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(1 − x)ZnMn2O4/xNiFe2O4 (x = 0, 0.05, 0.1, 0.15, 0.2) nanocomposite samples were prepared employing co-precipitation procedure. Phase analysis of the measured x-ray diffraction patterns manifested the formation nanocomposites of two phases ZnMn2O4 (ZMO) and NiFe2O4 (NFO), and the phase percentage of each was determined applying Rietveld method. Analysis established the exchange of cations Zn, Mn, Ni, and Fe among the (ZMO) and (NFO) phases. Also, the influence of alloying parameter (x) on the cell parameters of (ZMO) and (NFO), crystallite size, and different IR vibrational bands was studied. For the prepared (1 − x)ZMO/xNFO nanocomposite samples, the influence of NFO amount of the absorbance, extinction coefficient, refractive index, optical bandgap, and other optical parameters were examined over different wavelength ranges using UV diffused absorption technique. The nonlinear optical behavior of the nanocomposite samples was increased as the percentage of NFO increases. The variations in the photoluminescence intensity and different emitted colors for the prepared nanocomposite samples were explored in detail.

Iron or chromium doped nano ZnMn2O4 samples (ZnMn2−xFexO4 or ZnMn2−xCrxO4, x = 0, 0.1, 0.15, 0.2) were prepared by the sol-gel procedure. Rietveld method analysis applied for Synchrotron x-ray diffraction data revealed single phase ZnMn2O4 (ZMO) tetragonal phase for the samples. The variation in the lattice parameters and crystallite size of different samples upon doping are discussed. X-ray photo-electron spectroscopic (XPS) technique was used to verify the incorporation of doped elements in ZMO matrix and to determine the cation oxidation states. All samples absorb light in wavelengths longer than 500 nm, demonstrating that they can efficiently absorb light in the visible range. Fe or Cr modified the light absorbance characteristics of ZMO sample. The sensitivity of ZMO sample to the daylight was increased as it doped with either Fe or Cr. The optical band gap energy, the photoluminescence intensity and the emitted colors from ZMO sample were affected by the kind of dopant element and the doped concentration. The behavior of extinction coefficient, dielectric constant (real and imaginary) and the optical conductivity of all samples were also explored. Fe or Cr doped samples exhibited a paramagnetic behavior. The small dielectric value and the relative small bandgap nominated the doped materials to be used in optoelectronic applications.

Nano ZnMn2−xCrxO4 samples (x = 0, 0.05, 0.15, 0.2) were synthesized by the sol–gel procedure. The synchrotron X-ray diffraction technique was used to investigate the developed phases, cation distributions of different ions between different sites, lattice parameters, and crystallite size upon increasing the amount of Cr doping in nano ZnMn2O4. X-ray photoelectron spectroscopy (XPS) was utilized to explore the cation oxidation state and the elemental composition of the samples. The valence state of the incorporated chromium is determined to be Cr3+ only. The effect of Cr doping, frequency, and temperature on the dielectric constant, dielectric loss, ac conductivity, complex impedance, and modulus was studied in detail. At a low temperature range, the samples exhibited a semiconductor feature, while at a higher temperature range, the samples revealed metallic behavior. Also, the conduction-type mechanism for each doped sample was determined. The activation energy was affected by the amount of Cr doping. A sample with 15% Cr doping has the highest conductivity among the other samples. Also, the effect of doping and temperature on the Nyquist diagram was examined.

Patients with hematological malignancies (HM) appear to be at increased risk of acquiring COVID-19 infection and its complications. General measures to protect patients with HM from COVID-19 include limiting exposure of patients to medical environments with the use of telemedicine and virtual clinics, delaying elective diagnostic services, modifying treatment modalities in a manner that reduces the probability of further immune suppression such as shortening the treatment course or prolonging the interval between treatment courses, and growth factor support to reduce the risk of neutropenia. Reducing the threshold for packed RBC and platelet transfusions to mitigate reduced blood product supplies, and a careful attention to drug interactions in patients who get the COVID-19, are also important management measures. Physicians caring for patients with HM need to carefully evaluate each individual patient to optimize therapies, take measures to maximize safety of patients and staff, without significantly compromising outcomes. This paper discusses management of HM during the COVID-19 pandemic.

Undoped and doped with nano-ZnO (Zn0.9X0.1O, X = Co, Cu and Mn) blended polymers (70% polyvinyl alcohol/30% polyvinyl pyrrolidone) were formed using solid-state reaction and casting methods. X-ray diffraction measurements were used to examine the incorporation of the nanofiller into the polymer matrix. Rietveld analysis showed an average crystallite size of 20 nm for ZnO with a little change upon doping Co, Cu, or Mn. The variations in the absorbance, extinction coefficient, refractive index, direct optical band gap energy, the single-oscillator energy, the oscillator strength and static refractive index of the blend with the nanofiller were studied in detail. The optical bandgap of the pristine blend, 4.97 eV, was reduced upon doping reaching a minimum of 4.82 eV for pure ZnO. The obtained values of electric characteristics and nonlinear optical properties are affected by the kind of dopant and the value of wavelength used. The reduction obtained in the optical band gap can nominate the doped blended polymers to be used as an absorbing layer in a solar cell to improve the efficiency of photovoltaic devices. Also, the enhancement of the nonlinear parameters nominates them to be applied in different nonlinear optical and photonic applications. The emitted fluorescence spectra depended on the excitation wavelength and the kind of dopants.

Nano Zn0.75Cd0.25S and Zn0.65Cd0.25M0.1S (M = Co, Fe, Mn, V) doped 70%PVA/30%PVP polymer blends were formed. The synchrotron x-ray diffraction was employed to investigate the nature of the nanofiller. Rietveld analysis of x-ray diffraction data revealed a single ZnS phase for the nanofillers and confirmed the inclusion of the M-metal into the ZnS lattice. SEM images of PVA/PVP doped blends revealed uniform film morphology and nanofiller distribution. The highest transmittance (90%) was observed in the undoped blend at the visible region, and it decreased as the PVA/PVP doped with the nanofiller reached its minimum value (15%) as the blend doped with Zn0.75Cd0.25S (ZCS). The refractive index value of blended polymer changed in the order 0.750.25ZCS > ZCS/Co > ZCS/Mn > ZCS/V > ZCS/Fe > undoped blended polymer at 600 nm. The highest dielectric values were observed in PVA/PVP blend doped with ZSC/Mn or ZSC/Co. The nonlinear optical parameters reached their highest value in UV and visible regions as the blended polymer doped with ZSC/Mn and ZCS, respectively. The emitted colors of different blended polymers and their intensities were depended on the kind of nanofillers and the excitation wavelengths.

Objectives To estimate the current prevalence of bone marrow involvement in classical Hodgkin lymphoma (HL) patients diagnosed at King Khalid University Hospital (KKUH), Riyadh, Saudi Arabia. Methods A cross-sectional study was conducted among classical Hodgkin’s lymphoma patients, diagnosed between 2015 and 2021 at KKUH. We retrospectively collected clinical and pathological information from all adult patients aged 18 years or older with a diagnosis of HL. Survival analyses were performed using the log-rank test and Kaplan-Meier curves. Results The study included 140 patients, 60 (42.86%) of whom were female. Bone marrow involvement was seen in 15 (10.71%) patients, 58 (41.43%) patients had an advanced-stage disease, and 20 (14.29%) patients had gastrointestinal involvement. Patients with bone marrow involvement had a median survival of 71 months (95% confidence interval (CI): 16.7-125.3) compared to patients without bone marrow involvement who had a median survival of 68 months (95% CI: 50.7-85.3). Conclusion The prevalence of bone marrow involvement in HL patients, as well as the proportion of patients presenting with advanced disease at the time of diagnosis, was higher compared to Western data. This could be attributed to a delay in diagnosis or more aggressive disease biology.

(1-x)ZnMn2O4/xNiFe2O4 (x = 0, 0.05, 0.1, 0.15, 0.2) nanocomposite system was prepared using the sol–gel technique. Rietveld analysis revealed the presence of two phases ZnMn2O4 and NiFe2O4 for all composites, but with phase percentages different from nominated values of (x). The effect of alloying parameter (x) on the lattice parameters and crystallite size of the obtained phases was also examined. The oxidation states of different ions were determined using X-ray photoelectron spectroscopy (XPS) technique. For the prepared nanocomposite samples, the dependence of dielectric constant, impedance and electric modulus on the frequency and temperature was performed using complex impedance technique. It was found that the obtained samples have ferroelectric characteristics. The degree of correlation for the different nanocomposite samples was explored using ac conductivity.

Cu2ZnSnS4 (CZTS) nanoparticles were fabricated successfully using the hot injection method; CZTS films were deposited by spin coating of nanocrystal ink. The aim of this work is to study the effect of annealing parameters: temperature, time, ramping rate and atmosphere on CZTS thin film structure and optical properties. XRD, Raman Spectroscopy, SEM, EDX mapping are used to analyse the films and they demonstrate the increase in quality and improvement in the crystallinity of CZTS and the homogeneity of elements which is one of the important factors for CZTS thin film solar cells. The crystallinity, structure and chemical composition of CZTS thin films increased and improved under annealing in H2S+N2 atmosphere which demonstrated that annealing at 500 oC for 1 h with a ramping rate of 10 oC/min under H2S+N2 atmosphere is a suitable condition for the fabrication of CZTS thin films used in solar cell devices.

This work presents experimental investigations of the thermoelectric properties of p-type FeV0.64−xNbxHf0.16Ti0.2Sb half-Heusler alloys. Samples of the concerned system were prepared through sequent procedures starting with arc melting. Fine powders of the concerned samples were then obtained by mechanical alloying using two different ball milling regimes. Spark plasma sintering technique was employed for pressing the powders. The thermoelectric properties were studied as functions of temperature from 300 K to 800 K. Alloy scattering of phonons showed great contribution in the reduction of lattice thermal conductivity. High energy ball milled FeV0.39Nb0.25Hf0.16Ti0.2Sb sample possessed the lowest lattice thermal conductivity with a value of 1.81 Wm−1 K−1 at room temperature with a reduction of –82% compared with that of FeVSb. Additionally, the electrical conductivity was improved by the Nb doping leading to notable increase in the material’s power factor. As a result, a maximum power factor of 19.5 μW cm−1 K−2 was achieved at 800 K for Nb doped at x = 0.4 of the ball milled samples. The figure of merit was increased from 0.25 for FeV0.64Hf0.16Ti0.2Sb to 0.44 for FeV0.60Nb0.4Hf0.16Ti0.2Sb due to Nb doping. Which means that the figure of merit value is enhanced by –43%. The value was recorded at 725 K.

The heterostructure nanocomposites (1-x)ZnMn2O4/xZnFe2O4 (x = 0, 0.2, 0.5, 0.8, 1) are formed using the co-precipitation technique. X-ray diffraction and Fourier-transform infrared spectroscopy data disclosed the dissolving of some ions of one phase into the matrix of the other phase. Composite samples with x = 0.5 and 0.8 have an extra ZnO phase and its percentage increased with increased ZnFe2O4 (ZFO) amount in the matrix. The elements constituting the samples and the cations valence state are determined by X-ray photoelectron spectroscopy technique (XPS). The effect of composition parameter (x) on the absorbance spectra, extinction coefficient, refractive index, dielectric constant (real and imaginary), dielectric loss and optical conductivity is investigated by UV diffused reflectance technique. The optical band gap (Eg) of (1-x)ZMO/xZFO (x = 0.2, 0.5) nanocomposite samples was decreased to 2.4, 2.38 while the Eg of nanocomposite sample with x = 0.8 was increased to 2.54 eV. All nanocomposite samples have a normal dispersion similar to ZnMn2O4 (ZMO) sample. ZFO sample exhibited both normal and anomalous dispersion depended on the wavelength range. The 0.2ZMO/0.8ZFO nanocomposite sample exhibited a good nonlinear optical behavior at low frequency. The photoluminescence (PL) intensities of nanocomposite samples are quenched as ZMO alloyed with ZFO. Different emitted colors are observed as the ratio of ZMO and ZFO altered in the matrix.

Formamidinium lead bromide (FAPbBr3) thin films were prepared using two different solvents (N, N-Dimethylformamide, DMF and Methyl sulfoxide, MSO) with different ratios (1 DMF: 4 MSO and 4 DMF: 1 MSO) and different reaction times (4 h and 24 h). The effect of different solvents ratios and reaction time on the crystallinity and different phases percentage was examined using x-ray diffraction technique. Also, the influence on the transmittance, reflectance, absorbance coefficient, refractive index, extinction coefficient, real and imaginary parts of the dielectric constant and optical conductivity for FAPbBr3 thin films was explored using UV–vis spectrophotometer. All films showed interference, which verifies the high crystallinity of the films as confirmed from XRD data. The refractive index exhibited multi-oscillating peaks. The optical band gap energy for the FAPbBr3 perovskite thin films changed slightly either with varying the ratio between the solvents used in the preparation or the reaction time. FAPbBr3 thin films prepared with 1 DMF: 4 MSO are excellent nonlinear optical materials. FAPbBr3 perovskite thin films prepared with 1 DMF: 4 MSO exhibited the strong photoluminescence intensity and narrow full width at half maximum intensity.

This paper describes the factors that control elastic properties of organic shale, which is crucial for exploration and successful gas production from unconventional reservoirs. Mechanical and dynamic elastic properties are main shale characteristics that are not yet well understood as there have been a limited number of investigations involving organic rich shale samples. Synthetic shale core samples whose clay mineralogy, nonclay mineral content and Total Organic Carbon (TOC) content are known can be used to study variations of elastic parameters in a controlled experimental environment including in-situ stress conditions. More than 20 synthetic shale samples were created for our investigations under reservoir stress conditions with different mineral composition and TOC percentage. Ultrasonic transducers were used to measure body wave velocities, which were then used to calculate the elastic properties of different shale samples. The results demonstrate that P- and S-wave velocities vary with changing TOC under isotropic stress conditions. It is shown that the velocities of P-and S-waves are inversely proportional to TOC content. In addition, the increase in the TOC produced a decrease in density from approximately 2.4 g/cc to 2.15 g/cc and increase in porosity from approximately 16% to 20%.

Understanding the main factors that control elastic properties of organic shale is crucial for exploration and successful gas production from unconventional reservoirs. Mechanical and dynamic elastic properties are important shale characteristics that are not yet well understood as there have been a limited number of investigations involving organic rich shale samples. Synthetic shale core samples whose clay mineralogy, non-clay mineral content and Total Organic Carbon (TOC) content are known can be used to study variations of elastic parameters in a controlled experimental environment including in-situ stress conditions. A total of 17 synthetic shale samples with different mineral composition and TOC percentage were created for our investigations under isotropic stressed and unstressed conditions. Ultrasonic transducers were used to measure body wave velocities, which were then used to calculate the elastic properties of different shale samples. The results demonstrate that P- and S-wave velocities vary under isotropic stress conditions with respect to the TOC and clay mineral content. It is shown that isotropic stress significantly impacts velocity and the velocities of P- and S-waves are inversely proportional to TOC content. In addition, the increase in the TOC content reduced density and increased shale porosity. This study presents equations that allow us to estimate shale TOC content using compressional and shear wave velocities and density.

While the majority of natural gas is produced from conventional sources, there is significant growth from unconventional sources, including shale-gas reservoirs. To produce gas economically, candidate shale typically requires a range of characteristics, including a relatively high total organic carbon (TOC) content, and it must be gas mature. Mechanical and dynamic elastic properties are also important shale characteristics that are not well understood as there have been a limited number of investigations of well-preserved samples. In this study, the elastic properties of shale samples are determined by measuring wave velocities. An array of ultrasonic transducers are used to measure five independent wave velocities, which are used to calculate the elastic properties of the shale. The results indicated that for the shale examined in this research, P- and S-wave velocities vary depending on the isotropic stress conditions with respect to the fabric and TOC content. It was shown that the isotropic stress significantly impacts velocity. In addition, S-wave anisotropy was significantly affected by increasing stress anisotropy. Stress orientation, with respect to fabric orientation, was found to be an important influence on the degree of anisotropy of the dynamic elastic properties in the shale. Furthermore, the relationship between acoustic impedance (AI) and TOC was established for all the samples.