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Experimental Research (experimental + research)
Terms modified by Experimental Research Selected AbstractsExperimental Research and the Managerial Attitude: a tension to be resolved?EUROPEAN JOURNAL OF EDUCATION, Issue 3 2008MARTIN BENNINGHOFF This article analyses some typical consequences of a specific research policy on experimental research in biology. The policy is conducted by a national funding agency , the Swiss National Science Foundation , through a particular programme, the ,National Centres of Competence in Research' which is designed to promote both ,scientific excellence'and,managerial professionalism'. To study the possible tension between the two objectives, as a practical matter for researchers, the proposed analysis focuses on the interaction between two laboratory scientists and the administrators of a genomic platform. Access to the instruments of this platform is granted through a preliminary interview with those in charge of the platform. During that interview, researchers are required to explain why they want to use the platform services and what their expectations concerning their envisaged activities are. A tape-recorded interview is analysed in order to describe how turns at talking by the various parties, as well as the formulation of the problems encountered by a researcher, prove category-bound. The first part of the meeting (,problem exposition') is structured by the categorical device ,generalist researcher vs. specialist researcher', whilst the second part (,problem solving') is organised by the categorical device ,manager vs. user of the platform'. The ,scientific' problem becomes a ,technical' one and the choice of technique is partly based on financial reasons. The situation shows how managerial injunctions of research policy are not without practical consequences for research activities in situ. [source] Cautions and Concerns in Experimental Research on the Consumer InterestJOURNAL OF CONSUMER AFFAIRS, Issue 3 2008MARLA B. ROYNE Most published consumer research presents data from surveys or other data analyses that, at best, report that certain things tend to happen at the same time. However, correlation does not mean causation; cause and effect relationships can only be concluded from controlled experiments. A key problem is that the use of experimental designs calls for various conceptual and pragmatic trade-offs that cannot be ignored. [source] The Search for Mechanisms of Behavior Change in Evidence-Based Behavioral Treatments for Alcohol Use Disorders: OverviewALCOHOLISM, Issue 2007Robert B. Huebner Background:, Over the past three decades, the main question of interest to alcohol treatment researchers has concerned the main effects of a particular behavioral intervention or what works. Increasingly, alcohol treatment researchers are turning their attention to the underlying psychological, social, and even neurophysiologic processes or "active ingredients" that are driving therapeutic change. Method:, The articles contained in this supplement to Alcoholism: Clinical and Experimental Research grew out of invited presentations given at a one-day satellite session immediately preceding the 28th Annual Meeting of the Research Society on Alcoholism (RSA). The conference was a collaborative effort of the Center on Alcoholism, Substance Abuse, and Addiction at the University of New Mexico, the Center on Addiction and Substance Abuse at Columbia University, Brown University, and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health. Results:, The conference featured a mix of full-length presentations on conceptual and methodological issues, reports of original research findings, and lively discussion among speakers and conference participants. Understanding mechanisms of behavior change will benefit the field by identifying the key aspects of therapy that must be present for maximum effect, irrespective of the specific technique being applied; provide a new way to approach patient,treatment interactions; and lay the groundwork for understanding how change is affected by social and other extratreatment factors. Conclusions:, Although not a new topic to the field, understanding mechanisms of behavior change has begun to capture the interest of an increasing number of alcohol treatment researchers. Understanding behavior change is an exceedingly complex enterprise and innovative thinking and creative research designs will be required to advance the field. [source] The effect of jet array arrangement on the flow characteristics of the outlet hole in short confined channelsHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 1 2008Liu Haiyong Abstract This experimental study is part of the research program related to the aerodynamic characteristics of impingement in a confined channel. Experimental research on better understanding flow structure in confined channel with impingement cooling is rarely found in open literature. The main purposes of this project are (1) gaining greater insight into the structure of the impingement jet flow and flow in the outlet hole; (2) understanding the effect of impingement hole arrangement build up on the flow structure and aerodynamic parameters within holes and channels with different aspect ratios. The test models are two confined channels with three staggered circular jet holes, and a single large size outlet hole placed downstream of the jet plate. The structure parameters of these orifices are different. In this paper, detailed flow field in the outlet hole was measured with a straight five-hole probe, and the discharge coefficient of outlet holes with different aspect ratios was also studied in each channel. Experimental data shows that the jet arrangement has little influence on the flow behavior of the outlet hole when the aspect ratio of the passage was 1, but it played an important role on the discharge coefficient. Distinctively different flow patterns were found in two models with the aspect ratios of 3 and 5, while the variation of the discharge coefficient showed a slight influence on impingement hole arrangement. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(1): 20,28, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20188 [source] Experimental research of boiling heat transfer of smooth and screwed tubeHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 2 2007Maode Li Abstract In this paper, based on the analog theory of heat transfer research, we performed an analog experiment on boiling heat transfer in smooth tube and screwed tubes. These are widely used in the high pressure generator of lithium bromide absorption refrigeration. From the experimental research, we obtained a series of results on the boiling heat transfer of a single smooth tube and three screwed tubes. The working condition is near the zone of bubble boiling and the overheat wall temperature ranges from 2,7 °C, with a fluid medium of pure water and salt water solution. These results agreed well with the known results, and are significant for the practical design and application of a high pressure generator of lithium bromide absorption for refrigeration. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(2): 74,84, 2007; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/htj.20145 [source] Experimental research of pool boiling heat transfer in horizontal narrow spacesHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 5 2004Enshen Long Abstract Much progress has been made in high-performance electronic chips, the miniaturization of electronic circuits and other compact systems recently, which brings about a great demand for developing efficient heat removal techniques to accommodate these high heat fluxes. With this objective in mind, experiments were carried out on five kinds of test elements with distilled water and ethanol as working liquids. The test elements used in these experiments consisted of five parallel discs with diameters varying from 5 mm to 40 mm. The experiments were performed with the discs oriented horizontally and uniform heat fluxes applied at the bottom surfaces. The influence of narrow spacing, space size, working liquid property, and heat flux on boiling heat transfer performance in narrow spaces has been investigated. Experimental results showed that the boiling heat transfer coefficient of a narrow space was 3 to 6 times higher than that of pool boiling when the narrow space size and heat flux combine adequately, but the critical heat flux was lower than that of pool boiling. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(5): 307,315, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20017 [source] Experimental research and surgery: Why, how, and when?MICROSURGERY, Issue 4 2001Antonio Di Cataldo M.D. Experimental research faces two great problems: the significant reduction of public funding and the firm opposition of the public opinion. The law forbids the use of large animals, so that it is possible to use small animals only, which require microsurgical techniques. However, even a skillful surgeon does not know how to perform microsurgery and has to begin a long and tiring training to master techniques. We think that experimental surgery should play a role because it tests the validity and safety of new surgical techniques and allows special pathophysiological aspects to be studied. Furthermore experimental surgery could represent an essential stage in the training of young surgeons. We should find a balance between observance of the law and respect of the animals and, on the other hand, the role of experimental surgery because we should not forget that its most important aim is the improvement of the health of the humankind. La ricerca sperimentale presenta delle difficoltà che dipendono in gran parte dalla scarsezza dei fondi ad essa destinati e dalla latente ostilità dell'opinione pubblica. Le leggi hanno ormai praticamente abolito la possibilità di utilizzare animali di grossa taglia per cui si possono impiegare solo piccoli animali, con la necessità di ricorrere a tecniche microchirurgiche, che non sono patrimonio di tutti i chirurghi, per cui per acquisirle bisogna sottoporsi a lunghi ed estenuanti tirocinii. Noi riteniamo che alla chirurgia sperimentale debba essere riconosciuto un suo ruolo per le possibilità che essa fornisce di saggiare la validità di nuove tecniche chirurgiche, di studiare particolari aspetti di fisiopatologia e di consentire un adeguato training dei giovani chirurghi. Sarebbe forse più giusto trovare un migliore equilibrio tra l'osservanza delle leggi ed il rispetto degli animali da un lato e la giusta collocazione della chirurgia sperimentale dall'altro, non dimenticando che quest'ultima ha come scopo unico ed esclusivo il miglioramento della salute dell'uomo. © 2001 Wiley-Liss, Inc. MICROSURGERY 21:118,120 2001 [source] Experimental research on drag reduction by polymer additives in a turbulent pipe flowTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2002Shao Xueming Abstract In order to investigate the effects of injection position on drag reduction as well as further the effects of polymer additives on turbulent structures, LDA measurements of turbulent pipe flows were conducted. The results show that the amount of drag reduction grows with the increase of the Reynolds number, and injecting the polymer at the centre of pipe is more effective than at the wall. Due to the addition of polymer solution, the axial, radial r.m.s. velocity fluctuations and Reynolds stress decrease over the entire pipe cross-section, the time auto-correlation coefficients of axial and radial velocity fluctuation at the centre of pipe decay more slowly, the number of spectrum peaks is decreased, and the peak shifts towards lower wave numbers. The results also reveal that, due to the addition of polymer solution, the large-scale vortices are enhanced and small-scale vortices are suppressed. On a effectué des mesures par anémométrie laser Doppler d'écoulements turbulents dans des conduites afin d'étudier l'effet de la position de l'injection et l'effet de l'ajout d'additifs à base de polymères sur la réduction de traînée. Les résultats montrent que la réduction de traînée augmente avec le nombre de Reynolds et qu'il est plus efficace d'injecter le polymère au centre de la conduite qu'à la paroi. Du fait de l'ajout d'une solution de polymères, les fluctuations de vitesse efficace radiale et axiale et la contrainte de Reynolds diminuent sur toute la section transversale de la conduite, les coefficients d'auto-corrélation de temps de la fluctuation de vitesse efficace radiale et axiale au centre de la conduite décroissent plus lentement, le nombre de pics du spectre diminue et les pics tendent à avoir un nombre d'ondes moins grand. Les résultats montrent également que, grâce à l'ajout de la solution de polymères, les tourbillons de grande échelle sont plus nombreux tandis que les tourbillons de petite eéhelle disparaissent. [source] Structured review of enamel erosion literature (1980,1998): a critical appraisal of experimental, clinical and review publicationsORAL DISEASES, Issue 4 2000G. Maupome OBJECTIVE: To attain an objective account of the methods to measure enamel erosion used in 1980,1998 publications, a structured review of the literature was undertaken. METHODS: Inclusion and exclusion criteria were applied to 731 clinical/experimental research and review reportS. Eighty-five included papers were subsequently rated according to ,hierarchy of evidence' guidelines to assess the strength of the report's design and the relevance of the evidence to replicating enamel erosion in vivo in humanS. Scores were assigned to rate each aspect in the guidelines. RESULTS: A total of 16 clinical, 13 review and 56 experimental papers were assessed; 36.4% were published during 1996,1998.Excluding reviews, 16 papers were qualitative and 56 quantitative; 51 used human enamel. Our classification yielded nine groups of methods (five scoring systems and 26 measurement techniques).CTFPHE (Can Med Assoc J 1992; 147: 443) grading of research reports indicated that 2.8% provided evidence grade I; 20.8%, grade IIa; 63.9%, grade III; and 12.5%, grade IV. CONCLUSIONS: There has been a consistent increase in the body of knowledge. The overall quality of publications has not substantially changed over time. Experimental studies were more often quantitative, and quantitative studies had better research designS. No single group of research methods had obviously superior research designs. [source] Possible Environmental Factors Underlying Amphibian Decline in Eastern Puerto Rico: Analysis of U.S. Government Data ArchivesCONSERVATION BIOLOGY, Issue 4 2001Robert F. Stallard I examined changes in environmental conditions by examining time-series data sets that extend back at least into the 1980s, a period when frog populations were declining. The data include forest cover; annual mean, minimum, and maximum daily temperature; annual rainfall; rain and stream chemistry; and atmospheric-dust transport. I examined satellite imagery and air-chemistry samples from a single National Aeronautics and Space Administration aircraft flight across the Caribbean showing patches of pollutants, described as thin sheets or lenses, in the lower troposphere. The main source of these pollutants appeared to be fires from land clearing and deforestation, primarily in Africa. Some pollutant concentrations were high and, in the case of ozone, approached health limits set for urban air. Urban pollution impinging on Puerto Rico, dust generation from Africa ( potential soil pathogens), and tropical forest burning ( gaseous pollutants) have all increased during the last three decades, overlapping the timing of amphibian declines in eastern Puerto Rico. None of the data sets pointed directly to changes so extreme that they might be considered a direct lethal cause of amphibian declines in Puerto Rico. More experimental research is required to link any of these environmental factors to this problem. Resumen: Las pasadas tres décadas han visto grandes disminuciones poblacionales de especies de anfibios en altas elevaciones de Puerto Rico oriental, una región única en los trópicos húmedos debido al grado de monitoreo ambiental que se ha llevado a cabo mediante los esfuerzos de las agencias de gobierno de los Estados Unidos. Examiné los cambios en condiciones ambientales mediante el análisis de datos de series de tiempo que se extienden hasta los 1980s, un periodo en el que las poblaciones de ranas estaban declinando. Los datos incluyen cobertura forestal; temperatura diaria media, mínima y máxima anual; precipitación anual; química de la lluvia y arroyos; y el transporte atmosférico de polvo. Examiné imágenes de satélite y muestras de química del aire obtenidos de un solo vuelo de una nave de la NASA a lo largo del Caribe que mostraba parches de contaminantes descritas como capas delgadas de lentes en la inferior troposfera. La mayor fuente de contaminantes parece ser los incendios de tierras clareadas y la deforestación, principalmente en África. Algunas concentraciones de contaminantes fueron altas y en el caso del ozono, se aproximó a los límites de salud establecidos para aire urbano. La contaminación urbana afectando a Puerto Rico, la generación de polvo en África ( patógenos del suelo potenciales) y la quema de bosque tropical (contaminantes gaseosos) han incrementado durante las últimas tres décadas, superponiéndose con el periodo en que oturrieron las disminuciones de anfibios en Puerto Rico oriental. Ninguno de estos conjuntos de datos señaló directamente hacia cambios tan extremos que debieran ser considerados como una causa letal directa de las disminuciones en Puerto Rico. Se requiere de más investigación experimental que vincule a estos factores ambientales con este problema. [source] Audit Review: Managers' Interpersonal Expectations and Conduct of the Review,CONTEMPORARY ACCOUNTING RESEARCH, Issue 3 2002Michael Gibbins Abstract This paper presents an interpersonal model of audit file review centered on the audit manager. A manager's conduct of the review is affected by four components: the manager's expectations about the client, expectations about the preparer, expectations about the partner, and the manager's own approach and circumstances. The paper then presents a comprehensive field-based analysis of how a working paper review is conducted. It supplements the mostly experimental research on working paper review by reporting the results of a retrospective field questionnaire that asked audit managers to report on their behavior and their relationships with preparers and partners on actual audit engagements. The extent of review was sensitive to specific features of the client and the file (including risk factors), to features of the preparer, and particularly to the style of the reviewer, which was quite stable across cases. Although the evidence of managers' awareness of preparers' "stylizing" the file to suit the manager was weak, the evidence of managers' stylizing for the partners was pervasive, affecting both work done and documentation. Managers believed that good reviews emphasized key issues and risks rather than detail. Other new descriptive evidence on the nature of the review process is provided, including the purpose of the review process, how frequently surprises are found in the review process, and the qualities of good reviewers compared with poor reviewers. The implications of our model and our results for future research are outlined. [source] Cardiovascular disease prevalence and risk factors of persons with mental retardationDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 1 2006Christopher C. Draheim Abstract This paper reviews the recent literature on cardiovascular disease (CVD) prevalence, CVD-related mortality, physiological CVD risk factors, and behavioral CVD risk factors in adults with mental retardation (MR). The literature on the potential influences of modifiable behavioral CVD risk factors and the physiological CVD risk factors are also reviewed. Adults with mild to moderate MR residing in community settings appear to have an elevated disease prevalence, elevated CVD-related mortality, more adverse physiological CVD risk factors, and elevated behavioral risk compared to others with and without MR. Preliminary evidence supports the benefits of participating in the recommended physical activity levels and consuming the recommended diets to reduce the risk for CVD. The lack of large-scale longitudinal or experimental research indicates a gap in the research. The development of research-based, appropriate, primary prevention programs and intervention strategies aimed at lowering the risk for CVD is highly recommended. Programs should focus on educating individuals with MR along with direct care providers and family members on the importance of appropriate dietary concepts, physical activity habits, and regular health screenings by physicians. Programs should be individualized to regional and cultural issues. MRDD Research Reviews 2006;12:3,12. © 2006 Wiley-Liss, Inc. [source] Single cause, polymorphic neuronal migration disorders: an animal modelDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 10 2000Glenn D Rosen PhD Injury to the developing cortical plate can result in a variety of neuronal migration disorders. The results are reported of experimental research aimed at determining whether these different types of neocortical malformations are the consequence of comparable injury of varying intensity. Freezing probes were placed on the skulls of 44 newborn rats (age equivalent to 4 to 5 months of gestation in humans) and induced either one or two freezing injuries of durations ranging from 2 to 20 seconds. A variety of cortical malformations including minor laminar dysplasias, molecular layer ectopias, microgyria, and porencephalic cysts were seen in the brains of these animals when they were examined on postnatal day (P)2, P21, and P60. The severity of the malformation was directly related to the strength (number of hits and duration) of the freezing injury. These results suggest that a single etiologic event of varying severity during neuronal migration to the neocortex can induce widely disparate malformations of the cortex. [source] Experimental Research and the Managerial Attitude: a tension to be resolved?EUROPEAN JOURNAL OF EDUCATION, Issue 3 2008MARTIN BENNINGHOFF This article analyses some typical consequences of a specific research policy on experimental research in biology. The policy is conducted by a national funding agency , the Swiss National Science Foundation , through a particular programme, the ,National Centres of Competence in Research' which is designed to promote both ,scientific excellence'and,managerial professionalism'. To study the possible tension between the two objectives, as a practical matter for researchers, the proposed analysis focuses on the interaction between two laboratory scientists and the administrators of a genomic platform. Access to the instruments of this platform is granted through a preliminary interview with those in charge of the platform. During that interview, researchers are required to explain why they want to use the platform services and what their expectations concerning their envisaged activities are. A tape-recorded interview is analysed in order to describe how turns at talking by the various parties, as well as the formulation of the problems encountered by a researcher, prove category-bound. The first part of the meeting (,problem exposition') is structured by the categorical device ,generalist researcher vs. specialist researcher', whilst the second part (,problem solving') is organised by the categorical device ,manager vs. user of the platform'. The ,scientific' problem becomes a ,technical' one and the choice of technique is partly based on financial reasons. The situation shows how managerial injunctions of research policy are not without practical consequences for research activities in situ. [source] Is high strength concrete more susceptible to explosive spalling than normal strength concrete in fire?FIRE AND MATERIALS, Issue 3 2002Faris Ali There is a belief, within the fire research community, that high strength concrete is more susceptible to explosive spalling than normal strength concrete. This impression is based on studying concrete properties and collecting experimental data from different research sources. But there are still doubts about the credibility of this conjecture due to the lack of integrated experimental research, particularly designed to address this issue. This paper represents the outcomes of experimental study involving normal and high strength concrete columns tested under fire. The columns were subjected to a constant load and to different values of axial restraint. The paper attempts to address the question of the susceptibility of normal and high strength concrete to explosive spalling under fire. Copyright © 2002 John Wiley & Sons, Ltd. [source] Responses of jawbone to pressure,GERODONTOLOGY, Issue 2 2004Gunnar E. Carlsson Objective:, To provide a literature review of bone resorption of edentulous jaws focusing on responses to pressure. Background:, After the extraction of all teeth in a jaw there is a continuous reduction of the residual ridge. The individual variation of bone resorption is great, and the aetiology is complex and not yet well understood. Materials and methods:, A search of the literature published up to May 2003 on bone resorption and pressure was performed using PubMed/Medline. Results:, Animal studies have demonstrated that excessive and constant pressure induces bone resorption. Recent experimental research has indicated that bone resorption is a pressure-regulated phenomenon with a lower threshold for continuous than for intermittent pressure. Clinical studies have suggested that residual ridge resorption is due more to the effects of denture wearing than to disuse atrophy. However, the results of leaving out dentures at night are not conclusive. Nor does the literature offer any strong evidence for the so-called combination syndrome, which has been described as a result of unfavourable loading. Clinical studies using multivariate analyses indicate that female gender and systemic factors may be of greater importance than oral and denture factors. Implant-supported prostheses have a bone preserving effect rather than the continuing resorption under complete dentures. Conclusions:, The best way to reduce bone resorption is to avoid total extraction, preserve a few teeth and fabricate overdentures. In edentulous jaws, placement of implant-supported prostheses will lead to less bone loss and may even promote bone growth. To increase our knowledge of residual ridge resorption extended experimental, clinical and statistical methods will be needed, preferably including collaboration between dental and medical researchers. [source] Modeled interactive effects of precipitation, temperature, and [CO2] on ecosystem carbon and water dynamics in different climatic zonesGLOBAL CHANGE BIOLOGY, Issue 9 2008YIQI LUO Abstract Interactive effects of multiple global change factors on ecosystem processes are complex. It is relatively expensive to explore those interactions in manipulative experiments. We conducted a modeling analysis to identify potentially important interactions and to stimulate hypothesis formulation for experimental research. Four models were used to quantify interactive effects of climate warming (T), altered precipitation amounts [doubled (DP) and halved (HP)] and seasonality (SP, moving precipitation in July and August to January and February to create summer drought), and elevated [CO2] (C) on net primary production (NPP), heterotrophic respiration (Rh), net ecosystem production (NEP), transpiration, and runoff. We examined those responses in seven ecosystems, including forests, grasslands, and heathlands in different climate zones. The modeling analysis showed that none of the three-way interactions among T, C, and altered precipitation was substantial for either carbon or water processes, nor consistent among the seven ecosystems. However, two-way interactive effects on NPP, Rh, and NEP were generally positive (i.e. amplification of one factor's effect by the other factor) between T and C or between T and DP. A negative interaction (i.e. depression of one factor's effect by the other factor) occurred for simulated NPP between T and HP. The interactive effects on runoff were positive between T and HP. Four pairs of two-way interactive effects on plant transpiration were positive and two pairs negative. In addition, wet sites generally had smaller relative changes in NPP, Rh, runoff, and transpiration but larger absolute changes in NEP than dry sites in response to the treatments. The modeling results suggest new hypotheses to be tested in multifactor global change experiments. Likewise, more experimental evidence is needed for the further improvement of ecosystem models in order to adequately simulate complex interactive processes. [source] Experimental research of boiling heat transfer of smooth and screwed tubeHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 2 2007Maode Li Abstract In this paper, based on the analog theory of heat transfer research, we performed an analog experiment on boiling heat transfer in smooth tube and screwed tubes. These are widely used in the high pressure generator of lithium bromide absorption refrigeration. From the experimental research, we obtained a series of results on the boiling heat transfer of a single smooth tube and three screwed tubes. The working condition is near the zone of bubble boiling and the overheat wall temperature ranges from 2,7 °C, with a fluid medium of pure water and salt water solution. These results agreed well with the known results, and are significant for the practical design and application of a high pressure generator of lithium bromide absorption for refrigeration. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(2): 74,84, 2007; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/htj.20145 [source] Study on constant stress: Accelerated life tests of fouling thermal resistanceHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 2 2006Yang Shan-rang Abstract To shorten the time of fouling tests, fouling life was defined. The statistical analysis method for type II-censored exponential life data under constant-stress accelerated life testing models and the accelerated coefficients a and b were obtained. By using an accelerated model, the estimators of the fouling life under usual stress could be obtained. A computing example was given. Results indicated that it is credible and feasible to perform accelerated life tests of asymptotic fouling thermal resistance, and will be of important value to experimental research of fouling. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(2): 110,114, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20105 [source] The Experimental Appraisal Instrument: A brief overviewHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 3 2008Ash M. Genaidy Background Recently, there has been a great influx in experimental research to assess the health effects of nanoparticles/materials/fibers. Currently, there is no structured methodology to assess the methodological quality of the reported studies. Objective This article reports an experimental appraisal instrument with the goal to critically assess experimental studies. Methods A search of electronic databases was conducted to examine prior work on the subject and to extract the components of such an instrument. Results The electronic search revealed no major instrument designed to evaluate experimental strategies on health effects of nanoparticles/materials/fibers. An experimental appraisal instrument was developed and was patterned after the Epidemiological Appraisal Instrument reported by Genaidy and LeMasters (2006). Conclusions The validity and reliability of such an instrument will be reported in future work. © 2008 Wiley Periodicals, Inc. [source] Human reliability: A key to improved quality in manufacturingHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 4 2005Heiner Bubb For one to learn, one must make mistakes. Human error can be defined on the basis of the definition of quality. Because quality is influenced by human actions, the so-called performance shaping factors have an important influence on the human error probability. Different methods have been developed to predict human error probability. One of the most established and detailed methods is THERP (technique for human error rate prediction), which was originally developed for application in the nuclear power industry. Here this method is applied to a simple example of manufacturing. Further experimental research in the area of commission will be reported, where methods of error prediction were also applied. In both cases, measures of improving human reliability can be derived. © 2005 Wiley Periodicals, Inc. Hum Factors Man 15: 353,368, 2005. [source] Clinical networks for nursing researchINTERNATIONAL NURSING REVIEW, Issue 3 2002W. P. Gillibrand MS c Abstract As a central feature of national research and development strategies, clinical effectiveness emphasizes the importance of rigorous experimental research in nursing. It is naïve to assume that over-worked practitioners, with little research training and supervision, can undertake this type of research. Traditional approaches to research support rely on the practitioner registering for a higher degree and academic supervision. This assumes that the responsibility for research lies with practice, with higher education adopting a reactive stance in supporting research and development in nursing. The literature demonstrates a growing number of innovative models for facilitating nursing research. These, however, tend to focus on single appointments with limited and predefined access to clinical areas and patient populations. This article details a new initiative from the Clinical Nursing Practice Research Unit (CNPRU) that aims to support programmatic research in nursing practice through Clinical Networks for Nursing Research. Our research strategy is to contribute to the development of nursing science by facilitating effective collaboration between clinicians and higher education in core clinical specialties, including stroke rehabilitation, diabetes, mental health and community nursing. Each researcher has developed networks with a number of clinical areas, locally, regionally or nationally, through seminars, conferences or newsletters, to link practitioners and generate answerable research questions. Network communications also rely heavily on the establishment of interactive websites. This strategy has resulted in a number of collaborative, evaluative studies including clinical trials in rehabilitation, diabetic nursing and primary care. [source] Clouds make nerds look good: field evidence of the impact of incidental factors on decision makingJOURNAL OF BEHAVIORAL DECISION MAKING, Issue 2 2007Uri SimonsohnArticle first published online: 9 OCT 200 Abstract Abundant experimental research has documented that incidental primes and emotions are capable of influencing people's judgments and choices. This paper examines whether the influence of such incidental factors is large enough to be observable in the field, by analyzing 682 actual university admission decisions. As predicted, applicants' academic attributes are weighted more heavily on cloudier days and non-academic attributes on sunnier days. The documented effects are of both statistical and practical significance: changes in cloud cover can increase a candidate's predicted probability of admission by an average of up to 11.9%. These results also shed light on the causes behind the long demonstrated unreliability of experts making repeated judgments from the same data. Copyright © 2006 John Wiley & Sons, Ltd. [source] TNO's work on intensification: practical examples,JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2-3 2003Jan I Walpot Abstract TNO, a Dutch organisation for contract research, is and has been involved in numerous process intensification projects in close collaboration with national and international process industries. TNO has different facilities available to fulfil the demands of intensification projects. Depending on the focus of a project, a multidisciplinary team conducts experimental research, feasibility studies, process modelling, process design, pilot research and/or E-evaluations (economics, environment, energy). In this conference paper practical cases are described concerning novel processing techniques as well as novel reactors. © 2003 Society of Chemical Industry [source] Experiments in Environmental Economics and Some Close RelativesJOURNAL OF ECONOMIC SURVEYS, Issue 3 2006Bodo Sturm Abstract., It is not only the great number of papers written on environment economics that make it worth dealing with this special branch of experimental research, but the environmental problem in all its facets seems to serve as a catalyst for identifying some methodological problems of the experimental method. For this reason, we will not only try to give an overview of recent experiments in environmental economics but also add some thoughts on the methodological implications of this work. We identify three direct connecting factors for the experimental method and environmental economics. First, social dilemmas are, in many cases, at the core of environmental problems. Experiments are able to test theoretical hypotheses for individual behavior in such social dilemma situations. The second connecting factor comes from the field of applied experimental work and can be characterized as the testbedding of institutional arrangements for the solution of environmental problems. The last direct application of experimental methods to environmental economics concerns the individual evaluation of environmental resources. [source] Paradigm Shift for the Alcohol Breath TestJOURNAL OF FORENSIC SCIENCES, Issue 2 2010Michael P. Hlastala Ph.D. Abstract:, The alcohol breath test (ABT) has been used for quantification of ethyl alcohol in individuals suspected of driving under the influence for more than 50 years. In this time, there has been little change in the concepts underlying this single breath test. The old model, which assumes that end-exhaled breath alcohol concentration is closely related to alveolar air alcohol concentration, is no longer acceptable. This paper reviews experimental research and mathematical modeling which has evaluated the pulmonary exchange processes for ethyl alcohol. Studies have shown that alcohol exchanges dynamically with the airway tissue both during inspiration and expiration. The airway tissue interaction makes it impossible to deliver air with alveolar alcohol concentration to the mouth. It is concluded that the ABT is dependent on physiological factors that need to be assessed for accurate testing. [source] Basal replication of hepatitis C virus in nude mice harboring human tumorJOURNAL OF MEDICAL VIROLOGY, Issue 3 2002Patrick Labonté Abstract Hepatitis C virus (HCV) can infect and propagate in humans and chimpanzees. Whereas the chimpanzee has been used as an animal model for infection, ethical considerations, conservation, and the prohibitively high cost preclude progress for experimental research on the biology of the virus. The development of a small animal model for HCV infection is thus desirable to facilitate studies on the infectious cycle of the virus and for the evaluation of drugs for the treatment of HCV infections in humans. As an alternative to the chimpanzee model, we have established a model based on ex vivo infection of orthotopically-implanted human hepatocellular carcinoma cells (HCC) in athymic nude mice. The results show that up to 42 days post-infection, HCV RNA was present in the tumor cells as well as in the liver and serum of infected mice. Furthermore, a direct correlation between size of the tumor and the presence of HCV RNA in the liver was observed, which is concordant with the finding that HCV RNA was detectable only in mice harboring human tumor. Immunohistochemistry analysis of infected liver specimens showed cells expressing the HCV encoded NS5B protein. A few mice developed a humoral response against the nonstructural viral proteins, providing further evidence for expression of these proteins during viral infection. In summary, these results suggest that mice harboring orthotopic tumors support a basal level of HCV replication in vivo. J. Med. Virol. 66:312-319, 2002. © 2002 Wiley-Liss, Inc. [source] Teaching science problem solving: An overview of experimental workJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 4 2001R. Taconis The traditional approach to teaching science problem solving is having the students work individually on a large number of problems. This approach has long been overtaken by research suggesting and testing other methods, which are expected to be more effective. To get an overview of the characteristics of good and innovative problem-solving teaching strategies, we performed an analysis of a number of articles published between 1985 and 1995 in high-standard international journals, describing experimental research into the effectiveness of a wide variety of teaching strategies for science problem solving. To characterize the teaching strategies found, we used a model of the capacities needed for effective science problem solving, composed of a knowledge base and a skills base. The relations between the cognitive capacities required by the experimental or control treatments and those of the model were specified and used as independent variables. Other independent variables were learning conditions such as feedback and group work. As a dependent variable we used standardized learning effects. We identified 22 articles describing 40 experiments that met the standards we deemed necessary for a meta-analysis. These experiments were analyzed both with quantitative (correlational) methods and with a systematic qualitative method. A few of the independent variables were found to characterize effective strategies for teaching science problem solving. Effective treatments all gave attention to the structure and function (the schemata) of the knowledge base, whereas attention to knowledge of strategy and the practice of problem solving turned out to have little effect. As for learning conditions, both providing the learners with guidelines and criteria they can use in judging their own problem-solving process and products, and providing immediate feedback to them were found to be important prerequisites for the acquisition of problem-solving skills. Group work did not lead to positive effects unless combined with other variables, such as guidelines and feedback. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 442,468, 2001 [source] Phosphorus and phosphate metabolism in veterinary patientsJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 2 2007Diana M. Schropp DVM Abstract Objective: To review phosphorus and phosphate metabolism and the importance of phosphate abnormalities in veterinary patients. Data sources: A review of recent human and veterinary medical literature. Human data synthesis: There is a significant amount of original research on human patients with phosphate abnormalities. Hypophosphatemia has been studied in patients with diabetic ketoacidosis (DKA), head trauma, refeeding syndrome, hypothermia and in ventilator patients that fail to wean. Hyperphosphatemia has been studied in patients with renal failure and malignancy. Phosphate levels have also been evaluated for prognostic value in sepsis and acute liver failure. Veterinary data synthesis: Although animal models were used in early experimental research, fewer studies have been published on the effects of phosphate abnormalities in veterinary patients. Hypophosphatemia has been studied in animals with DKA, with refeeding syndrome and with hyperparathyroidism. Hyperphosphatemia has been studied in animals with renal failure and with secondary hypoparathyroidism. Conclusion: Phosphorus and phosphate are important in many biological functions. This paper is a review of their role in normal metabolism and the clinical importance of phosphate imbalances for our emergency and critical care patients. [source] Tissue engineering of peripheral nerves: Epineurial grafts with application of cultured Schwann cellsMICROSURGERY, Issue 1 2003H. Fansa M.D., Ph.D. After a simple nerve lesion, primary microsurgical suture is the treatment of choice. A nerve gap has to be bridged, with a nerve graft sacrificing a functioning nerve. Alternatively, tissue engineering of nerve grafts has become a subject of experimental research. It is evident that nerve regeneration requires not only an autologous, allogenous, or biodegradable scaffold, but additional interactions with regeneration-promoting Schwann cells. In this study, we compared epineurial and acellularized epineurial tubes with and without application of cultured Schwann cells as alternative grafts in a rat sciatic nerve model. Autologous nerve grafts served as controls. Evaluation was performed after 6 weeks; afterwards, sections of the graft and distal nerve were harvested for histological and morphometrical analysis. Compared to controls, all groups showed a significantly lower number of axons, less well-shaped remyelinizated axons, and a delay in clinical recovery (e.g., toe spread). The presented technique with application of Schwann cells into epineurial tubes did not offer any major advantages for nerve regeneration. Thus, in this applied model, neither the implantation of untreated nor the implantation of acellularized epineurial tubes with cultured Schwann cells to bridge nerve defects was capable of presenting a serious alternative to the present gold standard of conventional nerve grafts for bridging nerve defects in this model. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:72,77 2003 [source] | ||||||||||||||||||||||||||||