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Гринь, Григорий Иванович, Евгений Александрович Семенов та Павел Анатольевич Козуб. "Вопросы ресурсосбережения в пpoизвoдстве синтетических алмазов". Thesis, Зелена Буковина, 2004. http://repository.kpi.kharkov.ua/handle/KhPI-Press/30229.
Повний текст джерелаАнотація:
Рассмотрены жидкие отходы производства синтетических алмазов как источник ценных компонентов. Разделение потоков, содержащих тяжелые металлы, в производстве синтетических алмазов, на отдельные потоки содержащие соединения хрома и поток содержащий соединения марганца и никеля, с последующей их утилизацией позволяет не только значительно улучшить экологическую обстановку в районе алмазных заводов, но и получить в качеств продуктов хромовый концентрат и марганцево-никелевый сплав. Полученный сплав металлов может быть повторно использован при производстве алмазов в качестве катализатора.Production of synthetic diamonds as source of formation liquid wastes which includes heavy metals was considered. Splitting of streams conaning of metals compositions with following production of chromic concentrate and sludge which includes compounds of manganese and nickel was proposed. Reduction of manganese and nickel by hydrogen from sludge with production of alloy of manganese and nickel was proposed. This product may be return back to the diamond production.
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St, Omer Ingrid L. J. "The pressure response of synthetic polycrystalline diamond f ilms /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9737861.
Повний текст джерела
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Sharp, Sarah Jane. "Optical studies of high quality synthetic diamond." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313889.
Повний текст джерела
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Darwish, Hamida M. B. "Characterization of different types of synthetic diamonds by luminescence and spectro-microscopy." Thesis, University of Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435422.
Повний текст джерела
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Charles, Steven John. "Characterisation of irradiation damage and dopant distribution in synthetic diamonds by luminescence micro-spectroscopy." Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393876.
Повний текст джерела
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Семенов, Евгений Александрович, та Оксана Валериевна Толстоусова. "Некоторые экологические аспекты технологии получения синтетических алмазов". Thesis, НТУ "ХПІ", 2007. http://repository.kpi.kharkov.ua/handle/KhPI-Press/30024.
Повний текст джерелаАнотація:
Рассмотрены экологические аспекты технология получения синтетических алмазов из графита в присутствии металлов. Предложена принципиальная технологическая схема очистки сточных вод алмазного производства, содержащих ионы тяжелых металлов, которая позволяет предотвратить проникновение вредных веществ в окружающую среду.The ecological aspects of the technology of obtaining synthetic diamonds from graphite in the presence of metals are considered. A basic technological scheme for purification of waste water of diamond production containing ions of heavy metals is proposed, which allows to prevent the penetration of harmful substances into the environment.
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Sahlin, Anna. "APPRAISAL OF DIAMONDS AND GEMSTONES : How to facilitate the separation of natural and synthetic gemstones." Thesis, Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71984.
Повний текст джерелаАнотація:
One major problem in the gemstone industry is that it is difficult to determine whether if a gemstone is natural or synthetic. Natural gemstones are found in the interior of the earth while the synthetic gems are created by people. The company Gemometrics has come across a product that makes it possible to distinguish these gemstones from each other, thus it solves the problem. This portable product is called GemPen and it is a lamp with a special wavelength that makes it possible to see which gems that are natural or synthetic. Gemometrics have chosen to focus on diamonds, rubies, sapphires, and emeralds. For the product GemPen, there is a protective case included, this case also works as a blackout that enables you to investigate these gemstones. To examine the gemstones, place the gems in the dark non-reflective case and direct the light from the GemPen on the gemstones. There is a visual difference between the natural gemstones with the synthetic ones which makes it possible for the user to elucidate a result. When using the object GemPen, the gemstones that are natural has a natural clarity while the synthetic gemstones will shine by themselves (fluorescence). A prerequisite to be able to see the difference when using the GemPen, the gems that are about to be investigated should be placed in a darkening whereas little light as possible may come in. The GemPen reveals its best result of this study if you are in a dark surrounding or turn of the lights in a room. This could be an issue if you’re outside and don’t have access to a dark space. Gemometrics wants the product to work outside during the daytime and this is where my study comes in. The task of this master thesis was to examine how one can strengthen the proof of the difference in synthetic and natural gemstones. The design of the GemPen was not to be changed while it was said that the design of its case was possible. My role as a design engineer was to solve this dilemma and design a conceptual solution for people and the environment. An information gathering was completed and it was collected from articles, websites, interviews within the area of geology and optics. This resulted in three different solution suggestions: 1. To be able to use the same type of technique that can be found in cameras in the shape of a charged coupled device (CCD). A device that would be able to perceive wavelengths as the human eye can’t and therefore see the fluorescence which we can’t see when it is bright outside. 2. To use a band-pass filter. This would make it possible to let the wavelengths you want to see in, and the ones you do not want to see out. 3. Some sort of portable darkening that makes it possible to examine the gemstones while using the GemPen. The idea of a portable darkening device was chosen since darkness is proved that is worked from the beginning compared with the other two concepts wish would need more evidence that it really could work. During the remaining part of the design process, a number of different approaches have been used to achieve the final result. I have worked on developing a Moodboard, coordinated a workshop and gathered pictures for inspiration. A portable darkening that is now called “GemHood” is the result after 20 weeks. The details that make this GemHood unique are that it darkens your surroundings while it enables you to have your hands free for investigation. It is a folding hood that works as a darkening. It is easy to carry around and works as a complement for the GemPen and its associated case.Ett stort problem i ädelstensindustrin är att det är svårt att avgöra om en ädelsten är naturlig eller syntetisk på ett lätt och smidigt sätt. Naturliga ädelstenar hittas i jordens inre och de syntetiska ädelstenarna är tillverkad av människan. Företaget Gemometrics har kommit på en produkt som löser problematiken kring urskiljningen. Den bärbara produkten heter GemPen och är en lampa med en speciell våglängd som gör det möjligt att se vilka ädelstenar som är naturliga och syntetiska. Gemometrics har valt att inrikta sig på ädelstenarna: Diamant, rubin, safir och smaragd. GemPen har ett skyddande etui som även fungerar som mörkläggning för ädelstenarna man vill undersöka. För att undersöka ädelstenarna placerar man dem i den mörka icke reflekterande insidan av etuiet och riktar GemPens ljus mot ädelstenarna. För att avgöra skillnaden på ädelstenarna är det den visuell skillnad på de naturliga och syntetiska ädelstenarna som bevisar detta vid användning av GemPen med tillhörande etui. Vid användning av GemPen är det ädelstenarna som är naturliga som har sin naturliga klarhet och de ädelstenar som är syntetiska som själv lyser (fluorescerar). En förutsättning för att kunna se skillnaden vid användning av GemPen är att ädelstenarna som ska undersökas placeras på en mörk bakgrund där så lite ljus från omgivningen kommer åt. GemPen fungerar, men resultatet blir som bäst om man släcker ner eller befinner sig på en mörk plats vid användandet. Detta kan vara problematiskt då man är utomhus eller inte har tillgång till en mörk plats. Gemometrics vill att produkten ska kunna användas även på en ljus plats utan tillgång till mörker. Uppgiften var att undersöka hur man kan förstärka bevisningen av att det är syntetiska och naturliga ädelstenar. Ett krav var att GemPens utformning skulle vara oförändrad. Det var okej att ändra om etuiet. Min roll som designingenjör var att lösa problematiken samt att utforma en konceptuell lösning som är anpassad för människa och miljö. Det som har gjorts är en informationsinsamling där information har tagit från artiklar, webbsidor och intervjuer inom området geologi och ljus lära. Detta resulterade i tre olika lösningsförslag: 1.) Att använda sig av samma teknik som finns i en kamera i form av en Coupled Charge Device (CCD). Denna produkt ska kunna uppfatta ljusvåglängder som det mänskliga ögat inte kan och därmed kunna se fluorescens som vi inte ser när det är ljust ute. 2.) Att använda sig av ett bandpassfilter. Det skulle kunna släppa igenom de ljusvåglängder som man vill se och lämna ute det andra. 3.) Någon form av portabel mörkläggning som gör det möjligt att undersöka ädelstenarna tillsammans med GemPen. Idén om en portabel mörkläggning valdes att gå vidare med pga. att mörker är det som man vet från början fungerar. De andra två koncept förslagen skulle behöva mer undersökning och hade inte tillräckligt med bevis för om de skulle kunna fungera. Under resterande designprocess har ett antal olika tillvägagångssätt använts för att nå ett slutresultat. Jag har jobbat med att ta fram en ”Mood board”, hållit i en ”workshop”, ”prototypat” och sammanställt ”inspirationsbilder”.20 veckors arbete resulterade i en portabel mörkläggning som namngetts till GemHood. Det som gör GemHood unik är att den mörklägger och att man kan jobba med båda händerna fria på plats. Det är en utfällbar hoodie som fungerar som mörkläggning. Den går enkelt att bära med sig och fungerar som ett komplement till GemPen med sitt tillhörande etui.
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Гринь, Григорий Иванович, та Евгений Александрович Семенов. "Технология получения NiCl₂ из отходов производства синтетических алмазов". Thesis, Національний технічний університет України "Київський політехнічний інститут", 2008. http://repository.kpi.kharkov.ua/handle/KhPI-Press/30117.
Повний текст джерелаАнотація:
Рассмотрена технология, позволяющая получать из сточных вод алмазного производства, содержащих растворимые соединения марганца и никеля, NiCl₂, а так же очищать сточные воды до норм предельно допустимых концентраций, предотвращая проникновение вредных веществ в окружающую среду.The technology is considered that allows to receive from the sewage of diamond production containing soluble compounds of manganese and nickel, NiCl₂, as well as to purify wastewater to the norms of maximum permissible concentrations, preventing the penetration of harmful substances into the environment.
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Мухина, Людмила Васильевна, Павел Анатольевич Козуб, Григорий Иванович Гринь та Евгений Александрович Семенов. "Использование солей никеля, полученных в процессе очистки сточных вод алмазного производства в технологии химического никелирования синтетических алмазов". Thesis, Зелена Буковина, 2006. http://repository.kpi.kharkov.ua/handle/KhPI-Press/30141.
Повний текст джерелаАнотація:
В работе рассмотрено использование солей никеля, полученных в процессе очистки сточных вод алмазного производства в технологии химического никелирования синтетических алмазов, применяемых в производстве инструмента.The paper considers the use of nickel salts obtained in the process of sewage treatment of diamond production in the technology of chemical nickel plating of synthetic diamonds used in the production of tools.
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Japp, Stephen Glen. "Synthetic industrial diamond : a technological outlook." Doctoral thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/17170.
Повний текст джерелаАнотація:
Summary in English.Bibliography: pages 102-118.
Synthetic diamonds are successfully substituting for natural diamonds in the area of industrial application. Synthetic diamonds increased their market share from 10% in 1960 to 50% in 1968 and to 90% in 1994. The success of synthetic diamonds may be ascribed largely to technological advance in the area of diamond manufacture. Two technologies in particular contributed to this advance: (i) High pressure and high temperature (HPHT) processes for crystallising carbon material and (ii) chemical vapour deposition (CVD) of these materials. The substitution of synthetic for natural diamond occurred in a systematic and predictable manner. Further technological advance could threaten the concept of diamond as a unique and desirable substance in the minds of the consumers and may require the repositioning of its image.
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Mullan, Claire. "Shape analysis of synthetic diamond." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/10841.
Повний текст джерелаАнотація:
Two-dimensional images of synthetic industrial diamond particles were obtained using a camera, framegrabber and PC-based image analysis software. Various methods for shape quantification were applied, including two-dimensional shape factors, Fourier series expansion of radius as a function of angle, boundary fractal analysis, polygonal harmonics, and corner counting methods. The shape parameter found to be the most relevant was axis ratio, defined as the ratio of the minor axis to the major axis of the ellipse with the same second moments of area as the particle. Axis ratio was used in an analysis of the sorting of synthetic diamonds on a vibrating table. A model was derived based on the probability that a particle of a given axis ratio would travel to a certain bin. The model described the sorting of bulk material accurately but it was found not to be applicable if the shape mix of the feed material changed dramatically. This was attributed to the fact that the particle-particle interference was not taken into account. An expert system and a neural network were designed in an attempt to classify particles by a combination of four shape parameters. These systems gave good results when discriminating between particles from bin I and bin 9 but not for neighbouring bins or for more than two classes. The table sorting process was discussed in light of the findings and it was demonstrated that the shape distributions of sorted diamond fractions can be quantified in a useful and meaningful way.
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Walmsley, J. C. "The microstructure of superhard material compacts." Thesis, University of Bristol, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376620.
Повний текст джерела
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De, Feudis Mary. "Diamonds : synthesis and contacting for detector applications." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCD005/document.
Повний текст джерелаАнотація:
Ce travail de doctorat a été réalisé dans le cadre d'un accord de cotutelle international entre l'Université de Salento (L3, Italie) et l'Université de Paris 13 (LSPM, France). L'objectif principal était la fabrication de contacts ohmiques sur des surfaces de diamant pour des applications telles que les détecteurs et les dispositifs de l’électronique. Les travaux au L3 ont été consacrés à l'étude du processus de graphitisation du diamant induit par laser afin de produire des électrodes de graphite sur des diamants intrinsèques. L'étude se concentre en particulier sur le développement d’un appareil expérimental pour l’écriture laser sur diamant tant sur les aspects matériel que logiciel, et un protocole a ainsi été développé pour la fabrication de contacts graphitiques segmentés sur de larges surfaces de diamant (cm²). Des travaux approfondis de caractérisation ont démontré la transition de phase diamant-graphite et le comportement ohmique pour les contacts électriques avec une résistivité de l'ordre de 10⁻⁵ Ω.m. Des détecteurs tout-carbone ont ainsi été développés et testés avec des faisceaux électroniques et positroniques de 450 MeV. Ils permettent d’ouvrir des perspectives en tant que cible active pour de nouvelles expériences de physique des hautes énergies (PADME) dans le cadre de l’étude de la matière noire. Le travail au LSPM a été consacré au développement d'un protocole permettant d'obtenir des contacts ohmiques sur des films diamant faiblement dopé au bore et terminé oxygène, élaborés par MPACVD. Les procédés de fabrication de contacts métalliques Ti/Au sur une structure mesa ainsi que l’implantation par des ions He, ont été développés afin d'induire une couche de graphite juste en dessous de la surface de diamant. Les mesures électriques sur des diamants légèrement dopés ([B] = 4 × 10¹⁷ cm⁻³) avec seulement des contacts métalliques ou graphitiques / métalliques ont montré que la présence de la couche graphitique rend les contacts ohmiques et conduisent à une résistance spécifique de contact égale à 3.3 × 10⁻⁴ Ω.cm²This PhD work has been carried out in international cotutelle agreement between the University of Salento (L3, Italy) and the University of Paris 13 (LSPM, France). The main aim was the manufacturing of ohmic contacts on diamond surface for detector and electronic device applications. The work at L3 was dedicated to the laser-induced diamond graphitization process in order to produce graphitic electrodes on intrinsic diamonds. An experimental set-up dedicated to the laser writing technique on diamond has been developed in both hardware and software aspects and a protocol for the manufacturing of segmented graphitic contacts on diamond surface of large scale (cm²) has been implemented. An extensive characterization work has demonstrated the diamond-graphite phase transition and an ohmic electrical behaviour for the contacts with a resistivity of the order of ≈ 10⁻⁵ Ω.m. Eventually, an all-carbon detector has been developed and tested with 450 MeV electron and positron beams proving to be a good candidate in the role of active target for a new high-energy experiment (PADME) in the framework of the dark matter. The work at LSPM has been dedicated to the development of a protocol allowing reaching ohmic contacts on lightly boron doped diamond with oxygenated surface grown by MPACVD. The fabrication of Ti/Au metallic contact above a mesa structure has relied on a He ion implantation treatment to induce a graphitic layer underneath the diamond surface. The electrical measurements on lightly doped diamonds ([B] = 4 × 10¹⁷ cm⁻³) with metal or graphite / metal contacts have shown that the graphitic layer makes ohmic the contacts leading to a specific contact resistance as low as 3.3 × 10⁻⁴ Ω.cm²
Questo dottorato di ricerca è stato svolto in convenzione di cotutela internazionale tra l’Università del Salento (L3, Italia) e l’Università di Parigi 13 (LSPM, Francia). Il principale obiettivo è stato la fabbricazione di contatti ohmici su superficie di diamante per applicazioni come rivelatori e dispositivi elettronici. Il lavoro a L3 è stato dedicato allo studio del processo di grafitizzazione del diamante indotto da laser al fine di produrre elettrodi grafitici su diamanti intrinseci. In particolare, è stato sviluppato un apparato sperimentale dedicato alla tecnica di scrittura laser su diamante sia nelle componenti hardware che software, ed è stato realizzato un protocollo per la fabbricazione di contatti grafitici segmentati su superfici di diamante di grande scala (cm²). Un ampio lavoro di caratterizzazione ha dimostrato la transizione di fase diamante-grafite e il comportamento ohmico per i contatti elettrici con una resistività dell’ordine di 10⁻⁵ Ω.m. Pertanto, un rivelatore costituito solo di carbonio è stato sviluppato e testato con fasci elettronici e positronici di 450 MeV risultando essere un buon candidato nel ruolo di bersaglio attivo per un nuovo esperimento di fisica delle alte energie (PADME) nel contesto della materia oscura. Il lavoro a LSPM è stato dedicato allo sviluppo di un protocollo che ha consentito di ottenere contatti ohmici su diamanti leggermente drogati con boro e con superficie terminata con ossigeno, cresciuti mediante MPACVD. I processi di fabbricazione di contatti metallici Ti/Au sopra una struttura mesa sono stati sviluppato così come un trattamento di impiantazione a base di ioni di He al fine di indurre uno strato grafitico appena sotto la superficie del diamante. Le misure elettriche su diamanti leggermente drogati ([B] = 4 × 10¹⁷ cm⁻³) con contatti o solo metallici o grafitici / metallici hanno dimostrato che la presenza dello strato grafitico rende i contatti ohmici e comporta una resistenza specifica di contatto pari a 3.3 × 10⁻⁴ Ω.cm²
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Telling, Robert Henry. "The fracture of natural and synthetic diamond." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624385.
Повний текст джерела
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Peng, Xilin. "Synthesis and adhesion of diamond and diamond-like carbon (DLC) films." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624958.
Повний текст джерела
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Kirkwood, L. "Characterisation of wear resistance of natural and synthetic diamond tools during single point diamond turning." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/12277.
Повний текст джерелаАнотація:
Achievable cutting distance of a diamond tool during turning is finite and is a limiting factor in the size of component that can be turned. This limit is particularly problematic when attempting to turn brittle materials, such as those used in infra-red optics. Natural diamond tools have been used for this application. However natural diamond introduces problems: the gems can contain possible contamination with a range of impurities and strong residual stresses from formation. Cutting distance is therefore inconsistent when using natural diamond. Industry is keen to increase possible cutting distance and to increase the consistency of cutting distance. One possible solution is synthetic diamond materials. New CVD single crystal synthetic diamonds possess high purity and consistent growth conditions and therefore have the potential to be a superior tool-material that provides longer achievable cutting distance and extremely consistent cutting behaviour. This new material is compared against natural and HPHT synthetic diamonds in machining tests against silicon workpieces in a selection of tool-orientations. Aluminium workpieces are machined with MCC and natural diamond tools to assess the performance of the new material against this commonly diamond turned material. While analysing the results from these cutting trials the failure modes of diamond tools were examined closely, resulting in discovering the existence of two separate failure modes and the development of a new wear-model. Natural diamond tools were carefully tested using a range of techniques hoping to find a root cause of the wide variability seen. FTIR offered a strong clue as to the defect within natural diamond tools that leads to occasional high cutting life.
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Mina, Golshan. "High-resolution X-ray diffraction studies of synthetic diamond." Thesis, Royal Holloway, University of London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271313.
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Smith, Hannah Elaine. "Perturbation studies of intrinsic point defects in synthetic diamond." Thesis, King's College London (University of London), 2004. https://kclpure.kcl.ac.uk/portal/en/theses/perturbation-studies-of-intrinsic-point-defects-in-synthetic-diamond(54a6d242-5bac-4fb6-a93e-32a517d4dab1).html.
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Hu, Qiang. "Diamond Based-Materials: Synthesis, Characterization and Applications." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3158.
Повний текст джерелаАнотація:
The studies covered in this dissertation concentrate on the various forms of diamond films synthesized by chemical vapor deposition (CVD) method, including microwave CVD and hot filament CVD. According to crystallinity and grain size, a variety of diamond forms primarily including microcrystalline (most commonly referred to as polycrystalline) and nanocrystalline diamond films, diamond-like carbon (DLC) films were successfully synthesized. The as-grown diamond films were optimized by changing deposition pressure, volume of reactant gas hydrogen (H2) and carrier gas argon (Ar) in order to get high-quality diamond films with a smooth surface, low roughness, preferred growth orientation and high sp3 bond contents, etc. The characterization of diamond films was carried out by metrological and analytical techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and Raman spectroscopy. The results of characterization served as feedback to optimize experimental parameters, so as to improve the quality of diamond films. A good understanding of the diamond film properties such as mechanical, electrical, optical and biological properties, which are determined by the qualities of diamond films, is necessary for the selection of diamond films for different applications. The nanocrystalline diamond nanowires grown by a combination of vapor-liquid-solid (VLS) method and CVD method in two stages, and the graphene grown on silicon substrate with nickel catalytic thin film by single CVD method were also investigated in a touch-on level.
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Su, Shi. "Synthesis, characterisation and applications of diamond materials." Thesis, Aston University, 2013. http://publications.aston.ac.uk/20898/.
Повний текст джерелаАнотація:
This thesis presented a detailed research work on diamond materials. Chapter 1 is an overall introduction of the thesis. In the Chapter 2, the literature review on the physical, chemical, optical, mechanical, as well as other properties of diamond materials are summarised. Followed by this chapter, several advanced diamond growth and characterisation techniques used in experimental work are also introduced. Then, the successful installation and applications of chemical vapour deposition system was demonstrated in Chapter 4. Diamond growth on a variety of different substrates has been investigated such as on silicon, diamond-like carbon or silica fibres. In Chapter 5, the single crystalline diamond substrate was used as the substrate to perform femtosecond laser inscription. The results proved the potentially feasibility of this technique, which could be utilised in fabricating future biochemistry microfluidic channels on diamond substrates. In Chapter 6, the hydrogen-terminated nanodiamond powder was studied using impedance spectroscopy. Its intrinsic electrical properties and its thermal stability were presented and analysed in details. As the first PhD student within Nanoscience Research Group at Aston, my initial research work was focused on the installation and testing of the microwave plasma enhanced chemical vapour deposition system (MPECVD), which will be beneficial to all the future researchers in the group. The fundamental of the on MPECVD system will be introduced in details. After optimisation of the growth parameters, the uniform diamond deposition has been achieved with a good surface coverage and uniformity. Furthermore, one of the most significant contributions of this work is the successful pattern inscription on diamond substrates by femtosecond laser system. Previous research of femtosecond laser inscription on diamond was simple lines or dots, with little characterisation techniques were used. In my research work, the femtosecond laser has been successfully used to inscribe patterns on diamond substrate and fully characterisation techniques, e.g. by SEM, Raman, XPS, as well as AFM, have been carried out. After the femtosecond laser inscription, the depth of microfluidic channels on diamond film has been found to be 300~400 nm, with a graphitic layer thickness of 165~190 nm. Another important outcome of this work is the first time to characterise the electrical properties of hydrogenterminated nanodiamond with impedance spectroscopy. Based on the experimental evaluation and mathematic fitting, the resistance of hydrogen-terminated nanodiamond reduced to 0.25 MO, which were four orders of magnitude lower than untreated nanodiamond. Meanwhile, a theoretical equivalent circuit has been proposed to fit the results. Furthermore, the hydrogenterminated nanodiamond samples were annealed at different temperature to study its thermal stability. The XPS and FTIR results indicate that hydrogen-terminated nanodiamond will start to oxidize over 100ºC and the C-H bonds can survive up to 400ºC. This research work reports the fundamental electrical properties of hydrogen-terminated nanodiamond, which can be used in future applications in physical or chemical area.
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Brown, Louise Jayne. "Cumulative deformation of synthetic Type Ib and type IIb diamond." Thesis, University of Hull, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402498.
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Betzel, Gregory T. "Development of a Prototype Synthetic Diamond Detector for Radiotherapy Dosimetry." Thesis, University of Canterbury. Physics and Astronomy, 2010. http://hdl.handle.net/10092/3941.
Повний текст джерелаАнотація:
This thesis details an investigation of the suitability of commercially-available single crystal and polycrystalline diamond films made via chemical vapor deposition (CVD) that were not studied previously for use in radiotherapy dosimetry. Novel sandwich-type detectors were designed and constructed to investigate the dosimetric response of diamond films under clinical conditions. Relatively inexpensive diamond films were obtained from three manufacturers: Diamonex, Diamond Materials GmbH and Element Six. Spectrophotometry, Raman spectroscopy and bulk conductivity studies were used to characterize these films and correlate crystalline quality with detector performance. Novel detectors were designed and constructed to investigate detectors under clinical conditions, including Perspex encapsulations and PCBs to minimize fluence perturbations. The dosimetric response of these diamond detectors was examined using a 6 MV beam from a Varian Clinac 600C linear accelerator. Diamond detectors were evaluated by measuring a number of response characteristics.
Polycrystalline CVD diamond films from Diamonex (100, 200, 400-μm thicknesses) were considered unsuitable for dosimetric applications due to their lack of stability, low sensitivity, high leakage currents, high priming dose and dependence on dose rate. High-quality polycrystalline diamond films from Diamond Materials (100, 200, 400-μm thicknesses) displayed characteristics that varied with film thickness. A 100-μm film featured slow response dynamics and high priming doses. Thicker films featured suitable dosimetric characteristics, e.g. negligible leakage currents, low priming doses, fast response dynamics and good sensitivity with small sensitive volumes. Element Six single crystal CVD diamond films (500-μm thicknesses) with small sensitive volumes (0.39 mm³) exhibited suitable characteristics for dosimetry. These films showed negligible leakage currents (< 1.25 pA), low priming doses (1–10 Gy), quick response dynamics, high sensitivity (47–230 nC Gy⁻¹) and were weakly dependent on dose rate and directional dependence (±1%).
A relatively inexpensive single crystal CVD diamond film from Element Six that exhibited high sensitivity (230 nC Gy⁻¹ at 0.5 V μm⁻¹), amongst other favourable characteristics, was selected for further analyses. An appropriate operating voltage was determined before further clinically relevant measurements could be conducted. This included how changes in an applied electric field affected detector response, and determined whether an optimal operating voltage could be realized within the parameters of conventional instrumentation used in radiation therapy. The results of this study indicated a preference towards using 62.5 V (at ~0.13 V μm⁻¹) out of a range of 30.8–248.0 V for temporal response as required for modulated beams due to its minimal rise time (2 s) and fall time (2 s) yet sufficient sensitivity (37 nC Gy⁻¹) and weak dependence on polarity (±1.5%).
Investigations were then performed on the same diamond detector to evaluate its performance under more clinically relevant conditions. Repeatability experiments revealed a temporary loss in sensitivity due to charge detrapping effects following irradiation, which was modelled to make corrections that improved short-term precision. It was shown that this detector could statistically distinguish between dose values separated by a single Monitor Unit, which corresponded to 0.77 cGy. Dose rate dependence was observed when using low, fixed doses in contrast to using stabilized currents and higher doses. Depth dose measurements using this detector compared well with ion chambers and diode dosimeters. Comparisons of initial measurements with values in the literature indicate encouraging results for fields sizes < 4 x 4 cm², but further measurements and comparisons with Monte Carlo calculations are required. Using this detector to make off-axis measurements in the edge-on orientation reduced perturbation of the beam due to its sandwich configuration and thin 150 nm Ag contacts. This diamond detector was found to be suitable for routine dosimetry with conventional radiotherapy instrumentation with a materials cost of < NZ$200.
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Dahwich, Amad. "Spectroscopic studies of interstitial-related optical centres in synthetic diamond." Thesis, King's College London (University of London), 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414680.
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Jones, Geraint Owen. "Chemical state and luminescence imaging of natural and synthetic diamond." Thesis, Aberystwyth University, 2011. http://hdl.handle.net/2160/1a55cb5d-0e6a-47a7-b5e2-088c12c357ed.
Повний текст джерелаАнотація:
This thesis presents work undertaken using Synchrotron and Laboratory based techniques in parallel on the Chemical State and Luminescence Imaging of Natural and Synthetic Diamond. X-ray absorption spectroscopy (XAS) techniques have revealed information on the chemical structure and bonding within brown and variegated type Ia, IIa, CVD and high-pressure, high-temperature (HPHT) treated diamonds. XAS, Raman, X-ray Excited Optical Luminescence (XEOL) and Photoluminescence (PL) are some of the techniques that have been applied to characterise and investigate the cause of the brown colouration. The XAS measurements have been undertaken in imaging mode with the capabilities of correlating the luminescence image with the brown regions in partial luminescence yield (PLY) and total luminescence yield (TLY). OD-XAS spectrums have been obtained at non-brown and brown regions and have revealed a higher concentration of sp2-bonded carbon present at the brown sites. Raman spectroscopy utilized in imaging mode also supports this discovery.
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Johnston, Karl Anthony Andrew. "Experimental and theoretical studies of transition metal impurities in synthetic diamond." Thesis, University of London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392528.
Повний текст джерелаАнотація:
This thesis is concerned with the properties of transition metals in High Pressure High Temperature synthetic diamond. They have been studied using the following techniques: optical and electron paramagnetic resonance spectroscopies, and a local density approximation code to model various defect centres. Experimental studies of recently-discovered lines, attributed to Co-N complexes in diamond, are presented. Under uniaxial stress, it is found that a zero-phonon line at 2.367 eV has its optical transition from an E- to A_1-ground state at a defect with trigonal symmetry. Another line at 2.135 eV arises at a defect with monoclinic I symmetry. EPR work has revealed the first Co-related EPR centre - O4. This has monoclinic I symmetry, and, because of hyperfine interaction that results in a broadening of the spectral features, it is concluded that nitrogen is also present. Next, cobalt in diamond has been modelled. Using the ab-initio local density code, AIMPRO, many different cobalt-related structures in diamond have been examined, ranging from the isolated atom to complexes with several nitrogens. The empirical model developed by Ludwig and Woodbury is useful in describing these defects. The defects that have been studied experimentally have also been modelled theoretically. For the 2.367 eV system, a Co-N complex with spin zero has been found to be the most likely candidate for the defect centre. Finally, some optical and modelling work have been combined on nickel-nitrogen complexes in diamond. The S2 and S3 luminescence systems are present in natural and synthetic diamond and have been tentatively correlated with the EPR NE3/2 defect systems. Uniaxial stress results indicate that the centres are of low symmetry - typically triclinic. This agrees with the EPR work. Some complementary modelling investigating these systems further supports these results. The thesis is concluded with some discussions and suggestions for further work.
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Reilly, Sean. "Characterisation and implementation of synthetic diamond as a Raman laser material." Thesis, University of Strathclyde, 2015. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=25764.
Повний текст джерелаАнотація:
Diamond's unrivalled thermo-mechanical and optical properties make the material an attractive material for use in laser systems. Improvements in growth techniques over the past decade have led to a surge of research employing diamond in optical systems. This thesis presents the characterisation of diamond and its implementation in Raman lasers, utilising the materials high Raman gain as well as its impressive thermal properties. Diamond's potential as both an extremely compact and robust method for frequency conversion, allowing access to relevant but otherwise hard to reach wavelengths, and also as a means to convert low brightness sources to near diffraction limited beams will also be discussed. A pump-probe measurement is used to conduct the first systematic study of the Raman gain in diamond over a wide range of wavelengths, from 355nm to 1450nm, with a dependence observed. Using the high Raman gain measured, both CW and pulsed Raman systems were designed and characterised. An 11-fold brightness enhancement was achieved in an Nd:YAG pumped intra-cavity diamond Raman laser, while record powers of 7.6W are presented using an Yb:LuAG pumped diamond Raman laser. Two monolithic diamond Raman lasers are discussed, achieving near quantum limited conversion efficiencies. An investigation of the laser induced damage threshold of diamond surfaces is conducted, with attempts made to improve the measured value of 25Jcm-2 discussed.
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Carvalho, Alexandre Faia. "Simultaneous synthesis of diamond on graphene for electronic application." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/14801.
Повний текст джерелаАнотація:
Mestrado em Engenharia FísicaNeste trabalho é descrito o estudo de estruturas híbridas de grafeno e diamante nano-cristalino (GDH) sintetizadas por deposição química em fase vapor por plasma de micro-ondas (MPCVD) em cobre. Foram investigadas técnicas de controlo da nucleação do diamante nano-cristalino, tendo sido encontrados dois processos com sucesso. Procedeu-se ainda à caracterização estrutural, morfológica e ótica das amostras por análise de SEM, TEM, AFM, EFM, medidas de transmitância UV-Vis e espetroscopia de Raman. A avaliação das propriedades de transporte destes materiais foi efetuada pela medição da curva de transferência de transístores de efeito de campo produzidos para o efeito, sendo os GDHs produzidos o material ativo do canal. Foram observadas baixas mobilidades devido à hidrogenação do grafeno. Em linha com resultados teóricos da literatura, foram encontradas evidências de abertura do hiato energético do grafeno, um potencial desenvolvimento para a aplicação em dispositivos de comutação lógica.
In this work, hybrid structures of graphene and nano-crystalline diamond (GDH) produced by microwave plasma chemical vapor deposition (MPCVD) in copper substrates are studied. The control of the diamond clusters nucleation was investigated, having two different approaches been identified as promising. Structural, morphological and optical characterization was carried out by SEM, TEM, AFM, EFM, UV-Vis transmittance, and Raman spectroscopy. The transport properties of this material were analyzed through the transfer curve of field-effect transistors with GDH channels. Low mobilities were found due to graphene hydrogenation. In line with theoretical studies, evidences were found of graphene band gap opening, a potential breakthrough for the development of logical switching devices.
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Hui, Siu-kee, and 許兆基. "Characterization of a new commercial radiation detector : synthetic single crystal diamond detector." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206504.
Повний текст джерелаАнотація:
Diamond has long been the material of interest for radiotherapy dosimetry due to its high sensitivity, radiation hardness and near tissue equivalency. However natural diamond detector has not become a popular choice because of variability among detectors, high cost and response dependence on dose rate. The recent success in synthesizing single crystal diamond has reignited the interest. Synthetic diamond is highly reproducible in purity and electrical properties, combined with small size, it is a suitable candidate for small field dosimetry. A newly available synthetic single crystal diamond detector is being studied to determine the basic dosimetric characteristic and applicability in small field dosimetry. A series of measurements were made in comparison with a 0.125c.c ionization chamber, and two diode detectors. Response of the diamond detector is independent on dose, dose rate and energy. The output factors of small fields determined by the diamond detector is lower than that of the diode detectors and higher than that of the ionization chamber which are known to over response and under response respectively. In percentage depth dose and beam profile measurements, the diamond detector performs similarly with the two diode detectors. It is found that the diamond detector is suitable for small field relative dosimetry. Further investigation is required to study the spatial resolution of the diamond detector in different measurement geometry and the suitability in determining percentage depth dose in the buildup region.published_or_final_version
Diagnostic Radiology
Master
Master of Medical Sciences
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Alamoudi, Dalal. "Dose enhancement near metal interfaces in synthetic diamond based X-ray dosimeters." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/812968/.
Повний текст джерелаАнотація:
Diamond is an attractive material for medical dosimetry due to its radiation hardness, fast response, chemical resilience, small sensitive volume, high spatial resolution, near-tissue equivalence, and energy and dose rate independence. These properties make diamond a promising material for medical dosimetry compared to other semiconductor detector materials and wider radiation detection applications. This study is focused on one of the important factors to consider in the radiation detector; the influence of dose enhancement on the photocurrent performance at metallic interfaces in synthetic diamond radiation dosimeters with carbon based electrodes as a function of bias voltages. Monte Carlo (MC) simulations with BEAMnrc code were carried out to simulate the dose enhancement factor (DEF) and compared against the equivalent photocurrent ratio from experimental investigation. MC simulations show that the sensitive region for the absorbed dose distribution covers a few micrometers distances from the interface. Experimentally, two single crystal (SC) and one polycrystalline (PC) samples with carbon based electrodes were used. The samples were each mounted inside a tissue equivalent encapsulation design in order to minimize fluence perturbations. Copper, Gold and Lead have been investigated experimentally as generators of photoelectrons using 50 kVp and 100 kVp X-rays relevant for medical dosimetry. The results show enhancement in the detectors' photocurrent performance when different metals are butted up to the diamond detector. The variation in the photocurrent ratio measurements depends on the type of diamond samples, their electrode fabrication and the applied bias voltages indicating that the dose enhancement from diamond-metal interface modifies the electronic performance of the detector.
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Hiscock, Jonathan Nicholas. "An optoelectronic study of diamond grown by chemical vapour deposition." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313713.
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Chandra, Lalitesh. "Synthesis and mechanical stability of diamond and diamondlike carbon coatings." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362973.
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Wiacek, Kevin John. "SYNTHESIS AND ELECTRICAL PROPERTIES OF FLUORENYL POLYESTERS INCORPORATING DIAMOND FRAGMENTS." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1183079024.
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Rebello, Jagdish Hilary Diago. "Synthesis of Diamond by Selective Laser Excitation of Gaseous Precursors /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487928649986997.
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Burton, Nicholas C. "Characterisation of strain and microstructure variation in synthetic diamond by electron microscopy and cathodoluminescence." Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296701.
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Ramamurti, Rahul. "Synthesis of Diamond Thin Films for Applications in High Temperature Electronics." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1145630189.
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Xu, Zhenqing. "Synthesis, characterization, and applications of CVD micro- and nanocrystalline diamond thin films." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002077.
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Arai, Rei. "Application of synthetic aperture radar interferometry (InSAR) in defining groundwater-withdrawal-related subsidence, Diamond Valley, Nevada." abstract and full text PDF (UNR users only), 2009. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1467741.
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Sartori, André F. Verfasser], and Bernd [Akademischer Betreuer] [Stritzker. "Heteroepitaxial boron-doped diamond: from synthesis to application / André F. Sartori ; Betreuer: Bernd Stritzker." Augsburg : Universität Augsburg, 2016. http://d-nb.info/1120923670/34.
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Junior, Carlos Elias da Silva. "Estudo experimental das principais características de um dressador sinterizado com ênfase na dissipação de calor." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-11122015-114719/.
Повний текст джерелаАнотація:
No processo de retificação a dressagem desempenha um papel fundamental, uma vez que ela é responsável pela topografia da superfície de trabalho do rebolo, podendo afetar os resultados da retificação em termos da integridade superficial e precisão dimensional da peça, bem como a confiabilidade do processo. Portanto, como parte integrante da operação de retificação, a dressagem pode melhorar significativamente a qualidade das peças retificadas caso melhores dressadores sejam produzidos. Este trabalho tem o objetivo de estudar as principais características necessárias ao projeto de dressadores sinterizados que utilizam diamantes sintéticos de perfil constante e verificar experimentalmente a distribuição de temperaturas no dressador, obtidas através de ensaios práticos e simulação computacional pelo método dos elementos finitos. O modelo utilizado contém algumas limitações, porém os resultados obtidos mostraram que os níveis de temperaturas no dressador foram afetados pelos parâmetros de dressagem considerados no trabalho, a saber, a profundidade de dressagem (\'a IND. d\'), o grau de recobrimento de dressagem (\'U IND. d\') e a vazão do fluido refrigerante (Q). O desgaste do dressador foi afetado apenas pelos parâmetros de dressagem.In grinding operations, dressing tools are of major importance, since they are responsible for the topography of the wheel working surface and, consequently, can affect the grinding results in terms of surface integrity, dimensional accuracy and process reliability. Therefore, as an important part of the grinding operation, dressing can significantly improve the quality of ground parts if better dressing tools are produced. This work studies the main needs for designing sintered dressing tools made with constant cross sectional synthetic diamonds. It also analyses the temperature distribution over a novel dressing tool design using experimental measurements to feed computacional simulation by the finite element method (FEM). The temperature model employed showed some limitations but the obtained results indicated that temperature levels over the dressing tool were affected by the dressing parameters considered in this work, namely the dressing depth of cut (\'a IND. d\'), the dressing overlapping parameter (\'U IND. d\') and the flow rate (Q). Additionally, one can say that the dressing tool wear was affected only by the dressing parameters
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Chou, Shih-Feng. "Synthesis and characterization of diamond thin films by microwave plasma-enhanced chemical vapor deposition (MPECVD) /." Available to subscribers only, 2005. http://proquest.umi.com/pqdweb?did=1095432871&sid=9&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Повний текст джерелаАнотація:
Thesis (M.S.)--Southern Illinois University Carbondale, 2005."Department of Mechanical Engineering and Energy Processes." Includes bibliographical references (leaves 65-71). Also available online.
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Brunet, Frédéric. "Texture et microstructure de films de diamant : effet du dopage au bore." Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10176.
Повний текст джерелаАнотація:
Le diamant presente des proprietes physiques intrinseques extremement attractives qui sont notamment appropriees pour des applications electroniques. Cependant, il convient de rester prudent car les caracteristiques globales des films (purete de la phase diamant, tailles des cristallites, epaisseur, morphologie, texture, contraintes internes etc. . . ) dependent fortement des conditions de croissance et conditionnent les proprietes des films. L'analyse quantitative de la texture (logiciel d'analyse de texture beartex) de films de diamant polycristallins deposes sur substrat de silicium par mpcvd a permis d'estimer l'influence des parametres d'elaboration (temperature du substrat, 650-880c, taux de methane, 0. 3%-2%), de l'epaisseur des films (jusqu'a 70 m) et du taux d'incorporation de bore (jusqu'a 5x10#2#0 b-cm#-#3) sur le developpement d'une orientation preferentielle au cours de la croissance. L'analyse du profil des raies de diffraction a permis d'etudier l'influence du dopage au bore sur la microstructure des films polycristallins. Les resultats issus des methodes des largeurs integrales, de fourier et de la variance indiquent une evolution (amelioration jusqu'a 10#1#9 b-cm#-#3 puis deterioration) de la qualite cistalline des films avec le dopage. Une etude structurale conjointement menee sur des films polycristallins et monocristallins deposes respectivement sur substrat de silicium et de diamant monocristallins montre que le parametre cristallin du diamant augmente avec le dopage au bore. La dilatation atteint 0. 2% pour un dopage de 8x10#2#0 b-cm#-#3 et devient significative au dela de la transition semiconducteur-metal.
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Shahedipour, Fatemeh. "Diamond synthesis on steel substrates using magneto-active plasma chemical vapor deposition with novel in situ FTIR spectroscopy characterization /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9901278.
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Schmidt, Christian. "Experimental Study of the PVTX Properties in Part of the Ternary System H₂O-NaCl-CO₂." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30610.
Повний текст джерелаАнотація:
Phase equilibria and volumetric properties in the system water-sodium chloride-carbon dioxide were determined experimentally for pressures between about 1 to 6 kbar, temperatures of 300° to 800°C, and fluid compositions up to 40 wt% NaCl and 20 mol% carbon dioxide, both relative to water. This was accomplished by using the synthetic fluid inclusion technique in conjunction with conventional microthermometry, a hydrothermal diamond-anvil cell and Raman spectroscopy.
At constant salinity, the high-pressure portion of the solvus migrates to higher pressures and temperatures with increasing carbon dioxide concentration. Immiscibility is possible in this ternary system over almost the entire range of crustal P-T conditions at salinities equal to or in excess of 20 wt% NaCl and carbon dioxide concentrations between about 30 and 70 mol% carbon dioxide. The dP/dT slopes of lines of equal homogenization temperature decrease nonlinearly with increasing homogenization temperature; at constant homogenization temperature, these slopes become steeper (higher) along pseudobinaries with addition of carbon dioxide and particularly with addition of sodium chloride. Up to concentrations of 20 wt% NaCl and 20 mol% carbon dioxide, a sharp rise in the critical temperature was observed with increasing salinity at a fixed water/carbon dioxide ratio. The critical point shifts rapidly towards higher pressures with increasing carbon dioxide concentration. Addition of carbon dioxide to an aqueous 40 wt% NaCl solution results in a slight elevation of the halite dissolution temperature under vapor-saturated conditions.
A significant error can be associated with the calculation of molar volumes from measured densities of the carbonic phase of water-sodium chloride-carbon dioxide inclusions. To avoid such errors, phase diagrams were constructed based on the obtained lines of equal homogenization temperature for salinities between 6 and 40 wt% NaCl and carbon dioxide concentrations between 5 and 20 mol% relative to water. These diagrams are of direct applicability to the interpretation of natural fluid inclusions from a wide variety of geologic environments.Ph. D.
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Cai, Yixiao. "Bio-Nano Interactions : Synthesis, Functionalization and Characterization of Biomaterial Interfaces." Doctoral thesis, Uppsala universitet, Tillämpad materialvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-277121.
Повний текст джерелаАнотація:
Current strategies for designing biomaterials involve creating materials and interfaces that interact with biomolecules, cells and tissues. This thesis aims to investigate several bioactive surfaces, such as nanocrystalline diamond (NCD), hydroxyapatite (HA) and single crystalline titanium dioxide, in terms of material synthesis, surface functionalization and characterization. Although cochlear implants (CIs) have been proven to be clinically successful, the efficiency of these implants still needs to be improved. A CI typically only has 12-20 electrodes while the ear has approximately 3400 inner hair cells. A type of micro-textured NCD surface that consists of micrometre-sized nail-head-shaped pillars was fabricated. Auditory neurons showed a strong affinity for the surface of the NCD pillars, and the technique could be used for neural guidance and to increase the number of stimulation points, leading to CIs with improved performance. Typical transparent ceramics are fabricated using pressure-assisted sintering techniques. However, the development of a simple energy-efficient production method remains a challenge. A simple approach to fabricating translucent nano-ceramics was developed by controlling the morphology of the starting ceramic particles. Translucent nano-ceramics, including HA and strontium substituted HA, could be produced via a simple filtration process followed by pressure-less sintering. Furthermore, the application of such materials as a window material was investigated. The results show that MC3T3 cells could be observed through the translucent HA ceramic for up to 7 days. The living fluorescent staining confirmed that the MC3T3 cells were visible throughout the culture period. Single crystalline rutile possesses in vitro bioactivity, and the crystalline direction affects HA formation. The HA growth on (001), (100) and (110) faces was investigated in a simulated body fluid in the presence of fibronectin (FN) via two different processes. The HA layers on each face were analysed using different characterization techniques, revealing that the interfacial energies could be altered by the pre-adsorbed FN, which influenced HA formation. In summary, micro textured NCD, and translucent HA and FN functionalized single crystalline rutile, and their interactions with cells and biomimetic HA were studied. The results showed that controlled surface properties are important for enhancing a material’s biological performance.
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Kukreja, Ratandeep. "Synthesis of Thin Films in Boron-Carbon-Nitrogen Ternary System by Microwave Plasma Enhanced Chemical Vapor Deposition." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1285688216.
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Fish, Michael Lester. "Optical properties of synthetic diamond of different synthesis origin." Thesis, 1995. https://hdl.handle.net/10539/24379.
Повний текст джерелаАнотація:
A research report submitted to the Faculty of Science, University of the Witwatersrand,
Johannesburg in partial fulfilment of the requirements for the degree of Master of ScienceThe aim of this work was to evaluate the measurement of the optical properties as a means of obtaining information on the growth history of synthetic diamond. A suite of sample of known synthesis origin representing the different types of commercially produced synthetic diamond was analysed hy photoluminescence. The photoh.{fnmescence intensity was normalising by using the area of tbe Raman peak. This allowed a semi-quantitative comparison of the defect concentration. Three photoluminescent centres were identified, H3, 575 run and 1.945 eV (with zero-phonon lines at 2.463 eV, 2.156 eV, and 1.945 eV respectively). Differences between the intensities of the luminescence due to these centres were observed as a function of the type ot diamond The H3 amd the 1.945 eV intensity was found to increase with the proportion of cubic growth sector, In addition the 1.945 eV intensity was found to increase with heat treatment and was higher in (100) than in (111) growth sectors. As all three defects detected involve vacancies and nitrogen impurity, an analysis was done to quantify any correlation between the luminescent intensities from the different defects in the same SDA powder sample. The 1.945 eV and 575 run intensities were observed to be correlated .. An additional correlation 'was found between the 575 lim and the H3 intensities in the case of finer particle size samples. The luminescence intensity for all three defect types was observed to be a function of the particle size of the sample. The shapes and widths of zero-phonon lines were related to the types and concentration of lattice defects present in a crystal according to line broadening theory. An attempt was made to explain the results in the context of the known synthesis origin and growth conditions.
AC 2018
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Fallon, Paul Joseph. "Synthetic diamonds as pulse counting radiation detectors." Thesis, 2015. http://hdl.handle.net/10539/17246.
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Araikum, Shawn. "Thermally and optically stimulated luminescence in synthetic diamond." Thesis, 2016. http://hdl.handle.net/10539/21357.
Повний текст джерелаАнотація:
This study investigated the photo-excitation and thermoluminescence properties of diamonds which were synthesised primarily for thermoluminescence dosimetry.
For investigations of thermally stimulated processes occurring in these crystals an
analysis of the thermoluminiscence & low spectra and the temperature dependent
isothermal decay spectra was undertaken [Abbreviated abstract. Open document to view full version]GR2016
49
Ade, Nicholas. "Evaluation of the radiation detection properties of synthetic diamonds for medical applications." Thesis, 2015. http://hdl.handle.net/10539/17652.
Повний текст джерела
50
Longo, Micaela [Verfasser]. "Iron oxidation state in (Mg,Fe)0 : calibration of the Flank method on synthetic samples and applications on natural inclusions from lower mantle diamonds / vorgelegt von Micaela Longo." 2009. http://d-nb.info/1001168763/34.
Повний текст джерела