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Abstract Core body temperature (CBT) regulation is crucial for mammalian wellbeing and survival. Cattle pant to dissipate excess heat to regulate CBT when ambient conditions exceed thermoneutral zones. However, to date, neither the variability in cattle heat response, the lagged response of CBT to thermal indices, nor the diurnal patterns of thermal indices, CBT and panting have been reported in the literature. We decomposed thermal indices, CBT and panting time-series data for 99 feedlot heifers across three discrete heat events into diurnal, trend and residual components. Both raw and decomposed data were analysed to explore the lagged CBT and panting responses and the association between series. We show ambient thermal conditions impact CBT with a 1-h lag despite a lag of between 1.5 to 3 h from raw data. Average individual panting scores were used to identify heat-susceptible and heat-tolerant cattle. Heat-susceptible cattle showed greater CBT (P

The lowering of the groundwater table caused by increased groundwater use in the dry, Barind region has prompted sustainability concerns. In this study, water-table (WT) scenarios were simulated by the MODFLOW model under different crop rotations in Barind, a dry region of Bangladesh, to examine the effects of crop rotations on groundwater level. The studied crop rotations and recharge conditions were: with existing cropping pattern; 100, 30 and 50% of present Boro rice is replaced by Aus rice; existing cropping pattern, but with reduced recharge to 90 and 80% of present recharge. A calibrated MODFLOW model was used to develop WT scenarios. According to the modeling results, the declination of WT will be lessened and the situation with regard to WT will therefore be improved with the gradual substitution of Boro by Aus and Rabi (30, 50 and 100%). The simulated WT scenario will be useful for policymakers to set policies about cropping patterns or groundwater withdrawal amounts targeting the area's long-term sustainability of groundwater. HIGHLIGHTS Sustainable agricultural production in the Barind area is under threat due to unsustainable groundwater use.; A calibrated MODFLOW model was used to predict the water-table (WT) under different cropping patterns.; With the gradual substitution of Boro rice by Aus rice (e.g. 30%, 50%, and 100%), the situation for WT will be improved.; The simulated WT scenario will therefore be useful for the policymakers.;

Recently, inorganic perovskite materials have been attracting increasing attention owing to their exceptional structural, electronic, and optical characteristics in photovoltaic technology. Ca3AsI3 is a semiconductor material that shares similarities with the group of inorganic metal halide perovskites. Ca3AsI3 possesses a perovskite crystal structure that is cubic, which is classified under the space group Pm-3m (no. 221). Our research aims to analyze how the optical and electronic properties of Ca3AsI3 are influenced by spin–orbit coupling (SOC) and strain using the first-principles density-functional theory. The inorganic Ca3AsI3 perovskite has an electronic band structure that possesses a direct bandgap of roughly 1.58 eV at the Γ(gamma)-point. However, when the SOC relativistic effect is introduced, this value decreases to around 1.27 eV. As the level of compressive strain is increased, the bandgap becomes narrower, whereas with increasing tensile strain, the bandgap becomes wider. It has been observed through analysis of the dielectric functions, absorption coefficient, and electron loss function of these materials that the optical properties give Ca3AsI3 the ability to effectively absorb visible light. According to the study, the dielectric constant peaks of Ca3AsI3 shift toward a lower photon energy (redshift) as the level of compressive strain increases. On the other hand, when subjected to increased tensile strain, these peaks have a tendency to shift toward a higher photon energy (blueshift), as per the same study. Modifying the energy gap of Ca3AsI3 perovskites to suit optoelectronic and solar cell needs could be achieved by using techniques involving the SOC effect and by applying strain. These approaches have the potential to enable utilization of Ca3AsI3 in such applications in the future.

Dengue is one of the major health problems in Bangladesh and many people are died in recent years due to the severity of this disease. Therefore, in this paper, a SIRS model for the human and SI model for vector population with saturated incidence rate and constant treatment function has been presented to describe the transmission of dengue. The equilibrium points and the basic reproduction number have been computed. The conditions which lead the disease free equilibrium and the endemic equilibrium have been determined. The local stability for the equilibrium points has been established based on the eigenvalues of the Jacobian matrix and the global stability has been analyzed by using the Lyapunov function theory. It is found that the stability of equilibrium points can be controlled by the reproduction number. In order to calculate the infection rate, data for infected human populations have been collected from several health institutions of Bangladesh. Numerical simulations of various compartments have been generated using MATLAB to investigate the influence of the key parameters for the transmission of the disease and to support the analytical results. The effect of treatment function over the infected compartment has been illustrated. The sensitivity of the reproduction number concerning the parameters of the model has been analyzed. Finally, the most sensitive parameter that has the highest effect over reproduction number has been identified.

Controlling the defect in the perovskite absorber layer is a very crucial issue for developing highly efficient and stable perovskite solar cells (PSCs) as it exhibits the existence of unavoidable defects even after the careful fabrication process. In this study, the presence of defects in the perovskite layer has been evaluated through the analysis of its structural and optical properties. Then the investigations on the impact of defect density on perovskite absorber layer and its associated solar cell parameters have been carried out by numerical simulation utilizing SCAPS-1D software. Besides the defect density, the thickness of the absorber layer has also been varied to find optimum values of cell parameters. It has been found that when the thickness of absorber and shallow defect density is increased from 200 nm to 800 nm and 1 × 1013 cm-3 to 1 × 1018 cm-3 respectively, power conversion efficiency (PCE) is varied from 26.7% to 0.90%. However, when the thickness and deep defect density are raised from 200 nm to 800 nm and 1 × 1013 cm-3 to 1 × 1016 cm-3, respectively, the PCE is varied from 19.3% to 6.15%. It is revealed that optimum absorber thickness is 550 nm and the tolerances of shallow level and deep level defect density are 1 × 1017 cm-3 and 1 × 1015 cm-3, respectively.

Eco-friendly inorganic halide perovskite materials with numerous structural configurations and compositions are now in the leading place of researcher’s attention for outstanding photovoltaic and optoelectronic performance. In the present approach, density functional theory calculations have been performed to explore the structural, mechanical, electronic, and optical properties of perovskite-type CsGeCl3 under various hydrostatic pressures, up to 10 GPa. The result shows that the optical absorption and conductivity are directed toward the low-energy region (red shift) remarkably with increasing pressure. The analysis of mechanical properties certifies that CsGeCl3 has ductile entity and the ductile manner has increasing affinity with applied pressure. The decreasing affinity of the bandgap is also perceived with applied pressure, which notifies that the performance of the optoelectronic device can be tuned and developed under pressure.

All-inorganic cubic cesium germanium bromide (CsGeBr3) and cesium tin bromide (CsSnBr3) perovskites have attracted much attention because of their outstanding optoelectronic properties that lead to many modern technological applications. During their evolution process, it can be helpful to decipher the pressure dependence of structural, optical, electronic, and mechanical properties of CsXBr3 (X = Ge/Sn) based on ab initio simulations. The lattice parameter and unit cell volume have been decreased by applying pressure. This study reveals that the absorption peak of CsXBr3 (X = Ge/Sn) perovskites is radically changed toward the lower photon energy region with the applied pressure. In addition, the conductivity, reflectivity, and dielectric constant have an increasing tendency under pressure. The study of electronic properties suggested that CsXBr3 (X = Ge/Sn) perovskites have a direct energy bandgap. It is also found through the study of mechanical properties that CsXBr3 (X = Ge/Sn) perovskites are ductile under ambient conditions and their ductility has been significantly improved with pressure. The analysis of bulk modulus, shear modulus, and Young’s modulus reveals that hardness of CsXBr3 (X = Ge/Sn) perovskites has been enhanced under external pressure. These outcomes suggest that pressure has a significant effect on the physical properties of CsXBr3 (X = Ge/Sn) perovskites that might be promising for photonic applications.

This paper reports on the structural and magnetic properties of a ball-milled powder sample of (Fe1−xMnx)75P15C10 (x = 0, 0.05, 0.1, 0.2, and 0.3) mixed metallic amorphous ribbons. X-ray diffraction patterns of the as-made powder samples demonstrate a structural phase transition from amorphous to the nanocrystalline structure having a tetragonal (P) type structure. Field emission scanning electron microscopic micrographs show that the particles form a nanocrystalline structure presumably due to the stress relaxation upon ball milling the amorphous ribbons. The observed phase transformation and the changed magnetic properties, e.g., significant enhancement in the coercive field leading to magnetic hardness, are attributed to the controlled milling and Mn substitution in this mixed metallic alloy system, which is the novelty of this research work.

The polycrystalline perovskite La0.7Ca0.2Pb0.1CoO3 has been prepared by the conventional solid-state reaction technique, and then the structural, magnetic, magnetocaloric, and dielectric properties of the sample have been investigated. The monoclinic structure with space group I2/a of the sample is confirmed by X-ray diffraction investigation at room temperature. The microstructure was examined by scanning electron microscopy (SEM), and chemical composition was determined using an energy dispersive X-ray diffractometer attached to the SEM. Magnetic measurement reveals that the sample undergoes ferromagnetic to paramagnetic transition with increasing temperature and behaves as a soft magnetic material. Field cooled and zero-field cooled dc magnetization curves at low field and low temperature show divergence, indicating the coexistence of antiferromagnetic and ferro-magnetic clusters in the sample. Magnetic inhomogeneity of the sample has also been clearly confirmed by the divergence between the Curie temperature, Tc, and the paramagnetic Curie temperature, θ. The sample also shows a magnetocaloric effect at a very low field (H = 0.01 T). The high negative value of the real part of complex permittivity, ε′, reveals metallic behavior of the sample at low frequency around room temperature. However, the frequency dependent ac conductivity (σ) exhibits three distinct bands, namely, the metallic, insulating, and anomalous band, around room temperature. Temperature dependent ε′ reveals that the sample undergoes insulator to metallic transition above −20 °C.

Recent achievements, based on lead (Pb) halide perovskites, have prompted comprehensive research on low-cost photovoltaics, in order to avoid the major challenges that arise in this respect: Stability and toxicity. In this study, device modelling of lead (Pb)-free perovskite solar cells has been carried out considering methyl ammonium tin bromide (CH3NH3SnBr3) as perovskite absorber layer. The perovskite structure has been justified theoretically by Goldschmidt tolerance factor and the octahedral factor. Numerical modelling tools were used to investigate the effects of amphoteric defect and interface defect states on the photovoltaic parameters of CH3NH3SnBr3-based perovskite solar cell. The study identifies the density of defect tolerance in the absorber layer, and that both the interfaces are 1015 cm−3, and 1014 cm−3, respectively. Furthermore, the simulation evaluates the influences of metal work function, uniform donor density in the electron transport layer and the impact of series resistance on the photovoltaic parameters of proposed n-TiO2/i-CH3NH3SnBr3/p-NiO solar cell. Considering all the optimization parameters, CH3NH3SnBr3-based perovskite solar cell exhibits the highest efficiency of 21.66% with the Voc of 0.80 V, Jsc of 31.88 mA/cm2 and Fill Factor of 84.89%. These results divulge the development of environmentally friendly methyl ammonium tin bromide perovskite solar cell.

Objective The experiments were carried out to measure the effect of multivitamin, acidifier and Azolla on growth performance, profitability and lipid profiles of blood of broiler chickens to produce safe and cost effective broilers. Methods In experiment 1, 240 day-old Cobb-500 broiler chicks were fed diets; D1 (control), D2 (D1 with 1 mL multivitamin/liter water), D3 (D1 with 1 mL acidifier/liter water), D4 (D1 with 1 mL multivitamin and 2 mL acidifier/liter water) having 3 replications in each, and 20 chicks/replication. In experiment 2, 150 day-old Cobb-500 broiler chicks were fed diets; T1 (control), T2 (5% Azolla in the diet), T3 (7% Azolla in the diet) and T4 (T1 with 1 mL multivitamin and 1 mL acidifier/liter water) having 3 replications in each, and 20 chicks/replication in control, and 10 chicks/replication in the remaining dietary treatment groups for 35 days. Results In experiment 1, the highest live weight was observed in D4 (p0.05). The lowest feed conversion ratio (FCR) (p0.05). However, evidently but not significantly, the highest net profit was obtained in D2 followed by D4, D1, and D3, respectively. In experiment 2, the highest live weight (p0.05). Conclusion In conclusion, Azolla and acidifier reduced lipid profiles of broiler chickens. Considering net profit and lipid profiles, 5% Azolla may be the suitable dietary group for producing safe and profitable broilers. However, more studies are needed to confirm this study prior to suggesting using Azolla in the poultry industry.

Recent research specifies that game-based learning effectively engages students in classroom activities. Although there has been a prominent upsurge in game-based teaching and learning, this area has not received significant attention within the context of Gulf nations. This study investigates the perceptions, motivations, and benefits of game-based teaching-learning among school teachers, aiming to enhance the interactive learning environment. This study used a quantitative method and survey data from 505 school teachers who were actively teaching around the United Arab Emirates to reach its objectives. The majority of teachers believed that using games as a teaching tool in the classroom was a good idea. The study revealed the potential for game-based learning in the classroom and identified challenges, such as the need for rigorous game-based instructional design. We examined game-based teaching and learning's role in contributing to interactive learning environments and its apparent benefits of improving teamwork and lowering stress among teachers.

Computational thinking (CT) is vital for success in numerous domains. However, the nature, definition, and scope of CT are ill-defined, and research on how best to develop CT is very limited. This study focused on how thinking styles and STEM attitudes have effects on computational thinking. Using a proportionate stratified random sampling procedure, 1195 students from two universities were surveyed. A structural equation modeling analysis showed that students' thinking styles and STEM attitudes directly predicted their computational thinking skills and that thinking styles mediated the relationship between STEM attitudes and computational thinking skills. Thinking styles and STEM attitudes are strong predictors of CT skills. Based on the results, we recommended that the conceptualization of CT be broadened to reflect its trans-disciplinary nature within the context of STEM education. This study adds to the limited theoretical understanding of CT and CT-predictors in higher education, which has been studied much less than in K-12 education.

This study justifies the applicability of a simple respirometric technique to diagnose the biosolid materials collected from municipal sewer lines. Samples of active settled sludge were collected from three different sewer lines of Sylhet city area (Bangladesh) enriched with residential, commercial and industrial discharge respectively. Reaction vessel of the respirometer, partially filled with biosolid samples has been integrated with a compensation vessel to neutralize the temperature-pressure effect on the manometer readings. Results deduced from the systematic analysis of respirograms show that the biosolids from residential source could be used effectively as soil conditioner due to its high content of biodegradable materials while industrial sample exhibited toxic inhibitory effects on microbial degradation process.

The aim of the present study was to get a total physical and chemical characterization and comparison of the principal components in Bangladeshi buffalo (B), Holstein cross (HX), Indigenous cattle (IC) and Red Chittagong Cattle (RCC) milk. Protein and casein (CN) composition and type, casein micellar size (CMS), naturally occurring peptides, free amino acids, fat, milk fat globule size (MFGS), fatty acid composition, carbohydrates, total and individual minerals were analyzed. These components are related to technological and nutritional properties of milk. Consequently, they are important for the dairy industry and in the animal feeding and breeding strategies. Considerable variation in most of the principal components of milk were observed among the animals. The milk of RCC and IC contained higher protein, CN, β-CN, whey protein, lactose, total mineral and P. They were more or less similar in most of the all other components. The B milk was found higher in CN number, in the content of αs2-, κ-CN and α-lactalbumin, free amino acids, unsaturated fatty acids, Ca and Ca:P. The B milk was also lower in β-lactoglobulin content and had the largest CMS and MFGS. Proportion of CN to whey protein was lower in HX milk and this milk was found higher in β-lactoglobulin and naturally occuring peptides. Considering the results obtained including the ratio of αs1-, αs2-, β- and κ-CN, B and RCC milk showed best data both from nutritional and technological aspects.

Aim: To determine the extent of concurrent infection and seasonal distribution of gastrointestinal parasites in cross-bred cattle of Shahzadpur upazila of Sirajganj district, Bangladesh.Materials and Methods: Faecal samples from 4248 cross-bred cattle presented to the diagnostic centre of Milk Vita, Baghabari, Sirajganj with complains of digestive disturbances over the period from November, 2008 to October, 2009 were examined grossly with naked eye followed by microscopic examination with direct smear method, Will's floatation and sedimentation techniques.Results: Out of 4248 faecal samples examined, 3268 (76.93%) samples harboured one or more parasitic ova or cyst and the rest 980 (23.07%) samples found free of parasitic ova or cyst. Among the positive cases, single infection of fascioliasis (29.0.5%), paramphistomiasis (8.3%), toxocariasis (11.32%), haemonchosis (2.47%), monieziasis (0.7%), balantidiasis (4.19%), trichuriasis (1.1%), trichostrongylosis (1.4%) and strongyloidosis (1.6%) were diagnosed. Mixed infection with at least two (dual infection) and/ or any three of above mentioned parasitic species (triple infection) were also recorded. Cattle harbouring eggs of one parasite were more common [60.03% (95% Confidence interval (CI): 58.53, 61.51)] than those harbouring eggs of two [15.44% (95% CI, 14.36, 16.56)] or three [1.46% (95% CI, 1.12, 1.87)] parasites concurrently. Significantly (p0.05). A non-significant (p>0.005) decreasing trend of occurrence from winter through summer and rainy season was also observed in case of trichostrongylosis.Conclusion: The result of current study clearly indicate that helminth infections are highly prevalent in cross-bred cattle of the study area. The findings on abundance and distribution of gastrointestinal parasitism in different age groups of cattle, the poly-parasitism nature of the disease and the seasonal variation of occurrence obtained from present study will therefore assist the clinicians for forecasting of parasitism and make awareness among the farmers to take appropriate control measures against them.

Energy is an indispensable factor for the economic growth and development of a country. Energy consumption is rapidly increasing worldwide. To fulfill this energy demand, alternative energy sources and efficient utilization are being explored. Various sources of renewable energy and their efficient utilization are comprehensively reviewed and presented in this paper. Also the trend in research and development for the technological advancement of energy utilization and smart grid system for future energy security is presented. Results show that renewable energy resources are becoming more prevalent as more electricity generation becomes necessary and could provide half of the total energy demands by 2050. To satisfy the future energy demand, the smart grid system can be used as an efficient system for energy security. The smart grid also delivers significant environmental benefits by conservation and renewable generation integration.