In this study First Principles calculations were carried out in order to analyze the effects of Ho-doping rate on the electronic and optical properties of ZnO films. The band structure, optical ...properties and density of states of Ho-doped ZnO with the doping rates of 0%, 1.38%, 1.85%, 2.78%, 4.17%, 6.25%, 12.5% and 25% were calculated and compared with our previous experimental results. XRD graphs showed that the Ho-doped ZnO had hexagonal structure with (101) preferential orientation. The optical band gap value for undoped ZnO firstly decreases to 3.055 eV for 1.38% Ho content, then starts to increase to the values of 3.109 eV and 3.177 eV for 1.85% and 2.77% Ho-ratios. Band gap decreases to 2.999 eV with 4% Ho-doping ratio again like the decrease in 1.38% Ho-content. Its observed that bandgap decreases with the decrease in a and b supercell parameters, the bandgap increases with the decrease on c supercell parameter, to verify that the %6.25, %12.5 and %25 doping rates are also studied and the bandgap kept increasing to 3.071 eV for %6.25 Ho-doping rate, 3.147 eV for %12.5 Ho-doping rate. The last calculation for %25 Ho-doping rate showed that the bandgap decreased to 2.727 eV. The optical calculations revealed that Ho-doping leds to blue shift and red shifts in optical absorption, transmittance, dielectric function, reflectivity, refractive index, extinction coefficient, optical conductivity, and loss function characterizations. Result shows that ZnO can be healed by Ho-doping and the calculations carried out by First principles are in a good harmony with experimental results.
Summary
This work describes the theoretical and experimental investigation of an in‐house produced 63Ni radioisotope‐powered GaN‐based direct conversion (betavoltaic) nuclear battery. GaN p‐n ...junction device with 1‐mm2 area was fabricated and irradiated by the 63Ni plate source. Short‐circuit current and open‐circuit voltage of the battery were measured, and current‐voltage curves were plotted. The energy stored in battery, maximum power, and efficiency parameters were calculated. Monte Carlo modelling was used to investigate radioisotope's self‐absorption effect, the optimization of semiconductor and source thickness, transport, and penetration of beta particles in semiconductor junction. A large fraction of beta particle energy emitted from 63Ni source is absorbed within 1 μm of the semiconductor junction on the basis of the simulation results. Epitaxial growth of GaN was performed using metal‐organic chemical vapour deposition (MOCVD) system. Monte Carlo simulation with MCNPX was used to determine optimum 63Ni radioactive film thickness. 63Ni film was electroplated on one face of 1‐mm2 copper plate and mounted 1 mm over the semiconductor device. A 63Ni source with an apparent activity of 0.31 mCi produced 0.1 ± 0.001 nA short‐circuit current (Isc), 0.65 V ± 0.0022 open‐circuit voltage (Voc), and 0.016 nW ± 0.0002 maximum power (Pmax) in the semiconductor device. The filling factor (FF) of the betavoltaic cell was 25%, and the conversion efficiency (ɳ) was 0.05%. Finally, experimental results were compared with theoretical calculations.
Novelty statement: An innovative power source, Nickel‐63 radioisotope‐powered GaN betavoltaic cell.
In this study, we obtain the numerical solution of the different problem configurations of the 3-D Magnetohydrodynamic (MHD) flow. We solve the MHD flow inside an unbounded conducting domain or ...around a conducting solid problems which require to consider both MHD equations and the Laplace equation on the connected domains with the coupled boundary conditions. As a numerical procedure we will propose the BEM (Boundary Element Method) and FEM (Finite Element Method) coupling approach with stabilization in order to eliminate the instabilities due to the numeric formulation. We consider the formulations of the MHD equations on the spherical or cubic domains inside an unbounded domain as a first problem and also on the annular spherical or annular cubic region around a conducting solid for the second problem with stabilized FEM. Then obtained discretized equations are combined with BEM formulation of the Laplace equations just only on the boundary. Finally, the BEM is used in order to obtain the rest of the unknown values on the Laplace domain using the boundary values obtained from the coupled formulation. Different values of the problem parameters and configurations are tested, and obtained solutions are displayed in terms of the figures as the 2-D slices of the 3-D solutions.
The present study was mainly aimed at investigating the interobserver and intraobserver reproducibility of ultrasound (US) results in the assessment of Achilles tendon enthesopathy in patients with ...seronegative spondyloarthropathies (SpA).
A total of 28 patients with a diagnosis of SpA according to the European Spondyloarthropathy Study Group criteria were included. The patient female/male ratio was 1.8 (18/10), mean age was 42 (range 25-75) years and mean disease duration was 9 (range 1-35) years. Mean (SD) Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) scores were 32.4 (14.5) and 26.3 (9.2), respectively. Bilateral Achilles tendon US examinations were carried out independently by three investigators using a MyLab70 XVG (Esaote Biomedica, Genoa, Italy), equipped with a broadband 6-18 MHz linear probe. Each Achilles tendon was scanned for assessing the presence/absence of US findings indicative of enthesopathy according to the Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT) preliminary definition. The same findings were also scored on a 3-grade semiquantitative scoring system on which investigators reached a consensus prior to the study. Total additive scores per Achilles tendon were calculated.
Moderate to excellent interobserver and intraobserver agreements were found for most of the US findings indicative of enthesopathy. Similar results were obtained using semiquantitative assessments, with weighted kappa values estimating the interobserver and intraobserver agreements for soft tissue inflammation of 0.696 and 0.816, respectively and for tissue damage 0.711 and 0.901, respectively.
US assessment of Achilles tendon enthesopathy in patients with SpA, using the OMERACT preliminary definition, was found to be reliable. Bone irregularity and entheseal hypoechogenicity were the most difficult abnormalities to reach agreement on.
Glasses in the TeO2–WO3–Li2O system were prepared by using conventional melt-quenching technique. Glass formation range of the system and thermal, physical and structural features of the ternary ...glasses were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and FTIR analysis according to the equimolar substitution of TeO2 by WO3+Li2O and increasing Li2O content at constant TeO2. Thermal behavior of the glasses was studied in terms of glass transition temperature (Tg), crystallization temperature (Tc/Tp) and glass stability against crystallization (∆T). Density (ρ), molar volume (VM), oxygen molar volume (VO), oxygen packing density (OPD), average cross-link density (n—c), Poisson's ratio (μcal) and number of bonds per unit volume (nb) values were calculated for the physical investigation of the glasses. FTIR spectra of the glasses were interpreted in terms of the structural transformations on the glass network by the changing composition.
•Glass formation range of the TeO2–WO3–Li2O system was determined.•Thermal, physical and structural features of ternary glasses were investigated.•Li2O addition decreases network connectivity by creating nonbridging oxygen sites.•Equimolar substitution of TeO2 by WO3+Li2O forms a more compact glass network.
In this research, pure and Ho-loaded zinc oxide nano-rods have been synthesized with the sol–gel spin coating way. The impact of holmium-loading content changed between 0–4 at.% in step of 1 at.% on ...the structural, vibrational, surface, and optical characters was inquired. The hexagonal ZnO nano-rods with (002) and (101) preferential orientations were seen from SEM and XRD analyses. It was found that the surface character of ZnO nano-rods depended on Ho-loading content. The UV and green emission bands were observed from PL analysis. A blue shift with low-content Ho level was seen from UV/Vis spectrophotometer and PL measurements. The optical band-gap value primarily raised from 3.32 to 3.40 eV for low Ho content, and then, it went down for more Ho loading. The present study gives that the physical features of zinc oxide are greatly healed with holmium loading.
Guiyu, China is infamous for its involvement in primitive e-waste processing and recycling activities. Freshwater samples were collected in and outside of Guiyu for dissolved metal analysis. It was ...found that dissolved metal concentrations were higher in Lianjiang and Nanyang River within Guiyu than the reservoir outside of Guiyu. Lianjiang was enriched with dissolved As, Cr, Li, Mo, Sb and Se, while Nanyang River had elevated dissolved Ag, Be, Cd, Co, Cu, Ni, Pb and Zn. Temporal distributions of the metals suggested recent discharges of metals attributable to a strong acid leaching operation of e-waste, where dissolved Ag, Cd, Cu and Ni (0.344
±
0.014, 0.547
±
0.074, 87.6
±
3.0 and 93.0
±
1.4
μg/L, respectively) were significantly elevated. Pb isotopic composition of dissolved Pb confirmed that more than one non-indigenous Pb were present in Lianjiang and Nanyang River. In summary, it was evident that the riverine environment of Guiyu was heavily impacted by e-waste related activities.
Proliferation of primitive e-waste processing activities significantly elevated levels of dissolved metals in the riverine environment of Guiyu.
Guangzhou, the capital of the southeastern province of Guangdong, is one of the largest and most rapidly developing industrial cities in China. In recent years its rapid economic development has ...brought great prosperity to the Pearl River Delta (PRD) region, but has also given rise to a wide variety of environmental problems. The current level of lead (Pb) contamination (75–926 mg/kg) in the surface environment of Guangzhou remains a major concern, even though the use of leaded petrol in the city was banned in 1997. The Pb isotope ratios (
206Pb/
207Pb
min-max : 1.1612–1.1961 and
208Pb/
207Pb
min-max : 2.4495–2.4838) of the urban dusts from unconfined (road dusts and gully sediments) and relatively confined (vehicular tunnel) settings in Guangzhou remains in a relatively narrow range, comparable with those of the regional natural and anthropogenic sources. This study highlights the inherent shortcomings of the Pb isotope fingerprinting technique for provenancing Pb sources, as both the target media (urban dusts) and potential sources have similar and highly radiogenic Pb isotope values. This could not only lead to an overestimation of the effectiveness of phasing-out of leaded petrol, but also an underestimation of the ever-increasing relative contributions from other potential sources of pollution, including coal combustion, industrial emissions of local Pb-ores and non-additive Pb contents of crude oils. Re-suspended Pb-bearing particulates deposited from early vehicular exhaust emission of leaded petrol with distinctly low Pb isotope compositions are still an important source of Pb pollution in the region.
In the present work, a series of ternary glasses in the K2O–WO3–TeO2 system have been synthesized by conventional melt quenching technique. Glass formation range of the selected glass system was ...determined and physical, structural and radiation shielding properties of the glasses were investigated. Density (ρ), molar volume (VM), oxygen molar volume (VO), oxygen packing density (OPD), average cross-link density (nc¯), the number of bonds per unit volume (nb) and Poisson's ratio (μcal) values were evaluated for the interpretation of physical and structural properties. Fourier transform infrared (FTIR) spectra of the glasses were analyzed in order to obtain the information on the structural transformations in the glass network following the equimolar substitution of TeO2 by K2O + WO3 and changing K2O or WO3 at constant TeO2. Increasing K2O at constant TeO2 decreases the network connectivity due to the formation of non-bridging oxygen sites and the glass network became less tightly packed. On the other hand, equimolar substitution of TeO2 with WO3+K2O in these glasses resulted in a more compact glass network. The mass attenuation coefficients have been computed using WinXCom program and the obtained values were used to calculate the half value layer, the effective atomic number and the electron density. In addition, the macroscopic effective removal cross-section for fast neutron values are also evaluated. The variation of shielding parameters was discussed for WO3 variation in the glass composition and photon energy. From the derived results, it was found that K30W60T10 is the best glass in terms of shielding effectiveness among all the studied glasses due to higher values for mass attenuation coefficient, effective atomic number, and electron density and lower values of half value layer. These glasses show potentiality to be used as shielding materials and for an improved shielding effectiveness of the K2O–WO3–TeO2 glasses, a large WO3 content would be required.
•K2O–WO3–TeO2 glass system was studied and glass formation range was updated.•Physical, structural and shielding properties of the glasses were investigated.•WO3 acted as a network former, while K2O acts as a network modifier.•Shielding effectiveness increased with increasing WO3 content.•These glasses show potentiality to be used as shielding materials.
Adipose tissue is not a passive tissue storing triglycerides, but one that releases hormones, enzymes, growth factors, and cytokines. Currently, known to release more than 600 adipokines, the adipose ...is an active tissue involved in energy homeostasis and serving paracrine, autocrine and endocrinal functions. Besides, some adipokines (irisin and ghrelin, for example) are synthesized in the sebaceous glands of the skin and play important roles in certain dermatological diseases. This review will provide a systemic overview of adipokines, focusing on their tissue and organ distribution, functions in biological systems, and roles in dermatological diseases. Additionally, the areas where adipokines can be used in dermatological diseases and their possible future roles will be presented.
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