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The CMOS technology with MOSFETs below 70 nm node for Semiconductor Industry Association roadmap has outstanding resistance to short-channel effect and improves the scalability of the device. Cylindrical surrounding double-gate (CSDG) MOSFETs have been proposed as a suitable CMOS substitute to reduce the area and power tradeoff. This paper presents mathematical modeling of the electron density arrangement in the CSDG MOSFET for hybrid RF applications. In this device, the arbitrary alloy of Aluminum Gallium Arsenide (AlGaAs) has been used. This material lies between Aluminum Arsenide and Gallium Arsenide. High electron mobility and the lesser bandgap in AlGaAs make it suitable for the design of CSDG MOSFET for low-frequency applications. In the middle of CSDG MOSFET, the electron density (N2D) has been observed to be 1.92 × 1013 cm−2 for arbitrary alloy-based MOSFET and 1.02 × 1013 cm−2 for the conventional SiO2-based MOSFET towards the drain terminal. The electron density has been observed to be 7.90 × 1012 cm−2 for arbitrary alloy-based MOSFET and 5.86 × 1012 cm−2 for the conventional SiO2-based MOSFET along the channel. The results show that the average speed of the electron inside the device channel is submissive to the conventional MOSFET.

Photobiomodulation (PBM) has been emerging as a promising alternative therapy in dentistry. However, various parameters of PBM are used in different studies, and there is limited cumulative data on PBM for improving bone formation in clinical trials. The aim of this review was to evaluate the effectiveness of PBM in the process of bone remodeling in dentistry using randomized controlled trials. Initially, a total of 1,011 articles published from January 2008 to December 2021 were retrieved from five electronic databases (PubMed, Scopus, Cochrane Library, EMBASE, and CINAHL). After a two-step review, nine articles met the inclusion criteria. The parameter of PBM, group, treatment sessions, assessment times and outcomes of the included studies were reviewed. Eighty-nine percent of the studies revealed positive effects on bone formation between the laser group and the control group. Only one article reported that light-emitting diode did not significantly enhance osteogenesis. Additionally, the present study shows that Gallium aluminum arsenide of near infrared (NIR) laser with continuous mode is the most commonly used form of PBM. The biostimulatory effects are dependent on several parameters, with wavelength and dose being more important than others. Based on this review, it is suggested that the NIR range and an appropriate dose of PBM could be used to increase the efficiency of stimulating bone healing and remodeling. However, standardization of treatment protocols is needed to clarify therapeutic strategies in dentistry.

In this article, we present the main theoretical results, including electronic properties (band structure, total density of states (DOS), and partial density of states (PDOS)), as well as optical characteristics (dielectric function, refractive index, and absorption) for gallium arsenide (GaAs) and its ternary alloy (Ga 0.75 Al 0.25 As) in the zinc-blende (ZB) phase. The results are analyzed as a function of pressure within the range of 0, 5, 10, and 15 GPa, using the CASTEP code, which is based on density functional theory (DFT) and employs a combination of plane wave (PW) and pseudopotential (PP) techniques. The exchange-correlation potential is treated using the generalized gradient approximation (GGA-PBE), parameterized by Perdew–Burke–Ernzerhof. Our results reveal an increase in the direct band gap with pressure. We find a strong agreement between our findings and both experimental data and other theoretical studies available in the literature. We have presented the electronic band structures along with the total and partial density of states (TDOS, PDOS) for the ternary alloy (Ga 0.75 Al 0.25 As) at different pressures ranging from 0 GPa to 15 GPa in 5 GPa increments. It is observed that the real part of the dielectric function, ε 1 (0), and the refractive index, n(0), decrease with increasing pressure. Additionally, while the nature of the optical constant curves remains largely unchanged with increasing pressure, all peaks are shifted to higher energy values. These results demonstrate the impact of replacing a gallium (Ga) atom with an aluminum (Al) atom in the binary material (GaAs) at various pressure values, potentially enhancing the performance of (GaAlAs) in optoelectronic devices.

This study has presented the different suggested compounds based (CAWG) like silicon dioxide (SiO ), lithium niobate (LiNbO ) and gallium aluminum arsenide (Ga Al As) taking into consideration their operating wavelength range, their operating temperature range, their physical properties, and also their ability to be used in the manufacture of optical devices. The optimum performance was given in case of using the following materials such as SiO , LiNbO and Ga Al As materials, so these materials have been used as a proposed materials based CAWG devices, which have been investigated for high stability and low insertion loss in near infrared wavelength band. The comparison between these proposed materials are clarified through the design parameters of CAWG device such as the order of diffraction ( ), path length adjacent waveguides difference (Δ ), focal length ( ), free spectral range (FSR), max no. of I/O wavelength channels ( ), and arrayed waveguides ( ) number.

The aim of the current study was to evaluate the proliferative effect of low-level laser therapy on long-term cryopreserved dental pulp stem cells (DPSCS) and stem cells from human exfoliated deciduous teeth (SHEDS). The DPSCS and SHEDS were divided into 2 main groups according to gallium aluminum arsenide (GaAIAs) diode laser irradiation densities as 5 J/cm2 and 7 J/cm2. Each main group was further divided into 4 groups according to laser irradiation periods as 0, 24, 48, 72 h groups. During the incubation periods, cells received laser irradiation in every 24 h according to their groups and were put into incubator after irradiation. Cell groups that were not subjected to laser irradiation were served as control groups. Viabilities of cells were determined via MTT assay at the end of all incubation periods, and data were statistically analyzed. Laser irradiation demonstrated significant effects on proliferation rate of DPSCs and SHEDs in comparison with control. Intragroup comparison data of DPSCS revealed that repetitive laser irradiation for long term (72 h) increased the cellular viability significantly in comparison with all other treatment groups; however, no significant differences were found when energy densities were compared within each time interval, except for 48 h group at which irradiation with 7 J/cm2 provided significantly higher cell viability rates of SHEDS. DPSCs showed significantly higher cellular viability than SHEDs only for the 7 J/cm2 energy density in 72 h. Longer term (72 h) repetitive laser irradiation with energy densities of 5 and 7 J/cm2 (wavelength of 980 nm) may be recommended to induce the proliferative effect on long-term cryopreserved DPSCS and SHEDS.

Alveolar bone repair is a complex and extremely important process, so that functions such as the mastication, occlusion and osseointegration of implants can be properly reestablished. Therefore, in order to optimize this process, many procedures have been used, such as grafting with biomaterials and the application of platelet-rich fibrin (PRF). Another method that has been studied is the use of photobiomodulation (PBM) with the use of low-level laser therapy (LLLT), which, through the absorption of photons by the tissue, triggers photochemical mechanisms in the cells so that they start to act in the search for homeostasis of the affected region. Therefore, the objective of this review was to analyze the use of LLLT as a possible auxiliary tool in the alveolar bone repair process. A search was carried out in scientific databases (PubMed/MEDLINE, Web of Science, Scopus and Cochrane) regarding the following descriptors: “low-level laser therapy AND alveolar bone repair” and “photobiomodulation AND alveolar bone repair”. Eighteen studies were selected for detailed analysis, after excluding duplicates and articles that did not meet predetermined inclusion or non-inclusion criteria. According to the studies, it has been seen that LLLT promotes the acceleration of alveolar repair due to the stimulation of ATP production, activation of transcription and growth factors, attenuation of the inflammatory process and induction of angiogenesis. These factors depend on the laser application protocol, and the Gallium Aluminum Arsenide—GaAlAs laser, with a wavelength of 830 nm, was the most used and, when applications of different energy densities were compared, the highest dosages showed themselves to be more efficient. Thus, it was possible to conclude that PBM with LLLT has beneficial effects on the alveolar bone repair process due to its ability to reduce pain, the inflammatory process, induce vascular sprouting and, consequently, accelerate the formation of a new bone matrix, favoring the maintenance or increase in height and/or thickness of the alveolar bone ridge.

The realisation of photonic devices for different energy ranges demands materials with different bandgaps, sometimes even within the same device. The optimal solution in terms of integration, device performance and device economics would be a simple material system with widely tunable bandgap and compatible with the mainstream silicon technology. Here, we show that gallium arsenide nanowires grown epitaxially on silicon substrates exhibit a sizeable reduction of their bandgap by up to 40% when overgrown with lattice-mismatched indium gallium arsenide or indium aluminium arsenide shells. Specifically, we demonstrate that the gallium arsenide core sustains unusually large tensile strain with hydrostatic character and its magnitude can be engineered via the composition and the thickness of the shell. The resulted bandgap reduction renders gallium arsenide nanowires suitable for photonic devices across the near-infrared range, including telecom photonics at 1.3 and potentially 1.55 μm, with the additional possibility of monolithic integration in silicon-CMOS chips. Designing core/shell nanowires with desired optoelectronic properties of III-V semiconductor alloys remains a challenge. Here, the authors report an engineering strategy to surmount strain-induced difficulties in the growth achieving highly strained cores with a sizeable change in their band gap.

This study compared the outcome of photosensitization on the viability of four different cariogens in planktonic form as well as biofilms in human dentine. Photodynamic therapy was carried out with a gallium aluminium arsenide laser (670 nm wavelength) using Toluidine blue O (TBO) as the photosensitizer. Cariogenic bacteria ( , , and ) were exposed to TBO and then to the laser for 1 minute in planktonic suspension. Then, tooth slices previously incubated for 24 hours with broth cultures of broth culture of the four cariogenic organisms were exposed to antimicrobial photosensitization. The control samples consisted of planktonic and sessile cells that were exposed to TBO alone, laser alone and the bacterial cells that were not treated with TBO or laser. The results showed significant reductions in the viability of , and in both planktonic form (to 13%, 30%, and 55%, respectively) and sessile form hosted in dentinal tubules (to 19%, 13% and 52%, respectively), relative to the controls. was the least affected in planktonic (94% viability) and sessile form (86% viability). In conclusion, sensitivity to photosensitization is species-dependent and sessile biofilm cells are affected to the same extent as their planktonic counterparts.

Transistor concepts based on semiconductor nanowires promise high performance, lower energy consumption and better integrability in various platforms in nanoscale dimensions. Concerning the intrinsic transport properties of electrons in nanowires, relatively high mobility values that approach those in bulk crystals have been obtained only in core/shell heterostructures, where electrons are spatially confined inside the core. Here, it is demonstrated that the strain in lattice-mismatched core/shell nanowires can affect the effective mass of electrons in a way that boosts their mobility to distinct levels. Specifically, electrons inside the hydrostatically tensile-strained gallium arsenide core of nanowires with a thick indium aluminium arsenide shell exhibit mobility values 30–50 % higher than in equivalent unstrained nanowires or bulk crystals, as measured at room temperature. With such an enhancement of electron mobility, strained gallium arsenide nanowires emerge as a unique means for the advancement of transistor technology. Semiconductor nanowires are promising candidates for the realization of novel transistor concepts. Here, the authors demonstrate that electron mobility in strained coaxial nanowire heterostructures can be higher than in the corresponding bulk crystals.

We report Raman scattering experiments and aluminum (Al) ratio on self-assembled InAlAs quantum dots (QDs) in AlGaAs matrix with different coverage thickness and growth time. The Raman feature assigned to LO phonons in the dots, exhibit a downward frequency shift compared to the one of InAs/AlGaAs QDs. This shift is caused by the strain effects. It is also found that the Al intermixing from the barrier towards the QDs is more important in InAlAs/AlGaAs than in InAs/AlGaAs QDs. We have found that the decrease of the coverage thickness and growth time of the InAlAs/AlGaAs QDs leads to broadening of the Raman peak assigned to LO phonons. This result is attributed to the increase of the In concentration fluctuation in the QDs. In the second part of this report we have investigated the effect of aluminum (Al) concentration on size of In 1−x Al x As/Al 0.3 Ga 0.7 As QDs (x=0.28, 0.38, 0.5) by photoluminescence measurements.