WorldWideScience

Sample records for surface influenced injury

  1. The influence of an artificial playing surface on injury risk and perceptions of muscle soreness in elite Rugby Union.

    Science.gov (United States)

    Williams, S; Trewartha, G; Kemp, S P T; Michell, R; Stokes, K A

    2016-01-01

    This prospective cohort study investigated the influence of an artificial playing surface on injury risk and perceptions of muscle soreness in elite English Premiership Rugby Union players. Time loss (from 39.5 matches) and abrasion (from 27 matches) injury risk was compared between matches played on artificial turf and natural grass. Muscle soreness was reported over the 4 days following one match played on each surface by 95 visiting players (i.e., normally play on natural grass surfaces). There was a likely trivial difference in the overall injury burden relating to time-loss injuries between playing surfaces [rate ratio = 1.01, 90% confidence interval (CI): 0.73-1.38]. Abrasions were substantially more common on artificial turf (rate ratio = 7.92, 90% CI: 4.39-14.28), although the majority of these were minor and only two resulted in any reported time loss. Muscle soreness was consistently higher over the 4 days following a match on artificial turf in comparison with natural grass, although the magnitude of this effect was small (effect sizes ranging from 0.26 to 0.40). These results suggest that overall injury risk is similar for the two playing surfaces, but further surveillance is required before inferences regarding specific injury diagnoses and smaller differences in overall injury risk can be made. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Influence of Cleats-Surface Interaction on the Performance and Risk of Injury in Soccer: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Diogo C. F. Silva

    2017-01-01

    Full Text Available Objective. To review the influence of cleats-surface interaction on the performance and risk of injury in soccer athletes. Design. Systematic review. Data Sources. Scopus, Web of science, PubMed, and B-on. Eligibility Criteria. Full experimental and original papers, written in English that studied the influence of soccer cleats on sports performance and injury risk in artificial or natural grass. Results. Twenty-three articles were included in this review: nine related to performance and fourteen to injury risk. On artificial grass, the soft ground model on dry and wet conditions and the turf model in wet conditions are related to worse performance. Compared to rounded studs, bladed ones improve performance during changes of directions in both natural and synthetic grass. Cleat models presenting better traction on the stance leg improve ball velocity while those presenting a homogeneous pressure across the foot promote better kicking accuracy. Bladed studs can be considered less secure by increasing plantar pressure on lateral border. The turf model decrease peak plantar pressure compared to other studded models. Conclusion. The soft ground model provides lower performance especially on artificial grass, while the turf model provides a high protective effect in both fields.

  3. Influence of Cleats-Surface Interaction on the Performance and Risk of Injury in Soccer: A Systematic Review.

    Science.gov (United States)

    Silva, Diogo C F; Santos, Rubim; Vilas-Boas, João Paulo; Macedo, Rui; Montes, António Mesquita; Sousa, Andreia S P

    2017-01-01

    To review the influence of cleats-surface interaction on the performance and risk of injury in soccer athletes. Systematic review. Scopus, Web of science, PubMed, and B-on. Full experimental and original papers, written in English that studied the influence of soccer cleats on sports performance and injury risk in artificial or natural grass. Twenty-three articles were included in this review: nine related to performance and fourteen to injury risk. On artificial grass, the soft ground model on dry and wet conditions and the turf model in wet conditions are related to worse performance. Compared to rounded studs, bladed ones improve performance during changes of directions in both natural and synthetic grass. Cleat models presenting better traction on the stance leg improve ball velocity while those presenting a homogeneous pressure across the foot promote better kicking accuracy. Bladed studs can be considered less secure by increasing plantar pressure on lateral border. The turf model decrease peak plantar pressure compared to other studded models. The soft ground model provides lower performance especially on artificial grass, while the turf model provides a high protective effect in both fields.

  4. Surface Organization Influences Bistable Vision

    Science.gov (United States)

    Graf, Erich W.; Adams, Wendy J.

    2008-01-01

    A priority for the visual system is to construct 3-dimensional surfaces from visual primitives. Information is combined across individual cues to form a robust representation of the external world. Here, it is shown that surface completion relying on multiple visual cues influences relative dominance during binocular rivalry. The shape of a…

  5. Training habits, training surface and injuries among South African ...

    African Journals Online (AJOL)

    ... exercises to improve their core stability, NMC or proprioception. The cement playing surface delivered a 1.9 times higher injury rate than the synthetic surface. Netball coaches should be educated on the value and implementation of exercise modalities that could limit injuries to the ankle and knee joints of netball players.

  6. Factors that influence chest injuries in rollovers.

    Science.gov (United States)

    Digges, Kennerly; Eigen, Ana; Tahan, Fadi; Grzebieta, Raphael

    2014-01-01

    The design of countermeasures to reduce serious chest injuries for belted occupants involved in rollover crashes requires an understanding of the cause of these injuries and of the test conditions to assure the effectiveness of the countermeasures. This study defines rollover environments and occupant-to-vehicle interactions that cause chest injuries for belted drivers. The NASS-CDS was examined to determine the frequency and crash severity for belted drivers with serious (Abbreviated Injury Scale [AIS] 3+) chest injuries in rollovers. Case studies of NASS crashes with serious chest injuries sustained by belted front occupants were undertaken and damage patterns were determined. Vehicle rollover tests with dummies were examined to determine occupant motion in crashes with damage similar to that observed in the NASS cases. Computer simulations were performed to further explore factors that could contribute to chest injury. Finite element model (FEM) vehicle models with both the FEM Hybrid III dummy and THUMS human model were used in the simulations. Simulation of rollovers with 6 quarter-turns or less indicated that increases in the vehicle pitch, either positive or negative, increased the severity of dummy chest loadings. This finding was consistent with vehicle damage observations from NASS cases. For the far-side occupant, the maximum chest loadings were caused by belt and side interactions during the third quarter-turn and by the center console loading during the fourth quarter-turn. The results showed that the THUMS dummy produced more realistic kinematics and improved insights into skeletal and chest organ loadings compared to the Hybrid III dummy. These results suggest that a dynamic rollover test to encourage chest injury reduction countermeasures should induce a roll of at least 4 quarter-turns and should also include initial vehicle pitch and/or yaw so that the vehicle's axis of rotation is not aligned with its inertial roll axis during the initial stage

  7. The Influence of Injury Definition on Injury Burden in Preprofessional Ballet and Contemporary Dancers.

    Science.gov (United States)

    Kenny, Sarah J; Palacios-Derflingher, Luz; Whittaker, Jackie L; Emery, Carolyn A

    2018-03-01

    Study Design Cohort study. Background Multiple operational definitions of injury exist in dance research. The influence that these different injury definitions have on epidemiological estimations of injury burden among dancers warrants investigation. Objective To describe the influence of injury definition on injury prevalence, incidence, and severity in preprofessional ballet and contemporary dancers. Methods Dancers registered in full-time preprofessional ballet (n = 85; 77 female; median age, 15 years; range, 11-19 years) and contemporary (n = 60; 58 female; median age, 19 years; range, 17-30 years) training completed weekly online questionnaires (modified Oslo Sports Trauma Research Centre questionnaire on health problems) using 3 injury definitions: (1) time loss (unable to complete 1 or more classes/rehearsals/performances for 1 or more days beyond onset), (2) medical attention, and (3) any complaint. Physical therapists completed injury report forms to capture dance-related medical attention and time-loss injuries. Percent agreement between injury registration methods was estimated. Injury prevalence (seasonal proportion of dancers injured), incidence rates (count of new injuries per 1000 dance-exposure hours), and severity (total days lost) were examined across each definition, registration method, and dance style. Results Questionnaire response rate was 99%. Agreement between registration methods ranged between 59% (time loss) and 74% (injury location). Depending on definition, registration, and dance style, injury prevalence ranged between 9.4% (95% confidence interval [CI]: 4.1%, 17.7%; time loss) and 82.4% (95% CI: 72.5%, 89.8%; any complaint), incidence rates between 0.1 (95% CI: 0.03, 0.2; time loss) and 4.9 (95% CI: 4.1, 5.8; any complaint) injuries per 1000 dance-hours, and days lost between 111 and 588 days. Conclusion Time-loss and medical-attention injury definitions underestimate the injury burden in preprofessional dancers. Accordingly, injury

  8. The influence of motor vehicle legislation on injury claim incidence.

    Science.gov (United States)

    Lemstra, Mark; Olszynski, W P

    2005-01-01

    Although there have been numerous strategies to prevent motor vehicle collisions and their subsequent injuries, few have been effective in preventing motor vehicle injury claims. In this paper, we examine the role of legislation and compensation system in altering injury claim incidence. The population base for our natural experiment was all Saskatchewan, Manitoba, British Columbia and Quebec residents who submitted personal injury claims to their respective motor vehicle insurance provider from 1990 to 1999. The provinces of Saskatchewan and Manitoba switched from Tort to pure No-Fault insurance on January 1, 1995 and on March 1, 1994 respectively. British Columbia maintained tort insurance and Quebec maintained pure no-fault insurance throughout the entire 10-year period. The conversion from tort insurance to pure no-fault motor vehicle insurance resulted in a five-year 31% (RR = 0.69; 95% CI 0.68-0.70) reduction in total injury claims per 100,000 residents in Saskatchewan and a five-year 43% (RR = 0.57; 95% CI 0.56-0.58) reduction in Manitoba. At the same time, the province of British Columbia retained tort insurance and had a five-year 5% reduction (RR = 0.95; 95% CI 0.94-0.99). Quebec, which retained pure no-fault throughout the entire 10-year period, had less than one third of the injury claims per 100,000 residents than the tort province of British Columbia. The conversion from tort to pure no-fault legislation has a large influence in reducing motor vehicle injury claim incidence in Canada. Legislative system and injury compensation scheme have an observable impact on injury claim incidence and can therefore have significant impact on the health care system.

  9. Factors that influence on the confrontation the spinal cord injury

    Directory of Open Access Journals (Sweden)

    Montserrat Melchor Arteaga

    2011-05-01

    Full Text Available Definitions of spinal cord injury agree in the consequences of that injury is the loss in varying degrees of autonomic function; this will cause a change in the lifestyle of patients and their families.In the spinal injury, the priority is the recovery or maintenance of vital organ functions, the physical stabilization for people. Later, the priority here is the rehabilitation and adaptation. This should be integrated at all levels, physical, psychological and social. Confrontation is, by Callista Roy, a important variable for understanding the effect of stress on health and disease, health maintenance or recovery. The way, that the patients have to confront the disease, are the confrontation strategies. They are defined as thoughts and actions that persons put in place to deal with adverse changes. They are grouped into 3 categories: problems, emotions and avoidance.There are others factors that influence in the use of strategies, between them the personality. According to Eysenck this is determined by the functional interaction of four factors: cognitive (intelligence, conative (character, affective (temperament and somatic (construction. With this study we want to know the factors that influence in the confrontation of the spinal cord injury and to analyze the possible relation between them, and to be able to elaborate particular tools, on the most determinant factors, to obtain an effective confrontation about this type of disease.

  10. Surface energy and viscoelasticity influence caramel adhesiveness.

    Science.gov (United States)

    Wagoner, Ty B; Foegeding, Edward Allen

    2017-08-26

    Adhesion is an important textural attribute that directs consumer eating patterns and behaviors and can be a negative attribute during food processing. The objectives of this study were to modify caramel formulation and compare adhesion to different materials to quantify the influence of surface energetics and viscoelasticity on caramel adhesiveness. Mechanical adhesion was viewed in the context of pressure sensitive tack theory, where adhesion is controlled by viscoelasticity of the adhesive material and the surface energy relationship of material and probe. Caramel samples varied in total amount of fat and protein, and mechanical adhesion was measured using a series of materials with total surface energies of 39.7-53.2 mJ/m 2 . Adhesiveness decreased as fat and protein content increased, with a significant effect of total surface energy. Viscoelasticity was modeled using creep recovery data fit to a four-element Burger mechanistic model. Burger model parameters representing retarded elasticity correlated strongly with adhesiveness. The results suggest two zones of adhesion based on formulation, one driven by both surface energy relationships-most notably dispersive and total surface energy-and viscoelasticity, and the other driven solely by viscoelasticity. Relationships between mechanical properties and adhesion have been explored but are still not well understood, and could aid in the design of food products with a controlled level of adhesion. The results of this study indicate the importance of considering material surface energy when measuring mechanical adhesion or texture profile analysis. Understanding the relationships between viscoelastic behavior and adhesion can be used to make inferences on perceived texture. © 2017 Wiley Periodicals, Inc.

  11. The influence of immunological stressors on traumatic brain injury.

    Science.gov (United States)

    Sun, Mujun; McDonald, Stuart J; Brady, Rhys D; O'Brien, Terence J; Shultz, Sandy R

    2018-03-01

    Traumatic brain injury (TBI) is a leading cause of death and disability worldwide, and typically involves a robust immune response. Although a great deal of preclinical research has been conducted to identify an effective treatment, all phase III clinical trials have been unsuccessful to date. These translational shortcomings are in part due to a failure to recognize and account for the heterogeneity of TBI, including how extracranial factors can influence the aftermath of TBI. For example, most preclinical studies have utilized isolated TBI models in young adult males, while clinical trials typically involve highly heterogeneous patient populations (e.g., different mechanisms of injury, a range of ages, presence of polytrauma or infection). This paper will review the current, albeit limited literature related to how TBI is affected by common concomitant immunological stressors. In particular, discussion will focus on whether extracranial trauma (i.e., polytrauma), infection, and age/immunosenescence can influence TBI pathophysiology, and thereby may result in a different brain injury than what would have occurred in an isolated TBI. It is concluded that these immunological stressors are all likely to be TBI modifiers that should be further studied and could impact translational treatment strategies. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Influence of surface roughness of a desert

    Science.gov (United States)

    Sud, Y. C.; Smith, W. E.

    1984-01-01

    A numerical simulation study, using the current GLAS climate GCM, was carried out to examine the influence of low bulk aerodynamic drag parameter in the deserts. The results illustrate the importance of yet another feedback effect of a desert on itself, that is produced by the reduction in surface roughness height of land once the vegetation dies and desert forms. Apart from affecting the moisture convergence, low bulk transport coefficients of a desert lead to enhanced longwave cooling and sinking which together reduce precipitation by Charney's (1975) mechanism. Thus, this effect, together with albedo and soil moisture influence, perpetuate a desert condition through its geophysical feedback effect. The study further suggests that man made deserts is a viable hypothesis.

  13. Factors influencing sport participation among athletes with spinal cord injury.

    Science.gov (United States)

    Wu, S K; Williams, T

    2001-02-01

    This exploratory study examined the relationships between pre- and post-injury sport participation among active individuals with spinal cord injury (SCI) in the United Kingdom. In particular, factors that influence individuals with SCI into sport were identified. A total of 143 British individuals with SCI currently participating in wheelchair basketball, wheelchair rugby, wheelchair tennis, and wheelchair athletics were recruited. A total of 112 subjects were active prelesion, and 31 subjects were inactive preinjury. A Disability Sport Participation questionnaire developed by the authors was used for data collection. The questionnaire was distributed through the British Wheelchair Sport Associations. Personal, impairment, health and fitness, socialization, and participation data of athletes with SCI were collected. Groups of active preinjury and inactive preinjury were compared. For athletes who had been active pre-SCI, the in-hospital rehabilitation program and specialized sport club for people with disabilities were more important contexts for introducing the sport after injury to individuals. Friends and peers with disabilities were much more influential as initial and continuing socialization agents than rehabilitation therapists. The main reasons for athletes with SCI who participated in sports after injury were for fitness, fun, health, and competition, although many athletes noted that social aspects and rehabilitation also influenced their sport participation. This study identified social contexts, social agents, difficulties, sources of information, and reasons for sport participation of athletes with SCI. The results may offer some directions for the improvement of rehabilitation programs for people with SCI and also help the development of appropriate strategies to encourage people with SCI to participate in sports and leisure activities.

  14. Association of lower limb injury with boot cleat design and playing surface in elite soccer.

    Science.gov (United States)

    O'Connor, Anne-Marie; James, Iain T

    2013-06-01

    Reducing external injury risk factors associated with the boot-surface interaction is important in reducing the incidence and severity of foot and ankle injury. A review of prospective football (soccer) injury epidemiology studies determined that the incidence of noncontact ankle sprain injury is relatively high. Research on the impact of cleat shape and configuration and boot design on the boot-surface interaction is providing new understanding of the impact on player biomechanics and injury risk but is not keeping pace with commercial advances in boot design and innovation in natural and synthetic turf surface technology. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Exploring caregiver behavior and knowledge about unsafe sleep surfaces in infant injury death cases.

    Science.gov (United States)

    Chu, Tracy; Hackett, Martine; Kaur, Navpreet

    2015-06-01

    In the United States, infant deaths due to sleep-related injuries have quadrupled over the past two decades. One of the major risk factors is the placement of an infant to sleep on a surface other than a crib or bassinet. This study examines contextual circumstances and knowledge and behaviors that may contribute to the placement of infants on an unsafe sleep surface in infant injury death cases. This study employed a retrospective review of 255 sleep-related injury death cases in New York City from 2004 to 2010 where an infant was found sleeping on an unsafe sleep surface. Mixed-methods analyses, employing both quantitative analysis of vital statistics data and risk variables extracted from the medical examiner files and qualitative analysis of the narrative content of the files, were conducted. In 48% of cases, a crib or bassinet was identified in the home. Quantitative analysis revealed no significant differences in demographic or risk factor characteristics between infants who had a crib or bassinet and those who did not. Qualitative analysis highlighted factors in caregivers' decision making related to situational convenience, preference, and misconceptions concerning safe infant sleep. The health belief model (HBM), specifically the constructs of perceived susceptibility, severity, benefits, and barriers, was used as a lens to understand factors associated with caregiver behavior. This study provides evidence that infants are at risk of sleep-related injury death even when a crib or bassinet is present. Understanding the factors that may influence safe sleep behaviors can help produce more appropriate interventions. © 2014 Society for Public Health Education.

  16. Influence of surface topography on elastically backscattered electrons

    International Nuclear Information System (INIS)

    Ding, X; Da, B; Gong, J B; Ding, Z J; Mao, S F

    2014-01-01

    A Monte Carlo simulation, taking into account of the detailed surface roughness of a realistic solid sample, has been performed to study the surface topography influence on elastic peak intensity. To describe quantitatively the surface topography effect, here we introduce surface roughness parameter (SRP) according to the ratio of elastic peak intensities between a rough surface and an ideal planar surface. Simulation results for Al sample have shown that SRP varies with surface roughness particularly at large incidence/emission angles

  17. Understanding the Acute Skin Injury Mechanism Caused by Player-Surface Contact During Soccer

    Science.gov (United States)

    van den Eijnde, Wilbert A.J.; Peppelman, Malou; Lamers, Edwin A.D.; van de Kerkhof, Peter C.M.; van Erp, Piet E.J.

    2014-01-01

    Background: Superficial skin injuries are considered minor, and their incidence is probably underestimated. Insight into the incidence and mechanism of acute skin injury can be helpful in developing suitable preventive measures and safer playing surfaces for soccer and other field sports. Purpose: To gain insight into the incidence and severity of skin injuries related to soccer and to describe the skin injury mechanism due to player-surface contact. Study Design: Systematic review; Level of evidence, 4. Methods: The prevention model by van Mechelen et al (1992) combined with the injury causation model of Bahr and Krosshaug (2005) were used as a framework for the survey to describe the skin injury incidence and mechanism caused by player-surface contact. Results: The reviewed literature showed that common injury reporting methods are mainly based on time lost from participation or the need for medical attention. Because skin abrasions seldom lead to absence or medical attention, they are often not reported. When reported, the incidence of abrasion/laceration injuries varies from 0.8 to 6.1 injuries per 1000 player-hours. Wound assessment techniques such as the Skin Damage Area and Severity Index can be a valuable tool to obtain a more accurate estimation of the incidence and severity of acute skin injuries. Conclusion: The use of protective equipment, a skin lubricant, or wet surface conditions has a positive effect on preventing abrasion-type injuries from artificial turf surfaces. The literature also shows that essential biomechanical information of the sliding event is lacking, such as how energy is transferred to the area of contact. From a clinical and histological perspective, there are strong indications that a sliding-induced skin lesion is caused by mechanical rather than thermal injury to the skin. PMID:26535330

  18. Blasting injuries in surface mining with emphasis on flyrock and blast area security

    Energy Technology Data Exchange (ETDEWEB)

    Bajpayee, T.S.; Rehak, T.R.; Mowrey, G.L.; Ingram, D.K. [NIOSH, Pittsburgh, PA (USA). Pittsburgh Research Lab.

    2004-07-01

    Blasting is a hazardous component of surface mining. Serious injuries and fatalities result from improper judgment or practice during rock blasting. This paper describes several fatal injury case studies, analyzes causative factors, and emphasizes preventive measures. During the 21-year period from 1978 to 1998, the mean yearly explosive-related injuries (fatal and nonfatal) for surface coal mines was 8.86 (95% CI: 6.38-11.33), and for surface metal/nonmetal mines 10.76 (95% CI: 8.39-13.14). Flyrock and lack of blast area security accounted for 68.2% of these injuries. Case studies indicate that the causative factors for fatal injuries are primarily personal and task-related and to some extent environmental. A reduction in the annual injuries in surface coal mines was observed during the 10-year period of 1989-1998 (5.80 (95% CI: 2.71-8.89)) compared to the previous 10-year period of 1979-1988 (10.90 (95% CI: 7.77-14.14)). However, such reduction was not noticed in the metal/nometal sector (i.e., 9.30 (95% CI: 6.84-11.76) for the period 1989-1998 compared with 11.00 (95% CI: 7.11-14.89) for the period 1979-1988). Discussion of case studies during safety meetings will help to mitigate fatal injuries and derive important payoffs in terms of lower risks and costs of injuries.

  19. Factors Influencing Helmet Use, Head Injury, and Hospitalization Among Children Involved in Skateboarding and Snowboarding Accidents.

    Science.gov (United States)

    Sadeghian, Homa; Nguyen, Brian; Huynh, Nhan; Rouch, Joshua; Lee, Steven L; Bazargan-Hejazi, Shahrzad

    2017-01-01

    Up to 75% of skateboarders and snowboarders admitted to the hospital sustain head injuries. It is unclear why not all children and teenagers wear helmets while snowboarding and skateboarding given the protection they afford. To report on the prevalence of, and factors associated with, skateboarding and snowboarding in injured children and to explore factors that influence helmet use, head injury, and hospitalization in this sample. A cross-sectional study of skateboard- and snowboard-associated injuries from 2003 to 2012 among individuals younger than age 18 years using National Electronic Injury Surveillance System (NEISS) data from approximately 100 hospitals. Helmet use, head injury, and hospitalization. Of 1742 patients in the study, 852 (48.9%) and 890 (51.1%) were skateboarders and snowboarders, respectively. Overall, 907 (52.1%) did not use helmets, and 704 (40.4%) sustained head injuries. Multiple logistic regression analysis showed that age, race/ethnicity, location of boarding, and engaging in skateboarding influenced helmet use. Sex, race/ethnicity, helmet use, and skateboarding predicted head injury. Age, sex, skateboarding, and head injury predicted hospital admission. Statistically significant differences exist in helmet use, head injury, and hospitalization rates between skateboarders and snowboarders. Our findings suggest that injury prevention and outreach programs are needed to increase helmet use and reduce the risk of head injury and hospitalization in skateboarders and other at-risk groups. Further studies are needed to clarify the association between race/ethnicity and helmet use among skateboarders and snowboarders.

  20. Factors influencing the injury pattern and injury severity after high speed motor vehicle accident--a retrospective study.

    Science.gov (United States)

    Weninger, Patrick; Hertz, Harald

    2007-10-01

    Motor vehicular accidents (MVA) are the leading cause of death among people under 40 years of age. Despite improvement in car safety and driver awareness of the use of safety devices, fatalities and severe injuries continue to occur. From 1997 to 2004, 13,678 patients after MVA were admitted to our institution. Out of this cohort, 584 (4.3%) patients suffered blunt major trauma defined as Injury Severity Score (ISS) >or=16 and at least one life-threatening injury in one body region. Preclinical data were recorded in 458 patients matching the inclusion criteria. The circumstances of the trauma scene such as weather conditions were analysed as well as technical crash data such as direction of impact, security devices used and type and severity of automobile damage. In a retrospective trial, the influence of preclinical variables on the injury pattern and on injury severity was investigated. 314 (68.6%) patients were male and 144 (31.4%) female. Injury severity (p=0.015) and rate of multiple injuries (p=0.012) were higher in patients after side-impact crashes. If automobiles with SIPS were used, injury severity was significantly reduced in case of side-impact crashes (p=0.003). Patients after frontal impact crashes had a higher rate of severe traumatic brain injury (TBI) compared to the overall cohort (p=0.014). Patients suffering blunt aortic (n=29) dissection were involved in frontal crashes with seat belt use (pIn case of high speed MVA in rural areas the trauma mechanism and the circumstances (i.e., impact direction, automobile deformation) should be considered to identify patients at high risk of severe blunt trauma and multiple injuries.

  1. Surface characteristics, equipment height, and the occurrence and severity of playground injuries.

    Science.gov (United States)

    Laforest, S; Robitaille, Y; Lesage, D; Dorval, D

    2001-03-01

    To evaluate whether surface characteristics (absorption level (g-max), material) and the height of play equipment are related to the occurrence and severity of injuries from falls. During the summers of 1991 and 1995, conformity of play equipment to Canadian standards was assessed in a random sample (n = 102) of Montreal public playgrounds. Surface absorption (g-max) was tested using a Max Hic instrument and the height of equipment was measured. Concurrently, all injuries presenting at the emergency department of Montreal's two children's hospitals were recorded and parents were interviewed. Inspected equipment was implicated in 185 injuries. The g-max measurements (1995 only) were available for 110 of these playground accidents. One third of falls (35 %) occurred on a surface exceeding 200 g and the risk of injury was three times greater than for g level lower than 150 (95% confidence interval (CI) 1.45 to 6.35). On surfaces having absorption levels between 150 g and 200 g, injuries were 1.8 times more likely (95% CI 0.91 to 3.57). Injuries were 2.56 times more likely to occur on equipment higher than 2 m compared with equipment lower than 1.5 m. Analysis of risk factors by severity of injury failed to show any positive relationships between the g-max or height and severity, whereas surface material was a good predictor of severity. This study confirms the relationships between risk of injury, surface resilience, and height of equipment, as well as between type of material and severity of injury. Our data suggest that acceptable limits for surface resilience be set at less than 200 g, and perhaps even less than 150 g, and not exceed 2 m for equipment height. These findings reinforce the importance of installing recommended materials, such as sand, beneath play equipment.

  2. Nanoscale topography influences polymer surface diffusion.

    Science.gov (United States)

    Wang, Dapeng; He, Chunlin; Stoykovich, Mark P; Schwartz, Daniel K

    2015-02-24

    Using high-throughput single-molecule tracking, we studied the diffusion of poly(ethylene glycol) chains at the interface between water and a hydrophobic surface patterned with an array of hexagonally arranged nanopillars. Polymer molecules displayed anomalous diffusion; in particular, they exhibited intermittent motion (i.e., immobilization and "hopping") suggestive of continuous-time random walk (CTRW) behavior associated with desorption-mediated surface diffusion. The statistics of the molecular trajectories changed systematically on surfaces with pillars of increasing height, exhibiting motion that was increasingly subdiffusive and with longer waiting times between diffusive steps. The trajectories were well-described by kinetic Monte Carlo simulations of CTRW motion in the presence of randomly distributed permeable obstacles, where the permeability (the main undetermined parameter) was conceptually related to the obstacle height. These findings provide new insights into the mechanisms of interfacial transport in the presence of obstacles and on nanotopographically patterned surfaces.

  3. Burn injury influences the T cell homeostasis in a butyrate-acid sphingomyelinase dependent manner

    OpenAIRE

    Rice, Teresa C.; Armocida, Stephanie M.; Kuethe, Joshua W.; Midura, Emily F.; Jain, Ayushi; Hildeman, David A.; Healy, Daniel P.; Gulbins, Erich; Caldwell, Charles C.

    2016-01-01

    Following burn injury, a key factor for patients susceptible to opportunistic infections is immune suppression. Butyrate levels are important in maintaining a functional immune system and these levels can be altered after injury. The acid sphingomyelinase (Asm) lipid signaling system has been implicated in a T cell actions with some evidence of being influenced by butyrate. Here, we hypothesized that burn-injury changes in butyrate levels would mediate Asm activity and, consequently, T cell h...

  4. Factors influencing the implementation of soccer injury prevention ...

    African Journals Online (AJOL)

    Interest and participation in soccer continue to grow in every part of the world. The increase in the number of people participating in soccer in Rwanda is also prominent. However, with the increase in the number of people participating in soccer there is an increase in the risk of injuries, thus making prevention of injury more ...

  5. Longitudinal influence of musculo-skeletal injuries and extra physical education on physical fitness in schoolchildren

    DEFF Research Database (Denmark)

    Rexen, C T; Ersbøll, A K; Wedderkopp, N

    2016-01-01

    The aims of this study were to investigate if (A) injuries and (B) increased physical education (PE) influenced the development of physical fitness in schoolchildren. Simultaneously, to investigate if a possible PE effect was modified by sport participation outside school hours...... fitness tests measured four times. Information of injury and sport was derived from weekly automated mobile phone text messages surveying the presence of musculo-skeletal pain and organized sport participation. Injury and extra PE both influenced the development of physical fitness. Injury decreased...... development of physical fitness with -1.01 composite z-score units (95% CI: -1.57; -0.45). Extra PE increased physical fitness development with 0.80 (95% CI: 0.49; 1.10) composite z-score units. The influence of injury was not dependent on extra PE. No modifying effect was found by mean weekly sport...

  6. A new classification for cervical vertebral injuries: influence of CT

    Energy Technology Data Exchange (ETDEWEB)

    Daffner, R.H.; Brown, R.R.; Goldberg, A.L. [Department of Diagnostic Radiology, Allegheny University Hospitals, Allegheny General, Pittsburgh, PA (United States)

    2000-03-30

    Objective. Computed tomography (CT) has been demonstrated to be superior to radiography in identifying cervical vertebral injuries. However, many of these injuries may not be clinically significant, and require only minimal symptomatic and supportive treatment. It is therefore imperative that radiologists and spine surgeons have criteria for distinguishing between those injuries requiring surgical stabilization and those that do not. The authors propose a new classification of cervical vertebral injuries into two categories: major and minor.Design and patients. A data base, acquired on 1052 separate cervical injuries in 879 patients seen between 1983 and 1998, was reviewed. Four categories of injury based on mechanism [hyperflexion (four variants), hyperextension (two variants), rotary (two variants), and axial compression (five variants)] were identified. ''Major'' injuries are defined as having either radiographic or CT evidence of instability with or without associated localized or central neurologic findings, or have the potential to produce the latter. ''Minor'' injuries have no radiographic and/or CT evidence of instability, are not associated with neurologic findings, and have no potential to cause the latter.Results and conclusions. Cervical injury should be classified as ''major'' if the following radiographic and/or CT criteria are present: displacement of more than 2 mm in any plane, wide vertebral body in any plane, wide interspinous/interlaminar space, wide facet joints, disrupted posterior vertebral body line, wide disc space, vertebral burst, locked or perched facets (unilateral or bilateral), ''hanged man'' fracture of C2, dens fracture, and type III occipital condyle fracture. All other types of fractures may be considered ''minor''. (orig.)

  7. The level and influencing factors of quality of life in patients with brachial plexus injury

    Directory of Open Access Journals (Sweden)

    Jie Shen

    2014-06-01

    Conclusions: A brachial plexus injury significantly compromises an individual's quality of life. Multiple factors influence this quality, which should be targeted to augment the physical and psychological care provided.

  8. Influence of the surface finishing on ultrasound velocity in wood

    Directory of Open Access Journals (Sweden)

    Tomáš Špaček

    2008-01-01

    Full Text Available Non-destructive diagnostic methods are very useful for monumental buildings. This paper deals with one of these technique, namely with ultrasound testing and influence of surface finishing on ultrasound velocity measured by means of device the Arborsonic Decay Detector. Surface finishing (Primalex – thick synthetic film of the surface finishing, Luxol – Extra – thin synthetic film of the surface finishing and Impranal Profi SL – thick acryl film the surface finishing were selected and tested in this research. The transmittion time was measured and velocity was converted from it. This was compared before and after application of surface finishing.

  9. Factors influencing injury severity of crashes involving HAZMAT trucks

    Directory of Open Access Journals (Sweden)

    Majbah Uddin

    2018-03-01

    Full Text Available This paper investigates factors affecting injury severity of crashes involving HAZMAT large trucks. It uses the crash data in the state of California from the Highway Safety Information System, from 2005 to 2011. The explanatory factors include the occupant, crash, vehicle, roadway, environmental, and temporal characteristics. Both fixed- and random-parameters ordered probit models of injury severity (where possible outcomes are major, minor, and no injury were estimated; the random-parameters model captures possible unobserved effects related to factors not present in the data. The model results indicate that the occupants being male, truck drivers, crashes occurring in rural locations, under dark-unlighted, under dark-lighted conditions, and on weekdays were associated with increased probability of major injuries. Conversely, the older occupants (age 60 and over, truck making a turn, rear-end collision, collision with an object, crashes occurring on non-interstate highway, higher speed limit highway (≥65 mph, and flat terrain were associated with decreased probability of major injuries. This study has identified factors that explain injury severities of crashes involving HAZMAT, and as such, it could be used by policy makers and transportation agencies to improve HAZMAT transport, and thus, the overall highway safety.

  10. Risk of Anterior Cruciate Ligament Injury in Athletes on Synthetic Playing Surfaces: A Systematic Review.

    Science.gov (United States)

    Balazs, George C; Pavey, Gabriel J; Brelin, Alaina M; Pickett, Adam; Keblish, David J; Rue, John-Paul H

    2015-07-01

    The effect of synthetic playing surfaces on the risk of injury in athletes is frequently debated in the orthopaedic literature. Biomechanical studies have identified increased frictional force at the shoe-surface interface, theoretically increasing the risk of injury relative to natural grass. This increase in frictional force is potentially relevant for the risk of anterior cruciate ligament (ACL) rupture, where noncontact mechanisms are frequent. However, clinical studies examining this issue have shown mixed results. The purpose of this study was to systematically review the available literature on risk of ACL rupture on natural grass versus artificial turf. We hypothesized that the risk of ACL rupture on synthetic playing surfaces would not be higher than that of natural grass playing surfaces. Systematic review. A systematic keyword search was performed of OVID, EMBASE, the Cochrane Library of Systematic Reviews, and the PROSPERO International Prospective Register of Systematic Reviews. Candidate articles were included if they reported the risk ratio of ACL rupture on natural grass versus synthetic playing surfaces, were of level 3 evidence or better, and included only ACL injuries sustained during organized athletic events. Exclusion criteria included a study with non-field-related sports and the use of historical cohorts for calculating risk ratios. A total of 10 studies with 963 ACL injuries met criteria for inclusion, all of which reported on soccer and football cohorts. Among these, 4 studies (753 ACL injuries) found an increased risk of ACL injury on artificial playing surfaces. All 4 of these articles were conducted using American football cohorts, and they included both earlier-generation surfaces (AstroTurf) and modern, 3rd-generation surfaces. Only 1 study in football players found a reduced risk of ACL injury on synthetic playing surfaces. No soccer cohort found an increased risk of ACL injury on synthetic surfaces. High-quality studies support an

  11. Factors influencing graphene growth on metal surfaces

    International Nuclear Information System (INIS)

    Loginova, E; Bartelt, N C; McCarty, K F; Feibelman, P J

    2009-01-01

    Graphene forms from a relatively dense, tightly bound C-adatom gas when elemental C is deposited on or segregates to the Ru(0001) surface. Nonlinearity of the graphene growth rate with C-adatom density suggests that growth proceeds by addition of C atom clusters to the graphene edge. The generality of this picture has now been studied by use of low-energy electron microscopy (LEEM) to observe graphene formation when Ru(0001) and Ir(111) surfaces are exposed to ethylene. The finding that graphene growth velocities and nucleation rates on Ru have precisely the same dependence on adatom concentration as for elemental C deposition implies that hydrocarbon decomposition only affects graphene growth through the rate of adatom formation. For ethylene, that rate decreases with increasing adatom concentration and graphene coverage. Initially, graphene growth on Ir(111) is like that on Ru: the growth velocity is the same nonlinear function of adatom concentration (albeit with much smaller equilibrium adatom concentrations, as we explain with DFT calculations of adatom formation energies). In the later stages of growth, graphene crystals that are rotated relative to the initial nuclei nucleate and grow. The rotated nuclei grow much faster. This difference suggests firstly, that the edge-orientation of the graphene sheets relative to the substrate plays an important role in the growth mechanism, and secondly, that attachment of the clusters to the graphene is the slowest step in cluster addition, rather than formation of clusters on the terraces.

  12. Influence of surface roughness on the friction property of textured surface

    OpenAIRE

    Yuankai Zhou; Hua Zhu; Wenqian Zhang; Xue Zuo; Yan Li; Jianhua Yang

    2015-01-01

    In contrast with dimple textures, surface roughness is a texture at the micro-scale, essentially which will influence the load-bearing capacity of lubricant film. The numerical simulation was carried out to investigate the influence of surface roughness on friction property of textured surface. The lubricant film pressure was obtained using the method of computational fluid dynamics according to geometric model of round dimple, and the renormalization-group k–ε turbulent model was adopted in ...

  13. Shoe and Field Surface Risk Factors for Acute Lower Extremity Injuries Among Female Youth Soccer Players.

    Science.gov (United States)

    OʼKane, John W; Gray, Kristen E; Levy, Marni R; Neradilek, Moni; Tencer, Allan F; Polissar, Nayak L; Schiff, Melissa A

    2016-05-01

    To describe acute lower extremity injuries and evaluate extrinsic risk factors in female youth soccer. Nested case-control study. Youth soccer clubs in Seattle, WA. Female soccer players (n = 351) ages 11 to 15 years randomly selected from 4 soccer clubs from which 83% of their players were enrolled with complete follow-up for 92% of players. Injured players were interviewed regarding injury, field surface, shoe type, and position. Uninjured controls, matched on game or practice session, were also interviewed. The association between risk factors and acute lower extremity injury using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). One hundred seventy-three acute lower extremity injuries occurred involving primarily the ankle (39.3%), knee (24.9%), and thigh (11.0%). Over half (52.9%) recovered within 1 week, whereas 30.2% lasted beyond 2 weeks. During practices, those injured were approximately 3-fold (OR, 2.83; 95% CI, 1.49-5.31) more likely to play on grass than artificial turf and 2.4-fold (95% CI, 1.03-5.96) more likely to wear cleats on grass than other shoe and surface combinations. During games, injured players were 89% (95% CI, 1.03-4.17) more likely to play defender compared with forward. Half of the acute lower extremity injuries affected the ankle or knee. Grass surface and wearing cleats on grass increased training injuries. The majority, 64%, of female youth soccer players' acute injuries involve the ankle and knee and injury prevention strategies in this age group should target these areas. When considering playing surfaces for training, communities and soccer organizations should consider the third-generation artificial turf a safe alternative to grass.

  14. The systems approach to error reduction: factors influencing inoculation injury reporting in the operating theatre.

    Science.gov (United States)

    Cutter, Jayne; Jordan, Sue

    2013-11-01

    To examine the frequency of, and factors influencing, reporting of mucocutaneous and percutaneous injuries in operating theatres. Surgeons and peri-operative nurses risk acquiring blood-borne viral infections during surgical procedures. Appropriate first-aid and prophylactic treatment after an injury can significantly reduce the risk of infection. However, studies indicate that injuries often go unreported. The 'systems approach' to error reduction relies on reporting incidents and near misses. Failure to report will compromise safety. A postal survey of all surgeons and peri-operative nurses engaged in exposure prone procedures in nine Welsh hospitals, face-to-face interviews with selected participants and telephone interviews with Infection Control Nurses. The response rate was 51.47% (315/612). Most respondents reported one or more percutaneous (183/315, 58.1%) and/or mucocutaneous injuries (68/315, 21.6%) in the 5 years preceding the study. Only 54.9% (112/204) reported every injury. Surgeons were poorer at reporting: 70/133 (52.6%) reported all or >50% of their injuries compared with 65/71 nurses (91.5%). Injuries are frequently under-reported, possibly compromising safety in operating theatres. A significant number of inoculation injuries are not reported. Factors influencing under-reporting were identified. This knowledge can assist managers in improving reporting and encouraging a robust safety culture within operating departments. © 2012 John Wiley & Sons Ltd.

  15. Factors influencing the surface quality of polished tool steels

    International Nuclear Information System (INIS)

    Rebeggiani, S; Rosén, B-G

    2014-01-01

    Today’s demands on surface quality of moulds for injection moulding of plastic components involve no/low defect contents and roughness levels in the nm-range for high gloss applications. Material properties as well as operating conditions influence the mould finish, and thus the final surface of moulded products. This paper focuses on how particle content and different polishing strategies influence final surface qualities of moulds. Visual estimations of polished tool steel samples were combined with non-contact 3D-surface texture analysis in order to correlate traditional assessments to more quantitative methods, and to be able to analyse the surfaces at nanometre-level. It was found that steels with a lower proportion of particles, like carbides and oxides, gave rise to smoother polished surfaces. In a comparative study of polishers from different polishing shops, it was found that while different surface preparation strategies can lead to similar final roughness, similar preparation techniques can produce high-quality surfaces from different steel grades. However, the non-contact 3D-surface texture analysis showed that not all smooth polished surfaces have desirable functional topographies for injection moulding of glossy plastic components. (paper)

  16. Grinding and its influence to ground surface durability

    Science.gov (United States)

    Holesovsky, F.; Novak, M.

    2011-01-01

    A number of parameters of running process effect on the formed surface at grinding. Above all, the following influences can be mentioned: grinding wheel speed, workpiece speed, tool properties, rigidity of machine tool, etc. The plastic deformation and thermal load of surface layer are evoked at the action of cutting conditions. A new surface keeps the definite properties, which are given by its roughness, surface profile, geometry accuracy, intensity and residual stress distribution, respectively microhardness course in surface layer and changes of microstructure in this layer. The surface properties predict the surface behaviour in the real machinery at the dynamical, respectively static loading. At the load, the changes of surface properties proceed, e.g. roughness, residual stress. Simultaneously, changes of surface properties influence the durability of machine part and can also lead to surface damage and machine part breakdown. The slackness can also evoke the cracks, which leads to the fracture. The behaviour of part differs in the operating environment without and with oil or in the corrosion environment.

  17. Influence of surface topography on the sputtering yields of silver

    International Nuclear Information System (INIS)

    Pan Jisheng; Wang Zhenxia; Tao Zhenlan; Zhang Jiping

    1992-01-01

    The sputtering yields of silver have been measured as a function of the fluence of incident Ar + ions (27 keV) using the collector technique and RBS analysis. The irradiated surface was examined by scanning electron microscopy (SEM). It is shown that the sputtering yields of surfaces with topography are enhanced relative to smooth surfaces of silver, but the extent of the enhancement depends on the irradiation dose. The experimental results can be explained assuming that the surface topography and sputtering yield are a function of incident angle. It is obvious that the surface topography is an important factor to influence the sputtering yield. The term ''apparent sputtering yield'' has specifically been used when referring to the experimental sputtering yield of a surface with topography, to emphasize the difference with a smooth surface. (orig.)

  18. [Clinical observation on the influence of earthquake crush injury on postoperative wound healing of extremity fractures].

    Science.gov (United States)

    Chen, Fu-hong; Chen, Ze; Duan, Heng-qiong; Wan, Zhong-xian

    2008-10-01

    To observe the influence of earthquake crush injury on postoperative wound healing of extremity fractures. The study involved 85 patients with extremities fracture underwent internal fixation operation in 3 group, including 28 earthquake casualties with crush injuries in observation group, 27 earthquake casualties without crush injuries in control I group and 30 local patients during the same period in control II group. Urine routine, blood creatine kinase (CK) and wound conditions of patients in 3 groups were observed respectively. There was no significant difference in Urine routine and blood CK between 3 groups and was significant difference in wound conditions between observation group and each control group. Earthquake crush injuries can influence the postoperative wound healing of extremity fractures.

  19. Longitudinal influence of musculo-skeletal injuries and extra physical education on physical fitness in schoolchildren.

    Science.gov (United States)

    Rexen, C T; Ersbøll, A K; Wedderkopp, N; Andersen, L B

    2016-12-01

    The aims of this study were to investigate if (A) injuries and (B) increased physical education (PE) influenced the development of physical fitness in schoolchildren. Simultaneously, to investigate if a possible PE effect was modified by sport participation outside school hours. This was a longitudinal controlled school-based study. Six schools with 270 min of PE (extra PE) and four schools with 90 min of PE were followed up for 2.5 years. In total, 1054 children were included for analysis (normal PE = 443, extra PE = 611). Development in fitness was analyzed using composite z-scores from six fitness tests measured four times. Information of injury and sport was derived from weekly automated mobile phone text messages surveying the presence of musculo-skeletal pain and organized sport participation. Injury and extra PE both influenced the development of physical fitness. Injury decreased development of physical fitness with -1.01 composite z-score units (95% CI: -1.57; -0.45). Extra PE increased physical fitness development with 0.80 (95% CI: 0.49; 1.10) composite z-score units. The influence of injury was not dependent on extra PE. No modifying effect was found by mean weekly sport participation outside school hours. In conclusion, extra PE had a positive effect, whereas injuries had a negative effect on physical fitness development in schoolchildren. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Influence of Surface Energy Effects on Elastic Fields of a Layered Elastic Medium under Surface Loading

    Directory of Open Access Journals (Sweden)

    Supakorn Tirapat

    2017-01-01

    Full Text Available This paper presents the analysis of a layered elastic half space under the action of axisymmetric surface loading and the influence of the surface energy effects. The boundary value problems for the bulk and the surface are formulated based on classical linear elasticity and a complete Gurtin-Murdoch constitutive relation. An analytical technique using Love’s representation and the Hankel integral transform is employed to derive an integral-form solution for both displacement and stress fields. An efficient numerical quadrature is then applied to accurately evaluate all involved integrals. Selected numerical results are presented to portray the influence of various parameters on elastic fields. Numerical results indicate that the surface stress displays a significant influence on both displacement and stress fields. It is also found that the layered half space becomes stiffer with the presence of surface stresses. In addition, unlike the classical elasticity solution, size-dependent behavior of elastic fields is noted. The present analytical solutions provide fundamental understanding of the influence of surface energy on layered elastic materials. It can also be used as a benchmark solution for the development of numerical techniques such as FEM and BEM, for analysis of more complex problems involving a layered medium under the influence of surface energy effects.

  1. Influence of inhalation injury on energy expenditure in severely burned children.

    Science.gov (United States)

    Przkora, Rene; Fram, Ricki Y; Herndon, David N; Suman, Oscar E; Mlcak, Ronald P

    2014-12-01

    Determine the effect of inhalation injury on burn-induced hypermetabolism in children. Prospective study comparing hypermetabolism (i.e., resting energy expenditure and oxygen consumption) in burned children with and without inhalation injury during acute hospitalization. Single pediatric burn center. Eighty-six children (1-18 years) with ≥40% total body surface area burns were stratified to two groups: no inhalation injury and inhalation injury. None. Inhalation injury was diagnosed based on bronchoscopic evaluation. At admission, PaO2:FiO2 ratios (an index of respiratory distress) were significantly higher in patients with no inhalation injury than in patients with inhalation injury. No differences were detected in resting energy expenditure or percent of the predicted basal metabolic rate between groups. Additionally, oxygen consumption did not significantly differ between groups. Inhalation injury does not augment the burn-induced hypermetabolic stress response in children, as reflected by resting energy expenditure and oxygen consumption. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  2. Training loads and injury risk in Australian football-differing acute: chronic workload ratios influence match injury risk.

    Science.gov (United States)

    Carey, David L; Blanch, Peter; Ong, Kok-Leong; Crossley, Kay M; Crow, Justin; Morris, Meg E

    2017-08-01

    (1) To investigate whether a daily acute:chronic workload ratio informs injury risk in Australian football players; (2) to identify which combination of workload variable, acute and chronic time window best explains injury likelihood. Workload and injury data were collected from 53 athletes over 2 seasons in a professional Australian football club. Acute:chronic workload ratios were calculated daily for each athlete, and modelled against non-contact injury likelihood using a quadratic relationship. 6 workload variables, 8 acute time windows (2-9 days) and 7 chronic time windows (14-35 days) were considered (336 combinations). Each parameter combination was compared for injury likelihood fit (using R 2 ). The ratio of moderate speed running workload (18-24 km/h) in the previous 3 days (acute time window) compared with the previous 21 days (chronic time window) best explained the injury likelihood in matches (R 2 =0.79) and in the immediate 2 or 5 days following matches (R 2 =0.76-0.82). The 3:21 acute:chronic workload ratio discriminated between high-risk and low-risk athletes (relative risk=1.98-2.43). Using the previous 6 days to calculate the acute workload time window yielded similar results. The choice of acute time window significantly influenced model performance and appeared to reflect the competition and training schedule. Daily workload ratios can inform injury risk in Australian football. Clinicians and conditioning coaches should consider the sport-specific schedule of competition and training when choosing acute and chronic time windows. For Australian football, the ratio of moderate speed running in a 3-day or 6-day acute time window and a 21-day chronic time window best explained injury risk. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. Investigation of surface roughness influence on hyperbolic metamaterial performance

    Directory of Open Access Journals (Sweden)

    S. Kozik

    2014-12-01

    Full Text Available The main goal of this work was to introduce simple model of surface roughness which does not involve objects with complicated shapes and could help to reduce computational costs. We described and proved numerically that the influence of surface roughness at the interfaces in metal-dielectric composite materials could be described by proper selection of refractive index of dielectric layers. Our calculations show that this model works for roughness with RMS value about 1 nm and below.

  4. Surface roughness influences on the behaviour of flow inside microchannels

    Science.gov (United States)

    Farias, M. H.; Castro, C. S.; Garcia, D. A.; Henrique, J. S.

    2018-03-01

    This work discusses influence of the surface roughness on the behavior of liquids flowing inside microchannels. By measuring the flow profile using the micro-PIV technique, the flow of water inside two rectangular microchannels of different wall roughness and in a circular smooth microchannel was studied. Comparisons were made among the experimental results, showing that a metrological approach concerning surface characteristics of microdevices is required to ensure reliability of the measurements for flow analyses in microfluidic processes.

  5. The Mean Curvature of the Influence Surface of Wave Equation With Sources on a Moving Surface

    Science.gov (United States)

    Farassat, F.; Farris, Mark

    1999-01-01

    The mean curvature of the influence surface of the space-time point (x, t) appears in linear supersonic propeller noise theory and in the Kirchhoff formula for a supersonic surface. Both these problems are governed by the linear wave equation with sources on a moving surface. The influence surface is also called the Sigma - surface in the aeroacoustic literature. This surface is the locus, in a frame fixed to the quiescent medium, of all the points of a radiating surface f(x, t) = 0 whose acoustic signals arrive simultaneously to an observer at position x and at the time t. Mathematically, the Sigma- surface is produced by the intersection of the characteristic conoid of the space-time point (x, t) and the moving surface. In this paper, we derive the expression for the local mean curvature of the Sigma - space of the space-time point for a moving rigid or deformable surface f(x, t) = 0. This expression is a complicated function of the geometric and kinematic parameters of the surface f(x, t) = 0. Using the results of this paper, the solution of the governing wave equation of high speed propeller noise radiation as well as the Kirchhoff formula for a supersonic surface can be written as very compact analytic expression.

  6. Influence of starting material particle size on pellet surface roughness.

    Science.gov (United States)

    Sarkar, Srimanta; Ang, Bee Hwee; Liew, Celine Valeria

    2014-02-01

    The purpose of this study was to investigate the effect of pelletization aids, i.e., microcrystalline cellulose (MCC) and cross-linked polyvinyl pyrrolidone (XPVP), and filler, i.e., lactose, particle size on the surface roughness of pellets. Pellets were prepared from powder blends containing pelletization aid/lactose in 1:3 ratio by extrusion-spheronization. Surface roughness of pellets was assessed quantitatively and qualitatively using optical interferometry and scanning electron microscopy, respectively. Both quantitative and qualitative surface studies showed that surface roughness of pellets depended on the particle size of XPVP and lactose used in the formulation. Increase in XPVP or lactose particle size resulted in rougher pellets. Formulations containing MCC produced pellets with smoother surfaces than those containing XPVP. Furthermore, surface roughness of the resultant pellets did not appear to depend on MCC particle size. Starting material particle size was found to be a critical factor for determining the surface roughness of pellets produced by extrusion-spheronization. Smaller particles can pack well with lower peaks and valleys, resulting in pellets with smoother surfaces. Similar surface roughness of pellets containing different MCC grades could be due to the deaggregation of MCC particles into smaller subunits with more or less similar sizes during wet processing. Hence, for starting materials that deaggregate during the wet processing, pellet surface roughness is influenced by the particle size of the material upon deaggregation.

  7. Influence of substrate surfaces on the growth of organic films

    Science.gov (United States)

    Das, A.; Salvan, G.; Kampen, T. U.; Hoyer, W.; Zahn, D. R. T.

    2003-05-01

    3,4,9,10-Perylene tetracarboxylic dianhydride (PTCDA) films were grown by organic molecular beam deposition (OMBD) under UHV conditions on hydrogen terminated Si(1 0 0) and sulphur passivated GaAs(1 0 0) surfaces. X-ray diffraction (XRD), X-ray reflectivity (XRR), Raman spectroscopy, and atomic force microscopy (AFM) are employed to study the influence of substrate surfaces on the structural properties of the organic films. Both phases of PTCDA, α- and β-polymorphs, are found to grow on both substrates. The substrate surfaces determine the preferential growth of α- and β-phases of PTCDA crystals at room temperature.

  8. The influence of training and mental skills preparation on injury incidence and performance in marathon runners.

    Science.gov (United States)

    Hamstra-Wright, Karrie L; Coumbe-Lilley, John E; Kim, Hajwa; McFarland, Jose A; Huxel Bliven, Kellie C

    2013-10-01

    There has been a considerable increase in the number of participants running marathons over the past several years. The 26.2-mile race requires physical and mental stamina to successfully complete it. However, studies have not investigated how running and mental skills preparation influence injury and performance. The purpose of our study was to describe the training and mental skills preparation of a typical group of runners as they began a marathon training program, assess the influence of training and mental skills preparation on injury incidence, and examine how training and mental skills preparation influence marathon performance. Healthy adults (N = 1,957) participating in an 18-week training program for a fall 2011 marathon were recruited for the study. One hundred twenty-five runners enrolled and received 4 surveys: pretraining, 6 weeks, 12 weeks, posttraining. The pretraining survey asked training and mental skills preparation questions. The 6- and 12-week surveys asked about injury incidence. The posttraining survey asked about injury incidence and marathon performance. Tempo runs during training preparation had a significant positive relationship to injury incidence in the 6-week survey (ρ[93] = 0.26, p = 0.01). The runners who reported incorporating tempo and interval runs, running more miles per week, and running more days per week in their training preparation ran significantly faster than did those reporting less tempo and interval runs, miles per week, and days per week (p ≤ 0.05). Mental skills preparation did not influence injury incidence or marathon performance. To prevent injury, and maximize performance, while marathon training, it is important that coaches and runners ensure that a solid foundation of running fitness and experience exists, followed by gradually building volume, and then strategically incorporating runs of various speeds and distances.

  9. Influence of transverse mode on retinal spot size and retinal injury effect: A theoretical analysis on 532-nm laser

    Directory of Open Access Journals (Sweden)

    Jia-Rui Wang

    2014-05-01

    Full Text Available The fundamental transverse mode (TEM00 is preferable for experimental and theoretical study on the laser-induced retinal injury effect, for it can produce the minimal retinal image and establish the most strict laser safety standards. But actually lasers with higher order mode were frequently used in both earlier and recent studies. Generally higher order mode leads to larger retinal spot size and so higher damage threshold, but there are few quantitative analyses on this problem. In this paper, a four-surface schematic eye model is established for human and macaque. The propagation of 532-nm laser in schematic eye is analyzed by the ABCD law of Gaussian optics. It is shown that retinal spot size increases with laser transverse mode order. For relative lower mode order, the retinal spot diameter will not exceed the minimum laser-induced retinal lesion (25 ~ 30 μm in diameter, and so has little effect on retinal damage threshold. While for higher order mode, the larger retinal spot requires more energy to induce injury and so the damage threshold increases. When beam divergence is lowered, the retinal spot size decreases correspondingly, so the effect of mode order can be compensated. The retinal spot size of macaque is slightly smaller than that of human and the ratio between them is independent of mode order. We conclude that the laser mode order has significant influence on retinal spot size but limited influence on the retinal injury effect.

  10. INFLUENCE OF WORKPIECE SURFACE PREPARATION ON THERMAL BARRIER COATING DURABILITY

    Directory of Open Access Journals (Sweden)

    M. A. Petrova

    2014-01-01

    Full Text Available Article deals with the impact of workpiece surface quality on adhesive strength and durability of thermal barrier coating. The result revealed that the roughness of metal layer influences on the adhesion of ceramic coating and depends the thickness of ceramic crystals when using method of Electron beam deposition.

  11. Surface water assessment on the influence of space distribution on ...

    African Journals Online (AJOL)

    In this work, the influence of space distribution on physico-chemical parameters of refinery effluent discharge has been studied, using treated effluent water discharged from the Port Harcourt Refinery Company (PHRC) into the Ekerekana Creek in Okrika as reference. Samples were collected at surface level from the ...

  12. Influence of deposition rate on PL spectrum and surface morphology ...

    Indian Academy of Sciences (India)

    Influence of deposition rate on PL spectrum and surface morphology of ZnO nanolayers deposited on Si (100) substrate. A ZENDEHNAM. ∗. , M MIRZAEE and S MIRI. Thin Film Laboratory, Department of Physics, Faculty of Science, Arak University, Arak 38156-8-8349, Iran. MS received 26 March 2012; revised 5 May 2012.

  13. Influence of rigid boundary on the propagation of torsional surface ...

    Indian Academy of Sciences (India)

    Influence of rigid boundary on the propagation of torsional surface wave in an inhomogeneous layer. Shishir Gupta. ∗. , Rehena Sultana and Santimoy Kundu. Department of Applied Mathematics, Indian School of Mines, Dhanbad 826 004, India. ∗. Corresponding author. e-mail: shishir ism@yahoo.com. The present work ...

  14. Surface sterilization and duration of seed storage influenced ...

    African Journals Online (AJOL)

    The effects of factorial combinations of four storage duration (in days after seed extraction) and surface sterilization with three dilution levels of sodium hypochlorite on seedling emergence and seedling quality of African breadfruit were studied. Storage duration significantly influenced days to seedling emergence, ...

  15. Tribological influence of tool surface roughness within microforming

    DEFF Research Database (Denmark)

    Eriksen, Rasmus Solmer; Weidel, S.; Hansen, Hans Nørgaard

    2010-01-01

    A comparative friction study of tooling dies with a simple internal cylindrical geometry has been performed. The purpose of the experiment consist of studying the influence of the surface characteristics of tooling dies on the frictional behaviour in a micro bulk forming operation. This research ...

  16. Influence of the atomic structure of crystal surfaces on the surface diffusion in medium temperature range

    International Nuclear Information System (INIS)

    Cousty, J.P.

    1981-12-01

    In this work, we have studied the influence of atomic structure of crystal surface on surface self-diffusion in the medium temperature range. Two ways are followed. First, we have measured, using a radiotracer method, the self-diffusion coefficient at 820 K (0.6 T melting) on copper surfaces both the structure and the cleanliness of which were stable during the experiment. We have shown that the interaction between mobile surface defects and steps can be studied through measurements of the anisotropy of surface self diffusion. Second, the behavior of an adatom and a surface vacancy is simulated via a molecular dynamics method, on several surfaces of a Lennard Jones crystal. An inventory of possible migration mechanisms of these surface defects has been drawn between 0.35 and 0.45 Tsub(m). The results obtained with both the methods point out the influence of the surface atomic structure in surface self-diffusion in the medium temperature range [fr

  17. A study of factors that influence the number of visits following traumatic dental injuries.

    Science.gov (United States)

    Keasberry, J; Munyombwe, T; Duggal, M; Day, P F

    2013-06-01

    To investigate in children the factors that influence the number of visits per tooth following traumatic dental injuries (TDI) to the permanent dentition. A retrospective convenient sample of 100 children who had been treated for TDI at Leeds Dental Institute was identified. A multilevel negative binomial regression model was developed to identify factors influencing the number of visits per tooth. Data including age, gender, postcode, number of visits, treatment provided, number of teeth injured, type of periodontal and hard tissue diagnoses, healing modality, root maturity, pulp and tooth survival, and any history of previous or subsequent trauma to same tooth were analysed using SPSS 18.0 and MLWIN. 186 teeth were affected by trauma in 100 patients. Median total number of visits per tooth was six visits with a range of 1-22 visits. The factors that were found to influence number of visits included: distance travelled, hard tissue diagnosis, periodontal injury diagnosis and pulp survival (P < 0.05). A mile increase in distance travelled from home to clinic led to a 1.2% reduction in the number of visits per month (-0.012; SE 0.005), a diagnosis of a severe hard tissue injury was associated with 44% increase (0.362; SE 0.105) compared to no hard tissue injury, a diagnosis of a complicated periodontal injury compared to no periodontal injury was associated with a 30% increase (0.260; SE 0.124), a diagnosis of a uncomplicated periodontal injury compared to no periodontal injury was associated with a 31% increase (0.271; SE 0.124) and a diagnosis and treatment for a non-vital tooth in comparison to a vital tooth led to a 26% increase (0.230; SE 0.080) in the number of visits. There was a significant variation in the number of treatment visits at patient level (0.260; SE 0.048). Complicated hard tissue injuries, complicated and uncomplicated periodontal injuries, diagnosis and treatment for pulp necrosis and the distance between clinic and patient's home all

  18. Summary of: A study of factors that influence the number of visits following traumatic dental injuries.

    Science.gov (United States)

    Smith, Melvyn

    2013-06-01

    To investigate in children the factors that influence the number of visits per tooth following traumatic dental injuries (TDI) to the permanent dentition. A retrospective convenient sample of 100 children who had been treated for TDI at Leeds Dental Institute was identified. A multilevel negative binomial regression model was developed to identify factors influencing the number of visits per tooth. Data including age, gender, postcode, number of visits, treatment provided, number of teeth injured, type of periodontal and hard tissue diagnoses, healing modality, root maturity, pulp and tooth survival, and any history of previous or subsequent trauma to same tooth were analysed using SPSS 18.0 and MLWIN. 186 teeth were affected by trauma in 100 patients. Median total number of visits per tooth was six visits with a range of 1-22 visits. The factors that were found to influence number of visits included: distance travelled, hard tissue diagnosis, periodontal injury diagnosis and pulp survival (P < 0.05). A mile increase in distance travelled from home to clinic led to a 1.2% reduction in the number of visits per month (-0.012; SE 0.005), a diagnosis of a severe hard tissue injury was associated with 44% increase (0.362; SE 0.105) compared to no hard tissue injury, a diagnosis of a complicated periodontal injury compared to no periodontal injury was associated with a 30% increase (0.260; SE 0.124), a diagnosis of a uncomplicated periodontal injury compared to no periodontal injury was associated with a 31% increase (0.271; SE 0.124) and a diagnosis and treatment for a non-vital tooth in comparison to a vital tooth led to a 26% increase (0.230; SE 0.080) in the number of visits. There was a significant variation in the number of treatment visits at patient level (0.260; SE 0.048). CONCLUSION Complicated hard tissue injuries, complicated and uncomplicated periodontal injuries, diagnosis and treatment for pulp necrosis and the distance between clinic and patient's home

  19. Endocrine factors influencing radiation injury to central nervous tissue

    International Nuclear Information System (INIS)

    Aristizabal, S.A.; Boone, M.L.; Laguna, J.F.

    1979-01-01

    Corticosteroids have been shown experimentally to lower the tolerance of various normal tissues (lung, kidney, intestine) to irradiation. Pre-existing hypertension also modified the effect of irradiation on the rat spinal cord and brain. Hypercorticism and hypertension co-exist in patients with Cushing's disease. Although these patients are often approached therapeutically by irradiation, no reports concerning differences in the radiation sensitivity of nervous tissue between normal subjects (non-functioning pituitary adenomas) and those with hormonal imbalance and/or hypertension appear to be available. A comprehensive review of the literature revealed 14 patients with radiation damage to brain or to optic pathways following moderate doses for pituitary adenomas. Seven of the 14 patients (50%) had Cushing's disease. This apparent higher incidence of radiation injury is significant if we consider that less than 5% of all patients receiving irradiation for pituitary adenomas have Cushing's disease

  20. Higher shoe-surface interaction is associated with doubling of lower extremity injury risk in football codes: a systematic review and meta-analysis.

    Science.gov (United States)

    Thomson, Athol; Whiteley, Rod; Bleakley, Chris

    2015-10-01

    Turning or cutting on a planted foot may be an important inciting event for lower limb injury, particularly when shoe-surface traction is high. We systematically reviewed the relationship between shoe-surface interaction and lower-extremity injury in football sports. A systematic literature search of four databases was conducted up to November 2014. Prospective studies investigating the relationship between rotational traction and injury rate were included. Two researchers independently extracted outcome data and assessed the quality of included studies using a modified Downs and Black index. Effect sizes (OR+95% CIs) were calculated using RevMan software. Where possible, data were pooled using the fixed effect model. Three prospective studies were included (4972 male athletes). The methodological quality was generally good with studies meeting 68-89% of the assessment criteria. All studies categorised athletes into low (lowest mean value 15 nm) or high traction groups (highest mean value 74 nm) based on standardised preseason testing. In all cases, injury reporting was undertaken prospectively over approximately three seasons, with verification from a medical practitioner. Injury data focused on: all lower limb injuries, ankle/knee injuries or ACL injury only. There was a clear relationship between rotational traction and injury and the direction and magnitude of effect sizes were consistent across studies. The pooled data from the three studies (OR=2.73, 95% CI 2.13 to 3.15; χ(2)=3.19, df=2, p=0.21; I(2)=36.5%) suggest that the odds of injury are approximately 2.5 times higher when higher levels of rotational traction are present at the shoe-surface interface. Higher levels of rotational traction influence lower limb injury risk in American Football athletes. We conclude that this warrants considerable attention from clinicians and others interested in injury prevention across all football codes. Published by the BMJ Publishing Group Limited. For permission

  1. Influence of surface structure and chemistry on water droplet splashing.

    Science.gov (United States)

    Koch, Kerstin; Grichnik, Roland

    2016-08-06

    Water droplet splashing and aerosolization play a role in human hygiene and health systems as well as in crop culturing. Prevention or reduction of splashing can prevent transmission of diseases between animals and plants and keep technical systems such as pipe or bottling systems free of contamination. This study demonstrates to what extent the surface chemistry and structures influence the water droplet splashing behaviour. Smooth surfaces and structured replicas of Calathea zebrina (Sims) Lindl. leaves were produced. Modification of their wettability was done by coating with hydrophobizing and hydrophilizing agents. Their wetting was characterized by contact angle measurement and splashing behaviour was observed with a high-speed video camera. Hydrophobic and superhydrophilic surfaces generally showed fewer tendencies to splash than hydrophobic ones. Structuring amplified the underlying behaviour of the surface chemistries, increasing hydrophobic surfaces' tendency to splash and decreasing splash on hydrophilic surfaces by quickly transporting water off the impact point by capillary forces. The non-porous surface structures found in C. zebrina could easily be applied to technical products such as plastic foils or mats and coated with hydrophilizing agents to suppress splash in areas of increased hygiene requirements or wherever pooling of liquids is not desirable.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

  2. Influence of minor thermal injury on expression of complement receptor CR3 on human neutrophils.

    Science.gov (United States)

    Nelson, R D; Hasslen, S R; Ahrenholz, D H; Haus, E; Solem, L D

    1986-12-01

    Thermal injury is well known to inhibit functions of the circulating neutrophil related to its role in host defense against infection, but the mechanism(s) of this phenomenon are not fully understood. To gain further clues to these mechanisms, the authors have studied patients with thermal injury in terms of altered expression of neutrophil cell membrane receptors for the opsonic complement-derived ligand C3bi--complement receptor Type 3, or CR3. CR3 expression was selected for study because an increase in the number of receptors on the cell surface can be stimulated by products of complement activation known to accumulate after thermal injury and because of the role of CR3 in phagocytic and adherence functions of the neutrophil. Expression of CR3 was monitored semiquantitatively by flow cytometry with the use of a murine monoclonal antibody (OKM1) specific for an antigen (CD11) associated with this receptor. Patients evaluated were limited in this study to those with minor degrees of thermal injury (second-degree burn involving less than 20% of total body surface area) so that possible confounding effects of major injury and its complications could be eliminated. It was observed that patient neutrophil CR3 becomes significantly up-regulated during the first week, as early as 1 day after injury. The maximum level of expression of CR3 averaged greater than 150% (range, 70-314%) of the respective minimum level observed for each patient. The minimum levels of expression of CR3 on patient neutrophils, reached 11-37 days after injury for 7 of 8 patients, were comparable to the level of expression of CR3 on unstimulated control neutrophils. Such temporal up-regulation of patient neutrophil CR3 suggests the early generation of stimuli of CR3 mobilization in response to thermal injury. Increased numbers of CR3 on patient neutrophils may augment microbicidal function and enhance or inhibit delivery of cells to the burn site.

  3. The influence of soccer shoe design on player performance and injuries.

    Science.gov (United States)

    Hennig, Ewald M

    2011-01-01

    Although soccer is the most popular sport in the world, little research has been published in the field of soccer biomechanics, particularly on the importance of footwear for the game. The traction properties of soccer shoes on natural and artificial turf have been speculated to be responsible for acute and chronic injuries in soccer. This article reviewed the current knowledge on how soccer shoes influence the risk of injuries and how they may serve to improve player performance. Comfort is the highest priority that players want from their shoes, followed by traction and stability. Cleat design and arrangement are important shoe features that allow for fast accelerations and stops, rapid cuts, and turns. Soccer shoe design can influence shooting speed and, even more important for the game of soccer, kicking accuracy. To combine shoe characteristics for injury prevention and better performance will be a challenge for future research on optimizing soccer shoes.

  4. Influence of elevator acceleration induced loading on injury levels

    NARCIS (Netherlands)

    Funai, K.; Schijndel-de Nooij, M. van; Nunen, E. van

    2008-01-01

    The influence on human body of the acceleration caused by the elevator emergency stop has been studied. Experiments were performed with an automotive dummy in an elevator. The study is furthermore based on numerical simulations in MADYMO with an active human model. Kinematics and contact forces of

  5. Influence of building resolution on surface water inundation outputs

    Science.gov (United States)

    Green, Daniel; Yu, Dapeng; Pattison, Ian

    2016-04-01

    Surface water (pluvial) flooding occurs when intense precipitation events overwhelm the drainage capacity of an area and excess water is unable to infiltrate into the ground or drain via natural or artificial drainage channels. In the UK, over 3 million properties are at risk from surface water flooding alone, accounting for approximately one third of all UK flood risk. This risk is predicted to increase due to future climatic changes resulting in an increasing magnitude and frequency of intense precipitation events. Numerical modelling is a well-established method of investigating surface water flood risk, allowing the researcher to gain an understanding of the depth, extent and severity of actual or hypothetical flood scenarios. Although numerical models allow the simulation of surface water inundation in a particular region, the model parameters (e.g. roughness, hydraulic conductivity) and resolution of topographic data have been shown to exert a profound influence on the inundation outputs which often leads to an over- or under-estimation of flood depths and extent without the use of external validation data to calibrate model outputs. Although previous research has demonstrated that model outputs are highly sensitive to Digital Elevation Model (DEM) mesh resolution, with flood inundation over large and complex topographies often requiring mesh resolutions coarser than the structural features (e.g. buildings) present within the study catchment, the specific influence of building resolution on surface flowpaths and connectivity during a surface water flood event has not been investigated. In this study, a LiDAR-derived DEM and OS MasterMap buildings layer of the Loughborough University campus, UK, were rasterized into separate 1m, 5m and 10m resolution layers. These layers were combined to create a series of Digital Surface Models (DSM) with varying, mismatching building and DEM resolutions (e.g. 1m DEM resolution, 10m building resolution, etc.) to understand

  6. Influence of external subglottic air flow on dysphagic tracheotomized patients with severe brain injury- preliminary findings

    DEFF Research Database (Denmark)

    Kothari, Mohit; Bjerrum, Katje; Nielsen, Lars Hedemann

    2017-01-01

    Objective: The aim of this study was to determine if external subglottic air flow (ESAF) influences swallowing frequency in severely dysphagic tracheotomized patients with brain injury. Methods: Ten patients were recruited at the neurological intensive care unit. ESAF intervention was provided th...

  7. Biomarkers of asbestos-induced lung injury: the influence of fiber characteristics and exposure methodology

    Science.gov (United States)

    ATS 2013 Biomarkers of asbestos-induced lung injury: the influence of fiber characteristics and exposure methodology Urmila P Kodavanti, Debora Andrews, Mette C Schaldweiler, Jaime M Cyphert, Darol E Dodd, and Stephen H Gavett NHEERL, U.S. EPA, Research Triangle Park, NC; NIEH...

  8. [The influence of preventive programs on laboral injuries].

    Science.gov (United States)

    López-Rojas, Pablo; Salinas-Tovar, Santiago; Marín-Cotoñieto, Irma Araceli; Méndez-Vargas, María Martha; Quezada-Ortega, Rafael Martin; Martínez-Ramírez, Eva

    2010-01-01

    To evaluate the impact of preventive programs at enterprises affiliated to the Instituto Mexicano del Seguro Social (IMSS) during 2004. Transversal study in 987 enterprises. labor injuries (LI) of temporal disability, permanent disability and death. simple and relative frequencies, rates and Anova application to differences. 64.4% of the enterprises decrease LI (p < 0.04), with a decrement of 2602 LI (16%); the rate of LI per 100 workers declined from 4.19 to 3.60 (p < 0.08), with a decrease of 43,369 disability days (10.93%), which represents $8,456,955 MXP. States with larger decreases were: Queretaro (80%) p < 0.05; Sinaloa (63%) p < 0.05, and Morelos (61%) p < 0.05. Permanent incapacities diminished at 12.1%, p < 0.09; the rate of permanent disability per 1000 workers diminished from 1.37 to 1.32 and death cases increased from 42 to 49. the expenses on consultancy by IMSS was estimated as $9,341,955 MXP. The savings on temporal and permanent incapacities was $33,691,255 MXP with a cost containment of $19,701,310 MXP. Preventive programs are profitable, because they generate benefits to the workers, the IMSS and the enterprises.

  9. Attribution of observed surface humidity changes to human influence.

    Science.gov (United States)

    Willett, Katharine M; Gillett, Nathan P; Jones, Philip D; Thorne, Peter W

    2007-10-11

    Water vapour is the most important contributor to the natural greenhouse effect, and the amount of water vapour in the atmosphere is expected to increase under conditions of greenhouse-gas-induced warming, leading to a significant feedback on anthropogenic climate change. Theoretical and modelling studies predict that relative humidity will remain approximately constant at the global scale as the climate warms, leading to an increase in specific humidity. Although significant increases in surface specific humidity have been identified in several regions, and on the global scale in non-homogenized data, it has not been shown whether these changes are due to natural or human influences on climate. Here we use a new quality-controlled and homogenized gridded observational data set of surface humidity, with output from a coupled climate model, to identify and explore the causes of changes in surface specific humidity over the late twentieth century. We identify a significant global-scale increase in surface specific humidity that is attributable mainly to human influence. Specific humidity is found to have increased in response to rising temperatures, with relative humidity remaining approximately constant. These changes may have important implications, because atmospheric humidity is a key variable in determining the geographical distribution and maximum intensity of precipitation, the potential maximum intensity of tropical cyclones, and human heat stress, and has important effects on the biosphere and surface hydrology.

  10. Influence of surface roughness on the friction property of textured surface

    Directory of Open Access Journals (Sweden)

    Yuankai Zhou

    2015-02-01

    Full Text Available In contrast with dimple textures, surface roughness is a texture at the micro-scale, essentially which will influence the load-bearing capacity of lubricant film. The numerical simulation was carried out to investigate the influence of surface roughness on friction property of textured surface. The lubricant film pressure was obtained using the method of computational fluid dynamics according to geometric model of round dimple, and the renormalization-group k–ε turbulent model was adopted in the computation. The numerical simulation results suggest that there is an optimum dimensionless surface roughness, and near this value, the maximum load-bearing capacity can be achieved. The load-bearing capacity is determined by the surface texture, the surface roughness, and the interaction between them. To get information of friction coefficient, the experiments were conducted. This experiment was used to evaluate the simulation. The experimental results show that for the frequency of 4 and 6 Hz, friction coefficient decreases at first and then increases with decreasing surface roughness, which indicates that there exists the optimum region of surface roughness leading to the best friction reduction effect, and it becomes larger when area fractions increase from 2% to 10%. The experimental results agree well with the simulation results.

  11. The influence of acceleration loading curve characteristics on traumatic brain injury.

    Science.gov (United States)

    Post, Andrew; Blaine Hoshizaki, T; Gilchrist, Michael D; Brien, Susan; Cusimano, Michael D; Marshall, Shawn

    2014-03-21

    To prevent brain trauma, understanding the mechanism of injury is essential. Once the mechanism of brain injury has been identified, prevention technologies could then be developed to aid in their prevention. The incidence of brain injury is linked to how the kinematics of a brain injury event affects the internal structures of the brain. As a result it is essential that an attempt be made to describe how the characteristics of the linear and rotational acceleration influence specific traumatic brain injury lesions. As a result, the purpose of this study was to examine the influence of the characteristics of linear and rotational acceleration pulses and how they account for the variance in predicting the outcome of TBI lesions, namely contusion, subdural hematoma (SDH), subarachnoid hemorrhage (SAH), and epidural hematoma (EDH) using a principal components analysis (PCA). Monorail impacts were conducted which simulated falls which caused the TBI lesions. From these reconstructions, the characteristics of the linear and rotational acceleration were determined and used for a PCA analysis. The results indicated that peak resultant acceleration variables did not account for any of the variance in predicting TBI lesions. The majority of the variance was accounted for by duration of the resultant and component linear and rotational acceleration. In addition, the components of linear and rotational acceleration characteristics on the x, y, and z axes accounted for the majority of the remainder of the variance after duration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Influence of rugby injuries on players' subsequent health and lifestyle: beginning a long term follow up.

    Science.gov (United States)

    Lee, A J; Garraway, W M; Hepburn, W; Laidlaw, R

    2001-02-01

    To describe the current rugby playing status of a cohort of 1,169 men who had previously participated in an epidemiological survey of rugby injuries during the 1993-1994 season, and assess the consequences of rugby injuries sustained. In May 1998, 911 (78%) men completed a questionnaire reporting their current involvement in rugby and the influence that the 324 (71%) injuries they had sustained four years earlier had since had on their health and wellbeing. The most common reasons given by the 390 (43%) ex-players for ceasing to play rugby were family (10%), employment (25%), and an injury sustained while playing rugby (26%), 80% of which were dislocations, strains, and sprains, mainly to the knee (35%), back (14%), and shoulder (9%). A significantly (chi2 test 21.7, df = 1, pnegative effects to employment, family life, and health up to mid-1998 from injuries that occurred during the 1993-1994 season, although the impact on their lifestyle had been substantial in some cases. With the recent increase in the incidence of dislocation, strain, and sprain injuries in rugby football, the findings of this follow up could have a great impact on the game in the future. Although this survey has shown that, so far, only a small proportion of players suffer significant effects of rugby injuries, four years is not long enough to assess the long term effects. This cohort of rugby players need to be followed up for at least a further 20 years to determine whether there is a higher incidence of subsequent degenerative joint disease or other long term sequelae to injuries sustained while playing rugby.

  13. How thirty years of focused safety development has influenced injury outcome in volvo cars.

    Science.gov (United States)

    Isaksson-Hellman, I; Norin, H

    2005-01-01

    ABSTRACT This study points out how thirty years of focused safety development has produced a steady decrease in injury rates in car crashes, strongly influenced by a well-structured process. An important part of this process is the knowledge gained by accident research based on collection of data from real world crashes, and the feedback of this research into development work. Statistical analysis shows that the MAIS 2+ injury rate for the most recent car models has decreased by two-thirds compared to the rate for the oldest car models. Calculation of the effect of specific development steps will be given as examples.

  14. Motion direction influences surface segmentation in stereo transparency.

    Science.gov (United States)

    Goutcher, Ross

    2016-12-01

    To perceive multiple overlapping surfaces in the same location of the visual field (transparency), the visual system must determine which surface elements belong together, and should be integrated, and which should be kept apart. Spatial relations between surfaces, such as depth order, must also be determined. This article details two experiments examining the interaction of motion direction and disparity cues on the perception of depth order and surface segmentation in transparency. In Experiment 1, participants were presented with random-dot stereograms, where transparent planes were defined by differences in motion direction and disparity. Participants reported the direction of motion of the front surface. Results revealed marked effects of motion direction on perceived depth order. These biases interact with disparity in an additive manner, suggesting that the visual system integrates motion direction with other available cues to surface segmentation. This possibility was tested further in Experiment 2. Participants were presented with two intervals: one containing motion and disparity defined transparent planes, the other containing a volume of moving dots. Interplane disparity was varied to find thresholds for the correct identification of the transparent interval. Thresholds depended on motion direction: Thresholds were lower when disparities and directions in the transparency interval matched participants' preferred depth order, compared to conditions where disparity and direction were in conflict. These results suggest that motion direction influences the judgment of depth order even in the presence of other visual cues, and that the assignment of depth order may play an important role in segmentation.

  15. Surface plasmon resonance for detecting clenbuterol: Influence of monolayer structure

    Science.gov (United States)

    Suherman; Morita, Kinichi; Kawaguchi, Toshikazu

    2015-03-01

    Surface plasmon resonance sensor equipped with a fabricated immunosensor chip is used for detecting clenbuterol in this study. Since clenbuterol is a small analyte, indirect competitive inhibition immunoassay is employed. For fabricating the immunosurface, the Au-chip was functionalized by succinimidyl-terminated alkanethiol, and the terminal N-hydroxysuccinimide group of the self-assembled monolayer was either replaced with clenbuterol or blocked with ethanolamine. Scanning tunneling microscope experiments and electrochemical measurements depicted the domain structures of the succinimide group of succinimidyl-terminated propanethiol monolayer. The surface concentration and the orientation of succinimide group was significantly dependent on the concentration of dithiobis(succinimidyl) propionate (DSP) used in fabricating the monolayer. Furthermore, the structure of monolayer significantly influenced both the surface concentration and the orientation of clenbuterol on the sensor surface. Consequently, high coverage and standing-up configuration of clenbuterol showed high affinity for clenbuterol antibody. However, high affinity constant exhibited by the sensor surface was coupled with a low sensitivity. By contrast, lowest concentration of DSP solution (0.1 mM) used in fabricating the immunosurface showed a detection sensitivity of 3 ppt - the highest reported sensitivity for clenbuterol. For regeneration the immunosurface, 0.1 M NaOH was used and the same sensor surface could be reused for performing >100 rapid immunoreaction.

  16. An opaque surface influences the depth from the Pulfrich phenomenon.

    Science.gov (United States)

    Kham, Keetaek

    2004-01-01

    When a pendulum, swinging in a frontoparallel plane, is viewed with a neutral density filter before one eye, the pendulum bob appears to rotate in an elliptical path. This illusion, known as the Pulfrich phenomenon, was used to examine depth cue interaction in a natural environment. An opaque surface was placed behind the pendulum. This intervention put the 'Pulfrich depth' of the pendulum in conflict with the information provided by other depth cues, such as interposition, and observers reported that the 'far' part of the pendulum's Pulfrich trajectory appeared to be flat. This was not the case when the surface was transparent. If the opaque surface was placed farther behind the pendulum's physical path, the far trajectory became increasingly elliptical. These results suggest that the opaque surface influences the pendulum's depth qualitatively and quantitatively. That is, the depth order between the surface and the pendulum is determined by interposition, but the absolute depth of the pendulum's Pulfrich trajectory is constrained by the surface's depth.

  17. The effect of playing surface on the incidence of ACL injuries in National Collegiate Athletic Association American Football.

    Science.gov (United States)

    Dragoo, Jason L; Braun, Hillary J; Harris, Alex H S

    2013-06-01

    Artificial playing surfaces are widely used for American football practice and competition and anterior cruciate ligament (ACL) injuries are common. This study analyzed the National Collegiate Athletic Association (NCAA) Injury Surveillance System (ISS) men's football ACL injury database from 2004-2005 through 2008-2009 to determine the effect of playing surface on ACL injury in NCAA football athletes. This database was reviewed from the 2004-2005 through 2008-2009 seasons using the specific injury code, "Anterior cruciate ligament (ACL) complete tear." The injury rate was computed for competition and practice exposures. Ninety-five percent confidence intervals were calculated using assumptions of a Poisson distribution. Pair-wise, two-sample tests of equality of proportions with a continuity correction were used to estimate the associations of risk factors. There was an incidence rate of 1.73 ACL injuries per 10,000 athlete-exposures (A-Es) (95% CI 1.47-2.0) on artificial playing surfaces compared with a rate of 1.24 per 10,000 A-Es (1.05-1.45, pinjuries occurred more frequently on artificial turf surfaces (44.29%) than on natural grass (36.12%). NCAA football players experience a greater number of ACL injuries when playing on artificial surfaces. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. The influence of adherent surface preparation on bond durability

    International Nuclear Information System (INIS)

    Rider, A.N.; Arnott, D.R.; Olsson-Jacques, C.L.

    1999-01-01

    Full text: One of the major factors limiting the use of adhesive bonding is the problem associated with the production of adhesive joints that can maintain their initial strength over long periods of time in hostile environments. It is well known that the adherent surface preparation method is critical to the formation of a durable adhesive bond. Work presented in this paper focuses on the critical aspects of the surface preparation of aluminium employed for the manufacture of aluminium-epoxy joints. The surface preparation procedure examined is currently employed by the RAAF for repairs requiring metal to adhesive bonding. The influence of each step in the surface preparation on the ultimate bond durability performance of the adhesive joint is examined by a combination of methods. Double cantilever wedge style adhesive joints are loaded in mode 1 opening and then exposed to a humid environment. X-ray photoelectron spectroscopy (XPS) and contact angle measurements of the aluminium adherent before bonding provides information about the adherent surface chemistry. XPS is also employed to analyse the surfaces of the bonded specimens post failure to establish the locus of fracture. This approach provides important information regarding the properties influencing bond durability as well as the bond failure mechanisms. A two step bond degradation model was developed to qualitatively describe the observed bond durability performance and fracture data. The first step involves controlled moisture ingress by stress induced microporosity of the adhesive in the interfacial region. The second step determines the locus of fracture through the relative dominance of one of three competitive processes, viz: oxide degradation, polymer desorption, or polymer degradation. A key element of the model is the control exercised over the interfacial microporosity by the combined interaction of stress and the relative densities of strong and weak linkages at the metal to adhesive interface

  19. Ocular Injuries and Cultural Influences in Afghanistan During 5 Months of Operation Enduring Freedom.

    Science.gov (United States)

    Paz, David A; Thomas, Karin E; Primakov, Denis G

    2018-01-01

    In support of Operation Enduring Freedom, American, North American Treaty Organization (NATO) Coalition, and Afghan forces worked together in training exercises and counterinsurgency operations. While serving at the NATO Role 3 Multinational Medical Unit, Kandahar, Afghanistan, numerous patients with explosive blast injuries (Coalition and Afghan security forces, and insurgents) were treated. A disparity was noted between the ocular injury patterns of US and Coalition forces in comparison with their Afghan counterparts, which were overwhelmingly influenced by the use, or lack thereof, of eye protection. Computed tomography imaging coupled, with a correlative clinical examination, demonstrated the spectrum of ocular injuries that can result from an explosive blast. Patient examination was performed by Navy radiologists and an ophthalmologist. A cultural analysis by was performed to understand why eye protection was not used, even if available to Afghan forces, by the injured patients in hope of bridging the gap between Afghan cultural differences and proper operational risk management of combat forces. 2018.

  20. Influence of surface charge on lysozyme adsorption to ceria nanoparticles

    International Nuclear Information System (INIS)

    Wang Binghui; Wu Peng; Yokel, Robert A.; Grulke, Eric A.

    2012-01-01

    Understanding mechanisms for forming protein coronas on nanomaterial surfaces is essential to designing drug delivery systems and designing and interpreting the results of nanomaterial toxicity tests. The study reports the adsorption behavior of a positively charged protein, lysozyme, on cerium dioxide (ceria) nanoparticles with three different surface charges. Adsorption isotherms were modeled with the Toth and Sips equations. Isotherm loading levels were compared to monolayer coverage estimate for ‘side-on’ and ‘end-on’ lysozyme orientations as well as random packing (jamming) and maximum packing limits. Evaluation of adsorption site energy distributions (generated using the model coefficients) suggested that the negatively charged ceria surface had a very broad site energy distribution and that its surface heterogeneity controls the adsorption process. By contrast, the adsorption of lysozyme on the positively charged nanoparticles appears to be influenced by lateral effects from adsorbed protein species. The results illustrate the importance of nanoparticle surface chemistry to protein adsorption. The modeling and site energy distribution evaluations may be useful for interpreting the formation of protein coronas on nanoparticles.

  1. The foot-surface interaction and its impact on musculoskeletal adaptation and injury risk in the horse.

    Science.gov (United States)

    Parkes, R S V; Witte, T H

    2015-09-01

    The equine limb has evolved for efficient locomotion and high-speed performance, with adaptations of bone, tendon and muscle. However, the system lacks the ability seen in some species to dynamically adapt to different circumstances. The mechanical interaction of the limb and the ground is influenced by internal and external factors including fore-hind mass distribution, lead limb, moving on a curve, shoeing and surface properties. It is unclear which of the components of limb loading have the largest effect on injury and performance but peak load, impact and vibration all play a role. Factors related to the foot-ground interface that limit performance are poorly understood. Peak performance varies vastly between disciplines but at high speeds such as racing and polo, force and grip are key limits to performance. © 2015 EVJ Ltd.

  2. The influence of fabric surface characteristics on satellite bloodstain morphology.

    Science.gov (United States)

    Miles, H F; Morgan, R M; Millington, J E

    2014-07-01

    Bloodstains on fabrics such as clothing, soft furnishings or carpets are often encountered in casework. These stains often have a distinctive morphology that includes satellite stains, thought to be a highly sensitive feature that is a function of surface roughness. This study presents the findings of experimental studies conducted with proxy blood on two fabrics, similar in labeled composition, to assess the influence of fabric type on satellite stain generation. The morphology of proxy blood stains on the two fabric types were found to be statistically distinguishable from one another, with the volume of satellite stains generated being dependent upon the surface roughness of the fabric. These findings provide an initial step that illustrates the viability of providing an empirical evidence base for the interpretation of satellite stains in forensic blood pattern analysis (BPA). Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  3. The Influence of Medical Evaluation Board Status on Symptom Reporting Among Service Members with Traumatic Brain Injury

    Science.gov (United States)

    2017-04-21

    Symptom Reporting Among Service Members with Traumatic Brain Injury presented at/published to 2017 Military Health System Research Symposium (MHSRS); Date...T raumatic brain injury symptom reporting patterns accord ing to Medical EvaluatievJ 6. TITLE OF MATERIAL TO BE PUBLISHED OR PRESENTED: The...influence o f medical evaluation board status on symptom reporting among service members w ith traumatic brain injury 7. FUNDING RECEIVED FOR THIS STUDY? D

  4. Dynamic and reversible surface topography influences cell morphology.

    Science.gov (United States)

    Kiang, Jennifer D; Wen, Jessica H; del Álamo, Juan C; Engler, Adam J

    2013-08-01

    Microscale and nanoscale surface topography changes can influence cell functions, including morphology. Although in vitro responses to static topography are novel, cells in vivo constantly remodel topography. To better understand how cells respond to changes in topography over time, we developed a soft polyacrylamide hydrogel with magnetic nickel microwires randomly oriented in the surface of the material. Varying the magnetic field around the microwires reversibly induced their alignment with the direction of the field, causing the smooth hydrogel surface to develop small wrinkles; changes in surface roughness, ΔRRMS , ranged from 0.05 to 0.70 μm and could be oscillated without hydrogel creep. Vascular smooth muscle cell morphology was assessed when exposed to acute and dynamic topography changes. Area and shape changes occurred when an acute topographical change was imposed for substrates exceeding roughness of 0.2 μm, but longer-term oscillating topography did not produce significant changes in morphology irrespective of wire stiffness. These data imply that cells may be able to use topography changes to transmit signals as they respond immediately to changes in roughness. Copyright © 2013 Wiley Periodicals, Inc.

  5. Influence of surface vacancy defects on the carburisation of Fe 110 surface by carbon monoxide

    International Nuclear Information System (INIS)

    Chakrabarty, Aurab; Bouhali, Othmane; Mousseau, Normand; Becquart, Charlotte S.; El-Mellouhi, Fedwa

    2016-01-01

    Adsorption and dissociation of gaseous carbon monoxide (CO) on metal surfaces is one of the most frequently occurring processes of carburisation, known as primary initiator of metal dusting corrosion. Among the various factors that can significantly influence the carburisation process are the intrinsic surface defects such as single surface vacancies occurring at high concentrations due to their low formation energy. Intuitively, adsorption and dissociation barriers of CO are expected to be lowered in the vicinity of a surface vacancy, due to the strong attractive interaction between the vacancy and the C atom. Here the adsorption energies and dissociation pathways of CO on clean and defective Fe 110 surface are explored by means of density functional theory. Interestingly, we find that the O adatom, resulting from the CO dissociation, is unstable in the electron-deficit neighbourhood of the vacancy due to its large electron affinity, and raises the barrier of the carburisation pathway. Still, a full comparative study between the clean surface and the vacancy-defected surface reveals that the complete process of carburisation, starting from adsorption to subsurface diffusion of C, is more favourable in the vicinity of a vacancy defect.

  6. [Status quo and influencing factors of disabilities caused by injury in Guangdong province].

    Science.gov (United States)

    Dai, Jin-fang; Dong, Xiao-mei; Song, Zhuo-ping; Jiang, Ming-xu; Wang, Chang; Wang, Sheng-yong

    2011-09-01

    To analyze the epidemiology status and risk factors of disabilities caused by injury in Guangdong province. Stratified multi-stage cluster sampling was used to identify 1530 subjects with disabilities (among them, 415 disabilities caused by injury), in the villages or districts in the four regions of Guangzhou, Qingyuan, Zhaoqing and Huizhou in 2010. Subjects were interviewed by trained staff with self-made questionnaires about the status of the disabled, then 415 disabled caused by injury were interviewed about the process of the injury causing disability. The variables in this survey included gender, regions, rural (urban) residences, occupation, age and injury style. The difference of injury were analyzed through χ(2) test, and the influencing factors were explored through classification tree model. The top five causes of disability were road traffic injury, fall, work-related injury, medical accident, scald or burn, accounting for 32.53% (135/415), 21.45% (89/415), 12.77% (53/415), 8.43% (35/415) and 5.06% (21/415), respectively. The proportion of male was higher than female in all disabilities caused by injury (295 male, 117 female, 3 unknown). Female had higher proportion 8.55% (10/117) than male 3.05% (9/295) with the cause of scald or burn (χ(2) = 6.302, P = 0.012), the proportion of rural residents 38.89%(84/216)was also higher than urban residents 25.63% (51/199) in disabilities caused by traffic accident (χ(2) = 43.850, P disabilities caused by the fall (χ(2) = 8.257, P = 0.004). Different age groups and regions had different types of injury causing disability, 53.08% (69/130) traffic accident and 51.92% (27/52) work-injury mainly caused disability in 25 - 44 age group, 85.71% (30/35) medical accident and 76.20% (16/21) scald or burn mainly caused disability in 0 - 14 age group, the injury caused by the fall was 62.50% (5/8) in 65- age group. The proportions of fall in Qingyuan 29.09% (16/55) and Huizhou 28.23% (37/131) were significantly higher than

  7. Unstable Surface Improves Quadriceps:Hamstring Co-contraction for Anterior Cruciate Ligament Injury Prevention Strategies.

    Science.gov (United States)

    Shultz, Rebecca; Silder, Amy; Malone, Maria; Braun, Hillary Jane; Dragoo, Jason Logan

    2015-03-01

    Increasing quadriceps:hamstring muscular co-contraction at the knee may reduce the risk of anterior cruciate ligament (ACL) injury. The purpose of this investigation was to examine muscle activation in the quadriceps and hamstrings and peak kinematics of the knee, hip, and trunk when performing a single-leg drop (SLD) on to a Bosu ball (unstable surface) compared with on to the floor (stable surface). (1) The SLD on an unstable surface would lower the quadriceps to hamstrings electromyographic (EMG) activation ratio (Q:H EMG activation ratio) compared with being performed on the floor. (2) Lower Q:H EMG activation ratio would be caused by a relative increase in hamstring activation, with no significant change in quadriceps activation. Controlled laboratory study. Thirty-nine Division I National Collegiate Athletic Association (NCAA) female athletes performed 3 SLDs per leg onto a Bosu ball and onto the floor. Muscle activity of the vastus lateralis and lateral hamstrings were used to estimate peak quadriceps and hamstring activation, along with the Q:H EMG activation ratio. Kinematic measures at the knee, hip, and trunk were also estimated. Differences between landings were assessed using a 2-level analysis of variance (limb and surface). The maximum Q:H EMG activation ratio was significantly reduced when athletes performed an SLD onto the Bosu ball (20%, P hamstring activity was higher when athletes landed on a Bosu ball (18% higher, P = 0.029) compared with when they landed on the floor. Compared with landing on the floor (a stable surface), landing on a Bosu ball (unstable surface) changed the athlete's co-contraction at the knee and increased hamstring activity. However, landing on a Bosu ball also decreased the athlete's knee flexion, which was an undesired effect. These findings highlight the potential utility of unstable surfaces as a training tool to reduce the risk of ACL injury in female athletes.

  8. Neuroblast Distribution After Cortical Impact is Influenced by White Matter Injury in the Immature Gyrencephalic Brain.

    Directory of Open Access Journals (Sweden)

    Sabrina Taylor

    2016-08-01

    Full Text Available Cortical contusions are a common type of traumatic brain injury (TBI in children. Current knowledge of neuroblast response to cortical injury arises primarily from studies utilizing aspiration or cryoinjury in rodents. In infants and children, cortical impact affects both gray and white matter and any neurogenic response may be complicated by the large expanse of white matter between the subventricular zone (SVZ and the cortex, and the large number of neuroblasts in transit along the major white matter tracts to populate brain regions. Previously, we described an age-dependent increase of neuroblasts in the SVZ in response to cortical impact in the immature gyrencephalic brain. Here, we investigate if neuroblasts target the injury, if white matter injury influences repair efforts, and if postnatal population of brain regions are disrupted. Piglets received a cortical impact to the rostral gyrus cortex or sham surgery at postnatal day (PND 7, BrdU 2 days prior to (PND 5 and 6 or after injury (PND 7 and 8, and brains were collected at PND 14. Injury did not alter the number of neuroblasts in the white matter between the SVZ and the rostral gyrus. In the gray matter of the injury site, neuroblast density was increased in cavitated lesions, and the number of BrdU+ neuroblasts was increased, but comprised less than 1% of all neuroblasts. In the white matter of the injury site, neuroblasts with differentiating morphology were densely arranged along the cavity edge. In a ventral migratory stream, neuroblast density was greater in subjects with a cavitated lesion, indicating that TBI may alter postnatal development of regions supplied by that stream. Cortical impact in the immature gyrencephalic brain produced complicated and variable lesions, increased neuroblast density in cavitated gray matter, resulted in potentially differentiating neuroblasts in the white matter, and may alter the postnatal population of brain regions utilizing a population of

  9. Subspace based adaptive denoising of surface EMG from neurological injury patients

    Science.gov (United States)

    Liu, Jie; Ying, Dongwen; Zev Rymer, William; Zhou, Ping

    2014-10-01

    Objective: After neurological injuries such as spinal cord injury, voluntary surface electromyogram (EMG) signals recorded from affected muscles are often corrupted by interferences, such as spurious involuntary spikes and background noises produced by physiological and extrinsic/accidental origins, imposing difficulties for signal processing. Conventional methods did not well address the problem caused by interferences. It is difficult to mitigate such interferences using conventional methods. The aim of this study was to develop a subspace-based denoising method to suppress involuntary background spikes contaminating voluntary surface EMG recordings. Approach: The Karhunen-Loeve transform was utilized to decompose a noisy signal into a signal subspace and a noise subspace. An optimal estimate of EMG signal is derived from the signal subspace and the noise power. Specifically, this estimator is capable of making a tradeoff between interference reduction and signal distortion. Since the estimator partially relies on the estimate of noise power, an adaptive method was presented to sequentially track the variation of interference power. The proposed method was evaluated using both semi-synthetic and real surface EMG signals. Main results: The experiments confirmed that the proposed method can effectively suppress interferences while keep the distortion of voluntary EMG signal in a low level. The proposed method can greatly facilitate further signal processing, such as onset detection of voluntary muscle activity. Significance: The proposed method can provide a powerful tool for suppressing background spikes and noise contaminating voluntary surface EMG signals of paretic muscles after neurological injuries, which is of great importance for their multi-purpose applications.

  10. Mobilization of regulatory T cells in response to carotid injury does not influence subsequent neointima formation.

    Directory of Open Access Journals (Sweden)

    Amit Saxena

    Full Text Available AIM: T cells have been attributed an important role in modulating repair responses following vascular injury. The aim of this study was to investigate the role of different T cell subsets in this context. METHODS AND RESULTS: A non-obstructive collar was introduced to inflict carotid artery injury in mice and subsequent activation of immune cells in draining lymph nodes and spleen were studied by flow cytometry. Carotid artery injury of wild type mice was associated with mobilization of both Th1 type CD4(+IFNγ(+ and regulatory CD4(+CD25(+FoxP3(+ T cells in draining lymph nodes. Studies using FoxP3-green fluorescent protein (GFP transgenic C57/Bl6 mice demonstrated scattered presence of regulatory T cells in the adventitial tissue of injured arteries as well as a massive emigration of regulatory T cells from the spleen in response to carotid injury. However, deletion of antigen presentation to CD4+ T cells (H2(0 mice, as well as deletion of regulatory T cells (through treatment with blocking anti-CD25 antibodies, did not affect neointima formation. Also deletion of antigen presentation to CD8(+ T cells (Tap1(0 mice was without effect on carotid collar-induced neointima formation. CONCLUSION: The results demonstrate that carotid artery injury is associated with mobilization of regulatory T cells. Depletion of regulatory T cells does not, however, influence the subsequent repair processes leading to the formation of a neointima. The results also demonstrate that lack of CD8(+ T cells does not influence neointima formation in presence of functional CD4(+ T cells and B cells.

  11. Static Air Support Surfaces to Prevent Pressure Injuries: A Multicenter Cohort Study in Belgian Nursing Homes.

    Science.gov (United States)

    Serraes, Brecht; Beeckman, Dimitri

    2016-01-01

    The aim of this study was to investigate the incidence and risk factors for developing pressure injuries (PIs) in patients placed on a static air support surfaces: mattress overlay, heel wedge, and seat cushion. Multicenter cohort study. The sample comprised 176 residents; their mean age was 87 (SD = 6.76) years; their mean Braden Scale score was 14 (SD = 2.54). The study was performed on a convenience sample of 6 nursing homes in Belgium. Data were collected on 23 care units. The primary outcome measure, cumulative PI incidence (category [stage] II-IV) over a 30-day observation period, was calculated. Pressure injury occurrence was defined according to the 2014 European and US National Pressure Injury Advisory panels, Pan Pacific Pressure Injury Alliance classification system. The PI incidence for category (stage) II-IV was 5.1%. Six residents (3.4%) developed a category II PI, and 3 (1.7%) developed a category III PI; no category IV ulcers occurred. No significant risk factors for category II-IV PIs were identified using multivariate logistic regression. Time of sitting in a chair was found to be a risk factor for development of nonblanchable erythema (category I PI) (odds ratio = 21.608; 95% confidence interval [CI], 20.510-22.812; P = .013). The median time to develop a category II-IV PI was 16 days (interquartile range = 2-26). The interrater reliability between the observations of the researcher and nurses on-site was almost perfect (0.86; 95% CI, 0.81-0.91). We found a low incidence of PIs when using a static air overlay mattress for patients at risk in a nursing home population. Static air support surfaces, alongside patient-tailored patient repositioning protocols, should be considered to prevent PIs in this patient population.

  12. The influence of surface curvature on polymer behavior at inorganic surfaces

    Science.gov (United States)

    Nunnery, Grady A.

    Nanoscale surfaces were examined in order to determine the influence of surface curvature on polymer behavior at polymer-ceramic interfaces, as well as the influence of nanoparticles in cellulosic media. Poly(methyl methacrylate) and block copolymers thereof were adsorbed onto porous alumina substrates of various pore sizes in order to determine how polymer and copolymer adsorption behavior at nanoscale surfaces differs from adsorption onto flat surfaces. It was determined that chain density on concave surfaces dramatically decreases as curvature increases in much the same way that it does on convex surfaces (e.g. on the surface of nanoparticles), and physical models are provided to explain this similarity. Diblock copolymer adsorption is observed to vary dramatically with solvent quality and block asymmetry and can be correlated with the surface curvature very similarly to the adsorptive behavior of homopolymers on those same surfaces. The addition of nanoparticles to cellulosic media was investigated as a means to significantly modify the properties of cellulosic composites with minimal additions of nanoparticles. Although cellulose is among the most abundant polymers on earth, its primary uses are limited to bulk commodity goods, such as paper and textiles. This work demonstrates a simple means to control cellulosic fluid viscosity, thereby increasing the versatility of these biopolymers in additional applications with higher value-added potential. The formation of iron-cellulosic nanocomposites by the in-situ thermolysis of metal carbonyls to form metallic nanoparticles was performed and was analyzed by viscometry among other techniques. It was determined that the nanocomposites that were formed exhibited significantly increased viscosity, up to the point of gelation. Additionally, an introduction to the expansive field of nanocomposites is provided, including how and why composite properties change abruptly as filler size approaches the nanoscale. An extensive

  13. Effect of surface spinal stimulation on autonomic nervous system in the patients with spinal cord injury

    Directory of Open Access Journals (Sweden)

    Bhavkiran Kaur

    2014-01-01

    Full Text Available Background: The Autonomic Nervous System (ANS plays a key role in the regulation of many physiological processes, mediated by supraspinal control from centers in the central nervous system. Spinal cord injury (SCI decreases the ability to sympathetically control blood pressure and to regulate body temperature. Bladder dysfunction has been reported as a serious medical complication following SCI. The purpose of study is to find the effect of surface spinal stimulation on autonomic nervous system i.e., bladder function, skin resistance, and skin temperature. Materials and Methods: Five traumatic spinal cord injury subjects were selected for experimental pilot study; surface spinal stimulation for 45 minute period applied to the skin in T11-L2 area, with a carrier frequency of 2500Hz and modulated to beats frequency of 20Hz. Stimulation amplitude was raised to cause sensory stimulation. The pre- and post-stimulation values using the values of urodynamics testing, galvanic skin response, and infra-red thermometer compared in same patients and results were obtained. Results: Result of the present study indicates that four of five subjects demonstrate a decrease in the infused fluid volume, improved bladder sensation, but shown no effect over the bladder capacity. The skin resistance of the right lower limb was increased post-stimulation, but the improvement was not significant, and skin temperature of thigh and foreleg improved significantly. Conclusion: According to our results, surface spinal stimulation was effective to improve non-reflexive bladder, skin resistance and skin temperature, but further research is needed.

  14. [The influence of heat shock proteins on hepatic ischaemia reperfusion injury].

    Science.gov (United States)

    Rostás, Andrea; Sabry, Ahmed; Ghosh, Subhamay

    2016-10-01

    Hepatic ischemia-reperfusion injury as a result of inflow obstruction is a major cause of morbidity and mortality associated with liver pathologies and surgery. Heat shock proteins, a family of stress-inducible proteins involved in maintaining cell homeostasis and regulating the immune system play a major role in liver regeneration. They serve as crucial indicators of ischemia-reperfusion injury in human liver and influence liver function and recovery. The primary objectives of this article are to review the potential role of heat shock proteins as a diagnostic marker for liver diseases and therapeutic target in critical illness. The review will start by focusing on the essentials of heat shock proteins as an endogenous system as it relates to hepatic injury. It will elucidate the influence of heat shock protein-70 on hepatic diseases and ischemia-reperfusion. It will then look at their potential diagnostic role and finally highlights its activities as a possible therapeutic tool. Orv. Hetil., 2016, 157(42), 1659-1666.

  15. [The influence of estradiol on histomorphology of skin flaps with ischemia reperfusion injury].

    Science.gov (United States)

    Jianlong, Wu; Ruixing, Hou; Guangliang, Zhou; Jihui, Ju

    2015-09-01

    To study the influence of estradiol on histomorphology of skin flaps with ischemia reperfusion injury. 48 adult male Wistar rats aged 12-14 weeks old, were randomly divided into control group (group I), ischemia-reperfusion group (group II), saline group (group III), estradiol group (group IV). Superficial epigastric artery axial flap, 3 cm x 6 cm in size, was made in the left lower quadrant abdominal of each rat. Flap model with ischemia-reperfusion injury was established by using the nondestructive micro vascular clamp to clamp the superficial epigastric artery. The general condition of the flap was observed after operation. At 7 days after operation, the survival rate of the flap was detected, the flaps were harvested to receive histology and ultrastructural observation. The neutrophils level of the superficial epigastric vein were tested. 7 days after operation, the survival rate of the flap in group IV was significantly higher than that in group II, III (P organization structure in flap.

  16. Applied electric field enhances DRG neurite growth: influence of stimulation media, surface coating and growth supplements

    Science.gov (United States)

    Wood, Matthew D.; Willits, Rebecca Kuntz

    2009-08-01

    Electrical therapies have been found to aid repair of nerve injuries and have been shown to increase and direct neurite outgrowth during stimulation. This enhanced neural growth existed even after the electric field (EF) or stimulation was removed, but the factors that may influence the enhanced growth, such as stimulation media or surface coating, have not been fully investigated. This study characterized neurite outgrowth and branching under various conditions: EF magnitude and application time, ECM surface coating, medium during EF application and growth supplements. A uniform, low-magnitude EF (24 or 44 V m-1) was applied to dissociated chick embryo dorsal root ganglia seeded on collagen or laminin-coated surfaces. During the growth period, cells were either exposed to NGF or N2, and during stimulation cells were exposed to either unsupplemented media (Ca2+) or PBS (no Ca2+). Parallel controls for each experiment included cells exposed to the chamber with no stimulation and cells remaining outside the chamber. After brief electrical stimulation (10 min), neurite length significantly increased 24 h after application for all conditions studied. Of particular interest, increased stimulation time (10-100 min) further enhanced neurite length on laminin but not on collagen surfaces. Neurite branching was not affected by stimulation on any surface, and no preferential growth of neurites was noted after stimulation. Overall, the results of this report suggest that short-duration electric stimulation is sufficient to enhance neurite length under a variety of conditions. While further data are needed to fully elucidate a mechanism for this increased growth, these data suggest that one focus of those investigations should be the interaction between the growth cone and the substrata.

  17. Surface agents' influence on the flexural strength of bilaminated ceramics

    Directory of Open Access Journals (Sweden)

    Julia Magalhaes Costa Lima

    2013-07-01

    Full Text Available The objective of this study was to evaluate the influence of different surface agents on the flexural strength of a ceramic system. Eighty bar-shaped specimens of zirconia were divided into four groups according to the agent to be used: group Control - to be cleaned with alcohol; group VM9 - application of a fluid layer of porcelain; group Effect Bonder - application of a bonding agent; and group Coloring Liquid - application of coloring liquid. All specimens received the porcelain application by the layering technique and were then subjected to thermocycling. The four-point bending test was performed to calculate the strength values (σ, MPa and the failure modes were classified. ANOVA did not detect significant differences among the groups. The Weibull modulus were 5 (Control, VM9 and Effect Bonder and 6 (Coloring Liquid. The cracking of the porcelain ceramic toward the interface was the predominant failure mode. It was concluded that the surface agents tested had no effect on the flexural strength of the bilaminated ceramic specimens.

  18. The Influence of Slope Breaks on Lava Flow Surface Disruption

    Science.gov (United States)

    Glaze, Lori S.; Baloga, Stephen M.; Fagents, Sarah A.; Wright, Robert

    2014-01-01

    Changes in the underlying slope of a lava flow impart a significant fraction of rotational energy beyond the slope break. The eddies, circulation and vortices caused by this rotational energy can disrupt the flow surface, having a significant impact on heat loss and thus the distance the flow can travel. A basic mechanics model is used to compute the rotational energy caused by a slope change. The gain in rotational energy is deposited into an eddy of radius R whose energy is dissipated as it travels downstream. A model of eddy friction with the ambient lava is used to compute the time-rate of energy dissipation. The key parameter of the dissipation rate is shown to be rho R(sup 2/)mu, where ? is the lava density and mu is the viscosity, which can vary by orders of magnitude for different flows. The potential spatial disruption of the lava flow surface is investigated by introducing steady-state models for the main flow beyond the steepening slope break. One model applies to slow-moving flows with both gravity and pressure as the driving forces. The other model applies to fast-moving, low-viscosity, turbulent flows. These models provide the flow velocity that establishes the downstream transport distance of disrupting eddies before they dissipate. The potential influence of slope breaks is discussed in connection with field studies of lava flows from the 1801 Hualalai and 1823 Keaiwa Kilauea, Hawaii, and 2004 Etna eruptions.

  19. Perceived difficulties using everyday technology after acquired brain injury: influence on activity and participation.

    Science.gov (United States)

    Lindén, Anita; Lexell, Jan; Lund, Maria Larsson

    2010-12-01

    Using everyday technology (ET) is a prerequisite for activities and participation at home and in the community. It is well known that persons with an acquired brain injury (ABI) can have limitations in activities of daily living but our knowledge of their difficulties using ET is not known. Thirty-six persons (27 men and 9 women, mean age 44 years, age range 26-60) with an ABI (2-10 years post injury) were interviewed, using the Everyday Technology Use Questionnaire (ETUQ), about their perceived difficulties using ET and how these difficulties influenced their everyday activities and their possibilities to participate at home and in the community. A majority (78%) of the persons reported difficulties using ET. The most common difficulties were related to the use of telecommunication and computers. Despite these difficulties, a majority still used most objects and services independently. Twenty-six participants (72%) perceived that their difficulties using ET influenced their everyday activities and their possibility to participate at home and in the community. The results indicate that rehabilitation following an ABI should consider whether clients' use of ET influences their activity and participation and adopt interventions accordingly. The results also indicate that difficulties using ET need to be considered in the design of community services to prevent societal barriers.

  20. Modelling the effect of race surface and racehorse limb parameters on in silico fetlock motion and propensity for injury.

    Science.gov (United States)

    Symons, J E; Hawkins, D A; Fyhrie, D P; Upadhyaya, S K; Stover, S M

    2017-09-01

    The metacarpophalangeal joint (fetlock) is the most commonly affected site of racehorse injury, with multiple observed pathologies consistent with extreme fetlock dorsiflexion. Race surface mechanics affect musculoskeletal structure loading and injury risk because surface forces applied to the hoof affect limb motions. Race surface mechanics are a function of controllable factors. Thus, race surface design has the potential to reduce the incidence of musculoskeletal injury through modulation of limb motions. However, the relationship between race surface mechanics and racehorse limb motions is unknown. To determine the effect of changing race surface and racehorse limb model parameters on distal limb motions. Sensitivity analysis of in silico fetlock motion to changes in race surface and racehorse limb parameters using a validated, integrated racehorse and race surface computational model. Fetlock motions were determined during gallop stance from simulations on virtual surfaces with differing average vertical stiffness, upper layer (e.g. cushion) depth and linear stiffness, horizontal friction, tendon and ligament mechanics, as well as fetlock position at heel strike. Upper layer depth produced the greatest change in fetlock motion, with lesser depths yielding greater fetlock dorsiflexion. Lesser fetlock changes were observed for changes in lower layer (e.g. base or pad) mechanics (nonlinear), as well as palmar ligament and tendon stiffness. Horizontal friction and fetlock position contributed less than 1° change in fetlock motion. Simulated fetlock motions are specific to one horse's anatomy reflected in the computational model. Anatomical differences among horses may affect the magnitude of limb flexion, but will likely have similar limb motion responses to varied surface mechanics. Race surface parameters affected by maintenance produced greater changes in fetlock motion than other parameters studied. Simulations can provide evidence to inform race surface

  1. Factors influencing the implementation of anterior cruciate ligament injury prevention strategies by girls soccer coaches.

    Science.gov (United States)

    Joy, Elizabeth A; Taylor, John R; Novak, Melissa A; Chen, Michael; Fink, Barbara P; Porucznik, Christina A

    2013-08-01

    Women are 3 times more likely to injure their anterior cruciate ligament (ACL) while playing soccer than men. ACL injury prevention programs (IPPs) involving stretching and strengthening drills can reduce the incidence of ACL injury when incorporated into routine training. The rate of implementation among coaches is largely unknown. The purpose of this study was to determine the rate of implementation of ACL IPP, to identify factors that influence implementation, and to acquire information to assist in design dissemination and implementation strategies. Study subjects were coaches of woman soccer players aged 11-22 years in Utah (n = 756). Data were gathered using a Web-based survey followed by a qualitative study in which "best practice coaches"-coaches who met criteria for successful implementation of ACL IPP-were interviewed via telephone. A minority of survey respondents, 19.8% (27/136), have implemented ACL IPP. Factors associated with successful implementation include length of coaching experience and presence of additional support staff such as a strength and conditioning coach or athletic trainer. Best practice coaches (14/136) unanimously agreed on the following: (a) there are performance-enhancing benefits of ACL IPP, (b) education on ACL injury prevention should be required for licensure, and (c) dissemination and implementation will require soccer associations to enact policies that require IPPs. In conclusion, a minority of girls soccer coaches have implemented ACL IPP and those that have do so because they believe that prevention improves performance and that soccer organizations should enact policies requiring ACL injury prevention education and implementation. Efforts to implement ACL IPP should be driven by soccer organizations, emphasize performance-enhancing benefits, and engage additional coaching staff.

  2. The Influence of Circadian Variation on Aetiological Markers of Ankle Injury.

    Science.gov (United States)

    Brogden, Chris; Marrin, Kelly; Page, Richard; Greig, Matt

    2018-03-15

    Clinical and functional assessments are performed regularly in sporting environments to screen for performance deficits and injury risk. Circadian rhythms have been demonstrated to affect human performance, however the influence of time of day on a battery of multiple ankle injury risk factors has yet to be established within athletic populations. To investigate the influence of circadian variation on a battery of tests, used to screen for ankle aetiological risk factors. Randomised crossover design. University laboratory. Thirty-three semi-professional soccer players (age 24.9 ± 4.4 years; height 1.77 ± 0.17 m; body mass 75.47 ± 7.98 kg) completed three randomized experimental trials (07:00 h, 12:00 h, 19:00 h) Main Outcome Measures: Trials involved the completion of a standardized test battery comprising Biodex Stability System (BSS), Star Excursion Balance Test (SEBT), isokinetic inversion: eversion ratio, joint position sense, and a drop landing inversion cutting manoeuvre. Repeated measures analysis of variance revealed significantly (P < 0.05) lower values for all BSS indicia; Overall Stability Index (1.10 ± 0.31 a.u), Anterior-Posterior (0.76 ± 0.21 a.u) and Medio-Lateral (0.68 ± 0.23) at 12:00 h when compared to 07:00 h. (1.30 ± 0.45 a.u; 0.96 ± 0.26 a.u; 0.82 ± 0.40 a.u) respectively. However, no significant (P ≥ 0.05) main effects for time of day were reported for any other test. Circadian influence on ankle aetiological risk factors was task dependent, with measures of proprioception, strength and SEBT displaying no circadian variation, indicating no association between time of day and markers of injury risk. However, the BSS displayed improved performance at midday, indicating postural stability tasks requiring unanticipated movements to display a time of day effect and potential increased injury risk. Consequently, time of testing for this task should be standardized to ensure correct interpretations of assessments and/or interventions.

  3. Fog collecting biomimetic surfaces: Influence of microstructure and wettability

    International Nuclear Information System (INIS)

    Azad, M A K; Ellerbrok, D; Barthlott, W; Koch, K

    2015-01-01

    We analyzed the fog collection efficiency of three different sets of samples: replica (with and without microstructures), copper wire (smooth and microgrooved) and polyolefin mesh (hydrophilic, superhydrophilic and hydrophobic). The collection efficiency of the samples was compared in each set separately to investigate the influence of microstructures and/or the wettability of the surfaces on fog collection. Based on the controlled experimental conditions chosen here large differences in the efficiency were found. We found that microstructured plant replica samples collected 2–3 times higher amounts of water than that of unstructured (smooth) samples. Copper wire samples showed similar results. Moreover, microgrooved wires had a faster dripping of water droplets than that of smooth wires. The superhydrophilic mesh tested here was proved more efficient than any other mesh samples with different wettability. The amount of collected fog by superhydrophilic mesh was about 5 times higher than that of hydrophilic (untreated) mesh and was about 2 times higher than that of hydrophobic mesh. (paper)

  4. Connectomic and Surface-Based Morphometric Correlates of Acute Mild Traumatic Brain Injury

    Science.gov (United States)

    Dall'Acqua, Patrizia; Johannes, Sönke; Mica, Ladislav; Simmen, Hans-Peter; Glaab, Richard; Fandino, Javier; Schwendinger, Markus; Meier, Christoph; Ulbrich, Erika J.; Müller, Andreas; Jäncke, Lutz; Hänggi, Jürgen

    2016-01-01

    Reduced integrity of white matter (WM) pathways and subtle anomalies in gray matter (GM) morphology have been hypothesized as mechanisms in mild traumatic brain injury (mTBI). However, findings on structural brain changes in early stages after mTBI are inconsistent and findings related to early symptoms severity are rare. Fifty-one patients were assessed with multimodal neuroimaging and clinical methods exclusively within 7 days following mTBI and compared to 53 controls. Whole-brain connectivity based on diffusion tensor imaging was subjected to network-based statistics, whereas cortical surface area, thickness, and volume based on T1-weighted MRI scans were investigated using surface-based morphometric analysis. Reduced connectivity strength within a subnetwork of 59 edges located predominantly in bilateral frontal lobes was significantly associated with higher levels of self-reported symptoms. In addition, cortical surface area decreases were associated with stronger complaints in five clusters located in bilateral frontal and postcentral cortices, and in the right inferior temporal region. Alterations in WM and GM were localized in similar brain regions and moderately-to-strongly related to each other. Furthermore, the reduction of cortical surface area in the frontal regions was correlated with poorer attentive-executive performance in the mTBI group. Finally, group differences were detected in both the WM and GM, especially when focusing on a subgroup of patients with greater complaints, indicating the importance of classifying mTBI patients according to severity of symptoms. This study provides evidence that mTBI affects not only the integrity of WM networks by means of axonal damage but also the morphology of the cortex during the initial post-injury period. These anomalies might be greater in the acute period than previously believed and the involvement of frontal brain regions was consistently pronounced in both findings. The dysconnected subnetwork

  5. Connectomic and surface-based morphometric correlates of acute mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Patrizia eDall'Acqua

    2016-03-01

    Full Text Available Reduced integrity of white matter (WM pathways and subtle anomalies in gray matter (GM morphology have been hypothesized as mechanisms in mild traumatic brain injury (mTBI. However, findings on structural brain changes in early stages after mTBI are inconsistent and findings related to early symptoms severity are rare.Fifty-one patients were assessed with multimodal neuroimaging and clinical methods exclusively within 7 days following mTBI and compared to 53 controls. Whole-brain connectivity based on diffusion tensor imaging was subjected to network-based statistics, whereas cortical surface area, thickness, and volume based on T1-weighted MRI scans were investigated using surface-based morphometric analysis. Reduced connectivity strength within a subnetwork of 59 edges located predominantly in bilateral frontal lobes was significantly associated with higher levels of self-reported symptoms. In addition, cortical surface area decreases were associated with stronger complaints in five clusters located in bilateral frontal and postcentral cortices, and in the right inferior temporal region. Alterations in WM and GM were localized in similar brain regions and moderately-to-strongly related to each other. Furthermore, the reduction of cortical surface area in the frontal regions was correlated with poorer attentive-executive performance in the mTBI group. Finally, group differences were detected in both the WM and GM, especially when focusing on a subgroup of patients with greater complaints, indicating the importance of classifying mTBI patients according to severity of symptoms. This study provides evidence that mTBI affects not only the integrity of WM networks by means of axonal damage but also the morphology of the cortex during the initial post-injury period. These anomalies might be greater in the acute period than previously believed and the involvement of frontal brain regions was consistently pronounced in both findings. The dysconnected

  6. Influence of Surface Roughness of Stainless steel on Microbial Adhesion

    DEFF Research Database (Denmark)

    Bagge, D.; Hilbert, Lisbeth Rischel; Gram, L.

    2002-01-01

    status of the surface; it is assumed that microorganisms hide in scratches and cracks. It is also believed that the smoother a surface the better. And a surface with a few microorganisms after cleaning and disinfection is more hygienic and has a lower risk for cross contamination than a surface with many...

  7. Influence of spirituality, religion and beliefs in the quality of life of people with spinal cord injury

    OpenAIRE

    Magalhães,Samira Rocha; Carvalho,Zuila Maria de Figueiredo; Andrade,Luciene Miranda de; Pinheiro,Ana Karina Bezerra; Studart,Rita Mônica Borges

    2015-01-01

    The objective was to evaluate the influence of spirituality, religion and personal beliefs in the quality of life of people with spinal cord injury. This is a quantitative and exploratory longitudinal cross-sectional study. Data were collected from 49 people with spinal cord injury in two steps, in the hospital and at home, by applying the Quality of Life assessment tool - Spirituality, Religion and Personal Beliefs (WHOQOL-SRPB). Exploratory analyses were performed by using univariate freque...

  8. [Fractures of the lower extremity in skiing - the influence of ski boots and injury pattern].

    Science.gov (United States)

    Bürkner, A; Simmen, H P

    2008-12-01

    Though the injury patterns of the lower extremities in skiing have changed since 1970, tibial fractures remain daily work of hospitals near ski slopes. A lot of medical studies have analysed the relevance of well adjusted bindings of the common lesions of the knee joint ligaments. However the influence of the flexibility of the ski boot and the injury pattern has been neglected. 49 tibial fractures have been analysed in a hospital near a large ski resort in the alpes. All fractures occurred during alpine skiing. The type of the fracture, according to the AO-classification and the injury pattern have been documented. Also demographic data, ski experience and specification concerning the ski boot have been questioned. The type of the ski boot and the grade of flexibility, have been documented if possible. It has also been recorded whether the binding opened. In contrast to other studies our patients are represented in widely spread age-groups with a large share of elderly and experienced persons. Young or unexperienced sportsmen suffer primarily from fractures of the tibial diaphysis. With increasing skiing experience the injury pattern is widening on the whole leg. 62 % of all fractures are caused by rotation traumas. Compression, dorsal forces and direct collisions are the other causes. In 59 % of all accidents the binding failed to open. There is an increased risk of complex fractures in the proximal or distal epiphysis if the binding has not opened. 23 % of all fractures occurred with rented ski boots. Only 16 % of all ski boots are labelled with a flexibility index. There is no standardized value for the flexibility of ski boots. The trend can be derived that rigid ski boots with a high flexibility index cause above all fractures of the diaphysis. 10 % of all fractures happened to patients wearing "snowblades". These short skis without safety bindings contributed a considerable share to tibial fractures, even though there is no big leverage. Tibial fractures are

  9. Influence of a nanoporous zirconia implant surface of on cell viability of human osteoblasts

    NARCIS (Netherlands)

    Aboushelib, M.N.; Osman, E.; Jansen, I.; Everts, V.; Feilzer, A.J.

    2013-01-01

    Purpose: The dense nonretentive surface of zirconia implants was modified into a nanoporous surface using selective infiltration etching surface treatment. The aim of this study was to investigate the influence of such a nanoporous modified zirconia surface on the attachment of human osteoblasts.

  10. Analysis of the influence of various factors on the course of neurological disorders in children with spinal cord injury

    Directory of Open Access Journals (Sweden)

    Алексей Георгиевич Баиндурашвили

    2015-12-01

    Full Text Available Background. The study of the influence of various factors on the course of recovery of neurological disorders in children with spinal cord injuries is an important and relevant problem. The main causes of thoracic and lumbar injuries of the spine in children are road accidents and catatraumas. Anatomical and physiological features of the spine and spinal cord in children have a significant influence on the nature of spinal cord injury, clinical manifestations of the injury, and method of treatment. The degree of spinal canal deformity at the level of the damaged segment is directly proportional to the severity of the neurological disorder. The time between injury to when surgery is performed will strongly influence the nature and course of recovery of motor functions. Aim. To assess the influence of different factors in pediatric patients with complicated injuries of the spine at the thoracic and thoracolumbar levels on the recovery of neurological disorders. Materials and methods. The analysis of results of the surgical treatment of 36 children (24 boys and 12 girls aged 3-17 years with damage to the spine and spinal cord in the thoracic spine and thoracolumbar junction, accompanied with neurological deficit in the form of central or peripheral paresis and paralysis, was performed. All patients underwent surgical intervention depending on the type and extent of damage. Clinical methods (i.e., detailed neurological examination as well as X-ray, CT, and MRI were used as diagnostic methods. Results. The study revealed that the most severe damage concerning neurological disorders in children with spinal cord injury occurs in the thoracic spine. The extent of neurological changes depends not only on the level of damage to the spinal column but also on the magnitude of spinal canal stenosis. Surgery performed in the first hours of the injury leads to a more rapid and full recovery of the neurological deficit. Conclusion. Therefore, this study found

  11. Study of the influence and molecular mechanism of ticagrelor on cerebral ischemia reperfusion injury in rats

    Directory of Open Access Journals (Sweden)

    Gui-Fa Chen

    2017-06-01

    Full Text Available Objective: To study the influence and molecular mechanism of ticagrelor on cerebral ischemia reperfusion injury in rats. Methods: SD rats were selected as experimental animals and divided into control group, model group, ticagrelor group and clopidogrel group, cerebral ischemic reperfusion injury models were made, then ticagrelor group were given intragastric administration of 150 mg ticagrelor, clopidogrel group were given intragastric administration of 90 mg clopidogrel. 1 week after intervention, the brain water content as well as the contents of oxidative stress molecules and inflammatory factors were measured. Results: Water content in brain, MDA, Ox-LDL, NF-kB, TNF-α, IL-1β and IL-6 contents in brain tissue as well as TNF-α, IL-1β and IL-6 contents in serum of model group were significantly higher than those of control group while SOD, GSH-Px and Prdx6 contents in brain tissue were significantly lower than those of control group; water content in brain, MDA, Ox-LDL, NFkB, TNF-α, IL-1β and IL-6 contents in brain tissue as well as TNF-α, IL-1β and IL-6 contents in serum of ticagrelor group and clopidogrel group were significantly lower than those of model group while SOD, GSH-Px and Prdx6 contents in brain tissue were significantly higher than those of model group; water content in brain, MDA, Ox-LDL, NF-kB, TNF-α, IL-1β and IL-6 contents in brain tissue as well as TNF-α, IL-1β and IL-6 contents in serum of ticagrelor group were significantly lower than those of clopidogrel group while SOD, GSHPx and Prdx6 contents in brain tissue were significantly higher than those of clopidogrel group. Conclusion: Ticagrelor can be more effective in inhibiting oxidative stress response and inflammatory response, and reducing the cerebral ischemia reperfusion injury than clopidogrel.

  12. Influence of midsole hardness of standard cushioned shoes on running-related injury risk.

    Science.gov (United States)

    Theisen, Daniel; Malisoux, Laurent; Genin, Joakim; Delattre, Nicolas; Seil, Romain; Urhausen, Axel

    2014-03-01

    In this double-blind randomised controlled trial, we tested if leisure-time runners using shoes with less compliant midsoles have a higher running-related injury (RRI) risk. We provided 247 runners with standard running shoes having either a soft study shoes (soft-SS) or a hard study shoes (hard-SS) midsole and followed them prospectively for 5 months regarding RRI. All information about sports practice and injuries was uploaded on a dedicated internet platform and checked for consistency and completeness. RRI was defined as any first-time pain sustained during or as a result of running practice and impeding normal running activity for at least 1 day. Cox proportional hazards regressions were used to identify RRI risk factors. The type of study shoes used for running was not associated with RRIs (HR=0.92; 95% CI 0.57 to 1.48). The hard-SS had a 15% greater overall stiffness in the heel region. The two study groups were similar regarding personal and sports participation characteristics, except for years of running experience, which was higher (pshoes does not seem to influence RRI risk.

  13. The influence of anogenital injury on women's willingness to engage with the criminal justice process after rape.

    Science.gov (United States)

    Fisher, Bonnie Sue; Kaplan, Alyssa; Budescu, Mia; Fargo, Jamison; Tiller, Deborah; Everett, Janine; Sommers, Marilyn

    2013-01-01

    Medical-legal-social science research has documented that nongenital and/or anogenital injuries play a significant role throughout the criminal justice system from victims reporting to judges determining the length of a sentence. What remains an open question is whether the documentation of anogenital injury influences women's willingness to engage in the criminal justice system. A sample of women age 21 years and older residing in an urban area were asked about willingness to report to police, file charges, and work with the courts to prosecute after rape. Questions were framed with a qualifying statement about the forensic examination being able to detect injury related to forced sexual intercourse. Results show that women had a high willingness to act if the examination could detect anogenital injury and women with and without a history of forced sexual intercourse had significant differences in their responses to these questions. Implications for health care, criminal justice system, and future research are discussed.

  14. Surface influence on convoy electron emission at low energies

    International Nuclear Information System (INIS)

    Sanchez, E.A.

    1988-01-01

    It is studied the dependence of the production of convoy electrons induced by H + - 60 KeV with surface conditions of Al targets by in situ deposition of Na and O. The conclusion is that convoy electron production increases with the work function of the surface. (A.C.A.S.) [pt

  15. Surface plasma functionalization influences macrophage behavior on carbon nanowalls

    Energy Technology Data Exchange (ETDEWEB)

    Ion, Raluca [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Vizireanu, Sorin [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Stancu, Claudia Elena [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Luculescu, Catalin [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Cimpean, Anisoara, E-mail: anisoara.cimpean@bio.unibuc.ro [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Dinescu, Gheorghe [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania)

    2015-03-01

    The surfaces of carbon nanowall samples as scaffolds for tissue engineering applications were treated with oxygen or nitrogen plasma to improve their wettability and to functionalize their surfaces with different functional groups. X-ray photoelectron spectroscopy and water contact angle results illustrated the effective conversion of the carbon nanowall surfaces from hydrophobic to hydrophilic and the incorporation of various amounts of carbon, oxygen and nitrogen functional groups during the treatments. The early inflammatory responses elicited by un-treated and modified carbon nanowall surfaces were investigated by quantifying tumor necrosis factor-alpha and macrophage inflammatory protein-1 alpha released by attached RAW 264.7 macrophage cells. Scanning electron microscopy and fluorescence studies were employed to investigate the changes in macrophage morphology and adhesive properties, while MTT assay was used to quantify cell proliferation. All samples sustained macrophage adhesion and growth. In addition, nitrogen plasma treatment was more beneficial for cell adhesion in comparison with un-modified carbon nanowall surfaces. Instead, oxygen plasma functionalization led to increased macrophage adhesion and spreading suggesting a more activated phenotype, confirmed by elevated cytokine release. Thus, our findings showed that the chemical surface alterations which occur as a result of plasma treatment, independent of surface wettability, affect macrophage response in vitro. - Highlights: • N{sub 2} and O{sub 2} plasma treatments alter the CNW surface chemistry and wettability. • Cells seeded on CNW scaffolds are viable and metabolically active. • Surface functional groups, independent of surface wettability, affect cell response. • O{sub 2} plasma treatment of CNW leads to a more activated macrophage phenotype.

  16. Influence of groin incision, duration of ischemia, and prostaglandin E1 on ischemia-reperfusion injury of the lower limb

    NARCIS (Netherlands)

    Frässdorf, Jan; Luther, Bernd; Müllenheim, Jost; Otto, Florian; Preckel, Benedikt; Schlack, Wolfgang; Thämer, Volker

    2006-01-01

    OBJECTIVE: The influences of groin incision, duration of ischemia, and the effects of prostaglandin E1 (PGE1) on ischemia-reperfusion (I/R) injury of the hind limb in rabbits were evaluated. DESIGN: A prospective study. SETTING: Laboratory. PARTICIPANTS: In 64 rabbits, bilateral hind limb ischemia

  17. ACL graft re-rupture after double-bundle reconstruction: factors that influence the intra-articular pattern of injury

    NARCIS (Netherlands)

    van Eck, Carola F.; Kropf, Eric J.; Romanowski, James R.; Lesniak, Bryson P.; Tranovich, Michael J.; van Dijk, C. Niek; Fu, Freddie H.

    2011-01-01

    To determine the most common rupture patterns of previously reconstructed DB-ACL cases, seen at the time of revision surgery, and to determine the influence of age, gender, time between the initial ACL reconstruction and re-injury, tunnel angle and etiology of failure. Forty patients who presented

  18. Influence of water on the surface of graphene

    Science.gov (United States)

    Kaya, Yunus; Kalkan, Yalçin; Veenhof, Rob

    2018-02-01

    We have studied how water modifies the surface of graphene and in particular how the surface conductivity of graphene is affected. According to the literature, two types of interactions should be distinguished: physical, where a water molecule remains intact and is located at some distance from the mesh, and chemical, where a water molecule is imbricated in the graphene bond structure. We have developed theoretical models for both types of interactions using the density functional theory (DFT) with the B3LYP hybrid functional combined with the 6-31G(d) basis set. Our calculations show that the surface conductivity of graphene is reduced in the presence of water.

  19. The influence of demographics and working conditions on self-reported injuries among Latino day laborers.

    Science.gov (United States)

    Fernández-Esquer, Maria Eugenia; Fernández-Espada, Natalie; Atkinson, John A; Montano, Cecilia F

    2015-01-01

    The majority of day laborers in the USA are Latinos. They are engaged in high-risk occupations and suffer high occupational injury rates. To describe on-the-job injuries reported by Latino day laborers, explore the extent that demographic and occupational factors predict injuries, and whether summative measures for total job types, job conditions, and personal protective equipment (PPE) predict injuries. A community survey was conducted with 327 participants at 15 corners in Houston, Texas. Hierarchical and multiple logistic regressions explored predictors of occupational injury odds in the last year. Thirty-four percent of respondents reported an occupational injury in the previous year. Education, exposure to loud noises, cold temperatures, vibrating machinery, use of hard hats, total number of job conditions, and total PPE significantly predicted injury odds. Risk for injury among day laborers is not only the product of a specific hazard, but also the result of their exposure to multiple occupational hazards.

  20. Influence of surface treatment on the oxidation behavior of zirconium and zircaloy-4

    International Nuclear Information System (INIS)

    Costa, I.; Ramanathan, L.V.

    1986-01-01

    The influence of fluoride concentration in surface treatment solutions on the oxidation behavior of Zr and Zircaloy-4 in the temperature range 350-760 0 C have been studied by means of thermogravimetric analysis. Two solutions containing different concentrations of hydrofluoric acid have been used for surface treatments, following which surface roughness measurements were also carried out. The influence of fluoride ion concentration on oxidation behavior has been found to be significant at higher temperatures. (Author) [pt

  1. The Influence of Wind on HF Radar Surface Current Forecasts

    National Research Council Canada - National Science Library

    De Almeida, Francisco M

    2008-01-01

    The ability to predict surface currents can have a beneficial impact in several activities, such as Search and Rescue and Oil Spill Response, as well as others more purely scientific, operational or economic...

  2. Properties that influence the specific surface areas of carbon nanotubes and nanofibers.

    Science.gov (United States)

    Birch, M Eileen; Ruda-Eberenz, Toni A; Chai, Ming; Andrews, Ronnee; Hatfield, Randal L

    2013-11-01

    Commercially available carbon nanotubes and nanofibers were analyzed to examine possible relationships between their Brunauer-Emmett-Teller specific surface areas (SSAs) and their physical and chemical properties. Properties found to influence surface area were number of walls/diameter, impurities, and surface functionalization with hydroxyl and carboxyl groups. Characterization by electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and elemental analysis indicates that SSA can provide insight on carbon nanomaterials properties, which can differ vastly depending on synthesis parameters and post-production treatments. In this study, how different properties may influence surface area is discussed. The materials examined have a wide range of surface areas. The measured surface areas differed from product specifications, to varying degrees, and between similar products. Findings emphasize the multiple factors that influence surface area and mark its utility in carbon nanomaterial characterization, a prerequisite to understanding their potential applications and toxicities. Implications for occupational monitoring are discussed.

  3. Multimodal surface-based morphometry reveals diffuse cortical atrophy in traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Sorenson Donna J

    2009-12-01

    Full Text Available Abstract Background Patients with traumatic brain injury (TBI often present with significant cognitive deficits without corresponding evidence of cortical damage on neuroradiological examinations. One explanation for this puzzling observation is that the diffuse cortical abnormalities that characterize TBI are difficult to detect with standard imaging procedures. Here we investigated a patient with severe TBI-related cognitive impairments whose scan was interpreted as normal by a board-certified radiologist in order to determine if quantitative neuroimaging could detect cortical abnormalities not evident with standard neuroimaging procedures. Methods Cortical abnormalities were quantified using multimodal surfaced-based morphometry (MSBM that statistically combined information from high-resolution structural MRI and diffusion tensor imaging (DTI. Normal values of cortical anatomy and cortical and pericortical DTI properties were quantified in a population of 43 healthy control subjects. Corresponding measures from the patient were obtained in two independent imaging sessions. These data were quantified using both the average values for each lobe and the measurements from each point on the cortical surface. The results were statistically analyzed as z-scores from the mean with a p Results The TBI patient showed significant regional abnormalities in cortical thickness, gray matter diffusivity and pericortical white matter integrity that replicated across imaging sessions. Consistent with the patient's impaired performance on neuropsychological tests of executive function, cortical abnormalities were most pronounced in the frontal lobes. Conclusions MSBM is a promising tool for detecting subtle cortical abnormalities with high sensitivity and selectivity. MSBM may be particularly useful in evaluating cortical structure in TBI and other neurological conditions that produce diffuse abnormalities in both cortical structure and tissue properties.

  4. Influence of preparation and football skill level on injury incidence during an amateur football tournament.

    Science.gov (United States)

    Koch, Matthias; Zellner, Johannes; Berner, Arne; Grechenig, Stephan; Krutsch, Volker; Nerlich, Michael; Angele, Peter; Krutsch, Werner

    2016-03-01

    Scientific studies on injury characteristics are rather common in professional football but not in amateur football despite the thousands of amateur football tournaments taking place worldwide each year. The purpose of this study was to evaluate the preparation and injury patterns of players of two different football skill levels who participated in an international amateur football tournament. In a prospective cohort study, an international amateur football tournament of medical doctors in 2011 was analysed with regard to training and warm-up preparation, the level of football played before the tournament and injury data during the tournament by means of standardised injury definitions and data samples for football. Amateur players of registered football clubs had higher training exposure before the tournament (p football players showed a significantly higher overall injury incidence (p injuries (p injuries and complaints was the lower extremities. Orthopaedic and trauma surgeons had the lowest overall injury incidence and anaesthetists the highest (p = 0.049) during the tournament. For the first time, this study presents detailed information on the injury incidence and injury patterns of an amateur football tournament. Less-trained recreational players sustained significantly more injuries than better-trained amateur players, probably due to the lack of sufficient preparation before the tournament. Preventive strategies against overuse and traumatic injuries of recreational football players should start with regular training and warm-up programmes in preparation for a tournament.

  5. Erythroneura lawsoni abundance and feeding injury levels are influenced by foliar nutrient status in intensively managed American sycamore.

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, David, Robert: Aubrey, Doug, Patric; Bentz, Jo-Ann

    2010-01-01

    Abstract 1 Abundance and feeding injury of the leafhopper Erythroneura lawsoni Robinson was measured in an intensively-managed American sycamore Platanus occidentalis L. plantation. Trees were planted in spring 2000 in a randomized complete block design, and received one of three annual treatments: (i) fertilization (120 kg N/ha/year); (ii) irrigation (3.0 cm/week); (iii) fertilization + irrigation; or (iv) control (no treatment). 2 Foliar nutrient concentrations were significantly influenced by the treatments because only sulphur and manganese levels were not statistically greater in trees receiving fertilization. 3 Over 116 000 E. lawsoni were captured on sticky traps during the study. Leafhopper abundance was highest on nonfertilized trees for the majority of the season, and was positively correlated with foliar nutrient concentrations. Significant temporal variation in E. lawsoni abundance occurred, suggesting five discrete generations in South Carolina. 4 Significant temporal variation occurred in E. lawsoni foliar injury levels, with the highest injury ratings occurring in late June and August. Foliar injury was negatively correlated with foliar nutrient content, and higher levels of injury occurred more frequently on nonfertilized trees. 5 The results obtained in the present study indicated that increased E. lawsoni abundance occurred on trees that did not receive fertilization. Nonfertilized trees experienced greater foliar injury, suggesting that lower foliar nutrient status may have led to increased levels of compensatory feeding.

  6. Influence of the carbon fiber surface microstructure on the surface chemistry generated by a thermo-chemical surface treatment

    International Nuclear Information System (INIS)

    Vautard, F.; Ozcan, S.; Paulauskas, F.; Spruiell, J.E.; Meyer, H.; Lance, M.J.

    2012-01-01

    Highlights: ► Continuous thermo-chemical surface treatment used to functionalize different types of carbon fibers. ► Surface density of functional groups directly correlated to the size of the surface microstructure. ► Preferential creation of hydroxyls and carboxylic acids confirmed regardless of the type of carbon fiber. ► Effective surface treatment regardless of the fiber surface microstructure. ► Potential alternative to electro-chemical surface treatment. - Abstract: Carbon fibers made of textile and aerospace grade polyacrylonitrile precursor fibers were surface treated by a continuous gas phase thermochemical treatment. The surface chemistry generated by the surface treatment was characterized by X-ray photoelectron spectroscopy. The surface and the average entire microstructure of the fibers were characterized by Raman spectroscopy and X-ray diffraction, respectively. Depending on the grade of the precursor, the final surface concentration of oxygen was comprised between 14% and 24%, whereas the typical commercial electrochemical surface treatments led to concentrations of around 8% with the same fibers. The final concentration of oxygen was directly correlated to the size of the crystallites which was a function of the grade of the polyacrylonitrile precursor and to the corresponding surface microstructure. The thermochemical surface treatment enabled a better control of the nature of the oxygen-containing functionalities as well. Whatever the grade of the precursor, desired hydroxyl groups and carboxylic acid functionalities were preferably generated, which is observed to be difficult with electrochemical surface treatments.

  7. Influence of Microalgae onto submerged surfaces on Fouling

    Science.gov (United States)

    Kong, M.; Eom, C.; Yoon, B.; Yoon, H.; Kim, B.; Chung, K.

    2012-12-01

    Lots of algae together with organic matter deposited on the submerged surface can be easily observed occurring in the shallower water along the coast. This is mainly because only those organisms with the ability to adapt to the new situations created by man can firmly adhere enough to avoid being washed off. Chemical and microbiological characteristics of the fouling microalgae developed on various surfaces in contact with the seawater were made. The microbial compositions of the microalgae formed on the submerged surfaces were tested for. The quantities of the diverse microalgae in the samples developed on the prohibiting submerged surface were larger when there was no concern about materials for special selection for fouling. To confirm formation of microalgae on adsorbents was done SEM-EDS (Scanning Electron Microscope-Spectrometer) analysis. Microbial identified using optical microscope. In addition to, we quantified attaching microalgae as pass time. Experiment results, ten species which are Nitzshhia sp., Eucampia sp., Coscinodiscus sp., Licmophora sp., Rhizosolenia sp., Cylindrotheca sp., Striateela sp., Thalassionema sp., Guinardia sp., and Helicostomella sp. discovered to reservoir formed biofouling. They showed the important role microbial activity in fouling and corrosion of the surfaces in contact with the any seawater.

  8. Influence of multi-wavelength laser irradiation of enamel and dentin surfaces on surface morphology and permeability

    Science.gov (United States)

    Chang, Nai-Yuan N.; Jew, Jamison; Simon, Jacob C.; Chan, Kenneth H.; Lee, Robert C.; Fried, William A.; Cho, Jinny; Darling, Cynthia L.; Fried, Daniel

    2017-02-01

    UV and IR lasers can be used to specifically target protein, water, and the mineral phase of dental hard tissues to produce varying changes in surface morphology. In this study, we irradiated enamel and dentin surfaces with various combinations of lasers operating at 0.355, 2.94, and 9.4 μm, exposed those surfaces to topical fluoride, and subsequently evaluated the influence of these changes on surface morphology and permeability. Digital microscopy and surface dehydration rate measurements were used to monitor changes in the samples overtime. The surface morphology and permeability (dehydration rate) varied markedly with the different laser treatments on enamel. On dentin, fluoride was most effective in reducing the permeability.

  9. Influence of water on the surface of graphene

    Directory of Open Access Journals (Sweden)

    Kaya Yunus

    2018-01-01

    Full Text Available We have studied how water modifies the surface of graphene and in particular how the surface conductivity of graphene is affected. According to the literature, two types of interactions should be distinguished: physical, where a water molecule remains intact and is located at some distance from the mesh, and chemical, where a water molecule is imbricated in the graphene bond structure. We have developed theoretical models for both types of interactions using the density functional theory (DFT with the B3LYP hybrid functional combined with the 6-31G(d basis set. Our calculations show that the surface conductivity of graphene is reduced in the presence of water.

  10. Influence of polishing on surface roughness following toothbrushing wear of composite resins.

    Science.gov (United States)

    Dalla-Vecchia, Karine Battestin; Taborda, Talita Damas; Stona, Deborah; Pressi, Heloísa; Burnett Júnior, Luiz Henrique; Rodrigues-Junior, Sinval Adalberto

    2017-01-01

    This study aimed to evaluate the influence of different polishing systems on the surface roughness of composite resins following procedures to simulate the effects of toothbrushing over time. Four currently available commercial composites were used to make 128 cylindrical specimens. The specimens were randomly allocated to polishing with a 1-step polisher or 1 of 3 multistep polishers (n = 8 per group). The baseline surface roughness was measured, and the specimens were submitted to 5000, 10,000, and 20,000 brushing cycles to represent toothbrushing throughout 6, 12, and 24 months, respectively. Results showed that surface roughness was influenced by the type of composite and polishing system and was not influenced by the simulated toothbrushing time. However, the surface roughness, as challenged by toothbrushing wear, was affected by the interaction among the composite, the polisher, and the toothbrushing time. The 1-step polisher produced the highest surface roughness and influenced toothbrushing wear resistance of some composites.

  11. Incidence, mechanisms, and severity of match-related collegiate women's soccer injuries on FieldTurf and natural grass surfaces: a 5-year prospective study.

    Science.gov (United States)

    Meyers, Michael C

    2013-10-01

    Numerous injuries have been attributed to playing on artificial turf. Over the past 2 decades, however, newer generations of synthetic turf have been developed to duplicate the playing characteristics of natural grass. Although synthetic turf has been determined to be safer than natural grass in some studies, few long-term studies have been conducted comparing match-related collegiate soccer injuries between the 2 playing surfaces. Collegiate female soccer athletes do not experience any difference in the incidence, mechanisms, and severity of match-related injuries on FieldTurf and on natural grass. Cohort study: Level of evidence, 2. Female soccer athletes from 13 universities were evaluated over 5 competitive seasons for injury incidence, injury category, time of injury, injury time loss, player position, injury mechanism and situation, primary type of injury, injury grade and anatomic location, field location at the time of injury, injury severity, head and lower extremity trauma, cleat design, turf age, and environmental factors. In sum, 797 collegiate games were evaluated for match-related soccer injuries sustained on FieldTurf or natural grass during 5 seasons. Overall, 355 team games (44.5%) were played on FieldTurf versus 442 team games (55.5%) on natural grass. A total of 693 injuries were documented, with 272 (39.2%) occurring during play on FieldTurf and 421 (60.8%) on natural grass. Multivariate analysis per 10 team games indicated a significant playing surface effect: F₂,₆₉₀ = 6.435, P = .002, n-β = .904. A significantly lower total injury incidence rate (IIR) of 7.7 (95% confidence interval [CI], 7.2-8.1) versus 9.5 (95% CI, 9.3-9.7) (P = .0001) and lower rate of substantial injuries, 0.7 (95% CI, 0.5-1.0) versus 1.5 (95% CI, 1.2-1.9) (P = .001), were documented on FieldTurf versus natural grass, respectively. Analyses also indicated significantly less trauma on FieldTurf when comparing injury time loss, player position, injury grade

  12. Cultural Influences on Hepatitis B Surface Antigen Seropositivity in ...

    African Journals Online (AJOL)

    Objective: To determine the role of cultural influences, namely: circumcision, ear piercing and traditional scarification, on HbsAg seropositivity among primary school children in Nnewi. Subjects and Method: Two hundred and thirty seven randomly selected primary school children aged 5-12 years, were screened for HbsAg.

  13. Influence of discharged effluent on the quality of surface water ...

    African Journals Online (AJOL)

    ... higher values of determinants obtained from sampling points close to the wastewater treatment plant and the mine exit channels strongly revealed their influence on the general quality of the stream. Detection of metals such as cadmium and lead above acceptable limits has dire consequences across the food chain.

  14. Influence of shear velocity on frictional characteristics of rock surface

    Indian Academy of Sciences (India)

    Friction at the interface of the rock samples was developed by increasing shear strain at a con- stant rate by applying constant velocity using the tribometer. For shaly sandstone, state para- meters (a and b) played a major role in determining the friction values and roughness of the contact surfaces as well. Higher values of b ...

  15. Influence of shear velocity on frictional characteristics of rock surface

    Indian Academy of Sciences (India)

    Friction at the interface of the rock samples was developed by increasing shear strain at a constant rate by applying constant velocity using the tribometer. For shaly sandstone, state parameters ( and ) played a major role in determining the friction values and roughness of the contact surfaces as well. Higher values of  ...

  16. The influence of lithology on surface water sources | Science ...

    Science.gov (United States)

    Understanding the temporal and spatial variability of surface water sources within a basin is vital to our ability to manage the impacts of climate variability and land cover change. Water stable isotopes can be used as a tool to determine geographic and seasonal sources of water at the basin scale. Previous studies in the Coastal Range of Oregon reported that the variation in the isotopic signatures of surface water does not conform to the commonly observed “rainout effect”, which exhibits a trend of increasing isotopic depletion with rising elevation. The primary purpose of this research is to investigate the mechanisms governing seasonal and spatial variations in the isotopic signature of surface waters within the Marys River Basin, located in the leeward side of the Oregon Coastal Range. Surface water and precipitation samples were collected every 2-3 weeks for isotopic analysis of δ18O and δ2H for one year. Results indicate a significant difference in isotopic signature between watersheds underlain by basalt and sandstone. The degree of separation was the most distinct during the summer when low flows reflect deeper groundwater sources, whereas isotopic signatures during the rainy season (fall and winter) showed a greater degree of similarity between the two lithologies. This indicates that baseflow within streams drained by sandstone versus basalt is being supplied from two distinctly separate water sources. In addition, Marys River flow at the outle

  17. Influence of polymer additive molecular weight on surface and ...

    Indian Academy of Sciences (India)

    The adsorbed layer formed of PEG and chloride ion (Cl−) in the presence of copper ions has a definite role in controlling the deposition mechanism and the coating characteristics. The adsorption behaviour and suppressor nature of PEG with different MW (200–20000) on the physicochemical and the surface morphological ...

  18. Influence of argon plasma treatment on polyethersulphone surface

    Indian Academy of Sciences (India)

    2013-01-09

    Jan 9, 2013 ... waste water treatment from heavy and toxic metals, low-level nuclear waste management and separation of Zr from uranium in their wastes and enzyme immobilization. The aim of this work is to improve superficial hydrophilic properties of PES films by measuring contact angle (surface free energy, SFE), ...

  19. Influence of Ear Surface Area on Heat Tolerance of Composite ...

    African Journals Online (AJOL)

    Low correlation (r = 0.12) was observed between body weight and ear width. There were no correlations between ear width, respiratory rates and pulse rate. However, a residual correlation (r = -0.03) was obtained between ear width and body temperature. Large ear surface area in composite rabbits enhances better ...

  20. Influence of the surface layer characteristics on the regularities of the cutting process

    Directory of Open Access Journals (Sweden)

    Krainev Dmitriy V.

    2017-01-01

    Full Text Available The article considers the influence of the surface layer characteristics on the regularities of the cutting process and the formation of the quality of the surface machined. This effect has been confirmed by the study results of the combined cutting method with advanced plastic deformation (APD. The work estimates the impact of the change in the surface layer properties on the forces and temperature of cutting, stability of the chip formation and quality parameters of the surface machined.

  1. Influence of surface roughness of stainless steel on microbial adhesion and corrosion resistance

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Bagge-Ravn, Dorthe; Kold, John

    2003-01-01

    was evaluated in a commercial disinfectant and in 1 M NaCl. Electropolished and grit 4000 polished steel proved more corrosion resistant as opposed to grit 80 and 120 polished surfaces. In conclusion, the surface finish did not influence bacterial attachment, colonisation, or removal, but is an important...... was not affected by surface roughness (Ra) ranging from grit 4000 polished stainless steel (Ra resistance...... parameter for the corrosion resistance of the surface....

  2. Does soccer cleat design influence the rotational interaction with the playing surface?

    Science.gov (United States)

    Galbusera, Fabio; Tornese, Davide Zai; Anasetti, Federica; Bersini, Simone; Volpi, Piero; La Barbera, Luigi; Villa, Tomaso

    2013-09-01

    Non-contact injuries in soccer players may be related to the interplay between cleat type and playing surface, and bladed shoes were often blamed for non-contact injuries with no research support. The aim of this study was to compare the rotational resistance (stiffness and peak sustainable torque) among three types of soccer cleats (metal studs, molded rubber studs, and bladed) in a controlled laboratory environment. The shoes were tested on both natural and artificial turfs under a compressive preload of 1000 N and with internal and external rotations. The three shoe models showed comparable performances with a good repeatability for each individual test on both playing surfaces. A less stiff behavior was observed for the natural turf. A tendency toward highest peak torque was observed in the studded model on natural surface. The bladed cleats provided peak torque and rotational stiffness comparable to the other models. Studded and bladed cleats did not significantly differ in their interaction with the playing surface. Therefore, soccer shoes with bladed cleats should not be banned in the context of presumed higher risk for non-contact injuries.

  3. Influence of the surface roughness of coated and uncoated papers on the digital print mottle

    Directory of Open Access Journals (Sweden)

    Ivana Jurič

    2014-07-01

    Full Text Available Many factors influence the occurrence of print mottle in prints. In printing process three main components are involved: printing press, substrate and toner. They can be considered as separate components, but in most cases their interaction influences the quality of the print. The goal of this work was to examine the influence of surface roughness of different types of paper (coated and uncoated on print mottle of electrophotographic digital prints. We set up a hypothesis that print mottle will be more apparent on rougher surfaces. In the experimental part we printed four different substrates with different surface properties on electrophotographic printing press. Morphology of the papers surface was analysed using atomic force microscopy (AFM from which surface properties were calculated. For print mottle characterization Gray level co-occurrence matrix (GLCM method was used. Based on the measurements and results we can conclude, contrary to the initial hypothesis, that uncoated papers with rougher surfaces produce smaller print mottle values.

  4. Nanometer polymer surface features: the influence on surface energy, protein adsorption and endothelial cell adhesion

    Science.gov (United States)

    Carpenter, Joseph; Khang, Dongwoo; Webster, Thomas J.

    2008-12-01

    Current small diameter (lactic-co-glycolic acid) (PLGA) surfaces elevated endothelial cell adhesion, proliferation, and extracellular matrix synthesis when compared to nanosmooth surfaces. Nonetheless, these studies failed to address the importance of lateral and vertical surface feature dimensionality coupled with surface free energy; nor did such studies elicit an optimum specific surface feature size for promoting endothelial cell adhesion. In this study, a series of highly ordered nanometer to submicron structured PLGA surfaces of identical chemistry were created using a technique employing polystyrene nanobeads and poly(dimethylsiloxane) (PDMS) molds. Results demonstrated increased endothelial cell adhesion on PLGA surfaces with vertical surface features of size less than 18.87 nm but greater than 0 nm due to increased surface energy and subsequently protein (fibronectin and collagen type IV) adsorption. Furthermore, this study provided evidence that the vertical dimension of nanometer surface features, rather than the lateral dimension, is largely responsible for these increases. In this manner, this study provides key design parameters that may promote vascular graft efficacy.

  5. Influence of surface roughness skewness on rolling contact fatigue life

    Science.gov (United States)

    Akamatsu, Yoshinobu; Tsushima, Noriyuki; Goto, Toshihide; Hibi, Kenji

    1992-10-01

    This paper evaluates the effects of randomly distributed small indentations, or pits, on the lubricating properties when operating under these mixed or boundary lubrication conditions. Rings and needle rollers were textured with randomly distributed small indentations, or pits, for evaluation. Skewness (Sk) was used as a measure of surface finish to characterize the degree to which the material of these modified parts was above the mean line, a positive value, or below the mean line, a negative value. Fatigue life tests were conducted on these rolling elements, whose skewness ranged from -1.2 to -2.0, under mixed or boundary lubrication conditions. Test results showed rolling bearing fatigue life to increase with a decrease in skewness as related to the depth, width, and distribution of the surface indentations, or pits, on the parts.

  6. Surface Analytical Techniques for Microbiologically Influenced Corrosion. A Review

    Science.gov (United States)

    1994-01-01

    natural waters and colonize surfaces to produce biofilms. The biofilms are varied in composition but usually include bacteria, algae, and fungi, in...potential and dissolved oxgen oicitlauios associated ivith ate Anain, sp.ference andd tentation l biofili ptiuder a 61h light/dark regime. Ligtht ...depositing bacteria. and (c) crosssco thilrough pie 1%ed %en natural waters! has re Ited i areas conducive t acteri: should be known TING WAGNER AND RAY ON

  7. Influence of Relative Strength on Functional Independence of Patients With Spinal Cord Injury.

    Science.gov (United States)

    Ribeiro Neto, Frederico; Guanais, Patrícia; Lopes, Guilherme H; Dornelas, Elisa; de Campos Barbetta, Daniela; Coutinho, Alessandra C; Gonçalves, Carlos Wellington; Gomes Costa, Rodrigo Rodrigues

    2017-06-01

    To investigate the influence of strength values and fat mass on functional independence of men with different spinal cord injury (SCI) levels. Cross-sectional study. Hospital network. Men with SCI (N=45). Subjects were assessed in functional independence scales, a 1 repetition maximum (1RM) test, and body composition to detect absolute and relative strength: 1RM divided by body mass (BM) and lean body mass (LBM), respectively. Stepwise multiple regression analysis was used to verify the influence of predictors on functional independence (FIM and Spinal Cord Independence Measure [SCIM] scale and subscales). Receiver operating characteristic curves were created to identify cutoff points of strength for functional independence. The best models for FIM total, FIM mobility, and SCIM total used 1RM as the best predictor (adjusted R 2 =.75, .67, and .65, respectively; PSCIM mobility (adjusted R 2 =.62, Pscore of 69 has a 1RM cutoff point of 50.1kg, and a FIM score of 76 has cutoff points of .73 for 1RM/BM and .91 for 1RM/LBM. A SCIM score of 68 has cutoff points for 1RM, 1RM/BM, and 1RM/LBM of 50.1kg, .77, and .92, respectively. Cutoff points of relative strength should be used as determinant variables for independence, health, or sports performance. This study may contribute to more adequate guidance of physical activity during a rehabilitation program and after discharge. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  8. Influence of sociodemographic factors on the risk of unintentional childhood home injuries

    DEFF Research Database (Denmark)

    Laursen, Bjarne; Nielsen, Jeppe W

    2008-01-01

    children for specific injury mechanisms and involved products. METHODS: Information on injuries in 173 504 children treated at emergency departments was recorded for the period 1998-2003. The information was linked to data including parents' education and income and family type, and the results were...... compared with those for a random sample of the population. RESULTS: A total of 50 561 injuries were analysed. The risk was 1.5 (1.5-1.6) for children with mothers having only primary education compared to tertiary education, and 1.5 (1.4-1.6) for children in families with the lowest vs. the highest income......BACKGROUND: While social differences in childhood injuries are recognized, less is known about how social and demographic differences relate to injury mechanism. The purpose of the study was to reveal how sociodemographic factors affect the incidence of unintentional home injuries in Danish...

  9. The influence of wind speed on surface layer stability and turbulent ...

    Indian Academy of Sciences (India)

    wind regime (Mahrt et al. ... Influence of wind speed on surface layer stability and turbulent fluxes. 1401. Table 1. Specifications of the eddy ..... different soil and vegetation properties and other regional climatic factors. Earlier, it was found that.

  10. Substantial injuries influence ranking position in young elite athletes of athletics, cross-country skiing and orienteering.

    Science.gov (United States)

    von Rosen, P; Heijne, A

    2018-04-01

    The relationship between injury and performance in young athletes is scarcely studied. The aim of this study was therefore to explore the association between injury prevalence and ranking position among adolescent elite athletes. One hundred and sixty-two male and female adolescent elite athletes (age range 15-19), competing in athletics (n = 59), cross-country skiing (n = 66), and orienteering (n = 37), were monitored weekly over 22-47 weeks using a web-based injury questionnaire. Ranking lists were collected. A significant (P = .003) difference was found in the seasonal substantial injury prevalence across the ranked athletes over the season, where the top-ranked (median 3.6%, 25-75th percentiles 0%-14.3%) and middle-ranked athletes (median 2.3%, 25-75th percentiles 0%-10.0%) had a lower substantial injury prevalence compared to the low-ranked athletes (median 11.3%, 25-75th percentiles 2.5%-27.1%), during both preseason (P = .002) and competitive season (P = .031). Athletes who improved their ranking position (51%, n = 51) reported a lower substantial injury prevalence (median 0%, 25-75th percentiles 0%-10.0%) compared to those who decreased (49%, n = 49) their ranking position (md 6.7%, 25-75th percentiles 0%-22.5%). In the top-ranked group, no athlete reported substantial injury more than 40% of all data collection time points compared to 9.6% (n = 5) in the middle-ranked, and 17.3% (n = 9) in the low-ranked group. Our results provide supporting evidence that substantial injuries, such as acute and overuse injuries leading to moderate or severe reductions in training or sports performance, influence ranking position in adolescent elite athletes. The findings are crucial to stakeholders involved in adolescent elite sports and support the value of designing effective preventive interventions for substantial injuries. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Influence of engineered surface on cell directionality and motility

    International Nuclear Information System (INIS)

    Tang, Qing Yuan; Pang, Stella W; Tong, Wing Yin; Shi, Peng; Lam, Yun Wah; Shi, Jue

    2014-01-01

    Control of cell migration is important in numerous key biological processes, and is implicated in pathological conditions such as cancer metastasis and inflammatory diseases. Many previous studies indicated that cell migration could be guided by micropatterns fabricated on cell culture surfaces. In this study, we designed a polydimethylsiloxane cell culture substrate with gratings punctuated by corners and ends, and studied its effects on the behavior of MC3T3-E1 osteoblast cells. MC3T3-E1 cells elongated and aligned with the gratings, and the migration paths of the cells appeared to be guided by the grating pattern. Interestingly, more than 88% of the cells cultured on these patterns were observed to reverse their migration directions at least once during the 16 h examination period. Most of the reversal events occurred at the corners and the ends of the pattern, suggesting these localized topographical features induce an abrupt loss in directional persistence. Moreover, the cell speed was observed to increase temporarily right after each directional reversal. Focal adhesion complexes were more well-established in cells on the angular gratings than on flat surfaces, but the formation of filipodia appeared to be imbalanced at the corners and the ends, possibly leading to the loss of directional persistence. This study describes the first engineered cell culture surface that consistently induces changes in the directional persistence of adherent cells. This will provide an experimental model for the study of this phenomenon and a valuable platform to control the cell motility and directionality, which can be used for cell screening and selection. (paper)

  12. Influence of urban surface properties and rainfall characteristics on surface water flood outputs - insights from a physical modelling environment

    Science.gov (United States)

    Green, Daniel; Pattison, Ian; Yu, Dapeng

    2017-04-01

    Surface water (pluvial) flooding occurs when excess rainfall from intense precipitation events is unable to infiltrate into the subsurface or drain via natural or artificial drainage channels. Surface water flood events pose a major hazard to urban regions across the world, with nearly two thirds of flood damages in the UK being caused by surface water flood events. The perceived risk of surface water flooding appears to have increased in recent years due to several factors, including (i) precipitation increases associated with climatic change and variability; (ii) population growth meaning more people are occupying flood risk areas, and; (iii) land-use changes. Because urban areas are often associated with a high proportion of impermeable land-uses (e.g. tarmacked or paved surfaces and buildings) and a reduced coverage of vegetated, permeable surfaces, urban surface water flood risk during high intensity precipitation events is often exacerbated. To investigate the influence of urbanisation and terrestrial factors on surface water flood outputs, rainfall intensity, catchment slope, permeability, building density/layout scenarios were designed within a novel, 9m2 physical modelling environment. The two-tiered physical model used consists of (i) a low-cost, nozzle-type rainfall simulator component which is able to simulate consistent, uniformly distributed rainfall events of varying duration and intensity, and; (ii) a reconfigurable, modular plot surface. All experiments within the physical modelling environment were subjected to a spatiotemporally uniform 45-minute simulated rainfall event, while terrestrial factors on the physical model plot surface were altered systematically to investigate their hydrological response on modelled outflow and depth profiles. Results from the closed, controlled physical modelling experiments suggest that meteorological factors, such as the duration and intensity of simulated rainfall, and terrestrial factors, such as model slope

  13. Influence of the COL5A1 rs12722 on musculoskeletal injuries in professional soccer players.

    Science.gov (United States)

    Massidda, M; Bachis, V; Corrias, L; Piras, F; Scorcu, M; Calò, C M

    2015-11-01

    The aim of this study was to investigate whether COL5A1 rs12722 polymorphism is associated with musculoskeletal injuries in elite soccer players. Fifty-four male professional soccer players of European origin (25.9±4.3 years) were recruited from a team participating at the Official Italian Professional Championship during four consecutive seasons (2009-2013). The incidence and severity of musculoskeletal injuries and its relationship to COL5A1 rs12722 polymorphism were analyzed. DNA was extracted from buccal swab. The cohort was genotyped for the COL5A1 rs12722 single nucleotide polymorphism (SNP) through PCR and enzyme digestion with BstUI, and musculoskeletal injuries data were collected during the four seasons. Injuries were categorized under 5 degrees of severity based on the number of days' absence, while musculoskeletal injuries incidence was calculated per 1,000 hours of exposure to training and matches ((∑ injuries/∑ exposure hours) x 1000). No significant differences were found among genotypes for incidence of musculoskeletal injuries (P=0.683). Participants with TT genotype (3.71±0.5, N.=4) showed a trend (P=0.193) versus an higher severity of injuries than individuals with TC (2.98±0.8, N.=10) or CC (2.75±0.95, n=4) genotypes. The COL5A1 rs12722 accounted for 44% of severity of injuries (P=0.002). In conclusion, the COL5A1 rs12722 was found to be associated with severity of musculoskeletal injuries but not with incidence of musculoskeletal injuries in top-level soccer players.

  14. Multiplicity of solid organ injury: influence on management and outcomes after blunt abdominal trauma.

    Science.gov (United States)

    Malhotra, Ajai K; Latifi, Rifat; Fabian, Timothy C; Ivatury, Rao R; Dhage, S; Bee, Tiffany K; Miller, Preston R; Croce, Martin A; Yelon, Jay A

    2003-05-01

    The current study was undertaken to examine how concomitant injury to liver and spleen after blunt abdominal trauma affects management and outcomes. This study was a retrospective chart review of all blunt abdominal trauma patients admitted with a diagnosis of liver or spleen injury at two Level I trauma centers over a 4-year period. Presentation, injury grade, management, and outcomes were analyzed. Patients with single-organ injury (liver or spleen) were compared with patients having injury to both organs (liver and spleen). Significance was set at 95% confidence intervals. Of 1,288 patients who met entry criteria, 1,125 had single (spleen, 573; liver, 552) organ injury (group S) and 163 had injury to both organs (group B). Group B patients had significantly higher Injury Severity Score, higher admission lactate, and lower admission systolic blood pressure and base excess. Eighty-one percent (915 of 1,125) of group S and 69% (112 of 163) of group B patients were managed nonoperatively (p < 0.05). Of the nonoperatively managed patients, 5.8% (53 of 915) in group S and 11.6% (13 of 112) in group B failed this form of therapy (p < 0.05). Higher failure rate in group B was because of bleeding from injured solid organ(s), and not non-solid organ related failures. Mortality, intensive care unit and hospital lengths of stay, and transfusion requirements were all significantly higher in group B. Blunt trauma patients with concomitant injury to liver and spleen have higher Injury Severity Score, mortality, lengths of stay, and transfusion requirements. There is a higher failure rate with nonoperative management, and therefore extra vigilance is warranted when choosing this form of therapy in the presence of injury to both organs.

  15. Influence of hydrophobic surface treatment toward performance of air filter

    Science.gov (United States)

    Shahfiq Zulkifli, Nazrul; Zaini Yunos, Muhamad; Ahmad, Azlinnorazia; Harun, Zawati; Akhair, Siti Hajar Mohd; Adibah Raja Ahmad, Raja; Hafeez Azhar, Faiz; Rashid, Abdul Qaiyyum Abd; Ismail, Al Emran

    2017-08-01

    This study investigated the performance of hydrophobic surface treatment by using silica aerogel powder via spray coating techniques. Hydrophobic properties were determined by measuring the level of the contact angle. Meanwhile, performance was evaluated in term of the hydrogen gas flow and humidity rejection. The results are shown by contact angle that the microstructure filter, especially in the upper layer and sub-layer has been changed. The results also show an increase of hydrophobicity due to the increased quantity of silica aerogel powder. Results also showed that the absorption and rejection filter performance filter has increased after the addition of silica aerogel powder. The results showed that with the addition of 5 grams of powder of silica aerogel have the highest result of wetting angle 134.11°. The highest humidity rejection found with 5 grams of powder of silica aerogel.

  16. Factors that influence functional ability in individuals with spinal cord injury: A cross-sectional, observational study

    Directory of Open Access Journals (Sweden)

    Bronwyn M. Hastings

    2015-06-01

    Full Text Available Background: Spinal cord injuries result in devastating impairments that can produce severe functional limitations. However, few documented studies have investigated the levels of function and factors that influence functional ability at discharge from in-patient rehabilitation facilities in Gauteng following such injuries. This necessitated further investigation. Method: Fifty participants were recruited for this cross-sectional, observational study. Participants were recruited from one private and one government spinal rehabilitation unit in Gauteng. A custom-developed questionnaire was used to establish the physical and demographic characteristics of the sample, whilst existing classification scales and measures were used to establish the degree of a lesion and a patient’s associated functional ability. Data were analysed using descriptive statistics. Multiple regression analysis was performed to determine factors that influenced the level of functional ability. Results: Patients achieved an average functional independence score of 64.6 (± 27.6 at discharge according to the Spinal Cord Independence Measure III. Longer stays at rehabilitation facilities were associated with higher scores, whereas scores decreased with increasing patient age. Pressure sores and spasticity affected scores negatively. The type of funding also influenced patients’ scores, with government funding being associated with the best outcome. Both the degree and the level at which the injury occurred could be considered predictive measures that influenced functional independence scores. Conclusion: Most participants were not functionally independent at discharge. Factors such as patient age, length of rehabilitation, presence of pressure sores or spasticity, degree of motor ability and location of the injury should be considered in tailoring rehabilitation therapy.

  17. Influence of surface microstructure and chemistry on osteoinduction and osteoclastogenesis by biphasic calcium phosphate discs.

    NARCIS (Netherlands)

    Davison, N.L.; Su, J.; Yuan, H.; Beucken, J.J.J.P van den; Bruijn, J.D. de; rrere-de Groot, F. Ba

    2015-01-01

    It has been reported that surface microstructural dimensions can influence the osteoinductivity of calcium phosphates (CaPs), and osteoclasts may play a role in this process. We hypothesised that surface structural dimensions of

  18. Influence of surface preparation on the corrosion performance of epoxy coatings for ship ballast tank

    NARCIS (Netherlands)

    Zhang, X.; Buter, S.J.; Ferrari, G.M.

    2011-01-01

    The surface preparation has influence on the adhesion for coatings and consequently affect the corrosion performance of the coatings. The international Maritime Organization (IMO) has adopted a Performance Standard for Protective Coatings (PSPC) on the surface preparation for ballast tanks. However,

  19. Influence of Surface Morphology on the Antimicrobial Effect of Transition Metal Oxides in Polymer Surface.

    Science.gov (United States)

    Oh, Yoo Jin; Hubauer-Brenner, Michael; Hinterdorfer, Peter

    2015-10-01

    In this study, the physical properties of transition metal oxide surfaces were examined using scanning probe microscopic (SPM) techniques for elucidating the antimicrobial activity of molybdenum trioxide (MoO3), tungsten trioxide (WO3), and zinc oxide (ZnO) embedded into the polymers thermoplastic polyurethane (TPU) and polypropylene (PP). We utilized atomic force microscopy (AFM) in the contact imaging mode and its derivative single-pass Kelvin probe force microscopy for investigating samples that were presumably identical in their compositions, but showed different antimicrobial activity in bacterial adhesion tests. Our results revealed that surfaces with larger roughness and higher surface potential variation showed stronger antimicrobial activities compared to smoother and homogeneously charge-distributed surfaces. In addition, capacitance gradient (dC/dZ) measurements were performed to elucidate the antimicrobial activity arising from the different dielectric behavior of the transition metal oxides in this heterogeneous polymer surface. We found that the nano-scale exposure of transition metal oxides on polymer surfaces provided strong antimicrobial effects. Applications arising from our studies will be useful for public and healthcare environments.

  20. [Influence of Ankle Braces on the Prevalence of Ankle Inversion Injuries in the Swiss Volleyball National League A].

    Science.gov (United States)

    Jaggi, J; Kneubühler, S; Rogan, S

    2016-06-01

    Ankle inversion is a common injury among volleyball players. The injury rate during a game is 2.1 times higher than during training. As a result, the preventive use of ankle braces is frequently observed in Swiss volleyball leagues. Studies have shown that ankle braces have a preventive effect on the prevalence of ankle inversion. In Switzerland there has been no investigation into the preventive use of braces and their influence on prevalence. For this reason, the goals of this study are 1) to determine when, why and by whom ankle braces are worn and 2) to evaluate the injury rate of users and non-users of ankle braces. A modified questionnaire was sent to 18 men's and women's teams of the Swiss National League A. The questionnaire included questions about injury rates and the circumstances of ankle inversion injuries. The data were statistically analysed with Microsoft Excel 2012 and SPSS Version 20. The overall response rate was 61 %, allowing data from 181 players to be analysed. 33 % (59 of 181) of the players used an ankle brace. There was a statistically significant difference in the prevalence of ankle inversion between users (12 injured) and non-users (8 injured) (p = 0.006). Wearing an ankle brace during training or during a game made no difference in the prevention of injuries (p = 0.356). More athletes were injured during training (n = 13) than during a game (n = 7). The results of the present study indicate that volleyball players preferably wear ankle braces to prevent injury. More than one third of the players in the study wore an ankle brace, 60 % for primary prevention and 40 % for secondary prevention due to a previous injury. The study shows that significantly more users than non-users of ankle braces were injured. This is contrary to literature. Furthermore it was shown that more injuries occur during training than during a game. This finding results from the fact that ankle braces were rarely worn during training. It is

  1. Influence of Sea Surface Roughness on the Electromagnetic Wave Propagation in the Duct Environment

    OpenAIRE

    Zhao, X.; Huang, S.

    2010-01-01

    This paper deals with a study of the influence of sea surface roughness on the electromagnetic wave propagation in the duct environment. The problem of electromagnetic wave propagation is modeled by using the parabolic equation method. The roughness of the sea surface is computed by modifying the smooth surface Fresnel reflection coefficient to account for the reduction in the specular reflection due to the roughness resulting from sea wind speed. The propagation model is solved by the mixed ...

  2. Influence of sampling points on inspection accuracy of free-form surfaces using coordinate measuring machine

    Science.gov (United States)

    Xie, Mengmin; Chen, Yueping; Zhang, Anshe; Fang, Rui

    2018-03-01

    The inspection accuracy of free-form surfaces is mainly affected by the processing, the number of sampling points, the distribution of sampling points, the measurement equipment and other factors. This paper focuses on the influence of sampling points on inspection accuracy of free-form surfaces, and isoparametric distribution was used in sample point distribution. Different sampling points number was compared on a same surface and a probe, the measurement data were analyzed and the optimal sampling points number was obtained.

  3. Electrical conductivity of conductive carbon blacks: influence of surface chemistry and topology

    International Nuclear Information System (INIS)

    Pantea, Dana; Darmstadt, Hans; Kaliaguine, Serge; Roy, Christian

    2003-01-01

    Conductive carbon blacks from different manufacturers were studied in order to obtain some insight into the relation between their electrical conductivity and their surface properties. The surface chemistry was studied by X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectroscopy (SIMS), whereas the topology of the carbon black surface was investigated using low-pressure nitrogen adsorption. All these techniques yield information on the graphitic character of the surface. In general, the electrical conductivity of the conductive blacks increases with the graphitic character of the surface. For low surface area conductive blacks, the electrical conductivity correlates well with the surface chemistry. In the case of the XPS and SIMS data, this correlation is also valid when other types of carbon blacks such as thermal and furnace blacks are included, confirming the determining influence of the carbon black surface chemistry on the electrical conductivity

  4. The spatial heterogeneity of land surface conditions and its influence on surface fluxes over a typical underlying surface in the Tibetan Plateau

    Science.gov (United States)

    Sun, Genhou; Hu, Zeyong; Wang, Jiemin; Ma, Weiqiang; Gu, Lianglei; Sun, Fanglin; Xie, Zhipeng; Yan, Xiaoqiang

    2018-01-01

    Accurately estimating the surface fluxes of over the heterogeneous land surface in Tibetan Plateau will be helpful to advance the understanding of its influence on regional climate and hydrology. This paper presents a study on the spatial heterogeneity of land surface parameters in terms of the spatial variability and spatial structure of land surface parameters and the influence on surface fluxes over a typical land surface in Tibetan Plateau. The results suggest that the sensible heat fluxes (H) and latent heat fluxes (LE) in the study area in the rain and dry seasons show apparent spatial variabilities due to the spatial heterogeneity in the leaf area index (LAI) and land surface undulations. The relative frequency distribution of H and LE at the spatial resolution of 30 m suggests that the spatial variability of surface fluxes has a close relationship with the spatial heterogeneity of land surface temperature (LST) and LAI. The variogram analyses of LST, LAI, H, and LE in the study area in rain season indicate that the spatial structures of LST and LAI are different and the spatial structures of H and LE are strongly influenced by the spatial structures of LST and LAI in both rain and dry seasons. The optimal pixel sizes for LST, LAI, H, and LE in the study area are 506, 156, 500, and 225 m in the rain season. The optimal pixel sizes for LST, H, and LE in the study area are 165, 165, and 162 m in the dry season. An analysis of the relative frequency distributions (RFDs) of the LST, LAI, H, and LE at different spatial resolutions in the rain and dry seasons reveals that their values at the maximum relative frequency keep stable although their spatial variabilities become weak as the spatial resolution decreases. The averages of LST, LAI, H, and LE of different spatial resolutions of the study area in rain and dry seasons vary within small ranges, suggesting that the influence of spatial resolution on the averaged land surface parameters and surface fluxes in the

  5. The influence of hyperthermia on intracranial pressure, cerebral oximetry and cerebral metabolism in traumatic brain injury

    Science.gov (United States)

    Nyholm, Lena; Howells, Tim; Lewén, Anders; Hillered, Lars; Enblad, Per

    2017-01-01

    Background Hyperthermia is a common secondary insult in traumatic brain injury (TBI). The aim was to evaluate the relationship between hyperthermia and intracranial pressure (ICP), and if intracranial compliance and cerebral blood flow (CBF) pressure autoregulation affected that relationship. The relationships between hyperthermia and cerebral oximetry (BtipO2) and cerebral metabolism were also studied. Methods A computerized multimodality monitoring system was used for data collection at the neurointensive care unit. Demographic and monitoring data (temperature, ICP, blood pressure, microdialysis, BtipO2) were analyzed from 87 consecutive TBI patients. ICP amplitude was used as measure of compliance, and CBF pressure autoregulation status was calculated using collected blood pressure and ICP values. Mixed models and comparison between groups were used. Results The influence of hyperthermia on intracranial dynamics (ICP, brain energy metabolism, and BtipO2) was small, but individual differences were seen. Linear mixed models showed that hyperthermia raises ICP slightly more when temperature increases in the groups with low compliance and impaired CBF pressure autoregulation. There was also a tendency (not statistically significant) for increased BtipO2, and for increased pyruvate and lactate, with higher temperature, while the lactate/pyruvate ratio and glucose were stable. Conclusions The major finding was that the effects of hyperthermia on intracranial dynamics (ICP, brain energy metabolism, and BtipO2) were not extensive in general, but there were exceptional cases. Hyperthermia treatment has many side effects, so it is desirable to identify cases in which hyperthermia is dangerous. Information from multimodality monitoring may be used to guide treatment in individual patients. PMID:28463046

  6. Renal Epithelial Cell Injury Induced by Calcium Oxalate Monohydrate Depends on their Structural Features: Size, Surface, and Crystalline Structure.

    Science.gov (United States)

    Sun, Xin-Yuan; Ouyang, Jian-Ming; Gan, Qiong-Zhi; Liu, Ai-Jie

    2016-11-01

    Urinary crystals in normal and kidney stone patients often differ in crystal sizes and surface structures, but the effects of different crystal properties on renal tubular epithelial cells remain unclear. This study aimed to compare the cytotoxicity of micron/nano-calcium oxalate monohydrate (COM) crystals with sizes of 50 nm, 200 nm, 1 μm, 3 μm, and 10 μm to African green monkey renal epithelial (Vero) cells, to reveal the effect of crystal size and surface structure on cell injury, and to investigate the pathological mechanism of calcium oxalate kidney stones. Cell viability, cellular biochemical parameters, and internalized crystal amount in Vero cells were closely associated with the size of COM crystals. At the same concentration (200 μg/mL), COM-1 μm induced the most serious injury to Vero cells and caused the most significant change to cellular biochemical parameters, which were related to the specific porous structure and highest internalized amount in Vero cells. By contrast, COM-50 nm and COM-200 nm crystals lost their small size effect because of serious aggregation and weakened their toxicity to cells. COM-3 μm and COM-10 μm crystals were too large for cells to completely internalize; these crystals also exhibited a low specific surface area and thus weakened their toxicity. The excessive expression of intracellular ROS and reduction of the free-radical scavenger SOD were the main reasons for cell injury and eventually caused necrotic cell death. Crystal size, surface structure, aggregation, and internalization amount were closely related to the cytotoxicity of COM crystals.

  7. Influence of graphite and serpentine minerals along landslide failure surfaces

    Science.gov (United States)

    Alberti, Stefano; Battista Crosta, Giovanni; Wang, Gonghui; Dattola, Giuseppe; Bertolo, Davide

    2017-04-01

    Landslides and deep-seated gravitational slope deformation (DSGSD) often are concentrated in sedimentary and metasedimentary rocks (e.g. Ambrosi and Crosta, 2006) and in carbonaceous materials (CM), where weaker slip surfaces can be generated more easily, with a behaviour similar to that of fault zone (e.g. Zulauf et al., 1990; Craw, 2002; Oohashi et al., 2011, Nakamura et al., 2015). Among the carbonaceous minerals, graphite (grouped with other silicate sheet minerals) acts as a "solid lubrificant" and plays a key role on frictional properties of the slip surface (Yamasaki et al., 2015). These minerals have one key characteristic in common: the presence of weak bonding along (001) planes. Graphite also has one of the weakest bonding in the crystal structure, and it is characterized by a markedly low coefficient of friction (ca 0.1). A similar behaviour is found in serpentine minerals series and chlorite. We performed these tests on different samples derived from Mont de La Saxe landslide and Chervaz landslide. The first one is located in the upper Aosta Valley, the second in the central part of the Aosta Valley. Both these landslides are characterized by metasedimentary sequences. The undisturbed samples derived by core recovery surveys. We performed a petrographic characterization by XRD (X-Ray Diffraction), XRF (X-Ray Refraction) and SEM (Scansion Electron Microscope) with microprobe in addition to laboratory tests on samples from shear zones. Along these shear zones grains are crushed, their size and shapes are changed and these changes necessarily affect pore-water pressure due to volume change in the shear zone. We performed tests using a dynamic-loading ring-shear apparatus (DPRI-5, Sassa et al., 1997). This apparatus allows to simulate the entire process of failure, from initial static or dynamic loading, through shear failure, pore-pressure changes and possible liquefaction, to large-displacement, steady-state shear movement. It is also possible to

  8. Atmospheric teleconnection influence on North American land surface phenology

    Science.gov (United States)

    Dannenberg, Matthew P.; Wise, Erika K.; Janko, Mark; Hwang, Taehee; Kolby Smith, W.

    2018-03-01

    Short-term forecasts of vegetation activity are currently not well constrained due largely to our lack of understanding of coupled climate-vegetation dynamics mediated by complex interactions between atmospheric teleconnection patterns. Using ecoregion-scale estimates of North American vegetation activity inferred from remote sensing (1982-2015), we examined seasonal and spatial relationships between land surface phenology and the atmospheric components of five teleconnection patterns over the tropical Pacific, north Pacific, and north Atlantic. Using a set of regression experiments, we also tested for interactions among these teleconnection patterns and assessed predictability of vegetation activity solely based on knowledge of atmospheric teleconnection indices. Autumn-to-winter composites of the Southern Oscillation Index (SOI) were strongly correlated with start of growing season timing, especially in the Pacific Northwest. The two leading modes of north Pacific variability (the Pacific-North American, PNA, and West Pacific patterns) were significantly correlated with start of growing season timing across much of southern Canada and the upper Great Lakes. Regression models based on these Pacific teleconnections were skillful predictors of spring phenology across an east-west swath of temperate and boreal North America, between 40°N-60°N. While the North Atlantic Oscillation (NAO) was not strongly correlated with start of growing season timing on its own, we found compelling evidence of widespread NAO-SOI and NAO-PNA interaction effects. These results suggest that knowledge of atmospheric conditions over the Pacific and Atlantic Oceans increases the predictability of North American spring phenology. A more robust consideration of the complexity of the atmospheric circulation system, including interactions across multiple ocean basins, is an important step towards accurate forecasts of vegetation activity.

  9. The influence of spherical cavity surface charge distribution on the sequence of partial discharge events

    Energy Technology Data Exchange (ETDEWEB)

    Illias, Hazlee A [Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Chen, George; Lewin, Paul L, E-mail: h.illias@um.edu.my [Tony Davies High Voltage Laboratory, School of Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ (United Kingdom)

    2011-06-22

    In this work, a model representing partial discharge (PD) behaviour of a spherical cavity within a homogeneous dielectric material has been developed to study the influence of cavity surface charge distribution on the electric field distribution in both the cavity and the material itself. The charge accumulation on the cavity surface after a PD event and charge movement along the cavity wall under the influence of electric field magnitude and direction has been found to affect the electric field distribution in the whole cavity and in the material. This in turn affects the likelihood of any subsequent PD activity in the cavity and the whole sequence of PD events. The model parameters influencing cavity surface charge distribution can be readily identified; they are the cavity surface conductivity, the inception field and the extinction field. Comparison of measurement and simulation results has been undertaken to validate the model.

  10. The influence of machining condition and cutting tool wear on surface roughness of AISI 4340 steel

    Science.gov (United States)

    Natasha, A. R.; Ghani, J. A.; Che Haron, C. H.; Syarif, J.

    2018-01-01

    Sustainable machining by using cryogenic coolant as the cutting fluid has been proven to enhance some machining outputs. The main objective of the current work was to investigate the influence of machining conditions; dry and cryogenic, as well as the cutting tool wear on the machined surface roughness of AISI 4340 steel. The experimental tests were performed using chemical vapor deposition (CVD) coated carbide inserts. The value of machined surface roughness were measured at 3 cutting intervals; beginning, middle, and end of the cutting based on the readings of the tool flank wear. The results revealed that cryogenic turning had the greatest influence on surface roughness when machined at lower cutting speed and higher feed rate. Meanwhile, the cutting tool wear was also found to influence the surface roughness, either improving it or deteriorating it, based on the severity and the mechanism of the flank wear.

  11. A case-crossover study of transient risk factors influence on occupational injuries

    DEFF Research Database (Denmark)

    Oesterlund, Anna H; Lander, Flemming; Lauritsen, Jens

    2016-01-01

    , but so far no relevant research has been conducted in Europe. METHOD: Case-crossover studies of occupational injuries were collected from PubMed and Embase and read through. Previous experiences concerning method, exposure and outcome, time-related measurements and construction of the questionnaire were...... technique, change in working surroundings, using a phone, disagreement, feeling ill, being distracted and using malfunctioning machinery/tools or work material. Exposure time 'just before the injury' will be compared with two control periods, 'previous day at the same time of the injury' (pair match...

  12. The influence of spine surgeons' experience on the classification and intraobserver reliability of the novel AOSpine thoracolumbar spine injury classification system : an international study

    NARCIS (Netherlands)

    Sadiqi, Said; Oner, F. Cumhur; Dvorak, Marcel F.; Aarabi, Bizhan; Schroeder, Gregory D.; Vaccaro, Alexander R.

    2015-01-01

    Study Design. International validation study. Objective. To investigate the influence of the spine surgeons' level of experience on the intraobserver reliability of the novel AOSpine Thoracolumbar Spine Injury Classification system, and the appropriate classification according to this system.

  13. Influence of snow cover changes on surface radiation and heat balance based on the WRF model

    Science.gov (United States)

    Yu, Lingxue; Liu, Tingxiang; Bu, Kun; Yang, Jiuchun; Chang, Liping; Zhang, Shuwen

    2017-10-01

    The snow cover extent in mid-high latitude areas of the Northern Hemisphere has significantly declined corresponding to the global warming, especially since the 1970s. Snow-climate feedbacks play a critical role in regulating the global radiation balance and influencing surface heat flux exchange. However, the degree to which snow cover changes affect the radiation budget and energy balance on a regional scale and the difference between snow-climate and land use/cover change (LUCC)-climate feedbacks have been rarely studied. In this paper, we selected Heilongjiang Basin, where the snow cover has changed obviously, as our study area and used the WRF model to simulate the influences of snow cover changes on the surface radiation budget and heat balance. In the scenario simulation, the localized surface parameter data improved the accuracy by 10 % compared with the control group. The spatial and temporal analysis of the surface variables showed that the net surface radiation, sensible heat flux, Bowen ratio, temperature and percentage of snow cover were negatively correlated and that the ground heat flux and latent heat flux were positively correlated with the percentage of snow cover. The spatial analysis also showed that a significant relationship existed between the surface variables and land cover types, which was not obviously as that for snow cover changes. Finally, six typical study areas were selected to quantitatively analyse the influence of land cover types beneath the snow cover on heat absorption and transfer, which showed that when the land was snow covered, the conversion of forest to farmland can dramatically influence the net radiation and other surface variables, whereas the snow-free land showed significantly reduced influence. Furthermore, compared with typical land cover changes, e.g., the conversion of forest into farmland, the influence of snow cover changes on net radiation and sensible heat flux were 60 % higher than that of land cover changes

  14. Influence of viscoelastic property on laser-generated surface acoustic waves in coating-substrate systems

    International Nuclear Information System (INIS)

    Sun Hongxiang; Zhang Shuyi; Xu Baiqiang

    2011-01-01

    Taking account of the viscoelasticity of materials, the pulsed laser generation of surface acoustic waves in coating-substrate systems has been investigated quantitatively by using the finite element method. The displacement spectra of the surface acoustic waves have been calculated in frequency domain for different coating-substrate systems, in which the viscoelastic properties of the coatings and substrates are considered separately. Meanwhile, the temporal displacement waveforms have been obtained by applying inverse fast Fourier transforms. The numerical results of the normal surface displacements are presented for different configurations: a single plate, a slow coating on a fast substrate, and a fast coating on a slow substrate. The influences of the viscoelastic properties of the coating and the substrate on the attenuation of the surface acoustic waves have been studied. In addition, the influence of the coating thickness on the attenuation of the surface acoustic waves has been also investigated in detail.

  15. Factors influencing intracranial pressure monitoring guideline compliance and outcome after severe traumatic brain injury.

    NARCIS (Netherlands)

    Biersteker, H.A.; Andriessen, T.M.J.C.; Horn, J.; Franschman, G.; Naalt, J. van der; Hoedemaekers, C.W.E.; Lingsma, H.F.; Haitsma, I.; Vos, P.E.

    2012-01-01

    OBJECTIVE: To determine adherence to Brain Trauma Foundation guidelines for intracranial pressure monitoring after severe traumatic brain injury, to investigate if characteristics of patients treated according to guidelines (ICP+) differ from those who were not (ICP-), and whether guideline

  16. Factors influencing intracranial pressure monitoring guideline compliance and outcome after severe traumatic brain injury

    NARCIS (Netherlands)

    Biersteker, Heleen A. R.; Andriessen, Teuntje M. J. C.; Horn, Janneke; Franschman, Gaby; van der Naalt, Joukje; Hoedemaekers, Cornelia W. E.; Lingsma, Hester F.; Haitsma, Iain; Vos, Pieter E.

    2012-01-01

    Objective: To determine adherence to Brain Trauma Foundation guidelines for intracranial pressure monitoring after severe traumatic brain injury, to investigate if characteristics of patients treated according to guidelines (ICP+) differ from those who were not (ICP-), and whether guideline

  17. Factors influencing intracranial pressure monitoring guideline compliance and outcome after severe traumatic brain injury

    NARCIS (Netherlands)

    Biersteker, Heleen A. R.; Andriessen, Teuntje M. J. C.; Horn, Janneke; Franschman, Gaby; van der Naalt, Joukje; Hoedemaekers, Cornelia W. E.; Lingsma, Hester F.; Haitsma, Iain; Vos, Pieter E.

    Objective: To determine adherence to Brain Trauma Foundation guidelines for intracranial pressure monitoring after severe traumatic brain injury, to investigate if characteristics of patients treated according to guidelines (ICP+) differ from those who were not (ICP-), and whether guideline

  18. Influence of impact speed on head and brain injury outcome in vulnerable road user impacts to the car hood.

    Science.gov (United States)

    Fredriksson, Rikard; Zhang, Liying; Boström, Ola; Yang, King

    2007-10-01

    EuroNCAP and regulations in Europe and Japan evaluate the pedestrian protection performance of cars. The test methods are similar and they all have requirements for the passive protection of the hood area at a pedestrian to car impact speed of 40 km/h. In Europe, a proposal for a second phase of the regulation mandates a brake-assist system along with passive requirements. The system assists the driver in optimizing the braking performance during panic braking, resulting in activation only when the driver brakes sufficiently. In a European study this was estimated to occur in about 50% of pedestrian accidents. A future system for brake assistance will likely include automatic braking, in response to a pre-crash sensor, to avoid or mitigate injuries of vulnerable road users. An important question is whether these systems will provide sufficient protection, or if a parallel, passive pedestrian protection system will be necessary. This study investigated the influence of impact speed on head and brain injury risk, in impacts to the carhood. One car model was chosen and a rigid adjustable plate was mounted under the hood. Free-flying headform impacts were carried out at 20 and 30 km/h head impact velocities at different under-hood distances, 20 to 100 mm; and were compared to earlier tests at 40 km/h. The EEVC WG17 adult pedestrian headform was used for non-rotating tests and a Hybrid III adult 50th percentile head was used for rotational tests where linear and rotational acceleration was measured. Data from the rotational tests was used as input to a validated finite element model of the human head, the Wayne State University Head Injury Model (WSUHIM). The model was utilized to assess brain injury risk and potential injury mechanism in a pedestrian-hood impact. Although this study showed that it was not necessarily true that a lower HIC value reduced the risk for brain injury, it appeared, for the tested car model, under-hood distances of 60 mm in 20 km/h and 80 mm

  19. No influence of burn size on ventilator-associated pneumonia in burn patients with inhalation injury.

    Science.gov (United States)

    Tanizaki, Shinsuke; Suzuki, Koichiro

    2012-12-01

    Burn size and inhalation injury are important predictors of mortality following burn. The important factors for predicting ventilator-associated pneumonia (VAP) following burn remain unclear. The aim of our study was to investigate the effect of burn size on VAP in burn patients with inhalation injury. We retrospectively studied 52 burn patients with inhalation injury requiring mechanical ventilation admitted to the Department of Acute Medicine, Kawasaki Medical School Hospital, Okayama, Japan, between June 2007 and October 2010. The overall mortality for all patients was 15%. Twenty-six patients (50%) developed VAP. Patients with VAP required longer ICU stay and mechanical ventilation than those without VAP. There was no difference in age, gender, mortality, and TBSA between burn patients with inhalation injury with and Without VAP. VAP rate had no difference with increasing TBSA in burn patients with inhalation injury. Our data indicated that burn size had no relationship with the development of VAP in burn patients with inhalation injury. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  20. Does safety climate moderate the influence of staffing adequacy and work conditions on nurse injuries?

    Science.gov (United States)

    Mark, Barbara A; Hughes, Linda C; Belyea, Michael; Chang, Yunkyung; Hofmann, David; Jones, Cheryl B; Bacon, Cynthia T

    2007-01-01

    Hospital nurses have one of the highest work-related injury rates in the United States. Yet, approaches to improving employee safety have generally focused on attempts to modify individual behavior through enforced compliance with safety rules and mandatory participation in safety training. We examined a theoretical model that investigated the impact on nurse injuries (back injuries and needlesticks) of critical structural variables (staffing adequacy, work engagement, and work conditions) and further tested whether safety climate moderated these effects. A longitudinal, non-experimental, organizational study, conducted in 281 medical-surgical units in 143 general acute care hospitals in the United States. Work engagement and work conditions were positively related to safety climate, but not directly to nurse back injuries or needlesticks. Safety climate moderated the relationship between work engagement and needlesticks, while safety climate moderated the effect of work conditions on both needlesticks and back injuries, although in unexpected ways. DISCUSSION AND IMPACT ON INDUSTRY: Our findings suggest that positive work engagement and work conditions contribute to enhanced safety climate and can reduce nurse injuries.

  1. Influence of symptoms of depression and anxiety on injury hazard among collegiate American football players.

    Science.gov (United States)

    Yang, Jingzhen; Cheng, Gang; Zhang, Ying; Covassin, Tracey; Heiden, Erin O; Peek-Asa, Corinne

    2014-01-01

    The purpose of this study was to examine the effect of depression and anxiety symptoms on the prospective injury hazard among collegiate American football athletes. An open cohort of intercollegiate football players (n = 330) from two Division I universities were enrolled and followed during the 2008-2010 seasons. Of 330 enrolled players, 121 (36.7%) sustained at least one injury during the participation period. A total of 66 players (20.0%) reported experiencing symptoms of depression and 109 (33.0%) reported anxiety at the time of enrollment. Depression was associated with increased likelihood of injury (hazard ratio (HR) = 1.81, 95% confidence interval (CI): 1.65, 1.98). Anxiety had an opposite effect and was protective from injury hazard (HR= 0.79, 95% CI: 0.66, 0.93). Football players who experienced depression at enrollment were 10% less likely to remain injury-free than those who did not have depressive symptoms. Evidence from this study suggests injury prevention efforts need to include strategies targeting psychological risk factors.

  2. Influence of carbon monoxide to the surface layer of uranium metal and its oxides

    International Nuclear Information System (INIS)

    Wang Xiaoling; Fu Yibei; Xie Renshou; Huang Ruiliang

    1996-09-01

    The surface structures of uranium metal and triuranium octaoxide (U 3 O 8 ) and the influence of carbon monoxide to the surface layers have been studied by X-ray photoelectron spectroscopy (XPS). After exposure to carbon monoxide, contents of oxygen in the surface oxides of uranium metal and U 3 O 8 are decreased and O/U ratios decrease 7.2%, 8.0% respectively. The investigation indicated the surface layers of uranium metal and its oxides were forbidden to further oxidation in the atmosphere of carbon monoxide. (11 refs., 9 figs., 2 tabs.)

  3. Influence of surface roughness on the corrosion behaviour of magnesium alloy

    International Nuclear Information System (INIS)

    Walter, R.; Kannan, M. Bobby

    2011-01-01

    Research highlights: → Surface roughness of AZ91 magnesium alloy plays a critical role in the passivation behaviour of the alloy. → The passivation behaviour of the alloy influences the pitting tendency. → Increase in surface roughness of AZ91 magnesium alloy increases the pitting tendency of the alloy. -- Abstract: In this study, the influence of surface roughness on the passivation and pitting corrosion behaviour of AZ91 magnesium alloy in chloride-containing environment was examined using electrochemical techniques. Potentiodynamic polarisation and electrochemical impedance spectroscopy tests suggested that the passivation behaviour of the alloy was affected by increasing the surface roughness. Consequently, the corrosion current and the pitting tendency of the alloy also increased with increase in the surface roughness. Scanning electron micrographs of 24 h immersion test samples clearly revealed pitting corrosion in the highest surface roughness (Sa 430) alloy, whereas in the lowest surface roughness (Sa 80) alloy no evidence of pitting corrosion was observed. Interestingly, when the passivity of the alloy was disturbed by galvanostatically holding the sample at anodic current for 1 h, the alloy underwent high pitting corrosion irrespective of their surface roughness. Thus the study suggests that the surface roughness plays a critical role in the passivation behaviour of the alloy and hence the pitting tendency.

  4. Influences of surface hydrophilicity on frost formation on a vertical cold plate under natural convection conditions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhongliang; Zhang, Xinghua; Wang, Hongyan; Meng, Sheng; Cheng, Shuiyuan [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan 100, Beijing 100022 (China)

    2007-07-15

    Surface hydrophilicity has a strong influence on frost nucleation according to phase transition theory. To study this effect, a close observation of frost formation and deposition processes on a vertical plate was made under free convection conditions. The formation and shape variation of frost crystals during the initial period are described and the frost thickness variation with time on both hydrophobic and plain copper cold surfaces are presented. The various influencing factors are discussed in depth. The mechanism of surface hydrophilicity influence on frost formation was analyzed theoretically. This revealed that increasing the contact angle can increase the potential barrier and restrain crystal nucleation and growth and thus frost deposition. The experimental results show that the initial water drops formed on a hydrophobic surface are smaller and remain in the liquid state for a longer time compared with ones formed on a plain copper surface. It is also observed that the frost layer deposited on a hydrophobic surface is loose and weak. Though the hydrophobic surface can retard frost formation to a certain extent and causes a looser frost layer, our experimental results show that it does not depress the growth of the frost layer. (author)

  5. Do Surrogates of Injury Severity Influence the Occurrence of Heterotopic Ossification in Fractures of the Acetabulum?

    Science.gov (United States)

    dʼHeurle, Albert; Archdeacon, Michael T; Hiratzka, Shannon; Casstevens, Christopher; Finnan, Ryan; McCoy, Brett

    2016-04-01

    To determine the relationship between injury severity surrogates and other patient factors with the development and severity of heterotopic ossification (HO) following open reduction internal fixation of acetabular fractures treated with a posterior approach. Retrospective review. Academic level 1 trauma center. Two hundred forty-one patients who were treated through a posterior approach with a minimum of 6-month radiographic follow-up were identified from an acetabular fracture database. None. The occurrence and severity (Brooker Grade III/IV) of HO 6 months postsurgery. Length of stay (LOS) in the intensive care unit (ICU), non-ICU LOS >10 days, and HO prophylaxis with external radiation beam therapy (XRT) were significantly associated with the development of HO in a multivariate model [ICU LOS: 1-2 days, odds ratio (OR) = 4.33, 95% confidence interval (CI): 1.03-18.25; 3-6 days, OR = 4.1, 95% CI, 1.27-13.27; >6 days, OR = 11.7, 95% CI, 3.24-42.22; non-ICU LOS >10 days (vs. 0-6 days): OR = 7.6, 95% CI, 2.6-22.25; XRT HO prophylaxis: OR = 0.29, 95% CI, 0.10-0.85]. Other variables evaluated in multivariate modeling not significantly associated with development and severity of HO included age, gender, mechanism of injury, injury severity score, presence of neurologic injury, Letournel fracture type, occurrence of hip dislocation, interval from injury to surgery, operative time, and estimated blood loss. Surrogates of injury severity, including days in the ICU and non-ICU hospital LOS >10 days, were associated with the development of HO in our cohort of acetabular fracture patients. Prophylaxis with XRT was significantly protective against the development of HO, and the ability to provide prophylaxis is very likely related to the severity of injury. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

  6. Influence of patterned electrical neuromuscular stimulation on quadriceps activation in individuals with knee joint injury.

    Science.gov (United States)

    Glaviano, Neal R; Langston, William T; Hart, Joseph M; Saliba, Susan

    2014-12-01

    Neuromuscular Electrical Stimulation is a common intervention to address muscle weakness, however presents with many limitations such as fatigue, muscle damage, and patient discomfort that may influence its effectiveness. One novel form of electrical stimulation purported to improve neuromuscular re-education is Patterned Electrical Neuromuscular Stimulation (PENS), which is proposed to mimic muscle-firing patterns of healthy individuals. PENS provides patterned stimulating to the agonist muscle, antagonist muscle and then agonist muscle again in an effort to replicate firing patterns. The purpose of this study was to determine the effect of a single PENS treatment on knee extension torque and quadriceps activation in individuals with quadriceps inhibition. 18 subjects (10 males and 8 females: 24.2±3.4 years, 175.3±11.8cm, 81.8±12.4kg) with a history of knee injury/pain participated in this double-blinded randomized controlled laboratory trial. Participants demonstrated quadriceps inhibition with a central activation ratio of ≤90%. Maximal voluntary isometric contraction of the quadriceps and central activation ratio were measured before and after treatment. The treatment intervention was a 15-minute patterned electrical stimulation applied to the quadriceps and hamstring muscles with a strong motor contraction or a sham group, who received an identical set up as the PENS group, but received a 1mA subsensory stimulation. A 2×2 (group × time) ANCOVA was used to determine differences in maximal voluntary isometric contraction and central activation ratio between groups. The maximal voluntary isometric contraction was selected as a covariate due to baseline differences. There were no differences in change scores between pre- and post-intervention for maximal voluntary isometric contraction: (PENS: 0.09±0.32Nm/kg and Sham 0.15±0.18Nm/kg, p=0.713), or central activation ratio:(PENS: -1.22±6.06 and Sham: 1.48±3.7, p=0.270). A single Patterned Electrical

  7. Role of dexmedetomidine in stress control in traumatic brain injury and its influence on neuroendocrine system

    Directory of Open Access Journals (Sweden)

    Ji-shen LUO

    2013-11-01

    Full Text Available Objective To investigate the role of dexmedetomidine in stress control in moderate and severe traumatic brain injury (TBI and its influence on neuroendocrine system. Methods Ninety moderate or severe TBI patients (GCS 6-13 were admitted to ICU from May 2009 to January 2012, and they were divided into three groups according to the order of admission. Patients in group A (n=32 received 0.5-1.0μg/kg dexmedetomidine within 30min, maintained with 0.2-0.6μg/(kg.h dexmedetomidine for 24h, and morphine was administered by intravenous injection when necessary; patients in group B (n=31 received a 0.5-2.0mg/kg loading dose of propofol within 10min, maintained with 1.0-3.0mg/(kg.h for 72h, and morphine was administered by intravenous injection when necessary; patients in group C (n=27 received an intramuscular injection of pethidine or other optional drugs as control. A comprehensive evaluation was performed using Riker sedation-agitation scale combined with physiological and physical response indicators. The blood pressure, heart rate, respiration, tidal volume, arterial blood gas, plasma cortisol, plasma β-endorphin (β-EP, peripheral WBC count and blood glucose were measured and compared in 3 groups. Results The sedation rate of single-drug (i.e., without morphine administration in groups A, B and C was 86.7%, 80.6% and 77.8% respectively, and no significant difference was found among 3 groups (P>0.05. The mean arterial blood pressure at 30 min after administration was lower than that before administration in group A (P0.05. The WBC count and plasma cortisol level at 24h after treatment were lower than those before administration of the drugs in group A (P0.05. Conclusions Dexmedetomidine could alleviate the stress as a result of moderate and severe TBI, and its anti-stress and sedative effects were similar to those of propofol, but it is necessary to monitor the blood pressure. β-EP may play a coordinating role in the early stage of effect

  8. INFLUENCE OF AISI 316Ti STAINLESS STELL SURFACE TREATMENT ON PITTING CORROSION IN VARIOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Pavol Fajnor

    2010-12-01

    Full Text Available Investigation of the surface treatment effect on the resistance of AISI 316Ti stainless steel to pitting corrosion is presented in this paper. The grinded surfaces without additional chemical treatment, grinded and pickled, grinded, pickled and passivated surfaces are tested. The corrosion tests are carried out by exposition in solution which evoke pitting and by electrochemical cyclic potential - sweep method. According to the results the surface treatment has a great influence on the resistance of the tested material to pitting. It is not possible to estimate the best surface treatment because behavior of AISI 316Ti stainless steel with different surface state depends on the mechanism of corrosion processes which vary in the used experimental methods.

  9. Vehicle related factors that influence injury outcome in head-on collisions.

    Science.gov (United States)

    Blum, Jeremy J; Scullion, Paul; Morgan, Richard M; Digges, Kennerly; Kan, Cing-Dao; Park, Shinhee; Bae, Hanil

    2008-10-01

    This study specifically investigated a range of vehicle-related factors that are associated with a lower risk of serious or fatal injury to a belted driver in a head-on collision. This analysis investigated a range of structural characteristics, quantities that describes the physical features of a passenger vehicle, e.g., stiffness or frontal geometry. The study used a data-mining approach (classification tree algorithm) to find the most significant relationships between injury outcome and the structural variables. The algorithm was applied to 120,000 real-world, head-on collisions, from the National Highway Traffic Safety Administration's (NHTSA's) State Crash data files, that were linked to structural attributes derived from frontal crash tests performed as part of the USA New Car Assessment Program. As with previous literature, the analysis found that the heavier vehicles were correlated with lower injury risk to their drivers. This analysis also found a new and significant correlation between the vehicle's stiffness and injury risk. When an airbag deployed, the vehicle's stiffness has the most statistically significant correlation with injury risk. These results suggest that in severe collisions, lower intrusion in the occupant cabin associated with higher stiffness is at least as important to occupant protection as vehicle weight for self-protection of the occupant. Consequently, the safety community might better improve self-protection by a renewed focus on increasing vehicle stiffness in order to improve crashworthiness in head-on collisions.

  10. Bio-polymer coatings on neural probe surfaces: Influence of the initial sample composition

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Winnie W.Y. [Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala (Sweden); Herwik, Stanislav; Ruther, Patrick [Department of Microsystems Engineering (IMTEK), University of Freiburg (Germany); Goethelid, Emmanuelle [Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala (Sweden); Oscarsson, Sven, E-mail: sven@svenoscarsson.com [Department of Organic Chemistry, Stockholm University, Arrhenius Laboratory, SE-106 91 Stockholm (Sweden)

    2012-08-01

    This paper presents the results of the study of hyaluronic acid (HyA) coating on two structural materials, silicon oxide (dielectric) surface and platinum (Pt) surface used for fabrication of probes developed for neurological investigations in the framework of the EU-project NeuroProbes. The silicon-based neural probes consist of multiple Pt electrodes on the probe shafts for neural recording applications. HyA coatings were proposed to apply on the probe surfaces to enhance the biocompatibility. This study aims at understanding the influence of the initial composition of the probe surface on the structure and morphology of HyA coating. HyA was chemically functionalized by SS-pyridin using (N-Succinimidyl 3-[2-pyridyldithio]-propionate) (SPDP) and was immobilized on the surfaces via a covalent bond. The dielectric and Pt surfaces were derivatized by use of (3-mercaptopropyl) methyldimethoxysilane (MPMDMS). The silanol groups in MPMDMS bind to the dielectric surface, leaving the thiol groups at the uppermost surface and the thiol groups then bind covalently to the functionalized HyA. On the Pt surface, it is the thiol group which binds on the Pt surface. The coated surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). A well-defined HyA layer was observed on both dielectric and Pt surfaces. The coating of two molecular weights (340 kDa and 1.3 MDa) of HyA was examined. The influence of the silanized layer on the HyA coating was also investigated.

  11. Influence of the convective surface transfer coefficients on the Heat, Air, and Moisture (HAM) building performance

    DEFF Research Database (Denmark)

    Steskens, Paul Wilhelmus Maria Hermanus; Janssen, Hans; Rode, Carsten

    2009-01-01

    Current models to predict heat, air and moisture (HAM) conditions in buildings assume constant boundary conditions for the temperature and relative humidity of the neighbouring air and for the surface heat and moisture transfer coefficients. These assumptions may introduce errors in the predicted...... influence on the predicted hygrothermal conditions at the surface of a building component and on the heat and vapour exchange with the indoor environment....

  12. Influence of minor thermal injury on expression of complement receptor CR3 on human neutrophils.

    OpenAIRE

    Nelson, R. D.; Hasslen, S. R.; Ahrenholz, D. H.; Haus, E.; Solem, L. D.

    1986-01-01

    Thermal injury is well known to inhibit functions of the circulating neutrophil related to its role in host defense against infection, but the mechanism(s) of this phenomenon are not fully understood. To gain further clues to these mechanisms, the authors have studied patients with thermal injury in terms of altered expression of neutrophil cell membrane receptors for the opsonic complement-derived ligand C3bi--complement receptor Type 3, or CR3. CR3 expression was selected for study because ...

  13. Influence of the Surface and Cloud Nonuniformities in the Solar Energy Fluxes in the Arctic

    Science.gov (United States)

    Rozwadowska, A.; Cahalan, R. F.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Solar energy fluxes reaching the surface and absorbed by it are basic components of the energy balance of the Arctic. They depend mainly on the solar zenith angle, a state of the atmosphere, especially the cloudiness, and the surface albedo. However, they can also be modified by variabilities in the surface albedo and cloud optical thickness. The surface of the Arctic can be highly nonuniform. The surface of the Arctic Ocean, which covers the huge part of the Arctic can be view as a mosaic of sea water, sea ice, snow and, in the melting period, melting ponds. In our paper, results are presented of Monte Carlo simulations of the expected influence of nonuniform cloud structure and nonuniform surface albedo on radiative fluxes at the Arctic surface. In particular, the plane parallel biases in the surface absorptance and atmospheric transmittance are studied. The bias is defined as the difference between the real absorptance or transmittance (i.e. nonuniform conditions) averaged over a given area, and the uniform or plane parallel case with the same mean cloud optical thickness and the same mean surface albedo. The dependence of the biases is analysed with respect to the following: domain averaged values of the cloud optical thickness and surface albedo, scales of their spatial variabilities, correlation between cloud optical thickness and cloud albedo variabilities, cloud height, and the solar zenith angle. Ranges of means and standard deviations of the input parameters typical of Arctic conditions are obtained from the SHEBA experiment.

  14. Recovery of sensorimotor function and activities of daily living after cervical spinal cord injury: the influence of age

    OpenAIRE

    Wirz, Markus; Dietz, Volker

    2015-01-01

    This retrospective study was designed to examine the influence of age on the outcome of motor function and activities of daily living (ADLs) in patients with a cervical spinal cord injury (SCI). The study is based on the data registry of the EMSCI study group. Initial upper extremity motor score (UEMS) and its change over 5 months, as well as the initial Spinal Cord Independence Measure (SCIM) score did not differ between younger adults (20-39 years) and elderly (60-79 years) patients. Howeve...

  15. The influence of surface topography of UV coated and printed cardboard on the print gloss

    Directory of Open Access Journals (Sweden)

    Igor Karlović

    2010-09-01

    Full Text Available The incident light on the printed surface undergoes through several processes of scattering, absorbtion and reflectiondepending on the surface topography and structure of the material. The specular part of the surface reflection is commonlyattributed as the geometric component of the reflection, and when measured is associated with specular gloss.The diffuse part of the surface reflection contains the chromatic part of the reflection and is commonly calculatedthrough colorimetric values. Using UV coatings as surface enhacement materials which affect the optical propertiesof coated surfaces and final appearance of the printed product forms new surface topography over the existingone. We have investigated the influence of three different amounts of UV glossy and matte oveprint coating on themeasured specular gloss of printed cardboard samples. The different amount of coatings on the printed samples wereachived using three different screen stencils of 180 threads/cm, 150 threads/cm and 120 threads/cm thread count.The cardboard samples were analysed with AFM and SEM microscopes to obtain surface topography and roughnessvalues which were evaluated with the measured geometric values speficied as instrumental gloss. The surfaceswith a specific amount of UV coatings showed a new formed topography which influences the reflection of light.The changes in topography were evaluated through surface roughness parameters which showed a decline of surfaceroughness with tht additional ammount of glossy and matte coatings. The obtained and calculated correlations showthere is a high correlation between coating ammount and surface roughness change and gloss for the glossy UVcoating. The results for the matte UV coatings showed lower correlation for the gloss and surface roughness.

  16. Machining process influence on the chip form and surface roughness by neuro-fuzzy technique

    Science.gov (United States)

    Anicic, Obrad; Jović, Srđan; Aksić, Danilo; Skulić, Aleksandar; Nedić, Bogdan

    2017-04-01

    The main aim of the study was to analyze the influence of six machining parameters on the chip shape formation and surface roughness as well during turning of Steel 30CrNiMo8. Three components of cutting forces were used as inputs together with cutting speed, feed rate, and depth of cut. It is crucial for the engineers to use optimal machining parameters to get the best results or to high control of the machining process. Therefore, there is need to find the machining parameters for the optimal procedure of the machining process. Adaptive neuro-fuzzy inference system (ANFIS) was used to estimate the inputs influence on the chip shape formation and surface roughness. According to the results, the cutting force in direction of the depth of cut has the highest influence on the chip form. The testing error for the cutting force in direction of the depth of cut has testing error 0.2562. This cutting force determines the depth of cut. According to the results, the depth of cut has the highest influence on the surface roughness. Also the depth of cut has the highest influence on the surface roughness. The testing error for the cutting force in direction of the depth of cut has testing error 5.2753. Generally the depth of cut and the cutting force which provides the depth of cut are the most dominant factors for chip forms and surface roughness. Any small changes in depth of cut or in cutting force which provide the depth of cut could drastically affect the chip form or surface roughness of the working material.

  17. Influence of the Surface Layer on the Electrochemical Deposition of Metals and Semiconductors into Mesoporous Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Chubenko, E. B., E-mail: eugene.chubenko@gmail.com; Redko, S. V.; Sherstnyov, A. I.; Petrovich, V. A.; Kotov, D. A.; Bondarenko, V. P. [Belarusian State University of Information and RadioElectronics (Belarus)

    2016-03-15

    The influence of the surface layer on the process of the electrochemical deposition of metals and semiconductors into porous silicon is studied. It is shown that the surface layer differs in structure and electrical characteristics from the host porous silicon bulk. It is established that a decrease in the conductivity of silicon crystallites that form the surface layer of porous silicon has a positive effect on the process of the filling of porous silicon with metals and semiconductors. This is demonstrated by the example of nickel and zinc oxide. The effect can be used for the formation of nanocomposite materials on the basis of porous silicon and nanostructures with a high aspect ratio.

  18. Study on the influence of carbon monoxide to the surface oxide layer of uranium metal

    International Nuclear Information System (INIS)

    Wang Xiaolin; Duan Rongliang; Fu Yibei; Xie Renshou; Zuo Changming; Zhao Chunpei; Chen Hong

    1997-01-01

    The influence of carbon monoxide to the surface oxide layer of uranium metal has been studied by X-ray photoelectron spectroscopy (XPS) and gas chromatography (GC). Carbon monoxide adsorption on the oxide layer resulted in U4f peak shifting to the lower binding energy. The content of oxygen in the oxide is decreased and the atomic ratio (O/U) is decreased by 7.2%. The amount of carbon dioxide in the atmosphere after the surface reaction is increased by 11.0%. The investigation indicates that the surface layer can prevent the further oxidation uranium metal in the atmosphere of carbon monoxide

  19. Shoulder Pain in Cases of Spinal Injury: Influence of the Position of the Wheelchair Seat

    Science.gov (United States)

    Giner-Pascual, Manuel; Alcanyis-Alberola, Modesto; Millan Gonzalez, Luis; Aguilar-Rodriguez, Marta; Querol, Felipe

    2011-01-01

    The objective of this study was to determine the relationship between shoulder pain and the position of the seat of a wheelchair relative to the ground and to determine the relationship between shoulder pain and structural damage. A transversal study of a patient cohort of 140 patients with grade A and B spinal cord injuries below the T1 vertebra,…

  20. Psychosocial factors influencing the recovery of athletes with anterior cruciate ligament injury : A systematic review

    NARCIS (Netherlands)

    te Wierike, S. C. M.; van der Sluis, A.; van den Akker-Scheek, I.; Elferink-Gemser, M. T.; Visscher, C.

    2013-01-01

    This review describes the psychosocial factors that affect recovery following anterior cruciate ligament (ACL) injury and reconstructive surgery in athletes. A systematic search in literature with inclusion and exclusion criteria on PubMed, PsycINFO, and Embase was performed. Articles used in this

  1. Peer Influence and Nonsuicidal Self Injury: Longitudinal Results in Community and Clinically-Referred Adolescent Samples

    Science.gov (United States)

    Prinstein, Mitchell J.; Heilbron, Nicole; Guerry, John D.; Franklin, Joseph C.; Rancourt, Diana; Simon, Valerie; Spirito, Anthony

    2010-01-01

    Research suggests that adolescents' engagement in nonsuicidal self-injurious (NSSI) behaviors may be increasing over time, yet little is known regarding distal longitudinal factors that may promote engagement in these behaviors. Data from two longitudinal studies are presented to examine whether NSSI may be associated with peer influence…

  2. SHORT COMMUNICATION ON THE INFLUENCE OF POSITION ON ANTERIOR CRUCIATE LIGAMENT INJURY AND RECONSTRUCTION IN RECREATIONAL RUGBY FOOTBALL UNION PARTICIPANTS

    Directory of Open Access Journals (Sweden)

    Helen Dawes

    2003-03-01

    Full Text Available The different player positions in rugby union may place varying demands on a reconstructed anterior cruciate ligament (ACL in regards to 'cutting manoeuvres', this in turn may effect performance. In order to investigate sporting performance post reconstruction, a questionnaire was sent to amateur rugby clubs affiliated to the Oxfordshire Rugby Football Union (R.F.U. From the returned questionnaires player positions were placed into categories based on similar 'cutting manoeuvre' demands. Seventy five percent of Individuals playing in the category 1 (low 'cutting manoeuvre' demands at slow running speeds could play a full game with a damaged ACL and post-reconstruction the majority returned to play at a higher level. Fifty percent of ACL injuries occurred on category 2 (high 'cutting manoeuvre' demands at medium running speeds suggesting they may be more prone to ACL injury than other positions. The majority of individuals playing in category 3 (high 'cutting manoeuvre' demands at fast speeds played at a lower level of rugby post reconstruction. Positional demands may influence ACL injury and post reconstruction sporting performance. However, more research is needed

  3. Dialysis vintage and cardiovascular injury as factors influencing long-term survival in peritoneal dialysis and hemodialysis.

    Science.gov (United States)

    Hoppe, Krzysztof; Schwermer, Krzysztof; Olewicz-Gawlik, Anna; Klysz, Patrycja; Kawka, Anna; Baum, Ewa; Sikorska, Dorota; Ścigacz, Katarzyna; Roszak, Magdalena; Lindholm, Bengt; Pawlaczyk, Krzysztof; Oko, Andrzej

    2017-01-01

    Cardiovascular (CV) incidents are the major cause of mortality in maintenance dialysis (MD) patients undergoing peritoneal dialysis (PD) or hemodialysis (HD). CV injury indicators may be useful to investigate the dialysis modality influence on survival. The aim of this study was to compare selected laboratory and echocardiographic (ECHO) markers of CV injury in terms of dialysis vintage (DV), CV-related mortality and all-cause mortality. The study involved 301 patients on HD (n = 301) and PD (n = 58), who were divided into subgroups according to DV. The subjects' medical histories included diabetes mellitus (DM), myocardial infarction (MI), stroke, CV deaths and deaths from non-CV causes. Their CV parameters were measured with ECHO for the left ventricle ejection fraction (EF), posterior wall (LVW) and interventricular septum (IVS). Serum analyses of cardiac troponin T (TnT) and N-terminal pro-brain natriuretic peptide (BNP) were also carried out. In the subgroup with a DV of 4 years, the PD and HD patients were of a similar age, and had similar mortality and morbidity rates and CV markers, except for thicker IVS in the HD patients. Focusing on the data analysis based on mortality, and both laboratory and echocardiographic markers of cardiovascular injury, PD seems to be a more favorable method of dialysis. The advantage of PD was noted in subjects with a DV < 2 years. HD showed no outcome benefit over PD in longer DV.

  4. The experimental investigation of fibrinolytic system under the influence of flocalin in conditions of acute hypoxic kidney injury

    Directory of Open Access Journals (Sweden)

    A. I. Gozhenko

    2017-08-01

    Full Text Available In the experiments on rats subjected to acute hypoxic histochemical nephropathy, caused by sodium nitrite and 2,4-dinitrophenol, fibrinolytic activities of blood plasma, urine, renal cortex, medulla, and papilla after treatment with flocalin – the activator of KATP channels, were studied­. It was shown that in the conditions of acute kidney hypoxic injury flocalin administration resulted in the increase and essential restoration of fibrinolysis in blood plasma diminished under hypoxia, which was due to the growth of non-enzymatic fibrinolysis, whereas in urine and renal medulla the appreciable increase of enzymatic fibrinolytic activity took place. Moreover, the treatment of hypoxic nephropathy animals by flocalin resulted in the marked restoration of kidney ion regulatory and protein excretory functions that proves the positive influence of KATP channels activation on the one of the biochemical mechanisms of acute kidney injury as well as the protective effect of flocalin in relation to tubular cells of nephron. The obtained results testify to the beneficial effects of KATP channels activation in the conditions of acute hypoxic kidneys injury.

  5. Influence of material removal programming on ion beam figuring of high-precision optical surfaces

    Science.gov (United States)

    Liao, Wenlin; Dai, Yifan; Xie, Xuhui

    2014-09-01

    Ion beam figuring (IBF) provides a nanometer/subnanometer precision fabrication technology for optical components, where the surface materials on highlands are gradually removed by the physical sputtering effect. In this deterministic method, the figuring process is usually divided into several iterations and the sum of the removed material in each iteration is expected to approach the ideally removed material as nearly as possible. However, we find that the material removal programming in each iteration would influence the surface error convergence of the figuring process. The influence of material removal programming on the surface error evolution is investigated through the comparative study of the contour removal method (CRM) and the geometric proportion removal method (PRM). The research results indicate that the PRM can maintenance the smoothness of the surface topography during the whole figuring process, which would benefit the stable operation of the machine tool and avoid the production of mid-to-high spatial frequency surface errors. Additionally, the CRM only has the corrective effect on the area above the contour line in each iteration, which would result in the nonuniform convergence of the surface errors in various areas. All these advantages distinguish PRM as an appropriate material removal method for ultraprecision optical surfaces.

  6. Influence of surface conductivity on the apparent zeta potential of calcite.

    Science.gov (United States)

    Li, Shuai; Leroy, Philippe; Heberling, Frank; Devau, Nicolas; Jougnot, Damien; Chiaberge, Christophe

    2016-04-15

    Zeta potential is a physicochemical parameter of particular importance in describing the surface electrical properties of charged porous media. However, the zeta potential of calcite is still poorly known because of the difficulty to interpret streaming potential experiments. The Helmholtz-Smoluchowski (HS) equation is widely used to estimate the apparent zeta potential from these experiments. However, this equation neglects the influence of surface conductivity on streaming potential. We present streaming potential and electrical conductivity measurements on a calcite powder in contact with an aqueous NaCl electrolyte. Our streaming potential model corrects the apparent zeta potential of calcite by accounting for the influence of surface conductivity and flow regime. We show that the HS equation seriously underestimates the zeta potential of calcite, particularly when the electrolyte is diluted (ionic strength ⩽ 0.01 M) because of calcite surface conductivity. The basic Stern model successfully predicted the corrected zeta potential by assuming that the zeta potential is located at the outer Helmholtz plane, i.e. without considering a stagnant diffuse layer at the calcite-water interface. The surface conductivity of calcite crystals was inferred from electrical conductivity measurements and computed using our basic Stern model. Surface conductivity was also successfully predicted by our surface complexation model. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Influence of Wire Electrical Discharge Machining (WEDM) process parameters on surface roughness

    Science.gov (United States)

    Yeakub Ali, Mohammad; Banu, Asfana; Abu Bakar, Mazilah

    2018-01-01

    In obtaining the best quality of engineering components, the quality of machined parts surface plays an important role. It improves the fatigue strength, wear resistance, and corrosion of workpiece. This paper investigates the effects of wire electrical discharge machining (WEDM) process parameters on surface roughness of stainless steel using distilled water as dielectric fluid and brass wire as tool electrode. The parameters selected are voltage open, wire speed, wire tension, voltage gap, and off time. Empirical model was developed for the estimation of surface roughness. The analysis revealed that off time has a major influence on surface roughness. The optimum machining parameters for minimum surface roughness were found to be at a 10 V open voltage, 2.84 μs off time, 12 m/min wire speed, 6.3 N wire tension, and 54.91 V voltage gap.

  8. Influence of hand cycling on physical capacity in the rehabilitation of persons with a spinal cord injury: A longitudinal cohort study

    NARCIS (Netherlands)

    Valent, L.J.; Dallmeijer, A.J.; Houdijk, J.H.P.; Slootman, H.J.; Post, M.W.; van der Woude, L.H.V.

    2008-01-01

    Valent LJ, Dallmeijer AJ, Houdijk H, Slootman HJ, Post MW, van der Woude LH. Influence of hand cycling on physical capacity in the rehabilitation of persons with a spinal cord injury: a longitudinal cohort study. Objective: To investigate the influence of hand cycling on outcome measures of physical

  9. Influence of the surface finishing on electrochemical corrosion characteristics of AISI 316L stainless steel

    Directory of Open Access Journals (Sweden)

    Sylvia Dundeková

    2015-05-01

    Full Text Available Stainless steels from 316 group are very often and successfully uses for medical applications where the good mechanical and chemical properties in combination with non-toxicity of the material assure its safe and long term usage. Corrosion properties of AISI 361L stainless steel are strongly influenced by surface roughness and treatment of the engineering parts (specimens and testing temperature. Electrochemical characteristics of ground, mechanically polished and passivated AISI 316L stainless steel specimens were examined with the aim to identify the polarization resistance evolution due to the surface roughness decrease. Results obtained on mechanically prepared specimens where only natural oxide layer created due to the exposure of the material to the corrosion environment was protecting the materials were compared to the passivated specimens with artificial oxide layer. Also the influence of temperature and stabilization time before measurement were taken into account when discussing the obtained results. Positive influence of decreasing surface roughness was obtained as well as increase of polarization resistance due to the chemical passivation of the surface. Increase of the testing temperature and short stabilization time of the specimen in the corrosion environment were observed negatively influencing corrosion resistance of AISI 316L stainless steel.

  10. Self-affine roughness influence on the friction coefficient for rubbers onto solid surfaces

    NARCIS (Netherlands)

    Palasantzas, G

    2004-01-01

    In this paper we investigate the influence of self-affine roughness on the friction coefficient mu(f) of a rubber body under incomplete contact onto a solid surface. The roughness is characterized by the rms amplitude w, the correlation length xi, and the roughness exponent H. It is shown that with

  11. Influence of soil moisture content on surface albedo and soil thermal ...

    Indian Academy of Sciences (India)

    The large variability in the soil moisture content is attributed to the rainfall during all the seasons and also to the evaporation/movement of water to deeper layers. The relationship of surface albedo on soil moisture content on different time scales are studied and the influence of solar elevation angle and cloud cover are also ...

  12. Influence of chemical additives on the surface reactivity of Si in KOH solution

    NARCIS (Netherlands)

    Philipsen, H.G.G.; Kelly, J.J.

    2009-01-01

    It is known that the electrochemistry of silicon in alkaline solution is closely linked to the anisotropic etching of the semiconductor. In this work the influence of two commonly used additives, hydrogen peroxide and isopropyl alcohol, on the surface chemistry of silicon in KOH solution was

  13. Influence of cosolvents on the hydrophobic surface immobilization topography of Candida antarctica lipase B

    Science.gov (United States)

    The presence of cosolvents and co-solutes during the immobilization of lipases on hydrophobic supports may influence the extent of lipase immobilization and the long-term catalytic stability of the biocatalyst. Candida antarctica B lipase immobilization was examined on a hydrophobic surface, i.e., ...

  14. Crack resistance of pvd coatings : Influence of surface treatment prior to deposition

    NARCIS (Netherlands)

    Zoestbergen, E; de Hosson, J.T.M.

    The crack resistance of three different PVD coatings, TiN, Ti(C,N), and a multilayer system of alternating TiN and TiAlN, have been investigated. The three coating systems were deposited onto substrates with a different surface roughness to study the influence of this pretreatment on the crack

  15. The influence of wind speed on surface layer stability and turbulent ...

    Indian Academy of Sciences (India)

    The influence of wind speed on surface layer stability and turbulent fluxes over southern Indian peninsula station. M N Patil∗. , R T Waghmare, T Dharmaraj, G R Chinthalu,. Devendraa Siingh and G S Meena. Indian Institute of Tropical Meteorology, Dr Homi Bhabha Road, Pashan, Pune 411 008, India. ∗. Corresponding ...

  16. Interaction between two solid surfaces across PDMS : influence of chain length and end group

    NARCIS (Netherlands)

    Sun, G.X.; Stark, R.; Kappl, M.; Leermakers, F.A.M.; Butt, H.J.

    2005-01-01

    Forces between solid surfaces across polymer melts are poorly understood despite their importance for adhesion and composite materials. Using an atomic force microscope (AFM) this force was measured for poly(dimethyl siloxane) (PDMS) on silicon oxide. The influence of molecular weight (4.0-40 kDa)

  17. Surface temperature of wooden window frames under influence of solar radiation

    NARCIS (Netherlands)

    Castenmiller, C.J.J.

    2004-01-01

    Under influence of solar radiation the surface temperature of wooden window frames can reach values above 60 0C. High temperature can cause considerable tensions within the window frame; as a result joints can be cracked and rain water can penetrate into these joints. This penetration of rain water

  18. Influence of different surface treatments on push‑out bond strengths ...

    African Journals Online (AJOL)

    2015-06-26

    Jun 26, 2015 ... Despite all these advantages, fiber posts have several disadvantages. Debonding is one problem that causes. Influence of different surface treatments on push‑out bond strengths of fiber‑reinforced posts luted with dual‑cure resin cement ... of ceramics and metals for improved adhesion and bonding.

  19. Influence of plastic deformation on low temperature surface hardening of stainless steel by gaseous nitriding

    DEFF Research Database (Denmark)

    Bottoli, Federico; Winther, Grethe; Christiansen, Thomas Lundin

    2015-01-01

    This article addresses an investigation of the influence of plastic deformation on low temperature surface hardening by gaseous nitriding of three commercial austenitic stainless steels: AISI 304, EN 1.4369 and Sandvik Nanoflex® with various degrees of austenite stability. The materials were plas...

  20. Investigation and Evaluation on Influence of Machining (CNC Conditions on Surface Quality of Paulownia Wood

    Directory of Open Access Journals (Sweden)

    Mohammad Aghajani

    2012-01-01

    Full Text Available The aim of this study was to investigate the effective factors on surface quality of paulownia wood during machining by advanced computer numerical controled (CNC machine. For this aim paulownia logs were provided and were converted to proper sizes (2.5 x 10 x 15 cm and then air dried. The Variable of this study were cutting speed (8.37 and 15.07 m/s, feeding rate (6 and 12 m/min, cutting depth (1and 5 mm, cutting method (down and up-milling and cutting pattern (tangential and radial. Roughness of cut specimens edge were evaluated by profilometer method according to ISO 13565 standard. For evaluation of surface quality, average roughness (Ra, maximum roughness (R max, valley roughness (Rv and peak roughness (Rp were used. Degrees of effectiveness of the parameters were evaluated by fractional factorial design as completely random design at confidence level of 95%. The result showed that cutting speed, cutting method and feed rate are influencive factors on surface quality of machined specimens and their effects were significant. With increasing cutting speed and decreasing feeding rate the roughness decreased and surface quality improved. In up-milling cutting method, degree of roughness was higher and consequently surface quality was inferior. It is to be noted that cutting method in comparison to other factors had the high influence on surface quality. The rest variables did now have independent influence on surface quality at 95% Confidence level. This study for achieving the optimum surface quality recommends that cutting speed of 15.07 m/s, feeding rate of 6 m/min, cutting method of down-milling and cutting depth of 1 mm for tangential cross section.

  1. How surface composition of high milk proteins powders is influenced by spray-drying temperature.

    Science.gov (United States)

    Gaiani, C; Morand, M; Sanchez, C; Tehrany, E Arab; Jacquot, M; Schuck, P; Jeantet, R; Scher, J

    2010-01-01

    High milk proteins powders are common ingredients in many food products. The surface composition of these powders is expected to play an essential role during their storage, handling and/or final application. Therefore, an eventual control of the surface composition by modifying the spray-drying temperature could be very useful in the improvement of powder quality and the development of new applications. For this purpose, the influence of five spray-drying temperatures upon the surface composition of the powders was investigated by X-ray photoelectron spectroscopy. The major milk proteins were studied: native micellar casein and native whey, both more or less enriched in lactose. The results show a surface enrichment in lipids for all the powders and in proteins for many powders. Whatever the drying temperature, lipids and proteins are preferentially located near the surface whereas lactose is found in the core. This surface enrichment is also highly affected by the spray-drying temperature. More lipids, more proteins and less lactose are systematically observed at the surface of powders spray-dried at lower outlet air temperatures. The nature of proteins is also found essential; surface enrichment in lipids being much stronger for whey proteins containing powders than for casein containing powders. Additionally, we found a direct correlation between the lipids surface concentration and the wetting ability for the 25 powders studied.

  2. Influence of radioactivity on surface charging and aggregation kinetics of particles in the atmosphere.

    Science.gov (United States)

    Kim, Yong-Ha; Yiacoumi, Sotira; Lee, Ida; McFarlane, Joanna; Tsouris, Costas

    2014-01-01

    Radioactivity can influence surface interactions, but its effects on particle aggregation kinetics have not been included in transport modeling of radioactive particles. In this research, experimental and theoretical studies have been performed to investigate the influence of radioactivity on surface charging and aggregation kinetics of radioactive particles in the atmosphere. Radioactivity-induced charging mechanisms have been investigated at the microscopic level, and heterogeneous surface potential caused by radioactivity is reported. The radioactivity-induced surface charging is highly influenced by several parameters, such as rate and type of radioactive decay. A population balance model, including interparticle forces, has been employed to study the effects of radioactivity on particle aggregation kinetics in air. It has been found that radioactivity can hinder aggregation of particles because of similar surface charging caused by the decay process. Experimental and theoretical studies provide useful insights into the understanding of transport characteristics of radioactive particles emitted from severe nuclear events, such as the recent accident of Fukushima or deliberate explosions of radiological devices.

  3. Wetlands inform how climate extremes influence surface water expansion and contraction

    Directory of Open Access Journals (Sweden)

    M. K. Vanderhoof

    2018-03-01

    Full Text Available Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1 quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR and adjacent Northern Prairie (NP in the United States, and (2 explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015. The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density. To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less

  4. Wetlands inform how climate extremes influence surface water expansion and contraction

    Science.gov (United States)

    Vanderhoof, Melanie K.; Lane, Charles R.; McManus, Michael G.; Alexander, Laurie C.; Christensen, Jay R.

    2018-03-01

    Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985-2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic drainage

  5. Wetlands inform how climate extremes influence surface water expansion and contraction

    Science.gov (United States)

    Vanderhoof, Melanie; Lane, Charles R.; McManus, Michael L.; Alexander, Laurie C.; Christensen, Jay R.

    2018-01-01

    Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic

  6. The influence of vibrations on surface roughness formed during precision boring

    Directory of Open Access Journals (Sweden)

    Korzeniewski Dariusz

    2017-01-01

    Full Text Available In this paper, the analysis of vibrations on surface roughness generated during boring with the application of the conventional boring tool and one with the damper is presented. The experiments included the measurement of vibration accelerations carried out with the piezoelectric sensor, as well as the evaluation of surface roughness parameters after each machining pass. The obtained results reveal that in the investigated range, no stability loss was found. Furthermore, the growth of the rotational speed induces the increase of vibration level, as well as the growth of the differences between the vibration values generated during boring with the conventional tool and one equipped with damper. Vibrations have also the direct influence on the machined surface roughness. In case of the tool equipped with the damper, the tool’s overhang L had more intense influence than rotational speed n. However, for the conventional boring tool this dependency was unequivocal.

  7. Streaming potential revisited: the influence of convection on the surface conductivity.

    Science.gov (United States)

    Saini, Rakesh; Garg, Abhinandan; Barz, Dominik P J

    2014-09-16

    Electrokinetic phenomena play an important role in the electrical characterization of surfaces. In terms of planar or porous substrates, streaming potential and/or streaming current measurements can be used to determine the zeta potential of the substrates in contact with aqueous electrolytes. In this work, we perform electrical impedance spectroscopy measurements to infer the electrical resistance in a microchannel with the same conditions as for a streaming potential experiment. Novel correlations are derived to relate the streaming current and streaming potential to the Reynolds number of the channel flow. Our results not only quantify the influence of surface conductivity, and here especially the contribution of the stagnant layer, but also reveal that channel resistance and therefore zeta potential are influenced by the flow in the case of low ionic strengths. We conclude that convection can have a significant impact on the electrical double layer configuration which is reflected by changes in the surfaces conductivity.

  8. Influence of climatic factors and the ground surface on the required noise abatement from power equipment

    Science.gov (United States)

    Tupov, V. B.; Taratorin, A. A.

    2013-07-01

    The influence of climatic factors and the ground surface on the required noise abatement from the power equipment is analyzed. It is shown that annual oscillations of temperature and humidity lead to substantial variations in the levels of the sound and the sound pressure from the same source in the design point, while the ground effect surface can in some cases cause an increase in the sound pressure levels in the design point, and in other cases—their decrease. When developing the measures on sound suppression of the power equipment, it is recommended to take into account the influence of climatic factors depending on annual variations in temperature and humidity for this terrain as well as on the category of the ground surface.

  9. Influences of surface temperature on a low camber airfoil aerodynamic performances

    Directory of Open Access Journals (Sweden)

    Valeriu DRAGAN

    2016-03-01

    Full Text Available The current note refers to the comparison between a NACA 2510 airfoil with adiabatic walls and the same airfoil with heated patches. Both suction and pressure sides were divided into two regions covering the leading edge (L.E. and trailing edge (T.E.. A RANS method sensitivity test has been performed in the preliminary stage while for the extended 3D cases a DES-SST approach was used. Results indicate that surface temperature distribution influences the aerodynamics of the airfoil, in particular the viscous drag component but also the lift of the airfoil. Moreover, the influence depends not only on the surface temperature but also on the positioning of the heated surfaces, particularly in the case of pressure lift and drag. Further work will be needed to optimize the temperature distribution for airfoil with higher camber.

  10. Tracer Studies of the Influence of Foreign Substances at the Surface of the Electrodes. II Influence in electro crystallization phenomena

    International Nuclear Information System (INIS)

    Llopis, J.; Gamboa, J. M.; Arizmendi, L.

    1963-01-01

    The action of foreign substances present on the surface of the electrodes, in electro crystallization phenomena, has been studied. The number of Ag crystals per square centimeter of Pt electrode varies with the polishing, the current density and the presence of multilayers of stearic acid. The statistical distribution of Ag crystals without and with multilayers and their influence on the concentration index and the deformation of Ag crystals has been studied. the size of these crystals increases as the current density decreases. (Author) 16 refs

  11. Influence of Surface Properties on Adhesion Forces and Attachment of Streptococcus mutans to Zirconia In Vitro

    Science.gov (United States)

    Yu, Pei; Wang, Chuanyong; Zhou, Jinglin; Jiang, Li

    2016-01-01

    Zirconia is becoming a prevalent material in dentistry. However, any foreign bodies inserted may provide new niches for the bacteria in oral cavity. The object of this study was to explore the effect of surface properties including surface roughness and hydrophobicity on the adhesion and biofilm formation of Streptococcus mutans (S. mutans) to zirconia. Atomic force microscopy was employed to determine the zirconia surface morphology and the adhesion forces between the S. mutans and zirconia. The results showed that the surface roughness was nanoscale and significantly different among tested groups (P Medium (17.00 ± 3.81 nm) > Fine (11.89 ± 1.68 nm). The contact angles of the Coarse group were the highest, followed by the Medium and the Fine groups. Increasing the surface roughness and hydrophobicity resulted in an increase of adhesion forces and early attachment (2 h and 4 h) of S. mutans on the zirconia but no influence on the further development of biofilm (6 h~24 h). Our findings suggest that the surface roughness in nanoscale and hydrophobicity of zirconia had influence on the S. mutans initial adhesion force and early attachment instead of whole stages of biofilm formation. PMID:27975061

  12. Factors influencing prokaryotic community structure composition in sub-surface coastal sediments

    Science.gov (United States)

    Molari, Massimiliano; Giovannelli, Donato; d'Errico, Giuseppe; Manini, Elena

    2012-01-01

    Despite the major influence of the marine sub-surface area in carbon cycling and global biogeochemistry, there is little known of prokaryotic distribution and community structure information of the marine sub-surface and the factors that influence sub-surface prokaryotic assemblages. We provide quantitative estimations of active Bacteria and Archaea down vertical profiles of sub-surface coastal sediments from the southern Adriatic Sea (Manfredonia Gulf). Prokaryotic biomass, carbon incorporation and the metabolically active fraction were compared with environmental, trophic, and predatory variables down 100-cm sediment cores sectioned into 21 layers. Multiple regression analysis was used to identify variables that can explain the variance of community compositions down vertical profiles. CARD-FISH analysis showed Bacteria dominance for the first 11 cm below sediment surface. The community then changed significantly at increasing depth, towards Archaea dominance. The models tested show that prokaryotic abundance in superficial marine sediments is controlled by organic trophic resources, while in sub-surface sediments, active prokaryotic abundance is driven by environmental factors and predatory pressure, suggesting that the shift in prokaryotic community structure could be coupled to a change in life-style of microbial assemblages.

  13. A comprehensive analysis of factors influencing the injury severity of large-truck crashes.

    Science.gov (United States)

    Zhu, Xiaoyu; Srinivasan, Sivaramakrishnan

    2011-01-01

    Given the importance of trucking to the economic well being of a country and the safety concerns posed by the trucks, a study of large-truck crashes is critical. This paper contributes by undertaking an extensive analysis of the empirical factors affecting injury severity of large-truck crashes. Data from a recent, nationally representative sample of large-truck crashes are examined to determine the factors affecting the overall injury severity of these crashes. The explanatory factors include the characteristics of the crash, vehicle(s), and the driver(s). The injury severity was modeled using two measures. Several similarities and some differences were observed across the two models which underscore the need for improved accuracy in the assessment of injury severity of crashes. The estimated models capture the marginal effects of a variety of explanatory factors simultaneously. In particular, the models indicate the impacts of several driver behavior variables on the severity of the crashes, after controlling for a variety of other factors. For example, driver distraction (truck drivers), alcohol use (car drivers), and emotional factors (car drivers) are found to be associated with higher severity crashes. A further interesting finding is the strong statistical significance of several dummy variables that indicate missing data - these reflect how the nature of the crash itself could affect the completeness of the data. Future efforts should seek to collect such data more comprehensively so that the true effects of these aspects on the crash severity can be determined. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Variables influencing medical usage rates, injury patterns, and levels of care for mass gatherings.

    Science.gov (United States)

    Milsten, Andrew M; Seaman, Kevin G; Liu, Peter; Bissell, Rick A; Maguire, Brian J

    2003-01-01

    Mass gatherings create difficult environments for which to plan emergency medical responses. The purpose of this study was to identify those variables that are associated with increased medical usage rates (MURs) and certain injury patterns that can be used to facilitate the planning process. Patient information collected at three types of mass gatherings (professional American football and baseball games and rock concerts) over a three-year period was reviewed retrospectively. Specific variables were abstracted: (1) event type; (2) gender; (3) age; (4) weather; and (5) attendance. All 216 events (total attendance 9,708,567) studied were held in the same metropolitan region. All MURs are reported as patients per 10,000 (PPTT). The 5,899 patient encounters yielded a MUR of 6.1 PPTT. Patient encounters totaled 3,659 for baseball games (4.85 PPTT), 1,204 for football games (6.75 PPTT), and 1,036 for rock concerts (30 PPTT). The MUR for Location A concerts (no mosh pits) was 7.49 PPTT, whereas the MUR for the one Location B concert (with mosh pits) was 110 PPTT. The MUR for Location A concerts was higher than for baseball, but not football games (p = 0.005). Gender distribution was equal among patrons seeking medical care. The mean values for patient ages were 29 years at baseball games, 33 years at football games, and 20 years at concerts. The MUR at events held when the apparent temperature was 80 degrees F significantly lower statistically than that at events conducted at temperatures injuries (31%). Concerts with precipitation and rock concerts had a positive association with the incidence of trauma and the incidence of injuries; whereas age and gender were not associated with medical or traumatic diagnoses. Event type and apparent temperature were the variables that best predicted MUR as well as specific injury patterns and levels of care.

  15. Spatiotemporal Aeration and Lung Injury Patterns Are Influenced by the First Inflation Strategy at Birth.

    Science.gov (United States)

    Tingay, David G; Rajapaksa, Anushi; Zonneveld, C Elroy; Black, Don; Perkins, Elizabeth J; Adler, Andy; Grychtol, Bartłomiej; Lavizzari, Anna; Frerichs, Inéz; Zahra, Valerie A; Davis, Peter G

    2016-02-01

    Ineffective aeration during the first inflations at birth creates regional aeration and ventilation defects, initiating injurious pathways. This study aimed to compare a sustained first inflation at birth or dynamic end-expiratory supported recruitment during tidal inflations against ventilation without intentional recruitment on gas exchange, lung mechanics, spatiotemporal regional aeration and tidal ventilation, and regional lung injury in preterm lambs. Lambs (127 ± 2 d gestation), instrumented at birth, were ventilated for 60 minutes from birth with either lung-protective positive pressure ventilation (control) or as per control after either an initial 30 seconds of 40 cm H2O sustained inflation (SI) or an initial stepwise end-expiratory pressure recruitment maneuver during tidal inflations (duration 180 s; open lung ventilation [OLV]). At study completion, molecular markers of lung injury were analyzed. The initial use of an OLV maneuver, but not SI, at birth resulted in improved lung compliance, oxygenation, end-expiratory lung volume, and reduced ventilatory needs compared with control, persisting throughout the study. These changes were due to more uniform inter- and intrasubject gravity-dependent spatiotemporal patterns of aeration (measured using electrical impedance tomography). Spatial distribution of tidal ventilation was more stable after either recruitment maneuver. All strategies caused regional lung injury patterns that mirrored associated regional volume states. Irrespective of strategy, spatiotemporal volume loss was consistently associated with up-regulation of early growth response-1 expression. Our results show that mechanical and molecular consequences of lung aeration at birth are not simply related to rapidity of fluid clearance; they are also related to spatiotemporal pressure-volume interactions within the lung during inflation and deflation.

  16. The influence of nanoscale inorganic content over optical and surface properties of model composites.

    Science.gov (United States)

    Salgado, Vinícius Esteves; Cavalcante, Larissa Maria; Silikas, Nick; Schneider, Luis Felipe J

    2013-11-01

    To investigate the influence of nanoscale inorganic content over optical and surface properties of model composites before and after ageing. Three model composites were formulated with silica fillers in nanoscale of 7 nm (G1), 12 nm (G2) and 16 nm (G3), at 45.5% by weight in a matrix of BisGMA/TEGDMA 1:1. Color coordinates (CIE L*a*b* parameters), color difference (ΔE*), translucency parameter (TP), surface gloss (SG) and surface roughness (SR) were measured before and after ageing procedures of immersion in water and toothbrush abrasion. Surface hardness (SH) were evaluated before and after immersion in absolute ethanol. Results were submitted to two-way ANOVA followed by Tukey's post hoc test performed at a pre-set alpha of 0.05. Regarding CIE L*a*b* parameters, a darkening, a redness and a blueness effect, were respectively detected after water storage for all groups. Smaller filler sizes (G1) had the highest CIE b* values, whereas medium (G2) (p0.05), although a tendency towards lower values in smaller filler materials was observed. Ageing after immersion in absolute ethanol decreased SH for all model composites. Filler sizes and ageing procedures influenced the optical and surface properties of the nanostructured composites evaluated in this study. Filler size influenced optical and surface properties of resin composites. Materials containing smaller filler size offered improved optical stability and surface properties that can lead to longer maintenance of the restoration's appearance in the oral environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Psychosocial factors influencing the recovery of athletes with anterior cruciate ligament injury: a systematic review.

    Science.gov (United States)

    te Wierike, S C M; van der Sluis, A; van den Akker-Scheek, I; Elferink-Gemser, M T; Visscher, C

    2013-10-01

    This review describes the psychosocial factors that affect recovery following anterior cruciate ligament (ACL) injury and reconstructive surgery in athletes. A systematic search in literature with inclusion and exclusion criteria on PubMed, PsycINFO, and Embase was performed. Articles used in this review were divided in five different parts according to the biopsychosocial model of Wiese-Bjornstal, with the addition of intervention studies. The results showed that a high internal Health Locus of Control and a high self-efficacy were useful cognitive factors to facilitate the recovery. Athletes with a low level of fear of reinjury had the best knee outcome after the injury followed by a reconstruction. In addition, athletes who returned to sport had less fear of reinjury and were more experienced and established athletes compared with athletes who did not return to sport. Furthermore, researchers showed that there was a positive relation between goal setting and adherence, which in turn yielded a positive relation with the outcome of the rehabilitation of an ACL injury. There were several psychosocial interventions that appeared to be facilitating the rehabilitation process. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Self-reported activity level and knee function in amateur football players: the influence of age, gender, history of knee injury and level of competition.

    OpenAIRE

    Frobell, Richard; Svensson, E; Göthrick, M; Roos, Ewa

    2008-01-01

    The aim of this study is to investigate if self-reported activity level or knee functions are influenced by subject characteristics, level of competition and history of knee injury. Cross-Sectional study using questionnaires distributed at a personal visit. One hundred and eighty-eight (65 women) amateur football players in 10 football clubs from each division below national level participated in the study. Self-reported Tegner Activity Scale, and the Knee injury and Osteoarthritis Outcome Sc...

  19. Sonocatalytic injury of cancer cells attached on the surface of a nickel-titanium dioxide alloy plate.

    Science.gov (United States)

    Ninomiya, Kazuaki; Maruyama, Hirotaka; Ogino, Chiaki; Takahashi, Kenji; Shimizu, Nobuaki

    2016-01-01

    The present study demonstrates ultrasound-induced cell injury using a nickel-titanium dioxide (Ni-TiO2) alloy plate as a sonocatalyst and a cell culture surface. Ultrasound irradiation of cell-free Ni-TiO2 alloy plates with 1 MHz ultrasound at 0.5 W/cm(2) for 30s led to an increased generation of hydroxyl (OH) radicals compared to nickel-titanium (Ni-Ti) control alloy plates with and without ultrasound irradiation. When human breast cancer cells (MCF-7 cells) cultured on the Ni-TiO2 alloy plates were irradiated with 1 MHz ultrasound at 0.5 W/cm(2) for 30s and then incubated for 48 h, cell density on the alloy plate was reduced to approximately 50% of the controls on the Ni-Ti alloy plates with and without ultrasound irradiation. These results indicate the injury of MCF-7 cells following sonocatalytic OH radical generation by Ni-TiO2. Further experiments demonstrated cell shrinkage and chromatin condensation after ultrasound irradiation of MCF-7 cells attached on the Ni-TiO2 alloy plates, indicating induction of apoptosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. SURFACE FLUID REGISTRATION OF CONFORMAL REPRESENTATION: APPLICATION TO DETECT DISEASE BURDEN AND GENETIC INFLUENCE ON HIPPOCAMPUS

    Science.gov (United States)

    Shi, Jie; Thompson, Paul M.; Gutman, Boris; Wang, Yalin

    2013-01-01

    In this paper, we develop a new automated surface registration system based on surface conformal parameterization by holomorphic 1-forms, inverse consistentsurface fluid registration, and multivariate tensor-based morphometry (mTBM). First, we conformally map a surface onto a planar rectangle space with holomorphic 1-forms. Second, we compute surface conformal representation by combining its local conformal factor and mean curvature and linearly scale the dynamic range of the conformal representation to form the feature image of the surface. Third, we align the feature image with a chosen template image via the fluid image registration algorithm, which has been extended into the curvilinear coordinates to adjust for the distortion introduced by surface parameterization. The inverse consistent image registration algorithm is also incorporated in the system to jointly estimate the forward and inverse transformations between the study and template images. This alignment induces a corresponding deformation on the surface. We tested the system on Alzheimer's Disease Neuroimaging Initiative (ADNI) baseline dataset to study AD symptoms on hippocampus. In our system, by modeling a hippocampus as a 3D parametric surface, we nonlinearly registered each surface with a selected template surface. Then we used mTBM to analyze the morphometrydifference between diagnostic groups. Experimental results show that the new system has better performance than two publically available subcortical surface registration tools: FIRST and SPHARM. We also analyzed the genetic influence of the Apolipoprotein E ε4 allele (ApoE4),which is considered as the most prevalent risk factor for AD.Our work successfully detected statistically significant difference between ApoE4 carriers and non-carriers in both patients of mild cognitive impairment (MCI) and healthy control subjects. The results show evidence that the ApoE genotype may be associated with accelerated brain atrophy so that our workprovides

  1. The influence of Fe doping on the surface topography of GaN epitaxial material

    International Nuclear Information System (INIS)

    Cui Lei; Yin Haibo; Jiang Lijuan; Wang Quan; Feng Chun; Xiao Hongling; Wang Cuimei; Wang Xiaoliang; Gong Jiamin; Zhang Bo; Li Baiquan; Wang Zhanguo

    2015-01-01

    Fe doping is an effective method to obtain high resistivity GaN epitaxial material. But in some cases, Fe doping could result in serious deterioration of the GaN material surface topography, which will affect the electrical properties of two dimensional electron gas (2DEG) in HEMT device. In this paper, the influence of Fe doping on the surface topography of GaN epitaxial material is studied. The results of experiments indicate that the surface topography of Fe-doped GaN epitaxial material can be effectively improved and the resistivity could be increased after increasing the growth rate of GaN materials. The GaN material with good surface topography can be manufactured when the Fe doping concentration is 9 × 10 19 cm −3 . High resistivity GaN epitaxial material which is 1 × 10 9 Ω·cm is achieved. (paper)

  2. Influence of Sea Surface Roughness on the Electromagnetic Wave Propagation in the Duct Environment

    Directory of Open Access Journals (Sweden)

    X. Zhao

    2010-12-01

    Full Text Available This paper deals with a study of the influence of sea surface roughness on the electromagnetic wave propagation in the duct environment. The problem of electromagnetic wave propagation is modeled by using the parabolic equation method. The roughness of the sea surface is computed by modifying the smooth surface Fresnel reflection coefficient to account for the reduction in the specular reflection due to the roughness resulting from sea wind speed. The propagation model is solved by the mixed Fourier split-step algorithm. Numerical experiments indicate that wind-driven roughened sea surface has an impact on the electromagnetic wave propagation in the duct environment, and the strength is intensified along with the increment of sea wind speeds and/or the operating frequencies. In a fixed duct environment, however, proper disposition of the transmitter could reduce these impacts.

  3. Adhesion of Pathogenic Bacteria to Food Contact Surfaces: Influence of pH of Culture

    Directory of Open Access Journals (Sweden)

    Akier Assanta Mafu

    2011-01-01

    Full Text Available The adhesion of Aeromonas hydrophila, Escherichia coli O157:H7, Salmonella Enteritidis, and Staphylococcus aureus to hydrophobic and hydrophilic surfaces in cultures with different pHs (6, 7, and 8 was studied. The results indicated that the type of material had no effect on the attachment capacity of microorganisms, while environmental pH influenced the adhesion of A. hydrophila, E. coli, and S. aureus to both solid substrates. The attachment of S. Enteritidis (P>.05 was not affected by the type of substrate or the culture pH, whereas E. coli displayed the weakest affinity for both polystyrene and glass surfaces. No correlation was established between the physicochemical properties of the materials, or the bacterial and the rate of bacterial adhesion, except for S. aureus. Photomicrographs have shown that surfaces were contaminated by small clusters of S. Enteritidis while S. aureus invaded the food contact surfaces in the form of small chains or cell aggregates.

  4. Influence of nanopore surface charge and magnesium ion on polyadenosine translocation.

    Science.gov (United States)

    Lepoitevin, Mathilde; Coulon, Pierre Eugène; Bechelany, Mikhael; Cambedouzou, Julien; Janot, Jean-Marc; Balme, Sebastien

    2015-04-10

    We investigate the influence of a nanopore surface state and the addition of Mg(2+) on poly-adenosine translocation. To do so, two kinds of nanopores with a low aspect ratio (diameter ∼3-5 nm, length 30 nm) were tailored: the first one with a negative charge surface and the second one uncharged. It was shown that the velocity and the energy barrier strongly depend on the nanopore surface. Typically if the nanopore and polyA exhibit a similar charge, the macromolecule velocity increases and its global energy barrier of entrance in the nanopore decreases, as opposed to the non-charged nanopore. Moreover, the addition of a divalent chelating cation induces an increase of energy barrier of entrance, as expected. However, for a negative nanopore, this effect is counterbalanced by the inversion of the surface charge induced by the adsorption of divalent cations.

  5. Influence of surface treatment on bond strength of veneering ceramics fused to zirconia.

    Science.gov (United States)

    Tada, Kouki; Sato, Toru; Yoshinari, Masao

    2012-01-01

    In all-ceramic restorations involving a zirconia framework, surface treatment of the zirconia surface is required to enhance bonding strength with the veneering ceramics and thus prevent chipping. The purpose of the present study was to investigate the influence of surface roughness and heat treatment of the zirconia and use of liner porcelain on bond strength between veneering ceramics and a zirconia framework. Debonding/crack-initiation strength (τb) was determined according to ISO 9693. No significant difference was observed among conditions, except with use of a liner under heat treatment, which yielded a τb of 26.0±2.9-28.9±1.7 MPa. Electron probe microanalysis revealed that components of the veneering ceramics remained on the zirconia surface after debonding, suggesting that fractures occur in the veneering ceramics and that improving the strength of the veneering ceramics themselves might increase bond strength.

  6. Influence of the cooling liquid on surface quality characteristics in milling

    Science.gov (United States)

    Tampu, N. C.; Brabie, G.; Chirita, B. A.; Herghelegiu, E.; Radu, M. C.

    2015-11-01

    Cooling system and cooling liquid characteristics are among the main factors influencing surface quality and tool wear. The aim of this study is to analyse the effect of the cooling liquid, used in different concentrations and at different temperatures, on the quality of the surface layer processed by milling. In order to make this analysis a Minimum Quantity Lubrication (MQL) cooling device is used. Three different volumetric ratios were used to modify the concentration of the cooling fluid (25% water to 75% emulsion, 50% water to 50% emulsion, 75% water to 25% emulsion) and three different temperatures. The studies revealed that surface roughness can be correlated with the variation of the cooling liquid temperature while surface flatness can be correlated to both, cooling liquid temperature and concentration.

  7. Impurity scattering and magnetic field influence on a nodal surface of a d-wave superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Aida

    2012-02-17

    In the present work the surface of d-wave superconductors is studied. In such superconductors zero-energy Andreev bound states (ABSs) may appear at the surface depending on the orientation of the d-wave with respect to the surface normal. Existence of these states influences the properties of the superconductor on the length scale of the coherence length, the spatial extension of the bound states. Surface roughness, surface disorder, or diffuse scattering as well as an external magnetic field at the surface may affect the bound states and consequently the surface properties. Based on Eilenberger equations we perform self-consistent calculations in three different cases: in the presence of impurities, in the presence of an external magnetic field, and a combination of these two cases. We focus on the influence of bulk impurity scattering in the Born approximation limit. We show that the impurity scattering around zero energy is significantly increased near the surface as compared to the bulk due to the presence of ABSs. This leads to a larger broadening of the ABSs than expected from the scattering rate in the bulk and consequently a decrease of the peak height of the local density of states at zero energy. Due to the anomalous Meissner current flowing at the nodal surface, the magnetic field initially increases before the normal Meissner screening sets in and eventually screens out the magnetic field exponentially. The field increase is stronger at low temperatures and leads to an increase in the modulus of the vector potential towards low temperatures. The result is a nonmonotonous temperature dependence of the vector potential at the surface. Since the vector potential is proportional to the superfluid velocity, the size of the peak splitting in the local density of states is directly influenced by such a behavior of the vector potential. We observe that the splitting is large both for low temperatures and close to the critical temperature. As a result also the

  8. Influence of surface treatments on the surface properties of different zirconia cores and adhesion of zirconia-veneering ceramic systems.

    Science.gov (United States)

    Elsaka, Shaymaa E

    2013-10-01

    The aim of this study was to assess the influence of surface treatments on the surface characteristics of different zirconia cores and the adhesion of the zirconia-veneering ceramic systems by means of strain energy release rate (G-value, J/m(2)). Three types of zirconia cores (NANOZR (NZ), Vita In-Ceram YZ (VZ), and IPS e.max ZirCAD (IZ)) were used. The specimens were divided into four groups in each test according to the surface treatment used; Gr 1 (control; no treatment), Gr 2 (sandblasted), Gr 3 (CH2Cl2 for 60min), and Gr 4 (experimental hot etching solution for 60min). AFM, SEM, EDS, and XRD were carried out. Two types of veneering ceramics (Vita VM9 (V9) and IPS e.max Ceram (IC)) were used for testing the adhesion. The G-value (J/m(2)) was measured with a four-point bending configuration. Following fracture testing specimens were examined with SEM. Data were analyzed using ANOVA and Tukey's test. NZ treated with the experimental hot etching solution showed the highest Ra values (206.06±9.98nm) compared with the other groups (Pveneering ceramic systems. The experimental hot etching solution could be considered as alternative treatment modality to sandblasting for zirconia cores to avoid phase transition at the surface from tetragonal to monoclinic that may be detrimental for the longevity of the zirconia-veneering ceramic restoration. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. The influence of mouthrinses and simulated toothbrushing on the surface roughness of a nanofilled composite resin

    Directory of Open Access Journals (Sweden)

    Keico Graciela Sano Trauth

    2012-06-01

    Full Text Available The aim of this study was to determine the influence of mouthrinses on the surface roughness of a nanofilled composite resin after toothbrushing. One hundred nanofilled composite resin specimens were prepared and randomly distributed into two groups-brushed and non-brushed-and then assigned to five subgroups, according to the mouthrinse solutions (n = 10: Colgate Plax Fresh Mint, Oral B, Cepacol, Colgate Plax, and artificial saliva. Each sample was immersed in 20 mL of the mouthrinses for 1 minute, 5 days per week, twice a day, for a 3-week period. The control group used in the study was one in which the specimens were not subjected to brushing and remained only in artificial saliva. Toothbrushing was performed once a week for 1 minute, for 3 weeks. Surface roughness measurements (Ra were performed after the immersion period and toothbrushing, by means of a profilometer. Data were analyzed by two-way ANOVA and Tukey's test. Analysis revealed that the association between toothbrushing and Colgate Plax Fresh Mint produced the lowest surface roughness (p < 0.05. All other groups tested (Oral B, Cepacol, Colgate Plax, artificial saliva exhibited no statistically significant differences between surfaces, whether subjected to toothbrushing or not (p < 0.05. It was concluded that the surface roughness of the nanofilled composite resin tested can be influenced by the mouthrinse associated with toothbrushing.

  10. Influence of biological fluids in bacterial viability on different hospital surfaces and fomites.

    Science.gov (United States)

    Esteves, Deigilam C; Pereira, Valeria C; Souza, Joyce M; Keller, Rogéria; Simões, Rebeca D; Winkelstroter Eller, Lizziane K; Rodrigues, Marcus Vinicius P

    2016-03-01

    The hospital environment is susceptible to bacterial contamination along with survival in fomites and surfaces, allowing dissemination of potential pathogenic strains. The present research aimed to evaluate the influence of biological fluids in bacterial viability on fomites and surfaces commonly present in nosocomial environment. Four different fomites and surfaces (ceramic floor, cotton fabric fragments and synthetic fibers, and eggcrate foam mattress) were contaminated with potential pathogens (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, and Klebsiella pneumoniae), then submitted to influence of biological fluids (blood, urine, artificial saliva). The viability of strains was evaluated at 24 hours after contamination and then in intervals of 7 days, by the colony-forming unit count technique. S aureus presented viability (>70 days) in all conditions tested, E faecalis and K pneumoniae had decreased viability over time, and E coli did not exhibit a growth relationship with surfaces or fluids. Persistence and adaptability capacity of potential pathogens in fomites and surfaces exposed to the patient are important for guidance, planning, and outlining of protocols for microorganism dissemination control and prevention in the health care environment. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  11. Influence of milling process in the surface energy of glass tile frits

    International Nuclear Information System (INIS)

    Tamayo, A.; Rubio, F.; Otero, J. L.; Rubio, J.

    2013-01-01

    In this work has been studied the influence of the milling process of two ceramic frits used in the ceramic tile industry. Both glass frits were of similar chemical composition changing SiO 2 by 5% of B 2 O 3 and both of them were water or dry milled. Glass frit surfaces were characterized by FT-IR, Karl-Fischer (K-F) titration and Inverse Gas Chromatography at Infinite Dilution (IGC-ID). By K-F titration it was observed that water milled frits presented 28 and 26 OH groups for 100 A 2 if they do not contain or contain boron, respectively. These surface changes are also observed by IGC-ID. Thus, the glass frit without boron and dry milled presented the highest dispersive surface energy (44 mJ.m - 2) and the less acidic constant (0.13 kJ.mol - 1). Both glass frits are amphoteric with acidic and base surface active sites, and that frit without boron presents the higher basicity. Milling process influences in the acid-base surface characteristics of both frits by increasing the basicity for the one without boron and increasing for the other one. This has been assigned to the different location of hydroxyl groups where the higher interaction is the one that does not contain boron and dry milled as K-F results. (Author)

  12. Influence of surface rectangular defect winding layer on burst pressure of CNG-II composite cylinder

    Science.gov (United States)

    You, H. X.; Peng, L.; Zhao, C.; Ma, K.; Zhang, S.

    2018-01-01

    To study the influence of composite materials’ surface defect on the burst pressure of CNG-II composite cylinder, the surface defect was simplified as a rectangular slot of certain size on the basis of actually investigating the shape of cylinder’s surface defect. A CNG-II composite cylinder with a rectangular slot defect (2mm in depth) was used for burst test, and the numerical simulation software ANSYS was used to calculate its burst pressure. Through comparison between the burst pressure in the test and the numerical analysis result, the correctness of the numerical analysis method was verified. On this basis, the numerical analysis method was conducted for composite cylinders with surface defect in other depth. The result showed that surface defect in the form of rectangular slot had no significant effect on the liner stress of composite cylinder. Instead, it had a great influence on the stress of fiber-wrapped layer. The burst pressure of the composite cylinder decreased as the defect depth increasing. The hoop stress at the bottom of the defect in the shape of rectangular slot exceeded the maximum of the composite materials’ tensile strength, which could result in the burst pressure of composite cylinders decreasing.

  13. Can surface preparation with CVD diamond tip influence on bonding to dental tissues?

    Science.gov (United States)

    Aparecido Kawaguchi, Fernando; Brossi Botta, Sergio; Nilo Vieira, Samuel; Steagall Júnior, Washington; Bona Matos, Adriana

    2008-04-01

    This study evaluated the influence of chemical vapor deposition (CVD) tips surface treatments of enamel and dentin on bonding resistance of two adhesive systems. Thirty embedded samples were divided in 12 groups ( n = 10), according to factors: substrate (enamel and dentin), adhesive system [etch-and-rinse (SB) and self-etch]; and the surface treatments (paper discs, impact CVD tips and tangential CVD tip). When CVD tip was used in the impact mode the tip was applied perpendicular to dental surface, while at tangential mode, the tip worked parallel to dental surface. Specimens were tested in tension after 24 h at 0.5 mm/min of cross-head speed. ANOVA results, in MPa showed that in enamel, only adhesive system factor was statistically significant ( p = 0.015) under tested conditions, with higher bond strength observed for SB groups. However, in dentin the best bonding performance was obtained in SE groups ( p = 0.00). In both tested substrates, results did not show statistically significant difference for factors treatment and its interactions. ConclusionsIt may be concluded that CVD-tip surface treatment, in both tested modes, did not influence on adhesion to enamel and dentin. But, it is important to choose adhesive system according to the tissue available to bonding.

  14. Influence of geology on arsenic concentrations in ground and surface water in central Lesvos, Greece.

    Science.gov (United States)

    Aloupi, Maria; Angelidis, Michael O; Gavriil, Apostolos M; Koulousaris, Michael; Varnavas, Soterios P

    2009-04-01

    The occurrence of As was studied in groundwater used for human consumption and irrigation, in stream water and sediments and in water from thermal springs in the drainage basin of Kalloni Gulf, island of Lesvos, Greece, in order to investigate the potential influence of the geothermal field of Polichnitos-Lisvori on the ground and surface water systems of the area. Total dissolved As varied in the range geology exerts a determinant influence on As geochemical behaviour. On the other hand, the geothermal activity manifested in the area of Polichnitos-Lisvori does not affect the presence of As in groundwater and streams.

  15. Study on the influence of helical milling parameters on surface roughness of titanium alloy

    Directory of Open Access Journals (Sweden)

    Chunhui JI

    2015-06-01

    Full Text Available As a new technology, helical milling has been widely used in hole-making of titanium alloy, and the surface roughness is an important indicator for evaluating the quality of titanium alloy hole. In this paper, the helical milling experiments are carried out to study the effect of machining parameters on the surface roughness with the model established in Matlab. It is proved that the model can well predict the influence of the helical milling parameters on surface roughness. With screw pitch increasing, the surface roughness of titanium hole firstly decreases and then increases in the range of 0.15~0.25 mm/rev. However, the surface roughness increases gradually at first and then decreases with the increasing of the feed per tooth in the range of 0.03~0.05 mm/tooth. Similarly, with the increasing of spindle speed, the surface roughness firstly increases, then decreases, and again gradually increases smoothly in the range of 2 500~3 500 r/min. The results in the work can provide experimental basis for optimizing cutting parameters and decreasing surface roughness in helical milling process.

  16. Influence of Surface Treatments on the Bond Strength of Resin Cements to Monolithic Zirconia.

    Science.gov (United States)

    Elsaka, Shaymaa E

    To assess the influence of surface treatment on the microtensile bond strength (μTBS) of resin cements to monolithic zirconia materials. Two types of monolithic zirconia (Zenostar T [ZT] and Prettau Anterior [PA]) were evaluated. The specimens were assigned to three groups based on the surface treatment applied: group 1: control, assintered; group 2: sandblasted with 50-μm Al₂O₃; group 3: tribochemically silica sandblasted. Two types of resin cements (Multilink Speed [MS] and Multilink N [MN]) were applied to each group for evaluating the bond strength using the μTBS test. The fractured specimens were observed with a stereomicroscope and SEM. Surface roughness and topography of monolithic zirconia were examined after treatment. Data were analyzed using ANOVA and Tukey's test. A Weibull analysis was performed on the bond strength data. The bond strength was significantly affected by the surface treatment and the type of resin cement (p zirconia (p = 0.387). Surface treatment with tribochemical silica sandblasting revealed significantly higher bond strength (p zirconia was changed due to surface treatments. The surface treatment of monolithic zirconia with tribochemical silica sandblasting enhanced the bond strength between zirconia and resin cements. Resins cements containing adhesive phosphate monomer (APM, MS) provided higher bond strength to monolithic zirconia than non-APM (MN).

  17. Estimation of methane emission flux at landfill surface using laser methane detector: Influence of gauge pressure.

    Science.gov (United States)

    Park, Jin-Kyu; Kang, Jong-Yun; Lee, Nam-Hoon

    2016-08-01

    The aim of this study was to investigate the possibility of measuring methane emission fluxes, using surface methane concentration and gauge pressure, by analyzing the influence of gauge pressure on the methane emission flux and the surface methane concentration, as well as the correlation between the methane emission flux and surface methane concentrations. The surface methane concentration was measured using a laser methane detector. Our results show a positive linear relationship between the surface methane concentration and the methane emission flux. Furthermore, the methane emission flux showed a positive linear relationship with the gauge pressure; this implies that when the surface methane concentration and the surface gauge pressure are measured simultaneously, the methane emission flux can be calculated using Darcy's law. A decrease in the vertical permeability was observed when the gauge pressure was increased, because reducing the vertical permeability may lead to a reduced landfill gas emission to the atmosphere, and landfill gas would be accumulated inside the landfill. Finally, this method is simple and can allow for a greater number of measurements during a relatively shorter period. Thus, it provides a better representation of the significant space and time variations in methane emission fluxes. © The Author(s) 2016.

  18. Influence of surface oxides on the adsorption of naphthalene onto multiwalled carbon nanotubes.

    Science.gov (United States)

    Cho, Hyun-Hee; Smith, Billy A; Wnuk, Joshua D; Fairbrother, D Howard; Ball, William P

    2008-04-15

    As greater quantities of carbon nanotubes (CNTs) enter the environment, they will have an increasingly important effect on the availability and transport of aqueous contaminants. As a consequence of purification, deliberate surface functionalization, and/or exposure to oxidizing agents after release to the environment, CNTs often contain surface oxides (i.e., oxygen containing functional groups). To probe the influence that surface oxides exert on CNT sorption properties, multiwalled CNTs (MWCNTs) with varying oxygen concentrations were studied with respect to their sorption properties toward naphthalene. For pristine (as-received) MWCNTs, the sorption capacity was intermediate between that of a natural char and a granular activated carbon. Sorption data also reveal that a linear relationship exists between the oxygen content of MWCNTs and their maximum adsorption capacity for naphthalene, with 10% surface oxygen concentration resulting in a roughly 70% decrease in maximum adsorption capacity. The relative distribution of sorption energies, as characterized by Freundlich isotherm exponents was, however, unaffected by oxidation. Thus, the data are consistent with the idea that incorporated surface oxides create polar regions that reduce the surface area available for naphthalene sorption. These results highlight the important role of surface chemistry in controlling the environmental properties of CNTs.

  19. Influence of surface nudging on climatological mean and ENSO feedbacks in a coupled model

    Science.gov (United States)

    Zhu, Jieshun; Kumar, Arun

    2018-01-01

    Studies have suggested that surface nudging could be an efficient way to reconstruct the subsurface ocean variability, and thus a useful method for initializing climate predictions (e.g., seasonal and decadal predictions). Surface nudging is also the basis for climate models with flux adjustments. In this study, however, some negative aspects of surface nudging on climate simulations in a coupled model are identified. Specifically, a low-resolution version of the NCEP Climate Forecast System, version 2 (CFSv2L) is used to examine the influence of nudging on simulations of climatological mean and on the coupled feedbacks during ENSO. The effect on ENSO feedbacks is diagnosed following a heat budget analysis of mixed layer temperature anomalies. Diagnostics of the climatological mean state indicates that, even though SST biases in all ocean basins, as expected, are eliminated, the fidelity of climatological precipitation, surface winds and subsurface temperature (or the thermocline depth) could be highly ocean basin dependent. This is exemplified by improvements in the climatology of these variables in the tropical Atlantic, but degradations in the tropical Pacific. Furthermore, surface nudging also distorts the dynamical feedbacks during ENSO. For example, while the thermocline feedback played a critical role during the evolution of ENSO in a free simulation, it only played a minor role in the nudged simulation. These results imply that, even though the simulation of surface temperature could be improved in a climate model with surface nudging, the physics behind might be unrealistic.

  20. Ionic liquids influence on the surface properties of electron beam irradiated wood

    International Nuclear Information System (INIS)

    Croitoru, Catalin; Patachia, Silvia; Doroftei, Florica; Parparita, Elena; Vasile, Cornelia

    2014-01-01

    Highlights: • Wood veneers impregnated with three imidazolium-based ionic liquids and irradiated with electron beam were studied by FTIR-ATR, SEM/EDX, AFM, contact angle and image analysis. • ILs preserve the surface properties of the wood (surface energy, roughness, color) upon irradiation, in comparison with the reference wood, but the surface composition is changed by treatment with IL-s, mainly with 1-butyl-3-methylimidazolium tetrafluoroborate. • Under electron beam irradiation covalent bonding of the imidazolium moiety to wood determines a higher resistance to water penetration and spreading on the surface. - Abstract: In this paper, the influence of three imidazolium-based ionic liquids (1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-hexyl-3-methylimidazolium chloride) on the structure and surface properties of sycamore maple (Acer pseudoplatanus) veneers submitted to electron beam irradiation with a dose of 50 kGy has been studied by using Fourier transform infrared spectroscopy, as well as image, scanning electron microscopy/SEM/EDX, atomic force microscopy and contact angle analysis. The experimental results have proven that the studied ionic liquids determine a better preservation of the structural features of wood (cellulose crystallinity index and lignin concentration on the surface) as well as some of surface properties such as surface energy, roughness, color upon irradiation with electron beam, in comparison with the reference wood, but surface composition is changed by treatment with imidazolium-based ionic liquids mainly with 1-butyl-3-methylimidazolium tetrafluoroborate. Also, under electron beam irradiation covalent bonding of the imidazolium moiety to wood determines a higher resistance to water penetration and spreading on the surface

  1. Titanium Surfaces with Nanostructures Influence on Osteoblasts Proliferation: a Systematic Review

    Directory of Open Access Journals (Sweden)

    Maxim

    2014-10-01

    Full Text Available Objectives: Nanothechnology found to be increasingly implemented in implantology sphere over the recent years and it shows encouraging effect in this field. The aim of present review is to compare, based on the recent evidence, the influence of various nanostructure surface modifications of titanium for implants, on osteoblasts proliferation. Material and Methods: A literature review of English articles was conducted by using MEDLINE database restricted to 2009 - 2014 and constructed according PRISMA guidelines. Search terms included “Titanium implant”, “Titanium surface with nanostructure”, “Osteoblast”. Additional studies were identified in bibliographies. Only in vitro and/or in vivo studies on nano structured implant surfaces plus control sample, with specific evaluation method for osteoblasts proliferation and at least one Ti sample with nanostructure, were included in the review. Results: 32 studies with 122 groups of examined samples were selected for present review. Each study conducted in vitro experiment, two studies conducted additional in vivo experiments. All studies were dispensed by type of surface modification into two major groups; “Direct ablative titanium implant surface nano-modifications” with 19 studies and ”Nanocomposite additive implant surface modifications” with 13 studies. Overall 24 studies reporting on positive effect of nanostructured surface, 2 studies found no significant advantage and 6 studies reported on negative effect compared to other structure scales. Conclusions: From examination of selected articles we can notice marked advantage in implementation of various nanostructures onto implant surface. Yet for discovering the ultimate implant surface nanostructure, further comparable investigations of Ti surface nanostructures need to be done.

  2. Influence of slip-surface geometry on earth-flow deformation, Montaguto earth flow, southern Italy

    Science.gov (United States)

    Guerriero, L.; Coe, Jeffrey A.; Revellio, P.; Grelle, G.; Pinto, F.; Guadagno, F.

    2016-01-01

    We investigated relations between slip-surface geometry and deformational structures and hydrologic features at the Montaguto earth flow in southern Italy between 1954 and 2010. We used 25 boreholes, 15 static cone-penetration tests, and 22 shallow-seismic profiles to define the geometry of basal- and lateral-slip surfaces; and 9 multitemporal maps to quantify the spatial and temporal distribution of normal faults, thrust faults, back-tilted surfaces, strike-slip faults, flank ridges, folds, ponds, and springs. We infer that the slip surface is a repeating series of steeply sloping surfaces (risers) and gently sloping surfaces (treads). Stretching of earth-flow material created normal faults at risers, and shortening of earth-flow material created thrust faults, back-tilted surfaces, and ponds at treads. Individual pairs of risers and treads formed quasi-discrete kinematic zones within the earth flow that operated in unison to transmit pulses of sediment along the length of the flow. The locations of strike-slip faults, flank ridges, and folds were not controlled by basal-slip surface topography but were instead dependent on earth-flow volume and lateral changes in the direction of the earth-flow travel path. The earth-flow travel path was strongly influenced by inactive earth-flow deposits and pre-earth-flow drainages whose positions were determined by tectonic structures. The implications of our results that may be applicable to other earth flows are that structures with strikes normal to the direction of earth-flow motion (e.g., normal faults and thrust faults) can be used as a guide to the geometry of basal-slip surfaces, but that depths to the slip surface (i.e., the thickness of an earth flow) will vary as sediment pulses are transmitted through a flow.

  3. Influence of surface pretreatment in resistance spot welding of aluminum AA1050

    DEFF Research Database (Denmark)

    Al Naimi, Ihsan K.; Al Saadi, Moneer H.; Daws, Kasim M.

    2015-01-01

    -, medium-, and high-energy inputs. The as-received sheet showed higher electrical contact resistance because of thicker oxide layer. Lower values were noticed with pickled surfaces, whereas the lowest electrical contact resistance was obtained when glass blasting, resulting in the roughest surface......Resistance spot welding (RSW) of aluminum alloys implies a major problem of inconsistent quality from weld to weld due to problems of varying thickness of the oxide layer. The high resistivity of oxide layer causes strong heat development, which has significant influence on electrode life and weld...

  4. The influence of the surface parameter changes onto the phonon states in ultrathin crystalline films

    Science.gov (United States)

    Šetrajčić, Jovan P.; Ilić, Dušan I.; Jaćimovski, Stevo K.

    2018-04-01

    In this paper, we have analytically investigated how the changes in boundary surface parameters influence the phonon dispersion law in ultrathin films of the simple cubic crystalline structure. Spectra of possible phonon states are analyzed using the method of two-time dependent Green's functions and for the diverse combination of boundary surface parameters, this problem was presented numerically and graphically. It turns out that for certain values and combinations of parameters, displacement of dispersion branches outside of bulk zone occurs, leading to the creation of localized phonon states. This fact is of great importance for the heat removal, electrical conductivity and superconducting properties of ultrathin films.

  5. Influence of Acute Kidney Injury Defined by the Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease Score on the Clinical Course of PICU Patients.

    Science.gov (United States)

    Cabral, Felipe Cezar; Ramos Garcia, Pedro Celiny; Mattiello, Rita; Dresser, Daiane; Fiori, Humberto Holmer; Korb, Cecilia; Dalcin, Tiago Chagas; Piva, Jefferson Pedro

    2015-10-01

    To evaluate the predictive value of the pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease criteria for disease course severity in patients with or without acute kidney injury admitted to a PICU. Retrospective cohort study. A 12-bed PICU at a tertiary referral center in Southern Brazil. All patients admitted to the study unit over a 1-year period. A database of all eligible patients was analyzed retrospectively. Patients were classified by pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease score at admission and worst pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease score during PICU hospitalization. The outcomes of interest were length of PICU stay, duration of mechanical ventilation, duration of vasoactive drug therapy, and mortality. The Pediatric Index of Mortality 2 was used to assess overall disease severity at the time of PICU admission. Of 375 patients, 169 (45%) presented acute kidney injury at the time of admission and 37 developed acute kidney injury during PICU stay, for a total of 206 of 375 patients (55%) diagnosed with acute kidney injury during the study period. The median Pediatric Index of Mortality 2 score predicted a mortality rate of 9% among non-acute kidney injury patients versus a mortality rate of 16% among acute kidney injury patients (p = 0.006). The mortality of patients classified as pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease F was double that predicted by Pediatric Index of Mortality 2 (7 vs 3.2). Patients classified as having severe acute kidney injury (pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease I + F) exhibited higher mortality (14.1%; p = 0.001) and prolonged PICU length of stay (median, 7 d; p = 0.001) when compared with other patients. Acute kidney injury is a very frequent occurrence among patients admitted to PICUs. The degree of acute kidney injury severity, as assessed by the pediatric-modified Risk

  6. Influence of Ecological Factors on Estimation of Impervious Surface Area Using Landsat 8 Imagery

    Directory of Open Access Journals (Sweden)

    Yuqiu Jia

    2017-07-01

    Full Text Available Estimation of impervious surface area is important to the study of urban environments and social development, but surface characteristics, as well as the temporal, spectral, and spatial resolutions of remote sensing images, influence the estimation accuracy. To investigate the effects of regional environmental characteristics on the estimation of impervious surface area, we divided China into seven sub-regions based on climate, soil type, feature complexity, and vegetation phenology: arid and semi-arid areas, Huang-Huai-Hai winter wheat production areas, typical temperate regions, the Pearl River Delta, the middle and lower reaches of the Yangtze River, typical tropical and subtropical regions, and the Qinghai Tibet Plateau. Impervious surface area was estimated from Landsat 8 images of five typical cities, including Yinchuan, Shijiazhuang, Shenyang, Ningbo, and Kunming. Using the linear spectral unmixing method, impervious and permeable surface areas were determined at the pixel-scale based on end-member proportions. We calculated the producer’s accuracy, user’s accuracy, and overall accuracy to assess the estimation accuracy, and compared the accuracies among images acquired from different seasons and locations. In tropical and subtropical regions, vegetation canopies can confound the identification of impervious surfaces and, thus, images acquired in winter, early spring, and autumn are most suitable; estimations in the Pearl River Delta, the middle and lower reaches of the Yangtze River are influenced by soil, vegetation phenology, vegetation canopy, and water, and images acquired in spring, summer, and autumn provide the best results; in typical temperate areas, images acquired from spring to autumn are most effective for estimations; in winter wheat-growing areas, images acquired throughout the year are suitable; and in arid and semi-arid areas, summer and early autumn, during which vegetation is abundant, are the optimal seasons for

  7. Influence of aromatic compounds on the quantity and heterogeneity of surface lipids of Kalanchoe

    Directory of Open Access Journals (Sweden)

    L. S. Pacshenko

    2009-12-01

    Full Text Available The component composition of surface lipids of kalanchoe leaves under the influence of strong solutions of monochlorobenzene, nonylphenol and 2,4,6-trinitrophenol was studied. It was shown that the plants adaptations to the exogenous influence included the elongation processes of the oxocompounds specifically to the structure of the xenobiotic and the increasing of the total quantity of the surface lipids independently from their nature. Monochlorobenzene decreases the biosynthesis of oxocompounds and upsets its elongation. It results in creation of short-chain polar substances. Nonylphenol also decreases the biosynthesis of oxocompounds, but it is accompanied by the activation of its elongation. 2,4,6-trinitrophenol  increases of the oxocompounds fraction and activates its elongation.

  8. The influence of the circulation on surface temperature and precipitation patterns over Europe

    Directory of Open Access Journals (Sweden)

    P. D. Jones

    2009-06-01

    Full Text Available The atmospheric circulation clearly has an important influence on variations in surface temperature and precipitation. In this study we illustrate the spatial patterns of variation that occur for the principal circulation patterns across Europe in the standard four seasons. We use an existing classification scheme of surface pressure patterns, with the aim of considering whether the patterns of influence of specific weather types have changed over the course of the 20th century. We consider whether the long-term warming across Europe is associated with more favourable weather types or related to warming within some of the weather types. The results indicate that the latter is occurring, but not all circulation types show warming. The study also illustrates that certain circulation types can lead to marked differences in temperature and/or precipitation for relatively closely positioned sites when the sites are located in areas of high relief or near coasts.

  9. The influence of landing mat composition on ankle injury risk during a gymnastic landing: a biomechanical quantification.

    Science.gov (United States)

    Xiao, Xiaofei; Hao, Weiya; Li, Xuhong; Wan, Bingjun; Shan, Gongbing

    2017-01-01

    About 70% injury of gymnasts happened during landing - an interaction between gymnast and landing mat. The most injured joint is the ankle. The current study examined the effect of mechanical properties of landing mat on ankle loading with aims to identify means of decreasing the risk of ankle injury. Gymnastic skill - salto backward stretched with 3/2 twist was captured by two high-speed camcorders and digitized by using SIMI-Motion software. A subject-specific, 14-segment rigid-body model and a mechanical landing-mat model were built using BRG.LifeMODTM. The landings were simulated with varied landing-mat mechanical properties (i.e., stiffness, dampness and friction coefficients). Real landing performance could be accurately reproduced by the model. The simulations revealed that the ankle angle was relatively sensitive to stiffness and dampness of the landing mat, the ankle loading rate increased 26% when the stiffness was increased by 30%, and the changing of dampness had notable effect on horizontal ground reaction force and foot velocity. Further, the peak joint-reaction force and joint torque were more sensitive to friction than to stiffness and dampness of landing mat. Finally, ankle muscles would dissipate about twice energy (189%) when the friction was increased by 30%. Loads to ankles during landing would increase as the stiffness and dampness of the landing mat increase. Yet, increasing friction would cause a substantial rise of the ankle internal loads. As such, the friction should be a key factor influencing the risk of injury. Unfortunately, this key factor has rarely attracted attention in practice.

  10. The Influence of BMX Gene Polymorphisms on Clinical Symptoms after Mild Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Yu-Jia Wang

    2014-01-01

    Full Text Available Mild traumatic brain injury (mTBI is one of the most common neurological disorders. Most patients diagnosed with mTBI could fully recover, but 15% of patients suffer from persistent symptoms. In recent studies, genetic factors were found to be associated with recovery and clinical outcomes after TBI. In addition, results from our previous research have demonstrated that the bone marrow tyrosine kinase gene in chromosome X (BMX, a member of the Tec family of kinases, is highly expressed in rats with TBI. Therefore, our aim in this study was to identify the association between genetic polymorphisms of BMX and clinical symptoms following mTBI. Four tagging single nucleotide polymorphisms (tSNPs of BMX with minimum allele frequency (MAF >1% were selected from the HapMap Han Chinese database. Among these polymorphisms, rs16979956 was found to be associated with the Beck anxiety inventory (BAI and dizziness handicap inventory (DHI scores within the first week after head injury. Additionally, another SNP, rs35697037, showed a significant correlation with dizziness symptoms. These findings suggested that polymorphisms of the BMX gene could be a potential predictor of clinical symptoms following mTBI.

  11. Influence of Sexuality in Functional Recovery after Spinal Cord Injury in rats

    Directory of Open Access Journals (Sweden)

    Mohammadreza Emamhadi

    2016-01-01

    Full Text Available Background: Spinal cord injury (SCI is a major clinical condition and research is commonly done to find suitable treatment options. However, there are some degrees of spontaneous recovery after SCI and gender is said to be a contributing factor in recovery, but this is controversial. This study was done to compare the effects of sexual dimorphism on spontaneous recovery after spinal cord injury in Wistar Rats. Methods: Spinal cord lesions were made by compressing the cord at T9 level and making a spinal cord contusion. Routine care of each rat was done daily. The LSS scoring system was used to measure the locomotion of these rats and to compare the recovery rate between male and female rats. Results: The results suggested that there was no significant difference between the two sex in recovery. Conclusions: To be female does not seem to be a prognostic factor for recovery after SCI. However, this preliminary study should be repeated in other animals and in larger cohorts.

  12. Parameters Influencing Tracheostomy Decannulation in Patients Undergoing Rehabilitation after severe Acquired Brain Injury (sABI).

    Science.gov (United States)

    Perin, Cecilia; Meroni, Roberto; Rega, Vincenzo; Braghetto, Giacomo; Cerri, Cesare Giuseppe

    2017-10-01

    Introduction  Tracheostomy weaning in patients who suffered a severe acquired brain injury is often a challenge and decannulation failures are not uncommon. Objective  Our study objective is to describe the decannulation failure rate in patients undergoing rehabilitation following a severe acquired brain injury (sABI); to describe the factors associated with a successful tube weaning. Methods  We conduct a retrospective analysis of charts, consecutively retrieved considering a 3-year window. Variables analyzed were: age, sex, body mass index (BMI), Glasgow Coma Scale (GCS), cause of hospitalization (stroke, trauma, cardiac arrest), date of the pathological event, gap between the index event and the first day of hospitalization, duration of Neurorehabilitation Ward hospitalization, comorbidities, chest morphological alteration, kind of tracheostomy tube used (overall dimension, cap, fenestration), SpO2, presentation and quantification of pulmonary secretion, maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), respiratory frequency and pattern, cardiac frequency, presence of spontaneous cough, cough strength, and blood gas analysis. Results  We analyzed 45 tracheostomised sABI patients following stroke, trauma, or cardiac arrest. The weaning success percentage was higher in Head Trauma patients and in patients presenting positive spontaneous cough. Failures seem to be associated with presence of secretions and anoxic brain damage. GCS seemed not related to the decannulation outcome. Conclusions  Parameters that could be used as positive predictors of weaning are: mean expiratory pressure, presence of spontaneous cough, and cough strength. Provoked cough and GCS were not predictive of weaning success.

  13. Influence of surface properties of mix-monolayers on lipolytic hydrolysis

    DEFF Research Database (Denmark)

    Peters, Günther H. J.; Dahmen, U.; Brezesinski, G.

    2000-01-01

    Fluorescence microscopy, surface potential, and activity measurements were used to investigate the influence of fatty acids and fatty alcohols on the lipolytic activity of several lipases. We have determined the lateral lipid distribution and interfacial properties of Langmuir mixed monolayers co...... of available diacylglyceride area to the enzyme. Direct imaging of the lipolytic hydrolysis of these monolayers show that relatively small domains are formed, suggesting that the enzyme preferentially acts on pure diacylglyceride patches....

  14. The influence of surface type on the absorbed radiation by a human under hot, dry conditions

    Science.gov (United States)

    Hardin, A. W.; Vanos, J. K.

    2018-01-01

    Given the predominant use of heat-retaining materials in urban areas, numerous studies have addressed the urban heat island mitigation potential of various "cool" options, such as vegetation and high-albedo surfaces. The influence of altered radiational properties of such surfaces affects not only the air temperature within a microclimate, but more importantly the interactions of long- and short-wave radiation fluxes with the human body. Minimal studies have assessed how cool surfaces affect thermal comfort via changes in absorbed radiation by a human ( R abs) using real-world, rather than modeled, urban field data. The purpose of the current study is to assess the changes in the absorbed radiation by a human—a critical component of human energy budget models—based on surface type on hot summer days (air temperatures > 38.5∘C). Field tests were conducted using a high-end microclimate station under predominantly clear sky conditions over ten surfaces with higher sky view factors in Lubbock, Texas. Three methods were used to measure and estimate R abs: a cylindrical radiation thermometer (CRT), a net radiometer, and a theoretical estimation model. Results over dry surfaces suggest that the use of high-albedo surfaces to reduce overall urban heat gain may not improve acute human thermal comfort in clear conditions due to increased reflected radiation. Further, the use of low-cost instrumentation, such as the CRT, shows potential in quantifying radiative heat loads within urban areas at temporal scales of 5-10 min or greater, yet further research is needed. Fine-scale radiative information in urban areas can aid in the decision-making process for urban heat mitigation using non-vegetated urban surfaces, with surface type choice is dependent on the need for short-term thermal comfort, or reducing cumulative heat gain to the urban fabric.

  15. Influence of surface microstructure and chemistry on osteoinduction and osteoclastogenesis by biphasic calcium phosphate discs.

    Science.gov (United States)

    Davison, N L; Su, J; Yuan, H; van den Beucken, J J J P; de Bruijn, J D; Barrère-de Groot, F

    2015-06-20

    It has been reported that surface microstructural dimensions can influence the osteoinductivity of calcium phosphates (CaPs), and osteoclasts may play a role in this process. We hypothesised that surface structural dimensions of ≤ 1 μm trigger osteoinduction and osteoclast formation irrespective of macrostructure (e.g., concavities, interconnected macropores, interparticle space) or surface chemistry. To test this, planar discs made of biphasic calcium phosphate (BCP: 80% hydroxyapatite, 20% tricalcium phosphate) were prepared with different surface structural dimensions - either ~ 1 μm (BCP1150) or ~ 2-4 μm (BCP1300) - and no macropores or concavities. A third material was made by sputter coating BCP1150 with titanium (BCP1150Ti), thereby changing its surface chemistry but preserving its surface structure and chemical reactivity. After intramuscular implantation in 5 dogs for 12 weeks, BCP1150 formed ectopic bone in 4 out of 5 samples, BCP1150Ti formed ectopic bone in 3 out of 5 samples, and BCP1300 formed no ectopic bone in any of the 5 samples. In vivo, large multinucleated osteoclast-like cells densely colonised BCP1150, smaller osteoclast-like cells formed on BCP1150Ti, and osteoclast-like cells scarcely formed on BCP1300. In vitro, RAW264.7 cells cultured on the surface of BCP1150 and BCP1150Ti in the presence of osteoclast differentiation factor RANKL (receptor activator for NF-κB ligand) proliferated then differentiated into multinucleated osteoclast-like cells with positive tartrate resistant acid phosphatase (TRAP) activity. However, cell proliferation, fusion, and TRAP activity were all significantly inhibited on BCP1300. These results indicate that of the material parameters tested - namely, surface microstructure, macrostructure, and surface chemistry - microstructural dimensions are critical in promoting osteoclastogenesis and triggering ectopic bone formation.

  16. Recovery of sensorimotor function and activities of daily living after cervical spinal cord injury: the influence of age.

    Science.gov (United States)

    Wirz, Markus; Dietz, Volker

    2015-02-01

    This retrospective study was designed to examine the influence of age on the outcome of motor function and activities of daily living (ADLs) in patients with a cervical spinal cord injury (SCI). The study is based on the data registry of the European Multicenter Study of Spinal Cord Injury (EMSCI) study group. Initial upper-extremity motor score (UEMS) and its change over 5 months, as well as the initial Spinal Cord Independence Measure (SCIM) score, did not differ between younger adults (20-39 years) and elderly (60-79 years) patients. However, the change in SCIM score over 5 months was significantly greater in the younger patient group. Initial UEMS, SCIM, and ulnar compound motor action potentials (CMAP), reflecting peripheral nerve damage (motoneurons and roots), were significantly greater in incomplete, compared to complete, SCI, regardless of age group. The initial assessment of UEMS in combination with CMAP recordings allows an early prediction of ADLs outcomes in both younger adults and elderly subjects. The impaired translation of gain in motor score into increased ADL independence in elderly patients requires specifically tailored rehabilitation programs.

  17. Safety in the c-suite: How chief executive officers influence organizational safety climate and employee injuries.

    Science.gov (United States)

    Tucker, Sean; Ogunfowora, Babatunde; Ehr, Dayle

    2016-09-01

    According to social learning theory, powerful and high status individuals can significantly influence the behaviors of others. In this paper, we propose that chief executive officers (CEOs) indirectly impact frontline injuries through the collective social learning experiences and effort of different groups of organizational actors-including members of the top management team (TMT), organizational supervisors, and frontline employees. We found support for our collective social learning model using data from 2,714 frontline employees, 1,398 supervisors, and 229 members of TMTs in 54 organizations. TMT members' experiences within a CEO-driven TMT safety climate was positively related to organizational supervisors' reports of the broader organizational safety climate and their subsequent collective support for safety (reported by frontline employees). In turn, supervisory support for safety was associated with fewer employee injuries at the individual level. We discuss the theoretical and practical implications of these findings for workplace safety research and practice. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  18. CO2 sorption on surface-modified carbonaceous support: Probing the influence of the carbon black microporosity and surface polarity

    Science.gov (United States)

    Gargiulo, Valentina; Alfè, Michela; Ammendola, Paola; Raganati, Federica; Chirone, Riccardo

    2016-01-01

    The use of solid sorbents is a convenient option in post-combustion CO2 capture strategies. Sorbents selection is a key point because the materials are required to be both low-cost and versatile in typical post-combustion conditions in order to guarantee an economically advantageous overall process. This work compares strategies to tailor the chemico-physical features of carbon black (CB) by surface-modification and/or coating with a CO2-sorbent phase. The influence of the CB microporosity, enhanced by chemical/thermal treatments, is also taken into account. Three CB surface modifications are performed and compared: (i) oxidation and functionalization with amino-groups, (ii) coating with iron oxides and (iii) impregnation with an ionic liquid (IL). The CO2 capture performance is evaluated on the basis of the breakthrough curves measured at atmospheric pressure and room temperature in a lab-scale fixed bed micro-reactor. Most of tested solids adsorb a CO2 amount significantly higher than a 13X zeolite and DARCO FGD (Norit) activated carbon (up to 4 times more in the best case). The sorbents bearing basic functionalities (amino-groups and IL) exhibit the highest CO2 sorption capacity. The use of a microporous carbonaceous support limits the accessibility of CO2 toward the adsorbing phase (IL or FM) lowering the number of accessible binding sites for CO2.

  19. Influence of the Lubricant Type on the Surface Quality of Steel Parts Obtained by Ironing

    Directory of Open Access Journals (Sweden)

    D. Adamović

    2015-06-01

    Full Text Available If it is needed to achieve a higher strain rate during the ironing process, which is possible without inter-stage annealing, the ironing is performed in succession through multiple dies. During that process, changes of friction conditions occur due to the change of contact conditions (dislodging of lubricants, changes of surface roughness, formation of friction junctions, etc.. In the multistage ironing, after each stage, the completely new conditions on the contact surfaces occur, which will significantly affect the quality of the workpiece surface. Lubricant has a very important role during the steel sheet metal ironing process; to separate the sheet metal surface from the tool and to reduce the friction between the contact surfaces. The influence of tribological conditions in ironing process is extremely important and it was a subject of study among researches in recent years, both in the real processes and on the tribo-models. Investigation of tribological conditions in the real processes is much longer and more expensive, so testing on the tribo-models is more frequent. Experimental research on the original tribo-model presented in this paper was aimed to indicate the changes that occur during multistage ironing, as well as to consider the impact of some factors (tool material, lubricant on die and punch on increase or decrease of the sheet metal surface roughness in ironing stages.

  20. Influence of ground surface characteristics on the mean radiant temperature in urban areas.

    Science.gov (United States)

    Lindberg, Fredrik; Onomura, Shiho; Grimmond, C S B

    2016-09-01

    The effect of variations in land cover on mean radiant temperature (T mrt ) is explored through a simple scheme developed within the radiation model SOLWEIG. Outgoing longwave radiation is parameterised using surface temperature observations on a grass and an asphalt surface, whereas outgoing shortwave radiation is modelled through variations in albedo for the different surfaces. The influence of ground surface materials on T mrt is small compared to the effects of shadowing. Nevertheless, altering ground surface materials could contribute to a reduction in T mrt to reduce the radiant load during heat-wave episodes in locations where shadowing is not an option. Evaluation of the new scheme suggests that despite its simplicity it can simulate the outgoing fluxes well, especially during sunny conditions. However, it underestimates at night and in shadowed locations. One grass surface used to develop the parameterisation, with very different characteristics compared to an evaluation grass site, caused T mrt to be underestimated. The implications of using high temporal resolution (e.g. 15 minutes) meteorological forcing data under partly cloudy conditions are demonstrated even for fairly proximal sites.

  1. Influence of skin surface roughness degree on energy characteristics of light scattered by a biological tissue

    Science.gov (United States)

    Barun, V. V.; Ivanov, A. P.

    2017-05-01

    We present the results of modelling of photometric characteristics of light in soft tissues illuminated by a parallel beam along the normal to the surface, obtained with allowance for the skin roughness parameters and the angular structure of radiation approaching the surface from within the tissue. The depth structure of the fluence rate and the spectra of the diffuse reflection of light by the tissue in the interval of wavelengths 300 - 1000 nm are considered. We discuss the influence of the tilt angle variance of rough surface microelements and light refraction on the studied characteristics. It is shown that these factors lead to the reduction of the radiation flux only in the near-surface tissue layer and practically do not affect the depth of light penetration into the tissue. On the other hand, the degree of the surface roughness and the conditions of its illumination from within the tissue essentially affect the coefficient of diffuse reflection of light and lead to its considerable growth compared to the cases of a smooth interface and completely diffuse illumination, often considered to simplify the theoretical problem solution. The role of the roughness of skin surface is assessed in application to the solution of different direct and inverse problems of biomedical optics.

  2. Influence of surface topography on the secondary electron yield of clean copper samples.

    Science.gov (United States)

    Hu, Xiao-Chuan; Cao, Meng; Cui, Wan-Zhao

    2016-11-01

    Secondary electron yield (SEY) due to electron impact depends strongly on surface topography. The SEY of copper samples after Ar-ion bombardment is measured in situ in a multifunctional ultrahigh vacuum system. Increasing the ion energy or duration of ion bombardment can even enlarge the SEY, though it is relatively low under moderate bombardment intensity. The results obtained with scanning electron microscopy and atomic force microscopy images demonstrate that many valley structures of original sample surfaces can be smoothed due to ion bombardment, but more hill structures are generated with stronger bombardment intensity. With increasing the surface roughness in the observed range, the maximum SEY decreases from 1.2 to 1.07 at a surface characterized by valleys, while it again increases to 1.33 at a surface spread with hills. This phenomenon indicates that hill and valley structures are respectively effective in increasing and decreasing the SEY. These obtained results thus provide a comprehensive insight into the surface topography influence on the secondary electron emission characteristics in scanning electron microscopy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Combined influence of inertia, gravity, and surface tension on the linear stability of Newtonian fiber spinning

    Science.gov (United States)

    Bechert, M.; Scheid, B.

    2017-11-01

    The draw resonance effect appears in fiber spinning processes if the ratio of take-up to inlet velocity, the so-called draw ratio, exceeds a critical value and manifests itself in steady oscillations of flow velocity and fiber diameter. We study the effect of surface tension on the draw resonance behavior of Newtonian fiber spinning in the presence of inertia and gravity. Utilizing an alternative scaling makes it possible to visualize the results in stability maps of highly practical relevance. The interplay of the destabilizing effect of surface tension and the stabilizing effects of inertia and gravity lead to nonmonotonic stability behavior and local stability maxima with respect to the dimensionless fluidity and the dimensionless inlet velocity. A region of unconditional instability caused by the influence of surface tension is found in addition to the region of unconditional stability caused by inertia, which was described in previous works [M. Bechert, D. W. Schubert, and B. Scheid, Eur. J. Mech B 52, 68 (2015), 10.1016/j.euromechflu.2015.02.005; Phys. Fluids 28, 024109 (2016), 10.1063/1.4941762]. Due to its importance for a particular group of fiber spinning applications, a viscous-gravity-surface-tension regime, i.e., negligible effect of inertia, is analyzed separately. The mechanism underlying the destabilizing effect of surface tension is discussed and established stability criteria are tested for validity in the presence of surface tension.

  4. Predicting uncertainty in sediment transport and landscape evolution - the influence of initial surface conditions

    Science.gov (United States)

    Hancock, G. R.; Coulthard, T. J.; Lowry, J. B. C.

    2016-05-01

    Numerical landscape evolution models were initially developed to examine natural catchment hydrology and geomorphology and have become a common tool to examine geomorphic behaviour over a range of time and space scales. These models all use a digital elevation model (DEM) as a representation of the landscape surface and a significant issue is the quality and resolution of this surface. Here we focus on how subtle perturbations or roughness on the DEM surface can produce alternative model results. This study is carried out by randomly varying the elevations of the DEM surface and examining the effect on sediment transport rates and geomorphology for a proposed rehabilitation design for a post-mining landscape using multiple landscape realisations with increasing magnitudes of random changes. We show that an increasing magnitude of random surface variability does not appear to have any significant effect on sediment transport over millennial time scales. However, the random surface variability greatly changes the temporal pattern or delivery of sediment output. A significant finding is that all simulations at the end of the 10,000 year modelled period are geomorphologically similar and present a geomorphological equifinality. However, the individual patterns of erosion and deposition were different for repeat simulations with a different sequence of random perturbations. The alternative positions of random perturbations strongly influence local patterns of hillslope erosion and evolution together with the pattern and behaviour of deposition. The findings demonstrate the complex feedbacks that occur even within a simple modelled system.

  5. Influence of surface treatment on the crevice corrosion of super duplex stainless steel

    International Nuclear Information System (INIS)

    Malik, H.

    1997-01-01

    The aim of this work was to try and discover if changes i surface condition, derived through various methods could influence the resistance to crevice corrosion of super duplex stainless teel (SDS). Such data could then be employed to elucidate the main factors controlling crevice corrosion. Through the manipulation of these parameters it was envisaged that the crevice corrosion temperature of this material may be further advanced and to increase its application within harsher industrial environments. For this reason a series of crevice tests were performed on SDSS heat exchanger tubing both in the as received condition and after various surface treatments. Such modification was carried out by; shot blasting, passivation, pickling and combinations of annealing, shot blasting, pickling and passivation. Results have indicated that the main factor controlling the resistance to crevice corrosion is the level of Cr depletion within a few microns of the steel surface. Although various treatments such as shot blasting and pickling reduce Cr depletion by removal of surface material, the nature of the surface finish itself was not found to affect the corrosion resistance. An increase in Cr content from 20 to 25% within 2 microns of the surface of the tubing was able to increase the crevice corrosion temperature by 20 sub deg. C. (author)

  6. Influences of surface and solvent on retention of HEMA/mixture components after evaporation.

    Science.gov (United States)

    Garcia, Fernanda C P; Wang, Linda; Pereira, Lúcia C G; de Andrade e Silva, Safira M; Júnior, Luiz M; Carrilho, Marcela Rocha de Oliveira

    2010-01-01

    This study examined the retention of solvents within experimental HEMA/solvent primers after two conditions for solvent evaporation: from a free surface or from dentine surface. Experimental primers were prepared by mixing 35% HEMA with 65% water, methanol, ethanol or acetone (v/v). Aliquots of each primer (50 microl) were placed on glass wells or they were applied to the surface of acid-etched dentine cubes (2mm x 2mm x 2mm) (n=5). For both conditions (i.e. from free surface or dentine cubes), change in primers mass due to solvent evaporation was gravimetrically measured for 10min at 51% RH and 21 degrees C. The rate of solvent evaporation was calculated as a function of loss of primers mass (%) over time. Data were analysed by two-way ANOVA and Student-Newman-Keuls (pevaporation rate (%/min) depending on the solvent present in the primer and the condition for evaporation (from free surface or dentine cubes) (pevaporation for HEMA/acetone primer was almost 2- to 10-times higher than for HEMA/water primer depending whether evaporation occurred, respectively, from a free surface or dentine cubes. The rate of solvent evaporation varied with time, being in general highest at the earliest periods. The rate of solvent evaporation and its retention into HEMA/solvent primers was influenced by the type of the solvent and condition allowed for their evaporation.

  7. Exploring the biomechanical load of a sliding on the skin: understanding the acute skin injury mechanism of player-surface interaction

    NARCIS (Netherlands)

    Eijnde, W.A.J. van den; Meijer, K.; Lamers, E.; Peppelman, M.; Erp, P.E. van

    2017-01-01

    BACKGROUND: Currently, there is a shortage of biomechanical data regarding acute skin injury mechanisms that are involved in player-surface contact in soccer on artificial turf. It is hypothesized that peak loads on the skin during the landing phase are an important factor in causing an acute skin

  8. CO2 sorption on surface-modified carbonaceous support: Probing the influence of the carbon black microporosity and surface polarity

    International Nuclear Information System (INIS)

    Gargiulo, Valentina; Alfè, Michela; Ammendola, Paola; Raganati, Federica; Chirone, Riccardo

    2016-01-01

    Graphical abstract: - Highlights: • CO 2 -sorbent materials preparation by surface modification of CB. • CB functionalization (amino-groups), CB coating (Fe 3 O 4 ), CB impregnation (ionic liquid). • Sorbents bearing basic functionalities exhibit the higher CO 2 sorption capacity. • Microporous supporting material limits the CO 2 accessibility toward the adsorbing material. - Abstract: The use of solid sorbents is a convenient option in post-combustion CO 2 capture strategies. Sorbents selection is a key point because the materials are required to be both low-cost and versatile in typical post-combustion conditions in order to guarantee an economically advantageous overall process. This work compares strategies to tailor the chemico-physical features of carbon black (CB) by surface-modification and/or coating with a CO 2 -sorbent phase. The influence of the CB microporosity, enhanced by chemical/thermal treatments, is also taken into account. Three CB surface modifications are performed and compared: (i) oxidation and functionalization with amino-groups, (ii) coating with iron oxides and (iii) impregnation with an ionic liquid (IL). The CO 2 capture performance is evaluated on the basis of the breakthrough curves measured at atmospheric pressure and room temperature in a lab-scale fixed bed micro-reactor. Most of tested solids adsorb a CO 2 amount significantly higher than a 13X zeolite and DARCO FGD (Norit) activated carbon (up to 4 times more in the best case). The sorbents bearing basic functionalities (amino-groups and IL) exhibit the highest CO 2 sorption capacity. The use of a microporous carbonaceous support limits the accessibility of CO 2 toward the adsorbing phase (IL or FM) lowering the number of accessible binding sites for CO 2 .

  9. Influence of Energy Beverages on the Surface Texture of Glass lonomer Restorative Materials.

    Science.gov (United States)

    Al-Samadani, Khalid H

    2017-10-01

    The objective of the study was to find whether energy beverages have an erosive effect, leading to a risk in the clinical performance of glass ionomer restorative materials. This study evaluated the influence of energy beverages on the surface texture of glass ionomer restorative materials. Glass ionomer materials used were Ionofil Plus AC, GC EQUIA, and Ketac Molar; energy beverages are Code Red, Red Bull, and Power Horse. Specimens prepared were discs of 8 mm diameter and 3 mm thickness; specimens from each material were evaluated following aging with Code Red, Red Bull, and Power Horse energy beverages. Distilled water was used as a control. The surface roughness (Ra) was assessed by surface scanning interferometry. The surface roughness values (ΔRa and Ra) were measured for each specimen. The data were analyzed statistically using multiple repeated measures [analysis of variance (ANOVA)] and paired data t-test (p glass ionomers with increasing immersion time. Energy beverages have an erosive effect on glass ionomer, which influences the clinical importance of the material; it also has anticarious property because it releases the fluoride.

  10. Influence of cloud optical thickness on surface diffuse light and carbon uptake in forests and croplands

    Science.gov (United States)

    Cheng, S. J.; Steiner, A. L.; Nadelhoffer, K. J.

    2014-12-01

    Accurately modeling atmospheric CO2 removal by terrestrial ecosystems requires an understanding of how atmospheric conditions change the rate of photosynthesis across major vegetation types. Diffuse light, which is created from interactions between incident solar radiation and atmospheric aerosols and clouds, has been postulated to increase carbon uptake in terrestrial ecosystems. To determine how cloud conditions affect carbon uptake through its influence on diffuse light, we quantify the relationship between cloud optical thickness, which indicates surface light attenuation by clouds, and surface diffuse light. We then examine the relationship between cloud optical thickness and gross primary productivity (GPP) to determine whether cloud properties could modulate GPP in temperate ecosystems. Surface diffuse light and GPP data are obtained from publically available Ameriflux data (Mead Crop sites, University of Michigan Biological Station, Morgan Monroe, and Howland Forest) and cloud optical thickness data over the Ameriflux sites are retrieved from NASA's Moderate Resolution Imaging Spetroradiometer. We compare the response of GPP to cloud optical thickness between croplands and forests, as well as within ecosystem types to determine ecosystem-specific responses and the role of plant community composition on ecosystem-level GPP under varying cloud conditions. By linking atmospheric cloud properties to surface light conditions and ecosystem carbon fluxes, we refine understanding of land-atmosphere carbon cycling and how changes in atmospheric cloud conditions may influence the future of the land carbon sink.

  11. Influence of Cooling Lubricants on the Surface Roughness and Energy Efficiency of the Cutting Machine Tools

    Science.gov (United States)

    Jersák, J.; Simon, S.

    2017-08-01

    The Technical University of Liberec and Brandenburg University of Technology Cottbus-Senftenberg investigated the influence of cooling lubricants on the surface roughness and energy efficiency of cutting machine tools. After summarizing the achieved experimental results, the authors conclude that cooling lubricants extensively influence the cutting temperature, cutting forces and energy consumption. Also, it is recognizable that cooling lubricants affect the cutting tools lifetime and the workpiece surface quality as well. Furthermore, costs of these cooling lubricants and the related environmental burden need to be considered. A current trend is to reduce the amount of lubricants that are used, e.g., when the Minimum Quantity Lubrication (MQL) technique is applied. The lubricant or process liquid is thereby transported by the compressed air in the form of an aerosol to the contact area between the tool and workpiece. The cutting process was monitored during testing by the three following techniques: lubricant-free cutting, cutting with the use of a lubricant with the MQL technique, and only utilizing finish-turning and finish-face milling. The research allowed the authors to monitor the cutting power and mark the achieved surface quality in relation to the electrical power consumption of the cutting machine. In conclusions, the coherence between energy efficiency of the cutting machine and the workpiece surface quality regarding the used cooling lubricant is described.

  12. Influence of Cooling Lubricants on the Surface Roughness and Energy Efficiency of the Cutting Machine Tools

    Directory of Open Access Journals (Sweden)

    Jersák J.

    2017-08-01

    Full Text Available The Technical University of Liberec and Brandenburg University of Technology Cottbus-Senftenberg investigated the influence of cooling lubricants on the surface roughness and energy efficiency of cutting machine tools. After summarizing the achieved experimental results, the authors conclude that cooling lubricants extensively influence the cutting temperature, cutting forces and energy consumption. Also, it is recognizable that cooling lubricants affect the cutting tools lifetime and the workpiece surface quality as well. Furthermore, costs of these cooling lubricants and the related environmental burden need to be considered. A current trend is to reduce the amount of lubricants that are used, e.g., when the Minimum Quantity Lubrication (MQL technique is applied. The lubricant or process liquid is thereby transported by the compressed air in the form of an aerosol to the contact area between the tool and workpiece. The cutting process was monitored during testing by the three following techniques: lubricant-free cutting, cutting with the use of a lubricant with the MQL technique, and only utilizing finish-turning and finish-face milling. The research allowed the authors to monitor the cutting power and mark the achieved surface quality in relation to the electrical power consumption of the cutting machine. In conclusions, the coherence between energy efficiency of the cutting machine and the workpiece surface quality regarding the used cooling lubricant is described.

  13. Influence of Workpiece Surface Topography on the Mechanisms of Liquid Lubrication in Strip Drawing

    DEFF Research Database (Denmark)

    Shimizu, I; Andreasen, Jan Lasson; Bech, Jakob Ilsted

    2001-01-01

    Plasto HydroDynamic Lubrication (MPHDL). On the other hand, when the radius on the edge is small MPHDL is impeded and MicroPlasto HydroStatic Lubrication (MPHSL) appears instead implying forward escape of the lubricant. The occurrence of these mechanisms are quantitatively explained by a mathematical model......The workpiece surface topography is an important factor controlling the mechanisms of lubrication in metal forming processes. In the present work, the microscopic lubrication mechanisms induced by lubricant trapped in pockets of the surface in strip drawing are studied. The experiments...... are performed with macroscopic model pockets in the surface studying the influence of the shape of the pockets on the lubrication mechanisms. A large radius of curvature on the rear edge and a small angle to the edge of the lubricant pocket induce a large area of backward escape of lubricant caused by Micro...

  14. Interaction between carbon fibers and polymer sizing: Influence of fiber surface chemistry and sizing reactivity

    Science.gov (United States)

    Moosburger-Will, Judith; Bauer, Matthias; Laukmanis, Eva; Horny, Robert; Wetjen, Denise; Manske, Tamara; Schmidt-Stein, Felix; Töpker, Jochen; Horn, Siegfried

    2018-05-01

    Different aspects of the interaction of carbon fibers and epoxy-based polymer sizings are investigated, e.g. the wetting behavior, the strength of adhesion between fiber and sizing, and the thermal stability of the sizing layer. The influence of carbon fiber surface chemistry and sizing reactivity is investigated using fibers of different degree of anodic oxidation and sizings with different number of reactive epoxy groups per molecule. Wetting of the carbon fibers by the sizing dispersion is found to be specified by both, the degree of fiber activation and the sizing reactivity. In contrast, adhesion strength between fibers and sizing is dominated by the surface chemistry of the carbon fibers. Here, the number of surface oxygen groups seems to be the limiting factor. We also find that the sizing and the additional functionalities induced by anodic oxidation are removed by thermal treatment at 600 °C, leaving the carbon fiber in its original state after carbonization.

  15. Opportunities of influence of plasma streams formed in IKA with continuos nor king gas filling en the surface of materials

    International Nuclear Information System (INIS)

    Useinov, B.M.; Useinova, A.M.; Amrenova, A.U.; Pusankov, S.A.; Sartin, S.A.; Virko, P.G.

    2001-01-01

    The results of the investigation of influence of plasma stream formed in IKA with continuous working gas filling on the surface of stainless steel 12X18H10T and aluminum are given in this article. It is shown here that the effect of influence of plasma stream on the surface of materials depends on the way of working gas filling. There is the comparison of influence of plasma stream formed in plasma accelerator with impulse and continuous working gas filling

  16. Influence of the surface quality due to a hole derived in initial material processing of cold sheets with drawing

    OpenAIRE

    Cvetkov, Slavco; Kocov, Atanas

    2010-01-01

    A research was performed about the influence of the surface quality due to a hole derived in initial material processing of cold-rolled steel sheets with drawing. This influence was researched through the surface quality obtained bu the type of preparation of the hole surface without prejudice to the precise measurement of the achieved quality (asperity). the aim is to indicate how the type of manufacturing the holes can improve the workability of cold-rolled sheets and help solve technical p...

  17. Influence of atmospheric pressure plasma treatment on surface properties of PBO fiber

    International Nuclear Information System (INIS)

    Zhang Ruiyun; Pan Xianlin; Jiang Muwen; Peng Shujing; Qiu Yiping

    2012-01-01

    Highlights: ► PBO fibers were treated with atmospheric pressure plasmas. ► When 1% of oxygen was added to the plasma, IFSS increased 130%. ► Increased moisture regain could enhance plasma treatment effect on improving IFSS with long treatment time. - Abstract: In order to improve the interfacial adhesion property between PBO fiber and epoxy, the surface modification effects of PBO fiber treated by atmospheric pressure plasma jet (APPJ) in different time, atmosphere and moisture regain (MR) were investigated. The fiber surface morphology, functional groups, surface wettability for control and plasma treated samples were analyzed by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements, respectively. Meanwhile, the fiber interfacial shear strength (IFSS), representing adhesion property in epoxy, was tested using micro-bond pull-out test, and single fiber tensile strength was also tested to evaluate the mechanical performance loss of fibers caused by plasma treatment. The results indicated that the fiber surface was etched during the plasma treatments, the fiber surface wettability and the IFSS between fiber and epoxy had much improvement due to the increasing of surface energy after plasma treatment, the contact angle decreased with the treatment time increasing, and the IFSS was improved by about 130%. The processing atmosphere could influence IFSS significantly, and moisture regains (MR) of fibers also played a positive role on improving IFSS but not so markedly. XPS analysis showed that the oxygen content on fiber surface increased after treatment, and C=O, O-C=O groups were introduced on fiber surface. On the other hand, the observed loss of fiber tensile strength caused by plasma treatment was not so remarkable to affect the overall performance of composite materials.

  18. Influence of surface topography on friction, film breakdown and running-in in the mixed lubrication regime

    NARCIS (Netherlands)

    Lugt, Pieter Martin; Severt, R.W.M.; Fogelström, J.; Tripp, J.H.

    2001-01-01

    The influence of surface topography on the lubricant film build-up ability and the friction characteristics of potential rolling bearing surfaces has been investigated by experiments on two-disc rigs. Traction-friction torque measurements were made for a variety of surface combinations, together

  19. Fog Collection on Polyethylene Terephthalate (PET) Fibers: Influence of Cross Section and Surface Structure.

    Science.gov (United States)

    Azad, M A K; Krause, Tobias; Danter, Leon; Baars, Albert; Koch, Kerstin; Barthlott, Wilhelm

    2017-06-06

    Fog-collecting meshes show a great potential in ensuring the availability of a supply of sustainable freshwater in certain arid regions. In most cases, the meshes are made of hydrophilic smooth fibers. Based on the study of plant surfaces, we analyzed the fog collection using various polyethylene terephthalate (PET) fibers with different cross sections and surface structures with the aim of developing optimized biomimetic fog collectors. Water droplet movement and the onset of dripping from fiber samples were compared. Fibers with round, oval, and rectangular cross sections with round edges showed higher fog-collection performance than those with other cross sections. However, other parameters, for example, width, surface structure, wettability, and so forth, also influenced the performance. The directional delivery of the collected fog droplets by wavy/v-shaped microgrooves on the surface of the fibers enhances the formation of a water film and their fog collection. A numerical simulation of the water droplet spreading behavior strongly supports these findings. Therefore, our study suggests the use of fibers with a round cross section, a microgrooved surface, and an optimized width for an efficient fog collection.

  20. Influence on rod-pinch diode performance of suppressing electron emission from different cathode surfaces

    International Nuclear Information System (INIS)

    Gao Yi; Lv Min; Qiu Aici; Yang Hailiang; Liang Tianxue; Zhang Zhong

    2010-01-01

    The electron pinching process of a rod-pinch diode is simulated with UNIPIC. It indicates that the pinching characteristics of the electrons emitted from different cathode surfaces differ significantly. The electrons emitted from the downstream surface pinch worst, with large amount of electrons hitting upstream of the rod, which increases the axial bremsstrahlung X-ray spot size. The simulation results show that suppressing electron emission from the downstream surface will reduce the axial X-ray spot size and improve the pinching quality. Composite cathodes are designed to investigate the influence of suppressing electron emission from the upstream or downstream surface. Experiments are performed on the new-built IVA (Inductive Voltage Adder) device at the peak voltage of ∼1.5 MV, and the peak current of ∼44 kA. It is shown that the composite cathode is effective in suppressing electron emission from the specific surface, the axial X-ray spot size in the case of downstream suppression is about 14.5% less than the case of upstream suppression and in both cases, the axis-on X-ray dose at 1 meter from the rod tip is ∼1.9rads, validating the simulation results. (authors)

  1. DNA Adsorption to and Elution from Silica Surfaces: Influence of Amino Acid Buffers

    Science.gov (United States)

    Vandeventer, Peter E.; Mejia, Jorge; Nadim, Ali; Johal, Malkiat S.; Niemz, Angelika

    2014-01-01

    Solid phase extraction and purification of DNA from complex samples typically requires chaotropic salts that can inhibit downstream polymerase amplification if carried into the elution buffer. Amino acid buffers may serve as a more compatible alternative for modulating the interaction between DNA and silica surfaces. We characterized DNA binding to silica surfaces, facilitated by representative amino acid buffers, and the subsequent elution of DNA from the silica surfaces. Through bulk depletion experiments, we found that more DNA adsorbs to silica particles out of positively compared to negatively charged amino acid buffers. Additionally, the type of the silica surface greatly influences the amount of DNA adsorbed, and the final elution yield. Quartz crystal microbalance experiments with dissipation monitoring (QCM-D) revealed multiphasic DNA adsorption out of stronger adsorbing conditions such as arginine, glycine, and glutamine, with DNA more rigidly bound during the early stages of the adsorption process. The DNA film adsorbed out of glutamate was more flexible and uniform throughout the adsorption process. QCM-D characterization of DNA elution from the silica surface indicates an uptake in water mass during the initial stage of DNA elution for the stronger adsorbing conditions, which suggests that for these conditions the DNA film is partly dehydrated during the prior adsorption process. Overall, several positively charged and polar neutral amino acid buffers show promise as an alternative to methods based on chaotropic salts for solid phase DNA extraction. PMID:23931415

  2. Influence of Mold Surface Treatments on Flow of Polymer in Injection Moulding. Application to Weldlines

    Science.gov (United States)

    Chailly, M.; Charmeau, J.-Y.; Bereaux, Y.; Monasse, B.

    2007-04-01

    Due to increasing expectations from the market, the aspect of molded parts has to be improved constantly. Some of the defects observed on these parts such as weldlines are related to the filling stage. To limit this, we investigated the influence on weldlines using various surface deposits on the mold surface, mainly PVD and PACVD deposits : Chromium nitride (CrN), Titanium nitride (TiN), Diamond like Carbon (DLC), Chromium and polished steel (PG) on an instrumented plate mold. Injection campaign was led on three polymers which differ in terms of nature (amorphous, semi-crystalline, copolymers). We studied the evolution of the dimensions of weldlines appearing on the plate using the same injection parameters for a given polymer, but with various deposits and thicknesses. Another aspect that had been investigated is the morphology of the weldline through the thickness of the part, depending on polymer nature. Adhesion of polymer at the flow front with the mold surface proved to change. The modification of the initial contact in the filling stage and thus the thermal resistance at the mold implied a change in the process, increasing or reducing the pressure loss in the flow and differential shrinkage in the final part. The induced impact on dimensions of the weldlines allowed to distinguish which surface treatments were able to reduce the defect. A complementary study was led on both polymers in molten state and deposits in terms of wetting using a sessile drop method to confirm the adhesion at the polymer/mold interface. This study proved the influence of the use of surface treatments has clearly an impact on the filling stage of the injection molding process, and it is necessary to get a better knowledge of the interactions between physical adhesion, tribology of polymer/mold contact, and thermal properties of the coatings and their impact on solidification of the polymer.

  3. The influence of surface roughness on cloud cavitation flow around hydrofoils

    Science.gov (United States)

    Hao, Jiafeng; Zhang, Mindi; Huang, Xu

    2017-08-01

    The aim of this study is to investigate experimentally the effect of surface roughness on cloud cavitation around Clark-Y hydrofoils. High-speed video and particle image velocimetry (PIV) were used to obtain cavitation patterns images (Prog. Aerosp. Sci. 37: 551-581, 2001), as well as velocity and vorticity fields. Results are presented for cloud cavitating conditions around a Clark-Y hydrofoil fixed at angle of attack of α =8{°} for moderate Reynolds number of Re=5.6 × 105 . The results show that roughness had a great influence on the pattern, velocity and vorticity distribution of cloud cavitation. For cavitating flow around a smooth hydrofoil (A) and a rough hydrofoil (B), cloud cavitation occurred in the form of finger-like cavities and attached subulate cavities, respectively. The period of cloud cavitation around hydrofoil A was shorter than for hydrofoil B. Surface roughness had a great influence on the process of cloud cavitation. The development of cloud cavitation around hydrofoil A consisted of two stages: (1) Attached cavities developed along the surface to the trailing edge; (2) A reentrant jet developed, resulting in shedding and collapse of cluster bubbles or vortex structure. Meanwhile, its development for hydrofoil B included three stages: (1) Attached cavities developed along the surface to the trailing edge, with accumulation and rotation of bubbles at the trailing edge of the hydrofoil affecting the flow field; (2) Development of a reentrant jet resulted in the first shedding of cavities. Interaction and movement of flows from the pressure side and suction side brought liquid water from the pressure side to the suction side of the hydrofoil, finally forming a reentrant jet. The jet kept moving along the surface to the leading edge of the hydrofoil, resulting in large-scale shedding of cloud bubbles. Several vortices appeared and dissipated during the process; (3) Cavities grew and shed again.

  4. The influence of surface roughness on cloud cavitation flow around hydrofoils

    Science.gov (United States)

    Hao, Jiafeng; Zhang, Mindi; Huang, Xu

    2018-02-01

    The aim of this study is to investigate experimentally the effect of surface roughness on cloud cavitation around Clark-Y hydrofoils. High-speed video and particle image velocimetry (PIV) were used to obtain cavitation patterns images (Prog. Aerosp. Sci. 37: 551-581, 2001), as well as velocity and vorticity fields. Results are presented for cloud cavitating conditions around a Clark-Y hydrofoil fixed at angle of attack of α =8{°} for moderate Reynolds number of Re=5.6 × 105. The results show that roughness had a great influence on the pattern, velocity and vorticity distribution of cloud cavitation. For cavitating flow around a smooth hydrofoil (A) and a rough hydrofoil (B), cloud cavitation occurred in the form of finger-like cavities and attached subulate cavities, respectively. The period of cloud cavitation around hydrofoil A was shorter than for hydrofoil B. Surface roughness had a great influence on the process of cloud cavitation. The development of cloud cavitation around hydrofoil A consisted of two stages: (1) Attached cavities developed along the surface to the trailing edge; (2) A reentrant jet developed, resulting in shedding and collapse of cluster bubbles or vortex structure. Meanwhile, its development for hydrofoil B included three stages: (1) Attached cavities developed along the surface to the trailing edge, with accumulation and rotation of bubbles at the trailing edge of the hydrofoil affecting the flow field; (2) Development of a reentrant jet resulted in the first shedding of cavities. Interaction and movement of flows from the pressure side and suction side brought liquid water from the pressure side to the suction side of the hydrofoil, finally forming a reentrant jet. The jet kept moving along the surface to the leading edge of the hydrofoil, resulting in large-scale shedding of cloud bubbles. Several vortices appeared and dissipated during the process; (3) Cavities grew and shed again.

  5. Surface characterization and influence of anodizing process on fatigue life of Al 7050 alloy

    International Nuclear Information System (INIS)

    Shahzad, Majid; Chaussumier, Michel; Chieragatti, Remy; Mabru, Catherine; Rezai-Aria, Farhad

    2011-01-01

    Highlights: → We studied the effect of surface treatments on fatigue behaviour of 7050 alloy. → Dissolution of constituent particles in pickling solution result in pits formation. → Decrease is fatigue life caused by anodization is small. → Multi-site cracks initiation has been observed for pickled and anodized specimens. -- Abstract: The present study investigates the influence of anodizing process on fatigue life of aluminium alloy 7050-T7451 by performing axial fatigue tests at stress ratio 'R' of 0.1. Effects of pre-treatments like degreasing and pickling employed prior to anodizing on fatigue life were studied. The post-exposure surface observations were made by scanning electron microscope (SEM) to characterize the effect of each treatment before fatigue testing. The surface observations have revealed that degreasing did not change the surface topography while pickling solution resulted in the formation of pits at the surface. Energy dispersive spectroscopy (EDS) was used to identify those constituent particles which were responsible for the pits formation. These pits are of primary concern with respect to accelerated fatigue crack initiation and subsequent anodic coating formation. The fatigue test results have shown that pickling process was detrimental in reducing the fatigue life significantly while less decrease has been observed for anodized specimens. Analyses of fracture surfaces of pickled specimens have revealed that the process completely changed the crack initiation mechanisms as compared to non-treated specimens and the crack initiation started at the pits. For most of the anodized specimens, fatigue cracks still initiated at the pits with very few cracks initiated from anodic coating. The decrease in fatigue life for pickled and anodized specimens as compared to bare condition has been attributed to decrease in initiation period and multi-site crack initiations. Multi-site crack initiation has resulted in rougher fractured surfaces for

  6. Surface-water dynamics and land use influence landscape connectivity across a major dryland region.

    Science.gov (United States)

    Bishop-Taylor, Robbi; Tulbure, Mirela G; Broich, Mark

    2017-06-01

    Landscape connectivity is important for the long-term persistence of species inhabiting dryland freshwater ecosystems, with spatiotemporal surface-water dynamics (e.g., flooding) maintaining connectivity by both creating temporary habitats and providing transient opportunities for dispersal. Improving our understanding of how landscape connectivity varies with respect to surface-water dynamics and land use is an important step to maintaining biodiversity in dynamic dryland environments. Using a newly available validated Landsat TM and ETM+ surface-water time series, we modelled landscape connectivity between dynamic surface-water habitats within Australia's 1 million km 2 semiarid Murray Darling Basin across a 25-yr period (1987-2011). We identified key habitats that serve as well-connected "hubs," or "stepping-stones" that allow long-distance movements through surface-water habitat networks. We compared distributions of these habitats for short- and long-distance dispersal species during dry, average, and wet seasons, and across land-use types. The distribution of stepping-stones and hubs varied both spatially and temporally, with temporal changes driven by drought and flooding dynamics. Conservation areas and natural environments contained higher than expected proportions of both stepping-stones and hubs throughout the time series; however, highly modified agricultural landscapes increased in importance during wet seasons. Irrigated landscapes contained particularly high proportions of well-connected hubs for long-distance dispersers, but remained relatively disconnected for less vagile organisms. The habitats identified by our study may serve as ideal high-priority targets for land-use specific management aimed at maintaining or improving dispersal between surface-water habitats, potentially providing benefits to biodiversity beyond the immediate site scale. Our results also highlight the importance of accounting for the influence of spatial and temporal

  7. Analysis of the influence of chemical treatment to the strength and surface roughness of FDM

    Science.gov (United States)

    Hambali, R. H.; Cheong, K. M.; Azizan, N.

    2017-06-01

    The applications of Additive Manufacturing (AM) technology have a greater functionality and wider range of application beyond an intention of prototyping. AM is the process of joining materials to form objects from Computer-Aided Design (CAD) models via layer upon layer process. One of AM technologies is the Fused Deposition Modelling (FDM), which use an extrusion method to create a part. FDM has been applied in many manufacturing applications includes an end-used parts. However, FDM tends to have bad surface quality due to staircase effect and post treatment is required. This chemical treatment is one of a way to improve the surface roughness of FDM fabricated parts. This method is one of economical and faster method. In order to enhance the surface finish of Acrylonitrile-Butadiene-Styrene (ABS) FDM parts by performing chemical treatment in an acetone solution as acetone has very low toxicity, high diffusion and low cost chemical solution. Therefore, the aim of this research is to investigate the influence of chemical treatment to the FDM used part in terms of surface roughness as well as the strength. In this project, ten specimens of standard ASTM D638 dogbone specimens have been fabricated using MOJO 3D printer. Five specimens from the dogbone were tested for surface roughness and tensile testing while another five were immersed in the chemical solution before the same testing. Based on results, the surface roughness of chemically treated dogbone has dramatically improved, compared to untreated dogbone with 97.2% of improvement. However, in term of strength, the tensile strength of dogbone is reduced 42.58% due to the rearrange of material properties and chemical effects to the joining of the filaments. In conclusion, chemical treatment is an economical and sustainable approach to enhance the surface quality of AM parts.

  8. Influence of surface treatment on osseointegration of dental implants: histological, histomorphometric and radiological analysis in vivo.

    Science.gov (United States)

    Calvo-Guirado, José Luis; Satorres-Nieto, Marta; Aguilar-Salvatierra, Antonio; Delgado-Ruiz, Rafael Arcesio; Maté-Sánchez de Val, José Eduardo; Gargallo-Albiol, Jordi; Gómez-Moreno, Gerardo; Romanos, Georgios E

    2015-03-01

    The aim of this article is to compare the influence of surface treatment on the integration (at 2, 4 and 8 weeks) of 120 dental implants inserted in 60 tibiae of rabbits. Four different surfaces were double-blind tested: blasted, acid-etched and discrete crystal deposition (DCD) (group A); blasted (group B); acid-etched (group C) and blasted and acid-etched (group D). Bone-to-implant contact plus reverse torque and bone level were measured at the time of implant insertion and at 14, 28 and 56 days of healing. Group A showed the highest early and late bone-to-implant contact (BIC) values: 40.8 ± 2.3 % at 14 days decreasing to 27.7 ± 1.1 % after 28 days and 39.4 ± 1.4 % at 56 days. For group B, the average BIC values at 14, 28 and 56 days were 23.34 ± 2.1, 23.77 ± 1.9 and 29.47 ± 1.7 %, respectively. Group C showed a value of 25.72 ± 2.3 % after 14 days of integration, 34.92 ± 2.2 % at 28 days and 32.91 ± 1.6 % at 56 days. Group D showed a BIC value of 32 ± 2.5 % at 14 days, 32.85 ± 1.4 % at 28 days and 34.04 ± 2.3 % at 56 days. In the scanning electron microscopy (SEM) analysis, no statistically significant differences were found. The Ca/P ratio values were 1.762 for surface A, 1.625 for surface B, 1.663 for surface C and finally 1.722 for surface D. Therefore, we conclude that even if there seems to be a tendency to obtain better BIC results with surface A (blasted-etched and covered with hydroxyapatite (HA)), no statistical differences were obtained in this study. The study shows the influence of different implant surfaces in increasing osseointegation for immediate loading implants.

  9. Influence of absorbed moisture on surface hydrophobization of ethanol pretreated and plasma treated ramie fibers

    International Nuclear Information System (INIS)

    Zhou Zhou; Wang Jilong; Huang Xiao; Zhang Liwen; Moyo, Senelisile; Sun Shiyuan; Qiu Yiping

    2012-01-01

    The existence of moisture in the substrate material may influence the effect of atmospheric pressure plasma treatment. Our previous study has found that the employment of ethanol pretreatment and plasma treatment can effectively induce hydrophobic surface modification of cellulose fiber to enhance the compatibility to polypropylene (PP) matrix, and this study aims to investigate the influence of fiber moisture regain on the treatment effect of this technique. Ramie fibers with three different moisture regains (MR) (2.5, 6.1 and 23.5%) are pretreated with ethanol followed by atmospheric pressure plasma treatment. Scanning electron microscope (SEM) shows that the 2.5% MR group has the most significant plasma etching effect. X-ray photoelectron spectroscopy (XPS) analysis indicates an increase of C-C and a decrease of C-O bond in the plasma treated groups, and the largest raise of C-C bond for the 2.5% MR group. The water contact angles of the 2.5 and 6.1% MR groups increase, whereas no significant change is showed in the 23.5% MR group. The interfacial shear strengths (IFSS) measured by microbond pull-out test are raised by 44 and 25% when moisture regains are 2.5 and 6.1%, while presented no apparent improvement at high moisture regain of 23.5%. Therefore, it can be concluded that moisture regain has negative influence on the surface hydrophobization of ramie fibers in the improvement of adhesion property to PP matrix.

  10. Influence of the Precision of LIDAR Data in Surface Water Runoff Estimation for Road Maintenance

    Science.gov (United States)

    González-Jorge, H.; Díaz-Vilariño, L.; Lagüela, S.; Martínez-Sánchez, J.; Arias, P.

    2015-08-01

    Roads affect the natural surface and subsurface drainage pattern of a hill or a watershed. Road drainage systems are designed with the objective of reducing the energy generated by the flowing water and the presence of excess water or moisture within the road. A poorly designed drainage may affect to road maintenance causing cut or fill failures, road surface erosion and degrading the engineering properties of the materials with which it was constructed. Surface drainage pattern can be evaluated from Digital Elevation Models typically calculated from point clouds acquired with aerial LiDAR platforms. However, these systems provide low resolution point clouds especially in cases where slopes with steep grades exist. In this work, Mobile LiDAR systems (aerial and terrestrial) are combined for surveying roads and their surroundings in order to provide complete point cloud. As the precision of the point clouds obtained from these mobile systems is influenced by GNSS outages, Gaussian noise with different standard deviation values is introduced in the point cloud in order to determine its influence in the evaluation of water runoff direction. Results depict an increase in the differences of flow direction with the decrease of cell size of the raster dataset and with the increase of Gaussian noise. The last relation fits to a second-order polynomial Differences in flow direction up to 42º are achieved for a cell size of 0.5 m with a standard deviation of 0.15 m.

  11. INFLUENCE OF THE PRECISION OF LIDAR DATA IN SURFACE WATER RUNOFF ESTIMATION FOR ROAD MAINTENANCE

    Directory of Open Access Journals (Sweden)

    H. González-Jorge

    2015-08-01

    Full Text Available Roads affect the natural surface and subsurface drainage pattern of a hill or a watershed. Road drainage systems are designed with the objective of reducing the energy generated by the flowing water and the presence of excess water or moisture within the road. A poorly designed drainage may affect to road maintenance causing cut or fill failures, road surface erosion and degrading the engineering properties of the materials with which it was constructed. Surface drainage pattern can be evaluated from Digital Elevation Models typically calculated from point clouds acquired with aerial LiDAR platforms. However, these systems provide low resolution point clouds especially in cases where slopes with steep grades exist. In this work, Mobile LiDAR systems (aerial and terrestrial are combined for surveying roads and their surroundings in order to provide complete point cloud. As the precision of the point clouds obtained from these mobile systems is influenced by GNSS outages, Gaussian noise with different standard deviation values is introduced in the point cloud in order to determine its influence in the evaluation of water runoff direction. Results depict an increase in the differences of flow direction with the decrease of cell size of the raster dataset and with the increase of Gaussian noise. The last relation fits to a second-order polynomial Differences in flow direction up to 42º are achieved for a cell size of 0.5 m with a standard deviation of 0.15 m.

  12. Influence of the Institutional Structure of Surface Water Rights on Agricultural Production in the Central Valley

    Science.gov (United States)

    Nelson, K.; Burchfield, E. K.

    2017-12-01

    California's Central Valley region is one of the most productive agricultural systems on the planet. The high levels of agricultural production in this region require large amounts of fresh water for irrigation. However, the long-term availability of water required to sustain such levels of agricultural production has been questioned following the latest drought in California. In this study, we use Bayesian multilevel spatiotemporal modeling techniques to examine the influence of the institutional structure of surface water rights in the Central Valley on agricultural production during the recent drought. The R-INLA package is employed to account for spatial processes that have the potential to influence the effects of water right structures on crop productivity as well as on extent of cultivation. Model results suggest that seniority in surface water access significantly improves crop productivity on cultivated lands, but does not directly affect the ability to maintain cultivated extent. In addition, results suggest that areas with more junior surface water rights tend to reduce extent of cultivation, but maintain crop productivity, as cumulative drought stress increases.

  13. Medieval times' influencing figure Rhaze's approach to head injuries in Liber Almansoris.

    Science.gov (United States)

    Acıduman, Ahmet; Aşkit, Cağatay; Belen, Deniz

    2014-12-01

    To present the chapter "On wound of the head and fracture of the head bone" of Kitāb al-Manṣūrī / Liber Almansoris, which was one of the early works of Rhazes. Both Arabic (Süleymaniye Manuscript Library, Ayasofya collection, Nr. 3751 and Millet Library, Feyzullah Efendi collection, Nr. 1327) and the Latin (Basileae, 1544) texts of Kitāb al-Manṣūrī / Liber Almansoris were studied, and the 26th section of the 7th chapter, entitled "Fī al-shajja kasr al-'aẓm al-ra's / De plagis capitis et fractura cranei / On wound of the head and fracture of the head bone" was translated into English and English text created. Rhazes underlined removing bone fragments in depressed and separated fractures of cranium along with protection of the dura, but he did not describe any surgical technique in this chapter. Galen's contemplation for the care of the dura with its integrity and as well his proposal to remove the bone fragments for preventing the dura from injury were the golden standards at the time that Rhazes also followed in the treatment of skull fractures. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Influence of bladder lithiasis on lower urinary tract dynamics in patients with spinal cord injury.

    Science.gov (United States)

    Vírseda-Chamorro, M; Salinas-Casado, J; Barroso-Manso, Á; Gutiérrez-Martín, P; Fuertes, M E

    2017-08-01

    A prospective and a case-matched control study. To study the lower urinary tract dysfunction associated with bladder lithiasis in patients with spinal cord injury (SCI). Toledo (Spain). We have carried out a urodynamic study in 30 patients with SCI with lithiasis in their bladder before and 3 months after bladder endoscopic lithotripsy. This second study was compared with the urodynamic findings of a different group of 30 patients with SCI, without a history of bladder lithiasis, paired with cases by gender and date of urodynamic study. We have found that the prevalence of neurogenic detrusor overactivity (NDO) was significantly different after bladder lithotripsy, although the cystomanometric capacity was significantly increased. A group of patients with lithiasis showed a maximum flow rate, a voiding maximum detrusor pressure and the detrusor contractility parameter Wmax lower than that in controls. On the other hand, a voiding abdominal straining was found to be significantly greater than that in controls. Bladder lithiasis affects the presence of NDO in patients with SCI. Patients with SCI who develop bladder lithiasis present a lower detrusor contractility power compared with those who do not.

  15. Influence Of Whey Protein For Abrogating Liver Injury In Female Rats

    International Nuclear Information System (INIS)

    ANWAR, M.M.; MOHAMED, N.E.

    2009-01-01

    The objective of this study was to determine the possible benefits of whey protein concentrate (44% protein, 5% fat and 4.6% ash in dry weight) against liver injury induced by CCl 4 . It was carried out by evaluating the effect of the daily feeding of female rats on diet containing 15% whey protein instead of soybean protein for four weeks on some biochemical and histological changes in liver of female rats.The data showed that injection with CCl 4 (1 ml /kg body weight 3 times / week) caused significant decrease in body weight with disturbances in liver functions as significant increase in serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma glutamyl transferase and bilirubin and significant decrease in serum albumin, FT3 and an increase in AFP levels. A marked significant decrease in glutathione content and significant increase in lipid peroxidation was also observed in hepatic tissues. The histological examination revealed that CCl 4 treatment showed marked degenerative changes in liver hepatocytes and sinusoids.The results also showed that feeding on diet containing whey protein for two or four weeks during CCl 4 treatment minimized the disturbance of the liver functions and liver histology.

  16. Normal saline influences coagulation and endothelial function after traumatic brain injury and hemorrhagic shock in pigs

    DEFF Research Database (Denmark)

    Dekker, Simone E; Sillesen, Martin; Bambakidis, Ted

    2014-01-01

    BACKGROUND: Traumatic brain injury (TBI) and hemorrhagic shock (HS) are the leading causes of trauma-related deaths. These insults disrupt coagulation and endothelial systems. This study investigated whether previously reported differences in lesion size and brain swelling during normal saline (NS...... of endothelial activation (E-selectin, Intercellular adhesion molecule [ICAM]-1), coagulation activation (prothrombin fragment 1 + 2), and natural anticoagulation (activated protein C [aPC]) were determined in serum and brain whole cell lysates. RESULTS: Serum levels of aPC were greater in the NS group (203 ± 30...... pg/mL) compared with HEX (77 ± 28 pg/mL; P = .02) and FFP (110 ± 28 pg/mL; P = .09), as was PF 1 + 2 in the brain when compared with FFP (PF 1 + 2, 89 ± 46 vs 37 ± 14 ng/mL; P = .035). Brain E-selectin was greater in the NS group compared with FFP (3.36 ± 0.02 vs 3.31 ± 0.01 ng/mL; P = .029...

  17. Healthcare professionals' attitudes towards traumatic brain injury (TBI): the influence of profession, experience, aetiology and blame on prejudice towards survivors of brain injury.

    Science.gov (United States)

    Redpath, S J; Williams, W H; Hanna, D; Linden, M A; Yates, P; Harris, A

    2010-01-01

    To investigate the attitudes of healthcare professionals towards individuals with traumatic brain injury (TBI) and their relationship to intended healthcare behaviour. An independent groups design utilized four independent variables; aetiology, group, blame and gender to explore attitudes towards survivors of brain injury. The dependent variables were measured using the Prejudicial Evaluation and Social Interaction Scale (PESIS) and Helping Behaviour Scale (HBS). A hypothetical vignette based methodology was used. Four hundred and sixty participants (131 trainee nurses, 94 qualified nurses, 174 trainee doctors, 61 qualified doctors) were randomly allocated to one of six possible conditions. Regardless of aetiology, if an individual is to blame for their injury, qualified healthcare professionals have more prejudicial attitudes than those entering the profession. There is a significant negative relationship between prejudice and helping behaviour for qualified healthcare professionals. Increased prejudicial attitudes of qualified staff are related to a decrease in intended helping behaviour, which has the potential to impact negatively on an individual's recovery post-injury.

  18. Factors influencing pediatric Injury Severity Score and Glasgow Coma Scale in pediatric automobile crashes: results from the Crash Injury Research Engineering Network.

    Science.gov (United States)

    Ehrlich, Peter F; Brown, J Kristine; Sochor, Mark R; Wang, Stewart C; Eichelberger, Martin E

    2006-11-01

    Motor vehicle crashes account for more than 50% of pediatric injuries. Triage of pediatric patients to appropriate centers can be based on the crash/injury characteristics. Pediatric motor vehicle crash/injury characteristics can be determined from an in vitro laboratory using child crash dummies. However, to date, no detailed data with respect to outcomes and crash mechanism have been presented with a pediatric in vivo model. The Crash Injury Research Engineering Network is comprised of 10 level 1 trauma centers. Crashes were examined with regard to age, crash severity (DeltaV), crash direction, restraint use, and airbag deployment. Multiple logistic regression analysis was performed with Injury Severity Score (ISS) and Glasgow Coma Scale (GCS) as outcomes. Standard age groupings (0-4, 5-9, 10-14, and 15-18) were used. The database is biases toward a survivor population with few fatalities. Four hundred sixty-one motor vehicle crashes with 2500 injuries were analyzed (242 boys, 219 girls). Irrespective of age, DeltaV > 30 mph resulted in increased ISS and decreased GCS (eg, for 0-4 years, DeltaV 30: ISS = 19.5, GCS = 10.6; P 15) injuries than did backseat passengers (odds ratio, 1.7; 95% confidence interval, 0.7-3.4). A trend was noted for children younger than 12 years sitting in the front seat to have increased ISS and decreased GCS with airbag deployment but was limited by case number. A reproducible pattern of increased ISS and lower GCS characterized by high severity, lateral crashes in children was noted. Further analysis of the specific injuries as a function and the crash characteristic can help guide management and prevention strategies.

  19. Influence of mold surface temperature on polymer part warpage in rapid heat cycle molding

    Science.gov (United States)

    Berger, G. R.; Pacher, G. A.; Pichler, A.; Friesenbichler, W.; Gruber, D. P.

    2014-05-01

    Dynamic mold surface temperature control was examined for its influence on the warpage. A test mold, featuring two different rapid heat cycle molding (RHCM) technologies was used to manufacture complex plate-shaped parts having different ribs, varying thin-wall regions, and both, circular and rectangular cut-outs. The mold's nozzle side is equipped with the areal heating and cooling technology BFMOLD®, where the heating/cooling channels are replaced by a ball-filled slot near the cavity surface flooded through with hot and cold water sequentially. Two local electrical ceramic heating elements are installed into the mold's ejection side. Based on a 23 full-factorial design of experiments (DoE) plan, varying nozzle temperature (Tnozzle), rapid heat cycle molding temperature (TRHCM) and holding pressure (pn), specimens of POM were manufactured systematically. Five specimens were examined per DoE run. The resulting warpage was measured at 6 surface line scans per part using the non-contact confocal topography system FRT MicroProf®. Two warpage parameters were calculated, the curvature of a 2nd order approximation a, and the vertical deflection at the profile center d. Both, the influence strength and the acting direction of the process parameters and their interactions on a and d were calculated by statistical analysis. Linear mathematical process models were determined for a and d to predict the warpage as a function of the process parameter settings. Finally, an optimum process setting was predicted, based on the process models and Microsoft Excel GRG solver. Clear and significant influences of TRHCM, pn, Tnozzle, and the interaction of TRHCM and pn were determined. While TRHCM was dominant close to the gate, pn became more effective as the flow length increased.

  20. The influence of graphene surface configuration on molecular detection output signals

    International Nuclear Information System (INIS)

    Huang, Shiu-Ming; Jheng, Jhe-Lun

    2015-01-01

    Ethanol is detected by graphene sheet, and it is found that the resistance change is proportional to the ethanol concentration. The dynamic response of the evaporation is traced, showing longer recovery time for higher ethanol concentrations. The influence of the residual adsorbed molecules on the graphene sheet was also studied, and it was found that the resistance change is negatively proportional to the initial resistance of the graphene sheet corresponding to the effective surface area. The influence of the structure defects on the response resistance is also studied, and it was found that the structure defects enhance the resistance change. These investigations suggest a better way to extract a reliable signal for physical adsorption based material detection. (paper)

  1. The influence of surface reflectance anisotropy on estimation of soil properties

    Science.gov (United States)

    Bartholomeus, Harm; Roosjen, Peter; Clevers, Jan

    2014-05-01

    The spatial variation in soil properties is an important factor for agricultural management. Unmanned airborne vehicles (UAV's) equipped with a hyperspectral mapping system may provide these data, but anisotropic reflectance effects may have an influence on the derived soil properties. Besides influencing the reflectance, angular observations may deliver added information about soil properties. We investigated the anisotropic behavior of 59 soil samples with a large variation in soil composition, by measuring their reflectance (350-2500 nm) over 92 different angles using a robot-based laboratory goniometer system. The results show that the anisotropic behavior of the soils influences the measured reflectance significantly, which limits the accurate prediction of soil properties (OM and clay especially). However, prediction accuracies of OM increase when spectra are measured under specific angles. Prediction accuracies further increase when a combination of observation angles is being used. Apart from that, using UAV's the wavelength range is limited to about 1000 nm. In general, this will decrease the model performance, but our results show that this effect can largely be compensated by combining multiple observation angles. Altogether, we demonstrate that surface anisotropy influences the prediction of soil properties negatively. This effect can be reduced by combining spectra acquired under different angles. Moreover, predictions can be improved if combinations of different observation angles are used.

  2. Influence of different surface treatments on the fracture toughness of a commercial ZTA dental ceramic

    Directory of Open Access Journals (Sweden)

    Flavio Teixeira da Silva

    2007-03-01

    Full Text Available The objective of this study was to investigate how mechanical surface treatments performed for removal of excess of molten glass, influence the fracture toughness of a dental zirconia toughened alumina (In-Ceram® Zirconia. Infiltrated ZTA disks were submitted to three different surface treatments (grinding, sandblasting and grinding + sandblasting + annealing. Fracture toughness was accessed through indentation strength test (IS. X ray diffraction was used to investigate the metastability of tetragonal zirconia particles under all treatments proposed. Kruskall-Wallis non-parametrical test and Weibull statistics were used to analyze the results. Grinding (group 1 introduced defects which decreased the fracture toughness and reliability, presenting the lowest K IC. On the other hand, grinding followed by sandblasting and annealing (group 3 presented the highest K IC. Sandblasting (group 2 presented the highest reliability but lower K IC compared to group 3.

  3. Modelling the Influence of Ground Surface Relief on Electric Sounding Curves Using the Integral Equations Method

    Directory of Open Access Journals (Sweden)

    Balgaisha Mukanova

    2017-01-01

    Full Text Available The problem of electrical sounding of a medium with ground surface relief is modelled using the integral equations method. This numerical method is based on the triangulation of the computational domain, which is adapted to the shape of the relief and the measuring line. The numerical algorithm is tested by comparing the results with the known solution for horizontally layered media with two layers. Calculations are also performed to verify the fulfilment of the “reciprocity principle” for the 4-electrode installations in our numerical model. Simulations are then performed for a two-layered medium with a surface relief. The quantitative influences of the relief, the resistivity ratios of the contacting media, and the depth of the second layer on the apparent resistivity curves are established.

  4. Analysis of the Scattering Characteristics of Sea Surface with the Influence from Internal Wave

    Directory of Open Access Journals (Sweden)

    Wei Yi-wen

    2015-06-01

    Full Text Available The internal wave travels beneath the sea surface and modulate the roughness of the sea surface through the wave-current interaction. This makes some dark and bright bands can be observed in the Synthetic Aperture Radar (SAR images. In this paper, we first establish the profile of the internal wave based on the KdV equations; then, the action balance equation and the wave-current interaction source function are used to modify the sea spectrum; finally, the two-scale theory based facet model is combined with the modified sea spectrum to calculate the scattering characteristics of the sea. We have simulated the scattering coefficient distribution of the sea with an internal wave traveling through. The influence on the scattering coefficients and the Doppler spectra under different internal wave parameters and sea state parameters are analyzed.

  5. The influence of surface functionalisation on the electrical properties and thermal stability of nanodiamonds

    Energy Technology Data Exchange (ETDEWEB)

    Welch, Joseph O; Li, Pei; Chaudhary, Aysha; Edgington, Robert; Jackman, Richard B., E-mail: r.jackman@ucl.ac.uk [London Centre for Nanotechnology and the Department of Electronic and Electrical Engineering, University College London, 17-19 Gordon Street, London WC1H 0AH (United Kingdom)

    2014-10-07

    Detonation nanodiamond (ND) has recently emerged as a useful new class of diamond material. However, to date there has been little investigation of the electrical properties of this material. Due to the nanoscale dimensions, the surface functionalisation of the individual ND is of particular importance to the characteristics of ND films. Here, hydrogen and oxygen termination of ND, verified using Fourier transform infrared spectroscopy, are shown to strongly influence the electronic properties of NDs. Hydrogen terminated ND exhibiting a far greater resilience to thermal decomposition when compared to the oxygen terminated NDs. Moreover, H-NDs also displayed so-called “surface conductivity,” a property displayed by hydrogen-terminated bulk diamond films, whilst O-NDs display properties high resistivity. These results indicate that under the correct conditions ND layers can display similar electrical properties to “bulk” diamond thin films.

  6. Influence of ionic liquids on the surface properties of poplar veneers

    Science.gov (United States)

    Croitoru, Catalin; Patachia, Silvia; Cretu, Nicolae; Boer, Attila; Friedrich, Christian

    2011-05-01

    In this paper, the influence of four types of imidazolium-based ionic liquids (ILs) on the surface properties of common aspen ( Populus tremula) veneers has been studied by using contact angle, electrical conductivity and Fourier transform infrared spectroscopy analysis. The measurements showed that wood wettabillity is increased by IL treatment. The electrical conductivities of treated wood were in the 0.5-1 mS/cm range, higher than the ones reported in the reference literature. It has been determined that the ILs decrease the crystallinity and improve the flexibility of the cellulose matrix. It has been determined by photographic image analysis that the surface roughness of the IL treated veneers decreases in comparison with the untreated samples.

  7. Influence of surface treatments on corrosion resistance of stainless steels. Residual stresses in metals

    International Nuclear Information System (INIS)

    Berge, J. Philippe

    1968-05-01

    In a first part, this research thesis proposes presentation of the definition of a surface condition: chemical characteristics such as passivity and contamination, physical characteristics (obtained through micrographic methods, X ray diffusion, magnetic methods), and micro-geometrical characteristics. The author notably discusses the measurement of characteristics either by appropriate conventional methods or by an original method in the case of passivity. In a second part, the author reports the study of the influence of surface condition on different types of corrosion of stainless steels in chemical environments (corrosion in sulphuric acid, intergranular corrosion, stress corrosion cracking in magnesium chloride, pitting corrosion) and of high temperature oxidation (corrosion in pressurized water, oxidation in dry vapour or in carbon dioxide)

  8. Modeling of edge effect in subaperture tool influence functions of computer controlled optical surfacing.

    Science.gov (United States)

    Wan, Songlin; Zhang, Xiangchao; He, Xiaoying; Xu, Min

    2016-12-20

    Computer controlled optical surfacing requires an accurate tool influence function (TIF) for reliable path planning and deterministic fabrication. Near the edge of the workpieces, the TIF has a nonlinear removal behavior, which will cause a severe edge-roll phenomenon. In the present paper, a new edge pressure model is developed based on the finite element analysis results. The model is represented as the product of a basic pressure function and a correcting function. The basic pressure distribution is calculated according to the surface shape of the polishing pad, and the correcting function is used to compensate the errors caused by the edge effect. Practical experimental results demonstrate that the new model can accurately predict the edge TIFs with different overhang ratios. The relative error of the new edge model can be reduced to 15%.

  9. MRI assessment of calf injuries in Australian Football League players: findings that influence return to play

    Energy Technology Data Exchange (ETDEWEB)

    Waterworth, George; Wein, Sara; Rotstein, Andrew H. [Victoria House Medical Imaging, Prahran, Victoria (Australia); Gorelik, Alexandra [Royal Melbourne Hospital, University of Melbourne, Melbourne Epicentre, Parkville (Australia)

    2017-03-15

    Calf muscle strains have become increasingly prevalent in recent seasons of the Australian Football League (AFL) and represent a significant cause of time lost from competition. The purpose of this study was to examine the association between MRI features of calf muscle strains and games missed and to thereby identify parameters that are of prognostic value. A retrospective analysis of MRI scans of AFL players with calf strains referred to a musculoskeletal radiology clinic over a 5-year period (2008-2012) was performed. The muscle(s) and muscle component affected, the site and size of strain, and the presence of an intramuscular tendon tear or intermuscular fluid were recorded. These data were cross-referenced with whether a player missed at least one game. Imaging features of prognostic value were thus identified. Sixty-three athletes had MRI scans for calf muscle strains. Soleus strains were more common than strains of other muscles. Players with soleus strains were more likely to miss at least one game if they had multiple muscle involvement (p = 0.017), musculotendinous junction strains (p = 0.046), and deep strains (p = 0.036). In a combined analysis of gastrocnemius and soleus strains, intramuscular tendon tears were observed in a significantly greater proportion of players who missed games (p = 0.010). Amongst AFL players with calf injuries, there is an association between missing at least one game and multiple muscle involvement, musculotendinous junction strains, deep strain location, and intramuscular tendon tears. In this setting, MRI may therefore provide prognostic information to help guide return-to-play decisions. (orig.)

  10. Examining Contextual Influences on Fall-Related Injuries Among Older Adults for Population Health Management

    Science.gov (United States)

    Rodriguez, Hector P.

    2015-01-01

    Abstract The objectives were to assess the associations between fall-related injuries (FRIs) treated in the emergency department (ED) among older adults in California and contextual county-level physical, social, and economic characteristics, and to assess how county-level economic conditions are associated with FRIs when controlling for other county-level factors. Data from 2008 California ED discharge, Medicare Impact File, and County Health Rankings were used. Random effects logistic regression models estimated contextual associations between county-level factors representing economic conditions, the built environment, community safety, access to care, and obesity with patient-level FRI treatment among 1,712,409 older adults, controlling for patient-level and hospital-level characteristics. Patient-level predictors of FRI treatment were consistent with previous studies not accounting for contextual associations. Larger and rural hospitals had higher odds of FRI treatment, while teaching and safety net hospitals had lower odds. Better county economic conditions were associated with greater odds (ß=0.73, P=0.001) and higher county-level obesity were associated with lower odds (ß=−0.37, P=0.004), but safer built environments (ß=−0.31, P=0.38) were not associated with FRI treatment. The magnitude of association between county-level economic conditions and FRI treatment attenuated with the inclusion of county-level obesity rates. FRI treatment was most strongly and consistently related to more favorable county economic conditions, suggesting differences in treatment or preferences for treatment for FRIs among older individuals in communities of varying resource levels. Using population health data on FRIs, policy makers may be able to remove barriers unique to local contexts when implementing falls prevention educational programs and built environment modifications. (Population Health Management 2015;18:437–448) PMID:25919228

  11. Pharmacogenomic Variants May Influence the Urinary Excretion of Novel Kidney Injury Biomarkers in Patients Receiving Cisplatin.

    Science.gov (United States)

    Chang, Cara; Hu, Yichun; Hogan, Susan L; Mercke, Nickie; Gomez, Madeleine; O'Bryant, Cindy; Bowles, Daniel W; George, Blessy; Wen, Xia; Aleksunes, Lauren M; Joy, Melanie S

    2017-06-22

    Nephrotoxicity is a dose limiting side effect associated with the use of cisplatin in the treatment of solid tumors. The degree of nephrotoxicity is dictated by the selective accumulation of cisplatin in renal tubule cells due to: (1) uptake by organic cation transporter 2 (OCT2) and copper transporter 1 (CTR1); (2) metabolism by glutathione S-transferases (GSTs) and γ-glutamyltransferase 1 (GGT1); and (3) efflux by multidrug resistance-associated protein 2 (MRP2) and multidrug and toxin extrusion protein 1 (MATE1). The purpose of this study was to determine the significance of single nucleotide polymorphisms that regulate the expression and function of transporters and metabolism genes implicated in development of acute kidney injury (AKI) in cisplatin treated patients. Changes in the kidney function were assessed using novel urinary protein biomarkers and traditional markers. Genotyping was conducted by the QuantStudio 12K Flex Real-Time PCR System using a custom open array chip with metabolism, transport, and transcription factor polymorphisms of interest to cisplatin disposition and toxicity. Traditional and novel biomarker assays for kidney toxicity were assessed for differences according to genotype by ANOVA. Allele and genotype frequencies were determined based on Caucasian population frequencies. The polymorphisms rs596881 ( SLC22A2 /OCT2), and rs12686377 and rs7851395 ( SLC31A1 /CTR1) were associated with renoprotection and maintenance of estimated glomerular filtration rate (eGFR). Polymorphisms in SLC22A2 /OCT2, SLC31A1 /CTRI, SLC47A1 /MATE1, ABCC2 /MRP2, and GSTP1 were significantly associated with increases in the urinary excretion of novel AKI biomarkers: KIM-1, TFF3, MCP1, NGAL, clusterin, cystatin C, and calbindin. Knowledge concerning which genotypes in drug transporters are associated with cisplatin-induced nephrotoxicity may help to identify at-risk patients and initiate strategies, such as using lower or fractionated cisplatin doses or avoiding

  12. MRI assessment of calf injuries in Australian Football League players: findings that influence return to play

    International Nuclear Information System (INIS)

    Waterworth, George; Wein, Sara; Rotstein, Andrew H.; Gorelik, Alexandra

    2017-01-01

    Calf muscle strains have become increasingly prevalent in recent seasons of the Australian Football League (AFL) and represent a significant cause of time lost from competition. The purpose of this study was to examine the association between MRI features of calf muscle strains and games missed and to thereby identify parameters that are of prognostic value. A retrospective analysis of MRI scans of AFL players with calf strains referred to a musculoskeletal radiology clinic over a 5-year period (2008-2012) was performed. The muscle(s) and muscle component affected, the site and size of strain, and the presence of an intramuscular tendon tear or intermuscular fluid were recorded. These data were cross-referenced with whether a player missed at least one game. Imaging features of prognostic value were thus identified. Sixty-three athletes had MRI scans for calf muscle strains. Soleus strains were more common than strains of other muscles. Players with soleus strains were more likely to miss at least one game if they had multiple muscle involvement (p = 0.017), musculotendinous junction strains (p = 0.046), and deep strains (p = 0.036). In a combined analysis of gastrocnemius and soleus strains, intramuscular tendon tears were observed in a significantly greater proportion of players who missed games (p = 0.010). Amongst AFL players with calf injuries, there is an association between missing at least one game and multiple muscle involvement, musculotendinous junction strains, deep strain location, and intramuscular tendon tears. In this setting, MRI may therefore provide prognostic information to help guide return-to-play decisions. (orig.)

  13. Approaches for Controlled Ag+ Ion Release: Influence of Surface Topography, Roughness, and Bactericide Content.

    Science.gov (United States)

    Sukhorukova, I V; Sheveyko, A N; Shvindina, N V; Denisenko, E A; Ignatov, S G; Shtansky, D V

    2017-02-01

    Silver is the most famous bactericidal element known from ancient times. Its antibacterial and antifungal effects are typically associated with the Ag ionization and concentration of Ag + ions in a bacterial culture. Herein we thoroughly studied the influence of surface topography and roughness on the rate of Ag + ion release. We considered two types of biocompatible and bioactive TiCaPCON-Ag films with 1 and 2 at. % of Ag and nine types of Ti surfaces with an average roughness varying in the range from 5.4 × 10 -2 to 12.6 μm and different topographic features obtained through polishing, sandblasting, laser treatment, and pulsed electrospark deposition. It is demonstrated that the Ag + ion release rates do not depend on the Ag content in the films as the main parameter, and it is other factors, such as the state of Ag agglomeration, surface topography and roughness, as well as kinetics of surface oxidation, that play a critical role. The obtained results clearly show a synergistic effect of the Ag content in the film and surface topography and roughness on Ag + ion release. By changing the surface topographical features at a constant content of bactericidal element, we showed that the Ag + ion release can be either accelerated by 2.5 times or almost completely suppressed. Despite low Ag + ion concentration in physiological solution (antibacterial effect already after 3 h of immersion in E. coli bacterial culture. Thus, our results open up new possibilities for the production of cost-effective, scalable, and biologically safe implants with pronounced antibacterial characteristics for future applications in the orthopedic field.

  14. Influence of prophylaxis paste treatment on the abrasive wear of surface sealants.

    Science.gov (United States)

    Wegehaupt, Florian J; Tauböck, Tobias T; Attin, Thomas

    2013-01-01

    To investigate the abrasive wear of surface sealants (Seal&Protect and K-0184 (experimental sealant)) and the influence of pre-treatment with mineral deposit forming prophylaxis pastes (NUPRO Sensodyne and NUPRO) on this wear. One hundred and eight bovine dentine samples were randomly allocated to nine groups (1-9). Pre-treatment (10 s): groups 1-3: untreated, groups 4-6: NUPRO, groups 7-9: NUPRO Sensodyne. Sealing: groups 1, 4 and 7: unsealed, groups 2, 5 and 8: Seal&Protect, groups 3, 6 and 9: K-0184 (experimental sealer). Samples were then brushed with 12 000 brushing strokes (BS) with toothpaste slurry in an automatic brushing machine (120 BS/min; F = 2.5 N). Surface profiles were recorded at baseline, after pre-treatment and sealing and after each 2000 BS. Total profile change (wear or gain due to pre-treatment, treatment and 12 000 BS): groups 1, 4 and 7 (no surface sealant) showed a not significantly different wear of 18.48 ± 2.63 µm, 24.98 ± 3.02 µm and 21.50 ± 5.47 µm, respectively. Remaining groups (sealed) showed a gain in height with no significant difference among each other. Wear in sealed groups (2, 3, 5, 6, 8 and 9) were not significantly different at all numbers of brushing strokes. Starting with 4000 BS, the wear in unsealed groups (1, 4 and 7) was statistically significantly higher compared to all other groups. Stability and wear resistance of surface sealants are not affected by pre-treatment of dentine with NUPRO Sensodyne. The surface sealants tested provide a stable protective surface layer on dentine, which lasts for at least 12 000 brushing strokes.

  15. The influence of surface roughness on volatile transport on the Moon

    Science.gov (United States)

    Prem, P.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.

    2018-01-01

    The Moon and other virtually airless bodies provide distinctive environments for the transport and sequestration of water and other volatiles delivered to their surfaces by various sources. In this work, we conduct Monte Carlo simulations of water vapor transport on the Moon to investigate the role of small-scale roughness (unresolved by orbital measurements) in the migration and cold-trapping of volatiles. Observations indicate that surface roughness, combined with the insulating nature of lunar regolith and the absence of significant exospheric heat flow, can cause large variations in temperature over very small scales. Surface temperature has a strong influence on the residence time of migrating water molecules on the lunar surface, which in turn affects the rate and magnitude of volatile transport to permanently shadowed craters (cold traps) near the lunar poles, as well as exospheric structure and the susceptibility of migrating molecules to photodestruction. Here, we develop a stochastic rough surface temperature model suitable for simulations of volatile transport on a global scale, and compare the results of Monte Carlo simulations of volatile transport with and without the surface roughness model. We find that including small-scale temperature variations and shadowing leads to a slight increase in cold-trapping at the lunar poles, accompanied by a slight decrease in photodestruction. Exospheric structure is altered only slightly, primarily at the dawn terminator. We also examine the sensitivity of our results to the temperature of small-scale shadows, and the energetics of water molecule desorption from the lunar regolith - two factors that remain to be definitively constrained by other methods - and find that both these factors affect the rate at which cold trap capture and photodissociation occur, as well as exospheric density and longevity.

  16. Wavelet theory and belt finishing process, influence of wavelet shape on the surface roughness parameter values

    International Nuclear Information System (INIS)

    Khawaja, Z; Mazeran, P-E; Bigerelle, M; Guillemot, G; Mansori, M El

    2011-01-01

    This article presents a multi-scale theory based on wavelet decomposition to characterize the evolution of roughness in relation with a finishing process or an observed surface property. To verify this approach in production conditions, analyses were developed for the finishing process of the hardened steel by abrasive belts. These conditions are described by seven parameters considered in the Tagushi experimental design. The main objective of this work is to identify the most relevant roughness parameter and characteristic length allowing to assess the influence of finishing process, and to test the relevance of the measurement scale. Results show that wavelet approach allows finding this scale.

  17. The influence of contraction in the first interplane distance on the surface states of Ta(001)

    International Nuclear Information System (INIS)

    Baquero, R.; Coss, R. de

    1991-08-01

    We analyze the influence that the recently found Ta(001) first interatomic layer contraction has on the surface electronic structure. We find that the states near the Fermi energy at the Γ point on the 2D First Brillouin zone found in recent experiments are directly related to this contraction. In general, our calculation shows a better agreement with experiment than previous work. The remaining small differences might be attributable to a possible smaller but non-negligible contraction of the second interatomic layer distance. (author). 8 refs, 1 fig

  18. Influence of Plastic Deformation on Low Temperature Surface Hardening of Austenitic Stainless Steel by Gaseous Nitriding

    DEFF Research Database (Denmark)

    Bottoli, Federico; Winther, Grethe; Christiansen, Thomas Lundin

    2015-01-01

    This article addresses an investigation of the influence of plastic deformation on low temperature surface hardening by gaseous nitriding of two commercial austenitic stainless steels: AISI 304 and EN 1.4369. The materials were plastically deformed to different equivalent strains by uniaxial...... tension. Gaseous nitriding of the strained material was performed in ammonia gas at atmospheric pressure at 703 K. Microstructural characterization of the as-deformed states and the nitrided case produced included X-ray diffraction analysis, reflected light microscopy, microhardness testing. The results...

  19. Surface coating influence on elastic properties of spruce wood by means of holographic vibration mode visualization

    Science.gov (United States)

    Bongova, M.; Urgela, Stanislav

    1999-07-01

    Physicoacoustical properties of wood influenced by surface coating are studied by modal analysis. Resonant spruce plates were coated by stain, nitrocellulose varnish, special violin paint and shellac. The modal testing was performed by electronic speckle pattern interferometry. For this purpose, equipment called VIBROVIZER was used. The collected values of physicoacoustical characteristics (density, Young's modulus, acoustic constant) were compared using the graphic plots of data. The 3D plots help to evaluate wooden plates from a viewpoint of the quality control. This fact offers new opportunity for musical instrument manufacturers.

  20. Study of surface phenomena in biomaterials: The influence of physical factors

    Science.gov (United States)

    Sachelarie, Liliana; Vasiliu, Mihaela Papusa; Ciobanu, Catalina

    2015-10-01

    This study's purpose is pointing out the phenomenon that occurs at time of interaction between the tissue with implant. The materials used are Ti and its alloys. The oral tissue must be compatible with the materials used in surgical implant to human body. The bio-materials surface behavior is influenced by physical characteristics. The methods we use show a number of bio-compatibility aspects. The success of an implant in a hard tissue depends not only on the initial attachment and the osteogenic cells consecutive proliferation, but also on their capacity to create a new bone.

  1. Study of surface phenomena in biomaterials: The influence of physical factors

    Energy Technology Data Exchange (ETDEWEB)

    Sachelarie, Liliana, E-mail: lisachero@yahoo.com; Vasiliu, Mihaela Papusa; Ciobanu, Catalina

    2015-10-15

    This study's purpose is pointing out the phenomenon that occurs at time of interaction between the tissue with implant. The materials used are Ti and its alloys. The oral tissue must be compatible with the materials used in surgical implant to human body. The bio-materials surface behavior is influenced by physical characteristics. The methods we use show a number of bio-compatibility aspects. The success of an implant in a hard tissue depends not only on the initial attachment and the osteogenic cells consecutive proliferation, but also on their capacity to create a new bone.

  2. The influence of surface nanoroughness, texture and chemistry of TiZr implant abutment on oral biofilm accumulation.

    Science.gov (United States)

    Xing, Rui; Lyngstadaas, Ståle P; Ellingsen, Jan Eirik; Taxt-Lamolle, Sébastien; Haugen, Håvard J

    2015-06-01

    The aim of the study was to examine surface nanoroughness, texture and chemistry of dental implant abutment and to investigate how these parameters influence oral biofilm formation in healthy subjects. Eight different nanorough TiZr surfaces were produced by polishing, machining, cathodic polarization and acid etching. Surface topography was examined using field emission scanning electron microscope and a blue light laser profilometer. Surface chemistry was analyzed by secondary ion mass spectrometry and X-ray photoelectron spectroscopy. Surface hydrophilicity was tested by measuring contact angle on the surfaces. A human in vivo study using a splint model was employed to evaluate oral biofilm accumulation on these surfaces. Different surface textures (flat, grooved and irregular) were created with nanoroughness from 29 to 214 nm. Some test surfaces were incorporated with hydrogen by cathodic polarization and/or acid etching with HCl/H(2)SO(4). Nanoroughness (S(a)) positively correlated with microbial adhesion. Biofilm accumulation was less pronounced on flat and grooved than on irregular surfaces. No significant association between hydrogen content or hydrophilicity of the surface and biofilm accumulation was observed. Nanoroughness (< 214 nm) and surface texture influence oral biofilm accumulation independent of surface chemistry and hydrophilicity. Surface hydrogen, which has previously been shown to promote fibroblast growth, does not affect biofilm formation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Influence of the Number of Predicted Words on Text Input Speed in Participants With Cervical Spinal Cord Injury.

    Science.gov (United States)

    Pouplin, Samuel; Roche, Nicolas; Vaugier, Isabelle; Jacob, Antoine; Figere, Marjorie; Pottier, Sandra; Antoine, Jean-Yves; Bensmail, Djamel

    2016-02-01

    To determine whether the number of words displayed in the word prediction software (WPS) list affects text input speed (TIS) in people with cervical spinal cord injury (SCI), and whether any influence is dependent on the level of the lesion. A cross-sectional trial. A rehabilitation center. Persons with cervical SCI (N=45). Lesion level was high (C4 and C5, American Spinal Injury Association [ASIA] grade A or B) for 15 participants (high-lesion group) and low (between C6 and C8, ASIA grade A or B) for 30 participants (low-lesion group). TIS was evaluated during four 10-minute copying tasks: (1) without WPS (Without); (2) with a display of 3 predicted words (3Words); (3) with a display of 6 predicted words (6Words); and (4) with a display of 8 predicted words (8Words). During the 4 copying tasks, TIS was measured objectively (characters per minute, number of errors) and subjectively through subject report (fatigue, perception of speed, cognitive load, satisfaction). For participants with low-cervical SCI, TIS without WPS was faster than with WPS, regardless of the number of words displayed (Pnumber of words displayed in a word prediction list on TIS; however, perception of TIS differed according to lesion level. For persons with low-cervical SCI, a small number of words should be displayed, or WPS should not be used at all. For persons with high-cervical SCI, a larger number of words displayed increases the comfort of use of WPS. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  4. Eye Injuries (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Eye Injuries KidsHealth / For Parents / Eye Injuries What's in ... sand, dirt, and other foreign bodies on the eye surface) Wash your hands thoroughly before touching the ...

  5. Influence of surface modified dental implant abutments on connective tissue attachment: A systematic review.

    Science.gov (United States)

    Blázquez-Hinarejos, Mónica; Ayuso-Montero, Raúl; Jané-Salas, Enric; López-López, José

    2017-08-01

    Determine whether surface modified prosthetic abutments for dental implants influence connective tissue attachment to the implant-abutment system. A systematic review was conducted using the MEDLINE-PubMed database, with two independent reviewers filtering the titles and abstracts. Two reviewers assessed all potentially relevant articles. An assessment was carried out on the level of evidence of the research according to the guidelines of the Oxford Centre for Evidence-Based Medicine (OCEBM). After an initial search, 109 potentially relevant articles were found. After reading the titles and abstracts, 99 articles were excluded because the surface treatment was limited to the implant and not to the abutment, or because different materials were analysed instead of surface treatments; 28 were also duplicate articles. An additional 6 research studies were included that were of interest and were found by reading the references of the included articles. The studies included are: 7 in vitro studies, 5 experimental studies in animals, 2 clinical trials in humans and 2 clinical cases. Surface modification for prosthetic abutments on dental implants can achieve connective tissue attachment to the abutment; however, more studies should be conducted in humans to obtain more and better evidence of these results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Surface roughness and hardness of a composite resin: influence of finishing and polishing and immersion methods

    Directory of Open Access Journals (Sweden)

    Ana Luísa Botta Martins de Oliveira

    2010-09-01

    Full Text Available This study evaluated the finishing and polishing effect on the surface roughness and hardness of the Filtek Supreme XT, in fluoride solutions. Specimens were prepared (n = 140 with half of the samples finished and polished with Super-Snap® disks. The experimental groups were divided according to the presence or absence of finishing and polishing and immersion solutions (artificial saliva, sodium fluoride solution at 0.05% - manipulated, Fluordent Reach, Oral B, Fluorgard. The specimens remained immersed in artificial saliva for 24 hours and were then subjected to initial analysis (baseline of surface roughness and Vickers microhardness. Next, they were immersed in different fluoride solutions for 1 min/day, for 60 days. Afterwards, a new surface roughness and microhardness reading was conducted. The data were submitted to a two-way ANOVA and Tukey's test (5% significance level. For the comparison of mean roughness and hardness at baseline and after 60 days, the paired Student t test was used. The results showed that the surface roughness and microhardness of the Filtek Supreme XT were influenced by the finishing and polishing procedure, independently of the immersion methods.

  7. Influence of E-beam-irradiation on surface modification and micro hardness of recycled polyolefin's

    International Nuclear Information System (INIS)

    Atabaev, B.G.; Gafurov, U.

    2004-01-01

    Full text: The influence of high (E=5MeV) and low (E=0,125MeV) energy -beam irradiation on bulk and surface modification of recycled polypropylene and polyethylene has been investigated. The new techniques for measuring of polymer surface micro hardness, using decoration of indenter imprint under load lower than 100g are developed. It was shown that e-beam irradiation with high-energy lead to rise of surface micro hardness of recycled polypropylene up to two times for 50g load and 30 percent for 25g load with increasing of irradiation dose (D=100,125,150kGy). The bulk and surface modifications depend on cross-links and oxidation processes in recycled polymer under e-beam irradiation. For low energy e-beam irradiation of recycled polyethylene E=0,125MeV and doses D=50,125 kGy the like results took place. The correlation between increasing of micro hardness of irradiated polymers, E-beam radiation stimulated cross-linkage, oxidation processes by IR (FTIR) Spectroscopy method has been investigated

  8. Model tests for corrosion influence of electrode surface on electroosmosis in marine sludge

    Science.gov (United States)

    Zheng, Lingwei; Li, Jinzhu; Shi, Hanru

    2017-11-01

    The corrosion of metal electrodes is inevitable on electroosmosis in soil. Surface corrosion of electrodes is also one of the reasons for increasing energy consumption in electroosmosis treatment. A series of laboratory tests were conducted employing three kinds of materials, aluminium, steel, and brass. To explore the impact of surface corrosion degree on electroosmosis, metal electrodes were pretreated with durations 0 h, 12 h, 24 h, and 36 h. After the pretreatment, corroded electrodes are used as anodes on electroosmosis. Water discharge, current, voltage potential were measured during the tests; water content was also tested at three points after the electroosmosis. The results showed that aluminium was better than steel in electroosmotic drainage while brass provided the worst dewatering performance. Surface corrosion did not influence the aluminium and steel on electroosmosis in marine sludge, but brass did. In the pretreatment of brass electrodes, corrosion rate had started to slow down at later periods, with the deterioration rate of dewatering reduced afterwards. As the results showed, it is not recommended to employ those easily deteriorated electrode materials from surface corrosion in practical engineering, such as brass; electrode material with higher electroosmosis exchange rate is recommended, such as aluminium.

  9. Ozonation of benzothiazole saturated-activated carbons: Influence of carbon chemical surface properties

    International Nuclear Information System (INIS)

    Valdes, H.; Zaror, C.A.

    2006-01-01

    The combined or sequential use of ozone and activated carbon to treat toxic effluents has increased in recent years. However, little is known about the influence of carbon surface active sites on ozonation of organic adsorbed pollutants. This paper presents experimental results on the effect of metal oxides and oxygenated surface groups on gaseous ozonation of spent activated carbons. Benzothiazole (BT) was selected as a target organic compound in this study due to its environmental concern. Activated carbons with different chemical surface composition were prepared from a Filtrasorb-400 activated carbon. Pre-treatment included: ozonation, demineralisation, and deoxygenation of activated carbon. Ozonation experiments of BT saturated-activated carbons were conducted in a fixed bed reactor loaded with 2 g of carbon samples. The reactor was fed with an O 2 /O 3 gas mixture (2 dm 3 /min, 5 g O 3 /h), for a given exposure time, in the range 10-120 min, at 298 K and 1 atm. Results show that extended gaseous ozonation of activated carbon saturated with BT led to the effective destruction of the adsorbate by oxidation reactions. Oxidation of BT adsorbed on activated carbon seemed to occur via both direct reaction with ozone molecules, and by oxygen radical species generated by catalytic ozone decomposition on metallic surface sites

  10. Influence of autoclave sterilization on the surface parameters and mechanical properties of six orthodontic wires.

    Science.gov (United States)

    Pernier, C; Grosgogeat, B; Ponsonnet, L; Benay, G; Lissac, M

    2005-02-01

    Orthodontic wires are frequently packaged in individual sealed bags in order to avoid cross-contamination. The instructions on the wrapper generally advise autoclave sterilization of the package and its contents if additional protection is desired. However, sterilization can modify the surface parameters and the mechanical properties of many types of material. The aim of this research was to determine the influence of one of the most widely used sterilization processes, autoclaving (18 minutes at 134 degrees C, as recommended by the French Ministry of Health), on the surface parameters and mechanical properties of six wires currently used in orthodontics (one stainless steel alloy: Tru-Chrome RMO; two nickel-titanium shape memory alloys: Neo Sentalloy and Neo Sentalloy with Ionguard GAC; and three titanium-molybdenum alloys: TMA(R) and Low Friction TMA Ormco and Resolve GAC). The alloys were analysed on receipt and after sterilization, using surface structure observation techniques, including optical, scanning electron and atomic force microscopy and profilometry. The mechanical properties were assessed by three-point bending tests. The results showed that autoclave sterilization had no adverse effects on the surface parameters or on the selected mechanical properties. This supports the possibility for practitioners to systematically sterilize wires before placing them in the oral environment.

  11. Influence of ECR-RF plasma modification on surface and thermal properties of polyester copolymer

    Directory of Open Access Journals (Sweden)

    Fray Miroslawa El

    2015-12-01

    Full Text Available In this paper we report a study on influence of radio-frequency (RF plasma induced with electron cyclotron resonance (ECR on multiblock copolymer containing butylene terephthalate hard segments (PBT and butylene dilinoleate (BDLA soft segments. The changes in thermal properties were studied by DSC. The changes in wettability of PBT-BDLA surfaces were studied by water contact angle (WCA. We found that ECR-RF plasma surface treatment for 60 s led to decrease of WCA, while prolonged exposure of plasma led to increase of WCA after N2 and N2O2 treatment up to 70°–80°. The O2 reduced the WCA to 50°–56°. IR measurements confirmed that the N2O2 plasma led to formation of polar groups. SEM investigations showed that plasma treatment led to minor surfaces changes. Collectively, plasma treatment, especially O2, induced surface hydrophilicity what could be beneficial for increased cell adhesion in future biomedical applications of these materials.

  12. Influence of growth temperature on inactivation and injury of Escherichia coli O157:H7 by heat, acid, and freezing.

    Science.gov (United States)

    Semanchek, J J; Golden, D A

    1998-04-01

    The influence of growth temperature on heat-, lactic acid-, and freeze-induced inactivation and injury of Escherichia coli O157:H7 in 0.1% peptone water was investigated. Three strains of E. coli O157:H7 isolated respectively from salami, apple cider, and ground beef were evaluated. Growth of strains at 10 degrees C compared with growth at 37 degrees C had a significant impact on reducing (P heating (DH value), acid exposure (DA value), with the exception of the cider strain stored in lactic acid solutions. When strains were cultivated at 10 and 37 degrees C and heated at 54 and 56 degrees C, the salami strain possessed the highest (P heating at 52, 54, and 56 degrees C (11.2, 4.1 and 2.5 min, respectively). The salami strain grown at 10 degrees C had the highest (P storage in 0.1 and 0.25% lactic acid, while DA values for the salami and beef strains did not differ (P > 0.05) when stored in 0.5% lactic acid. Portions of strain populations were sublethally injured by heat and lactic acid treatments, as evidenced by the inability of injured organisms to form colonies on tryptone soy agar containing 2% NaCl. Strains cultured at 10 degrees C were more susceptible to sublethal heat injury than the strains cultured at 37 degrees C. Storage of test strains at -20 degrees C for 7 months resulted in a 4- to 6-log CFU/ml reduction in viable population, but induced only minimal sublethal injury. After 5 months at -20 degrees C, strains cultured at 10 degrees C were more sensitive to freeze inactivation than strains cultured at 37 degrees C. When grown at 10 and cultured at 37 degrees C. When grown at 10 and 37 degrees C and stored at -20 degrees C for 7 months, the cider strain possessed higher (P < 0.01) DF values than the beef and salami strains.

  13. The Influence of Surface Roughness on Volatile Transport on the Moon

    Science.gov (United States)

    Prem, Parvathy; Artemieva, Natalia A.; Goldstein, David B.; Varghese, Philip L.; Trafton, Laurence M.

    2015-11-01

    comparison of results from impact-generated atmosphere simulations with and without the surface roughness model in order to understand how small-scale roughness influences transient deposition patterns and the rate and magnitude of cold trap capture.

  14. The influence of surface roughness and solution concentration on pool boiling process in Diethanolamine aqueous solution

    Science.gov (United States)

    Khoshechin, Mohsen; Salimi, Farhad; Jahangiri, Alireza

    2018-04-01

    roughness A heated surface area d departure ONB onset of nucleate boiling w surface wall s saturation v vapor l liquid θ groove angle (o) γ influence parameter of heating surface material σ surface tension, N/m.

  15. A hyperoxic lung injury model in premature rabbits: the influence of different gestational ages and oxygen concentrations.

    Directory of Open Access Journals (Sweden)

    Roberta Munhoz Manzano

    Full Text Available BACKGROUND: Many animal models have been developed to study bronchopulmonary dysplasia (BPD. The preterm rabbit is a low-cost, easy-to-handle model, but it has a high mortality rate in response to the high oxygen concentrations used to induce lung injury. The aim of this study was to compare the mortality rates of two models of hyperoxia-induced lung injury in preterm rabbits. METHODS: Pregnant New Zealand white rabbits were subjected to caesarean section on gestational day 28 or 29 (full term  = 31 days. The premature rabbits in the 28-day gestation group were exposed to room air or FiO₂ ≥95%, and the rabbits in the 29-day gestation group were exposed to room air or FiO₂  = 80% for 11 days. The mean linear intercept (Lm, internal surface area (ISA, number of alveoli, septal thickness and proportion of elastic and collagen fibers were quantified. RESULTS: The survival rates in the 29-day groups were improved compared with the 28-day groups. Hyperoxia impaired the normal development of the lung, as demonstrated by an increase in the Lm, the septal thickness and the proportion of elastic fibers. Hyperoxia also decreased the ISA, the number of alveoli and the proportion of collagen fibers in the 28-day oxygen-exposed group compared with the control 28-day group. A reduced number of alveoli was found in the 29-day oxygen exposed animals compared with the control 29-day group. CONCLUSIONS: The 29-day preterm rabbits had a reduced mortality rate compared with the 28-day preterm rabbits and maintained a reduction in the alveoli number, which is comparable to BPD in humans.

  16. Pharmacogenomic Variants May Influence the Urinary Excretion of Novel Kidney Injury Biomarkers in Patients Receiving Cisplatin

    Directory of Open Access Journals (Sweden)

    Cara Chang

    2017-06-01

    Full Text Available Nephrotoxicity is a dose limiting side effect associated with the use of cisplatin in the treatment of solid tumors. The degree of nephrotoxicity is dictated by the selective accumulation of cisplatin in renal tubule cells due to: (1 uptake by organic cation transporter 2 (OCT2 and copper transporter 1 (CTR1; (2 metabolism by glutathione S-transferases (GSTs and γ-glutamyltransferase 1 (GGT1; and (3 efflux by multidrug resistance-associated protein 2 (MRP2 and multidrug and toxin extrusion protein 1 (MATE1. The purpose of this study was to determine the significance of single nucleotide polymorphisms that regulate the expression and function of transporters and metabolism genes implicated in development of acute kidney injury (AKI in cisplatin treated patients. Changes in the kidney function were assessed using novel urinary protein biomarkers and traditional markers. Genotyping was conducted by the QuantStudio 12K Flex Real-Time PCR System using a custom open array chip with metabolism, transport, and transcription factor polymorphisms of interest to cisplatin disposition and toxicity. Traditional and novel biomarker assays for kidney toxicity were assessed for differences according to genotype by ANOVA. Allele and genotype frequencies were determined based on Caucasian population frequencies. The polymorphisms rs596881 (SLC22A2/OCT2, and rs12686377 and rs7851395 (SLC31A1/CTR1 were associated with renoprotection and maintenance of estimated glomerular filtration rate (eGFR. Polymorphisms in SLC22A2/OCT2, SLC31A1/CTRI, SLC47A1/MATE1, ABCC2/MRP2, and GSTP1 were significantly associated with increases in the urinary excretion of novel AKI biomarkers: KIM-1, TFF3, MCP1, NGAL, clusterin, cystatin C, and calbindin. Knowledge concerning which genotypes in drug transporters are associated with cisplatin-induced nephrotoxicity may help to identify at-risk patients and initiate strategies, such as using lower or fractionated cisplatin doses or avoiding

  17. Pharmacogenomic Variants May Influence the Urinary Excretion of Novel Kidney Injury Biomarkers in Patients Receiving Cisplatin

    Science.gov (United States)

    Chang, Cara; Hu, Yichun; Hogan, Susan L.; Mercke, Nickie; Gomez, Madeleine; O’Bryant, Cindy; Bowles, Daniel W.; George, Blessy; Wen, Xia; Aleksunes, Lauren M.; Joy, Melanie S.

    2017-01-01

    Nephrotoxicity is a dose limiting side effect associated with the use of cisplatin in the treatment of solid tumors. The degree of nephrotoxicity is dictated by the selective accumulation of cisplatin in renal tubule cells due to: (1) uptake by organic cation transporter 2 (OCT2) and copper transporter 1 (CTR1); (2) metabolism by glutathione S-transferases (GSTs) and γ-glutamyltransferase 1 (GGT1); and (3) efflux by multidrug resistance-associated protein 2 (MRP2) and multidrug and toxin extrusion protein 1 (MATE1). The purpose of this study was to determine the significance of single nucleotide polymorphisms that regulate the expression and function of transporters and metabolism genes implicated in development of acute kidney injury (AKI) in cisplatin treated patients. Changes in the kidney function were assessed using novel urinary protein biomarkers and traditional markers. Genotyping was conducted by the QuantStudio 12K Flex Real-Time PCR System using a custom open array chip with metabolism, transport, and transcription factor polymorphisms of interest to cisplatin disposition and toxicity. Traditional and novel biomarker assays for kidney toxicity were assessed for differences according to genotype by ANOVA. Allele and genotype frequencies were determined based on Caucasian population frequencies. The polymorphisms rs596881 (SLC22A2/OCT2), and rs12686377 and rs7851395 (SLC31A1/CTR1) were associated with renoprotection and maintenance of estimated glomerular filtration rate (eGFR). Polymorphisms in SLC22A2/OCT2, SLC31A1/CTRI, SLC47A1/MATE1, ABCC2/MRP2, and GSTP1 were significantly associated with increases in the urinary excretion of novel AKI biomarkers: KIM-1, TFF3, MCP1, NGAL, clusterin, cystatin C, and calbindin. Knowledge concerning which genotypes in drug transporters are associated with cisplatin-induced nephrotoxicity may help to identify at-risk patients and initiate strategies, such as using lower or fractionated cisplatin doses or avoiding

  18. Influence of zirconia surface treatment on veneering porcelain shear bond strength after cyclic loading.

    Science.gov (United States)

    Nishigori, Atsushi; Yoshida, Takamitsu; Bottino, Marco C; Platt, Jeffrey A

    2014-12-01

    The influence of yttria-stabilized tetragonal zirconia polycrystal surface treatment on veneering porcelain shear bond strength after cyclic loading is not fully understood. The purpose of this study was to investigate the influence of yttria-stabilized tetragonal zirconia polycrystal surface treatment on veneering porcelain shear bond strength and cyclic loading on the shear bond strength between the 2 materials. A total of 48 cylinder-shaped yttria-stabilized tetragonal zirconia polycrystal specimens were fabricated with computer-aided design and computer-aided manufacturing (CAD/CAM), sintered for 8 hours at 1500°C, ground with 320-grit diamond paper, and divided into 4 groups (n = 12) according to surface treatment as follows: no treatment/control; heat treatment of 650°C to 1000°C at 55°C/min; airborne-particle abrasion with 50-μm alumina at 0.4 MPa pressure for 10 seconds; or heat treatment after abrasion. A veneering porcelain cylinder was built and fired on the prepared yttria-stabilized tetragonal zirconia polycrystal specimens. The shear bond strength was tested with a universal testing machine. Six specimens from each group were subjected to cyclic loading (10000 cycles, 1.5 Hz, 10 N load) before testing. The mean ± SD ranged from 10.7 ± 15.4 to 34.1 ± 10.0. Three-way ANOVA found no statistically significant (P > .05) effect of surface treatment and cyclic loading on shear bond strength. The Sidak multiple comparisons procedure found that cyclic loading specimens had significantly lower shear bond strength than noncyclic loading specimens after airborne-particle abrasion without heat treatment (P = .013). Within the limitations of this study, the shear bond strength between yttria-stabilized tetragonal zirconia polycrystal and veneering porcelain was not significantly affected by surface treatment. Airborne-particle abrasion without subsequent heat treatment should be avoided as a surface treatment in fabrication methods. Copyright © 2014

  19. The possible influence of terracettes on surface hydrology of steep-sloping and subalpine environments

    Science.gov (United States)

    Greenwood, Philip; Kuonen, Samuel; Fister, Wolfgang; Kuhn, Nikolaus

    2015-04-01

    Alpine and mountain slopes represent important pathways that link high altitude grazing areas to meadows and rangelands at lower elevations. Given the often acute gradients associated with such environments, they potentially represent highly efficient runoff conveyance routes that presumably facilitate the downslope movement of runoff and associated material during erosion events. Many such slopes host series of small steps, or `terracettes`. The position of terracette systems, usually juxtaposed across the natural downslope flow-path of acute slopes, lead us to hypothesise that their presence may influence typical hillslope processes by intercepting or capturing surface runoff during its downslope transit. Here we report preliminary results and some tentative conclusions from on-going work to explore this possibility. Google Earth was used to initially identify a ca. 400 m2 area of well-developed terracette system situated on a west-facing slope with gradients ranging from 25-40o (46-84%). A digital elevation model (DEM) of a section of the terracette system was constructed using spatial data taken from a relevant excerpt of a topographic map. The DEM was then queried using a flow accumulation algorithm and the results were displayed in a Geographic Information System (GIS). The output data provided 'proof of concept' that terracettes are able to capture surface runoff. A series of rainfall / runoff simulations was then performed on the same section of terracettes. Results from both components of the investigation indicate that certain sections of a terracette system intercepted surface runoff and acted as preferential flow-pathways during runoff events. By contrast, and despite being subjected to intense rainfall, some sections of the same terracette system did not generate surface runoff. Based on these contrasting findings, we cautiously predict that areas where surface runoff was not generated may actually act as depositional sites, or retention zones, and

  20. Influence of the Ion Treatment Regime on Defects Density and Surface Destruction of the Polycrystalline Glass

    Directory of Open Access Journals (Sweden)

    D. V. Duhopel'nikov

    2014-01-01

    Full Text Available The ion beam technology is used for finish treatment of large-scale optic parts to achieve highest precision and minimal surface roughness. The surface roughness increases during the ion treatment of polycrystalline materials in contrast to usual optic materials. This is caused, first, by polycrystalline structure of material and, second, by micro-defects appearing on its surface. The aim of the work is to investigate the influence of ion processing conditions on the amount of defects formed on the polycrystalline glass CO-115M.As an ion source, was used the anode layer accelerator with electromagnetically focusing ion beam and with excess charge compensation on the residual gas. The ion accelerator provided Gaussian ion current distribution on the treated sample surface. The accelerator had three operation conditions: 1 – Ud = 2 kV, Id = 110 mA; 2 – Ud = 3 kV, Id = 110 mA; 3 – Ud = 3,8 kV, Id = 50 mA (Ud – discharge voltage, Id – discharge current. Processing time was 30 min.For quantitative estimation of surface destruction degree the surface defects density was used which is equal to the ratio of total area of defects within the region under consideration to entire area. Defects area was calculated using the microphotography of treated surface.The investigations have shown that the defects occurred as microscopic chips in all operation conditions of treatment. The defects density distribution corresponds to ion current distribution on the sample surface. With increasing ion current power density a size of defects has grown and their amount has increased. With the constant power density an increasing acceleration voltage results in decreasing density of defects. It was shown that a process of appearing defects is of the threshold nature. For each accelerated voltage there is a power density at which defects do not appear. The work results may be useful to choose the ion beam processing operation conditions in manufacturing large

  1. [Influence of polyester gauze on evaporation capacity and healing of the surface of microskin graft wound after escharectomy].

    Science.gov (United States)

    Chen, Jiong; Tang, Zhi-Jian; Xia, Zhao-Fan; Zheng, Xu-Dong; Zhang, Li-Cheng

    2009-01-13

    To investigate the influence of polyester gauze on evaporation capacity and its clinical effect after escharectomy of deep burn wound and micro-skin grafting. Twenty patients with deep burn admitted within 24 hours after injury underwent escharectomy and Meek skin grafting. Two surfaces of wound with the area of about 1% as the whole wound surface were used, one covered by Meek skin graft and polyester gauze as inner dressing (polyester gauze group), and the other covered by split-thickness skin sheet 0.3 mm x 0.3 mm in size and vaseline oil gauze as inner dressing (vaseline oil gauze group). Five days after skin grafting, the evaporation capacities of the surface of inner dressing, wound surface without dressing (nude wound), and normal skin near the wound were tested by evaporation test equipment. The complete healing time and survival rate of skin sheet in both groups were observed. The degree of pain during dressing change was evaluated with visual analog scale. The evaporation capacity of the inner dressing surface of polyester gauze group was (24.8 +/- 5.2) ml x h(-1) x m(-2), significantly lower than those of the vaseline oil gauze group [(35.4 +/- 5.0) ml x h(-1) x m(-2), P 0.05]. The evaporation capacity of the inner dressing surface of vaseline oil gauze group was significantly lower than nude wound [(40.7 +/- 3.6) ml x h(-1) x m(-2), P 0.05). The wound healing rates on days 10, 15, and 20 of the polyester gauze group were 80% +/- 20%, 96% +/- 7%, and 100% respectively, all significantly higher than those of the vaseline oil gauze group (70% +/- 33%, 81% +/- 21%, and 97% +/- 11% respectively, all P < 0.01). The complete healing time of the polyester gauze group was (13.6 +/- 1.9) days, significantly shorter than that of the vaseline oil gauze group [(16.7 +/- 2.6) days, P < 0.01]. The pain scores during dressing change 5 and 10 days after grafting of the polyester gauze group were (3.2 +/- 0.8) and (4.9 +/- 0.4) respectively, both significantly lower than

  2. Influence of surface modification on friction coefficient of the titanium-elastomer couple.

    Science.gov (United States)

    Chladek, Wiesław; Hadasik, Eugeniusz; Chladek, Grzegorz

    2007-01-01

    This paper presents the results of a study of the friction coefficient of titanium-elastomer couple. The study was carried out with a view to potential future utilization of its results for constructing retentive elements of implanted prostheses. Changes in the friction force were recorded while removing titanium specimens placed between two silicone counter specimens made of Ufi Gel. The influence of the titanium specimen movement speed in relation that of to the counter specimens and the influence of clamping force on the friction force were assessed. Additionally, the surface roughness of titanium specimens differed; in one case, titanium was coated with polyethylene. The effect of introducing artificial saliva between the cooperating surfaces on the friction force and friction coefficient was analyzed as well. Based on the characteristics recorded, the possibilities of shaping the friction coefficient have been assessed, since it is the friction coefficient that determines effective operation of a friction couple through increasing the titanium specimen roughness. The artificial saliva being introduced between the specimens reduces considerably the friction coefficient through a change of the phenomenon model. An increase in the pressure force for the specimens of high roughness entails a reduction of the friction coefficient. The study carried out allows us to identify the roughness parameters, which in turn will enable obtaining the prescribed retention force for friction/membrane couplings.

  3. Sound propagation through a rarefied gas. Influence of the gas–surface interaction

    International Nuclear Information System (INIS)

    Kalempa, Denize; Sharipov, Felix

    2012-01-01

    Highlights: ► Non-equilibrium gas properties due to sound propagation. ► Influence of gas–surface accommodation coefficients. ► Heat transfer due to thermo-acoustic waves. ► Reciprocal relations. ► Range of validity of the Navier–Stokes equations. - Abstract: Acoustic waves propagating through a rarefied gas between two plates induced by both oscillation and unsteady heating of one of them are considered on the basis of a model of the linearized Boltzmann equation. The gas flow is considered as fully established so that the dependence of all quantities on time is harmonical. The problem is solved for several values of two main parameters determining its solution, namely, the gas rarefaction defined as the ratio of the distance between the plates to the equivalent free path of gaseous molecules, and the oscillation parameter given as the ratio of the intermolecular collision frequency to the wave frequency. The reciprocal relation for such flows is obtained and verified numerically. An influence of the gas–surface accommodation coefficients on the wave characteristics is analyzed by employing the Cercignani–Lampis scattering kernel to the boundary conditions.

  4. Critical insight into the influence of the potential energy surface on fission dynamics

    International Nuclear Information System (INIS)

    Mazurek, K.; Schmitt, C.; Wieleczko, J. P.; Ademard, G.; Nadtochy, P. N.

    2011-01-01

    The present work is dedicated to a careful investigation of the influence of the potential energy surface on the fission process. The time evolution of nuclei at high excitation energy and angular momentum is studied by means of three-dimensional Langevin calculations performed for two different parametrizations of the macroscopic potential: the Finite Range Liquid Drop Model (FRLDM) and the Lublin-Strasbourg Drop (LSD) prescription. Depending on the mass of the system, the topology of the potential throughout the deformation space of interest in fission is observed to noticeably differ within these two approaches, due to the treatment of curvature effects. When utilized in the dynamical calculation as the driving potential, the FRLDM and LSD models yield similar results in the heavy-mass region, whereas the predictions can be strongly dependent on the Potential Energy Surface (PES) for medium-mass nuclei. In particular, the mass, charge, and total kinetic energy distributions of the fission fragments are found to be narrower with the LSD prescription. The influence of critical model parameters on our findings is carefully investigated. The present study sheds light on the experimental conditions and signatures well suited for constraining the parametrization of the macroscopic potential. Its implication regarding the interpretation of available experimental data is briefly discussed.

  5. Influence of tempering and contraction mismatch on crack development in ceramic surfaces.

    Science.gov (United States)

    Anusavice, K J; DeHoff, P H; Hojjatie, B; Gray, A

    1989-07-01

    Tempering of glass produces a state of compressive stress in surface regions which can enhance the resistance to crack initiation and growth. The objective of this study was to determine the influence of tempering on the sizes of surface cracks induced within the tempered surfaces of opaque porcelain-body porcelain discs, with contraction coefficient differences (alpha O-alpha B) of +3.2, +0.7, 0.0, -0.9, and -1.5 ppm/degrees C. We fired the discs to the maturing temperature (982 degrees C) of body porcelain and then subjected them to three cooling procedures: slow cooling in a furnace (SC), fast cooling in air (FC), and tempering (T) by blasting the body porcelain surface with compressed air for 90 s. We used body porcelain discs as the thermally compatible (delta alpha = 0) control specimens. We measured the diameters of cracks induced by a microhardness indenter at an applied load of 4.9 N at 80 points along diametral lines within the surface of body porcelain. The mean values of the crack diameters varied from 75.9 microns (delta alpha = -1.5 ppm/degrees C) to 103.3 microns (delta alpha = +3.2 ppm/degrees C). The results of ANOVA indicate that significant differences in crack dimensions were controlled by cooling rate, contraction mismatch, and their combined effect (p less than 0.0001). Multiple contrast analysis (Tukey's HSD Test) revealed significantly lower (p less than 0.05) crack sizes for tempered specimens compared with those of fast-cooled and slow-cooled specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Tile Drainage Management Influences on Surface-Water and Groundwater Quality following Liquid Manure Application.

    Science.gov (United States)

    Frey, Steven K; Topp, Ed; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Zoski, Erin; Lapen, David R

    2013-01-01

    This study investigated the potential for controlled tile drainage (CD) to reduce bacteria and nutrient loading to surface water and groundwater from fall-season liquid manure application (LMA) on four macroporous clay loam plots, of which two had CD and two had free-draining (FD) tiles. Rhodamine WT (RWT) was mixed into the manure and monitored in the tile water and groundwater following LMA. Tile water and groundwater quality were influenced by drainage management. Following LMA on the FD plots, RWT, nutrients, and bacteria moved rapidly via tiles to surface water; at the CD plots, tiles did not flow until the first post-LMA rainfall, so the immediate risk of LMA-induced contamination of surface water was abated. During the 36-d monitoring period, flow-weighted average specific conductance, redox potential, and turbidity, as well as total Kjeldahl N (TKN), total P (TP), NH-N, reactive P, and RWT concentrations, were higher in the CD tile effluent; however, because of lower tile discharge from the CD plots, there was no significant ( ≤ 0.05) difference in surface water nutrient and RWT loading between the CD and FD plots when all tiles were flowing. The TKN, TP, and RWT concentrations in groundwater also tended to be higher at the CD plots. Bacteria behaved differently than nutrients and RWT, with no significant difference in total coliform, , fecal coliform, fecal streptococcus, and concentrations between the CD and FD tile effluent; however, for all but , hourly loading was higher from the FD plots. Results indicate that CD has potential for mitigating bacteria movement to surface water. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. Influence of an Increasing Surface Melt Over Decadal Timescales on Land Terminating Outlet Glaciers

    Science.gov (United States)

    Gagliardini, O.; Werder, M. A.; Durand, G.

    2015-12-01

    During the last decades, Greenland surface melt has shown an increase both in intensity and spatial extent. Part of this water probably reaches the bedrock and enhances the glacier speed, advecting larger volume of ice into the ablation area. In the context of a warming climate, this mechanism will contribute to the future rate of retreat and thinning of the land-terminating glaciers of Greenland. Complex couplings, implying both positive and negative feedbacks, prevail between surface mass balance, ice flow, basal hydrology and the evolution of the glacier geometry. Larger amount of melt water might increase or decrease the mean ice flow of a glacier, depending on the capacity of the basal hydrology network to evacuate this surplus of water, which in turn will influence the surface crevassing and the ability of water to reach the bedrock at higher elevations. Here, using a coupled basal hydrology and prognostic ice flow model, the evolution of a Greenland-type glacier subject to an increasing surface melt is studied over few decades. The basal hydrology model, based on the GlaDS model, includes an inefficient cavity-type water sheet and a network of efficient discrete channels. Both systems are connected and evolve in time in response to the water inputs. The prognostic equations for ice flow and the hydrology model are implemented in the open source, finite element, ice sheet / ice flow model Elmer/Ice. Assuming a surface melt increase over the next decades, the evolution of crevassed areas and the ability of water to reach the bedrock is inferred. Our results indicate that the currently observed crevasse distribution is likely to extend upstream, leading to an increase in ice flow which, in turn, accelerates the retreat and thinning of land-terminating glaciers.

  8. The Influence of Surface Alumina and Silica on the Photocatalytic Degradation of Organic Pollutants

    Directory of Open Access Journals (Sweden)

    Terry A. Egerton

    2013-03-01

    Full Text Available Practical photocatalysis for degradation of organic pollutants must take into account the influence of other chemicals. Significant Al deposition on titania can occur at naturally occurring concentrations of dissolved Al. This paper reviews the author’s work on the influence of deliberately deposited hydrous oxides of aluminium on the behavior of a ~130 m2 g−1 rutile TiO2, and then compares the behavior of deposited alumina with that of deposited silica. On rutile some adsorbed nitrogen is infrared-active. Alumina and silica deposited on the rutile reduce, and ultimately eliminate, this infrared-active species. They also reduce photocatalytic oxidation of both propan-2-ol and dichloroacetate ion and the photocatalytic reduction of diphenyl picryl hydrazine. The surface oxides suppress charge transfer and may also reduce reactant adsorption. Quantitative measurement of TiO2 photogreying shows that the adsorbed inorganics also reduce photogreying, attributed to the capture of photogenerated conduction band electrons by Ti4+ to form Ti3+. The influence of adsorbed phosphate on photocatalysis is briefly considered, since phosphate reduces photocatalytic disinfection. In the context of classical colloid studies, it is concluded that inorganic species in water can significantly reduce photoactivity from the levels that measured in pure water.

  9. The influence of mouthrinses and simulated toothbrushing on the surface roughness of a nanofilled composite resin.

    Science.gov (United States)

    Trauth, Keico Graciela Sano; Godoi, Ana Paula Terossi de; Colucci, Vivian; Corona, Silmara Aparecida Milori; Catirse, Alma Blásida Concepción Elizaur Benitez

    2012-01-01

    The aim of this study was to determine the influence of mouthrinses on the surface roughness of a nanofilled composite resin after toothbrushing. One hundred nanofilled composite resin specimens were prepared and randomly distributed into two groups-brushed and non-brushed-and then assigned to five subgroups, according to the mouthrinse solutions (n = 10): Colgate Plax Fresh Mint, Oral B, Cepacol, Colgate Plax, and artificial saliva. Each sample was immersed in 20 mL of the mouthrinses for 1 minute, 5 days per week, twice a day, for a 3-week period. The control group used in the study was one in which the specimens were not subjected to brushing and remained only in artificial saliva. Toothbrushing was performed once a week for 1 minute, for 3 weeks. Surface roughness measurements (Ra) were performed after the immersion period and toothbrushing, by means of a profilometer. Data were analyzed by two-way ANOVA and Tukey's test. Analysis revealed that the association between toothbrushing and Colgate Plax Fresh Mint produced the lowest surface roughness (p toothbrushing or not (p toothbrushing.

  10. The influence of the surface chemistry of silver nanoparticles on cell death

    International Nuclear Information System (INIS)

    Sur, Ilknur; Altunbek, Mine; Kahraman, Mehmet; Culha, Mustafa

    2012-01-01

    The influence of the surface chemistry of silver nanoparticles (AgNPs) on p53 mediated cell death was evaluated using human dermal fibroblast (HDF) and lung cancer (A549) cells. The citrate reduced AgNPs (C-AgNPs) were modified with either lactose (L-AgNPs) or a 12-base long oligonucleotide (O-AgNPs). Both unmodified and modified AgNPs showed increased concentration and time dependent cytotoxicity and genotoxicity causing an increased p53 up-regulation within 6 h and led to apoptotic or necrotic cell deaths. The C-AgNPs induced more cytotoxicity and cellular DNA damage than the surface modified AgNPs. Modifying the C-AgNPs with lactose or the oligonucleotide reduced both necrotic and apoptotic cell deaths in the HDF cells. The C-AgNPs caused an insignificant necrosis in A549 cells whereas the modified AgNPs caused necrosis and apoptosis in both cell types. Compared to the O-AgNPs, the L-AgNPs triggered more cellular DNA damage, which led to up-regulation of p53 gene inducing apoptosis in A549 cells compared to HDF cells. This suggests that the different surface chemistries of the AgNPs cause different cellular responses that may be important not only for their use in medicine but also for reducing their toxicity. (paper)

  11. Influence of coffee on reflectance and chemistry of resin composite protected by surface sealant.

    Science.gov (United States)

    Soares, Luís Eduardo Silva; Cesar, Ilene Cristine Rosia; Santos, Carla Gabriela Couto; De Cardoso, Ana Luiza Merigo Oliveira; Liporoni, Priscila Christiane Suzy; Munin, Egberto; Martin, Airton Abrahão

    2007-10-01

    To assess the influence of the light-curing unit type and whether or not it was worth using surface sealant protection on resin composite restorative materials stained by coffee. Another objective was to propose the monitoring of coffee staining by FT-Raman spectroscopy using carbon-hydrogen (C-H) bonds as reference to the composite matrix degradation. Sixty cylindrical specimens of resin composite were prepared and divided into six groups: HC (control)--cured with a halogen light; LC (control) cured with a LED; HF--cured with a halogen light + Fortify Plus; LF--cured with a LED + Fortify Plus; HP--cured with a halogen light + PermaSeal; LP--cured with a LED + PermaSeal. After storage for 24 hours at 37% and 100% of relative humidity, the top surface was protected, and the other surfaces isolated. Polishing with paper discs was performed after 24 hours of curing and prior to FT-Raman spectroscopy and reflectance measurements. All specimens were submitted to coffee staining for 14 days and evaluated by both systems. Results were statistically analyzed by ANOVA and Tukey tests. FT-Raman spectrum only showed significant changes in groups LC and LP (P< 0.05). Reflectance demonstrated that staining was present in all specimens protected by sealants. Sealant staining was larger in the HF (P < 0.001) group.

  12. Influence of ceramic surface texture on the wear of gold alloy and heat-pressed ceramics.

    Science.gov (United States)

    Saiki, Osamu; Koizumi, Hiroyasu; Nogawa, Hiroshi; Hiraba, Haruto; Akazawa, Nobutaka; Matsumura, Hideo

    2014-01-01

    The purpose of this study was to evaluate the influence of ceramic surface texture on the wear of rounded rod specimens. Plate specimens were fabricated from zirconia (ZrO2), feldspathic porcelain, and lithium disilicate glass ceramics (LDG ceramics). Plate surfaces were either ground or polished. Rounded rod specimens with a 2.0-mm-diameter were fabricated from type 4 gold alloy and heat-pressed ceramics (HP ceramics). Wear testing was performed by means of a wear testing apparatus under 5,000 reciprocal strokes of the rod specimen with 5.9 N vertical loading. The results were statistically analyzed with a non-parametric procedure. The gold alloy showed the maximal height loss (90.0 µm) when the rod specimen was abraded with ground porcelain, whereas the HP ceramics exhibited maximal height loss (49.8 µm) when the rod specimen was abraded with ground zirconia. There was a strong correlation between height loss of the rod and surface roughness of the underlying plates, for both the gold alloy and HP ceramics.

  13. The color of the Martian sky and its influence on the illumination of the Martian surface

    Science.gov (United States)

    Thomas, N.; Markiewicz, W.J.; Sablotny, R.M.; Wuttke, M.W.; Keller, H.U.; Johnson, J. R.; Reid, R.J.; Smith, R.H.

    1999-01-01

    The dust in the atmosphere above the Mars Pathfinder landing site produced a bright, red sky that increases in redness toward the horizon at midday. There is also evidence for an absorption band in the scattered light from the sky at 860 nm. A model of the sky brightness has been developed [Markiewicz et al., this issue] and tested against Imager for Mars Pathfinder (IMP) observations of calibration targets on the lander. The resulting model has been used to quantify the total diffuse flux onto a surface parallel to the local level for several solar elevation angles and optical depths. The model shows that the diffuse illumination in shadowed areas is strongly reddened while areas illuminated directly by the Sun (and the blue forward scattering peak) see a more solar-type spectrum, in agreement with Viking and IMP observations. Quantitative corrections for the reddening in shadowed areas are demonstrated. It is shown quantitatively that the unusual appearance of the rock Yogi (the east face of which appeared relatively blue in images taken during the morning but relatively red during the afternoon) can be explained purely by the changing illumination geometry. We conclude that any spectrophotometric analysis of surfaces on Mars must take into account the diffuse flux. Specifically, the reflectances of surfaces viewed under different illumination geometries cannot be investigated for spectral diversity unless a correction has been applied which removes the influence of the reddened diffuse flux. Copyright 1999 by the American Geophysical Union.

  14. Influence of Alkali Treatment on the Surface Area of Aluminium Dross

    Directory of Open Access Journals (Sweden)

    N. S. Ahmad Zauzi

    2016-01-01

    Full Text Available Aluminium dross is an industrial waste from aluminium refining industry and classified as toxic substances. However, the disposal of dross as a waste is a burden to aluminium manufacturer industries due to its negative effects to the ecosystem, surface, and ground water. Therefore the purpose of this study is to evaluate the influence of sodium hydroxide (NaOH on the surface area and pore size of aluminium dross. There were 3 stages in the treatment activities, which were leaching, precipitation, and calcination process. The optimum result from this study was the surface area of aluminium dross increases from 10.1 m2/g up to 80.0 m2/g at 40°C, 1% NaOH, and 15-minute reaction time. Thus, aluminium dross has a potential to be converted into other useful material such as catalyst and absorbent. The benefit of this research is that the hazardous industrial waste can be turned into wealth to be used in other applications such as in catalytic activities and absorber in waste water treatment. Further investigation on the physicochemical of aluminium dross with different acid or alkali should be conducted to get deeper understanding on the aluminium dross as a catalyst-type material.

  15. Influence of tungsten microstructure and ion flux on deuterium plasma-induced surface modifications and deuterium retention

    NARCIS (Netherlands)

    Buzi, L.; De Temmerman, G.; Unterberg, B.; M. Reinhart,; Dittmar, T.; Matveev, D.; Linsmeier, C.; Breuer, U.; Kreter, A.; Van Oost, G.

    2015-01-01

    The influence of surface temperature, particle flux density and material microstructure on the surface morphology and deuterium retention was studied by exposing tungsten targets (20 μm and 40 μm grain size) to deuterium plasma at the same particle fluence (1026 m−2) and

  16. The Influence of Rain Sensible Heat and Subsurface Energy Transport on the Energy Balance at the Land Surface

    NARCIS (Netherlands)

    Kollet, S.J.; Cvijanovic, I.; Schüttemeyer, D.; Maxwell, R.M.; Moene, A.F.; Bayer, P.

    2009-01-01

    In land surface models, which account for the energy balance at the land surface, subsurface heat transport is an important component that reciprocally influences ground, sensible, and latent heat fluxes and net radiation. In most models, subsurface heat transport parameterizations are commonly

  17. Acute Superoxide Radical Scavenging Reduces Blood Pressure but Does Not Influence Kidney Function in Hypertensive Rats with Postischemic Kidney Injury

    Directory of Open Access Journals (Sweden)

    Zoran Miloradović

    2014-01-01

    Full Text Available Acute kidney injury (AKI is associated with significant morbidity and mortality in hypertensive surroundings. We investigated superoxide radical molecules influence on systemic haemodynamic and kidney function in spontaneously hypertensive rats (SHR with induced postischemic AKI. Experiment was performed in anesthetized adult male SHR. The right kidney was removed, and left renal artery was subjected to ischemia by clamping for 40 minutes. The treated group received synthetic superoxide dismutase mimetic TEMPOL in the femoral vein 5 minutes before, during, and 175 minutes after the period of reperfusion, while the control AKI group received the vehicle via the same route. All parameters were measured 24 h after renal reperfusion. TEMPOL treatment significantly decreased mean arterial pressure and total peripheral resistance P<0.05 compared to AKI control. It also increased cardiac output and catalase activity P<0.05. Lipid peroxidation and renal vascular resistance were decreased in TEMPOL P<0.05. Plasma creatinine and kidney morphological parameters were unchanged among TEMPOL treated and control groups. Our study shows that superoxide radicals participate in haemodynamic control, but acute superoxide scavenging is ineffective in glomerular and tubular improvement, probably due to hypertension-induced strong endothelial dysfunction which neutralizes beneficial effects of O2− scavenging.

  18. Biopsychosocial influence on exercise-induced injury: genetic and psychological combinations are predictive of shoulder pain phenotypes

    Science.gov (United States)

    George, Steven Z.; Parr, Jeffrey J.; Wallace, Margaret R.; Wu, Samuel S.; Borsa, Paul A.; Dai, Yunfeng; Fillingim, Roger B.

    2014-01-01

    Chronic pain is influenced by biological, psychological, social, and cultural factors. The current study investigated potential roles for combinations of genetic and psychological factors in the development and/or maintenance of chronic musculoskeletal pain. An exercise-induced shoulder injury model was used and a priori selected genetic (ADRB2, COMT, OPRM1, AVPR1A, GCH1, and KCNS1) and psychological (anxiety, depressive symptoms, pain catastrophizing, fear of pain, and kinesiophobia) factors were included as predictors. Pain phenotypes were shoulder pain intensity (5-day average and peak reported on numerical rating scale), upper-extremity disability (5-day average and peak reported on the QuickDASH), and shoulder pain duration (in days). After controlling for age, sex, and race the genetic and psychological predictors were entered as main effects and interaction terms in separate regression models for the different pain phenotypes. Results from the recruited cohort (n = 190) indicated strong statistical evidence for interactions between the COMT diplotype and 1) pain catastrophizing for 5-day average upper-extremity disability and 2) depressive symptoms for pain duration. There was moderate statistical evidence for interactions for other shoulder pain phenotypes between additional genes (ADRB2, AVPR1A, and KCNS1) and depressive symptoms, pain catastrophizing, or kinesiophobia. These findings confirm the importance of the combined predictive ability of COMT with psychological distress, and reveal other novel combinations of genetic and psychological factors that may merit additional investigation in other pain cohorts. PMID:24373571

  19. Is trauma transfer influenced by factors other than medical need? An examination of insurance status and transfer in patients with mild head injury.

    Science.gov (United States)

    Babu, Maya A; Nahed, Brian V; Demoya, Marc A; Curry, William T

    2011-09-01

    The Emergency Medical Treatment and Active Labor Act was meant to provide access to emergency medical care irrespective of financial resources. Yet, many Level I trauma Centers have raised concerns about the financial drivers influencing transfer. : To study the relationship between insurance status and transfer, we focused on patients with mild head injury to tease apart the medical necessity for transfer from other potential drivers, such as financial factors. Using the 2002 to 2006 American College of Surgeons National Trauma Databank and Massachusetts General Hospital's Trauma Databank from 1993 to 2009, we conducted a retrospective study and limited our population to patients with mild head injuries and mild to moderate systemic injuries as determined by the Glasgow Coma Scale, Abbreviated Injury Scale, or Injury Severity Score. Statistical analyses were conducted with STATA software. In a nationalized database, (1) uninsured patients with mild head injury are more likely to be transferred out of a Level II or III facility (adjusted odds ratio [OR]: 2.07; P = .000) compared with privately insured patients and (2) uninsured patients are less likely to be accepted by a Level II or III facility for transfer compared with privately insured patients (adjusted OR: = .143; P = .000l). For transfers received by 1 Level I trauma center (Massachusetts General Hospital), uninsured patients are more likely to be transferred to (1) Massachusetts General Hospital between midnight and 6 am (adjusted OR: 5.201; P = .000) compared with other time periods throughout the day and (2) Massachusetts General Hospital on Sunday (adjusted OR: 1.09; P = .000) compared with other days of the week. Insurance status appears to influence transfer patterns.

  20. Physical impaction injury effects on bacterial cells during spread plating influenced by cell characteristics of the organisms.

    Science.gov (United States)

    Thomas, P; Mujawar, M M; Sekhar, A C; Upreti, R

    2014-04-01

    To understand the factors that contribute to the variations in colony-forming units (CFU) in different bacteria during spread plating. Employing a mix culture of vegetative cells of ten organisms varying in cell characteristics (Gram reaction, cell shape and cell size), spread plating to the extent of just drying the agar surface (50-60 s) was tested in comparison with the alternate spotting-and-tilt-spreading (SATS) approach where 100 μl inoculum was distributed by mere tilting of plate after spotting as 20-25 microdrops. The former imparted a significant reduction in CFU by 20% over the spreader-independent SATS approach. Extending the testing to single organisms, Gram-negative proteobacteria with relatively larger cells (Escherichia, Enterobacter, Agrobacterium, Ralstonia, Pantoea, Pseudomonas and Sphingomonas spp.) showed significant CFU reduction with spread plating except for slow-growing Methylobacterium sp., while those with small rods (Xenophilus sp.) and cocci (Acinetobacter sp.) were less affected. Among Gram-positive nonspore formers, Staphylococcus epidermidis showed significant CFU reduction while Staphylococcus haemolyticus and actinobacteria (Microbacterium, Cellulosimicrobium and Brachybacterium spp.) with small rods/cocci were unaffected. Vegetative cells of Bacillus pumilus and B. subtilis were generally unaffected while others with larger rods (B. thuringiensis, Brevibacillus, Lysinibacillus and Paenibacillus spp.) were significantly affected. A simulated plating study coupled with live-dead bacterial staining endorsed the chances of cell disruption with spreader impaction in afflicted organisms. Significant reduction in CFU could occur during spread plating due to physical impaction injury to bacterial cells depending on the spreader usage and the variable effects on different organisms are determined by Gram reaction, cell size and cell shape. The inoculum spreader could impart physical disruption of vegetative cells against a hard surface

  1. Evaluation of muscle fatigue of wheelchair basketball players with spinal cord injury using recurrence quantification analysis of surface EMG.

    Science.gov (United States)

    Uzun, S; Pourmoghaddam, A; Hieronymus, M; Thrasher, T A

    2012-11-01

    Wheelchair basketball is the most popular exercise activity among individuals with spinal cord injury (SCI). The purpose of this study was to investigate muscular endurance and fatigue in wheelchair basketball athletes with SCI using surface electromyography (SEMG) and maximal torque values. SEMG characteristics of 10 wheelchair basketball players (WBP) were compared to 13 able-bodied basketball players and 12 sedentary able-bodied subjects. Participants performed sustained isometric elbow flexion at 50% maximal voluntary contraction until exhaustion. Elbow flexion torque and SEMG signals were recorded from three elbow flexor muscles: biceps brachii longus, biceps brachii brevis and brachioradialis. SEMG signals were clustered into 0.5-s epochs with 50% overlap. Root mean square (RMS) and median frequency (MDF) of SEMG signals were calculated for each muscle and epoch as traditional fatigue monitoring. Recurrence quantification analysis was used to extract the percentage of determinism (%DET) of SEMG signals. The slope of the %DET for basketball players and WBP showed slower increase with time than the sedentary able-bodied control group for three different elbow flexor muscles, while no difference was observed for the slope of the %DET between basketball and WBP. This result indicated that the athletes are less fatigable during the task effort than the nonathletes. Normalized MDF slope decay exhibited similar results between the groups as %DET, while the slope of the normalized RMS failed to show any significant differences among the groups (p > 0.05). MDF and %DET could be useful for the evaluation of muscle fatigue in wheelchair basketball training. No conclusions about special training for WBP could be determined.

  2. Influence of impurities and ion surface alloying on the corrosion resistance of E110 alloy

    International Nuclear Information System (INIS)

    Kalin, B. A.; Volkov, N. V.; Valikov, R. A.; Novikov, V. V.; Markelov, V. A.; Pimenov, Yu. V.

    2013-01-01

    The corrosion resistance of zirconium alloys depends on their structural-phase state, the type of core coolant and operating factors. The formation of a protective oxide film on the zirconium alloys is sensitive to the content of impurity atoms present in the charge base of alloys and accumulating in them in the manufacture of products. The impurity composition of the initial zirconium is determined by the method of its manufacture and generally remains unchanged in the products, deter-mining their properties, including their corrosion resistance. An increased content of impurities (C, N, Al, Mo, Fe) both individually and in their combination negatively affects the corrosion resistance of zirconium and its alloys. One of the potentially effective methods to increase the protective properties of oxide films on zirconium alloys is a surface alloying using the regime of mixing the atoms of a film, preliminarily coated on the surface, and the atoms of a target. This method makes it possible to form a given structural-phase state in the thin surface layer with unique physicochemical properties and thus to in-crease the corrosion resistance and wear resistance of fuel claddings. In this context, the object of investigation was samples of cladding tubes from alloy E110 with various content of impurity elements (nitrogen, aluminum, and carbon) with the aim to reduce the negative influence of impurities on the corrosion resistance by changing the structural-phase state of the surface layer of fuel claddings and fuel assembly components with alloying in the regime of ion mixing of atoms

  3. The influence of surface microchemistry in protective film formation on multi-phase magnesium alloys

    International Nuclear Information System (INIS)

    Gray-Munro, J.E.; Luan, B.; Huntington, L.

    2008-01-01

    The high strength:weight ratio of magnesium alloys makes them an ideal metal for automotive and aerospace applications where weight reduction is of significant concern. Unfortunately, magnesium alloys are highly susceptible to corrosion particularly in salt-spray conditions. This has limited their use in the automotive and aerospace industries, where exposure to harsh service conditions is unavoidable. The simplest way to avoid corrosion is to coat the magnesium-based substrate by a process such as electroless plating, which is a low-cost, non line of sight process. Magnesium is classified as a difficult to plate metal due to its high reactivity. This means that in the presence of air magnesium very quickly forms a passive oxide layer that must be removed prior to plating. Furthermore, high aluminium content alloys are especially difficult to plate due to the formation of intermetallic species at the grain boundaries, resulting in a non-uniform surface potential across the substrate and thereby further complicating the plating process. The objective of this study is to understand how the magnesium alloy microstructure influences the surface chemistry of the alloy during both pretreatment and immersion copper coating of the substrate. A combination of scanning electron microscopy, energy dispersive spectroscopy and scanning Auger microscopy has been used to study the surface chemistry at the various stages of the coating process. Our results indicate that the surface chemistry of the alloy is different on the aluminum rich β phase of the material compared to the magnesium matrix which leads to preferential deposition of the metal on the aluminum rich phase of the alloy

  4. Factors Influencing Surface Emissions of CO and NOx From a Brazilian Savanna

    Science.gov (United States)

    Zepp, R. G.; Kisselle, K. W.; Burke, R. A.; Pinto, A. S.; Bustamante, M. M.

    2002-12-01

    Human activities in savannas such as biomass burning and land conversion influence soil and plant emissions of atmospheric carbon monoxide (CO) and NOx [nitric oxide (NO) plus nitrogen dioxide (NO2)]. Direct emissions of these gases from burning are a major global source. In addition, emissions of CO and NOX from soils and plant litter also provide a significant source of the gases. Here, we report field and laboratory investigations of the production of CO and NOx from soils and surface litter derived from two natural vegetation types in central Brazil, cerrado stricto sensu (20-50% canopy cover) and campo sujo (open scrubland). The field studies were conducted using opaque and transparent flux chambers to investigate the effects of illumination and heating of the land surface on the gas fluxes. These studies showed that both NOx and CO fluxes were elevated in the transparent chambers. The largest increases in NOx and CO fluxes were observed from recently burned surfaces, indicating that photochemical or temperature-sensitive precursors of the gases were produced in the surface residue by fire. Laboratory studies of the thermal production of CO from plant litter were species specific with activation energies ranging from 72 to 100 kJ mol-1. Activation energies for deciduous plant litter from the Brazilian sites were higher than those previously reported for African savanna grass litter. Other laboratory studies using simulated solar radiation demonstrated that removal of UV radiation by light filters strongly reduced CO fluxes, indicating that the observed enhancement of CO production under illumination was primarily due to photodegradation of the litter rather than enhanced thermal production.

  5. Influence of ice thickness and surface properties on light transmission through Arctic sea ice.

    Science.gov (United States)

    Katlein, Christian; Arndt, Stefanie; Nicolaus, Marcel; Perovich, Donald K; Jakuba, Michael V; Suman, Stefano; Elliott, Stephen; Whitcomb, Louis L; McFarland, Christopher J; Gerdes, Rüdiger; Boetius, Antje; German, Christopher R

    2015-09-01

    The observed changes in physical properties of sea ice such as decreased thickness and increased melt pond cover severely impact the energy budget of Arctic sea ice. Increased light transmission leads to increased deposition of solar energy in the upper ocean and thus plays a crucial role for amount and timing of sea-ice-melt and under-ice primary production. Recent developments in underwater technology provide new opportunities to study light transmission below the largely inaccessible underside of sea ice. We measured spectral under-ice radiance and irradiance using the new Nereid Under-Ice (NUI) underwater robotic vehicle, during a cruise of the R/V Polarstern to 83°N 6°W in the Arctic Ocean in July 2014. NUI is a next generation hybrid remotely operated vehicle (H-ROV) designed for both remotely piloted and autonomous surveys underneath land-fast and moving sea ice. Here we present results from one of the first comprehensive scientific dives of NUI employing its interdisciplinary sensor suite. We combine under-ice optical measurements with three dimensional under-ice topography (multibeam sonar) and aerial images of the surface conditions. We investigate the influence of spatially varying ice-thickness and surface properties on the spatial variability of light transmittance during summer. Our results show that surface properties such as melt ponds dominate the spatial distribution of the under-ice light field on small scales (<1000 m 2 ), while sea ice-thickness is the most important predictor for light transmission on larger scales. In addition, we propose the use of an algorithm to obtain histograms of light transmission from distributions of sea ice thickness and surface albedo.

  6. Influence of bulk and surface phenomena on the hydrogen permeation through metals

    International Nuclear Information System (INIS)

    Waelbroeck, F.; Wienhold, P.; Winter, J.; Rota, E.; Bauno, T.

    1984-12-01

    We discuss the permeation of hydrogen through metals and alloys such as iron, nickel, steels and Inconel wherein H dissolves endothermically from an H 2 gas. We assume first that trapping centers, surface contamination layers, the saturation of the H surface coverage and the implantation profile - when energetic ions drive the permeation - can be neglected, that a quasi-equilibrium exists between the H atom concentration ν in the adsorbed layer and c in the near surface layers and that the H solubility and diffusivity are homogeneous in the membrane. We evaluate thereafter separately the influence of these various effects and identify the parameter domains where appreciable corrections result. The permeation phenomenon is complex even when these simplifications are made: the penetration rate is proportional to the flux of thermal molecules, atoms or energetic ions - depending upon the case - which strike the surface; the diffusion in the metal is proportional to the gradient of c; the release rate depends on c 2 ; the time-dependent diffusion equation includes a double spatial derivative of c. Permeation can only be fully described when computer codes such as PERI is used. Simple analytical relations are however obtained in several limiting cases. They are the object of this report. Some of them had already been derived by other authors but they were not shown to be part of a single, self consistent permeation model. A comparison of predicted and experimental results shows that the simplified model describes surprisingly accurately the hydrogen exchange between gas and metal solutions. (orig./GSCH)

  7. Influence of minimally invasive hematoma evacuation combined with nerve growth factor preparation on neurological function injury in patients with hypertensive cerebral hemorrhage

    Directory of Open Access Journals (Sweden)

    Jiang Tao

    2017-05-01

    Full Text Available Objective: To study the influence of minimally invasive hematoma evacuation combined with nerve growth factor preparation on neurological function injury in patients with hypertensive cerebral hemorrhage. Methods: A total of 112 patients with hypertensive cerebral hemorrhage who were treated in our hospital between July 2013 and February 2016 were collected, and according to random number table, they were divided into the control group (n=56 who underwent minimally invasive hematoma evacuation therapy and the observation group (n=56 who underwent minimally invasive hematoma evacuation combined with nerve growth factor preparation therapy. Serum contents of inflammatory mediators, nerve injury indexes and neurotransmitters were compared between two groups of patients before and after treatment. Results: Before treatment, there were no significant differences in serum contents of inflammatory mediators, nerve injury indexes and neurotransmitters between the two groups. After treatment, serum contents of inflammatory mediators such as CRP, PCT, IL-1β and IL-6 in observation group were lower than those in control group; serum contents of nerve injury indexes such as NSE, S100B, GEAP and MBP were lower than those in control group; serum contents of neurotransmitters such as SP, NPY, Glu and Asp were lower than those in control group while GABA and Gly were higher than those in control group. Conclusion: Minimally invasive hematoma evacuation combined with nerve growth factor preparation can effectively reduce neurological function injury, and has positive clinical significance.

  8. Calcium carbonate saturation in the surface water of the Arctic Ocean: undersaturation in freshwater influenced shelves

    Directory of Open Access Journals (Sweden)

    A. Fransson

    2009-11-01

    Full Text Available In the summer of 2005, we sampled surface water and measured pH and total alkalinity (AT underway aboard IB Oden along the Northwest Passage from Cape Farewell (South Greenland to the Chukchi Sea. We investigated the variability of carbonate system parameters, focusing particularly on carbonate concentration [CO32−] and calcium carbonate saturation states, as related to freshwater addition, biological processes and physical upwelling. Measurements on AT, pH at 15°C, salinity (S and sea surface temperature (SST, were used to calculate total dissolved inorganic carbon (CT, [CO32−] and the saturation of aragonite (ΩAr and calcite (ΩCa in the surface water. The same parameters were measured in the water column of the Bering Strait. Some surface waters in the Canadian Arctic Archipelago (CAA and on the Mackenzie shelf (MS were found to be undersaturated with respect to aragonite (ΩAr<1. In these areas, surface water was low in AT and CT (<1500 μmol kg−1 relative to seawater and showed low [CO32−]. The low saturation states were probably due to the likely the effect of dilution due to freshwater addition by sea ice melt (CAA and river runoff (MS. High AT and CT and low pH, corresponded with the lowest [CO32−], ΩAr and ΩCa, observed near Cape Bathurst and along the South Chukchi Peninsula. This was linked to the physical upwelling of subsurface water with elevated CO2. The highest surface ΩAr and ΩCa of 3.0 and 4.5, respectively, were found on the Chukchi Sea shelf and in the cold water north of Wrangel Island, which is heavily influenced by high CO2 drawdown and lower CT from intense biological production. In the western Bering Strait, the cold and saline Anadyr Current carries water that is enriched in AT and

  9. Seasonal Influences on Ground-Surface Water Interactions in an Arsenic-Affected Aquifer in Cambodia

    Science.gov (United States)

    Richards, L. A.; Magnone, D.; Van Dongen, B.; Bryant, C.; Boyce, A.; Ballentine, C. J.; Polya, D. A.

    2015-12-01

    Millions of people in South and Southeast Asia consume drinking water daily which contains dangerous levels of arsenic exceeding health-based recommendations [1]. A key control on arsenic mobilization in aquifers in these areas has been controversially identified as the interaction of 'labile' organic matter contained in surface waters with groundwaters and sediments at depth [2-4], which may trigger the release of arsenic from the solid- to aqueous-phase via reductive dissolution of iron-(hyr)oxide minerals [5]. In a field site in Kandal Province, Cambodia, which is an arsenic-affected area typical to others in the region, there are strong seasonal patterns in groundwater flow direction, which are closely related to monsoonal rains [6] and may contribute to arsenic release in this aquifer. The aim of this study is to explore the implications of the high susceptibility of this aquifer system to seasonal changes on potential ground-surface water interactions. The main objectives are to (i) identify key zones where there are likely ground-surface water interactions, (ii) assess the seasonal impact of such interactions and (iii) quantify the influence of interactions using geochemical parameters (such as As, Fe, NO3, NH4, 14C, 3T/3He, δ18O, δ2H). Identifying the zones, magnitude and seasonal influence of ground-surface water interactions elucidates new information regarding potential locations/pathways of arsenic mobilization and/or transport in affected aquifers and may be important for water management strategies in affected areas. This research is supported by NERC (NE/J023833/1) to DP, BvD and CJB and a NERC PhD studentship (NE/L501591/1) to DM. References: [1] World Health Organization, 2008. [2] Charlet & Polya (2006), Elements, 2, 91-96. [3] Harvey et al. (2002), Science, 298, 1602-1606. [4] Lawson et al. (2013), Env. Sci. Technol. 47, 7085 - 7094. [5] Islam et al. (2004), Nature, 430, 68-71. [6] Benner et al. (2008) Appl. Geochem. 23(11), 3072 - 3087.

  10. The Influence of the Tool Surface Texture on Friction and the Surface Layers Properties of Formed Component

    Directory of Open Access Journals (Sweden)

    Jana Šugárová

    2018-03-01

    Full Text Available The morphological texturing of forming tool surfaces has high potential to reduce friction and tool wear and also has impact on the surface layers properties of formed material. In order to understand the effect of different types of tool textures, produced by nanosecond fibre laser, on the tribological conditions at the interface tool-formed material and on the integrity of formed part surface layers, the series of experimental investigations have been carried out. The coefficient of friction for different texture parameters (individual feature shape, including the depth profile of the cavities and orientation of the features relative to the material flow was evaluated via a Ring Test and the surface layers integrity of formed material (surface roughness and subsurface micro hardness was also experimentally analysed. The results showed a positive effect of surface texturing on the friction coefficients and the strain hardening of test samples material. Application of surface texture consisting of dimple-like depressions arranged in radial layout contributed to the most significant friction reduction of about 40%. On the other hand, this surface texture contributed to the increase of surface roughness parameters, Ra parameter increased from 0.49 μm to 2.19 μm and the Rz parameter increased from 0.99 μm to 16.79 μm.

  11. Influence on grip of knife handle surface characteristics and wearing protective gloves.

    Science.gov (United States)

    Claudon, Laurent

    2006-11-01

    Ten subjects were asked to apply maximum torques on knife handles with either their bare hand or their hand wearing a Kevlar fibre protective glove. Four knife handles (2 roughnesses, 2 hardnesses) were tested. Surface electromyograms of 6 upper limb and shoulder muscles were recorded and subject opinions on both knife handle hardness and friction in the hand were also assessed. The results revealed the significant influence of wearing gloves (pgloves greatly increased the torque independently of the other two parameters. Under the bare hand condition, a 90 degrees ShA slightly rough handle provided the greatest torque. Subject opinion agreed with the observed effects on recorded torque values except for the hardness factor, for which a preference for the 70 degrees ShA value over the 90 degrees ShA value emerged.

  12. Influence of Surface Roughness on Optical Characteristics of Multilayer Solar Cells

    Directory of Open Access Journals (Sweden)

    Lubomir Scholtz

    2014-01-01

    Full Text Available Increasing efficiency of solar cells is still a discussed problem. Even if it is well-known that specially formed substrates as Asahi U-type for solar cells are produced, there is still a continuing attention given to the applications of surface roughness to achieve better light trapping and absorptance in solar cells. It was found out the even an exact interface morphology can play an important role in light trapping. In this paper we focused on the issue how final absorptance of a solar cell structure could be affected and possibly increased. The goal of this article is to show which of interfaces has the greatest influence on specular absorptance of the whole structure.

  13. Persistent influence of tropical North Atlantic wintertime sea surface temperature on the subsequent Atlantic hurricane season

    Science.gov (United States)

    Wang, Xidong; Liu, Hailong; Foltz, Gregory R.

    2017-08-01

    This study explores the seasonally lagged impact of wintertime sea surface temperature (SST) in the Atlantic main development region (MDR) on the subsequent Atlantic hurricane season. It is found that wintertime SST anomalies in the MDR can persist into the summer, explaining 42% of the variance in the subsequent hurricane season's SST during 1951-2010. An anomalously warm wintertime in the MDR is usually followed by an anomalously active hurricane season. Analysis shows an important constraint on the seasonal evolution of the MDR SST by the water vapor feedback process, in addition to the well-known wind-evaporation-SST and cloud-SST feedback mechanisms over the tropical North Atlantic. The water vapor feedback influences the seasonal evolution of MDR SST by modulating seasonal variations of downward longwave radiation. This wintertime thermal control of hurricane activity has significant implications for seasonal predictions and long-term projections of hurricane activity over the North Atlantic.

  14. Influence of electrolytes on growth, phototropism, nutation and surface potential in etiolated cucumber seedlings

    Science.gov (United States)

    Spalding, E. P.; Cosgrove, D. J.

    1993-01-01

    A variety of electrolytes (10-30 mol m-3) increased the relative growth rate of etiolated cucumber (Cucumis sativus L. cv. Burpee's Pickler) hypocotyls by 20-50% relative to water-only controls. The nonelectrolyte mannitol inhibited growth by 10%. All salts tested were effective, regardless of chemical composition or valence. Measurements of cell-sap osmolality ruled out an osmotic mechanism for the growth stimulation by electrolytes. This, and the nonspecificity of the response, indicate that an electrical property of the solutions was responsible for their growth-stimulating activity. Measurements of surface electrical potential supported this reasoning. Treatment with electrolytes also enhanced nutation and altered the pattern of phototropic curvature development. A novel analytical method for quantitating these effects on growth was developed. The evidence indicates that electrolytes influence an electrophysiological parameter that is involved in the control of cell expansion and the coordination of growth underlying tropisms and nutations.

  15. Predictability of rainfall and teleconnections patterns influencing on Southwest Europe from sea surfaces temperatures

    Science.gov (United States)

    Lorenzo, M. N.; Iglesias, I.; Taboada, J. J.; Gómez-Gesteira, M.; Ramos, A. M.

    2009-04-01

    This work assesses the possibility of doing a forecast of rainfall and the main teleconnections patterns that influences climate in Southwest Europe by using sea surface temperature anomalies (SSTA). The area under study is located in the NW Iberian Peninsula. This region has a great oceanic influence on its climate and has an important dependency of the water resources. In this way if the different SST patterns are known, the different rainfall situations can be predicted. On the other hand, the teleconnection patterns, which have strong weight on rainfall, are influenced by the SSTA of different areas. In the light of this, the aim of this study is to explore the relationship between global SSTAs, rainfall and the main teleconnection patterns influencing on Europe. The SST data with a 2.0 degree resolution was provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA. A monthly averaged data from 1 January 1951 through December 2006 was considered. The monthly precipitation data from 1951-2006 were obtained from the database CLIMA of the University of Santiago de Compostela with data from the Meteorological State Agency (AEMET) and the Regional Government of Galicia. The teleconnection indices were taken of the Climate Prediction Center of the NOAA between 1950 and 2006. A monthly and seasonal study was analysed considering up to three months of delay in the first case and up to four seasons of delay in the second case. The Pearson product-moment correlation coefficient r was considered to quantify linear associations between SSTA and precipitation and/or SSTA and teleconnection indices. A test for field-significance was applied considering the properties of finiteness and interdependence of the spatial grid to avoid spurious correlations. Analysing the results obtained with the global SSTA and the teleconnection indices, a great number of ocean regions with high correlations can be found. The spatial patterns show very high correlations with Indian Ocean waters

  16. Influence of natural organic matter on the extraction efficiency of flame retardants from surface waters.

    Science.gov (United States)

    Gustavsson, Jakob; Ahrens, Lutz; Nguyen, Minh A; Josefsson, Sarah; Berggren Kleja, Dan; Wiberg, Karin

    2017-11-17

    The influence of natural organic matter (NOM) on the solid-phase extraction (SPE) efficiency was investigated for legacy and emerging flame retardants (FRs; n=26) in surface water. Three different groups of FRs were analyzed: polybrominated diphenyl ethers (PBDEs), halogenated flame retardants (HFRs), and organophosphorus flame retardants (OPFRs). In addition, five sorbents (Amberlite XAD-2, Amberlite IRA-743, Oasis HLB, Chromabond HR-P, and Chromabond HR-X) were evaluated for the extraction of FRs (n=33) in water, of which Oasis HLB eluted with dichloromethane and acetone:n-hexane (1:1, v/v) provided the highest overall recoveries. In subsequent NOM experiments, where FRs were extracted from water containing different NOM concentrations, both increased and decreased extraction efficiency with increasing NOM level were observed. Physicochemical and semi-empirical quantum chemistry properties were calculated for the FRs and used for analyzing relations between FRs. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that the FRs separated into four different groups based on their properties. The FRs within each group responded similarly to increasing NOM, while differences in behavior were observed between the groups. This suggests that the structural properties of micropollutants highly influence NOM-FR interaction mechanisms. For instance, at high NOM levels, recoveries decreased substantially for FRs containing a moiety that can form strong hydrogen bonds (such as the double-bonded oxygen in e.g., OPFRs). Many of the compounds showed maximum extraction efficiency at higher levels of NOM. This suggests that binding of NOM to the sorbent and subsequent interaction between sorbent-bound NOM and FRs is an important mechanism for extraction of micropollutants from surface waters. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Endogenous minerals have influences on surface electrochemistry and ion exchange properties of biochar.

    Science.gov (United States)

    Zhao, Ling; Cao, Xinde; Zheng, Wei; Wang, Qun; Yang, Fan

    2015-10-01

    The feedstocks for biochar production are diverse and many of them contain various minerals in addition to being rich in carbon. Twelve types of biomass classified into 2 categories: plant-based and municipal waste, were employed to produce biochars under 350 °C and 500 °C. Their pH, point of zero net charge (PZNC), zeta potential, cation and anion exchange capacity (CEC and AEC) were analyzed. The municipal waste-based biochars (MW-BC) had higher mineral levels than the plant-based biochars (PB-BC). However, the water soluble mineral levels were lower in the MW-BCs due to the dominant presence of less soluble minerals, such as CaCO3 and (Ca,Mg)3(PO4)2. The higher total minerals in MW-BCs accounted for the higher PZNC (5.47-9.95) than in PB-BCs (1.91-8.18), though the PZNCs of the PB-BCs increased more than that of the MW-BCs as the production temperature rose. The minerals had influence on the zeta potentials via affecting the negative charges of biochars and the ionic strength of solution. The organic functional groups in PB-BCs such as -COOH and -OH had a greater effect on the CEC and AEC, while the minerals had a greater effect on that of MW-BCs. The measured CEC and AEC values had a strong positive correlation with the total amount of soluble cations and anions, respectively. Results indicated that biochar surface charges depend not only on the organic functional groups, but also on the minerals present and to some extent, minerals have more influences on the surface electrochemistry and ion exchange properties of biochar. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Do organic surface films on sea salt aerosols influence atmospheric chemistry? ─ a model study

    Directory of Open Access Journals (Sweden)

    R. von Glasow

    2007-11-01

    Full Text Available Organic material from the ocean's surface can be incorporated into sea salt aerosol particles often producing a surface film on the aerosol. Such an organic coating can reduce the mass transfer between the gas phase and the aerosol phase influencing sea salt chemistry in the marine atmosphere. To investigate these effects and their importance for the marine boundary layer (MBL we used the one-dimensional numerical model MISTRA. We considered the uncertainties regarding the magnitude of uptake reduction, the concentrations of organic compounds in sea salt aerosols and the oxidation rate of the organics to analyse the possible influence of organic surfactants on gas and liquid phase chemistry with a special focus on halogen chemistry. By assuming destruction rates for the organic coating based on laboratory measurements we get a rapid destruction of the organic monolayer within the first meters of the MBL. Larger organic initial concentrations lead to a longer lifetime of the coating but lead also to an unrealistically strong decrease of O3 concentrations as the organic film is destroyed by reaction with O3. The lifetime of the film is increased by assuming smaller reactive uptake coefficients for O3 or by assuming that a part of the organic surfactants react with OH. With regard to tropospheric chemistry we found that gas phase concentrations for chlorine and bromine species decreased due to the decreased mass transfer between gas phase and aerosol phase. Aqueous phase chlorine concentrations also decreased but aqueous phase bromine concentrations increased. Differences for gas phase concentrations are in general smaller than for liquid phase concentrations. The effect on gas phase NO2 or NO is very small (reduction less than 5% whereas liquid phase NO2 concentrations increased in some cases by nearly 100%. We list suggestions for further laboratory studies which are needed for improved model studies.

  19. Influence of minimally invasive hematoma evacuation combined with nerve growth factor preparation on neurological function injury in patients with hypertensive cerebral hemorrhage

    OpenAIRE

    Jiang Tao; Feng Ai-Ping; Liu Lun-Bo; Huang Qi-Jun; Du Chen

    2017-01-01

    Objective: To study the influence of minimally invasive hematoma evacuation combined with nerve growth factor preparation on neurological function injury in patients with hypertensive cerebral hemorrhage. Methods: A total of 112 patients with hypertensive cerebral hemorrhage who were treated in our hospital between July 2013 and February 2016 were collected, and according to random number table, they were divided into the control group (n=56) who underwent minimally invasive he...

  20. Overlapping genetic and environmental influences on nonsuicidal self-injury and suicidal ideation: different outcomes, same etiology?

    NARCIS (Netherlands)

    Maciejewski, D.F.; Creemers, H.E.; Lynskey, M.T.; Madden, P.A.F.; Heath, A.C.; Statham, D.J.; Martin, N.G.; Verweij, K.J.H.

    2014-01-01

    Importance: Nonsuicidal self-injury (NSSI) and suicidal self-injury are very harmful behaviors and are associated with several psychiatric disorders. In the recently developed fifth edition of the DSM, NSSI and suicidal behavior disorder are for the first time introduced as conditions in their own

  1. Influence of acidosis and hypoxia on liver ischemia and reperfusion injury in an in vivo rat model

    NARCIS (Netherlands)

    Heijnen, Bob H. M.; Elkhaloufi, Yasser; Straatsburg, Irene H.; van Gulik, Thomas M.

    2002-01-01

    The contribution of acidosis to the development of reperfusion injury is controversial. In this study, we examined the effects of respiratory acidosis and hypoxia in a frequently used in vivo liver ischemia and reperfusion (I/R) injury rat model. Rats were anesthetized with intraperitoneal

  2. Influence of various surface-conditioning methods on the bond strength of metal brackets to ceramic surfaces

    NARCIS (Netherlands)

    Schmage, P; Nergiz, [No Value; Herrmann, W; Ozcan, M; Nergiz, Ibrahim; �zcan, Mutlu

    With the increase in adult orthodontic treatment comes the need to find a reliable method for bonding orthodontic brackets onto metal or ceramic crowns and fixed partial dentures. In this study, shear bond strength and surface roughness tests were used to examine the effect of 4 different surface

  3. Automated Surface Classification of SRF Cavities for the Investigation of the Influence of Surface Properties onto the Operational Performance

    International Nuclear Information System (INIS)

    Wenskat, Marc

    2015-07-01

    Superconducting niobium radio-frequency cavities are fundamental for the European XFEL and the International Linear Collider. To use the operational advantages of superconducting cavities, the inner surface has to fulfill quite demanding requirements. The surface roughness and cleanliness improved over the last decades and with them, the achieved maximal accelerating field. Still, limitations of the maximal achieved accelerating field are observed, which are not explained by localized geometrical defects or impurities. The scope of this thesis is a better understanding of these limitations in defect free cavities based on global, rather than local, surface properties. For this goal, more than 30 cavities underwent subsequent surface treatments, cold RF tests and optical inspections within the ILC-HiGrade research program and the XFEL cavity production. An algorithm was developed which allows an automated surface characterization based on an optical inspection robot. This algorithm delivers a set of optical surface properties, which describes the inner cavity surface. These optical surface properties deliver a framework for a quality assurance of the fabrication procedures. Furthermore, they shows promising results for a better understanding of the observed limitations in defect free cavities.

  4. Influence of Chemical Surface Modification of Woven Fabrics on Ballistic and Stab Protection of Multilayer Packets

    Directory of Open Access Journals (Sweden)

    Diana GRINEVIČIŪTĖ

    2014-06-01

    Full Text Available In order to achieve enhanced protective and wear (flexibility, less bulkiness properties of ballistic and stab protecting panels the investigation of chemical surface modification of woven p-aramid fabrics was performed applying different chemical composition shear thickening fluid (STF which improves friction inside fabric structure. For the chemical treatment silicic acid and acrylic dispersion water solutions were used and influence of their different concentrations on panels’ protective properties were investigated. Results of ballistic tests of multilayer protective panel have revealed that shear thickening effect was negligible when shooting at high energy range (E > 440 J. Determination of stab resistance of p-aramid panels has shown that different chemical composition of STFs had different influence on protective properties of the panels. Application of low concentrations of silicic acid determined higher stab resistance values comparing to higher concentrations of acrylic dispersion water solutions. At this stage of research stab tests results as ballistic ones determined that STF application for multilayer p-aramid fabrics protective panels is more efficient at low strike energy levels. DOI: http://dx.doi.org/10.5755/j01.ms.20.2.3138

  5. Surface ozone background in the United States: Canadian and Mexican pollution influences

    Science.gov (United States)

    Wang, Huiqun; Jacob, Daniel J.; Le Sager, Philippe; Streets, David G.; Park, Rokjin J.; Gilliland, Alice B.; van Donkelaar, A.

    We use a global chemical transport model (GEOS-Chem) with 1° × 1° horizontal resolution to quantify the effects of anthropogenic emissions from Canada, Mexico, and outside North America on daily maximum 8-hour average ozone concentrations in US surface air. Simulations for summer 2001 indicate mean North American and US background concentrations of 26 ± 8 ppb and 30 ± 8 ppb, as obtained by eliminating anthropogenic emissions in North America vs. in the US only. The US background never exceeds 60 ppb in the model. The Canadian and Mexican pollution enhancement averages 3 ± 4 ppb in the US in summer but can be occasionally much higher in downwind regions of the northeast and southwest, peaking at 33 ppb in upstate New York (on a day with 75 ppb total ozone) and 18 ppb in southern California (on a day with 68 ppb total ozone). The model is successful in reproducing the observed variability of ozone in these regions, including the occurrence and magnitude of high-ozone episodes influenced by transboundary pollution. We find that exceedances of the 75 ppb US air quality standard in eastern Michigan, western New York, New Jersey, and southern California are often associated with Canadian and Mexican pollution enhancements in excess of 10 ppb. Sensitivity simulations with 2020 emission projections suggest that Canadian pollution influence in the Northeast US will become comparable in magnitude to that from domestic power plants.

  6. Influence of full-contour zirconia surface roughness on wear of glass-ceramics.

    Science.gov (United States)

    Luangruangrong, Palika; Cook, N Blaine; Sabrah, Alaa H; Hara, Anderson T; Bottino, Marco C

    2014-04-01

    The purpose of this study was to evaluate the influence of full-contour (Y-TZP) zirconia surface roughness (glazed vs. as-machined) on the wear behavior of glass-ceramics. Thirty-two full contour Y-TZP (Diazir®) specimens (hereafter referred to as zirconia sliders) (ϕ = 2 mm, 1.5 mm in height) were fabricated using CAD/CAM and sintered according to the manufacturer's instructions. Zirconia sliders were embedded in brass holders using acrylic resin and then randomly assigned (n = 16) according to the surface treatment received, that is, as-machined or glazed. Glass-ceramic antagonists, Empress/EMP and e.max/EX, were cut into tabs (13 × 13 × 2 mm(3) ), wet-finished, and similarly embedded in brass holders. Two-body pin-on-disk wear testing was performed at 1.2 Hz for 25,000 cycles under a 3 kg load. Noncontact profilometry was used to measure antagonist height (μm) and volume loss (mm(3) ). Qualitative data of the zirconia testing surfaces and wear tracks were obtained using SEM. Statistics were performed using ANOVA with a significance level of 0.05. As-machined yielded significantly higher mean roughness values (Ra = 0.83 μm, Rq = 1.09 μm) than glazed zirconia (Ra = 0.53 μm, Rq = 0.78 μm). Regarding glass-ceramic antagonist loss, as-machined zirconia caused significantly less mean height and volume loss (68.4 μm, 7.6 mm(3) ) for EMP than the glazed group (84.9 μm, 9.9 mm(3) ), while no significant differences were found for EX. Moreover, EMP showed significantly lower mean height and volume loss than EX (p glass-ceramics tested. e.max wear was not affected by zirconia surface roughness; however, Empress wear was greater when opposing glazed zirconia. Overall, surface glazing on full-contour zirconia did not minimize glass-ceramic wear when compared with as-machined zirconia. © 2013 by the American College of Prosthodontists.

  7. Glazed ceramic roof tiles: influence of surface features in the solar reflectance index

    International Nuclear Information System (INIS)

    Bortoli, Leitcia Silva de; Stapait, Camila Cristina; Marinoski, Deivis Luis; Fredel, Marcio Celso; Schabbach, Luciana M.

    2016-01-01

    In this study the influence of surface features of ceramic roof tiles in the solar reflectance index were evaluated. Two glazed ceramic roof tiles (type stoneware) with the same color (ivory) but with different appearance (matte and brilliant) were the focus of the analysis. The Solar Reflectance Index (SRI) of the roofs tiles were determined by the solar reflectance values (UV-VIS-NIR) and emittance, measured in laboratory. The samples showed SRI> 39 in accordance with LEED certification criteria (Leadership in Energy and Environmental Design), contributing to minimizing the Heat Island Effects. Although the matte roof tile shows a slightly higher SRI value (82) than the brilliant one (78), the results for the variables that composes the SRI value (reflectance and emittance) were very similar. Analysis of XRD, SEM and EDS performed on the surfaces of the two roofs indicated for the matte glaze the presence of microcrystals (with barium and zinc) that can contribute to the slightly highest value of SRI. The roughness (optical interferometer white light) and the brightness (brightness meter) of the samples were also measured. (author)

  8. Influence of composite processing on the properties of CNT grown on carbon surfaces

    Science.gov (United States)

    Guignier, Claire; Bueno, Marie-Ange; Camillieri, Brigitte; Durand, Bernard

    2018-01-01

    Carbon nanotubes (CNT) grafted on carbon fibres (CF) are the subject of more and more studies on the reinforcement of composite materials thanks to the CNT' mechanical properties. This study concerns the growth of CNT directly on CF by the flame method, which is an assembly-line process. However the industrial-scale use of this method and of the composite processing leads to stresses on the CNT-grafted fabrics, such as friction and pulling-out. The aim of this study is to determine the behaviour of the CNT under these kinds of stresses and to study theirs consequences in composite processing. For this purpose, adhesion tests and friction tests were performed as well as analysis of the surface by Scanning Electron Microscopy (SEM), Raman spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). In friction tests, CNT formed a transfer film, and its effect on the wettability of the fabric with epoxy resin is determined. Finally, the wear of the CNT does not influence the wettability of the fabric. Furthermore, it is proven that the nature of the catalyst needed to grow the CNT modifies the behaviour of the surface.

  9. The influence of changes in glacier extent and surface elevation on modeled mass balance

    Directory of Open Access Journals (Sweden)

    F. Paul

    2010-12-01

    Full Text Available Glaciers are widely recognized as unique demonstration objects for climate change impacts, mostly due to the strong change of glacier length in response to small climatic changes. However, glacier mass balance as the direct response to the annual atmospheric conditions can be better interpreted in meteorological terms. When the climatic signal is deduced from long-term mass balance data, changes in glacier geometry (i.e. surface extent and elevation must be considered as such adjustments form an essential part of the glacier reaction to new climatic conditions. In this study, a set of modelling experiments is performed to assess the influence of changes in glacier geometry on mass balance for constant climatic conditions. The calculations are based on a simplified distributed energy/mass balance model in combination with information on glacier extent and surface elevation for the years 1850 and 1973/1985 for about 60 glaciers in the Swiss Alps. The results reveal that over this period about 50–70% of the glacier reaction to climate change (here a one degree increase in temperature is "hidden" in the geometric adjustment, while only 30–50% can be measured as the long-term mean mass balance. For larger glaciers, the effect of the areal change is partly reduced by a lowered surface elevation, which results in a slightly more negative balance despite a potential increase of topographic shading. In view of several additional reinforcement feedbacks that are observed in periods of strong glacier decline, it seems that the climatic interpretation of long-term mass balance data is rather complex.

  10. Influence of roughness of machined surface on adhesion of anticorrosion system

    Directory of Open Access Journals (Sweden)

    Jiří Votava

    2013-01-01

    Full Text Available The goal of this experiment is to analyse dependence of roughness of machined surface on adhesion performance of various anticorrosion systems. In order to prepare samples for the experiment, samples were milled on a knee and column type of a horizontal milling machine. Depending on cutting conditions and machining tool, there were set intervals of roughness of machined surface which are commonly achievable on this type of machine. It is a roughness in the interval of 0.4–1.6 µm (finishing, 1.6–6.3 µm (standard milling a 6.3–12.5 µm (roughening. Removable cutting tips were used as a machining tool and for roughening, a shell end milling cutter NAREX 63x40 HSS 90 was used. Three types of anticorrosion systems were used in order to analyse the adhesion, that is a water-thinnable system Eternal, synthetic single layer coating Hostagrund and a duplex system, whose first layer is formed by dipped zinc and a top layer by a single-layer acrylate system Zinorex. Testing of the influence of surface roughness (anchoring system on adhesion of the individual anticorrosion systems were processed in compliance with the norm ČSN EN ISO 4624, a tearing test. The main criterion of adhesion of anticorrosion system is defined as a power which needed for tear-off testing object stuck to a tested sample. This analysis was processed also during the corrosion test in the salt spray environment according to the norm ČSN EN ISO 9227. In order to better identify the adhesion of the individual anticorrosion systems, the analysis of undercorrosion according to the norm ISO 4628-8 was processed.

  11. Quantitative characterization of the influence of the nanoscale morphology of nanostructured surfaces on bacterial adhesion and biofilm formation.

    Directory of Open Access Journals (Sweden)

    Ajay Vikram Singh

    Full Text Available Bacterial infection of implants and prosthetic devices is one of the most common causes of implant failure. The nanostructured surface of biocompatible materials strongly influences the adhesion and proliferation of mammalian cells on solid substrates. The observation of this phenomenon has led to an increased effort to develop new strategies to prevent bacterial adhesion and biofilm formation, primarily through nanoengineering the topology of the materials used in implantable devices. While several studies have demonstrated the influence of nanoscale surface morphology on prokaryotic cell attachment, none have provided a quantitative understanding of this phenomenon. Using supersonic cluster beam deposition, we produced nanostructured titania thin films with controlled and reproducible nanoscale morphology respectively. We characterized the surface morphology; composition and wettability by means of atomic force microscopy, X-ray photoemission spectroscopy and contact angle measurements. We studied how protein adsorption is influenced by the physico-chemical surface parameters. Lastly, we characterized Escherichia coli and Staphylococcus aureus adhesion on nanostructured titania surfaces. Our results show that the increase in surface pore aspect ratio and volume, related to the increase of surface roughness, improves protein adsorption, which in turn downplays bacterial adhesion and biofilm formation. As roughness increases up to about 20 nm, bacterial adhesion and biofilm formation are enhanced; the further increase of roughness causes a significant decrease of bacterial adhesion and inhibits biofilm formation. We interpret the observed trend in bacterial adhesion as the combined effect of passivation and flattening effects induced by morphology-dependent protein adsorption. Our findings demonstrate that bacterial adhesion and biofilm formation on nanostructured titanium oxide surfaces are significantly influenced by nanoscale morphological

  12. Uptake, retention and internalization of quantum dots in Daphnia is influenced by particle surface functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Feswick, A., E-mail: afeswick@yahoo.ca [Center for Environmental and Human Toxicology, University of Florida, PO Box 110885, Gainesville, FL 32611 (United States); Canadian Rivers Institute, University of New Brunswick, PO Box 5050, Saint John NB, CA (United States); Griffitt, R.J., E-mail: joe.griffitt@usm.edu [Department of Coastal Sciences, University of Southern Mississippi, 703 East Beach Drive, Ocean Springs, MS 39564 (United States); Siebein, K., E-mail: kerry.siebein@nist.gov [Major Analytical Instrumentation Center, University of Florida, PO Box 116400, Gainesville, FL 32611 (United States); Barber, D.S., E-mail: barberd@vetmed.ufl.edu [Center for Environmental and Human Toxicology, University of Florida, PO Box 110885, Gainesville, FL 32611 (United States)

    2013-04-15

    Highlights: ► Daphnia underwent a waterborne exposure of PEG, NH{sub 2} and COOH functionalized quantum dot nanoparticles. ► There was preferential retention of COOH nanoparticles. ► TEM demonstrated that NH{sub 2} and COOH nanoparticles were internalized in cells adjacent to the GI tract. ► This cellular internalization was confirmed using energy dispersive spectroscopy. -- Abstract: Nanomaterials are a diverse group of compounds whose inevitable release into the environment warrants study of the fundamental processes that govern the ingestion, uptake and accumulation in aquatic organisms. Nanomaterials have the ability to transfer to higher trophic levels in aquatic ecosystems, and recent evidence suggests that the surface chemistry of both the nanoparticle and biological membrane can influence uptake kinetics. Therefore, our study investigates the effect of surface functionalization on uptake, internalization and depuration in Daphnia spp. Uncharged (polyethylene glycol; PEG), positively charged (amino-terminated: NH{sub 2}) and negatively charged (carboxyl-modified; COOH) cadmium selenide/zinc sulfide quantum dots were used to monitor ingestion, uptake and depuration of nanometals in Daphnia magna and Ceriodaphnia dubia over 24 h of exposure. These studies demonstrated that particles with higher negative charge (COOH quantum dots) were taken up to a greater extent by Daphnia (259.17 ± 17.70 RFU/20 Daphnia) than either the NH{sub 2} (150.01 ± 18.91) or PEG quantum dots (95.17 ± 9.78), however this is likely related to the functional groups attached to the nanoparticles as there were no real differences in zeta potential. Whole body fluorescence associates well with fluorescent microscopic images obtained at the 24 h timepoint. Confocal and electron microscopic analysis clearly demonstrated that all three types of quantum dots could cross the intestinal epithelial barrier and be translocated to other cells. Upon cessation of exposure, elimination of

  13. Understanding practice: the factors that influence management of mild traumatic brain injury in the emergency department--a qualitative study using the Theoretical Domains Framework.

    Science.gov (United States)

    Tavender, Emma J; Bosch, Marije; Gruen, Russell L; Green, Sally E; Knott, Jonathan; Francis, Jill J; Michie, Susan; O'Connor, Denise A

    2014-01-13

    Mild traumatic brain injury is a frequent cause of presentation to emergency departments. Despite the availability of clinical practice guidelines in this area, there is variation in practice. One of the aims of the Neurotrauma Evidence Translation program is to develop and evaluate a targeted, theory- and evidence-informed intervention to improve the management of mild traumatic brain injury in Australian emergency departments. This study is the first step in the intervention development process and uses the Theoretical Domains Framework to explore the factors perceived to influence the uptake of four key evidence-based recommended practices for managing mild traumatic brain injury. Semi-structured interviews were conducted with emergency staff in the Australian state of Victoria. The interview guide was developed using the Theoretical Domains Framework to explore current practice and to identify the factors perceived to influence practice. Two researchers coded the interview transcripts using thematic content analysis. A total of 42 participants (9 Directors, 20 doctors and 13 nurses) were interviewed over a seven-month period. The results suggested that (i) the prospective assessment of post-traumatic amnesia was influenced by: knowledge; beliefs about consequences; environmental context and resources; skills; social/professional role and identity; and beliefs about capabilities; (ii) the use of guideline-developed criteria or decision rules to inform the appropriate use of a CT scan was influenced by: knowledge; beliefs about consequences; environmental context and resources; memory, attention and decision processes; beliefs about capabilities; social influences; skills and behavioral regulation; (iii) providing verbal and written patient information on discharge was influenced by: beliefs about consequences; environmental context and resources; memory, attention and decision processes; social/professional role and identity; and knowledge; (iv) the practice of

  14. Influence of surface remodelling using burs on the macro and micro surface morphology of anatomically formed fibre posts.

    Science.gov (United States)

    Plotino, G; Grande, N M; Pameijer, C H; Somma, F

    2008-04-01

    To evaluate the effect of modifying preformed fibre-reinforced composite (FRC) endodontic posts on their surface morphology and to determine how this procedure affects the integrity of the posts. Surfaces of 10 preformed glass-fibre posts (group 1) and carbon-fibre posts (group 2) were compared with those of individually formed glass-fibre posts (group 3). Ten FRC posts were modelled in order to give them a shape as close as possible to the anatomy of oval root canals. Starting from a preformed cylindrical fibre post 2.5 mm in diameter, it was modelled in such a way as to passively occupy the entire post-space length, using a cast previously created as a guide. Microscopic analyses (optical stereomicroscope and scanning electron microscope) of the post surfaces revealed similar features in all three groups. All posts had regular surfaces after cutting with a diamond bur. Smear layer mainly attributable to the cutting procedures covered the cut surface of some specimens. In conclusion, modulation of a fibre post using a diamond-coated bur did not show a loss of integrity of the post. *Because of the importance of micromechanical retention, the surface integrity of fibre posts may be important for adhesion between post and composite resin. *Modification of a fibre post using a diamond-coated bur did not damage the surface integrity of the posts. *Fibre posts can be ground to a different shape without losing their surface integrity, resulting in posts with a surface that is not visibly different from unmodified commercially available fibre posts.

  15. Influence of the crystallographic structure of the electrode surface on the structure of the electrical double layer and adsorption of organic molecules

    International Nuclear Information System (INIS)

    Kochorovski, Z.; Zagorska, I.; Pruzhkovska-Drakhal, R.; Trasatti, S.

    1995-01-01

    The results of systematic investigation of influence of crystal structure of Bi-, Sb- and Cd-electrode surfaces on regularities of double electric layer structure in aqueous and nonaqueous solutions of surface-nonactive electrolyte are given. Influence of electrode surface characteristics on adsorptive behaviour of different organic molecules has been studied. General regularities of of chemical nature influence and surface crystallographic structure on the double layer structure and on organic compounds adsorption have been established. 57 refs., 7 figs., 4 tabs

  16. The influence of the solar radiation model on the calcutated solar radiation from a horizontal surface to a tilted surface

    DEFF Research Database (Denmark)

    Andersen, Elsa; Lund, Hans; Furbo, Simon

    2004-01-01

    in the calculation. The weather data are measured at the solar radiation measurement station, SMS at the Department of Civil Engineering at the Technical University of Denmark. In this study the weather data are combined with solar collector calculations based on solar collector test carried out at Solar Energy...... Center, SEC, Denmark. With measured solar radiation on horizontal and the different solar radiation processing models the total radiation is calculated on differently tilted and oriented surfaces and compared with the measured solar radiation on the different surfaces. Further, the impact on the yearly......Measured solar radiation data are most commonly available as total solar radiation on a horizontal surface. When using solar radiation measured on horizontal to calculate the solar radiation on tilted surfaces and thereby the thermal performance of different applications such as buildings and solar...

  17. Influence of heat treatment and veneering on the storage modulus and surface of zirconia ceramic.

    Science.gov (United States)

    Siavikis, Georgius; Behr, Michael; van der Zel, Jef M; Feilzer, Albert J; Rosentritt, Martin

    2011-04-01

    Glass-ceramic veneered zirconia is used for the application as fixed partial dentures. The aim of this investigation was to evaluate whether the heat treatment during veneering, the application of glass-ceramic for veneering or long term storage has an influence on the storage modulus of zirconia. Zirconia bars (Cercon, DeguDent, G; 0.5x2x20 mm) were fabricated and treated according to veneering conditions. Besides heating regimes between 680°C and 1000°C (liner bake and annealing), sandblasting (Al(2)O(3)) or steam cleaning were used. The bars were investigated after 90 days storage in water and acid. For investigating the influence of veneering, the bars were veneered in press- or layer technique. Dynamic mechanical analysis (DMA) in a three-point-bending design was performed to determine the storage modulus between 25°C and 200°C at a frequency of 1.66 Hz. All specimens were loaded on top and bottom (treatment on pressure or tensile stress side). Scanning electron microscopy (SEM) was used for evaluating the superficial changes of the zirconia surface due to treatment. Statistical analysis was performed using Mann Whitney U-test (α=0.05). Sintered zirconia provided a storage modulus E' of 215 (203/219) GPa and tan δ of 0.04 at 110°C. A 10%-decrease of E' was found up to 180°C. The superficial appearance changed due to heating regime. Sandblasting reduced E' to 213 GPa, heating influenced E' between 205 GPa (liner bake 1) and 222 GPa (dentin bake 1). Steam cleaning, annealing and storage changed E' between 4 GPa and 22 GPa, depending on the side of loading. After veneering, strong E'-reduction was found down to 84 GPa and 125 GPa. Veneering of zirconia with glass-ceramic in contrast to heat treating during veneering procedure had a strong influence on the modulus. The application of the glass-ceramic caused a stronger decrease of the storage modulus.

  18. Influence of the condition of the adjacent tooth surface on fluorescence measurements for the detection of approximal caries.

    Science.gov (United States)

    Lussi, A; Zimmerli, B; Hellwig, E; Jaeggi, T

    2006-12-01

    The aim of this study was to test whether the status of the adjacent tooth surface has an influence on the signal of a new laser fluorescence (LF) device for the detection of approximal caries. Seventy-eight teeth were selected from a pool of extracted permanent human molars, frozen at -20 degrees C until use. Before being measured the teeth were defrosted, cleaned, and any calculus removed. As a control, a defined approximal surface of each tooth was measured with the LF device holding the tip with the detecting- and the reverse-side on it, but without a neighboring tooth contacting the surface. The proximal site under examination was then placed adjacent to a tooth, which had deep dentinal caries, a composite restoration, a provisional ZnO-Eugenol restoration, or a ceramic restoration. The adjacent tooth with the ZnO-Eugenol restoration, the composite restoration, and the dentinal caries all demonstrated a statistically significant increase of LF readings on sound tooth surfaces. Teeth with enamel or dentinal caries were only slightly (and not statistically significantly) influenced by the different types of neighboring surfaces compared with the control LF readings. It can be concluded that caries detection of approximal tooth surfaces with the new LF system might be influenced by the condition of the adjacent tooth surface.

  19. [Factors related to the influence on congenital malformation of body surface in Shaanxi province].

    Science.gov (United States)

    Ying, J; Lei, Q; Qin, B W; Qu, P F; Lei, F L; Dang, S N; Zeng, L X; Yan, H

    2016-12-10

    Objective: To investigate the influencing factors on congenital malformation of body surface. Methods: Multi-stage stratified random sampling method was adopted. A questionnaire survey was conducted among the childbearing aged women who experienced more than 28 weeks pregnancy or having definite pregnancy outcomes in Shaanxi, during 2010-2013. Results: Results from the logistic regression model showed that factors as: intrahepatic cholestasis of pregnancy ( OR =21.76, 95 %CI : 4.46-106.25), histories with abnormal pregnancy or reproduction ( OR =11.88, 95 %CI : 9.14-15.45), having birth defects in the family ( OR =6.15, 95 %CI : 2.66-14.23), being twins ( OR =5.74, 95 % CI : 3.34-9.86), being worker (compared with others, OR =2.47, 95 % CI : 1.30-4.68) or farmer (compared with others, OR =1.91, 95 %CI : 1.14-3.20), less than 4 times of antenatal care (compared with >7, OR =1.84, 95 % CI : 1.28-2.64), occupational exposure to related risks during pregnancy ( OR =1.74, 95 % CI : 1.26-2.42), mother's hometown was from mid-part of Shaanxi (compared with northern Shaanxi, OR =1.65, 95 %CI : 1.20-2.28), mother's native residence was from the rural areas ( OR =1.75, 95 % CI : 1.13-2.71), drug use ( OR =1.64, 95 % CI : 1.26-2.13) etc . were risk factors for congenital malformation of body surface. Iron supplement during pregnancy ( OR =0.46, 95 %CI : 0.21-0.99) appeared as protective factor for congenital malformation of body surface. Conclusion: The following factors seemed to be of risk for congenital malformation of body surface, including: mother's native area was from the middle part of Shaanxi and living in rural area, being worker or farmer, histories of abnormal pregnancy and reproduction, history of birth defects in the family, being twins, with antenatal care less than 4 times, occupational exposure to dangerous materials, drug use, intrahepatic cholestasis during pregnancy etc .

  20. Influence of different land surfaces on atmospheric conditions measured by a wireless sensor network

    Science.gov (United States)

    Lengfeld, Katharina; Ament, Felix

    2010-05-01

    Atmospheric conditions close to the surface, like temperature, wind speed and humidity, vary on small scales because of surface heterogeneities. Therefore, the traditional measuring approach of using a single, highly accurate station is of limited representativeness for a larger domain, because it is not able to determine these small scale variabilities. However, both the variability and the domain averages are important information for the development and validation of atmospheric models and soil-vegetation-atmosphere-transfer (SVAT) schemes. Due to progress in microelectronics it is possible to construct networks of comparably cheap meteorological stations with moderate accuracy. Such a network provides data in high spatial and temporal resolution. The EPFL Lausanne developed such a network called SensorScope, consisting of low cost autonomous stations. Each station observes air and surface temperature, humidity, wind direction and speed, incoming solar radiation, precipitations, soil moisture and soil temperature and sends the data via radio communication to a base station. This base station forwards the collected data via GSM/GPRS to a central server. Within the FLUXPAT project in August 2009 we deployed 15 stations as a twin transect near Jülich, Germany. One aim of this first experiment was to test the quality of the low cost sensors by comparing them to more accurate reference measurements. It turned out, that although the network is not highly accurate, the measurements are consistent. Consequently an analysis of the pattern of atmospheric conditions is feasible. For example, we detect a variability of ± 0.5K in the mean temperature at a distance of only 2.3 km. The transect covers different types of vegetation and a small river. Therefore, we analyzed the influence of different land surfaces and the distance to the river on meteorological conditions. On the one hand, some results meet our expectations, e.g. the relative humidity decreases with increasing

  1. Influence of steel composition and plastic deformation on the surface properties induced by low temperature thermochemical processing

    DEFF Research Database (Denmark)

    Bottoli, Federico

    products. The activities carried out encompass the study and the characterization of the following aspects: ‐ Influence of plastic deformation prior to the low-temperature thermochemical process ‐ Influence of initial phase composition on the properties and morphology of thenitrided/nitrocarburized surface......Low-temperature thermochemical surface hardening by nitriding, carburizing and nitrocarburizing is used to improve the performance of stainless steels with respect to wear, fatigue and corrosion resistance.The dissolution of nitrogen and/or carbon atoms in the materials surface leads...... with the improvement of these properties, the corrosion resistance of the stainless steel is fully maintained or even enhanced. Despite low-temperature thermochemical processing of austenitic stainless steels has been widely studied in literature, other stainless steel classes and the influence of steel´s initial...

  2. Cold injuries.

    Science.gov (United States)

    Kruse, R J

    1995-01-01

    There are two categories of cold injury. The first is hypothermia, which is a systemic injury to cold, and the second is frostbite, which is a local injury. Throughout history, entire armies, from George Washington to the Germans on the Russian Front in World War II, have fallen prey to prolonged cold exposure. Cold injury is common and can occur in all seasons if ambient temperature is lower than the core body temperature. In the 1985 Boston Marathon, even though it was 76 degrees and sunny, there were 75 runners treated for hypothermia. In general, humans adapt poorly to cold exposure. Children are at particular risk because of their relatively greater surface area/body mass ratio, causing them to cool even more rapidly than adults. Because of this, the human's best defense against cold injury is to limit his/her exposure to cold and to dress appropriately. If cold injury has occurred and is mild, often simple passive rewarming such as dry blankets and a warm room are sufficient treatment.

  3. The Influence of Structure Heights and Opening Angles of Micro- and Nanocones on the Macroscopic Surface Wetting Properties

    Science.gov (United States)

    Schneider, Ling; Laustsen, Milan; Mandsberg, Nikolaj; Taboryski, Rafael

    2016-01-01

    We discuss the influence of surface structure, namely the height and opening angles of nano- and microcones on the surface wettability. We show experimental evidence that the opening angle of the cones is the critical parameter on sample superhydrophobicity, namely static contact angles and roll-off angles. The textured surfaces are fabricated on silicon wafers by using a simple one-step method of reactive ion etching at different processing time and gas flow rates. By using hydrophobic coating or hydrophilic surface treatment, we are able to switch the surface wettability from superhydrophilic to superhydrophobic without altering surface structures. In addition, we show examples of polymer replicas (polypropylene and poly(methyl methacrylate) with different wettability, fabricated by injection moulding using templates of the silicon cone-structures. PMID:26892169

  4. The Influence of Structure Heights and Opening Angles of Micro- and Nanocones on the Macroscopic Surface Wetting Properties

    DEFF Research Database (Denmark)

    Sun, Ling; Laustsen, Milan; Mandsberg, Nikolaj

    2016-01-01

    -off angles. The textured surfaces are fabricated on silicon wafers by using a simple one-step method of reactive ion etching at different processing time and gas flow rates. By using hydrophobic coating or hydrophilic surface treatment, we are able to switch the surface wettability from superhydrophilic......We discuss the influence of surface structure, namely the height and opening angles of nano-and microcones on the surface wettability. We show experimental evidence that the opening angle of the cones is the critical parameter on sample superhydrophobicity, namely static contact angles and roll...... to superhydrophobic without altering surface structures. In addition, we show examples of polymer replicas (polypropylene and poly(methyl methacrylate) with different wettability, fabricated by injection moulding using templates of the silicon cone-structures....

  5. The Influence of Supportive and Ethical Work Environments on Work-Related Accidents, Injuries, and Serious Psychological Distress among Hospital Nurses.

    Science.gov (United States)

    Tei-Tominaga, Maki; Nakanishi, Miharu

    2018-01-31

    The healthcare industry in Japan has experienced many cases of work-related injuries, accidents, and workers' compensation claims because of mental illness. This study examined the influence of supportive and ethical work environments on work-related accidents, injuries, and serious psychological distress among hospital nurses. Self-reported questionnaires were distributed to nurses ( n = 1114) from 11 hospitals. Valid responses ( n = 822, 93% women, mean age = 38.49 ± 10.09 years) were used for analyses. The questionnaire included items addressing basic attributes, work and organizational characteristics, social capital and ethical climate at the workplace, psychological distress, and experience of work-related accidents or injuries in the last half year. The final model of a multivariate logistic regression analysis revealed that those who work less than 4 h of overtime per week (OR = 0.313), those who work on days off more than once per month (OR = 0.424), and an exclusive workplace climate (OR = 1.314) were significantly associated with work-related accidents or injuries. Additionally, an exclusive workplace climate (OR = 1.696) elevated the risk of serious psychological distress. To prevent work-related compensation cases, which are caused by these variables, strengthening hospitals' occupational health and safety is necessary.

  6. Influence of the plain-parallel electrode surface dimensions on the type A measurement uncertainty of GM counter

    Directory of Open Access Journals (Sweden)

    Stanković Koviljka Đ.

    2011-01-01

    Full Text Available This paper investigates, through theory and experiment, the influence of the plain-parallel electrode surface dimensions change on the type A measurement uncertainty of a GM counter. The possibilities of applying these results to practical structures are examined by using the methods of mathematical statistics. Special attention is devoted to the influence of electrode surface enlargement on the statistical behavior of the pulse number random variable, expressed in the form of the enlargement law. In the theoretical part of the paper, the general surface enlargement law is derived. Comparison of experimental results with those predicted by the surface enlargement law proved its validity for expressing the type A measurement uncertainty of GM counters constructed with a plain-parallel electrode configuration with a homogenous electric field.

  7. Spermidine Inversely Influences Surface Interactions and Planktonic Growth in Agrobacterium tumefaciens.

    Science.gov (United States)

    Wang, Yi; Kim, Sok Ho; Natarajan, Ramya; Heindl, Jason E; Bruger, Eric L; Waters, Christopher M; Michael, Anthony J; Fuqua, Clay

    2016-10-01

    In bacteria, the functions of polyamines, small linear polycations, are poorly defined, but these metabolites can influence biofilm formation in several systems. Transposon insertions in an ornithine decarboxylase (odc) gene in Agrobacterium tumefaciens, predicted to direct synthesis of the polyamine putrescine from ornithine, resulted in elevated cellulose. Null mutants for odc grew somewhat slowly in a polyamine-free medium but exhibited increased biofilm formation that was dependent on cellulose production. Spermidine is an essential metabolite in A. tumefaciens and is synthesized from putrescine in A. tumefaciens via the stepwise actions of carboxyspermidine dehydrogenase (CASDH) and carboxyspermidine decarboxylase (CASDC). Exogenous addition of either putrescine or spermidine to the odc mutant returned biofilm formation to wild-type levels. Low levels of exogenous spermidine restored growth to CASDH and CASDC mutants, facilitating weak biofilm formation, but this was dampened with increasing concentrations. Norspermidine rescued growth for the odc, CASDH, and CASDC mutants but did not significantly affect their biofilm phenotypes, whereas in the wild type, it stimulated biofilm formation and depressed spermidine levels. The odc mutant produced elevated levels of cyclic diguanylate monophosphate (c-di-GMP), exogenous polyamines modulated these levels, and expression of a c-di-GMP phosphodiesterase reversed the enhanced biofilm formation. Prior work revealed accumulation of the precursors putrescine and carboxyspermidine in the CASDH and CASDC mutants, respectively, but unexpectedly, both mutants accumulated homospermidine; here, we show that this requires a homospermidine synthase (hss) homologue. Polyamines are small, positively charged metabolites that are nearly ubiquitous in cellular life. They are often essential in eukaryotes and more variably in bacteria. Polyamines have been reported to influence the surface-attached biofilm formation of several

  8. Influence of surface oxidation on the radiative properties of ZrB{sub 2}-SiC composites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ning, E-mail: lncaep@163.com [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, 621900 (China); Xing, Pifeng; Li, Cui [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, 621900 (China); Wang, Peng [School of Material Science and Engineering, Shandong University of Technology, Zibo 255049 (China); Jin, Xinxin [College of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040 (China); Zhang, Xinghong [Science and Technology on Advanced Composites in Special Environments Laboratory, Harbin Institute of Technology, Harbin 150001 (China)

    2017-07-01

    Highlights: • Surface component affected radiative properties of ZrB{sub 2}-SiC composites significantly. • Emissivity in long-wave range gradually increased with the thickness of oxide scale. • The surface temperature had a little effect on radiative properties of composites. • Influence of surface roughness on emissivity could be negligible. • Covering the surface with glass is a method for improving radiative properties. - Abstract: The spectral emissivities of ZrB{sub 2}-20 vol.% SiC composites with various surface components of ZrB{sub 2}/SiC (ZS1), silica-rich glass (ZS2) and porous zirconia (ZS3) were measured using infrared spectrometer in the wavelength range from 2.5 to 25.0 μm. The relationship between surface oxidation (associated with surface component, thickness of oxide scale, testing temperature as well as roughness) and the radiative properties of ZrB{sub 2}-SiC composites were investigated systematically. Surface component affected the radiative properties of composites significantly. The total emissivity of ZS1 varied from 0.22 to 0.81 accompanied with surface oxidation in the temperature range 300–900 °C. The emissivity of ZS2 was about 1.5 times as that of ZS3 under the same testing conditions. The oxide scale on specimen surface enhanced the radiative properties especially in terms of short-wave range, and the emissivity in the long-wave range gradually increased with the thickness of oxide scale within a certain range. The influence of testing temperature and surface roughness was also investigated. The testing temperature had a little effect on radiative properties, whereas effect of surface roughness could be negligible.

  9. In vitro Candida colonization on acrylic resins and denture liners: influence of surface free energy, roughness, saliva, and adhering bacteria.

    Science.gov (United States)

    Pereira-Cenci, Tatiana; Pereira, Tatiana; Cury, Altair Antoninha Del Bel; Cenci, Maximiliano Sérgio; Rodrigues-Garcia, Renata Cunha Matheus

    2007-01-01

    This study aimed to determine the influence of surface roughness (Ra), surface free energy (SFE), saliva, and bacteria on Candida adhesion to denture materials. The Ra and SFE of 2 acrylic resin specimens and 2 denture liner specimens were measured and assayed in a flow chamber for bacteria culture perfusion plus Candida albicans or C glabrata cultures. Adhesion was determined by counting under light microscopy. Candida adhesion showed significant differences depending on the factors involved. The overall colonization was significantly decreased by saliva and influenced by bacteria. Candida adhesion was strongly affected by Ra, saliva, and bacteria, but not by SFE.

  10. Influence of manufacturing processes on cell surface properties of probiotic strain Lactobacillus rhamnosus Lcr35®.

    Science.gov (United States)

    Nivoliez, Adrien; Veisseire, Philippe; Alaterre, Elina; Dausset, Caroline; Baptiste, Fabrice; Camarès, Olivier; Paquet-Gachinat, Marylise; Bonnet, Muriel; Forestier, Christiane; Bornes, Stéphanie

    2015-01-01

    The influence of the industrial process on the properties of probiotics, administered as complex manufactured products, has been poorly investigated. In the present study, we comparatively assessed the cell wall characteristics of the probiotic strain Lactobacillus rhamnosus Lcr35® together with three of its commercial formulations with intestinal applications. Putative secreted and transmembrane-protein-encoding genes were initially searched in silico in the genome of L. rhamnosus Lcr35®. A total of 369 candidate genes were identified which expressions were followed using a custom Lactobacillus DNA chip. Among them, 60 or 67 genes had their expression either upregulated or downregulated in the Lcr Restituo® packet or capsule formulations, compared to the native Lcr35® strain. Moreover, our data showed that the probiotic formulations (Lcr Lenio®, Lcr restituo® capsule and packet) showed a better capacity to adhere to intestinal epithelial Caco-2 cells than the native Lcr35® strain. Microbial (MATS) tests showed that the probiotic was an electron donor and that they were more hydrophilic than the native strain. The enhanced adhesion capacity of the active pharmaceutical ingredients (APIs) to epithelial Caco-2 cells and their antipathogen effect could be due to this greater surface hydrophilic character. These findings suggest that the manufacturing process influences the protein composition and the chemical properties of the cell wall. It is therefore likely that the antipathogen effect of the formulation is modulated by the industrial process. Screening of the manufactured products' properties would therefore represent an essential step in evaluating the effects of probiotic strains.

  11. Influence of aluminium sheet surface modification on the self-piercing riveting process and the joint static lap shear strength

    OpenAIRE

    Li, Dezhi

    2017-01-01

    Self-piercing riveting (SPR) has been widely used in automotive as one of the major joining technologies for aluminium structures due to its advantages over some of the more traditional joining technologies. Research has shown that friction is a very important factor that influences both the riveting process and the joint strength for SPR, but these influences have not been fully understood. In this paper, AA5754 sheets with different surface textures, such as original with solid wax, hot wat...

  12. INFLUENCE OF SURFACE-ACTIVE AGENT CONCENTRATION ON THE SPECTROPHOTOMETRIC BIOMASS ESTIMATION DURING SUBMERGED GROWTH OF Mycobacterium bovis

    Directory of Open Access Journals (Sweden)

    Sakai M.C.

    1997-01-01

    Full Text Available The influence of the surface-active agent Tween 80 (polyoxyethylene 20 sorbitan monoleate on the dispersed growth of Mycobacterium bovis - BCG - was studied. The slopes of the bacterial dry mass / absorbance curves, were significantly reduced, by the increase of the Tween 80 concentration in the medium. Such an influence was probably due to the effect Tween 80 had on the average size of bacterial clumps during the culture carried out in a bench fermenter

  13. The influence of seam height on lost-time injury and fatality rates at small underground bituminous coal mines.

    Science.gov (United States)

    Peters, R H; Fotta, B; Mallett, L G

    2001-11-01

    Due to variations in the thickness of U.S. coal seams, there is great variability in the height of the roof where underground miners work. Restrictions imposed by low seam heights have important safety consequences. As the height of their workplace decreases, miners must stoop, duck walk, or crawl, and their vision, posture, and mobility become increasingly restricted. Low seam height also places important restrictions on the design of mobile equipment and other mining machinery. Using the employment and injury data reported to the Mine Safety and Health Administration (MSHA) from 1990 to 1996, small underground bituminous coal mines with less than 50 employees were stratified by average coal seam height according to the following categories: low ( or =61"). Injury rates for both nonfatal days lost and fatality cases were examined by seam height and leading type of injury incidents. The leading types of incidents associated with fatalities were roof falls and powered haulage equipment. In comparison to high-seam mines, miners working in low or medium seams are at higher risk of being killed by powered haulage equipment, roof bolting machines, and falls of unsupported roof. The leading types of incidents associated with nonfatal injuries were handling materials and powered haulage. As mining height decreases, miners are at increasingly higher risk of having a nonfatal injury from incidents involving roof bolting machines, load-haul-dump equipment, personnel carriers, and powered haulage conveyors. As mining height increases, miners are at increasingly higher risk of having a nonfatal injury from slips and falls and incidents involving shuttle cars and roof and rib falls. Knee injuries are a particularly severe problem in low-seam mines. The rate of injuries to miners while crawling or kneeling is 10 times higher in low seams than in high seams.

  14. The Influence of Playing Experience and Position on Injury Risk in NCAA Division I College Football Players.

    Science.gov (United States)

    McCunn, Robert; Fullagar, Hugh H K; Williams, Sean; Halseth, Travis J; Sampson, John A; Murray, Andrew

    2017-11-01

    American football is widely played by college student-athletes throughout the United States; however, the associated injury risk is greater than in other team sports. Numerous factors likely contribute to this risk, yet research identifying these risk factors is limited. The present study sought to explore the relationship between playing experience and position on injury risk in NCAA Division I college football players. Seventy-six male college student-athletes in the football program of an American NCAA Division I university participated. Injuries were recorded over 2 consecutive seasons. Players were characterized based on college year (freshman, sophomore, junior, or senior) and playing position. The effect of playing experience and position on injury incidence rates was analyzed using a generalized linear mixed-effects model, with a Poisson distribution, log-linear link function, and offset for hours of training exposure or number of in-game plays (for training and game injuries, respectively). The overall rates of non-time-loss and time-loss game-related injuries were 2.1 (90% CI: 1.8-2.5) and 0.6 (90% CI: 0.4-0.8) per 1000 plays, respectively. The overall rates of non-time-loss and time-loss training-related injuries were 26.0 (90% CI: 22.6-29.9) and 7.1 (90% CI: 5.9-8.5) per 1000 h, respectively. During training, seniors and running backs displayed the greatest risk. During games, sophomores, juniors, and wide receivers were at greatest risk. Being aware of the elevated injury risk experienced by certain player groups may help coaches make considered decisions related to training design and player selection.

  15. Evolution of Mediterranean sea surface temperatures 3.5-1.5 Ma: Regional and hemispheric influences

    Science.gov (United States)

    Herbert, Timothy D.; Ng, Gideon; Cleaveland Peterson, Laura

    2015-01-01

    We present a composite time series of Mediterranean sea surface temperature (SST) and marine biomarker accumulation for the time span from 3.5 to 1.525 Ma, based on alkenone unsaturation and concentration from hemipelagic sediments outcropping in southern Italy and Sicily. Paleotemperature data define three regimes: a late Pliocene climate on average 4- 5 °C warmer than modern, a latest Pliocene to early Pleistocene onset of 41 kyr cycles, and a major increase in the range of glacial-interglacial temperature change at ∼ 1.84 Ma that shortly precedes the former definition of the Plio-Pleistocene boundary in the Crotone sequence. Pliocene sea surface temperature (SST) cycles are dominated by precession, with a ∼ 1.5 °C range. Obliquity-related rhythms influence SST significantly shortly after ∼ 2.8 Ma (equivalent to MIS G10) and dominate after ∼ 2.51 Ma (equivalent to MIS 100). However, little, if any, long-term cooling occurred on an interglacial basis until after ∼ 1.85 Ma. Alkenone concentrations provide a good proxy for the accumulation of marine organic matter, and primarily reflect regional hydrology. Organic sedimentation, including the formation of layers highly enriched in organic matter ("sapropels") was paced throughout by precessional variations despite changes in both average regional temperature, and the shift in temperature variance to the 41 kyr obliquity cycle in the latest Pliocene and early Pleistocene. Our reconstruction therefore highlights the intermingling of both hemispheric-wide changes in temperature and regional variations in the hydrological cycle that combined to force major evolutionary changes in the fauna and flora of northern Africa and the southern Mediterranean in late Pliocene to mid-Pleistocene time.

  16. Influence of Light Emitting Diode-Derived Blue Light Overexposure on Mouse Ocular Surface.

    Science.gov (United States)

    Lee, Hyo Seok; Cui, Lian; Li, Ying; Choi, Ji Suk; Choi, Joo-Hee; Li, Zhengri; Kim, Ga Eon; Choi, Won; Yoon, Kyung Chul

    2016-01-01

    To investigate the influence of overexposure to light emitting diode (LED)-derived light with various wavelengths on mouse ocular surface. LEDs with various wavelengths were used to irradiate C57BL/6 mice at an energy dose of 50 J/cm2, twice a day, for 10 consecutive days. The red, green, and blue groups represented wavelengths of 630 nm, 525 nm, and 410 nm, respectively. The untouched group (UT) was not exposed to LED light and served as the untreated control. Tear volume, tear film break-up time (TBUT), and corneal fluorescein staining scores were measured on days 1, 3, 5, 7, and 10. Levels of interferon (IFN)-γ, interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were measured in the cornea and conjunctiva using a multiplex immunobead assay at day 10. Levels of malondialdehyde (MDA) were measured with an enzyme-linked immunosorbent assay. Flow cytometry, 2'7'-dichlorofluorescein diacetate (DCF-DA) assay, histologic analysis, immunohistochemistry with 4-hydroxynonenal, and terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) staining were also performed. TBUT of the blue group showed significant decreases at days 7 and 10, compared with the UT and red groups. Corneal fluorescein staining scores significantly increased in the blue group when compared with UT, red, and green groups at days 5, 7, and 10. A significant increase in the corneal levels of IL-1β and IL-6 was observed in the blue group, compared with the other groups. The blue group showed significantly increased reactive oxygen species production in the DCF-DA assay and increased inflammatory T cells in the flow cytometry. A significantly increased TUNEL positive cells was identified in the blue group. Overexposure to blue light with short wavelengths can induce oxidative damage and apoptosis to the cornea, which may manifest as increased ocular surface inflammation and resultant dry eye.

  17. Influence of surface relaxation of strained layers on atomic resolution ADF imaging.

    Science.gov (United States)

    Beyer, Andreas; Duschek, Lennart; Belz, Jürgen; Oelerich, Jan Oliver; Jandieri, Kakhaber; Volz, Kerstin

    2017-10-01

    Surface relaxation of thin transmission electron microscopy (TEM) specimens of strained layers results in a severe bending of lattice planes. This bending significantly displaces atoms from their ideal channeling positions which has a strong impact on the measured annular dark field (ADF) intensity. With the example of GaAs quantum wells (QW) embedded in a GaP barrier, we model the resulting displacements by elastic theory using the finite element (FE) formalism. Relaxed and unrelaxed super cells served as input for state of the art frozen phonon simulation of atomic resolution ADF images. We systematically investigate the dependencies on the sample´s geometric parameters, i.e. QW width and TEM sample thickness, by evaluating the simulated intensities at the atomic column´s positions as well as at the background positions in between. Depending on the geometry the ADF intensity can be affected in a range several nm from the actual interface. Moreover, we investigate the influence of the surface relaxation on the angular distribution of the scattered intensity. At high scattering angles we observe an intensity reduction at the interface as well as in the GaP barrier due to de-channeling. The amount of intensity reduction at an atomic column is directly proportional to its mean square displacement. On the contrary we find a clearly increased intensity at low angles caused by additional diffuse scattering. We discuss the implications for quantitative evaluations as well as strategies to compensate for the reduced intensities. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. ERA-40-aided assessment of the atmospheric influence on satellite retrieval of Adriatic Sea surface temperature

    Science.gov (United States)

    Tomažić, Igor; Kuzmić, Milivoj

    2009-06-01

    The aim of this work is assessment of regional atmospheric influence on satellite derivation of Adriatic Sea surface temperature (SST). To this end the European Centre for Medium-Range Weather Forecast (ECMWF) ERA-40 reanalysis dataset has been employed to provide the temperature and humidity profiles and surface data, while the RTTOV 8.7 radiative transfer model was used to calculate the top-of-atmosphere brightness temperatures for the advanced very high-resolution radiometer (AVHRR) channels. Ten ERA-40 grid points over the Adriatic Sea were used in the analysis, providing 29,590, 00 UTC and 12 UTC, clear-sky profiles. Climatological analysis of the ERA-40 profiles demonstrated distinct seasonal variability over the Adriatic Sea. Seasonality noted in the temperature and specific humidity profiles also evinced in the atmospheric transmittance, thermal channels temperature deficit, and derived γ and ρ parameters. A multivariate analysis was applied to relate the simulated top-of-atmosphere brightness temperatures to the Adriatic SSTs in order to generate exploratory sets of SST retrieval coefficients. All derived coefficient sets exhibited smaller noise amplification factor than the global counterpart. A test comparison of satellite-derived SST with an 11-month in situ SST series showed than locally derived coefficients provide smaller scatter (improved precision), and skin-centred bias that requires additional adjustment. Almost identical SST residual and error metric was obtained with seasonally adjusted classical split-window coefficients and with coefficients explicitly accommodating water-vapor dependence. Comparison with data reinforces the notion that the atmosphere over the Adriatic may exhibit variability that cannot be fully accommodated by globally adjusted correction.

  19. Survey of Permafrost Thaw Influence on Surface Water Dissolved Organic Matter in Sub-Arctic Alaska

    Science.gov (United States)

    Gagne, K.; Walter Anthony, K. M.; Guerard, J.

    2016-12-01

    The chemical and functional group composition of permafrost organic matter largely remains unknown. Characterizing dissolved organic matter (DOM) chemical composition offers insight into the quality and extent of the permafrost carbon pool that may mobilize and transform into smaller components or greenhouse gasses upon thaw. The Goldstream watershed in interior Alaska is underlain by discontinuous permafrost with varying stage of talik (thaw bulb) development, allowing for the comparison of thaw stage on DOM composition. Surface water samples were collected from lakes and streams in regions of the watershed with varying degrees of permafrost thaw in order to investigate seasonal variability and associated trends in DOM composition. Additionally, select permafrost cores were obtained and utilized in leachate experiments to identify the fraction and reactivity of the soil organic carbon pool leached from active layer and permafrost soil upon thaw. Leached organic moieties were compared to the total permafrost organic carbon pool and the DOM of the overlying surface water. Extracted isolates from both permafrost and active layer were characterized by 3D excitation-emission fluorescence, UV-vis spectroscopy, PARAFAC, SPR-W5-WATERGATE 1H- NMR, total organic carbon, ICP-MS, and ion chromatography, coupled with photolysis experiments to determine reactive oxygen species production to characterize potential reactivity. Differences in carbon pool composition were resolved between seasons and with the extent of permafrost thaw. This is a key first step to determine how permafrost degradation influences DOM pool composition on a molecular level, which is essential for assessing permafrost organic matter impact on biogeochemical cycling and other ecological functions as it becomes incorporated into a warming landscape.

  20. A Multidisciplinary Assessment of River Surface Water Quality in Areas Heavily Influenced by Human Activities.

    Science.gov (United States)

    Charalampous, Nikolina; Kindou, Aggeliki; Vlastos, Dimitris; Tsarpali, Vasiliki; Antonopoulou, Maria; Konstantinou, Ioannis; Dailianis, Stefanos

    2015-08-01

    The present study could serve as a multidisciplinary approach for the assessment of river surface water quality with the use of chemical and biological methods. Specifically, physicochemical parameters, heavy metals, and pesticides were measured in water samples from three different stations (sampling station S1, S2, and S3) along Asopos River (Greece). In parallel, algal species (primary producers)-such as Scenedesmus rubescens and Chlorococcum sp.; consumer invertebrate species, such as the fairy shrimp Thamnocephalus platyurus and the rotifer Brachionus calyciflorus; as well as human lymphocytes-were exposed to those samples for assessing their toxic and genotoxic/mutagenic effects. According to the results, although the values of almost all of the physicochemical parameters tested, heavy metals (zinc, cadmium, lead, and mercury) and pesticides were lower than or within the respective environmental quality standards, thus offering no clear evidence for their natural or anthropogenic origin. Values recorded for nickel, chromium, hexavalent chromium, and malathion represent a typical case of mixed influence from natural and anthropogenic enrichments. In contrast, the algal growth arrest, the acute toxic effects on the freshwater invertebrates, and the increased micronuclei frequencies observed in human lymphocytes showed the presence of human-derived hazardous substances, which were hardly determinable with the use of conventional chemical methods. Given that the presence of priority pollutants in river surface waters, heavily burdened by anthropogenic activities, could give no clear evidence for their biological risk, the results of the present study showed that chemical and biological assays should be applied in parallel, thus serving as a reliable tool for the assessment of river water quality.

  1. An Investigation of Ice Surface Albedo and Its Influence on the High-Altitude Lakes of the Tibetan Plateau

    OpenAIRE

    Jiahe Lang; Shihua Lyu; Zhaoguo Li; Yaoming Ma; Dongsheng Su

    2018-01-01

    Most high-altitude lakes are more sensitive to global warming than the regional atmosphere. However, most existing climate models produce unrealistic surface temperatures on the Tibetan Plateau (TP) lakes, and few studies have focused on the influence of ice surface albedo on high-altitude lakes. Based on field albedo measurements, moderate resolution imaging spectrometer (MODIS) albedo products and numerical simulation, this study evaluates the ice albedo parameterization schemes in existing...

  2. Influence of constant magnetic field on the tribological parameters of rubbing couples steel-brass in surface active substances

    Directory of Open Access Journals (Sweden)

    М.М. Свирид

    2009-03-01

    Full Text Available  Maintainability of surfaces of sensitive pairs of friction is analysed in surroundings with high electrical resistance in the conditions of friction. The model of tribological unit, determining conditions and conformities to the law of formation of protective tribological pellicles, is worked out. The parameters of reparation of friction surfaces are determined by a tribomagnetic method. The parameters of renewal of sensitive tribopairs are also defined on uncollapsible technologies by joint influence of triboelectrochemical method and tribomagnetic components.

  3. The influence of surface modified poly(L-lactic acid) films on the differentiation of human monocytes into macrophages

    OpenAIRE

    Correia, Clara R.; Gaifem, Joana; Oliveira, Mariana Braga; Silvestre, Ricardo Jorge Leal; Mano, J. F.

    2017-01-01

    Macrophages play a crucial role in the biological performance of biomaterials, as key factors in defining the optimal inflammation-healing balance towards tissue regeneration and implant integration. Here, we investigate how different surface modifications performed on poly(L-lactic acid) (PLLA) films would influence the differentiation of human monocytes into macrophages. We tested PLLA films without modification, surface-modified by plasma treatment (pPLLA) or by combining plasma treatment ...

  4. The influence of tool path strategies on cutting force and surface texture during ball end milling of low curvature convex surfaces.

    Science.gov (United States)

    Shajari, Shaghayegh; Sadeghi, Mohammad Hossein; Hassanpour, Hamed

    2014-01-01

    Advancement in machining technology of curved surfaces for various engineering applications is increasing. Various methodologies and computer tools have been developed by the manufacturers to improve efficiency of freeform surface machining. Selection of the right sets of cutter path strategies and appropriate cutting conditions is extremely important in ensuring high productivity rate, meeting the better quality level, and lower cutting forces. In this paper, cutting force as a new decision criterion for the best selection of tool paths on convex surfaces is presented. Therefore, this work aims at studying and analyzing different finishing strategies to assess their influence on surface texture, cutting forces, and machining time. Design and analysis of experiments are performed by means of Taguchi technique and analysis of variance. In addition, the significant parameters affecting the cutting force in each strategy are introduced. Machining strategies employed include raster, 3D-offset, radial, and spiral. The cutting parameters were feed rate, cutting speed, and step over. The experiments were carried out on low curvature convex surfaces of stainless steel 1.4903. The conclusion is that radial strategy provokes the best surface texture and the lowest cutting forces and spiral strategy signifies the worst surface texture and the highest cutting forces.

  5. Electron mobility on the surface of liquid Helium: influence of surface level atoms and depopulation of lowest subbands

    International Nuclear Information System (INIS)

    Grigoriev, P. D.; Dyugaev, A. M.; Lebedeva, E. V.

    2008-01-01

    The temperature dependence of electron mobility is examined. We calculate the contribution to the electron scattering rate from the surface level atoms (SLAs), proposed in [10]. This contribution is substantial at low temperatures T < 0.5, when the He vapor concentration is exponentially small. We also study the effect of depopulation of the lowest energy subband, which leads to an increase in the electron mobility at high temperature. The results explain certain long-standing discrepancies between the existing theory and experiment on electron mobility on the surface of liquid helium

  6. The influence of particles on bioavailability and toxicity of pesticides in surface water.

    Science.gov (United States)

    Knauer, Katja; Homazava, Nadzeya; Junghans, Marion; Werner, Inge

    2017-07-01

    Environmental risk assessment is an essential part of the approval process for pesticides. Exposure concentrations are compared with ecotoxicological data obtained from standardized laboratory studies and, if available, from field studies to determine the risk of a substance or formulation for aquatic communities. Predicted concentrations in surface waters are derived using, for example, the European FOrum for the Co-ordination of pesticide fate models and their USe (FOCUS) or the German Exposit models, which distinguish between exposure to dissolved and particle-associated pesticide concentrations, because the dissolved concentration is thought to be the best predictor of bioavailability and toxicity. Water and particle-associated concentrations are estimated based on the organic carbon-water partitioning coefficient (K OC ). This review summarizes published information on the influence of natural suspended solids on bioavailability and toxicity of pesticides to aquatic organisms (algae, invertebrates and fish), and the value of log K OC and log K OW (octanol-water coefficient) as sole predictors of the bioavailable fraction is discussed. The information showed that: 1) the quality and origin of suspended solids played an important role in influencing pesticide bioavailability and toxicity; 2) a decrease in toxicity due to the presence of suspended solids was shown only for pyrethroid insecticides with log K OW greater than 5, but the extent of this reduction depended on particle concentration and size, and potentially also on the ecotoxicological endpoint; 3) for pesticides with a log K OW less than 3 (e.g., triazines, carbamates, and organophosphates), the impact of particles on bioavailability and toxicity is small and species dependent; and 4) pesticide bioavailability is greatly influenced by the test species and their physiology (e.g., feeding behavior or digestion). We conclude that exposure of aquatic organisms to pesticides and environmental risk of many

  7. Surface Chemistry of Polymers. The Influence of Thermal and Chemical Treatments on the Surface Properties of Polyvinylchloride

    OpenAIRE

    Jeanneret, C.; Stoeckli, Fritz

    2007-01-01

    The influence of thermal and chemical treatments (tetrahydrofuran and dioxane) on the adsorption properties of polyvinylchloride is investigated by gas chromatographic methods. It is shown, that heating to the glass-transition temperature has an erasing effect. Methanol was used as the main molecular probe.

  8. The influence of the surface composition of mixed monolayer films on the evaporation coefficient of water.

    Science.gov (United States)

    Miles, Rachael E H; Davies, James F; Reid, Jonathan P

    2016-07-20

    We explore the dependence of the evaporation coefficient of water from aqueous droplets on the composition of a surface film, considering in particular the influence of monolayer mixed component films on the evaporative mass flux. Measurements with binary component films formed from long chain alcohols, specifically tridecanol (C13H27OH) and pentadecanol (C15H31OH), and tetradecanol (C14H29OH) and hexadecanol (C16H33OH), show that the evaporation coefficient is dependent on the mole fractions of the two components forming the monolayer film. Immediately at the point of film formation and commensurate reduction in droplet evaporation rate, the evaporation coefficient is equal to a mole fraction weighted average of the evaporation coefficients through the equivalent single component films. As a droplet continues to diminish in surface area with continued loss of water, the more-soluble, shorter alkyl chain component preferentially partitions into the droplet bulk with the evaporation coefficient tending towards that through a single component film formed simply from the less-soluble, longer chain alcohol. We also show that the addition of a long chain alcohol to an aqueous-sucrose droplet can facilitate control over the degree of dehydration achieved during evaporation. After undergoing rapid gas-phase diffusion limited water evaporation, binary aqueous-sucrose droplets show a continued slow evaporative flux that is limited by slow diffusional mass transport within the particle bulk due to the rapidly increasing particle viscosity and strong concentration gradients that are established. The addition of a long chain alcohol to the droplet is shown to slow the initial rate of water loss, leading to a droplet composition that remains more homogeneous for a longer period of time. When the sucrose concentration has achieved a sufficiently high value, and the diffusion constant of water has decreased accordingly so that bulk phase diffusion arrest occurs in the monolayer

  9. Bond strength of three luting agents to zirconia ceramic - influence of surface treatment and thermocycling

    Directory of Open Access Journals (Sweden)

    Ahmed Attia

    2011-08-01

    Full Text Available OBJECTIVE: This in vitro study aimed to evaluate the influence of different surface treatments, 3 luting agents and thermocycling on microtensile bond strength (µTBS to zirconia ceramic. Material and METHODS: A total of 18 blocks (5x5x4 mm were fabricated from zirconia ceramic (ICE Zirkonia and duplicated into composite blocks (Alphadent. Ceramic blocks were divided into 3 groups (n=6 according to the following surface treatments: airborne-particle abrasion (AA, silica-coating, (SC (CoJet and silica coating followed by silane application (SCSI (ESPE Sil. Each group was divided into 3 subgroups (n=2 according to the 3 luting agents used. Resin-modified glass-ionomer cement (RMGIC, Ketac Cem Plus, self-adhesive resin cement (UN, RelyX Unicem and adhesive resin cement (ML, MultiLink Automix were used for bonding composite and zirconia blocks. Each bonding assembly was cut into microbars (10 mm long and 1±0.1 mm². Seven specimens of each subgroup were stored in water bath at 37ºC for 1 week. The other 7 specimens were stored in water bath at 37ºC for 30 days then thermocycled (TC for 7,500 cycles. µTBS values were recorded for each specimen using a universal testing machine. Statistical analyses were performed using a 3-way ANOVA model followed by serial 1-way ANOVAs. Comparison of means was performed with Tukey's HSD test at (α=0.05. RESULTS: µTBS ranged from 16.8 to 31.8 MPa after 1 week and from 7.3 to 16.4 MPa after 30 days of storage in water and thermocycling. Artificial aging significantly decreased µTBS (p<0.05. Considering surface treatment, SCSI significantly increased µTBS (p<0.05 compared to SC and AA. Resin cements (UN and ML demonstrated significantly higher µTBS (p<0.05 compared to RMGIC cement. CONCLUSIONS: Silica coating followed by silane application together with adhesive resin cements significantly increased µTBS, while thermocycling significantly decreased µTBS.

  10. Bond strength of three luting agents to zirconia ceramic - Influence of surface treatment and thermocycling

    Science.gov (United States)

    ATTIA, Ahmed

    2011-01-01

    Objective This in vitro study aimed to evaluate the influence of different surface treatments, 3 luting agents and thermocycling on microtensile bond strength (µTBS) to zirconia ceramic. Material and Methods A total of 18 blocks (5x5x4 mm) were fabricated from zirconia ceramic (ICE Zirkonia) and duplicated into composite blocks (Alphadent). Ceramic blocks were divided into 3 groups (n=6) according to the following surface treatments: airborne-particle abrasion (AA), silica-coating, (SC) (CoJet) and silica coating followed by silane application (SCSI) (ESPE Sil). Each group was divided into 3 subgroups (n=2) according to the 3 luting agents used. Resin-modified glass-ionomer cement (RMGIC, Ketac Cem Plus), self-adhesive resin cement (UN, RelyX Unicem) and adhesive resin cement (ML, MultiLink Automix) were used for bonding composite and zirconia blocks. Each bonding assembly was cut into microbars (10 mm long and 1±0.1 mm2). Seven specimens of each subgroup were stored in water bath at 37ºC for 1 week. The o ther 7 specimens were stored in water bath at 37ºC for 30 days then thermocycled (TC) for 7,500 cycles. µTBS values were recorded for each specimen using a universal testing machine. Statistical analyses were performed using a 3-way ANOVA model followed by serial 1-way ANOVAs. Comparison of means was performed with Tukey's HSD test at (α=0.05). Results µTBS ranged from 16.8 to 31.8 MPa after 1 week and from 7.3 to 16.4 MPa after 30 days of storage in water and thermocycling. Artificial aging significantly decreased µTBS (p<0.05). Considering surface treatment, SCSI significantly increased µTBS (p<0.05) compared to SC and AA. Resin cements (UN and ML) demonstrated significantly higher µTBS (p<0.05) compared to RMGIC cement. Conclusions Silica coating followed by silane application together with adhesive resin cements significantly increased µTBS, while thermocycling significantly decreased µTBS. PMID:21710091

  11. Thermal and UV Hydrosilylation of Alcohol-Based Bifunctional Alkynes on Si (111) surfaces: How surface radicals influence surface bond formation

    OpenAIRE

    Khung, Y. L.; Ngalim, S. H.; Scaccabarozi, A.; Narducci, D.

    2015-01-01

    Using two different hydrosilylation methods, low temperature thermal and UV initiation, silicon (111) hydrogenated surfaces were functionalized in presence of an OH-terminated alkyne, a CF3-terminated alkyne and a mixed equimolar ratio of the two alkynes. XPS studies revealed that in the absence of premeditated surface radical through low temperature hydrosilylation, the surface grafting proceeded to form a Si-O-C linkage via nucleophilic reaction through the OH group of the alkyne. This led ...

  12. Influence of repetitive pulsed laser irradiation on the surface characteristics of an aluminum alloy in the melting regime

    International Nuclear Information System (INIS)

    Choi, Sung Ho; Jhang, Kyung Young

    2015-01-01

    We have investigated the influence of repetitive near-infrared (NIR) pulsed laser shots in the melting regime on the surface characteristics of an aluminum 6061-T6 alloy. Characteristics of interest include surface morphology, surface roughness, and surface hardness in the melted zone as well as the size of the melted zone. For this study, the proper pulse energy for inducing surface melting at one shot is selected using numerical simulations that calculate the variation in temperature at the laser beam spot for various input pulse energies in order to find the proper pulse energy for raising the temperature to the melting point. In this study, 130 mJ was selected as the input energy for a Nd:YAG laser pulse with a duration of 5 ns. The size of the melted zone measured using optical microscopy (OM) increased logarithmically with an increasing shot number. The surface morphology observed by scanning electron microscopy (SEM) clearly showed a re-solidified microstructure evolution after surface melting. The surface roughness and hardness were measured by atomic force microscopy (AFM) and nano-indentation, respectively. The surface roughness showed almost no variation due to the surface texturing after laser shots over 10. The hardness inside the melted zone was lower than that outside the zone because the β'' phase was transformed to a β phase or dissolved into a matrix.

  13. Thermal and UV Hydrosilylation of Alcohol-Based Bifunctional Alkynes on Si (111) surfaces: How surface radicals influence surface bond formation

    Science.gov (United States)

    Khung, Y. L.; Ngalim, S. H.; Scaccabarozi, A.; Narducci, D.

    2015-06-01

    Using two different hydrosilylation methods, low temperature thermal and UV initiation, silicon (111) hydrogenated surfaces were functionalized in presence of an OH-terminated alkyne, a CF3-terminated alkyne and a mixed equimolar ratio of the two alkynes. XPS studies revealed that in the absence of premeditated surface radical through low temperature hydrosilylation, the surface grafting proceeded to form a Si-O-C linkage via nucleophilic reaction through the OH group of the alkyne. This led to a small increase in surface roughness as well as an increase in hydrophobicity and this effect was attributed to the surficial etching of silicon to form nanosize pores (~1-3 nm) by residual water/oxygen as a result of changes to surface polarity from the grafting. Furthermore in the radical-free thermal environment, a mix in equimolar of these two short alkynes can achieve a high contact angle of ~102°, comparable to long alkyl chains grafting reported in literature although surface roughness was relatively mild (rms = ~1 nm). On the other hand, UV initiation on silicon totally reversed the chemical linkages to predominantly Si-C without further compromising the surface roughness, highlighting the importance of surface radicals determining the reactivity of the silicon surface to the selected alkynes.

  14. Influence of glacial ice sheets on the Atlantic meridional overturning circulation through surface wind change

    Science.gov (United States)

    Sherriff-Tadano, Sam; Abe-Ouchi, Ayako; Yoshimori, Masakazu; Oka, Akira; Chan, Wing-Le

    2018-04-01

    Coupled modeling studies have recently shown that the existence of the glacial ice sheets intensifies the Atlantic meridional overturning circulation (AMOC). However, most models show a strong AMOC in their simulations of the Last Glacial Maximum (LGM), which is biased compared to reconstructions that indicate both a weaker and stronger AMOC during the LGM. Therefore, a detailed investigation of the mechanism behind this intensification of the AMOC is important for a better understanding of the glacial climate and the LGM AMOC. Here, various numerical simulations are conducted to focus on the effect of wind changes due to glacial ice sheets on the AMOC and the crucial region where the wind modifies the AMOC. First, from atmospheric general circulation model experiments, the effect of glacial ice sheets on the surface wind is evaluated. Second, from ocean general circulation model experiments, the influence of the wind stress change on the AMOC is evaluated by applying wind stress anomalies regionally or at different magnitudes as a boundary condition. These experiments demonstrate that glacial ice sheets intensify the AMOC through an increase in the wind stress at the North Atlantic mid-latitudes, which is induced by the North American ice sheet. This intensification of the AMOC is caused by the increased oceanic horizontal and vertical transport of salt, while the change in sea ice transport has an opposite, though minor, effect. Experiments further show that the Eurasian ice sheet intensifies the AMOC by directly affecting the deep-water formation in the Norwegian Sea.

  15. Influence of hummocks and emergent vegetation on hydraulic performance in a surface flow wastewater treatment wetland

    Science.gov (United States)

    Keefe, Steffanie H.; Daniels, Joan S.; Runkel, Robert L.; Wass, Roland D.; Stiles, Eric A.; Barber, Larry B.

    2010-01-01

    A series of tracer experiments were conducted biannually at the start and end of the vegetation growing season in a surface flow wastewater treatment wetland located near Phoenix, AZ. Tracer experiments were conducted prior to and following reconfiguration and replanting of a 1.2 ha treatment wetland from its original design of alternating shallow and deep zones to incorporate hummocks (shallow planting beds situated perpendicular to flow). Tracer test data were analyzed using analysis of moments and the one‐dimensional transport with inflow and storage numerical model to evaluate the effects of the seasonal vegetation growth cycle and hummocks on solute transport. Following reconfiguration, vegetation coverage was relatively small, and minor changes in spatial distribution influenced wetland hydraulics. During start‐up conditions, the wetland underwent an acclimation period characterized by small vegetation coverage and large transport cross‐sectional areas. At the start of the growing season, new growth of emergent vegetation enhanced hydraulic performance. At the end of the growing season, senescing vegetation created short‐circuiting. Wetland hydrodynamics were associated with high volumetric efficiencies and velocity heterogeneities. The hummock design resulted in breakthrough curves characterized by multiple secondary tracer peaks indicative of varied flow paths created by bottom topography.

  16. The influence of chemical composition on vaporisation of LNG and LPG on unconfined water surfaces

    International Nuclear Information System (INIS)

    Conrado, C.; Vesovic, V.

    2000-01-01

    A model is proposed for estimating the rate of vaporisation of LNG and LPG cryogen mixtures spreading on unconfined water surfaces. The model is used to examine the influence of chemical composition on the vaporisation rate of LNG and LPG during spreading. Calculations have been performed whereby the vaporisation rate of the LNG and LPG mixtures has been compared to the vaporisation of pure methane and propane, respectively, under the same initial conditions. The detailed results indicate that the vaporisation rate of LNG mixture is markedly different to that of pure methane, while the vaporisation rate of LPG mixture is similar to that of pure propane. The difference can be attributed primarily to the contributions of the direct and indirect component of the total, different, isobaric latent heat to the boiling process. For LNG, as the liquid mixture gets rich in ethane, the total, differential, isobaric latent heat increases rapidly, leading to a large decrease in the vaporisation of LNG compared to pure methane. For LPG, because of the shape of the phase envelope, only a small increase of the total latent heat and the boiling temperature is observed and consequently the change in the vaporisation is marginal. The overall results suggest that treating an LNG spill as a pure methane spill results in underestimation of the total spillage time of the order of 10-15% and in qualitatively wrong dynamics of the rate of vapour formation: thus warranting a full treatment of the thermodynamics of the mixture. (Author)

  17. Influence of bioactive materials used on the dentin surface whitened with carbamide peroxide 16%

    Directory of Open Access Journals (Sweden)

    Helena Burlamaqui Pinheiro

    2010-06-01

    Full Text Available This study investigated the influence of bioactive materials on the dentin surface whitened. MATERIAL AND METHODS: Three bovine teeth were shaped into three dentin wafers. Each wafer was then sectioned, into six dentin slices. One slice from each tooth was distributed into one of 6 groups: 1.CG = control group (distilled water; 2.WT = whitening treatment; 3.WT + MI Paste Plus, applied once a day; 4.WT + Relief ACP30, applied once a day for 30 mintes; 5.WT + Relief ACP60, applied once a day for 60 minutes; 6.WT + Biosilicate®, applied once a week. All groups were treated over 14 days. RESULTS: CG presented all dentinal tubules occluded by smear layer; WT group was observed all dentinal tubules opened. In the groups 3, 4 and 6, tubules were occluded. Group 5, dentinal tubules were completely occluded by mineral deposits. CONCLUSION: The use of bioactive materials immediately after whitening treatment can reduce or even avoid the demineralization effect of whitening and avoid exposing dentinal tubules.

  18. Influence of residual stress on the adhesion and surface morphology of PECVD-coated polypropylene

    Science.gov (United States)

    Jaritz, Montgomery; Hopmann, Christian; Behm, Henrik; Kirchheim, Dennis; Wilski, Stefan; Grochla, Dario; Banko, Lars; Ludwig, Alfred; Böke, Marc; Winter, Jörg; Bahre, Hendrik; Dahlmann, Rainer

    2017-11-01

    The properties of plasma-enhanced chemical vapour deposition (PECVD) coatings on polymer materials depend to some extent on the surface and material properties of the substrate. Here, isotactic polypropylene (PP) substrates are coated with silicon oxide (SiO x ) films. Plasmas for the deposition of SiO x are energetic and oxidative due to the high amount of oxygen in the gas mixture. Residual stress measurements using single Si cantilever stress sensors showed that these coatings contain high compressive stress. To investigate the influence of the plasma and the coatings, residual stress, silicon organic (SiOCH) coatings with different thicknesses between the PP and the SiO x coating are used as a means to protect the substrate from the oxidative SiO x coating process. Pull-off tests are performed to analyse differences in the adhesion of these coating systems. It could be shown that the adhesion of the PECVD coatings on PP depends on the coatings’ residual stress. In a PP/SiOCH/SiO x -multilayer system the residual stress can be significantly reduced by increasing the thickness of the SiOCH coating, resulting in enhanced adhesion.

  19. Influence of surface free energy of denture base and liner materials on Candida albicans biofilms.

    Science.gov (United States)

    da Silva, Wander J; Leal, Cristiane Maria B; Viu, Flávia C; Gonçalves, Letícia M; Barbosa, Célia Marisa R; Del Bel Cury, Altair A

    2015-05-01

    This study aimed to evaluate the influence of surface free energy (SFE) of denture base and liner materials on Candida albicans biofilm development. Discs were fabricated using poly(methyl methacrylate) acrylic resin and poly(ethyl methacrylate) denture liner, according to the manufacturers' instructions. For SFE test, discs were pellicle-coated with saliva alone, saliva + blood plasma, or blood plasma alone. Candida albicans biofilms were allowed to form on pellicle-coated discs for 48 h. Biofilms were evaluated for cell counts, metabolic activity, and structural characteristics at adhesion phase (after 1.5 h of development) and at biofilm maturity (after 48 h of development). Data were analyzed by anova and Tukey tests using a significance level of 5%. Saliva + blood plasma pellicles had a higher SFE compared to pellicles of saliva or blood plasma alone (P  0.05). In contrast, the presence of blood plasma resulted in higher cell counts, biovolume, and thickness of mature biofilms on both materials (P < 0.001). Increases in SFE from pellicle-coating leads to robust mature C. albicans biofilms on both denture materials. © 2014 Wiley Publishing Asia Pty Ltd.

  20. Characterization of surface dielectric barrier discharge influenced by intermediate frequency for ozone production

    International Nuclear Information System (INIS)

    Abdelaziz, Ayman A; Ishijima, Tatsuo; Seto, Takafumi; Otani, Yoshio; Osawa, Naoki; Wedaa, Hassan

    2016-01-01

    The aim of this study is to investigate the effect of the intermediate frequency (1–10 kHz) of the sinusoidal driving voltage on the characteristics of a developed surface dielectric barrier discharge (SDBD)-based reactor having spikes on its discharge electrode. Moreover, its influence on the production of ozone and nitrogen oxide byproducts is evaluated. The results show that SDBD is operated in the filamentary mode at all the frequencies. Nevertheless, the pulses of the discharge current at high frequencies are much denser and have higher amplitudes than those at low frequencies. The analysis of the power consumed in the reactor shows that a small portion of the input power is dissipated in the dielectric material of SDBD source, whereas the major part of the power is consumed in the plasma discharge. The results of the ozone production show that higher frequencies have a slightly adverse effect on the ozone production at relatively high energy density values, where the ozone concentration is slightly decreased when the frequency is increased at the same energy density. The temperature of the discharge channels and gas is not a crucial factor for the decomposition of ozone in this reactor, while the results of the measurements of nitrogen oxides characteristics indicate that the formation of NO and NO 2 has a significant adverse effect on the production efficiency of ozone due to their oxidation to another nitrogen oxides and their catalytic effect. (paper)

  1. Influence of steam generator surface state on corrosion and oxide formation

    International Nuclear Information System (INIS)

    Mazenc, Arnaud; Leclercq, Stephanie; Seyeux, Antoine; Galtayries, Anouk; Marcus, Philippe

    2012-09-01

    The corrosion and release of nickel-based alloy Steam Generator tubes are partly due to their surface state. Among the most important parameters influencing the corrosion, the effect of grain size and the effect of grain crystallographic orientation have been chosen to be studied. The aim of this study is to determine how these parameters have an impact on the corrosion of Steam Generator tubes. Thermal treatments (700 deg. C and 1050 deg. C) have been performed on several samples in Alloy 690 to obtain homogeneous grain sizes, varying from 25 μm to 110 μm. Two samples have been oxidised for four days in a recirculating autoclave, reproducing primary conditions. The changes of oxide composition and thickness were examined by ToF-SIMS on samples exposed to primary water conditions. The intensity profiles versus thicknesses of characteristic oxide anions, such as CrO - , NiO - or FeO - enable us to evaluate the effect of grain size and crystallographic orientation on the formation of an enriched inner chromium layer. As regards to the grain size, there was no effect on the growth, but smaller grains led to a chromium-rich oxide layer. The effect of crystallographic orientation was observed on the oxidation kinetics and the composition of oxide scales. (authors)

  2. Influence of Genetically Modified Human Umbilical Cord Blood Mononuclear Cells on the Expression of Schwann Cell Molecular Determinants in Spinal Cord Injury.

    Science.gov (United States)

    Galieva, L R; Mukhamedshina, Y O; Akhmetzyanova, E R; Gilazieva, Z E; Arkhipova, S S; Garanina, E E; Rizvanov, A A

    2018-01-01

    Spinal cord injury (SCI) unavoidably results in death of not only neurons but also glial cells. In particular, the death of oligodendrocytes leads to impaired nerve impulse conduction in intact axons. However, after SCI, the Schwann cells (SCs) are capable of migrating towards an area of injury and participating in the formation of functional myelin. In addition to SCI, cell-based therapy can influence the migration of SCs and the expression of their molecular determinants. In a number of cases, it can be explained by the ability of implanted cells to secrete neurotrophic factors (NTFs). Genetically modified stem and progenitor cells overexpressing NTFs have recently attracted special attention of researchers and are most promising for the purposes of regenerative medicine. Therefore, we have studied the effect of genetically modified human umbilical cord blood mononuclear cells on the expression of SC molecular determinants in SCI.

  3. Performance success or failure is influenced by weeks lost to injury and illness in elite Australian track and field athletes: A 5-year prospective study.

    Science.gov (United States)

    Raysmith, Benjamin P; Drew, Michael K

    2016-10-01

    To investigate the impact of training modification on achieving performance goals. Previous research demonstrates an inverse relationship between injury burden and success in team sports. It is unknown whether this relationship exists within individual sport such as athletics. A prospective, cohort study (n=33 International Track and Field Athletes; 76 athlete seasons) across five international competition seasons. Athlete training status was recorded weekly over a 5-year period. Over the 6-month preparation season, relationships between training weeks completed, the number of injury/illness events and the success or failure of a performance goal at major championships was investigated. Two-by-two table were constructed and attributable risks in the exposed (AFE) calculated. A mixed-model, logistic regression was used to determine the relationship between failure and burden per injury/illness. Receiver Operator Curve (ROC) analysis was performed to ascertain the optimal threshold of training week completion to maximise the chance of success. Likelihood of achieving a performance goal increased by 7-times in those that completed >80% of planned training weeks (AUC, 0.72; 95%CI 0.64-0.81). Training availability accounted for 86% of successful seasons (AFE=0.86, 95%CI, 0.46 to 0.96). The majority of new injuries occurred within the first month of the preparation season (30%) and most illnesses occurred within 2-months of the event (50%). For every modified training week the chance of success significantly reduced (OR=0.74, 95%CI 0.58 to 0.94). Injuries and illnesses, and their influence on training availability, during preparation are major determinants of an athlete's chance of performance goal success or failure at the international level. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  4. Influence of the surface drag coefficient (young waves) on the current structure of the Berre lagoon

    Science.gov (United States)

    Alekseenko, Elena; Roux, Bernard; Kharif, Christian; Sukhinov, Alexander; Kotarba, Richard; Fougere, Dominique; Chen, Paul Gang

    2013-04-01

    Due to the shallowness, currents and hydrodynamics of Berre lagoon (South of France) are closely conditioned by the bottom topography, and wind affects the entire water column, as for many other Mediterranean lagoons (Perez-Ruzafa, 2011). Wind stress, which is caused by moving atmospheric disturbance, is known to have a major influence in lagoon water circulation. According to the numerical simulation for the main directions of the wind: N-NW, S-SE and W (wind speed of 80 km/h) it is observed that the current is maximal alongshore in the wind direction; the bottom nearshore current being larger in shallower area. This fact is coherent with fundamental principle of wind-driven flows in closed or partially closed basins which states that in shallow water the dominant force balance is between surface wind stress and bottom friction, yielding a current in the direction of the wind (Mathieu et al, 2002, Hunter and Hearn, 1987; Hearn and Hunter,1990). A uniform wind stress applied at the surface of a basin of variable depth sets up a circulation pattern characterized by relatively strong barotropic coastal currents in the direction of the wind, with return flow occurring over the deeper regions (Csanady, 1967; Csanady, 1971). One of the key parameters characterizing the wind stress formulation is a surface drag coefficient (Cds). Thus, an effect of a surface drag coefficient, in the range 0.0016 - 0.0032, will be analyzed in this work. The value of surface drag coefficient Cds = 0.0016 used in our previous studies (Alekseenko et al., 2012), would correspond to mature waves (open sea). But, in the case of semi-closed lagoonal ecosystem, it would be more appropriate to consider "young waves" mechanism. A dependency of this coefficient in terms of the wind speed is given by Young (1999) in both cases of mature waves and young waves. For "young waves" generated at a wind speed of 80 km/h, Cds = 0.0032. So, the influence of Cds on the vertical profile of the velocity in the

  5. Influence of surface morphology and microstructure on performance of CVD tungsten coating under fusion transient thermal loads

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Youyun, E-mail: lianyy@swip.ac.cn [Southwestern Institute of Physics, Chengdu (China); Liu, Xiang; Wang, Jianbao; Feng, Fan [Southwestern Institute of Physics, Chengdu (China); Lv, Yanwei; Song, Jiupeng [China National R& D Center for Tungsten Technology, Xiamen Tungsten Co. Ltd, 361026 Xiamen (China); Chen, Jiming [Southwestern Institute of Physics, Chengdu (China)

    2016-12-30

    Highlights: • Thick CVD-W coatingswere deposited at a rapid growth rate. • The polished CVD-W coatings have highly textured structure and exhibited a very strong preferred orientation. • The polished CVD tungsten coatings show superior thermal shock resistance as compared with that of the as-deposited coatings. • The crack formation of the polished CVD-W was almost suppressed at an elevated temperature. - Abstract: Thick tungsten coatings have been deposited by chemical vapor deposition (CVD) at a rapid growth rate. A series of tungsten coatings with different thickness and surface morphology were prepared. The surface morphology, microstructure and preferred orientation of the CVD tungsten coatings were investigated. Thermal shock analyses were performed by using an electron beam facility to study the influence of the surface morphology and the microstructure on the thermal shock resistance of the CVD tungsten coatings. Repetitive (100 pulses) ELMs-like thermal shock loads were applied at various temperatures between room temperature and 600 °C with pulse duration of 1 ms and an absorbed power density of up to 1 GW/m{sup 2}. The results of the tests demonstrated that the specific surface morphology and columnar crystal structure of the CVD tungsten have significant influence on the surface cracking threshold and crack propagation of the materials. The CVD tungsten coatings with a polished surface show superior thermal shock resistance as compared with that of the as-deposited coatings with a rough surface.

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

    Science.gov (United States)

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

    2018-02-04

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

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

    Science.gov (United States)

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

    2018-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Guoxing Liang

    2018-02-01

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

  9. THE INFLUENCE OF SURFACE-FREE ENERGY ON SUPRAGINGIVAL AND SUBGINGIVAL PLAQUE MICROBIOLOGY - AN IN-VIVO STUDY ON IMPLANTS

    NARCIS (Netherlands)

    QUIRYNEN, M; VANDERMEI, HC; BOLLEN, CML; VANDENBOSSCHE, LH; DOORNBUSCH, GI; VANSTEENBERGHE, D; BUSSCHER, HJ

    THE INFLUENCE OF SURFACE FREE ENERGY on supra- and subgingival plaque microbiology was examined in 9 patients with functional fixed prostheses supported by endosseous titanium implants. Two abutments (trans-mucosal part of the 2 stage implant) were replaced by either a new titanium abutment or a

  10. The influence of surface versus free-air decoupling on temperature trend patterns in the western United States

    Science.gov (United States)

    N.C. Pepin; C. Daly; J. Lundquist

    2011-01-01

    We analyzed temperature trends from 460 GHCNv2 weather stations in the western United States for 1948¨C2006 to determine whether the extent of decoupling of surface temperatures from the free atmosphere influences past change. At each location we derived monthly indices representative of anticyclonicity using NCEP/NCAR 700 hPa reanalysis pressure fields. The number of...

  11. Influence of Plastic Deformation on Low Temperature Surface Hardening of Austenitic and Precipitation Hardening Stainless Steels by Gaseous Nitriding

    DEFF Research Database (Denmark)

    Bottoli, Federico; Winther, Grethe; Christiansen, Thomas Lundin

    2015-01-01

    This article addresses an investigation of the influence of plastic deformation on low temperature surface hardening by gaseous nitriding of three commercial austenitic stainless steels: AISI 304, EN 1.4369 and Sandvik Nanoflex® with various degrees of austenite stability. The materials were...

  12. The toxicity of plastic nanoparticles to green algae as influenced by surface modification, medium hardness and cellular adsorption

    NARCIS (Netherlands)

    Nolte, Tom M.; Hartmann, Nanna B.; Kleijn, Mieke; Garnæs, Jørgen; Meent, van de Dik; Jan Hendriks, A.; Baun, Anders

    2017-01-01

    To investigate processes possibly underlying accumulation and ecological effects of plastic nano-particles we have characterized their interaction with the cell wall of green algae. More specifically, we have investigated the influence of particle surface functionality and water hardness (Ca2+

  13. Conditions pertaining to the influence of electrode surface roughness upon the insulation strength of compressed SF6 systems

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson; Crichton, George C

    1997-01-01

    On the basis of a series of experimental investigations reported in the literature, electrode microscopic surface roughness was dismissed as a factor influencing breakdown levels in compressed SF6, irrespective of field non-uniformity. This conclusion appears to be tenable if one restricts observ...

  14. Decades-old silvicultural treatments influence surface wildfire severity and post-fire nitrogen availability in a ponderosa pine forest

    Science.gov (United States)

    Ann L. Lezberg; Michael A. Battaglia; Wayne D. Shepperd; Anna W. Schoettle

    2008-01-01

    Wildfire severity and subsequent ecological effects may be influenced by prior land management, via modification of forest structure and lingering changes in fuels. In 2002, the Hayman wildfire burned as a low to moderate-severity surface fire through a 21-year pine regeneration experiment with two overstory harvest cuttings (shelterwood, seed-tree) and two site...

  15. Assessing the influence of groundwater and land surface scheme in the modelling of land surface-atmosphere feedbacks over the FIFE area in Kansas, USA

    DEFF Research Database (Denmark)

    Larsen, Morten Andreas Dahl; Højmark Rasmussen, Søren; Drews, Martin

    2016-01-01

    by HIRHAM simulated precipitation. The last two simulations include iv) a standard HIRHAM simulation, and v) a fully coupled HIRHAM-MIKE SHE simulation locally replacing the land surface scheme by MIKE SHE for the FIFE area, while HIRHAM in standard configuration is used for the remaining model area......The land surface-atmosphere interaction is described differently in large scale surface schemes of regional climate models and small scale spatially distributed hydrological models. In particular, the hydrological models include the influence of shallow groundwater on evapotranspiration during dry...... experiments include five simulations. First MIKE SHE is forced by observed climate data in two versions i) with groundwater at a fixed uniform depth, and ii) with a dynamical groundwater component simulating shallow groundwater conditions in river valleys. iii) In a third simulation MIKE SHE is forced...

  16. Influence of cell surface appendages on the bacterium-substratum interface measured real-time using QCM-D.

    Science.gov (United States)

    Olsson, Adam L J; van der Mei, Henny C; Busscher, Henk J; Sharma, Prashant K

    2009-02-03

    Quartz crystal microbalance with dissipation (QCM-D) utilizes an oscillating quartz crystal to register adsorption of rigid masses through a decrease in its resonance frequency f. In addition, QCM-D has the ability to measure the dissipative nature of nonrigid masses adhering to the crystal surface in the form of oscillation amplitude decay time. Although QCM has been applied to register bacterial adhesion to the crystal surface, full interpretation of the frequency change and dissipation signal has hitherto been impossible due to the complex interactions within the distance of 250 nm between the substratum and the bacterial cell surface. Here, we study adhesion of a series of Streptococcus salivarius mutants, possessing various surface appendages of known lengths, as a function of time using QCM-D. In addition, the number of bacteria adhering to the crystal surface was determined. The results show that adhesion of a "bald" bacterium, completely devoid of surface appendages, is registered as a frequency decrease. Adhesion of bacteria possessing surface appendages yields either a much smaller decrease or an increase in frequency, despite the fact they adhere in higher numbers. Furthermore, the magnitude of frequency and dissipation shifts was found to be influenced by the distance at which the cell body was held from the sensor surface by its surface appendages.

  17. Uncontrolled methane emissions from a MSW landfill surface: influence of landfill features and side slopes.

    Science.gov (United States)

    Di Trapani, Daniele; Di Bella, Gaetano; Viviani, Gaspare

    2013-10-01

    Sanitary landfills for Municipal Solid Waste (MSW) disposal have been identified as one of the most important anthropogenic sources of methane (CH4) emissions; in order to minimize its negative effects on the environment, landfill gas (LFG) recovery is a suitable tool to control CH4 emissions from a landfill site; further, the measurement of CH4 emissions can represent a good way to evaluate the effectiveness of LFG recovering systems. In general, LFG will escape through any faults in the landfill capping or in the LFG collection system. Indeed, some areas of the capping can be more permeable than others (e.g. portions of a side slope), especially when considering a temporarily capped zone (covered area that is not expected to receive any further waste for a period of at least 3 months, but for engineering reasons does not have a permanent cap yet). These areas, which are characterized by abnormal emissions, are usually defined as "features": in particular, a feature is a small, discrete area or an installation where CH4 emissions significantly differ from the surrounding zones. In the present study, the influence that specific features have on CH4 emissions has been investigated, based on direct measurements carried out in different seasons by means of a flux chamber to the case study of Palermo (IT) landfill (Bellolampo). The results showed that the flux chamber method is reliable and easy to perform, and the contoured flux maps, obtained by processing the measured data were found to be a suitable tool for identifying areas with abnormal (high) emissions. Further, it was found that a relationship between methane emission rates and landfill side slope can be established. Concerning the influence of the temporary HDPE cover system on CH4 recovery efficiency, it contributed to a significant decrease of the free surface area available for uncontrolled emissions; this aspect, coupled to the increase of the CH4 volumes collected by the LFG recovery system, led to a

  18. Creep of MDF panels under constant load and cyclic environmental conditions. Influence of surface coating

    Directory of Open Access Journals (Sweden)

    Fernández-Golfín, J. I.

    1997-06-01

    Full Text Available Four different strategies of surface coating (based on 80 g m2 melamin impregnated papers were used on 19 mm thick commercial MDF panels to assess its reological behaviour under cyclic humidity conditions (20ºC 30 % rh-20ºC 90 % rh. Three different levels of stress (20 %, 30 % and 40 %, based on the ultimate load in bending, were used. Tests were conducted by means of the three points load system. For the same stress level, the relative creep of MDF panels was higher than that in particle boards with si