Diamond

A novel technique for synthesizing a diamond-like carbon (DLC) film by pulsed laser deposition (PLD) is proposed. In the technique, additional lasers irradiated the plume in order to increase the density of the ionic carbon. By irradiating with an ArF excimer laser, the emission intensity of the atomic carbon was increased greatly. By irradiating with the third harmonic output and the fundamental output of an Nd:YAG laser, the emission intensity of the atomic and ionic carbon also increased greatly. The sp3 content increased from 51% without to 76% with two additional irradiation of the fundamental output of two Nd:YAG laser beams. The differences in the binding energy and surface morphology between the films with and without the irradiation of the additional lasers to the plume were observed by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively.

By measuring the drift velocity of electrons in diamond as a function of applied electric field, we
demonstrate that ultra-pure diamond exhibits negative differential electron mobility in the [100] direction
below 140 K. Negative electron mobility is normally associated with III–V or II–VI semiconductors with
an energy difference between different conduction band valleys. The observation of negative mobility in
diamond, an elemental group IV semiconductor, is explained in terms of repopulation effects between
different equivalent conduction band valleys using a model based on the Boltzmann equation.

We describe an x-ray absorption method for in situ density measurement of non-crystalline materials in the diamond anvil cell using a monochromatic synchrotron x-ray microbeam. Sample thickness, which is indispensable in the absorption method, can be determined precisely by extrapolating the thickness profile of the gasket obtained by x-ray absorption and diffraction measurements. Diamond deformation across the sample chamber becomes

The synthesis of new materials for thermal infrared (IR) detection has been an intensive research
area in recent years. Among new semiconductor materials, synthetic diamond has the ability to
function even under very high temperature and high radiation conditions. In the present work,
diamond Schottky diodes with boron concentrations in the range of 1014<B<1017cm3 are
presented as candidates for IR thermal sensors with an excellent temperature coefficient of
resistance (8.42%/K) and very low noise levels around 6.6 10^-15 V2/Hz. This enables huge
performance enhancements for a wide variety of systems, e.g., automotive and space applications.

PIllole di diamante: Giallo, Grande e Misterioso, la Leggenda del "Fiorentino" Questa e' la storia del "Fiorentino" (ma anche noto come il Toscano, il Granduca di Toscana o il Giallo Austriaco), uno dei diamanti piu' grandi e riveriti del suo tempo, ossia di quando queste gemme avevano da poco iniziato a riacquistare popolarita' in Europa. Esso appartenne ai Medici, e agli Asburgo fino a quando, nel XX secolo, scomparve. Con un peso di 139 vecchi carati, pari a 137.27 carati metrici moderni (27.454 g), di quasi certa origine indiana, la pietra, a forma di mandorla, era di colore giallo con sentori di verde. Essa veniva descritta come avente un profilo ottagonale irregolare (a volte chiamato a scudo) con un taglio a doppia rosa che includeva 126 sfaccettature distribuite su nove lati che irradiavano una luce scintillante. Il nome "Fiorentino" e' quasi certamente un omaggio alla stirpe medicea, che risiedeva e regnava appunto su Firenze. Secoli fa Poche e confuse sono le testimonianze scritte delle origini del Fiorentino. Esistono piu' versioni che spesso sono in conflitto tra loro. Ferdinando I de' Medici è generalmente considerato come il primo proprietario attestato del diamante che, stando alle antiche descrizioni, era di un colore che si avvicinava a quello del cedro. Prima di giungere nelle mani del potente nobile toscano, il suo passato e' circondato da mito. Una delle leggende più persistenti e'quella che lo vede giungere in Europa per volere di Carlo il Temerario (1433-1477), Gran Duca di Borgogna. Secondo questa narrativa, la gemma venne tagliata per la prima volta da Lodovico Van Bercken (date ignote), da molti considerato l'inventore dello "scaif", la ruota coperta di olio e polvere di diamanti utilizzata per sfaccettare le pietre preziose, tra il 1458 ed il 1476. Estremamente ricco, Carlo possedeva un'importante collezione di pietre preziose e si pensa che avesse la consuetudine d'indossarne alcune, montate su speciali amuleti, quando si preparava ad uno scontro armato. La leggenda narra che era proprio il Fiornentino la gemma che portava con se il 5 gennaio 1477, giorno in cui trovo' la morte mentre combatteva contro il Duca di Lorena, Renato II, nella battaglia di Nancy (altre fonti parlano della battaglia di Morat, questo dato e' probabilmente inesatto visto che questa avvenne nel 1476). La pietra non riuscì a proteggerlo, come prevedeva la superstizione, e il nobile guerriero venne ucciso. Passarono diversi giorni prima che il suo corpo fosse scoperto. Si dice che, nel frattempo, un contadino locale avesso scorto il Fiorentino sul campo di guerra e, scambiandolo per un pezzo di vetro, lo avesse rivenduto per per un solo fiorino (o pochi fiorini secondo altre versioni). Secondo un altro mito, il piccolo tesoro giallo, a causa della sua bellezza esotica, avrebbe catturato i lunghi sguardi della Chiesa che lo avrebbe fatto acquistare dai funzionari vaticani, attraverso i banchieri Fugger, con l'intento di porlo sulla tiara del Papa. Il fortunato prelato che avrebbe avuto la possibilità di sfoggiare in pubblico questo diamante sarebbe stato, sempre secondo questa leggenda, Papa Giulio II (nato Giuliano della Rovere-1443-1513-216º papa, in carica pontificale dal 1503 al 1513), grande nemico dei Medici. Da Giulio II, per qualche motivo sconosciuto, il grosso cristallo passo' nelle mani del successivo proprietario, un cittadino di Berna, tale Bartholomeus Mayus (il cui nome appare solo nelle storie legate al Fiorentino). Lo svizzero rivendette la gemma a dei mercanti genovesi che lo riportarono in Italia dove, sempre secondo questa versione, essa fu acquistato da Ludovico il Moro (1452-1508), duca di Milano o, piu' probailmente, vista la coincidenza delle date, ad uno dei suoi

Having previously dominated diamond supply and exercised near total control over diamond distribution, the diamond industry market leader De Beers now accounts for just 40% of global diamond production and 45% of distribution. In the face of competitive and regulatory pressures, De Beers has recently sought to adapt its role from being the custodian of the industry to acting merely as a major player. However, its retreat from a position of industry dominance is creating tensions within De Beers and among industry participants.This paper seeks to explain De Beers' behaviour and the reaction of the industry in terms of paradox management and identifies the requirement for a new form of leadership to replace the previous monopoly situation and guide the diamond industry into a better future.Having previously dominated diamond supply and exercised near total control over diamond distribution, the diamond industry market leader De Beers now accounts for just 40% of global diamond production and 45% of distribution. In the face of competitive and regulatory pressures, De Beers has recently sought to adapt its role from being the custodian of the industry to acting merely as a major player. However, its retreat from a position of industry dominance is creating tensions within De Beers and among industry participants.This paper seeks to explain De Beers' behaviour and the reaction of the industry in terms of paradox management and identifies the requirement for a new form of leadership to replace the previous monopoly situation and guide the diamond industry into a better future.Copyright © 2008 John Wiley & Sons, Ltd.

People these days know the Universe as a Whole, because not knowing the edge between This and That. Its secret is the secret of a forgotten body, the seventh in the series of multifaceted as Life, Seven. We know six of it now. But the Ancestors knew all seven. // Люди ныне не знают Вселенной как Целого, не зная грани меж Этим и Тем. Тайна  ее есть тайна забытого тела, седьмого в строю многогранных как Жизнь, Семь. Мы знаем шесть ныне. А Пращуры знали все семь.

The current paper gives an overview of the development of Raman spectrometry in gemmological laboratories. While before 1990s, no commercial gemmological laboratory possessed such an instrument, all larger international labs have acquired these instruments by now. The Raman spectrometer is routinely used for the detection of emerald fillers, HPHT treatment of diamonds, analysis of the nature of a gemstone, analysis of gemstone inclusions and treatments, and the characterisation of natural or colour enhanced pearls and corals. Future developments in gemstone research lie in the closer analysis of the features of Raman and PL spectra and in the combination of several instruments.► This paper gives an overview of the development of Raman spectrometer in gemmology. ► It is used for analysis of the nature of a gemstone. ► It is also used for analysis of gemstone inclusions and treatments. ► Combination of Raman spectrometer with other instruments would help gemmology.

Although surface finish can be a critical variable in clinical performance, there is a dearth of information regarding surface characteristics of teeth prepared for artificial crowns. This study characterized teeth prepared for complete cast restorations using three representative types of rotary instruments. One hundred and five standardized tooth preparations for complete crowns were performed using a modified milling machine on extracted human teech with diamond, tungsten carbide, and tungsten carbide finishing burs of similar shape (n = 35). The prepared dentin was analyzed with a surface profilometer and a scanning electron microscope (SEM). Differences between rotary instrument groups were determined with parametric ANOVA and Tukey's Studentized Range (HSD). Statistically significant differences in the surface topography of prepared teeth were seen. Mean surface roughnesses (Ra) were 8.6 and 6.8 μm for teeth prepared with diamond and tungsten carbide burs. Teeth completed with finishing burs appeared to result in a smoother surface (1.2 μm).

This review of the evolution of diamond cuts during the 16th to 18th centuries is illustrated with Portuguese jewellery and sacred objects from this period. We follow the evolution from point cuts already in existence prior to Portuguese navigational discoveries in the late 15th century, to table and rose cuts that co-existed for most of the 16th and 17th centuries, to the now-called old brilliant (or old mine) cut, which became popular a few decades after the discovery of the Brazilian diamond fields in the 1720s. The use of each cut and shifts in their popularity are discussed. These observations of diamond cuts in Portuguese jewellery and devotional objects may also be applicable to trends within wider European manufacture.

This paper aims not only to correct misconceptions, but to summarise what is already known about the discovery of the Cullinan and the events that followed, and at the same time reveal some important and unexplored evidence that eluded contemporary historians. The research is based on archival records in South Africa as well as on articles that appeared in the local and international press within the first two decades after the diamond had been found.
110 years after the discovery of this exceptional crystal, perhaps the time has come to tell the full story of the Cullinan diamond, from which nine major gemstones were created, known as Cullinan I – IX. Today these diamonds adorn the Sovereign’s Sceptre, Imperial State Crown of Great Britain and other major jewels belonging to Her Majesty Queen Elisabeth II.
Wonders of nature excite people’s imagination, and the Cullinan is no exception. While it is almost impossible to obtain accurate facts about the origin of historic diamonds such as the Regent, the Orlov or the Koh-i-noor, claims regarding the Cullinan can be verified. Hitherto unexplored sources from 1905–1910 have brought to light unknown and relevant facts.

Paper presented as a lecture at the 10th Contact Day Jewish Studies on the Low Countries, organized by the Institute of Jewish Studies, University of Antwerp, May 16, 2017. Session 3: The Dutch "Diamond Jews" in Bergen-Belsen, Chair: Dr. Dienke Hondius, VU Amsterdam. (Please note that this paper was not linguistically edited by a native speaker.)

Effective use of rotary cutting burs and bonded, coated, and loose abrasives can greatly simplify and improve the effectiveness of finishing and polishing procedures. Fluted carbide finishing burs appear to be the optimal rotary contouring devices for posterior composite resins. Finishing diamonds are preferred for gross finishing of adjusted porcelain. Coated abrasive discs and strips provide unique interproximal and incisal access and are preferred for finishing and polishing of microfil resins. Rubberized bonded abrasives have evolved to provide a greater range of finishing and polishing action on composite resin and for polishing porcelain. A wide selection of aluminum oxide and diamond polishing pastes, together with highly effective felt and foam application devices, are now available to polish composite and porcelain to an enamel-like appearance. Aluminum oxide composite polishing pastes are highly effective and strongly recommended for use on highly filled hybrid composites ...

Heat sink is an essential component to nanoelectronics, microelectronics, and optoelectronics applications because it allows the thermal management of devices such as integrated circuits (ICs), microelectromechanical systems (MEMSs), and graphic unit processing. There are different materials being employed for heat sink production. Among them, diamond has stood out due to its excellent chemical and physical properties. This book chapter focuses on the development, properties, and applications of CVD diamond heat sinks. It covers the basic concepts of heat conduction applied to CVD diamond as a heat sink material and its production as freestanding CVD wafers of polycrystalline CVD diamond, since the literature about this topic is extensive, giving the reader a comprehensive overview. We will comprise the use and potential widening of applications of in CVD diamond heat sink technology, providing the reader with a substantial background at the current development of solutions and new frontiers in the practical use of CVD diamond thermal management devices.

Hirashasan is the term used for governance of diamond mining and trade-with a small bureaucracy and an exclusive set of rules and regulations-by the district administration of Panna in the state of Madhya Pradesh in India. Diamond mining in Panna encompasses diverse extractive practices that range from fully mechanised large-scale mining operations owned by the state, to small-scale and semi-mechanised mining carried out by farmers and landowners in groups, to individuals carrying out seasonal and part-time mining of diamonds in an artisanal manner. Based on an ethnographic study was undertaken from September 2016 to April 2017, we argue that Hirashasan has created an "extractive assemblage" that comprises four genres of mining and production systems: large-scale, small-scale, licensed artisanal and unlicensed artisanal. This assemblage is a product of historical, cultural and geographical contingencies as much as place-specificities, and does not lend itself to a single mode of governance. Mineral resource governance in a particular place, therefore, necessitates understanding and internalising the variegated and pluri-form extractive assemblages, such as that of the diamond economy in Panna.

Most studies of cavity preparation using Er:YAG lasers have employed permanent teeth. This study&#39;s purpose was to compare the cutting efficiency of an Er:YAG laser versus diamond burs in primary and permanent teeth in order to measure thermal effects on the pulp and evaluate lased surfaces using scanning electron microscopy (SEM). A total of 80 primary and permanent teeth were used. Crater depths and mass loss were measured after delivering laser pulses at varying energies onto sound or carious enamel or dentin using the Key-3 laser. Control samples were cut using diamond burs in an air turbine handpiece. Thermal changes were measured using miniature thermocouples placed into the pulp chamber. Lased surfaces were evaluated using SEM. Laser ablation crater-like defects were deeper in dentin than enamel at the same pulse energy. Greater ablation rates for dentin and enamel and significantly more efficient removal of carious tooth structure by laser was present in primary teeth. Te...