Molybdenum carbide (Mo2C) distinguishes itself among transition metal carbides due to its high melting point, thermal stability, and hardness. The potential use of Mo2C in both hydrogen production as a catalyst for hydrogen evolution reaction, and as corrosion resistive material in bipolar plates of fuel cells, has increased further interest in growth and synthesis of Mo2C via various approaches. Mo2C thin films are generally synthesized by chemical vapor deposition method (CVD) at high temperatures in the literature. In this study, Mo2C thin films were synthesized via the Plasma Enhanced CVD (PECVD) method by carburization of precursor Mo thin films deposited on soda lime glass (SLG) substrates. The precursor SLG/Mo thin films, deposited via rf. magnetron sputtering were subjected to different carburization times under H-2 and CH4 flow at a process temperature of 550 degrees C. Structural investigations have revealed that 60 min carburization leads to formation of similar to 116 nm thick mixed phase (90.7 % orthorhombic and 9.3 % hexagonal) Mo2C-graphite composite structure over similar to 490 nm thick Mo thin film. These results are attributed to the dynamics of the CVD process leading to formation of a more stable orthorhombic phase. The resistivity of this composite structure is determined to be approximately 20 times smaller than the precursor Mo thin film. Combining the structural details with the electrical properties it is deduced that excess C atoms not being able to diffuse into Mo2C matrix form approximately 17 nm large diamond like carbon (DLC) clusters interconnecting Mo2C grains at the very surface of the samples ending up resulting a Mo2C-DLC composite structure.

In this study, synthesis of CuS thin films on soda lime glass (SLG) substrates has been investigated. The synthesis method is based on high vacuum post-sulphidation of Cu thin films deposited by rf. magnetron sputtering. Sputtering conditions have been optimized so as to reduce grain size for better diffusion of S atoms through grain boundaries. XRD pattern of the precursor Cu sample revealed fcc structure with an average crystallite size of 24 nm. Best sulphidation was obtained at 175 oC for 60 min. The crystallite size of CuS calculated from the dominant peak of (110) planes was approximately 48 nm while average grain size observed via SEM was about 400 nm. Raman spectroscopy confirmed CuS structure by scattering peaks at around 467-472 cm-1. Elemental mapping unveiled homogenous distribution of Cu and S atoms over the surface. According to EDS data, at% compositions of Cu and S were 51.6% and 48.4%, respectively. Moreover, SIMS investigation has demonstrated uniformity of S atoms through the thickness of CuS thin film. Although XRD, Raman, and EDS analysis have resulted in predominant formation of CuS structure, existence of Cu2S phase with a strong luminescence peak located at 1.8 eV was determined by PL spectroscopy.

In this study, a set of representative banded rhyolitic pumice xenoliths collected from the ejecta of a basaltic cinder cone around Göllüdağ volcanic center, Central Anatolia, Türkiye, were characterized through whole-rock and mineral analyses, scanning electron microscopy (SEM), microcomputed tomography (µ-CT), and magnetization studies. The light- and dark-colored bands exhibit similar whole-rock chemistry, mainly distributed in rhyolite composition (71.35–71.66 wt.% SiO2). The dark pumice band shows high crystallinity (12–14 vol.%) with abundant subhedral-euhedral phenocrystals, microphenocrystals, and microlites, and a glass composition consisting of 71–76 wt.% SiO2. In contrast, the light pumice band exhibits relatively low crystallinity (1.86–8.08 vol.%) with phenocrystals and/or microphenocrystals, and a slightly higher silica content (74–77 wt.% SiO2). Both pumice bands display homogeneous distribution patterns with partially deformed and highly coalesced vesicles as observed through µ-CT and SEM studies. Additionally, we determined that the dark bands also contain magnetic minerals, which have a high attenuation coefficient and impart magnetic properties to the bands. The discrepancy in the crystal population between the light and dark pumice bands is attributed to the process occurring within the magma ascending throughout the conduit. We suggest that the response of the crystals involves separation and enrichment within their flow patterns, which prevents homogenization and results in a degree of a mechanical immiscibility of the layers.

We report the insertion of a new intermediate layer, a multi-layered graphitic carbon (MLGC), at Mo/CZTS interface and its impact on the structural and morphological characteristics of the back interface and absorber. MLGC was synthesized directly on Mo-coated SLG under a gas mixture flow of H2/CH4 at 550 °C via PECVD for 3 and 5 h. CZTS precursors were prepared on SLG/Mo and MLGC-coated SLG/Mo in a hybrid physical vapor deposition system, including evaporation and sputtering techniques, then subjected to sulfurization at 550 °C. The sheet resistance of back contact, microstructural parameters of the absorbers, the distributions of C and constituent elements were investigated. The diffraction peaks of the hexagonal Mo2C indicated the reaction between the C and Mo before the MLGC’s growth. Raman analysis confirmed the formation of the MLGC during the long deposition time after the Mo2C formation. With the addition of MLGC, the sheet resistance of the back contact decreased from 2 to 0.5 Ω/sq, and the crystallite size of the absorbers improved. Raman spectra from the interface exhibited that MoS2 peaks’ intensities significantly reduced with increasing the growth time. This implied that the 5 h-deposited MLGC was more effective in blocking the reaction between Mo and S. The absorbers with the MLGC had more uniform surface morphologies, densely packed grains, and fewer secondary phases. FIB analysis revealed the separation of the absorber with the 5 h-deposited MLGC into two parts due to C impurity. More C diffusion into the absorber for this sample was confirmed by SIMS.

The main objective of our study is to develop a new approach to the annealed proton exchange (APE) method for the fabrication of the multifunctional integrated optical chip (MIOC) used in fiber-optic gyro systems and to eliminate the loss of time and material, especially in mass production applications. In this work, self-polarized waveguides, which are the basic components of a MIOC device, were produced by the APE method and studied. With the developed method, controlled annealing trials have been carried out from a certain region on the LiNbO3 substrate used in waveguide production, and the annealing time specific to the annealing process was determined. By utilizing a special setup for the hot acid process, the proton exchange process was accomplished without a sudden temperature change of the substrate. Using prism coupling measurements of the fabricated waveguides, annealing times were determined to obtain index change values suitable for 45%-50% optical throughput. Mode profiles of devices with high optical throughput that were produced by the proposed method were measured, and it was seen that devices from different proton exchange runs had similar profiles. As a result, many undamaged substrates were fabricated, and their optical quality was found to be within the expected values.

Zinc oxide (ZnO) nanostructures have become the foremost prevalent metal oxide materials for technological applications due to their tunable optical properties. However, a simple, cheap and green method is required for the mass production of these nanostructures. In the present investigation ball-milling technique was used to tune the band gap of ZnO nanocrystallites. Samples were synthesized using metallic Zn powder and distilled water via wet-milling followed by dry-milling. The crystallite size of the ZnO samples were determined in the range of 24.9 – 22.0 nm depending on the dry milling time. UV-vis absorbance measurements and Kubelka-Munk theory were used to calculate the band gap of the ZnO nanocrystallites. The energy band gap of the samples was successfully tuned in the range of 3.15 - 3.02 eV depending on the nanocrystallite size. This behavior was explained by the surface states and energy traps on the band edge, created by delocalization of molecular orbitals.

Despite the advances in the diagnosis and treatment of neonatal sepsis, it remains an important cause of morbidity and mortality.This study aimed to investigate the effectiveness of N-terminal pro-B-type natriuretic peptide (NT-ProBNP) levels in the diagnosis and prognosis of neonatal sepsis.Fifty neonates diagnosed with clinical sepsis in the neonatal intensive care unit were included in the study.The control group was composed of 50 healthy neonates.As a result of the study, a statistically significant difference was observed between the groups in terms of NT-proBNP, C-reactive protein, leukocyte count, platelet count and I/M ratio(p <0.05).NT-ProBNP level was 19624.1±15027.6pg/ml in the case group, while it was 3203.8±4506.8pg/ml in the control group.There was a positive correlation between NT-ProBNP and neonatal sepsis in the case group.NT-ProBNP measurements were found to be significant in differentiating neonatal sepsis.In the case group, 33 patients discharged with recovery, 17 patients died, and the mean NT-ProBNP levels were 12732.2±12954.3pg/ml and 35000 pg/ml, respectively.NT-ProBNP levels were statistically significantly higher in died patients.NT-ProBNP levels should be measured in the early diagnosis of neonatal sepsis and to determine the prognosis of patients diagnosed with neonatal sepsis.The use of NT-ProBNP with other biomarkers helps the early diagnosis of neonatal sepsis.Further multicenter, prospective studies with large samples are needed to identify NT-ProBNP levels in the diagnosis and prognosis of neonatal sepsis.

Inertial rotation sensors, interferometric fiber-optic gyroscopes (IFOGs), are widely used in military and industrial applications due to their high sensitivity and stability. In this Letter, a new, to the best of our knowledge, fiber coil design is proposed to reduce magnetic field sensitivity without adding any optical components or electronic algorithms to the IFOG system. It is shown that this design can be applied without disturbing the simplest IFOG structure. Considering the fact that the magnetic field has an invertible effect on polarization, the compensation of the Faraday-effect-induced bias error has been demonstrated theoretically and experimentally by allowing two different polarizations to travel inside the fiber coil. According to the experimental results, the bias error was reduced approximately 20 times from ±9.6∘/h/mT to ±0.5∘/h/mT.

AbstractThin films are commonly utilized in industries such as electronics, packaging, decoration, and protection. The two primary techniques for thin‐film deposition include physical vapor deposition (PVD) and chemical vapor deposition (CVD). The selection and application of a particular technique depends on the desired properties of thin films. For example, for electronic applications where via filling is a requirement, preference is for the CVD process where gaseous precursor finds its way to all spaces, forming a uniform thin film on the whole topography. PVD techniques have limitation that the substrate surface has to be in the line of sight of the incoming flux. Contoured surfaces require special source and substrate manipulation for conformal coatings. Likewise, where large flat surface area coverage is needed, like thin films on decorative window glass, a simpler process such as PVD, both as evaporation and sputtering, is preferred over CVD. This article describes PVD and CVD techniques and their multiple variants. PVD processes, evaporation, sputtering, and pulsed laser deposition (PLD) with their variants, ion plating and high‐power impulse magnetron sputtering (HIPIMS), form the first part of the article, whereas the second part contains descriptions of CVD processes, including metalorganic chemical vapor deposition (MOCVD) and plasma‐assisted (or enhanced) chemical vapor deposition (PACVD). Notably absent in this article are molecular beam epitaxy (MBE), a PVD process and atomic layer epitaxy (ALE), a CVD process. These are very controlled deposition processes and require sophisticated control hardware. It is this sophistication that requires MBE and ALD to be dealt separately and, therefore, not included in this article.

Zinc oxide (ZnO) nanostructures have become the foremost prevalent metal oxide materials for technological applications due to their tunable optical properties. However, a simple, cheap and green method is required for the mass production of these nanostructures. In the present investigation ball-milling technique was used to tune the band gap of ZnO nanocrystallites. Samples were synthesized using metallic Zn powder and distilled water via wet-milling followed by dry-milling. The crystallite size of the ZnO samples were determined in the range of 24.9 – 22.0 nm depending on the dry milling time. UV-vis absorbance measurements and Kubelka-Munk theory were used to calculate the band gap of the ZnO nanocrystallites. The energy band gap of the samples was successfully tuned in the range of 3.15 3.02 eV depending on the nanocrystallite size. This behavior was explained by the surface states and energy traps on the band edge, created by delocalization of molecular orbitals.

In this letter, a new approach for the synthesis of SnS thin films is introduced. In this approach, Sn thin films were first deposited on glass substrates by r.f. magnetron sputtering under forming gas (95% Ar+ %5 H-2) atmosphere and post-sulfidation of the sputtered Sn thin films was performed under high vacuum (<10(-5) Torr). Due to low pressure, complete sulphurisation of Sn thin films via diffusion of evaporated S atoms took place at a relatively lower temperature. For a 400 nm Sn thin film, 250 degrees C and 150 min were determined as the optimum sulfidation temperature and time to obtain orthorhombic SnS thin film. It has been determined that while short sulfidation time (<120 min) leads to residual metallic Sn, high sulfidation temperature (>250 degrees C) induces SnS2 formation. (C) 2017 Elsevier B.V. All rights reserved.

Ge nanoparticles embedded in ZnO thin films (synthesized on p-type Si substrates) were investigated to explore their potential usage possibilities as diodes for opto-electronic devices and photovoltaics, thin-film transistors, and solar cells. Nano scale structural details under the effect of different gas pressure of O-2 may include some hints to understand and develop structure-property correlations of the focused type materials. With this purpose, GISAXS (Grazing-incidence small-angle X ray scattering) was used for 3D structural analysis of the films according to the thermal process (Rapid Thermal Annealing: RTA and Absence of Thermal Effect: AS-MADE) and O-2 partial pressure during the deposition of ZnO matrix. As a result of the study, it may be said that size and shape controlled growth processes are possible for these types of films. Especially, increase in pressure indicates orthogonal like prismatic morphology at 1 mTorr, cylindrical at 3 mTorr and more compact spherical formation at 5 mTorr. That way, morphology controlled nanoscale growth can be achieved by changing the oxygen partial pressure for the oxide matrices. On the other hand, size of the nano aggregations decreases with increased partial pressure for both of RTA processed and AS MADE samples. Decreasing ratio in the size of AS-MADE sample is bigger than that of RTA samples.

We present the frequency- and temperature-dependent dielectric response of Eu1-x Ba x TiO3 (0  ⩽  x  ⩽  0.5) in detail. Excluding grain boundary effects, four relaxation mechanisms were observed. Relaxation dynamics were observed to arise due to hopping conduction associated with defects, namely oxygen vacancies as well as Eu3+ and Ti3+ ions. Dielectric relaxation analysis led to the identification of Ti ions in two different environments with different relaxation rates in the overall EuTiO3 perovskite structure. The emergence of another relaxation mechanism associated with ferroelectric order as a consequence of the formation of polar regions was also observed for higher Ba concentrations. The addition of Ba led to the identification of relaxation dynamics associated with hopping conduction between Eu ions, Ti ions (in the regions with and without oxygen vacancies) and with the formation of ferroelectric polar regions. Furthermore, the polydispersivity and relaxation times were extracted within the framework of the modified Debye model. Relaxation times have been observed to increase with a decrease in temperature while larger values of polydispersivity reveal a wide distribution of relaxation times due to the presence of lattice parameter and energy barrier distributions.

In this work, we present in depth structural investigations of nanocomposite ZnO: Ge thin films by utilizing a state of the art grazing incidence small angle x-ray spectroscopy (GISAXS) technique. The samples have been deposited by sequential r.f. and d.c. sputtering of ZnO and Ge thin film layers, respectively, on single crystal Si(100) substrates. Transformation of Ge layers into Ge nanoparticles (Ge-np) has been initiated by ex-situ rapid thermal annealing of asprepared thin film samples at 600 °C for 30, 60, and 90 s under forming gas atmosphere. A special attention has been paid on the effects of reactive and nonreactive growth of ZnO layers on the structural evolution of Ge-np. GISAXS analyses have been performed via cylindrical and spherical form factor calculations for different nanostructure types. Variations of the size, shape, and distributions of both ZnO and Ge nanostructures have been determined. It has been realized that GISAXS results are not only remarkably consistent with the electron microscopy observations but also provide additional information on the large scale size and shape distribution of the nanostructured components.

The aim of this study was to evaluate the effectiveness of different drug combinations for treatment of brucellosis in children. Sixty children (mean age 9.2 +/- 3.1 years, range 10 months to 15 years) were treated with four different drug combinations. The diagnosis of brucellosis was established by positive serum agglutination titer, and/or the isolation of Brucella species from blood cultures. The most frequent findings were fever and arthritis in 12 (20%) and 13 (21.6%) patients respectively. The children under 8 years old comprised Group 1 and 2, and older than 8 years comprised Group 3 and 4 according to treatment regimens. Nine patients (Group 1) were treated with trimethoprim-sulfamethoxazole (TMP-SMZ) for 45 days plus ceftriaxone for 5 days and, rest nine patients (Group 2) were managed with TMP-SMZ for 45 days plus gentamicin for 5 days. Twenty-one patients (Group 3) were managed with doxycycline for 45 days and ceftriaxone for 5 days and, other 21 (Group 4) patients were managed with doxycycline for 45 days and gentamicin for 5 days. All patients recovered. Relapse and improvement rates were similar for all groups (P > 0.05). Each regimen was effective in the treatment of childhood brucellosis. Using cheaper drugs such as doxycycline and gentamicin in children 8 years of age and older, and TMP-SMZ and gentamicin in children 7 years of age or younger for the treatment of brucellosis in children is a practical and useful approach in our region and in the developing countries.

In this study, germanium nanoparticles (Ge-np) embedded ZnO multilayered thin films were produced on z-cut quartz and Si substrates by sequential r.f. sputtering of ZnO and d.c. sputtering of Ge targets followed by an ex-situ rapid thermal annealing (RTA) process performed at 600 °C for 30, 60, and 90 s. Evolution of Ge-np via an RTA process has been investigated in detail especially by using a small angle x-ray scattering (SAXS) technique. X-ray diffraction (XRD) patterns showed that fcc diamond phase Ge-np were successfully formed in c-axis oriented ZnO host. Crystallite sizes of diamond phase Ge-np calculated by the Scherrer formula were in the range of 18–27 nm. Analysis of SAXS patterns revealed that optimum RTA time at 600 °C to form monodispersed Ge-np is 60 s. Moreover, 30 s RTA was inadequate for the complete crystallization and segregation of crystalline Ge-np; 90 s RTA turned out to be improving the crystallite size as well as deteriorating the isolation of Ge-np possibly by inter diffusion of Ge atoms back to ZnO host. These results suggest that RTA applied under certain conditions is a robust and scalable route to form monodispersed well crystallized Ge-np in ZnO multilayered thin films for various applications.

We have investigated the structural and local atomic properties of Ge nanocrystals (Ge-ncs) embedded ZnO (ZnO: Ge) thin films. The films were deposited by sequential sputtering of ZnO and Ge thin film layers on z-cut quartz substrates followed by an ex-situ rapid thermal annealing (RTA) at 600 °C for 30, 60, and 90 s under forming gas atmosphere. Effects of RTA time on the evolution of Ge-ncs were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), hard x-ray photoelectron spectroscopy (HAXPES), and extended x-ray absorption fine structure (EXAFS). XRD patterns have clearly shown that fcc diamond phase Ge-ncs of sizes ranging between 18 and 27 nm are formed upon RTA and no Ge-oxide peak has been detected. However, cross-section SEM images have clearly revealed that after RTA process, Ge layers form varying size nanoclusters composed of Ge-ncs regions. EXAFS performed at the Ge K-edge to probe the local atomic structure of the Ge-ncs has revealed that as prepared ZnO:Ge possesses Ge-oxide but subsequent RTA leads to crystalline Ge structure without the oxide layer. In order to study the occupied electronic structure, HAXPES has been utilized. The peak separation between the Zn 2p and Ge 3d shows no significant change due to RTA. This implies little change in the valence band offset due to RTA.

BACKGROUND:Hepatitis A is a common infectious disease during childhood worldwide. Recently, great deal of changes in the epidemiology has been reported. The seroepidemiologic studies of this infection are not sufficient in Eastern region of Turkey.OBJECTIVE:To investigate the seroprevalence and association with socio-demographic variables of hepatitis A in 1-15 year old children in Van.PATIENTS AND METHODS:This study was performed on 510 one to fifteen year old children from outpatient pediatric clinics in Yüzüncü Yıl University, Faculty of Medicine during last three months of 2009. Anti-HAV IgG was measured in sera by enzyme-linked immunosorbent assay. The information about subjects was recorded on standardized forms and a chart review survey was performed.RESULTS:The overall ratio for seropositivity was 54.9%. Statistical significance was found between hepatitis A seroprevalence and age, collective use of domestic items, fresh water resources, localization and type of toilet and the number of households.CONCLUSION:This study provided the most recent data of seropositivity and revealed the preliminary indication of epidemiological shift in seroprevalence of Hepatitis A virus in a region with high endemicity.

In this work, we focus on the Ge nanoparticles (Ge-np) embedded ZnO multilayered thin films. Effects of reactive and nonreactive growth of ZnO layers on the rapid thermal annealing (RTA) induced formation of Ge-np have been specifically investigated. The samples were deposited by sequential r.f. and d.c. sputtering of ZnO and Ge thin film layers, respectively on Si substrates. As-prepared thin film samples have been exposed to an ex-situ RTA at 600°C for 60s under forming gas atmosphere. Structural characterizations have been performed by X-ray Diffraction (XRD), Raman scattering, Secondary Ion Mass Spectroscopy (SIMS), and Scanning Electron Microscopy (SEM) techniques. It has been realized that reactive or nonreactive growth of ZnO layers significantly influences the morphology of the ZnO: Ge samples, most prominently the crystal structure of Ge-np. XRD and Raman analysis have revealed that while reactive growth results in a mixture of diamond cubic (DC) and simple tetragonal (ST12) Ge-np, nonreactive growth leads to the formation of only DC Ge-np upon RTA process. Formation of ST12 Ge-np has been discussed based on structural differences due to reactive and nonreactive growth of ZnO embedding layer.

The preparation conditions for Co doping process into the ZnO structure were studied by the ultrasonic spray pyrolysis technique. Structural and optical properties of the Co:ZnO thin films as a function of Co concentrations were examined. It was observed that hexagonal wurtzite structure of ZnO is dominant up to the critical value, and after the value, the cubic structural phase of the cobalt oxide appears in the X-ray diffraction patterns. Every band-edge of Co:ZnO films shifts to the lower energies and all are confirmed with the PL measurements. Co substitution in ZnO lattice has been proved by the optical transmittance measurement which is observed as the loss of transmission appearing in specific region due to Co2+ characteristic transitions. (C) 2014 Elsevier B.V. All rights reserved.