Transfer-free, scalable vertical heterostructure FET on MoS2/WS2continuous films.

Taking into account the novel layered structure and unusual electronic properties of MoS2and WS2on the side the lack of dangling bonds between these two components and donor-acceptor linkage effects, growth of the MoS2/WS2vertical heterojunction film on the amorphous SiO2/Si substrate have created high demand. In this study, we reported the continuous, scalable, and vertical MoS2/WS2heterostructure film by using a sputtering without a transfer step. The WS2film was continuously grown on MoS2and eventually led to the formation of the MoS2/WS2vertical heterojunction film. Dozens of FETs fabricated on MoS2/WS2continuous heterojunction film were created on the same substrate in a single lithographic fabrication step, allowing them to be commercialized and not only used in research applications. RAMAN spectra proved the formation of the MoS2/WS2heterostructure film. In XPS measurements, it was shown that a separate MoS2and WS2layer was grown instead of the alloy structure. The polarity behavior of the MoS2/WS2heterostructure FET was found to be modulated with different drain voltages as p-type to ambipolar and finally n-type conductivity because of the transition of band structure and Schottky barrier heights at different drain voltages. Electron mobility (7.2 cm2V.s-1) and on/off ratio (104-105) exhibited by the MoS2/WS2heterostructure FETs displayed a more improved electrical performance than that of individual WS2, MoS2devices. It was observed that the mobility value of MoS2/WS2FET was approximately 514 times greater than WS2FET and 800 times greater than MoS2FET. Additionally, the MoS2/WS2FET on/off ratio was larger than 2 order MoS2FET and 1 order WS2FET. The film of continuous vertical heterojunctions as in the MoS2/WS2currents in the study would be a promising candidate for nanoelectronics fields. This work demonstrated the progress towards realizing carrier-type controlled high-performance MoS2/WS2heterojunction-based FETs for future logic devices.

Enhancing the stability of environmental resistance of alloyed CdZnSeS@ZnS quantum dots by doping Ti ions into shell layer.

Colloidal quantum dots (QDs) are promising luminescent materials for display and lighting, but their stability has long been an issue. Here, we designed a passivation strategy of doping Ti ions into the shell of alloyed CdZnSeS@ZnS QDs. The results showed that Ti ions were successfully doped into the ZnS shell and the stability of QDs was improved. In the aging test, the Ti ions doped QDs maintained 51.4% of the initial performance after 90 h of aging, while the pristine QDs decreased to less than 25% of the initial value. In addition, we discuss the reasons why Ti ions doping improves the stability of QDs. Ti ions are found to form Ti-S bonds in the ZnS shell, which has high binding energy and strong oxidation resistance. Most importantly, since there is no external physical insulating coating, the optimized QDs can also be directly used in electroluminescent devices, showing great potential in electroluminescence applications.

A Hydrogen Gas Sensor Based on TiO2 Nanoparticles on Alumina Substrate.

High demand of semiconductor gas sensor works at low operating temperature to as low as 100 °C has led to the fabrication of gas sensor based on TiO2 nanoparticles. A sensing film of gas sensor was prepared by mixing the sensing material, TiO2 (P25) and glass powder, and B2O3 with organic binder. The sensing film was annealed at temperature of 500 °C in 30 min. The morphological and structural properties of the sensing film were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The gas sensor was exposed to hydrogen with concentration of 100⁻1000 ppm and was tested at different operating temperatures which are 100 °C, 200 °C, and 300 °C to find the optimum operating temperature for producing the highest sensitivity. The gas sensor exhibited p-type conductivity based on decreased current when exposed to hydrogen. The gas sensor showed capability in sensing low concentration of hydrogen to as low as 100 ppm at 100 °C.

Structural, Morphological and Optical Properties of Well-Ordered CdO Nanostructures Synthesized by Easy-Economical Chemical Bath Deposition Technique.

In this Study, Cadmium Oxide (CdO) nanostructures were synthesized by using Chemical Bath Deposition Technique. The synthesized process was carried out at room temperature. The structural and optical properties of nanostructures was characterized by XRD, SEM and UV-Vis techniques. As a result, the CdO nanostructures are oriented along (111) plane of cubic crystal structure. The morphology of CdO nanostructures showed interconnected prism-like and cauliflower-type cluster nanostructure. The UV results of this structures with high absorbtion coefficient are observed to be in accordance with the CdO nanoparticles.

Efficacy and Reliability of T-Cell-Depleted Haploidentical Stem Cell Transplantation in Hematologic Disorders: A Retrospective Study.

BACKGROUND: A promising recent strategy for haploidentical transplantation is the depletion of T lymphocytes based on the selective elimination of T cells by manipulation, which enables a very low incidence of nonrelapse mortality and graft-vs-host disease. It is more expensive than conventional unmanipulated methods and requires dedicated transplant centers and sufficient stem cell processing facilities. This retrospective study aimed to evaluate the relapse, survival, and clinical data of the patients and to analyze the outcomes of the technique. METHODS: The study included 56 adult patients who underwent haploidentical stem cell transplantation via αß T-cell depletion. RESULTS: The median age of the patients at the time of hematopoietic stem cell transplantation was 41.5 years (range, 20-70 years); 22 patients (39.3%) were women. After the transplantation, half of the patients (50.0%) needed immunosuppressive drugs, and 17.9% of the patients experienced a post-transplant relapse. The mortality rate was 55.4%, and nonrelapse mortality was 25.0%. The 100-day mortality rate was 19.6%. The median overall days was 1101 days (142-3813 days), whereas the median progression-free overall was 302.5 days (11-2479 days). Being older (age >40), having hypertension, having acute liver graft-vs-host disease, and having systemic fungal infection were found as risk factors that significantly increased mortality (with 3.5-, 2.8-, 3.7-, and 2.7-fold increases, respectively). CONCLUSION: To conclude, T-cell-depleted hematopoietic stem cell transplantation is an effective and reliable technique that has the potential to decrease morbidity and improve relapse-free survival, especially for young patients requiring haploidentical donor transplantation for hematologic malignancy.

Working Voltage Switching the Photo-/Thermo-Electric Effect for Distinct Ultraviolet and Infrared Signal Detection.

The combination of sensing invisible ultraviolet photons and infrared radiation can significantly enhance target recognition by offsetting their own limit in a short sensing range and poor spatial resolution. However, the difference in their wavelength sets unique requirements for sensing materials and devices, which makes it hard to establish their implementation in a single detector. In this work, we present the design of a single detector with CH3NH3PbCl3 (MAPbCl3) for distinguishing ultraviolet and IR signals by switching its operating mode in the photo-/thermo-electric effect. The large optical band gap of ∼3.2 eV in MAPbCl3 ensures the response toward an ultraviolet photon, while its efficient thermoelectric effect allows the sensing of an IR signal. As a result, the detector exhibits a specific detectivity of 4.5 × 1012 Jones for 395 nm ultraviolet photons under 0 V, while under the working voltage of 2.5 V, it demonstrates a superior temperature coefficient of resistance of -3.7% K-1, a specific detectivity of 4.8 × 108 Jones, and a limit of detection of 0.58 mW/cm2 for 4 µm photons. The functionality of the switching response to ultraviolet or IR photons by working voltage allows background subtraction and enhances the target discrimination in the imaging.

Differential uncertainty analysis for evaluating the accuracy of S-parameter retrieval methods for electromagnetic properties of metamaterial slabs.

We apply a complete uncertainty analysis, not studied in the literature, to investigate the dependences of retrieved electromagnetic properties of two MM slabs (the first one with only split-ring resonators (SRRs) and the second with SRRs and a continuous wire) with single-band and dual-band resonating properties on the measured/simulated scattering parameters, the slab length, and the operating frequency. Such an analysis is necessary for the selection of a suitable retrieval method together with the correct examination of exotic properties of MM slabs especially in their resonance regions. For this analysis, a differential uncertainty model is developed to monitor minute changes in the dependent variables (electromagnetic properties of MM slabs) in functions of independent variables (scattering (S-) parameters, the slab length, and the operating frequency). Two complementary approaches (the analytical approach and the dispersion model approach) each with different strengths are utilized to retrieve the electromagnetic properties of various MM slabs, which are needed for the application of the uncertainty analysis. We note the following important results from our investigation. First, uncertainties in the retrieved electromagnetic properties of the analyzed MM slabs drastically increase when values of electromagnetic properties shrink to zero or near resonance regions where S-parameters exhibit rapid changes. Second, any low-loss or medium-loss inside the MM slabs due to an imperfect dielectric substrate or a finite conductivity of metals can decrease these uncertainties near resonance regions because these losses hinder abrupt changes in S-parameters. Finally, we note that precise information of especially the slab length and the operating frequency is a prerequisite for accurate analysis of exotic electromagnetic properties of MM slabs (especially multiband MM slabs) near resonance regions.

Domestic livestock resources of Turkey: water buffalo.

Water buffalo are an ancient component of Turkey's domestic livestock resources. Commonly referred to as the Anatolian buffalo the animal is part of the Mediterranean group which includes Syrian, Egyptian and Southeast European animals. Once quite numerous, there have been drastic reductions in their numbers since the 1970s due to intensification of dairy activities, agricultural mechanization and changing consumer preferences. The main areas of distribution are in northwest Turkey in the Marmara and Black Sea Regions. Buffalo are kept in small herds by livestock and mixed crop-livestock farmers. Milk is the main product, meat is largely a by-product of the dairy function and provision of the once-important draught power is now a minor output. Buffalo milk is used to prepare a variety of speciality products but output of both milk and meat is very low in comparison to cattle. Conditions of welfare and health status are not optimal. Internal parasites are a constraint on productivity. Some buffalo are being used for conservation grazing in the Black Sea area to maintain optimal conditions for bird life in a nature reserve. Long neglected by government there are recent activities to establish conservation herds, set up in vitro banks and undertake molecular characterization. More effort is needed by government to promote buffalo production and to engage the general public in conservation of their national heritage.

Thermally Processed Quantum-Dot Polypropylene Composite Color Converter Film for Displays.

Quantum dots (QDs) have attracted much attention as one of the most promising candidates for next-generation display materials. However, stability is still a big challenge for QDs. Herein, we encapsulated QDs in a thermoplastic polypropylene (PP) matrix by thermal processing technology to prepare a stabler color conversion film for the first time. Thermal processing technology expands the packaging materials of QDs from traditional soluble polymers to thermoplastic polymers such as PP with easy processing and a low cost. We showed that the QDs in the PP film exhibited longer-lasting stability than the traditional PMMA film. After 216 h of blue light accelerated aging test, the QDs maintained more than 90% of the initial performance in the PP film but dropped to less than 25% in the PMMA film. Moreover, the reasons for the improved stability have been further discussed. It was found that the PP-H film not only possessed better barriers to moisture and oxygen, but the absence of ester groups also led to a milder environment around the QDs. The results show that ester groups have stronger electronegativity and easily cause the ligands on the surface of QDs to fall off, which lead to performance degradation.

Effect of different housing systems on fattening performance, slaughter and carcass characteristics of Akkeçi (White Goat) male kids.

The aim of this study was to determine the fattening performance and the slaughter and carcass characteristics of Akkeçi (Saanen × Kilis (B(1)) crossbred) male kids raised in individual crates (IC) or in group pen housing (GP). In both GP and IC groups, total 13 heads of male kids, whose initial body weights were 21.43 ± 1.03 kg and 20.61 ± 0.98 kg, respectively, evaluated for their fattening performances. After 56 days of the fattening period, the final body weights and average daily weight gains of the GP and IC kids were recorded as 30.84 ± 0.82 kg and 25.84 ± 0.76 kg; 182.42 ± 14.77 g and 92.09 ± 13.76 g, respectively (P < 0.001). Adrenal gland weights of the GP and IC groups were similar as 1.66 ± 0.25 g and 1.77 ± 0.22 g, respectively. Although, the carcass conformation of kids was similar between groups, there were significant differences between GP and IC groups for some slaughter and carcass characteristics. In general, although housing kids reared in individual crates provides opportunity to individually feed and monitor a kid, the results obtained from the individual crates in the present study were not satisfactorily from the ethological and production points of view.

A Study on Microwave Absorption Properties of Carbon Black and Ni0.6Zn0.4Fe2O4 Nanocomposites by Tuning the Matching-Absorbing Layer Structures.

Microwave absorption properties were systematically studied for double-layer carbon black/epoxy resin (CB) and Ni0.6Zn0.4Fe2O4/epoxy resin (F) nanocomposites in the frequency range of 8 to 18 GHz. The Ni0.6Zn0.4Fe2O4 nanoparticles were synthesized via high energy ball milling with subsequent sintering while carbon black was commercially purchased. The materials were later incorporated into epoxy resin to fabricate double-layer composite structures with total thicknesses of 2 and 3 mm. The CB1/F1, in which carbon black as matching and ferrite as absorbing layer with each thickness of 1 mm, showed the highest microwave absorption of more than 99.9%, with minimum reflection loss of -33.8 dB but with an absorption bandwidth of only 2.7 GHz. Double layer absorbers with F1/CB1(ferrite as matching and carbon black as absorbing layer with each thickness of 1 mm) structure showed the best microwave absorption performance in which more than 99% microwave energy were absorbed, with promising minimum reflection loss of -24.0 dB, along with a wider bandwidth of 4.8 GHz and yet with a reduced thickness of only 2 mm.

Investigation of K X-ray intensity ratios of some 4d transition metals depending on the temperature.

In this paper, we have studied the intensity ratios Kß/Kα depending on the temperature for transition elements Mo, Nb, Zr and Y by 59.5keV γ-rays from a 100 mCi (241)Am radioisotope point source. The Kα and Kß emission spectra of Mo, Nb, Zr and Y were measured by using a Si (Li) solid-state detector at temperature between 40 and 400°C. σKα and σKß production cross-sections, Kß/Kα intensity ratios, asymmetry factor, energy shifts and full width half maximum (FWHM) values of the elements have been calculated. Temperature-dependent changes of the parameters are tabulated and given in the graphical forms. Based on the results obtained, Kß/Kα X-ray intensity ratios of the elements are dependent on the temperature. It is shown that σKß fluorescence cross sections of Mo, Nb and Zr have more increase rate than σKα fluorescence cross sections with increasing temperature. For Y, σKα and σKß production cross-sections firstly decrease, then increase. In general, Kß/Kα X-ray intensity ratios tend to increase with increasing temperature. Some significant shifts are observed in Kα and Kß emission spectra of Mo and Y. These results may contribute to the XRF studies of transition metals.

Stature and sex estimate using foot and shoe dimensions.

The aim of the study was to develop a formula to estimate the stature and sex of an individual using foot and shoe dimensions. To this aim the stature, right and left shoe sizes, and maximum and minimum feet length and width measurements of a target group of 569 individuals were taken. The group was composed of 294 males and 275 females. The highest correlation coefficient was found in length measurements. A notable difference between males and females existed with regard to both right and left foot and shoe length and width averages and shoe sizes (p < 0.001). Among the group, a significant correlation was found in regard to stature and right shoe length (r = 0.591, p < 0.001), with the correlation between stature and right foot length and stature and right shoe length being 0.579 (p < 0.001); as for the female group, there was a significant correlation between stature and right foot length and stature and right shoe length (r = 0.460, p < 0.001). Thus the regression formula obtained are as follows: for the right side: sex = 69.169 + 0.173 (maximum foot length) - 0.368 (maximum foot width) - 0.820 (shoe length) + 0.224 (shoe width) - 1.280 (shoe number). For the left side: sex = 69.551 + 0.276 (maximum foot length) - 0.504 (maximum foot width) - 0.739 (shoe length) + 0.344 (shoe width) - 1.360 (shoe number). In application of the formula, if sex is lower than 0.50, the shoe belongs to a male, if higher, then to female. The formula which was obtained in regression analysis in order to estimate the stature when the measurements of shoe and foot were known. For the right side, stature = 47.93 + 1.083 (maximum foot length) + 0.788 (shoe length) 1.813 (shoe number) (SEE:31.410). For the left side: stature = 47.33 + 1.139 (maximum foot length) + 0.593 (shoe length) x 1.924 (shoe number) (SEE:31.607). It was understood that foot and shoe sizes are a criteria to estimate the stature of a person that there was a strong relationship between foot and shoe length and width and that these can be used to aid estimation. It was found that in sex estimate, foot and shoe lengths are better in helping the estimate than width measurements, and that the use of shoe measurements rather than bare foot measurements are better to obtain meaningful results.

Measurement of L3 subshell fluorescence yields of some elements in the atomic range 57 < or = Z < or = 68 using photoionisation.

L3 X-ray production cross sections have been measured for the elements in the atomic range 57< or = Z < or = 68 at 59.5 keV. The values of L3 subshell fluorescence yields (omega3) have been measured for the same elements using the presently measured cross section values and the theoretical Li subshell photoionisation cross sections, Coster-Kronig transition probabilities, emission rates and vacancy transfer probabilities. The measured X-ray production cross section values are in general agreement with the theoretical values evaluated using L3 subshell fluorescence yields, Coster-Kronig transition probabilities, emission rates, vacancy transfer probabilities and subshell photoionisation cross sections. Furthermore, the values of L3 subshell fluorescence yields are in good agreement with the theoretical values.

Measurement of Coster-Kronig vacancy transfer factor for L3 subshell X-rays of Au, Hg, Pb, Tl, Bi, Th and U at 59.5 keV.

The Coster-Kronig vacancy transfer factors were measured for L3 subshell X-rays using the experimental L(alpha) X-ray production cross section, the fraction of L(alpha) X-rays, L3 subshell fluorescence yield and L3 shell photoionization cross section. The obtained experimental results were compared with the theoretical values. It showed that the agreement between the present experimental and theoretical results was very good.