Construction and experimental study of an elevation linear Fresnel reflector

This paper outlines a novel elevation linear Fresnel reflector (ELFR) and presents and validates theoretical models defining its thermal performance. To validate the models, a series of experiments were carried out for receiver temperatures in the range of 30-100 °C to measure the heat loss coefficient, gain in heat transfer fluid (HTF) temperature, thermal efficiency, and stagnation temperature. The heat loss coefficient was underestimated due to the model exclusion of collector end heat losses. The measured HTF temperature gains were found to have a good correlation to the model predictions - less than a 5% difference. In comparison to model predictions for the thermal efficiency and stagnation temperature, measured values had a difference of -39% to +31% and 22-38%, respectively. The difference between the measured and predicted values was attributed to the low-temperature region for the experiments. It was concluded that the theoretical models are suitable for examining linear Fresnel reflector (LFR) systems and can be adopted by other researchers.

Simulation and experimental analysis of a brushless electrically excited synchronous machine with a hybrid rotor

Electrically excited synchronous machines with brushes and slip rings are popular but hardly used in inflammable and explosive environments. This paper proposes a new brushless electrically excited synchronous motor with a hybrid rotor. It eliminates the use of brushes and slip rings so as to improve the reliability and cost-effectiveness of the traction drive. The proposed motor is characterized with two sets of stator windings with two different pole numbers to provide excitation and drive torque independently. This paper introduces the structure and operating principle of the machine, followed by the analysis of the air-gap magnetic field using the finite-element method. The influence of the excitation winding's pole number on the coupling capability is studied and the operating characteristics of the machine are simulated. These are further examined by the experimental tests on a 16 kW prototype motor. The machine is proved to have good static and dynamic performance, which meets the stringent requirements for traction applications.

Theoretical and experimental analysis of excessively tilted fiber gratings

We have theoretically and experimentally investigated the dual-peak feature of tilted fiber gratings with excessively tilted structure (named as Ex-TFGs). We have explained the dual-peak feature by solving eigenvalue equations for TM0m and TE0m of a circular waveguide, in which the TE (transverse electric) and TM (transverse magnetic) core modes are coupled into TE and TM cladding modes, respectively. Meanwhile, in the experiment, we have verified that one of the dual peaks at the shorter wavelength is due to the TM mode coupling whereas the other one at the longer wavelength arises from TE mode coupling when a linearly polarized light launched into the Ex-TFG. We have also investigated the peak separation of TE and TM cladding mode for different surrounding medium refractive indexes (SRI), revealed that the dual peaks separation is decreasing as increasing of SRI, which agrees very well with the theoretical analysis results.

Kameralizmus, történelmi iskola, osztrák gazdaságtan. Három vázlat a német és osztrák közgazdasági diskurzus történetéből (Cameralism, the historical school and Austrian economics. Three outlines from the history of German and Austrian economic debate)

A kameralizmus a 16-18. századi német gyakorlati államtudomány és egyetemi tantárgy volt, amely összefoglalta a hivatalnokok képzéséhez szükséges elméleti és gyakorlati gazdasági ismereteket. Felfogása szerint az alattvalók jóléte és boldogsága feltétele az uralkodó gazdagságának, de az alattvalók önmaguktól nem képesek utat találni ehhez a boldogsághoz, szükség van az állandó külső irányításra. Igazgatásközpontúsága és egyetemi intézményesülése miatt nem tekinthető a merkantilizmus helyi változatának. Az 1840 és 1945 közötti német történeti iskola hagyományos ábrázolása több mint egy évszázadon át a német és a neoklasszikus tradíció szembenállását hangsúlyozta, kiemelve az organicizmus, a fejlődésgondolat és az egyediség jelentőségét, a szociális kérdés fontosságát, illetve a deduktív módszer és a gazdaság változatlan törvényeinek tagadását. A modern rekonstrukciók a történeti iskolát a posztklasszikus válságra adott egyik európai válaszként fogják fel, amely a történelemből levont, empirikusan megalapozott induktív alternatívát kínált. Az 1871-től kialakult osztrák iskola a neoklasszikus paradigmának egyszerre volt alkotórésze és versenytársa. A módszertani individualizmus, a szubjektivizmus, az idő fontossága, a tudás szerepe, az alternatív költségek elmélete stb. ugyan beépültek a mainstream közgazdaságtanba, de hangsúlyos kiemelésük lehetővé tette, hogy a társadalomelméleti magyarázat igényét őrző osztrák iskola megtartson valamit önálló beszédmódjából. / === / Cameralism was a practical political science and university subject in 16th–18th century Germany, summarizing the theoretical and practical economic knowledge required in the training of officials. The assumption was that the prosperity of the ruler depended on the welfare and happiness of the subjects, but the subjects themselves were not capable of achieving this happiness without permanent directions from above. Cameralism’s emphasis on administration and university institutionalization means that this approach cannot be seen as a local variant of mercantilism. The traditional account of the German historical school from 1840 to 1945 emphasized for over a century the contrast between the German and the Neoclassical traditions. It underlined the significance of the organic approach, the concept of development and individuality, the importance of the social question, and the denial of the deductive method and unalterable laws of the economy. Modern reconstructions see the historical school as one European response to the post-Classical crisis, offering an inductive alternative grounded empirically on history. The Austrian school formed in 1871 was at once a constituent of the Neoclassical paradigm and a rival to it. Methodological individualism, subjectivism, the importance of time, the role of knowledge, the theory of alternative costs etc. were absorbed into mainstream economics, but the focusing on these issues allowed the Austrian school, in keeping alive its demand for a social-theoretical explanation, to preserve something of an alternative discourse.

A gazdaságpolitikai döntéshozatal nemzetek fölötti centralizációja és a közösségi gazdaságtan. Az adóverseny elméletének néhány tanulsága (Supranational centralization of economic policy-making and community economics: some lessons from the theory of tax competition)

Mennyiben képes jelenleg a közösségi gazdaságtan az adópolitikák nemzetek fölötti centralizációjára vonatkozó politikai döntések megalapozására? Válaszunk röviden az lesz, hogy a közösségi gazdaságtan főárama - noha számos releváns gazdasági és politikai tényező hatását sikeresen elemzi - jelenleg nem kínál kielégítőnek tekinthető döntési kritériumokat a döntéshozók számára. Ennek oka, hogy központi szerepet játszik benne egy, a modellek szempontjából exogén és a közgazdasági elmélettől idegen tényező: a kormányzatok jóindulatára, pontosabban annak mértékére vonatkozó premissza. Tanulmányunk az adóverseny fiskális föderalista elméletét vizsgálja, és megpróbál általánosabb szinten is a közszektor gazdaságelméletének jelenlegi állapotára, valamint továbbfejlesztésére vonatkozó tanulságokat levonni. A kiutat az elméleti zsákutcából a kormányzati működés és döntéshozatal, valamint a kívánatos gazdaságpolitikai döntések elméletének összekapcsolása jelentheti. Erre megtörténtek az első kísérletek, de a szisztematikus és átfogó elemzés egyelőre várat magára. / === / How far can community economics provide a basis for political decision-making on supranational centralization of taxation policies? The short answer here will be that although the mainstream of community economics succeeds in analysing many relevant economic and political factors, it fails at present to provide satisfactory criteria for decisionmakers. This is because a central role is played in it by a factor exogenous to the models and alien to economic theory: the premise of the measure of goodwill from governments. The study examines the fiscal federalist theory of tax competition. It tries to draw conclusions, on a more general level, about the present state of the economic theory of the public sector and future development of it. The way out of the theoretical blind alley could be to link the theories of government operation and decision-making and of desirable economic-policy decision-making. The first attempts to do so have been made, but a systematic and comprehensive analysis is still awaited.

Gender differences in behavioral and psychosocial correlates of substance abuse among adolescents in residential treatment

This dissertation reports the results of a study that examined differences between genders in a sample of adolescents from a residential substance abuse treatment facility. The sample included 72 males and 65 females, ages 12 through 17. The data were archival, having been originally collected for a study of elopement from treatment. The current study included 23 variables. The variables were from multiple dimensions, including socioeconomic, legal, school, family, substance abuse, psychological, social support, and treatment histories. Collectively, they provided information about problem behaviors and psychosocial problems that are correlates of adolescent substance abuse. The study hypothesized that these problem behaviors and psychosocial problems exist in different patterns and combinations between genders.^ Further, it expected that these patterns and combinations would constitute profiles important for treatment. K-means cluster analysis identified differential profiles between genders in all three areas: problem behaviors, psychosocial problems, and treatment profiles. In the dimension of problem behaviors, the predominantly female group was characterized as suicidal and destructive, while the predominantly male group was identified as aggressive and low achieving. In the dimension of psychosocial problems, the predominantly female group was characterized as abused depressives, while the male group was identified as asocial, low problem severity. A third group, neither predominantly female or male, was characterized as social, high problem severity. When these dimensions were combined to form treatment profiles, the predominantly female group was characterized as abused, self-harmful, and social, and the male group was identified as aggressive, destructive, low achieving, and asocial. Finally, logistic regression and discriminant analysis were used to determine whether a history of sexual and physical abuse impacted problem behavior differentially between genders. Sexual abuse had a substantially greater influence in producing self-mutilating and suicidal behavior among females than among males. Additionally, a model including sexual abuse, physical abuse, low family support, and low support from friends showed a moderate capacity to predict unusual harmful behavior (fire-starting and cruelty to animals) among males. Implications for social work practice, social work research, and systems science are discussed. ^

Short and long hydroperiod Everglades periphyton mats: Community characterization and experimental hydroperiod manipulation

Hydroperiod, or the distribution, duration and timing of flooding affects both plant and animal distributions. The Florida Everglades is currently undergoing restoration that will result in altered hydroperiods. This study was conducted in Everglades National Park to document the variability in periphyton community structure and function between long and short hydroperiod Everglades marshes. Periphyton is an important primary producer and important food resource in the Everglades. Periphyton is also involved in marl soil formation and nutrient cycling. Although periphyton is an important component of the Everglades landscape, little is known about periphyton structural-functional variation between hydroperiods. ^ For this study diatoms, as well as fresh algae slides of diatoms, cyanobacteria and green algae were identified and enumerated. Short verse long hydroperiod soil and water column nutrients were compared. Short and long hydroperiod algal periphyton mat productivity rates were compared using BOD incubations. Experimental manipulations were performed to determine the effects of desiccation duration and rewetting on periphyton productivity, community structure, and nutrient flux. ^ Variation in periphyton community structure was significantly greater between hydroperiods than within hydroperiods. Short and long hydroperiod periphyton mats have the same algal species, it is the distribution and abundance that varies between hydroperiods. Long hydroperiod mats have greater diatom abundance while short hydroperiod mats have greater relative filamentous cyanobacterial abundance. ^ Long hydroperiod mats had greater net primary production (npp) than short hydroperiod mats. Short hydroperiod mats respond to rewetting more rapidly than do long hydroperiod mats. Dry short hydroperiod mats became net primary producers within 24 hours of rehydration. Increasing desiccation duration led to greater cyanobacterial abundance in long hydroperiod mats and decreased diatom abundance in both long and short hydroperiod mats. ^

Adaptation in knowledge-based teams: An examination of team composition, leader sensegiving, and cognitive, behavioral, and motivational mechanisms

Organizations are increasingly relying on teams to do the work that has traditionally been done by individuals. At the same time, the environments in which these organizations and teams operate have been becoming progressively more complex and uncertain. These trends raise important questions about the factors that enable teams to adapt. In response to these questions, the current study sought to identify the cognitive, behavioral, and motivational processes and emergent states that promote a team's adaptation to unforeseen changes and novel events, and the team compositional characteristics and leadership processes that enabled these processes and emergent states. Two hundred twenty two undergraduate students from a large Southeastern University composed 74 3-person teams, and participated in a computerized decision-making simulation where each team formed the governing body (i.e., Mayor's cabinet) for two separate simulated cities, and made strategic decisions about city operations. Participants were randomly assigned to one of three roles, distributing expertise and creating mutual interdependence. External team leader sensegiving was manipulated through video recorded communications from an external team leader. Results indicate that team cognitive ability, achievement striving, and psychological collectivism, as well as external team leader sensegiving, were all related to the similarity and quality of team members' strategy-focused mental models (cognitive emergent states), and to the amount of information sharing among members (behavioral process). In turn, teams with more similar and higher quality mental models, and who shared greater levels of information, were found to have a greater ability to react and adapt to environmental changes, and to have greater levels of decision-making effectiveness. Results indicate a pattern of relationships consistent with hypotheses, and have important implications for organizations and knowledge-based teams charged with management responsibilities. Organizations should staff teams with the compositional characteristics that enable the development of similar and high quality mental models, and that promote information sharing among teammates. Similarly, organizations which train and develop leaders to engage in sensegiving behaviors enable team adaptability and promote enhanced decision-making effectiveness when faced with unforeseen changes and novel situations.

Judging psychology experts: Can judges and attorneys distinguish between clinical and experimental psychologists?

A trial judge serves as gatekeeper in the courtroom to ensure that only reliable expert witness testimony is presented to the jury. Nevertheless, research shows that while judges take seriously their gatekeeper status, legal professionals in general are unable to identify well conducted research and are unable to define falsifiability, error rates, peer review status, and scientific validity (Gatkowski et al., 2001; Kovera & McAuliff, 2000). However, the abilities to identify quality scientific research and define scientific concepts are critical to preventing "junk" science from entering courtrooms. Research thus far has neglected to address that before selecting expert witnesses, judges and attorneys must first evaluate experts' CVs rather than their scientific testimony to determine whether legal standards of admissibility have been met. The quality of expert testimony, therefore, largely depends on the ability to evaluate properly experts' credentials. Theoretical models of decision making suggest that ability/knowledge and motivation are required to process information systematically. Legal professionals (judges and attorneys) were expected to process CVs heuristically when rendering expert witness decisions due to a lack of training in areas of psychology expertise.^ Legal professionals' (N = 150) and undergraduate students' (N = 468) expert witness decisions were examined and compared. Participants were presented with one of two versions of a criminal case calling for the testimony of either a clinical psychology expert or an experimental legal psychology expert. Participants then read one of eight curricula vitae that varied area of expertise (clinical vs. legal psychology), previous expert witness experience (previous experience vs. no previous experience), and scholarly publication record (30 publications vs. no publications) before deciding whether the expert was qualified to testify in the case. Follow-up measures assessed participants' decision making processes.^ Legal professionals were not better than college students at rendering quality psychology expert witness admissibility decisions yet they were significantly more confident in their decisions. Legal professionals rated themselves significantly higher than students in ability, knowledge, and motivation to choose an appropriate psychology expert although their expert witness decisions were equally inadequate. Findings suggest that participants relied on heuristics, such as previous expert witness experience, to render decisions.^

Demographic, Behavioral and Perceptual Comparisons of U.S Visitor Experience with Group Package Tours and Free Independent Travel to China

U.S. visitor demand for the China travel experience is anticipated to rise significantly through 2105, causing the Chinese government to employ 100 million service providers over the next six years and raising concern about service delivery and perceptions of the on-site China experience. In an effort to better understand these issues concerning U.S. visitors, this study investigated two specific types of U.S. travelers to China: Group Package Tour (GPT) visitors and Free Independent Travel (FIT) visitors. Results indicated that GPT visitors were more likely to be older and have higher household income than FIT visitors. Four trip-related characteristics of GPT and FIT visitors were found to be significantly different, with GPT visitors showing higher levels of satisfaction with the overall China on-site travel experience.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Activity and expression of Na/K-ATPase in thoracic aorta of normal pregnant and experimental preeclamptic rats

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Theoretical modeling and experimental validation of fluid-loaded micro rectangular plates

This paper presents a theoretical model on the vibration analysis of micro scale fluid-loaded rectangular isotropic plates, based on the Lamb's assumption of fluid-structure interaction and the Rayleigh-Ritz energy method. An analytical solution for this model is proposed, which can be applied to most cases of boundary conditions. The dynamical experimental data of a series of microfabricated silicon plates are obtained using a base-excitation dynamic testing facility. The natural frequencies and mode shapes in the experimental results are in good agreement with the theoretical simulations for the lower order modes. The presented theoretical and experimental investigations on the vibration characteristics of the micro scale plates are of particular interest in the design of microplate based biosensing devices. Copyright © 2009 by ASME.

Activity and expression of Na/K-ATPase in thoracic aorta of normal pregnant and experimental preeclamptic rats

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Essays on Firm Heterogeneity with Empirical Applications in Economic History and Agricultural Economics

This thesis uses models of firm-heterogeneity to complete empirical analyses in economic history and agricultural economics. In Chapter 2, a theoretical model of firm heterogeneity is used to derive a statistic that summarizes the welfare gains from the introduction of a new technology. The empirical application considers the use of mechanical steam power in the Canadian manufacturing sector during the late nineteenth century. I exploit exogenous variation in geography to estimate several parameters of the model. My results indicate that the use of steam power resulted in a 15.1 percent increase in firm-level productivity and a 3.0-5.2 percent increase in aggregate welfare. Chapter 3 considers various policy alternatives to price ceiling legislation in the market for production quotas in the dairy farming sector in Quebec. I develop a dynamic model of the demand for quotas with farmers that are heterogeneous in their marginal cost of milk production. The econometric analysis uses farm-level data and estimates a parameter of the theoretical model that is required for the counterfactual experiments. The results indicate that the price of quotas could be reduced to the ceiling price through a 4.16 percent expansion of the aggregate supply of quotas, or through moderate trade liberalization of Canadian dairy products. In Chapter 4, I study the relationship between farm-level productivity and participation in the Commercial Export Milk (CEM) program. I use a difference-in-difference research design with inverse propensity weights to test for causality between participation in the CEM program and total factor productivity (TFP). I find a positive correlation between participation in the CEM program and TFP, however I find no statistically significant evidence that the CEM program affected TFP.