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Mineralogy and Geochemistry of Gems

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ISBN: 9783039280766 9783039280773 Year: Pages: 528 DOI: 10.3390/books978-3-03928-077-3 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Geology --- Earth Sciences
Added to DOAB on : 2020-04-07 23:07:09
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Gems have been used in the manufacture of jewellery and as ornaments since antiquity. Considering gems, recent statistics have shown that about 15 billion Euros are annually at stake. Nowadays, gemmology, i.e., the study of gem materials, is one of the most expanding fields in the earth sciences, positioned between academia and industry. As an applied science, in gemmology, the instruments used should be non- or microdestructive, and their cost should be reasonable both in terms of equipment and time consumption. Gemmology can also be used contribute to the development of pure science and in some cases, destructive techniques may have to be used. Taking into account the fact that gems are albeit rarely available for scientific research, this compilation of 20 articles by around 100 researchers from over 30 different institutions situated in 20 countries from around the globe, presented in the Special Issue entitled “Mineralogy and Geochemistry of Gems”, offers very good examples on the application of various methods for their study which will hopefully contribute to our better understanding of gem formation in general and will enhance scientific debates attracting more scientists from various disciplines to get involved in this field.

Keywords

danburite --- trace elements --- REE --- femtosecond LA-ICP-MS --- CHNS elemental analyzer --- pegmatites --- skarn --- gemstones --- placer --- heavy and light minerals --- landforms --- climate --- geodynamic setting --- green quartz --- prase --- amethyst --- color --- amphibole --- actinolite --- skarn --- Serifos --- Greece --- zircon --- xenocryst --- alkali basalt --- Ratanakiri Volcanic Province --- trace elements --- O-isotopes and Hf-isotopes --- U-Pb --- (U-Th)/He --- granitic pegmatite --- gem-quality tourmaline --- Adamello Massif --- Central Alps --- Italy --- ruby --- Mogok --- Mong Hsu --- New South Wales --- trace elements --- LA-ICP-MS analysis --- inclusions --- U–Pb age-dating --- genetic diversity --- geographic typing --- corundum --- blue sapphire --- meta-ultramafic rocks --- LA-ICP-MS --- Rb-Sr and Sm-Nd isotopy --- Ilmenogorsky complex --- Ural Mountains --- metasomatism --- corundum megacrysts --- ruby --- sapphire --- plumasite --- metamorphic-metasomatic origin --- Greece --- zircon megacrysts --- placer deposits --- rare earth elements (REE) --- carbonatite-dominant melts --- Central Highlands --- Vietnam --- hyperspectral photoluminescence imaging --- LA-ICP-MS --- rubies --- corundum --- in-situ oxygen isotopes --- Paranesti Greece --- Nestos Shear Zone --- Secondary ion mass spectrometry (SIMS) --- emerald deposits --- classification --- typology --- metamorphism --- magmatism --- sedimentary --- alkaline metasomatism --- fluids --- stable and radiogenic isotopes --- genetic models --- exploration --- andradite --- demantoid --- gemstone --- Raman spectroscopy --- UV-Vis-NIR spectroscopy --- X-ray fluorescence spectroscopy --- gem-quality --- garnet --- gem-bearing pegmatite --- fluid inclusions --- P-T-X equilibria --- spodumene --- Ar/Ar dating --- blue sapphire --- anorthosites --- kyshtymites --- sapphire geochemistry --- Ilmenogorsky-Vishnevogorsky complex --- in situ LA-ICP-MS U-Pb zircon dating --- kyanite --- Mn-rich silicates --- Rhodope --- Thassos --- amphibolite facies --- metasomatism --- opal --- hyalite --- silica --- X-ray diffraction --- Raman --- Infrared --- 29Si nuclear magnetic resonance --- SEM --- provenance --- pearls --- freshwater --- saltwater --- LA-ICP-MS --- X-ray luminescence --- sapphires --- corundum --- in situ oxygen isotopes --- Orosmayo Argentina --- lamprophyre --- secondary ion mass spectrometry (SIMS) --- carbonatite --- gemstones --- corundum --- beryl --- jadeitite --- garnet --- quartz varieties --- Greece --- emeralds --- LA-ICP-MS --- UV-Vis-NIR --- FTIR --- Raman --- PL --- n/a

Advances in Hard-to-Cut Materials: Manufacturing, Properties, Process Mechanics and Evaluation of Surface Integrity

Authors: --- ---
ISBN: 9783039283545 9783039283552 Year: Pages: 222 DOI: 10.3390/books978-3-03928-355-2 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: General and Civil Engineering --- Technology (General)
Added to DOAB on : 2020-04-07 23:07:09
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The rapid growth of modern industry has resulted in a growing demand for construction materials with excellent operational properties. However, the improved features of these materials can significantly hinder their manufacture and, therefore, they can be defined as hard-to-cut. The main difficulties during the manufacturing/processing of hard-to-cut materials are attributed especially to their high hardness and abrasion resistance, high strength at room or elevated temperatures, increased thermal conductivity, as well as resistance to oxidation and corrosion. Nowadays, the group of hard-to-cut materials is extensive and still expanding, which is attributed to the development of a novel manufacturing techniques (e.g., additive technologies). Currently, the group of hard-to-cut materials mainly includes hardened and stainless steels, titanium, cobalt and nickel alloys, composites, ceramics, as well as the hard clads fabricated by additive techniques. This Special Issue, “Advances in Hard-to-Cut Materials: Manufacturing, Properties, Process Mechanics and Evaluation of Surface Integrity”, provides the collection of research papers regarding the various problems correlated with hard-to-cut materials. The analysis of these studies reveals the primary directions regarding the developments in manufacturing methods, characterization, and optimization of hard-to-cut materials.

Wide Bandgap Semiconductor Based Micro/Nano Devices

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ISBN: 9783038978428 9783038978435 Year: Pages: 138 DOI: 10.3390/books978-3-03897-843-5 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering --- Electrical and Nuclear Engineering
Added to DOAB on : 2019-08-28 11:21:27
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While group IV or III-V based device technologies have reached their technical limitations (e.g., limited detection wavelength range or low power handling capability), wide bandgap (WBG) semiconductors which have band-gaps greater than 3 eV have gained significant attention in recent years as a key semiconductor material in high-performance optoelectronic and electronic devices. These WBG semiconductors have two definitive advantages for optoelectronic and electronic applications due to their large bandgap energy. WBG energy is suitable to absorb or emit ultraviolet (UV) light in optoelectronic devices. It also provides a higher electric breakdown field, which allows electronic devices to possess higher breakdown voltages. This Special Issue seeks research papers, short communications, and review articles that focus on novel synthesis, processing, designs, fabrication, and modeling of various WBG semiconductor power electronics and optoelectronic devices.

Keywords

optical band gap --- tungsten trioxide film --- annealing temperature --- electrochromism --- AlGaN/GaN HEMT --- DIBL effect --- channel length modulation --- power amplifier --- W band --- high electron mobility transistors --- high electron mobility transistor (HEMT) --- AlGaN/GaN --- ohmic contact --- regrown contact --- ammonothermal GaN --- power amplifier --- I–V kink effect --- AlGaN/GaN HEMT --- large signal performance --- 4H-SiC --- MESFET --- ultrahigh upper gate height --- power added efficiency --- harsh environment --- space application --- 1T DRAM --- wide-bandgap semiconductor --- high-temperature operation --- TCAD --- amorphous InGaZnO (a-IGZO) --- thin-film transistor (TFT) --- positive gate bias stress (PGBS) --- passivation layer --- characteristic length --- edge termination --- silicon carbide (SiC) --- junction termination extension (JTE) --- breakdown voltage (BV) --- Ku-band --- GaN high electron mobility transistor (HEMT) --- power amplifier --- asymmetric power combining --- amplitude balance --- phase balance --- micron-sized patterned sapphire substrate --- growth of GaN --- sidewall GaN --- flip-chip light-emitting diodes --- distributed Bragg reflector --- light output power --- external quantum efficiency --- threshold voltage (Vth) stability --- gallium nitride (GaN) --- high electron mobility transistors (HEMTs) --- analytical model --- high-temperature operation --- T-anode --- GaN --- buffer layer --- anode field plate (AFP) --- cathode field plate (CFP) --- n/a

Synthesis and Modification of Nanostructured Thin Films

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ISBN: 9783039284542 9783039284559 Year: Pages: 276 DOI: 10.3390/books978-3-03928-455-9 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering
Added to DOAB on : 2020-04-07 23:07:09
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The Special Issue “Synthesis and Modification of Nanostructured Thin Films” highlights the recent progress in thin film synthesis/modification and characterization. New methods are reviewed for the synthesis and/or modification of thin films based on laser, magnetron, chemical, and other techniques. The obtained thin nanostructures are characterized by complex and complementary techniques. We think that most of proposed methods can be directly applied in production, but some others still need further elaboration for long-term prospective applications in lasers, optics, materials, electronics, informatics, telecommunications, biology, medicine, and probably many other domains. The Guest Editor and the MDPI staff are therefore pleased to offer this Special Issue to interested readers, including graduate and PhD students as well as postdoctoral researchers, but also to the entire community interested in the field of nanomaterials. We share the conviction that this can serve as a useful tool for updating the literature, but also to aid in the conception of new production and/or research programs. There is plenty of room for further dedicated R&D advances based on new instruments and materials under development.

Keywords

AlGaN --- nanopatterned sapphire substrate --- hydride vapor phase epitaxy --- stress --- transmission electron microscopy --- copper nanowires --- CuNWs --- degradation --- encapsulation --- PDMS --- PMMA --- solution-based --- transparent electrode --- photonic crystal fiber --- demultiplexer --- dense wavelength division multiplexing --- lithium niobate --- waveguide --- photonic integrated circuit --- propagation loss --- optical lithography --- chemo-mechanical polishing --- gold thin film --- nonlinear absorption --- nonlinear refraction --- transient absorption --- nanoparticles --- high-order harmonics --- electroluminescence --- nanolaminate --- Al2O3 --- Tm2O3 --- atomic layer deposition --- germanium --- DLC --- doped biomaterials --- pulsed laser deposition --- reactive oxygen species --- apoptosis --- cytotoxicity --- titanium film --- interlayer --- cohesion --- residual stress --- nano-indenter --- nanocrystal --- CdTe --- Cu-doped --- ZnTe --- solar cells --- solution processed --- pulsed laser deposition --- chalcogenide thin films --- Raman spectroscopy --- spectroscopic ellipsometry --- noble metal nanoparticles --- pulsed laser ablation --- surface enhanced Raman spectroscopy --- antiepileptic drugs --- Zn2+ substituted Coll-CaPs biomimetic layers --- MAPLE --- spin coating --- dye-sensitized solar cells --- photovoltaic conversion efficiency --- TiO2 thin films --- pulsed laser deposition --- DLC bio-functionality --- silicon doping --- diffusion barrier --- biocompatibility --- proliferation improvement --- endothelial cells --- ZnO nanofilms --- SHG --- Ga doping --- polarization angle --- Cu2MgxZn1?xSnS4 --- thin films --- photoelectric performance --- sol–gel --- sulfuration treatment --- solar cell --- nanomaterial --- zinc oxide --- barium titanate --- composite --- ethylene vinyl acetate --- elastic modulus --- toughness --- flexural rigidity --- radiopacity --- piezoelectricity --- laser surface texturing --- laser-induced periodic surface structures --- LIPSS --- silicon --- PTFE --- friction --- n/a

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