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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
381

Ensuring Respiratory Protection through Respirator Fit Testing and Real-Time Monitoring

Wu, Bingbing 30 October 2018 (has links)
No description available.
382

Non-parametric nonlinearity detection under broadband excitation

Kolluri, Murali Mohan January 2019 (has links)
No description available.
383

Comparison of the lead-leakage in Pb-Sn hybrid perovskite solar cells and Pb-based perovskite solar cells

Cui, Chao January 2023 (has links)
Perovskite solar cells exhibit outstanding device performance and photovoltaic potential in recent ten years. However, the photoactive layer of the majority of perovskite solar cells with outstanding efficiency currently contains toxic lead. Although perovskite solar cells will be encapsulated prior to application to enhance the device's stability and prevent lead leakage, it is still possible for the devices to be broken or exposed to the environment during actual use. Correspondingly, Pb may enter water or soil through rainfall, posing health risks to humans and other creatures. To prepare perovskite solar cell devices with both high performance and low toxicity, current research concentrates primarily on Pb-Sn hybrid perovskite solar cells as Sn is less toxic than Pb from an environmental standpoint. To intuitively compare the lead leakage of Pb-based perovskite solar cells and Pb-Sn hybrid perovskite solar cells, this study simulated the lead leakage scenario under heavy rainfall conditions using self-prepared, good-performance solar cell devices. Our results indicate that Pb-Sn hybrid perovskite solar cells have less lead leakage than Pb-based perovskite solar cells. The lead leakage concentration of Pb-Sn hybrid perovskite solar cells was 36.8% (in the dripping test) and 41.2% (in the soaking test) lower than that of Pb-based perovskite solar cells.
384

Electrical Degradation of 15 kV Polymer Insulators under Accelerated Tracking and Erosion Test Conditions

Tripathi, Rahul 17 August 2013 (has links)
Polymer insulators are used in the power transmission and distribution industry as a good substitute to the porcelain and glass insulators. These polymer insulators have many advantages compared to porcelain insulators respectively. Significant improvement has been made in the performance of polymer insulators with continuous evaluation involving its performance and reliability under contaminated conditions for transmission and distribution purposes. This thesis investigates about the performance of polymer insulation under accelerated tracking and erosion test conditions conducted on distribution class polymer equipment’s like composite insulators and polymeric cutouts having a rated voltage of 15 kV. Further electrical tests, additional tests are done for investigating the dielectric strength of composite insulators and polymeric cutouts for studying its degradation process at macroscopic level.
385

Läckor på PE-ledningar : Statistiksammanställning & analys / PE-pipes leakage : Compilation & analysis of statistics

Appelfeldt, Daniel, Kohler, Johan January 2014 (has links)
Det absolut vanligaste materialet vid nybyggnad av dricksvattenledningar var år 2008 polyeten. Flera VA-huvudmän i Sverige och Norge upptäckte dock att vissa av dessa ledningar gick sönder efter bara några få år i drift, trots det faktum att de skulle ha en drifttid på upp mot 150 år. Flera VA-bolag gick då ihop och skapade en branschorganisation under namnet 4S med syftet att stimulera till utveckling av ledningsmaterialet. Organisationen visste dock inte hur utbrett problemet med läckande PE-ledningar var och hade bara indikationer om bakomliggande orsaker. Det vill säga att PE-ledningar av stora dimensioner gick sönder efter få år i drift på grund av fel på skarven. Uppgiften med detta examensarbete var att ta fram ett statistiskt underlag som påvisar hur omfattande problemet var och kunna hitta samband som visar var och varför problemen uppkom. Ett frågeformulär som beskrev för VA-huvudmännen vilken information som eftersöktes för att kunna göra en bra undersökning sattes ihop och skickades ut. De data som sen inkom sammanställdes i ett dokument i programmet Excel för att få en enhetlig och övergripande bild. Resultaten som kom in visade sig dock ha stora brister och det var svårt att dra några statistiskt säkerställda slutsatser. Det fanns dock antydan till att problemet var på skarvar och i mindre dimensioner, oftast på servisledningar. Problembilden som uppkom under arbetets gång var att de data som tillhandahölls oftast var antingen bristfälligt eller obefintligt, och något VA-huvudmännen måste arbeta mer med. Det gick heller inte att se några ålderssamband, det vill säga att PE-ledningarna skulle gå sönder efter kort eller lång tid i drift. / The most common material used when producing new water pipes in Sweden in 2008 was polyethylene. A couple of pipe owners in Sweden discovered that pipes made out of PE who only had been operating a few years broke, despite the fact they are supposed to have a service life of 150 years. The pipe owners therefore created an organization named 4S with the target to develop the PE pipe system. The problem was that the organization did not know how widespread the problem with leaking PE pipes was and they only had indications of why it is caused. The objective with this project was to collect statistics to show how widespread the problem is and to find where and why the problem arises. A couple of question that described to the pipe owners what kind of data that was needed, on order to make a good examination, was put together and sent out. The data that came in was put together in an Excel document to get a better picture of the problem. The results that came in proved to have major flaws and it was difficult to draw statistically based conclusions. The results, however, showed a hint that the problem mainly was in the joints and in smaller dimensions. The biggest problem was that the received data most often was either inadequate or non-existent, and the pipe owners have to work harder improving the system. The statistics also cannot find any age related problem.
386

共通番号(マイナンバー)制度の民間サービス利用時における個人情報漏洩のリスク評価に関する研究 / キョウツウ バンゴウ(マイ ナンバー)セイド ノ ミンカン サービス リヨウジ ニオケル コジン ジョウホウ ロウエイ ノ リスク ヒョウカ ニカンスル ケンキュウ / 共通番号マイナンバー制度の民間サービス利用時における個人情報漏洩のリスク評価に関する研究

新山 剛司, Takeshi Niiyama 31 March 2016 (has links)
2016年1月施行予定の共通番号(マイナンバー)制度によって日本に居住する外国人を含む全住民に付与されるマイナンバーの漏洩防止は、個人情報の保護という点だけでなく今後の我が国の情報通信産業の競争力強化という観点からも重要な課題である。本研究の目的はマイナンバーを民間利用する場合のリスク評価を行い、そのリスクに対する対策立案を行うことである。 / 博士(技術・革新的経営) / Doctor of Philosophy in Technology and Innovative Management / 同志社大学 / Doshisha University
387

A Study on Plasma Process-Induced Defect Creation in Si-Based Devices / シリコン系デバイスにおけるプラズマプロセス誘起欠陥生成に関する研究

Sato, Yoshihiro 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第24580号 / 工博第5086号 / 新制||工||1974(附属図書館) / 京都大学大学院工学研究科航空宇宙工学専攻 / (主査)教授 江利口 浩二, 教授 土屋 智由, 教授 平方 寛之 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
388

An in-vitro comparison of the microleakage of RealSeal/Resilon and RealSeal Self-Etch/Resilon root canal obturation system

Iqbal, Haris January 2011 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this investigation was to evaluate and compare microleakage of teeth obturated using either RealSeal/Resilon or RealSeal Self-Etch/Resilon systems. The goal was to determine whether a significant difference in microleakage exists between these two groups. To date, no study has been done comparing the microleakage of root canal systems obturated with using RealSeal/Resilon versus RealSeal SE/Resilon. Sixty-two human, single-rooted, anterior teeth were accessed and instrumented for non-surgical root canal therapy. Teeth were randomly assigned to two experimental groups of 27 teeth each. Group I consisted of teeth obturated with the RealSeal/Resilon system, whereas Group II consisted of teeth obturated with the RealSeal SE/Resilon system. In addition, two control groups containing four teeth each served as positive and negative controls, Group (+) and Group (-), respectively. The teeth were then evaluated for microleakage using a dual-chamber microleakage model. Visual turbidity in the lower chamber denoted microleakage within the experimental groups observed for 33 days. RealSeal SE Group II had a significantly higher proportion of samples than Real Seal Group I. Time to microleakage was also significantly lower in RealSeal SE Group II than in Real Seal Group I. No microleakage was observed in the negative control and microleakage was observed in all four samples in the positive control. To date, this is the first study comparing the microleakage of RealSeal/Resilon and RealSeal SE/Resilon systems. The higher microleakage associated with RealSeal SE is attributed to the higher pH of the self-etch (SE) sealer in comparison with the self-etch primer of RealSeal. The self-etching potential of the sealer system is particularly critical in areas inaccessible to calcium chelating agents such as EDTA in root canal systems. Further research needs to be done to corroborate the microleakage results from this study. The microbial leakage apparatus devised in this study, which used a selective growth medium with streptomycin, has also been validated by the results of the study. The bacterial leakage apparatus has been considered to be clinically relevant and acceptable by the Journal of Endodontics. Thus, the modified dual-chambered microleakage apparatus with a selective growth medium used in this research can be replicated easily in future microleakage studies.
389

Fissure penetration and microleakage of a conventional pit and fissure sealant and a flowable composite: a comparative study using three different bonding systems

Chan, Terence January 2002 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The concepts of using a pit and fissure sealant material to prevent dental caries have been well established in dental research. Effectiveness of a pit and fissure sealant material is limited to its ability to remain bonded to the occlusal surfaces. Adding a dentin-bonding agent between the etched enamel and the sealant material has been demonstrated as a way of optimizing bond strength in the face of moisture and salivary contamination. The purpose of this study was to examine if there was a difference in fissure penetration or microleakage between a conventional pit and fissure sealant or a flowable composite when used as a pit and fissure sealant, while using three different adhesive systems. Delton Direct Delivery System (Dentsply), an opaque, light cured pit and fissure sealant and the commercially available flowable composite, Revolution Formula 2 (Kerr) was selected for this study. Three clinically used adhesive systems selected for this study were: conventional phosphoric acid etching; Opti-bond Solo Plus(Kerr), a single bottle system; and Prompt L-Pop (3M ESPE), an all-in-one primer adhesive. One hundred fifty extracted caries-free third molars, selected for well-defined occlusal pits, were randomly divided into six treatment groups. Fissure penetration and microleakage was examined after immersion of the treated teeth in 5.0-percent methylene blue solution for 18 hours; the teeth were removed and thoroughly cleaned. Mesial and distal flat-ground sections were obtained and examined at X20; microleakage was recorded as either present or absent, and penetration was recorded as either complete or incomplete. The interaction between the material and the adhesive system was non-significant based on the logistic regression model for the penetration and the microleakage, so that only the main effects of material and adhesive system were included in the final model. Enamel conditioning with the total-etch and single-bottle adhesive system provided consistently microleakage resistance when compared with the use of the all-in-one bonding system. The all-in-one adhesive system demonstrated the most microleakage regardless of the material used for the pit and fissure sealant. The hypothesis of this thesis was that there would be no significant difference in fissure penetration or microleakage between the conventional pit and fissure sealant or the flowable composite, regardless of the adhesive system used. The results of this study support the hypothesis that there was no significant difference in fissure penetration between the materials. The result did demonstrate that there was significant difference in microleakage between the three different adhesive systems used.
390

Feasibility of Satellite Water Tanks for Urban Areas in Developing Countries

Shrestha, Manish M. January 2012 (has links)
No description available.

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