<p>Cake filtration is a unit operation to separate solids from fluids in industrial processes. The build up of a filter cake is usually accompanied with a decrease in overall permeability over the filter leading to an increased pressure drop over the filter. For an incompressible filter cake that builds up on a homogeneous filter cloth, a linear pressure drop profile over time is expected for a constant fluid volume flow. However, experiments show curved pressure drop profiles, which are also attributed to inhomogeneities of the filter (filter medium and/or residual filter cake).</p><p>In this work, a mathematical filter model is developed to describe the relationship between time and overall permeability. The model considers a filter with an inhomogeneous permeability and accounts for fluid mechanics by a one-dimensional formulation of Darcy's law and for the cake build up by solid continuity. The model can be solved analytically in the time domain. The analytic solution allows for the unambiguous inversion of the model to determine the inhomogeneous permeability from the time resolved overall permeability, e.g. pressure drop measurements. An error estimation of the method is provided by rewriting the model as convolution transformation.</p><p>This method is applied to simulated and experimental pressure drop data of gas filters with textile filter cloths and various situations with non-uniform flow situations in practical problems are explored. A routine is developed to generate characteristic filter cycles from semi-continuous filter plant operation. The model is modified to investigate the impact of non-uniform dust concentrations.</p>

Cake filtration is a unit operation to separate solids from fluids in industrial processes. The build up of a filter cake is usually accompanied with a decrease in overall permeability over the filter leading to an increased pressure drop over the filter. For an incompressible filter cake that builds up on a homogeneous filter cloth, a linear pressure drop profile over time is expected for a constant fluid volume flow. However, experiments show curved pressure drop profiles, which are also attributed to inhomogeneities of the filter (filter medium and/or residual filter cake). In this work, a mathematical filter model is developed to describe the relationship between time and overall permeability. The model considers a filter with an inhomogeneous permeability and accounts for fluid mechanics by a one-dimensional formulation of Darcy's law and for the cake build up by solid continuity. The model can be solved analytically in the time domain. The analytic solution allows for the unambiguous inversion of the model to determine the inhomogeneous permeability from the time resolved overall permeability, e.g. pressure drop measurements. An error estimation of the method is provided by rewriting the model as convolution transformation. This method is applied to simulated and experimental pressure drop data of gas filters with textile filter cloths and various situations with non-uniform flow situations in practical problems are explored. A routine is developed to generate characteristic filter cycles from semi-continuous filter plant operation. The model is modified to investigate the impact of non-uniform dust concentrations.

We carry objects from place to place in bags, all the while maintaining that they are trivial objects. If we categorize objects as mundane, then why do we carry them everywhere we go? I interviewed female students at the Claremont Colleges about what they carry in their bags. College women articulate many distinct reasons for carrying a bag and for carrying the items within that bag. My participants perceive the items they carry as mundane, and do not question the presence of those items in their lives. Yet they also claim to need the items they categorize as trivial. They perceive the need to carry items as natural, and so do not question that need. My project demonstrates the ways college women make objects seem trivial and make needs seem natural. Through ethnographic interviews, I highlight how things perceived as mundane have significance. Additionally, I show that carrying a bag and carrying objects enables college women to be prepared to care for the well-being of themselves and the people around them. Between perceptions of objects as inessential and perceptions of the functions of objects as superficial, college women find value in carrying items.

Background: Aerosol therapy has been established as an efficient form of drug delivery to pediatric and adult patients with respiratory diseases; however, aerosol delivery to the pediatric population is quite challenging. While some studies compare jet nebulizer (JN), vibrating mesh nebulizer (VMN), or JN and pMDI, there is no study comparing these three devices in pediatric and young children. The aim of this study quantifies aerosol deposition using JN, VMN, and pMDI/VHC in a simulated pediatric with active and passive breathing patterns. Methods: Each aerosol generator was placed between manual resuscitator bag (Ambu SPUR II Disposable Resuscitator, Ambu Inc, Glen Burnie, MD) and infant facemask (Mercury Medical, Cleanwater, FL), which was held tightly against the SAINT model. Breathing parameters used in this study were Vt of 100 mL, RR of 30 breaths/min, and I:E ratio of 1: 1.4. Active and passive breathing patterns were used in this study with aerosol device; active breathing pattern was created using a ventilator (Esprit Ventilator, Respironics/Philips Healthcare, Murrysville, PA) connected to a dual chamber test lung (Michigan Instruments, Grand Rapids, MI), which was attached to an absolute filter (Respirgard II, Vital Signs Colorado Inc, Englewood, CO), to collect aerosolized drug, connected to the SAINT model. Pediatric resuscitator bag was run at 10 L/min of oxygen and attached to aerosol generator with facemask. In passive breathing pattern, SAINT model was attached to test lung and ventilated using the resuscitator bag with the same breathing parameters. Each aerosol device was tested three times (n=3) with each breathing patterns. Drug was eluted from the filter and analyzed using spectrophotometry. The amount of drug deposited on the filter was quantified and expressed as a percentage of the total drug dose. To measure the differences in the inhaled drug mass between JN, VMN, and pMDI/VHC in active or passive breathing, one-way analysis of variance (one-way ANOVA) was performed. To quantify the difference in aerosol depositions between the two breathing patterns, independent t-test was performed. A p < 0.05 was considered to be statistically significant. Results: Although the amount of aerosol deposition with the JN was the same in passive and active breathing without any significant difference, the VMN was more efficient in active breathing than the JN (p = 0.157 and p = 0.729, respectively). pMDI/VHC had the greatest deposition in the simulated spontaneous breathing (p=0.013) Conclusion: Aerosol treatment may be administered to young children using JN, VMN, or pMDI/VHC combined with resuscitator bag. Using pMDI/VHC with resuscitator bag is the best choice to deliver albuterol in spontaneously breathing children. Further studies are needed to determine the effectiveness of these aerosol generators with different type of resuscitator bag and different breathing parameters.

Abstract The research compares the efficiency of particle removal from exhaust of ritual money burning by an electrostatic precipitator (ESP) and a bag-house filter (BH), both have a capacity of around 30-35 Am3/min. A stainless steel chamber of 0.6 m in diameter and 1.0 m in height was used for the ritual money burning. Combustion gas from the chamber was cooled to 300-400oC by mixing with a certain proportion of ambient air and further cooled to around 100-130oC by a fin tube gas cooler before entering either to the ESP or the BH. Results indicate that TSP in the influent gas could be reduced from 6-392 (average 83) to 1-143 (average 22) mg/Nm3 by the ESP with gas velocities of 5-10 cm/s at 100-120 oC through the spacing between collecting plates. TSP emission factors of 0.0295-9.94 (average ¡Ó standard deviation = 1.81¡Ó2.25) and 0.031-3.36 (average ¡Ó standard deviation = 0.27¡Ó0.26) g/(kg combusted ritual money), respectively, were obtained before and after the ESP filtration. Although the ESP had an initial TSP removal of 80-99%, the performance dropped in a few operation hours because of a fouling of the plate surfaces by the collected fume dusts. Cleaning of the plate surfaces helped in the recovery of the performance, however, it dropped after a few cycles of collection and cleaning. Results from BH tests indicate that TSP in the influent gas to it could be reduced from 9-182 (average 72) to 0-12 (average 2.0) mg/Nm3 with the gas flow through the filter cloth with a velocity of 3.3 cm/s at 120-130 oC which resulted in an initial pressure drop of around 100 mmAq. It was observed that some fine dusts would escape from the cloth fiber spaces when the backwash pulse was operated. It is recommended that the backwash cycle should be minimized and trigged after the gas pressure drop over the cloth reaches up to 300 mmAq. TSP emission factors of 0.0176-1.64 (average ¡Ó standard deviation = 0.52¡Ó0.33) and 0-0.491 (average ¡Ó standard deviation = 0.02¡Ó0.05) g/(kg combusted ritual money), respectively, were obtained before and after the BH filtration. BH filtration is recommended for the TSP control in the ritual money buring. XRD(X-Ray Diffraction) examination of a bottom ash sample indicates that the ash has an elemental composition of O, Na, Al, and Si of 49.9, 11.8, 23.8, and 15.1%, respectively. SEM(Scanning Electron Microscope) analysis indicates that the collected fly ash and the bottom ash have particle sizes of 20-110 (mostly 45-60 nm) and 50-300 (average 250) nm, respectively.

A novel approach is proposed for real-time retrieval of images from a large database of overlapping images of an indoor environment. The procedure extracts visual features from images using selected computer vision techniques, and processes the extracted features to create a reduced list of features annotated with the frame numbers they appear in. This method is named landmark indexing. Unlike some state-of-the-art approaches, the proposed method does not need to consider large image adjacency graphs because the overlap of the images in the map sufficiently increases information gain, and mapping of similar features to the same landmark reduces the search space to improve search efficiency. Empirical evidence from experiments on real datasets shows high (90-100%) accuracy in image retrieval, and improvement in search time from the order of 100-200 milliseconds to the order of 10-30 milliseconds. The image retrieval technique is also demonstrated by integrating it into a 3D real-time navigation system. This system is tested in several indoor environments and all experiments show accurate localization results in large indoor areas with errors in the order of 15-20 centimeters only. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-04-24 12:44:41.429

In this paper, an object recognition system has been developed that uses local image features. In the system, multiple classes of objects can be recognized in an image. This system is basically divided into two parts: object detection and object identification. Object detection is based on SIFT features, which are invariant to image illumination, scaling and rotation. SIFT features extracted from a test image are used to perform a reliable matching between a database of SIFT features from known object images. Method of DBSCAN clustering is used for multiple object detection. RANSAC method is used for decreasing the amount of false detection. Object identification is based on 'Bag-of-Words' model. The 'BoW' model is a method based on vector quantization of SIFT descriptors of image patches. In this model, K-means clustering and Support Vector Machine (SVM) classification method are applied.

Thesis (M.S.)--University of California, Davis, 2004. / Text document in PDF format. Title from PDF title page (viewed on September 15, 2009). "Received by ITS-Davis: June 2004"--Publication detail webpage. Includes bibliographical references (p. 115-122 and p. 175).

This study focuses on women vendors' perspectives on plastic bag consumption in markets in Mali. It also investigates how women across the urban and rural divide are affected by plastic bag pollution and to what extent women in Mali are included in policy formulation addressing plastic bag issues. I interviewed thirty women vendors in three research sites: Bougouni, Koulikoro and Bamako. In addition, I interviewed five Mali Officials including the Prime Minister and the Minister of Environment. Plastic bags continue to be used widely in all African countries, including Mali. This has created increased environmental pollution as there is no recycling due to the lack of appropriate technology or political will. Reducing the use of plastic bags, and thus pollution, requires social and economic change that may be difficult to implement without involving one of the largest consumers of plastic bags, women, specifically those selling at the market.

Este trabalho teve como objetivo principal avaliar a capacidade adsorvente do bagaço da uva Isabel (Vitis labrusca x Vitis vinifera) na remoção do fármaco diclofenaco de sódio (DCF) presente em meio aquoso. O material foi inicialmente caracterizado por meio de diversas técnicas, incluindo a espectroscopia de ressonância magnética nuclear de carbono-13 no estado sólido (RMN 13C), a análise elementar (CHNS), a espectroscopia de infravermelho com Transformada de Fourier (IV), a análise termogravimétrica (TG), e a microscopia eletrônica de varredura (MEV). A área superficial específica, assim como o diâmetro médio das partículas e o pH no ponto de carga zero (pHPCZ), foram igualmente determinados. Posteriormente, a capacidade de adsorção do bagaço de uva foi investigada, sob agitação mecânica, utilizando-se a técnica de espectroscopia de absorção molecular na região do ultravioleta (UV). Os parâmetros como massa de adsorvente e velocidade de agitação foram previamente otimizados, a fim de se conseguir acompanhar esse processo. O efeito do pH, do tempo de contato, da concentração inicial de DCF, e da temperatura também foram avaliados. Verificou-se que o processo de adsorção, para concentrações de DCF maiores do que 10 mg L-1, ocorreu em duas etapas. O modelo cinético de pseudossegunda ordem foi o que melhor descreveu a velocidade do processo na primeira etapa. Além disso, o percentual de remoção (~20%) foi semelhante para todas as concentrações estudadas. Para a segunda etapa, o processo de difusão intrapartícula foi o que melhor se ajustou aos dados experimentais, sendo que o percentual de remoção aumentou com o aumento da concentração inicial do fármaco (de 57 a 74%). No que se refere ao equilíbrio do processo, a isoterma de Freundlich foi a que melhor se ajustou aos resultados experimentais a 22°C, sendo que a adsorção do DCF pelo bagaço de uva apresentou um valor de KF e de n iguais a 1,72 L g-1 e 1,18, respectivamente. Do ponto de vista termodinâmico, o processo foi exotérmico (ΔH°ads = – 36,86 kJ mol-1), não-espontâneo (ΔG°ads > 2,99 kJ mol-1), ocorrendo com uma diminuição na aleatoriedade do sistema (ΔS°ads = – 135,85 J mol-1 K-1). Isso aconteceu possivelmente pelo fato de ambas as espécies (bagaço de uva e DCF) estarem carregadas negativamente na condição de pH avaliada (pH em torno de 5,0). / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-23T11:57:04Z No. of bitstreams: 1 Dissertacao Marjore Antunes.pdf: 2101531 bytes, checksum: c2df0b11d77d0b1644ccf36cd64e1499 (MD5) / Made available in DSpace on 2014-06-23T11:57:04Z (GMT). No. of bitstreams: 1 Dissertacao Marjore Antunes.pdf: 2101531 bytes, checksum: c2df0b11d77d0b1644ccf36cd64e1499 (MD5) / The aim of the present work was to evaluate the adsorption capacity of the Isabel grape bagasse (Vitis labrusca x Vitis vinifera) in the removal of the pharmaceutical diclofenac sodium (DCF) present in aqueous media. The biomass was initially characterized by several techniques including solid-state 13C nuclear magnetic resonance spectroscopy (13C NMR), elemental analysis (CHNS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The specific surface area as well as the average diameter of the particles and the pH at the point of zero charge (pHPZC) were also determined. Subsequently, the adsorption capacity of the grape bagasse was investigated, under mechanical stirring, by molecular absorption spectroscopy in the ultraviolet (UV) region. The parameters such as adsorbent mass and stirring speed were previously optimized in order to be able to follow this process. The effect of pH, contact time, initial concentration of DCF, and temperature were also evaluated. It was observed that the adsorption process for DCF concentrations greater than 10 mg L-1 occurred in two stages. The pseudo-second-order kinetic model was more significant in the rate-controlling step in the first stage. In addition, the removal percentage (~ 20%) was similar for all concentrations studied. For the second step, on the other hand, the intraparticle diffusion process showed the best fit to the experimental data and the removal percentage increased with increasing initial concentration of the drug (from 57 to 74%). Concerning to the equilibrium process, the Freundlich isotherm showed the best fit to the experimental results at 22°C, and the adsorption of DCF onto grape bagasse presented a value of KF and n equal to 1.72 g L-1 and 1.18, respectively. From the thermodynamic point of view, the process was exothermic (ΔH°ads = – 36.86 kJ mol-1), non-spontaneous (ΔG°ads > 2.99 kJ mol-1), occurring with a decrease in the randomness of the system (ΔS°ads = – 135.85 J mol-1 K-1). This occurred probably because both species (grape bagasse and DCF) were negatively charged at pH condition evaluated (pH around 5.0).