Search results for "Hard"
showing 10 items of 2294 documents
Assessing Radiation Hardness of SIC MOS Structures
2018
It is widely known that devices based on wide gap semiconductors show potential benefits in terms of saving mass, increasing power densities compared with standard Silicon ones [1]. The higher operating temperatures these components can withstand can also reduce the power budget currently used for cooling down power electronics. These factors are critical in space applications where, for example SiC devices are very promising. However, in this field reliability is a paramount requirement, and radiation conditions can compromise the usage of these new technologies.
Effects of treatment with three types of varnish remineralizing agents on the microhardness of demineralized enamel surface
2019
Background Remineralization of incipient caries is one of the goals in dental health care ,especially in pediatric dentistry. The present study aimed at comparing the effects of MI varnish (3M (United states)) , Nano paste( FGM(Brezil) ), 5% sodium fluoride varnish) DuraphatColgate (united states) ) on remineralization of enamel lesions. Material and Methods In this in-vitrostudy, 60 intact human pre-molars, were randomly allocated to four groups of 15. Baseline surface microhardness in three points in the center of the polished area was measured. After two days of immersion in demineralizing solution, microhardness of all samples was measured. Afterward, groups 1-3 under-went treatment wit…
Impact of Gamma Radiation on Dynamic RDSON Characteristics in AlGaN/GaN Power HEMTs
2019
GaN high-electron-mobility transistors (HEMTs) are promising next-generation devices in the power electronics field which can coexist with silicon semiconductors, mainly in some radiation-intensive environments, such as power space converters, where high frequencies and voltages are also needed. Its wide band gap (WBG), large breakdown electric field, and thermal stability improve actual silicon performances. However, at the moment, GaN HEMT technology suffers from some reliability issues, one of the more relevant of which is the dynamic on-state resistance (R) regarding power switching converter applications. In this study, we focused on the drain-to-source on-resistance (R) characteristic…
Experimental investigation of effect of printing direction and surface roughness on the mechanical properties of AlSi10Mg-alloy produced by selective…
2021
The additive manufacturing has initially gained popularity for production of non-loadbearing parts and components or in the fields where the material strength and ductility are less important such as modelling and rapid prototyping. But as the technology develops, availability of metal additive manufacturing naturally dictates the desire to use the produced components in load-bearing parts. This requires not-only a thorough documentation on the mechanical properties but also additional and independent research to learn the expected level of variation of the mechanical properties and what factors affect them. The presented paper investigates strength, ductility, hardness, and microstructure …
<title>Photo-induced structural changes in near-surface layers of chalcogenide semiconductors</title>
1997
Photoinduced structural changes in near-surface layers of amorphous As-Se and As-S films have been investigated using the microhardness method. Microhardness via indentation depth data for as-deposited, illuminated and aged in ambient atmosphere films is presented. The results obtained show that photoinduced increase in microhardness of surface layers up to approximately 1 - 1.5 micrometer are more pronounced in comparison with deeper layers. Increase in microhardness of the investigated films under exposure to atmosphere was also observed. Atmosphere-induced effect was more pronounced in the case of As-S films. Photo- and atmosphere-induced effects in the near-surface layers were found to …
Pressure sensor development based on Dielectric Electro Active Polymers
2012
The Dielectric Electro Active Polymer's (DEAP's) sensing capabilities is one of the main trio-characteristics of the material applicable area's, the trio-formations as applicable use are actuator, transducer and last but not least sensor. It is noted here that one of the main value propositions whenever DEAP material is used is the dual characteristics as the sensing/actuating capability.
Nanocrystal memories for FLASH device applications
2004
Nanocrystals memory cells, in which the conventional polysilicon floating gate is replaced by an array of silicon nanocrystals, have been fabricated and characterized. Single cells and cell arrays of 1 Mb and 10 k have been realized by using a conventional 0.15 μm FLASH technology. Si nanocrystals are deposited on top of tunnel oxide by chemical vapor deposition. Properties of the memory cell have been investigated both for NAND and NOR applications in terms of program/erase window and programming times. Suitable program/erase threshold voltage window can be achieved with fast voltage pulses by adequate choice of tunnel and control dielectric. The feasibility of dual bit storage is also pro…
Optical and photonic material hardness for energetic environments
2009
We studied the effects of dielectric change in the chemical composition and in the realization procedures under radiation exposure. We have compared the radiation effects on Ge-doped and F-doped fibers and preforms: the first play a crucial role in the photosensitivity property, the second improves the dielectric radiation hardness even at low concentrations. The use of different spectroscopic techniques (RIA, OA, EPR) allow the identification of the point defect formation mechanisms at the origin of the optical degradation properties.
Transparent conductive oxide photonic crystals on textured substrates
2011
Three-dimensional ZnO:Al photonic crystals were fabricated by atomic layer deposition on highly textured substrates. It turns out that these inverted opals consist of a thin intermediate disordered layer close to the textured substrate followed by a highly-ordered photonic crystal layer. The photonic crystals themselves exhibit comparable optical properties to those on planar substrates.
Feedback Biasing Based Adjustable Gain Ultrasound Preamplifier for CMUTs in 45nm CMOS
2018
As CMOS technology is scaled down, supply voltages are decreasing and intrinsic gain of the nanoscale CMOS transistors is dropping while the threshold voltages of transistors are remaining relatively constant. In such scaled down nanoscale CMOS technologies, conventional vertical stacking architectures (for example. cascode architectures) for high-gain becomes no more attractive. In this paper we present the analysis and design of a feedback biasing based adjustable gain ultrasound preamplifier which is capable of amplifying signals from 15 MHz to 45 MHz from Capacitive Micromachined Ultrasound Transducers (CMUTs) in 45nm CMOS technology for medical ultrasound imaging applications. From the…