To see the other types of publications on this topic, follow the link: The effects of environmental performance.
Dissertations / Theses on the topic 'The effects of environmental performance'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'The effects of environmental performance.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Lunsford, Garrett P. "Environmental effects on student performance /." Available to subscribers only, 2009. http://proquest.umi.com/pqdweb?did=1885755991&sid=4&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Full text
2
Lunsford, Garrett Paul. "Environmental Effects on Student Performance." OpenSIUC, 2009. https://opensiuc.lib.siu.edu/theses/11.
Full textAbstract:
AN ABSTRACT OF THE THESIS OF Garrett P. Lunsford, for the Masters degree in Architecture, presented on July 10th 2009, at Southern Illinois University Carbondale. TITLE: ENVIRONMENTAL EFFECTS ON STUDENT PERFORMANCE MAJOR PROFESSOR: Dr. Walter Wendler With the increasing concern for sub par student performance in America, it has become more vital than ever for designers to create optimal learning environments. Student performance is significantly dependent on the quality of teaching as well as the pupil-instructor relationship. However, it is rare for even our best instructors to receive adequate performance from their students when teaching in poor environments. Research for more than 30 years has displayed explicit correlation between physical characteristics of school buildings and educational outcomes. These physical characteristics include lighting, acoustics, thermal control, indoor air quality, as well as class size. By taking each of these factors into consideration, architects can produce settings that do not hinder student performance. Better educated children today will make the world a smarter, improved, more sustainable environment tomorrow.
3
Westgate, Robert. "Environmental effects on a suspension bridge's performance." Thesis, University of Sheffield, 2012. http://etheses.whiterose.ac.uk/2884/.
Full textAbstract:
Current Structural Health Monitoring (SHM) research uses changes in a bridge’s behaviour to locate and quantify the damage in a structure. However the structural responses are also linked to environmental effects, such as its temperature and the traffic load. In order to understand a typical suspension bridge’s behaviour to environmental conditions, studies on the Tamar Suspension Bridge’s response to temperature and traffic are contained in this thesis. This was achieved by observing data collected from long-term monitoring systems installed on the structure, and simulated responses derived from a three-dimensional finite element model of the bridge. The data of the bridge have shown that the profile of the suspension bridge reconfigures when the temperature of its structure increases, causing the deck to sag and expand. The natural frequencies of the bridge were noted to drop during the day. Transient thermal responses were also indentified; the differing rates of warming up between the deck, towers and cables manifested in the structural responses of the bridge. Phenomena caused by the temperature differential across the bridge’s surface were also studied. Investigations on the effect of traffic demonstrated its additional mass causes the natural frequencies to decrease for certain modes. This was identifiable in the time series data, where the largest reduction in frequencies is during rush hours. The investigations have shown that the changes the modal frequencies and modal mass are dependent on the eccentricity of the traffic flow on the bridge, which may increase or decrease depending on the mode shape. The loading of an abnormally heavy trailer on the bridge has also demonstrated the deformation to the bridge’s quasi-static shape as the vehicle travelled across. The location of the vehicle on the bridge was also able to affect the modal properties of the suspension bridge, according to simulated results.
4
Song, Danbee. "Effects of the ISO 14001 Voluntary Environmental Program on Economic and Environmental Performance." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1560641816980076.
Full text
5
Wellock, Ian J. "Modelling the effects of environmental stressors on pig performance." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/27633.
Full textAbstract:
The performance of pigs reared commercially is often considerably below that of their potential as seen under good experimental conditions. At least some of this decrease in performance can be attributed to environmental stressors. The aims and corresponding chapters of this thesis were to; (1) Choose a suitable predictor of potential pig growth. (2) Develop a deterministic dynamic model to predict the effects of genotype and the nutritional and thermal environments on the voluntary feed intake, growth and body composition of growing pigs. (3) Test and evaluate the model developed in chapter 2 against experimental data from the literature. (4) Quantify the effects of social stressors on the performance of growing pigs and incorporate these into the previously developed model, including variation in ability to cope with encountered social stressors. (5) Extend the model to deal with individual pig variation. (6) Compare the variation predicted by the population model w ith that observed under experimental conditions. The Gompertz function was chosen as a predictor of potential pig growth and as the starting point for model simulation, i.e., to provide an upper limit to growth. It uses few parameters, holds over a wide degree of maturity and the values of its parameters can be estimated simply. Unconstrained voluntary feed intake, predicted from the current state of the pig and composition of the feed, is that required to achieve potential growth. Actual food intake and the consequent gain were predicted taking into account the capacity of the animal to consume bulk and its ability to maintain thermoneutrality. The physical environment, described by the ambient temperature, wind speed, floor type and humidity, sets the maximum and minimum heat the pig is able to lose and determines whether the environment is hot, cold or thermoneutral. Model predictions were generally in good quantitative agreement w ith the observed data over the wide range of treatments tested and give support to the models value and accuracy. The social environment was described by group size, space allowance, feeder space allowance and the occurrence or not of mixing. All of these factors may act as stressors and it is assumed in the model that they decrease performance by lowering the capacity of the animal to attain its potential. The parameter EX accounts for differences in ability to cope when exposed to social stressors. The introduction of individual variation in growth potential, initial state and EX allowed the mean population response to be compared with that of the average individual. Whether these responses differed depended in part upon the social stressors encountered. The addition of variation in initial state and EX allowed better estimates of the phenotypic variation observed in real experiments to be achieved. The developed simulation framework is able to explore, and at least in principle, predict the performance of both individuals and populations differing in growth potential, initial state and ability to cope when raised under given dietary, physical and social environmental conditions. One of the main advantages of simulation models is that they allow the effects of a multiple factors on animal performance to be considered simultaneously, including any interactions that may exist, in a way that cannot be done by direct experimentation. These interactions may be crucial in decision-making processes as different individuals and populations may react differently in response to the same environmental stressors.
6
Ali, A. "The effects of environmental stresses on performance of spring wheat genotypes." Thesis, Bangor University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382246.
Full text
7
Barlow, Matthew John. "The effects of anthropometrical, physiological and environmental factors on surfing performance." Thesis, University of Plymouth, 2013. http://hdl.handle.net/10026.1/2773.
Full textAbstract:
The aim of this thesis was to investigate how physiological and environmental factors affect surfing performance. Studies were performed that assessed the effect of anthropometric and physiological characteristics of surfers on rank and ability, the effect of creatine supplementation on surfing performance and the effect of wave size, wave period and the ability of surfers on physiological and performance indices of surfing. Study one investigated the effect of the anthropometric variables on rank and rating of ability. This was measured across a sample of 79 surfers ranging from intermediate to professional surfers. Significant correlations were found for endomorphy (r = -0.366, P <0.01), sum of six skinfolds (r = -0.274, P <0.05), Body fat percentage (r = -0.268, P <0.01) and mesomorphy (r = 0.442, P <0.01). Findings suggest that levels of adiposity and muscularity might influence the potential for progression between intermediate and professional level surfing performance. Study two investigated the effect of physiological variables on the national ranking of 18 elite male junior surfers using assessments of maximal oxygen uptake, lower body explosive power, upper body power, agility, and balance. Partial correlations were used to account for the influence of age within the sample and a significant correlation was found between power output at (rp = -0.879, P <0.01). Findings suggest that power output at is an important factor for achieving competitive success in high performance junior surfers. Study three investigated the effect of short term (20g.day-1 for 5 days) creatine supplementation on body composition, repeated upper body anaerobic power and competition performance was assessed in 17 club level surfers. Testing comprised assessment of body mass and total body water using bioelectrical impedance analysis, a repeated upper body Wingate based on time motion analysis of competitive surfing. A two-way repeated measures ANOVA found no significant effects of supplementation on laboratory measures of anaerobic power or competitive performance. The fourth study investigated the effects of changes in wave conditions on physiological response and performance parameters of surfing. This was assessed using 39 surfers who participated in 60 surfing sessions where wave conditions were recorded and performance was measured using GPS. The study found that wave height was significantly related to energy expenditure (rp =-0.351, P <0.05), maximum ride speed (rp = 0.866, P <0.01), the standard deviation of maximum ride speeds (rp = 0.654, P <0.01), mean ride time (rp = 0.354, P <0.01), maximum ride time (rp = -0.296, P <0.05), the standard deviation of the ride times expenditure (rp = -0.344, P <0.01), mean ride distance (rp = 0.398, P <0.01), maximum ride time (rp = 0.318, P <0.05), minimum ride distance (rp = 0.268, P <0.05), standard deviation of the ride distances (rp = -0.362, P <0.01), percentage of total distance riding (rp = 0.310, P <0.05), percentage of time spent waiting (rp = -0.272, P = 0.05), percentage of total time spent riding (rp = 0.396, P < 0.01), percentage of total time in miscellaneous activities (rp = 0.471, P <0.01), total distance riding (rp = 0.310, P =0.05), total distance per hour (rp = 0.427, P <0.01). Wave period was found to be significantly related to average heart rate as a percentage of maximum (rp = 0.490, P <0.01), the percentage of time spent in the “easy” training zone (rp = -0.408, P <0.01), maximum ride speed (rp = 0.371, P <0.01), mean ride time (rp = 0.283, P <0.05), maximum ride distance (rp = 0.279, P <0.05), and the standard deviation of the ride distances (rp = 0.325, P <0.05). The ability levels of the surfers were found to be significantly related to average heart rate as a percentage of maximum (rp = -0.412, P <0.01), percentage of time in the “steady” zone (rp = 0.435, P <0.01), percentage of time in the “intermittent” zone (rp = 0.483, P <0.01), maximum ride speed (rp = 0.454, P <0.01), mean ride distance (rp = 0.392, P <0.05), standard deviation of the ride distances (rp = 0.264, P <0.05), percentage of the total distance riding(rp = 0.267, P <0.05), percentage of time paddling (rp = 0.364, P <0.05), percentage of time in miscellaneous activities (rp = -0.299, P <0.05), total distance riding (rp = 0.267, P <0.05) and average speed (rp = 0.428, P <0.01). This thesis has found that ability in surfing is related to anthropometric and physiological measures, creatine supplementation improves peak anaerobic power but does not significantly improve surfing performance in club level surfers and that wave conditions and the skill levels of surfers are significantly related to the physiological and performance parameters of surfing.
8
Prill, Nadine. "Effects of environmental change on plant performance and plant-herbivore interactions." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:c58761e9-666c-4b7d-a78a-d70de7f253d4.
Full textAbstract:
Global environmental change fundamentally affects plants and their interactions with other species, and this has profound impacts on communities and ultimately ecosystems. In order to understand the mechanisms involved, we need to elaborate on the combined effects of different global change drivers on multiple levels of plant organization, including the biochemical level (production of defence compounds), the whole organism, the population, and the plant-herbivore interaction level. This thesis investigates (1) the combined effects of factors related to climate change and habitat fragmentation on Brassica nigra and (2) the effects of Zn soil pollution on the heavy metal hyperaccumulator Noccaea caerulescens at these different levels. Common garden and greenhouse experiments with B. nigra applied drought stress and elevated CO2 to examine climate change impacts, while crossing treatments (inbreeding and between-population outbreeding) were used to investigate habitat fragmentation effects. Heterosis was lost under drought stress, and there were several interactive effects of the experimental treatments that varied within and among populations. In a greenhouse experiment with N. caerulescens, plants were grown on soil with different amounts of zinc. Plants had greater herbivore resistance when grown on Zn-amended soil, and invested more in herbivore tolerance when grown on soil without added Zn. In general, the results indicate that factors related to global environmental change have complex and interactive effects on different levels of plant organization. The findings are discussed in terms of their implications for ecology, evolution and conservation.
9
Gurr, Anna. "The Effects of Positive and Negative Environmental Responsibility on Financial Performance." Scholarship @ Claremont, 2018. http://scholarship.claremont.edu/cmc_theses/1800.
Full textAbstract:
As environmental responsibility (ER) gains momentum in the corporate and stakeholder world, it is imperative to understand the relationship between ER and financial performance. While there is prior research looking at this relationship, this study provides further insight into the specific effects of negative and positive ER. In addition, it looks over the years 2008-2011 having implications for companies about the effects of their ER even through financial hardships. This study uses a widely respected corporate social responsibility database, in which ER scores were separated from. In this study, 287 firms in the S&P 500 are examined through times-series regression analyses. The results reveal that positive ER had a negative relationship with financial performance indicators Tobin’s q and ROA. However, negative ER had such strong positive relationship with financial performance in both measures, that when looking at the effect of net ER, the relationship was tipped back to positive. This indicates that negative ER worsens a company’s financial position more than spending on positive ER initiatives.
10
Byrd, Desiree Anastacia. "The effects of early environmental experiences on African-American neuropsychological test performance /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2001. http://wwwlib.umi.com/cr/ucsd/fullcit?p3026369.
Full text
11
Hester, Joshua C. (Joshua Colón). "Measuring clay property variation and effects on ceramic pot filter performance." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/70755.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, February 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 69-70).
Pure Home Water (PHW) is a non-profit organization in Ghana whose mission is to provide safe drinking water to Ghana's Northern Region - the poorest part of the country. Originally a distributor of ceramic pot filters (CPFs) manufactured in Accra, PHW began construction of a new factory outside of Tamale in late 2009 when it was recognized that importing filters from Accra was too inefficient to meet the demands for household water treatment and safe storage. One aspect of CPF manufacturing that has a significant impact on the quality of the finished product is the clay "recipe." In 2010, Reed Miller and Travis Watters conducted research to determine the optimal ratio of combustible material to clay that would yield filters with suitable flow rates, water quality, and strength. However, until 2011, limited research was done on the clay itself, and the relationship between clay properties and PHW filter performance was largely unexplored. Clay has been harvested from a site in Gbalahi, 1 mile away from the PHW factory. Since PHW's acquisition of a second clay source in Wayamba, it has become important to determine to what extent the clays from the two sites are different, as well as which clay properties have the largest impact on quality filter production. To answer these questions, the author measured the plasticity and particle size distribution of 12 clay samples collected from each site. Filters were made from each sample and their performance evaluated based on removal of turbidity, coliform, and E. coli. Statistical analyses were conducted to determine the significance of the observed differences between and relationships among the measured parameters. The Gbalahi clay was found to be more plastic and have a higher clay content (less sand and silt), and filters made from this clay had lower flow rates and better turbidity removal.
by Joshua Hester.
M.Eng.
12
Rugless, Fedoria E. "The Effects of Manganese Exposure on Neuromotor Performance in Children." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1336683051.
Full text
13
Collop, Andrew Charles. "Effects of traffic and temperature on flexible pavement wear." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336400.
Full text
14
Ordoñez, García Arturo. "Effects of architectural design variables on energy and environmental performance of office buildings." Doctoral thesis, Universitat Rovira i Virgili, 2016. http://hdl.handle.net/10803/395212.
Full textAbstract:
Aquesta
tesi
aborda
la
comprensió
dels
efectes
que
les
principals
variables
de
disseny
arquitectònic
tenen
en
les
prestacions
energètiques,
mediambientals
i
econòmiques
dels
edificis
d'oficines,
mitjançant
l'exploració
d'alguns
dels
mètodes
d'anàlisi
que
ofereixen
un
major
potencial
en
l'actualitat.
Busca
contribuir
al
desenvolupament
d'enfocaments,
mètodes
i
eines
que
facilitin
la
presa
de
decisions
durant
el
procés
de
disseny
arquitectònic,
especialment
en
les
primeres
etapes.
També
està
dirigit
a
generar
informació
que
ajudi
a
millorar
els
criteris
aplicats
en
el
desenvolupament
de
codis
energètics
i
sistemes
de
certificació
de
sostenibilitat.
La
investigació
ha
consistit
en
quatre
parts
principals:
•
La
primera
part
consisteix
en
el
desenvolupament
d'un
projecte
paramètric
basat
en
els
programes
EnergyPlus
i
jEPlus.
•
La
segona
part
consisteix
en
una
anàlisi
d'optimització
mitjançant
algoritmes
evolutius.
L'anàlisi
es
va
realitzar
amb
el
programa
jEPlus
+
EA,
i
està
destinat
a
identificar
les
solucions
de
disseny
arquitectònic
que
produeixen
impactes
mediambientals
i
econòmics
més
baixos.
•
La
tercera
part
consisteix
en
l'aplicació
dels
dos
mètodes
d'anàlisi
de
sensibilitat,
Morris
i
Sobol,
per
tal
d'establir
la
importància
relativa
de
cada
variable
de
disseny
arquitectònic
en
les
prestacions
dels
edificis.Esta tesis aborda el estudio de los efectos que las principales variables de diseño arquitectónico tienen en el desempeño energético, medioambiental y económico de los edificios de oficinas, mediante la exploración de algunos de los métodos de análisis que ofrecen un mayor potencial en la actualidad. Busca contribuir al desarrollo de enfoques, métodos y herramientas que faciliten la toma de decisiones durante el proceso de diseño arquitectónico, especialmente en las primeras etapas. También busca generar información que ayude a mejorar los criterios aplicados en el desarrollo de códigos energéticos y sistemas de certificación de sostenibilidad. La investigación consistió en cuatro partes principales: • Desarrollo de un proyecto paramétrico basado en los programas EnergyPlus y jEPlus, con el objeto de identificar y caracterizar las variables de diseño arquitectónico más significativas • Aplicación de un análisis de optimización mediante algoritmos evolutivos. El análisis se realizó con el programa jEPlus + EA. • Ejecución de dos métodos de análisis de sensibilidad, Morris y Sobol, con el fin de establecer la importancia relativa de cada variable de diseño arquitectónico en el desempeño energético, medioambiental y económico de los edificios
This thesis addresses the understanding of the effects that main architectural design variables have on energy, environmental and economic performance of office buildings, exploring some of the analytical methods that offer greater potential nowadays. It is aimed to contribute to the development of approaches, methods and tools that facilitate the decision-making during the architectural design processes, especially in the early stages. It is also aimed to generate information that helps to improve the criteria applied in the development of building energy codes and sustainability certifications. The research consisted of four major parts: • Development of a parametric project based on the programs EnergyPlus and jEPlus software. • Implementation of Optimization analysis by means of evolutionary algorithms. The analysis is performed with the program jEPlus+EA. • Application of two sensitivity analysis methods, Morris and Sobol, in order to investigate the relative importance of each architectural design variable. • Implementation of artificial neural networks to create meta-models that are able to predict, with reasonable accuracy, the energy, environmental and economic performance of buildings
15
Clark, William Robinson Hayes. "Monitoring Environmental Effects on High Performance Tetraglycidyl Methylenedianiline Epoxy and PMR-15 Polyimide." W&M ScholarWorks, 1989. https://scholarworks.wm.edu/etd/1539625516.
Full text
16
Dorinson, Diana M. (Diana Marie) 1974. "The evolution of airline distribution channels and their effects on revenue management performance." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/29391.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004.Includes bibliographical references (p. 132-134).
Over the past ten years, the development of more advanced computer systems and the growth in the use of the Internet have led to numerous changes in airline ticket distribution strategies. For example, the use of websites for booking and ticketing air travel continues to increase, and the Internet is often cited as the preferred model for a low-cost distribution channel. At the same time, Network Revenue Management methods are now viewed as a key tool for airlines to maximize revenue in an increasingly competitive marketplace. These new systems and tools have helped the airlines achieve record profits in the strong economy of the late 1990s, but these profits may have masked hidden costs of using the new technology. Examples of hidden costs include the added computational burden of increased search engine requests to the computer reservations system as well as the increased opportunity for automated systems to bypass the booking limits set by the revenue management system. Such costs have yet to be examined and quantified in an academic research effort. The purpose of this thesis research is to understand a variety of issues related to how the technologies of more advanced distribution channels and more sophisticated revenue management systems interact with each other and impact air travel providers.
(cont.) First, an empirical analysis of ticketing data is used to demonstrate that there are significant differences in ticket purchasing behavior among customers who use different distribution channels. Second, a review of previous experiments showing the negative revenue impacts of Inventory Control Bypass are presented, together with a discussion of some of the more promising solutions to Bypass. Next, these prior results are compared to a new set of experiments covering both path-based and leg-based Caching techniques. The new experiments show that the negative revenue impacts of Caching are at least as serious as those of Bypass, and may be more serious, depending on an airline's choice of how to interface with distributors who cache.
by Diana M. Dorinson.
S.M.
17
Al-Homidan, Abrahim A. "The effect of environmental conditions on broiler performance." Thesis, University of Aberdeen, 1997. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU483542.
Full textAbstract:
1- Body weight was significantly affected by temperature at 49 days in all three experiments. Body weight was higher at the lower temperature (2591 vs 2518 g).2- Body weight was significantly affected by the light regime at 6 weeks of age. Body weight was higher with intermittent light (9L : 3D) compared to continuous light (23L : 1D) (2223 vs 2164 g).3 - As expected, given the differences in body weight at 49 days, at 6 weeks of age daily weight gain was significantly affected by temperature, and by light regime (52.5 vs 50.8 and 50.4 vs 51.8 g respectively).4- Ammonia concentrations increased greatly with the age of the birds. The mean concentrations in experiments 1 and 3 all fell below the recommended for animal threshold limit value of 20 ppm ( but in experiment 2 the mean concentrations of ammonia were higher (28 ppm) than the recommended TLV of 20 ppm.5- Ammonia concentration was significantly greater in rooms with a litter depth of 30 mm (32 ppm) compared with 45mm, (24.2 ppm).6- Ammonia concentration was greater than 'Litterite' than wood shavings after the third week (11.2 vs 7.9 ppm)7- Inspirable dust concentration was significantly greater in rooms at the higher temperature in all the three experiments (10 vs 13.3 mg/m3) and in rooms with near-continuous light in experiment 1 (8.5 vs 5.7 mg/m3).8- Settled dust concentration was significantly greater in rooms at higher temperature in all experiment 2 and 3 (614.5 vs 474.35 mg/m2).9- Ammonia concentration was higher (but NS) in rooms at the higher temperature (21°C) compared with rooms at the low temperature (19°C) in all three trials (19.3 vs 22.3 ppm).10- Stocking density significantly affected ammonia concentrations in the 5th week and from 3-7 weeks of age (8.9 vs 13.3 ppm) (8.5 vs 11.2) respectively. Overall, the lower temperature (19 C), intermittent light, a litter depth of 45mm and a low stocking density (16 birds/m2) led to reduced ammonia and dust concentrations, an increased body weight, and daily weight gain and reduced mortality (NS).
18
Ur, Rehman Masood. "Characterisation of human body and environmental effects on the performance of mobile terminal antennas." Thesis, Queen Mary, University of London, 2010. http://qmro.qmul.ac.uk/xmlui/handle/123456789/385.
Full textAbstract:
Provision of efficient services to the user anywhere at anytime is being a centre of research and development in Wireless Personal Area Networks (WPAN) and Wireless Body Area Networks (WBAN). Antenna is the essential part of WPAN/WBAN applications that got affected by two major factors: human body presence and nature of the surrounding environment. The presence of the human body in the proximity of the antenna causes electromagnetic (EM) reflections from the body surface and absorptions in the lossy body tissues resulting in antenna detuning, radiation pattern degradations and impedance mismatch. On the other hand, incident radio waves undergo reflections, difractions and scattering from the surrounding environment objects including buildings, trees, vehicles and ground, causing multipath fading. The thesis gives an overview of the main investigations, results and analyses accomplished in a study concerning the commercially available Bluetooth and GPS antennas working in the vicinity of the human body. Detailed numerical modelling process is adopted followed by measurements for validation. The thesis highlights the role of surface waves as a potential transmission medium in an on-body Bluetooth wireless communication link taking into account the effects of antenna-body separations and presence of the surrounding objects blocking the direct communication path. The thesis also presents a novel statistical model to evaluate the performance of GPS mobile terminal antennas in the multipath environment. This model characterises the antenna performance and identifies the key factors that can be used to enhance it, in a real working environment outside an anechoic chamber. The study also deals with presence of the human body in the multipath environment and its effects on the operation of the GPS antennas.
19
Joubert, Retief. "Influence of geometric and environmental parameters on air-cooled steam condenser performance." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4153.
Full textAbstract:
Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: Air-cooled steam condensers (ACSCs) are used in the power generation industry to directly condense turbine exhaust steam in areas where cooling water is expensive or unavailable. Large axial flow fans force ambient air through A-frame heat exchanger bundles made up of a number of rows of finned tubes through which the steam is ducted and consequently condensed during the heat transfer process to the air. The heat rejection rate or performance of an ACSC is proportional to the air mass flow rate, determined by fan volumetric performance, and the temperature difference between the finned tubes and the air. The air flow through a 30 fan ACSC (termed the generic ACSC) operating under windy conditions is solved using the commercial computational fluid dynamics (CFD) code FLUENT and the required data is extracted from the solution to calculate performance trends. It is found that fan performance is reduced due to a combination of factors. The first is additional upstream flow losses caused by separated flow occurring primarily at the leading edge of the ACSC and secondarily at the fan bellmouth inlets. The second factor leading to reduced fan performance is the presence of distorted flow conditions at the fan inlets. Hot plume air recirculation is responsible for decreased ACSC thermal performance due to increased fan inlet air temperatures. It is found that reduced fan performance is the greater contributor to reduced ACSC performance. The performance effects of varying two geometrical parameters of the generic ACSC, namely the fan platform height and the windwall height, are investigated under windy conditions. It is found that each parameter is linked to a specific mechanism of performance reduction with the fan platform height affecting fan performance and the windwall height affecting recirculation. The respective platform and windwall heights specified for the generic ACSC are found to provide acceptable performance results. To mitigate wind induced performance reductions a number of modification and additions to the ACSC are investigated. These primarily aim at improving fan performance and included the addition of walkways or skirts, the addition of wind screens beneath the fan platform, removing the bellmouth fan inlets, using different types of fans and increasing fan power. The addition of a periphery walkway and windscreens is considered to be the most practical methods of improving ACSC performance under windy conditions. The generic ACSC is modified to include both modifications and under high wind conditions the performance is found to increase measurably. The modifications also resulted in the ACSC performance being less sensitive to wind direction effects.
AFRIKAANSE OPSOMMING: Lugverkoelde kondensators word in die kragopwekkings industrie gebruik om turbine uitlaatstoom te kondenseer, veral in gebiede waar verkoelingwater duur of onbeskikbaar is. Aksiaalvloei-waaiers forseer omgewingslug deur A-raam warmteuitruiler bondels wat bestaan uit verskeie rye vinbuise. Die uitlaatstoom vloei in die vinbuise en kondenseer as gevolg van die warmteoordrag na die lug. Die warmteoordragkapasiteit van die lugverkoelde stoom kondensator is eweredig aan die massavloei-tempo van die lug, wat bepaal word deur die waaierwerkverigting, en die temperatuur verskil tussen die vinbuise en die lug. Die lugvloei deur 'n 30 waaier lugverkoelde stoom kondensator (genoem die generiese lugverkoelde stoom kondensator) onderworpe aan winderige toestande word opgelos deur die gebruik van die kommersiële vloeidinamika-pakket, FLUENT. Die nodige data is onttrek uit die oplossing en werkverrigting neigings is bereken. Dit is gevind dat waaierwerkverigting verminder as gevolg van 'n kombinasie van faktore. Die eerste is bykomende vloeiverliese wat veroorsaak word deur vloeiwegbreking wat plaasvind primêr by die voorste rand van die lugverkoelde stoom kondensator asook by die klokvormige waaier-inlate. 'n Tweede faktor wat lei tot vermindere waaierwerkverigting is die teenwoordigheid van lugvloeiversteurings by die waaier-inlate. Hersirkulering van warm pluim lug is ook verantwoordelik vir verminderde lugverkoelde stoom kondensator werkverrigting. Daar word bevind dat die vermindering in waaierwerkverrigting die grootste bydraende faktor tot vermindere lugverkoelde stoom kondensator werkverrigting is. Die effek van verandering van twee geometriese lugverkoelde stoom kondensator parameters, naamlik die waaierplatformhoogte en die windwandhoogte is ondersoek onder winderige toestande. Daar word bevind dat elk van die parameters gekoppel is aan 'n spesifieke meganisme van vermindere lugverkoelde stoom kondensator verrigting: Die waaierplatformhoogte beïnvloed waaierverrigting terwyl die windwandhoogte hersirkulering beinvloed. Daar word ook bevind dat die onderskeie waaierplatform- and windwandhoogtes van die generiese lugverkoelde stoom kondensator, van so 'n aard is dat dit aanvaarbare werkverrigting tot gevolg het. Om verlaging in werksverrigting in winderige toestande te verminder is verskeie modifikasies en byvoegings tot die lugverkoelde stoom kondensator ondersoek wat primêr gemik is op verbetering in waaierwerkverigting. Die ondersoek dek die byvoeging van 'n loopvlak, die byvoeging van windskerms onder die waaierplatform, verwydering van die klokvormige waaier-inlate, die gebruik van verskillende waaiers en die verhoging van waaierdrywing. Daar was besluit dat die byvoeging van 'n loopvlak rondom die rand van die lugverkoelde stoom kondensator en die byvoeging van windskerms die mees praktiese manier was om die lugverkoelde stoom kondensator verigting te verbeter. Die generiese lugverkoelde stoom kondensator was aangepas om beide veranderings in te sluit en meetbare verbetering in werkrigting was verkry. Die veranderings het ook meegebring dat die lugverkoelde stoom kondensator minder sensitief is vir windrigting effekte.
20
Touny, Mahmoud A. "The effects of environmental regulations on industrial plant inefficiency and the determinants of plant environmental performance : a case study of Egypt." Thesis, University of East Anglia, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410071.
Full textAbstract:
In 1994, the government of Egypt issued a comprehensive environmental law concerning environmental protection from pollution sources in Egypt. The first main goal of this study is to examine to what extent inefficiency scores of plants in both private and public sectors are affected by environmental regulations done by these plants through the period 1996-2001. Most empirical literature on this area focused mainly on developed countries especially the U.S. due to the availability of data. Thus, this study tries to add some to previous literature through examining this relationship under different economic and development stages. To investigate this relationship, we designed and executed a survey of manufacturing plants in three Egyptian cities, and used a stochastic frontier cost function to measure inefficiency levels of plants and test factors affecting these scores. The results of the econometric models indicate that plants more affected by environmental regulations are associated with higher inefficiency levels. Also, we find strong evidence that plants working under private ownership are more efficient than public plants. Additionally, these results reveal that plant-size has a negative effect on inefficiency levels, which mains that larger plants are more efficient than smaller ones. However, the effect of plant-age on cost inefficiency is ambiguous. The second goal of this study is to examme possible factors determining plant's environmental performance. Two methodologies (truncated regression and ordered probit model) are used in this part depending on dependent variable used. Results of the truncated regression highlight the role played by regulators, market pressures, and worker security as the main factors accounting for plants' environmental performance. Plants face high international competition, produce final consumer goods, and subject to high rate of inspections are more likely to have better environmental performance. Results of the probit model reveal that plant characteristics have a significant effect on plant's environmental expenditure, where private, older, and larger plants tend to spend more in environmental concerns. Also, variation in inspection rates and consumer pressures are seen to have a strong impact on plant's environmental expenditure.
21
Naperalsky, Michael E. "Effect of post-exercise environmental temperature on glycogen resynthesis." The University of Montana, 2009. http://etd.lib.umt.edu/theses/available/etd-06052009-115319/.
Full textAbstract:
Hotter environments can often alter the normal exercises responses of metabolism and work performance compared to exercise in a more neutral condition. The goal of this study was to determine the effects of a hot (H) and room temperature (RT) environment on glycogen resynthesis during recovery from exercise. Recreationally active males (n = 9) completed two trials, each with 60-min of cycling exercise at 60% of maximum watts in a temperature-controlled chamber (32.6°C), followed by 4 hours of recovery at the same temperature (H) or 22.2°C (RT). Subjects were fed a carbohydrate beverage (1.8 g/kg bodyweight) at 0 and 2 hours post-exercise. Muscle biopsies were taken from the vastus lateralis at 0, 2, and 4 hours post-exercise for analysis of muscle glycogen. Blood samples were collected at 0, 30, 60, 120, 150, 180, and 240 minutes of recovery for glucose and insulin analysis. Ambient and core temperatures were monitored for the duration of the trial. Expired gas was collected prior to 2- and 4-hour biopsies for calculation of whole-body carbohydrate (CHO) oxidation. Glycogen, core temperature, CHO oxidation, and blood marker values were analyzed using two-way ANOVA with repeated measures. Average core temperature was significantly higher in H compared to RT (38.1°C ± 0.01° vs. 37.9°C ± 0.08°, p<0.05) during recovery. Glycogen was not different at 0 and 2 hours post-exercise. However, at 4 hours post-exercise muscle glycogen was significantly higher in RT vs. H (105 ± 28 vs. 88 ± 24 mmolkg-1 wet weight, respectively). Blood glucose levels were similar between H and RT for the first two hours, but showed lower values (p<0.05) in RT compared to H at time points 150, 180, and 240 minutes post-exercise. CHO oxidation during recovery was higher in H compared to RT (0.36 ± 0.04 g/min vs. 0.22 ± 0.03 g/min, respectively, p<0.05), with greater CHO oxidation at 4-hours post-exercise in both trials. Glycogen resynthesis during recovery is impaired in a hot environment, likely due to increased oxidation of CHO instead of synthesis.
22
Hughes, Raymond E. "The effects of different thermal environmental conditions on the performance of automatic and controlled processes." Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-03032009-040645/.
Full text
23
Cox, Marcus Z. "When and Where Does It Pay to Be Green: Intra- and Inter-organizational Factors Influencing the Environmental/Financial Performance Link." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc500091/.
Full textAbstract:
Managers are coming under increasing pressure from a wide array of stakeholders to improve the environmental performance of their firms while still achieving financial performance objectives. One of the most researched questions in the business and the natural environment (B&NE) literature is whether it pays to be green. Despite more than three decades of research, scholars have been unable to clearly answer this question. The purpose of this dissertation was to attempt to identify the antecedents that lead to increased, firm-level environmental performance and the conditions in which firms are then able to profit from enhanced environmental performance. First, I assessed three intra-organizational factors of top management teams (i.e. female representation, concern for non-financial stakeholders, and risk-seeking propensity) that theory indicated are associated with increased corporate environmental performance (CEP). Theory also leads us to believe that top management teams with these attributes should perform better in dynamic settings, so I tested to see if industry dynamism moderates these relationships. Second, I then examined industry-level forces that theory indicates would moderate the relationship between CEP and corporate financial performance (CFP). These moderating forces include industry profitability, industry dynamism, and the degree of industry environmental regulation. Hypotheses were tested using panel data obtained from the KLD, Compustat, and Environmental Protection Agency databases for the years 2000 to 2011. The sample consists of firms comprising the Standard and Poor’s 500 and was analyzed using fixed-effect regression and moderating variables were analyzed using the Johnson-Neyman technique.
24
Jensen, Cartolano Emy. "Klimatarbetets effekter på företagets lönsamhet : En studie om uppfattningar bland svenska företag." Thesis, Linköpings universitet, Tema Miljöförändring, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177356.
Full textAbstract:
Industrin gör att samhället utifrån det ekonomiska system som det verkar i, fungerar. På samma gång står industrin för stora delar av de växthusgasutsläpp som värmer upp jorden och den globala kris som det innebär. Att företag mäter sina utsläpp, jobbar för att sänka de, genomför klimatpositiva åtgärder, klimatanpassar och jobbar förebyggande blir av vikt för att kunna minska på utsläppen såväl globalt som lokalt. Ett företag drivs utifrån olika faktorer så som att vara lönsamma på olika vis. I den här studien, som är ett samarbete med Hagainitiativet, undersöks vad 102 svenska börsnoterade företag anser om sitt klimatarbete och hur det påverkar företagets lönsamhet. Företagen svarar även på hur de menar att politiska beslut och Covid-19-pandemin påverkar deras klimatarbete. Material inhämtades med hjälp av kvantitativ metod, webbenkät. Studien visar på att företagen över lag ställer sig positiva till att engagera sig i klimatfrågan och menar att klimatarbetet får positiva effekter för företagets lönsamhet. Allra starkast tycks synergin vara mellan klimatarbetet och en positiv effekt för varumärket samt för attraktiviteten som arbetsgivare. När Hagainitiativets enkätsvar från 2019 jämfördes med svaren från denna undersökning i 2021, svarar fler att klimatarbetet får en positiv effekt för företagets lönsamhet och färre att det får en negativ effekt. Det klimatpolitiska läget samt Covid-19 skulle kunna presentera en del av förklaringen till varför. Resultaten indikerar på att det finns ett flertal frågor som hade varit intressant att ställa framöver för att få mer information om vad företagen gör, vad de inte gör och varför. Att ytterligare fördjupa förståelsen kring de uppfattningar som finns kan vara en del av det som krävs för att bana vägen framåt för företag att kunna jobba för hållbar utveckling och på samma gång uppnå en god lönsamhet.The industry keeps society spinning in its current system. At the same time, it accounts for large parts of the greenhouse gas emissions which are heating up the earth and is responsible for the global crisis that it entails. Companies measuring their emissions, working to reduce them, implementing climate-positive measures, adapting to climate- change and working preventively is important to reduce emissions both globally and locally. For a company to survive, it runs based on various factors, such as being profitable in different ways. This study, which is a collaboration with the Hagainitiativet, examines what 102 Swedish listed companies think about their climate work and how it affects various profitability aspects of the business. The companies also respond to how they believe that political decisions and the Covid-19 pandemic affect their climate work. Materials were obtained using a quantitative method, web survey. The study shows that companies in general are positive about getting involved in the climate issue and believe that their responses to climate change result in positive effects on the company's profitability. The synergy seems to be strongest between climate responses and a positive effect on the brand and the attractiveness as an employer. When the questionnaire from Hagainitiativet in 2019 were compared to the responses from this survey in 2021, more companies answered that climate work has a positive effect on the profitability and fewer that it has a negative effect. The climate policy situation and Covid-19 could present part of the explanation for why this is. The results indicate that there are several questions that would be interesting to ask in the future to get more information about what companies do, what they do not do and why. Further deepening the understanding of existing perceptions, can be part of what is required to pave the way for companies to work for sustainable development and at the same time achieve profitability.
25
Lusth, Tobias. "The Effect of Environmental Policy Instruments : -An empirical study of the OECD countries’ environmental performance." Thesis, Umeå universitet, Nationalekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-146282.
Full textAbstract:
The concept of environmental performance is in this study regarded as either countries’ carbon dioxide (CO2) emissions per capita, or an index that considers not only reduction in emission levels but also produced output. Two environmental policies that are available for mitigating CO2 emissions will be discussed. First, the use of environmentally related taxes (ERT:s), where both a general measure and specific ozone tax is used when examining the effect of ERT:s on environmental performance. The results are ambiguous and in many cases not statistically significant. Second, the effect on countries’ environmental performance caused by participating in the EU ETS system is tested. A conclusion that can be made is, that participating in the EU ETS system reduces CO2 emissions per capita. Time lags of one and four years are used to evaluate the rigidity of these two policies. The results are unclear, but the effect of a four-year lag seems to be stronger for the EU ETS case.
26
Clifton, A. Paige. "Solvent induced microcracking in high performance polymeric composites." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-11182008-063245/.
Full text
27
Wu, Chumeng. "Effects of varying environmental conditions on performance of completely autotrophic nitrogen removal from dewatered sludge liquors." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43236.
Full textAbstract:
Centrate, an ammonia rich wastewater, usually contains high concentrations of ammonia (around 1000 mg/L) and accounts for about 20% of total nitrogen loading to wastewater treatment plants. However, the conventional nitrification/denitrification approach for centrate treatment is costly to operate and releases a large quantity of carbon dioxide, due to the addition of organic compounds for denitrification. A brand new approach for nitrogen management is a novel process called anaerobic ammonium oxidation (ANAMMOX). ANAMMOX offers a cost effective solution for centrate treatment. Compared to the conventional biological nitrogen removal process, ANAMMOX can save 63% oxygen and 100% exogenous carbon source usage.
In this research, a 400 L pilot-scale CANON SBR was studied at the J.A.M.E.S. WWTP in Abbotsford, B.C. and tested for treating on-site centrate. During 317 days of reactor running period, maximum ammonia removal rate (ARR) of 98.9 % was achieved with an average ARR of 91.0%. The reactor also achieved a maximum of 0.81 kgN/m³•d ammonia loading rate (ALR) with a minimum hydraulic retention time (HRT) of 1.46 d. The performance of the CANON SBR was highly influenced by environmental conditions. Better reactor performance was achieved at the highest tested temperature of 32ºC and maximum air flow rate of 14 L/min. Testing under 26ºC would reduce ARR by 12% and generate high nitrite concentration peaks. Compared to an airflow rate of 10 L/min, the ARR was increased by 9% and HRT was reduced by 10%, at 14 L/min. Higher initial ammonia concentrations in the reactor could also lead to better reactor performance. A maximum nitrogen removal rate of 0.36 kgN/m³•d and minimum HRT of 1.79 d was achieved at the highest initial ammonia concentration of 455 mg/L. The feeding rate did not affect the results of nitrogen removal. However, slow feeding with 500 mL/min did not create any nitrite concentration peak during the reaction. Solids concentrations in the reactor could be effectively controlled by sludge settling time. Sludge settling times between 4 to 10 min were recommended, for achieving purposes of sludge enrichment or system optimization.
28
Van, Der Merwe Daryl. "Investigating the effects of environmental variables on martial eagle breeding performance in the Kruger National Park." Master's thesis, Faculty of Science, 2019. https://hdl.handle.net/11427/31813.
Full textAbstract:
Within South Africa martial eagles reporting rates have decreased by almost 60% over the last two decades. Similar declines have also been reported within Kruger National Park (KNP), which is regarded as a stronghold for this species. Declines within KNP have been attributed to the low productivity rates. As apex predators, marital eagles are considered to be good indicators of ecosystem health, being sensitive to the cumulative effects of disturbance down the food chain. Changes in the breeding performance of martial eagles may therefore indicate broader environmental change within the ecosystem. In this study, we aim to explore which environmental variables (e.g. climate, land cover, tree cover, fire and elephant abundance) within each territory correlated with martial eagle breeding performance in the hope that we may better understand which variables affect martial eagles breeding performance and whether these may have changed over time to cause the low levels of fecundity presently seen within KNP. We found that breeding productivity (young per territorial pair) was positively influenced by higher precipitation and Normalized Difference Vegetation Index (NDVI) and negatively impacted by high temperatures during the previous year. Breeding rate (breeding attempt per territorial pair) appeared to be negatively influenced by higher tree cover within 6 km of the nest site. Nesting success (outcome of a breeding attempt) was correlated with higher NDVI and lower relative levels of precipitation during the previous year. Using longer term climatic data and the relationship between climate in the previous year and productivity, (the variable which directly relates to annual fecundity), we hindcast the predicted productivity over the last three decades (2018-1986) to explore whether change in climate conditions (precipitation, temperature and NDVI) might reveal declines in productivity. No such declines were predicted, thus, our results do not explain why productivity has declined within KNP.
29
Hollabaugh, Eric M. "Field performance of instrumentation for monitoring effects of timber harvesting on water quality." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4541.
Full textAbstract:
Thesis (M.S.) University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 23, 2007) Includes bibliographical references.
30
Rodriguez, Leo E. "Temperature Effects On Integral Abutment Bridges For The Long-Term Bridge Performance Program." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1221.
Full textAbstract:
The United States Department of Transportation (US-DOT) Federal Highway Administration (FHWA) initiated in 2009 the Long-Term Bridge Performance (LTBP) program to gather high-quality data on a representative sample of bridges over a twenty-year period of time. The goal of this program is to quantify how bridges behave during their service life while being exposed to different types of loadings and deterioration due to corrosion, fatigue and various climate conditions along with their corresponding maintenances. The data gathered will result in the creation of databases of high quality data, acquired through long-term instrumentation, to be used for improved design practices and effective management of infrastructures by employing best practices for maintenance. As part of the LTBP Program two integral abutment bridges, a California Bridge near Sacramento, CA and a Utah Bridge near Perry, UT, were selected to be monitored for temperature changes as well as to undergo periodic live-load testing. Live-load testing included slowly driving a truck over the bridges. The bridges were instrumented to collect test data and use it to calibrate a finite-element model. This finite-element model was used to determine the actual bridge behavior and compare it with the AASHTO LRFD Specifications. This thesis also examined how different parameters such as thermal gradients, mean temperature, and end-rotation affect these two integral abutment bridges.
31
Macleod, Hannah. "The effects of hydration status and hot environmental conditions on performance of elite female field hockey players." Thesis, Nottingham Trent University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.510173.
Full text
32
Diaz, Nicholas. "Acute effects of the power snatch on vertical jump performance." Scholarly Commons, 2016. https://scholarlycommons.pacific.edu/uop_etds/304.
Full textAbstract:
The purpose of this study was to examine the acute effects of the power snatch exercise at specific intensities on vertical jump performance. 10 weightlifters attended two sessions: a power snatch (PS) and control (CON) condition. Each session was separated with at least 48 hours in between. This study used a 1-group experimental design. During the PS condition, participants performed the power snatch exercise at increasing intensities (40% 1 repetition max [RM], 60% 1RM, and 80% 1RM) after a dynamic warm up. Vertical jump performance was measured prior to the warm up, and after each power snatch exercise in the PS condition. During the CON condition, vertical jump performance was measured at the same times, with the participants substituting the power snatch exercise for a seated position. The results showed no significance ( p > 0.05) in vertical jump performance during each condition, with a trend being seen during the gradual increase in intensities. These results suggest further research is needed utilizing a larger sample size to show significance.
33
Lai, Chwan-Fu. "THE EFFECTS OF ENVIRONMENTAL LIGHTING, SHOE WEAR/TEAR AND LOAD CARRIAGE DURING DYNAMIC TASK PERFORMANCE ON SLIPPERY SURFACES." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin976037439.
Full text
34
Snow, Michael P. "Charting Presence in Virtual Environments and its Effects on Performance." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30329.
Full textAbstract:
Virtual reality (VR) involves an attempt to create an illusion that the user of the VR system is actually present in a synthetic (usually computer-generated) environment. Little is known about how various system parameters affect the illusion of presence in a virtual environment (VE). In particular, there seem to be very little quantitative data on which to base VR system design decisions. Also, while presence (or immersion) in VEs is a primary goal of VR, not much is known about how this variable affects task performance. The goal of this research was to provide a ratio-scale measure of perceived presence in a VE, to explore the effects of a number of environmental parameters on this measure and construct empirical models of these effects, and to relate perceived presence to user performance. This was done by manipulating eleven independent variables in a series of three experiments. The independent variables manipulated were scene update rate, visual display resolution, field of view, sound, textures, head-tracking, stereopsis, virtual personal risk, number of possible interactions, presence of a second user, and environmental detail. Participants performed a set of five tasks in the VE and rated perceived presence at the end of each set using the technique of free-modulus magnitude estimation. The amount of time spent in the VE was also recorded. The results indicate that the VR system parameters manipulated and analyzed in this research did affect participants' subjective feeling of presence in the VE. Field of view, sound, and head-tracking showed the largest effects. Other significant effects found were those of visual display resolution, texture-mapping, stereopsis, and the presence of a second user.
Free-modulus magnitude estimation worked well as a measure of perceived presence. A positive relationship was found between perceived presence and task performance, but this relationship was relatively weak. Second-order empirical models were constructed that predicted perceived presence with moderate success and, with less success, task performance.Ph. D.
35
Perrone, Paul. "The Effects of Experience and Familiarity on Performance in Virtual Environments." Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/cmc_theses/1420.
Full textAbstract:
League of Legends is one of the most played video games in the world with millions of hours played each year. I examine if both a player’s experience and level of familiarity with teammates within the League of Legends virtual environment have significant relationships with individual performance. Utilizing regression analysis I have concluded that individual experience does not have a statistically significant effect on individual performance and that individual familiarity has a statistically significant negative effect on individual performance.
36
Lopez, Ibaceta Alvaro Francisco. "Seismic Performance of Substandard Reinforced Concrete Bridge Columns under Subduction-Zone Ground Motions." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/4977.
Full textAbstract:
A large magnitude, long duration subduction earthquake is impending in the Pacific Northwest, which lies near the Cascadia Subduction Zone (CSZ). Great subduction zone earthquakes are the largest earthquakes in the world and are the sole source zones that can produce earthquakes greater than M8.5. Additionally, the increased duration of a CSZ earthquake may result in more structural damage than expected. Given such seismic hazard, the assessment of reinforced concrete substructures has become crucial in order to prioritize the bridges that may need to be retrofitted and to maintain the highway network operable after a major seismic event. Recent long duration subduction earthquakes occurred in Maule, Chile (Mw 8.8, 2010) and Tohoku, Japan (Mw 9.0, 2011) are a reminder of the importance of studying the effect of subduction ground motions on structural performance. For this purpose, the seismic performance of substandard circular reinforced concrete bridge columns was experimentally evaluated using shake table tests by comparing the column response from crustal and subduction ground motions. Three continuous reinforced columns and three lap-spliced columns were tested using records from 1989 Loma Prieta, 2010 Maule and 2011 Tohoku. The results of the large-scale experiments and numerical studies demonstrated that the increased duration of subduction ground motions affects the displacement capacity and can influence the failure mode of bridge columns. Furthermore, more damage was recorded under the subduction ground motions as compared to similar maximum deformations under the crustal ground motion. The larger number of plastic strain cycles imposed by subduction ground motions influence occurrence of reinforcement bar buckling at lower displacement compared to crustal ground motions. Moreover, based on the experimental and numerical results, subduction zone ground motion effects are considered to have a significant effect on the performance of bridge columns. Therefore, it is recommended to consider the effects of subduction zone earthquakes in the performance assessment of substandard bridges, or when choosing ground motions for nonlinear time-history analysis, especially in regions prone to subduction zone mega earthquakes. Finally, for substandard bridges not yet retrofitted or upgraded seismically, the following performance limit recommendation is proposed: for the damage state of collapse, which is related to the ODOT's Life Safety performance level, the maximum strain in the longitudinal reinforcement should be reduced from 0.09 (in./in.) to a value of 0.032 (in./in.) for locations where subduction zone earthquakes are expected, to take into consideration the occurrence of bar buckling.
37
Shehab, Maryam. "Use of novel sensors to assess human exposure to airborne pollutants and its effects on cognitive performance." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8161/.
Full textAbstract:
Exposure to air pollution can cause adverse health effects, may also adversely affect the central nervous system and affect cognitive performance. Epidemiological studies depend on central site monitors as surrogates to assess personal exposure to air pollution, which can be inaccurate because they do not assess personal exposure in a variety of activities and microenvironments. This thesis aims to assess the level of misclassification in data from central site monitors by using portable modern sensors with high temporal resolution to characterize personal inhaled doses of BC, PM2.5, and UFP, and compare the measurements with surrogate exposure metrics. It also seeks to identify contributing activities and sources associated with the highest concentrations of the three pollutants, and to determine the contribution of these activities and microenvironments to personal exposure, and to study the impact of short-term exposure to air pollution on cognitive function. The first finding is that central site monitors are not a good surrogate for personal exposure. Secondly, travelling in vehicles is linked to the highest concentrations of the three pollutants, while other outdoors activities and outdoors commuting are linked to the highest concentrations of BC and PM2.5, cooking is linked to the highest concentrations of UFP, and activities and time spent indoors are the highest contributors to personal exposure. Thirdly, the results provide strong evidence that short-term exposure to PM2.5 from candle burning and commuting has an adverse effect on cognitive performance.
38
Almeida, Leah Zoe. "Legacies of early-life experiences on individual, cohort, and population performance of Lake Erie Walleye." The Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1614019841185563.
Full text
39
Zhao, Jiangning. "The effect of the ISO-14001 environmental management system on corporate financial performance." online access from Digital Dissertation Consortium, 2006. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?3222116.
Full text
40
Prakash, Preethi. "Effect of indoor environmental quality on occupant's perception of performance a comparative study /." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0013301.
Full text
41
Bae, Hee Sung. "Investigating the effect of environmental uncertainty on supply chain collaboration and operational performance." Thesis, University of Hull, 2014. http://hydra.hull.ac.uk/resources/hull:12550.
Full textAbstract:
Supply chain collaboration is an important strategic consideration for manufacturing firms, which need to effectively manage the globalization of the value chains of manufacturing firms. Like any other manufacturing firms, Korean manufacturing firms in China have to structure a whole new value creation network. Moreover, from the viewpoint of manufacturing firms, the analysis of the market and resources is the basis of formulating strategy. Consequently, this research investigates the impact of environmental uncertainty as an antecedent of supply chain collaboration based upon previous investigations. Because prior literature has indicated that supply chain collaboration could create value and superior performance in a supply chain and perhaps also in newly created supply networks, this research aims to find the reasons behind improved performance. In this regard, there are two aims of this research: 1) to confirm the relationship between supply chain collaboration and operational performance and 2) to verify the roles of environmental uncertainty on the relationship between supply chain collaboration and operational performance. The thesis refers to prior research and contingency theory, resource-based theory, strategic choice theory, relational view and information processing theory to explain the relationships between the above variables (environmental uncertainty, supply chain collaboration and operational performance). Conceptual and operational definitions of the variables are extracted from prior research and applied to this research. A questionnaire was sent to Korean manufacturing firms in China and 208 data collected by the survey are used in the analysis. To achieve the aims of this research, various analytical methods are used. First, reliability and validity of the questionnaire instrument are verified as follows. The characteristic of the responding firms is proved through descriptive statistics. Content validity is verified by extracting items, verification by experts and the average of items. Estimation and purification of data are carried out. These include data screening, evaluation of assumptions (linearity, homoscedasticity and normality), internal consistency and exploratory factor analysis. Construct validity is tested by convergent validity through confirmatory factor analysis, discriminant validity and multicollinearity analysis. Second, the hypotheses are tested by two analytical methods: an analysis of structural equation modelling and moderating effect analysis. In this research, contingency theory explains the relationship between environmental uncertainty and supply chain collaboration and resource-based theory, relational view; information processing theory and strategic choice theory explain the relationship between supply chain collaboration and operational performance. These theoretical relationships are verified by empirical tests. The results of the analyses can elucidate various theoretical implications. First, the relationship between supply chain collaboration and operational performance is significantly verified and this means that Korean manufacturing firms reduce costs and improve service through internal collaboration with departments and external collaboration with suppliers and customers. Second, the role of environmental uncertainty on the relationship between supply chain collaboration and operational performance is a moderator and this is explained by contingency theory and fit as moderation. The former is to start from the supposition; that is, there is no organisational structure which satisfies all conditions. From this viewpoint, firms need to find the fittest structure which is equal to the environment which they face and this is connected with high performance. The latter has two viewpoints such as a moderator and a mediator. In this research, environmental uncertainty is the role of a moderator on the relationship between supply chain collaboration and operational performance. When Korean manufacturing firms in China face environmental uncertainty, they acquire high performance through enhancing supply chain collaboration. The results provide managers with managerial implications as follows. First, managers should grasp their present level of supply chain collaboration and formulate supply chain strategy for performance improvement. Second, the analysis of environment is a precondition to perform supply chain strategy, followed by high performance. If managers perform supply chain collaboration on the basis of these implications, they can achieve high cost performance and high service performance.
42
Muhammad, Jamil Che Zuriana. "The moderating and mediating effect of the environmental management control systems on environmental performance : the case of Malaysian hotel sector." Thesis, Bangor University, 2008. https://research.bangor.ac.uk/portal/en/theses/the-moderating-and-mediating-effect-of-the-environmental-management-control-systems-on-environmental-performance--the-case-of-malaysian-hotel-sector(c2fcbe35-c8df-4cb1-ab3a-e1372908d01c).html.
Full textAbstract:
This study seeks to contribute to the field of environmental management and management control literature as the study resolves the existing conflicts in the literature regarding environmental management practice and at the same time develops a theoretical foundation for the management control system in the framework of the environmental management perspective. This study also introduces the moderating and mediating framework to enhance the understanding of the contingent factor related to the practice-control relationship in the environmental management perspective. Previous studies such as Henri and Journeault (2006) and Baba (2004) examined environmental management practices within manufacturing firms, thus ignoring the significant impact of the service-based sector on environmental problems. Building from Simons's (1995) four levers of management control system, this study examines empirically the influence of environmental management control systems on environmental performance in the hotel sector. This study used questionnaires and phone interview surveys to collect the data. Linear regression analysis and hierarchical (moderated) multiple regression analysis are used to analyse the data. Environmental management practice and four elements of management control systems, i. e. interactive control systems, budgeting control systems, environmental information systems and cultural control systems, are considered to have a significant influenced on environmental performance. Size, structure and chain are also included in the model as control variables. The results indicate that management control systems are not necessarily applicable in assisting hotel management to enhance their environmental performance. The budgeting control system was the only management control element which directly influences environmental performance. Environmental management practice is found not to have a direct significant effect on environmental performance. However, the results reveal that the budgeting control system and interactive control system mediate the relationship between environmental management practice and envirom-nental performance, while the environmental information system and cultural control system moderate the relationship. The results of the study are expected to have implications on the awareness in the hotel sector of how important it is for hotels to practise environmental activities beyond-compliance and integrate them with management control systems to improve their environmental performance.
43
Parvatareddy, Hari. "The effect of environmental aging/exposure on the durability of high performance polymeric composites." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06102009-063332/.
Full text
44
Yilmaz, Vedat. "Enhancing The Performance Of Anaerobic Digestion Of Dairy Manure Through Phase-separation." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608460/index.pdf.
Full textAbstract:
Anaerobic digestion (AD) is an effective way to convert animal manures into profitable byproducts as well as to reduce the pollution of water, air, and soil caused by these wastes. Conventional high-rate anaerobic reactors cannot effectively process high-solids containing animal manures. The two-phase configuration for AD has several advantages over conventional one-phase processes such as increased stability of the process, smaller and cost efficient process configurations, etc.
This study investigated the two-phase AD of dairy manure with particular emphasis on the effects of solids retention time (SRT), organic loading rate (OLR) and pH on anaerobic acidification of unscreened dairy manurethe effects of temperature on biogas production and the comparison of one-phase and two-phase system performance of AD. The results revealed that pre-acidification of dairy manure in daily-fed continuously-mixed reactors with no recycle led to substantial volatile fatty acids production. The optimum operational conditions for anaerobic acidification were determined as SRT and OLR of 2 days and 15 g VS/L.day. The pH control at a range of 5.0-5.5 was not found to be necessary for optimum acidification. Molecular analysis indicated that acidogenic bacteria population increased whilst the aerobic bacteria population decreased as time passed in acidogenic phase. The effect of temperature was clearly observed on biogas production efficiency. Two-phase configuration was determined more efficient than one-phase system. The biogas production in two-phase system was calculated to be 41% higher than that of the one-phase for the same OLR of 3.5 g VS/L.day. This translates into significant performance improvement and reduced volume requirement. This finding represents a further step in the achievement of wider use of simple anaerobic reactor configurations in rural areas.
45
Figueira, Silvia Maria Barbosa. "Modeling the effects of contention on application performance in multi-user environments /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9719868.
Full text
46
Davies, Andrew Meredith. "The effects of different thermal environments on performance of manual handling tasks." Thesis, Sheffield Hallam University, 2006. http://shura.shu.ac.uk/19539/.
Full textAbstract:
Many people work in uncomfortable thermal environments where the need to perform manual handling tasks is a fundamental requirement. A review of the research into the effects of performing manual handling in these environments revealed design limitations and gaps in knowledge. Current industry guidance merely states that 'extremes of heat and humidity should be avoided'. The purpose of this thesis was to study participants' physiological and subjective responses while lifting in hot, warm and cold environments. Three studies were conducted using the psychophysical approach where participants self-selected the load in a floor to knuckle-height lift. For the first study 12 males (mean +/- sd), age 25.2 +/- 6 yrs, mass 74.9 +/-11.9 kg, stature 1.73 +/- 0.1m were recruited and acclimated over five days (1 hr sessions) in an environmental chamber at 38°C, 70% relative humidity (RH). They completed 15x35-min trials on consecutive weekdays in five environments: thermoneutral, 21 °C, 45% RH (17°C WBGT); warm-dry, 30°C, 25% RH (22°C WBGT); warm-humid, 30°C, 65% RH (27°C WBGT); hot-dry, 39°C, 22% RH (27°C WBGT); hot-humid, 38°C, 70% RH (34°C WBGT) and three lift frequencies: 1, 4.3 and 6.7 lifts.min -1. Heart rate and aural temperature were significantly higher and maximum acceptable weight of lift (MAWL) significantly lower in the hot-humid environment compared to all others. Ratings of perceived exertion (RPE) were significantly higher in hot-humid compared to both warm-dry and thermoneutral. Although participants reduced workloads in the heat, they did not compensate adequately. There were no significant differences in response between two environments with the same WBGT (27°C).Secondly, 12 males, age 26 +/- 5.6 yrs, mass 75.1 +/- 9.2kg, stature 1.77 +/- 0.1m were recruited. They completed 15x35-min trials in five environments: thermoneutral, 16°C, 65% RH; 10°C, 55% RH; 5°C, 45% RH; 0°C, 55% RH (standard ensemble); 0°C, 55% RH (enhanced ensemble) and the same three lift frequencies. MAWL significantly decreased at higher lift frequencies. Mean aural temperature was significantly lower at 0°C (standard) compared to thermoneutral. Mean MAWLs were higher than in the heat suggesting that participants increased activity to keep warm possibly placing them at greater risk of musculoskeletal injury. In all environments below thermoneutral the mean end aural temperature was < 36.2°C when lifting at 1 lift.min[-1].Finally, 10 males, age 28.4 +/- 5.1 yrs, mass 79.5 +/- 13.1 kg, stature 1.8 +/- 0.1 m were recruited to assess the effects of face-cooling on physiological strain and perceived exertion while lifting at 6.7 lifts.min[-1] in 30°C, 65% RH (27°C WBGT). Face-cooling significantly reduced local skin temperature and heart rate. There were no other significant differences. Face-cooling seems to be limited to mediating RPE (encompassing thermal strain) independent of core temperature which might continue to rise. The following recommendations are suggested for inclusion in future industry guidance. Workers should not regulate their own workloads in uncomfortable environments. RH does not impose additional strain in air temperatures up to 30°C. At ~39°C care must be taken when RH exceeds 25%. Attention must be paid to workers' clothing ensembles in temperatures below 16°C so that they provide adequate insulation. Finally, face-cooling should not be thought of as a protective mechanism against heat stress.
47
Hyatt, Abigail. "Engaging the Senses for Performance: a Framework for Researching Sensory Design Elements and Their Effects on Productivity in the Workplace." Thesis, Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-11222005-122709/.
Full text
48
LI, TAI-HSIANG, and 李泰祥. "Corporate Environmental Social Responsibility and Financial Performance : The Mediating Effect of Environment Performance." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/jhfrvf.
Full textAbstract:
碩士德明財經科技大學
財務金融系理財與稅務管理碩士班
106
In view of the increasing awareness of environmental protection and the profound influence of business activities on the environment, the general public has paid more attention on firms’ environmental protection activities. Simultaneously, firms still seek to make excellent financial performance. Thus, this study investigates how a firm’s fulfillment of environmental corporate social responsibility (CSR) influences its financial performance and whether environmental performance exerts a mediating effect on the relationship. Different from previous studies that measure CSR using the results of evaluation conducted by external organizations, this study performs questionnaire survey on corporate high-level managers to obtain the data of the CSR and environmental performance variables. This method enables a deep understanding of whether a firm’s fulfillment of environmental CSR exerts positive influence on its financial performance through the improvement of environmental performance. The empirical results of this study show that the meditating effect of environmental performance on the relationship between corporate environmental and social responsibility (CESR) and financial performance was unclear. However, such effect can still facilitate clarifying the process of how a firm’s fulfillment of CESR influences its financial performance. Accordingly, an effective mechanism that can prompt firms to fulfill CESR was developed. Keywords: corporate environmental and social responsibility (CESR), environmental performance, corporate social responsibility, financial performance
49
"Neighborhood Effects on Restaurant Food Safety Performance." Tulane University, 2016.
Find full textAbstract:
acase@tulane.eduThere are an estimated 48 million cases of foodborne illness per annum in the United States, with a majority of the illnesses associated with eating in a restaurant. Previous research into the causes of foodborne illness have primarily focused on factors that are internal to the restaurant. This research examines both internal components as well as external factors from the surrounding community that could influence how a food establishment operates. Inspection data, providing the basis for this analysis, came from routine inspection reports from Maricopa County, Arizona and the State of Florida. Additional evaluations are from randomly sampled restaurants, containing information on the occurrence of specific risk factors for foodborne illness, captured from States A and B. External community demographic data from the U.S. Census Bureau’s American Community Survey was also used. The routine inspection data was analyzed using a general estimating equations approach, and the risk factor study data was analyzed via a tobit regression. This approach allowed for the identification of the specific variables and their relative effect on the food safety performance of the establishment The only external factor to have an influence on restaurant food safety performance was the level of market competition, both near the restaurant and at a further distance from the restaurant. Other socio-demographic variables of the area were not found to have a significant effect. Internal factors, such as the level of food-handling and the food-safety related training held by employees were found to have an effect on the restaurants food safety performance. This study has shown the utility in assessing the compliance status of each risk factor, and the limitations of only using a count of violations. Additionally, concordant with most facilities operating in a sanitary manner, large sample sizes are required to identify an effect from a covariate.
1
Adam Kramer
50
Tsun, Lin Chen, and 林政村. "The Effects of Environmental Factors on New Product Development Performance." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/15792360049642846238.
Full textAbstract:
碩士中國文化大學
國際企業管理研究所
92
In the capricious age, the future market is gradually deviating from its trajectory. The vision of the enterprise leaders is so narrow that they can hardly perceive, predict and plan a project. They must find a new way out and renew their own thoughts so as to create new components in proper proportion. This essay will analyze how the external milieus and company strategies influence the new product development performance, while the high-tech industries in Taiwan are developing new products. In this article, we specify a baseline model with firm innovativeness, market orientation and top manage-ment risk taking as antecedents to market environment; these in turn are modeled as an-tecedents to new product development performance. Two conceptualizations of the role of market environmental turbulence are examined that market turbulence and techno-logical turbulence. The high-tech industries in Taiwan were selected as research objects. 183 valid questionnaires were collected. The result of empirical analysis shows that (1) The effect of firm innovativeness on the new product development performance is not statistically significant. (2) Market orientation has positive effect on the new product development performance. (3) Top management risk taking has positive effect on the new product development performance. (4) Market environment has positive effect on the new product development performance. (5) Market orientation and top management risk taking have positive indirect impact on new product development performance by mar-ket environment, but firm innovativeness does not.