• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 330
  • 285
  • 155
  • 78
  • 36
  • 31
  • 29
  • 22
  • 22
  • 21
  • 20
  • 14
  • 12
  • 9
  • 9
  • Tagged with
  • 1176
  • 1059
  • 330
  • 307
  • 189
  • 188
  • 181
  • 167
  • 162
  • 159
  • 147
  • 144
  • 141
  • 140
  • 132
  • 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

Patterns of Sugars Intake, Total Energy Intake, and Body Mass Index in Healthy Individuals

January 2019 (has links)
abstract: Background: Higher intake of carbohydrates in the evening and later eating times has been associated with higher total energy intake (TEI)1-3 and higher risk of being overweight or obese.1,4 Though existing evidence indicates a link between added sugars intake and increased body mass index (BMI), the effect of daily patterns of added sugars intake on TEI and BMI is unknown. Research on added sugars has relied on self-report dietary assessments with limited days of dietary data, resulting in unreliable estimates. The purpose of this thesis was to describe patterns of added sugars consumption, and to investigate the relationship between dietary sugars, eating patterns, TEI, and BMI using 15-days of dietary data from a feeding study. Methods: 40 participants age 18 to 70 years completed a 15-d highly controlled feeding study which imitated their normal diet, while recording meal times. Meals and snacks were coded based on participant identified, time-of-day, and meal content specific criteria. All consumed foods and beverages were carefully weighed and entered into the Nutrition Data System for Research (NDSR) for analysis. Pearson correlation, independent t-test, one-way repeated measures analysis of variance (ANOVA) with post hoc tests, and multiple linear regressions were used to investigate the association between patterns of added sugars and energy intake, as well as eating frequency (EF), with TEI and BMI. Results: 15-d median added sugars intake was 9.7% of total calories. The highest contribution to added sugars intake (% of g/d) came from snacks (44%) in women and from afternoon (39%) consumption in men. The highest contribution to TEI came from dinner (30%) and afternoon (34%) consumption in women, and from lunch (31%) or dinner (30%) and afternoon (35%) consumption in men. Total eating occasion (EO) frequency had a negative association with TEI (r = -0.31) and no association with % energy from added sugars. In multivariate regression models, besides sex, % energy from beverages only (Adjusted R2 = 0.41) and % added sugars from dinner (Adjusted R2 = 0.39) were significant predictors of TEI, while none of the variables were associated with BMI. Conclusion: Changing one’s pattern of eating, (EF and % energy from beverages only and % added sugars from dinner), may reduce TEI, potentially reducing BMI. / Dissertation/Thesis / Masters Thesis Nutrition 2019
92

Surge free added resistance tests in oblique wave headings for the KRISO container ship model

Stocker, Mark Ryan 01 August 2016 (has links)
Surge Free Added Resistance testing in variable head wave conditions were completed for a container ship model. The added resistance experiments include calm water, head wave, and oblique wave cases with a focus on establishing a validation benchmark for CFD codes computing the added resistance and motions of the ship model during maneuvering. The ship used is a 1/85.19 scale KRISO Container Ship, KCS, model with a length of 2.70 m. Tests were performed at the IIHR wave basin. The 20 x 40 x 4.5 m wave basin is equipped with 6 inline plunger type wave makers and a 3 degrees of freedom carriage. A 4 degrees of freedom, surge, heave, roll, and pitch free mount with a mass spring damper system was used to tow the model. Calm water tests were performed for 13 Froude numbers between 0.0867 and 0.2817. The resistance coefficients, sinkage, and trim were found for each test. The calm water results were obtained and compared to results from towing tank facilities, with traditional mounts, to estimate facility biases at the IIHR wave basin. The results show that the size difference of the IIHR model and surge free motion create magnitude differences between facilities. Head and oblique wave tests were performed at Froude number 0.26 and wave height to wavelength ratio, H/λ, of 0.0167. For all wave tests, time histories of wave amplitude, resistance, and 4 DOF were measured. Fourier analysis was completed for all time histories of waves, forces, and motions and the 0th, 1st, and 2nd harmonic amplitudes and phases are presented. All head wave results are compared to other facilities data taken in a towing tank with a traditional mount. The data from all wave heading data was analyzed with a focus on the trends with incremented wave encounter angle. Most harmonic amplitudes show good agreement between all facilities, but removal of the small model used by IIHR shows even better agreement between facilities. The oblique wave heading data shows good agreement with the only other experimental oblique wave added resistance testing. Complete uncertainty analysis was completed for select cases for calm water, head wave, and oblique wave conditions. The uncertainty showed accurate data form most wavelength settings.
93

URANS V&V for KCS free running course keeping and maneuvering simulations in calm water and regular head/oblique waves

Kim, Dong-Hwan 01 January 2019 (has links)
The capability of CFD is assessed by utilizing CFDShip-Iowa V4.5 for the prediction of the 6DOF motion responses, forces, moments and the local flow field of the 2.7m KCS model in various weather/operating conditions. The discretized propeller is preferred and the rudder is designed to be active up to ±35 degrees. Grid triplets are generated with the refinement ratio √2 and verification is achieved for the resistance and propeller open water tests while for the other tests is only partially fulfilled. The verification shows unsmooth convergence, however, the errors from grid triplets are small. The propeller open water test validates the performance of the discretized propeller successfully. The free decay tests could predict reasonable heave/pitch/roll natural frequencies. The resistance test verifies the nominal wake distribution. The self-propulsion test using discretized propeller shows 18% higher propeller inflow and 0.1 thrust deduction factor compared to resistance test. A propeller blade that sweeps the starboard experienced higher thrust inducing non-axisymmetric propeller wake and thus affecting the angle of attack of the rudder. Neutral rudder angle diminishes effective angle of attack and keeps the course straight. Maneuvering simulations could predict qualitatively good agreement for validation variables while the trajectory needs more improvement. Using the discretized propeller for the head/oblique wave course-keeping simulations achieved validation successfully. The RAO of added thrust, torque and propeller rotational speed resembles the RAO of added-resistance except showing larger values during long waves. The mean propeller efficiency is at the minimum when the ship experiences a resonance. The first harmonic amplitude of the propeller efficiency increases followed by the increase of the wavelength.
94

The effects of value-added modeling decisions on estimates of teacher effectiveness

Cunningham, Paula Lynn 01 December 2014 (has links)
This study was undertaken to evaluate the impact of modeling decisions made by those charged with implementing teacher evaluation systems that incorporate student achievement data; such choices include how growth is to be modeled, whether student characteristics are to be controlled for, how many years of data are to be used, and which test subject is to be selected. Using a three-cohort longitudinal data set from a school district in which reading and mathematics test scores from a vertically-scaled assessment allowed determination of growth in grades three, four, and five, estimated teacher effects were derived from five value-added models, and the resulting rank orderings of the teachers were examined. The models compared were a covariate adjustment model that conditioned on prior achievement only, a covariate adjustment model that conditioned on certain student characteristics as well as prior achievement, a gain score model, the growth model underlying the vertically-scaled assessment, and student growth percentiles. Teacher rank orderings derived under the five models were highly consistent with one another using either one or three classroom years of test scores. Only when the movement of teachers between quartiles was examined did a difference in performance between some models emerge. The high degree of consistency between the two covariate adjustment models suggested that control for student-level characteristics was unnecessary. Using three years of test scores rather than one led to a small decrease in between-model correlations and a small increase in teacher movement between quartiles. Comparison of teacher value-added based on reading scores versus mathematics scores gave mixed results, with between-model correlations in mathematics being slightly higher than those for reading but with reading showing greater consistency in quartile movement between cohorts. The year-to-year change in teacher rank orderings was very striking, as low, and even negative, correlations emerged between years. Movement of teachers between quartiles from one year to the next was far greater than that observed when comparing the modeling conditions. Using a teacher rating scheme in which groups of teachers were distinguished from average effectiveness if they appeared in the extremes of the rankings, nearly half of teachers changed ratings from one year to the next. Such low inter-temporal stability of teacher value-added is a significant result that should be considered by all stakeholders in teacher evaluation.
95

Bonussystem : Sambandet mellan Sambandet mellan EVA och ersättning till företagsledare i börsnoterade bolag

Erixon Wennersten, Anders, Hällgren, Magnus January 2007 (has links)
<p>Syfte: Syftet med denna studie är att undersöka om det föreligger något samband mellan företags värdeskapande och nivå på ersättning till VD.</p><p>Metod: Den metod som används i denna studie är deduktiv, då undersökningsmaterialet till störst del består av årsredovisningar. Utifrån årsredovisningarna beräknas ett specifikt EVA-värde för varje företag.</p><p>Resultat/Slutsats: Av jämförelsen mellan EVA/Sysselsatt kapital och en VD:s totala ersättning kan inget direkt samband påvisas. En anledning till detta torde vara att modellen ställer höga krav på värdeskapande. Detta medför möjligen att företagen använder andra system för utvärdering av ersättningsnivåer, exempelvis utvecklingen av börskursen.</p><p>Studien kompletteras med en jämförelse av ersättningsnivå och börsvärde. Resultaten av denna granskning är att samband mellan de båda kan bevisas. En trolig anledning till att ersättningsnivåerna verkar vara generösare i företag med högre börsvärde kan vara att dessa företagsledare har ett större ansvar.</p>
96

Economic Value Added : Som investeringsstrategi under en ekonomisk recession

Norström, Johan, Wange, Erik, Lundin, Morten January 2010 (has links)
No description available.
97

Value Activation with vertical annual rings - material, production, products.

Sandberg, Dick January 1998 (has links)
No description available.
98

Increasing the business spectrum : Created values in purchasing

Zetterberg, Hanna, Åkerström, Jenny January 2008 (has links)
The purpose of this master’s thesis is to examine the process of creating values in a purchasing organisation; meaning in which areas created values can be added and what affects the possibility to do so. In addition, the study looks into what can be improved to further enlarge the business spectrum. Through these outlines, a survey has been made to investigate the view on created values from a purchaser, management and supplier perspective. This gives several aspects of within which areas you can work with added values. The study is based on a questionnaire to 60 purchasers at Scania CV AB. The thesis demonstrates that to a certain extent sourcing managers already work with increasing the business spectrum by adding values. But even though Scania is a company with a mature purchasing organisation there are still several areas where the work with created values can be improved, for example within process development and administration.
99

Bonussystem : Sambandet mellan Sambandet mellan EVA och ersättning till företagsledare i börsnoterade bolag

Erixon Wennersten, Anders, Hällgren, Magnus January 2007 (has links)
Syfte: Syftet med denna studie är att undersöka om det föreligger något samband mellan företags värdeskapande och nivå på ersättning till VD. Metod: Den metod som används i denna studie är deduktiv, då undersökningsmaterialet till störst del består av årsredovisningar. Utifrån årsredovisningarna beräknas ett specifikt EVA-värde för varje företag. Resultat/Slutsats: Av jämförelsen mellan EVA/Sysselsatt kapital och en VD:s totala ersättning kan inget direkt samband påvisas. En anledning till detta torde vara att modellen ställer höga krav på värdeskapande. Detta medför möjligen att företagen använder andra system för utvärdering av ersättningsnivåer, exempelvis utvecklingen av börskursen. Studien kompletteras med en jämförelse av ersättningsnivå och börsvärde. Resultaten av denna granskning är att samband mellan de båda kan bevisas. En trolig anledning till att ersättningsnivåerna verkar vara generösare i företag med högre börsvärde kan vara att dessa företagsledare har ett större ansvar.
100

Catalytic conversion of glycerol to value-added liquid chemicals

Pathak, Kapil Dev 21 November 2005
<p>Glycerol is one of the by-products of transesterification of fatty acids for the production of bio-diesel. Value-added products such as hydrogen, wood stabilizers and liquid chemicals from catalytic treatment of glycerol can improve the economics of the bio-diesel production process. Catalytic conversion of glycerol can be used for production of value-added liquid chemicals. In this work, a systematic study has been conducted to evaluate the effects of operating conditions on glycerol conversion to liquid chemical products in the presence of acid catalysts. </p><p>Central composite design for response surface method was used to design the experimental plan. Experiments were performed in a fixed-bed reactor using HZSM-5, HY, silica-alumina and ã-alumina catalysts. The temperature, carrier gas flow rate and weight hourly space velocity (WHSV) were maintained in the range of 350-500 oC, 20-50 mL/min and 5.40-21.60 h -1, respectively. </p><p>The main liquid chemicals detected in liquid product were acetaldehyde, acrolein, formaldehyde and hydroxyacetone. Under all experimental conditions complete glycerol conversion was obtained over silica-alumina and ã-alumina. A maximum liquid product yield of approximately 83 g/100g feed was obtained with these two catalysts when the operating conditions were maintained at 380 oC, 26 mL/min and 8.68 h-1. Maximum glycerol conversions of 100 wt% and 78.8 wt% were obtained in the presence of HY and HZSM-5 at temperature, carrier gas flow rate and WHSV of 470 oC, 26 mL/min and 8.68 h-1. HY and HZSM-5 produced maximum liquid product of 80.9 and 59.0 g/100 g feed at temperature of 425 and 470 oC, respectively.</p><p>Silica-alumina produced the maximum acetaldehyde (~24.5 g/100 g feed) whereas ã-alumina produced the maximum acrolein (~25 g/100 g feed). Also, silica-alumina produced highest formaldehyde yield of 9g/100 g feed whereas HY produced highest acetol yield of 14.7 g/100 g feed. The effect of pore size of these catalysts was studied on optimum glycerol conversion and liquid product yield. Optimum conversion increased from 80 to 100 wt% and optimum liquid product increased from 59 to 83.3 g/100 g feed when the pore size of catalyst was increased from 0.54 in case of HZSM-5 to 0.74 nm in case of HY, after which the effect of pore size was minimal.

Page generated in 0.0288 seconds