Dissertations / Theses on the topic 'Boar exposure'

Thesis (M.S.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 31, 2007) Includes bibliographical references.

Thesis (M.S.) -- University of Maryland, College Park, 2008.
Thesis research directed by: Dept. of Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

Syfte: Syftet med detta projekt var att utvärdera kvaliteten på de digitala röntgenbilder som genereras med en On-Board imager® (OBI), monterad på en medicinsk linjäraccelerator på radioterapiavdelningen på Karolinska Universitetssjukhuset. Dessa kilovoltbilder används för att verifiera patientens position på behandlingsbordet, inför behandling, för att reducera risken att friskvävnad bestrålas i onödan. Detta utförs genom en online ortogonal 2D-2D matchningsteknik innan strålningen leveras. Material och metoder: OBI-system, utvecklad av Varian Medical System, erbjuder en protokoll med exponeringsparametrar för att hjälpa användaren att välja lämpliga inställningar för exempelvis lämplig rörström och spänning under bildtagningen de digitala kilovoltbilderna. Under detta projekt skapades flera testbilder tagna med ändrade exponeringsparametrarna i de befintliga protokollen. Dessa testbilders kontrast bedömdes sedan och jämfördes med bilder tagna med de förinställda parametrar från Varians protokoll. Resultat och slutsats: En utvärdering av de experimentella testbilderna, i jämförelse med bilder skapade med det befintliga protokollet, visade att en justering av exponeringsfaktorer inte leder till något signifikant förbättring av bildernas kontrast.
Purpose: The purpose of this project was to evaluate the quality of kilo Voltage- digital radiography images that are provided by an On-Board imager® (OBI) mounted on a medical linear accelerator at the Radiotherapy department of Karolinska University Hospital. The digital kV-images are used to verify patient position on the treatment table, in order to reduce healthy tissue irradiation, using an online orthogonal set of 2D-2D matching technique, before the treatment delivery. Material and methods: The OBI- system elaborated by Varian Medical System offers an exposure factor protocol in order to help users to choice proper exposure factors, as proper tube current and tube voltage, during acquisition of kV-images. In this project several test images were performed by changing the exposure factors. Further the test images quality regarding, quality index contrast, was assessed and compared with the image performed by the existent Varian protocol. Result and Conclusion: Evaluation of the tests images shows that changing of the exposure factors doesn’t result in any significant improvement of kV-images contrast as compared to images created with the existent protocols parameters.

Globalt pågår debatter kring mångfald inom ledningsgrupper. Forskare på området är hittills inte överens om de effekter som mångfald inom affärsvärlden medför, ändå finns starka åsikter kring hur en ledningsgrupp bör utformas utifrån kön, ålder, utbildning och etnicitet. Spekulation avseende mångfalds betydelse för hållbar utveckling förekommer och i takt med ökade krav på hållbarhetsrapportering växer intresset för faktorer som kan främja denna form av rapportering. I dagsläget saknas tvingande standarder för hållbarhetsrapportering, men den miljömässiga delen inom hållbarhetsrapportering, som i studien betecknas CED-rapportering,är offentlig information och uppmärksammas i media. Media, som dels bildar normer, dels avspeglar allmänhetens förväntningar, har makten att påverka ett företags rykte. Relationen mellan mångfald i bolagsstyrelse, CED-rapportering och medieexponering är således ett aktuellt område värt att fördjupa sig i. Det huvudsakliga syftet med studien var att beskriva och analysera om mångfald i bolagsstyrelse påverkar CED-rapportering och om rapporteringen i sin tur inverkar på den grad av exponering som multinationella företag ges i media. Urvalsramen utgjordes av multinationella företag från GRI:s databas. Av 447 företag uppfyllde 202 studiens krav. Strukturella ekvationsmodeller visar att mångfald i bolagsstyrelse inte påverkar CEDrapportering. Rapporteringen påverkar däremot företags exponering i media. Företags storlek och georgrafiska placering har en inverkan på mångfald, CED-rapportering och medieexponering.
Debates about diversity among board directors are in progress globally. Scientists are in disagreement about the impacts of diversity in the business world. Yet there are strong opinions about a group’s formation on the distribution of gender, age, education and ethnicity. There are speculations of a possible relationship between diversity and sustainability reporting. The growing demands of such reporting increases the interest to determine which factors promote sustainability reporting. This study intends to explore theCorporate Environmental Disclosure (CED) of sustainability reporting. Currently there are no mandatory standard for sustainability reporting, such information is public though and exposures in media. Media compares the reports to public expectations and has the power to affect a company’s reputation. The relationship between board diversity, environmentalreporting and media exposure is hence an area worth exploring.The main intent of this study was to describe and analyse whether board diversity affects CED. Further the intent was to explore whether CED affects media exposure. The sampling for the study consisted of multinational companies. Of 447 examined, 202 formed the basis. The results of the study established by structural equation modeling, stated that board diversity is not associated with CED. Yet the study indicates that CED affects media exposure. External variables that were found to have effect on board diversity, CED or media exposure were firm size and geographical

Women still face invisible barriers that delay their upward mobility in organisations. These invisible barriers are poorly understood or ignored by organisations, as a result, gender transformation at the top is perpetually slow. Building from the (In)visibility theory, this study examined how invisible dynamics that underpin the shortage of women on boards can be addressed. The feminist literature has gained increasing attention, yet solutions to invisible barriers faced by women are lacking. This paper pulled the (In)visibility and Critical Mass Theories together to examine whether the presence of a Critical Mass resolves the invisible gendered dynamics in the boardroom. A qualitative method was used to collect and analyse data on sixteen women and their lived experiences of male-dominated boardrooms. The findings supported the criticsÕ argument that numeric representation is too simplistic to resolve invisible gendered dynamics. The study established that four main forces can counter the invisible dynamics that women face in the boardroom. These include Self-awareness and Confidence; The Role of a Chairperson; Resilience and Purpose, as well as Competence and Experience. Contrary to the (In)visibility theory, participants in this study did not withdraw or conceal their gender when exposed to hostile boardroom dynamics. The reasons for this are explored.
Mini Dissertation (MBA)--University of Pretoria, 2017.
lt2018
Gordon Institute of Business Science (GIBS)
MBA
Unrestricted

På redovisningsområdet pågår det ständigt förändringar och under den senaste tiden har stort fokus legat på BFN. Nämnden har sedan 2004 arbetat med det så kallade K-projektet där målet är att ta fram samlade regelverk för företag i olika form och storlek. I denna uppsats ligger fokus på K3-regelverket som huvudsakligen är anpassat för större onoterade aktiebolag samt ekonomiska föreningar. Tanken är att regelverket ska baseras på IFRS for SMEs som är IASBs regelverk för små och medelstora företag. I dagsläget finns inget samlat regelverk för dessa bolag i Sverige för upprättande av årsredovisning. Syftet med K3 är att det ska förenkla redovisningsarbetet och på det sättet minska de administrativa kostnaderna.I slutet av år 2010 skickade BFN ut K3 på remiss till 52 instanser. Av dessa valde 28 att skicka in remissvar av olika omfattning. Vi har behandlat 13 utav dessa eftersom resterande inte varit tillräckligt innehållsrika för att bidra med relevant information till uppsatsen.Syftet med uppsatsen har varit att undersöka och redogöra för vilka huvudargument som de olika instanserna har yttrat i sina remissvar gällande K3-regelverket. Studien är av kvalitativ karaktär med en induktiv ansats där empirin har bestått av de utvalda remissvaren.Instanserna har framfört konstruktiv kritik av olika karaktär. Huvudargumenten har vi delat in i fyra olika kategorier. Dessa har varit användarvänlighet, förhållandet till svenska lagar, förhållandet till IFRS for SMEs samt förhållandet till god redovisningssed. Resultatet av studien visar att en stor majoritet anser att användarvänligheten i K3 är undermålig och att strukturen måste förbättras för att kunna tillämpas i praktiken. Flera instanser menar även att BFN i sitt arbete att utforma K3 tagit sig stora friheter att inskränka på regler som anges i ÅRL. I vissa fall har instanser yttrat att normerna i K3 strider mot regeringsformen och ifrågasatt BFNs skrivelser. Positivt ser instanserna dock på att nämnden valt att basera K3 på IFRS for SMEs men att det i flera fall sker avvikelser från det internationella regelverket vilket inte välkomnas av ett antal instanser. Vår slutsats är att K3 i dagsläget inte är tillräckligt välutvecklat för att kunna tillämpas i praktiken eftersom majoriteten av instanserna har sammantaget fler negativa än positiva synpunkter kring regelverket.
Program: Civilekonomprogrammet

In lactation, sows are typically anoestrus, with ovulation occurring three to seven days after weaning at approximately 24 days post-partum. Increasing piglet age to greater than 28 days improves piglet performance and welfare; however, it also results in reduced sow farrowing frequencies, making the commercial adoption of increasing piglet weaning age unsustainable. Stimulating a sow to ovulate in lactation represents a solution as it enables lactation length to be increased whilst maintaining reproductive efficiencies. The aims of the research reported in this thesis were to investigate mechanisms to reliably stimulate a lactation oestrus in multiparous and primiparous sows. Secondly, to determine the effect of these strategies on piglet growth, subsequent pregnancy rate, farrowing rate and litter size. The mechanisms investigated were focused on: reducing the suckling input to the sow through split weaning or low-confinement alternative lactation housing; and fence, or full physical, boar exposure. The importance of a reduced suckling input was demonstrated in Chapter Two. The proportion of sows expressing a lactation oestrus increased as the number of piglets weaned on day 18 of lactation increased from zero, three, five to seven. Additionally, early weaning did not compromise growth of the split weaned piglets, with both early and late weaned piglets experiencing similar body weights by day 40 of age. Chapter Three evaluated the effect of full physical boar exposure commencing at day 10, 14 or 18 postpartum on the incidence of lactation oestrus in primiparous and multiparous sows. A high proportion of multiparous sows expressed a lactation oestrus in response to boar exposure compared to first parity sows; however, the summer months impacted this expression. No benefits of commencing boar exposure before day 18 post-partum on lactation oestrus expression were observed. Chapter Four coupled full physical boar exposure with split weaning of piglets at day 18 post-partum within a commercial piggery. Boar exposure was effective at stimulating a lactation oestrus in multiparous sows whereas primiparous sows require, in addition to boar exposure, a reduction in suckled litter size. A high incidence (24%) of lactating multiparous sows that received no stimulation spontaneously ovulated before weaning resulting in a prolonged weaning to oestrus interval. These results suggest that for the modern sow, weaning is not necessary for ovulation. Lastly, Chapter Five demonstrated that low confinement lactation housing from seven days post-partum, in combination with fence line boar exposure, was not sufficient to stimulate a lactation oestrus. Overall, split weaning to seven piglets in conjunction with physical boar exposure resulted in the highest proportion of lactation oestrus expression with this response greater in multiparous sows than primiparous sows. Season affected the proportion of lactation oestrus expression, and this requires further investigation. Furthermore, the incidence of spontaneous ovulation during lactation suggests that the inhibition of LH release during lactation is less severe in modern genotypes. In conclusion, this thesis has demonstrated that boar exposure effectively stimulates lactation oestrus with a further increase observed when a distinct reduction in the suckling stimulus has occurred, particularly in the multiparous sow.
Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Animal and Veterinary Sciences, 2015.

碩士
國立臺灣科技大學
自動化及控制研究所
97
This thesis aims to build up Ontology model of an exposure machine for printed circuit board and innovates some new patents. The proposed model can help researchers to create innovated patents in the field of exposure machines for printed circuit boards. Firstly, this study analyzes 50 related patents. The ontology method is used to establish ontology knowledge model and technical efficiency matrix for an exposure machine. This matrix can help researchers to realize the distribution of each technical efficiency for a patent. An analysis for TRIZ contradiction matrix is also built to help researchers to avoid invented patents and obtain a new conception direction.　 This study integrates the Ontology, the technical efficiency matrix and the TRIZ contradiction matrix to establish the innovation flow chart. It includes system knowledge, question description, solution guide and new patents. Three different questions were given to evaluate the flow chart. Finally, three new conceptions were obtained to show that the flow chart is useful to help the researchers to solve related questions and innovate new patents.

碩士
國立陽明大學
環境衛生研究所
90
ABSTRACT 2-Butoxyethanol is widely used in printed circuit board manufacturers due to its hydro-lipophilic properties. Several animal studies have demonstrate the hematological and other toxicity. The objective of the study was conducted exposure assessment and biological monitoring of printed process workers in a printed circuit board factory, to explore the workers potential health effect. In this study, we sampled four times in two weeks period for air sampling and urine collection, it takes 8 hours both the morning shift and night shift. The amount of 44 air samples were collected from 11 workers, 11 exposure workers were included（3 in printed section and 2 in development section in the morning shift; 3 in printed section, 2 in development section, and 1 in word printed section in the night shift）, 32 environment sampling by 3M passive sampler. For determining the internal dose of butoxyacetic acid , we collected the pre-shift and post-shift of workers urine in the same time of air sampling, totally 88 samples. 15 of administrative section employees were random sampled as a reference group. The concentration of 2-butoxyethanol and butoxyacetic acid were analysed by using GC/FID technique, and health questionnaire was adopted and physical examination was performed, to understand subject symptoms and hemolytic anemia of the workers of the printed process whether have significant difference to reference group. In this study, the average air exposure concentration（2.2±1.02, 2.70±1.77ppm, respectively）both found in the workplace and the printed section workers in the night shift. In the acidic metabolite of urine, the average concentration（98.7mg/g creatinine） were found of butoxyacetic acid in the urine of the printed section workers in the night shift. The correlation between external dose and internal dose are at high significant level（r=0.854）. The results show that the subject symptoms of the printed process workers have no significant difference to reference group. Compared with the reference group, the abnormal of MCH and MCHC were significantly different（X2 test, P＜0.05）. This study show that the 2-butoxyethanol exposure in the workplace was not high, but the printed process workers still have internal exposure. Furthermore, the butoxyacetic acid had been sure a good biomarker of 2-butoxyethanol exposure in the study. Key words：Printed Circuit Board, 2-Butoxyethanol, exposure assessment, biological monitoring

碩士
輔仁大學
公共衛生學系碩士班
106
The printed circuit board （PCB ） is an important electronic component in electronic products. The productions of flexible PCBs and PCBs are composed of several techniques such as printing, photography, etching, electroplating and etc to produce precise wiring. PCB serves as an assembly base to support electronic components and circuits between them. The screen templates for a printing process are reusable. After finishing the printing process, the screen template is cleaned by organic solvents. Banana oil and ethylene glycol monobutyl ether are the common solutions for cleaning the residual ink on the screen template. This project was initiated by an abnormal high concentration of toluene in the screen cleaning room and ineffective management of the hand protection program being observed. A walkthrough survey was performed to assess the exposure scenario of the cleaning task and the effectiveness of the existing local exhaust ventilation system（LEV）. The LEV was modified by opening three exhaust slits at the heights of 82 cm （192 cm in length）, 107 cm and 137 cm（both 150 cm in length） to increase the exhaust effectiveness. The real-time VOCs concentrations, face velocities, and task-based toluene personal exposure levels were measured before and after the LEV’s modification. The results showed the VOCs was 136.8 ppm before the change and decreased to 36.4 ppm after the change. The wind velocities were 4 - 5 m/sec at the heights of 107 cm and 137 cm which were 0 m/sec in the original design. The short-term exposure level time-weighted average（STEL-TWA ） concentrations of toluene were decreased from 103.18 ppm to 27.98 ppm after the modification. The gloves protection effectiveness while challenging by banana oil were tested by ASTM F739 method. The breakthrough time of the currently used natural rubber gloves were 40 – 50 minutes. No breakthrough was observed for 4-hr Silver Shield tests. It implied the Silver Shield could provide protection for at least 240 minutes. Workers can still wear the natural rubber gloves but the change frequency should be shorter than that of the present schedule. Engineering control is always the first priority in exposure control from the occupational hygiene aspect. This study applied this strategy to reduce the workers’ exposures by improving the ventilation system. As a result, the personal exposure to toluene was reduced significantly. The hand protection gloves were evaluated by challenging the solvent mixture, banana oil, which were using on-site and recommended the glove changing time frame. The administrative system played a critical role of this project success. This case demonstrated a practical and effective solution to prevent the workers’ exposures from both inhalation and dermal contact.

Modern image guided radiation therapy involves the use of an isocentrically mounted imaging system to take radiographs of a patient's position before the start of each treatment. Image guidance helps to minimize errors associated with a patients setup, but the radiation dose received by patients from imaging must be managed to ensure no additional risks. The Varian On-Board Imager (OBI) (Varian Medical Systems, Inc., Palo Alto, CA) does not have an automatic exposure control system and therefore requires exposure factors to be manually selected. Without patient specific exposure factors, images may become saturated and require multiple unnecessary exposures. A software based automatic exposure control system has been developed to predict optimal, patient specific exposure factors. The OBI system was modelled in terms of the x-ray tube output and detector response in order to calculate the level of detector saturation for any exposure situation. Digitally reconstructed radiographs are produced via ray-tracing through the patients' volumetric datasets that are acquired for treatment planning. The ray-trace determines the attenuation of the patient and subsequent x-ray spectra incident on the imaging detector. The resulting spectra are used in the detector response model to determine the exposure levels required to minimize detector saturation. Images calculated for various phantoms showed good agreement with the images that were acquired on the OBI. Overall, regions of detector saturation were accurately predicted and the detector response for non-saturated regions in images of an anthropomorphic phantom were calculated to generally be within 5 to 10 % of the measured values. Calculations were performed on patient data and found similar results as the phantom images, with the calculated images being able to determine detector saturation with close agreement to images that were acquired during treatment. Overall, it was shown that the system model and calculation method could potentially be used to predict patients' exposure factors before their treatment begins, thus preventing the need for multiple exposures.
Graduate
0760
0574
0756