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1
Marangopoulos, Ioannis P. "Ultrasonic cleaning baths : field measurements and cleaning efficiency." Thesis, University of Aberdeen, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342194.
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Ultrasonic cleaning baths are routinely used for cleaning dental and surgical instruments. The importance of efficient cleaning prior to sterilisation is great. Micro-organisms can survive the sterilisation process as debris can act as an insulator. The information available on ultrasonic field distributions in cleaning baths is limited. A thermal technique, employing a thermistor probe coated with an absorbing material measures the temperature rise when the field is switched on compared to no sound temperature. Contour plots of the field of the cleaning bath resulted from point-to-temperature. Contour plots of the field of the cleaning bath resulted from point-to-point measurements. Optical methods were also employed for qualitative measurements of the field. The main optical method used in this study is the Sarvazyan, dye/paper method where dye patterns represent the distribution of the field's cavitation activity at that area. Titanium coated mica was also used for seeding the bath. When the field was switched on, these particles migrated towards the antinodes, the distribution of particles in the field gives qualitative measure for the field. Aluminium surfaces were sonicated and erosion with pitting was evident after 30-60 minutes sonication time. Some plates were examined under an SEM. Cleaning efficiency was directly examined by coating perspex and stainless steel plates with blood. The plates were left to dry for 24 hours then sonicated. Water and Decon-90® detergent gave very similar removal times, with the detergent to achieve cleaning marginally faster compared to water. A disinfectant-detergent was also used, Virkon®. The results with Virkon were disappointing, red cells were caused to lyse up by Virkon and as a result a colloidal mixture was formed. This mixture was not able to be removed ultrasonically, even after an hour or more sonication time. Manual brushing was required in that case. In general all baths tested showed a non-uniform field pattern that can result in insufficient cleaning.
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Haleva, Kristina. "Cleaning with vacuum." Thesis, Mittuniversitetet, Avdelningen för industridesign, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-20265.
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The following document describes a process of new vacuum cleaner design development. The focus for this project fell on the problems that elderly and peoplewith different musculoskeletal disorders in the body experience with the product and how this issues could be eliminated trough the design.A Design for All methods were used during the whole process in order to deliver successful product. Elderly and users with different back, legs, hips, armsand hands problem were highly involved in the whole process. They periodically tested and evaluated new design suggestions and ideas through models andsketches.The results from the research and process showed that there are significant problems regarding the vacuum cleaner usage. One of the main issues is that usinga vacuum cleaner requires a lot bending and movement that might be painful and inconvenient for certain group.The final design proposal was proven to solve many of the problems that were outlined. Special attention was paid to minimize the bending moments whentransporting and maintaining the vacuum cleaner, as well as to eliminate unnatural and inconvenient postures when the cleaning task is performed.
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Fang, Lih-chuan. "Hydrodynamic cleaning of cavities." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263772.
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Mulder, Rickert. "Accelerating point cloud cleaning." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25512.
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Capturing the geometry of a large heritage site via laser scanning can produce thousands of high resolution range scans. These must be cleaned to remove unwanted artefacts. We identified three areas that can be improved upon in order to accelerate the cleaning process. Firstly the speed at which the a user can navigate to an area of interest has a direct impact on task duration. Secondly, design constraints in generalised point cloud editing software result in inefficient abstraction of layers that may extend a task duration due to memory pressure. Finally, existing semi-automated segmentation tools have difficulty targeting the diverse set of segmentation targets in heritage scans. We present a point cloud cleaning framework that attempts to improve each of these areas. First, we present a novel layering technique aimed at segmentation, rather than generic point cloud editing. This technique represents 'layers' of related points in a way that greatly reduces memory consumption and provides efficient set operations between layers. These set operations (union, difference, intersection) allow the creation of new layers which aid in the segmentation task. Next, we introduce roll-corrected 3D camera navigation that allows a user to look around freely while reducing disorientation. A user study shows that this camera mode significantly reduces a user's navigation time (29.8% to 57.8%) between locations in a large point cloud thus reducing the overhead between point selection operations. Finally, we show how Random Forests can be trained interactively, per scan, to assist users in a point cloud cleaning task. We use a set of features selected for their discriminative power on a set of challenging heritage scans. Interactivity is achieved by down-sampling training data on the fly. A simple map data structure allows us to propagate labels in the down-sampled data back to the input point set. We show that training and classification on down-sampled point clouds can be performed in under 10 seconds with little effect on accuracy. A user study shows that a user's total segmentation time decreases between 8.9% and 20.4% when our Random Forest classifier is used. Although this initial study did not indicate a significant difference in overall task performance when compared to manual segmentation, performance improvement is likely with multi-resolution features or the use of colour range images, which are now commonplace.
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Shorrock, Chris. "Membrane cleaning : cleaning-in-place of a microfiltration membrane fouled during yeast harvesting." Thesis, University of Bath, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285410.
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Sandén, Pernilla, and Jeff Pertot. "Autonomous cleaning robot as a service : Exploring value co-creation opportunities for an autonomous cleaning robot in the context of a cleaning service." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-166828.
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The purpose of this thesis is to explore the value co-creation opportunities for an autonomous cleaning robot, in the context of a cleaning service, by using several prototyping methods. Assuming a service perspective, with an exploratory, multi-stakeholder, and collaborative approach, a case study of an autonomous cleaning robot currently in development is conducted. With the methodological approach of sequentially and iteratively going through the phases of Mapping and Ideation, Conceptualization, Prototyping, and Data analysis, a total of 10 co-creative, stakeholder-centric workshops were conducted, using various prototyping methods e.g. Contextual value network mapping and Desktop walkthrough. Findings show that the value that an autonomous cleaning robot can bring different stakeholders in the context of a cleaning service is multi-facetted and can be divided in to eight different Aspects, where each value carries a different implication at the level of the individual and the level of the system. Furthermore, a list of seven different Design parameters and four different Design problems are presented, which should be used as guidelines when further developing a cleaning service that uses an autonomous cleaning robot. Finally, the implications of the findings are put into a broader perspective through discussion, with topics such as the impact of more robots in society.
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Marangoni, Federico. "Filter cleaning with liquid droplets." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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L’obiettivo del lavoro svolto è quello di identificare una modalità economica ed applicabile per la pulizia e rigenerazione di filtri di profondità, in particolare nella filtrazione di solidi da correnti gassose. Si ha attualmente mancanza di un tale metodo, che consentirebbe di poter rigenerare il filtro senza che debba essere necessariamente sostituito.
Il lavoro consiste in un approccio sperimentale che studia una singola fibra impolverata da particelle solide. Sono stati proposti dei modelli che descrivono le interazioni tra particella, fibra e liquido. Da questo è stato ricavato un criterio teorico per determinare la riuscita o meno della rimozione di una singola particella solida adesa ad una fibra posta verticalmente e sottoposta al passaggio di un film di liquido con un determinato spessore.
L’apparato sperimentale predisposto permette il fissaggio della fibra, sulla quale vengono fatte scorrere le gocce del liquido di pulizia. Tali gocce sono osservate nella discesa con una fotocamera ad alta frequenza. L'appartato sperimentale ha permesso di variare i principali parametri sperimentali e di testare diverse combinazioni fibra-particelle.
Il parametro chiave nella pulizia è stato individuato nella forza di adesione, dipendente dal liquido utilizzato per la pulizia. Dal punto di vista geometrico, la geometria più affine alla pulizia si è rivelata la geometria cilindrica di piccolo diametro a sfavore di una geometria planare.
L’utilizzo di gocce di liquido più grandi e l’uso di un numero elevato di gocce permette di migliorare il livello di pulizia: entrambi i fattori possono restituire un vantaggio nella pulizia ma si contrappongono al costo materiale del liquido.
Nel complesso, la metodologia di pulizia proposta si è rivelata promettente, con ampie possibilità di essere estesa a filtri industriali.
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Natvig, Ingunn Roald. "Gas cleaning with Granular Filters." Thesis, Norwegian University of Science and Technology, Department of Energy and Process Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-8822.
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The panel bed filter (PBF) is a granular filter patented by A. M. Squires in the late sixties. PBFs consist of louvers with stationary, granular beds. Dust is deposited in the top layers and on the bed surface when gas flows through. PBFs are resistant to high temperatures, variations in the gas flow and hot particles. The filter is cleaned by releasing a pressure pulse in the opposite direction of the bulk flow (a puff back pulse). A new louver geometry patented by A. M. Squires is the filter tray louvers. The new design is believed to reduce the pressure drop and the number of louvers, and to make the filter more compact. We have designed and built a laboratory scale PBF with filter tray louvers based on the patent. Experiments with the prototype show that the new louver can be cleaned with a puff back pulse. A PBF system for a hypothetical biomass combustion plant has been designed. The heat from the flue gas will be used for district heating. The proposed PBF system design consists of double-sided modules with 46 filter tray louvers on top of each other. Five modules are mounted together in module columns, sharing the same clean gas duct and puff back pipe. The granular medium chosen is Sintered Bauxite 20/40 (SB). The module columns are placed in an enveloping house. SB and dust fall into bins in the bottom of the enveloping house during puff back cleaning. A vacuum pneumatic conveying system brings the dust and SB to the top of the filter. Dust and SB are separated in a sieve. Dust is deposited, and SB is transported back to the modules. NTNU is currently involved in the BioSOFC project. The objective of this project is to increase efficiency in energy production from biomass by using producer gas from a biomass gasification plant in a Solid Oxide Fuel Cell. Field tests will be performed at a plant in Güssing, Austria. A PBF will be used for gas filtration. The operating temperature will be 500 °C to avoid tar condensation. We have performed heating experiments on the BioSOFC filter system. The results were not satisfactory, as the temperature in the filter ranged from 384 to 625 °C. The filter system was due to be shipped, and new tests could not be performed. This work proposes that modifications to the heating cable circuits are made, and new heating tests are performed before the field testing.
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Demir, Emre. "Cleaning Of Sirnak Karatepe Asphaltites." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12611392/index.pdf.
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Asphaltite is petroleum originated substance and formed by metamorphism. Turkey has 82 million tons of asphaltite reserves in Sirnak and Silopi region of Southeastern part of Anatolia. The proximate analysis of Sirnak Karatepe asphaltite
sample indicated that the ash and sulfur content were 46.86 % and 5.56 %, respectively.
In this study, Sirnak Karatepe asphaltite sample was concentrated by gravity separation and flotation methods. The aim of this research was to decrease the ash and sulfur content below 20% and 2%, respectively, which are the requirements of Sirnak Municipality.
Gravity based cleaning equipments such as multi gravity separator, shaking table and Falcon concentrator gave no satisfactory results in terms of ash and sulfur removal. The products with lowest ash content were obtained with Falcon
concentrator after two stage cleaning of -100 micrometer feed.
Flotation parameters of Karatepe asphaltite were also examined during the study. As a result of multi-stage flotation with stage addition of Collector Accoal 9630 and depressant
Na2SiO3 , ash content of asphaltite was decreased to 17.59 % with 15.31 % combustible recovery. Even though the ash content specification met by flotation, the sulfur content of cleaned asphaltite (6.68 % S) was more than the sulfur limit of Sirnak Municipality.
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Bird, Michael Roger. "Cleaning of food process plant." Thesis, University of Cambridge, 1993. https://www.repository.cam.ac.uk/handle/1810/251541.
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Kaye, Peter Langford. "The erosive cleaning of surfaces." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364393.
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Pires, Margarida Calejo. "Laser cleaning of precious metals." Thesis, University of Liverpool, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539476.
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Cooper, Martin I. "Laser cleaning of stone sculpture." Thesis, Loughborough University, 1994. https://dspace.lboro.ac.uk/2134/6841.
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This thesis is concerned with different aspects of laser cleaning of stone sculpture including the interaction of laser radiation with stone, evaluation and monitoring of the cleaning process and the development of a practical cleaning tool. Results show that a Q-switched Nd:YAG laser is the most suitable type of laser for the removal of black encrustations from marble and limestone surfaces. Measurements of the absorptivity of polluted and clean stone surfaces at 1.06 itm show that a typical black crust, resulting from atmospheric pollution, absorbs 2.5-3.5 times as much of the incident radiation as typical clean limestone and marble surfaces. This is shown to lead to the controlled removal of black crust material, by several thermal and mechanical mechanisms, without damaging the underlying stone. Measurements of ablation thresholds, by deflection of a probe beam, reveal that material is removed from a black crust at a fluence approximately half that required to remove material from a clean limestone or marble surface. Monitoring of the acoustic pulse generated during the laser beam/stone interaction is used to characterise the cleaning process. Results also show that cleaning is more efficient when a thin layer of water is applied to the surface prior to irradiation. Surface analysis techniques show that if cleaning is carried out below the damage threshold of the stone there is no modification to its physical or chemical structure. Cleaning of limestone sculpture from Lincoln Cathedral and terracotta sculpture from the Victoria and Albert Museum shows laser cleaning to be more refined than conventional cleaning techniques and to have considerable advantages in the area of health and safety.
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Pérez, Mohedano Raúl. "Cleaning principles in automatic dishwashers." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6590/.
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Cleaning inside automatic dishwashers (ADWs) represents an example of a ‘black box’ problem. The description of the phenomena occurring during a typical wash cycle is not currently well known. This thesis aims to illustrate and expand the in-depth knowledge required to better understand the wash process by analysing the different mechanical and chemical factors involved as well as the interactions between them. Online measurements techniques (Positron Emission Particle Tracking, scanning Fluid Dynamic Gauge or Image Analysis) were combined with statistical and numerical modelling to investigate the evolution over time of the cleaning system.
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Moawad, E. M. "Shaping and cleaning in endodontics." Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3011911/.
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Benjamin, Michael L. "Investigations of Cleaning Product Sprays." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504873614623952.
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Laing, Richard Alexander. "Stone cleaning : a value assessment." Thesis, Robert Gordon University, 1999. http://hdl.handle.net/10059/530.
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Buildings are an important record of a country's history and cultural heritage, and make an important contribution to modern cultural identity. Any intervention which changes their appearance, or the manner in which they contribute towards the living environment,should therefore be considered rigorously prior to such intervention being carried out. Stone cleaning has been applied widely to many buildings over a period of more than three decades, producing a varied range of results. This project is concerned with the development of a reliable methodology which can be employed as part of a decision making process, to help ensure that future stone cleaning takes full account of the implications for overall value (overall value is conceived of as the aggregate of financial, environmental and heritage values). Stone cleaning has been completed in the past within an environment where although guidelines of best practice have been available, questions of the resultant value changes have been considered only indirectly through client preference, planning consideration and availability of finance. This project strove to explore the Value system surrounding stone cleaning, and thus provide an assessment mechanism through which value can be considered in the future. Assessment of the financial requirements and implications of stone cleaning indicates strongly that not only are short term gains in financial value uncertain, but that any longer term maintenance requirements as a result of cleaning will be likely to balance those gains. The environmental assessment methodology (using the contingent valuation method) has produced encouraging results, indicating that the level of bid is influenced by both the respondent knowledge of cleaning and the stone type. These provide powerful indicators for use in the overall assessment. Methodologies used previously to assess heritage value have been considered, and an approach developed through which the objective and subjective elements of the value assessment can be related. The approach to overall assessment emanating from this research structures a series of assessments, ensuring that gains in the short term cannot override potential losses over the remaining life cycle. An ultimate aim of all stone cleaning is to enhance the built environment in some respects. The aim of this value assessment is to ensure that cleaning is completed only where an overall gain or benefit in value is attainable.
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Yue, Liyang. "Laser cleaning of slotted components." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/laser-cleaning-of-slotted-components(c66c7114-d1d7-40be-a2c9-b99329435a43).html.
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Laser cleaning is a non contact, highly controllable process for the removal of contaminants from a surface with minimum or no damage to the substrate material. Laser cleaning has been applied mainly on flat and curved surfaces. Little is known on the phenomena and feasibility of laser cleaning of slotted structures. Slots are common structures in engineering, and can be found in many components. In this PhD work, the feasibility of laser cleaning of alpha case on flat titanium alloy surfaces was initially explored, and then an investigation was made on the use of a pulsed laser for the cleaning of micro to macro slots in silicon and metallic materials. The effects of laser processing parameters on the contaminant removal from these slots were experimentally studied. Laser cleaning thresholds and cleanliness was examined. Meanwhile, finite element modelling (FEM) and time domain finite difference modelling techniques were used to simulate the processes involved to aid the understanding of the technique for process optimisation. The experiments were undertaken to verify if such models are able to accurately predict the cleaning thresholds. The surface and sub-surface characteristics before and after laser cleaning were examined using optical microscopy and scanning electron microscopy (SEM). It has been shown that the slot structure and its material properties were not damaged or changed by laser cleaning process. A novel contribution is that surface morphology after the laser ablation could be used as a diagnostic method to indentify the presence of alpha case and measure its thickness due to the specific characteristics of the surface roughness and generated cracks on the ablated surface after laser irradiation. Besides, it has been found that an axial beam which propagates into the narrow slots can successfully clean the tiny particles on the slot sidewalls whose width ranges from 3.5 mm to 13mm. These phenomena had never been reported before.
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Lang, Florian. "Steam Laser Cleaning von Siliziumwafern." [S.l. : s.n.], 2003. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10405592.
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Noor, Hisham Nur Ain. "Self-cleaning Photovoltaic (PV) Modules." Thesis, Noor Hisham, Nur Ain (2017) Self-cleaning Photovoltaic (PV) Modules. Honours thesis, Murdoch University, 2017. https://researchrepository.murdoch.edu.au/id/eprint/41910/.
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The effect of soiling accumulation towards photovoltaic (PV) could cause a reduction in the PV system performance. The decrease in PV system output due to soiling has been proven crucial(Jiang, Lu, and Sun 2011). Thus signifies the significance of further research on the effect of soiling on a PV system. This project is a research based on the climate in Murdoch, Western Australia. This project consists of three parts; Photovoltaic (PV) performance testing, Air quality testing, Light transmittance testing. The PV performances were analysed based on three different dust mitigation conditions. The first module labelled as A is washed regularly as part of the dust mitigation strategies applied. The second module, labelled as B has a hydrophobic coating which functions when rainwater fall on the panel, the water would roll off the module at the same time rolling dust off the module. The third module, labelled as C is kept without any dust mitigation method. All three modules were tested out and washing performs the best giving a reduction in performance of 30.8% after 18 days, while B reduces in 47.4% performance and C has a 31.4% reduction in performance. Test 2 involves correlating the air quality with the dust accumulation on the PV modules. An optical dust sensor is used for this test. Test 3 has the same concept as Test 2 but is more closely related to the dust adhering to the PV modules. A glass panel is used to simulate the dust accumulation with a Light Emitting Diode (LED) and an Light Dependent Resistor (LDR) in between. A ratio-based calculation is made for test 3 to correlate the transmittance with voltage output and comparing the value when the glass is clean compared to dirty. The washed module performs the best with an average air quality of 0.025mg/m3. The worst module was the one without dust mitigation strategies, where the light transmittance reduced in 22% after two weeks of dust accumulation.
Consequently, to improve the performance of the PV in the industry, soiling should not be ignored as it should be a big issue in the PV industry.
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Sullivan, Lawrence. "Cleaning and Preserving Animal Skulls." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/146937.
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4 pp.Often the examination of an animal skull is used to determine the species and the examination of dentition is much easier on cleaned skulls. This publication addresses the methods used to clean, bleach, and preserve animal skulls.
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Ouimette, Monique Y. "Cleaning House: Considerations of Ecological Health and Sustainability in the Selection of Household Cleaning Products." Thesis, Boston College, 2011. http://hdl.handle.net/2345/3054.
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Thesis advisor: Juliet B. SchorIn an era of increasing awareness about the impacts of everyday consumption on ecological sustainability, this study investigates the factors that influence mothers' selection of household cleaning products. The data for this study are from 28 in-depth interviews with mothers who maintain diverse preferences across a cleaning product profile spectrum. Incorporating the concepts of risk, trust, and convenience, the analysis highlights the ways in which considerations of ecological health in relation to cleaning products influence purchasing decisions of some participants but not others. This study contributes to understandings of how consumer practices shift toward environmental sustainability
Thesis (MA) — Boston College, 2011
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Sociology
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Zorcolo, Alberto. "Study of the interaction among abrasive particles, applicator and cleaning surfaces in household and tooth cleaning." Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.575867.
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Tooth cleaning and household cleaning are common tasks people undertake on a daily basis and they share significant analogies. Both rely on the combined action of a detergent - usually a fluid which may contain abrasive particles - and an applicator on a cleaning surface. While scientific information covers some of the aspects related to abrasive tooth cleaning, such as the main tooth wear mechanisms and the influence of dental care products on tooth cleaning and wear, household cleaning has not been covered in such detail. The aim of this work was to investigate abrasive tooth cleaning and abrasive household cleaning from a tribological perspective in terms of the interactions between human/applicator, applicator/abrasive particles and abrasive particles/substrate, in order to expand the knowledge on both subjects and gather information useful to improve the design of current cleaning products. A study has been carried out by means of a hand operated friction rig to measure the loads applied by human subjects while performing simulated abrasive cleaning operations in order to better understand the interaction between human test subject and applicator. The analysis investigated the loads applied during tooth cleaning processes and household cleaning processes, and the results (from 180g to 4230g for tooth cleaning tests and from 290g to 4.3Skg for household cleaning tests) helped Unilever in developing their friction analysis techniques. Particle entrainment into the contact area between the applicator and the surface has been analysed using two types of test rig- one with a unidirectional motion and the other a reciprocating motion - and an optical apparatus featuring a microscope and a camera for image and video capturing. The scratches produced by abrasive particles were studied with an optical microscope and a Scanning Electron Microscope in order to understand how they scratch the surface during abrasive cleaning processes. The investigation helped to gather information on how abrasive particles were trapped at the tip of the toothbrush filaments and between the cloth fibres and the observation of the scratched surfaces led to identify grooving abrasion as the main wear mechanism taking place in both abrasive tooth cleaning and household cleaning. A friction analysis of both tooth cleaning and household cleaning processes was carried out using the hand operated rig and a friction rig on which the applicators were mounted, to study the connection between the friction coefficient )l and the ability of the particles to remove material from the test surface. It was found that under the adopted experimental conditions, the lubricating action exerted by the carrying fluids in both tooth cleaning and household cleaning is mainly based on boundary lubrication. The values of the friction coefficient determined from the experiments ranged from around 0.20 (in wet condition, without abrasive particles) to 0.37 (in dry condition, without abrasive particles) for brushing tests, and from around 0.20 (in lubricated condition, with 5 urn Calcium Carbonate particles) to 0.66 (in dry condition, without abrasive particles) for cloth tests. The influence of the applied load, the particle size and concentration on friction coefficient was also investigated. Finally, a semi-empirical model was developed to estimate the rate of material removal during a simulated household cleaning process, in order to gather information useful to improve the ability of cleaning fluids to remove stain while reducing the damage to the cleaning surfaces. Results from the modelling were compared with data from reciprocating cleaning tests. Although the model often overestimated the amount of material removed from the test surface due to the assumptions made in order to simplify its implementation, it produced results of the same magnitude order of those obtained from material removal experiments within the ranges of applied loads, particle sizes and concentrations. lJ
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Goode, Kylee Rebecca. "Characterising the cleaning behaviour of brewery foulants, to minimise the cost of cleaning in place operations." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3908/.
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Industry operations require a clean plant to make safe, quality products consistently. As well as product quality, the environmental impact of processes has become increasingly important to industry and consumers. Cleaning In Place (CIP) is the ubiquitous method used to ensure plant cleanliness and hygiene. It is therefore vital the system is optimal and efficient. I.e. the correct cleaning agent is delivered to the fouled surface at the right time, temperature, flow rate and concentration. This cannot be assured without effective online measurement technologies. Fryer and Asteriadou (2009) describe how the nature of a fouling deposit can be related to the cost of cleaning. The evolution of three key deposit types has also enabled current fouling and cleaning literature to be easily classified. In the brewery there are many types of soil that need to be cleaned of which the cost of cleaning was unknown. The cost of fermenter CIP in one brewery was found to be £106 k per year. Effective fouling methods for yeast and caramel; and the relationship between flow, temperature, and caustic concentration in the removal of yeast and caramel soils seen in industry has been done. This work has helped determine effective cleaning methods for these soils from stainless steel coupons and pipes. Fermentation vessels have been found by Goode et al., (2010) to have two types of soil: A – fouling above the beer resulting from the act of fermentation, and B – fouling below the beer resulting from emptying the fermenter. The type B fouling below the beer was found to be a type 1 soil that could be removed with water. An increase in flow velocity and Reynolds number decreased cleaning time. An increase in temperature did not decrease cleaning time significantly at higher flow velocities, 0.5 m s-1. Fouling above the beer occurs when material is transported to and stick on to the wall during fermentation foaming. This happens initially and as a result the fouling has a long aging time. This yeast film represents a type 2 deposit, removed in part by water and in part by chemical. Most of the deposit could be removed by rinsing with warm water. At 50°C the greatest amount of deposit was removed in the shortest time. A visually clean surface could be achieved at all temperatures, 20, 30, 50 and 70°C, using both 2 and 0.2 wt % Advantis 210 (1 and 0.1 wt % NaOH respectively). A visually clean surface was achieved quicker at higher detergent temperatures rather than rinsing at higher flow velocity or concentration. This finding suggests most deposit can be removed with warm water and cleaned with lower detergent concentrations. Currently in the brewery 2 % NaOH is used at 70°C. Caramel represents a type 3 soil. When heated it sticks to stainless steel and requires chemical action for removal. Confectionary caramel was cooked onto pipes and coupons and the effect of flow velocity, temperature and concentration on removal determined. At high flow velocity most of the deposit could be removed from the pipe using water. There was no significant difference in the mass of caramel removed by the water however. A visually clean surface was achieved by rinsing at 80°C with 2.5% Advantis. A visually clean surface could not be achieved at lower temperatures at higher concentration, 5% Advantis, or at higher flow velocity. The measurement of online conductivity and flow rate values was invaluable during each experiment. Turbidity values did indicate the removal of yeast and caramel from pipes however offline measurements were required to confirm removal. Caramel removal could be wholly quantified by mass when cleaning pipes. The integration of the turbidity values measured during each rinse correlated well with the mass of deposit removed in most cases. Coupon cleaning was wholly quantified by area . A cost saving of £69 k can be made by optimising fermenter CIP to warm pre-rinsing followed by ambient caustic circulation. An £8 k saving can be made by optimising yeast tank CIP to pre-rinsing only and acid sanitisation. Industry must ensure effective online CIP measurements are made throughout cleaning to describe the process effectively and enable optimisation. It is crucial to have cleaning measurement information to hand because that is how we ensure our customers they are buying a quality product. Also you cannot optimise what you do not measure effectively.
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Tourdot, Justin M. "A comparison of wet manual cleaning processes to carbon dioxide cleaning processes in the semiconductor industry." Online version, 2001. http://www.uwstout.edu/lib/thesis/2001/2001tourdotj.pdf.
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Weis, Andreas. "Fouling and cleaning synergy in ultrafiltration membrane systems : chemical cleaning after filtration of spent sulphite liquor." Thesis, University of Bath, 2004. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425883.
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Anglani, Francesco. "Computer modelling and experimental testing of spray cleaning methodologies for concentrated solar thermal (CST) mirror cleaning." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/116180/1/Francesco_Anglani_Thesis.pdf.
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This project was a step forward in establishing an effective high-pressurised cleaning procedure to investigate soil detachment from CSP reflectors through fluid dynamic simulations evaluated the overall force generated by the jet on dust particles. Outcomes reveal an increase of cleaning efficiency of high-pressure spray jets when the standoff distance is in the range X = 6D-15D with the angle of impingement set to =75° and inlet pressure in the range Pin = 50-70 bar.
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Arzigian, J. S. "Cleaning of Printed Circuit Assemblies with Surface-Mounted Components." International Foundation for Telemetering, 1989. http://hdl.handle.net/10150/614697.
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International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, CaliforniaThe need for ever-increasing miniaturization of airborne instrumentation through the use of surface mounted components closely placed on printed circuit boards highlights problems with traditional board cleaning methods. The reliability of assemblies which have been cleaned with vapor degreasing and spray cleaning can be seriously compromised by residual contaminants leading to solder joint failure, board corrosion, and even electrical failure of the mounted parts. In addition, recent government actions to eliminate fully halogenated chlorofluorocarbons (CFC) and chlorinated hydrocarbons from the industrial environment require the development of new cleaning materials and techniques. This paper will discuss alternative cleaning materials and techniques and results that can be expected with them. Particular emphasis will be placed on problems related to surface-mounted parts. These new techniques may lead to improved circuit reliability and, at the same time, be less expensive and less environmentally hazardous than the traditional systems.
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Ødegård, Johnny. "Gas Cleaning with Granular Bed Filter." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-12892.
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A literature study is first presented then the practical experiments are described. The theoretical chapter provides an overview of filtration mechanisms and available gas cleaning technologies, with an emphasis on hot gas and cake filtration. The experimental chapters describe the setup and testing of the filter tray test rig and the L10-56 test rig.The filter tray test rig was built, instrumentation was installed and programming performed. Puff-back calibration and heating tests were performed. The puff-back calibration showed that a significantly lower delta p minimum was obtained with this design compared to previous designs. Filtration tests were conducted at an elevated temperature (120 C) with different dust concentrations (1 and 3 g/m3) and filtration velocities (10 - 20 cm/s). The results showed that the rig was working in accordance with the design criteria, with a filtration efficiency above 99,5%.A previously used filter test rig, the L10-56 test rig, was installed at the slipstream of the exhaust of a oil sand extraction pilot plant at 350⁰C. A horizontal bed unit (HBU) was also developed to investigate the impacts of the exhaust gas on the granular filter media. Once completed, the rig was re-tested and the puff-back calibration and heating tests that were performed achieved results corresponding with the previous testis performed on this test rig. The test rig was ready to start filtration tests but they were not initiated due to time limitations and unpredicted halt of the oil sand extraction pilot plant.
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Vestlund, Karin. "Aspects of automation of selective cleaning /." Umeå : Dept. of Silviculture, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200574.pdf.
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Whiteman, Elizabeth Anne. "Social interactions in Caribbean cleaning gobies." Thesis, University of East Anglia, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251442.
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Arthur, Lia Frieda. "Silicate sorbents for flue gas cleaning /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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Sitkiewitz, Steven Donald. "Design of photocatalytic air cleaning reactors /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Bartlett, Meloney. "Chemical cleaning of fouled membrane systems." Thesis, University of Bath, 1998. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285409.
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Tang, Lynn. "An oral history of women cleaning workers in Hong Kong." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37224761.
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Molyneux, Melissa. "Assessment of the baseline thoroughness of cleaning at one hospital dialysis suite." Thesis, The University of Arizona, 2014. http://hdl.handle.net/10150/315905.
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A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine.One fifth to one third of hemodialysis patients develop infections from bacterial and viral pathogens over the total course of their treatment, many of which are healthcare acquired, leading to significant morbidity and mortality. Over recent years, significant strides have been made to decrease the rate of healthcare-acquired infections (HAIs) by reducing the risk of transmission of pathogens, including increased compliance to hand-washing of healthcare workers (HCW) and improved quality of environmental cleaning. The goal of the project was to improve the thoroughness of cleaning of a hemodyalysis (HD) suite using objective monitoring and a program of education and feedback. To achieve this goal, the project was broken down into three aims: 1. Determine the baseline thoroughness of cleaning using a novel marker system; 2. Educate and provide feedback to hospital administration and environmental services staff involved in overseeing and in cleaning the HD suite, and; 3. Determine if the program improves the thoroughness of cleaning when compared to baseline. Due to institutional constraints, the third aim of the project was not performed. This investigation demonstrated a baseline thoroughness of cleaning for all high-touch surfaces to be 42% of surfaces cleaned, indicating there are opportunities for improvement in the sanitation practices of the hospital hemodialysis suite. Most individual surface types fell below the internal goal of 90% cleaned. Through presenting the baseline data to hospital administration and environmental services staff, areas of potential improvement in hemodialysis suite sanitation practices were identified, which included the assignment of the cleaning of individual surfaces to specific hospital departments. Though the follow-up testing could not be performed, it is likely that the identification of these areas for process improvement resulted in increased cleaning of overlooked surfaces.
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Sinsheimer, Peter. "Fashioning a greener shade of clean integrating pollution prevention into public policy : the case of professional wet cleaning /." Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=1835200081&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Spuller, Matthew Thomas. "Resist and Residue Removal Using Gas-Expanded Liquids." Diss., Available online, Georgia Institute of Technology, (2003), 2003. http://etd.gatech.edu/theses/available/etd-11072003-150305/.
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Fanin, Giovanni. "Optimising the Scheduling of Train Unit Cleaning." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
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Scheduling of Train Unit Cleaning is one of the planning processes required at DSB, The Danish Railway Company. In order to ensure an adequate service level to its customers, train cleaning must be planned as efficiently as possible. The presence of several decision variables and even more constraints requires the utilization of a tool to ensure the respect of all the requests while cost of operations is minimized.
This thesis project proposes an optimisation model to solve the train cleaning scheduling problem. A mathematical formulation based on a space-time network describing the movement of the rolling stock is presented. A Label Setting Algorithm based on this network can solve to optimality the reduced scheduling
problem associated with each train unit. In order to obtain a cleaning operation plan for all the train set, the Label Setting Algorithm generates it in a recursive way and a heuristic approach verifies the respect of further restrictions.
The algorithm was tested on real instances from DSB. The main parameters of evaluation were the total time of execution of the cleaning operations and the service level provided. The Label Setting Algorithm with its flexibility has permitted us to implement different assumptions on parameters. In each of these situation
the proposed model has generated good results in terms of cost minimization.
The use of a greedy heuristic approach in a second stage has demonstrated to be the weakest part of the approach, on which future improvement can be considered.
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Casas, Ruiz Lidia 1978. "Microbial exposures, cleaning products and child health." Doctoral thesis, Universitat Pompeu Fabra, 2013. http://hdl.handle.net/10803/133453.
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Background and aims: The immune, respiratory and central nervous system start
developing during pregnancy and continue during the first years of life. Therefore,
environmental exposures during these periods may play a role on the maturation of
these systems. In particular, the exposure to indoor microbial agents, indoor factors
such as pets or dampness, and to household cleaning products during infancy or
childhood may have important implications in the development processes. This thesis
aims to assess the long term effects of indoor exposure to microbial agents and
chemical based cleaning products on respiratory and mental health among children
from birth to the age of 13 years old.
Methods: We used data from nine European birth cohorts that are part of three
projects: the European HITEA project, the Spanish INMA project; and the German
GINIplus and LISAplus birth cohort studies. Information on the exposure to indoor
dampness, pet ownership, the use of cleaning products and allergy and respiratory
health was periodically collected through questionnaires and health tests. Living room
dust samples were collected when the children were 2-3 months and analysed for
microbial agents concentrations (bacterial endotoxin, fungal extracellular
polysaccharides (EPS) from Aspergillus spp. and Penicillium spp, and mould β(1,3)-
glucans). Multivariable regression models were used to assess the associations
between the exposures and the health outcomes.
Results: 1) Concentrations of measured microbial agents varied differently across the
cohorts. 2) Season of dust sampling, dog ownership, indoor report of dampness, and
number of people living in the home is associated with the concentrations of microbial
agents. 3) Early life exposure to endotoxin and dogs in the home is associated with
lower levels of FeNO at school age. 4) Domestic use of cleaning sprays, air fresheners
and solvents during pregnancy is associated with a higher prevalence of wheezing and
LRTI during the first year of life. 5) At school age, bystander exposure to domestic
cleaning sprays increases the levels of FeNO, and exposure to air freshening sprays
and solvents decreases the lung function. 6) Persistent exposure to indoor dampness
during early life has negative effects on the cognitive function and social competences
at 4 years old. 7) Exposure to visible mould, dampness and pet ownership during the
first 10 years of life increases the risk of borderline or abnormal scores in the SDQ at
10 years of age.
Conclusion: Our results suggest that indoor exposure to microbial agents during early
life and exposure to chemical based cleaning products during pregnancy, infancy and
childhood play a role in the development of the respiratory, immune and central
nervous systems.Introducció i objectius: El desenvolupament dels sistemes immunitari, respiratori i nerviós central comença durant l’embaràs i continua al llarg la infància. Així, els primers anys de vida són moments crucials en que qualsevol exposició ambiental pot influir el desenvolupament d’aquests sistemes. Concretament, l’exposició durant la infància a agents microbiològics, humitat, animals de companyia i productes de neteja pot tenir implicacions importants en els processos de maduració d’aquests sistemes. L’objectiu principal d’aquesta tesi és el d’avaluar els efectes a llarg termini de la exposició a agents microbiològics i a productes de neteja de base química a la llar, sobre la salut respiratòria i mental des del naixement fins a l’edat de 13 anys. Mètodes: En aquesta tesi hem fet servir dades de nou cohorts de naixement europees que formen part de tres projectes: el projecte europeu HITEA, el projecte espanyol INMA, i els estudis alemanys GINIplus i LISAplus. La informació sobre la exposició a humitat, a animals de companyia, la utilització de productes de neteja, al·lèrgies i salut respiratòria es va recollir en tots els projectes mitjançant qüestionaris administrats als pares/mares i proves mèdiques o tests neuropsicològics. A més, es van recollir mostres de pols dels menjadors de les cases quan els nens/es tenien 2-3 mesos d’edat que es van analitzar per determinar les concentracions d’agents microbiològics (endotoxines bacterianes, polisacàrids extracel·lulars (EPS) d’Aspergillus spp. i Penicillium spp i β(1,3)-glucans fúngics). Per l’avaluació de les associacions entre exposicions i resultats de salut s’han desenvolupat models de regressió múltiple. Resultats: 1) Les concentracions d’agents microbiològics mesurats en pols de les llars varien per cohort. 2) L’estació de l’any en que es recull la mostra de pols, la presència de gossos a la casa, reportar humitat a la casa i el número de persones que hi viuen estan associats amb la concentració d’agents microbiològics a la pols. 3) L’exposició durant els primers mesos de vida a endotoxines i gossos a la llar s’associa amb nivells baixos de FeNO a edat escolar. 4) L’ús d’esprais i dissolvents per la neteja de la casa, i ambientadors durant l’embaràs està relacionat amb un increment en la prevalença de sibilants i infeccions respiratòries de vies baixes al llarg del primer any de vida. 5) En edat escolar, la exposició passiva a productes de neteja domèstics utilitzats en forma d’esprais incrementa els nivells de FeNO, i l’exposició a esprais ambientadors i dissolvents per la neteja de la llar disminueix la funció pulmonar. 6) L’exposició persistent a humitat a la llar durant els 2 primers anys de vida té un efecte negatiu sobre la funció cognitiva i les competències socials mesurades als 4 anys d’edat. 7) L’exposició a fongs procedents de la humitat, a humitat i a animals de companyia a casa al llarg dels primers 10 anys de vida incrementa el risc de puntuacions “borderline” o anormals al questionari SDQ administrat als 10 anys. Conclusió: els resultats presentats en aquesta tesi suggereixen que l’exposició a agents microbiològics durant els primers mesos de vida i l’exposició a productes de neteja durant l’embaràs i la infància juguen un paper important en el desenvolupament dels sistemes respiratori, immunològic i nerviós central.
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Ekambaram, Rajmadhan. "Label Noise Cleaning Using Support Vector Machines." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/5943.
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Mislabeled examples affect the performance of supervised learning algorithms. Two novel approaches to this problem are presented in this Thesis. Both methods build on the hypothesis that the large margin and the soft margin principles of support vector machines provide the characteristics to select mislabeled examples. Extensive experimental results on several datasets support this hypothesis. The support vectors of the one-class and two-class SVM classifiers captures around 85% and 99% of the randomly generated label noise examples (10% of the training data) on two character recognition datasets. The numbers of examples that need to be reviewed can be reduced by creating a two-class SVM classifier with the non-support vector examples, and then by only reviewing the support vector examples based on their classification score from the classifier. Experimental results on four datasets show that this method removes around 95% of the mislabeled examples by reviewing only around about 14% of the training data. The parameter independence of this method is also verified through the experiments. All the experimental results show that most of the label noise examples can be removed by (re-)examining the selective support vector examples. This property can be very useful while building large labeled datasets.
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Hess, Jürgen Michael [Verfasser], Wolfram [Akademischer Betreuer] Burgard, and Bernhard [Akademischer Betreuer] Nebel. "Efficient approaches to cleaning with mobile robots." Freiburg : Universität, 2015. http://d-nb.info/1118409302/34.
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Christian, Grace Kathleen. "Cleaning of carbohydrate and dairy protein deposits." Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553766.
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Abdullah, Syed Zaki. "Membrane ageing due to chemical cleaning agent." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46862.
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Sodium hypochlorite is commonly used as a cleaning agent to remove adsorbed foulants from PVDF-based micro/ultra filtration membranes in water and wastewater treatment applications. Although effective for fouling control, extended sodium hypochlorite exposure can affect the physical/chemical characteristics and hinder the treatment performance of these membranes. In the present study, experiments were conducted to comprehensively quantify the effects of sodium hypochlorite exposure on changes in the physical/chemical characteristics and the filtration performances of blended PVDF-based supported hollow-fiber membranes and identifying the mechanism(s) responsible for the changes. Both the effect of the sodium hypochlorite concentration (C) and the duration of exposure (t) on the membrane characteristics are investigated. The physical/chemical characteristics and the filtration performances of virgin and aged (i.e., weathered due to exposure to sodium hypochlorite) membranes were compared. The membranes were characterized based on chemical composition (FTIR and NMR), mechanical strength (yield strength), surface hydrophilicity (contact angle), pore size and porosity (scanning electron microscopy and challenge test), membrane resistance (clean water permeation test), and affinity of the membrane for foulants (cleaning efficiency). The results indicated that exposure dose and concentration of the sodium hypochlorite used have a significant influence on the membrane characteristics. For the exposure conditions considered, the impact of sodium hypochlorite exposure on the parameters investigated could be most accurately and consistently correlated to an exposure dose relationship of the form Cnt (where, C=concentration and t=exposure time) rather than the Ct relationship commonly used to define the extent of exposure to cleaning agents. For all the parameters investigated, the power coefficient n was less than 1 indicating that time had a greater impact on the changes than did the concentration of the sodium hypochlorite. The results suggest that the use of sodium hypochlorite for chemical cleaning, at concentrations that are higher than those typically used for chemical cleaning would have less of an effect on the characteristics of the membrane materials. Changes in the characteristics were attributed to the oxidation of the hydrophilic additives (HA) present in blended PVDF membranes. A new non-destructive membrane characterization technique to evaluate the amount of membrane ageing is proposed.
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Cheung, W. F. "Filtration and cleaning characteristics of ceramic media." Thesis, University of Surrey, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234580.
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Popa, Mihaela. "Tooth cleaning : abrasive particles but no abrasion." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI034.
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En 1997 Stuard L. Fischman a dit « Certainement on mange bien, on parle bien, on a l'air bien et on « sent frais » - mais on a aussi la plaque dentaire, la gingivite et les caries dentaires. Le lecteur peut déterminer les progrès réalisés en réfléchissant à son état de santé bucco-dentaire personnel! ». Vingt ans plus tard cette affirmation reste valide. L'acte le plus commun d'hygiène buccale est de se nettoyer les dents par brosse à dents, eau et dentifrice. Le rôle principal de la brosse à dents et du dentifrice est d'éliminer le biofilm dentaire responsable des maladies buccales. Il est largement admis que le biofilm dentaire est éliminé au moyen de particules de nettoyage trouvés dans la composition du dentifrice. Puisque le mécanisme des particules nettoyantes est couramment supposé abrasif, la recherche sur le nettoyage des dents a été principalement conduite du point de vue « abrasif », elles sont ainsi appelées « particules abrasives ». Néanmoins, le nettoyage des dents est un processus complexe impliquant plusieurs mécanismes (biochimiques, physico-chimiques et mécaniques), chacun activé par des facteurs à la fois internes (comme l'environnement oral individuel et les habitudes individuelles d'hygiène buccale) et externes La conception de la brosse à dents et la composition de dentifrice). Ce travail a commencé à partir de l'idée que le nettoyage des dents ne peut pas être réduit à un processus d'abrasion; par conséquence, afin d'acquérir une connaissance plus profonde du comportement réel des particules nettoyantes, il est nécessaire de comprendre la contribution de chaque mécanisme d'action impliqué. Un système biomimétique a été développé pour reproduire la brosse à dents, l'émail dentaire, la pellicule exogène acquise et le dentifrice (une suspension simplifiée à base de silice). Le système a été analysé d'un point de vue tribologique, en adoptant la théorie du « troisième corps » et en utilisant différentes techniques expérimentales (spectroscopie infrarouge, microscopie à force atomique, la microscopie électronique à balayage). On a déterminé la contribution de la mécanique et de la physico-chimie de la surface de l'émail dentaire, de la chimie du dentifrice et de la mécanique de la brosse à dents. Les résultats ont montré que la pellicule exogène acquise biomimétique n'a pas été rayée pendant le nettoyage des dents, mais plutôt lissée ou enlevée, ce qui suggère que l'abrasion n'est pas le mécanisme «gouvernant» du processus de brossage des dents. En effet, un mécanisme de «lubrification fractionnée» est supposé intervenir, favorisant la formation des agglomérats de silice supportent la charge normale dans des zones de contact localisées. L'efficacité du processus de nettoyage des dents est censée être contrôlée par la taille des agglomérats de silice, qui dépend à son tour de la mécanique et la physico-chimie de la surface de l’émail dentaire, de la chimie du dentifrice et de la mécanique de la brosse à dentsIn 1997, Stuart L. Fischman wrote “We certainly eat well, speak well, look fine and ‘smell fresh’—but we also have plaque, gingivitis and dental caries. The reader can determine how much progress has been made by reflecting on his or her personal oral health status!” Two decades later, this affirmation is still valid. The most common act of oral hygiene is to clean one’s teeth via toothbrush, water, and dentifrice. The main role of toothbrush and dentifrice is to remove the dental biofilm responsible for oral diseases. Over the years, several studies have focused on improving toothbrushing techniques, toothbrush design, and dentifrice composition, often leading to conflicting results. It is largely accepted that dental biofilm is removed by means of cleansing particles, which can be found in many dentifrice compositions. Since the mechanism of the cleansing particles is commonly believed to be abrasive, research on teeth cleaning has been mainly conducted from an ‘abrasive’ point of view, so much so that cleansing particles are frequently referred to as ‘abrasive particles’. Nonetheless, teeth cleaning is a complex process involving several mechanisms (bio-chemical, physico-chemical, and mechanical), each one activated by factors that are both internal (such as individual oral environment and individual oral hygiene habits) and external (such as toothbrush design and dentifrice composition). This work started from the idea that teeth cleaning cannot be reduced to an abrasion process; consequently, in order to gain deeper knowledge about the actual behavior of the cleansing particles, it is necessary to understand the contribution of each mechanism involved. A biomimetic system was developed to reproduce toothbrush, dental enamel, acquired enamel pellicle, and dentifrice (modeled as a silica-based slurry). The system was analyzed from a tribological point of view, adopting the ‘third-body approach’ and employing different experimental techniques such as infrared spectroscopy, atomic force microscopy, and environmental scanning electron microscopy. The contribution of the dental enamel surface mechanics and physico-chemistry, of the dentifrice chemistry, and of toothbrush mechanics was assessed. Results showed that the biomimetic acquired enamel pellicle was not scratched during teeth cleaning, but rather smoothened or removed, suggesting that abrasion is not the governing mechanism of the toothbrushing process. Indeed, a ‘fractionated lubrication’ mechanism is believed to take part, promoting the formation of silica agglomerates that bear normal load at localized contact areas. The effectiveness of the teeth cleaning process is believed to be controlled by the size of the silica agglomerates, which in turn depends on dental enamel surface mechanics and physico-chemistry, dentifrice chemistry, and toothbrush mechanics
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Lawing, Andrew S. (Andrew Scott). "Gas-phase cleaning of silicon wafer surfaces." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/38852.
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Chan, Leo. "Creating an Air-Cleaning Cat Litter Box." Digital Commons at Loyola Marymount University and Loyola Law School, 2010. https://digitalcommons.lmu.edu/etd/383.
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This project is an attempt to build an automatic air-cleaning cat litter box using system engineering methodology and process. Multiple skill sets such as computer engineering and electrical engineering are used in order to create this system-of-systems. The entire process is divided into 3 major phases: planning phase, development phase, and the final phase.
In planning phase, the project will first identify the top level requirements. The top three requirements for this air-cleaning cat litter box are: It shall reduce the smell of excrement; It shall not frighten the cat; and it shall be capable of being placed anywhere in the house. These requirements (Mission Requirements) will then be broken down into smaller requirements (System Requirements) from which forms specifications of the air-cleaning litter box.
After requirements decomposition, it is time to define the system architecture. For this project, the Department of Defense Architecture Framework (DODAF) was chosen to describe the architecture because of its ease of adaption. Only a few of the key views will be used, such as: the High-Level Operational Concept Graphic (OV-1) which shows the concept of operation in easy to understand graphics; the system interface description (SV-1) which shows the components or systems involved and how they interact with each other, along with other key views that pertain to the project. This provides a common foundation for all three elements for the development phase.
In development phase, there are three elements: software, circuit, and vent. Each element can be developed independently thanks to the architecture that was defined earlier. In software, development consists of software design and validation. In circuit, there are material acquisition, circuit design, circuit build-out, and finally circuit validation. Vent element consists of material acquisition and vent construction.
In the final phase, all three elements will be integrated into a single entity. A final validation will be performed to ensure that all requirements established are met, and the product is functioning properly.
Unfortunately things never happened exactly as planned. Along the way there were many problems encountered such as simulation inaccuracy and material failure. They have a big impact on the schedule, however they were overcome and the project was completed. On the bright side, these problems have been a great learning experience and will serve as lessons learned for many future projects.
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Mohamed, Abdulaziz Hemmali. "Process intensification in syngas production and cleaning." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2135.
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The aim of this work was to develop an intensified syngas cleaning system for different applications of the cleaned gas. The main target of syngas cleaning is the destruction of tars although the removal of heavy metals is also important. The syngas cleaning strategies include water scrubbing followed by further cleaning and moisture reduction, low temperature capture of tars and destruction of tars at high temperatures preferably at the gasifier exit temperature. In the present study, initially a novel downdraft intensive 50kWe air-blown auto-thermal gasifier was used for the gasification of refinery sludge indicating that refinery sludge could be gasified with low levels of tar as a result of catalytic tar cracking during gasification since refinery sludge initially contained large amounts of catalytic rare earth elements. It contained tar and particulate matter of less than 90 ± 6.0 mg/Nm3 and calorific value of 3.71 ± 0.4 MJ/Nm3 (wet gas), which is sufficient for power generation using an internal combustion engine (ICE). Gas composition, tar content and heat content of the produced gas were determined. Results were compared with those obtained with wood chips (reference feedstock). In the development of intensified syngas cleaning systems, we used a model syngas (carbon dioxide) and model tar (crude oil). A new/novel, multi-functional tar removal rig was designed and fabricated. It can be used as a water scrubber or for tar removal under electric field in the absence or presence of biphilic (both hydrophilic to adsorb water and lipophilic to adsorb tars) adsorbents in the form of functionalized PolyHIPE Polymers (PHPs). These PHPs were produced, functionalized and characterized using environmental scanning electron microscopy (ESEM) and surface area analysis (SAA) and then used in the form of packed bed for the adsorption of model tars from model syngas. According to the literature, using the syngas in a power production application, the tar concentration in syngas needs to be less than 100 mg/Nm3 which requires particle and tars reduction efficiencies of 90 % for a satisfactory operation of an Internal Composition Engine (ICE) using syngas produced in a downdraft gasifier. vii Maximum tar removal efficiencies under the prevailing process conditions were: water scrubbing 45.9 ± 4.5 %; adsorption by the sulphonated PolyHIPE Polymers (s-PHP) 61.8 ± 2.5 %; high voltage application with conductive electrodes 97.5 ± 1.5 % at 25kV; and the combination of s-PHP with electric field resulted in 96.7 ± 1.9 % % tar removal efficiency. The advantage of high voltage gas cleaning is that it can be used at high temperatures and that no other material is used as adsorbent which requires regeneration once they are saturated with tar, etc. Finally, another electrical method was designed to crack the model tars using plasma induced catalytic conversion. The results indicate that hydrocarbon profile of crude oil in the model syngas shifted towards low carbon number.
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Lee, Lester H. "THE CLEANING AND TESTING OF MAGNETIC TAPES." International Foundation for Telemetering, 1986. http://hdl.handle.net/10150/615563.
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International Telemetering Conference Proceedings / October 13-16, 1986 / Riviera Hotel, Las Vegas, NevadaDescription of various off-line magnetic tape cleaning techniques and testing process to measure defects of tape before using it for tape recording applications. Discussions are made on the type of cleaning methods and also the ways and means to achieve better evaluation results.