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  • 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.
71

Matte matters: When matte packaging increases perceptions of food naturalness

Marckhgott, Eva, Kamleitner, Bernadette January 2019 (has links) (PDF)
Matte surfaces, that is, those that are dull or lusterless not glossy and shiny, are a current trend in packaging. But does packaging surface affect what consumers think about the product inside it? We focus on consumers' perception of packaged food products at the point of sale. Using three experiments, we show that food in matte packaging can be perceived as more natural. Notably, the effect of matte packaging only holds for rather artificial products. When matte packaging increases perceptions of product naturalness, consumers also expect the product to be tastier and are more likely to buy it.
72

Seleção de materiais para embalado de transporte de Mo-99 / Material selection for a transportation package of Mo-99

Hara, Débora Harumi Suzuki 05 March 2015 (has links)
O transporte de materiais radioativos deve ser realizado em embalados capazes de suportar tanto condições normais, quanto acidentais de transporte. O objetivo deste trabalho foi a seleção de materiais que possam viabilizar a fabricação de um embalado para o transporte de substâncias que sejam fontes de alta radioatividade, em especial o Mo-99, cujo produto do decaimento radioativo é o Tc-99m, utilizado para fins diagnósticos na medicina nuclear. Para tanto, foi realizada a seleção dos possíveis materiais que podem ser utilizados para a fabricação de um embalado, com o auxílio do programa CES EduPack e a metodologia desenvolvida por Ashby. O programa ESTAR foi utilizado para verificar a ocorrência de radiação de freamento e o programa XCOM para o cálculo do coeficiente de atenuação da radiação gama de alguns dos materiais selecionados para compor a blindagem do embalado. Posteriormente, a espessura necessária para a blindagem da radiação foi calculada. A partir dos resultados obtidos, os materiais selecionados como candidatos potenciais para a fabricação da blindagem foram as ligas de tungstênio. Com relação à parte do embalado que oferece isolamento térmico e proteção ao impacto, destacam-se as madeiras, os aglomerados e os compensados. No que concerne ao revestimento interno e externo, os materiais selecionados se concentram nos aços. / The transport of radioactive materials must be done in packages able to withstand both normal and accidental conditions of transport. The aim of this work was the material selection that can enable the manufacture of a package for the transport of substances which are of high radioactivity sources, especially Mo-99, whose radioactive decay product is Tc-99m, used for diagnosis purposes in nuclear medicine. For this, the selection of possible materials that can be used for the manufacture of the main parts of the package was performed with the aid of CES Edupack program and the methodology developed by Ashby. The ESTAR program was used to check occurrence of Bremsstrahlung and the XCOM program was used to calculate the attenuation coefficient of gamma radiation from some of the selected materials for the shield. After, the thickness needed for the radiation shielding was calculated. From the results, the materials selected as potential candidates for the manufacture of the shielding was the tungsten alloys. Related to the thermal insulation and the impact protection, woods, plywoods and particleboards stand out. With regard to internal and external recipients, the selected materials focus on steels.
73

Advances in the use of aerobic sequencing batch reactors for biological wastewater treatment

Rasheed, Adamu Abubakar January 2017 (has links)
The overall aim of this research was to contribute to the optimisation of aerobic wastewater treatment processes in sequencing batch reactors, by investigating the performance of the process with real and model wastewaters in order to achieve the highest possible reduction of influent COD with the minimum reactor volume and oxygen consumption. Six industrial wastewaters from the food and drink companies were treated in lab-scale aerobic sequencing batch reactors (SBRs) inoculated with soil and monitored for COD and total suspended solids (TSS) removal. The results showed high COD removal efficiencies for all the wastewaters, in the range of 64-95 %. Extended aeration tests were carried out on the reactor effluents and the results indicated that the residual soluble COD was not further biodegradable. This indicates that the soluble BOD removal in the reactors was virtually 100 %. The biodegradation efficiency was investigated over two values of the solids retention time (SRT) and the performance of the reactors was essentially unaffected by the SRT (in the range of 7-18 days considered in this study). This means that very good COD removal can be achieved at relatively lower SRT, with potential savings in capital and operating costs. The removal of TSS for the wastewaters was not satisfactory, largely due to the low food to microorganism (F/M) ratios (0.13-0.29 kg COD/kg biomass.day) in the reactors. Three batch tests at different initial substrate to biomass (So/Xo) ratios were carried out on each of the two industrial wastewaters for kinetic characterisation of the wastewaters. Oxygen uptake rate (OUR) was measured during the tests and the OUR profiles were used for the estimation of the kinetic parameters using a mathematical model consisting of substrate hydrolysis, biomass growth and endogenous metabolism. The results showed large variations with regards to the values of the parameters for each wastewater due to day-to-day variability in the biomass's response to substrate utilisation. For the two industrial wastewaters, the hydrolysis rate constant (kh) and half saturation constant for slowly biodegradable substrate (KX) were found to be in the range of 2.21-14.8 kg COD/kg biomass.day and 0.006-0.45 kg COD/kg biomass respectively. The maximum growth rate (μmax) and the half saturation rate constant for readily biodegradable substrates (KS) ranged between 1.21-7.3 day-1 and 0.004-0.89 kg COD/m3 respectively. The biomass growth yield (YX/S) and the endogenous metabolism coefficient (b) were found to be 0.3-0.57 kg biomass/kg COD and 0.001-0.41 day -1 respectively. The hydraulic retention time (HRT) and SRT were optimised in order to minimise the SBR volume and maximise the organic loading rate (OLR) of the SBR process. Two model wastewaters, glucose and ethanol, were used in the study. An experiment of eleven different SBR runs (HRT in the range of 0.25-4 days and SRT of 1-65.3 days) was carried on the glucose wastewater. Nine different SBR runs were carried out on ethanol wastewater (HRT in the range of 0.5-4 days and SRT of 1-73.6 days). The minimum HRT and SRT values for the successful operation for glucose wastewater treatment were 0.25 days and 3.1 days respectively while the minimum HRT and SRT for ethanol were 0.5 days and 4.9 days respectively. The highest corresponding OLR values from the minimum HRT and SRT which gave satisfactory process performance were 4.28 g COD/l.day and 4.14 g COD/l.day for glucose and ethanol wastewaters respectively, which are among the highest OLRs reported in the literature for aerobic conventional dispersed-growth processes. The calculated oxygen consumption and biomass production were found to depend on the SRT as well as the OLR, where in general, oxygen consumption increased while biomass production decreased at higher OLR. Batch tests were also carried out on the two model wastewaters for kinetic characterisation. The kinetic parameters for glucose wastewater were: 1.07-4.79 day -1 for μmax, 0.24-0.45 kg COD/m3 for KS, 0.04-0.1 day-1 and 0.47-0.6 kg biomass/kg COD for b and YX/S respectively. For ethanol wastewater, the kinetic parameters were: 0.99-2.3 day -1 for μmax, 0.001-0.04 kg COD/m3 for KS, 0.05-0.2 day-1 and 0.38-0.51 kg biomass/kg COD for b and YX/S respectively. A new mathematical model and procedure to calculate the periodic steady state of the SBR using a kinetic model of the biological process and values of the kinetic parameters was developed. This new procedure allows the direct calculation of the steady state profiles of biomass and substrate in the SBR without calculating the dynamics of the system from start up to steady state. The numerical accuracy of the procedure was discussed and the model was applied to show the effect of the operating parameters (SRT, HRT, length of the phases and number of cycles) on the steady state performance in terms of biomass and substrate concentrations. It was also shown how the model can be used for various applications like: optimisation of operating parameters for a minimum reactor volume; simulation of the competition between filamentous and floc-forming bacteria for bulking control; and calculation of the minimum volumetric mass-transfer coefficient required to maintain a desired oxygen concentration. In the end, the periodic steady state of the SBR was simulated for the industrial and model wastewaters at various values of the operating conditions (e.g. HRT, SRT, number of cycles) using the developed SBR model with values of kinetic parameters obtained from the various batch tests. The predicted model performance in terms of effluent quality and biomass concentration was compared with experimental results achieved during the treatment of the wastewaters. The simulation gave very good prediction of the extent of substrate removal for all the wastewaters. However, the prediction was not very accurate for biomass concentration. The study indicated that a good model prediction in terms of biomass production is strongly dependent on the values of the kinetic parameters especially b and YX/S.
74

Measuring the perceived service quality of group package tours in China : a conceptual model and empirical evidence

He, Xiaomin 01 January 2004 (has links)
No description available.
75

THE IMPACT OF CHILDHOOD SOCIOECONOMIC STATUS ON ADULT REACTIONS TOWARD QUANTITY SURCHARGES

Li, Wenjing 01 January 2018 (has links)
Quantity surcharges have been widespread in the marketplace for decades. However, little is known about what kinds of consumers and under what conditions they are more likely to be impacted by this pricing practice. The current research contributes to the existing literature by investigating how a person’s childhood socioeconomic status affects their reaction toward quantity surcharges during adulthood. Across four studies, we find that childhood socioeconomic status has a positive impact on the purchase of a large and surcharged package size. However, when the economic conditions are threatening, the positive effect of childhood socioeconomic status disappears. The current research also provides a theoretical explanation for the interaction effect of childhood socioeconomic status and economic conditions. The focus on acquiring sufficient resources accounts for the interaction effect.
76

Development and trial of a low-cost aerobic greywater treatment system

Okalebo, Susan, University of Western Sydney, College of Science, Technology and Environment, School of Engineering and Industrial Design January 2004 (has links)
This study was undertaken to examine the feasibilty of a low-cost aerobic system to treat greywater for reuse.Its purpose was to provide a system that would be easy to maintain, flexible and be affordable for households and small communities in developing countries. This thesis outlines and evaluates the key biological and chemical hazards associated with greywater reuse. It discusses the performance of a variety of wastewater treatment options in use. It presents details of the components of the greywater system,namely, an aerobic grease trap and slow sand filter. Reference is made to the evaporation and treatment bed and ultraviolet disinfection components, but these are not examined. The incorporation of vermitechnology in the preliminary stages of the system for reduction of organics in greywater is reviewed. This study takes the traditional approach to water quality assessment with the measurement of physical, chemical and biological indicators. Assessment of the system involved examining the input characteristics of the greywater, monitoring the vermiculture system and sampling the liquid discharge from the aerobic grease trap and slow sand filter for analysis of the quality indicators. The results obtained under the framework of this study have provided recommendations for further use of the aerobic grease trap and slow sand filter, while propsing an approach for an appropriate long-term monitoring program. / Master of Engineering (Hons)
77

The impact of adding front-of-package sodium content labels to grocery products: an experimental study

Goodman, Samantha January 2011 (has links)
A high sodium diet is a predominant risk factor for hypertension, which is in turn a major risk factor for cardiovascular disease. Canadians consume approximately twice the daily Adequate Intake of sodium, most of which comes from processed foods. Enhancing nutrition labelling for sodium in the form of front-of-package (FOP) labels may help consumers select healthier products. This experimental study examined the efficacy of 4 types of FOP nutrition labels on participant selection of low versus high sodium products. 430 adults from the Waterloo Region were randomly assigned to one of 5 experimental conditions: (1) a control condition with no FOP label; (2) a basic numeric FOP label; (3) a numeric FOP label with “high” and “low” sodium content descriptors; (4) a detailed Traffic Light (TL) label with colour coding, content descriptors and numeric information; and (5) a simple TL label that did not include numeric information. Participants were shown pairs of grocery products that varied primarily in sodium content, and asked to select a free product. Selection of the low versus high sodium product served as the primary behavioural outcome; rankings and ratings of the experimental labels were also examined. Regression models were used to determine the relative efficacy of the 4 labelling formats, as well as the socio-demographic and diet and health-related predictors of these outcomes. Results indicated that participants in the FOP conditions with “low” and “high” sodium content descriptors (conditions 3, 4 and 5) were significantly more likely to choose the low sodium product compared to the control group. The detailed TL was ranked as the most effective at helping participants select low sodium products; this label was also rated significantly higher than other formats in liking, understanding and believability. Product selection did not differ significantly across socio-demographic groups, suggesting that FOP labelling might reduce the disparity in the use and understanding of nutrition labels among groups of varying socioeconomic status. This study has important policy implications. Results suggest that FOP labels should include content descriptors, which add prescriptive value and may help consumers select healthier products by improving understanding. TL labels, which incorporate content descriptors and colour coding, are recommended for future FOP labelling initiatives.
78

Design, Modeling, and Optimization of Compact Broadband and Multiband 3D System-On-Package (SOP) Antenna Architectures for Wireless Communications and Millimeter-Wave Applications

DeJean, Gerald Reuben 31 January 2007 (has links)
In recent years, the miniaturization of cell phones and computers has led to a requirement for antennas to be small and lightweight. Antennas, desired to operate in the WLAN frequency range, often possess physical sizes that are too large for integration with radio-frequency (RF) devices. When integrating antennas into three-dimensional (3D) system-on-package (SOP) transceivers, the maintenance of a compact size also provides isolation from other devices, hence, surface wave propagation or high dielectric constant materials such as low temperature cofired ceramics (LTCC) does not affect nearby components of the transceiver such as filters, baluns, and other embedded passives. Therefore, the application of design methods is necessary for realizing compact antennas in the wireless community that can be integrated to RF packages. Furthermore, it is essential that these compact antennas maintain acceptable performance characteristics, such as impedance bandwidth, low cross-polarization, and high efficiency. In addition, the analysis of circuit modeling techniques that could be used to obtain a better understanding of the physical phenomena of the antenna is quite necessary as modules become more and more complex. Based on these requirements, the focus of this research is to improve the design of compact antennas for wireless communications, wireless local area networks (WLAN), and millimeter-wave applications by using time-domain electromagnetic and circuit modeling techniques and optimizations. These compact antenna designs are applied to practical wireless communications systems such as global system of mobile communications (GSM), Bluetooth Industrial-Scientific-Medical (ISM) devices, IEEE802.11a WLAN, and Local Multipoint Distribution Systems (LMDS) applications. Parametric analyses are conducted to study critical parameters that may affect the antenna designs. Moreover, optimizations are performed to optimize the structures, and measured results are presented to validate design techniques.
79

Design of High Speed Packages and Boards Using Embedded Decoupling Capacitors.

Muthana, Prathap 11 May 2007 (has links)
Miniaturization of electronic products due to the current trend in the electronics industry has led to the integration of components within the chip and package. Traditionally, individual decoupling capacitors placed on the surface of the board or the package have been used to decouple active switching circuits. However, with an increase in the clock rates and its harmonics with technology nodes, decoupling has to be provided in the GHz range. Discrete decoupling capacitors are no longer effective in this region because of the increased inductive effects of the current paths of the capacitors, which limits its effectiveness in the tens of MHz range. The use of embedded individual thick film capacitors within the package is a feasible solution for decoupling core logic above 100 MHz. They overcome the limitations of SMDs (Surface Mount Discretes), primarily in decoupling active circuits in the mid-frequency band. Inclusion of embedded planar capacitors in the board stack up have shown improvements in the overall impedance profile and have shown to exhibit better noise performance. The main contributor to the superior performance is the reduced inductive effects of the power-ground planes because of the thinner dielectrics of the embedded capacitor. The modeling, measurement and characterization of embedded decoupling capacitors in the design of PDNs (Power Distribution Networks) has been investigated in this thesis.
80

Stacked Package MIMO Antenna and Isolator Design of MIMO Antenna

Lee, Cheng-Han 30 July 2012 (has links)
This thesis is divided into two parts. In the first part, the antenna is integrated into the stacked package. The antenna and the semiconductor chip are co-designed together. We utilize the advantage of IPD manufacturing to develop strong capacitively coupled-fed miniaturization technology and fractal slots miniaturization technology. We design a miniaturized antenna operating at WLAN 2.4GHz band. The size of the antenna is only 4 mm¡Ñ8.625 mm (0.0327£f¡Ñ0.0707£f). The operating bandwidth is over 100 MHz. The radiation efficiency is over 60%. In the second part, we design a stacked structure using FR4 substrate. The MIMO antenna is miniaturized by strong capacitively coupled-fed miniaturization technique, and we propose an S-shaped isolator which has wider isolation bandwidth to improve the isolation problem. The separation of both antennas is only 12 mm. The size of the isolator is only 10 mm¡Ñ10 mm. The measured operating bandwidth is 200 MHz, and the radiation efficiency is over 60%. We also design a 10 mm¡Ñ10 mm size of MIMO antenna with 2 mm¡Ñ8 mm isolator on the stacked package structure. The antenna is operating at WLAN 2.45 GHz band, and the operating bandwidth is over 100 MHz. the radiation efficiency is over 40%. Finally, we propose two different stacked package antenna applications. The first one is a dual-frequency design. The proposed antenna is operating at GPS (1.57 GHz) band and WLAN 2.4 GHz band. Another is a broadband design. The size of IPD is only 3 mm¡Ñ3 mm. The operating bandwidth is 40% (from 4.8 GHz to 7.2 GHz).

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