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In the present era of advanced technology, the surge for suitable multifunctional materials capable of operating above 300 °C has increased for the utilization of high-temperature piezoelectric devices. For this purpose, a pseudo-tetragonal phased CaBi4Ti3.98 (Nb0.5Fe0.5)0.02O15:xwt%MnO2 (CBTNF:xMn), with x = 0–0.20, ceramic system has been engineered for the investigation of structural, ferroelectric, dielectric and high-temperature-dependent piezoelectric properties. XRD analysis confirms that low-content Mn-ion insertion at the lattice sites of CBTNF does not distort the pseudo-tetragonal phase lattice of CBTNF:xMn ceramics, but enhances the functional behavior of the ceramic system, specifically at x = 0.15 wt%Mn. Compared to pure CBT and CBTNF ceramics, CBTNF:0.15Mn has demonstrated a highly dense relative density (~96%), a saturated polarization (PS) of 15.89 µC/cm2, a storage energy density (WST) of ~1.82 J/cm3, an energy-conversion efficiency (ƞ) of ~51% and an upgraded piezoelectric behavior (d33) of 27.1 pC/N at room temperature. Sharp temperature-dependent dielectric constant (εr) peaks display the solid ferroelectric behavior of the CBTNF:0.15Mn sample with a Curie temperature (TC) of 766 °C. The thermally stable piezoelectric performance of the CBTNF:0.15Mn ceramic was observed at 600 °C, with just a 0.8% d33 loss (25 pC/N). The achieved results signify that multi-valence Mn ions have effectively intercalated at the lattice sites of the pseudo-tetragonal phased CBTNF counterpart and enhanced the multifunctional properties of the ceramic system, proving it to be a durable contender for utilization in energy-storage applications and stable high-temperature piezoelectric applications.

This study communicates the structural, electronic, optical, and thermoelectric properties of a perovskite TlXF3 (X: Zn, Sr) crystal structure using first-principles calculations. Both compounds were found structurally as well as thermodynamically stable in cubic phase. To check the kinetic stability, the phonon frequancy band structure is calculated which indicates that there is no negative frequency in the phonon spectrum, which confirms the dynamic stability of TlXF3. The bandgaps of both compounds belong to insulating region. The TlSrF3 exhibits direct bandgap of 4.37 eV at X symmetry point while TlZnF3 possess indirect bandgap of 3.95 eV (M-X). Using HSE functional, the calculated electronic bandgaps of TlSrF3 and TlZnF3 are 5.74 eV(X-X) and 5.36 eV (M-X), respectively. The analysis of electronic states in band structure shows that for TlSrF3, the top of valence band is composed of the F-p states whereas the states in lower potion of conduction band are impacted by the significant contribution of Tl-p orbital states. In case of TlZnF3, the states near the valence band maxima and conduction band minima are coming mainly form Tl atom. The effect of spin–orbit coupling (SOC) on the electronic band structure is also considered. The SOC in the valance band is negligible, while in the conduction band it shows a dominant effect at Γ-point in both TlSrF3 and TlZnF3 compounds. The dependence of thermoelectric properties such as electrical conductivity σ, Seebeck coefficient (S), Power factor (PF), electronic thermal conductivity (κ) and figure-of-merit (ZT) as a function of carrier concentration and temperature are investigated. The optical properties were also studied to understand the response of TlXF3 to incident photons of energies upto 14 eV. We conclude that the TlXF3 are promising candidates for electronic, thermoelectric and optoelectronic devices.

The laser differential equations are used to transform them into identical coupled maps. Valuable results are deduced during analytical and numerical studies on cavity loss. Phase and spatiotemporal synchronized attractors are observed via quasi-chaos under a certain range of controlling parameters, and symmetry breaking of chaotic attractors due to collision with their basin boundaries, and transpire differently from the previous attractors. During the numerical simulation, it is found that the sequence of repeated strange attractors if the coupling strength further increases, which are orthogonal mirror images (the dynamics of the system is the same at different values of controlling parameters). Moreover, it can help us to predict future problems and their solutions based on current issues, if we develop this model in more general.

The C and N atomic doping and co-doping at all possible lattice sites in (STO) perovskite crystal structure have been investigated using density functional theory (DFT) calculations. Calculated formation energies indicate that C and N doping at O site in STO is more stable than at Sr site and Ti site. C incorporation at anion site significantly affects the electronic bandgap of STO by inducing spin-polarized defect states in bandgap region. Consequently transforming the non-magnetic STO to a magnetic with a magnetic moment of 2.0 per C atom and reduced the direct (indirect) bandgap 0.86 eV (0.18 eV) for spin-up (spin-down) channel, respectively. Further, with an increase of C atom concentration the magnetic moment of 2.0 per C atom remains constant, and also, half-metallicity is observed due to spin-down channel. Similarly, N atom substitution at anion site in STO crystal structure induces magnetism of 1.0 . N causes defect states due to which the bandgap of the spin-up channel decreased to 1.68 eV and shows half-metallicity due to the spin-down channel. We found that further increasing the N atom concentration enhanced the half-metallicity by increasing the number of states of the spin-down channel at Fermi energy. Finally, we studied the FM and AFM alignment of the magnetic moments at the dopants C, N and their co-doping in STO with different distances. We found that the C atom prefers AFM states, while the N atom prefers FM states. The calculated Curie temperature for two N atoms at near and far dopants is 722.16 K and 860.91 K, respectively. The results of tailored electronic and magnetic properties above room temperature are interesting from a theoretical perspective and may open opportunities for STO in electronic and spintronic devices.

Using first-principles calculations, the effects of Yb

Combination of heavy elements in forming a stable system leads to enhancement in effective atomic number making it desirable in many applications such as detection and shielding of radiation. We present our theoretical investigations on new Thallium based heavy fluoroperovskites TlAF3 (A = Ge, Sn and Pb). The study is carried out to explore the structural, elastic, electronic, and optical properties through the Density Functional Theory (DFT) using the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method implemented in WIEN2k. Generalized Gradient Approximation with consideration of electronic correlation effects (GGA+U) was employed for calculations. The lattice constants deduced from the optimization curves were found to be in the range of 4.00 Å to 4.85 Å. Elastic properties were obtained from the calculated elastic constants. From band structure calculations, it is evident that the bandgaps range from 0.84 to 1.89 eV. All the studied compounds exhibit indirect bandgap nature. Fluorine atom contributes significant number of electronic states in valence and conduction bands of all studied compounds. The optical response in terms of refractive index, extinction coefficient, optical conductivity, reflectivity, and absorption coefficients are calculated and discussed in the energy range of (0-20) eV. The properties of compounds in this study are being reported for the first time.

We present our work on the structural, electronic and magnetic properties of monolayer-CdS which was subjected to bi-axial strain and hydrogenation at possible adsorption sites using the first-principles calculations. The results show that both bulk-CdS and monolayer-CdS are non-magnetic direct (Γ − Γ) band-gap semiconductors. By applying a compressive strain up to −10% the monolayer-CdS remain direct band-gap semiconductor with a maximum band gap value of 2.11 eV. In contrast, a semiconductor to metal transition occurred at 17% applied tensile strain. Moreover, hydrogenation on all possible adsorption sites induces ferromagnetism and p-type conductivity in monolayer-CdS. Among all possible adsorption sites, H added on the Cd-top site is the most probable site showing strong ferromagnetism and half-metallicity. The strong ferromagnetism means 100% spin polarization is retained up to applied bi-axial strain of −5% to +15%. Also, half-metallicity is robust under the bi-axial strain in the range of −4% to +2%. To determine the strength of the exchange-coupling parameter, the FM (ferromagnetic) and AFM (anti-ferromagnetic) coupling between added atoms was investigated under the bi-axial strain of −5% to + 5%. Our findings show that H added on the Cd-top site makes it ferromagnetic and half-metallic above room temperature. The maximum Curie temperature Tc = 651.41 K is achieved at a strain of ɛ = −2% of ferromagnetic state. This high Curie temperature has not been achieved for any 2D material to-date. The present work provides a route to harness the ferromagnetism and thermal stability of 2D monolayer-CdS for electronic and spintronic applications.

Using first-principles calculations based on density functional theory (DFT) with generalized gradient approximation (GGA), the electronic and thermoelectric properties of KCaF3 are calculated. The electronic structure calculated with GGA shows that KCaF3 is an insulator. The thermoelectric properties of KCaF3 are computed as a function of chemical potential μ and charge carrier concentrations (1018–1022 cm−3). Both hole and electron doping decrease the absolute value of Seebeck coefficient. The calculated power factor shows that p-type KCaF3 has a larger power factor at the optimized charge carriers. The maximum figure of merit (ZT) occurs around 1021 cm−3 hole carrier concentrations and the largest value of ZT ∼0.7 is achieved at 800 K. When KCaF3 is doped with electron, the maximum ZT occurs around 1020 cm−3 and the largest value of ZT at 800 K is about 0.4. Hence, high ZT in KCaF3 is possible at high hole carrier concentrations as compared with electron carrier concentrations. Compared with n-type KCaF3, p-type KCaF3 has good thermoelectric properties, which are attributed to larger effective mass and low thermal conductivity of holes.

Bubble detection and tracking, which is essential for the enhancement of gas–liquid two-phase flow applications, is difficult due to optical noise surrounding bubble boundaries. Two-phase flow applications involving unconventional wavy channels further complicate these tasks by introducing non-linearity. In this work, the authors apply a path-based approach to transform a sinusoidal channel into a straightened horizontal channel for bubble detection and tracking. Segmented morphological operations are applied to the linear channel to identify each bubble as a single entity and to eliminate noise caused due to illumination conditions. The bubbles are detected through blob analysis and are associated across different frames based on motion, estimated by Kalman filter in both sinusoidal and path-based approach to the sinusoidal channel. The results show that the proposed path-based straightened channel gives more accurate results for the benchmark parameters of bubble count and bubble velocities than the sinusoidal channel with a percentage error reduction of 31.61% for bubble count and 27.36% for velocity.

Controlling oxygen vacancy in undoped SrTiO3 was used to realize the phonon-glass electron-crystal (PGEC) concept. The undoped SrTiO3 samples were synthesized through solid-state-reaction method in air and then reduced through annealing under low oxygen partial pressure conditions. We show that decreasing the oxygen partial pressure (Po2) results in increase of the electrical conductivity, and the oxygen vacancies act as phonon scattering centers, which lead to decrease in the lattice thermal conductivity. Both the enhanced electrical conductivity (σ) and reduced thermal conductivity (κ) were achieved simultaneously through oxygen vacancy in undoped SrTiO3. This significantly increases the ratio of σ/κ that results in an enormously enhanced ZT value of about 13 times larger as compared with the samples reduced under relatively high Po2. Density-functional theory calculations also reveal that oxygen vacancies in SrTiO3 reduce the band-gap, and consequently increase the electrical conductivity.

Using first-principles calculations, functionalization of the monolayer-GaS crystal structure through N or Cr-doping at all possible lattice sites has been investigated. Our results show that pristine monolayer-GaS is an indirect-bandgap, non-magnetic semiconductor. The bandgap can be tuned and a magnetic moment (MM) can be induced by the introduction of N or Cr atomic anion/cation doping in monolayer GaS. For instance, the intrinsic character of monolayer GaS can be changed by substitution of N for the S-site to p-type, while substitution of Cr at the S-site or Ga-site induces half-metallicity at sufficiently high concentrations. The defect states are located in the electronic bandgap region of the GaS monolayer. These findings help to extend the application of monolayer-GaS structures in nano-electronics and spintronics. Since the S-sites at the surface are more easily accessible to doping in experiment, we chose the S-site for further investigations. Finally, we perform calculations with ferromagnetic (FM) and antiferromagnetic (AFM) alignment of the MMs at the dopants. For pairs of impurities of the same species at low concentrations we find Cr atoms to prefer the FM state, while N atoms prefer the AFM state, both for impurities on opposite surfaces of the GaS monolayer and for impurities sharing a common Ga neighbor sitting at the same surface. Extending our study to higher concentrations of Cr atoms, we find that clusters of four Cr atoms prefer AFM coupling, whereas the FM coupling is retained for Cr atoms at larger distance arranged on a honeycomb lattice. For the latter arrangement, we estimate the FM Curie temperatureTCto be 241 K. We conclude that the Cr-doped monolayer-GaS crystal structure offers enhanced electronic and magnetic properties and is an appealing candidate for spintronic devices operating close to room temperature.

Contamination of water with organic dyes is a major environmental concern as it causes serious life-threatening environmental problems. The present research was designed to evaluate the potential of three different natural inorganic clays (NICs) i.e., Pakistani bentonite clay (PB), bentonite purchased from Alfa Aesar (BT), and Turkish red mud (RM) for malachite green (MG) dye removal from an aqueous solution. Various analytical techniques, namely X-ray fluorescence spectrometry (XRF), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), Brunauer–Emmett–Teller surface area measurement (BET), and thermogravimetric analysis (TGA), were used to investigate the physicochemical properties of the NICs samples. The effect of adsorption operational parameters such as contact time, aqueous phase pH, dye concentration, and amount of NICs on the adsorption behavior of MG onto NICs samples were investigated under the batch adsorption system. The equilibrium and kinetic inspection reflected the best description of MG adsorption behavior by the Langmuir isotherm model and pseudo-first-order kinetic model, respectively. The results indicated that the adsorption was favorable at higher pH. The maximum adsorption capacities calculated by Langmuir isotherm for PB, BT, and RM were found to be 243.90 mg/g, 188.68 mg/g, and 172.41 mg/g, respectively. It can be concluded that natural inorganic clays with a higher surface area can be used as an effective adsorbent material to remove the MG dye from an aqueous solution.

A first-principles theoretical study of the enhanced electronic and magnetic properties of a single-layer CdS (denoted as SL-CdS) was conducted via Li substitutional doping at possible sites. Previous work shows that SL-CdS is a non-magnetic and direct bandgap semiconductor. Our work demonstrated that electronic bandgap tuned to smaller and larger values, e.g., the calculated bandgap (pseudo bandgap) for LiCd (Lih) are 1.80 eV and 1.62 eV, respectively. Local magnetic moment induced via Li atomic doping at possible dopants sites except for Lih. The LiCd gives a maximum magnetic moment of 0.98 μB and shows the half-metallic character with a small dispersion for the spin-down channel at the Γ point. Among all the possible sites, the LiCd in SL-CdS is magnetic and being most favorable thermodynamically under both S-rich and Cd-rich conditions. The LiCd in SL-CdS indicates spin polarization with increased bandgap for spin-up and spin-down channels. In contrast, the LiS induces a magnetic moment of 0.86 μB with a reduced bandgap of 0.60 eV for both the spin-up and spin-down channels. The partial magnetic moment is due to the fact small concentration of the dopant. Interestingly, Lih in SL-CdS shows non-magnetic semiconducting nature with decreased bandgap. For further investigation, we considered the most favorable Cd-Site. For room-temperature ferromagnetism, we did ferromagnetic and anti-ferromagnetic calculations. We considered interactions between two Li atoms substituted at far positions (1, 2) and near positions (1, 3) in SL-CdS. It was found that 2LiCd in SL-CdS at near positions (1, 3) has FM order with Curie temperature (Tc) of 339.95 K at − 5% compressive biaxial strain. The effect of Li doping on electronic and magnetic properties of SL-CdS can help to utilize SL-CdS materials in electronics and spintronics devices applications.

Herein, using first-principles calculations, we studied the electronic and thermoelectric properties of isolated perovskites CaTiO3, CaZrO3 and double perovskite Ca2ZrTiO6 crystal structure under ambient conditions, biaxial compression, and biaxial tensile strain. We used generalized gradient approximation and the Hubbard parameter (GGA ​+ ​U) to calculate exchange and correlation interactions. The isolated perovskite CaTiO3 and CaZrO3 are indirect bandgap (Γ ​− ​R) semiconductors of values 1.90 ​eV, 3.2 ​eV, respectively. The construction of a double perovskite Ca2ZrTiO6 results in a direct (Γ ​− ​Γ) bandgap semiconductor material. The bandgap values under 2% & 5% biaxial tensile strain and compressive strain are in the range of 2.3 ​eV and 2.2 ​eV. We studied the thermoelectric properties by taking the two chemical potential values (μ) equal to CBM and VBM, respectively. The thermoelectric properties of Ca2ZrTiO6 under 2% & 5% biaxial tensile strain were improved at CBM, while thermoelectric properties under 2% & 5% biaxial compression strain were enhanced at VBM as compared to thermoelectric properties under ambient conditions. At CBM, the maximum value of the figure of merit (ZT) is about 4.4 ​at 500 ​K, required for the next generation of the thermoelectric device. The ZT value shows that the novel double perovskite is a very suitable candidate for thermoelectric devices.

Using first-principles calculations, the effects of Yb2+ substitutional doping on structural, electronic, and optical properties of a series of perovskite compounds CsCaX 3 (X: Cl, Br, I), have been investigated. We employed generalized gradient approximation (GGA) and HSE hybrid functional to study the electronic and optical properties. A series of pristine CsCaX 3 (X: Cl, Br, I) is characterized as a non-magnetic insulator with indirect bandgap perovskite materials. These phosphor materials are suitable candidates for doping with lanthanide series elements to tune their electronic bandgaps according to our requirements because of their wide bandgaps. The calculated electronic bandgaps of CsCaX 3 (X: Cl, Br, I) are 3.7 eV (GGA) and 4.5 eV (HSE) for CsCaI3, 4.5 eV (GGA) and 5.3 eV (HSE) for CsCaBr3, and 5.4 eV (GGA) and 6.4 eV (HSE) for CsCaCl3. According to formation energies, the Yb2+ doped at the Ca-site is thermodynamically more stable as compared to all possible atomic sites. The electronic band structures show that the Yb2+ doping induces defective states within the bandgaps of pristine CsCaX 3 (X: Cl, Br, I). As a result, the Yb2+ doped CsCaX 3 (X: Cl, Br, I) become the direct bandgap semiconductors. The defective states above the valence band maximum are produced due to the f-orbital of the Yb atom. The impurity states near the conduction band minimum are induced due to the major contribution of d-orbital of the Yb atom and the minor contribution of s-orbital of the Cs atom. The real and imaginary parts of the dielectric function, optical reflectivity, electron energy loss spectrum, extinction coefficient, and refractive index of pristine and Yb2+ doped CsCaX 3 (X: Cl, Br, I) were studied. The optical dispersion results of dielectric susceptibility closely match their relevant electronic structure and align with previously reported theoretical and experimental data. We conclude that the Yb2+ doped CsCaX 3 (X: Cl, Br, I) are appealing candidates for optoelectronic devices.

Two distinct-phenomena were reported for anodic elemental-incorporation; structural-doping/heterostructure formation. Herein, by adding V for the first time in TiO2-nanotubes via anodization; the foreign elemental incorporation is peered. The bandgap (3.2 eV), flat band (0.07 VRHE) and valence band (VB) positions of V-incorporated anatase-TiO2 nanotubes remained invariant which ruled out structural doping of TiO2. The first-step in anodization is Ti-oxidation that occurs momentarily; thereby, the oxidation/dissolution dominancy of anodization in later stages impeded V-structural doping even for varying times (1–24 h) and voltages (6–60 V) and thus a small fraction of V2O5 was observed in surface and microscopic studies. Density functional theory realistic simulations revealed TiO2/V2O5 forms commensurate-heterostructure at common lattice constants with charge transfer from TiO2 to V2O5 at the heterostructure interface; exhibiting type-II band-alignment having CB from V2O5 and VB from TiO2 with decreasing bandgap. In photoelectrochemical-setup, the photogenerated electron transfer from V2O5 to the heterostructure interface was suppressed due to barrier-height which decreased photocurrent for TiO2/V2O5 (52 µA/cm2) as compared to pure-TiO2 (140 µA/cm2) at ~1.0 VRHE. Contrarily, in photolysis, improved light absorption and facile carrier migration from TiO2/V2O5 resulted in better photodegradation activity of methylene-blue. We unlocked anodization is ineffective for structural-doping, indeed it results in uniform low-content elemental incorporation forming oxides heterostructure.

Thermoelectric properties of cubic (C) and tetragonal (T) BaTiO 3 (BTO) and PbTiO 3 (PTO) are investigated using density functional theory together with semiclassical Boltzmann's transport theory. Both electron and hole doped BTO and PTO are considered in 300–500 K temperature range. We observed that C-BTO has larger power factor( PF ) when doped with holes, whereas n-type carrier concentration in C-PTO has larger PF . Comparing both BTO and PTO, C-PTO has larger figure of merit ZT . Tetragonal distortion reduces the Seebeck coefficient S in n-doped PTO, and the electronic structures revealed that such reduction in S is mainly caused by the increase in the optical band gaps ( Γ − Γ and Γ-X).

Here, in this manuscript, we studied the structural, electronic, and thermoelectric properties of Pb doped thallium antimony telluride crystal structure both experimentally and theoretically. Lead (Pb) doped thallium antimony telluride with different concentration (x) have been prepared by solid state reaction method and Ball milling technique. X-Ray Diffraction reveals that the crystal structure of Tl8.33Sb1.67−xPbxTe6 nano-structured compounds are iso-structural with Tl4SbTe3 compound. We showed that increasing the Pb concentrations results in an increase of the electrical conductivity and Seebeck coefficient, and is also confirmed by Density-Functional Theory (DFT) calculations. The power factor (PF = S2σ) enhanced by a larger factor as compared to the enhancement of the electronic thermal conductivity that was achieved simultaneously through Pb doping in thallium antimony telluride nano-compounds. This significantly increases the ratio of PF/κ that results in an enormously enhanced figure-of-merit (ZT) value from 0.19 to 0.46 at T = 560 K. DFT calculations also show the enhancement in S due to the reduction in density of states (DOS) at Fermi energy. The highest ZT = 0.46(0.22) was recorded for Pb doped thallium antimony telluride compound experimentally (theoretically). These results indicate a route to harness the thermoelectric properties of thallium antimony telluride based materials for electronic and thermoelectric applications.

Aflatoxin M1 (AFM1) is a metabolite of aflatoxin B1 (AFB1) and secreted in milk of animals that are kept on a moldy diet. AFB1 is produced by several toxigenic species of fungi. In this study, the comparative efficacy of two mycotoxin binders was evaluated in terms of reducing excretion of AFM1, total viable bacterial count and somatic cell count in milk obtained from goats fed with AFB1 contaminated diet. A total of 32 lactating Beetal goats were reared and divided into 4 equal groups: Animals of group A were kept as control, while those in groups B, C, and D were individually fed with AFB1 at 40 µg alone, 40 µg AFB1 along with mycotoxin binder Toxfin® at 3 g kg−1 of cotton seed cake, and 40 µg AFB1 along with mycotoxin binder Elitox® at a dose rate of 1 g kg−1 of cotton seed cake, respectively. Toxfin® significantly decreased the excretion of AFM1 in goats’ milk by 49.57 % while Elitox® non-significantly reduced the excretion of AFM1 in goats’ milk by 19.49 %. Total viable bacterial count in milk samples of group C and D, and somatic cell count in milk samples of group C did not reduce significantly. However, somatic cell count in milk samples of group D reduced significantly. We conclude that the addition of Toxfin® in the moldy diet significantly reduce the excretion of AFM1 in animals’ milk and minimize the risk of mycotoxin toxicity to public health.

Herein, monolayer-CdS substitutional elemental doping with metal (X; Fe) and non-metal (X; H, N, F) atoms has been investigated by the first-principle calculations. In non-magnetic monolayer-CdS, magnetism can be induced by metal and non-metal atom substitution at possible dopant sites except for F S (F doped at the chalcogen site). In particular, Fe doping at Cd-Site ( Fe Cd ) results in a maximum magnetic moment of 4.0 μ B , and half-metallic character with a small dispersion at Γ point. Among all the substitutional dopants at the hole-site, F h is ferromagnetic, being most energetically favorable under both atomic and molecular phases. The H h in monolayer-CdS retained the semiconducting nature with reduced band gaps for spin-up and spin-down channels. N h exhibits half-metallic character with a small dispersion of 0.13 eV at K- Γ point. The F h and Fe h show metallic behavior. To determine the exchange-field strength ferromagnetic (FM) and anti-ferromagnetic (AFM) coupling between the two dopants at far positions (1, 3) and near positions (1, 2) have been considered. The effect of dopants concentration on FM and AFM coupling were also investigated. It was found N S ( Θ = 4 % ) at near positions (1, 2) shows FM state with Curie temperature ( T c ) of 106 K. As the biaxial strain of -5 % is applied the maximum FM state was achieved with T c of 164 K. The functionalization of monolayer-CdS with the proposed elements provided in this work can help tailoring two-dimensional (2D) materials applied in spintronics and electronics devices.

Here, the structure-dependent electronic, thermal, and transport properties of nanostructured thallium telluride (Tl8Pb x Sb2−x Te6) through controlled variation in Pb and Sb (x = 1.96, 1.97, 1.98, 1.99) concentrations have been investigated. In the temperature and concentration-dependent electrical conductivity measurements, the highest electrical conductivity 131.96 × 103 Ω − 1 m − 1 at 300 K was measured for x = 1.99 and the maximum observed Seebeck value for the optimized Tl8Pb1.96Sb0.04Te6 nanoparticles was 110.7 μV/K at 550 K. Such an increased value of the Seebeck coefficient led to the achievement of a significantly improved high-power factor, which was found to be increasing with temperature and decreasing with the increase of Pb concentration. The density functional theory calculations performed for Pb and Sb co-doped Tl5Te3 resulted in the enhanced σ e and S with a significant reduction in electronic thermal conductivity (κ e ) and is found consistent with experimentally measured κ e . The highest ZT = 0.35 and 0.18 were recorded experimentally and theoretically for Pb and Sb co-doped in Tl5Te3 nanoparticles.

Every individual in his/her life experiences cervical pain at some stage which may restrict daily activities. Various approaches are available for the management of cervical pain, which include surgical, pharmacological and physical therapy. Different Manual therapy techniques are used for the treatment of neck pain. Muscle energy techniques and active isolated stretching are under consideration. This case series study was conducted at physical therapy department of North West General Hospital, Peshawar from August 2015 to January 2016 to find out the effectiveness of muscles energy techniques on cervical range of motion and pain. A total of 20 patients suffering neck pain, both genders having age of 25 - 50 years, cervical ROM limitation and muscles spasm were included in the study. Patients were treated by muscles energy technique (MET). The patient's outcome measures were Inclinometer and Visual Analogue Scale (VAS). Data was analyzed using SPSS version 20. The mean age was 32.3±6.53 years. The patient treated with muscles energy technique showed clinically improvement in the range of motion and pain. Results showed that pre and post treatment differences were statistically significant for cervical flexion (0.001), cervical extension (0.001), cervical right side rotation (0.001), cervical left side rotation (0.001), cervical right side bending (0.001), and cervical left side bending (0.01). Paired t-test finding for the pain showed statistically significant difference (0.005). It was concluded that Muscles Energy Technique is effective in the treatment of restricted range of motion and cervical pain.

The structural, electronic, and magnetic properties of two-dimensional (2D) GaS are investigated using density functional theory (DFT). After confirming that the pristine 2D GaS is a non-magnetic, indirect band gap semiconductor, we consider N and F as substitutional dopants or adsorbed atoms. Except for N substituting for Ga (NGa), all considered cases are found to possess a magnetic moment. Fluorine, both in its atomic and molecular form, undergoes a highly exothermic reaction with GaS. Its site preference (FS or FGa) as substitutional dopant depends on Ga-rich or S-rich conditions. Both for FGa and F adsorption at the Ga site, a strong F-Ga bond is formed, resulting in broken bonds within the GaS monolayer. As a result, FGa induces p-type conductivity in GaS, whereas FS induces a dispersive, partly occupied impurity band about 0.5 e below the conduction band edge of GaS. Substitutional doping with N at both the S and the Ga site is exothermic when using N atoms, whereas only the more favourable site under the prevailing conditions can be accessed by the less reactive N2 molecules. While NGa induces a deep level occupied by one electron at 0.5 eV above the valence band, non-magnetic NS impurities in sufficiently high concentrations modify the band structure such that a direct transition between N-induced states becomes possible. This effect can be exploited to render monolayer GaS a direct-band gap semiconductor for optoelectronic applications. Moreover, functionalization by N or F adsorption on GaS leads to in-gap states with characteristic transition energies that can be used to tune light absorption and emission. These results suggest that GaS is a good candidate for design and construction of 2D optoelectronic and spintronics devices. © 2018 IOP Publishing Ltd.