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A selection model for automated guided vehiclesShelton, Debra Kay January 1985 (has links)
This research identifies the attributes to be considered in the selection of an automated guided vehicle (AGV). A distinction is made between automated guided vehicles (AGVs) and an automated guided vehicle system (AGVS). This research is concerned only with the selection of automated guided vehicles (AGVs).
A selection model is developed which forces the user to evaluate attributes. his requirements and preferences for AGV The first step of the model allows the user to enter his specifications for AGV attributes which are applicable to his production environment. The second step in the selection model is for the user to determine 8-15 attributes to use as selection criteria. In the third phase, the user inputs his preferences and priorities with respect to the attributes chosen as selection criteria in the second step. model ranks the Based on this information, the selection AGV models in the feasible set. A description of the model and a numerical example are included.
Steps 1 and 2, described above, are implemented using an R:BASE™ program. The BASIC computer language was used to perform the interrogation of the user with respect to his priorities and preferences among attributes in Step 3. The IBM PC™ is the hardware chosen for running the selection model. / M.S.
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Development and evaluation of silicone membrane as aerators for membrane bioreactorsMbulawa, Xolani Proffessor January 2005 (has links)
Thesis (M.Tech.: Chemical Engineering)-Dept. of Chemical Engineering, Durban University of Technology, 2005 1 v. (various pagings) / In bubble-less aeration oxygen diffuses through the membrane in a molecular form and dissolves in the liquid. Oxygen is fed through the lumen side of silicone rubber tube. On the outer surface of the membrane there is a boundary layer that is created by oxygen. This then gets transported to the bulk liquid by convective transport created by water circulation through the pump. The driving force of the convective transport is due to concentration difference between the dissolved oxygen in water and oxygen saturation concentration in water at a particular temperature and pressure. The design of a membrane aerated bioreactor needs an understanding of the factors that govern oxygen mass transfer. It is necessary to know the effects of operating conditions and design configurations. Although various methods of bubble-less aeration have been reported, there still exists a lack of knowledge on the immersed membrane systems. This study is aiming at contributing to the development of an immersed membrane bioreactor using silicone rubber tubular membrane as means of providing oxygen. The secondary objective was to investigate the influence that the operating conditions and module configuration have on the system behaviour. From the experimental study, the characteristic dissolved oxygen -time curve show that there is a saturation limit equivalent to the equilibrium dissolved oxygen concentration, after which there is no increase in dissolved oxygen with time. At ambient conditions the equilibrium dissolved oxygen is approximately 8 mg/L. This is when water is in contact with air at one atmospheric pressure. At the same conditions the equilibrium dissolved oxygen concentration when water is in contact with pure oxygen is approximately 40 mg/L. This is why all the experiments were conducted from 2mg/L dissolved oxygen concentration in water, to enable enough time to reach equilibrium so as to determine mass transfer coefficient. The most important parameters that were investigated to characterise the reactor were, oxygen supply pressure, crossflow velocity, temperature and module orientation. Observations from the experimental study indicated that when the system is controlled by pressure, crossflow does not have a significant effect on mass transfer. When the system is controlled by the convective transport from the membrane surface to the bulk liquid, pressure does not have a significant effect on mass transfer. All four effects that were investigated in the study are discussed.
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The development of a dynamic engine-testing facilityConradie, P. A. (Petrus Alwyn) 11 1900 (has links)
Thesis (MScEng.)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The last two decades have seen many changes within the automotive industry. Many
advances have been made in the design, research and development of the internal
combustion engine and technological progress made in the integrated-circuit and computer
industry has resulted in the availability of reliable low-cost electronic components. These
components have, over time, been incorporated into the very hearts of engines, thereby
allowing for the accurate control of engine functions and processes to an extent that was
previously impossible. Parallel to these developments is the growing concern for the
environment and the realisation that resources are being consumed at ever-increasing rates.
This has placed vehicle manufacturers under continual pressure to optimise their engines,
not only for fuel efficiency, but also to reduce harmful emissions while continuing to
deliver better performance and drivability characteristics.
At the same time, engine testing equipment and facilities have had to keep abreast with
these advances and this has required the development of more sophisticated testing
facilities. One such facility is the dynamic engine test-bed. Among other features, this
facility has the ability to subject test-bed mounted engines to loads similar to what would
be experienced in a vehicle on the road. This approach allows for the optimisation of
engine components and performance under more realistic conditions, yielding results far
superior to those obtainable using more conventional steady-state testing and development
procedures.
This document discusses the development of such a dynamic engine test-bed at the Centre
for Automotive Engineering at the University of Stellenbosch. The project was initiated by
conducting a literature survey to establish the current state of technology in the field. The
dynamic test-bed was developed around an existing direct-current electric motor and
industrial speed controller configured in a regenerative manner. This setup enabled the
unit to both absorb and deliver power, essential for the simulation of vehicle dynamics.
Great care was taken to ensure that signals obtained from the test-bed were accurate and
useful for further computer manipulation. Anti-aliasing filters were designed and
manufactured to guarantee that signals could not be misinterpreted due to sampling effects. A computer-implemented vehicle model was developed to simulate, in real-time, vehicle
response to torque developed by the engine on the test stand. The model included a
manual transmission, clutch and a rigid drive-shaft. Driver input (accelerator, brake, clutch
and gear selection) was by means of a set of pedals and hand-held gear selector switches.
Various vehicle speed control strategies were investigated and recommendations made
regarding their possible future implementation. System evaluation was accomplished by
the simulated acceleration of a large truck. The simulations indicated that repeatable
results could be obtained from the system. The system was also found to be adequately
sensitive to reflect the effect of subtle changes made to engine parameters on vehicle
acceleration. It was concluded that the dynamic engine test-bed did indeed offer the
capability to conduct research and testing not previously available in South Africa.
Finally, recommendations were made for the future improvement and expansion of the
system's performance and capabilities. / AFRIKAANSE OPSOMMING: Die laaste twee dekades het baie veranderinge in die outomobiel industrie megebring.
Groot vooruitgang is gemaak in die ontwerp, navorsing en ontwikkeling van die
binnebrand enjin, terwyl tegnologiese vooruitgang in die geïntegreerde-stroombaan en
rekenaar industrië betroubare elektroniese komponente teen lae koste beskikbaar gemaak
het. Hierdie komponente is mettertyd in enjins geïnkorporeer en het die akkurate beheer
van enjin funksies en prosesse moontlik gemaak. Saam met hierdie ontwikkeling, is daar
toenemende kommer oor die omgewing en 'n bewuswording dat hulpbronne verbruik word
teen 'n groeinde tempo. Hierdie feite plaas voertuig vervaardigers onder volgehoude druk
om enjins te optimeer vir brandstof doeltreffendheid, maar ook om skadelike emissies te
bekamp terwyl beter werksverrigting en bestuurbaarheid vereis word.
Enjin toetstoerusting en fasiliteite moes terselfdetyd met hierdie vooruitgang byhou en het
die ontwikkeling van meer gesofistikeerde toetsfasiliteite vereis. Een sodanige fasiliteit is
die dinamiese enjin toetsbank. Een van die kenmerke van hierdie fasiliteit is dat dit
toetsbank-gemonteerde enjins kan onderwerp aan 'n las soortgelyk as wat ondervind sou
word in 'n voertuig op die pad. Hierdie benadering stel ingenieurs in staat om enjin
komponente en werksverrigting te optimeer onder meer realistiese kondisies en lewer
resultate van 'n baie hoër gehalte as wat verkry kan word deur gebruik te maak van meer
konvensionele gestadigde-toestand toets- en ontwikkelings-prosedures.
Hierdie dokument bespreek die ontwikkeling van so 'n dinamiese enjin toetsbank by die
Sentrum vir Automobielingenieurswese aan die Universiteit van Stellenbosch. Die projek
is geïnisieer deur 'n literatuurstudie te doen om die huidige stand van tegnologie in die
gebied vas te stel. Die dinamiese enjintoetsbank is ontwikkel rondom 'n bestaande
gelykstroom-motor en industriële spoed beheerder wat in 'n regeneratiewe konfigurasie
opgestel is. Hierdie opstelling het die absorpsie en lewering van drywing moontlik
gemaak, 'n vereiste vir die simulasie van voertuig dinamika. Baie tyd is gespandeer om te
verseker dat seine afkomstig van die toetsbank akkuraat en bruikbaar was vir verdere
rekenaar manipulasie. Anti-aliaseringsfilters is ontwerp en vervaardig om te verseker dat
seine nie verkeerd geïnterpreteer kon word as gevolg van diskritiserings effekte nie. 'n Rekenaar ge-implementeerde voertuigmodel is ontwikkel om 'n voertuig se reaksie op
draairnoment ontwikkel deur die enjin op die toetsbank intyds te simuleer. Die model het
'n handrat transmissie, koppelaar en starre dryf-as ingesluit. Bestuurder intree
(vernellingspedaal, rem, koppelaar en rat seleksie) is bewerkstellig deur middel van 'n stel
pedale en 'n hand geoperateurde rat skakelaar. Verskeie voertuig spoed-beheerders is
ondersoek en aanbevelings is gemaak aangaande die toekomstige implementering daarvan.
Die sisteem is geëvalueer deur die versnellingsimulasie van 'n groot vragmotor. Die
simulasies het daarop gedui dat herhaalbare resultate van die sisteem verkry kon word.
Daar is ook bevind dat die sisteem sensitief genoeg was om subtiele veranderinge aan
enjinparameters in die resultate te weerspieël. Die gevolgtrekking is gemaak dat die
dinamiese enjin toetsbank inderdaad die vermoëns gebied het om ontwikkeling en
toetswerk te doen wat nie voorheen in Suid-Afrika moontlik was nie. Voorstelle is
laastens gemaak aangaande die toekomstige verbetering en uitbreiding van die sisteem se
vermoëns.
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Development of a project plan to enhance the import process for Clear Blue InternationalPeters, Marc 12 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: Clear Blue International (pty) Ltd (CBI) is a swimming pool construction company
that is in need of a high performance swimming pool pump in order to offer a
competitive tender for the construction of an intricate swimming pool at a prestigious
resort. There is one supplier of this particular pump in South Africa and due to their
sole distributorship and the pump's technical specifications, it is sold at a very
expensive price. The result being that CBI can't offer a competitive tender by this
means, instead they need to source the pump from another source at a lower price. It
was decided to develop a project plan to facilitate the importation process, which is
the outcome of this study.
A thorough analysis of project management is conducted and incorporated into the
importation process. The study takes into consideration the intricacy of the
importation process and how this can be facilitated by project management that will
lead to success for CBI.
CBI recognises that in order to stand out in a highly competitive industry they need to
re-invent themselves by new and innovative means in order to stand out from the rest.
Project management has proven to be the means by which they can add value to their
corporate image.
This study provides a useful template that can be of benefit to other importers that
wish to use project management and it can be adjusted accordingly to a particular
commodity and importers requirements. / AFRIKAANSE OPSOMMING: Clear Blue International (Edms) Bpk (CBI) is 'n swembad konstruksie-maatskappy.
Hulle benodig 'n hoe verrigting pomp met die oog op 'n mededingende tender vir die
bou van 'n ingewikkelde swembad-konstruksie by 'n toonaangewende oord. Daar is
huidiglik net een verskaffer van hierdie spesifieke pomp in Suid-Afrika en vanwee
hulle alleen-verspreiding, plus die pomp se spesifieke tegniese spesifikasies, word dit
teen 'n baie hoe prys verkoop. CBI kan tans nie 'n mededingende tender verskaf nie
en wil daarom die pomp eers teen 'n laer prys vanuit 'n ander oord bekom. Die besluit
was dus om 'n projek-plan te inisieer om die invoer-proses te vergemaklik, wat die
resultaat van hierdie studie is.
'n Deeglike analise van projek bestuur is aangevoer en by die invoer-proses geinkorporeer.
Hierdie studie neem ook die ingewikkeldheid van die invoer-proses
in ag en hoe projek bestuur dit kan vergemaklik en sodoende kan bydra tot die sukses
vir CBI.
CBI besef dat, om uit te staan in 'n hoogs mededingende industrie, hulle hulself moet
vernuwe op 'n innoverende wyse. Projek bestuur is bewys as die metode waarby hulle
hul korporatiewe beeld kan verhoog.
Die studie verskaf 'n waardevolle profielvorm waarby ander invoerders wat projek
bestuur wil implementeer, ook kan baat vind. Dit kan aangepas word volgens
spesifieke handelsartikels en invoer-voorskrifte.
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A spatial decision support system for pipe break susceptibility analysis and impact assessment of municipal water distribution systemsSinske, Stefan (Stefan Andreas) 03 1900 (has links)
Dissertation (PhD)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Municipal water distribution maintenance is very important for sustainable urban
development. Water pipe breaks result not only in a disruption in service but
also in significant loss of water, which otherwise could have been sold to the
consumer. In countries where water is scarce, such as South Africa, water
losses can be detrimental to the living standard of people. Water pipe breaks
can furthermore cause extensive damage to nearby lower-lying properties.
Existing decision support systems available in the field of water distribution
system maintenance are mainly focused on leak detection and pipe
rehabilitation/replacement strategy. These existing systems, however, do not
address the actual causes of pipe breaks and pipe break impact is also not
supported.
The aim of this research is to develop a spatial decision support system (SDSS)
for pipe break susceptibility analysis and impact assessment. The engineer (or
public works administrator) can apply the SDSS to model the complex pipe
break phenomena in the municipal water distribution system. The SDSS can
identify pipes susceptible to breaking and pipes with potentially high break
impact as far as water loss and damage caused to nearby property are
concerned. This combined pipe break susceptibility analysis and potential
impact assessment should promote more informed decision-making on
preventative maintenance measures to be taken and their prioritisation.
The dissertation consists offive parts. In the first part (Chapters 1-4) theories on
information systems, fuzzy logic, object-oriented modelling, Unified Modelling
Language (UML) and pipe break causes are presented. This literature review
provides a basis on which the SDSS for pipe break susceptibility analysis and
impact assessment can be developed.
In the second part (Chapter 5) the general user requirements and design of the
SDSS are given. The general SDSS architecture, the general system functionality and the user interface are described and designed in this part of the
dissertation.
The third part (Chapter 6) provides the detailed user requirements and design of
the subsystems of the SDSS. Specialised functionality for pipe break
susceptibility analysis and impact assessment is added to the general design of
the SDSS. Subsystems are designed for analysing the pipe break susceptibility
due to age, air-pocket formation and tree-root attack. Pipe break impact
assessment subsystems are also designed for assessing water loss and
potential damage caused to nearby property. Finally, a combined analysis
subsystem is designed for combined pipe break susceptibility analysis and
impact assessment.
In the fourth part (Chapter 7), the SDSS is applied to the water distribution
system of the Paarl Municipality to identify pipes in the network that have both
high break susceptibility and also high break impact. The pipe break
susceptibility analysis model of the SDSS is also tested and calibrated by
comparing the model results with actual pipe break occurrence data of the study
area.
The final chapter (Chapter 8) contains the summary and recommendations
regarding the functionality of the newly developed SDSS. / AFRIKAANSE OPSOMMING: Die instandhouding van munisipale waterverspreidingstelsels is uiters belangrik
vir volhoubare stedelike ontwikkeling. Waterpypbreuke lei nie alleenlik tot
onderbreking in diensverskaffing nie, maar ook tot beduidende waterverlies en
verlies aan inkomste uit waterverkope. In lande waar water skaars is, soos in
Suid-Afrika, kan waterverliese die lewenstandaard van die bevolking nadelig
beïnvloed. Waterpypbreuke kan ook groot skade aan naby-geleë laag-liggende
eiendomme aanrig.
Besluitnemingstelsels tans beskikbaar op die gebied van instandhouding van
waterverspreidingstelsels is hoofsaaklik gerig op lekkasie-opsporing en
pyprehabilitasie- en pypvervangingstrategieë. Hierdie bestaande stelsels
spreek egter nie die eintlike oorsake van pypbreuke aan nie, daar word ook nie
op die impak van pypbreuke ingegaan nie.
Die doelwit van hierdie navorsing is om 'n ruimtelike besluitnemingstelsel (RBS)
-
vir pypbreuk-risiko-analise en impakberaming te ontwikkel. Die ingenieur (of
stelselbestuurder) kan met behulp van die RBS die komplekse pypbreukverskynsel
in 'n munisipale waterverspreidingstelsel modelleer. Die RBS kan
pype met hoë breek-potensiaal identifiseer asook pype wat, indien dit breek,
groot waterverlies of skade aan naby-geleë eiendomme sal veroorsaak.
Hierdie gekombineerde pypbreuk-risiko-analise en impakberaming behoort
meer oordeelkundige besluitneming te bevorder deur beter prioritisering van
voorkomende instandhoudingsmaatreëls en die uitvoering daarvan.
Die proefskrif bestaan uit vyf dele. In die eerste deel (Hoofstukke 1-4) word die
teorieë oor inligtingstelsels, 'fuzzy logic', objek-georiënteerde modellering,
'unified modelling language (UML)' en die oorsake van pypbreuke behandel.
Hierdie literatuurstudie skep die basis waaruit die RBS vir pypbreukrisikobepaling
en impakberaming ontwikkel sal word. In die tweede deel (Hoofstuk 5) word die algemene gebruikersbehoeftes en die
ontwerp van die RBS uiteengesit. Die algemene RBS struktuur en die
gebruikerskoppelvlak word in hierdie deel van die proefskrif beskryf en ontwerp.
In die derde deel (Hoofstuk 6) word die gedetailleerde gebruikersbehoeftes en
die ontwerp van die substelsels van die RBS uiteengesit. Gespesialiseerde
funksionaliteit vir pypbreuk-risikobepaling en impakberaming is tot die algemene
ontwerp van die RBS bygevoeg. Substelsels is ontwerp vir die ontleding van
pypbreuk-risiko as gevolg van ouderdom, lugblaas-vorming en boomwortelaanval.
Substelsels vir impakberaming is ook ontwerp om waterverlies en
potensiële skade aan eiendomme vas te stel. Ten slotte word 'n gekombineerde
ontledingsubstelsel vir gekombineerde pypbreuk-risikobepaling en
impakberaming opgestel.
In die vierde deel (Hoofstuk 7) word die RBS toegepas op die
waterverspreidingstelsel van die Paarlse munisipaliteit om pype uit te ken wat
beide 'n hoë breuk-risiko en 'n hoë breuk-impak bevat. Die pypbreuk-analise
model van die RBS is ook getoets en gekalibreer deur die resultate van die
model te vergelyk met data van werklike pypbreuke in die studiegebied.
Die laaste hoofstuk (Hoofstuk 8) bevat die samevatting en die aanbevelings
rakende die funksionaliteit van die voorgestelde RBS.
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A retrospective review of the most common safety concerns encountered at a range of international recompression facilities when applying the Risk Assessment Guide for Recompression Chambers over a period of 13 yearsBurman, Francois 04 1900 (has links)
Thesis (MScMedSc)-- Stellenbosch University, 2014. / ENGLISH ABSTRACT: Diving medical doctors frequently make use of Hyperbaric Facilities without fully realising
their legal and ethical responsibilities towards the safety of their patients and their staff. Few
have specific training in the technical or operational aspects of these facilities; this deficiency
is exacerbated when these are established in remote areas. The potential dangers are real and
the results can be devastating. Most current regulatory, manufacturing, safety and operational
guidance documents are not flexible enough to be applied universally, nor do they offer
practical guidance on the recognition and the mitigation of the unique and relevant hazards at
a given facility. The goal of integrated safety is rarely achieved.
The Risk Assessment Guide (RAG) was developed by the investigator as a tool to qualify the
actual safety status of a hyperbaric facility and to offer guidance on how to improve and
maintain it. Although the RAG has been subject to extensive peer review and field
implementation over the past 13 years, it has not been subject to scientific validation.
Therefore, the objective of this thesis was to do so by (1) retrospectively reviewing the most
common safety concerns affecting facility status as identified by the RAG; (2) using the data
derived from the analysis to produce a predictive model of likely safety status for un-assessed
facilities; and (3) consolidating the results in the form of specific recommendations to
improve and maintain safety status.
Data collected from a consistent application of the RAG over a period of 13 years, covering
105 applicable facilities, was analysed to determine the common safety concerns, particularly
those affecting safety status by means of a consolidated Risk Assessment Score (RAS). The
RAS values permitted comparisons between the facilities assessed. The various factors
associated with a higher RAS were determined by means of a multivariate regression.
Thereupon, the most significant determinant factors were built into a predictive model for the
likely safety status of an un-assessed facility. Finally, the most common safety concerns were
identified and summarised so that medical practitioners are empowered to determine,
improve and maintain the safety status of a given facility. The conclusions of this project are that: (1) the RAG is an appropriate tool to assess facilities
for risk elements relevant to their safety status while simultaneously filling the knowledge
gaps to equip medical practitioners and staff to improve and maintain safety; (2) reliable
predictions on unknown facilities can be made to provide medical practitioners with the
necessary information on whether a given facility is appropriate for patient referral; and (3)
the RAG is a suitable benchmark for determining hyperbaric facility safety; the review of its
application has provided objective data that will permit the formulation of future safety
guidelines based on empirical rather than arbitrary information. / AFRIKAANSE OPSOMMING: Duikmediese dokters maak dikwels gebruik van hiperbariese fasiliteite sonder om die wetlike
en etiese verantwoordelikhede ten opsigte van die veiligheid van hul pasiënte en personeel te
besef. Weinig het spesifieke opleiding in die tegniese of operasionele aspekte van hierdie
fasiliteite; hierdie tekort is gewoonlik erger in afgeleë gebiede. Die potensiële gevare is
wesenlik en die gevolge kan verwoestend wees. Meeste van die huidige regulatoriese-,
vervaardigings-, veiligheids en operasionele leidingsdokumente is nie buigsaam genoeg om
in die algemeen toegepas te kan word nie. Hulle bied ook nie praktiese leiding oor die
erkenning en die versagting van unieke en relevante gevare by 'n gegewe fasiliteit nie. Die
doelwit van geïntegreerde veiligheid word selde bereik.
Die “Risk Asssessment Guide” (RAG) is voorheen deur die navorser ontwikkel as 'n
instrument om die werklike veiligheidsstatus van 'n hiperbariese fasiliteit te kwantifiseer en
leiding te bied oor hoe om dit te verbeter en in stand te hou. Alhoewel die RAG onderhewig
was aan uitgebreide eweknie hersiening en praktiese uitvoering oor die afgelope 13 jaar, was
dit nie voorheen onderhewig aan wetenskaplike validasie nie. Die doelwit van hierdie tesis is
dus om hierdie te bewerkstellig deur (1) die mees algemene veiligheidskommernisse wat
fasiliteitstatus beïnvloed, soos deur die RAG geïdentifiseer, retrospektiewelik te hersien; (2)
die data wat deur die hersiening verkry is te gebruik om 'n model te ontwikkel vir
onbeoordeelde fasiliteite, wat die waarskynlike veiligheidsstatus kan voorspel, en (3) die
resultate te konsolideer in die vorm van spesifieke aanbevelings om veiligheidsstatus te
verbeter en in stand te hou.
Die data wat ingesamel is deur die konsekwente toepassing van die RAG oor 'n tydperk van
13 jaar en wat 105 fasiliteite gedek het, is ontleed om die algemene veiligheidskommernisse,
veral die wat die veiligheidsstatus beïnvloed, deur middel van 'n gekonsolideerde Risikoassesserings
waarde (RAW) te bepaal. Die duidelike en aangepaste RAW laat toe om
vergelykings tussen die fasiliteite te tref. Faktore wat verband hou met 'n hoër RAW was deur
middel van 'n meervoudige regressie bepaal. Daarna is die belangrikste determinante in 'n
voorspellende model gebou om die waarskynlike veiligheidsstatus van 'n onbeoordeelde
fasiliteit te bepaal. Ten slotte was die mees algemene veiligheidskommernisse geïdentifiseer
en opgesom om sodoende mediese praktisyns te bemagtig om die veiligheidsstatus van 'n
gegewe fasiliteit vas te stel, te verbeter en in stand te hou. Die gevolgtrekkings van hierdie projek is dat: (1) die RAG 'n geskikte instrument is om
fasiliteite te evalueer vir risiko-elemente wat relevant is tot hul eie veiligheidsstatus en
terselfdertyd die kennisgapings te vul om geneeshere en personeel toe te rus om veiligheid te
verbeter en in stand te hou; (2) redelik betroubare voorspellings oor onbekende fasiliteite kan
gemaak word om vir mediese praktisyns die nodige inligting te verskaf aangaande die
geskiktheid van 'n gegewe fasiliteit vir pasiënt-verwysing, en (3) dat die RAG 'n geskikte
maatstaf is vir die bepaling van hiperbariese fasiliteit veiligheid. Die hersiening van die
toepassing het objektiewe data voorsien wat die formulering van toekomstige
veiligheidsriglyne, geskoei op empiriese eerder as arbitrêre inligting, sal toelaat.
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Integration methods for enhanced trapping and spectroscopy in optofluidicsAshok, Praveen Cheriyan January 2011 (has links)
“Lab on a Chip” technologies have revolutionized the field of bio-chemical analytics. The crucial role of optical techniques in this revolution resulted in the emergence of a field by itself, which is popularly termed as “optofluidics”. The miniaturization and integration of the optical parts in the majority of optofluidic devices however still remains a technical challenge. The works described in this thesis focuses on developing integration methods to combine various optical techniques with microfluidics in an alignment-free geometry, which could lead to the development of portable analytical devices, suitable for field applications. The integration approach was applied to implement an alignment-free optofluidic chip for optical chromatography; a passive optical fractionation technique fractionation for cells or colloids. This system was realized by embedding large mode area photonic crystal fiber into a microfluidic chip to achieve on-chip laser beam delivery. Another study on passive sorting envisages an optofluidic device for passive sorting of cells using an optical potential energy landscape, generated using an acousto-optic deflector based optical trapping system. On the analytical side, an optofluidic chip with fiber based microfluidic Raman spectroscopy was realized for bio-chemical analysis. A completely alignment-free optofluidic device was realized for rapid bio-chemical analysis in the first generation by embedding a novel split Raman probe into a microfluidic chip. The second generation development of this approach enabled further miniaturization into true microfluidic dimensions through a technique, termed Waveguide Confined Raman Spectroscopy (WCRS). The abilities of WCRS for online process monitoring in a microreactor and for probing microdroplets were explored. Further enhanced detection sensitivity of WCRS with the implementation of wavelength modulation based fluorescent suppression technique was demonstrated. WCRS based microfluidic devices can be an optofluidic analogue to fiber Raman probes when it comes to bio-chemical analysis. This allows faster chemical analysis with reduced required sample volume, without any special sample preparation stage which was demonstrated by analyzing and classifying various brands of Scotch whiskies using this device. The results from this study also show that, along with Raman spectroscopic information, WCRS picks up the fluorescence information as well, which might enhance the classification efficiency. A novel microfabrication method for fabricating polymer microlensed fibers is also discussed. The microlensed fiber, fabricated with this technique, was combined with a microfluidic gene delivery system to achieve an integrated system for optical transfection with localized gene delivery.
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"Avaliação e comparação de diferentes tipos de trocadores de calor e umidade" / Evaluation and comparison among different heat and moisture exchangersLucato, Jeanette Janaina Jaber 30 June 2005 (has links)
As tarefas de umidificação e aquecimento do ar inspirado podem ser realizadas por meio de trocadores de calor e umidade (HMEs - Heat and moisture exchangers). Os objetivos do nosso estudo são avaliar e comparar a capacidade de umidificação e aquecimento de oito diferentes tipos de HMEs em um modelo experimental com pulmão animal isolado e avaliar o impacto de cada um dos HMEs na ventilação alveolar em um modelo mecânico do sistema respiratório, com adição de CO2 a um fluxo de 0,65L/min. Os níveis de umidade e temperatura foram medidos durante a situação controle (nenhum HME) e com os diferentes HMEs quando volume corrente; freqüência respiratória e fluxo foram variados. A recuperação da umidade absoluta da expiração durante a próxima inspiração (% RAH) foi calculada. A % RAH aumentou com o uso do HME comparado ao controle. O volume corrente teve um significante efeito na % RAH, o que não ocorreu com alterações na frequência respiratória ou fluxo. O aumento do ETCO2 foi proporcional ao aumento do espaço morto dos HMEs. As alterações de fluxo ou a saturação dos HMEs não determinaram relevantes alterações no ETCO2 / When tracheal intubation is necessary during ventilatory support, the physiological mechanisms of heating and humidifying the inspired air are supressed, so it is vital the preconditioning of the inspired gases with the goal of offering water and heat contents similar to those normally provided by the upper airways. These tasks of humidification and heating can be accomplished through the use of heat and moisture exchangers (HMEs). Objectives: 1- Evaluate and compare the humidification and heating capacity of eight different types of HMEs in a respiratory system analog using preserved swine lung. 2- Evaluate the impact of each one of the tested HMEs over alveolar ventilation in a mevhanical model of the respiratory system
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Projeto, desenvolvimento e avaliação pré-clínica de uma bomba de sangue ápico aórtica para assistência ventricular esquerda / Project, development and pre-clinical evaluation of an apico-aortic blood pump for left ventricle assistanceSilva, Bruno Utiyama da 08 August 2016 (has links)
O presente estudo apresenta o desenvolvimento de uma Bomba de Sangue Ápico Aórtica (BSAA) para uso como dispositivo de assistência ventricular esquerda. A BSAA é um dispositivo que já se encontrava em desenvolvimento antes do início deste trabalho e o ponto de partida deste estudo foi a realização de ensaios In Vivo. Os ensaios In Vivo foram realizados em porcos (Landrace, sem gênero definido e massa de 45 a 90 Kg) o tempo de pós-operatório programado foi de 6 horas. Ao total foram realizados 7 experimentos, sendo que um dos experimentos não foi incluso na análise dos resultados devido a complicações na cirurgia. Em três experimentos, as 6 horas de pós-operatório foram cumpridas, em 1 experimento, o animal veio a óbito após 5h30 e em dois experimentos o animal veio a óbito antes da BSAA entrar em uso. Através dos ensaios In Vivo, foi possível implementar diversas melhorias no dispositivo, principalmente no sistema de conexão das cânulas. Foi realizado um ensaio para determinar a geometria de topo da cânula de entrada, mostrando que o modelo com cânula tubular simples é o mais adequado. Em um ensaio de durabilidade foram observadas duas falhas: o desacoplamento do rotor por desgaste do pivô inferior do mancal e uma fratura no eixo do mancal. A fratura no eixo foi analisada por uma simulação computacional. Foi proposta uma modificação no eixo do mancal para eliminar uma região com acúmulo de tensões. Para solucionar o degaste do pivô inferior foi proposta uma modificação na topologia do estator que, deixando de ser axial e se tornando radial. Para verificar o efeito do estator radial na redução do desgaste no mancal foi realizado um ensaio de desgaste, este ensaio mostrou a influência da carga no mancal em relação ao desgaste e serviu para fundamentar a implementação do estator radial. O protótipo da BSAA com estator radial foi construído. Neste modelo, foi possível reduzir o tamanho do dispositivo. Os resultados do ensaio para determinar o Índice Normalizado de Hemólise (INH) do modelo com estator radial mostraram que um INH clinicamente satisfatório. O estudo do desempenho hidrodinâmico do modelo com estator radial mostrou que o dispositivo é capaz de gerar pressão e fluxo para seu uso na assistência ventricular esquerda. Os resultados deste trabalho permitiram aprofundar o conhecimento sobre o desempenho da BSAA em condições reais de uso, possibilitando a melhoria do dispositivo e redução do desgaste visando seu uso em terapias de longo prazo. / This study presents the development of an Apico-Aortic Blood Pump (AABP) a left ventricle assist device. AABP is a device that was already in development before the beginning of this research and the starting point were Acute In Vivo experiments. The In Vivo experiments were performed in pigs (Landrace, gender not defined and weight 45 to 90 Kg), post operatory time was 6 hours. 7 experiments were performed and one of them was not included in the data analysis due to complications in the surgical procedure that lead to animal\'s early death and thus its exclusion. In 3 experiments, the 6 hours of post operatory were achieved, in one experiment the animal died after 5h30 minutes and in two experiments, the animal died before AAPB implantation. These In Vivo experiments allowed AAPB improvement mainly in the connection system. A study to select the edge geometry of the inlet cannulae was performed, the results appointed that a tube shape cannulae model would be more appropriated for the device ease implantation. In the durability test two failures occurred: rotor decoupling due to wear in the lower pivot of the bearing system and a fracture in the bearing axis. The fracture in the bearing axis was further studied by computer simulation, which results lead to a modification in the axis geometry to eliminate a region with accumulated tension. To solve wear problem in the lower pivot, a stator topology modification was explored, AABP\'s stator would became radial instead of axial as it was in the original model. In order to verify the effect of the radial stator in reducing wear on the lower pivot, a wear test was performed. In this test, the influence of load on the wear production rate was observed and the results appointed that reducing the load would reduce the wear. These results were the basis for stator change to the radial topology. An AAPB prototype with the radial stator was constructed and this model had lower dimensions than the original model with axial stator. Normalized Index of Hemolysis (NIH) obtained with the prototype with the radial stator was in the clinically satisfactory limit. Hydrodynamic performance of the model with the radial stator indicated that this device could provide pressure and flow for its use as a left ventricle assist device. Results from this thesis allowed a deeper knowledge from AABP performance in real use conditions, which lead to the improvement of the device and through this study was possible to know and implement features aiming to enhance AAPB\'s durability for its use in long-term therapies.
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Feasibility study on operating specialty retail shops for personal office equipment in Jardine office systems.January 1990 (has links)
by Li Kar-cheung. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1990. / Bibliography: leaves 78-79. / ABSTRACT --- p.ii / TABLE OF CONTENTS --- p.iii / LIST OF TABLES --- p.v / PREFACE --- p.ix / Chapter I. --- INTRODUCTION --- p.1 / Company Background --- p.1 / The Office Equipment Market --- p.3 / Action Adopted --- p.5 / Objective of Study --- p.6 / Chapter II. --- RESEARCH METHODOLOGY --- p.8 / Customer Perception Survey --- p.8 / Data Collection Method --- p.8 / Focus Group Study --- p.9 / Questionnaire Design --- p.9 / Sample Design --- p.9 / Data Collection --- p.10 / Method of Analysis --- p.10 / Limitations of the Study --- p.11 / Personal Interview --- p.11 / Breakeven Analysis --- p.11 / Chapter III. --- SURVEY FINDINGS --- p.13 / Demographic Characteristics --- p.13 / Demand and Usage --- p.14 / Channel Preference --- p.15 / Key Considerations to Buy --- p.16 / Brand Name and Vendor Reputation --- p.17 / Shop Location --- p.18 / Shopping Habit --- p.19 / Price --- p.20 / Summary of Findings --- p.20 / Chapter IV. --- BREAKEVEN ANALYSIS --- p.22 / Personal Interview Findings --- p.22 / Determination of Breakeven Sales Revenue --- p.25 / Chapter V. --- RECOMMENDATIONS --- p.28 / Product --- p.28 / Brand --- p.30 / Location --- p.30 / Price --- p.30 / Advertising and Promotion --- p.31 / Chapter VI. --- CONCLUSION --- p.32 / APPENDIXES / Chapter Appendix 1 --- Organization Chart --- p.33 / Chapter Appendix 2 --- Focus Group Study --- p.34 / Chapter Appendix 3 --- Questionnaire --- p.37 / Chapter Appendix 4 --- Tables --- p.48 / BIBLIOGRAPHY --- p.78
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