• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11179
  • 7701
  • 3592
  • 3348
  • 1866
  • 172
  • 76
  • 31
  • 30
  • 28
  • 27
  • 25
  • 18
  • 17
  • 16
  • Tagged with
  • 34235
  • 12815
  • 12774
  • 12554
  • 5654
  • 4852
  • 4569
  • 4525
  • 4095
  • 3888
  • 3871
  • 3667
  • 3545
  • 3452
  • 3110
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Utilizing Habit Reversal and Contingency Contracting to Impact Eating Habits With Obese Individuals

Scull, Christopher Thomas 01 January 2013 (has links)
One of the most difficult set of behaviors for individuals to engage in is weight management. The United States boasts an astonishing 35% obesity rate in adults while children show almost a 20% obesity rate. These statistics identify the importance of developing effective methods to help change an individual's eating habits. There are many eating habits that may contribute to an individual gaining or losing weight over a period of time. Simplified habit reversal (SHR) has an impressive history in shaping desirable responses to compete with many different types of habitual behaviors. The present study extended the SHR procedure to eating habits in an attempt to affect change in types of foods and timing of eating for the purpose of weight reduction. Additionally, contingency contracting was added to increase the potential for adherence to eating habit goals. The three targeted behaviors were late night eating (LNE), consuming high sugar content beverages (HSCB), and unhealthy snacking (UHS). It was found that utilizing a treatment package utilizing a contingency contract plus SHR with typically developing adults could aide in reducing specific and well defined eating habits. A reduction in weight by all participants was also observed.
92

A study of the health education program of thirty-six schools in Houston County, Texas for the school year 1944-1945

Ware, Addie Metria 01 August 1945 (has links)
No description available.
93

Study of solar absorption cooling systems

Kumar, P. January 1984 (has links)
Solar energy is a vast and inexhaustible source of energy. However, solar radiation approaching the earth's surface is variable. Efficient use of this radiation is complicated by this variable nature. The work described in this thesis deals mainly with the use of solar energy for absorption cooling systems. Basic cooling and heat pump systems are described in brief. A literature survey of the absorption cooling systems is given and the scope for research work in this area is discussed. The effect of variations of the parameters in the closed cycle and open cycle absorption cooling systems has been analysed in order to optimise the performance of the systems. Experimental verification of the above analysis for a closed cycle system using water-lithium bromide as a working pair is presented along with some typical characteristic performance data for certain conditions. These conditions are lower generator temperatures, which lead to more efficient solar energy collection systems and higher absorber/condenser temperatures providing the feasibility of air cooling. Computer programs for the above analyses are given. A closed cycle absorption system using water-lithium bromide has also been theoretically analysed for simultaneous cooling and heating. A computer program developed for the above analysis is presented. A modification in the practical cycle to achieve high temperature lifts for simultaneous heating and cooling appears to be very attractive. An expression for coefficient of performance of an ideal absorption cycle system, when condensing temperature is not equal to absorber temperature, has been derived. Experimental verification of the above concept in a single stage cycle is also reported. An experimental unit to generate design data for a solar generator, of an open cycle absorption cooling system has been designed and installed. This unit is described in detail. Solar simulation has been done in two ways. The first way is by a radiation source consisting of CSI lamps and the second way is by providing an equivalent electrical heat flux. The relationship between the two is discussed. Based on the experimental data obtained, correlations in conventional forms for heat and mass transfer operations in the generator are presented. A mathematical model of the solar generator incorporating the above correlations is discussed. A computer program for the prediction of the performance of the generator is presented. The experimental results are compared with the predicted results and optimum conditions for various situations are discussed.
94

Ultrasonic and viscoelastic studies on liquids at different pressures

Ellis, J. January 1976 (has links)
This thesis describes experimental researches in ultrasonic and viscoelastic relaxation in pure liquids, mixtures and a polymer solution. The measurements were made over a range of temperatures and pressures in the frequency range 5 to 78 MHz. Density, steady flow viscosity, real part and imaginary part of the shear impedance were measured on five liquids. Four of the liquids obeyed the Time-Temperature Superposition principle and could be described by the Barlow, Erginsav and Lamb (B.E.L) model. The fifth liquid did not obey the Time-Temperature Superposition principle and deviated from the model. This was attributed to the distribution of relaxation times widening as the temperature is decreased. The shear compliance for all five liquids varied linearly with temperature at atmospheric pressure. At higher pressures it was the shear modulus that varied linearly with pressure. Both low and high frequency longitudinal velocities were found to vary linearly with temperature at atmospheric pressure, while at higher pressures only the low frequency velocity varied linearly with pressure, the high frequency velocity results were too scattered. Values of the bulk moduli obtained from the longitudinal moduli and shear moduli were normalised and the variation with reduced I frequency was found to be of the same shape as for the shear moduli but displaced along the reduced frequency axis. Therefore the shear and bulk relaxation properties have a common origin. From this displacement and the values of G(w) and the relaxing part of the bulk modulus K(O) the ratio of volume to shear viscosity was calculated for three liquids at atmospheric pressure and two liquids at higher pressures. The ratio Tlv/T, varied from 2.7 to 4.2 at atmospheric pressure with slightly lower values at higher pressures but the difference was not statistically significant. Measurements of density and velocity were made on solutions of a surfactant at elevated pressures. The density measurements were fitted to the linear secant modulus equation. Investigation of the shear properties of a gel-soap solution showed that it was thixotropic. Finally, a conformational analysis at pressures above atmospheric pressure showed that the relaxation frequency was not significantly changed by increasing the pressure.
95

A study of the invertebrate fauna and crustacean zooplankton of the Shropshire Union Canal and the Llangollen Canal

Milad, S. S. January 1974 (has links)
Five sites were chosen on the main Shropshire Union Canal and three on the Llangollen Canal. Monthly quantitative samples of the bottom fauna. shore fauna •. and crustacean zooplankton were 'taken from all sites over a period of 24 months from the Shropshire Union Canal. and over 18 months from the Llangollen Canal. An account for the topography and the geographical location of the sampling sites on the Shropshire Union and Llangollen Canals are given. for it is believed. that these are important and affect the physical conditions of the·canal waters. Sampling apparatus and procedures are described suitable for quantitative collection of the bottom-fauna. shore-fauna and crustacean zooplankton of the two canals. including the sites with rough and uneven bottoms. Experiments were done. as a further contribution on the assessment of the accuracy of the dredge. Which was designed for sampling the bottom fauna of canals. 2. The qualitative and quantitative composition of the invertebrate ,varied with season and prevailing physical and chemical conditions. The seasonal qualitative and quantitative changes of the more common invertebrates are described. Monthly size frequency distributions of the more common species are illustrated graphically and in tables. The water chemistry of the two,canals was investigated by collecting samples from all sites. The results obtained by standard analytical techniques showed that the following constituents all exhibited definite gradients along the cana1:- PH, Total hardness, Calcium and Magnesium concentrations (as mg per litre). These constituents showed a difference in concentration from one site to another. The Llangollen Canal water chemistry was significantly. different from the Shropshire Union Canal. Undoubtedly, many reasons for the restriction of any particular species to a particular environment lies in the basic chemical and physical features .pertaining to that environment. described and discussed in results and discussion. These have been Some groups, (notably Tubificidae, Chironomidae larvae and pupae,Limne.phllidae larvae) could not be fully identified within the scope of this study. The general composition of the invertebrate fauna at all sites can be seen in the tables. The work provides guide linQs which might be profitably used in investigating the life cycle of some Eph~meroptera, Trichoptera and Hemiptera. It should also be useful for work concerned with maintenance of fish and fish food organisms and the assessment of pollution in canals.
96

Development of novel flame retardants for polyurethane foams

Coleman, G. V. January 1994 (has links)
In line with current environmental concerns, a non—halogenated, high phosphorus content flame retardant for polyurethane foams is preferred. Cyclic phosphorus compounds have a high percentage of phosphorus and should therefore exhibit good flame retardant activity when incorporated into polyurethane foams. One such group of compounds, known as phospholenes, had previously been successfully synthesised but in poor yields and with only a few derivatives being prepared. This work was concerned with identifying and then optimising synthesis routes to a variety of model phospholene oxide esters, that were proposed to have potential as novel flame retardants. Kinetic and mechanistic studies of the simplest synthesis reaction were also investigated. Once optimisation of both stages of the two stage synthesis were successful in raising the yields from -25% to >90%, a flow reactor was designed and constructed to facilitate production of the model compounds in large quantities (-P 1/2 kg) required and then incorporated into polyurethane foams at a variety of loadings. These flame retarded polyurethane foams were prepared and extensive flammability tests were subsequently performed to fully evaluate the model compounds' performance as flame retardants. The model compounds exhibited favourable flame retardant properties, but their physical properties prohibited their use as commercial flame retardants. However the work completed has shown the potential, within this area of compounds, for the commercial development of suitable flame retardants.
97

Human resource management in multinational enterprises

Kidger, P. J. K. January 1999 (has links)
The multinational enterprise (MNE) is now a significant part of the world economy both in temis of trade and employment. The performance of an MINE is in part dependent on the capability of its human resource. The knowledge and experience of employees is a source of competitive advantage, but whether this is realised or not may depend on having the right human resource policies. Managers therefore seek to implement best practice, and in multinationals there is the potential for intraorganizational learning across national boundaries. The aim of this thesis is to examine a number of questions arising from the proposition that multinational firms are contributing to the development of international norms of best practice in human resource management as a result of a trend towards greater coordination of management practice in MNEs. It is suggested that multinationals are developing mechanisms to encourage the transfer of knowledge and experience across national boundaries, and this is therefore an important aspect of international human resource management (HRM). The thesis contains a review of the literature, firstly on the management of multinationals, secondly on the development of a strategic view of human resource management, and thirdly on HRM in the MINE. From this material, a theoretical framework is developed that links together a number of research questions. These formed the basis for the design and execution of a qualitative research project in which information on strategy, structure and management practice was obtained from twentyfour companies. These represented a cross-section of country ownership, including the UK, other European countries, the USA and Japan. The design of the research project is explained, and this is followed by a presentation of the results. These support the proposition that as a consequence of the globalization of markets, multinationals are tending to adopt a more global perspective in which there is greater cross-national integration of operations, coordination of management practice, and the development of internationally orientated management. The analysis discusses the implications of this for international human resource management, and offers a number of recommendations for HRM in the multinational enterprise. Finally some suggestions are made for future research to build on and extend the findings of this project.
98

An in-situ combustion simulator for enhanced oil recovery

Oklany, J. S. F. A. January 1992 (has links)
A multi-dimensional three phase flow simulator is written to simulate the process of in-situ combustion. It has six components (oxygen, inert gas, a light oil, a heavy oil, water, and coke). The inert gas consists of all the noncondensible gases other than oxygen. The vaporization and condensation of both water and oil is governed by vapour-liquid equilibria, using temperature and pressure dependent equilibrium coefficients. Splitting of the oil into fractions is done to include the distillation effect. The model includes four chemical reactions. These represent in turn the formation of coke from the heavy oil, the oxidation of the coke, and the oxidation of the light and the heavy oil. Heat transport is assumed to take place by convection and conduction. The effects of gravity, capillary pressure between any two fluid phases, and heat losses to the surrounding rock via conduction are also included. The model is validated using the ISCOM simulator. This has been carried out by comparing the results from the present simulator with these from similar calculations performed using the ISCOM simulator. ISCOM is a fully implicit multi-dimensional finite difference general thermal simulator developed by the computing modelling group (CMG) at Calgary. This comparison is needed in order to establish confidence In the predictive capability of the present model for a particular reservoir. In addition, a comprehensive study of the effect of the main input parameters on the performance characteristics of the in-situ combustion process is carried out. This study is made in order to indicate which data are "important" in the sense of having a significant influence on the performance characteristics of the process and to test the robustness of the program to changes in the input parameters.
99

The development of a structured approach to the design for economic manufacture of engineering products

Ramadan, A. A. January 1984 (has links)
The present work has been concerned with establishing a rational approach to product design for economic manufacture. This has invloved the de velopment of an organised design approach together with proposals for a structure for an ideal organisational system to support a design for economic manufacture activity. Surveys of relevant literature and industry have been conducted to review practices and techniques which are currently available to the industry to aid the processed of design for economic manufacture. As a result of the survey it was possible to define analyse the major areas of activities in relation to product design and manufacture to identify where maximum attention should be given by the management and designers to effect economy of product manufacture. It was concluded that although the mangement in several companies have adopted certain policies towards designing for economic ' manufacture, a more structure and organised approach is required to meet the growing need to apply design of economic manufacture as a means of reducing manufacturing costs. As a result of the analysis, it has been POSBible to identify the actions which must be taken at the different stages of product design and devleopment to ensure economy of manufacture. These findings are supported by two design case studies which individually demostrate the type Of Cost savings which can be achieved by giving consideration to the product concept at an early stage of design, in addition to optimising the component desine for manfacture. The above case studies highlighted the fundamental factors which influence the product manufacuring COBtSThe above work has allowed proposals to be made for an overall integrated organisational system which should aid the process. of design for economic manufacture in most engineering companies.
100

The measurement of muscle strength in allergic response

Al Hamdani, A. January 1990 (has links)
The purpose of this thesis was to show a relationship between muscle strength and allergic reactions. Clinics have for many years relied on what have become traditional methods for testing for allergic reactions. These include such tests as the Patch test and the Skin-Prick test. Both these tests cause discomfort and irritation to sensitive patients. The historical development of allergies is outlined, showing that scientists and clinicians in the late 18th and early 19th century were aware of certain reactions which people showed to apparently normal non-reactive foods. The development of methods of diagnosing allergies such as the elimination diet, which dates back to approx 1940, are surveyed. Current practices are also studied with the use of photographs. The reaction of the skin to modern day testing practices is shown. In some cases these reactions are quite violent. The Applied Kinesiology Test is examined as a universally used test which when carried out by an experienced Kinesiologist can give a true but highly subjective response to a patients allergic condition. A system has been developed based on the relationship between muscle strength and allergies, the components of this system were readily available at little cost. Once a basic system was built it was possible to perform trials on patients at an established allergy clinic. With the aid of a data printer it became possible to prove first graphically and second statistically that there was a statistically valid relationship between the measured muscle strength and allergies. The conclusion shows that the final version of the operating system is capable of equaling the performance of an experienced Kinesiologist, showing its results both digitally and graphically rather than subjectively. The various deductions and recommendations which are detailed, point towards a readily marketable device which could represent a potential break through in modern allergy testing. The system will also open the way for clinicians to make an objective assessment of the relationship between muscle strength and allergic sensitivity via further research.

Page generated in 0.0496 seconds