based metrics revealed that toxicity was independent of size. Our studies suggest that nanoparticle surfaces play a critical role in the uptake and toxicity of AgSi NPs, while the impact of size may be a function of the exposure metric used. Overall, uptake and toxicity can be dramatically altered by small changes in surface functionalization or exposure media. Only after understanding the magnitude of these changes, can we begin to understand the biologically available dose following nanoparticle exposure.

  17. Climate Impacts of Fire-Induced Land-Surface Changes

    Science.gov (United States)

    Liu, Y.; Hao, X.; Qu, J. J.

    2017-12-01

    One of the consequences of wildfires is the changes in land-surface properties such as removal of vegetation. This will change local and regional climate through modifying the land-air heat and water fluxes. This study investigates mechanism by developing and a parameterization of fire-induced land-surface property changes and applying it to modeling of the climate impacts of large wildfires in the United States. Satellite remote sensing was used to quantitatively evaluate the land-surface changes from large fires provided from the Monitoring Trends in Burning Severity (MTBS) dataset. It was found that the changes in land-surface properties induced by fires are very complex, depending on vegetation type and coverage, climate type, season and time after fires. The changes in LAI are remarkable only if the actual values meet a threshold. Large albedo changes occur in winter for fires in cool climate regions. The signs are opposite between the first post-fire year and the following years. Summer day-time temperature increases after fires, while nigh-time temperature changes in various patterns. The changes are larger in forested lands than shrub / grassland lands. In the parameterization scheme, the detected post-fire changes are decomposed into trends using natural exponential functions and fluctuations of periodic variations with the amplitudes also determined by natural exponential functions. The final algorithm is a combination of the trends, periods, and amplitude functions. This scheme is used with Earth system models to simulate the local and regional climate effects of wildfires.

  18. Reconfiguring trade mark law

    DEFF Research Database (Denmark)

    Elsmore, Matthew James

    2013-01-01

    -border setting, with a particular focus on small business and consumers. The article's overall message is to call for a rethink of received wisdom suggesting that trade marks are effective trade-enabling devices. The case is made for reassessing how we think about European trade mark law.......First, this article argues that trade mark law should be approached in a supplementary way, called reconfiguration. Second, the article investigates such a reconfiguration of trade mark law by exploring the interplay of trade marks and service transactions in the Single Market, in the cross...

  19. Impact on surface water quality due to coke oven effluents

    International Nuclear Information System (INIS)

    Ghose, M.K.; Roy, S.

    1994-01-01

    Large quantities of water are used for the quenching of hot coke and also for washing the gas produced from the coke ovens. Liquid effluents thus generated are highly polluted and are being discharged into the river Damodar without proper treatment. Four coke plants of Bharat Coking Coal Ltd.(BCCL) have been surveyed for characterization and to assess the impact on surface water quality. About 175-200 kilolitres of waste water is being generated per day by each of the coke plants. The concentration of CO, BOD, COD, TSS, phenol and cyanide in each of the coke plants were found to exceed the limits specified by pollution control board. Ammonia, oil and grease and TDS were found to be 19.33 mg/l, 7.81 mg/l, 1027.75 mg/l respectively. Types of samples collected, sampling frequencies, sample preservation and the results obtained have been discussed. (author). 6 refs., 1 tab., 1 fig

  20. Droplet impaction on solid surfaces exposed to impinging jet fires

    Energy Technology Data Exchange (ETDEWEB)

    Kazemi, Zia

    2005-12-15

    The thermal response of hot surfaces exposed to impinging jet fire and subsequent impacting water droplets is investigated. The research was done mainly experimentally by utilizing three different concepts. This included experiments on a laboratory scale steel plate and large outdoor fire tests with a quadratic steel channel and steel plates. Besides the horizontal jet flame itself was characterized in a comprehensive study. As a comparative study, the last three types of the experiment were additionally modeled by the CFD-code Kameleon FireEx for validation of results. The purpose of the experiments done on bench scale steel plate (L x W x T : 300 x 200 x 8 mm) was mainly to map data on wetting temperature, water droplet size, droplet impingement angle, and droplet velocity prior to large scale jet fire tests. The droplet release angle normal to hot surface gives best cooling effect, when the surface is oriented in upright position. The partial wetting begins at about 165 degrees C. When the surface is positioned in horizontal plane, the droplet of about 5 mm in diameter wets the hot surface partially at around 240-250 degrees C within an impaction distance of 20 cm. At about 150 degrees C, the droplet is entirely attached to the surface with almost zero contact angle, and cools down the solid at a critical heat flux equivalent to 1750 kW/m{sup 2}. The cooling effectiveness is about 8 % with a Weber number of 68. Although in the event of horizontal channel (L x W x T : 1000 x 200 x 8 mm) water droplets were not applied, however, the knowledge gained with jet fire tests gave valuable information about temperature progress in solids (steels and insulation) and their response to impinging jet fire during long duration experiments. The temperature of the insulated area of the channel keeps 200 degrees C below that of the exposed surface, as long as the insulation material remained intact. Upon long test fire durations, the insulation either burns or degrades despite

  1. The impact of land use on microbial surface water pollution.

    Science.gov (United States)

    Schreiber, Christiane; Rechenburg, Andrea; Rind, Esther; Kistemann, Thomas

    2015-03-01

    Our knowledge relating to water contamination from point and diffuse sources has increased in recent years and there have been many studies undertaken focusing on effluent from sewage plants or combined sewer overflows. However, there is still only a limited amount of microbial data on non-point sources leading to diffuse pollution of surface waters. In this study, the concentrations of several indicator micro-organisms and pathogens in the upper reaches of a river system were examined over a period of 16 months. In addition to bacteria, diffuse pollution caused by Giardia lamblia and Cryptosporidium spp. was analysed. A single land use type predestined to cause high concentrations of all microbial parameters could not be identified. The influence of different land use types varies between microbial species. The microbial concentration in river water cannot be explained by stable non-point effluent concentrations from different land use types. There is variation in the ranking of the potential of different land use types resulting in surface water contamination with regard to minimum, median and maximum effects. These differences between median and maximum impact indicate that small-scale events like spreading manure substantially influence the general contamination potential of a land use type and may cause increasing micro-organism concentrations in the river water by mobilisation during the next rainfall event. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. Minimal Marking: A Success Story

    Directory of Open Access Journals (Sweden)

    Anne McNeilly

    2014-11-01

    Full Text Available The minimal-marking project conducted in Ryerson’s School of Journalism throughout 2012 and early 2013 resulted in significantly higher grammar scores in two first-year classes of minimally marked university students when compared to two traditionally marked classes. The “minimal-marking” concept (Haswell, 1983, which requires dramatically more student engagement, resulted in more successful learning outcomes for surface-level knowledge acquisition than the more traditional approach of “teacher-corrects-all.” Results suggest it would be effective, not just for grammar, punctuation, and word usage, the objective here, but for any material that requires rote-memory learning, such as the Associated Press or Canadian Press style rules used by news publications across North America.

  3. Mark Tompkins Canaccord

    OpenAIRE

    Mark Tompkins Canaccord

    2018-01-01

    Mark Tompkins Canaccord is a senior technologist for ecosystem and water resources management in SEC SAID Oakland, California office. In his career which lasts over fifteen years Mark has worked on project involving lake restorations, clean water engineering, ecological engineering and management, hydrology, hydraulics, sediment transport and other projects for environmental planning all over the country. Mark Tompkins Canaccord tries to blend his skills of planning and engineering with s...

  4. Lujan Mark-4

    Energy Technology Data Exchange (ETDEWEB)

    Mocko, Michael Jeffrey [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zavorka, Lukas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Koehler, Paul E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-13

    This is a review of Mark-IV target neutronics design. It involved the major redesign of the upper tier, offering harder neutron spectra for upper-tier FPs; a redesign of the high-resolution (HR) moderator; and a preservation of the rest of Mark-III features.

  5. Mark Stock | NREL

    Science.gov (United States)

    Stock Mark Stock Scientific Visualization Specialist Mark.Stock@nrel.gov | 303-275-4174 Dr. Stock , virtual reality, parallel computing, and manipulation of large spatial data sets. As an artist, he creates . Stock built the SUNLIGHT artwork that is installed on the Webb Building in downtown Denver. In addition

  6. Droplet Impact on a Heated Surface under a Depressurized Environment

    Science.gov (United States)

    Hatakenaka, Ryuta; Tagawa, Yoshiyuki

    2016-11-01

    Behavior of a water droplet of the diameter 1-3mm impacting on a heated surface under depressurized environment (100kPa -1kPa) has been studied. A syringe pump for droplet generation and a heated plate are set into a transparent acrylic vacuum chamber. The internal pressure of the chamber is automatically controlled at a target pressure with a rotary pump, a pressure transducer, and an electrical valve. A silicon wafer of the thickness 0.28 mm is mounted on the heater plate, whose temperature is directly measured by attaching a thermocouple on the backside. The droplet behavior is captured using a high-speed camera in a direction perpendicular to droplet velocity. Some unique behaviors of droplet are observed by decreasing the environmental pressure, which are considered to be due to two basic elements: Enhancement of evaporation due to the lowered saturation temperature, and shortage of pneumatic spring effect between the droplet and heated wall due to the lowered pressure of the air.

  7. Human Mars Landing Site and Impacts on Mars Surface Operations

    Science.gov (United States)

    Hoffman, Stephen J.; Bussey, Ben

    2016-01-01

    to sustain multiple crews of exploring astronauts, AND potential resource deposits for ISRU indicating the current EZ definition is viable and should be retained for now, (b) new data types (needed for more definitive analysis of EZs) argued strongly for a new orbiter mission, and possibly one or more surface missions, to obtain these data, (c) a general consensus that this Workshop was an excellent start to identifying a place where future human missions to Mars can productively explore this planet and learn to live and work there for the long term. Building on these findings, HEOMD and SMD are: (a) refining the EZ selection criteria and overall selection process to improve on lessons learned from the first EZ workshop, (b) using these proposed locations to develop "reference EZs" for assessment purposes (primarily engineering assessments), (c) gathering data and conducting analyses to better understanding the different potential sources for water, including the ease of extraction and purification, and (d) assessing trends in additional data that are needed to better characterize EZs proposed at the workshop and how these data needs impact the design and operation of future robotic Mars missions.

  8. Potential Impact of Rainfall on the Air-Surface Exchange of Total Gaseous Mercury from Two Common Urban Ground Surfaces

    Science.gov (United States)

    The impact of rainfall on total gaseous mercury (TGM) flux from pavement and street dirt surfaces was investigated in an effort to determine the influence of wet weather events on mercury transport in urban watersheds. Street dirt and pavement are common urban ground surfaces tha...

  9. Quantifying the impact of climate change on enteric waterborne pathogen concentrations in surface water

    NARCIS (Netherlands)

    Hofstra, N.

    2011-01-01

    Climate change, among other factors, will impact waterborne pathogen concentrations in surface water worldwide, possibly increasing the risk of diseases caused by these pathogens. So far, the impacts are only determined qualitatively and thorough quantitative estimates of future pathogen

  10. Electrochemistry and in situ scanning tunnelling microscopy of pure and redox-marked DNA- and UNA-based oligonucleotides on Au(111)-electrode surfaces

    DEFF Research Database (Denmark)

    Hansen, Allan Glargaard; Salvatore, Princia; Karlsen, K.

    2013-01-01

    the strongest and in accord with multiple site Ru-attachment. In situ STM disclosed molecular scale features in varying coverage on addition of the metal ions. The Ru-derivatives showed a bias voltage dependent broad maximum in the tunnelling current–overpotential correlation which could be correlated......We have studied adsorption and electrochemical electron transfer of several 13- and 15-base DNA and UNA (unlocked nucleic acids) oligonucleotides (ONs) linked to Au(111)-electrode surfaces via a 50-C6-SH group using cyclic voltammetry (CV) and scanning tunnelling microscopy in aqueous buffer under...

  11. Impact location of objects hitting the water surface

    Science.gov (United States)

    Kadri, Usama

    2017-04-01

    Analysis of data, recorded on March 8th 2014 at the Comprehensive Test ban Treaty Organisation's hydroacoustic station off Cape Leeuwin Western Australia, reveal pressure signatures of objects impacting at the sea surface which could be associated with falling meteorites as well as the missing Malaysian MH370 airplane. The location of the sources are identified analytically by an inverse solution based on acoustic-gravity wave theory (e.g. see references below) which have been developed and validated experimentally. Apart from the direct contribution to the search efforts after the missing airplane, the method we describe here is very efficient for identifying the location of sources that result in a sudden change in the water pressure in general. References 1. T.Yamamoto,1982.Gravity waves and acoustic waves generated by submarine earthquakes, Soil Dyn. Earthquake Eng., 1, 75-82. 2. M. Stiassnie, 2010. Tsunamis and acoustic-gravity waves from underwater earthquakes, J. Eng. Math., 67, 23-32, doi:10.1007/s10665-009-9323-x. 3. U. Kadri and M. Staissnie, 2012. Acoustic-gravity waves interacting with the shelf break. J. Geophys. Res., 117, C03035, doi: 10.1029/2011JC007674. 4. E. Eyov, A. Klar, U. Kadri and M. Stiassnie, 2013. Progressive waves in a compressible ocean with elastic bottom, Wave Motion 50, 929-939. doi: 10.1016/j.wavemoti.2013.03.003 5. G. Hendin and M. Stiassnie, 2013. Tsunami and acoustic-gravity waves in water of constant depth, Phys. Fluids 25, 086103, doi: 10.1063/1.481799. 6. U. Kadri, 2016. Acoustic-gravity waves from an oscillating ice-block in arctic zones. Advances in Acoustics and Vibration, 8076108, http://dx.doi.org/10.1155/2016/8076108 7. T.C.A. Oliveira, U. Kadri, 2016. Acoustic-gravity waves from the 2004 Indian Ocean earthquake and tsunami. Journal of Geophysical Research: Oceans. doi: 10.1002/2016JC011742

  12. Mark 1 Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Mark I Test Facility is a state-of-the-art space environment simulation test chamber for full-scale space systems testing. A $1.5M dollar upgrade in fiscal year...

  13. Mark Raidpere portreefotod Kielis

    Index Scriptorium Estoniae

    1999-01-01

    Kieli Linnagaleriis avatud 2. Ars Baltica fototriennaalil 'Can You Hear Me?' esindab Eestit Mark Raidpere seeriaga 'Portreed 1998'. Näituse Eesti-poolne kuraator Anu Liivak, kataloogiteksti kirjutas Anders Härm. Tuntumaid osalejaid triennaalil Wolfgang Tillmans

  14. Impact of an Environmental Cleaning Intervention on the Presence of Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci on Surfaces in Intensive Care Unit Rooms

    Science.gov (United States)

    Goodman, Eric R.; Platt, Richard; Bass, Richard; Onderdonk, Andrew B.; Yokoe, Deborah S.; Huang, Susan S.

    2009-01-01

    OBJECTIVES To evaluate the adequacy of discharge room cleaning and the impact of a cleaning intervention on the presence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) on environmental surfaces in intensive care unit (ICU) rooms. DESIGN Prospective environmental study. SETTING AND SAMPLE Convenience sample of ICU rooms in an academic hospital. METHODS AND INTERVENTION The intervention consisted of (1) a change from the use of pour bottles to bucket immersion for applying disinfectant to cleaning cloths, (2) an educational campaign, and (3) feedback regarding adequacy of discharge cleaning. Cleaning of 15 surfaces was evaluated by inspecting for removal of a preapplied mark, visible only with an ultraviolet lamp (“black light”). Six surfaces were cultured for MRSA or VRE contamination. Outcomes of mark removal and culture positivity were evaluated by χ2 testing and generalized linear mixed models, clustering by room. RESULTS The black-light mark was removed from 44% of surfaces at baseline, compared with 71% during the intervention (P <.001). The intervention increased the likelihood of removal of black-light marks after discharge cleaning (odds ratio, 4.4; P < .001), controlling for ICU type (medical vs surgical) and type of surface. The intervention reduced the likelihood of an environmental culture positive for MRSA or VRE (proportion of cultures positive, 45% at baseline vs 27% during the intervention; adjusted odds ratio, 0.4; P = .02). Broad, flat surfaces were more likely to be cleaned than were doorknobs and sink or toilet handles. CONCLUSIONS Increasing the volume of disinfectant applied to environmental surfaces, providing education for Environmental Services staff, and instituting feedback with a black-light marker improved cleaning and reduced the frequency of MRSA and VRE contamination. PMID:18624666

  15. Marks of Metal Copenhell

    DEFF Research Database (Denmark)

    2015-01-01

    Planchebaseret udendørs udstilling på musikfestivalen Copenhell 18-20/6 2015. En mindre udgave af udstillingen Marks of Metal - Logodesign og visualitet i heavy metal. Udarbejdet i samarbejde med Mediemuseet.......Planchebaseret udendørs udstilling på musikfestivalen Copenhell 18-20/6 2015. En mindre udgave af udstillingen Marks of Metal - Logodesign og visualitet i heavy metal. Udarbejdet i samarbejde med Mediemuseet....

  16. Nanofabrication on a Si surface by slow highly charged ion impact

    International Nuclear Information System (INIS)

    Tona, Masahide; Watanabe, Hirofumi; Takahashi, Satoshi; Nakamura, Nobuyuki; Yoshiyasu, Nobuo; Sakurai, Makoto; Terui, Toshifumi; Mashiko, Shinro; Yamada, Chikashi; Ohtani, Shunsuke

    2007-01-01

    We have observed surface chemical reactions which occur at the impact sites on a Si(1 1 1)-(7 x 7) surface and a highly oriented pyrolytic graphite (HOPG) surface bombarded by highly charged ions (HCIs) by using a scanning tunneling microscope (STM). Crater structures are formed on the Si(1 1 1)-(7 x 7) surface by single I 50+ -impacts. STM-observation for the early step of oxidation on the surface suggests that the impact site is so active that dangling bonds created by HCI impacts are immediately quenched by reaction with residual gas molecules. We show also the selective adsorption of organic molecules at a HCI-induced impact site on the HOPG surface

  17. COMPUTER HARDWARE MARKING

    CERN Multimedia

    Groupe de protection des biens

    2000-01-01

    As part of the campaign to protect CERN property and for insurance reasons, all computer hardware belonging to the Organization must be marked with the words 'PROPRIETE CERN'.IT Division has recently introduced a new marking system that is both economical and easy to use. From now on all desktop hardware (PCs, Macintoshes, printers) issued by IT Division with a value equal to or exceeding 500 CHF will be marked using this new system.For equipment that is already installed but not yet marked, including UNIX workstations and X terminals, IT Division's Desktop Support Service offers the following services free of charge:Equipment-marking wherever the Service is called out to perform other work (please submit all work requests to the IT Helpdesk on 78888 or helpdesk@cern.ch; for unavoidable operational reasons, the Desktop Support Service will only respond to marking requests when these coincide with requests for other work such as repairs, system upgrades, etc.);Training of personnel designated by Division Leade...

  18. X-ray impact induced desorption of gases from surfaces

    International Nuclear Information System (INIS)

    Brumbach, S.; Kaminsky, M.

    1976-02-01

    Measurements of gases released from 302 stainless steel and gold surfaces before and after discharge cleaning were made in ultrahigh vacuum using x-rays with an energy distribution typical of a tungsten bremsstrahlung spectrum. Similar measurements were also made for Al 2 O 3 surfaces which had not been discharge cleaned. For the non-discharge-cleaned surfaces of stainless steel, Al 2 O 3 , and gold the predominant gas species observed mass spectrometrically was CO 2 . For some stainless steel and Al 2 O 3 surfaces CO and O 2 were also readily observed. Mean quantum yields for CO, O 2 and CO 2 release from such stainless steel surfaces, for example, ranged from less than 6 x 10 -5 to 9 x 10 -4 molecules per photons in the bremsstrahlung spectrum characteristic for 50 keV electron energy. After discharge cleaning a decrease in the mean quantum yields was observed for the stainless steel and gold surfaces

  19. Development of a Spring-Loaded Impact Device to Deliver Injurious Mechanical Impacts to the Articular Cartilage Surface

    Science.gov (United States)

    Alexander, Peter G.; Song, Yingjie; Taboas, Juan M.; Chen, Faye H.; Melvin, Gary M.; Manner, Paul A.

    2013-01-01

    Objective: Traumatic impacts on the articular joint surface in vitro are known to lead to degeneration of the cartilage. The main objective of this study was to develop a spring-loaded impact device that can be used to deliver traumatic impacts of consistent magnitude and rate and to find whether impacts cause catabolic activities in articular cartilage consistent with other previously reported impact models and correlated with the development of osteoarthritic lesions. In developing the spring-loaded impactor, the operating hypothesis is that a single supraphysiologic impact to articular cartilage in vitro can affect cartilage integrity, cell viability, sulfated glycosaminoglycan and inflammatory mediator release in a dose-dependent manner. Design: Impacts of increasing force are delivered to adult bovine articular cartilage explants in confined compression. Impact parameters are correlated with tissue damage, cell viability, matrix and inflammatory mediator release, and gene expression 24 hours postimpact. Results: Nitric oxide release is first detected after 7.7 MPa impacts, whereas cell death, glycosaminoglycan release, and prostaglandin E2 release are first detected at 17 MPa. Catabolic markers increase linearly to maximal levels after ≥36 MPa impacts. Conclusions: A single supraphysiologic impact negatively affects cartilage integrity, cell viability, and GAG release in a dose-dependent manner. Our findings showed that 7 to 17 MPa impacts can induce cell death and catabolism without compromising the articular surface, whereas a 17 MPa impact is sufficient to induce increases in most common catabolic markers of osteoarthritic degeneration. PMID:26069650

  20. Morphing and vectoring impacting droplets by means of wettability-engineered surfaces.

    Science.gov (United States)

    Schutzius, Thomas M; Graeber, Gustav; Elsharkawy, Mohamed; Oreluk, James; Megaridis, Constantine M

    2014-11-13

    Driven by its importance in nature and technology, droplet impact on solid surfaces has been studied for decades. To date, research on control of droplet impact outcome has focused on optimizing pre-impact parameters, e.g., droplet size and velocity. Here we follow a different, post-impact, surface engineering approach yielding controlled vectoring and morphing of droplets during and after impact. Surfaces with patterned domains of extreme wettability (high or low) are fabricated and implemented for controlling the impact process during and even after rebound--a previously neglected aspect of impact studies on non-wetting surfaces. For non-rebound cases, droplets can be morphed from spheres to complex shapes--without unwanted loss of liquid. The procedure relies on competition between surface tension and fluid inertial forces, and harnesses the naturally occurring contact-line pinning mechanisms at sharp wettability changes to create viable dry regions in the spread liquid volume. Utilizing the same forces central to morphing, we demonstrate the ability to rebound orthogonally-impacting droplets with an additional non-orthogonal velocity component. We theoretically analyze this capability and derive a We(-.25) dependence of the lateral restitution coefficient. This study offers wettability-engineered surfaces as a new approach to manipulate impacting droplet microvolumes, with ramifications for surface microfluidics and fluid-assisted templating applications.

  1. The impact of implementing the bare essentials of surface transfer land surface scheme into the BMRC GCM

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Z.L. [Univ. of Arizona, Tucson, AZ (United States); Pitman, A.J. [Macquarie Univ., Sydney (Australia); McAvaney, B. [Bureau of Meterology Research Centre, Melbourne (Australia)] [and others

    1995-07-01

    This study describes the first order impacts of incorporating a complex land-surface scheme, the bare essentials of surface transfer (BEST), into the Australian Bureau of Meteorology Research Centre (BMRC) global atmospheric general circulation model (GCM). Land seasonal climatologies averaged over the last six years of integrations after equilibrium from the GCM with BEST and without BEST (the control) are compared. The modeled results are evaluated with comprehensive sources of data, including the layer-cloud climatologies project (ISCCP) data from 1983 to 1991 and the surface-observed global data of Warrent et al., a five-year climatology of surface albedo estimated from earth radiation budget experiment (ERBE) top-of-the-atmosphere (TOA) radiative fluxes, global grid point datasets of precipitation, and the climatological analyses of surface evaporation and albedo. Emphasis is placed on the surface evaluation of simulations of land-surface conditions such as surface roughness, surface albedo and the surface wetness factor, and on their effects on surface evaporation, precipitation, layer-cloud and surface temperature. The improvements due to the inclusion of BEST are: a realistic geographical distribution of surface roughness, a decrease in surface albedo over areas with seasonal snow cover, an an increase in surface albedo over snow-free land. The simulated reduction in surface evaporation due, in part, to the bio-physical control of vegetation, is also consistent with the previous studies. Since the control climate has a dry bias, the overall simulations from the GCM with BEST are degraded, except for significant improvements for the northern winter hemisphere because of the realistic vegetation-masking effects. The implications of our results for synergistic developments of other aspects of model parameterization schemes such as boundary layer dynamics, clouds, convection and rainfall are discussed. 82 refs., 9 figs., 3 tabs.

  2. The impact of uncontrolled waste disposal on surface water quality ...

    African Journals Online (AJOL)

    The main threat to the surface water quality in Addis Ababa is environmental pollution derived from domestic and industrial activities. Due to the inadequacy of controlled waste management strategies and waste treatment plants, people are forced to discharge wastes both on open surface and within water bodies.

  3. Augmented marked graphs

    CERN Document Server

    Cheung, King Sing

    2014-01-01

    Petri nets are a formal and theoretically rich model for the modelling and analysis of systems. A subclass of Petri nets, augmented marked graphs possess a structure that is especially desirable for the modelling and analysis of systems with concurrent processes and shared resources.This monograph consists of three parts: Part I provides the conceptual background for readers who have no prior knowledge on Petri nets; Part II elaborates the theory of augmented marked graphs; finally, Part III discusses the application to system integration. The book is suitable as a first self-contained volume

  4. The impacts of surface polarity on the solubility of nanoparticle

    International Nuclear Information System (INIS)

    Zhu, Jianzhuo; Su, Jiguo; Ou, Xinwen; Li, Jingyuan

    2016-01-01

    In order to study the dependence of water solubility and hydration behavior of nanoparticles on their surface polarity, we designed polar nanoparticles with varying surface polarity by assigning atomic partial charge to the surface of C60. The water solubility of the nanoparticle is enhanced by several orders of magnitude after the introduction of surface polarity. Nevertheless, when the atomic partial charge grows beyond a certain value (q M ), the solubility continuously decreases to the level of nonpolar nanoparticle. It should be noted that such q M is comparable with atomic partial charge of a variety of functional groups. The hydration behaviors of nanoparticles were then studied to investigate the non-monotonic dependence of solubility on the surface polarity. The interaction between the polar nanoparticle and the hydration water is stronger than the nonpolar counterpart, which should facilitate the dissolution of the nanoparticles. On the other hand, the surface polarity also reduces the interaction of hydration water with the other water molecules and enhances the interaction between the nanoparticles which may hinder their dispersion. Besides, the introduction of surface polarity disturbs and even rearranges the hydration structure of nonpolar nanoparticle. Interestingly, the polar nanoparticle with less ordered hydration structure tends to have higher water solubility.

  5. Global impacts of surface ozone changes on crop yields and land use

    NARCIS (Netherlands)

    Chuwah, C.D.; Noije, van Twan; Vuuren, van Detlef P.; Stehfest, Elke; Hazeleger, Wilco

    2015-01-01

    Exposure to surface ozone has detrimental impacts on vegetation and crop yields. In this study, we estimate ozone impacts on crop production and subsequent impacts on land use in the 2005-2050 period using results of the TM5 atmospheric chemistry and IMAGE integrated assessment model. For the

  6. Global impacts of surface ozone changes on crop yields and land use

    NARCIS (Netherlands)

    Chuwah, Clifford; van Noije, Twan; van Vuuren, Detlef P.; Stehfest, Elke; Hazeleger, Wilco

    2015-01-01

    Exposure to surface ozone has detrimental impacts on vegetation and crop yields. In this study, we estimate ozone impacts on crop production and subsequent impacts on land use in the 2005-2050 period using results of the TM5 atmospheric chemistry and IMAGE integrated assessment model. For the crops

  7. Impact of additional surface observation network on short range ...

    Indian Academy of Sciences (India)

    Stations (AWS) surface observations (temperature and moisture) on the short range forecast over the Indian ... models, which are able to resolve mesoscale fea- ... J. Earth Syst. Sci. ..... terization of the snow field in a cloud model; J. Climate.

  8. Identification markings for gemstones

    International Nuclear Information System (INIS)

    Dreschhoff, G.A.M.; Zeller, E.J.

    1980-01-01

    A method is described of providing permanent identification markings to gemstones such as diamond crystals by irradiating the cooled gemstone with protons in the desired pattern. The proton bombardment results in a reaction limited to a defined plane and converting the bombarded area of the plane into a different crystal lattice from that of the preirradiated stone. (author)

  9. Effects of wind on the dynamics of the central jet during drop impact onto a deep-water surface

    Science.gov (United States)

    Liu, Xinan; Wang, An; Wang, Shuang; Dai, Dejun

    2018-05-01

    The cavity and central jet generated by the impact of a single water drop on a deep-water surface in a wind field are experimentally studied. Different experiments are performed by varying the impacting drop diameter and wind speed. The contour profile histories of the cavity (also called crater) and central jet (also called stalk) are measured in detail with a backlit cinematic shadowgraph technique. The results show that shortly after the drop hits the water surface an asymmetrical cavity appears along the wind direction, with a train of capillary waves on the cavity wall. This is followed by the formation of an inclined central jet at the location of the drop impact. It is found that the wind has little effect on the penetration depth of the cavity at the early stage of the cavity expansion, but markedly changes the capillary waves during the retraction of the cavity. The capillary waves in turn shift the position of the central jet formation leeward. The dynamics of the central jet are dominated by two mechanisms: (i) the oblique drop impact produced by the wind and (ii) the wind drag force directly acting on the jet. The maximum height of the central jet, called the stalk height, is drastically affected by the wind, and the nondimensional stalk height H /D decreases with increasing θ Re-1 , where D is the drop diameter, θ is the impingement angle of drop impact, and Re=ρaUwD /μa is the Reynolds number with air density ρa, wind speed Uw, and air viscosity μa.

  10. Assessing Impact Direction in 3-point Bending of Human Femora: Incomplete Butterfly Fractures and Fracture Surfaces,.

    Science.gov (United States)

    Isa, Mariyam I; Fenton, Todd W; Deland, Trevor; Haut, Roger C

    2018-01-01

    Current literature associates bending failure with butterfly fracture, in which fracture initiates transversely at the tensile surface of a bent bone and branches as it propagates toward the impact surface. The orientation of the resulting wedge fragment is often considered diagnostic of impact direction. However, experimental studies indicate bending does not always produce complete butterfly fractures or produces wedge fragments variably in tension or compression, precluding their use in interpreting directionality. This study reports results of experimental 3-point bending tests on thirteen unembalmed human femora. Complete fracture patterns varied following bending failure, but incomplete fractures and fracture surface characteristics were observed in all impacted specimens. A flat, billowy fracture surface was observed in tension, while jagged, angular peaks were observed in compression. Impact direction was accurately reconstructed using incomplete tension wedge butterfly fractures and tension and compression fracture surface criteria in all thirteen specimens. © 2017 American Academy of Forensic Sciences.

  11. Surface roughness effects on plasma near a divertor plate and local impact angle

    Directory of Open Access Journals (Sweden)

    Wanpeng Hu

    2017-08-01

    Full Text Available The impact of rough surface topography on the electric potential and electric field is generally neglected due to the small scale of surface roughness compared to the width of the plasma sheath. However, the distributions of the electric potential and field on rough surfaces are expected to influence the characteristics of edge plasma and the local impact angle. The distributions of plasma sheath and local impact angle on rough surfaces are investigated by a two dimension-in-space and three dimension-in-velocity (2d3v Particle-In-Cell (PIC code. The influences of the plasma temperature andsurface morphology on the plasma sheath, local impact angle and resulting physical sputtering yield on rough surfaces are investigated.

  12. Impact of polishing on the light scattering at aerogel surface

    International Nuclear Information System (INIS)

    Barnyakov, A.Yu.; Barnyakov, M.Yu.; Bobrovnikov, V.S.; Buzykaev, A.R.; Danilyuk, A.F.; Katcin, A.A.; Kononov, S.A.; Kirilenko, P.S.; Kravchenko, E.A.; Kuyanov, I.A.; Onuchin, A.P.; Ovtin, I.V.; Predein, A.Yu.; Protsenko, R.S.

    2016-01-01

    Particle identification power of modern aerogel RICH detectors strongly depends on optical quality of radiators. It was shown that wavelength dependence of aerogel tile transparency after polishing cannot be described by the standard Hunt formula. The Hunt formula has been modified to describe scattering in a thin layer of silica dust on the surface of aerogel tile. Several procedures of polishing of aerogel tile have been tested. The best result has been achieved while using natural silk tissue. The resulting block has optical smooth surfaces. The measured decrease of aerogel transparency due to surface scattering is about few percent. This result could be used for production of radiators for the Focusing Aerogel RICH detectors.

  13. Influence of Surface Properties and Impact Conditions on Adhesion of Insect Residues

    Science.gov (United States)

    Wohl, Christopher J.; Smith, Joseph G.; Connell, John W.; Siochi, Emilie J.; Doss, Jereme R.; Shanahan, Michelle H.; Penner, Ronald K.

    2015-01-01

    Insect residues can cause premature transition to turbulent flow on laminar flow airfoils. Engineered surfaces that mitigate the adhesion of insect residues provide, therefore, a route to more efficient aerodynamics and reduced fuel burn rates. Areal coverage and heights of residues depend not only on surface properties, but also on impact conditions. We report high speed photography of fruit fly impacts at different angles of inclination on a rigid aluminum surface, optical microscopy and profilometry, and contact angle goniometry to support the design of engineered surfaces. For the polyurethane and epoxy coatings studied, some of which exhibited superhydrophobicity, it was determined that impact angle and surface compositions play critical roles in the efficacy of these surfaces to reduce insect residue adhesion.

  14. Ionization by ion impact at grazing incidence on insulator surface

    CERN Document Server

    Martiarena, M L

    2003-01-01

    We have calculated the energy distribution of electrons produced by ionization of the ionic crystal electrons in grazing fast ion-insulator surface collision. The ionized electrons originate in the 2p F sup - orbital. We observe that the binary peak appears as a double change in the slope of the spectra, in the high energy region. The form of the peak is determined by the initial electron distribution and its position will be affected by the binding energy of the 2p F sup - electron in the crystal. This BEP in insulator surfaces will appear slightly shifted to the low energy side with respect the ion-atom one.

  15. The impacts of surface ozone pollution on winter wheat productivity in China--An econometric approach.

    Science.gov (United States)

    Yi, Fujin; Jiang, Fei; Zhong, Funing; Zhou, Xun; Ding, Aijun

    2016-01-01

    The impact of surface ozone pollution on winter wheat yield is empirically estimated by considering socio-economic and weather determinants. This research is the first to use an economic framework to estimate the ozone impact, and a unique county-level panel is employed to examine the impact of the increasing surface ozone concentration on the productivity of winter wheat in China. In general, the increment of surface ozone concentration during the ozone-sensitive period of winter wheat is determined to be harmful to its yield, and a conservative reduction of ozone pollution could significantly increase China's wheat supply. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Shale gas development impacts on surface water quality in Pennsylvania

    Science.gov (United States)

    Olmstead, Sheila M.; Muehlenbachs, Lucija A.; Shih, Jhih-Shyang; Chu, Ziyan; Krupnick, Alan J.

    2013-01-01

    Concern has been raised in the scientific literature about the environmental implications of extracting natural gas from deep shale formations, and published studies suggest that shale gas development may affect local groundwater quality. The potential for surface water quality degradation has been discussed in prior work, although no empirical analysis of this issue has been published. The potential for large-scale surface water quality degradation has affected regulatory approaches to shale gas development in some US states, despite the dearth of evidence. This paper conducts a large-scale examination of the extent to which shale gas development activities affect surface water quality. Focusing on the Marcellus Shale in Pennsylvania, we estimate the effect of shale gas wells and the release of treated shale gas waste by permitted treatment facilities on observed downstream concentrations of chloride (Cl−) and total suspended solids (TSS), controlling for other factors. Results suggest that (i) the treatment of shale gas waste by treatment plants in a watershed raises downstream Cl− concentrations but not TSS concentrations, and (ii) the presence of shale gas wells in a watershed raises downstream TSS concentrations but not Cl− concentrations. These results can inform future voluntary measures taken by shale gas operators and policy approaches taken by regulators to protect surface water quality as the scale of this economically important activity increases. PMID:23479604

  17. The impact of mechanical log surface damage on chip size ...

    African Journals Online (AJOL)

    Mechanised harvesting operations are becoming more prevalent in South Africa with the realisation that motormanual and manual harvesting operations pose significant health and safety risks to workers. The damage inflicted by single-grip harvester feed rollers and delimbing knives on log surfaces during debranching ...

  18. Interview with Mark Watson

    Directory of Open Access Journals (Sweden)

    Katy Shaw

    2016-04-01

    Full Text Available Mark Watson is a British comedian and novelist. His five novels to date – 'Bullet Points' (2004, 'A Light-Hearted Look At Murder' (2007, 'Eleven' (2010, 'The Knot' (2012 and 'Hotel Alpha' (2014 – explore human relationships and communities in contemporary society. His latest novel Hotel Alpha tells the story of an extraordinary hotel in London and two mysterious disappearances that raise questions no one seems willing to answer. External to the novel, readers can also discover more about the hotel and its inhabitants in one hundred extra stories that expand the world of the novel and can be found at http://www.hotelalphastories.com. In conversation here with Dr Katy Shaw, Mark offers some reflections on his writing process, the field of contemporary literature, and the vitality of the novel form in the twenty-first century.

  19. Enamel-based mark performance for marking Chinese mystery snail Bellamya chinensis

    Science.gov (United States)

    Wong, Alec; Allen, Craig R.; Hart, Noelle M.; Haak, Danielle M.; Pope, Kevin L.; Smeenk, Nicholas A.; Stephen, Bruce J.; Uden, Daniel R.

    2013-01-01

    The exoskeleton of gastropods provides a convenient surface for carrying marks, and i the interest of improving future marking methods our laboratory assessed the performance of an enamel paint. The endurance of the paint was also compared to other marking methods assessed in the past. We marked the shells of 30 adult Chinese mystery snails Bellamya chinensis and held them in an aquarium for 181 days. We observed no complete degradation of any enamel-paint mark during the 181 days. The enamel-paint mark was superior to a nai;-polish mark, which lasted a median of 100 days. Enamel-paint marks also have a lower rate of loss (0.00 month-1 181 days) than plastic bee tags (0.01 month-1, 57 days), gouache paint (0.07 month-1, 18.5 days), or car body paint from studies found in scientific literature. Legibility of enamel-paint marks had a median lifetime of 102 days. The use of enamel paint on the shells of gastropods is a viable option for studies lasting up to 6 months. Furthermore, visits to capture-mark-recapture site 1 year after application of enamel-paint marks on B. chinesnis shells produced several individuals on which the enamel paint was still visible, although further testing is required to clarify durability over longer periods.

  20. Impact of surface waves in a Regional Climate Model

    DEFF Research Database (Denmark)

    Rutgersson, Anna; Sætra, Oyvind; Semedo, Alvaro

    2010-01-01

    A coupled regional atmosphere-wave model system is developed with the purpose of investigating the impact of climate changes on the wave field, as well as feed-back effects of the wave field on the atmospheric parameters. This study focuses on the effects of introducing a two-way atmosphere...

  1. Quantifying the changes of soil surface microroughness due to rainfall impact on a smooth surface

    Directory of Open Access Journals (Sweden)

    B. K. B. Abban

    2017-09-01

    Full Text Available This study examines the rainfall-induced change in soil microroughness of a bare smooth soil surface in an agricultural field. The majority of soil microroughness studies have focused on surface roughness on the order of ∼ 5–50 mm and have reported a decay of soil surface roughness with rainfall. However, there is quantitative evidence from a few studies suggesting that surfaces with microroughness less than 5 mm may undergo an increase in roughness when subject to rainfall action. The focus herein is on initial microroughness length scales on the order of 2 mm, a low roughness condition observed seasonally in some landscapes under bare conditions and chosen to systematically examine the increasing roughness phenomenon. Three rainfall intensities of 30, 60, and 75 mm h−1 are applied to a smoothened bed surface in a field plot via a rainfall simulator. Soil surface microroughness is recorded via a surface-profile laser scanner. Several indices are utilized to quantify the soil surface microroughness, namely the random roughness (RR index, the crossover length, the variance scale from the Markov–Gaussian model, and the limiting difference. Findings show a consistent increase in roughness under the action of rainfall, with an overall agreement between all indices in terms of trend and magnitude. Although this study is limited to a narrow range of rainfall and soil conditions, the results suggest that the outcome of the interaction between rainfall and a soil surface can be different for smooth and rough surfaces and thus warrant the need for a better understanding of this interaction.

  2. The impact of surface coverage on the kinetics of electron transfer through redox monolayers on a silicon electrode surface

    International Nuclear Information System (INIS)

    Ciampi, Simone; Choudhury, Moinul H.; Ahmad, Shahrul Ainliah Binti Alang; Darwish, Nadim; Brun, Anton Le; Gooding, J.Justin

    2015-01-01

    Graphical abstract: The impact of surface coverage on the kinetics of electron transfer through redox monolayers on a silicon electrode surface. ABSTRACT: The impact of the coverage of ferrocene moieties, attached to a silicon electrode modified via hydrosilylation of a dialkyne, on the kinetics of electron transfer between the redox species and the electrode is explored. The coverage of ferrocene is controlled by varying the coupling time between azidomethylferrocene and the distal alkyne of the monolayer via the copper assisted azide-alkyne cycloaddition reaction. All other variables in the surface preparation are maintained identical. What is observed is that the higher the surface coverage of the ferrocene moieties the faster the apparent rates of electron transfer. This surface coverage-dependent kinetic effect is attributed to electrons hopping between ferrocene moieties across the redox film toward hotspots for the electron transfer event. The origin of these hotspots is tentatively suggested to result from minor amounts of oxide on the underlying silicon surface that reduce the barrier for the electron transfer.

  3. Effect of surface topography upon micro-impact dynamics

    International Nuclear Information System (INIS)

    Mohammadpour, M; Morris, N J; Leighton, M; Rahnejat, H

    2016-01-01

    Often the effect of interactions at nano-scale determines the tribological performance of load bearing contacts. This is particularly the case for lightly loaded conjunctions where a plethora of short range kinetic interactions occur. It is also true of larger load bearing conjunctions where boundary interactions become dominant. At the diminutive scale of fairly smooth surface topography the cumulative discrete interactions give rise to the dominance of boundary effects rather than the bulk micro-scale phenomena, based on continuum mechanics. The integration of the manifold localized discrete interactions into a continuum is the pre-requisite to the understanding of characteristic boundary effects, which transcend the physical length scales and affect the key observed system attributes. These are energy efficiency and vibration refinement. This paper strives to present such an approach. It is shown that boundary and near boundary interactions can be adequately described by surface topographical measures, as well the thermodynamic conditions. (paper)

  4. Impacts of Future Grassland Changes on Surface Climate in Mongolia

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2013-01-01

    Full Text Available Climate change caused by land use/cover change (LUCC is becoming a hot topic in current global change, especially the changes caused by the grassland degradation. In this paper, based on the baseline underlying surface data of 1993, the predicted underlying surface data which can be derived through overlaying the grassland degradation information to the map of baseline underlying surface, and the atmospheric forcing data of RCP 6.0 from CMIP5, climatological changes caused by future grassland changes for the years 2010–2020 and 2040–2050 with the Weather Research Forecast model (WRF are simulated. The model-based analysis shows that future grassland degradation will significantly result in regional climate change. The grassland degradation in future could lead to an increasing trend of temperature in most areas and corresponding change range of the annual average temperature of −0.1°C–0.4°C, and it will cause a decreasing trend of precipitation and corresponding change range of the annual average precipitation of 10 mm–50 mm. This study identifies lines of evidence for effects of future grassland degradation on regional climate in Mongolia which provides meaningful decision-making information for the development and strategy plan making in Mongolia.

  5. The Impact of Road Maintenance Substances on Metals Surface Corrosion

    Directory of Open Access Journals (Sweden)

    Jolita Petkuvienė

    2011-04-01

    Full Text Available The purpose of research is to assess changes in the visual metal surface due to the exposure of road maintenance salts and molasses (‘Safecote’. Chlorides of deicing salts (NaCl, CaCl2 are the main agents affecting soil and water resources as well as causing the corrosion of roadside metallic elements. Molasses (‘Safecote’ is offered as an alternative to deice road pavement by minimizing the corrosion of metal elements near the road. A laboratory experiment was carried out to immerse and spray metals with NaCl, CaCl2, NaCl:CaCl2 and NaCl:Safecote solutions. The obtained results showed that NaCl:Safecote solution had the lowest coating with corrosion products (the average 17±4 % of the surface. The solutions of NaCl, CaCl2 and NaCl:CaCl2 had the highest percentage rate of the corrosion product on the metal surface reaching an average of 33±5 %. Article in English

  6. Nitride surface passivation of GaAs nanowires: impact on surface state density.

    Science.gov (United States)

    Alekseev, Prokhor A; Dunaevskiy, Mikhail S; Ulin, Vladimir P; Lvova, Tatiana V; Filatov, Dmitriy O; Nezhdanov, Alexey V; Mashin, Aleksander I; Berkovits, Vladimir L

    2015-01-14

    Surface nitridation by hydrazine-sulfide solution, which is known to produce surface passivation of GaAs crystals, was applied to GaAs nanowires (NWs). We studied the effect of nitridation on conductivity and microphotoluminescence (μ-PL) of individual GaAs NWs using conductive atomic force microscopy (CAFM) and confocal luminescent microscopy (CLM), respectively. Nitridation is found to produce an essential increase in the NW conductivity and the μ-PL intensity as well evidence of surface passivation. Estimations show that the nitride passivation reduces the surface state density by a factor of 6, which is of the same order as that found for GaAs/AlGaAs nanowires. The effects of the nitride passivation are also stable under atmospheric ambient conditions for six months.

  7. Impact of the Sun on Remote Sensing of Sea Surface Salinity from Space

    National Research Council Canada - National Science Library

    Le Vine, David M; Abraham, Saji; Wentz, F; Lagerloef, G. S

    2005-01-01

    ... to monitor soil moisture and sea surface salinity. Radiation from the sun can impact passive remote sensing systems in several ways, including line-of-sight radiation that comes directly from the sun and enters through antenna side lobes...

  8. Drop impacts onto cold and heated rigid surfaces: Morphological comparisons, disintegration limits and secondary atomization

    International Nuclear Information System (INIS)

    Moita, A.S.; Moreira, A.L.N.

    2007-01-01

    This paper addresses an experimental study aimed at characterizing the mechanisms of disintegration which occur when individual water and fuel droplets impact onto heated surfaces. The experiments consider the use of a simplified flow configuration and make use of high-speed visualization together with image processing techniques to characterize the morphology of the impact and to quantify the outcome of secondary atomization in terms of droplet size and number. The results evidence that surface topography, wettability and liquid properties combine in a complex way to alter the wetting behaviour of droplets at impact at different surface temperatures. The relative importance of the dynamic vapor pressure associated with the rate of vaporization and surface roughness increases with surface temperature and becomes dominant at the film boiling regime. The analysis is aimed at giving a phenomenological description of droplet disintegration within the various heat transfer regimes

  9. Skating on a Film of Air: Drops Impacting on a Surface

    Science.gov (United States)

    Kolinski, John M.; Rubinstein, Shmuel M.; Mandre, Shreyas; Brenner, Michael P.; Weitz, David A.; Mahadevan, L.

    2012-02-01

    The commonly accepted description of drops impacting on a surface typically ignores the essential role of the air that is trapped between the impacting drop and the surface. Here we describe a new imaging modality that is sensitive to the behavior right at the surface. We show that a very thin film of air, only a few tens of nanometers thick, remains trapped between the falling drop and the surface as the drop spreads. The thin film of air serves to lubricate the drop enabling the fluid to skate on the air film laterally outward at surprisingly high velocities, consistent with theoretical predictions. Eventually this thin film of air breaks down as the fluid wets the surface via a spinodal-like mechanism. Our results show that the dynamics of impacting drops are much more complex than previously thought, with a rich array of unexpected phenomena that require rethinking classic paradigms.

  10. SU-G-JeP3-02: Comparison of Magnitude and Frequency of Patient Positioning Errors in Breast Irradiation Using AlignRT 3D Optical Surface Imaging and Skin Mark Techniques

    International Nuclear Information System (INIS)

    Yao, R; Chisela, W; Dorbu, G

    2016-01-01

    Purpose: To evaluate clinical usefulness of AlignRT (Vision RT Ltd., London, UK) in reducing patient positioning errors in breast irradiation. Methods: 60 patients undergoing whole breast irradiation were selected for this study. Patients were treated to the left or right breast lying on Qfix Access breast board (Qfix, Avondale, PA) in supine position for 28 fractions using tangential fields. 30 patients were aligned using AlignRT by aligning a breast surface region of interest (ROI) to the same area from a reference surface image extracted from planning CT. When the patient’s surface image deviated from the reference by more than 3mm on one or more translational and rotational directions, a new reference was acquired using AlignRT in-room cameras. The other 30 patients were aligned to the skin marks with room lasers. On-Board MV portal images of medial field were taken daily and matched to the DRRs. The magnitude and frequency of positioning errors were determined from measured translational shifts. Kolmogorov-Smirnov test was used to evaluate statistical differences of positional accuracy and precision between AlignRT and non-AlignRT patients. Results: The percentage of port images with no shift required was 46.5% and 27.0% in vertical, 49.8% and 25.8% in longitudinal, 47.6% and 28.5% in lateral for AlignRT and non-AlignRT patients, respectively. The percentage of port images requiring more than 3mm shifts was 18.1% and 35.1% in vertical, 28.6% and 50.8% in longitudinal, 11.3% and 24.2% in lateral for AlignRT and non-AlignRT patients, respectively. Kolmogorov-Smirnov test showed that there were significant differences between the frequency distributions of AlignRT and non-AlignRT in vertical, longitudinal, and lateral shifts. Conclusion: As confirmed by port images, AlignRT-assisted patient positioning can significantly reduce the frequency and magnitude of patient setup errors in breast irradiation compared to the use of lasers and skin marks.

  11. Impact of river restoration on groundwater - surface water - interactions

    Science.gov (United States)

    Kurth, Anne-Marie; Schirmer, Mario

    2014-05-01

    Since the end of the 19th century, flood protection was increasingly based on the construction of impermeable dams and side walls (BWG, 2003). In spite of providing flood protection, these measures also limited the connectivity between the river and the land, restricted the area available for flooding, and hampered the natural flow dynamics of the river. Apart from the debilitating effect on riverine ecosystems due to loss of habitats, these measures also limited bank filtration, inhibited the infiltration of storm water, and affected groundwater-surface water-interactions. This in turn had a profound effect on ecosystem health, as a lack of groundwater-surface water interactions led to decreased cycling of pollutants and nutrients in the hyporheic zone and limited the moderation of the water temperature (EA, 2009). In recent decades, it has become apparent that further damages to riverine ecosystems must be prohibited, as the damages to ecology, economy and society surmount any benefits gained from exploiting them. Nowadays, the restoration of rivers is a globally accepted means to restore ecosystem functioning, protect water resources and amend flood protection (Andrea et al., 2012; Palmer et al., 2005; Wortley et al., 2013). In spite of huge efforts regarding the restoration of rivers over the last 30 years, the question of its effectiveness remains, as river restorations often reconstruct a naturally looking rather than a naturally functioning stream (EA, 2009). We therefore focussed our research on the effectiveness of river restorations, represented by the groundwater-surface water-interactions. Given a sufficiently high groundwater level, a lack of groundwater-surface water-interactions after restoration may indicate that the vertical connectivity in the stream was not fully restored. In order to investigate groundwater-surface water-interactions we determined the thermal signature on the stream bed and in +/- 40 cm depth by using Distributed Temperature

  12. The Impact of Road Maintenance Substances on Metals Surface Corrosion

    OpenAIRE

    Jolita Petkuvienė; Dainius Paliulis

    2011-01-01

    The purpose of research is to assess changes in the visual metal surface due to the exposure of road maintenance salts and molasses (‘Safecote’). Chlorides of deicing salts (NaCl, CaCl2) are the main agents affecting soil and water resources as well as causing the corrosion of roadside metallic elements. Molasses (‘Safecote’) is offered as an alternative to deice road pavement by minimizing the corrosion of metal elements near the road. A laboratory experiment was carried out to immerse and s...

  13. Isotopic marking and tracers

    International Nuclear Information System (INIS)

    Morel, F.

    1997-01-01

    The use of radioactive isotopes as tracers in biology has been developed thanks to the economic generation of the required isotopes in accelerators and nuclear reactors, and to the multiple applications of tracers in the life domain; the most usual isotopes employed in biology are carbon, hydrogen, phosphorus and sulfur isotopes, because these elements are present in most of organic molecules. Most of the life science knowledge appears to be dependent to the extensive use of nuclear tools and radioactive tracers; the example of the utilization of radioactive phosphorus marked ATP to study the multiple reactions with proteins, nucleic acids, etc., is given

  14. Ceremony marking Einstein Year

    CERN Multimedia

    2005-01-01

    Sunday 13th November at 10:00amat Geneva's St. Peter's Cathedral To mark Einstein Year and the importance of the intercultural dialogue of which it forms a part, a religious service will take place on Sunday 13 November at 10 a.m. in St. Peter's Cathedral, to which CERN members and colleagues are warmly welcomed. Pastor Henry Babel, senior minister at the Cathedral, will speak on the theme: 'God in Einstein's Universe'. Diether Blechschmidt will convey a message on behalf of the scientific community.

  15. Minimal Marking: A Success Story

    Science.gov (United States)

    McNeilly, Anne

    2014-01-01

    The minimal-marking project conducted in Ryerson's School of Journalism throughout 2012 and early 2013 resulted in significantly higher grammar scores in two first-year classes of minimally marked university students when compared to two traditionally marked classes. The "minimal-marking" concept (Haswell, 1983), which requires…

  16. SEM Analysis of Surface Impact on Biofilm Antibiotic Treatment.

    Science.gov (United States)

    Gomes, Luciana Calheiros; Mergulhão, Filipe José

    2017-01-01

    The aim of this work was to use scanning electron microscopy (SEM) to investigate the effect of ampicillin treatment on Escherichia coli biofilms formed on two surface materials with different properties, silicone (SIL) and glass (GLA). Epifluorescence microscopy (EM) was initially used to assess biofilm formation and killing efficiency on both surfaces. This technique showed that higher bacterial colonization was obtained in the hydrophobic SIL than in the hydrophilic GLA. It has also shown that higher biofilm inactivation was attained for GLA after the antibiotic treatment (7-log reduction versus 1-log reduction for SIL). Due to its high resolution and magnification, SEM enabled a more detailed analysis of the antibiotic effect on biofilm cells, complementing the killing efficiency information obtained by EM. SEM micrographs revealed that ampicillin-treated cells have an elongated form when compared to untreated cells. Additionally, it has shown that different materials induced different levels of elongation on cells exposed to antibiotic. Biofilms formed on GLA showed a 37% higher elongation than those formed on SIL. Importantly, cell elongation was related to viability since ampicillin had a higher bactericidal effect on GLA-formed biofilms. These findings raise the possibility of using SEM for understanding the efficacy of antimicrobial treatments by observation of biofilm morphology.

  17. Surface modifications induced by pulsed-laser texturing—Influence of laser impact on the surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Costil, S., E-mail: sophie.costil@utbm.fr [IRTES-LERMPS, Université de Technologie de Belfort - Montbéliard, site de Sévenans, 90010 Belfort Cedex (France); Lamraoui, A.; Langlade, C. [IRTES-LERMPS, Université de Technologie de Belfort - Montbéliard, site de Sévenans, 90010 Belfort Cedex (France); Heintz, O.; Oltra, R. [ICB, Université de Bourgogne, 21078 Dijon Cedex (France)

    2014-01-01

    Laser cleaning technology provides a safe, environmentally friendly and very cost effective way to improve cleaning and surface preparation of metallic materials. Compared with efficient cleaning processes, it can avoid the disadvantages of ductile materials prepared by conventional technologies (cracks induced by sand-blasting for example) and treat only some selected areas (due to the optical fibers). By this way, laser technology could have several advantages and expand the range of thermal spraying. Moreover, new generations of lasers (fiber laser, disc laser) allow the development of new methods. Besides a significant bulk reduction, no maintenance, low operating cost, laser fibers can introduce alternative treatments. Combining a short-pulse laser with a scanner allows new applications in terms of surface preparation. By multiplying impacts using scanning laser, it is possible to shape the substrate surface to improve the coating adhesion as well as the mechanical behaviour. In addition, during the interactions of the laser beam with metallic surfaces, several modifications can be induced and particularly thermal effects. Indeed, under ambient conditions, a limited oxidation of the clean surface can occur. This phenomenon has been investigated in detail for silicon but few works have been reported concerning metallic materials. This paper aims at studying the surface modifications induced on aluminium alloy substrates after laser texturing. After morphological observations (SEM), a deeper surface analysis will be performed using XPS (X-ray photoelectron spectroscopy) measures and microhardness testing.

  18. Surface effects on in-shoe plantar pressure and tibial impact during running

    Directory of Open Access Journals (Sweden)

    Weijie Fu

    2015-12-01

    Conclusion: There may not be an inevitable relationship between the surface and the lower-limb impact in runners. It is, however, still noteworthy that the effects of different treadmill surfaces should be considered in the interpretation of plantar pressure performance and translation of such results to overground running.

  19. Fibromyalgia has a larger impact on physical health than on psychological health, yet both are markedly affected: the al-Ándalus project.

    Science.gov (United States)

    Segura-Jiménez, Víctor; Álvarez-Gallardo, Inmaculada C; Carbonell-Baeza, Ana; Aparicio, Virginia A; Ortega, Francisco B; Casimiro, Antonio J; Delgado-Fernández, Manuel

    2015-04-01

    To characterize a representative sample of fibromyalgia women based on a set of relevant factors known to be related to this disease. To distinguish specific factors of the disease from other symptoms that might also exist in non-fibromyalgia women. To test whether fibromyalgia affects more severely physical or psychological outcomes. A total of 459 fibromyalgia women vs. 214 non-fibromyalgia (control) women from Southern Spain (Andalusia) took part in this cross-sectional study. Several instruments were used to assess tenderness, impact of fibromyalgia, fatigue, health-related quality of life, mental health, and cognitive performance. Overall, fibromyalgia women showed a worse status in pain, fatigue, health-related quality of life, depression, and anxiety than controls (P fibromyalgia and controls were observed in cognitive and memory performance, except for delayed recall, but the observed effect size was low (~0.25). The effect size observed for the global physical component (~3.3) was larger than that for the global psychological component (~1.3), all P fibromyalgia as a polysymptomatic distress condition with pain as its main symptom. Our findings support that fibromyalgia seems to have a greater impact on physical than on psychological outcomes, though both are largely affected. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Impact of cranberry on Escherichia coli cellular surface characteristics

    International Nuclear Information System (INIS)

    Johnson, Brandy J.; Lin Baochuan; Dinderman, Michael A.; Rubin, Robert A.; Malanoski, Anthony P.; Ligler, Frances S.

    2008-01-01

    The anti-adhesive effects of cranberry have been attributed to both interactions of its components with the surface of bacterial cells and to inhibition of p-fimbriae expression. Previous reports also suggested that the presence of cranberry juice changed the Gram stain characteristics of Escherichia coli. Here, we show that the morphology of E. coli is changed when grown in the presence of juice or extract from Vaccinium macrocarpon (cranberry). Gene expression analysis indicates the down regulation of flagellar basal body rod and motor proteins. Consistent with this finding and previous reports, the SEM images indicate a decrease in the visible p-fimbriae. The iodine used in Gram-staining protocols was found to interact differently with the bacterial membrane when cells were cultured in spiked media. Slight alterations in the Gram stain protocol demonstrated that culturing in the presence of cranberry juice does not change the Gram stain characteristics contradicting other reports.

  1. Secondary ion mass spectrometry (SIMS) analysis of hypervelocity microparticle impact sites on LDEF surfaces

    Science.gov (United States)

    Simon, C. G.; Buonaquisti, A. J.; Batchelor, D. A.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. R.; Wortman, J. J.; Brownlee, D. E.; Best, S. R.

    1995-01-01

    Two dimensional elemental ion maps have been recorded for hundreds of microparticle impact sites and contamination features on LDEF surfaces. Since the majority of the analyzed surfaces were metal-oxide-silicon (MOS) impact detectors from the Interplanetary Dust Experiment, a series of 'standard' and 'blank' analyses of these surfaces are included. Hypervelocity impacts of forsterite olivine microparticles on activated flight sensors served as standards while stylus and pulsed laser simulated 'impacts' served as analytical blanks. Results showed that despite serious contamination issues, impactor residues can be identified in greater than 1/3 of the impact sites. While aluminum oxide particles could not be detected on aluminum surfaces, they were detected on germanium surfaces from row 12. Remnants of manmade debris impactors consisting of paint chips and bits of metal were identified on surfaces from LDEF Rows 3 (west or trailing side), 6 (south), 9 (ram or leading side), 12 (north) and the space end. Higher than expected ratios of manmade microparticle impacts to total microparticle impacts were found on the space end and the trailing side. These results were consistent with time-tagged and time-segregated microparticle impact data from the IDE and other LDEF experiments. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences include pre-, post and inflight deposited surface contaminants as well as indigenous heterogeneous material contaminants. Non-flight contaminations traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with location on LDEF, even on a micro scale. In-flight deposited (low velocity) contaminants include urine droplets and bits of metal film from eroded thermal

  2. Impact of plasma-sprayed metal particles on hot and cold glass surfaces

    International Nuclear Information System (INIS)

    McDonald, A.; Lamontagne, M.; Moreau, C.; Chandra, S.

    2006-01-01

    Plasma-sprayed molten molybdenum and amorphous steel particles (38-55 μm diameter) were photographed during impact (velocity 120-200 m/s) and spreading on a smooth glass surface that was maintained at either room temperature or 400 deg. C. Droplets approaching the surface were identified by a photodetector and after a known delay, a 5-ns laser pulse was triggered to illuminate the spreading splat and photograph it with a charge-coupled device (CCD) camera. A rapid two-color pyrometer was used to collect thermal radiation from particles during flight and impact to follow the evolution of their temperature and size. Particles that impacted the surface at room temperature ruptured and splashed, leaving a small central solidified core on the substrate. On a surface held at 400 deg. C, there was no splashing and a circular, disk-like splat remained on the surface. Splats on a glass surface held at room temperature had a maximum spread diameter almost three times that on a hot surface. A simple analysis was done to estimate the area of the splat in contact with the non-heated glass surface during spreading. The analysis supports the hypothesis that only a portion of the splat is in good contact with the surface at room temperature, while the rest of the fluid is separated from the substrate by a gas barrier

  3. Transfer of impact ejecta material from the surface of Mars to Phobos and Deimos.

    Science.gov (United States)

    Chappaz, Loïc; Melosh, Henry J; Vaquero, Mar; Howell, Kathleen C

    2013-10-01

    The Russian Phobos-Grunt spacecraft originally planned to return a 200 g sample of surface material from Phobos to Earth. Although it was anticipated that this material would mainly be from the body of Phobos, there is a possibility that such a sample may also contain material ejected from the surface of Mars by large impacts. An analysis of this possibility is completed by using current knowledge of aspects of impact cratering on the surface of Mars and the production of high-speed ejecta that might reach Phobos or Deimos.

  4. The impacts of surface ozone pollution on winter wheat productivity in China – An econometric approach

    International Nuclear Information System (INIS)

    Yi, Fujin; Jiang, Fei; Zhong, Funing; Zhou, Xun; Ding, Aijun

    2016-01-01

    The impact of surface ozone pollution on winter wheat yield is empirically estimated by considering socio-economic and weather determinants. This research is the first to use an economic framework to estimate the ozone impact, and a unique county-level panel is employed to examine the impact of the increasing surface ozone concentration on the productivity of winter wheat in China. In general, the increment of surface ozone concentration during the ozone-sensitive period of winter wheat is determined to be harmful to its yield, and a conservative reduction of ozone pollution could significantly increase China's wheat supply. - Highlights: • We examine the impacts of the surface ozone exposure on winter wheat yield in China. • An econometric method is used to measure the ozone impacts. • The results conclude that surface ozone is harmful to winter wheat yield in China. • We confirm that stress conditions such as drought and air particles can mitigate the adverse effect of ozone. - Surface ozone pollution is harmful to winter wheat yield in China by considering socio-economic determinants, weather, and other stress conditions like drought and air particles.

  5. Impact of vegetation growth on urban surface temperature distribution

    International Nuclear Information System (INIS)

    Buyadi, S N A; Mohd, W M N W; Misni, A

    2014-01-01

    Earlier studies have indicated that, the temperature distribution in the urban area is significantly warmer than its surrounding suburban areas. The process of urbanization has created urban heat island (UHI). As a city expands, trees are cut down to accommodate commercial development, industrial areas, roads, and suburban growth. Trees or green areas normally play a vital role in mitigating the UHI effects especially in regulating high temperature in saturated urban areas. This study attempts to assess the effects of vegetation growth on land surface temperature (LST) distribution in urban areas. An area within the City of Shah Alam, Selangor has been selected as the study area. Land use/land cover and LST maps of two different dates are generated from Landsat 5 TM images of the year 1991 and 2009. Only five major land cover classes are considered in this study. Mono-window algorithm is used to generate the LST maps. Landsat 5 TM images are also used to generate the NDVI maps. Results from this study have shown that there are significant land use changes within the study area. Although the conversion of green areas into residential and commercial areas significantly increase the LST, matured trees will help to mitigate the effects of UHI

  6. Alternative to chrome in the aluminium surface finishing industry. Low environmental impact surface treatments

    International Nuclear Information System (INIS)

    Aballe Villero, A.; Bethencourt Nunez, M.; Botana Pedemonte, F. J.; Marco Barcena, M.; Sanchez-Amaya, J. M.

    2001-01-01

    Chromates are one of the most commonly used compounds in anti corrosive protection systems because of its excellent rate efficiency/cost. In the case of aluminium alloys, these compounds are employed as inhibitors as well as in the anti-corrosive pretreatments to develop protective films. However, chromates are highly toxic and its use involves a high risk for health and environment. Consequently, in the last years intensive efforts have been achieved in the surface treatment industry to find ecological alternatives to this kind of compounds. In this work, the main alternatives proposed in literature to substitute chromates in the surface treatments of aluminium alloys are reviewed. To begin with, the role of chromates in these systems and their environmental consequences has been briefly reviewed. (Author) 16 refs

  7. Ultrasonic impact treatment of CoCrMo alloy: Surface composition and properties

    Energy Technology Data Exchange (ETDEWEB)

    Chenakin, S.P., E-mail: chenakin@list.ru; Filatova, V.S.; Makeeva, I.N.; Vasylyev, M.A.

    2017-06-30

    Highlights: • Ultrasonic impact treatment in air enhances oxidation of CoCrMo alloy. • Impact treatment promotes segregation and accumulation of carbon on the surface. • Intense deformation brings about partial dissolution of carbides. • Impact-induced fcc-to-hcp transformation and hardening of the alloy. • Impact treatment improves corrosion properties of the alloy. - Abstract: X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry and X-ray diffraction were employed to study the effect of intense mechanical treatment on the surface chemical state, composition and structure of a commercial biomedical CoCrMo alloy (‘Bondi-Loy’). The ultrasonic impact treatment of the alloy in air with duration up to 30 s was found to cause the deformation-enhanced oxidation and deformation-induced surface segregation of the components and impurities from the bulk. The compositionally inhomogeneous mixed oxide layer formed under impact treatment was composed mainly of Cr{sub 2}O{sub 3} and silicon oxide with admixture of CoO, MoO{sub 2}, MoO{sub 3} and iron oxide/hydroxide, the latter being transferred onto the alloy surface from the steel pin. The impact treatment promoted a progressive accumulation of carbon on the alloy surface due to its deformation-induced segregation from the bulk and deformation-induced uptake of hydrocarbons from the ambient; concurrently, the dissolution/refinement of carbides originally present in the as-cast CoCrMo alloy occurred. The impact treatment gave rise to a two-fold increase in the volume fraction of the martensitic hcp ε-phase, a 30% increase in the surface microhardness and improved resistance to corrosion in the solution of artificial saliva compared to the as-polished alloy.

  8. Impact of nanostructured surfaces on endothelial β-catenin signaling

    International Nuclear Information System (INIS)

    Schernthaner, M.

    2013-01-01

    In this thesis, we set out to investigate the influence of differently structured polyethylene terephtalate (PET) surfaces on human microvascular endothelial cells (HMEC). First, we tested so called ripples with a periodicity of 300 nm and second, wall structures with a periodicity of 1.5 µm. both generated by laser irradiation of PET substrates. We investigated cell adhesion and orientation by electron microscopy and determined cell proliferation levels. Endothelial proliferation is controlled by the junctional protein β-catenin, which translocates to the nucleus to activate target gene expression when released from is normal localization in cell-cell contacts. We observed that β-catenin translocates to the nucleus of endothelial cells grown on both types of structured substrates. However, the expression levels of the target gene cyclin D1 were enhanced in cells grown on ripples only. The use of different tyrosine kinase inhibitors revealed Src and Abl kinases as upstream signaling elements of β-catenin-mediated cell proliferation on ripples, while Src was found not involved in cell proliferation on walls. Since Src activation is strongly linked to Ca 2+ signaling, we tested for differences in store-operated Ca 2+ -entry (SOCE) and mechanically induced Ca 2+ -entry. Cells grown on ripples displayed significantly enhanced SOCE compared to cells grown on walls. Moreover, SOCE and shear-induced Ca 2+ -entry showed clear gadolinium (Gd 3+ ) sensitivity in cells grown on ripples only. Taken together, our results demonstrated that both structures induce endothelial β-catenin signaling by enhanced tyrosine phosphorylation leading to increased cell proliferation. The signaling process on ripples further involves Src activation and SOCE signaling. The proliferation enhancing features of the nanostructured PET substrates investigated in this thesis might be used for tissue engineering strategies.(author) [de

  9. Newtonian liquid jet impaction on a high-speed moving surface

    International Nuclear Information System (INIS)

    Keshavarz, B.; Green, S.I.; Davy, M.H.; Eadie, D.T.

    2011-01-01

    Highlights: ► We studied experimentally the interaction of a liquid jet with a moving surface. ► Decreasing the Reynolds number reduced the incidence of splash. ► The Weber number had a much smaller impact on splash than the Reynolds number. ► The jet impingement angle had only a small effect on the splash. ► Increasing the surface roughness substantially decreased the splash threshold. - Abstract: In the railroad industry a friction modifying agent may be applied to the rail or wheel in the form of a liquid jet. In this mode of application the interaction between the high-speed liquid jet and a fast moving surface is important. Seven different Newtonian liquids with widely varying shear viscosities were tested to isolate the effect of viscosity from other fluid properties. Tests were also done on five surfaces of different roughness heights to investigate the effects of surface roughness. High-speed video imaging was employed to scrutinize the interaction between the impacting jet and the moving surface. For all surfaces, decreasing the Reynolds number reduced the incidence of splash and consequently enhanced the transfer efficiency. At the elevated Weber numbers of the testing, the Weber number had a much smaller impact on splash than the Reynolds number. The ratio of the surface velocity to the jet velocity has only a small effect on the splash, whereas increasing the roughness-height-to-jet-diameter ratio substantially decreased the splash threshold.

  10. Continuum modeling of ion-beam eroded surfaces under normal incidence: Impact of stochastic fluctuations

    International Nuclear Information System (INIS)

    Dreimann, Karsten; Linz, Stefan J.

    2010-01-01

    Graphical abstract: Deterministic surface pattern (left) and its stochastic counterpart (right) arising in a stochastic damped Kuramoto-Sivashinsky equation that serves as a model equation for ion-beam eroded surfaces and is systematically investigated. - Abstract: Using a recently proposed field equation for the surface evolution of ion-beam eroded semiconductor target materials under normal incidence, we systematically explore the impact of additive stochastic fluctuations that are permanently present during the erosion process. Specifically, we investigate the dependence of the surface roughness, the underlying pattern forming properties and the bifurcation behavior on the strength of the fluctuations.

  11. Identification marking by means of laser peening

    Science.gov (United States)

    Hackel, Lloyd A.; Dane, C. Brent; Harris, Fritz

    2002-01-01

    The invention is a method and apparatus for marking components by inducing a shock wave on the surface that results in an indented (strained) layer and a residual compressive stress in the surface layer. One embodiment of the laser peenmarking system rapidly imprints, with single laser pulses, a complete identification code or three-dimensional pattern and leaves the surface in a state of deep residual compressive stress. A state of compressive stress in parts made of metal or other materials is highly desirable to make them resistant to fatigue failure and stress corrosion cracking. This process employs a laser peening system and beam spatial modulation hardware or imaging technology that can be setup to impress full three dimensional patterns into metal surfaces at the pulse rate of the laser, a rate that is at least an order of magnitude faster than competing marking technologies.

  12. Wakes behind surface-mounted obstacles: Impact of aspect ratio, incident angle, and surface roughness

    Science.gov (United States)

    Tobin, Nicolas; Chamorro, Leonardo P.

    2018-03-01

    The so-called wake-moment coefficient C˜h and lateral wake deflection of three-dimensional windbreaks are explored in the near and far wake. Wind-tunnel experiments were performed to study the functional dependence of C˜h with windbreak aspect ratio, incidence angle, and the ratio of the windbreak height and surface roughness (h /z0 ). Supported with the data, we also propose basic models for the wake deflection of the windbreak in the near and far fields. The near-wake model is based on momentum conservation considering the drag on the windbreak, whereas the far-wake counterpart is based on existing models for wakes behind surface-mounted obstacles. Results show that C˜h does not change with windbreak aspect ratios of 10 or greater; however, it may be lower for an aspect ratio of 5. C˜h is found to change roughly with the cosine of the incidence angle, and to depend strongly on h /z0 . The data broadly support the proposed wake-deflection models, though better predictions could be made with improved knowledge of the windbreak drag coefficient.

  13. 15 CFR 1150.3 - Approved markings.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Approved markings. 1150.3 Section 1150.3 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued... permanently affixed to the exterior surface of the barrel, covering the circumference of the barrel from the...

  14. SLARette Mark 2 system

    International Nuclear Information System (INIS)

    Burnett, D.J.

    1992-01-01

    The SLAR (Spacer Location and Repositioning) program has developed the technology and tooling necessary to locate and reposition the fuel channel spacers that separate the pressure tube from the calandria tube in a CANDU reactor. The in-channel SLAR tool contains all the inspection probes, and is capable of moving spacers under remote control. The SLAR inspection computer system translates all eddy currents and ultrasonic signals from the in-channel tool into various graphic displays. The in-channel SLAR tool can be delivered and manipulated in a fuel channel by either a SLAR delivery machine or a SLARette delivery machine. The SLAR delivery machine consists of a modified fuelling machine, and is capable of operating under totally remote control in automatic or semi-automatic mode. The SLARette delivery machine is a smaller less automated version, which was designed to be quickly installed, operated, and removed from a limited number of fuel channels during regular annual maintenance outages. This paper describes the design and operation of the SLARette Mark 2 system. 5 figs

  15. Biofuels: on your marks

    International Nuclear Information System (INIS)

    Scheromm, P.

    1993-01-01

    Biomass fuels are in France: ethanol (from wheat, sugar beets, potatoes, jerusalem artichoke, ligno-cellulose wastes or forests) and its derived ETBE (ethyltertiobutylether), methanol (from petroleum) and its derived MTBE (methyltertiobutylether), vegetable oils and its derived DIESTER (methylester of colza or sunflower). Economic and energy balances are given with environmental impacts. (A.B.). 6 refs

  16. The dynamics of the water droplet impacting onto hot solid surfaces at medium Weber numbers

    Science.gov (United States)

    Mitrakusuma, Windy H.; Kamal, Samsul; Indarto; Dyan Susila, M.; Hermawan; Deendarlianto

    2017-10-01

    The effects of the wettability of a droplet impacting onto a hot solid surface under medium Weber numbers were studied experimentally. The Weber numbers used in the present experiment were 52.1, 57.6, and 63.1. Three kinds of solid surfaces with different wettability were used. These were normal stainless steel (NSS), TiO2 coated NSS, and TiO2 coated NSS radiated with ultraviolet rays. The surface temperatures were varied from 60 to 200 °C. The image of side the view and 30° from horizontal were taken to explain the spreading and the interfacial behavior of a single droplet during impact the hot solid surfaces. It was found that under medium Weber numbers, the surface wettability plays an important role on the droplet spreading and evaporation time during the impact on the hot solid surfaces. The higher the wettability, the larger the droplet spreading on the hot surface, and the lower the evaporation time.

  17. EcoMark 2.0

    DEFF Research Database (Denmark)

    Guo, Chenjuan; Yang, Bin; Andersen, Ove

    2015-01-01

    Eco-routing is a simple yet effective approach to substantially reducing the environmental impact, e.g., fuel consumption and greenhouse gas (GHG) emissions, of vehicular transportation. Eco-routing relies on the ability to reliably quantify the environmental impact of vehicles as they travel...... in a spatial network. The procedure of quantifying such vehicular impact for road segments of a spatial network is called eco-weight assignment. EcoMark 2.0 proposes a general framework for eco-weight assignment to enable eco-routing. It studies the abilities of six instantaneous and five aggregated models......, and experiments for assessing the utility of the impact models in assigning eco-weights. The application of EcoMark 2.0 indicates that the instantaneous model EMIT and the aggregated model SIDRA-Running are suitable for assigning eco-weights under varying circumstances. In contrast, other instantaneous models...

  18. The Four Marks of Holistic Kinesiology

    Science.gov (United States)

    Twietmeyer, Gregg

    2012-01-01

    What, to borrow a theological phrase, are the marks of a truly holistic kinesiology department? "In Kinesis and the Nature of the Human Person" (2010), I examined the theoretical impact of Aristotle's definition of "kinesis" and Polanyi's theory of "tacit knowledge" on kinesiology. The intention here, however, is practical rather than theoretical.…

  19. Elastic wave generated by granular impact on rough and erodible surfaces

    Science.gov (United States)

    Bachelet, Vincent; Mangeney, Anne; de Rosny, Julien; Toussaint, Renaud; Farin, Maxime

    2018-01-01

    The elastic waves generated by impactors hitting rough and erodible surfaces are studied. For this purpose, beads of variable materials, diameters, and velocities are dropped on (i) a smooth PMMA plate, (ii) stuck glass beads on the PMMA plate to create roughness, and (iii) the rough plate covered with layers of free particles to investigate erodible beds. The Hertz model validity to describe impacts on a smooth surface is confirmed. For rough and erodible surfaces, an empirical scaling law that relates the elastic energy to the radius Rb and normal velocity Vz of the impactor is deduced from experimental data. In addition, the radiated elastic energy is found to decrease exponentially with respect to the bed thickness. Lastly, we show that the variability of the elastic energy among shocks increases from some percents to 70% between smooth and erodible surfaces. This work is a first step to better quantify seismic emissions of rock impacts in natural environment, in particular on unconsolidated soils.

  20. Cavitation induced by high speed impact of a solid surface on a liquid jet

    Science.gov (United States)

    Farhat, Mohamed; Tinguely, Marc; Rouvinez, Mathieu

    2009-11-01

    A solid surface may suffer from severe erosion if it impacts a liquid jet at high speed. The physics behind the erosion process remains unclear. In the present study, we have investigated the impact of a gun bullet on a laminar water jet with the help of a high speed camera. The bullet has a flat front and 11 mm diameter, which is half of jet diameter. The impact speed was varied between 200 and 500 ms-1. Immediately after the impact, a systematic shock wave and high speed jetting were observed. As the compression waves reflect on the jet boundary, a spectacular number of vapour cavities are generated within the jet. Depending on the bullet velocity, these cavities may grow and collapse violently on the bullet surface with a risk of cavitation erosion. We strongly believe that this transient cavitation is the main cause of erosion observed in many industrial applications such as Pelton turbines.

  1. Elastic–plastic adhesive impacts of tungsten dust with metal surfaces in plasma environments

    Energy Technology Data Exchange (ETDEWEB)

    Ratynskaia, S., E-mail: svetlana.ratynskaia@ee.kth.se [KTH Royal Institute of Technology, Association EUROfusion-VR, Stockholm (Sweden); Tolias, P. [KTH Royal Institute of Technology, Association EUROfusion-VR, Stockholm (Sweden); Shalpegin, A. [Université de Lorraine, Institut Jean Lamour, Vandoeuvre-lès-Nancy (France); Vignitchouk, L. [KTH Royal Institute of Technology, Association EUROfusion-VR, Stockholm (Sweden); De Angeli, M. [Istituto di Fisica del Plasma – Consiglio Nazionale delle Ricerche, Milan (Italy); Bykov, I. [KTH Royal Institute of Technology, Association EUROfusion-VR, Stockholm (Sweden); Bystrov, K.; Bardin, S. [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Edisonbaan 14, 3439MN Nieuwegein (Netherlands); Brochard, F. [Université de Lorraine, Institut Jean Lamour, Vandoeuvre-lès-Nancy (France); Ripamonti, D. [Istituto per l’Energetica e le Interfasi – Consiglio Nazionale delle Ricerche, Milan (Italy); Harder, N. den; De Temmerman, G. [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Edisonbaan 14, 3439MN Nieuwegein (Netherlands)

    2015-08-15

    Dust-surface collisions impose size selectivity on the ability of dust grains to migrate in scrape-off layer and divertor plasmas and to adhere to plasma-facing components. Here, we report first experimental evidence of dust impact phenomena in plasma environments concerning low-speed collisions of tungsten dust with tungsten surfaces: re-bouncing, adhesion, sliding and rolling. The results comply with the predictions of the model of elastic-perfectly plastic adhesive spheres employed in the dust dynamics code MIGRAINe for sub- to several meters per second impacts of micrometer-range metal dust.

  2. Impact of Dust on Mars Surface Albedo and Energy Flux with LMD General Circulation Model

    Science.gov (United States)

    Singh, D.; Flanner, M.; Millour, E.; Martinez, G.

    2015-12-01

    Mars, just like Earth experience different seasons because of its axial tilt (about 25°). This causes growth and retreat of snow cover (primarily CO2) in Martian Polar regions. The perennial caps are the only place on the planet where condensed H2O is available at surface. On Mars, as much as 30% atmospheric CO2 deposits in each hemisphere depending upon the season. This leads to a significant variation on planet's surface albedo and hence effecting the amount of solar flux absorbed or reflected at the surface. General Circulation Model (GCM) of Laboratoire de Météorologie Dynamique (LMD) currently uses observationally derived surface albedo from Thermal Emission Spectrometer (TES) instrument for the polar caps. These TES albedo values do not have any inter-annual variability, and are independent of presence of any dust/impurity on surface. Presence of dust or other surface impurities can significantly reduce the surface albedo especially during and right after a dust storm. This change will also be evident in the surface energy flux interactions. Our work focuses on combining earth based Snow, Ice, and Aerosol Radiation (SNICAR) model with current state of GCM to incorporate the impact of dust on Martian surface albedo, and hence the energy flux. Inter-annual variability of surface albedo and planet's top of atmosphere (TOA) energy budget along with their correlation with currently available mission data will be presented.

  3. Distinguishing butchery cut marks from crocodile bite marks through machine learning methods.

    Science.gov (United States)

    Domínguez-Rodrigo, Manuel; Baquedano, Enrique

    2018-04-10

    All models of evolution of human behaviour depend on the correct identification and interpretation of bone surface modifications (BSM) on archaeofaunal assemblages. Crucial evolutionary features, such as the origin of stone tool use, meat-eating, food-sharing, cooperation and sociality can only be addressed through confident identification and interpretation of BSM, and more specifically, cut marks. Recently, it has been argued that linear marks with the same properties as cut marks can be created by crocodiles, thereby questioning whether secure cut mark identifications can be made in the Early Pleistocene fossil record. Powerful classification methods based on multivariate statistics and machine learning (ML) algorithms have previously successfully discriminated cut marks from most other potentially confounding BSM. However, crocodile-made marks were marginal to or played no role in these comparative analyses. Here, for the first time, we apply state-of-the-art ML methods on crocodile linear BSM and experimental butchery cut marks, showing that the combination of multivariate taphonomy and ML methods provides accurate identification of BSM, including cut and crocodile bite marks. This enables empirically-supported hominin behavioural modelling, provided that these methods are applied to fossil assemblages.

  4. Damage at a tungsten surface induced by impacts of self-atoms

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yong [Data Center for High Energy Density Physics, Institute of Applied Physics and, Computational Mathematics, P. O. Box 8009, Beijing 100088 (China); Krstic, Predrag, E-mail: predrag.krstic@stonybrook.edu [Institute for Advanced Computational Science, Stony Brook University, Stony Brook, NY 11794-5250 (United States); Zhou, Fu Yang [College of Material Sciences and Optoelectronic Technology, University of the Chinese Academy of Sciences, P. O. Box 4588, Beijing 100049 (China); Meyer, Fred [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6372 (United States)

    2015-12-15

    We study evolution of the surface defects of a 300 K tungsten surface due to the cumulative impact of 0.25–10 keV self-atoms. The simulation is performed by molecular dynamics with bond-order Tersoff-form potentials. At all studied impact energies the computation shows strong defect-recombination effect of both created Frenkel pairs as well as recombination of the implanted atoms with the vacancies created by the sputtering. This leads to a saturation of the cumulative count of vacancies, evident at energies below 2 keV, as long as the implantation per impact atom exceeds sputtering and to a saturation of the interstitial count when production of the sputtered particles per impact atom becomes larger than 1 (in the energy range 2-4 keV). The number of cumulative defects is fitted as functions of impact fluence and energy, enabling their analytical extrapolation outside the studied range of parameters. - Highlights: • We calculated cumulative creation of defects in tungsten by self-atom impact. • At some energies, the defect count saturate with increasing damage dose. • The defects are accumulated in the first few layers of the tungsten surface. • The interstitials are formed predominantly as adatoms.

  5. Fracture Surface Morphology and Impact Strength of Cellulose/PLA Composites.

    Science.gov (United States)

    Gao, Honghong; Qiang, Tao

    2017-06-07

    Polylactide (PLA)-based composite materials reinforced with ball-milled celluloses were manufactured by extrusion blending followed by injection molding. Their surface morphology from impact fracture were imaged with scanning electron microscopy (SEM) and investigated by calculating their fractal dimensions. Then, linear regression was used to explore the relationship between fractal dimension and impact strength of the resultant cellulose/PLA composite materials. The results show that filling the ball-milled celluloses into PLA can improve the impact toughness of PLA by a minimum of 38%. It was demonstrated that the fracture pattern of the cellulose/PLA composite materials is different from that of pristine PLA. For the resultant composite materials, the fractal dimension of the impact fractured surfaces increased with increasing filling content and decreasing particle size of the ball-milled cellulose particles. There were highly positive correlations between fractal dimension of the fractured surfaces and impact strength of the cellulose/PLA composites. However, the linearity between fractal dimension and impact strength were different for the different methods, due to their different R-squared values. The approach presented in this work will help to understand the structure-property relationships of composite materials from a new perspective.

  6. Comparison of the impact of scaler material composition on polished titanium implant abutment surfaces.

    Science.gov (United States)

    Hasturk, Hatice; Nguyen, Daniel Huy; Sherzai, Homa; Song, Xiaoping; Soukos, Nikos; Bidlack, Felicitas B; Van Dyke, Thomas E

    2013-08-01

    The purpose of this study was to compare the impact of the removal of biofilm with hand scalers of different material composition on the surface of implant abutments by assessing the surface topography and residual plaque after scaling using scanning electron microscopy (SEM). Titanium implant analogs from 3 manufacturers (Straumann USA LLC, Andover, Maine, Nobel BioCare USA LLC, Yorba Linda, Cali, Astra Tech Implant Systems, Dentsply, Mölndal, Sweden) were mounted in stone in plastic vials individually with authentic prosthetic abutments. Plaque samples were collected from a healthy volunteer, inoculated into growth medium and incubated with the abutments anaerobically for 1 week. A blinded, calibrated hygienist performed scaling to remove the biofilm using 6 implant scalers (in triplicate), 1 scaler for 1 abutment. The abutments were mounted on an imaging stand and processed for SEM. Images were captured in 3 randomly designated areas of interest on each abutment. Analysis of the implant polished abutment surface and plaque area measurements were performed using ImageJ image analysis software. Surface alterations were characterized by the number, length, depth and the width of the scratches observed. Glass filled resin scalers resulted in significantly more and longer scratches on all 3 abutment types compared to other scalers, while unfilled resin scalers resulted in the least surface change (p abutments with regard to plaque removal. The impact of scalers on implant abutment surfaces varies between abutment types presumably due to different surface characteristics with no apparent advantage of one abutment type over the other with regard to resistance to surface damage. Unfilled resin was found consistently to be the least damaging to abutment surfaces, although all scalers of all compositions caused detectable surface changes to polished surfaces of implant abutments.

  7. Impact of the surface wind flow on precipitation characteristics over the southern Himalayas: GPM observations

    Science.gov (United States)

    Zhang, Aoqi; Fu, Yunfei; Chen, Yilun; Liu, Guosheng; Zhang, Xiangdong

    2018-04-01

    The distribution and influence of precipitation over the southern Himalayas have been investigated on regional and global scales. However, previous studies have been limited by the insufficient emphasis on the precipitation triggers or the lack of droplet size distribution (DSD) data. Here, precipitating systems were identified using Global Precipitation Mission dual-frequency radar data, and then categorized into five classes according to surface flow from the European Centre for Medium-Range Weather Forecast Interim data. The surface flow is introduced to indicate the precipitation triggers, which is validated in this study. Using case and statistical analysis, we show that the precipitating systems with different surface flow had different precipitation characteristics, including spatio-temporal features, reflectivity profile, DSD, and rainfall intensity. Furthermore, the results show that the source of the surface flow influences the intensity and DSD of precipitation. The terrain exerts different impacts on the precipitating systems of five categories, leading to various distributions of precipitation characteristics over the southern Himalayas. Our results suggest that the introduction of surface flow and DSD for precipitating systems provides insight into the complex precipitation of the southern Himalayas. The different characteristics of precipitating systems may be caused by the surface flow. Therefore, future study on the orographic precipitations should take account the impact of the surface flow and its relevant dynamic mechanism.

  8. Mark Kostabi soovib muuta inimesi õnnelikumaks / Kalev Mark Kostabi

    Index Scriptorium Estoniae

    Kostabi, Kalev Mark, 1960-

    2008-01-01

    Kalev Mark Kostabi oma sisekujunduslikest eelistustest, ameeriklaste ja itaallaste kodude sisekujunduse erinevustest, kunstist kui ruumikujunduse ühest osast, oma New Yorgi ja Rooma korterite kujundusest

  9. IMPACT OF VIBRATORY AND ROTATIONAL SHOT PEENING ONTO SELECTED PROPERTIES OF TITANIUM ALLOY SURFACE LAYER

    Directory of Open Access Journals (Sweden)

    Kazimierz Zaleski

    2014-06-01

    Full Text Available This study presents the results of tests on impact of vibratory and rotational shot peening of the Ti6A12Mo2Cr titanium alloy onto the processed object surface roughness and surface layer microhardness. The external surfaces of ring-shaped samples were shot peened. The preceding process consisted of turning with a cubic boron nitride blade knife. Steel beads, having a diameter of 6 mm, were used as a processing medium. The variable parameters of shot peening were vibrator amplitude and shot peening time. The range of recommended technological parameters for vibratory and rotational shot peening was determined. As a result of shot peening, the surface roughness could be reduced by approximately 4 times and the surface layer could be hardened to the depth of approximately 0.4 mm.

  10. Impact of including surface currents on simulation of Indian Ocean variability with the POAMA coupled model

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Mei; Wang, Guomin; Hendon, Harry H.; Alves, Oscar [Bureau of Meteorology, Centre for Australian Weather and Climate Research, Melbourne (Australia)

    2011-04-15

    Impacts on the coupled variability of the Indo-Pacific by including the effects of surface currents on surface stress are explored in four extended integrations of an experimental version of the Bureau of Meteorology's coupled seasonal forecast model POAMA. The first pair of simulations differs only in their treatment of momentum coupling: one version includes the effects of surface currents on the surface stress computation and the other does not. The version that includes the effect of surface currents has less mean-state bias in the equatorial Pacific cold tongue but produces relatively weak coupled variability in the Tropics, especially that related to the Indian Ocean dipole (IOD) and El Nino/Southern Oscillation (ENSO). The version without the effects of surface currents has greater bias in the Pacific cold tongue but stronger IOD and ENSO variability. In order to diagnose the role of changes in local coupling from changes in remote forcing by ENSO for causing changes in IOD variability, a second set of simulations is conducted where effects of surface currents are included only in the Indian Ocean and only in the Pacific Ocean. IOD variability is found to be equally reduced by inclusion of the local effects of surface currents in the Indian Ocean and by the reduction of ENSO variability as a result of including effects of surface currents in the Pacific. Some implications of these results for predictability of the IOD and its dependence on ENSO, and for ocean subsurface data assimilation are discussed. (orig.)

  11. Impact of Surface Functionalization on the Quantum Coherence of Nitrogen-Vacancy Centers in Nanodiamonds.

    Science.gov (United States)

    Ryan, Robert G; Stacey, Alastair; O'Donnell, Kane M; Ohshima, Takeshi; Johnson, Brett C; Hollenberg, Lloyd C L; Mulvaney, Paul; Simpson, David A

    2018-04-18

    Nanoscale quantum probes such as the nitrogen-vacancy (NV) center in diamonds have demonstrated remarkable sensing capabilities over the past decade as control over fabrication and manipulation of these systems has evolved. The biocompatibility and rich surface chemistry of diamonds has added to the utility of these probes but, as the size of these nanoscale systems is reduced, the surface chemistry of diamond begins to impact the quantum properties of the NV center. In this work, we systematically study the effect of the diamond surface chemistry on the quantum coherence of the NV center in nanodiamonds (NDs) 50 nm in size. Our results show that a borane-reduced diamond surface can on average double the spin relaxation time of individual NV centers in nanodiamonds when compared to thermally oxidized surfaces. Using a combination of infrared and X-ray absorption spectroscopy techniques, we correlate the changes in quantum relaxation rates with the conversion of sp 2 carbon to C-O and C-H bonds on the diamond surface. These findings implicate double-bonded carbon species as a dominant source of spin noise for near surface NV centers. The link between the surface chemistry and quantum coherence indicates that through tailored engineering of the surface, the quantum properties and magnetic sensitivity of these nanoscale systems may approach that observed in bulk diamond.

  12. The impact of faceplate surface characteristics on detection of pulmonary nodules

    Science.gov (United States)

    Toomey, R. J.; Ryan, J. T.; McEntee, M. F.; McNulty, J.; Evanoff, M. G.; Cuffe, F.; Yoneda, T.; Stowe, J.; Brennan, P. C.

    2009-02-01

    Introduction In order to prevent specular reflections, many monitor faceplates have features such as tiny dimples on their surface to diffuse ambient light incident on the monitor, however, this "anti-glare" surface may also diffuse the image itself. The purpose of the study was to determine whether the surface characteristics of monitor faceplates influence the detection of pulmonary nodules under low and high ambient lighting conditions. Methods and Materials Separate observer performance studies were conducted at each of two light levels (250 lux). Twelve examining radiologists with the American Board of Radiology participated in the darker condition and eleven in the brighter condition. All observers read on both smooth "glare" and dimpled "anti-glare" faceplates in a single lighting condition. A counterbalanced methodology was utilized to minimise memory effects. In each reading, observers were presented with thirty chest images in random order, of which half contained a single simulated pulmonary nodule. They were asked to give their confidence that each image did or did not contain a nodule and to mark the suspicious location. ROC analysis was applied to resultant data. Results No statistically significant differences were seen in the trapezoidal area under the ROC curve (AUC), sensitivity, specificity or average time per case at either light level for chest specialists or radiologists from other specialities. Conclusion The characteristics of the faceplate surfaces do not appear to affect detection of pulmonary nodules. Further work into other image types is being conducted.

  13. Elastic–plastic adhesive impacts of tungsten dust with metal surfaces in plasma environments

    NARCIS (Netherlands)

    Ratynskaia, S.; Tolias, P.; Shalpegin, A.; Vignitchouk, L.; de Angeli, M.; I. Bykov,; Bystrov, K.; Bardin, S.; Brochard, F.; Ripamonti, D.; N. den Harder,; De Temmerman, G.

    2015-01-01

    Dust-surface collisions impose size selectivity on the ability of dust grains to migrate in scrape-off layer and divertor plasmas and to adhere to plasma-facing components. Here, we report first experimental evidence of dust impact phenomena in plasma environments concerning low-speed collisions of

  14. On the impact of a concave nosed axisymmetric body on a free surface

    NARCIS (Netherlands)

    Mathai, Varghese; Govardhan, R.N.; Arakeri, V.H.

    2015-01-01

    We report on an experimental study of the vertical impact of a concave nosed axisymmetric body on a free surface. Previous studies have shown that bodies with a convex nose, like a sphere, produce a well defined splash with a relatively large cavity behind the model. In contrast, we find that with a

  15. Impact of surface energy on the shock properties of granular explosives

    Science.gov (United States)

    Bidault, X.; Pineau, N.

    2018-01-01

    This paper presents the first part of a two-fold molecular dynamics study of the impact of the granularity on the shock properties of high explosives. Recent experimental studies show that the granularity can have a substantial impact on the properties of detonation products {i.e., variations in the size distributions of detonation nanodiamonds [V. Pichot et al., Sci. Rep. 3, 2159 (2013)]}. These variations can have two origins: the surface energy, which is a priori enhanced from micro- to nano-scale, and the porosity induced by the granular structure. In this first report, we study the impact of the surface-energy contribution on the inert shock compression of TATB, TNT, α-RDX, and β-HMX nano-grains (triaminotrinitrobenzene, trinitrotoluene, hexogen and octogen, respectively). We compute the radius-dependent surface energy and combine it with an ab initio-based equation of state in order to obtain the resulting shock properties through the Rankine-Hugoniot relations. We find that the enhancement of the surface energy results in a moderate overheating under shock compression. This contribution is minor with respect to porosity, when compared to a simple macroscopic model. This result motivates further atomistic studies on the impact of nanoporosity networks on the shock properties.

  16. Structure fragmentation of a surface layer of commercial purity titanium during ultrasonic impact treatment

    International Nuclear Information System (INIS)

    Kozelskaya, Anna; Kazachenok, Marina; Sinyakova, Elena; Pochivalov, Yurii; Perevalova, Olga; Panin, Alexey; Hairullin, Rustam

    2015-01-01

    The mechanisms of surface layer fragmentation of titanium specimens subjected to ultrasonic impact treatment is investigated by atomic force microscopy, transmission electron microscopy and electron backscatter diffraction. It is shown that the twin boundaries Σ7b and Σ11b are unable to be strong obstacles for propagation of dislocations and other twins

  17. Surface Damage and Treatment by Impact of a Low Temperature Nitrogen Jet

    Science.gov (United States)

    Laribou, Hicham; Fressengeas, Claude; Entemeyer, Denis; Jeanclaude, Véronique; Tazibt, Abdel

    2011-01-01

    Nitrogen jets under high pressure and low temperature have been introduced recently. The process consists in projecting onto a surface a low temperature jet obtained from releasing the liquid nitrogen stored in a high pressure tank (e.g. 3000 bars) through a nozzle. It can be used in a range of industrial applications, including surface treatment or material removal through cutting, drilling, striping and cleaning. The process does not generate waste other than the removed matter, and it only releases neutral gas into the atmosphere. This work is aimed at understanding the mechanisms of the interaction between the jet and the material surface. Depending on the impacted material, the thermo-mechanical shock and blast effect induced by the jet can activate a wide range of damage mechanisms, including cleavage, crack nucleation and spalling, as well as void expansion and localized ductile failure. The test parameters (standoff distance, dwell time, operating pressure) play a role in selecting the dominant damage mechanism, but combinations of these various modes are usually present. Surface treatment through phase transformation or grain fragmentation in a layer below the surface can also be obtained by adequate tuning of the process parameters. In the current study, work is undertaken to map the damage mechanisms in metallic materials as well as the influence of the test parameters on damage, along with measurements of the thermo-mechanical conditions (impact force, temperature) in the impacted area.

  18. Impact of nanosilver on various DNA lesions and HPRT gene mutations - effects of charge and surface coating

    Czech Academy of Sciences Publication Activity Database

    Huk, A.; Izak-Nau, E.; el Yamani, N.; Uggerud, H.; Vadset, M.; Zasońska, Beata Anna; Duschl, A.; Dusinska, M.

    2015-01-01

    Roč. 12, 24 July (2015), 25_1-25_20 ISSN 1743-8977 Institutional support: RVO:61389013 Keywords : silver nanomaterials * surface charge * surface coating Subject RIV: CD - Macromolecular Chemistry Impact factor: 8.649, year: 2015

  19. Single quantum dot tracking reveals the impact of nanoparticle surface on intracellular state.

    Science.gov (United States)

    Zahid, Mohammad U; Ma, Liang; Lim, Sung Jun; Smith, Andrew M

    2018-05-08

    Inefficient delivery of macromolecules and nanoparticles to intracellular targets is a major bottleneck in drug delivery, genetic engineering, and molecular imaging. Here we apply live-cell single-quantum-dot imaging and tracking to analyze and classify nanoparticle states after intracellular delivery. By merging trajectory diffusion parameters with brightness measurements, multidimensional analysis reveals distinct and heterogeneous populations that are indistinguishable using single parameters alone. We derive new quantitative metrics of particle loading, cluster distribution, and vesicular release in single cells, and evaluate intracellular nanoparticles with diverse surfaces following osmotic delivery. Surface properties have a major impact on cell uptake, but little impact on the absolute cytoplasmic numbers. A key outcome is that stable zwitterionic surfaces yield uniform cytosolic behavior, ideal for imaging agents. We anticipate that this combination of quantum dots and single-particle tracking can be widely applied to design and optimize next-generation imaging probes, nanoparticle therapeutics, and biologics.

  20. Impact of dynamic vegetation phenology on the simulated pan-Arctic land surface state

    Science.gov (United States)

    Teufel, Bernardo; Sushama, Laxmi; Arora, Vivek K.; Verseghy, Diana

    2018-03-01

    The pan-Arctic land surface is undergoing rapid changes in a warming climate, with near-surface permafrost projected to degrade significantly during the twenty-first century. Vegetation-related feedbacks have the potential to influence the rate of degradation of permafrost. In this study, the impact of dynamic phenology on the pan-Arctic land surface state, particularly near-surface permafrost, for the 1961-2100 period, is assessed by comparing two simulations of the Canadian Land Surface Scheme (CLASS)—one with dynamic phenology, modelled using the Canadian Terrestrial Ecosystem Model (CTEM), and the other with prescribed phenology. These simulations are forced by atmospheric data from a transient climate change simulation of the 5th generation Canadian Regional Climate Model (CRCM5) for the Representative Concentration Pathway 8.5 (RCP8.5). Comparison of the CLASS coupled to CTEM simulation to available observational estimates of plant area index, spatial distribution of permafrost and active layer thickness suggests that the model captures reasonably well the overall distribution of vegetation and permafrost. It is shown that the most important impact of dynamic phenology on the land surface occurs through albedo and it is demonstrated for the first time that vegetation control on albedo during late spring and early summer has the highest potential to impact the degradation of permafrost. While both simulations show extensive near-surface permafrost degradation by the end of the twenty-first century, the strong projected response of vegetation to climate warming and increasing CO2 concentrations in the coupled simulation results in accelerated permafrost degradation in the northernmost continuous permafrost regions.

  1. Guided asteroid deflection by kinetic impact: Mapping keyholes to an asteroid's surface

    Science.gov (United States)

    Chesley, S.; Farnocchia, D.

    2014-07-01

    The kinetic impactor deflection approach is likely to be the optimal deflection strategy in most real-world cases, given the likelihood of decades of warning time provided by asteroid search programs and the probable small size of the next confirmed asteroid impact that would require deflection. However, despite its straightforward implementation, the kinetic impactor approach can have its effectiveness limited by the astrodynamics that govern the impactor spacecraft trajectory. First, the deflection from an impact is maximized when the asteroid is at perihelion, while an impact near perihelion can in some cases be energetically difficult to implement. Additionally, the asteroid change in velocity Δ V should aligned with the target's heliocentric velocity vector in order to maximize the deflection at a potential impact some years in the future. Thus the relative velocity should be aligned with or against the heliocentric velocity, which implies that the impactor and asteroid orbits should be tangent at the point of impact. However, for natural bodies such as meteorites colliding with the Earth, the relative velocity vectors tend to cluster near the sunward or anti- sunward directions, far from the desired direction. This is because there is generally a significant crossing angle between the orbits of the impactor and target and an impact at tangency is unusual. The point is that hitting the asteroid is not enough, but rather we desire to hit the asteroid at a point when the asteroid and spacecraft orbits are nearly tangent and when the asteroid is near perihelion. However, complicating the analysis is the fact that the impact of a spacecraft on an asteroid would create an ejecta plume that is roughly normal to the surface at the point of impact. This escaping ejecta provides additional momentum transfer that generally adds to the effectiveness of a kinetic deflection. The ratio β between the ejecta momentum and the total momentum (ejecta plus spacecraft) can

  2. Socio-economic and other non-radiological impacts of the near surface disposal of radioactive waste

    International Nuclear Information System (INIS)

    2002-09-01

    The objective of this report is to introduce, in a generic sense, the elements that could comprise a socio-economic and non-radiological environmental impact assessment. The various social, economic and environmental impacts that could be associated with surface and near surface disposal are discussed through factors that could apply at the local, regional or national level. Impact management is also discussed. The report also introduces concepts to help Member States develop their own approaches to undertaking impact assessment and management. The report is intended to complement IAEA documents on the technology and safety aspects of the near surface disposal of radioactive waste. The scope of this report includes a discussion of a range of social, economic and nonradiological environmental impacts relevant to surface and near surface disposal and illustrations of some impact management measures

  3. High volume hydraulic fracturing operations: potential impacts on surface water and human health.

    Science.gov (United States)

    Mrdjen, Igor; Lee, Jiyoung

    2016-08-01

    High volume, hydraulic fracturing (HVHF) processes, used to extract natural gas and oil from underground shale deposits, pose many potential hazards to the environment and human health. HVHF can negatively affect the environment by contaminating soil, water, and air matrices with potential pollutants. Due to the relatively novel nature of the process, hazards to surface waters and human health are not well known. The purpose of this article is to link the impacts of HVHF operations on surface water integrity, with human health consequences. Surface water contamination risks include: increased structural failure rates of unconventional wells, issues with wastewater treatment, and accidental discharge of contaminated fluids. Human health risks associated with exposure to surface water contaminated with HVHF chemicals include increased cancer risk and turbidity of water, leading to increased pathogen survival time. Future research should focus on modeling contamination spread throughout the environment, and minimizing occupational exposure to harmful chemicals.

  4. The impact of accelerometer mounting methods on the level of vibrations recorded at ground surface

    Directory of Open Access Journals (Sweden)

    Krzysztof Czech

    2014-08-01

    Full Text Available The paper presents the results of field research based on the measurements of accelerations recorded at ground surface. The source of the vibration characterized by high repetition rate of pulse parameters was light falling weight deflectometer ZFG-01. Measurements of vibrations have been carried out using top quality high-precision measuring system produced by Brüel&Kiær. Accelerometers were mounted on a sandy soil surface at the measuring points located radially at 5-m and 10-m distances from the source of vibration. The paper analyses the impact that the method of mounting accelerometers on the ground has on the level of the recorded values of accelerations of vibrations. It has been shown that the method of attaching the sensor to the surface of the ground is crucial for the credibility of the performed measurements.[b]Keywords[/b]: geotechnics, surface vibrations, ground, vibration measurement

  5. Erosion of a grooved surface caused by impact of particle-laden flow

    Science.gov (United States)

    Jung, Sohyun; Yang, Eunjin; Kim, Ho-Young

    2016-11-01

    Solid erosion can be a life-limiting process for mechanical elements in erosive environments, thus it is of practical importance in many industries such as construction, mining, and coal conversion. Erosion caused by particle-laden flow occurs through diverse mechanisms, such as cutting, plastic deformation, brittle fracture, fatigue and melting, depending on particle velocity, total particle mass and impingement angle. Among a variety of attempts to lessen erosion, here we investigate the effectiveness of millimeter-sized grooves on the surface. By experimentally measuring the erosion rates of smooth and triangular-grooved surfaces under various impingement angles, we find that erosion can be significantly reduced within a finite range of impingement angles. We show that such erosion resistance is attributed to the swirls of air within grooves and the differences in erosive strength of normal and slanted impact. In particular, erosion is mitigated when we increase the effective area under normal impact causing plastic deformation and fracture while decreasing the area under slanted impact that cuts the surface to a large degree. Our quantitative model for the erosion rate of grooved surfaces considering the foregoing effects agrees with the measurement results.

  6. Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

    1982-08-01

    The thermal effects associated with the emplacement of aged radioactive wastes in a geologic repository were studied, with emphasis on the following subjects: the waste characteristics, repository structure, and rock properties controlling the thermally induced effects; the current knowledge of the thermal, thermomechanical, and thermohydrologic impacts, determined mainly on the basis of previous studies that assume 10-year-old wastes; the thermal criteria used to determine the repository waste loading densities; and the technical advantages and disadvantages of surface cooling of the wastes prior to disposal as a means of mitigating the thermal impacts. The waste loading densities determined by repository designs for 10-year-old wastes are extended to older wastes using the near-field thermomechanical criteria based on room stability considerations. Also discussed are the effects of long surface cooling periods determined on the basis of far-field thermomechanical and thermohydrologic considerations. The extension of the surface cooling period from 10 years to longer periods can lower the near-field thermal impact but have only modest long-term effects for spent fuel. More significant long-term effects can be achieved by surface cooling of reprocessed high-level waste.

  7. Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

    International Nuclear Information System (INIS)

    Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

    1982-08-01

    The thermal effects associated with the emplacement of aged radioactive wastes in a geologic repository were studied, with emphasis on the following subjects: the waste characteristics, repository structure, and rock properties controlling the thermally induced effects; the current knowledge of the thermal, thermomechanical, and thermohydrologic impacts, determined mainly on the basis of previous studies that assume 10-year-old wastes; the thermal criteria used to determine the repository waste loading densities; and the technical advantages and disadvantages of surface cooling of the wastes prior to disposal as a means of mitigating the thermal impacts. The waste loading densities determined by repository designs for 10-year-old wastes are extended to older wastes using the near-field thermomechanical criteria based on room stability considerations. Also discussed are the effects of long surface cooling periods determined on the basis of far-field thermomechanical and thermohydrologic considerations. The extension of the surface cooling period from 10 years to longer periods can lower the near-field thermal impact but have only modest long-term effects for spent fuel. More significant long-term effects can be achieved by surface cooling of reprocessed high-level waste

  8. Impacts of Climate Change on Surface Ozone and Intercontinental Ozone Pollution: A Multi-Model Study

    Science.gov (United States)

    Doherty, R. M.; Wild, O.; Shindell, D. T.; Zeng, G.; MacKenzie, I. A.; Collins, W. J.; Fiore, A. M.; Stevenson, D. S.; Dentener, F. J.; Schultz, M. G.; hide

    2013-01-01

    The impact of climate change between 2000 and 2095 SRES A2 climates on surface ozone (O)3 and on O3 source-receptor (S-R) relationships is quantified using three coupled climate-chemistry models (CCMs). The CCMs exhibit considerable variability in the spatial extent and location of surface O3 increases that occur within parts of high NOx emission source regions (up to 6 ppbv in the annual average and up to 14 ppbv in the season of maximum O3). In these source regions, all three CCMs show a positive relationship between surface O3 change and temperature change. Sensitivity simulations show that a combination of three individual chemical processes-(i) enhanced PAN decomposition, (ii) higher water vapor concentrations, and (iii) enhanced isoprene emission-largely reproduces the global spatial pattern of annual-mean surface O3 response due to climate change (R2 = 0.52). Changes in climate are found to exert a stronger control on the annual-mean surface O3 response through changes in climate-sensitive O3 chemistry than through changes in transport as evaluated from idealized CO-like tracer concentrations. All three CCMs exhibit a similar spatial pattern of annual-mean surface O3 change to 20% regional O3 precursor emission reductions under future climate compared to the same emission reductions applied under present-day climate. The surface O3 response to emission reductions is larger over the source region and smaller downwind in the future than under present-day conditions. All three CCMs show areas within Europe where regional emission reductions larger than 20% are required to compensate climate change impacts on annual-mean surface O3.

  9. The costs of avoiding environmental impacts from shale-gas surface infrastructure.

    Science.gov (United States)

    Milt, Austin W; Gagnolet, Tamara D; Armsworth, Paul R

    2016-12-01

    Growing energy demand has increased the need to manage conflicts between energy production and the environment. As an example, shale-gas extraction requires substantial surface infrastructure, which fragments habitats, erodes soils, degrades freshwater systems, and displaces rare species. Strategic planning of shale-gas infrastructure can reduce trade-offs between economic and environmental objectives, but the specific nature of these trade-offs is not known. We estimated the cost of avoiding impacts from land-use change on forests, wetlands, rare species, and streams from shale-energy development within leaseholds. We created software for optimally siting shale-gas surface infrastructure to minimize its environmental impacts at reasonable construction cost. We visually assessed sites before infrastructure optimization to test whether such inspection could be used to predict whether impacts could be avoided at the site. On average, up to 38% of aggregate environmental impacts of infrastructure could be avoided for 20% greater development costs by spatially optimizing infrastructure. However, we found trade-offs between environmental impacts and costs among sites. In visual inspections, we often distinguished between sites that could be developed to avoid impacts at relatively low cost (29%) and those that could not (20%). Reductions in a metric of aggregate environmental impact could be largely attributed to potential displacement of rare species, sedimentation, and forest fragmentation. Planners and regulators can estimate and use heterogeneous trade-offs among development sites to create industry-wide improvements in environmental performance and do so at reasonable costs by, for example, leveraging low-cost avoidance of impacts at some sites to offset others. This could require substantial effort, but the results and software we provide can facilitate the process. © 2016 Society for Conservation Biology.

  10. Survivability of bare, individual Bacillus subtilis spores to high-velocity surface impact: Implications for microbial transfer through space

    Science.gov (United States)

    Barney, Brandon L.; Pratt, Sara N.; Austin, Daniel E.

    2016-06-01

    Laboratory experiments show that endospores of Bacillus subtilis survive impact against a solid surface at velocities as high as 299 ±28 m/s. During impact, spores experience and survive accelerations of at least 1010 m/s2. The spores were introduced into a vacuum chamber using an electrospray source and accelerated to a narrow velocity distribution by entrainment in a differentially pumped gas flow. Different velocity ranges were studied by modifying the gas flow parameters. The spores were electrically charged, allowing direct measurement of the velocity of each spore as it passed through an image charge detector prior to surface impact. Spores impacted a glass surface and were collected for subsequent analysis by culturing. Most spores survived impact at all measured velocities. These experiments differ fundamentally from other studies that show either shock or impact survivability of bacteria embedded within or on the surface of a projectile. Bacteria in the present experiments undergo a single interaction with a solid surface at the full impact velocity, in the absence of any other effects such as cushioning due to microbe agglomerations, deceleration due to air or vapor, or transfer of impact shock through solid or liquid media. During these full-velocity impact events, the spores experience extremely high decelerations. This study is the first reported instance of accelerations of this magnitude experienced during a bacteria impact event. These results are discussed in the context of potential transfer of viable microbes in space and other scenarios involving surface impacts at high velocities.

  11. Urban Soil: Assessing Ground Cover Impact on Surface Temperature and Thermal Comfort.

    Science.gov (United States)

    Brandani, Giada; Napoli, Marco; Massetti, Luciano; Petralli, Martina; Orlandini, Simone

    2016-01-01

    The urban population growth, together with the contemporary deindustrialization of metropolitan areas, has resulted in a large amount of available land with new possible uses. It is well known that urban green areas provide several benefits in the surrounding environment, such as the improvement of thermal comfort conditions for the population during summer heat waves. The purpose of this study is to provide useful information on thermal regimes of urban soils to urban planners to be used during an urban transformation to mitigate surface temperatures and improve human thermal comfort. Field measurements of solar radiation, surface temperature (), air temperature (), relative humidity, and wind speed were collected on four types of urban soils and pavements in the city of Florence during summer 2014. Analysis of days under calm, clear-sky condition is reported. During daytime, sun-to-shadow differences for , apparent temperature index (ATI), and were significantly positive for all surfaces. Conversely, during nighttime, differences among all surfaces were significantly negative, whereas ATI showed significantly positive differences. Moreover, was significantly negative for grass and gravel. Relative to the shaded surfaces, was higher on white gravel and grass than gray sandstone and asphalt during nighttime, whereas gray sandstone was always the warmest surface during daytime. Conversely, no differences were found during nighttime for ATI and measured over surfaces that were exposed to sun during the day, whereas showed higher values on gravel than grass and asphalt during nighttime. An exposed surface warms less if its albedo is high, leading to a significant reduction of during daytime. These results underline the importance of considering the effects of surface characteristics on surface temperature and thermal comfort. This would be fundamental for addressing urban environment issues toward the heat island mitigation considering also the impact of urban

  12. Deep Impact: Effects of Mountaintop Mining on Surface Topography, Bedrock Structure, and Downstream Waters.

    Science.gov (United States)

    Ross, Matthew R V; McGlynn, Brian L; Bernhardt, Emily S

    2016-02-16

    Land use impacts are commonly quantified and compared using 2D maps, limiting the scale of their reported impacts to surface area estimates. Yet, nearly all land use involves disturbances below the land surface. Incorporating this third dimension into our estimates of land use impact is especially important when examining the impacts of mining. Mountaintop mining is the most common form of coal mining in the Central Appalachian ecoregion. Previous estimates suggest that active, reclaimed, or abandoned mountaintop mines cover ∼7% of Central Appalachia. While this is double the areal extent of development in the ecoregion (estimated to occupy mines extend 10s to 100s of meters below the current land surface. Here, we provide the first estimates for the total volumetric and topographic disturbance associated with mining in an 11 500 km(2) region of southern West Virginia. We find that the cutting of ridges and filling of valleys has lowered the median slope of mined landscapes in the region by nearly 10 degrees while increasing their average elevation by 3 m as a result of expansive valley filling. We estimate that in southern West Virginia, more than 6.4km(3) of bedrock has been broken apart and deposited into 1544 headwater valley fills. We used NPDES monitoring datatsets available for 91 of these valley fills to explore whether fill characteristics could explain variation in the pH or selenium concentrations reported for streams draining these fills. We found that the volume of overburden in individual valley fills correlates with stream pH and selenium concentration, and suggest that a three-dimensional assessment of mountaintop mining impacts is necessary to predict both the severity and the longevity of the resulting environmental impacts.

  13. The evolution of droplet impacting on thin liquid film at superhydrophilic surface

    Science.gov (United States)

    Li, Yun; Zheng, Yi; Lan, Zhong; Xu, Wei; Ma, Xuehu

    2017-12-01

    Thin films are ubiquitous in nature, and the evolution of a liquid film after droplet impact is critical in many industrial processes. In this paper, a series of experiments and numerical simulations are conducted to investigate the distribution and evolution features of local temperature as the droplet impacts a thin film on the superhydrophilic surface by the thermal tracing method. A cold area is formed in the center after droplet impacts on heated solid surfaces. For the droplet impact on thin heated liquid film, a ring-shaped low temperature zone is observed in this experiment. Meanwhile, numerical simulation is adopted to analyze the mechanism and the interaction between the droplet and the liquid film. It is found that due to the vortex velocity distribution formed inside the liquid film after the impact, a large part of the droplet has congested. The heating process is not obvious in the congested area, which leads to the formation of a low-temperature area in the results.

  14. Underground black-coal mining and its impact on the land surface

    International Nuclear Information System (INIS)

    Pollmann, H.J.; Wilke, F.L.

    1994-01-01

    This book wants to describe the special requirements and consequences resulting from natural conditions at the deposit as well as from decisions and processes of mining operations. On this basis it should be possible to assess the degree to which the impact of mining on defined areas of the land surface can be influenced with reasonable effort. Furthermore, the consequences from conditions governing mining activities for the planning and realization of mining operations and their impact and the granting of permissions and approvals on the part of the mining authorities are discussed. (HS) [de

  15. On the impact of a concave nosed axisymmetric body on a free surface

    OpenAIRE

    Mathai, Varghese; Govardhan, Raghuraman N.; Arakeri, Vijay H.

    2017-01-01

    We report on an experimental study of the vertical impact of a concave nosed axisymmetric body on a free surface. Previous studies have shown that bodies with a convex nose, like a sphere, produce a well defined splash with a relatively large cavity behind the model. In contrast, we find that with a concave nose, there is hardly a splash and the cavity extent is greatly reduced. This may be explained by the fact that in the concave nosed case, the initial impact is between a confined air pock...

  16. Muzzle imprint mark: a patterned injury which may be constituted of intradermal blood extravasations.

    Science.gov (United States)

    Pircher, R; Bielefeld, L; Geisenberger, D; Große Perdekamp, M; Pollak, S; Thierauf-Emberger, A

    2014-11-01

    The muzzle imprint mark in contact shots is usually regarded as a patterned pressure abrasion depicting the barrel end as well as adjacent constructional components of the weapon. Due to parching after exposure to air, the affected skin assumes a brown color, especially along the contours of the impacting structures. Apart from this well-known type of epidermal damage, the imprint mark may also be formed by intradermal hemorrhages. In some cases, these intracutaneous bleedings manifest themselves as circular, curved or straight reddish lines mirroring the surface relief of the weapon's muzzle end. To estimate the frequency of skin hematomas in muzzle imprints, 35 consecutive contact shots to the head (temple, forehead, submental and occipital region) were evaluated. In 3 cases, the muzzle imprint mark exclusively consisted of intracutaneous bruises surrounding the bullet entrance hole. In 14 cases, the muzzle imprint was composed of both excoriations and intradermal hematomas. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Review: Impacts of permafrost degradation on inorganic chemistry of surface fresh water

    Science.gov (United States)

    Colombo, Nicola; Salerno, Franco; Gruber, Stephan; Freppaz, Michele; Williams, Mark; Fratianni, Simona; Giardino, Marco

    2018-03-01

    Recent studies have shown that climate change is impacting the inorganic chemical characteristics of surface fresh water in permafrost areas and affecting aquatic ecosystems. Concentrations of major ions (e.g., Ca2 +, Mg2 +, SO42 -, NO3-) can increase following permafrost degradation with associated deepening of flow pathways and increased contributions of deep groundwater. In addition, thickening of the active layer and melting of near-surface ground ice can influence inorganic chemical fluxes from permafrost into surface water. Permafrost degradation has also the capability to modify trace element (e.g., Ni, Mn, Al, Hg, Pb) contents in surface water. Although several local and regional modifications of inorganic chemistry of surface fresh water have been attributed to permafrost degradation, a comprehensive review of the observed changes is lacking. The goal of this paper is to distil insight gained across differing permafrost settings through the identification of common patterns in previous studies, at global scale. In this review we focus on three typical permafrost configurations (pervasive permafrost degradation, thermokarst, and thawing rock glaciers) as examples and distinguish impacts on (i) major ions and (ii) trace elements. Consequences of warming climate have caused spatially-distributed progressive increases of major ion and trace element delivery to surface fresh water in both polar and mountain areas following pervasive permafrost degradation. Moreover, localised releases of major ions and trace elements to surface water due to the liberation of soluble materials sequestered in permafrost and ground ice have been found in ice-rich terrains both at high latitude (thermokarst features) and high elevation (rock glaciers). Further release of solutes and related transport to surface fresh water can be expected under warming climatic conditions. However, complex interactions among several factors able to influence the timing and magnitude of the impacts

  18. Atmospheric sensitivity to land surface changes: comparing the impact of albedo, roughness, and evaporative resistance on near-surface air temperature using an idealized land model.

    Science.gov (United States)

    Lague, M. M.; Swann, A. L. S.; Bonan, G. B.

    2017-12-01

    Past studies have demonstrated how changes in vegetation can impact the atmosphere; however, it is often difficult to identify the exact physical pathway through which vegetation changes drive an atmospheric response. Surface properties (such as vegetation color, or height) control surface energy fluxes, which feed back on the atmosphere on both local and global scales by modifying temperatures, cloud cover, and energy gradients. Understanding how land surface properties influence energy fluxes is crucial for improving our understanding of how vegetation change - past, present, and future - impacts the atmosphere, global climate, and people. We explore the sensitivity of the atmosphere to perturbations of three land surface properties - albedo, roughness, and evaporative resistance - using an idealized land model coupled to an Earth System Model. We derive a relationship telling us how large a change in each surface property is required to drive a local 0.1 K change in 2m air temperature. Using this idealized framework, we are able to separate the influence on the atmosphere of each individual surface property. We demonstrate that the impact of each surface property on the atmosphere is spatially variable - that is, a similar change in vegetation can have different climate impacts if made in different locations. This analysis not only improves our understanding of how the land system can influence climate, but also provides us with a set of theoretical limits on the potential climate impact of arbitrary vegetation change (natural or anthropogenic).

  19. Evaluation of underground pipe-structure interface for surface impact load

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shen, E-mail: swang@terrapower.com

    2017-06-15

    Highlights: • A simple method is proposed for the evaluation of underground pipelines for surface impact load considering the effect of a nearby pipe-structure interface. • The proposed simple method can be used to evaluate the magnitude of damage within a short period of time after accidental drop occurs. • The proposed method is applied in a practical example and compared by using finite element analysis. - Abstract: Nuclear safety related buried pipelines need to be assessed for the effects of postulated surface impact loads. In published solutions, the buried pipe is often considered within an elastic half space without interference with other underground structures. In the case that a surface impact occurs in short distance from an underground pipe-structure interface, this boundary condition will further complicate the buried pipe evaluation. Neglecting such boundary effect in the assessment may lead to underestimating potential damage of buried pipeline, and jeopardizing safety of the nuclear power plant. Comprehensive analysis of such structure-pipe-soil system is often subjected to availability of state-of-art finite element tools, as well as costly and time consuming. Simple, but practical conservative techniques have not been established. In this study, a mechanics based solution is proposed in order to assess the magnitude of damage to a buried pipeline beneath a heavy surface impact considering the effect of a nearby pipe-structure interface. The proposed approach provides an easy to use tool in the early stage of evaluation before the decision of applying more costly technique can be made by owner of the nuclear facility.

  20. A Numerical Study on Impact of Taiwan Island Surface Heat Flux on Super Typhoon Haitang (2005)

    OpenAIRE

    Xu, Hongxiong

    2015-01-01

    Three to four tropical cyclones (TCs) by average usually impact Taiwan every year. This study, using the Developmental Tested Center (DTC) version of the Hurricane WRF (HWRF) model, examines the effects of Taiwan’s island surface heat fluxes on typhoon structure, intensity, track, and its rainfall over the island. The numerical simulation successfully reproduced the structure and intensity of super Typhoon Haitang. The model, especially, reproduced the looped path and landfall at nearly the ...

  1. Channeling effect in electronic spectra produced by grazing impact of fast protons on insulator surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Archubi, C D; Gravielle, M S, E-mail: archubi@iafe.uba.a, E-mail: msilvia@iafe.uba.a [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428, Buenos Aires (Argentina)

    2009-11-01

    Electron emission due to grazing scattering of fast protons from LiF and KCl surfaces is studied under axial incidence conditions. The differential emission probability is calculated within a distorted-wave formalism, taking into account axial channeled trajectories. For different emission angles, electronic spectra for proton incidence along the two principal crystal axes ([100] and [110]) are compared with those corresponding to an impact velocity in a random direction, finding effects associated with the channeling conditions.

  2. Evaluation of underground pipe-structure interface for surface impact load

    International Nuclear Information System (INIS)

    Wang, Shen

    2017-01-01

    Highlights: • A simple method is proposed for the evaluation of underground pipelines for surface impact load considering the effect of a nearby pipe-structure interface. • The proposed simple method can be used to evaluate the magnitude of damage within a short period of time after accidental drop occurs. • The proposed method is applied in a practical example and compared by using finite element analysis. - Abstract: Nuclear safety related buried pipelines need to be assessed for the effects of postulated surface impact loads. In published solutions, the buried pipe is often considered within an elastic half space without interference with other underground structures. In the case that a surface impact occurs in short distance from an underground pipe-structure interface, this boundary condition will further complicate the buried pipe evaluation. Neglecting such boundary effect in the assessment may lead to underestimating potential damage of buried pipeline, and jeopardizing safety of the nuclear power plant. Comprehensive analysis of such structure-pipe-soil system is often subjected to availability of state-of-art finite element tools, as well as costly and time consuming. Simple, but practical conservative techniques have not been established. In this study, a mechanics based solution is proposed in order to assess the magnitude of damage to a buried pipeline beneath a heavy surface impact considering the effect of a nearby pipe-structure interface. The proposed approach provides an easy to use tool in the early stage of evaluation before the decision of applying more costly technique can be made by owner of the nuclear facility.

  3. Uncertainty in Land Cover observations and its impact on near surface climate

    Science.gov (United States)

    Georgievski, Goran; Hagemann, Stefan

    2017-04-01

    Land Cover (LC) and its bio-geo-physical feedbacks are important for the understanding of climate and its vulnerability to changes on the surface of the Earth. Recently ESA has published a new LC map derived by combining remotely sensed surface reflectance and ground-truth observations. For each grid-box at 300m resolution, an estimate of confidence is provided. This LC data set can be used in climate modelling to derive land surface boundary parameters for the respective Land Surface Model (LSM). However, the ESA LC classes are not directly suitable for LSMs, therefore they need to be converted into the model specific surface presentations. Due to different design and processes implemented in various climate models they might differ in the treatment of artificial, water bodies, ice, bare or vegetated surfaces. Nevertheless, usually vegetation distribution in models is presented by means of plant functional types (PFT), which is a classification system used to simplify vegetation representation and group different vegetation types according to their biophysical characteristics. The method of LC conversion into PFT is also called "cross-walking" (CW) procedure. The CW procedure is another source of uncertainty, since it depends on model design and processes implemented and resolved by LSMs. These two sources of uncertainty, (i) due to surface reflectance conversion into LC classes, (ii) due to CW procedure, have been studied by Hartley et al (2016) to investigate their impact on LSM state variables (albedo, evapotranspiration (ET) and primary productivity) by using three standalone LSMs. The present study is a follow up to that work and aims at quantifying the impact of these two uncertainties on climate simulations performed with the Max Planck Institute for Meteorology Earth System Model (MPI-ESM) using prescribed sea surface temperature and sea ice. The main focus is on the terrestrial water cycle, but the impacts on surface albedo, wind patterns, 2m temperatures

  4. Elemental analyses of hypervelocity microparticle impact sites on Interplanetary Dust Experiment sensor surfaces

    Science.gov (United States)

    Simon, Charles G.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. A.; Wortman, Jim J.; Brownlee, D. E.

    1993-01-01

    The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity microparticles (approximately 0.2 to approximately 100 micron diameter) that struck the active sensors with enough energy to break down the 0.4 or 1.0 micron thick SIO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. The high purity Al-SiO2-Si substrates allowed detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) was used to create two-dimensional elemental ion intensity maps of microparticle impact sites on the IDE sensors. The element intensities in the central craters of the impacts were corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results were used to classify the particles' origins as 'manmade,' 'natural,' or 'indeterminate.' The last classification resulted from the presence of too little impactor residue, analytical interference from high background contamination, the lack of information on silicon and aluminum residues, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters of these features. Thus far a total of 79 randomly selected microparticle impact sites from the six primary sides of the LDEF have been analyzed: 36 from tray C-9 (Leading (ram), or East, side), 18 from tray C-3

  5. The Pseudomonas aeruginosa chemotaxis methyltransferase CheR1 impacts on bacterial surface sampling.

    Directory of Open Access Journals (Sweden)

    Juliane Schmidt

    Full Text Available The characterization of factors contributing to the formation and development of surface-associated bacterial communities known as biofilms has become an area of intense interest since biofilms have a major impact on human health, the environment and industry. Various studies have demonstrated that motility, including swimming, swarming and twitching, seems to play an important role in the surface colonization and establishment of structured biofilms. Thereby, the impact of chemotaxis on biofilm formation has been less intensively studied. Pseudomonas aeruginosa has a very complex chemosensory system with two Che systems implicated in flagella-mediated motility. In this study, we demonstrate that the chemotaxis protein CheR1 is a methyltransferase that binds S-adenosylmethionine and transfers a methyl group from this methyl donor to the chemoreceptor PctA, an activity which can be stimulated by the attractant serine but not by glutamine. We furthermore demonstrate that CheR1 does not only play a role in flagella-mediated chemotaxis but that its activity is essential for the formation and maintenance of bacterial biofilm structures. We propose a model in which motility and chemotaxis impact on initial attachment processes, dispersion and reattachment and increase the efficiency and frequency of surface sampling in P. aeruginosa.

  6. On the impact of a concave nosed axisymmetric body on a free surface

    Science.gov (United States)

    Mathai, Varghese; Govardhan, Raghuraman N.; Arakeri, Vijay H.

    2015-02-01

    We report on an experimental study of the vertical impact of a concave nosed axisymmetric body on a free surface. Previous studies have shown that bodies with a convex nose, like a sphere, produce a well defined splash with a relatively large cavity behind the model. In contrast, we find that with a concave nose, there is hardly a splash and the cavity extent is greatly reduced. This may be explained by the fact that in the concave nosed case, the initial impact is between a confined air pocket and the free surface unlike in the convex nosed case. From measurements of the unsteady pressure in the concave nose portion, we show that in this case, the maximum pressures are significantly lower than the classically expected "water hammer" pressures and also lower than those generally measured on other geometries. Thus, the presence of an air pocket in the case of a concave nosed body adds an interesting dimension to the classical problem of impact of solid bodies on to a free surface.

  7. Impacts of surface gold mining on land use systems in Western Ghana.

    Science.gov (United States)

    Schueler, Vivian; Kuemmerle, Tobias; Schröder, Hilmar

    2011-07-01

    Land use conflicts are becoming increasingly apparent from local to global scales. Surface gold mining is an extreme source of such a conflict, but mining impacts on local livelihoods often remain unclear. Our goal here was to assess land cover change due to gold surface mining in Western Ghana, one of the world's leading gold mining regions, and to study how these changes affected land use systems. We used Landsat satellite images from 1986-2002 to map land cover change and field interviews with farmers to understand the livelihood implications of mining-related land cover change. Our results showed that surface mining resulted in deforestation (58%), a substantial loss of farmland (45%) within mining concessions, and widespread spill-over effects as relocated farmers expand farmland into forests. This points to rapidly eroding livelihood foundations, suggesting that the environmental and social costs of Ghana's gold boom may be much higher than previously thought.

  8. Monte Carlo prediction of crater formation by single ion impact on solid surface

    International Nuclear Information System (INIS)

    Perez-Martin, A.M.C.; Dominguez-Vazquez, J.; Jimenez-Rodriguez, J.J.; Collins, R.; Gras-Marti, A.

    1994-01-01

    A method is presented for predicting the topography changes following the impact of one energetic ion on the plane surface of a monatomic amorphous solid. This is done in two stages. The first is a Monte Carlo calculation of the sputter yield and interior distribution relocated atoms, with no compensation for local departures from equilibrium density. In the second stage there is a systematic relaxation of the solid, in which the density returns to its previous constant value and a crater develops in the surface. Two alternative methods of carrying out stage two are compared. In the first the solid is subdivided into cells within which relaxation is carried out normal to the surface, as in previous one-dimensional studies. The second method treats the solid as a 3-dimensional incompressible medium. Both seem to reproduce quite well the main features found experimentally. (orig.)

  9. Shallow surface etching of organic and inorganic compounds by electrospray droplet impact

    International Nuclear Information System (INIS)

    Hiraoka, Kenzo; Sakai, Yuji; Iijima, Yoshitoki; Asakawa, Daiki; Mori, Kunihiko

    2009-01-01

    The electrospray droplet impact (EDI) was applied to bradykinin, polyethylene terephthalate (PET), SiO 2 /Si, and indium phosphide (InP). It was found that bradykinin deposited on the stainless steel substrate was ionized/desorbed without the accumulation of radiation products. The film thickness desorbed by a single collisional event was found to be less than 10 monolayers. In the EDI mass spectra for PET, several fragment ions were observed but the XPS spectra did not change with prolonged cluster irradiation. The etching rate for SiO 2 by EDI was measured to be ∼0.2 nm/min. The surface roughness of InP etched by EDI was found to be one order of magnitude smaller than that etched by 3 keV Ar + for about the same etching depths. EDI is capable of shallow surface etching with little damage left on the etched surface.

  10. Impact of Utilizing Photos and Deimos as Waypoints for Mars Human Surface Missions

    Science.gov (United States)

    Cianciolo, Alicia D.; Brown, Kendall

    2015-01-01

    Phobos and Deimos, the moons of Mars, are interesting exploration destinations that offer extensibility of the Asteroid Redirect Mission (ARM) technologies. Solar Electric Propulsion (SEP), asteroid rendezvous and docking, and surface operations can be used to land on and explore the moons of Mars. The close Mars vicinity of Phobos and Deimos warrant examining them as waypoints, or intermediate staging orbits, for Mars surface missions. This paper outlines the analysis performed to determine the mass impact of using the moons of Mars both as an intermediate staging point for exploration as well as for in-situ recourse utilization, namely propellant, to determine if the moons are viable options to include in the broader Mars surface exploration architecture.

  11. Elements of the Chicxulub Impact Structure as Revealed in SRTM and Surface GPS Topographic Data

    Science.gov (United States)

    Kinsland, Gary L.; Sanchez, Gary; Kobrick, Michael; Cardador, Manuel Hurtado

    2003-01-01

    Pope et al. [1] utilized the elevations from the Petroleos Mexicanos (PEMEX) gravity data files to show that the main component of the surface expression of the Chicxulub Impact Structure is a roughly semi-circular, lowrelief depression about 90 km in diameter. They also identified other topographic features and the elements of the buried impact, which possibly led to the development of these features. These are summarized in Table 1. Kinsland et al. [2] presented a connection between these topographic anomalies, small gravity anomalies and buried structure of the impact. Very recently we have acquired digital topography data from NASA s Shuttle Radar Topography Mission (SRTM). Our subset covers 6 square degrees from 20deg N 91degW to 22deg N 88degW (corner to corner) with a pixel size of about 90m. This area includes all of the identified portion of the crater on land.

  12. High-Speed Imaging of a Water Droplet Impacting a Super Cold Surface

    KAUST Repository

    Khaled, Narimane

    2016-08-01

    Frost formation is of a major research interest as it can affect many industrial processes. Frost appears as a thin deposit of ice crystals when the temperature of the surface is below the freezing point of the liquid. The objective of this research is to study icing with hope to propose new anti-icing and deicing methods. In the beginning of the research, cracking of the ice layer was observed when a deionized water droplet impacts a ?50 oC cooled sphere surface that is in contact with dry ice. To further investigate the cracks occurrence, multiple experiments were conducted. It was observed that the sphere surface temperature and droplet temperature (ranges from 10-80 oC) have no effect on the crack formation. On the other hand, it was observed that formation of a thin layer of frost on the sphere before the drop impact leads the lateral cracking of the ice. Thus, attempts to reproduce the cracks on clean super cold sphere surfaces were made using scratched and sandblasted spheres as well as superhydrophobized and polymer particle coated spheres. Furthermore, innovative methods were tried to initiate the cracks by placing epoxy glue bumps and ice-islands coatings on the surface of the spheres. All of these attempts to reproduce the crack formation without the presence of frost, failed. Nonetheless, the adding of isolated frost on the sphere surfaces always leads to the crack formation. Generally, frost forms on the small spheres faster than it does on the bigger ones. Additionally, the cold water droplet produces thicker water and ice layer compared to a hot water droplet; and the smaller the sphere the larger its water and ice layer thicknesses.

  13. Civilsamfundets ABC: M for Marked

    DEFF Research Database (Denmark)

    Lund, Anker Brink; Meyer, Gitte

    2016-01-01

    Bogstaveligt talt: Hvad er civilsamfundet? Anker Brink Lund og Gitte Meyer fra CBS Center for Civil Society Studies gennemgår civilsamfundet bogstav for bogstav. Vi er nået til M for Marked.......Bogstaveligt talt: Hvad er civilsamfundet? Anker Brink Lund og Gitte Meyer fra CBS Center for Civil Society Studies gennemgår civilsamfundet bogstav for bogstav. Vi er nået til M for Marked....

  14. Marks on the petroleum fiscality

    International Nuclear Information System (INIS)

    2007-02-01

    This document offers some marks on the petroleum fiscality in France: the taxes as the 'accises' and the 'TVA', the part of the taxes in the sale price at the service station, the comparison with other countries of Europe, the tax revenues and the Government budget. It provides also marks on the fuels prices formation (margins), the world petroleum markets (supply and demand) and the part of the petroleum companies on the petroleum market. (A.L.B.)

  15. Linguistic gender marking and its international business ramifications

    OpenAIRE

    Estefania Santacreu-Vasut; Oded Shenkar; Amir Shoham

    2014-01-01

    We analyze the impact of language-based gender distinctions within languages’ grammatical structures on women’s corporate presence. Using four different data sets, we find that countries where the dominant language marks gender more intensely have significantly lower female participation on boards of directors and in senior management, as well as smaller female-led corporate teams. We also find that the gender marking of the language used in the headquarters’ home country impacts female prese...

  16. Deformations on Hole and Projectile Surfaces Caused By High Velocity Friction During Ballistic Impact

    Science.gov (United States)

    Karamış, M. B.

    2018-01-01

    In this study, the deformations caused by the ballistic impact on the MM composites and on projectile surfaces are examined. The hole section and grain deformation of unreinforced targets are also examined after impact. The relatively high complexity of impact problems is caused by the large number of intervening parameters like relative velocity of projectile and target, shape of colliding objects, relative stiffness and masses, time-dependent surface of contact, geometry and boundary conditions and material characteristics. The material used in this investigation are 2024 and 7075 aluminum alloys as matrix reinforced with SiC and Al2O3 particles. The matrix materials are extensively used in defense applications due to its favorable ballistic properties, moderate strength, high corrosion resistance and super plastic potential. Two different composites were produced; one by casting and the other by lamination. The ballistic tests of the composite targets were carried out according to NIJ Standard-0101.04, Temperature 21 °C, RH=65% with 7.62 mm projectiles. The bullet weight was 9.6 g and their muzzle velocities were in the range of 770-800 m/s. The projectiles consisted of a steel core, copper jacket and lead material. The composite targets were positioned 15 m from the rifle. The interaction between projectiles and the target hole created after impact were examined by light microscopy and photography. Different damage and failure mechanisms such as petalling, cracking, spalling, dishing, etc., were observed on the target body. On the other hand, dramatic wear and damages on the projectile surface were also observed. The targets were supported with Al-5083 backing blocks having 40 mm thickness.

  17. Impact of dissipation on the energy spectrum of experimental turbulence of gravity surface waves

    Science.gov (United States)

    Campagne, Antoine; Hassaini, Roumaissa; Redor, Ivan; Sommeria, Joël; Valran, Thomas; Viboud, Samuel; Mordant, Nicolas

    2018-04-01

    We discuss the impact of dissipation on the development of the energy spectrum in wave turbulence of gravity surface waves with emphasis on the effect of surface contamination. We performed experiments in the Coriolis facility, which is a 13-m-diam wave tank. We took care of cleaning surface contamination as well as possible, considering that the surface of water exceeds 100 m2. We observe that for the cleanest condition the frequency energy spectrum shows a power-law decay extending up to the gravity capillary crossover (14 Hz) with a spectral exponent that is increasing with the forcing strength and decaying with surface contamination. Although slightly higher than reported previously in the literature, the exponent for the cleanest water remains significantly below the prediction from the weak turbulence theory. By discussing length and time scales, we show that weak turbulence cannot be expected at frequencies above 3 Hz. We observe with a stereoscopic reconstruction technique that the increase with the forcing strength of energy spectrum beyond 3 Hz is mostly due to the formation and strengthening of bound waves.

  18. BWR Mark I pressure suppression study: bench mark experiments

    International Nuclear Information System (INIS)

    Lai, W.; McCauley, E.W.

    1977-01-01

    Computer simulations representative of the wetwell of Mark I BWR's have predicted pressures and related phenomena. However, calculational predictions for purposes of engineering decision will be possible only if the code can be verified, i.e., shown to compute in accord with measured values. Described in the report is a set of single downcomer spherical flask bench mark experiments designed to produce quantitative data to validate various air-water dynamic computations; the experiments were performed since relevant bench mark data were not available from outside sources. Secondary purposes of the study were to provide a test bed for the instrumentation and post-experiment data processing techniques to be used in the Laboratory's reactor safety research program and to provide additional masurements for the air-water scaling study

  19. Isolated Bacterial Spores at High-velocity Survive Surface Impacts in Vacuum

    Science.gov (United States)

    Austin, Daniel; Barney, Brandon

    We present experiments in which bacterial spores were found to survive being accelerated in vacuum to velocities in the range 30-120 m/s and impacted on a dense target. In these experiments, spores of Bacillus subtilis spores were charged using electrospray at atmospheric pressure, dried, and then introduced into high vacuum. Through choice of skimmers and beam tubes, different velocity ranges were achieved. An image-charge detector observed the charged spores, providing total charge and velocity. The spores then impacted a glass target within a collection vessel. After the experiment, the collection vessel contents were extracted and cultured. Several positive and negative controls were used, including the use of antibiotic-resistant spores and antibiotic-containing (rifampicin) agar for culturing. These impact velocities are of particular interest for possible transport of bacterial spores from Mars to Phobos, and may have implications for planetary protection in a Phobos sample return mission. In addition, bacteria may reach similar velocities during a spacecraft crash (e.g., within components, or from spacecraft to surface materials during impact, etc.), raising concerns about forward contamination. The velocities of interest to transport of life between planets (panspermia) are somewhat higher, but these results complement shock-based experiments and contribute to the general discussion of impact survivability of organisms.

  20. Ultimate Cavity Dynamics of Hydrophobic Spheres Impacting on Free Water Surfaces

    KAUST Repository

    Mansoor, Mohammad M.

    2012-12-01

    Cavity formation resulting from the water-entry of solid objects has been the subject of extensive research owing to its practical relevance in naval, military, industrial, sports and biological applications. The cavity formed by an impacting hydrophobic sphere normally seals at two places, one below (deep seal) and the other above the water surface (surface seal). For Froude numbers , the air flow into the resulting cavity is strong enough to suck the splash crown above the surface and disrupt the cavity dynamics before it deep seals. In this research work we eliminate surface seals by means of a novel practice of using cone splash-guards and examine the undisturbed transient cavity dynamics by impact of hydrophobic spheres for Froude numbers ranging . This enabled the measurement of extremely accurate pinch-off heights, pinch-off times, radial cavity collapse rates, and jet speeds in an extended range of Froude numbers compared to the previous work of Duclaux et al. (2007). Results in the extended regime were in remarkable agreement with the theoretical prediction of scaled pinch-off depth, and experimentally derived pinch-off time for . Furthermore, we investigated the influence of confinement on cavity formation by varying the cross-sectional area of the tank of liquid. In conjunction with surface seal elimination we observed the formation of multiple pinch-off points where a maximum of four deep seals were obtained in a sequential order for the Froude number range investigated. The presence of an elongated cavity beneath the first pinch-off point 5 resulted in evident "kinks" primarily related to the greatly diminished air pressure at the necking region caused by supersonic air flows (Gekle et al. 2010). Such flows passing through second pinch-offs were also found to choke the cavities beneath the first pinch- off depths causing radial expansion and hence disappearance of downward jets.

  1. Rumble surfaces

    CSIR Research Space (South Africa)

    National Institute for Transport and Road

    1977-01-01

    Full Text Available Rumble surfaces are intermittent short lengths of coarse-textured road surfacings on which vehicle tyres produce a rumbling sound. used in conjunction with appropriate roadsigns and markings, they can reduce accidents on rural roads by alerting...

  2. Preliminary safety evaluation of an aircraft impact on a near-surface radioactive waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Lo Frano, R.; Forasassi, G.; Pugliese, G. [Department of Industrial and Civil Engineering (DICI), University of Pisa, Pisa (Italy)

    2013-07-01

    The aircraft impact accident has become very significant in the design of a nuclear facilities, particularly, after the tragic September 2001 event, that raised the public concern about the potential damaging effects that the impact of a large civilian airplane could bring in safety relevant structures. The aim of this study is therefore to preliminarily evaluate the global response and the structural effects induced by the impact of a military or commercial airplane (actually considered as a 'beyond design basis' event) into a near surface radioactive waste (RWs) disposal facility. The safety evaluation was carried out according to the International safety and design guidelines and in agreement with the stress tests requirements for the security track. To achieve the purpose, a lay out and a scheme of a possible near surface repository, like for example those of the El Cabril one, were taken into account. In order to preliminarily perform a reliable analysis of such a large-scale structure and to determine the structural effects induced by such a types of impulsive loads, a realistic, but still operable, numerical model with suitable materials characteristics was implemented by means of FEM codes. In the carried out structural analyses, the RWs repository was considered a 'robust' target, due to its thicker walls and main constitutive materials (steel and reinforced concrete). In addition to adequately represent the dynamic response of repository under crashing, relevant physical phenomena (i.e. penetration, spalling, etc.) were simulated and analysed. The preliminary assessment of the effects induced by the dynamic/impulsive loads allowed generally to verify the residual strength capability of the repository considered. The obtained preliminary results highlighted a remarkable potential to withstand the impact of military/large commercial aircraft, even in presence of ongoing concrete progressive failure (some penetration and spalling of the

  3. Radiological impact of surface water and sediment near uranium mining sites.

    Science.gov (United States)

    Ivanova, K; Stojanovska, Z; Badulin, V; Kunovska, B; Yovcheva, M

    2015-12-01

    The aim of this study is to assess the radiological impact of surface water and sediment around uranium mining sites 20 years after their closing. The areas under observations are 31 former classical underground uranium mining and exploratory sites in Bulgaria, named as objects. The extraction and processing of uranium ores in the Republic of Bulgaria were ended in 1992. To assess the radiological impact of radionuclides field expeditions were performed to sample water and bottom sediment. The migration of uranium through surface water was examined as one of the major pathways for contamination spread. The range of uranium concentration in water flowing from the mining sites was from 0.012 to 6.8 mgU l(-1) with a geometric mean of 0.192 mgU l(-1). The uranium concentrations in water downstream the mining sites were approximately 3 times higher than the background value (upstream). The concentrations of Unat, (226)Ra, (210)Pb, and (232)Th in the sediment of downstream river were higher than those upstream by 3.4, 2.6, 2, and 1.7 times, respectively. The distribution coefficient of uranium reflects its high mobility in most of the sites. In order to evaluate the impact on people as well as site prioritization for more detailed assessment and water management, screening dose assessments were done.

  4. Land Surface Model Biases and their Impacts on the Assimilation of Snow-related Observations

    Science.gov (United States)

    Arsenault, K. R.; Kumar, S.; Hunter, S. M.; Aman, R.; Houser, P. R.; Toll, D.; Engman, T.; Nigro, J.

    2007-12-01

    Some recent snow modeling studies have employed a wide range of assimilation methods to incorporate snow cover or other snow-related observations into different hydrological or land surface models. These methods often include taking both model and observation biases into account throughout the model integration. This study focuses more on diagnosing the model biases and presenting their subsequent impacts on assimilating snow observations and modeled snowmelt processes. In this study, the land surface model, the Community Land Model (CLM), is used within the Land Information System (LIS) modeling framework to show how such biases impact the assimilation of MODIS snow cover observations. Alternative in-situ and satellite-based observations are used to help guide the CLM LSM in better predicting snowpack conditions and more realistic timing of snowmelt for a western US mountainous region. Also, MODIS snow cover observation biases will be discussed, and validation results will be provided. The issues faced with inserting or assimilating MODIS snow cover at moderate spatial resolutions (like 1km or less) will be addressed, and the impacts on CLM will be presented.

  5. Long-term CO2 injection and its impact on near-surface soil microbiology.

    Science.gov (United States)

    Gwosdz, Simone; West, Julia M; Jones, David; Rakoczy, Jana; Green, Kay; Barlow, Tom; Blöthe, Marco; Smith, Karon; Steven, Michael; Krüger, Martin

    2016-12-01

    Impacts of long-term CO 2 exposure on environmental processes and microbial populations of near-surface soils are poorly understood. This near-surface long-term CO 2 injection study demonstrated that soil microbiology and geochemistry is influenced more by seasonal parameters than elevated CO 2 Soil samples were taken during a 3-year field experiment including sampling campaigns before, during and after 24 months of continuous CO 2 injection. CO 2 concentrations within CO 2 -injected plots increased up to 23% during the injection period. No CO 2 impacts on geochemistry were detected over time. In addition, CO 2 -exposed samples did not show significant changes in microbial CO 2 and CH 4 turnover rates compared to reference samples. Likewise, no significant CO 2 -induced variations were detected for the abundance of Bacteria, Archaea (16S rDNA) and gene copy numbers of the mcrA gene, Crenarchaeota and amoA gene. The majority (75%-95%) of the bacterial sequences were assigned to five phyla: Firmicutes, Proteobacteria, Actinobacteria, Acidobacteria and Bacteroidetes The majority of the archaeal sequences (85%-100%) were assigned to the thaumarchaeotal cluster I.1b (soil group). Univariate and multivariate statistical as well as principal component analyses showed no significant CO 2 -induced variation. Instead, seasonal impacts especially temperature and precipitation were detected. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Effects of Hypervelocity Impacts on Silicone Elastomer Seals and Mating Aluminum Surfaces

    Science.gov (United States)

    deGroh, Henry C., III; Steinetz, Bruce M.

    2009-01-01

    While in space silicone based elastomer seals planned for use on NASA's Crew Exploration Vehicle (CEV) are exposed to threats from micrometeoroids and orbital debris (MMOD). An understanding of these threats is required to assess risks to the crew, the CEV orbiter, and missions. An Earth based campaign of hypervelocity impacts on small scale seal rings has been done to help estimate MMOD threats to the primary docking seal being developed for the Low Impact Docking System (LIDS). LIDS is being developed to enable the CEV to dock to the ISS (International Space Station) or to Altair (NASA's next lunar lander). The silicone seal on LIDS seals against aluminum alloy flanges on ISS or Altair. Since the integrity of a seal depends on both sealing surfaces, aluminum targets were also impacted. The variables considered in this study included projectile mass, density, speed, incidence angle, seal materials, and target surface treatments and coatings. Most of the impacts used a velocity near 8 km/s and spherical aluminum projectiles (density = 2.7 g/cubic cm), however, a few tests were done near 5.6 km/s. Tests were also performed using projectile densities of 7.7, 2.79, 2.5 or 1.14 g/cubic cm. Projectile incidence angles examined included 0 deg, 45 deg, and 60 deg from normal to the plane of the target. Elastomer compounds impacted include Parker's S0383-70 and Esterline's ELA-SA-401 in the as received condition, or after an atomic oxygen treatment. Bare, anodized and nickel coated aluminum targets were tested simulating the candidate mating seal surface materials. After impact, seals and aluminum plates were leak tested: damaged seals were tested against an undamaged aluminum plate; and undamaged seals were placed at various locations over craters in aluminum plates. It has been shown that silicone elastomer seals can withstand an impressive level of damage before leaking beyond allowable limits. In general on the tests performed to date, the diameter of the crater in

  7. Mark Napier / Mark Napier ; interv. Tilman Baumgärtel

    Index Scriptorium Estoniae

    Napier, Mark

    2006-01-01

    Ameerika kunstnikust Mark Napierist (sünd. 1961) ja tema loomingust, 2001. a. tehtud meiliintervjuu kunstnikuga. Võrguteosest "The Digital Landfill" (1998), koos Andy Deckiga loodud tööst "GrafficJam" (1999), töödest "Shredder" (1998), "Feed", "Riot", "P-Soup" (2000), võrgukunstist ja muust

  8. Impact of Surface Type, Wheelchair Weight, and Axle Position on Wheelchair Propulsion by Novice Older Adults

    Science.gov (United States)

    Cowan, Rachel E.; Nash, Mark S.; Collinger, Jennifer L.; Koontz, Alicia M.; Boninger, Michael L.

    2009-01-01

    Objective To examine the impact of surface type, wheelchair weight, and rear axle position on older adult propulsion biomechanics. Design Crossover trial. Setting Biomechanics laboratory. Participants Convenience sample of 53 ambulatory older adults with minimal wheelchair experience (65−87y); men = 20, women = 33. Intervention Participants propelled 4 different wheelchair configurations over 4 surfaces; tile, low carpet, high carpet, and an 8% grade ramp (surface, chair order randomized). Chair configurations included: (1) unweighted chair with an anterior axle position, (2) 9.05kg weighted chair with an anterior axle position, (3) unweighted chair with a posterior axle position (Δ0.08m), and (4) 9.05kg weighted chair with a posterior axle position (Δ0.08m). Weight was added to a titanium folding chair, simulating the weight difference between very light and depot wheelchairs. Instrumented wheels measured propulsion kinetics. Main Outcome Measures Average self-selected velocity, push-frequency, stroke length, peak resultant and tangential force. Results Velocity decreased as surface rolling resistance or chair weight increased. Peak resultant and tangential forces increased as chair weight increased, surface resistance increased, and with a posterior axle position. The effect of a posterior axle position was greater on high carpet and the ramp. The effect of weight was constant, but more easily observed on high carpet and ramp. The effects of axle position and weight were independent of one another. Conclusion Increased surface resistance decreases self-selected velocity and increases peak forces. Increased weight decreases self-selected velocity and increases forces. Anterior axle positions decrease forces, more so on high carpet. Effects of weight and axle position are independent. Greatest reductions in peak forces occur in lighter chairs with anterior axle positions. PMID:19577019

  9. Impacts of model initialization on an integrated surface water - groundwater model

    KAUST Repository

    Ajami, Hoori

    2015-04-01

    Integrated hydrologic models characterize catchment responses by coupling the subsurface flow with land surface processes. One of the major areas of uncertainty in such models is the specification of the initial condition and its influence on subsequent simulations. A key challenge in model initialization is that it requires spatially distributed information on model states, groundwater levels and soil moisture, even when such data are not routinely available. Here, the impact of uncertainty in initial condition was explored across a 208 km2 catchment in Denmark using the ParFlow.CLM model. The initialization impact was assessed under two meteorological conditions (wet vs dry) using five depth to water table and soil moisture distributions obtained from various equilibrium states (thermal, root zone, discharge, saturated and unsaturated zone equilibrium) during the model spin-up. Each of these equilibrium states correspond to varying computation times to achieve stability in a particular aspect of the system state. Results identified particular sensitivity in modelled recharge and stream flow to the different initializations, but reduced sensitivity in modelled energy fluxes. Analysis also suggests that to simulate a year that is wetter than the spin-up period, an initialization based on discharge equilibrium is adequate to capture the direction and magnitude of surface water–groundwater exchanges. For a drier or hydrologically similar year to the spin-up period, an initialization based on groundwater equilibrium is required. Variability of monthly subsurface storage changes and discharge bias at the scale of a hydrological event show that the initialization impacts do not diminish as the simulations progress, highlighting the importance of robust and accurate initialization in capturing surface water–groundwater dynamics.

  10. Impacts of Solid Waste Leachate on Groundwater and Surface Water Quality

    International Nuclear Information System (INIS)

    Karim, S.

    2010-01-01

    The present investigation was carried out to assess the impacts of solid waste leachate on groundwater and surface water quality at unlined dumping site. Six leachate samples collected from different locations have average values of COD and BOD 2563 mg/L and 442 mg/L, respectively. Surface water samples were collected in two different seasons (rainy and non- rainy). Samples collected during non-rainy season were found to be more contaminated than rainy season. Soil samples collected from the depth of 1.5 m are contaminated with heavy metals (Cd, Cr, Fe and Zn) and E.coli. Presence of E.coli shows that leachate has deteriorated groundwater quality. (author)

  11. Impacts of land cover transitions on surface temperature in China based on satellite observations

    Science.gov (United States)

    Zhang, Yuzhen; Liang, Shunlin

    2018-02-01

    China has experienced intense land use and land cover changes during the past several decades, which have exerted significant influences on climate change. Previous studies exploring related climatic effects have focused mainly on one or two specific land use changes, or have considered all land use and land cover change types together without distinguishing their individual impacts, and few have examined the physical processes of the mechanism through which land use changes affect surface temperature. However, in this study, we considered satellite-derived data of multiple land cover changes and transitions in China. The objective was to obtain observational evidence of the climatic effects of land cover transitions in China by exploring how they affect surface temperature and to what degree they influence it through the modification of biophysical processes, with an emphasis on changes in surface albedo and evapotranspiration (ET). To achieve this goal, we quantified the changes in albedo, ET, and surface temperature in the transition areas, examined their correlations with temperature change, and calculated the contributions of different land use transitions to surface temperature change via changes in albedo and ET. Results suggested that land cover transitions from cropland to urban land increased land surface temperature (LST) during both daytime and nighttime by 0.18 and 0.01 K, respectively. Conversely, the transition of forest to cropland tended to decrease surface temperature by 0.53 K during the day and by 0.07 K at night, mainly through changes in surface albedo. Decreases in both daytime and nighttime LST were observed over regions of grassland to forest transition, corresponding to average values of 0.44 and 0.20 K, respectively, predominantly controlled by changes in ET. These results highlight the necessity to consider the individual climatic effects of different land cover transitions or conversions in climate research studies. This short

  12. Percentage Retail Mark-Ups

    OpenAIRE

    Thomas von Ungern-Sternberg

    1999-01-01

    A common assumption in the literature on the double marginalization problem is that the retailer can set his mark-up only in the second stage of the game after the producer has moved. To the extent that the sequence of moves is designed to reflect the relative bargaining power of the two parties it is just as plausible to let the retailer move first. Furthermore, retailers frequently calculate their selling prices by adding a percentage mark-up to their wholesale prices. This allows a retaile...

  13. Forecasting surface water flooding hazard and impact in real-time

    Science.gov (United States)

    Cole, Steven J.; Moore, Robert J.; Wells, Steven C.

    2016-04-01

    Across the world, there is increasing demand for more robust and timely forecast and alert information on Surface Water Flooding (SWF). Within a UK context, the government Pitt Review into the Summer 2007 floods provided recommendations and impetus to improve the understanding of SWF risk for both off-line design and real-time forecasting and warning. Ongoing development and trial of an end-to-end real-time SWF system is being progressed through the recently formed Natural Hazards Partnership (NHP) with delivery to the Flood Forecasting Centre (FFC) providing coverage over England & Wales. The NHP is a unique forum that aims to deliver coordinated assessments, research and advice on natural hazards for governments and resilience communities across the UK. Within the NHP, a real-time Hazard Impact Model (HIM) framework has been developed that includes SWF as one of three hazards chosen for initial trialling. The trial SWF HIM system uses dynamic gridded surface-runoff estimates from the Grid-to-Grid (G2G) hydrological model to estimate the SWF hazard. National datasets on population, infrastructure, property and transport are available to assess impact severity for a given rarity of SWF hazard. Whilst the SWF hazard footprint is calculated in real-time using 1, 3 and 6 hour accumulations of G2G surface runoff on a 1 km grid, it has been possible to associate these with the effective rainfall design profiles (at 250m resolution) used as input to a detailed flood inundation model (JFlow+) run offline to produce hazard information resolved to 2m resolution. This information is contained in the updated Flood Map for Surface Water (uFMfSW) held by the Environment Agency. The national impact datasets can then be used with the uFMfSW SWF hazard dataset to assess impacts at this scale and severity levels of potential impact assigned at 1km and for aggregated county areas in real-time. The impact component is being led by the Health and Safety Laboratory (HSL) within the NHP

  14. Impact of Mina Ratones (Albala, Caceres) in surface and ground waters: hydro geochemistry modelling

    International Nuclear Information System (INIS)

    Gomez Gonzalez, P.

    2002-01-01

    Weathering of rock materials, tailings and mine dumps produce acidic and metal-enriched waters that contaminate surface and groundwaters. The understanding and quantification of the environmental impact of the Ratones old uranium mine (Albala, Caceres) are the main objectives of this work. For this purpose, the hydro geochemistry around the mine has been studied based on a precise knowledge of the structure and hydrogeology of the zone. The hydrochemical study aims to establish the chemical phases that control the concentration of the possible contaminants of the groundwaters. (Author)

  15. Numerical Study of High-Speed Droplet Impact on Surfaces and its Physical Cleaning Effects

    Science.gov (United States)

    Kondo, Tomoki; Ando, Keita

    2015-11-01

    Spurred by the demand for cleaning techniques of low environmental impact, one favors physical cleaning that does not rely on any chemicals. One of the promising candidates is based on water jets that often involve fission into droplet fragments and collide with target surfaces to which contaminant particles (often micron-sized or even smaller) stick. Hydrodynamic force (e.g., shearing and lifting) arising from the droplet impact will play a role to remove the particles, but its detailed mechanism is still unknown. To explore the role of high-speed droplet impact in physical cleaning, we solve compressible Navier-Stokes equations with a finite volume method that is designed to capture both shocks and material interfaces in accurate and robust manners. Water hammer and shear flow accompanied by high-speed droplet impact at a rigid wall is simulated to evaluate lifting force and rotating torque, which are relevant to the application of particle removal. For the simulation, we use the numerical code recently developed by Computational Flow Group lead by Tim Colonius at Caltech. The first author thanks Jomela Meng for her help in handling the code during his stay at Caltech.

  16. The recognition and interpretation of micro-particle impacts on space craft surfaces

    Science.gov (United States)

    Kearsley, Anton

    Modern analysis instruments now allow the rapid examination of returned spacecraft surfaces, enabling the location and identification of impact features, and the attribution of their impactor origins. This paper describes application of novel electron, ion and micro-X-ray Fluorescence techniques to impacts on diverse compositions of substrate, including solar cell glass, poly-sulfone and fluoro-polymer-impregnated glass fibre composites, multilayer insulation foils, aluminium and titanium alloys. Examples will include two generations of solar cells and stiffener materials from the Hubble Space Telescope (HST), Beta-cloth from the NASA Mir-Trek cover blanket, aluminised Kapton foils from the Japanese Space Flyer Unit (SFU) and the European Retrievable Carrier (EuReCa), Al-alloy plates from the Long Duration Exposure Facility (LDEF), Al foils from the NASA Stardust mission, Al-alloy and Zinc orthotitanate (ZOT) painted alloy plate from HST, and titanium alloys from a re-entered titanium pressure tank. Each type of spacecraft surface poses unique problems of analysis, especially in the recognition of extraneous signatures from the impacting particle, especially if a complex chemical composition is already present in the target. For example, solar cells provide an excellent capture and analysis medium for monitoring fluxes of micrometre-scale orbital debris from solid rocket motor firings in low Earth orbit. However, they provide a hard and dense capture medium upon which substantial modification of the impactor may occur, making the precise identification of micrometeoroid components difficult. Unfortunately, extensive spallation by larger (> 100 micrometre) particle impacts on the thin and brittle structure of solar cells also usually results in complete loss of impactor signature. Although thick alloy surfaces may prevent complete impact penetration, the analysis of particle residues within their deep concavity has proven difficult, until the recent introduction of

  17. Impact of Water Withdrawals from Groundwater and Surface Water on Continental Water Storage Variations

    Science.gov (United States)

    Doell, Petra; Hoffmann-Dobrev, Heike; Portmann, Felix T.; Siebert, Stefan; Eicker, Annette; Rodell, Matthew; Strassberg, Gil

    2011-01-01

    Humans have strongly impacted the global water cycle, not only water flows but also water storage. We have performed a first global-scale analysis of the impact of water withdrawals on water storage variations, using the global water resources and use model WaterGAP. This required estimation of fractions of total water withdrawals from groundwater, considering five water use sectors. According to our assessment, the source of 35% of the water withdrawn worldwide (4300 cubic km/yr during 1998-2002) is groundwater. Groundwater contributes 42%, 36% and 27% of water used for irrigation, households and manufacturing, respectively, while we assume that only surface water is used for livestock and for cooling of thermal power plants. Consumptive water use was 1400 cubic km/yr during 1998-2002. It is the sum of the net abstraction of 250 cubic km/yr of groundwater (taking into account evapotranspiration and return flows of withdrawn surface water and groundwater) and the net abstraction of 1150 km3/yr of surface water. Computed net abstractions indicate, for the first time at the global scale, where and when human water withdrawals decrease or increase groundwater or surface water storage. In regions with extensive surface water irrigation, such as Southern China, net abstractions from groundwater are negative, i.e. groundwater is recharged by irrigation. The opposite is true for areas dominated by groundwater irrigation, such as in the High Plains aquifer of the central USA, where net abstraction of surface water is negative because return flow of withdrawn groundwater recharges the surface water compartments. In intensively irrigated areas, the amplitude of seasonal total water storage variations is generally increased due to human water use; however, in some areas, it is decreased. For the High Plains aquifer and the whole Mississippi basin, modeled groundwater and total water storage variations were compared with estimates of groundwater storage variations based on

  18. Impact of Gastric Acid Induced Surface Changes on Mechanical Behavior and Optical Characteristics of Dental Ceramics.

    Science.gov (United States)

    Kulkarni, Aditi; Rothrock, James; Thompson, Jeffery

    2018-01-14

    To test the impact of exposure to artificial gastric acid combined with toothbrush abrasion on the properties of dental ceramics. Earlier research has indicated that immersion in artificial gastric acid has caused increased surface roughness of dental ceramics; however, the combined effects of acid immersion and toothbrush abrasion and the impact of increased surface roughness on mechanical strength and optical properties have not been studied. Three commercially available ceramics were chosen for this study: feldspathic porcelain, lithium disilicate glass-ceramic, and monolithic zirconium oxide. The specimens (10 × 1 mm discs) were cut, thermally treated as required, and polished. Each material was divided into four groups (n = 8 per group): control (no exposure), acid only, brush only, acid + brush. The specimens were immersed in artificial gastric acid (50 ml of 0.2% [w/v] sodium chloride in 0.7% [v/v] hydrochloric acid mixed with 0.16 g of pepsin powder, pH = 2) for 2 minutes and rinsed with deionized water for 2 minutes. The procedure was repeated 6 times/day × 9 days, and specimens were stored in deionized water at 37°C. Toothbrush abrasion was performed using an ISO/ADA design brushing machine for 100 cycles/day × 9 days. The acid + brush group received both treatments. Specimens were examined under SEM and an optical microscope for morphological changes. Color and translucency were measured using spectrophotometer CIELAB coordinates (L*, a*, b*). Surface gloss was measured using a gloss meter. Surface roughness was measured using a stylus profilometer. Biaxial flexural strength was measured using a mechanical testing machine. The data were analyzed by one-way ANOVA followed by Tukey's HSD post hoc test (p gloss, and surface roughness for porcelain and e.max specimens. No statistically significant changes were found for any properties of zirconia specimens. The acid treatment affected the surface roughness, color, and gloss of porcelain and e

  19. Prosodic Focus Marking in Bai.

    NARCIS (Netherlands)

    Liu, Zenghui; Chen, A.; Van de Velde, Hans

    2014-01-01

    This study investigates prosodic marking of focus in Bai, a Sino-Tibetan language spoken in the Southwest of China, by adopting a semi-spontaneous experimental approach. Our data show that Bai speakers increase the duration of the focused constituent and reduce the duration of the post-focus

  20. Better marking means cheaper pruning.

    Science.gov (United States)

    Kenneth R. Eversole

    1953-01-01

    Careful selection of trees to be pruned can make the difference between profit and loss on the pruning investment, especially in stands where no thinning is contemplated. Expert marking is required to make sure that the pruned trees will grow rapidly. The most important variable influencing the cost of clear wood produced by pruning is growth rate. For example, at 3...

  1. Surface microtextures of quartz grains from the central coast of Tamil Nadu

    Digital Repository Service at National Institute of Oceanography (India)

    Udayaganesan, P.; Angusamy, N.; Gujar, A.R.; Rajamanickam, G.V.

    into three sectors on the basis of drainage, geomorphology and nature of the beach and shelf topography. Surface textures of the northern sector display an array of mechanical features like conchoidal fracture, V marks and impact pits, indicating...

  2. Impact of climate change on surface ozone and deposition of sulphur and nitrogen in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Langner, J.; Bergstroem, R.; Foltescu, V. [Swedish Meteorological and Hydrological Institute, Norrkoeping (Sweden)

    2005-02-01

    The potential impact of regional climate change on the distribution and deposition of air pollutants in Europe has been studied using a regional chemistry/transport/deposition model, MATCH. MATCH was set up using meteorological output from two 10-year climate change experiments made with the Rossby Centre regional Atmospheric climate model version 1 (RCA1). RCA1 was forced by boundary conditions from two different global climate models using the IPCC IS92a (business as usual) emission scenario. The global mean warming in both the GCMs was 2.6 K and was reached in the period 2050-2070. Simulations with MATCH indicate substantial potential impact of regional climate change on both deposition of oxidised nitrogen and concentrations of surface ozone. The simulations show a strong increase in surface ozone expressed as AOT40 and mean of daily maximum over southern and central Europe and a decrease in northern Europe. The simulated changes in April-September AOT40 are significant in relation to inter-annual variability over extended areas. Changes in deposition of oxidised nitrogen are much smaller and also less coherent due to the strong inter-annual variability in precipitation in the RCA1 simulations and differences in the regional climate change simulated with RCA1 in the two regional scenarios. Changes in simulated annual deposition are significant in relation to inter-annual variability only over small areas. This indicates that longer simulation periods are necessary to establish changes in deposition. (author)

  3. Impact of climate change on surface ozone and deposition of sulphur and nitrogen in Europe

    Science.gov (United States)

    Langner, Joakim; Bergström, Robert; Foltescu, Valentin

    The potential impact of regional climate change on the distribution and deposition of air pollutants in Europe has been studied using a regional chemistry/transport/deposition model, MATCH. MATCH was set up using meteorological output from two 10-year climate change experiments made with the Rossby Centre regional Atmospheric climate model version 1 (RCA1). RCA1 was forced by boundary conditions from two different global climate models using the IPCC IS92a (business as usual) emission scenario. The global mean warming in both the GCMs was 2.6 K and was reached in the period 2050-2070. Simulations with MATCH indicate substantial potential impact of regional climate change on both deposition of oxidised nitrogen and concentrations of surface ozone. The simulations show a strong increase in surface ozone expressed as AOT40 and mean of daily maximum over southern and central Europe and a decrease in northern Europe. The simulated changes in April-September AOT40 are significant in relation to inter-annual variability over extended areas. Changes in deposition of oxidised nitrogen are much smaller and also less coherent due to the strong inter-annual variability in precipitation in the RCA1 simulations and differences in the regional climate change simulated with RCA1 in the two regional scenarios. Changes in simulated annual deposition are significant in relation to inter-annual variability only over small areas. This indicates that longer simulation periods are necessary to establish changes in deposition.

  4. Atmospheric river impacts on Greenland Ice Sheet surface melt and mass balance

    Science.gov (United States)

    Mattingly, K.; Mote, T. L.

    2017-12-01

    Mass loss from the Greenland Ice Sheet (GrIS) has accelerated during the early part of the 21st Century. Several episodes of widespread GrIS melt in recent years have coincided with intense poleward moisture transport by atmospheric rivers (ARs), suggesting that variability in the frequency and intensity of these events may be an important driver of the surface mass balance (SMB) of the GrIS. ARs may contribute to GrIS surface melt through the greenhouse effect of water vapor, the radiative effects of clouds, condensational latent heating within poleward-advected air masses, and the energy provided by liquid precipitation. However, ARs may also provide significant positive contributions to GrIS SMB through enhanced snow accumulation. Prior research on the role of ARs in Arctic climate has consisted of case studies of ARs associated with major GrIS melt events or examined the effects of poleward moisture flux on Arctic sea ice. In this study, a long-term (1979-2016) record of intense moisture transport events affecting Greenland is compiled using a conventional AR identification algorithm as well as a self-organizing map (SOM) classification applied to integrated water vapor transport (IVT) data from several atmospheric reanalysis datasets. An analysis of AR effects on GrIS melt and SMB is then performed with GrIS surface melt data from passive microwave satellite observations and the Modèle Atmosphérique Régional (MAR) regional climate model. Results show that meltwater production is above normal during and after AR impact days throughout the GrIS during all seasons, with surface melt enhanced most by strong (> 85th percentile IVT) and extreme (> 95th percentile IVT) ARs. This relationship holds at the seasonal scale, as the total amount of water vapor transported to the GrIS by ARs is significantly greater during above-normal melt seasons. ARs exert a more complex influence on SMB. Normal (< 85th percentile IVT) ARs generally do not have a substantial impact on

  5. The Surface of Venus is Saturated With Ancient Impact Structures, and its Plains are Marine Sediments

    Science.gov (United States)

    Hamilton, W. B.

    2009-05-01

    Conventional interpretations of Venus are forced to fit dubious pre-Magellan conjectures that the planet is as active internally as Earth and preserves no ancient surface features. Plate tectonics obviously does not operate, so it is commonly assumed that the surface must record other endogenic processes, mostly unique to Venus. Imaginative systems of hundreds of tiny to huge rising and sinking plumes and diapirs are invoked. That much of the surface in fact is saturated with overlapping large circular depressions with the morphology of impact structures is obscured by postulating plume origins for selected structures and disregarding the rest. Typical structures are rimmed circular depressions, often multiring, with lobate debris aprons; central peaks are common. Marine-sedimentation features are overlooked because dogma deems the plains to be basalt flows despite their lack of source volcanoes and fissures. The unearthly close correlation between geoid and topography at long to moderate wavelengths requires, in conventional terms, dynamic maintenance of topography by up and down plumes of long-sustained precise shapes and buoyancy. A venusian upper mantle much stronger than that of Earth, because it is cooler or poorer in volatiles, is not considered. (The unearthly large so-called volcanoes and tessera plateaus often are related to rimmed circular depressions and likely are products of impact fluidization and melting.) Plains-saturating impact structures (mostly more obvious in altimetry than backscatter) with diameters of hundreds of km are superimposed as cookie-cutter bites, are variably smoothed and smeared by apparent submarine impact and erosion, and are differentially buried by sediments compacted into them. Marine- sedimentation evidence includes this compaction; long sinuous channels and distributaries with turbidite- channel characteristics and turbidite-like lobate flows (Jones and Pickering, JGSL 2003); radar-smooth surfaces and laminated aspect in

  6. Ancient Maya impacts on the Earth's surface: An Early Anthropocene analog?

    Science.gov (United States)

    Beach, Tim; Luzzadder-Beach, Sheryl; Cook, Duncan; Dunning, Nicholas; Kennett, Douglas J.; Krause, Samantha; Terry, Richard; Trein, Debora; Valdez, Fred

    2015-09-01

    The measure of the "Mayacene," a microcosm of the Early Anthropocene that occurred from c. 3000 to 1000 BP, comes from multiple Late Quaternary paleoenvironmental records. We synthesized the evidence for Maya impacts on climate, vegetation, hydrology and the lithosphere, from studies of soils, lakes, floodplains, wetlands and other ecosystems. Maya civilization had likely altered local to regional ecosystems and hydrology by the Preclassic Period (3000-1700 BP), but these impacts waned by 1000 BP. They altered ecosystems with vast urban and rural infrastructure that included thousands of reservoirs, wetland fields and canals, terraces, field ridges, and temples. Although there is abundant evidence that indicates the Maya altered their forests, even at the large urban complex of Tikal as much as 40% of the forest remained intact through the Classic period. Existing forests are still influenced by ancient Maya forest gardening, particularly by the large expanses of ancient stone structures, terraces, and wetland fields that form their substrates. A few studies suggest deforestation and other land uses probably also warmed and dried regional climate by the Classic Period (1700-1100 BP). A much larger body of research documents the Maya impacts on hydrology, in the form of dams, reservoirs, canals, eroded soils and urban design for runoff. Another metric of the "Mayacene" are paleosols, which contain chemical evidence for human occupation, revealed by high phosphorus concentrations and carbon isotope ratios of C4 species like maize in the C3-dominated tropical forest ecosystem. Paleosol sequences exhibit "Maya Clays," a facies that reflects a glut of rapidly eroded sediments that overlie pre-Maya paleosols. This stratigraphy is conspicuous in many dated soil profiles and marks the large-scale Maya transformation of the landscape in the Preclassic and Classic periods. Some of these also have increased phosphorous and carbon isotope evidence of C4 species. We synthesize

  7. Impact of 4 Lactobacillus plantarum capsular polysaccharide clusters on surface glycan composition and host cell signaling

    Directory of Open Access Journals (Sweden)

    Remus Daniela M

    2012-11-01

    Full Text Available Abstract Background Bacterial cell surface-associated polysaccharides are involved in the interactions of bacteria with their environment and play an important role in the communication between pathogenic bacteria and their host organisms. Cell surface polysaccharides of probiotic species are far less well described. Therefore, improved knowledge on these molecules is potentially of great importance to understand the strain-specific and proposed beneficial modes of probiotic action. Results The Lactobacillus plantarum WCFS1 genome encodes 4 clusters of genes that are associated with surface polysaccharide production. Two of these clusters appear to encode all functions required for capsular polysaccharide formation (cps2A-J and cps4A-J, while the remaining clusters are predicted to lack genes encoding chain-length control functions and a priming glycosyl-transferase (cps1A-I and cps3A-J. We constructed L. plantarum WCFS1 gene deletion mutants that lack individual (Δcps1A-I, Δcps2A-J, Δcps3A-J and Δcps4A-J or combinations of cps clusters (Δcps1A-3J and Δcps1A-3I, Δcps4A-J and assessed the genome wide impact of these mutations by transcriptome analysis. The cps cluster deletions influenced the expression of variable gene sets in the individual cps cluster mutants, but also considerable numbers of up- and down-regulated genes were shared between mutants in cps cluster 1 and 2, as well as between mutant in cps clusters 3 and 4. Additionally, the composition of overall cell surface polysaccharide fractions was altered in each mutant strain, implying that despite the apparent incompleteness of cps1A-I and cps3A-J, all clusters are active and functional in L. plantarum. The Δcps1A-I strain produced surface polysaccharides in equal amounts as compared to the wild-type strain, while the polysaccharides were characterized by a reduced molar mass and the lack of rhamnose. The mutants that lacked functional copies of cps2A-J, cps3A-J or cps4A

  8. Towards spatially smart abatement of human pharmaceuticals in surface waters: defining impact of sewage treatment plants on susceptible functions

    NARCIS (Netherlands)

    Gils, J.A.G.; Coppens, L.J.C.; Laak, ter T.L.; Raterman, B.W.; Wezel, van A.P.

    2015-01-01

    For human pharmaceuticals, sewage treatment plants (STPs) are a major point of entry to surface waters. The receiving waters provide vital functions. Modeling the impact of STPs on susceptible functions of the surface water system allows for a spatially smart implementation of abatement options at,

  9. Towards spatially smart abatement of human pharmaceuticals in surface waters : Defining impact of sewage treatment plants on susceptible functions

    NARCIS (Netherlands)

    Coppens, Lieke J C; van Gils, Jos A G; Ter Laak, Thomas L|info:eu-repo/dai/nl/304831026; Raterman, Bernard W; van Wezel, Annemarie P|info:eu-repo/dai/nl/141376074

    2015-01-01

    For human pharmaceuticals, sewage treatment plants (STPs) are a major point of entry to surface waters. The receiving waters provide vital functions. Modeling the impact of STPs on susceptible functions of the surface water system allows for a spatially smart implementation of abatement options at,

  10. Assessing the impact of model spin-up on surface water-groundwater interactions using an integrated hydrologic model

    KAUST Repository

    Ajami, Hoori; McCabe, Matthew; Evans, Jason P.; Stisen, Simon

    2014-01-01

    is to minimize the impact of initialization while using the smallest spin-up time possible. In this study, multicriteria analysis was performed to assess the spin-up behavior of the ParFlow.CLM integrated groundwater-surface water-land surface model over a 208 km

  11. Impact or push-off lameness presentation is not altered by the type of track surface where horses are trotted

    Directory of Open Access Journals (Sweden)

    M.S. Azevedo

    2015-12-01

    Full Text Available This study aimed to evaluate the influence of the track surface on which horses are examined, regarding the phase of lameness presentation. Ten horses with lameness in at least one limb were evaluated with wireless inertial sensors on three track surfaces (concrete, loose sand and grass. Six crossover track sequences were established. The variables vector sum, maximum and minimum height of the head and pelvis, variation coefficient of the maximum and minimum height of the head and pelvis were analyzed using ANOVA, followed by Tukey test to compare means between track surface and sequence, at 5% significance level. The lameness phase (impact or pushoff was analyzed considering the proportion of affected animals. There were no differences on vector sum, maximum and minimum height or variation coefficient of head and pelvis. Difference was observed on the number of strides registered on sand compared to grass and concrete (p <0.0001 for fore and hindlimbs. Impact lameness on forelimbs was presented by a larger number of animals on the concrete surface; pushoff lameness was more evident on the grass surface. In the hindlimbs, impact lameness was more evident on the grass surface, while pushoff lameness was in greater number of animals on concrete surfaces. The track sequence on which horses were trotted during evaluation does not seem to be a factor, but the number of lame horses and the phase of lameness manifestation can vary between track surfaces, as some horses showed impact lameness on soft ground and elevation lameness on hard ground.

  12. Effect of a Quaternary Meteoroid Impact in Indo-China on the Surface Sedimentary Record

    Science.gov (United States)

    Carling, Paul; Songtham, Wickanet; Tada, Riuji; Tada, Toshihiro; Duangkrayon, Jaa

    2017-04-01

    Effects of meteoroid impacts on terrestrial geology primarily have been considered with respect of proximal effects near the impact location; such as cratering, fracturing and melt. However, other than the use of rare elements (iridium) as event markers and tektite chemistry for dating control, distal effects of impacts are less-well documented. Distal effects might include: fireball, air blast, heat, water vaporization, catastrophic flooding, earthquakes, ejecta fallout (tektites & dust), large quantities of N2O from shock heating of the atmosphere, release of CO2 and sulphur aerosols causing heating or cooling of atmosphere, IR radiation causing vegetation fires, smoke and pyrotoxins, and altered native rock geochemistry. Such processes may affect the distal surface geology, degrade vegetation cover and cause extirpation of flora and fauna. Quaternary sedimentary sections have been examined in northern and central Cambodia, in southern China and in north-east Thailand. These locality lie within the Australian strewn tektite field ̶ reliably dated to 0.77-0.78Ma BP ̶ just before the 0.80Ma BP Brunhes/Matayama reversal. The location of the primary impact crater (if any) is uncertain but a local major crater probably lies within central Laos or just offshore to the east. The described sections are considered distal from the main impact. Stratigraphic evidence indicates a temporal sequence of catastrophic stripping of alluvial-gravel surfaces followed by catastrophic redistribution of gravel (incorporating tektites), followed by deposition of atmospheric dust. Grain-size and grain-density trends, XRD, spherule distributions, luminescence profiles, tektite, and microtektite and shock quartz assay, are used to with the stratigraphic evidence to examine an hypothesis that the sections represent the distal effects of a meteorite. Additional insight is gained with respect to prior claims that large accumulations of woody debris in Thai Quaternary river terraces were due

  13. Modeling The Urban Impact On Semiarid Surface Climate: A Case Study In Marrakesh, Morocco

    Science.gov (United States)

    Lachir, Asia; Bounoua, Lahouari; Zhang, Ping; Thome, Kurtis; Messouli, Mohamed

    2016-01-01

    We combine Landsat and MODIS data in the Simple Biosphere Model to assess the impact of urbanization on surface climate in a semiarid city in North Africa. The model simulates highest temperatures in urban class, with spring average maximum temperature differences to other land cover classes ranging between 1.6 C and 6.0 C. During summer, these maximum temperature differences are smallest (0.5 C) with barelands and highest (8.3 C) with irrigated lawns. This excess heating is simulated above and beyond a seasonal temperature average of about 30 C during spring and 44 C during summer. On annual mean, a full urbanization scenario decreases the carbon fixation by 0.13 MtC and increases the daytime mean surface temperature by 1.3 C. This may boost the city energy consumption by 5.72%. Under a 'smart growth' scenario, whereby the city expands on barelands to cover 50% of the study region and all remaining barelands converted to orchards, the carbon fixation is enhanced by 0.04 MtC with a small daytime temperature increase of 0.2 C. Our results indicate that vegetation can mitigate the urban heating. The hydrological cycle indicates that highest ratio of surface runoff to precipitation (43.8%) occurs in urban areas, versus only 16.7 % for all cover types combined.

  14. Modeling the Urban Impact on Semiarid Surface Climate: A Case Study in Marrakech, Morocco

    Science.gov (United States)

    Lachir, Asia; Bounoua, Lahouari; Zhang, Ping; Thome, Kurtis; Moussouli, Mohamed

    2016-01-01

    We combine Landsat and MODIS data in the Simple Biosphere Model to assess the impact of urbanization on surface climate in a semiarid city in North Africa. The model simulates highest temperatures in urban class, with spring average maximum temperature differences to other land cover classes ranging between 1.6 C and 6.0 C. During summer, these maximum temperature differences are smallest (0.5 C) with barelands and highest (8.3 C) with irrigated lawns. This excess heating is simulated above and beyond a seasonal temperature average of about 30 C during spring and 44 C during summer. On annual mean, a full urbanization scenario decreases the carbon fixation by 0.13 MtC and increases the daytime mean surface temperature by 1.3 C. This may boost the city energy consumption by 5.72%. Under a 'smart growth' scenario, whereby the city expands on barelands to cover 50% of the study region and all remaining barelands converted to orchards, the carbon fixation is enhanced by 0.04 MtC with a small daytime temperature increase of 0.2 C. Our results indicate that vegetation can mitigate the urban heating. The hydrological cycle indicates that highest ratio of surface runoff to precipitation (43.8%) occurs in urban areas, versus only 16.7 % for all cover types combined.

  15. Modeling the Impacts of Boreal Deforestation on the Near-Surface Temperature in European Russia

    Directory of Open Access Journals (Sweden)

    Zhihui Li

    2013-01-01

    Full Text Available Boreal deforestation plays an important role in affecting regional and global climate. In this study, the regional temperature variation induced by future boreal deforestation in European Russia boreal forest region was simulated based on future land cover change and the Weather Research and Forecasting (WRF model. This study firstly tested and validated the simulation results of the WRF model. Then the land cover datasets in different years (2000 as baseline year, 2010, and 2100 was used in the WRF model to explore the impacts of boreal deforestation on the near-surface temperature. The results indicated that the WRF model has good ability to simulate the temperature change in European Russia. The land cover change in European Russia boreal forest region, which will be characterized by the conversion from boreal forests to croplands (boreal deforestation in the future 100 years, will lead to significant change of the near-surface temperature. The regional annual temperature will decrease by 0.58°C in the future 100 years, resulting in cooling effects to some extent and making the near-surface temperature decrease in most seasons except the spring.

  16. A Numerical Study on Impact of Taiwan Island Surface Heat Flux on Super Typhoon Haitang (2005

    Directory of Open Access Journals (Sweden)

    Hongxiong Xu

    2015-01-01

    Full Text Available Three to four tropical cyclones (TCs by average usually impact Taiwan every year. This study, using the Developmental Tested Center (DTC version of the Hurricane WRF (HWRF model, examines the effects of Taiwan’s island surface heat fluxes on typhoon structure, intensity, track, and its rainfall over the island. The numerical simulation successfully reproduced the structure and intensity of super Typhoon Haitang. The model, especially, reproduced the looped path and landfall at nearly the right position. Sensitive experiments indicated that Taiwan’s surface heat fluxes have significant influence on the super Typhoon Haitang. Compared to sensible heat (SH fluxes, latent heat (LH is the dominant factor affecting the intensity and rainfall, but they showed opposite effects on intensity and rainfall. LH (SH flux of Taiwan Island intensified (weakened Typhoon Haitang’s intensity and structure by transferring more energy from (to surface. However, only LH played a major role in the looped path before the landfall of the Typhoon Haitang.

  17. The impact of surface geometry, cavitation, and condensation on wetting transitions: posts and reentrant structures

    Science.gov (United States)

    Panter, J. R.; Kusumaatmaja, H.

    2017-03-01

    The fundamental impacts of surface geometry on the stability of wetting states, and the transitions between them are elucidated for square posts and reentrant structures in three dimensions. We identify three principal outcomes of particular importance for future surface design of liquid-repellent surfaces. Firstly, we demonstrate and quantify how capillary condensation and vapour cavitation affect wetting state stabilities. At high contact angles, cavitation is enhanced about wide, closely-spaced square posts, leading to the existence of suspended states without an associated collapsed state. At low contact angles, narrow reentrant pillars suppress condensation and enable the suspension of even highly wetting liquids. Secondly, two distinct collapse mechanisms are observed for 3D reentrant geometries, base contact and pillar contact, which are operative at different pillar heights. As well as morphological differences in the interface of the penetrating liquid, each mechanism is affected differently by changes in the contact angle with the solid. Finally, for highly-wetting liquids, condensates are shown to critically modify the transition pathways in both the base contact and pillar contact modes.

  18. Impacts of urban and industrial development on Arctic land surface temperature in Lower Yenisei River Region.

    Science.gov (United States)

    Li, Z.; Shiklomanov, N. I.

    2015-12-01

    Urbanization and industrial development have significant impacts on arctic climate that in turn controls settlement patterns and socio-economic processes. In this study we have analyzed the anthropogenic influences on regional land surface temperature of Lower Yenisei River Region of the Russia Arctic. The study area covers two consecutive Landsat scenes and includes three major cities: Norilsk, Igarka and Dudingka. Norilsk industrial region is the largest producer of nickel and palladium in the world, and Igarka and Dudingka are important ports for shipping. We constructed a spatio-temporal interpolated temperature model by including 1km MODIS LST, field-measured climate, Modern Era Retrospective-analysis for Research and Applications (MERRA), DEM, Landsat NDVI and Landsat Land Cover. Those fore-mentioned spatial data have various resolution and coverage in both time and space. We analyzed their relationships and created a monthly spatio-temporal interpolated surface temperature model at 1km resolution from 1980 to 2010. The temperature model then was used to examine the characteristic seasonal LST signatures, related to several representative assemblages of Arctic urban and industrial infrastructure in order to quantify anthropogenic influence on regional surface temperature.

  19. Dynamic Impacts of Water Droplets onto Icephobic Soft Surfaces at High Weber Numbers

    Science.gov (United States)

    Ma, Liqun; Liu, Yang; Hu, Hui; Wang, Wei; Kota, Arun

    2017-11-01

    An experimental investigation was performed to examine the effects of the stiffness of icephobic soft PDMS materials on the impact dynamics of water drops at high weber numbers pertinent to aircraft icing phenomena. The experimental study was performed in the Icing Research Tunnel available at Iowa State University (ISU-IRT). During the experiments, both the shear modulus of the soft PDMS surface and the Weber numbers of the impinging water droplets are controlled for the comparative study. While the shear modulus of the soft PDMS surface was changed by tuning the recipes to make the PDMS materials, the Weber number of the impinging water droplets was altered by adjusting the airflow speed in the wind tunnel. A suite of advanced flow diagnostic techniques, which include high-speed photographic imaging, digital image projection (DIP), and infrared (IR) imaging thermometry, were used to quantify the transient behavior of water droplet impingement, unsteady heat transfer and dynamic ice accreting process over the icephobic soft airfoil surfaces. The findings derived from the icing physics studies can be used to improve current icing accretion models for more accurate prediction of ice formation and accretion on aircraft wings and to develop effective anti-/deicing strategies for safer and more efficient operation of aircraft in cold weather.

  20. Basin-scale heterogeneity in Antarctic precipitation and its impact on surface mass variability

    Directory of Open Access Journals (Sweden)

    J. Fyke

    2017-11-01

    Full Text Available Annually averaged precipitation in the form of snow, the dominant term of the Antarctic Ice Sheet surface mass balance, displays large spatial and temporal variability. Here we present an analysis of spatial patterns of regional Antarctic precipitation variability and their impact on integrated Antarctic surface mass balance variability simulated as part of a preindustrial 1800-year global, fully coupled Community Earth System Model simulation. Correlation and composite analyses based on this output allow for a robust exploration of Antarctic precipitation variability. We identify statistically significant relationships between precipitation patterns across Antarctica that are corroborated by climate reanalyses, regional modeling and ice core records. These patterns are driven by variability in large-scale atmospheric moisture transport, which itself is characterized by decadal- to centennial-scale oscillations around the long-term mean. We suggest that this heterogeneity in Antarctic precipitation variability has a dampening effect on overall Antarctic surface mass balance variability, with implications for regulation of Antarctic-sourced sea level variability, detection of an emergent anthropogenic signal in Antarctic mass trends and identification of Antarctic mass loss accelerations.

  1. Time-resolved imaging of a compressible air disc under a drop impacting on a solid surface

    KAUST Repository

    Li, Erqiang; Thoroddsen, Sigurdur T

    2015-01-01

    When a drop impacts on a solid surface, its rapid deceleration is cushioned by a thin layer of air, which leads to the entrapment of a bubble under its centre. For large impact velocities the lubrication pressure in this air layer becomes large

  2. An innovative road marking quality assessment mechanism using computer vision

    Directory of Open Access Journals (Sweden)

    Kuo-Liang Lin

    2016-06-01

    Full Text Available Aesthetic quality acceptance for road marking works has been relied on subjective visual examination. Due to a lack of quantitative operation procedures, acceptance outcome can be biased and results in great quality variation. To improve aesthetic quality acceptance procedure of road marking, we develop an innovative road marking quality assessment mechanism, utilizing machine vision technologies. Using edge smoothness as a quantitative aesthetic indicator, the proposed prototype system first receives digital images of finished road marking surface and has the images processed and analyzed to capture the geometric characteristics of the marking. The geometric characteristics are then evaluated to determine the quality level of the finished work. System is demonstrated through two real cases to show how it works. In the end, a test comparing the assessment results between the proposed system and expert inspection is conducted to enhance the accountability of the proposed mechanism.

  3. Closing the loop: integrating human impacts on water resources to advanced land surface models

    Science.gov (United States)

    Zaitchik, B. F.; Nie, W.; Rodell, M.; Kumar, S.; Li, B.

    2016-12-01

    Advanced Land Surface Models (LSMs), including those used in the North American Land Data Assimilation System (NLDAS), offer a physically consistent and spatially and temporally complete analysis of the distributed water balance. These models are constrained both by physically-based process representation and by observations ingested as meteorological forcing or as data assimilation updates. As such, they have become important tools for hydrological monitoring and long-term climate analysis. The representation of water management, however, is extremely limited in these models. Recent advances have brought prognostic irrigation routines into models used in NLDAS, while assimilation of Gravity Recovery and Climate Experiment (GRACE) derived estimates of terrestrial water storage anomaly has made it possible to nudge models towards observed states in water storage below the root zone. But with few exceptions these LSMs do not account for the source of irrigation water, leading to a disconnect between the simulated water balance and the observed human impact on water resources. This inconsistency is unacceptable for long-term studies of climate change and human impact on water resources in North America. Here we define the modeling challenge, review instances of models that have begun to account for water withdrawals (e.g., CLM), and present ongoing efforts to improve representation of human impacts on water storage across models through integration of irrigation routines, water withdrawal information, and GRACE Data Assimilation in NLDAS LSMs.

  4. Meteorological and Land Surface Properties Impacting Sea Breeze Extent and Aerosol Distribution in a Dry Environment

    Science.gov (United States)

    Igel, Adele L.; van den Heever, Susan C.; Johnson, Jill S.

    2018-01-01

    The properties of sea breeze circulations are influenced by a variety of meteorological and geophysical factors that interact with one another. These circulations can redistribute aerosol particles and pollution and therefore can play an important role in local air quality, as well as impact remote sensing. In this study, we select 11 factors that have the potential to impact either the sea breeze circulation properties and/or the spatial distribution of aerosols. Simulations are run to identify which of the 11 factors have the largest influence on the sea breeze properties and aerosol concentrations and to subsequently understand the mean response of these variables to the selected factors. All simulations are designed to be representative of conditions in coastal sub tropical environments and are thus relatively dry, as such they do not support deep convection associated with the sea breeze front. For this dry sea breeze regime, we find that the background wind speed was the most influential factor for the sea breeze propagation, with the soil saturation fraction also being important. For the spatial aerosol distribution, the most important factors were the soil moisture, sea-air temperature difference, and the initial boundary layer height. The importance of these factors seems to be strongly tied to the development of the surface-based mixed layer both ahead of and behind the sea breeze front. This study highlights potential avenues for further research regarding sea breeze dynamics and the impact of sea breeze circulations on pollution dispersion and remote sensing algorithms.

  5. Automated road marking recognition system

    Science.gov (United States)

    Ziyatdinov, R. R.; Shigabiev, R. R.; Talipov, D. N.

    2017-09-01

    Development of the automated road marking recognition systems in existing and future vehicles control systems is an urgent task. One way to implement such systems is the use of neural networks. To test the possibility of using neural network software has been developed with the use of a single-layer perceptron. The resulting system based on neural network has successfully coped with the task both when driving in the daytime and at night.

  6. Simulation of the Impact of New Ocean Surface Wind Measurements on H*Wind Analyses

    Science.gov (United States)

    Miller, Timothy; Atlas, Robert; Black, Peter; Chen, Shuyi; Hood, Robbie; Johnson, James; Jones, Linwood; Ruf, Chris; Uhlhorn, Eric

    2008-01-01

    The H*Wind analysis, a product of the Hurricane Research Division of NOAA's Atlantic Oceanographic and Meteorological Laboratory, brings together wind measurements from a variety of observation platforms into an objective analysis of the distribution of surface wind speeds in a tropical cyclone. This product is designed to improve understanding of the extent and strength of the wind field, and to improve the assessment of hurricane intensity. See http://www.aoml.noaa.gov/hrd/data sub/wind.html. The Hurricane Imaging Radiometer (HIRAD) is a new passive microwave remote sensor for hurricane observations that is currently under development by NASA Marshall Space Flight Center, NOAA Hurricane Research Division, the University of Central Florida and the University of Michigan. HIRAD is being designed to enhance the current real-time airborne ocean surface winds observation capabilities of NOAA and USAF Weather Squadron hurricane hunter aircraft using the operational airbome Stepped Frequency Microwave Radiometer (SFMR). Unlike SFMR, which measures wind speed and rain rate along the ground track directly beneath the aircraft, HIRAD will provide images of the surface wind and rain field over a wide swath (approximately 3 x the aircraft altitude, or approximately 2 km from space). The instrument is described in a separate paper presented at this conference. The present paper describes a set of Observing System Simulation Experiments (OSSEs) in which measurements from the new instrument as well as those from existing instruments (air, surface, and space-based) are simulated from the output of a numerical model from the University of Miami, and those results are used to construct H*Wind analyses. Evaluations will be presented on the relative impact of HIRAD and other instruments on H*Wind analyses, including the use of HIRAD from 2 aircraft altitudes and from a space-based platform.

  7. Shear wave profiles from surface wave inversion: the impact of uncertainty on seismic site response analysis

    International Nuclear Information System (INIS)

    Boaga, J; Vignoli, G; Cassiani, G

    2011-01-01

    Inversion is a critical step in all geophysical techniques, and is generally fraught with ill-posedness. In the case of seismic surface wave studies, the inverse problem can lead to different equivalent subsoil models and consequently to different local seismic response analyses. This can have a large impact on an earthquake engineering design. In this paper, we discuss the consequences of non-uniqueness of surface wave inversion on seismic responses, with both numerical and experimental data. Our goal is to evaluate the consequences on common seismic response analysis in the case of different impedance contrast conditions. We verify the implications of inversion uncertainty, and consequently of data information content, on realistic local site responses. A stochastic process is used to generate a set of 1D shear wave velocity profiles from several specific subsurface models. All these profiles are characterized as being equivalent, i.e. their responses, in terms of a dispersion curve, are compatible with the uncertainty in the same surface wave data. The generated 1D shear velocity models are then subjected to a conventional one-dimensional seismic ground response analysis using a realistic input motion. While recent analyses claim that the consequences of surface wave inversion uncertainties are very limited, our test points out that a relationship exists between inversion confidence and seismic responses in different subsoils. In the case of regular and relatively smooth increase of shear wave velocities with depth, as is usual in sedimentary plains, our results show that the choice of a specific model among equivalent solutions strongly influences the seismic response. On the other hand, when the shallow subsoil is characterized by a strong impedance contrast (thus revealing a characteristic soil resonance period), as is common in the presence of a shallow bedrock, equivalent solutions provide practically the same seismic amplification, especially in the

  8. The impact of changing climate on surface and ground water quality in southeast of Ireland

    Science.gov (United States)

    Tribak, Kamal

    2015-04-01

    In the current changing climate globally, Ireland have been experiencing a yearly recurrent extreme heavy rainfall events in the last decade, with damaging visible effects socially, economically and on the environment. Ireland intensive agriculture production is a major treat to the aquatic environment, Nitrogen and phosphorus losses to the water courses are major causes to eutrophication. The European Water Frame Directive (WFD 2000/60/EC) and Nitrates Directive (91/676/EEC) sets a number of measures to better protect and improve water status. Five years of high temporal resolution river water quality data measurement from two contrasting catchment in the southeast of Ireland were correlated with rain fall and nutrients losses to the ground and surface water, additional to the integrated Southeast River District Basin ground and surface water quality to establish spatiotemporal connection to the agriculture activities, the first well-drained soil catchment had high coefficient correlation with rain fall with higher losses to groundwater, on the other hand higher nutrients losses to surface water were higher with less influence from groundwater recharge of N and P transfer, the poorly clay base soil contributed to higher increased losses to surface water during excessive rain fall. Agriculture activities, hydrology, geology and human interaction can interact according to their site specific setting and the effects will fluctuate dependent on the conditions influencing the impact on water quality, there is a requirement to better distinguish those effects together and identify areas and land uses control and nutrients management to improve the water quality, stakeholders co-operation along with effective polices, long term monitoring, nutrients pathways management and better understanding of the environmental factors interaction on national, regional and catchment scale to enable planning policies and enforcement measures to be more focused on areas of high risk

  9. Impact Capacity Reduction in Railway Prestressed Concrete Sleepers with Surface Abrasions

    Science.gov (United States)

    Ngamkhanong, Chayut; Li, Dan; Kaewunruen, Sakdirat

    2017-10-01

    Railway sleepers (also called ‘railroad tie’ in North America) embedded in ballasted railway tracks are a main part of railway track structures. Its important role is to transfer the loads evenly from the rails to a wider area of ballast bed and to secure rail gauge and enable safe passages of rolling stocks. By nature, railway infrastructure is nonlinear, evidenced by its behaviours, geometry and alignment, wheel-rail contact and operational parameters such as tractive efforts. Based on our critical review, the dynamic behaviour of railway sleepers has not been fully investigated, especially when the sleepers are deteriorated by excessive wears. In fact, the ballast angularity causes differential abrasions on the soffit or bottom surface of sleepers (especially at railseat zone). Furthermore, in sharp curves and rapid gradient change, longitudinal and lateral dynamics of rails increase the likelihood of railseat abrasions in concrete sleepers due to the unbalanced loading conditions. This paper presents a structural capacity of concrete sleepers under dynamic transient loading. The modified compression field theory for ultimate strength design of concrete sleepers under impact loading will be highlighted in this study. The influences of surface abrasions, including surface abrasion and soffit abrasion, on the dynamic behaviour of prestressed concrete sleepers, are firstly highlighted. The outcome of this study will improve the rail maintenance and inspection criteria in order to establish appropriate and sensible remote track condition monitoring network in practice. Moreover, this study will also improve the understanding of the fundamental dynamic behaviour of prestressed concrete sleepers with surface abrasions. The insight into these behaviours will not only improve safety and reliability of railway infrastructure but will enhance the structural safety of other concrete structures.

  10. Coal and Open-pit surface mining impacts on American Lands (COAL)

    Science.gov (United States)

    Brown, T. A.; McGibbney, L. J.

    2017-12-01

    Mining is known to cause environmental degradation, but software tools to identify its impacts are lacking. However, remote sensing, spectral reflectance, and geographic data are readily available, and high-performance cloud computing resources exist for scientific research. Coal and Open-pit surface mining impacts on American Lands (COAL) provides a suite of algorithms and documentation to leverage these data and resources to identify evidence of mining and correlate it with environmental impacts over time.COAL was originally developed as a 2016 - 2017 senior capstone collaboration between scientists at the NASA Jet Propulsion Laboratory (JPL) and computer science students at Oregon State University (OSU). The COAL team implemented a free and open-source software library called "pycoal" in the Python programming language which facilitated a case study of the effects of coal mining on water resources. Evidence of acid mine drainage associated with an open-pit coal mine in New Mexico was derived by correlating imaging spectrometer data from the JPL Airborne Visible/InfraRed Imaging Spectrometer - Next Generation (AVIRIS-NG), spectral reflectance data published by the USGS Spectroscopy Laboratory in the USGS Digital Spectral Library 06, and GIS hydrography data published by the USGS National Geospatial Program in The National Map. This case study indicated that the spectral and geospatial algorithms developed by COAL can be used successfully to analyze the environmental impacts of mining activities.Continued development of COAL has been promoted by a Startup allocation award of high-performance computing resources from the Extreme Science and Engineering Discovery Environment (XSEDE). These resources allow the team to undertake further benchmarking, evaluation, and experimentation using multiple XSEDE resources. The opportunity to use computational infrastructure of this caliber will further enable the development of a science gateway to continue foundational COAL

  11. Impact of Future Emissions and Climate Change on Surface Ozone over China

    Science.gov (United States)

    Ma, C. T.; Westervelt, D. M.; Fiore, A. M.; Rieder, H. E.; Kinney, P.; Wang, S.; Correa, G. J. P.

    2017-12-01

    China's immense ambient air pollution problem and world-leading greenhouse gas emissions place it at the forefront of global efforts to address these related environmental concerns. Here, we analyze the impact of ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants) future emissions scenarios representative of current legislation (CLE) and maximum technically feasible emissions reductions (MFR) on surface ozone (O3) concentrations over China in the 2030s and 2050s, in the context of a changing climate. We use a suite of simulations performed with the NOAA Geophysical Fluid Dynamics Laboratory's AM3 global chemistry-climate model. To estimate the impact of climate change in isolation on Chinese air quality, we hold emissions of air pollutants including O3 precursors fixed at 2015 levels but allow climate (global sea surface temperatures and sea ice cover) to change according to decadal averages for the years 2026-2035 and 2046-2055 from a three-member ensemble of GFDL-CM3 simulations under the RCP8.5 high warming scenario. Evaluation of the present-day simulation (2015 CLE) with observations from 1497 chiefly urban air quality monitoring stations shows that simulated surface O3 is positively biased by 26 ppb on average over the domain of China. Previous studies, however, have shown that the modeled ozone response to changes in NOx emissions over the Eastern United States mirrors the magnitude and structure of observed changes in maximum daily average 8-hour (MDA8) O3 distributions. Therefore, we use the model's simulated changes for the 2030s and 2050s to project changes in policy-relevant MDA8 O3 concentrations. We find an overall increase in MDA8 O3 for CLE scenarios in which emissions of NOx precursors are projected to increase, and under MFR scenarios, an overall decrease, with the highest changes occurring in summertime for both 2030 and 2050 MFR. Under climate change alone, the model simulates a mean summertime decrease of 1.3 ppb

  12. Mark Twain: inocente ou pecador? = Mark Twain: innocent or sinner?

    Directory of Open Access Journals (Sweden)

    Heloisa Helou Doca

    2009-01-01

    Full Text Available A leitura cuidadosa do texto do “Tratado de Paris”, em 1900, leva Mark Twain a concluir que a intenção política norte-americana era, claramente, a de subjugação. Declara-se, abertamente, antiimperialista, nesse momento, apesar das inúmeras críticasrecebidas por antagonistas políticos que defendiam o establishment dos Estados Unidos. Após viajar para a Europa e Oriente, em 1867, como correspondente do jornal Daily Alta Califórnia, Mark Twain publica, em 1869, seu relato de viagem, The Innocents Abroad or TheNew Pilgrim’s Progress. Nosso estudo demonstra que o autor, apesar das diversas máscaras usadas em seus relatos, narra histórias, culturas e tradições, tanto da Europa quanto do Oriente, já com os olhos bem abertos pelo viés antiimperialista. Faz uso da paródia, sátira, ironia e humor para dessacralizar impérios, monarcas e a Igreja que subjugavam os mais fracos, iluminando, desde então, os estudos sobre culturas. Nosso estudo, outrossim, faz uma reflexão sobre cultura, tradição e o olhar do viajante, justificando o “olhar inocente” do narrador em seu relato.After carefully reading the Treaty of Paris in 1900, Mark Twain concluded that the goal of U.S. policy was clearly one ofsubjugation. He openly declared himself an anti-imperialist at that time, in spite of the numerous criticisms he received from political opponents who supported the United States status quo. After traveling to Europe and the East in 1867 as a correspondent for The DailyAlta California newspaper, Mark Twain published his travel report, The Innocents Abroad or The New Pilgrim’s Progress in 1869. Our study demonstrates that the author, in spite of using different guises in his reports, narrated histories, cultures and traditions – from both Europe and the East – with a viewpoint already imbued by his anti-imperialistic ideals. Twain made use of parody, satire, irony and humor within his texts in order to desecrate empires,monarchs and

  13. Infrared technique for decoding of invisible laser markings

    Science.gov (United States)

    Haferkamp, Heinz; Jaeschke, Peter; Stein, Johannes; Goede, Martin

    2002-03-01

    Counterfeiting and product piracy continues to be an important issue not only for the Western industry, but also for the society in general. Due to the drastic increase in product imitation and the request for plagiarism protection as well as for reducing thefts there is a high interest in new protection methods providing new security features. The method presented here consists of security markings which are included below paint layers. These markings are invisible for the human eye due to the non-transparency of the upper layers in the visible spectral range. However, the markings can be detected by an infrared technique taking advantage on the partial transparency of the upper paint layers in the IR-region. Metal sheets are marked using laser radiation. The beam of a Nd:YAG-laser provides a modification of the surface structure, resulting in dark markings due to the annealing effect. After coating of the laser-marked material, the markings are invisible for the bare eye. In order to read out the invisible information below the coating, an infrared reflection technique is used. The samples are illuminated with halogen lamps or infrared radiators. Many coating materials (i. e. paints) show a certain transparency in the mid-infrared region, especially between 3 - 5 micrometers . The reflected radiation is detected using an IR-camera with a sensitivity range from 3.4 - 5 micrometers . Due to the different reflection properties between the markings and their surrounding, the information can be detected.

  14. The Impact of Solid Surface Features on Fluid-Fluid Interface Configuration

    Science.gov (United States)

    Araujo, J. B.; Brusseau, M. L. L.

    2017-12-01

    Pore-scale fluid processes in geological media are critical for a broad range of applications such as radioactive waste disposal, carbon sequestration, soil moisture distribution, subsurface pollution, land stability, and oil and gas recovery. The continued improvement of high-resolution image acquisition and processing have provided a means to test the usefulness of theoretical models developed to simulate pore-scale fluid processes, through the direct quantification of interfaces. High-resolution synchrotron X-ray microtomography is used in combination with advanced visualization tools to characterize fluid distributions in natural geologic media. The studies revealed the presence of fluid-fluid interface associated with macroscopic features on the surfaces of the solids such as pits and crevices. These features and respective fluid interfaces, which are not included in current theoretical or computational models, may have a significant impact on accurate simulation and understanding of multi-phase flow, energy, heat and mass transfer processes.

  15. Micro-bubble morphologies following drop impacts onto a pool surface

    KAUST Repository

    Thoroddsen, Sigurdur T; Thoraval, M.-J.; Takehara, K.; Etoh, T.G.

    2012-01-01

    When a drop impacts at low velocity onto a pool surface, a hemispheric air layer cushions and can delay direct contact. Herein we use ultra-high-speed video to study the rupture of this layer, to explain the resulting variety of observed distribution of bubbles. The size and distribution of micro-bubbles is determined by the number and location of the primary punctures. Isolated holes lead to the formation of bubble necklaces when the edges of two growing holes meet, whereas bubble nets are produced by regular shedding of micro-bubbles from a sawtooth edge instability. For the most viscous liquids the air film contracts more rapidly than the capillary-viscous velocity through repeated spontaneous ruptures of the edge. From the speed of hole opening and the total volume of micro-bubbles we conclude that the air sheet ruptures when its thickness approaches ?100.

  16. Enhancement of impact strength of poly (methyl methacrylate) with surface fine-tuned nano-silica

    International Nuclear Information System (INIS)

    Wen, Bin; Dong, Yixiao; Wu, Lili; Long, Chao; Zhang, Chaocan

    2015-01-01

    Highly dispersible nanoparticles in organic solvent always receive wide interests due to their compatibility with polymer materials. This paper reported a kind of isopropanol alcohol silica dispersion which obtained using a method of azeotropic distillation. The isopropanol alcohol dispersed silica (IPADS) were treated with coupling agents to fine-tune their surface properties. Polymethyl methacrylate (PMMA) was then used as a research object to test the compatibility between IPADS and polymer. UV-vis spectra indicate that IPADS would reach its high compatibility with PMMA if coupling with trimethoxypropylsilane (PTMS). Followed experiments on PMMA proved that the high compatibility can prominently enhance the impact strength about 30%. The results may provide reference both for nano-silica modification and better understanding of nano-enhanced materials. (paper)

  17. Micro-bubble morphologies following drop impacts onto a pool surface

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2012-10-01

    When a drop impacts at low velocity onto a pool surface, a hemispheric air layer cushions and can delay direct contact. Herein we use ultra-high-speed video to study the rupture of this layer, to explain the resulting variety of observed distribution of bubbles. The size and distribution of micro-bubbles is determined by the number and location of the primary punctures. Isolated holes lead to the formation of bubble necklaces when the edges of two growing holes meet, whereas bubble nets are produced by regular shedding of micro-bubbles from a sawtooth edge instability. For the most viscous liquids the air film contracts more rapidly than the capillary-viscous velocity through repeated spontaneous ruptures of the edge. From the speed of hole opening and the total volume of micro-bubbles we conclude that the air sheet ruptures when its thickness approaches ?100.

  18. Examination of returned solar-max surfaces for impacting orbital debris and meteoroids

    Science.gov (United States)

    Kessler, D. J.; Zook, H. A.; Potter, A. E.; Mckay, D. S.; Clanton, U. S.; Warren, J. L.; Watts, L. A.; Schultz, R. A.; Schramm, L. S.; Wentworth, S. J.

    1985-01-01

    Previous theoretical studies predicted that in certain regions of earth orbit, the man-made earth orbiting debris environment will soon exceed the interplanetary meteoroid environment for sizes smaller than 1 cm. The surfaces returned from the repaired Solar Max Mission (SMM) by STS 41-C on April 12, 1984, offered an excellent opportunity to examine both the debris and meteoroid environments. To date, approximately 0.7 sq. met. of the thermal insulation and 0.05 sq. met of the aluminum louvers have been mapped by optical microscope for crater diameters larger than 40 microns. Craters larger in diameter than about 100 microns found on the initial 75 micron thick Kapton first sheet on the MEB (Main Electronics Box) blanket are actually holes and constitute perforations through that blanket. The following populations have been found to date in impact sites on these blankets: (1) meteoritic material; (2) thermal paint particles; (3) aluminum droplets; and (4) waste particles.

  19. The dispersal and impact of salt from surface storage piles the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Reith, C.C.; Louderbough, E.T.

    1986-01-01

    A comprehensive program of ecological studies occurs at the Waste Isolation Pilot Plant (WIPP) in an effort to detect and quantify impacts of excavated salt which is stored on the surface in two piles: one having originated in 1980, the other in 1984. Both piles are surrounded by berms which channel runoff to holding ponds, so nearly all dispersal is due to the resuspension, transport, and deposition of salt particles by wind. Ecological parameters which have been monitored since 1984 include: visual evidence (via photography), soil properties, microbial activity, leaf-litter decomposition, seedling emergence, plant foliar cover, and plant species diversity. These are periodically assessed at experimental plots near the salt piles, and at control plots several kilometers away

  20. Enhancement of impact strength of poly (methyl methacrylate) with surface fine-tuned nano-silica

    Science.gov (United States)

    Wen, Bin; Dong, Yixiao; Wu, Lili; Long, Chao; Zhang, Chaocan

    2015-07-01

    Highly dispersible nanoparticles in organic solvent always receive wide interests due to their compatibility with polymer materials. This paper reported a kind of isopropanol alcohol silica dispersion which obtained using a method of azeotropic distillation. The isopropanol alcohol dispersed silica (IPADS) were treated with coupling agents to fine-tune their surface properties. Polymethyl methacrylate (PMMA) was then used as a research object to test the compatibility between IPADS and polymer. UV-vis spectra indicate that IPADS would reach its high compatibility with PMMA if coupling with trimethoxypropylsilane (PTMS). Followed experiments on PMMA proved that the high compatibility can prominently enhance the impact strength about 30%. The results may provide reference both for nano-silica modification and better understanding of nano-enhanced materials.

  1. Shape of shock wave produced by a concentrated impact on a surface

    International Nuclear Information System (INIS)

    Nutt, G.; Klein, L.

    1981-01-01

    An approximate similarity solution, derived by Raizer, of a concentrated impact (or intense explosion) at the boundary of a semi-infinite volume of a perfect gas is used to determine the propagation velocity of the shock front as a function of its position. This velocity function is then used to obtain the shape of the propagating shock wave. It is shown that dish-shaped shock fronts are formed when the movement of the gas at the surface is into the gas region and that cup-shaped shock fronts are formed when the movement is out of the gas region. Comparison of these results with the shapes of explosions and meteorite craters are discussed

  2. The impact of changing surface ocean conditions on the dissolution of aerosol iron

    Science.gov (United States)

    Fishwick, Matthew P.; Sedwick, Peter N.; Lohan, Maeve C.; Worsfold, Paul J.; Buck, Kristen N.; Church, Thomas M.; Ussher, Simon J.

    2014-11-01

    The proportion of aerosol iron (Fe) that dissolves in seawater varies greatly and is dependent on aerosol composition and the physicochemical conditions of seawater, which may change depending on location or be altered by global environmental change. Aerosol and surface seawater samples were collected in the Sargasso Sea and used to investigate the impact of these changing conditions on aerosol Fe dissolution in seawater. Our data show that seawater temperature, pH, and oxygen concentration, within the range of current and projected future values, had no significant effect on the dissolution of aerosol Fe. However, the source and composition of aerosols had the most significant effect on the aerosol Fe solubility, with the most anthropogenically influenced samples having the highest fractional solubility (up to 3.2%). The impact of ocean warming and acidification on aerosol Fe dissolution is therefore unlikely to be as important as changes in land usage and fossil fuel combustion. Our experimental results also reveal important changes in the size distribution of soluble aerosol Fe in solution, depending on the chemical conditions of seawater. Under typical conditions, the majority (77-100%) of Fe released from aerosols into ambient seawater existed in the colloidal (0.02-0.4 µm) size fraction. However, in the presence of a sufficient concentration of strong Fe-binding organic ligands (10 nM) most of the aerosol-derived colloidal Fe was converted to soluble Fe (<0.02 µm). This finding highlights the potential importance of organic ligands in retaining aerosol Fe in a biologically available form in the surface ocean.

  3. Impact of improved Greenland ice sheet surface representation in the NASA GISS ModelE2 GCM on simulated surface mass balance and regional climate

    Science.gov (United States)

    Alexander, P. M.; LeGrande, A. N.; Fischer, E.; Tedesco, M.; Kelley, M.; Schmidt, G. A.; Fettweis, X.

    2017-12-01

    Towards achieving coupled simulations between the NASA Goddard Institute for Space Studies (GISS) ModelE2 general circulation model (GCM) and ice sheet models (ISMs), improvements have been made to the representation of the ice sheet surface in ModelE2. These include a sub-grid-scale elevation class scheme, a multi-layer snow model, a time-variable surface albedo scheme, and adjustments to parameterization of sublimation/evaporation. These changes improve the spatial resolution and physical representation of the ice sheet surface such that the surface is represented at a level of detail closer to that of Regional Climate Models (RCMs). We assess the impact of these changes on simulated Greenland Ice Sheet (GrIS) surface mass balance (SMB). We also compare ModelE2 simulations in which winds have been nudged to match the European Center for Medium-Range Weather Forecasts (ECMWF) ERA-Interim reanalysis with simulations from the Modèle Atmosphérique Régionale (MAR) RCM forced by the same reanalysis. Adding surface elevation classes results in a much higher spatial resolution representation of the surface necessary for coupling with ISMs, but has a negligible impact on overall SMB. Implementing a variable surface albedo scheme increases melt by 100%, bringing it closer to melt simulated by MAR. Adjustments made to the representation of topography-influenced surface roughness length in ModelE2 reduce a positive bias in evaporation relative to MAR. We also examine the impact of changes to the GrIS surface on regional atmospheric and oceanic climate in coupled ocean-atmosphere simulations with ModelE2, finding a general warming of the Arctic due to a warmer GrIS, and a cooler North Atlantic in scenarios with doubled atmospheric CO2 relative to pre-industrial levels. The substantial influence of changes to the GrIS surface on the oceans and atmosphere highlight the importance of including these processes in the GCM, in view of potential feedbacks between the ice sheet

  4. A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo and cloud radiative forcing

    Energy Technology Data Exchange (ETDEWEB)

    Sedlar, Joseph; Tjernstroem, Michael; Leck, Caroline [Stockholm University, Department of Meteorology, Stockholm (Sweden); Mauritsen, Thorsten [Max-Planck-Institute for Meteorology, Hamburg (Germany); Shupe, Matthew D.; Persson, P.O.G. [University of Colorado, NOAA-ESRL-PSD, Boulder, CO (United States); Brooks, Ian M.; Birch, Cathryn E. [University of Leeds, School of Earth and Environment, Leeds (United Kingdom); Sirevaag, Anders [University of Bergen, Bjerknes Center for Climate Research, Bergen (Norway); Nicolaus, Marcel [Norwegian Polar Institute, Tromsoe (Norway); Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany)

    2011-10-15

    Snow surface and sea-ice energy budgets were measured near 87.5 N during the Arctic Summer Cloud Ocean Study (ASCOS), from August to early September 2008. Surface temperature indicated four distinct temperature regimes, characterized by varying cloud, thermodynamic and solar properties. An initial warm, melt-season regime was interrupted by a 3-day cold regime where temperatures dropped from near zero to -7 C. Subsequently mean energy budget residuals remained small and near zero for 1 week until once again temperatures dropped rapidly and the energy budget residuals became negative. Energy budget transitions were dominated by the net radiative fluxes, largely controlled by the cloudiness. Variable heat, moisture and cloud distributions were associated with changing air-masses. Surface cloud radiative forcing, the net radiative effect of clouds on the surface relative to clear skies, is estimated. Shortwave cloud forcing ranged between -50 W m{sup -2} and zero and varied significantly with surface albedo, solar zenith angle and cloud liquid water. Longwave cloud forcing was larger and generally ranged between 65 and 85 W m{sup -2}, except when the cloud fraction was tenuous or contained little liquid water; thus the net effect of the clouds was to warm the surface. Both cold periods occurred under tenuous, or altogether absent, low-level clouds containing little liquid water, effectively reducing the cloud greenhouse effect. Freeze-up progression was enhanced by a combination of increasing solar zenith angles and surface albedo, while inhibited by a large, positive surface cloud forcing until a new air-mass with considerably less cloudiness advected over the experiment area. (orig.)

  5. Atomic interactions at the (100) diamond surface and the impact of surface and interface changes on the electronic transport properties

    Science.gov (United States)

    Deferme, Wim

    Centuries and centuries already, diamond is a material that speaks to ones imagination. Till the 18th century it was only mined in India, after it was also found in Brazil and South-Africa. But along the fascinating properties of diamond, it is also a very interesting material for industry. After the discovery at the end of the 18th century that diamond consists of carbon, it took until the 50's of the previous century before research groups from Russia, Japan and the USA were able to reproduce the growth process of diamond. In 1989 it was discovered that the surface of intrinsic, insulation diamond can be made conductive by hydrogenating the surface. It was clear that not only hydrogen at the surface but also the so called "adsorbates" were responsible for this conductivity. It was still not completely clear what was the influence of other species (like oxygen) on the mechanism of surface conductivity and therefore in this thesis the influence of oxygen on the electronic transport properties of atomically flat diamond are researched. Besides the growth of atomically flat diamond with the use of CVD (chemical vapour deposition) en the study of the grown surfaces with characterising techniques such as AFM (atomic force microscopy) and STM (scanning tunnelling microscopy), the study of the surface treatment with plasma techniques is the main topic of this thesis. The influence of oxygen on the surface conductivity is studied and with the ToF (Time-of-Flight) technique the transport properties of the freestanding diamond are examined. With a short laserflash, electrons and holes are created at the diamond/aluminium interface and due to an electric field (up to 500V) the charge carriers are translated to the back contact. In this way the influence of the surface and the changes at the aluminum contacts is studied leading to very interesting results.

  6. Restoration of metal properties of circulation pump blades by the method of surface ultrasonic impact treatment

    Science.gov (United States)

    Povarov, V. P.; Urazov, O. V.; Bakirov, M. B.; Pakhomov, S. S.; Belunik, I. A.

    2017-10-01

    During the transition period to a market economy, the works producing equipment for the nuclear industry became lame duck companies. The market of heavy industry equipment reduced dramatically, and quality control requirements imposed to goods became lower. Deviations from regulations' requirements and technical specifications for equipment manufacture results in inevitable decrease of reliability during operation but also to failure during check tests. It is not always possible to replace promptly ill-conditioned equipment; in such cases, it is necessary to carry out compensatory measures for restoring working properties up to an acceptable level in order to ensure operational reliability due to the strength improvement of the components of machines and constructions during the whole service life or up to the scheduled date of equipment replacement. This paper is dedicated to development and practical implementation of restorative technology of strengthening ultrasonic treatment used for the metal of the blades of impellers of 16DPA10-28 circulation pumps of 10URS unit pump station located at Novovoronezh NPP-2. The dynamic surface treatment was implemented for compensating the technological defects of the metal of blades. It was revealed that the impact elastic-plastic deformation has a comprehensive compensation effect on the metal of blades in the initial state of delivery and creates the surface-strengthening layer with higher strength properties (strain hardening) of the depth up to 1.5 mm. The surface strain hardening increases the cyclic strength, re-distributes beneficially the residual technological and repair stresses, and heals small surface cracks improving the surface quality. The developed technology was used for treatment of 32 blades of impellers of 10PAC01AP001, 10PAC02AP001, 10PAC03AP001, 10PAC04AP001 circulation pumps. The implemented 100-h full-scale test of the pumps revealed the high efficiency of the developed technology and made it possible

  7. Impacts of Ambient and Ablation Plasmas on Short- and Ultrashort-Pulse Laser Processing of Surfaces

    Directory of Open Access Journals (Sweden)

    Nadezhda M. Bulgakova

    2014-12-01

    Full Text Available In spite of the fact that more than five decades have passed since the invention of laser, some topics of laser-matter interaction still remain incompletely studied. One of such topics is plasma impact on the overall phenomenon of the interaction and its particular features, including influence of the laser-excited plasma re-radiation, back flux of energetic plasma species, and massive material redeposition, on the surface quality and processing efficiency. In this paper, we analyze different plasma aspects, which go beyond a simple consideration of the well-known effect of plasma shielding of laser radiation. The following effects are considered: ambient gas ionization above the target on material processing with formation of a “plasma pipe”; back heating of the target by both laser-driven ambient and ablation plasmas through conductive and radiative heat transfer; plasma chemical effects on surface processing including microstructure growth on liquid metals; complicated dynamics of the ablation plasma flow interacting with an ambient gas that can result in substantial redeposition of material around the ablation spot. Together with a review summarizing our main to-date achievements and outlining research directions, we present new results underlining importance of laser plasma dynamics and photoionization of the gas environment upon laser processing of materials.

  8. Watershed-Scale Impacts from Surface Water Disposal of Oil and Gas Wastewater in Western Pennsylvania.

    Science.gov (United States)

    Burgos, William D; Castillo-Meza, Luis; Tasker, Travis L; Geeza, Thomas J; Drohan, Patrick J; Liu, Xiaofeng; Landis, Joshua D; Blotevogel, Jens; McLaughlin, Molly; Borch, Thomas; Warner, Nathaniel R

    2017-08-01

    Combining horizontal drilling with high volume hydraulic fracturing has increased extraction of hydrocarbons from low-permeability oil and gas (O&G) formations across the United States; accompanied by increased wastewater production. Surface water discharges of O&G wastewater by centralized waste treatment (CWT) plants pose risks to aquatic and human health. We evaluated the impact of surface water disposal of O&G wastewater from CWT plants upstream of the Conemaugh River Lake (dam controlled reservoir) in western Pennsylvania. Regulatory compliance data were collected to calculate annual contaminant loads (Ba, Cl, total dissolved solids (TDS)) to document historical industrial activity. In this study, two CWT plants 10 and 19 km upstream of a reservoir left geochemical signatures in sediments and porewaters corresponding to peak industrial activity that occurred 5 to 10 years earlier. Sediment cores were sectioned for the collection of paired samples of sediment and porewater, and analyzed for analytes to identify unconventional O&G wastewater disposal. Sediment layers corresponding to the years of maximum O&G wastewater disposal contained higher concentrations of salts, alkaline earth metals, and organic chemicals. Isotopic ratios of 226 Ra /228 Ra and 87 Sr /86 Sr identified that peak concentrations of Ra and Sr were likely sourced from wastewaters that originated from the Marcellus Shale formation.

  9. Presence and Impact of Surface Films formed on Mg in Chloroaluminate Electrolytes.

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Nathan [Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kotula, Paul G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wetzel, David J. [Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR); Univ. of Illinois, Urbana-Champaign, IL (United States); Malone, Marvin A. [Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR); Univ. of Illinois, Urbana-Champaign, IL (United States); Nuzzo, Ralph G. [Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR); Univ. of Illinois, Urbana-Champaign, IL (United States); Zavadil, Kevin R. [Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    The impact of surface film formation on Mg is explored during electrodeposition and electrodissolution in two high activity, aprotic electrolytes: the all phenyl complex (APC) and the magnesium aluminum chloride complex (MACC). Where past studies have argued such films are benign, results show that interfacial films are responsible for controlling the Mg deposit structure when deposition and dissolution are conducted at the rates required for practical Mg batteries. Chronopotentiometry is shown to provide clear signatures of the impact of interfacial films on deposition and dissolution. The particular combination of cycling punctuated by periods of open circuit equilibration is shown to yield a noticeable decrease in coulombic efficiency over a 50 cycle sequence. High resolution electron imaging shows that cycling results in porosity development and accumulation of electrolyte constituents within the deposit. Reduced coulombic efficiency signaling Mg loss appears related to progressive isolation of a fraction of the deposit. Mg and electrolyte loss must be compensated for in a practical cell through the introduction of excess inventory and resulting in a reduced energy density of the system.

  10. Impact of East Asian Summer Monsoon on Surface Ozone Pattern in China

    Science.gov (United States)

    Li, Shu; Wang, Tijian; Huang, Xing; Pu, Xi; Li, Mengmeng; Chen, Pulong; Yang, Xiu-Qun; Wang, Minghuai

    2018-01-01

    Tropospheric ozone plays a key role in regional and global atmospheric and climate systems. In East Asia, ozone can be affected both in concentration level and spatial pattern by typical monsoon climate. This paper uses three different indices to identify the strength of East Asian summer monsoon (EASM) and explores the possible impact of EASM intensity on the ozone pattern through synthetic and process analysis. The difference in ozone between three strong and three weak monsoon years was analyzed using the simulations from regional climate model RegCM4-Chem. It was found that EASM intensity can significantly influence the spatial distribution of ozone in the lower troposphere. When EASM is strong, ozone in the eastern part of China (28°N - 42° N) is reduced, but the inverse is detected in the north and south. The surface ozone difference ranges from -7 to 7 ppbv during the 3 months (June to August) of the EASM, with the most obvious difference in August. Difference of the 3 months' average ozone ranges from -3.5 to 4 ppbv. Process analysis shows that the uppermost factor controlling ozone level during summer monsoon seasons is the chemistry process. Interannual variability of EASM can impact the spatial distribution of ozone through wind in the lower troposphere, cloud cover, and downward shortwave radiation, which affect the transport and chemical formation of ozone. The phenomenon should be addressed when considering the interaction between ozone and the climate in East Asia region.

  11. Recent results for Mark III

    International Nuclear Information System (INIS)

    Brient, J.C.

    1987-12-01

    This paper presents recent results from the Mark III detector at SPEAR, in the open charm sector. The first topic discussed is the reanalysis of the direct measurement of the D hadronic branching fractions, where a detailed study has been made of the Cabibbo suppressed and multi-π 0 's D decays backgrounds in the double tag sample. Next, the Dalitz plot analysis of the D decays to Kππ is presented, leading to the relative fractions of three-body versus pseudoscalarvector decays. 7 refs., 5 figs

  12. The Mark III vertex chamber

    International Nuclear Information System (INIS)

    Adler, J.; Bolton, T.; Bunnell, K.

    1987-07-01

    The design and construction of the new Mark III vertex chamber is described. Initial tests with cosmic rays prove the ability of track reconstruction and yield triplet resolutions below 50 μm at 3 atm using argon/ethane (50:50). Also performed are studies using a prototype of a pressurized wire vertex chamber with 8 mm diameter straw geometry. Spatial resolution of 35mm was obtained using dimethyl ether (DME) at 1 atm and 30 μm using argon/ethane (50/50 mixture) at 4 atm. Preliminary studies indicate the DME to adversely affect such materials as aluminized Mylar and Delrin

  13. Impact of regional ventilation changes on surface particulate matter concentrations in South Korea

    Science.gov (United States)

    Kim, H. C.; Stein, A. F.; Chai, T.; Ngan, F.; Kim, B. U.; Jin, C. S.; Hong, S. Y.; Park, R.; Son, S. W.; Bae, C.; Bae, M.; Song, C. K.; Kim, S.

    2017-12-01

    The recent increase in surface particulate matter (PM) concentrations in South Korea is intriguing due to its disagreement with current intensive emission reduction efforts. The long-term trend of surface PM concentrations in South Korea declined in the 2000s, but since 2012 its concentrations have tended to increase, resulting in frequent severe haze events in the region. This study demonstrates that the interannual variation of surface PM concentrations in South Korea is not only affected by changes in local or regional emission sources, but also closely linked with the interannual variations in regional ventilation. Using EPA Community Multiscale Air Quality modeling system, a 12-year (2004-2015) regional air quality simulation was conducted to assess the impact of the meteorological conditions under constant anthropogenic emissions. In addition, NOAA HYSPLIT dispersion model was utilized to estimate the strength of regional ventilation that dissipates local pollutions. Simulated PM concentrations show a strong negative correlation (i.e. R=-0.86) with regional wind speed, implying that reduced regional ventilation is likely associated with more stagnant conditions that cause severe pollutant episodes in South Korea. We conclude that the current PM concentration trend in South Korea is a combination of long-term decline by emission control efforts and short-term fluctuations in regional wind speed interannual variability. When the meteorology-driven variations are removed, PM concentrations in South Korea have declined continuously even after 2012, with -1.45±0.12, -1.41±0.16, and -1.09±0.16 mg/m3 per year in Seoul, the Seoul Metropolitan Area, and South Korea, respectively.

  14. [Impact of microwave dealing with the cutting surface on the hepatocellular carcinoma recurrence after hepatectomy].

    Science.gov (United States)

    Wu, Zhengshan; Wang, Xing; Wang, Dong; Fan, Ye; Li, Donghua; Kong, Lianbao; Wang, Xuehao; Wang, Ke

    2015-12-01

    To explore the impact of microwave dealing with cutting surface on perioperative liver function recovery and recurrence and metastasis after hepatectomy for HCC. Clinical data of 133 patients with HCC from March 2009 to November 2010 were retrospectively analyzed. They were divided into the conventional surgery group (66 cases) and microwave treatment group (67 cases). A domestic ECO-100 microwave knife was inserted into the liver cutting surface 0.5 cm from the cutting edge, and repeated multi-point burning with an average time of 25 minutes in the microwave treatment group. Then the perioperative liver function recovery and recurrence and metastasis in the two groups were compared. The operation time of conventional surgery group was (158.0 ± 31.0) minutes, and that of microwave treatment group was significantly longer (181.0 ± 28.0) minutes (P=0.027). There were no significant differences in the liver function recovery between the two groups (P>0.05). There were 6 cases of recurrence and metastasis after 6 months and 9 cases after 12 months in the microwave treatment group, while there were 15 cases of recurrence and metastasis after 6 months and 20 cases after 12 months in the conventional surgery group, showing a significant difference (P=0.034 and 0.022, respectively). Microwave dealing with the cutting surface has no significant effect on perioperative liver function recovery in hepatectomy. However, microwave treatment can reduce the in situ recurrence in HCC patients within the first year after surgery, indicating a good clinical application value.

  15. Natural background radioactivity of the earth's surface -- essential information for environmental impact studies

    International Nuclear Information System (INIS)

    Tauchid, M.; Grasty, R.L.

    2002-01-01

    An environmental impact study is basically a study of change. This change is compared to the preexisting conditions that are usually perceived to be the original one or the 'pristine' stage. Unfortunately reliable information on the 'so called' pristine stage is far from adequate. One of the essential parts of this information is a good knowledge of the earth's chemical make up, or its geochemistry. Presently available data on the geochemistry of the earth's surface, including those related to radioactive elements, are incomplete and inconsistent. The main reason why a number of regulations are judged to be too strict and disproportional to the risks that might be caused by some human activities, is the lack of reliable information on the natural global geochemical background on which environmental regulations should be based. The main objective of this paper is to present a view on the need for complete baseline information on the earth's surface environment and in particular its geochemical character. It is only through the availability of complete information, including reliable baseline information on the natural radioactivity, that an appropriate study on the potential effect of the various naturally occurring elements on human health be carried out. Presented here are a number of examples where the natural radioactivity of an entire country has been mapped, or is in progress. Also described are the ways these undertakings were accomplished. There is a general misconception that elevated radioactivity can be found only around uranium mines, nuclear power reactors and similar nuclear installations. As can be seen from some of these maps, the natural background radioactivity of the earth's surface closely reflects the underlying geological formations and their alteration products. In reality, properly regulated and managed facilities, the levels of radioactivity associated with many of these facilities are generally quite low relative to those associated with

  16. 46 CFR 185.602 - Hull markings.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Hull markings. 185.602 Section 185.602 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Markings Required § 185.602 Hull markings. (a) Each vessel must be marked as required by part 67...

  17. 27 CFR 28.193 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.193... Drawback Filing of Notice and Removal § 28.193 Export marks. In addition to the marks and brands required... chapter, the exporter shall mark the word “Export” on the Government side of each case or Government head...

  18. 27 CFR 28.103 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.103... Manufacturing Bonded Warehouse § 28.103 Export marks. (a) General. In addition to the marks and brands required... provisions of part 19 of this chapter, the proprietor shall mark the word “Export” on the Government side of...

  19. 27 CFR 28.144 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.144... § 28.144 Export marks. (a) General Requirement. In addition to the marks and brands required to be... brewer shall mark the word “Export” on each container or case of beer, or the words “Beer concentrate for...

  20. 27 CFR 28.154 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.154..., for Exportation or Transfer to a Foreign-Trade Zone § 28.154 Export marks. In addition to the marks... provisions of part 19 of this chapter, the proprietor shall mark the word “Export” on the Government side of...

  1. Long-term Impacts of Hurricane Wilma on Land Surface-Atmosphere Exchanges

    Science.gov (United States)

    Fuentes, J. D.; Dowell, K. K.; Engel, V. C.; Smith, T. J.

    2008-05-01

    In October 2005, Hurricane Wilma made landfall along the mangrove forests of western Everglades National Park, Florida, USA. Damage from the storm varied with distance from landfall and included widespread mortality and extensive defoliation. Large sediment deposition events were recorded in the interior marshes, with erosion taking place along the coastal margins. Wilma made landfall near a 30 m flux tower where eddy-covariance measurements of ecosystem-level carbon and energy fluxes started in 2003. Repairs to the structure were completed in 2006, enabling comparisons of surface fluxes before and after the storm. One year after the hurricane, both the average and daily integrated CO2 fluxes are consistently lower than the pre-storm values. The storm's impact on standing live biomass and the slow recovery of leaf area appear to have resulted in decreased photosynthetic uptake capacity. Nighttime respiratory CO2 fluxes above the canopy are unchanged from pre-storm values. During some periods, daily integrated fluxes show the forest as a net source of CO2 to the atmosphere. Soil CO2 fluxes are not measured directly, but daytime soil temperatures and vertical heat fluxes have shown consistently higher values after the storm. Nighttime soil temperatures values have been slightly lower. These stronger diurnal soil temperature fluctuations indicate enhanced radiative fluxes at the soil surface, possibly as a result of the reduced leaf area. The increases in daytime soil temperatures are presumably leading to higher below-ground respiration rates and, along with the reduced photosynthetic capacity, contributing to the lower net CO2 assimilation rates. This hypothesis is supported by nearby measurements of declining surface elevations of the organic soils which have been correlated with mangrove mortality in impacted areas. Both sensible and latent heat fluxes above the canopy are found to be reduced following the hurricane, and soil heat storage is higher. Together

  2. Interview with Professor Mark Wilcox.

    Science.gov (United States)

    Wilcox, Mark

    2016-08-01

    Mark Wilcox speaks to Georgia Patey, Commissioning Editor: Professor Mark Wilcox is a Consultant Microbiologist and Head of Microbiology at the Leeds Teaching Hospitals (Leeds, UK), the Professor of Medical Microbiology at the University of Leeds (Leeds, UK), and is the Lead on Clostridium difficile and the Head of the UK C. difficile Reference Laboratory for Public Health England (PHE). He was the Director of Infection Prevention (4 years), Infection Control Doctor (8 years) and Clinical Director of Pathology (6 years) at the Leeds Teaching Hospitals. He is Chair of PHE's Rapid Review Panel (reviews utility of infection prevention and control products for National Health Service), Deputy Chair of the UK Department of Health's Antimicrobial Resistance and Healthcare Associated Infection Committee and a member of PHE's HCAI/AR Programme Board. He is a member of UK/European/US working groups on C. difficile infection. He has provided clinical advice as part of the FDA/EMA submissions for the approval of multiple novel antimicrobial agents. He heads a healthcare-associated infection research team at University of Leeds, comprising approximately 30 doctors, scientists and nurses; projects include multiple aspects of C. difficile infection, diagnostics, antimicrobial resistance and the clinical development of new antimicrobial agents. He has authored more than 400 publications, and is the coeditor of Antimicrobial Chemotherapy (5th/6th/7th Editions, 15 December 2007).

  3. Laboratory study of hyper-elocity impact-driven chemical reactions and surface evolution in icy targets.

    Science.gov (United States)

    Ulibarri, Z.; Munsat, T.; Dee, R.; Horanyi, M.; James, D.; Kempf, S.; Nagle, M.; Sternovsky, Z.

    2017-12-01

    Although ice is prevalent in the solar system and the long-term evolution of many airless icy bodies is affected by hypervelocity micrometeoroid bombardment, there has been little experimental investigation into these impact phenomena, especially at the impact speeds encountered in space. For example, there is little direct information about how dust impacts alter the local chemistry, and dust impacts may be an important mechanism for creating complex organic molecules necessary for life. Laser ablation and light-gas gun experiments simulating dust impacts have successfully created amino acid precursors from base components in ice surfaces. Additionally, the Cassini mission revealed CO2 deposits in icy satellites of Saturn, which may have been created by dust impacts. With the creation of a cryogenically cooled ice target for the dust accelerator facility at the NASA SSERVI-funded Institute for Modeling Plasma, Atmospheres, and Cosmic Dust (IMPACT), it is now possible to study the effects of micrometeoroid impacts in a controlled environment under conditions and at energies typically encountered in nature. Complex ice-target mixtures are created with a flash-freezing target which allows for homogeneous mixtures to be frozen in place even with salt mixtures that otherwise would form inhomogeneous ice surfaces. Coupled with the distinctive capabilities of the IMPACT dust facility, highly valuable data concerning the evolution of icy bodies under hypervelocity bombardment and the genesis of complex organic chemistry on these icy bodies can be gathered in unique and tightly controlled experiments. Results from recent and ongoing investigations will be presented.

  4. Impact of highway construction on land surface energy balance and local climate derived from LANDSAT satellite data.

    Science.gov (United States)

    Nedbal, Václav; Brom, Jakub

    2018-08-15

    Extensive construction of highways has a major impact on the landscape and its structure. They can also influence local climate and heat fluxes in the surrounding area. After the removal of vegetation due to highway construction, the amount of solar radiation energy used for plant evapotranspiration (latent heat flux) decreases, bringing about an increase in landscape surface temperature, changing the local climate and increasing surface run-off. In this study, we evaluated the impact of the D8 highway construction (Central Bohemia, Czech Republic) on the distribution of solar radiation energy into the various heat fluxes (latent, sensible and ground heat flux) and related surface functional parameters (surface temperature and surface wetness). The aim was to describe the severity of the impact and the distance from the actual highway in which it can be observed. LANDSAT multispectral satellite images and field meteorological measurements were used to calculate surface functional parameters and heat balance before and during the highway construction. Construction of a four-lane highway can influence the heat balance of the landscape surface as far as 90m in the perpendicular direction from the highway axis, i.e. up to 75m perpendicular from its edge. During a summer day, the decrease in evapotranspired water can reach up to 43.7m 3 per highway kilometre. This means a reduced cooling effect, expressed as the decrease in latent heat flux, by an average of 29.7MWh per day per highway kilometre and its surroundings. The loss of the cooling ability of the land surface by evaporation can lead to a rise in surface temperature by as much as 7°C. Thus, the results indicate the impact of extensive line constructions on the local climate. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Terrestrial Analogs for Surface Properties Associated with Impact Cratering on the Moon - Self-secondary Impact Features at Kings Bowl, Idaho

    Science.gov (United States)

    Matiella Novak, M. A.; Zanetti, M.; Neish, C.; Kukko, A.; Fan, K.; Heldmann, J.; Hughes, S. S.

    2017-12-01

    The Kings Bowl (KB) eruptive fissure and lava field, located in the southern end of Craters of the Moon National Monument, Idaho, is an ideal location for planetary analogue field studies of surface properties related to volcanic and impact processes. Here we look at possible impact features present in the KB lava field near the main vent that resulted in squeeze-ups of molten lava from beneath a semi-solid lava lake crust. These may have been caused by the ejection of blocks during the phreatic eruption that formed the Kings Bowl pit, and their subsequent impact into a partially solidified lava pond. We compare and contrast these features with analogous self-secondary impact features, such as irregular, rimless secondary craters ("splash craters") observed in lunar impact melt deposits, to better understand how self-secondary impacts determine the surface properties of volcanic and impact crater terrains. We do this by analyzing field measurements of these features, as well as high-resolution DEM data collected through the Kinematic LiDAR System (KLS), both of which give us feature dimensions and distributions. We then compare these data with self-secondary impact features on the Moon and related surface roughness constrained through Lunar Reconnaissance Orbiter observations (Mini-RF and LROC NACs). Possible self-secondary impact features can be found in association with many lunar impact craters. These are formed when ballistic ejecta from the crater falls onto the ejecta blanket and melt surrounding the newly formed crater. Self-secondary impact features involving impact melt deposits are particularly useful to study because the visibly smooth melt texture serves to highlight the impact points in spacecraft imagery. The unusual morphology of some of these features imply that they formed when the melt had not yet completely solidified, strongly suggesting a source of impactors from the primary crater itself. We will also discuss ongoing efforts to integrate field

  6. Impact of Vegetation Cover Fraction Parameterization schemes on Land Surface Temperature Simulation in the Tibetan Plateau

    Science.gov (United States)

    Lv, M.; Li, C.; Lu, H.; Yang, K.; Chen, Y.

    2017-12-01

    The parameterization of vegetation cover fraction (VCF) is an important component of land surface models. This paper investigates the impacts of three VCF parameterization schemes on land surface temperature (LST) simulation by the Common Land Model (CoLM) in the Tibetan Plateau (TP). The first scheme is a simple land cover (LC) based method; the second one is based on remote sensing observation (hereafter named as RNVCF) , in which multi-year climatology VCFs is derived from Moderate-resolution Imaging Spectroradiometer (MODIS) NDVI (Normalized Difference Vegetation Index); the third VCF parameterization scheme derives VCF from the LAI simulated by LSM and clump index at every model time step (hereafter named as SMVCF). Simulated land surface temperature(LST) and soil temperature by CoLM with three VCF parameterization schemes were evaluated by using satellite LST observation and in situ soil temperature observation, respectively, during the period of 2010 to 2013. The comparison against MODIS Aqua LST indicates that (1) CTL produces large biases for both four seasons in early afternoon (about 13:30, local solar time), while the mean bias in spring reach to 12.14K; (2) RNVCF and SMVCF reduce the mean bias significantly, especially in spring as such reduce is about 6.5K. Surface soil temperature observed at 5 cm depth from three soil moisture and temperature monitoring networks is also employed to assess the skill of three VCF schemes. The three networks, crossing TP from West to East, have different climate and vegetation conditions. In the Ngari network, located in the Western TP with an arid climate, there are not obvious differences among three schemes. In Naqu network, located in central TP with a semi-arid climate condition, CTL shows a severe overestimates (12.1 K), but such overestimations can be reduced by 79% by RNVCF and 87% by SMVCF. In the third humid network (Maqu in eastern TP), CoLM performs similar to Naqu. However, at both Naqu and Maqu networks

  7. About the non-identity of the technological impact upon its repeat realization in the case of surface plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Grigorov, Veselin I. [University of Rousse, Rousse (Bulgaria)

    2013-07-01

    Discussed are the cases when during the repeated applying surface plastic deformation (SPD) there is a significant manifestation of alternative combinations and otter effect and factors in addition to the factor number of processing runs. Then there are signs of non-identity of their technological impact. except for the influence of the factor frequency of the processing, there are a significant availability of alternative combinations of effects and other factors and there are signs of non-identity of the technological impact. Such combinations occur in relation to: mismatch of the overlaying of contact zones; generation random characteristics of the technological impact; System-driven differences in the condition of contact interaction between the deforming elements and the machined surfaces. Key words: surface plastic deformation.

  8. Deposition in St. Mark's Basilica of Venice.

    Science.gov (United States)

    Morabito, E; Zendri, E; Piazza, R; Ganzerla, R; Montalbani, S; Marcoleoni, E; Bonetto, F; Scandella, A; Barbante, C; Gambaro, A

    2013-04-01

    Atmospheric pollutants may cause damage to monuments and historical buildings. Besides air contaminants, soluble salts are also responsible for stone deterioration and decay in outdoor and indoor monuments. The problem of how to conserve works of arts thus requires a deep knowledge of contaminants' concentration and distribution inside buildings. In this work, water-soluble ions inside St. Mark's Basilica in Venice were studied, with the aim of understanding their principal source and distribution inside the building. With the aid of Fourier transform infrared spectroscopy and scanning electron microscopy analysis, the interaction between ions and surface's material was also investigated. Ion chromatographic analysis of depositions highlighted a large amount of "deteriorating agents" such as sulphates and chlorides. A possible source in the innermost area of the basilica has been found for formates and nitrates. On the contrary, a decrease of chloride, from the entrance to the innermost area, has been found, which indicates that the source is outside the building. It is emphasized that different contaminants behave differently on different material, and the effect of pollution inside churches and monuments is not easy to predict. Wood and brick seem to react differently than stone and mortar to the damaging action of salts and pollutants. The present work should be considered a useful tool for the future preservation of St. Mark's Basilica in Venice.

  9. AUTOMATIC EXTRACTION OF ROAD MARKINGS FROM MOBILE LASER SCANNING DATA

    Directory of Open Access Journals (Sweden)

    H. Ma

    2017-09-01

    Full Text Available Road markings as critical feature in high-defination maps, which are Advanced Driver Assistance System (ADAS and self-driving technology required, have important functions in providing guidance and information to moving cars. Mobile laser scanning (MLS system is an effective way to obtain the 3D information of the road surface, including road markings, at highway speeds and at less than traditional survey costs. This paper presents a novel method to automatically extract road markings from MLS point clouds. Ground points are first filtered from raw input point clouds using neighborhood elevation consistency method. The basic assumption of the method is that the road surface is smooth. Points with small elevation-difference between neighborhood are considered to be ground points. Then ground points are partitioned into a set of profiles according to trajectory data. The intensity histogram of points in each profile is generated to find intensity jumps in certain threshold which inversely to laser distance. The separated points are used as seed points to region grow based on intensity so as to obtain road mark of integrity. We use the point cloud template-matching method to refine the road marking candidates via removing the noise clusters with low correlation coefficient. During experiment with a MLS point set of about 2 kilometres in a city center, our method provides a promising solution to the road markings extraction from MLS data.

  10. Automatic Extraction of Road Markings from Mobile Laser Scanning Data

    Science.gov (United States)

    Ma, H.; Pei, Z.; Wei, Z.; Zhong, R.

    2017-09-01

    Road markings as critical feature in high-defination maps, which are Advanced Driver Assistance System (ADAS) and self-driving technology required, have important functions in providing guidance and information to moving cars. Mobile laser scanning (MLS) system is an effective way to obtain the 3D information of the road surface, including road markings, at highway speeds and at less than traditional survey costs. This paper presents a novel method to automatically extract road markings from MLS point clouds. Ground points are first filtered from raw input point clouds using neighborhood elevation consistency method. The basic assumption of the method is that the road surface is smooth. Points with small elevation-difference between neighborhood are considered to be ground points. Then ground points are partitioned into a set of profiles according to trajectory data. The intensity histogram of points in each profile is generated to find intensity jumps in certain threshold which inversely to laser distance. The separated points are used as seed points to region grow based on intensity so as to obtain road mark of integrity. We use the point cloud template-matching method to refine the road marking candidates via removing the noise clusters with low correlation coefficient. During experiment with a MLS point set of about 2 kilometres in a city center, our method provides a promising solution to the road markings extraction from MLS data.

  11. Nano-sized surface modifications induced by the impact of slow highly charged ions - A first review

    International Nuclear Information System (INIS)

    Aumayr, F.; El-Said, A.S.; Meissl, W.

    2008-01-01

    Irradiation of crystalline solid targets with swift heavy ions can lead to the formation of latent tracks in the solid and the creation of (mostly-hillock type) nanostructures on the surface. Recently similar surface modifications with nanometer dimensions have been demonstrated for the impact of individual, very slow but highly charged ions on various surfaces. We will review the current state of this new field of research. In particular we will discuss the circumstances and conditions under which nano-sized features (hillocks or craters) on different surfaces due to impact of slow highly charged ions can be produced. The use of slow highly charged ions instead of swift heavy ions might be of considerable interest for some practical applications

  12. Time-resolved imaging of a compressible air disc under a drop impacting on a solid surface

    KAUST Repository

    Li, Erqiang

    2015-09-07

    When a drop impacts on a solid surface, its rapid deceleration is cushioned by a thin layer of air, which leads to the entrapment of a bubble under its centre. For large impact velocities the lubrication pressure in this air layer becomes large enough to compress the air. Herein we use high-speed interferometry, with 200 ns time-resolution, to directly observe the thickness evolution of the air layer during the entire bubble entrapment process. The initial disc radius and thickness shows excellent agreement with available theoretical models, based on adiabatic compression. For the largest impact velocities the air is compressed by as much as a factor of 14. Immediately following the contact, the air disc shows rapid vertical expansion. The radial speed of the surface minima just before contact, can reach 50 times the impact velocity of the drop.

  13. Dialectica Interpretation with Marked Counterexamples

    Directory of Open Access Journals (Sweden)

    Trifon Trifonov

    2011-01-01

    Full Text Available Goedel's functional "Dialectica" interpretation can be used to extract functional programs from non-constructive proofs in arithmetic by employing two sorts of higher-order witnessing terms: positive realisers and negative counterexamples. In the original interpretation decidability of atoms is required to compute the correct counterexample from a set of candidates. When combined with recursion, this choice needs to be made for every step in the extracted program, however, in some special cases the decision on negative witnesses can be calculated only once. We present a variant of the interpretation in which the time complexity of extracted programs can be improved by marking the chosen witness and thus avoiding recomputation. The achieved effect is similar to using an abortive control operator to interpret computational content of non-constructive principles.

  14. Global occurrence of anti-infectives in contaminated surface waters: Impact of income inequality between countries.

    Science.gov (United States)

    Segura, Pedro A; Takada, Hideshige; Correa, José A; El Saadi, Karim; Koike, Tatsuya; Onwona-Agyeman, Siaw; Ofosu-Anim, John; Sabi, Edward Benjamin; Wasonga, Oliver V; Mghalu, Joseph M; dos Santos Junior, Antonio Manuel; Newman, Brent; Weerts, Steven; Yargeau, Viviane

    2015-07-01

    The presence anti-infectives in environmental waters is of interest because of their potential role in the dissemination of anti-infective resistance in bacteria and other harmful effects on non-target species such as algae and shellfish. Since no information on global trends regarding the contamination caused by these bioactive substances is yet available, we decided to investigate the impact of income inequality between countries on the occurrence of anti-infectives in surface waters. In order to perform such study, we gathered concentration values reported in the peer-reviewed literature between 1998 and 2014 and built a database. To fill the gap of knowledge on occurrence of anti-infectives in African countries, we also collected 61 surface water samples from Ghana, Kenya, Mozambique and South Africa, and measured concentrations of 19 anti-infectives. A mixed one-way analysis of covariance (ANCOVA) model, followed by Turkey-Kramer post hoc tests was used to identify potential differences in anti-infective occurrence between countries grouped by income level (high, upper-middle and lower-middle and low income) according to the classification by the World Bank. Comparison of occurrence of anti-infectives according to income level revealed that concentrations of these substances in contaminated surface waters were significantly higher in low and lower-middle income countries (p=0.0001) but not in upper-middle income countries (p=0.0515) compared to high-income countries. We explained these results as the consequence of the absence of or limited sewage treatment performed in lower income countries. Furthermore, comparison of concentrations of low cost anti-infectives (sulfonamides and trimethoprim) and the more expensive macrolides between income groups suggest that the cost of these substances may have an impact on their environmental occurrence in lower income countries. Since wastewaters are the most important source of contamination of anti-infectives and other

  15. Cavernous hemangioma presenting marked hyperostosis

    International Nuclear Information System (INIS)

    Kobata, Hitoshi; Miyake, Hiroji; Kitamura, Junji; Kajikawa, Hiroshi; Ohta, Tomio

    1988-01-01

    The authors report here a case of hemangioma of the left parietal bone which presented headache and papilledema. This patient is a 37-year-old female who had, prior to admission, complained of increasing headache for one year and blurred vision for three months. She had no history of head injury. Local physical examinations revealed a slight bulging in her left parietal region which was insensitive to palpation and not adherent to the overlying scalp. Neurological examinations revealed bilateral papilledema and an incongruous bitemporal upper quadrant defect in the visual field. All the other neurological and laboratory data were normal. A plain skull roentogenogram showed a 9 x 9 cm osteolytic and characteristic honeycomb lesion in the parietal region. Systemic bone survey revealed a similar lesion in the right tibia which was not histologically examined. A marked accumulation of isotopes was detected on the bone scintigrams at both lesions. Selective external carotid angiograms demonstrated a tumor stain fed by the superficial temporal, occipital, and middle meningial arteries. CT scans of the brain and skull clearly showed a local thickening of and structural changes in the skull bone and also a mass effect on the brain and lateral ventricle. The lesioned bone was removed en bloc and replaced by an artificial bone. It was highly vascular, but not adherent to the overlying dura. The post-operative course was uneventful, and the headache and papilledema disappeared. Hemangioma of the skull presenting marked hyperostosis, as reported above, seems to be rare. In addition, in this case, skeletal angioma without any clinical manifestation was detected. Clinical and radiological pictures of the hemangioma of the skull and other bones were briefly discussed. (author)

  16. Temperature and precipitation effects on wheat yield across a European transect: a crop model ensemble analysis using impact response surfaces

    Czech Academy of Sciences Publication Activity Database

    Pirttioja, N. K.; Carter, T. R.; Fronzek, S.; Bindi, M.; Hoffmann, H. D.; Palosuo, T.; Ruiz-Ramos, M.; Tao, F.; Trnka, Miroslav; Acutis, M.; Asseng, S.; Baranowski, P.; Basso, B.; Bodin, P.; Buis, S.; Cammarano, D.; Deligios, P.; Destain, M. F.; Dumont, B.; Ewert, F.; Ferrise, R.; Francois, L.; Gaiser, T.; Hlavinka, Petr; Jacquemin, I.; Kersebaum, K. C.; Kollas, C.; Krzyszczak, J.; Lorite, I. J.; Minet, J.; Minquez, M. I.; Montesino, M.; Moriondo, M.; Müller, C.; Nendel, C.; Öztürk, I.; Perego, A.; Rodriguez, A.; Ruane, A. C.; Ruget, F.; Sanna, M.; Semenov, M. A.; Slawinski, C.; Stratonovitch, P.; Supit, I.; Waha, K.; Wang, E.; Wu, L.; Zhao, Z.; Rötter, R. P.

    2015-01-01

    Roč. 65, č. 31 (2015), s. 87-105 ISSN 0936-577X R&D Projects: GA MZe QJ1310123; GA MŠk(CZ) LD13030 Grant - others:German Federal Ministries of Education and Research, and Food and Agriculture(DE) 2812ERA115 Institutional support: RVO:67179843 Keywords : climate * crop model * impact response surface * IRS * sensitivity analysis * wheat * yield Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.690, year: 2015

  17. Impacts of Wildfires on Land Surface Phenology of Western US Forests

    Science.gov (United States)

    Wang, J.; Zhang, X.

    2017-12-01

    Land surface phenology (LSP) characterizes seasonal dynamics of vegetation communities within a satellite pixel. The temporal variation of LSP has been widely associated with recent global climate change. However, few studies have focused on the influence of land disturbance, such as wildfire, on LSP variations, which is particularly true at a continental scale. Wildfire has increased in size and severity in the western United States (US) during last few decades. To explore wildfire impacts on LSP in the western US forest, we analyzed the start of growing season (SOS) integrated from the entire forest area, the burned area, and the unburned area, respectively. Specifically, SOS was derived from time series of daily MODIS surface reflectance product at 250 m using a hybrid piecewise logistic detection model. The annual burn perimeters during 2000-2014 were obtained from Monitoring Trends in Burn Severity maps to study the wildfire effect on the SOS in the subsequent years (2001-2015). The wildfire effect was analyzed at three levels: the entire western US, Environmental Protection Agency's Level III ecoregions, and states. Results show that wildfires basically advance SOS but have diverse effects with different regions and years. Comparing SOS in the burned areas with that in surrounding unburned areas from 2001-2015, it was found that the SOS shift was -3.4 days (-: earlier; +: later) on average in the western US forests, and varied from -16.1 to 13.1 days across ecoregions and from -11.4 to 4.3 days across states. Because of the small proportion of annual burned areas (SOS shift in the burned areas had limited influences on the overall SOS, which caused shifts of -0.06 days over the entire western US, from -0.2 to 0.2 days across ecoregions, and -0.06 to 0.13 days across states. Overall, this study demonstrates that wildfires strongly impact SOS at local areas although the effect in the large region is relatively limited.

  18. Sound Wave Energy Resulting from the Impact of Water Drops on the Soil Surface.

    Directory of Open Access Journals (Sweden)

    Magdalena Ryżak

    Full Text Available The splashing of water drops on a soil surface is the first step of water erosion. There have been many investigations into splashing-most are based on recording and analysing images taken with high-speed cameras, or measuring the mass of the soil moved by splashing. Here, we present a new aspect of the splash phenomenon's characterization the measurement of the sound pressure level and the sound energy of the wave that propagates in the air. The measurements were carried out for 10 consecutive water drop impacts on the soil surface. Three soils were tested (Endogleyic Umbrisol, Fluvic Endogleyic Cambisol and Haplic Chernozem with four initial moisture levels (pressure heads: 0.1 kPa, 1 kPa, 3.16 kPa and 16 kPa. We found that the values of the sound pressure and sound wave energy were dependent on the particle size distribution of the soil, less dependent on the initial pressure head, and practically the same for subsequent water drops (from the first to the tenth drop. The highest sound pressure level (and the greatest variability was for Endogleyic Umbrisol, which had the highest sand fraction content. The sound pressure for this soil increased from 29 dB to 42 dB with the next incidence of drops falling on the sample The smallest (and the lowest variability was for Fluvic Endogleyic Cambisol which had the highest clay fraction. For all experiments the sound pressure level ranged from ~27 to ~42 dB and the energy emitted in the form of sound waves was within the range of 0.14 μJ to 5.26 μJ. This was from 0.03 to 1.07% of the energy of the incident drops.

  19. Impact of Urban Climate Landscape Patterns on Land Surface Temperature in Wuhan, China

    Directory of Open Access Journals (Sweden)

    Yasha Wang

    2017-09-01

    Full Text Available Facing urban warming, mitigation and adaptation strategies are not efficient enough to tackle excessive urban heat, especially at the local scale. The local climate zone (LCZ classification scheme is employed to examine the diversity and complexity of the climate response within a city. This study suggests that zonal practice could be an efficient way to bridge the knowledge gap between climate research and urban planning. Urban surfaces classified by LCZ are designated as urban climate landscapes, which extends the LCZ concept to urban planning applications. Selecting Wuhan as a case study, we attempt to explore the climatic effect of landscape patterns. Thermal effects are compared across the urban climate landscapes, and the relationships between patch metrics and land surface temperature (LST are quantified. Results indicate that climate landscape layout is a considerable factor impacting local urban climate. For Wuhan, 500 m is an optimal scale for exploring landscape pattern-temperature relationships. Temperature contrast between surrounding landscape patches has a major influence on LST. Generally, fragmental landscape patches contribute to heat release. For most climate landscape types, patch metrics also have a significant effect on thermal response. When three metrics are included as predictive variables, 53.3% of the heating intensity variation can be explained for the Large Lowrise landscape, while 57.4% of the cooling intensity variation can be explained for the Water landscape. Therefore, this article claims that land-based layout optimization strategy at local scale, which conforms to planning manner, should be taken into account in terms of heat management.

  20. Impact of land use changes on surface feedbacks in sudanian region of West Africa

    Science.gov (United States)

    Cohard, J. M.; Galle, S.; Mamadou, O.; Peugeot, C.; Seghieri, J.; Kounouhewa, B.; Awanou, N. C.

    2014-12-01

    In West Africa, surface atmosphere exchanges have been found to impact both regional and local features of the Monsoon. At local scale the spatial patterns of Evaporative Fraction can drive the trajectories of mesoscale convective systems. Under Sudanian climate a mean of ~80% of the precipitation return to atmosphere through evapotranspiration but this important amount and its dynamics may vary with the vegetation cover. In consequence, any land use or climate changes can lead to modifications on the surface feedbacks and thus on both the atmospheric and the continental water cycle. In West Africa, Sudanian regions are submitted to a ~3% demographical increase per year, which leads to regular deforestation to the benefit of cultivated areas. This study aims at quantifying the changes in evapotranspiration regime caused by such a land use change under Sudanian climate. Within the framework of The AMMA-CATCH observatory, energy and water vapor fluxes were investigated in west Africa since 2007. Herein, a pluri-annual (2007 - 2010) energy budget of a clear forest and a cultivated area located in northern Benin are analysed. Results show that evapotranspiration rates over the sudanian forest are higher than those of cultivated area, because of agricultural practice and water availability for trees. After harvest, the residual vegetation is burned to bring nutriment to soil and to clean the landscape around the villages. Thus, during the dry season, the cultivated areas are bare. At the same time, a significant evapotranspiration is measured over the forest area despite the lack of precipitations. The deep root system of such vegetation allow the trees to get access to water during the dry season. During the rainy season, a significant difference in evapotransiration rates are also observed. These differences lead to a large deficit of water vapor that returns to the atmosphere and will significantly change the continental water cycle when forests will be replaced by

  1. Sound Wave Energy Resulting from the Impact of Water Drops on the Soil Surface.

    Science.gov (United States)

    Ryżak, Magdalena; Bieganowski, Andrzej; Korbiel, Tomasz

    2016-01-01

    The splashing of water drops on a soil surface is the first step of water erosion. There have been many investigations into splashing-most are based on recording and analysing images taken with high-speed cameras, or measuring the mass of the soil moved by splashing. Here, we present a new aspect of the splash phenomenon's characterization the measurement of the sound pressure level and the sound energy of the wave that propagates in the air. The measurements were carried out for 10 consecutive water drop impacts on the soil surface. Three soils were tested (Endogleyic Umbrisol, Fluvic Endogleyic Cambisol and Haplic Chernozem) with four initial moisture levels (pressure heads: 0.1 kPa, 1 kPa, 3.16 kPa and 16 kPa). We found that the values of the sound pressure and sound wave energy were dependent on the particle size distribution of the soil, less dependent on the initial pressure head, and practically the same for subsequent water drops (from the first to the tenth drop). The highest sound pressure level (and the greatest variability) was for Endogleyic Umbrisol, which had the highest sand fraction content. The sound pressure for this soil increased from 29 dB to 42 dB with the next incidence of drops falling on the sample The smallest (and the lowest variability) was for Fluvic Endogleyic Cambisol which had the highest clay fraction. For all experiments the sound pressure level ranged from ~27 to ~42 dB and the energy emitted in the form of sound waves was within the range of 0.14 μJ to 5.26 μJ. This was from 0.03 to 1.07% of the energy of the incident drops.

  2. On the impact of the resolution on the surface and subsurface Eastern Tropical Atlantic warm bias

    Science.gov (United States)

    Martín-Rey, Marta; Lazar, Alban

    2016-04-01

    The tropical variability has a great importance for the climate of adjacent areas. Its sea surface temperature anomalies (SSTA) affect in particular the Brazilian Nordeste and the Sahelian region, as well as the tropical Pacific or the Euro-Atlantic sector. Nevertheless, the state-of the art climate models exhibits very large systematic errors in reproducing the seasonal cycle and inter-annual variability in the equatorial and coastal Africa upwelling zones (up to several °C for SST). Theses biases exist already, in smaller proportions though, in forced ocean models (several 1/10th of °C), and affect not only the mixed layer but also the whole thermocline. Here, we present an analysis of the impact of horizontal and vertical resolution changes on these biases. Three different DRAKKAR NEMO OGCM simulations have been analysed, associated to the same forcing set (DFS4.4) with different grid resolutions: "REF" for reference (1/4°, 46 vertical levels), "HH" with a finer horizontal grid (1/12°, 46 v.l.) and "HV" with a finer vertical grid (1/4°, 75 v.l.). At the surface, a more realistic seasonal SST cycle is produced in HH in the three upwellings, where the warm bias decreases (by 10% - 20%) during boreal spring and summer. A notable result is that increasing vertical resolution in HV causes a shift (in advance) of the upwelling SST seasonal cycles. In order to better understand these results, we estimate the three upwelling subsurface temperature errors, using various in-situ datasets, and provide thus a three-dimensional view of the biases.

  3. Black Sea impact on its west-coast land surface temperature

    Science.gov (United States)

    Cheval, Sorin; Constantin, Sorin

    2018-03-01

    This study investigates the Black Sea influence on the thermal characteristics of its western hinterland based on satellite imagery acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS). The marine impact on the land surface temperature (LST) values is detected at daily, seasonal and annual time scales, and a strong linkage with the land cover is demonstrated. The remote sensing products used within the study supply LST data with complete areal coverage during clear sky conditions at 1-km spatial resolution, which is appropriate for climate studies. The sea influence is significant up to 4-5 km, by daytime, while the nighttime influence is very strong in the first 1-2 km, and it gradually decreases westward. Excepting the winter, the daytime temperature increases towards the plateau with the distance from the sea, e.g. with a gradient of 0.9 °C/km in the first 5 km in spring or with 0.7 °C/km in summer. By nighttime, the sea water usually remains warmer than the contiguous land triggering higher LST values in the immediate proximity of the coastline in all seasons, e.g. mean summer LST is 19.0 °C for the 1-km buffer, 16.6 °C for the 5-km buffer and 16.0 °C for the 10-km buffer. The results confirm a strong relationship between the land cover and thermal regime in the western hinterland of the Black Sea coast. The satellite-derived LST and air temperature values recorded at the meteorological stations are highly correlated for similar locations, but the marine influence propagates differently, pledging for distinct analysis. Identified anomalies in the general observed trends are investigated in correlation with sea surface temperature dynamics in the coastal area.

  4. Surface water areas significantly impacted 2014 dengue outbreaks in Guangzhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Huaiyu; Huang, Shanqian [State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Zhou, Sen [Ministry of Education Key Laboratory for Earth System Modelling, Center for Earth System Science, Tsinghua University, Beijing (China); Department of Pediatrics, Harvard Medical School, Boston, MA (United States); Bi, Peng [Discipline of Public Health, University of Adelaide, Adelaide (Australia); Yang, Zhicong, E-mail: yangzc@gzcdc.org.cn [Guangzhou Center for Disease Control and Prevention, Guangzhou (China); Li, Xiujun [School of Public Health, Shandong University, Jinan (China); Chen, Lifan [State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Cazelles, Bernard [UMMISCO, UMI 209 IRD – UPMC, 93142 Bondy (France); Eco-Evolutionary Mathematic, IBENS UMR 8197, ENS, 75230 Paris Cedex 05 (France); Yang, Jing [State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Luo, Lei; Jing, Qinlong [Guangzhou Center for Disease Control and Prevention, Guangzhou (China); Yuan, Wenping [State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Pei, Yao; Sun, Zhe [Ministry of Education Key Laboratory for Earth System Modelling, Center for Earth System Science, Tsinghua University, Beijing (China); Yue, Tianxiang [State Key Laboratory of Resources and Environment Information System, Chinese Academy of Sciences, Beijing (China); Kwan, Mei-Po [Department of Geography and Geographic Information Science, University of Illinois at Urbana-Champaign, Champaign, IL 61820 (United States); and others

    2016-10-15

    Dengue transmission in urban areas is strongly influenced by a range of biological and environmental factors, yet the key drivers still need further exploration. To better understand mechanisms of environment–mosquito–urban dengue transmission, we propose an empirical model parameterized and cross-validated from a unique dataset including viral gene sequences, vector dynamics and human dengue cases in Guangzhou, China, together with a 36-year urban environmental change maps investigated by spatiotemporal satellite image fusion. The dengue epidemics in Guangzhou are highly episodic and were not associated with annual rainfall over time. Our results indicate that urban environmental changes, especially variations in surface area covered by water in urban areas, can substantially alter the virus population and dengue transmission. The recent severe dengue outbreaks in Guangzhou may be due to the surge in an artificial lake construction, which could increase infection force between vector (mainly Aedes albopictus) and host when urban water area significantly increased. Impacts of urban environmental change on dengue dynamics may not have been thoroughly investigated in the past studies and more work needs to be done to better understand the consequences of urbanization processes in our changing world. - Highlights: • Urban dengue outbreak is associated with water area in Guangzhou, 1978–2014. • Surface water area can alter population size of dengue virus in urban area. • Urban dengue outbreak is not associated with annual rainfall in Guangzhou. • Spatiotemporal satellite image fusion can investigate urban environmental change. • Urban environmental change could induce virus, vector, and dengue epidemic change.

  5. Surface water areas significantly impacted 2014 dengue outbreaks in Guangzhou, China

    International Nuclear Information System (INIS)

    Tian, Huaiyu; Huang, Shanqian; Zhou, Sen; Bi, Peng; Yang, Zhicong; Li, Xiujun; Chen, Lifan; Cazelles, Bernard; Yang, Jing; Luo, Lei; Jing, Qinlong; Yuan, Wenping; Pei, Yao; Sun, Zhe; Yue, Tianxiang; Kwan, Mei-Po

    2016-01-01

    Dengue transmission in urban areas is strongly influenced by a range of biological and environmental factors, yet the key drivers still need further exploration. To better understand mechanisms of environment–mosquito–urban dengue transmission, we propose an empirical model parameterized and cross-validated from a unique dataset including viral gene sequences, vector dynamics and human dengue cases in Guangzhou, China, together with a 36-year urban environmental change maps investigated by spatiotemporal satellite image fusion. The dengue epidemics in Guangzhou are highly episodic and were not associated with annual rainfall over time. Our results indicate that urban environmental changes, especially variations in surface area covered by water in urban areas, can substantially alter the virus population and dengue transmission. The recent severe dengue outbreaks in Guangzhou may be due to the surge in an artificial lake construction, which could increase infection force between vector (mainly Aedes albopictus) and host when urban water area significantly increased. Impacts of urban environmental change on dengue dynamics may not have been thoroughly investigated in the past studies and more work needs to be done to better understand the consequences of urbanization processes in our changing world. - Highlights: • Urban dengue outbreak is associated with water area in Guangzhou, 1978–2014. • Surface water area can alter population size of dengue virus in urban area. • Urban dengue outbreak is not associated with annual rainfall in Guangzhou. • Spatiotemporal satellite image fusion can investigate urban environmental change. • Urban environmental change could induce virus, vector, and dengue epidemic change.

  6. Elements of the Chicxulub Impact Structure as revealed in SRTM and surface GPS topographic data

    Science.gov (United States)

    Kobrick, M.; Kinsland, G. L.; Sanchez, G.; Cardador, M. H.

    2003-04-01

    Pope et al have utilized elevations from the Petroleos Mexicanos (PEMEX) gravity data files to show that the main component of the surface expression of the Chicxu-lub Impact Structure is a roughly semi-circular, low-relief depression about 90 km in diameter. They also identified other topographic features and the elements of the buried impact which possibly led to the development of these features. Kinsland et al presented a connection between these topographic anomalies, small gravity anomalies and buried structure of the impact. Shaded relief images from recently acquired SRTM elevation data clearly show the circular depression of the crater and the moat/cenote ring. In addition we can readily identify Inner trough 1, Inner trough 2 and Outer trough as defined by Pope et al. The agreement between the topographic maps of Pope et al, Kinsland et al and SRTM data are remarkable considering that the distribution and types of data in the sets are so different. We also have ground topographic data collected with a special "autonomous differ-ential GPS" system during summer 2002. Profiles from these data generally agree with both the gravity data based topographic maps and profiles extracted from the SRTM data. Preliminary analyses of our new data, SRTM and GPS, have uncovered features not previously recognized: 1) as shown by the GPS data the moat/cenote ring consists of two distinct depressions separated by about 10 km...perhaps separate ring faults, 2) in the SRTM data over the southern part of the crater and on southward for perhaps 20 km beyond the moat/ cenote ring there exists a pattern, as yet unexplained, of roughly concentric topographic features whose center lies at about 21deg 40min N and 89deg 25min W, about 50km NNE of the moat/cenote ring center. The corroboration and better definition of the previously recognized topographic features yielded by the two new forms of data strengthens the cases for these fea-tures and for their relevance to the underlying

  7. Electronic Structure of the Perylene / Zinc Oxide Interface: A Computational Study of Photoinduced Electron Transfer and Impact of Surface Defects

    KAUST Repository

    Li, Jingrui

    2015-07-29

    The electronic properties of dye-sensitized semiconductor surfaces consisting of pery- lene chromophores chemisorbed on zinc oxide via different spacer-anchor groups, have been studied at the density-functional-theory level. The energy distributions of the donor states and the rates of photoinduced electron transfer from dye to surface are predicted. We evaluate in particular the impact of saturated versus unsaturated aliphatic spacer groups inserted between the perylene chromophore and the semiconductor as well as the influence of surface defects on the electron-injection rates.

  8. Electronic Structure of the Perylene / Zinc Oxide Interface: A Computational Study of Photoinduced Electron Transfer and Impact of Surface Defects

    KAUST Repository

    Li, Jingrui; Li, Hong; Winget, Paul; Bredas, Jean-Luc

    2015-01-01

    The electronic properties of dye-sensitized semiconductor surfaces consisting of pery- lene chromophores chemisorbed on zinc oxide via different spacer-anchor groups, have been studied at the density-functional-theory level. The energy distributions of the donor states and the rates of photoinduced electron transfer from dye to surface are predicted. We evaluate in particular the impact of saturated versus unsaturated aliphatic spacer groups inserted between the perylene chromophore and the semiconductor as well as the influence of surface defects on the electron-injection rates.

  9. Surface heterogeneity impacts on boundary layer dynamics via energy balance partitioning

    Science.gov (United States)

    The role of land-atmosphere interactions under heterogeneous surface conditions is investigated in order to identify mechanisms responsible for altering surface heat and moisture fluxes. Twelve coupled land surface – large eddy simulation scenarios with four different length scales of surface variab...

  10. What will be the impacts of climate change on surface hydrology in France by 2070?

    International Nuclear Information System (INIS)

    Chauveau, Mathilde; Chazot, Sebastien; David, Julian; Norotte, Thomas; Perrin, Charles; Bourgin, Pierre-Yves; Sauquet, Eric; Vidal, Jean-Philippe; Rouchy, Nathalie; Martin, Eric; Maugis, Pascal; De Lacaze, Xavier

    2013-01-01

    Within the Explore 2070 project, an evaluation of the possible impacts of climate change on surface water between the 1961-1990 reference period and the 2046-2065 period was carried out in continental France and i n overseas departments on the basis of the A1B greenhouse gas emission scenario, seven general circulation models an d two hydrological models (Isba-Modcou and GR4J). In continental France, results indicate: (1) a possible increase in ai r temperature between +1.4 deg. C and +3 deg. C; (2) an uncertain evolution of precipitation, most models however agreeing on a decreasing trend in summer precipitation; (3) a significant decrease (10% to 40%) of mean annual flows at the country scale, especially pronounced in the Seine-Normandie and Adour-Garonne districts; (4) a strong decrease in summer lo w flows in most basins; (5) more heterogeneous and less significant evolutions for floods. A special care was given to the quantification of the uncertainties linked to these results. They provide an indication of the significance of projected changes. The evolutions calculated in the overseas zones can be considered non-significant given the level of uncertainty linked to the hydro-climatic modelling chain. These results urge to implement adaptation strategies based on a better management of water resources, among others. (authors)

  11. A numerical investigation of the impact of surface topology on laminar boundary layers

    Science.gov (United States)

    Beratlis, Nikolaos; Squires, Kyle; Balaras, Elias

    2015-11-01

    Surface topology, such as dimples or trip wires, has been utilized in the past for passive separation control over bluff bodies. The majority of the work, however, has focused on the indirect effects on the drag and lift forces, while the details of the impact on the boundary layer evolution are not well understood. Here we report a series of DNS of flow over a single row of spherical and hexagonal dimples, as well as, circular grooves. The Reynolds number and the thickness of the incoming laminar boundary layer is carefully controlled. In all cases transition to turbulence downstream of the elements comes with reorientation of the spanwise vorticity into hairpin like vortices. Although qualitatively the transition mechanism amongst different dimples and grooves is similar, important quantitative differences exist: two-dimensional geometries such as the groove, are more stable than three-dimensional geometries. In addition, it was found that the cavity geometry controls the initial thickness of the boundary layer and practically results in a shift of the virtual origin of the turbulent boundary layer. Important differences in the momentum transport downstream of the dimples exist, but in all cases the boundary layer evolves in a self-similar manner.

  12. Mini-review: impact and dynamics of surface fouling by solitary and compound ascidians.

    Science.gov (United States)

    Aldred, Nick; Clare, Anthony S

    2014-01-01

    Globally, ascidians are a significant contributor to benthic marine fouling communities, but have remained poorly studied in this context. In some cases, such as in shellfish and finfish aquaculture, ascidians are the most problematic of all fouling organisms. The disproportionate impact of ascidian fouling in some specific geographic locations has been related directly to anthropogenic translocation of these organisms around the globe. In the case of ascidians, therefore, the economic issue of biofouling and the ecological ramifications of invasion are inextricably linked. This mini-review briefly discusses the introduction of non-native ascidians to areas where they have subsequently proven to be a significant fouling pest. The elements of ascidian reproductive ecology that support their aggressive fouling character are discussed and the scant information pertaining to their adhesion and adhesives is presented. Finally, strategies for mitigating ascidian fouling are examined. It is suggested that sufficient working knowledge currently exists to support the inclusion of one or more common ascidian species as 'standard' test organisms used for evaluation of novel fouling-resistant surfaces.

  13. Estimating the impact of land use change on surface energy partition based on the Noah model

    Science.gov (United States)

    Chen, Shaohui; Su, Hongbo; Zhan, Jinyan

    2014-03-01

    It is well known that land use has an important impact on surface energy partition. It is important to study the evolving trend of the partition of sensible heat flux (SHF) and latent heat flux (LHF) from the net radiance (NR) with land use change in the context of regional climate changes. In this paper, we studied the response of energy partition to land use using the Noah model. First, the Noah model simulation results of SHF and LHF between 2003 and 2005 were comprehensively validated using the observation data from the Changbai Mountain Station, the Xilinhot Station, and the Yucheng Station. The study domains represent three different types of land use change: excessive deforestation, grassland degeneration aggravation, and groundwater level decline, respectively. The study period was subsequently extended from 2015 through 2034, using four projected land use maps and forcing data from Princeton (2000-2004). The simulation results show that during the land use conversions, the annual average of LHF drops by 10.7%, rises by 10.1%, and drops by 11.5% for the Changbai Mountain, Inner Mongolia, and Northern China stations, respectively while the annual average of SHF rises by 10.6%, drops by 10.1%, and drops by 11.3% for the three areas.

  14. Soil Erosion and Surface Water Quality Impacts of Natural Gas Development in East Texas, USA

    Directory of Open Access Journals (Sweden)

    Matthew McBroom

    2012-11-01

    Full Text Available Due to greater demands for hydrocarbons and improvements in drilling technology, development of oil and natural gas in some regions of the United States has increased dramatically. A 1.4 ha natural gas well pad was constructed in an intermittent stream channel at the Alto Experimental Watersheds in East Texas, USA (F1, while another 1.1 ha well pad was offset about 15 m from a nearby intermittent stream (F2. V-notch weirs were constructed downstream of these well pads and stream sedimentation and water quality was measured. For the 2009 water year, about 11.76 cm, or almost 222% more runoff resulted from F1 than F2. Sediment yield was significantly greater at F1, with 13,972 kg ha−1 yr−1 versus 714 kg ha−1yr−1 at F2 on a per unit area disturbance basis for the 2009 water year. These losses were greater than was observed following forest clearcutting with best management practices (111–224 kg ha−1. Significantly greater nitrogen and phosphorus losses were measured at F1 than F2. While oil and gas development can degrade surface water quality, appropriate conservation practices like retaining streamside buffers can mitigate these impacts.

  15. Impacts of sea-surface salinity in an eddy-resolving semi-global OGCM

    Science.gov (United States)

    Furue, Ryo; Takatama, Kohei; Sasaki, Hideharu; Schneider, Niklas; Nonaka, Masami; Taguchi, Bunmei

    2018-02-01

    To explore the impacts of sea-surface salinity (SSS) on the interannual variability of upper-ocean state, we compare two 10-year runs of an eddy-resolving ocean general circulation model (OGCM): in one, SSS is strongly restored toward a monthly climatology (World Ocean Atlas '98) and in the other, toward the SSS of a monthly gridded Argo product. The inclusion of the Argo SSS generally improves the interannual variability of the mixed layer depth; particularly so in the western tropical Pacific, where so-called "barrier layers" are reproduced when the Argo SSS is included. The upper-ocean subsurface salinity variability is also improved in the tropics and subtropics even below the mixed layer. To understand the reason for the latter improvement, we separate the salinity difference between the two runs into its "dynamical" and "spiciness" components. The dynamical component is dominated by small-scale noise due to the chaotic nature of mesoscale eddies. The spiciness difference indicates that as expected from the upper-ocean general circulation, SSS variability in the mixed layer is subducted into the thermocline in subtropics; this signal is generally advected downward, equatorward, and westward in the equator-side of the subtropical gyre. The SSS signal subducted in the subtropical North Pacific appears to enter the Indian Ocean through the Indonesian Throughflow, although this signal is weak and probably insignificant in our model.

  16. Surface radiation changes and their impact on climate in Central Europe[Dissertation 17578

    Energy Technology Data Exchange (ETDEWEB)

    Ruckstuhl, Ch.

    2008-07-01

    The rapid temperature increase of 0.7 {sup o}C averaged over the Northern Hemisphere and of 1 {sup o}C over mainland Europe since 1980 is considerably larger than expected from anthropogenic greenhouse warming. The present thesis addresses questions like whether this rapid climate change is due to unexpected large greenhouse forcing that includes strong water vapor feedback or whether the temperature rise is strengthened by an increase in shortwave radiation fluxes observed since the mid-1980s. Solar dimming, a decrease of solar radiation measured at the Earth's surface, has been observed during several decades before the 1980s. Since then a reversed trend with increasing solar radiation has been observed. Our investigations show that this solar brightening has apparently added to the temperature rise since the 1980s. The analyses give evidence for a substantial decline in aerosol concentrations over Europe, which has led to a significant increase of solar radiation reaching the ground. Aerosol optical depth (AOD) observations at six remote locations from the Baltic Sea to the Central Alps show a decrease in AOD by up to 63 percent from 1986 to 2005. Solar radiation, concurrently measured under cloud-free skies and averaged over eight German and twenty-five Swiss radiation stations below 1000 m a.s.l., shows a statistically significant increase of +1.15 [+0.68 to +1.62] W m{sup -2} dec {sup -1} between 1981 and 2005. Hence, the direct aerosol effect is clearly measured. On the other hand, all-sky solar radiation shows a statistically significant increase only due to the extraordinary year 2003, with its strongly reduced cloud amount. Without considering the year 2003, which has only a marginal impact on the temperature trends, the increase in solar radiation due to changes in clouds is +0.78 [-1.26 to +2.82] W m{sup -2} dec {sup -1}. This shortwave cloud forcing is further reduced due to the counterbalancing longwave cloud effect. With respect to climate

  17. Cooperative Shark Mark Recapture Database (MRDBS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Shark Mark Recapture Database is a Cooperative Research Program database system used to keep multispecies mark-recapture information in a common format for...

  18. On-road Bicycle Pavement Markings

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — A mile by mile breakdown of the on-street bicycle pavement markings installed within the City of Pittsburgh. These include bike lanes, shared lane markings...

  19. Serviceable pavement marking retroreflectivity levels : technical report.

    Science.gov (United States)

    2009-03-01

    This research addressed an array of issues related to measuring pavement markings retroreflectivity, factors : related to pavement marking performance, subjective evaluation process, best practices for using mobile : retroreflectometers, sampling pav...

  20. Analysis of the land surface heterogeneity and its impact on atmospheric variables and the aerodynamic and thermodynamic roughness lengths

    NARCIS (Netherlands)

    Ma, Y.M.; Menenti, M.; Feddes, R.A.; Wang, J.M.

    2008-01-01

    The land surface heterogeneity has a very significant impact on atmospheric variables (air temperature T-a, wind speed u, and humidity q), the aerodynamic roughness length z(0m), thermodynamic roughness length z(0h), and the excess resistance to heat transfer kB(-1). First, in this study the land

  1. Is the Linné impact crater morphology influenced by the rheological layering on the Moon's surface? Insights from numerical modeling

    Science.gov (United States)

    Martellato, Elena; Vivaldi, Valerio; Massironi, Matteo; Cremonese, Gabriele; Marzari, Francesco; Ninfo, Andrea; Haruyama, Junichi

    2017-07-01

    Linné is a simple crater, with a diameter of 2.23 km and a depth of 0.52 km, located in northwestern Mare Serenitatis. Recent high-resolution data acquired by the Lunar Reconnaissance Orbiter Camera revealed that the shape of this impact structure is best described by an inverted truncated-cone. We perform morphometric measurements, including slope and profile curvature, on the Digital Terrain Model of Linné, finding the possible presence of three subtle topographic steps, at the elevation of +20, -100, and -200 m relative to the target surface. The kink at -100 m might be related to the interface between two different rheological layers. Using the iSALE shock physics code, we numerically model the formation of Linné crater to derive hints on the possible impact conditions and target physical properties. In the initial setup, we adopt a basaltic projectile impacting the Moon with a speed of 18 km s-1. For the local surface, we consider either one or two layers, in order to test the influence of material properties or composite rheologies on the final crater morphology. The one-layer model shows that the largest variations in the crater shape take place when either the cohesion or the friction coefficient is varied. In particular, a cohesion of 10 kPa marks the threshold between conical- and parabolic-shaped craters. The two-layer model shows that the interface between the two layers would be exposed at the observed depth of 100 m when an intermediate value ( 200 m) for the upper fractured layer is set. We have also found that the truncated-cone morphology of Linné might originate from an incomplete collapse of the crater wall, as the breccia lens remains clustered along the crater walls, while the high-albedo deposit on the crater floor can be interpreted as a very shallow lens of fallout breccia. The modeling analysis allows us to derive important clues on the impactor size (under the assumption of a vertical impact and collision velocity equal to the mean

  2. [Marked hemosiderosis in myelodysplastic syndrome].

    Science.gov (United States)

    Klinz, C

    1999-01-29

    A 68-year-old man was admitted because of symptoms of lumbar pain. He was known to have chronic anemia with ring sideroblasts and diabetes melitus and to be in heart failure. Three months before he had been given 7 units of red cell concentrate. On admission the outstanding features were brown discoloration of the skin, absent body hair, tachycardia, hepatomegaly and small testicles. He had a normocytic anemia, hyperglycemia and raised transaminases, hypogonadism and vitamin D3 deficiency. The serum levels of iron, transferrin saturation and feritin were markedly elevated. Liver iron content/g dried liver was 4.2 g (by biomagnetometer). Radiology of the lumbar vertebrae showed osteoporosis and sonography confirmed hepatomegaly. The known myelodysplastic syndrome (MDS) had fed to secondary hemosiderosis with heart failure, liver involvement, diabetes mellitus, hypogonadism and osteoporosis. Symptomatic treatment was unsuccessfully complemented by desferoxamine (up to 4 g/12 h) to release iron. But very good iron excretion was then achieved with deferiprone (3 x 1 g/d). The patient later died of the sequelae of hemosiderosis. Even when they have not required transfusions, patients with long-standing MDS should be examined regularly for the possible development of secondary hemosiderosis so that iron-chelating agents can be administered as needed.

  3. EDMS - Reaching the Million Mark

    CERN Multimedia

    2009-01-01

    When Christophe Seith from the company Cegelec sat down to work on 14 May 2009 at 10:09 a.m. to create the EDMS document entitled "Rapport tournée PH semaine 20", little did he know that he would be the proud creator of the millionth EDMS document and the happy prize winner of a celebratory bottle of champagne to mark the occasion. In the run up to the creation of the millionth EDMS document the EDMS team had been closely monitoring the steady rise in the EDMS number generator, so as to ensure the switch from the six figured i.d. to seven figures would run smoothly and of course, to be able to congratulate the creator of the millionth EDMS document. From left to right: Stephan Petit (GS-ASE- EDS Section Leader), Christophe Delamare (GS- ASE Group Leader), Christophe Seith, creator of the millionth EDMS document, David Widegren, (GS-ASE- EPS Section Leader). The millionth EDMS document. For t...

  4. Experimental research on microhardness and wear resistances of pure Cu subjected to surface dynamic plastic deformation by ultrasonic impact

    Science.gov (United States)

    Chen, Zhaoxia; He, Yangming

    2018-04-01

    Dynamic plastic deformation (DPD) has been induced in the surface of pure Cu by ultrasonic impact treating (UIT) with the varied impact current and coverage percentage. The microstructures of the treated surface were analyzed by a scanning electron microscope (SEM). And the wear resistance of pure Cu was experimentally researched both with the treated and untreated specimens. The effect of DPD on the hardness was also investigated using microhardness tester. The results show that the grains on the top surfaces of pure Cu are highly refined. The maximum depth of the plastic deformation layer is approximately 1400 µm. The larger the current and coverage percentage, the greater of the microhardness and wear resistance the treated surface layer of pure Cu will be. When the impact current is 2 A and coverage percentage is 300%, the microhardness and wear resistance of the treated sample is about 276.1% and 68.8% higher than that of the untreated specimen, respectively. But the properties of the treated sample deteriorate when the UIT current is 3 A and the coverage percentage is 300% because of the formation of a new phase forms in the treated surface.

  5. Impact of chemical polishing on surface roughness and dimensional quality of electron beam melting process (EBM) parts

    Science.gov (United States)

    Dolimont, Adrien; Rivière-Lorphèvre, Edouard; Ducobu, François; Backaert, Stéphane

    2018-05-01

    Additive manufacturing is growing faster and faster. This leads us to study the functionalization of the parts that are produced by these processes. Electron Beam melting (EBM) is one of these technologies. It is a powder based additive manufacturing (AM) method. With this process, it is possible to manufacture high-density metal parts with complex topology. One of the big problems with these technologies is the surface finish. To improve the quality of the surface, some finishing operations are needed. In this study, the focus is set on chemical polishing. The goal is to determine how the chemical etching impacts the dimensional accuracy and the surface roughness of EBM parts. To this end, an experimental campaign was carried out on the most widely used material in EBM, Ti6Al4V. Different exposure times were tested. The impact of these times on surface quality was evaluated. To help predicting the excess thickness to be provided, the dimensional impact of chemical polishing on EBM parts was estimated. 15 parts were measured before and after chemical machining. The improvement of surface quality was also evaluated after each treatment.

  6. Surface Pressure Dependencies in the GEOS-Chem-Adjoint System and the Impact of the GEOS-5 Surface Pressure on CO2 Model Forecast

    Science.gov (United States)

    Lee, Meemong; Weidner, Richard

    2016-01-01

    In the GEOS-Chem Adjoint (GCA) system, the total (wet) surface pressure of the GEOS meteorology is employed as dry surface pressure, ignoring the presence of water vapor. The Jet Propulsion Laboratory (JPL) Carbon Monitoring System (CMS) research team has been evaluating the impact of the above discrepancy on the CO2 model forecast and the CO2 flux inversion. The JPL CMS research utilizes a multi-mission assimilation framework developed by the Multi-Mission Observation Operator (M2O2) research team at JPL extending the GCA system. The GCA-M2O2 framework facilitates mission-generic 3D and 4D-variational assimilations streamlining the interfaces to the satellite data products and prior emission inventories. The GCA-M2O2 framework currently integrates the GCA system version 35h and provides a dry surface pressure setup to allow the CO2 model forecast to be performed with the GEOS-5 surface pressure directly or after converting it to dry surface pressure.

  7. Lowering the environmental impact of high-kappa/ metal gate stack surface preparation processes

    Science.gov (United States)

    Zamani, Davoud

    ABSTRACT Hafnium based oxides and silicates are promising high-κ dielectrics to replace SiO2 as gate material for state-of-the-art semiconductor devices. However, integrating these new high-κ materials into the existing complementary metal-oxide semiconductor (CMOS) process remains a challenge. One particular area of concern is the use of large amounts of HF during wet etching of hafnium based oxides and silicates. The patterning of thin films of these materials is accomplished by wet etching in HF solutions. The use of HF allows dissolution of hafnium as an anionic fluoride complex. Etch selectivity with respect to SiO2 is achieved by appropriately diluting the solutions and using slightly elevated temperatures. From an ESH point of view, it would be beneficial to develop methods which would lower the use of HF. The first objective of this study is to find new chemistries and developments of new wet etch methods to reduce fluoride consumption during wet etching of hafnium based high-κ materials. Another related issue with major environmental impact is the usage of large amounts of rinsing water for removal of HF in post-etch cleaning step. Both of these require a better understanding of the HF interaction with the high-κ surface during the etching, cleaning, and rinsing processes. During the rinse, the cleaning chemical is removed from the wafers. Ensuring optimal resource usage and cycle time during the rinse requires a sound understanding and quantitative description of the transport effects that dominate the removal rate of the cleaning chemicals from the surfaces. Multiple processes, such as desorption and re-adsorption, diffusion, migration and convection, all factor into the removal rate of the cleaning chemical during the rinse. Any of these processes can be the removal rate limiting process, the bottleneck of the rinse. In fact, the process limiting the removal rate generally changes as the rinse progresses, offering the opportunity to save resources

  8. Behavior of surface residual stress in explosion hardened high manganese austenitic cast steel due to repeated impact loads

    International Nuclear Information System (INIS)

    Oda, Akira; Miyagawa, Hideaki

    1985-01-01

    Explosion hardened high manganese austenitic cast steel is being tried for rail crossing recently. From the previous studies, it became clear that high tensile residual stress was generated in the hardened surface layer by explosion and microcracks were observed. In this study, therefore, the behavior of surface residual stress in explosion hardened steel due to repeated impact loads was examined and compared with those of the original and shot peened steels. The results obtained are summarized as follows: (1) In the initial stage of the repetition of impact, high tensile surface residual stress in explosion hardened steel decreased rapidly with the repetition of impact, while those of the original and shot peened steels increased rapidly. This difference was attributed to the difference in depth of the work hardened layer in three testing materials. (2) Beyond 20 impacts the residual stress of three test specimens decreased gradually, and at more than 2000 impacts the compressive stress of about 500 MPa was produced regardless of the histories of working of testing materials. (3) The linear law in the second stage of residual stress fading was applicable to this case, and the range of the linear relationship was related to the depth of the work hardened layer of testing material. (4) From the changes in half-value breadth and peak intensity of diffraction X-ray, it was supposed that a peculiar microscopic strain exists in explosion hardened steel. (author)

  9. Effect of internal short fibers, steel reinforcement, and surface layer on impact and penetration resistance of concrete

    Directory of Open Access Journals (Sweden)

    Ali Abd_Elhakam Aliabdo

    2013-09-01

    Full Text Available This paper presents an experimental program to investigate the impact and penetration resistance of concrete. The research work is divided into two approaches. These approaches are effect of concrete constituents and effect of surface layer. Effect of concrete aggregate type, w/c ratio, fiber type, fiber shape, fiber volume fraction, and steel reinforcement is considered in the first approach. The second approach includes using fiber reinforced concrete and glass fiber reinforced polymer as surface layers. The evaluating tests include standard impact test according to ASTM D 1557 and suggested simulated penetration test to measure the impact and penetration resistance of concrete. The test results of plain and fibrous concrete from ASTM D 1557 method indicated that steel fiber with different configurations and using basalt have a great positive effect on impact resistance of concrete. Moreover, the simulated penetration test indicates that steel fibers are more effective than propylene fibers, type of coarse aggregate has negligible effect, and steel fiber volume fraction has a more significant influence than fiber shape for reinforced concrete test panels. Finally, as expectable, surface properties of tested concrete panels have a significant effect on impact and penetration resistance.

  10. AFM studies of a new type of radiation defect on mica surfaces caused by highly charged ion impact

    International Nuclear Information System (INIS)

    Ruehlicke, C.; Briere, M.A.; Schneider, D.

    1994-01-01

    Radiation induced defects on mica caused by the impact of slow very highly charged ions (SVHCI) have been investigated with an atomic force microscope (AFM). Freshly cleaved surfaces of different types of muscovite were irradiated with SVHCI extracted from the LLNL electron beam ion trap (EBIT) at velocities of ca. 2 keV/amu. Atomic force microscopy of the surface reveals the formation of blisterlike defects associated with single ion impact. The determined defect volume which appears to increase linearly with the incident charge state and exhibits a threshold incident charge state has been determined using the AFM. These results indicate that target atoms are subjected to mutual electrostatic repulsion due to ionization through potential electron emission upon approach of the ion. If the repulsion leads to permanent atomic displacement, surface defects are formed

  11. 46 CFR 122.602 - Hull markings.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Hull markings. 122.602 Section 122.602 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150....602 Hull markings. (a) Each vessel must be marked as required by part 67, subpart I, of this chapter...

  12. 7 CFR 160.32 - Marking containers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Marking containers. 160.32 Section 160.32 Agriculture... STANDARDS FOR NAVAL STORES Analysis, Inspection, and Grading on Request § 160.32 Marking containers. The interested person shall provide any labor necessary for marking the containers, after the contents have been...

  13. 46 CFR 160.176-23 - Marking.

    Science.gov (United States)

    2010-10-01

    ... of the vessel. (2) The type of vessel. (3) Specific purpose or limitation approved by the Coast Guard...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Inflatable Lifejackets § 160.176-23 Marking. (a) General. Each inflatable lifejacket must be marked with the information required by this section. Each marking must be...

  14. 27 CFR 28.123 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.123..., or Transportation to a Manufacturing Bonded Warehouse § 28.123 Export marks. (a) General. In addition... filled under the provisions of part 24 of this chapter, the proprietor shall mark the word “Export” on...

  15. 27 CFR 28.223 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.223... Export marks. In addition to the marks and brands required to be placed on kegs, barrels, cases, crates... “Export” on each container or case before removal for export, for use on vessels or aircraft, or for...

  16. Bacterial surface appendages strongly impact nanomechanical and electrokinetic properties of Escherichia coli cells subjected to osmotic stress.

    Directory of Open Access Journals (Sweden)

    Grégory Francius

    Full Text Available The physicochemical properties and dynamics of bacterial envelope, play a major role in bacterial activity. In this study, the morphological, nanomechanical and electrohydrodynamic properties of Escherichia coli K-12 mutant cells were thoroughly investigated as a function of bulk medium ionic strength using atomic force microscopy (AFM and electrokinetics (electrophoresis. Bacteria were differing according to genetic alterations controlling the production of different surface appendages (short and rigid Ag43 adhesins, longer and more flexible type 1 fimbriae and F pilus. From the analysis of the spatially resolved force curves, it is shown that cells elasticity and turgor pressure are not only depending on bulk salt concentration but also on the presence/absence and nature of surface appendage. In 1 mM KNO(3, cells without appendages or cells surrounded by Ag43 exhibit large Young moduli and turgor pressures (∼700-900 kPa and ∼100-300 kPa respectively. Under similar ionic strength condition, a dramatic ∼50% to ∼70% decrease of these nanomechanical parameters was evidenced for cells with appendages. Qualitatively, such dependence of nanomechanical behavior on surface organization remains when increasing medium salt content to 100 mM, even though, quantitatively, differences are marked to a much smaller extent. Additionally, for a given surface appendage, the magnitude of the nanomechanical parameters decreases significantly when increasing bulk salt concentration. This effect is ascribed to a bacterial exoosmotic water loss resulting in a combined contraction of bacterial cytoplasm together with an electrostatically-driven shrinkage of the surface appendages. The former process is demonstrated upon AFM analysis, while the latter, inaccessible upon AFM imaging, is inferred from electrophoretic data interpreted according to advanced soft particle electrokinetic theory. Altogether, AFM and electrokinetic results clearly demonstrate the

  17. Impacts of urban land-surface forcing on ozone air quality in the Seoul metropolitan area

    Directory of Open Access Journals (Sweden)

    Y.-H. Ryu

    2013-02-01

    Full Text Available Modified local meteorology owing to heterogeneities in the urban–rural surface can affect urban air quality. In this study, the impacts of urban land-surface forcing on ozone air quality during a high ozone (O3 episode in the Seoul metropolitan area, South Korea, are investigated using a high-resolution chemical transport model (CMAQ. Under fair weather conditions, the temperature excess (urban heat island significantly modifies boundary layer characteristics/structures and local circulations. The modified boundary layer and local circulations result in an increase in O3 levels in the urban area of 16 ppb in the nighttime and 13 ppb in the daytime. Enhanced turbulence in the deep urban boundary layer dilutes pollutants such as NOx, and this contributes to the elevated O3 levels through the reduced O3 destruction by NO in the NOx-rich environment. The advection of O3 precursors over the mountains near Seoul by the prevailing valley-breeze circulation in the mid- to late morning results in the build-up of O3 over the mountains in conjunction with biogenic volatile organic compound (BVOC emissions there. As the prevailing local circulation in the afternoon changes to urban-breeze circulation, the O3-rich air masses over the mountains are advected over the urban area. The urban-breeze circulation exerts significant influences on not only the advection of O3 but also the chemical production of O3 under the circumstances in which both anthropogenic and biogenic (natural emissions play important roles in O3 formation. As the air masses that are characterized by low NOx and high BVOC levels and long OH chain length are advected over the urban area from the surroundings, the ozone production efficiency increases in the urban area. The relatively strong vertical mixing in the urban boundary layer embedded in the

  18. Effect of ice surface size on collision rates and head impacts at the World Junior Hockey Championships, 2002 to 2004.

    Science.gov (United States)

    Wennberg, Richard

    2005-03-01

    To determine if collision rates and head impacts in elite junior hockey differed between games played on the small North American ice surface (85 ft wide), an intermediate-size Finnish ice surface (94 ft wide), and the large standard international ice surface (100 ft wide). Videotape analysis of all games involving Team Canada from the 2002 (large ice, Czech Republic), 2003 (small ice, Canada), and 2004 (intermediate ice, Finland) World Junior Championships. All collisions were counted and separated into various categories (volitional player/player bodychecks, into boards or open ice, plus accidental/incidental player/boards, player/ice, head/stick, head/puck). Further subdivisions included collisions involving the head directly or indirectly and notably severe head impacts. Small, intermediate, and large ice surface mean collisions/game, respectively, were 295, 258, 222, total collisions; 251, 220, 181, volitional bodychecks; 126, 115, 88, into boards; 125, 106, 93, open ice; 71, 52, 44, total head; 44, 36, 30, indirect head; 26, 16, 13, direct head; and 1.3, 0.5, 0.3, severe head (P < 0.05 for small-intermediate ice and intermediate-large ice differences in total collisions; P < 0.005 for small-large ice difference; P < 0.05 for small-intermediate ice differences in head impacts; P < 0.01 for small-large ice differences in total and severe head impacts). There is a significant inverse correlation between ice size and collision rates in elite hockey, including direct, indirect, and severe head impacts. These findings suggest that uniform usage of the larger international rinks could reduce the risk of injury, and specifically, concussions in elite hockey by decreasing the occurrence of collisions and head impacts.

  19. Impact of enumeration method on diversity of Escherichia coli genotypes isolated from surface water.

    Science.gov (United States)

    Martin, E C; Gentry, T J

    2016-11-01

    There are numerous regulatory-approved Escherichia coli enumeration methods, but it is not known whether differences in media composition and incubation conditions impact the diversity of E. coli populations detected by these methods. A study was conducted to determine if three standard water quality assessments, Colilert ® , USEPA Method 1603, (modified mTEC) and USEPA Method 1604 (MI), detect different populations of E. coli. Samples were collected from six watersheds and analysed using the three enumeration approaches followed by E. coli isolation and genotyping. Results indicated that the three methods generally produced similar enumeration data across the sites, although there were some differences on a site-by-site basis. The Colilert ® method consistently generated the least diverse collection of E. coli genotypes as compared to modified mTEC and MI, with those two methods being roughly equal to each other. Although the three media assessed in this study were designed to enumerate E. coli, the differences in the media composition, incubation temperature, and growth platform appear to have a strong selective influence on the populations of E. coli isolated. This study suggests that standardized methods of enumeration and isolation may be warranted if researchers intend to obtain individual E. coli isolates for further characterization. This study characterized the impact of three USEPA-approved Escherichia coli enumeration methods on observed E. coli population diversity in surface water samples. Results indicated that these methods produced similar E. coli enumeration data but were more variable in the diversity of E. coli genotypes observed. Although the three methods enumerate the same species, differences in media composition, growth platform, and incubation temperature likely contribute to the selection of different cultivable populations of E. coli, and thus caution should be used when implementing these methods interchangeably for

  20. Impact of catchment geophysical characteristics and climate on the regional variability of dissolved organic carbon (DOC) in surface water.

    Science.gov (United States)

    Cool, Geneviève; Lebel, Alexandre; Sadiq, Rehan; Rodriguez, Manuel J

    2014-08-15

    Dissolved organic carbon (DOC) is a recognized indicator of natural organic matter (NOM) in surface waters. The aim of this paper is twofold: to evaluate the impact of geophysical characteristics, climate and ecological zones on DOC concentrations in surface waters and, to develop a statistical model to estimate the regional variability of these concentrations. In this study, multilevel statistical analysis was used to achieve three specific objectives: (1) evaluate the influence of climate and geophysical characteristics on DOC concentrations in surface waters; (2) compare the influence of geophysical characteristics and ecological zones on DOC concentrations in surface waters; and (3) develop a model to estimate the most accurate DOC concentrations in surface waters. The case study involved 115 catchments from surface waters in the Province of Quebec, Canada. Results showed that mean temperatures recorded 60 days prior to sampling, total precipitation 10 days prior to sampling and percentages of wetlands, coniferous forests and mixed forests have a significant positive influence on DOC concentrations in surface waters. The catchment mean slope had a significant negative influence on DOC concentrations in surface waters. Water type (lake or river) and deciduous forest variables were not significant. The ecological zones had a significant influence on DOC concentrations. However, geophysical characteristics (wetlands, forests and slope) estimated DOC concentrations more accurately. A model describing the variability of DOC concentrations was developed and can be used, in future research, for estimating DBPs in drinking water as well evaluating the impact of climate change on the quality of surface waters and drinking water. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Chromocentre integrity and epigenetic marks

    Czech Academy of Sciences Publication Activity Database

    Harničarová, Andrea; Galiová-Šustáčková, Gabriela; Legartová, Soňa; Kozubek, Stanislav; Matula, P.; Bártová, Eva

    2010-01-01

    Roč. 169, č. 1 (2010), s. 124-133 ISSN 1047-8477 R&D Projects: GA MŠk ME 919; GA MŠk(CZ) LC06027; GA MŠk(CZ) LC535 Grant - others:GA MŠk(CZ) ME919 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : SUV39h * histone methylation * epigenetics Subject RIV: BO - Biophysics Impact factor: 3.497, year: 2010

  2. Multiplexing clonality: combining RGB marking and genetic barcoding

    Science.gov (United States)

    Cornils, Kerstin; Thielecke, Lars; Hüser, Svenja; Forgber, Michael; Thomaschewski, Michael; Kleist, Nadja; Hussein, Kais; Riecken, Kristoffer; Volz, Tassilo; Gerdes, Sebastian; Glauche, Ingmar; Dahl, Andreas; Dandri, Maura; Roeder, Ingo; Fehse, Boris

    2014-01-01

    RGB marking and DNA barcoding are two cutting-edge technologies in the field of clonal cell marking. To combine the virtues of both approaches, we equipped LeGO vectors encoding red, green or blue fluorescent proteins with complex DNA barcodes carrying color-specific signatures. For these vectors, we generated highly complex plasmid libraries that were used for the production of barcoded lentiviral vector particles. In proof-of-principle experiments, we used barcoded vectors for RGB marking of cell lines and primary murine hepatocytes. We applied single-cell polymerase chain reaction to decipher barcode signatures of individual RGB-marked cells expressing defined color hues. This enabled us to prove clonal identity of cells with one and the same RGB color. Also, we made use of barcoded vectors to investigate clonal development of leukemia induced by ectopic oncogene expression in murine hematopoietic cells. In conclusion, by combining RGB marking and DNA barcoding, we have established a novel technique for the unambiguous genetic marking of individual cells in the context of normal regeneration as well as malignant outgrowth. Moreover, the introduction of color-specific signatures in barcodes will facilitate studies on the impact of different variables (e.g. vector type, transgenes, culture conditions) in the context of competitive repopulation studies. PMID:24476916

  3. Non-shielded transport package impact response to unyielding and semi-yielding surfaces

    International Nuclear Information System (INIS)

    Gablin, K.A.; Jefferson, R.M.; Pope, R.B.; Vigil, M.G.; Joseph, B.J.; Yoshimura, H.R.

    1983-01-01

    The Super Tiger, licensed under US NRC Permit No. 6400, is a box 2.44 m wide by 2.44 m high by 6.1 long constructed of steel encased urethane foam. It is designed to carry fissile and other large-quantity hazardous materials. The Super Tiger weighs about 7.4 metric-tons and can carry a 13 metric-ton payload. The inner cavity of the super Tiger is 1.93 m wide by 1.93 m high by 5.1 m long. The end-wall cross section consists of an outer wall of 17.5-mm-thick carbon steel. Two full-scale Super Tiger Type B nonshielded packages have been dropped in a center-of-gravity over corner orientation onto unyielding (rigid) and semi-yielding (semi-rigid) surface in separate tests. The recent drop testing of the Super Tiger at ORNL damaged the packaging more than did the earlier 1970 prototype testing. This conclusion is based upon the extensive weld failures (tearing), greater deformation of the impacted corner, interior cavity deformation, and shattering of the ISO corner attachment in the recently tested Super Tiger. A review of both target structures indicates significant differences in construction; the earlier target structure may have been much softer. Although the target used to test the prototype appeared rigid, the 1982 test demonstrated that it was probably not a perfectly rigid target. To obtain a perfectly rigid target, a very large amount of mass and a very rigid material are necessary so that essentially all the energy goes into container deformation. In either case, the containers did not lose their contents. In conclusion, some thought should be given by the industry to the developing standards for similar testing severity, in order to eliminate variables of this nature. The use of government-owned testing facilities by private industry may be a useful goal to pursue

  4. Synergistic impacts of anthropogenic and biogenic emissions on summer surface O3 in East Asia.

    Science.gov (United States)

    Qu, Yu; An, Junling; Li, Jian

    2013-03-01

    A factor separation technique and an improved regional air quality model (RAQM) were applied to calculate synergistic contributions of anthropogenic volatile organic compounds (AVOCs), biogenic volatile organic compounds (BVOCs) and nitrogen oxides (NOx) to daily maximum surface 03 (O3DM) concentrations in East Asia in summer (June to August 2000). The summer averaged synergistic impacts of AVOCs and NOx are dominant in most areas of North China, with a maximum of 60 ppbv, while those of BVOCs and NOx are notable only in some limited areas with high BVOC emissions in South China, with a maximum of 25 ppbv. This result implies that BVOCs contribute much less to summer averaged O3DM concentrations than AVOCs in most areas of East Asia at a coarse spatial resolution (1 degree x 1 degree) although global emissions of BVOCs are much greater than those of AVOCs. Daily maximum total contributions of BVOCs can approach 20 ppbv in North China, but they can reach 40 ppbv in South China, approaching or exceeding those in some developed countries in Europe and North America. BVOC emissions in such special areas should be considered when 03 control measures are taken. Synergistic contributions among AVOCs, BVOCs and NOx significantly enhance O3 concentrations in the Beijing-Tianjin-Tangshan region and decrease them in some areas in South China. Thus, the total contributions of BVOCs to O3DM vary significantly from day to day and from location to location. This result suggests that 03 control measures obtained from episodic studies could be limited for long-term applications.

  5. The impact of anthropogenic and biogenic emissions on surface ozone concentrations in Istanbul.

    Science.gov (United States)

    Im, Ulas; Poupkou, Anastasia; Incecik, Selahattin; Markakis, Konstantinos; Kindap, Tayfun; Unal, Alper; Melas, Dimitros; Yenigun, Orhan; Topcu, Sema; Odman, M Talat; Tayanc, Mete; Guler, Meltem

    2011-03-01

    Surface ozone concentrations at Istanbul during a summer episode in June 2008 were simulated using a high resolution and urban scale modeling system coupling MM5 and CMAQ models with a recently developed anthropogenic emission inventory for the region. Two sets of base runs were performed in order to investigate for the first time the impact of biogenic emissions on ozone concentrations in the Greater Istanbul Area (GIA). The first simulation was performed using only the anthropogenic emissions whereas the second simulation was performed using both anthropogenic and biogenic emissions. Biogenic NMVOC emissions were comparable with anthropogenic NMVOC emissions in terms of magnitude. The inclusion of biogenic emissions significantly improved the performance of the model, particularly in reproducing the low night time values as well as the temporal variation of ozone concentrations. Terpene emissions contributed significantly to the destruction of the ozone during nighttime. Biogenic NMVOCs emissions enhanced ozone concentrations in the downwind regions of GIA up to 25ppb. The VOC/NO(x) ratio almost doubled due to the addition of biogenic NMVOCs. Anthropogenic NO(x) and NMVOCs were perturbed by ±30% in another set of simulations to quantify the sensitivity of ozone concentrations to the precursor emissions in the region. The sensitivity runs, as along with the model-calculated ozone-to-reactive nitrogen ratios, pointed NO(x)-sensitive chemistry, particularly in the downwind areas. On the other hand, urban parts of the city responded more to changes in NO(x) due to very high anthropogenic emissions. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Recognition in context: Implications for trade mark law.

    Science.gov (United States)

    Humphreys, Michael S; McFarlane, Kimberley A; Burt, Jennifer S; Kelly, Sarah J; Weatherall, Kimberlee G; Burrell, Robert G

    2017-10-01

    Context effects in recognition have played a major role in evaluating theories of recognition. Understanding how context impacts recognition is also important for making sound trade mark law. Consumers attempting to discriminate between the brand they are looking for and a look-alike product often have to differentiate products which share a great deal of common context: positioning on the supermarket shelf, the type of store, aspects of the packaging, or brand claims. Trade mark and related laws aim to protect brands and reduce consumer confusion, but courts assessing allegations of trade mark infringement often lack careful empirical evidence concerning the impact of brand and context similarity, and, in the absence of such evidence, make assumptions about how consumers respond to brands that downplay the importance of context and focus on the similarity of registered marks. The experiments reported in this paper aimed to test certain common assumptions in trade mark law, providing evidence that shared context can cause mistakes even where brand similarity is low.

  7. Presence, distribution, and diversity of iron-oxidizing bacteria at a landfill leachate-impacted groundwater surface water interface

    DEFF Research Database (Denmark)

    Yu, R.; Gan, P.; Mackay, A.A.

    2010-01-01

    ) were dominated by members of the Bradyrhizobiaceae and Comamonadaceae; clones from the deeper sediments were phylogenetically more diverse, dominated by members of the Rhodocyclaceae. The iron deposition profiles indicated that active iron oxidation occurred only within the near-to-surface GSI......We examined the presence of iron-oxidizing bacteria (IOB) at a groundwater surface water interface (GSI) impacted by reduced groundwater originating as leachate from an upgradient landfill. IOB enrichments and quantifications were obtained, at high vertical resolution, by an iron/oxygen opposing...... site mirrored the IOB distribution. Clone libraries from two separate IOB enrichments indicated a stratified IOB community with clear differences at short vertical distances. Alpha- and Betaproteobacteria were the dominant phylotypes. Clones from the near-surface sediment (1-2 cm below ground surface...

  8. Impact of satellite-based lake surface observations on the initial state of HIRLAM. Part II: Analysis of lake surface temperature and ice cover

    Directory of Open Access Journals (Sweden)

    Homa Kheyrollah Pour

    2014-09-01

    Full Text Available This paper presents results from a study on the impact of remote-sensing Lake Surface Water Temperature (LSWT observations in the analysis of lake surface state of a numerical weather prediction (NWP model. Data assimilation experiments were performed with the High Resolution Limited Area Model (HIRLAM, a three-dimensional operational NWP model. Selected thermal remote-sensing LSWT observations provided by the Moderate Resolution Imaging Spectroradiometer (MODIS and Advanced Along-Track Scanning Radiometer (AATSR sensors onboard the Terra/Aqua and ENVISAT satellites, respectively, were included into the assimilation. The domain of our experiments, which focussed on two winters (2010–2011 and 2011–2012, covered northern Europe. Validation of the resulting objective analyses against independent observations demonstrated that the description of the lake surface state can be improved by the introduction of space-borne LSWT observations, compared to the result of pure prognostic parameterisations or assimilation of the available limited number of in-situ lake temperature observations. Further development of the data assimilation methods and solving of several practical issues are necessary in order to fully benefit from the space-borne observations of lake surface state for the improvement of the operational weather forecast. This paper is the second part of a series of two papers aimed at improving the objective analysis of lake temperature and ice conditions in HIRLAM.

  9. Effect of the surface roughness on the seismic signal generated by a single rock impact: insight from laboratory experiments

    Science.gov (United States)

    Bachelet, Vincent; Mangeney, Anne; de Rosny, Julien; Toussaint, Renaud

    2016-04-01

    The seismic signal generated by rockfalls, landslides or avalanches is a unique tool to detect, characterize and monitor gravitational flow activity, with strong implication in terms of natural hazard monitoring. Indeed, as natural flows travel down the slope, they apply stresses on the ground, generating seismic waves in a wide frequency band. Our ultimate objective is to relate the granular flow properties to the generated signals that result from the different physical processes involved. We investigate here the more simple process: the impact of a single bead on a rough surface. Farin et al. [2015] have already shown theoretically and experimentally the existence of a link between the properties of an impacting bead (mass and velocity) on smooth surfaces, and the emitted signal (radiated elastic energy and mean frequency). This demonstrates that the single impactor properties can be deduced from the form of the emitted signal. We extend this work here by investigating the impact of single beads and gravels on rough and erodible surfaces. Experimentally, we drop glass and steel beads of diameters from 2 mm to 10 mm on a PMMA plate. The roughness of this last is obtained by gluing 3mm-diameter glass beads on one of its face. Free beads have been also added to get erodible beds. We track the dropped impactor motion, times between impacts and the generated acoustic waves using two fast cameras and 8 accelerometers. Cameras are used in addition to estimate the impactor rotation. We investigate the energy balance during the impact process, especially how the energy restitution varies as a function of the energy lost through acoustic waves. From these experiments, we clearly observe that even if more dissipative processes are involved (friction, grain reorganization, etc.), the single bead scaling laws obtained on smooth surfaces remain valid. A main result of this work is to quantify the fluctuations of the characteristic quantities such as the bounce angle, the

  10. In vitro investigation on the impact of the surface-active excipients Cremophor EL, Tween 80 and Solutol HS 15 on the metabolism of midazolam.

    Science.gov (United States)

    Bravo González, Roberto C; Huwyler, Jörg; Boess, Franziska; Walter, Isabelle; Bittner, Beate

    2004-01-01

    The impact of the surface-active formulation ingredients Cremophor EL, Tween 80 and Solutol HS 15 on the intrinsic clearance (Clint) of midazolam (MDZ) was investigated in rat hepatocytes and microsomes. In rat hepatocytes with 0.003%, 0.03% and 0.3% (w/v) Solutol HS 15 already present in the incubation medium, the Clint was significantly reduced in a dose-dependent manner by about 25%, 30% and 50%, respectively. In the presence of Cremophor EL and Tween 80 a significant reduction in Clint by about 30% and 25%, respectively, was observed at 0.03% surfactant concentration. At 0.3% of Cremophor EL and Tween 80, Clint was reduced by about 50% and 20%, respectively. A reduction in Clint was also observed in experiments with rat liver microsomes. At surfactant concentrations up to 0.03%, cytotoxicity assays (lactate dehydrogenase release, adenosine triphosphate content) as well as light microscope investigations did not reveal any cytotoxic impact of the surfactants on the hepatocyte monolayer. A potential interaction of the surfactants with biological membranes was determined using phosphatidylcholine-cholesterol liposomes loaded with self-quenching concentrations of carboxyfluorescein. No marked release of carboxyfluorescein from the liposomes (that would be an indication for a surfactant-dependent disruption of membrane integrity) was observed up to concentrations of 0.03% of the different surfactants. It is concluded that cytochrome P450 3A mediated metabolism of MDZ seems to be prevented by all surfactants at concentrations above 0.03%. In our experiments the surfactants did not show toxic effects at concentrations that resulted in a decreased Clint of MDZ. Thus, a direct inhibition of the metabolizing enzymes, a molecular interaction with the microsomes as well as an alteration of membrane properties that did not yet result in a release of LDH have to be taken into consideration as reasons for the observed changes in the metabolism of MDZ. Copyright 2004 John

  11. Heterogeneous Ice Nucleation: Interplay of Surface Properties and Their Impact on Water Orientations.

    Science.gov (United States)

    Glatz, Brittany; Sarupria, Sapna

    2018-01-23

    Ice is ubiquitous in nature, and heterogeneous ice nucleation is the most common pathway of ice formation. How surface properties affect the propensity to observe ice nucleation on that surface remains an open question. We present results of molecular dynamics studies of heterogeneous ice nucleation on model surfaces. The models surfaces considered emulate the chemistry of kaolinite, an abundant component of mineral dust. We investigate the interplay of surface lattice and hydrogen bonding properties in affecting ice nucleation. We find that lattice matching and hydrogen bonding are necessary but not sufficient conditions for observing ice nucleation at these surfaces. We correlate this behavior to the orientations sampled by the metastable supercooled water in contact with the surfaces. We find that ice is observed in cases where water molecules not only sample orientations favorable for bilayer formation but also do not sample unfavorable orientations. This distribution depends on both surface-water and water-water interactions and can change with subtle modifications to the surface properties. Our results provide insights into the diverse behavior of ice nucleation observed at different surfaces and highlight the complexity in elucidating heterogeneous ice nucleation.

  12. Electron beam irradiation impact on surface structure and wettability of ethylene-vinyl alcohol copolymer

    Science.gov (United States)

    El-Saftawy, A. A.; Ragheb, M. S.; Zakhary, S. G.

    2018-06-01

    In the present study, electron beam (EB) is utilized to tailor the surface structure and wetting behavior of ethylene-vinyl alcohol (EVOH) copolymer. The structural deformation is examined by x-ray diffractometer (XRD). The recorded patterns reveal the formation of disordered systems on the irradiated surface. Also, the surface crystallinity degree, crystallite size, and micro-strain are studied. The microstructure induced modifications of the irradiated samples are investigated by 1-dimensional proton nuclear magnetic resonance 1H NMR spectroscopic analysis. The recorded spectra showed that the hydroxyl group (O-H) absorption intensity, enhanced compared to that of methylene (-CH2) and methine (>C-H) groups. Likewise, the changes of the polymer surface chemistry are studied by Fourier transform infrared spectroscopy (FTIR) and showed that the surface polarity improved after irradiation. The contact angle method is used to prove the surface wettability improvements after irradiation. Additionally, the fucoidan-coated samples exhibit great enhancements in surface wettability and have a reduced recovery effect compared to the uncoated samples. The surface free energy and bonding adhesion are studied as well. The fucoidan-coated samples are found to have a larger adhesion strength than that of the EVOH samples (pristine and irradiated). Finally, surface morphology and roughness are traced by atomic force microscopy (AFM). The improvements in surface wettability and adhesion are attributed to the modified surface roughness and the increased surface polarity. To sum up, combining EB irradiation and fucoidan enhance the surface wettability of EVOH in a controlled way keeping the bulk properties unaffected.

  13. Effect of Ultrasonic Surface Impact on the Fatigue Behavior of Ti-6Al-4V Subject to Simulated Body Fluid

    Directory of Open Access Journals (Sweden)

    Xiaojian Cao

    2017-10-01

    Full Text Available The effect of ultrasonic nanocrystal surface modification (UNSM on the fatigue behavior of Ti6Al4V (TC4 in simulated body fluid (SBF was investigated. UNSM with the condition of a static load of 25 N, vibration amplitude of 30 μm and 36,000 strikes per unit produced about 35 μm surface severe plastic deformation (SPD layers on the TC4 specimens. One group was treated with a hybrid surface treatment (UNSM + TiN film. UNSM technique improves the micro hardness and the compressive residual stress. The surface roughness is increased slightly, but it can be remarkably improved by the TiN film. The fatigue strength of TC4 is improved by about 7.9% after UNSM. Though the current density of corrosion is increased and the pitting corrosion is accelerated, UNSM still improved the fatigue strength of TC4 after pre-soaking in SBF by 10.8%. Interior cracks initiate at the deformed carbide and oxide inclusions due to the ultrasonic impacts of UNSM. Corrosion products are always observed at the edge of fracture surface to both interior cracks and surface cracks. Coating a TiN film on the UNSMed surface helps to improve the whole properties of TC4 further.

  14. Pinus sylvestris L. needle surface wettability parameters as indicators of atmospheric environment pollution impacts: Novel contact angle hysteresis methodology

    Science.gov (United States)

    Pogorzelski, Stanisław J.; Rochowski, Pawel; Szurkowski, Janusz

    2014-02-01

    An investigation of water contact angles (CAs), contact angle hysteresis (CAH) was carried out for 1-year to 4-year old needles (Pinus sylvestris) collected in urban (Gdansk) and rural (Karsin) locations using an original measuring technique based on the geometry of the drop on a vertical filament. Concentrations of air pollutants (SO2, NOx, C6H6, and suspended particular matter - SPM) currently considered to be most important in causing direct damage to vegetation were simultaneously monitored. A set of the surface wettability parameters: the apparent surface free energy γSV, adhesive film tension Π, work of adhesion WA, and spreading WS, were determined from CAH data using the approach developed by Chibowski (2003) to quantify the surface energetics of the needle substrata affected by aging and pollution impacts. This formalism relates the total apparent surface free energy of the solid γSV with only three measurable quantities: the surface tension of the probe liquid γLV and its advancing θA and receding θR contact angle hysteresis. Since CAH depends on the outermost wax layer surface roughness and spatial physicochemical heterogeneity of a solid surface, CA data were corrected using surface architecture profiles registered with confocal scanning laser microscopy. It was found that the roughness parameter r is significantly negatively correlated (R = -0.74) with the needle age (collected at Karsin). The needle surface aging process resulted in its surface hydrophilization (CA↓ and CAH↓ with γSV↑ and WA↑). A temporal evolution of the needles wettability was traced with the data point distribution in the 2D space of CAH plotted versus WS. The wettability parameters were closely correlated to pollutant concentrations as evidenced from Spearman's rank correlation procedure (R = 0.63-0.91; p biological systems.

  15. Climate change impact of livestock CH4 emission in India: Global temperature change potential (GTP) and surface temperature response.

    Science.gov (United States)

    Kumari, Shilpi; Hiloidhari, Moonmoon; Kumari, Nisha; Naik, S N; Dahiya, R P

    2018-01-01

    Two climate metrics, Global surface Temperature Change Potential (GTP) and the Absolute GTP (AGTP) are used for studying the global surface temperature impact of CH 4 emission from livestock in India. The impact on global surface temperature is estimated for 20 and 100 year time frames due to CH 4 emission. The results show that the CH 4 emission from livestock, worked out to 15.3 Tg in 2012. In terms of climate metrics GTP of livestock-related CH 4 emission in India in 2012 were 1030 Tg CO 2 e (GTP 20 ) and 62 Tg CO 2 e (GTP 100 ) at the 20 and 100 year time horizon, respectively. The study also illustrates that livestock-related CH 4 emissions in India can cause a surface temperature increase of up to 0.7mK and 0.036mK over the 20 and 100 year time periods, respectively. The surface temperature response to a year of Indian livestock emission peaks at 0.9mK in the year 2021 (9 years after the time of emission). The AGTP gives important information in terms of temperature change due to annual CH 4 emissions, which is useful when comparing policies that address multiple gases. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. An initial assessment of the impact of Australian aerosols on surface ultraviolet radiation and implications for human health

    International Nuclear Information System (INIS)

    Chee, C Y; Mills, F P

    2010-01-01

    Aerosols can have significant influence on surface radiation, and the intense surface ultraviolet radiation Australia experiences contributes to Australia's high incidence rates for related human diseases. Aerosol properties, such as total column aerosol optical depth, have been measured over several years for varying lengths of time at sites across Australia using sunphotometers. Statistical analysis of the average daily aerosol optical depth over sites near Alice Springs, Canberra, Darwin, and Perth provides one measure of the annual atmospheric loading of aerosols over these sites. The sunphotometers used at these sites do not make measurements in the UV-B spectral region and have only one channel in the UV-A spectral region, the regions of most interest for assessing human health impact. Consequently, model calculations using standard aerosol types have been used to make an initial estimate of the impact of the aerosols found over these four sites on surface ultraviolet radiation. The aerosol loading is at times sufficient to significantly reduce the surface ultraviolet radiation, but few such days occur each year. The annual average effect of aerosols on surface ultraviolet radiation, thus, appears to be small compared to lifestyle factors, such as clothing and use of sunscreen.

  17. Factors influencing survival and mark retention in postmetamorphic boreal chorus frogs

    Science.gov (United States)

    Swanson, Jennifer E; Bailey, Larissa L.; Muths, Erin L.; Funk, W. Chris

    2013-01-01

    The ability to track individual animals is crucial in many field studies and often requires applying marks to captured individuals. Toe clipping has historically been a standard marking method for wild amphibian populations, but more recent marking methods include visual implant elastomer and photo identification. Unfortunately, few studies have investigated the influence and effectiveness of marking methods for recently metamorphosed individuals and as a result little is known about this life-history phase for most amphibians. Our focus was to explore survival probabilities, mark retention, and mark migration in postmetamorphic Boreal Chorus Frogs (Psuedacris maculata) in a laboratory setting. One hundred forty-seven individuals were assigned randomly to two treatment groups or a control group. Frogs in the first treatment group were marked with visual implant elastomer, while frogs in the second treatment group were toe clipped. Growth and mortality were recorded for one year and resulting data were analyzed using known-fate models in Program MARK. Model selection results suggested that survival probabilities of frogs varied with time and showed some variation among marking treatments. We found that frogs with multiple toes clipped on the same foot had lower survival probabilities than individuals in other treatments, but individuals can be marked by clipping a single toe on two different feet without any mark loss or negative survival effects. Individuals treated with visual implant elastomer had a mark migration rate of 4% and mark loss rate of 6%, and also showed very little negative survival impacts relative to control individuals.

  18. Magnetite Fe3O4 (111) Surfaces: Impact of Defects on Structure, Stability, and Electronic Properties

    KAUST Repository

    Noh, Jung Hyun

    2015-08-04

    We present a comprehensive investigation, via first-principles density functional theory (DFT) calculations, of various surface terminations of magnetite, Fe3O4 (111), a major iron oxide which has also a number of applications in electronics and spintronics. We compare the thermodynamic stability and electronic structure among the different surfaces terminations. Interestingly, we find that surfaces modified with point defects and adatoms can be more stable than bulk-like terminations. These surfaces show different surface chemistry, electronic structures and distinctive spin polarization features near the Fermi level from those previously considered in the literature. Our studies provide an atomic level insight for magnetite surfaces, which is a necessary step to understanding their interfaces with organic layers in OLED and spintronic devices.

  19. Magnetite Fe3O4 (111) Surfaces: Impact of Defects on Structure, Stability, and Electronic Properties

    KAUST Repository

    Noh, Jung Hyun; Osman, Osman I; Aziz, Saadullah G.; Winget, Paul; Bredas, Jean-Luc

    2015-01-01

    We present a comprehensive investigation, via first-principles density functional theory (DFT) calculations, of various surface terminations of magnetite, Fe3O4 (111), a major iron oxide which has also a number of applications in electronics and spintronics. We compare the thermodynamic stability and electronic structure among the different surfaces terminations. Interestingly, we find that surfaces modified with point defects and adatoms can be more stable than bulk-like terminations. These surfaces show different surface chemistry, electronic structures and distinctive spin polarization features near the Fermi level from those previously considered in the literature. Our studies provide an atomic level insight for magnetite surfaces, which is a necessary step to understanding their interfaces with organic layers in OLED and spintronic devices.

  20. The impact of microgeometry pistons with a stepped bearing surface for the friction loss of the internal combustion engine

    Directory of Open Access Journals (Sweden)

    Wroblewski Emil

    2017-01-01

    Full Text Available This paper present the results of experimental piston friction losses on stepped bearing surface microgeometry obtained on the test rig. This test rig is equipped with special temperature control system, which provides better stability to temperature than in standard systems. The results of station tests was discussed. Tests was analyzed depending the moment caused by the friction on the oil temperature in the oil sump. Specified conclusions allow to assess the impact of the stepped profile of the pistons bearing surface microgeometry for different values of engine speed and the oil temperature at the friction losses in the main kinematic engine node which is piston-cylinder.

  1. High contrast laser marking of alumina

    International Nuclear Information System (INIS)

    Penide, J.; Quintero, F.; Riveiro, A.; Fernández, A.; Val, J. del; Comesaña, R.; Lusquiños, F.; Pou, J.

    2015-01-01

    Highlights: • Laser marking of alumina using near infrared (NIR) lasers was experimentally analyzed. • Color change produced by NIR lasers is due to thermally induced oxygen vacancies. • Laser marking results obtained using NIR lasers and green laser are compared. • High contrast marks on alumina were achieved. - Abstract: Alumina serves as raw material for a broad range of advanced ceramic products. These elements should usually be identified by some characters or symbols printed directly on them. In this sense, laser marking is an efficient, reliable and widely implemented process in industry. However, laser marking of alumina still leads to poor results since the process is not able to produce a dark mark, yielding bad contrast. In this paper, we present an experimental study on the process of marking alumina by three different lasers working in two wavelengths: 1064 nm (Near-infrared) and 532 nm (visible, green radiation). A colorimetric analysis has been carried out in order to compare the resulting marks and its contrast. The most suitable laser operating conditions were also defined and are reported here. Moreover, the physical process of marking by NIR lasers is discussed in detail. Field Emission Scanning Electron Microscopy, High Resolution Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy were also employed to analyze the results. Finally, we propose an explanation for the differences of the coloration induced under different atmospheres and laser parameters. We concluded that the atmosphere is the key parameter, being the inert one the best choice to produce the darkest marks

  2. Analysis of the surface density and reactivity of perfluorophenylazide and the impact on ligand immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Zorn, Gilad, E-mail: zorn@ge.com; Castner, David G. [National ESCA and Surface Analysis Center for Biomedical Problems, Departments of Bioengineering and Chemical Engineering, University of Washington, Box 351653, Seattle, Washington 98195-1653 (United States); Tyagi, Anuradha; Wang, Xin; Wang, Hui; Yan, Mingdi, E-mail: Mingdi-Yan@uml.edu [Department of Chemistry, Portland State University, Portland, Oregon 97207-0751 (United States)

    2015-03-15

    Perfluorophenylazide (PFPA) chemistry is a novel method for tailoring the surface properties of solid surfaces and nanoparticles. It is general and versatile, and has proven to be an efficient way to immobilize graphene, proteins, carbohydrates, and synthetic polymers. The main thrust of this work is to provide a detailed investigation on the chemical composition and surface density of the PFPA tailored surface. Specifically, gold surfaces were treated with PFPA-derivatized (11-mercaptoundecyl)tetra(ethylene glycol) (PFPA-MUTEG) mixed with 2-[2-(2-mercaptoethoxy)ethoxy]ethanol (MDEG) at varying solution mole ratios. Complementary analytical techniques were employed to characterize the resulting films including Fourier transform infrared spectroscopy to detect fingerprints of the PFPA group, x-ray photoelectron spectroscopy and ellipsometry to study the homogeneity and uniformity of the films, and near edge x-ray absorption fine structures to study the electronic and chemical structure of the PFPA groups. Results from these studies show that the films prepared from 90:10 and 80:20 PFPA-MUTEG/MDEG mixed solutions exhibited the highest surface density of PFPA and the most homogeneous coverage on the surface. A functional assay using surface plasmon resonance with carbohydrates covalently immobilized onto the PFPA-modified surfaces showed the highest binding affinity for lectin on the PFPA-MUTEG/MDEG film prepared from a 90:10 solution.

  3. Topography measurements and applications in ballistics and tool mark identifications*

    Science.gov (United States)

    Vorburger, T V; Song, J; Petraco, N

    2016-01-01

    The application of surface topography measurement methods to the field of firearm and toolmark analysis is fairly new. The field has been boosted by the development of a number of competing optical methods, which has improved the speed and accuracy of surface topography acquisitions. We describe here some of these measurement methods as well as several analytical methods for assessing similarities and differences among pairs of surfaces. We also provide a few examples of research results to identify cartridge cases originating from the same firearm or tool marks produced by the same tool. Physical standards and issues of traceability are also discussed. PMID:27182440

  4. Classifying Multi-Model Wheat Yield Impact Response Surfaces Showing Sensitivity to Temperature and Precipitation Change

    Science.gov (United States)

    Fronzek, Stefan; Pirttioja, Nina; Carter, Timothy R.; Bindi, Marco; Hoffmann, Holger; Palosuo, Taru; Ruiz-Ramos, Margarita; Tao, Fulu; Trnka, Miroslav; Acutis, Marco; hide

    2017-01-01

    Crop growth simulation models can differ greatly in their treatment of key processes and hence in their response to environmental conditions. Here, we used an ensemble of 26 process-based wheat models applied at sites across a European transect to compare their sensitivity to changes in temperature (minus 2 to plus 9 degrees Centigrade) and precipitation (minus 50 to plus 50 percent). Model results were analysed by plotting them as impact response surfaces (IRSs), classifying the IRS patterns of individual model simulations, describing these classes and analysing factors that may explain the major differences in model responses. The model ensemble was used to simulate yields of winter and spring wheat at four sites in Finland, Germany and Spain. Results were plotted as IRSs that show changes in yields relative to the baseline with respect to temperature and precipitation. IRSs of 30-year means and selected extreme years were classified using two approaches describing their pattern. The expert diagnostic approach (EDA) combines two aspects of IRS patterns: location of the maximum yield (nine classes) and strength of the yield response with respect to climate (four classes), resulting in a total of 36 combined classes defined using criteria pre-specified by experts. The statistical diagnostic approach (SDA) groups IRSs by comparing their pattern and magnitude, without attempting to interpret these features. It applies a hierarchical clustering method, grouping response patterns using a distance metric that combines the spatial correlation and Euclidian distance between IRS pairs. The two approaches were used to investigate whether different patterns of yield response could be related to different properties of the crop models, specifically their genealogy, calibration and process description. Although no single model property across a large model ensemble was found to explain the integrated yield response to temperature and precipitation perturbations, the

  5. Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area

    Science.gov (United States)

    Yu, Liang; Rozemeijer, Joachim; van Breukelen, Boris M.; Ouboter, Maarten; van der Vlugt, Corné; Broers, Hans Peter

    2018-01-01

    The Amsterdam area, a highly manipulated delta area formed by polders and reclaimed lakes, struggles with high nutrient levels in its surface water system. The polders receive spatially and temporally variable amounts of water and nutrients via surface runoff, groundwater seepage, sewer leakage, and via water inlets from upstream polders. Diffuse anthropogenic sources, such as manure and fertiliser use and atmospheric deposition, add to the water quality problems in the polders. The major nutrient sources and pathways have not yet been clarified due to the complex hydrological system in lowland catchments with both urban and agricultural areas. In this study, the spatial variability of the groundwater seepage impact was identified by exploiting the dense groundwater and surface water monitoring networks in Amsterdam and its surrounding polders. A total of 25 variables (concentrations of total nitrogen (TN), total phosphorus (TP), NH4, NO3, HCO3, SO4, Ca, and Cl in surface water and groundwater, N and P agricultural inputs, seepage rate, elevation, land-use, and soil type) for 144 polders were analysed statistically and interpreted in relation to sources, transport mechanisms, and pathways. The results imply that groundwater is a large source of nutrients in the greater Amsterdam mixed urban-agricultural catchments. The groundwater nutrient concentrations exceeded the surface water environmental quality standards (EQSs) in 93 % of the polders for TP and in 91 % for TN. Groundwater outflow into the polders thus adds to nutrient levels in the surface water. High correlations (R2 up to 0.88) between solutes in groundwater and surface water, together with the close similarities in their spatial patterns, confirmed the large impact of groundwater on surface water chemistry, especially in the polders that have high seepage rates. Our analysis indicates that the elevated nutrient and bicarbonate concentrations in the groundwater seepage originate from the decomposition of

  6. Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area

    Directory of Open Access Journals (Sweden)

    L. Yu

    2018-01-01

    Full Text Available The Amsterdam area, a highly manipulated delta area formed by polders and reclaimed lakes, struggles with high nutrient levels in its surface water system. The polders receive spatially and temporally variable amounts of water and nutrients via surface runoff, groundwater seepage, sewer leakage, and via water inlets from upstream polders. Diffuse anthropogenic sources, such as manure and fertiliser use and atmospheric deposition, add to the water quality problems in the polders. The major nutrient sources and pathways have not yet been clarified due to the complex hydrological system in lowland catchments with both urban and agricultural areas. In this study, the spatial variability of the groundwater seepage impact was identified by exploiting the dense groundwater and surface water monitoring networks in Amsterdam and its surrounding polders. A total of 25 variables (concentrations of total nitrogen (TN, total phosphorus (TP, NH4, NO3, HCO3, SO4, Ca, and Cl in surface water and groundwater, N and P agricultural inputs, seepage rate, elevation, land-use, and soil type for 144 polders were analysed statistically and interpreted in relation to sources, transport mechanisms, and pathways. The results imply that groundwater is a large source of nutrients in the greater Amsterdam mixed urban–agricultural catchments. The groundwater nutrient concentrations exceeded the surface water environmental quality standards (EQSs in 93 % of the polders for TP and in 91 % for TN. Groundwater outflow into the polders thus adds to nutrient levels in the surface water. High correlations (R2 up to 0.88 between solutes in groundwater and surface water, together with the close similarities in their spatial patterns, confirmed the large impact of groundwater on surface water chemistry, especially in the polders that have high seepage rates. Our analysis indicates that the elevated nutrient and bicarbonate concentrations in the groundwater seepage originate

  7. An LES study on the spatial variability impact of surface sensible heat flux (SHF) on the convective boundary layer (CBL)

    Science.gov (United States)

    Kang, S. L.; Chun, J.; Kumar, A.

    2015-12-01

    We study the spatial variability impact of surface sensible heat flux (SHF) on the convective boundary layer (CBL), using the Weather Research and Forecasting (WRF) model in large eddy simulation (LES) mode. In order to investigate the response of the CBL to multi-scale feature of the surface SHF field over a local area of several tens of kilometers or smaller, an analytic surface SHF map is crated as a function of the chosen feature. The spatial variation in the SHF map is prescribed with a two-dimensional analytical perturbation field, which is generated by using the inverse transform technique of the Fourier series whose coefficients are controlled, of which spectrum to have a particular slope in the chosen range of wavelength. Then, the CBL responses to various SHF heterogeneities are summarized as a function of the spectral slope, in terms of mean structure, turbulence statistics and cross-scale processes. The range of feasible SHF heterogeneities is obtained from the SHF maps produced by a land surface model (LSM) of the WRF system. The LSM-derived SHF maps are a function of geographical data on various resolutions. Based on the numerical experiment results with the surface heterogeneities in the range, we will discuss the uncertainty in the SHF heterogeneity and its impact on the atmosphere in a numerical model. Also we will present the range of spatial scale of the surface SHF heterogeneity that significantly influence on the whole CBL. Lastly, we will report the test result of the hypothesis that the spatial variability of SHF is more representative of surface thermal heterogeneity than is the latent heat flux over the local area of several tens of kilometers or smaller.

  8. RAPID INSPECTION OF PAVEMENT MARKINGS USING MOBILE LIDAR POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2016-06-01

    Full Text Available This study aims at building a robust semi-automated pavement marking extraction workflow based on the use of mobile LiDAR point clouds. The proposed workflow consists of three components: preprocessing, extraction, and classification. In preprocessing, the mobile LiDAR point clouds are converted into the radiometrically corrected intensity imagery of the road surface. Then the pavement markings are automatically extracted with the intensity using a set of algorithms, including Otsu’s thresholding, neighbor-counting filtering, and region growing. Finally, the extracted pavement markings are classified with the geometric parameters using a manually defined decision tree. Case studies are conducted using the mobile LiDAR dataset acquired in Xiamen (Fujian, China with different road environments by the RIEGL VMX-450 system. The results demonstrated that the proposed workflow and our software tool can achieve 93% in completeness, 95% in correctness, and 94% in F-score when using Xiamen dataset.

  9. A Reassessment of the Integrated Impact of Tropical Cyclones on Surface Chlorophyll in the Western Subtropical North Atlantic

    Energy Technology Data Exchange (ETDEWEB)

    Foltz, Gregory R.; Balaguru, Karthik; Leung, Lai-Yung R.

    2015-02-28

    The impact of tropical cyclones on surface chlorophyll concentration is assessed in the western subtropical North Atlantic Ocean during 1998–2011. Previous studies in this area focused on individual cyclones and gave mixed results regarding the importance of tropical cyclone-induced mixing for changes in surface chlorophyll. Using a more integrated and comprehensive approach that includes quantification of cyclone-induced changes in mixed layer depth, here it is shown that accumulated cyclone energy explains 22% of the interannual variability in seasonally-averaged (June–November) chlorophyll concentration in the western subtropical North Atlantic, after removing the influence of the North Atlantic Oscillation (NAO). The variance explained by tropical cyclones is thus about 70% of that explained by the NAO, which has well-known impacts in this region. It is therefore likely that tropical cyclones contribute significantly to interannual variations of primary productivity in the western subtropical North Atlantic during the hurricane season.

  10. The impact of tool wear on the functionality of replicated polymer surface with micro structures

    DEFF Research Database (Denmark)

    Li, Dongya; Zhang, Yang; Regi, Francesco

    Wear happened frequently in the tooling process of mold for polymer production. The scope of this paper is to understand how the wear of the milling tool affected the function of the replicated polymer surface. This study is part of the process chain of fabrication of optical functional surfaces ...

  11. Impact of 4 Lactobacillus plantarum capsular polysaccharide clusters on surface glycan composition and host cell signaling

    NARCIS (Netherlands)

    Remus, D.M.; Kranenburg, van R.; Swam, van I.I.; Taverne, N.; Bongers, R.S.; Wels, M.; Wells, J.; Bron, P.A.; Kleerebezem, M.

    2012-01-01

    Background - Bacterial cell surface-associated polysaccharides are involved in the interactions of bacteria with their environment and play an important role in the communication between pathogenic bacteria and their host organisms. Cell surface polysaccharides of probiotic species are far less well

  12. Impacts of population growth, urbanisation and sanitation changes on global human Cryptosporidium emissions to surface water

    NARCIS (Netherlands)

    Hofstra, Nynke; Vermeulen-Henstra, Lucie

    2016-01-01

    Cryptosporidium is a pathogenic protozoan parasite and is a leading cause of diarrhoea worldwide. The concentration of Cryptosporidium in the surface water is a determinant for probability of exposure and the risk of disease. Surface water concentrations are expected to change with population

  13. Impact of potassium and water on the electronic properties of InN(0001) surfaces

    International Nuclear Information System (INIS)

    Reiss, S.; Eisenhardt, A.; Krischok, S.; Himmerlich, M.

    2014-01-01

    In this work we investigate the interaction of potassium and water with 2 x 2 reconstructed InN(0001) surfaces prepared by plasma-assisted molecular beam epitaxy. The influence of adsorbate-substrate-interaction on surface properties is characterized in-situ by photoelectron spectroscopy. Potassium exposure leads to a strong reduction in the work function Φ to 1.6 eV revealing a charge transfer from the adsorbate to the InN surface. In parallel, a reduction of the surface downward band bending by 0.2 eV and hence a reduced electron accumulation density is observed. While interaction of water with clean InN(0001)-2 x 2 surfaces induces only minor changes in the surface band bending, water adsorption at potassium covered InN(0001) leads to a reversal of the K-induced reduction in surface band bending and a slight increase of Φ to 2.4 eV. These results show that surrounding water modifies the interaction of potassium with InN(0001) surfaces. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Laser marking as a result of applying reverse engineering

    Science.gov (United States)

    Mihalache, Andrei; Nagîţ, Gheorghe; Rîpanu, Marius Ionuţ; Slǎtineanu, Laurenţiu; Dodun, Oana; Coteaţǎ, Margareta

    2018-05-01

    The elaboration of a modern manufacturing technology needs a certain quantum of information concerning the part to be obtained. When it is necessary to elaborate the technology for an existing object, such an information could be ensured by using the principles specific to the reverse engineering. Essentially, in the case of this method, the analysis of the surfaces and of other characteristics of the part must offer enough information for the elaboration of the part manufacturing technology. On the other hand, it is known that the laser marking is a processing method able to ensure the transfer of various inscriptions or drawings on a part. Sometimes, the laser marking could be based on the analysis of an existing object, whose image could be used to generate the same object or an improved object. There are many groups of factors able to affect the results of applying the laser marking process. A theoretical analysis was proposed to show that the heights of triangles obtained by means of a CNC marking equipment depend on the width of the line generated by the laser spot on the workpiece surface. An experimental research was thought and materialized to highlight the influence exerted by the line with and the angle of lines intersections on the accuracy of the marking process. By mathematical processing of the experimental results, empirical mathematical models were determined. The power type model and the graphical representation elaborated on the base of this model offered an image concerning the influences exerted by the considered input factors on the marking process accuracy.

  15. Mark II magnetic detector for SPEAR

    International Nuclear Information System (INIS)

    Larsen, R.R.

    1975-01-01

    The Mark II Detector, presently in the design stage, is a SLAC/LBL detector project to replace the Mark I now in operation at SPEAR. While similar in concept to the Mark I it will have improved momentum resolution, shower detection, solid angle coverage for both triggering and tracking and a magnet design providing easier access to those particles transmitted through the aluminum coil

  16. Classifying multi-model wheat yield impact response surfaces showing sensitivity to temperature and precipitation change

    Czech Academy of Sciences Publication Activity Database

    Fronzek, S.; Pirttioja, N. K.; Carter, T. R.; Bindi, M.; Hoffmann, H.; Palosuo, T.; Ruiz-Ramos, M.; Tao, F.; Trnka, Miroslav; Acutis, M.; Asseng, S.; Baranowski, P.; Basso, B.; Bodin, P.; Buis, S.; Cammarano, D.; Deligios, P.; Destain, M. F.; Dumont, B.; Ewert, F.; Ferrise, R.; Francois, L.; Gaiser, T.; Hlavinka, Petr; Jacquemin, I.; Kersebaum, K. C.; Kollas, C.; Krzyszczak, J.; Lorite, I. J.; Minet, J.; Ines Minguez, M.; Montesino, M.; Moriondo, M.; Mueller, C.; Nendel, C.; Öztürk, I.; Perego, A.; Rodriguez, A.; Ruane, A. C.; Ruget, F.; Sanna, M.; Semenov, M. A.; Slawinski, C.; Stratonovitch, P.; Supit, I.; Waha, K.; Wang, E.; Wu, L.; Zhao, Z.; Rötter, R.

    2018-01-01

    Roč. 159, jan (2018), s. 209-224 ISSN 0308-521X Institutional support: RVO:86652079 Keywords : climate - change * crop models * probabilistic assessment * simulating impacts * british catchments * uncertainty * europe * productivity * calibration * adaptation * Classification * Climate change * Crop model * Ensemble * Sensitivity analysis * Wheat Subject RIV: GC - Agronomy OBOR OECD: Agronomy, plant breeding and plant protection Impact factor: 2.571, year: 2016

  17. An analysis of hospital brand mark clusters.

    Science.gov (United States)

    Vollmers, Stacy M; Miller, Darryl W; Kilic, Ozcan

    2010-07-01

    This study analyzed brand mark clusters (i.e., various types of brand marks displayed in combination) used by hospitals in the United States. The brand marks were assessed against several normative criteria for creating brand marks that are memorable and that elicit positive affect. Overall, results show a reasonably high level of adherence to many of these normative criteria. Many of the clusters exhibited pictorial elements that reflected benefits and that were conceptually consistent with the verbal content of the cluster. Also, many clusters featured icons that were balanced and moderately complex. However, only a few contained interactive imagery or taglines communicating benefits.

  18. Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

    Science.gov (United States)

    Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

    2013-01-01

    Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0-100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this

  19. Do Contaminants Originating from State-of-the-Art Treated Wastewater Impact the Ecological Quality of Surface Waters?

    Science.gov (United States)

    Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

    2013-01-01

    Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this

  20. Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

    Directory of Open Access Journals (Sweden)

    Daniel Stalter

    Full Text Available Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0-100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn, 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in

  1. Analysing the impact of reflectance distributions and well geometries on vertical surface daylight levels in atria for overcast skies

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jiangtao; Sharples, Steve [School of Architecture, University of Sheffield, Crookesmoor Building, Conduit Road, Sheffield S10 1FL (United Kingdom)

    2010-07-15

    This study investigated the impacts of different diffuse reflectance distributions and well geometries on vertical daylight factors and vertical internally reflected components in atria. Two forms of reflectance distribution patterns of wall surface were examined: horizontal and vertical reflectance band variation. The square atrium models studied have a broader WI range of 0.25-2.0, which represent shallow, medium and high atria. Radiance, a powerful package based on backward ray tracing technique, was used for the simulations of vertical daylight levels. The results show that different reflectance distributions of square atrium walls do have an impact on the vertical daylight factors and vertical internally reflected components under overcast sky condition. The impact relates to the orientation of the band with different reflectance distributions on the wall. Compared with the vertical band surface, the horizontal band surface has a much more complicated effect. The horizontal distributions of the reflectances significantly affects the vertical daylight levels at the locations more than 30% atrium height on the wall. For an atrium with a height more than 1/2 the width, the effect tends to increase with the increasing well index. The vertical distributions of the reflectance, nevertheless, do not substantially take effect on the vertical daylight levels in atria except for some special reflectance distribution patterns. (author)

  2. Atmospheric and surface water pollution interpretation in the Gdansk beltway impact range by the use of multivariate analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dubiella-Jackowska, Aleksandra; Polkowska, Zaneta; Kudlak, Blazej; Namiesnik, Jacek [Chemical Faculty, Department of Analytical Chemistry, Gdansk University of Technology, Gdansk (Poland); Astel, Aleksander [Environmental Chemistry Research Unit, Institute of Biology and Environmental Protection, Pomeranian Academy, Slupsk (Poland); Staszek, Wojciech [Faculty of Physical Geography and Environmental Management, University of Gdansk, Gdansk (Poland)

    2010-09-15

    The present study deals with the application of the hierarchical cluster analysis and non-parametric tests in order to interpret the Gdansk Beltway impact range. The data set represents concentration values for major inorganic ions (Na{sup +}, NH{sub 4}{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, F{sup -}, Cl{sup -}, NO{sub 3}{sup -}, and SO{sub 4}{sup 2-}) as well as electrolytic conductivity and pH measured in various water samples [precipitation, throughfall water, road runoff, and surface water (drainage ditches, surface water reservoirs, and spring water)] collected in the vicinity of the beltway. Several similarity groups were discovered both in the objects and in the variables modes according to the water sample. In the majority of cases clear anthropogenic (fertilizers usage and transport, road salting in winter) and semi-natural (sea salt aerosols, erosion of construction materials) impacts were discovered. Spatial variation was discovered for road runoff samples and samples collected from surface water reservoirs and springs. Surprisingly no clear seasonal variability was discovered for precipitation chemistry, while some evidences for existing of summer and winter specific chemical profile was discovered for road runoff samples. In general, limited range of the Gdansk Beltway impact was proven. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  3. Desorption of 1,3,5-Trichlorobenzene from Multi-Walled Carbon Nanotubes: Impact of Solution Chemistry and Surface Chemistry

    Directory of Open Access Journals (Sweden)

    Sheikh Uddin

    2013-05-01

    Full Text Available The strong affinity of carbon nanotubes (CNTs to environmental contaminants has raised serious concern that CNTs may function as a carrier of environmental pollutants and lead to contamination in places where the environmental pollutants are not expected. However, this concern will not be realized until the contaminants are desorbed from CNTs. It is well recognized that the desorption of environmental pollutants from pre-laden CNTs varies with the environmental conditions, such as the solution pH and ionic strength. However, comprehensive investigation on the influence of solution chemistry on the desorption process has not been carried out, even though numerous investigations have been conducted to investigate the impact of solution chemistry on the adsorption of environmental pollutants on CNTs. The main objective of this study was to determine the influence of solution chemistry (e.g., pH, ionic strength and surface functionalization on the desorption of preloaded 1,3,5-trichlorobenzene (1,3,5-TCB from multi-walled carbon nanotubes (MWNTs. The results suggested that higher pH, ionic strength and natural organic matter in solution generally led to higher desorption of 1,3,5-TCB from MWNTs. However, the extent of change varied at different values of the tested parameters (e.g., pH 7. In addition, the impact of these parameters varied with MWNTs possessing different surface functional groups, suggesting that surface functionalization could considerably alter the environmental behaviors and impact of MWNTs.

  4. Simultaneous impact of neutron irradiation and sputtering on the surface structure of self–damaged ITER–grade tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Belyaeva, A. I., E-mail: aibelyaeva@mail.ru; Savchenko, A. A. [National Technical University “Kharkov Politechnical Institute”, Kharkov, 61002 (Ukraine); Galuza, A. A.; Kolenov, I. V. [Institute of Electrophysics and Radiation Technologies, National Academy of Science of Ukraine, Kharkov, 61024 (Ukraine)

    2014-07-15

    Simultaneous effects of neutron irradiation and long–term sputtering on the surface relief of ITER–grade tungsten were studied. The effects of neutron–induced displacement damage have been simulated by irradiation of tungsten target with W{sup 6+} ions of 20 MeV energy. Ar{sup +} ions with energy 600 eV were used as imitation of charge exchange atoms in ITER. The surface relief was studied after each sputtering act. The singularity in the WJ–IG surface relief was ascertained experimentally at the first time, which determines the law of roughness extension under sputtering. As follows from the experimental data, the neutron irradiation has not to make a decisive additional contribution in the processes developing under impact of charge exchange atoms only.

  5. Impact of the Topological Surface State on the Thermoelectric Transport in Sb2Te3 Thin Films.

    Science.gov (United States)

    Hinsche, Nicki F; Zastrow, Sebastian; Gooth, Johannes; Pudewill, Laurens; Zierold, Robert; Rittweger, Florian; Rauch, Tomáš; Henk, Jürgen; Nielsch, Kornelius; Mertig, Ingrid

    2015-04-28

    Ab initio electronic structure calculations based on density functional theory and tight-binding methods for the thermoelectric properties of p-type Sb2Te3 films are presented. The thickness-dependent electrical conductivity and the thermopower are computed in the diffusive limit of transport based on the Boltzmann equation. Contributions of the bulk and the surface to the transport coefficients are separated, which enables to identify a clear impact of the topological surface state on the thermoelectric properties. When the charge carrier concentration is tuned, a crossover between a surface-state-dominant and a Fuchs-Sondheimer transport regime is achieved. The calculations are corroborated by thermoelectric transport measurements on Sb2Te3 films grown by atomic layer deposition.

  6. Downscaling the Impacts of Large-Scale LUCC on Surface Temperature along with IPCC RCPs: A Global Perspective

    Directory of Open Access Journals (Sweden)

    Xiangzheng Deng

    2014-04-01

    Full Text Available This study focuses on the potential impacts of large-scale land use and land cover changes (LUCC on surface temperature from a global perspective. As important types of LUCC, urbanization, deforestation, cultivated land reclamation, and grassland degradation have effects on the climate, the potential changes of the surface temperature caused by these four types of large-scale LUCC from 2010 to 2050 are downscaled, and this issue analyzed worldwide along with Representative Concentration Pathways (RCPs of the Intergovernmental Panel on Climate Change (IPCC. The first case study presents some evidence of the effects of future urbanization on surface temperature in the Northeast megalopolis of the United States of America (USA. In order to understand the potential climatological variability caused by future forest deforestation and vulnerability, we chose Brazilian Amazon region as the second case study. The third selected region in India as a typical region of cultivated land reclamation where the possible climatic impacts are explored. In the fourth case study, we simulate the surface temperature changes caused by future grassland degradation in Mongolia. Results show that the temperature in built-up area would increase obviously throughout the four land types. In addition, the effects of all four large-scale LUCC on monthly average temperature change would vary from month to month with obviously spatial heterogeneity.

  7. Anomalously high yield of doubly charged Si ions sputtered from cleaned Si surface by keV neutral Ar impact

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.; Morita, K. E-mail: k-morita@mail.nucl.nagoya-u.ac.jp; Dhole, S.D.; Ishikawa, D

    2001-08-01

    The energy spectra of positively charged and neutral species ejected from the Si(1 1 1) surfaces by keV Ar impact have been measured by means of a combined technique of the time-of-flight (TOF) analysis with the multi-photon resonance ionization spectroscopy (MPRIS). It is shown that positively charged species of Si{sup +}, Si{sup 2+} and SiO{sup +} are ejected from the as-cleaned 7x7 surface by 11 keV Ar impact. It is also shown that Ar sputter cleaning of the as-cleaned 7x7 surface for 14 min at the flux of 2x10{sup 13}/cm{sup 2}s removes completely the oxygen impurity and the yields of Si{sup 2+} is comparable to that of Si{sup +}. Moreover, the ionization probability of Si atoms sputtered is shown to be expressed as an exponential function of the inverse of their velocity. The production mechanism for the doubly charged Si ion is discussed based on the L-shell ionization of Si atoms due to quasi-molecule formation in the collisions of the surface atoms with energetic recoils and subsequent Auger decay of the L-shell vacancy to doubly ionized Si ions.

  8. Impact of Volcanic Ash on Road and Airfield Surface Skid Resistance

    Directory of Open Access Journals (Sweden)

    Daniel M. Blake

    2017-08-01

    Full Text Available Volcanic ash deposited on paved surfaces during volcanic eruptions often compromises skid resistance, which is a major component of safety. We adopt the British pendulum test method in laboratory conditions to investigate the skid resistance of road asphalt and airfield concrete surfaces covered by volcanic ash sourced from various locations in New Zealand. Controlled variations in ash characteristics include type, depth, wetness, particle size and soluble components. We use Stone Mastic Asphalt (SMA for most road surface experiments but also test porous asphalt, line-painted road surfaces, and a roller screed concrete mix used for airfields. Due to their importance for skid resistance, SMA surface macrotexture and microtexture are analysed with semi-quantitative image analysis, microscopy and a standardised sand patch volumetric test, which enables determination of the relative effectiveness of different cleaning techniques. We find that SMA surfaces covered by thin deposits (~1 mm of ash result in skid resistance values slightly lower than those observed on wet uncontaminated surfaces. At these depths, a higher relative soluble content for low-crystalline ash and a coarser particle size results in lower skid resistance. Skid resistance results for relatively thicker deposits (3–5 mm of non-vesiculated basaltic ash are similar to those for thin deposits. There are similarities between road asphalt and airfield concrete, although there is little difference in skid resistance between bare airfield surfaces and airfield surfaces covered by 1 mm of ash. Based on our findings, we provide recommendations for maintaining road safety and effective cleaning techniques in volcanic ash environments.

  9. Retrieval and Validation of aerosol optical properties from AHI measurements: impact of surface reflectance assumption

    Science.gov (United States)

    Lim, H.; Choi, M.; Kim, J.; Go, S.; Chan, P.; Kasai, Y.

    2017-12-01

    This study attempts to retrieve the aerosol optical properties (AOPs) based on the spectral matching method, with using three visible and one near infrared channels (470, 510, 640, 860nm). This method requires the preparation of look-up table (LUT) approach based on the radiative transfer modeling. Cloud detection is one of the most important processes for guaranteed quality of AOPs. Since the AHI has several infrared channels, which are very advantageous for cloud detection, clouds can be removed by using brightness temperature difference (BTD) and spatial variability test. The Yonsei Aerosol Retrieval (YAER) algorithm is basically utilized on a dark surface, therefore a bright surface (e.g., desert, snow) should be removed first. Then we consider the characteristics of the reflectance of land and ocean surface using three visible channels. The known surface reflectivity problem in high latitude area can be solved in this algorithm by selecting appropriate channels through improving tests. On the other hand, we retrieved the AOPs by obtaining the visible surface reflectance using NIR to normalized difference vegetation index short wave infrared (NDVIswir) relationship. ESR tends to underestimate urban and cropland area, we improved the visible surface reflectance considering urban effect. In this version, ocean surface reflectance is using the new cox and munk method which considers ocean bidirectional reflectance distribution function (BRDF). Input of this method has wind speed, chlorophyll, salinity and so on. Based on validation results with the sun-photometer measurement in AErosol Robotic NETwork (AERONET), we confirm that the quality of Aerosol Optical Depth (AOD) from the YAER algorithm is comparable to the product from the Japan Aerospace Exploration Agency (JAXA) retrieval algorithm. Our future update includes a consideration of improvement land surface reflectance by hybrid approach, and non-spherical aerosols. This will improve the quality of YAER

  10. Impacts of transportation infrastructure on storm water and surfaces waters in Chittenden County, Vermont, USA.

    Science.gov (United States)

    2014-06-01

    Transportation infrastructure is a major source of stormwater runoff that can alter hydrology and : contribute significant loading of nutrients, sediment, and other pollutants to surface waters. These : increased loads can contribute to impairment of...

  11. Surface Traps in Colloidal Quantum Dot Solar Cells, their Mitigation and Impact on Manufacturability

    KAUST Repository

    Kirmani, Ahmad R.

    2017-01-01

    charge transport and threaten their otherwise wonderful optoelectronic properties. Surface traps have also, indirectly, impeded scalable and industry-compatible fabrication of these solar cells, as all of the reports, to date, have relied on spin

  12. The Impacts of Daily Surface Forcing in the Upper Ocean over Tropical Pacific: A Numerical Study

    Science.gov (United States)

    Sui, C.-H.; Rienecker, Michele M.; Li, Xiaofan; Lau, William K.-M.; Laszlo, Istvan; Pinker, Rachel T.

    2001-01-01

    Tropical Pacific Ocean is an important region that affects global climate. How the ocean responds to the atmospheric surface forcing (surface radiative, heat and momentum fluxes) is a major topic in oceanographic research community. The ocean becomes warm when more heat flux puts into the ocean. The monthly mean forcing has been used in the past years since daily forcing was unavailable due to the lack of observations. The daily forcing is now available from the satellite measurements. This study investigates the response of the upper ocean over tropical Pacific to the daily atmospheric surface forcing. The ocean surface heat budgets are calculated to determine the important processes for the oceanic response. The differences of oceanic responses between the eastern and western Pacific are intensively discussed.

  13. GSFLOW model simulations used to evaluate the impact of irrigated agriculture on surface water - groundwater interaction

    Data.gov (United States)

    Department of the Interior — Watershed-scale coupled surface water (SW) – groundwater (GW) flow modeling was used to examine changes in streamflow and SW – GW interaction resulting from...

  14. The impact of industries on surface water quality of River Ona and ...

    African Journals Online (AJOL)

    Samples of water from two rivers (River Ona and River Alaro) in Oluyole ... were higher in the industrial zones than those found in the upstream of both rivers. ... Key words: River Ona, River Alaro, industrial discharges, surface water quality.

  15. Impacts of model initialization on an integrated surface water - groundwater model

    KAUST Repository

    Ajami, Hoori; McCabe, Matthew; Evans, Jason P.

    2015-01-01

    Integrated hydrologic models characterize catchment responses by coupling the subsurface flow with land surface processes. One of the major areas of uncertainty in such models is the specification of the initial condition and its influence

  16. Assessing chemical exposure and ecological impacts of environmental surface waters using cell culture-based metabolomic

    Science.gov (United States)

    Waste water treatment plants (WWTPs), as well as industrial and agricultural operations release complex mixtures of anthropogenic chemicals that negatively affect surface water quality. Previous studies have shown that exposure to such complex chemical mixtures can produce adver...

  17. Interaction Mechanisms between Air Bubble and Molybdenite Surface: Impact of Solution Salinity and Polymer Adsorption.

    Science.gov (United States)

    Xie, Lei; Wang, Jingyi; Yuan, Duowei; Shi, Chen; Cui, Xin; Zhang, Hao; Liu, Qi; Liu, Qingxia; Zeng, Hongbo

    2017-03-07

    The surface characteristics of molybdenite (MoS 2 ) such as wettability and surface interactions have attracted much research interest in a wide range of engineering applications, such as froth flotation. In this work, a bubble probe atomic force microscope (AFM) technique was employed to directly measure the interaction forces between an air bubble and molybdenite mineral surface before/after polymer (i.e., guar gum) adsorption treatment. The AFM imaging showed that the polymer coverage on the surface of molybdenite could achieve ∼5.6, ∼44.5, and ∼100% after conditioning in 1, 5, and 10 ppm polymer solution, respectively, which coincided with the polymer coverage results based on contact angle measurements. The electrolyte concentration and surface treatment by polymer adsorption were found to significantly affect bubble-mineral interaction and attachment. The experimental force results on bubble-molybdenite (without polymer treatment) agreed well with the calculations using a theoretical model based on the Reynolds lubrication theory and augmented Young-Laplace equation including the effect of disjoining pressure. The overall surface repulsion was enhanced when the NaCl concentration decreased from 100 to 1 mM, which inhibited the bubble-molybdenite attachment. After conditioning the molybdenite surface in 1 ppm polymer solution, it was more difficult for air bubbles to attach to the molybdenite surface due to the weakened hydrophobic interaction with a shorter decay length. Increasing the polymer concentration to 5 ppm effectively inhibited bubble attachment on mineral surface, which was mainly due to the much reduced hydrophobic interaction as well as the additional steric repulsion between the extended polymer chains and bubble surface. The results provide quantitative information on the interaction mechanism between air bubbles and molybdenite mineral surfaces on the nanoscale, with useful implications for the development of effective polymer

  18. Impact of roughness, wettability and hydrodynamic conditions on the incrustation on stainless steel surfaces

    International Nuclear Information System (INIS)

    Bogacz, Wojciech; Lemanowicz, Marcin; Al-Rashed, Mohsen H.; Nakonieczny, Damian; Piotrowski, Tomasz; Wójcik, Janusz

    2017-01-01

    Highlights: • Steel plates (X5CrNi18-10) with different roughness and wettability were prepared. • Incrustation of MgSO 4 ·7H 2 O under laminar flow (Re = 59–178) was investigated. • Influence of surface properties and fluid velocity on incrustation was found. • Wettability and surface roughness cannot be considered separately. • Analysis of heat transfer and incrustation time-lapse videos are presented. - Abstract: The goal of this work was to investigate the influence of the stainless steel surface roughness and wettability on incrustation of MgSO 4 ·7H 2 O from aqueous solutions and resulting heat transfer resistance. The experiments were done for laminar flow (Re = 59–178) which is characteristic for regions of apparatus where fouling usually begin. A series of steel plates (X5CrNi18-10) were prepared and used as a heat transfer surfaces. Their properties, i.e. roughness, wettability and elementary composition of surfaces were determined. The experiments were done using specially designed flow cell equipped with Peltier element. Each incrustation measurement lasted for two hours, during which heat transfer resistance was measured as a function of time. After the experiments the mass of crystalline deposit was weighted. It was proved that wettability as well as surface roughness cannot be considered separately in the case of incrustation phenomenon. The knowledge of surface roughness is insufficient due to the fact, that it is possible to obtain surfaces with similar roughness but substantially different wettability for the same material.

  19. The Impact of Sonication on the Surface Quality of Single-Walled Carbon Nanotubes.

    Science.gov (United States)

    Koh, Byumseok; Cheng, Wei

    2015-08-01

    Sonication process is regularly adopted for dispersing single-walled carbon nanotubes (SWCNTs) in an aqueous medium. This can be achieved by either covalent functionalization of SWCNTs with strong acid or by noncovalent functionalization using dispersants that adsorb onto the surface of SWCNTs during dispersion. Because the dispersion process is usually performed using sonication, unintentional free radical formation during sonication process may induce covalent modification of SWCNT surface. Herein, we have systematically investigated the status of SWCNT surface modification under various sonication conditions using Raman spectroscopy. Comparing ID /IG (Raman intensities between D and G bands) ratio of SWCNTs under various sonication conditions suggests that typical sonication conditions (1-6 h bath sonication with sonication power between 3 and 80 W) in aqueous media do not induce covalent modification of SWCNT surface. In addition, we confirm that SWCNT dispersion with single-stranded DNA (ssDNA) involves noncovalent adsorption of ssDNA onto the surface of SWCNTs, but not covalent linkage between ssDNA and SWCNT surface. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  20. Impact of Beads and Drops on a Repellent Solid Surface: A Unified Description

    Science.gov (United States)

    Arora, S.; Fromental, J.-M.; Mora, S.; Phou, Ty; Ramos, L.; Ligoure, C.

    2018-04-01

    We investigate freely expanding sheets formed by ultrasoft gel beads, and liquid and viscoelastic drops, produced by the impact of the bead or drop on a silicon wafer covered with a thin layer of liquid nitrogen that suppresses viscous dissipation thanks to an inverse Leidenfrost effect. Our experiments show a unified behavior for the impact dynamics that holds for solids, liquids, and viscoelastic fluids and that we rationalize by properly taking into account elastocapillary effects. In this framework, the classical impact dynamics of solids and liquids, as far as viscous dissipation is negligible, appears as the asymptotic limits of a universal theoretical description. A novel material-dependent characteristic velocity that includes both capillary and bulk elasticity emerges from this unified description of the physics of impact.

  1. Ultimate Cavity Dynamics of Hydrophobic Spheres Impacting on Free Water Surfaces

    KAUST Repository

    Mansoor, Mohammad M.

    2012-01-01

    Cavity formation resulting from the water-entry of solid objects has been the subject of extensive research owing to its practical relevance in naval, military, industrial, sports and biological applications. The cavity formed by an impacting

  2. 49 CFR 1520.13 - Marking SSI.

    Science.gov (United States)

    2010-10-01

    ... SECURITY INFORMATION § 1520.13 Marking SSI. (a) Marking of paper records. In the case of paper records... back cover, including a binder cover or folder, if the document has a front and back cover; (2) Any.... 552 and 49 CFR parts 15 and 1520. (d) Other types of records. In the case of non-paper records that...

  3. Lessons learned : pavement marking warranty contract.

    Science.gov (United States)

    2013-12-01

    In 2012, UDOT implemented a performance-based warranty on a portion of an I-15 pavement marking : project. The awarded contract requested a contractor warranty on the implemented markings for a total : duration of six years. This is the first time th...

  4. 49 CFR 178.338-18 - Marking.

    Science.gov (United States)

    2010-10-01

    ... pounds. (7) Maximum design density of lading (Max. Lading density), in pounds per gallon. (8) Material... cryogenic liquid, in hours, and the name of that cryogenic liquid (MRHT __ hrs, name of cryogenic liquid). Marked rated holding marking for additional cryogenic liquids may be displayed on or adjacent to the...

  5. 25 CFR 141.16 - Price marking.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Price marking. 141.16 Section 141.16 Indians BUREAU OF... AND ZUNI RESERVATIONS General Business Practices § 141.16 Price marking. The price of each article... visible to the customer and that affords the customer a reasonable opportunity to learn the price of the...

  6. Do employers prefer Mark over Mohammed?

    NARCIS (Netherlands)

    Iris Andriessen; Eline Nievers; Laila Faulk; Jaco Dagevos

    2010-01-01

    Original title: Liever Mark dan Mohammed? Does Mohammed have less chance of succeeding on the Dutch labour market than Mark, even though they both have the same qualifications and work experience? And are employers less friendly towards Sonaya than Paula? This study investigates the

  7. 7 CFR 956.162 - Container markings.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Container markings. 956.162 Section 956.162... WALLA VALLEY OF SOUTHEAST WASHINGTON AND NORTHEAST OREGON Rules and Regulations § 956.162 Container markings. Effective April 15, 1997, no handler shall ship any container of Walla Walla Sweet Onions except...

  8. Impact of chemical lateral boundary conditions in a regional air quality forecast model on surface ozone predictions during stratospheric intrusions

    Science.gov (United States)

    Pendlebury, Diane; Gravel, Sylvie; Moran, Michael D.; Lupu, Alexandru

    2018-02-01

    A regional air quality forecast model, GEM-MACH, is used to examine the conditions under which a limited-area air quality model can accurately forecast near-surface ozone concentrations during stratospheric intrusions. Periods in 2010 and 2014 with known stratospheric intrusions over North America were modelled using four different ozone lateral boundary conditions obtained from a seasonal climatology, a dynamically-interpolated monthly climatology, global air quality forecasts, and global air quality reanalyses. It is shown that the mean bias and correlation in surface ozone over the course of a season can be improved by using time-varying ozone lateral boundary conditions, particularly through the correct assignment of stratospheric vs. tropospheric ozone along the western lateral boundary (for North America). Part of the improvement in surface ozone forecasts results from improvements in the characterization of near-surface ozone along the lateral boundaries that then directly impact surface locations near the boundaries. However, there is an additional benefit from the correct characterization of the location of the tropopause along the western lateral boundary such that the model can correctly simulate stratospheric intrusions and their associated exchange of ozone from stratosphere to troposphere. Over a three-month period in spring 2010, the mean bias was seen to improve by as much as 5 ppbv and the correlation by 0.1 depending on location, and on the form of the chemical lateral boundary condition.

  9. The impact of climatic and non-climatic factors on land surface temperature in southwestern Romania

    Science.gov (United States)

    Roşca, Cristina Florina; Harpa, Gabriela Victoria; Croitoru, Adina-Eliza; Herbel, Ioana; Imbroane, Alexandru Mircea; Burada, Doina Cristina

    2017-11-01

    Land surface temperature is one of the most important parameters related to global warming. It depends mainly on soil type, discontinuous vegetation cover, or lack of precipitation. The main purpose of this paper is to investigate the relationship between high LST, synoptic conditions and air masses trajectories, vegetation cover, and soil type in one of the driest region in Romania. In order to calculate the land surface temperature and normalized difference vegetation index, five satellite images of LANDSAT missions 5 and 7, covering a period of 26 years (1986-2011), were selected, all of them collected in the month of June. The areas with low vegetation density were derived from normalized difference vegetation index, while soil types have been extracted from Corine Land Cover database. HYSPLIT application was employed to identify the air masses origin based on their backward trajectories for each of the five study cases. Pearson, logarithmic, and quadratic correlations were used to detect the relationships between land surface temperature and observed ground temperatures, as well as between land surface temperature and normalized difference vegetation index. The most important findings are: strong correlation between land surface temperature derived from satellite images and maximum ground temperature recorded in a weather station located in the area, as well as between areas with land surface temperature equal to or higher than 40.0 °C and those with lack of vegetation; the sandy soils are the most prone to high land surface temperature and lack of vegetation, followed by the chernozems and brown soils; extremely severe drought events may occur in the region.

  10. The impact of atomization on the surface composition of spray-dried milk droplets.

    Science.gov (United States)

    Foerster, Martin; Gengenbach, Thomas; Woo, Meng Wai; Selomulya, Cordelia

    2016-04-01

    The dominant presence of fat at the surface of spray-dried milk powders has been widely reported in the literature and described as resulting in unfavourable powder properties. The mechanism(s) causing this phenomenon are yet to be clearly identified. A systematic investigation of the component distribution in atomized droplets and spray-dried particles consisting of model milk systems with different fat contents demonstrated that atomization strongly influences the final surface composition. Cryogenic flash-freezing of uniform droplets from a microfluidic jet nozzle directly after atomization helped to distinguish the influence of the atomization stage from the drying stage. It was confirmed that the overrepresentation of fat on the surface is independent of the atomization technique, including a pressure-swirl single-fluid spray nozzle and a pilot-scale rotary disk spray dryer commonly used in industry. It is proposed that during the atomization stage a disintegration mechanism along the oil-water interface of the fat globules causes the surface predominance of fat. X-ray photoelectron spectroscopic measurements detected the outermost fat layer and some adjacent protein present on both atomized droplets and spray-dried particles. Confocal laser scanning microscopy gave a qualitative insight into the protein and fat distribution throughout the cross-sections, and confirmed the presence of a fat film along the particle surface. The film remained on the surface in the subsequent drying stage, while protein accumulated underneath, driven by diffusion. The results demonstrated that atomization induces component segregation and fat-rich surfaces in spray-dried milk powders, and thus these cannot be prevented by adjusting the spray drying conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Procedure for marking, encryption, labelling and optical coding

    OpenAIRE

    Barranco, Ángel; Rodríguez-González, Agustín; Sánchez Valencia, Juan Ramón; Aparicio, Francisco J.; Blaszczyk-Lezak, Iwona Krystina; Holgado Bolaños, Miguel; Casquel del Campo, Rafael; Ocaña, J. L.; Molpeceres, C.; García-Ballesteros Ramírez, Juan José; Morales Furió, Miguel

    2009-01-01

    [EN] It permits marking or recording motifs (301) on surfaces whereon there has been deposited previously a fluorescent polymer layer (300) through a procedure of plasma polymerisation (100) of molecules of a colourant. The procedure combines the special characteristics of the polymer layers making them suitable for being capable of recording diverse motifs (301) thereon, and the possibility of recording by laser (10 1) or other techniques. Among such characteristics s...

  12. The theological significance of the Isaiah citation in Mark 4:12 ...

    African Journals Online (AJOL)

    The well-known passage Mark 4:1–34 is no stranger to New Testament scientific scrutiny, not to even mention the hotly debated phrases in Mark 4:10–12. To avoid repetition, the aim with this article is to determine the extent of the impact the Isaiah 6:9–10 citation in Mark 4:12 might have had on the interpretation and ...

  13. Geometric nonlinear effects on the planar dynamics of a pivoted flexible beam encountering a point-surface impact

    International Nuclear Information System (INIS)

    Li Qing; Wang Tianshu; Ma Xingrui

    2009-01-01

    Flexible-body modeling with geometric nonlinearities remains a hot topic of research by applications in multibody system dynamics undergoing large overall motions. However, the geometric nonlinear effects on the impact dynamics of flexible multibody systems have attracted significantly less attention. In this paper, a point-surface impact problem between a rigid ball and a pivoted flexible beam is investigated. The Hertzian contact law is used to describe the impact process, and the dynamic equations are formulated in the floating frame of reference using the assumed mode method. The two important geometric nonlinear effects of the flexible beam are taken into account, i.e., the longitudinal foreshortening effect due to the transverse deformation, and the stress stiffness effect due to the axial force. The simulation results show that good consistency can be obtained with the nonlinear finite element program ABAQUS/Explicit if proper geometric nonlinearities are included in the floating frame formulation. Specifically, only the foreshortening effect should be considered in a pure transverse impact for efficiency, while the stress stiffness effect should be further considered in an oblique case with much more computational effort. It also implies that the geometric nonlinear effects should be considered properly in the impact dynamic analysis of more general flexible multibody systems

  14. Surface wastewater in Samara and their impact on water basins as water supply sources

    Science.gov (United States)

    Strelkov, Alexander; Shuvalov, Mikhail; Gridneva, Marina

    2017-10-01

    The paper gives an overview of surface wastewater outlets in Samara through the rainwater sewer system into the Saratov water reservoir and the Samara river. The rainwater sewer system in Samara is designed and executed according to a separate scheme, except for the old part of the city, where surface run-off is dumped into the sewer system through siphoned drain. The rainwater system disposes of surface, drainage, industrial clean-contamined waters, emergency and technology discharges from the city’s heat supply and water supply systems. The effluent discharge is carried out by means of separate wastewater outlets into ravines or directly into the Samara river and the Saratov water reservoir without cleaning. The effluent discharge is carried out through the rainwater sewer system with 17 wastewater outlets into the Saratov water reservoir. In the Samara river, surface runoff drainage and clean-contamined water of industrial enterprises is carried out through 14 wastewater outlets. This study emphasizes the demand to arrange effluent discharge and construction of sewage treatment plants to prevent contamination of water objects by surface run-off from residential areas and industrial territories.

  15. Impact of microstructure evolution on the difference between geometric and reactive surface areas in natural chalk

    Science.gov (United States)

    Yang, Y.; Bruns, S.; Stipp, S. L. S.; Sørensen, H. O.

    2018-05-01

    The coupling between flow and mineral dissolution drives the evolution of many natural and engineered flow systems. Pore surface changes as microstructure evolves but this transient behaviour has traditionally been difficult to model. We combined a reactor network model with experimental, greyscale tomography data to establish the morphological grounds for differences among geometric, reactive and apparent surface areas in dissolving chalk. This approach allowed us to study the effects of initial geometry and macroscopic flow rate independently. The simulations showed that geometric surface, which represents a form of local transport heterogeneity, increases in an imposed flow field, even when the porous structure is chemically homogeneous. Hence, the fluid-reaction coupling leads to solid channelisation, which further results in fluid focusing and an increase in geometric surface area. Fluid focusing decreases the area of reactive surface and the residence time of reactant, both contribute to the over-normalisation of reaction rate. In addition, the growing and merging of microchannels, near the fluid entrance, contribute to the macroscopic, fast initial dissolution rate of rocks.

  16. Impact of Optimized Land Surface Parameters on the Land-Atmosphere Coupling in WRF Simulations of Dry and Wet Extremes

    Science.gov (United States)

    Kumar, S.; Santanello, J. A.; Peters-Lidard, C. D.; Harrison, K.

    2011-12-01

    Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture budgets, as well as controlling feedbacks with clouds and precipitation that lead to the persistence of dry and wet regimes. Recent efforts to quantify the strength of L-A coupling in prediction models have produced diagnostics that integrate across both the land and PBL components of the system. In this study, we examine the impact of improved specification of land surface states, anomalies, and fluxes on coupled WRF forecasts during the summers of extreme dry (2006) and wet (2007) conditions in the U.S. Southern Great Plains. The improved land initialization and surface flux parameterizations are obtained through the use of a new optimization and uncertainty module in NASA's Land Information System (LIS-OPT), whereby parameter sets are calibrated in the Noah land surface model and classified according to the land cover and soil type mapping of the observations and the full domain. The impact of the calibrated parameters on the a) spinup of land surface states used as initial conditions, and b) heat and moisture fluxes of the coupled (LIS-WRF) simulations are then assessed in terms of ambient weather, PBL budgets, and precipitation along with L-A coupling diagnostics. In addition, the sensitivity of this approach to the period of calibration (dry, wet, normal) is investigated. Finally, tradeoffs of computational tractability and scientific validity (e.g.,. relating to the representation of the spatial dependence of parameters) and the feasibility of calibrating to multiple observational datasets are also discussed.

  17. Active thermography and post-processing image enhancement for recovering of abraded and paint-covered alphanumeric identification marks

    DEFF Research Database (Denmark)

    Montanini, R.; Quattrocchi, A.; Piccolo, Sebastiano

    2016-01-01

    Alphanumeric marking is a common technique employed in industrial applications for identification of products. However, the realised mark can undergo deterioration, either by extensive use or voluntary deletion (e.g. removal of identification numbers of weapons or vehicles). For recovery of the l......Alphanumeric marking is a common technique employed in industrial applications for identification of products. However, the realised mark can undergo deterioration, either by extensive use or voluntary deletion (e.g. removal of identification numbers of weapons or vehicles). For recovery...... by means of different manufacturing processes (laser, dot peen, impact, cold press and scribe). Optical excitation of the target surface has been achieved using pulse (PT), lock-in (LT) and step heating (SHT) thermography. Raw infrared images were analysed with a dedicated image processing software...... originally developed in Matlab™, exploiting several methods, which include thermographic signal reconstruction (TSR), guided filtering (GF), block guided filtering (BGF) and logarithmic transformation (LN). Proper image processing of the raw infrared images resulted in superior contrast and enhanced...

  18. Impact of Soil Moisture Assimilation on Land Surface Model Spin-Up and Coupled LandAtmosphere Prediction

    Science.gov (United States)

    Santanello, Joseph A., Jr.; Kumar, Sujay V.; Peters-Lidard, Christa D.; Lawston, P.

    2016-01-01

    Advances in satellite monitoring of the terrestrial water cycle have led to a concerted effort to assimilate soil moisture observations from various platforms into offline land surface models (LSMs). One principal but still open question is that of the ability of land data assimilation (LDA) to improve LSM initial conditions for coupled short-term weather prediction. In this study, the impact of assimilating Advanced Microwave Scanning Radiometer for EOS (AMSR-E) soil moisture retrievals on coupled WRF Model forecasts is examined during the summers of dry (2006) and wet (2007) surface conditions in the southern Great Plains. LDA is carried out using NASAs Land Information System (LIS) and the Noah LSM through an ensemble Kalman filter (EnKF) approach. The impacts of LDA on the 1) soil moisture and soil temperature initial conditions for WRF, 2) land-atmosphere coupling characteristics, and 3) ambient weather of the coupled LIS-WRF simulations are then assessed. Results show that impacts of soil moisture LDA during the spin-up can significantly modify LSM states and fluxes, depending on regime and season. Results also indicate that the use of seasonal cumulative distribution functions (CDFs) is more advantageous compared to the traditional annual CDF bias correction strategies. LDA performs consistently regardless of atmospheric forcing applied, with greater improvements seen when using coarser, global forcing products. Downstream impacts on coupled simulations vary according to the strength of the LDA impact at the initialization, where significant modifications to the soil moisture flux- PBL-ambient weather process chain are observed. Overall, this study demonstrates potential for future, higher-resolution soil moisture assimilation applications in weather and climate research.

  19. Using isotopes to improve impact and hydrological predictions of land-surface schemes in global climate models

    International Nuclear Information System (INIS)

    McGuffie, K.; Henderson-Sellers, A.

    2002-01-01

    Global climate model (GCM) predictions of the impact of large-scale land-use change date back to 1984 as do the earliest isotopic studies of large-basin hydrology. Despite this coincidence in interest and geography, with both papers focussed on the Amazon, there have been few studies that have tried to exploit isotopic information with the goal of improving climate model simulations of the land-surface. In this paper we analyze isotopic results from the IAEA global data base specifically with the goal of identifying signatures of potential value for improving global and regional climate model simulations of the land-surface. Evaluation of climate model predictions of the impacts of deforestation of the Amazon has been shown to be of significance by recent results which indicate impacts occurring distant from the Amazon i.e. tele-connections causing climate change elsewhere around the globe. It is suggested that these could be similar in magnitude and extent to the global impacts of ENSO events. Validation of GCM predictions associated with Amazonian deforestation are increasingly urgently required because of the additional effects of other aspects of climate change, particularly synergies occurring between forest removal and greenhouse gas increases, especially CO 2 . Here we examine three decades distributions of deuterium excess across the Amazon and use the results to evaluate the relative importance of the fractionating (partial evaporation) and non-fractionating (transpiration) processes. These results illuminate GCM scenarios of importance to the regional climate and hydrology: (i) the possible impact of increased stomatal resistance in the rainforest caused by higher levels of atmospheric CO2 [4]; and (ii) the consequences of the combined effects of deforestation and global warming on the regions climate and hydrology

  20. Impact of organic overlayers on a-Si:H/c-Si surface potential

    KAUST Repository

    Seif, Johannes P.

    2017-04-11

    Bilayers of intrinsic and doped hydrogenated amorphous silicon, deposited on crystalline silicon (c-Si) surfaces, simultaneously provide contact passivation and carrier collection in silicon heterojunction solar cells. Recently, we have shown that the presence of overlaying transparent conductive oxides can significantly affect the c-Si surface potential induced by these amorphous silicon stacks. Specifically, deposition on the hole-collecting bilayers can result in an undesired weakening of contact passivation, thereby lowering the achievable fill factor in a finished device. We test here a variety of organic semiconductors of different doping levels, overlaying hydrogenated amorphous silicon layers and silicon-based hole collectors, to mitigate this effect. We find that these materials enhance the c-Si surface potential, leading to increased implied fill factors. This opens opportunities for improved device performance.

  1. Lunar atmosphere. How surface composition and meteoroid impacts mediate sodium and potassium in the lunar exosphere.

    Science.gov (United States)

    Colaprete, A; Sarantos, M; Wooden, D H; Stubbs, T J; Cook, A M; Shirley, M

    2016-01-15

    Despite being trace constituents of the lunar exosphere, sodium and potassium are the most readily observed species due to their bright line emission. Measurements of these species by the Ultraviolet and Visible Spectrometer (UVS) on the Lunar Atmosphere and Dust Environment Explorer (LADEE) have revealed unambiguous temporal and spatial variations indicative of a strong role for meteoroid bombardment and surface composition in determining the composition and local time dependence of the Moon's exosphere. Observations show distinct lunar day (monthly) cycles for both species as well as an annual cycle for sodium. The first continuous measurements for potassium show a more repeatable variation across lunations and an enhancement over KREEP (Potassium Rare Earth Elements and Phosphorus) surface regions, revealing a strong dependence on surface composition. Copyright © 2016, American Association for the Advancement of Science.

  2. Impact of organic overlayers on a-Si:H/c-Si surface potential

    KAUST Repository

    Seif, Johannes P.; Niesen, Bjoern; Tomasi, Andrea; Ballif, Christophe; De Wolf, Stefaan

    2017-01-01

    Bilayers of intrinsic and doped hydrogenated amorphous silicon, deposited on crystalline silicon (c-Si) surfaces, simultaneously provide contact passivation and carrier collection in silicon heterojunction solar cells. Recently, we have shown that the presence of overlaying transparent conductive oxides can significantly affect the c-Si surface potential induced by these amorphous silicon stacks. Specifically, deposition on the hole-collecting bilayers can result in an undesired weakening of contact passivation, thereby lowering the achievable fill factor in a finished device. We test here a variety of organic semiconductors of different doping levels, overlaying hydrogenated amorphous silicon layers and silicon-based hole collectors, to mitigate this effect. We find that these materials enhance the c-Si surface potential, leading to increased implied fill factors. This opens opportunities for improved device performance.

  3. Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

    International Nuclear Information System (INIS)

    Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

    1982-01-01

    The age of nuclear waste - the length of time between its removal from the reactor cores and its emplacement in a repository - is a significant factor in determining the thermal loading of a repository. The surface cooling period as well as the density and sequence of waste emplacement affects both the near-field repository structure and the far-field geologic environment. To investigate these issues, a comprehensive review was made of the available literature pertaining to thermal effects and thermal properties of mined geologic repositories. This included a careful evaluation of the effects of different surface cooling periods of the wastes, which is important for understanding the optimal thermal loading of a repository. The results led to a clearer understanding of the importance of surface cooling in evaluating the overall thermal effects of a radioactive waste repository. The principal findings from these investigations are summarized in this paper

  4. X-ray impact induced desorption of gases from stainless steel surfaces

    International Nuclear Information System (INIS)

    Brumbach, S.; Kaminsky, M.

    1975-01-01

    During the operation of plasma devices the interaction of energetic photons with surfaces can cause gas release by photodesorption, and thereby contribute to plasma contamination. Measurements of gases released from stainless steel surfaces were made in an ultrahigh vacuum environment using x-rays characteristic for a tungsten target bremsstrahlung spectrum for electron energies varying from 15 to 50 keV. The predominant gas species observed mass spectrometically are CO 2 (m/e = 44), CO (m/e = 28), and O 2 (m/e = 32). Mean quantum yields for the release of these species from stainless steel were determined. For example, for fresh stainless steel surfaces irradiated by x-rays produced by 50 keV electrons, a mean quantum yield for molecular CO 2 release of 3 x 10 -4 molecules per photons in a bremsstrahlung spectrum at 50 keV electron energy was observed. Based on such a quantum yield an outgassing rate was determined

  5. Forward impact extrusion of surface textured steel blanks using coated tooling

    Science.gov (United States)

    Hild, Rafael; Feuerhack, Andreas; Trauth, Daniel; Arghavani, Mostafa; Kruppe, Nathan C.; Brögelmann, Tobias; Bobzin, Kirsten; Klocke, Fritz

    2017-10-01

    A method to enable dry metal forming by the means of a self-lubricating coating and surface textures was researched using an innovative Pin-On-Cylinder-Tribometer. The experimental analysis was complemented by a numerical model of the complex contact conditions between coated tools and the surface textured specimen at the micro-level. Based on the results, the explanation of the tribological interactions between surface textured specimens and the tool in dry full forward extrusion is the objective of this work. Therefore, experimental dry extrusion tests were performed using a tool system. The extruded specimens were evaluated regarding their geometry as well as by the required punch force. Thereby, the effectiveness and the feasibility of dry metal forming on the example of full forward extrusion was evaluated. Thus, one more step towards the technical realization of dry metal forming of low alloy steels under industrial conditions was realized.

  6. Visualization of high speed liquid jet impaction on a moving surface.

    Science.gov (United States)

    Guo, Yuchen; Green, Sheldon

    2015-04-17

    Two apparatuses for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device (for examining surface speeds between 0 and 25 m/sec) and a spinning disk device (for examining surface speeds between 15 and 100 m/sec). The air cannon linear traverse is a pneumatic energy-powered system that is designed to accelerate a metal rail surface mounted on top of a wooden projectile. A pressurized cylinder fitted with a solenoid valve rapidly releases pressurized air into the barrel, forcing the projectile down the cannon barrel. The projectile travels beneath a spray nozzle, which impinges a liquid jet onto its metal upper surface, and the projectile then hits a stopping mechanism. A camera records the jet impingement, and a pressure transducer records the spray nozzle backpressure. The spinning disk set-up consists of a steel disk that reaches speeds of 500 to 3,000 rpm via a variable frequency drive (VFD) motor. A spray system similar to that of the air cannon generates a liquid jet that impinges onto the spinning disc, and cameras placed at several optical access points record the jet impingement. Video recordings of jet impingement processes are recorded and examined to determine whether the outcome of impingement is splash, splatter, or deposition. The apparatuses are the first that involve the high speed impingement of low-Reynolds-number liquid jets on high speed moving surfaces. In addition to its rail industry applications, the described technique may be used for technical and industrial purposes such as steelmaking and may be relevant to high-speed 3D printing.

  7. Impact of nanohydroxyapatite on enamel surface roughness and color change after orthodontic debonding

    OpenAIRE

    Shabnam Ajami; Hamid Reza Pakshir; Neda Babanouri

    2016-01-01

    Abstract Background The aim of this prospective in vitro study was to evaluate the effect of nanohydroxyapatite (nanoHAP) serum on the enamel surface roughness and tooth color stability after orthodontic debonding procedure. Methods The crowns of 30 premolars were embedded in acrylic blocks with a 4 mm × 5-mm-sized window on the middle third of buccal surfaces. Primary roughness values were evaluated by an atomic force microscope (AFM). After bracket debonding, and polishing procedures, the s...

  8. Understanding the Impact of Intensive Horticulture Land-Use Practices on Surface Water Quality in Central Kenya

    Directory of Open Access Journals (Sweden)

    Faith K. Muriithi

    2015-11-01

    Full Text Available Rapid expansion of commercial horticulture production and related activities contribute to declining surface water quality. The study sought to understand the impacts on select rivers in Laikipia and Meru, production hotspots. The specific aims were (1 to identify prevailing surface water quality by examining variations of 14 physico-chemical parameters, and (2 to categorize measured surface water quality parameters into land use types highlighting potential pollutant source processes. Water samples were collected in July and August 2013 along 14 rivers in the study area. The data were analyzed using principal component analysis (PCA and discriminant analysis (DA. Principal components (PCs explained 70% of the observed total variability of water quality, indicating a prevalence of heavy metal traces (cadmium, phosphate, and zinc. These were linked to the rigorous use of phosphate fertilizers and copper-based agrochemicals in intensive farming. DA provided four significant (p < 0.05 discriminant functions, with 89.5% correct assignment enabling the association of land use with observed water quality. Concentrations of dissolved solids, electro-conductivity, and salinity spiked at locations with intensive small-scale and large-scale horticulture. Understanding the impacts of intensive commercial horticulture and land use practices on water quality is critical to formulating ecologically sound watershed management and pollution abatement plans.

  9. The Impact of Energy Consumption on the Surface Urban Heat Island in China’s 32 Major Cities

    Directory of Open Access Journals (Sweden)

    Weilin Liao

    2017-03-01

    Full Text Available Supported by the rapid economic development in the last few decades, China has become the largest energy consumer in the world. Alongside this, the effect of the anthropogenic heat released from energy consumption is increasingly apparent. We quantified the daytime and nighttime surface urban heat island intensity (SUHII for the 32 major cities in mainland China, using MODIS land surface temperature data from 2008 to 2012, and estimated the energy consumption intensity (ECI based on the correlation between energy consumption and the sum of nighttime lights. On this basis, the impact of energy consumption on the surface urban heat island in China’s 32 major cities was analyzed, by directly examining the relationship between SUHII and the urban-suburban difference in ECI. The results show that energy consumption has a significantly positive correlation with the nighttime SUHII, but no correlation with the daytime SUHII. It indicates that the cities with a larger urban-suburban difference in ECI have a far greater impact on SUHII during the nighttime. Therefore, the statistical analysis of the historical observation data in this study provides evidence for a long-held hypothesis that the anthropogenic heat released from energy consumption is an important contributor to the urban thermal environment.

  10. Impact of feed additives on surface mucosal health and columnaris susceptibility in channel catfish fingerlings, Ictalurus punctatus.

    Science.gov (United States)

    Zhao, Honggang; Li, Chao; Beck, Benjamin H; Zhang, Ran; Thongda, Wilawan; Davis, D Allen; Peatman, Eric

    2015-10-01

    One of the highest priority areas for improvement in aquaculture is the development of dietary additives and formulations which provide for complete mucosal health and protection of fish raised in intensive systems. Far greater attention has been paid to dietary impact on gut health than to protective effects at other mucosal surfaces such as skin and gill. These exterior surfaces, however, are important primary targets for pathogen attachment and invasion. Flavobacterium columnare, the causative agent of columnaris disease, is among the most prevalent of all freshwater disease-causing bacteria, impacting global aquaculture of catfish, salmonids, baitfish and aquaria-trade species among others. This study evaluated whether the feeding of a standard catfish diet supplemented with Alltech dietary additives Actigen(®), a concentrated source of yeast cell wall-derived material and/or Allzyme(®) SSF, a fermented strain of Aspergillus niger, could offer protection against F. columnare mortality. A nine-week feeding trial of channel catfish fingerlings with basal diet (B), B + Allzyme(®) SSF, B + Actigen(®) and B + Actigen(®)+Allzyme(®) SSF revealed good growth in all conditions (FCR additives may provide protection extending beyond the gut to surface mucosa. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Investigating the Potential Impact of the Surface Water and Ocean Topography (SWOT) Altimeter on Ocean Mesoscale Prediction

    Science.gov (United States)

    Carrier, M.; Ngodock, H.; Smith, S. R.; Souopgui, I.

    2016-02-01

    NASA's Surface Water and Ocean Topography (SWOT) satellite, scheduled for launch in 2020, will provide sea surface height anomaly (SSHA) observations with a wider swath width and higher spatial resolution than current satellite altimeters. It is expected that this will help to further constrain ocean models in terms of the mesoscale circulation. In this work, this expectation is investigated by way of twin data assimilation experiments using the Navy Coastal Ocean Model Four Dimensional Variational (NCOM-4DVAR) data assimilation system using a weak constraint formulation. Here, a nature run is created from which SWOT observations are sampled, as well as along-track SSHA observations from simulated Jason-2 tracks. The simulated SWOT data has appropriate spatial coverage, resolution, and noise characteristics based on an observation-simulator program provided by the SWOT science team. The experiment is run for a three-month period during which the analysis is updated every 24 hours and each analysis is used to initialize a 96 hour forecast. The forecasts in each experiment are compared to the available nature run to determine the impact of the assimilated data. It is demonstrated here that the SWOT observations help to constrain the model mesoscale in a more consistent manner than traditional altimeter observations. The findings of this study suggest that data from SWOT may have a substantial impact on improving the ocean model analysis and forecast of mesoscale features and surface ocean transport.

  12. The Impact and Oxidation Survival of Selected Meteoritic Compounds: Signatures of Asteroid Organic Material on Planetary Surfaces

    Science.gov (United States)

    Cooper, George; Horz, Fred; Oleary, Alanna; Chang, Sherwood

    2013-01-01

    Polar, non-volatile organic compounds may be present on the surfaces (or near surfaces) of multiple Solar System bodies. If found, by current or future missions, it would be desirable to determine the origin(s) of such compounds, e.g., asteroidal or in situ. To test the possible survival of meteoritic compounds both during impacts with planetary surfaces and under subsequent (possibly) harsh ambient conditions, we subjected known meteoritic compounds to relatively high impact-shock pressures and/or to varying oxidizing/corrosive conditions. Tested compounds include sulfonic and phosphonic acids (S&P), polyaromatic hydrocarbons (PAHs) amino acids, keto acids, dicarboxylic acids, deoxy sugar acids, and hydroxy tricarboxylic acids (Table 1). Meteoritic sulfonic acids were found to be relatively abundant in the Murchison meteorite and to possess unusual S-33 isotope anomalies (non mass-dependent isotope fractionations). Combined with distinctive C-S and C-P bonds, the S&P are potential signatures of asteroidal organic material.

  13. Groundwater and surface-water interactions and impacts of human activities in the Hailiutu catchment, northwest China

    Science.gov (United States)

    Yang, Zhi; Zhou, Yangxiao; Wenninger, Jochen; Uhlenbrook, Stefan; Wang, Xusheng; Wan, Li

    2017-08-01

    The interactions between groundwater and surface water have been significantly affected by human activities in the semi-arid Hailiutu catchment, northwest China. Several methods were used to investigate the spatial and temporal interactions between groundwater and surface water. Isotopic and chemical analyses of water samples determined that groundwater discharges to the Hailiutu River, and mass balance equations were employed to estimate groundwater seepage rates along the river using chemical profiles. The hydrograph separation method was used to estimate temporal variations of groundwater discharges to the river. A numerical groundwater model was constructed to simulate groundwater discharges along the river and to analyze effects of water use in the catchment. The simulated seepage rates along the river compare reasonably well with the seepage estimates derived from a chemical profile in 2012. The impacts of human activities (river-water diversion and groundwater abstraction) on the river discharge were analyzed by calculating the differences between the simulated natural groundwater discharge and the measured river discharge. Water use associated with the Hailiutu River increased from 1986 to 1991, reached its highest level from 1992 to 2000, and decreased from 2001 onwards. The reduction of river discharge might have negative impacts on the riparian ecosystem and the water availability for downstream users. The interactions between groundwater and surface water as well as the consequences of human activities should be taken into account when implementing sustainable water resources management in the Hailiutu catchment.

  14. Interactions between nano-TiO2 and the oral cavity: impact of nanomaterial surface hydrophilicity/hydrophobicity.

    Science.gov (United States)

    Teubl, Birgit J; Schimpel, Christa; Leitinger, Gerd; Bauer, Bettina; Fröhlich, Eleonore; Zimmer, Andreas; Roblegg, Eva

    2015-04-09

    Titanium dioxide (TiO2) nanoparticles are available in a variety of oral applications, such as food additives and cosmetic products. Thus, questions about their potential impact on the oro-gastrointestinal route rise. The oral cavity represents the first portal of entry and is known to rapidly interact with nanoparticles. Surface charge and size contribute actively to the particle-cell interactions, but the influence of surface hydrophilicity/hydrophobicity has never been shown before. This study addresses the biological impact of hydrophilic (NM 103, rutile, 20 nm) and hydrophobic (NM 104, rutile, 20 nm) TiO2 particles within the buccal mucosa. Particle characterization was addressed with dynamic light scattering and laser diffraction. Despite a high agglomeration tendency, 10% of the particles/agglomerates were present in the nanosized range and penetrated into the mucosa, independent of the surface properties. However, significant differences were observed in intracellular particle localization. NM 104 particles were found freely distributed in the cytoplasm, whereas their hydrophobic counterparts were engulfed in vesicular structures. Although cell viability/membrane integrity was not affected negatively, screening assays demonstrated that NM 104 particles showed a higher potential to decrease the physiological mitochondrial membrane potential than NM 103, resulting in a pronounced generation of reactive oxygen species. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. 9 CFR 310.6 - Carcasses and parts passed for cooking; marking.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Carcasses and parts passed for cooking... INSPECTION AND CERTIFICATION POST-MORTEM INSPECTION § 310.6 Carcasses and parts passed for cooking; marking. Carcasses and parts passed for cooking shall be marked conspicuously on the surface tissues thereof by a...

  16. Environmental impact of coal mining and coal seam gas production on surface water quality in the Sydney basin, Australia.

    Science.gov (United States)

    Ali, A; Strezov, V; Davies, P; Wright, I

    2017-08-01

    The extraction of coal and coal seam gas (CSG) will generate produced water that, if not adequately treated, will pollute surface and groundwater systems. In Australia, the discharge of produced water from coal mining and related activities is regulated by the state environment agency through a pollution licence. This licence sets the discharge limits for a range of analytes to protect the environment into which the produced water is discharged. This study reports on the impact of produced water from coal mine activities located within or discharging into high conservation environments, such as National Parks, in the outer region of Sydney, Australia. The water samples upstream and downstream from the discharge points from six mines were taken, and 110 parameters were tested. The results were assessed against a water quality index (WQI) which accounts for pH, turbidity, dissolved oxygen, biochemical oxygen demand, total dissolved solids, total phosphorus, nitrate nitrogen and E .coli. The water quality assessment based on the trace metal contents against various national maximum admissible concentration (MAC) and their corresponding environmental impacts was also included in the study which also established a base value of water quality for further study. The study revealed that impacted water downstream of the mine discharge points contained higher metal content than the upstream reference locations. In many cases, the downstream water was above the Australia and New Zealand Environment Conservation Council and international water quality guidelines for freshwater stream. The major outliers to the guidelines were aluminium (Al), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn). The WQI of surface water at and downstream of the discharge point was lower when compared to upstream or reference conditions in the majority of cases. Toxicology indices of metals present in industrial discharges were used as an additional tool to assess water quality, and the newly

  17. Immunization with a recombinant subunit OspA vaccine markedly impacts the rate of newly acquired Borrelia burgdorferi infections in client-owned dogs living in a coastal community in Maine, USA.

    Science.gov (United States)

    Eschner, Andrew K; Mugnai, Kristen

    2015-02-10

    In North America, Borrelia burgdorferi is the causative bacterial agent of canine Lyme borreliosis and is transmitted following prolonged attachment and feeding of vector ticks, Ixodes scapularis or Ixodes pacificus. Its prevention is predicated upon tick-avoidance, effective on-animal tick control and effective immunization strategies. The purpose of this study is to characterize dogs that are newly seropositive for Borrelia burgdorferi infection in relation to compliant use of a recombinant OspA canine Lyme borreliosis vaccine. Specifically, Preventive Fractions (PF) and Risk Ratios (RR) associated with the degree of vaccine compliancy (complete versus incomplete) are determined. 6,202 dogs were tested over a five year period in a single veterinary hospital utilizing a non-adjuvanted, recombinant OspA vaccine according to a 0, 1, 6 month (then yearly) protocol. Rates of newly acquired "Lyme-positive" antibody test results were compared between protocol compliant and poorly compliant (incompletely and/or non-vaccinated) dogs. Over the five-year span, one percent (range 0.39 - 1.3) of protocol compliant vaccinated, previously antibody negative dogs became seropositive for infection. Approximately twenty-one percent (range 16.8 - 33.3) of incompletely vaccinated dogs became positive for infection-specific antibodies. The Preventative Fraction for testing positive for antibodies specific for infection with Borrelia burgdorferi in any given year based on optimal vaccine compliance was, on average, 95.3% (range 93.29 - 98.08). The Risk Ratio for becoming infected with Borrelia burgdorferi antibodies in any given year if vaccine non-compliant was 21.41 (range 14.9 - 52.1). There was a high statistically significant relationship (p = <0.0001) in the observed data in terms of vaccination protocol compliance and the probability of Borrelia burgdorferi infection in each of the five years under study. The recombinant outer surface protein A (rOspA) vaccine for dogs is highly

  18. High contrast laser marking of alumina

    Science.gov (United States)

    Penide, J.; Quintero, F.; Riveiro, A.; Fernández, A.; del Val, J.; Comesaña, R.; Lusquiños, F.; Pou, J.

    2015-05-01

    Alumina serves as raw material for a broad range of advanced ceramic products. These elements should usually be identified by some characters or symbols printed directly on them. In this sense, laser marking is an efficient, reliable and widely implemented process in industry. However, laser marking of alumina still leads to poor results since the process is not able to produce a dark mark, yielding bad contrast. In this paper, we present an experimental study on the process of marking alumina by three different lasers working in two wavelengths: 1064 nm (Near-infrared) and 532 nm (visible, green radiation). A colorimetric analysis has been carried out in order to compare the resulting marks and its contrast. The most suitable laser operating conditions were also defined and are reported here. Moreover, the physical process of marking by NIR lasers is discussed in detail. Field Emission Scanning Electron Microscopy, High Resolution Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy were also employed to analyze the results. Finally, we propose an explanation for the differences of the coloration induced under different atmospheres and laser parameters. We concluded that the atmosphere is the key parameter, being the inert one the best choice to produce the darkest marks.

  19. Court presentation of bite mark evidence.

    Science.gov (United States)

    Drinnan, A J; Melton, M J

    1985-12-01

    The uniqueness of an individual's bite mark is generally accepted. The use of bite mark analysis to identify or exclude those suspected of crimes is now a well established activity in forensic dentistry. Although the techniques for evaluating bite mark evidence are extremely sophisticated, it is important that the courtroom presentation of such evidence should be as simple as possible and be directed towards those who must judge it. Dentists likely to be involved in the courtroom presentation of bite mark evidence should: be certain that their local law enforcement personnel are frequently updated on the techniques to be used for producing the optimum evidence needed to evaluate bite marks; become acquainted with the current techniques of evaluating bite mark evidence and understand their difficulties and pitfalls; meet with the lawyers (prosecution or defence) before a courtroom appearance, briefing them on the significance of the particular findings; prepare clear and easily understandable visual aids to present to the court the techniques used in the analysis and the bases for the conclusion reached; and offer conclusions derived from the bite mark investigation.

  20. Changing Context of Trade Mark Protection in India: A Review of the Trade Marks Act, 1999

    OpenAIRE

    Pathak, Akhileshwar

    2004-01-01

    With liberalisation and globalisation of the Indian economy, it has become possible for anyone to get into production and services in most of the sectors. This has led to rampant misuse and appropriation of trade marks. In an insulated economy, with monopoly markets, law protecting trade marks had a limited role. In the changed context, however, trade mark law will be a field of much interest for academics and practitioners. Towards this, the paper explores the formation of trade mark law in ...

  1. Relation between the Atmospheric Boundary Layer and Impact Factors under Severe Surface Thermal Conditions

    Directory of Open Access Journals (Sweden)

    Yinhuan Ao

    2017-01-01

    Full Text Available This paper reported a comprehensive analysis on the diurnal variation of the Atmospheric Boundary Layer (ABL in summer of Badain Jaran Desert and discussed deeply the effect of surface thermal to ABL, including the Difference in Surface-Air Temperature (DSAT, net radiation, and sensible heat, based on limited GPS radiosonde and surface observation data during two intense observation periods of experiments. The results showed that (1 affected by topography of the Tibetan Plateau, the climate provided favorable external conditions for the development of Convective Boundary Layer (CBL, (2 deep CBL showed a diurnal variation of three- to five-layer structure in clear days and five-layer ABL structure often occurred about sunset or sunrise, (3 the diurnal variation of DSAT influenced thickness of ABL through changes of turbulent heat flux, (4 integral value of sensible heat which rapidly converted by surface net radiation had a significant influence on the growth of CBL throughout daytime. The cumulative effect of thick RML dominated the role after CBL got through SBL in the development stage, especially in late summer, and (5 the development of CBL was promoted and accelerated by the variation of wind field and distribution of warm advection in high and low altitude.

  2. Graphite surface topography induced by Ta cluster impact and oxidative etching

    International Nuclear Information System (INIS)

    Reimann, C.T.; Olsson, L.; Erlandsson, R.; Henkel, M.; Urbassek, H.M.

    1998-01-01

    Freshly cleaved highly oriented pyrolytic graphite (HOPG), when baked in air at ∝630 C, forms one-monolayer(ML)-deep circular pits due to oxidation initiated at surface defect sites. We found that the areal density and depths of these pits could be modulated by deliberately introducing surface and sub-surface defects by energetic ion bombardment prior to baking. Bombardment by 555-eV/atom Ta 1 + , Ta 2 + , Ta 4 + , or Ta 9 + , always enhanced the areal density of etch pits, but only bombardment by Ta 4 + , or Ta 9 + significantly enhanced the depths of the pits. We performed molecular dynamics simulations of Ta n cluster bombardment of HOPG (n = 1, 2, 4, and 9) with the aim of characterizing the damage structures induced by the bombardment and correlating them with the experimental data. For Ta 9 + , the simulations showed a high level of damage extending from the surface down to nine MLs, in agreement with the most probable etch pit depth observed. For other cluster species, predicted etch pit depths were deeper than the observed ones. Annealing or steric requirements for initiating oxidation may account for some of the differences between simulations and experimental results. (orig.)

  3. Impacts of Climate Change and Land use Changes on Land Surface Radiation and Energy Budgets

    Science.gov (United States)

    Land surface radiation and energy budgets are critical to address a variety of scientific and application issues related to climate trends, weather predictions, hydrologic and biogeophysical modeling, and the monitoring of ecosystem health and agricultural crops. This is an introductory paper to t...

  4. Impact of electrode geometry on an atmospheric pressure surface barrier discharge

    Science.gov (United States)

    Hasan, M. I.; Morabit, Y.; Dickenson, A.; Walsh, J. L.

    2017-06-01

    Several of the key characteristics of an atmospheric pressure surface barrier discharge (SBD) are heavily dependent on the geometrical configuration of the plasma generating electrodes. This paper reveals that increasing the surface area of an SBD device by reducing the gaps within the electrodes can have major and unforeseen consequence on the discharge properties. It is experimentally demonstrated that a critical limit exists when reducing the diameter of a circular electrode gap below 5 mm, beyond which the required breakdown voltage increases exponentially and the power deposited in the discharge is impeded. Using a numerical model, it is shown that a reduced electrode gap diameter yields a decrease in the voltage difference between the electrode and dielectric surface, thus lowering the maximum electric field. This study indicates a link between the electrode geometry and the nature of the reactive chemistry produced in the plasma, findings which have wide-reaching implications for many applications where multiple closely packed surface barrier discharges are employed to achieve uniform and large area plasma processing.

  5. Oxygen Evolution at Hematite Surfaces: The Impact of Structure and Oxygen Vacancies on Lowering the Overpotential

    NARCIS (Netherlands)

    Zhang, X.; Klaver, P.; van Santen, R.; van de Sanden, M. C. M.; Bieberle, A.

    2016-01-01

    Simulations of the oxygen evolution reaction (OER) are essential for understanding the limitations of water splitting. Most research has focused so far on the OER at flat metal oxide surfaces. The structure sensitivity of the OER has, however, recently been highlighted as a promising research

  6. The impact of surface chemistry on the performance of localized solar-driven evaporation system.

    Science.gov (United States)

    Yu, Shengtao; Zhang, Yao; Duan, Haoze; Liu, Yanming; Quan, Xiaojun; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

    2015-09-04

    This report investigates the influence of surface chemistry (or wettability) on the evaporation performance of free-standing double-layered thin film on the surface of water. Such newly developed evaporation system is composed of top plasmonic light-to-heat conversion layer and bottom porous supporting layer. Under solar light illumination, the induced plasmonic heat will be localized within the film. By modulating the wettability of such evaporation system through the control of surface chemistry, the evaporation rates are differentiated between hydrophilized and hydrophobized anodic aluminum oxide membrane-based double layered thin films. Additionally, this work demonstrated that the evaporation rate mainly depends on the wettability of bottom supporting layer rather than that of top light-to-heat conversion layer. The findings in this study not only elucidate the role of surface chemistry of each layer of such double-layered evaporation system, but also provide additional design guidelines for such localized evaporation system in applications including desalination, distillation and power generation.

  7. Research project AUS-10370/CF: electron impact ionization and surface induced reactions of edge plasma constituents

    International Nuclear Information System (INIS)

    Maerk, T.D.

    1999-01-01

    In order to better understand elementary reactions which are taking place at the plasma edge of thermonuclear fusion devices, three areas of research were persuaded: I) Experimental studies about electron ionization of neutrals and ions and electron attachment to molecules, II) Theoretical studies about electron ionisation of neutrals and ions and III) Reactive interaction of molecular ions with surfaces

  8. Land management and land-cover change have impacts of similar magnitude on surface temperature

    DEFF Research Database (Denmark)

    Luyssaert, Sebastiaan; Jammet, Mathilde; Stoy, Paul C.

    2014-01-01

    Anthropogenic changes to land cover (LCC) remain common, but continuing land scarcity promotes the widespread intensification of land management changes (LMC) to better satisfy societal demand for food, fibre, fuel and shelter1. The biophysical effects of LCC on surface climate are largely unders...

  9. Impact of Bay-Breeze Circulations on Surface Air Quality and Boundary Layer Export

    Science.gov (United States)

    Loughner, Christopher P.; Tzortziou, Maria; Follette-Cook, Melanie; Pickering, Kenneth E.; Goldberg, Daniel; Satam, Chinmay; Weinheimer, Andrew; Crawford, James H.; Knapp, David J.; Montzka, Denise D.; hide

    2014-01-01

    Meteorological and air-quality model simulations are analyzed alongside observations to investigate the role of the Chesapeake Bay breeze on surface air quality, pollutant transport, and boundary layer venting. A case study was conducted to understand why a particular day was the only one during an 11-day ship-based field campaign on which surface ozone was not elevated in concentration over the Chesapeake Bay relative to the closest upwind site and why high ozone concentrations were observed aloft by in situ aircraft observations. Results show that southerly winds during the overnight and early-morning hours prevented the advection of air pollutants from the Washington, D.C., and Baltimore, Maryland, metropolitan areas over the surface waters of the bay. A strong and prolonged bay breeze developed during the late morning and early afternoon along the western coastline of the bay. The strength and duration of the bay breeze allowed pollutants to converge, resulting in high concentrations locally near the bay-breeze front within the Baltimore metropolitan area, where they were then lofted to the top of the planetary boundary layer (PBL). Near the top of the PBL, these pollutants were horizontally advected to a region with lower PBL heights, resulting in pollution transport out of the boundary layer and into the free troposphere. This elevated layer of air pollution aloft was transported downwind into New England by early the following morning where it likely mixed down to the surface, affecting air quality as the boundary layer grew.

  10. Ultrafast lasers for precise and corrosion free marking on chirurgical steels

    Science.gov (United States)

    Neugebauer, Christoph; Aalderink, Dennis; Maurer, Erich; Faisst, Birgit; Budnicki, Aleksander

    2017-02-01

    The unique properties of ultrashort laser pulses and the decrease of invest pave the way to numerous novel applications. Even in the very price sensitive field of laser marking, ultrashort laser can compete due to a new cost structure and remarkable properties of the marking results. In this study we concentrated on industrial marking of medical equipment by using IR ultrashort lasers and compared the results with common marking laser systems. We demonstrate the benefits of ultrashort lasers marking on chirurgical devices, observing the influence of pulse energy, pulse duration, scanning velocity in respect to the visibility, corrosion resistance and long term durability under clinical conditions. Nowadays many parts and products are marked for the purpose of identification and traceability. One kind of laser marking is the well known annealing of stainless steel by nanosecond marking lasers. When annealing occurs a colored oxide layer grows due to the local heating of the material surface. Compared to the raw material, the annealed marking shows increased corrosion sensitivity. Regarding the traceability, the poor durability of the ns marking resulting in contrast reduction and the corrosion susceptibility are a huge problem. Therefore three different laser sources with ns-psfs pulse duration were observed. The focus rests on the realization of parameter studies (various lasers) and their effect on the corrosion and passivation behavior. Furthermore analysis of the oxide layers by use of EDX and XRD were performed to obtain further information on the composition and structure of the markings.

  11. Impact of thermoplastic mask on X-ray surface dose calculated with Monte Carlo code

    International Nuclear Information System (INIS)

    Zhao Yanqun; Li Jie; Wu Liping; Wang Pei; Lang Jinyi; Wu Dake; Xiao Mingyong

    2010-01-01

    Objective: To calculate the effects of thermoplastic mask on X-ray surface dose. Methods: The BEAMnrc Monte Carlo Code system, designed especially for computer simulation of radioactive sources, was performed to evaluate the effects of thermoplastic mask on X-ray surface dose.Thermoplastic mask came from our center with a material density of 1.12 g/cm 2 . The masks without holes, with holes size of 0.1 cm x 0.1 cm, and with holes size of 0. 1 cm x 0.2 cm, and masks with different depth (0.12 cm and 0.24 cm) were evaluated separately. For those with holes, the material width between adjacent holes was 0.1 cm. Virtual masks with a material density of 1.38 g/cm 3 without holes with two different depths were also evaluated. Results: Thermoplastic mask affected X-rays surface dose. When using a thermoplastic mask with the depth of 0.24 cm without holes, the surface dose was 74. 9% and 57.0% for those with the density of 1.38 g/cm 3 and 1.12 g/cm 3 respectively. When focusing on the masks with the density of 1.12 g/cm 3 , the surface dose was 41.2% for those with 0.12 cm depth without holes; 57.0% for those with 0. 24 cm depth without holes; 44.5% for those with 0.24 cm depth with holes size of 0.1 cm x 0.2 cm;and 54.1% for those with 0.24 cm depths with holes size of 0.1 cm x 0.1 cm.Conclusions: Using thermoplastic mask during the radiation increases patient surface dose. The severity is relative to the hole size and the depth of thermoplastic mask. The surface dose change should be considered in radiation planning to avoid severe skin reaction. (authors)

  12. Impact of gastric acidic challenge on surface topography and optical properties of monolithic zirconia.

    Science.gov (United States)

    Sulaiman, Taiseer A; Abdulmajeed, Aous A; Shahramian, Khalil; Hupa, Leena; Donovan, Terrence E; Vallittu, Pekka; Närhi, Timo O

    2015-12-01

    To evaluate the surface topography and optical properties of monolithic zirconia after immersion in simulated gastric acid. Four partially stabilized (PSZ) and one fully stabilized (FSZ) zirconia materials were selected for the study: Prettau (PRT, Zirkonzahn), Zenostar (ZEN, Ivoclar), Bruxzir (BRX, Glidewell), Katana (KAT, Noritake) and FSZ Prettau Anterior (PRTA, Zirkonzahn). IPS e.max (Ivoclar) was used as a control. The specimens (10×10×1.2mm, n=5 per material) were cut, sintered, polished and cleaned before immersed in 5ml of simulated gastric acid solution (Hydrochloric acid (HCl) 0.06M, 0.113% solution in deionized distal water, pH 1.2) for 96h in a 37°C incubator. Specimens were weighed and examined for morphological changes under scanning electron microscope (SEM) coupled with energy dispersive X-ray spectroscopy (EDX). Surface roughness was evaluated by a confocal microscope. Surface gloss and translucency parameter (TP) values were determined by a reflection spectrophotometer before and after acid immersion. The data was analyzed by one-way ANOVA followed by Tukey's HSD post hoc test (pgloss of ZEN, PRTA and IPS e.max increased (p<0.05). Monolithic zirconia materials show some surface alterations in an acidic environment with minimum effect on their optical properties. Whether a smoother surface is in fact a sign of true corrosion resistance or is purely the result of an evenly progressive corrosive process is yet to be confirmed by further research. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  13. Elemental marking of arthropod pests in agricultural systems: single and multigenerational marking

    Science.gov (United States)

    Jane Leslie Hayes

    1991-01-01

    Use of elemental markers to study movement of arthropod pests of field crops is reviewed. Trace elements, rubidium (Rb) and cesium (Cs), have provided a nondisruptive method of marking natural adult populations via developmental stage consumption of treated host plants. Multigenerational marking occurs with the transfer of elemental markers from marked adults to...

  14. Impacts of surface water diversions for marijuana cultivation on aquatic habitat in four northwestern California watersheds.

    Directory of Open Access Journals (Sweden)

    Scott Bauer

    Full Text Available Marijuana (Cannabis sativa L. cultivation has proliferated in northwestern California since at least the mid-1990s. The environmental impacts associated with marijuana cultivation appear substantial, yet have been difficult to quantify, in part because cultivation is clandestine and often occurs on private property. To evaluate the impacts of water diversions at a watershed scale, we interpreted high-resolution aerial imagery to estimate the number of marijuana plants being cultivated in four watersheds in northwestern California, USA. Low-altitude aircraft flights and search warrants executed with law enforcement at cultivation sites in the region helped to validate assumptions used in aerial imagery interpretation. We estimated the water demand of marijuana irrigation and the potential effects water diversions could have on stream flow in the study watersheds. Our results indicate that water demand for marijuana cultivation has the potential to divert substantial portions of streamflow in the study watersheds, with an estimated flow reduction of up to 23% of the annual seven-day low flow in the least impacted of the study watersheds. Estimates from the other study watersheds indicate that water demand for marijuana cultivation exceeds streamflow during the low-flow period. In the most impacted study watersheds, diminished streamflow is likely to have lethal or sub-lethal effects on state- and federally-listed salmon and steelhead trout and to cause further decline of sensitive amphibian species.

  15. Assessing the impact of global changes on the surface water resources of Southwestern Nigeria

    CSIR Research Space (South Africa)

    Ayeni, AO

    2014-12-01

    Full Text Available Understanding the relative impact of land use, land cover and climate change (LULCC) on basin runoff is necessary in assessing basin water stress. This assessment requires long-term observed rainfall time series and land-use/land-cover (LULC...

  16. Kinetic electron emission from metal surfaces induced by impact of slow ions

    Czech Academy of Sciences Publication Activity Database

    Šroubek, Zdeněk; Lorinčík, Jan

    -, č. 625 (2014), s. 7-9 ISSN 0039-6028 R&D Projects: GA MŠk(CZ) ME10086 Institutional support: RVO:67985882 Keywords : Ion induced kinetic electron emission * Electronic excitation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.925, year: 2014

  17. The impact of nano-coating on surface charge accumulation of epoxy resin insulator: characteristic and mechanism

    Science.gov (United States)

    Qi, Bo; Gao, Chunjia; Lv, Yuzhen; Li, Chengrong; Tu, Youping; Xiong, Jun

    2018-06-01

    The flashover phenomenon of the insulator is the main cause for insulating failure of GIS/GIL, and one of the most critical impacting factors is the accumulation of surface charge. The common methods to restrain the surface charge accumulation are reviewed in this paper. Through the reasonable comparison and analysis of these methods, nano-coatings for the insulator were selected as a way to restrain the surface charge accumulation. Based on this, six nano-coated epoxy resin samples with different concentrations of P25-TiO2 nanoparticles were produced. A high precision 3D surface charge measurement system was developed in this paper with a spatial resolution of 4.0 mm2 and a charge resolution of 0.01 µC (m2 · mV)‑1. The experimental results for the epoxy resin sample showed that with the concentration of nanoparticles of the coating material increasing, the surface charge density tended to first decrease and then increase. In the sample coated with 0.5% concentration of nanoparticles, the suppression effect is the optimum, leading to a 63.8% reduction of charge density under DC voltage. The application test for actual nano-coated GIS/GIL basin insulator indicated that the maximum suppression degree for the charge density under DC voltage could reach 48.3%, while it could reach 22.2% for switching impulse voltage and 12.5% for AC context. The control mechanism of nano-coatings on charge accumulation was proposed based on the analysis for surface morphology features and traps characteristics; the shallow traps dominate in the migration of charges while the deep traps operate on the charge accumulation. With the concentration of nanoparticles in nano-coating material mounting up, the density of shallow traps continuously increases, while for deep traps, it first decreases and then increases. For the sample with 0.5% concentration of nanoparticles coated, the competition between shallow traps and deep traps comes to the most balanced state, producing the most

  18. Impacts of dust aerosol and adjacency effects on the accuracy of Landsat 8 and RapidEye surface reflectances

    KAUST Repository

    Houborg, Rasmus; McCabe, Matthew

    2017-01-01

    desert model. This adaptation was particularly pertinent for the Landsat bands in the shortwave infrared. Failure to correct for adjacency effects increased the overall surface reflectance MAD to around 18%. The impact was especially significant for the visible bands over vegetated surface targets, as evidenced by relative MADs increasing to > 200%. In comparison, a relatively minor adjacency effect was observed within the near-infrared and over the more reflective bare soil and desert sites. Overall, the impact of adjacency effects was substantial (20–25% MAD) for all of the studied vegetation indices. This investigation fills a research gap in the quantification of uncertainties and evaluation of achievable accuracy levels in high spatial resolution surface reflectance imagery over desert agriculture and highlights the need for accurate and regionally representative atmospheric correction techniques.

  19. Impacts of dust aerosol and adjacency effects on the accuracy of Landsat 8 and RapidEye surface reflectances

    KAUST Repository

    Houborg, Rasmus

    2017-03-29

    desert model. This adaptation was particularly pertinent for the Landsat bands in the shortwave infrared. Failure to correct for adjacency effects increased the overall surface reflectance MAD to around 18%. The impact was especially significant for the visible bands over vegetated surface targets, as evidenced by relative MADs increasing to > 200%. In comparison, a relatively minor adjacency effect was observed within the near-infrared and over the more reflective bare soil and desert sites. Overall, the impact of adjacency effects was substantial (20–25% MAD) for all of the studied vegetation indices. This investigation fills a research gap in the quantification of uncertainties and evaluation of achievable accuracy levels in high spatial resolution surface reflectance imagery over desert agriculture and highlights the need for accurate and regionally representative atmospheric correction techniques.

  20. Energy absorption during impact on the proximal femur is affected by body mass index and flooring surface.

    Science.gov (United States)

    Bhan, Shivam; Levine, Iris C; Laing, Andrew C

    2014-07-18

    Impact mechanics theory suggests that peak loads should decrease with increase in system energy absorption. In light of the reduced hip fracture risk for persons with high body mass index (BMI) and for falls on soft surfaces, the purpose of this study was to characterize the effects of participant BMI, gender, and flooring surface on system energy absorption during lateral falls on the hip with human volunteers. Twenty university-aged participants completed the study with five men and five women in both low BMI (27.5 kg/m(2)) groups. Participants underwent lateral pelvis release experiments from a height of 5 cm onto two common floors and four safety floors mounted on a force plate. A motion-capture system measured pelvic deflection. The energy absorbed during the initial compressive phase of impact was calculated as the area under the force-deflection curve. System energy absorption was (on average) 3-fold greater for high compared to low BMI participants, but no effects of gender were observed. Even after normalizing for body mass, high BMI participants absorbed 1.8-fold more energy per unit mass. Additionally, three of four safety floors demonstrated significantly increased energy absorption compared to a baseline resilient-rolled-sheeting system (% increases ranging from 20.7 to 28.3). Peak system deflection was larger for high BMI persons and for impacts on several safety floors. This study indicates that energy absorption may be a common mechanism underlying the reduced risk of hip fracture for persons with high BMI and for those who fall on soft surfaces. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  1. The impact of grid and spectral nudging on the variance of the near-surface wind speed

    DEFF Research Database (Denmark)

    Vincent, Claire Louise; Hahmann, Andrea N.

    2015-01-01

    Grid and spectral nudging are effective ways of preventing drift from large scale weather patterns in regional climate models. However, the effect of nudging on the wind-speed variance is unclear. In this study, the impact of grid and spectral nudging on near-surface and upper boundary layer wind...... nudging at and above 1150 m above ground level (AGL). Nested 5 km simulations are not nudged directly, but inherit boundary conditions from the 15 km experiments. Spatial and temporal spectra show that grid nudging causes smoothing of the wind in the 15 km domain at all wavenumbers, both at 1150 m AGL...... and near the surface where nudging is not applied directly, while spectral nudging mainly affects longer wavenumbers. Maps of mesoscale variance show spatial smoothing for both grid and spectral nudging, although the effect is less pronounced for spectral nudging. On the inner, 5 km domain, an indirect...

  2. Imaging spectroscopy to assess the composition of ice surface materials and their impact on glacier mass balance

    Science.gov (United States)

    Naegeli, Kathrin; Huss, Matthias; Damm, Alexander; de Jong, Rogier; Schaepman, Michael; Hoelzle, Martin

    2014-05-01

    The ice-albedo feedback plays a crucial role in various glaciological processes, but especially influences ice melt. Glacier surface albedo is one of the most important variables in the energy balance of snow and ice, but depends in a complicated way on many factors, such as cryoconite concentration, impurities due to mineral dust, soot or organic matter, grain size or ice surface morphology. Our understanding on how these various factors influence glacier albedo is still limited hindering a spatially and temporally explicit parameterization of energy balance models and requiring strongly simplified assumptions on actual albedo values. Over the last two decades, several studies have focused on glacier surface albedo using automatic in-situ weather stations in combination with radiation measurement setups or satellite images. Due to limitations of both approaches in matching either the spatial or the temporal length scale of glacier albedo, still fairly little is known about the state, changes and impact of glacier surface albedo in the Swiss Alps, although there are obvious changes in surface characteristics on most alpine glaciers over the last years. With use of the APEX (Airborne Prism EXperiment) image spectrometer, measurements of reflected radiation were acquired in high spatial and spectral resolution on Glacier de la Plaine Morte, Switzerland, to explicitly analyse the ice surface. In-situ radiometric measurements were acquired with an ASD field spectrometer in parallel to APEX overflights. These data are intended to be used for validation purposes as well as input data for the linear spectral unmixing analysis of the APEX data. Seasonal glacier mass balance is monitored since five years using the direct glaciological method. This contribution presents a first evaluation of the data collected in summer 2013. The obtained in-situ and airborne reflectance measurements were used in combination with a spectral mixture analysis (SMA) approach to assess the

  3. Land-Surface Characteristics and Climate in West Africa: Models’ Biases and Impacts of Historical Anthropogenically-Induced Deforestation

    Directory of Open Access Journals (Sweden)

    Souleymane Sy

    2017-10-01

    Full Text Available Land Use Land-Cover Change (LULCC, such as deforestation, affects the climate system and land-atmosphere interactions. Using simulations carried out within the LUCID (Land Use and Climate, IDentification of robust Impacts project framework, we first quantify the role of historical land-cover change induced by human activities on surface climate in West Africa. Focusing on two contrasted African regions, we find that climate responses of land-use changes are small but they are still statistically significant. In Western Sahel, a statistically significant near-surface atmospheric cooling and a decrease in water recycling are simulated in summer in response to LULCC. Over the Guinean zone, models simulate a significant decrease in precipitation and water recycling in autumn in response to LULCC. This signal is comparable in magnitude with the effect induced by the increase in greenhouse gases. Simulated climate changes due to historical LULCC could however be underestimated because: (i the prescribed LULCC can be underestimated in those regions; (ii the climate models underestimate the coupling strength between West African surface climate and leaf area index (LAI and (iii the lack of interactive LAI in some models. Finally, our study reveals indirect atmospheric processes triggered by LULCC. Over the Western Sahel, models reveal that a significant decrease in solar reflection tend to cool down the surface and thus counteract the atmospheric feedback. Conversely, over the Guinea zone, models reveal that the indirect atmospheric processes and turbulent heat fluxes dominate the climatic responses over the direct effects of LULCC.

  4. Impacts of land use and land cover on surface and air temperature in urban landscapes

    Science.gov (United States)

    Crum, S.; Jenerette, D.

    2015-12-01

    Accelerating urbanization affects regional climate as the result of changing land cover and land use (LCLU). Urban land cover composition may provide valuable insight into relationships among urbanization, air, and land-surface temperature (Ta and LST, respectively). Climate may alter these relationships, where hotter climates experience larger LULC effects. To address these hypotheses we examined links between Ta, LST, LCLU, and vegetation across an urban coastal to desert climate gradient in southern California, USA. Using surface temperature radiometers, continuously measuring LST on standardized asphalt, concrete, and turf grass surfaces across the climate gradient, we found a 7.2°C and 4.6°C temperature decrease from asphalt to vegetated cover in the coast and desert, respectively. There is 131% more temporal variation in asphalt than turf grass surfaces, but 37% less temporal variation in concrete than turf grass. For concrete and turf grass surfaces, temporal variation in temperature increased from coast to desert. Using ground-based thermal imagery, measuring LST for 24 h sequences over citrus orchard and industrial use locations, we found a 14.5°C temperature decrease from industrial to orchard land use types (38.4°C and 23.9°C, respectively). Additionally, industrial land use types have 209% more spatial variation than orchard (CV=0.20 and 0.09, respectively). Using a network of 300 Ta (iButton) sensors mounted in city street trees throughout the region and hyperspectral imagery data we found urban vegetation greenness, measured using the normalized difference vegetation index (NDVI), was negatively correlated to Ta at night across the climate gradient. Contrasting previous findings, the closest coupling between NDVI and Ta is at the coast from 0000 h to 0800 h (highest r2 = 0.6, P urbanized regions of southern California, USA decrease Ta and LST and spatial variation in LST, while built surfaces and land uses have the opposite effect. Furthermore

  5. Surface Traps in Colloidal Quantum Dot Solar Cells, their Mitigation and Impact on Manufacturability

    KAUST Repository

    Kirmani, Ahmad R.

    2017-07-30

    Colloidal quantum dots (CQDs) are potentially low-cost, solution-processable semiconductors which are endowed, through their nanoscale dimensions, with strong absorption, band gap tunability, high dielectric constants and enhanced stability. CQDs are contenders as a standalone PV technology as well as a potential back layer for augmenting established photovoltaic (PV) technologies, such as Si. However, owing to their small size (ca. few nanometers), CQDs are prone to surface trap states that inhibit charge transport and threaten their otherwise wonderful optoelectronic properties. Surface traps have also, indirectly, impeded scalable and industry-compatible fabrication of these solar cells, as all of the reports, to date, have relied on spin-coating with sophisticated and tedious ligand exchange schemes, some of which need to be performed in low humidity environments. In this thesis, we posit that an in-depth understanding of the process-structure-property-performance relationship in CQDs can usher in fresh insights into the nature and origin of surface traps, lead to novel ways to mitigate them, and finally help achieve scalable fabrication. To this end, we probe the CQD surfaces and their interactions with process solvents, linkers, and ambient environment employing a suite of spectroscopic techniques. These fundamental insights help us develop facile chemical and physical protocols to mitigate surface traps such as solvent engineering, remote molecular doping, and oxygen doping, directly leading to better-performing solar cells. Our efforts finally culminate in the realization of >10% efficient, air-stable CQD solar cells scalably fabricated in an ambient environment of high, uncontrolled R.H. (50-65%). As-prepared solar cells fabricated in high humidity ambient conditions are found to underperform, however, an oxygen-doping recipe is devised to mitigate the moisture-induced surface traps and recover device performances. Importantly, these solar cells are

  6. Impact of anisotropic slip on transient three dimensional MHD flow of ferrofluid over an inclined radiate stretching surface

    Directory of Open Access Journals (Sweden)

    A.M. Rashad

    2017-04-01

    Full Text Available The present study explores the impact of anistropic slip on transient three dimensional MHD flow of Cobalt-kerosene ferrofluid over an inclined radiate stretching surface. The governing partial differential equations for this study are solved by the Thomas algorithm with finite-difference type. The impacts of several significant parameters on flow and heat transfer characteristics are exhibited graphically. The conclusion is revealed that the local Nusselt number is significantly promoted due to influence of thermal radiation whereas diminished with elevating the solid volume fraction, magnet parameter and slip factors. Further, the skin friction coefficients visualizes a considerable enhancement with boosting the magnet and radiation parameters, but a prominent reduction is recorded by elevating the solid volume fraction and slip factors.

  7. Feasibility of a continuous surface mining machine using impact breakers. First quarterly report, October 1-December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, A. T.

    1980-01-01

    This is the first quarterly report on the efforts to evaluate the feasibility of excavating coal and overburden from surface mines using impact breakers. The initial stages of the project are devoted to a literature search, equipment selection, test site selection, and conceptual test system design. Hence, this report details the progress made in these areas; the next quarter will see the finalization of Phase I. Included as appendices to this report are FMA internal reports on the individual mines visited. These reports are the basis of the test site selection, and have been censored here to remove data the mine operators deemed as confidential.

  8. Surface Composition Near the Trailing Hemisphere Apex on Europa: The Manannán Impact Crater and Neighboring Terrain

    Science.gov (United States)

    Dalton, J. B.; Prockter, L. M.; Shirley, J. H.; Kamp, L.; Phillips, C. B.; Valenti, M.

    2012-12-01

    The Manannán impact crater and surrounding areas were imaged by Galileo's Near Infrared Mapping Spectrometer (NIMS) during the C3 orbital encounter. We have applied a linear mixture model based on cryogenic infrared reflectance spectroscopy to a "despiked" version of this NIMS observation (C3ENLINEA01A) to estimate abundances of sulfuric acid hydrate, hydrated sulfate salts, water ice and brines in surface exposures. Here we supplement our previously reported abundance estimates (Dalton et al., 2011) with additional results from our ongoing investigation. New geologic mapping precisely registered to the NIMS observation allows the extraction of high-quality near-infrared spectra specific to individual geologic units and morphological features. Detailed high resolution geologic mapping indicates the likely presence of extensive deposits of impact melt materials largely filling the crater floor (Moore et al. 2001), together with surrounding continuous ejecta deposits that may have been excavated from Europa's interior. We find that the crater floor and nearby ejecta exhibit low sulfuric acid abundance relative to the surroundings, with the abundance increasing with radial distance. Where the ejecta begins to thin and break up, the spectral mixture resembles a combination of pre-existing, high-acid-content materials and cleaner, excavated water ice. Several geologic units exhibit significantly lower sulfuric acid hydrate than expected for this region near the trailing hemisphere apex, varying from 53-64 wt% over the observation. This suggests that these surface units have received a reduced cumulative radiation dose (electrons and ions) compared to nearby terrain; this in turn implies geologic youth. We will present model compositions for several of Manannán's key stratigraphic units, including the crater floor deposits and the adjacent chaos and linea. We will interpret these results in the context of ongoing investigations of the interplay of exogenic and

  9. The impact of heat waves on surface urban heat island and local economy in Cluj-Napoca city, Romania

    Science.gov (United States)

    Herbel, Ioana; Croitoru, Adina-Eliza; Rus, Adina Viorica; Roşca, Cristina Florina; Harpa, Gabriela Victoria; Ciupertea, Antoniu-Flavius; Rus, Ionuţ

    2017-07-01

    The association between heat waves and the urban heat island effect can increase the impact on environment and society inducing biophysical hazards. Heat stress and their associated public health problems are among the most frequent. This paper explores the heat waves impact on surface urban heat island and on the local economy loss during three heat periods in Cluj-Napoca city in the summer of 2015. The heat wave events were identified based on daily maximum temperature, and they were divided into three classes considering the intensity threshold: moderate heat waves (daily maximum temperature exceeding the 90th percentile), severe heat waves (daily maximum temperature over the 95th percentile), and extremely severe heat waves (daily maximum temperature exceeding the 98th percentile). The minimum length of an event was of minimum three consecutive days. The surface urban heat island was detected based on land surface temperature derived from Landsat 8 thermal infrared data, while the economic impact was estimated based on data on work force structure and work productivity in Cluj-Napoca derived from the data released by Eurostat, National Bank of Romania, and National Institute of Statistics. The results indicate that the intensity and spatial extension of surface urban heat island could be governed by the magnitude of the heat wave event, but due to the low number of satellite images available, we should consider this information only as preliminary results. Thermal infrared remote sensing has proven to be a very efficient method to study surface urban heat island, due to the fact that the synoptic conditions associated with heat wave events usually favor cloud free image. The resolution of the OLI_TIRS sensor provided good results for a mid-extension city, but the low revisiting time is still a drawback. The potential economic loss was calculated for the working days during heat waves and the estimated loss reached more than 2.5 mil. EUR for each heat wave day

  10. Impact of surface texture on natural convection boundary layer of nanofluid

    Directory of Open Access Journals (Sweden)

    Mehmood Ahmer

    2018-01-01

    Full Text Available Heat transfer characteristics are investigated in natural convection flow of water-based nanofluid near a vertical rough wall. The analysis considers five different nanoparticles: silver, copper, alumina, magnetite, and silica. The concentration has been limited between 0-20% for all types of nanoparticle. The governing equations are modeled using the Boussinesq approximation and Tiwari and Das models are utilized to represent the nanofluid. The analysis examines the effects of nanoparticle volume fraction, type of nanofluid, and the wavy surface geometry parameter on the skin friction and Nusselt number. It is observed that for a given nanofluid the skin friction and Nusselt number can be maximized via an appropriate tuning of the wavy surface geometry parameter along with the selection of suitable nanoparticle. Particular to this study cooper is observed to be more productive towards the flow and heat transfer enhancement. In total the metallic oxides are found to be less beneficial as compared to the pure metals.

  11. Impact of surface morphology on the properties of light emission in InGaN epilayers

    Science.gov (United States)

    Kristijonas Uždavinys, Tomas; Marcinkevičius, Saulius; Mensi, Mounir; Lahourcade, Lise; Carlin, Jean-François; Martin, Denis; Butté, Raphaël; Grandjean, Nicolas

    2018-05-01

    Scanning near-field optical microscopy was used to study the influence of the surface morphology on the properties of light emission and alloy composition in InGaN epitaxial layers grown on GaN substrates. A strong correlation between the maps of the photoluminescence (PL) peak energy and the gradient of the surface morphology was observed. This correlation demonstrates that the In incorporation strongly depends on the geometry of the monolayer step edges that form during growth in the step-flow mode. The spatial distribution of nonradiative recombination centers — evaluated from PL intensity maps — was found to strongly anticorrelate with the local content of In atoms in the InGaN alloy.

  12. Corrosion mechanism of a Ni-based alloy in supercritical water: Impact of surface plastic deformation

    International Nuclear Information System (INIS)

    Payet, Mickaël; Marchetti, Loïc; Tabarant, Michel; Chevalier, Jean-Pierre

    2015-01-01

    Highlights: • The dissolution of Ni and Fe cations occurs during corrosion of Ni-based alloys in SCW. • The nature of the oxide layer depends locally on the alloy microstructure. • The corrosion mechanism changes when cold-work increases leading to internal oxidation. - Abstract: Ni–Fe–Cr alloys are expected to be a candidate material for the generation IV nuclear reactors that use supercritical water at temperatures up to 600 °C and pressures of 25 MPa. The corrosion resistance of Alloy 690 in these extreme conditions was studied considering the surface finish of the alloy. The oxide scale could suffer from dissolution or from internal oxidation. The presence of a work-hardened zone reveals the competition between the selective oxidation of chromium with respect to the oxidation of nickel and iron. Finally, corrosion mechanisms for Ni based alloys are proposed considering the effects of plastically deformed surfaces and the dissolution.

  13. The impact of climate and composition on playa surface roughness: Investigation of atmospheric mineral dust emission mechanisms

    Science.gov (United States)

    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

  14. First results from Mark III at SPEAR

    International Nuclear Information System (INIS)

    Einsweiler, K.F.

    The paper presents data on meson decays obtained using the MARK III detector operating at SPEAR. Results on hadronic decays; decays of the etasub(e); and results on radiative decays; are all described. (U.K.)

  15. User's guide : pavement marking management system database.

    Science.gov (United States)

    2011-12-01

    Pavement markings play a critical role in maintaining a safe and efficient driving environment for road users, especially during nighttime conditions. The Texas Department of Transportation (TxDOT) spends millions of dollars each year for installatio...

  16. Mark Twain, Fenimore Cooper, and Batman.

    Science.gov (United States)

    Crick, Robert Alan

    1992-01-01

    Describes how Mark Twain's essay "Fenimore Cooper's Literary Offenses" helped students to get interested in writing and inspired them to write a similar essay critiquing the movie "Batman." Provides excerpts from students' essays. (PRA)

  17. 46 CFR 160.054-6 - Marking.

    Science.gov (United States)

    2010-10-01

    ... “To Close, Press Together Full Length”. The marking may be applied to the container by the silk screen process, using a suitable ink or paint, or may be applied by other means shown to be acceptable. (b...

  18. 49 CFR 180.213 - Requalification markings.

    Science.gov (United States)

    2010-10-01

    ... eddy current examination combined with a visual inspection, the marking is as illustrated in paragraph..., securely affixed in a manner prescribed by the cylinder manufacturer, near the original manufacturer's...

  19. Microscopic saw mark analysis: an empirical approach.

    Science.gov (United States)

    Love, Jennifer C; Derrick, Sharon M; Wiersema, Jason M; Peters, Charles

    2015-01-01

    Microscopic saw mark analysis is a well published and generally accepted qualitative analytical method. However, little research has focused on identifying and mitigating potential sources of error associated with the method. The presented study proposes the use of classification trees and random forest classifiers as an optimal, statistically sound approach to mitigate the potential for error of variability and outcome error in microscopic saw mark analysis. The statistical model was applied to 58 experimental saw marks created with four types of saws. The saw marks were made in fresh human femurs obtained through anatomical gift and were analyzed using a Keyence digital microscope. The statistical approach weighed the variables based on discriminatory value and produced decision trees with an associated outcome error rate of 8.62-17.82%. © 2014 American Academy of Forensic Sciences.

  20. How wear affects road surface texture and its impact on tire/road noise

    OpenAIRE

    Siebert, Doreen

    2017-01-01

    Mechanical pavement wear in the Nordic countries is essentially influenced by the use of studded tires during long winter seasons. The abrasive effect of the studded tires is the cause of significant damage on the pavement and a contributor to rutting. In addition, the mechanical aggregate removal due to the studded tires is the reason for significant changes in the road surface texture. At traditional dense asphalt pavements, the mechanical wear is initiated by the abrasion of the mortar, wh...