Search Results (10)

For the first time, density functional theory (DFT) calculations have been employed for the measurement of the structural, mechanical, optical, and electrical properties of a bismuth-layered structure ferroelectrics (BLSFs) family member possessing an orthorhombic structure with Cmc2₁ space group. Based on the exchange–correlation approximation, our calculations show that Pb₂Bi₄Ti₅O₁₈ possesses an indirect band gap, while the materials X₂Bi₄Ti₅O₁₈ (X = Ba, Ca, and Sr) demonstrate direct band gap, where the estimated density functional fundamental band gap values lie between 1.84 to 2.33 eV, which are ideal for photovoltaic applications. The optical performance of these materials has been investigated by tuning the band gaps. The materials demonstrated outstanding optical characteristics, such as high absorption coefficients and low reflection. They exhibited impressive absorption coefficient (α = 10⁵ cm⁻¹) throughout a broad energy range, especially in the visible spectrum (10⁵ cm⁻¹ region). The findings show that the compounds demonstrate lower reflectivity in the visible and UV regions, making them suitable for single-junction photovoltaic cells and optoelectronic applications. The Voigt–Reuss–Hill averaging technique has been employed to derive elastic parameters like bulk modulus (B), Young’s modulus, shear modulus (G), the Pugh ratio (B/G) and the Frantesvich ratio (G/B) at 0.1 GPa. The mechanical stability of the compounds was analyzed using the Born stability criteria. Pugh’s ratio and Frantesvich’s ratio show that all the compounds are ductile, making them ideal for flexible optical applications. Full article

High concentrations of zinc along with other metals are released by steel mills, and this has a number of negative effects on organism health; most notably, neurological symptoms have been recorded with a high risk of brain atrophy. In the current study, Zn (II) was eliminated from steel mill effluent, utilizing chemically processed Pteris vittata plant leaves as a biosorbent. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and energy dispersive X-ray spectroscopy (EDX) were applied to characterize the chemically modified Pteris vittata leaves, from now onward abbreviated as CMPVL. In order to identify the ideal parameter, batch studies were conducted varying a single parameter affecting the biosorption process at a time, including variations in temperature (293–323 K), initial metal concentration (20–300 mg/L), and adsorbent doses (0.01–0.12 g), pH (2–8), as well as contact time (10–140 min). To describe the isothermal experimental results, a number of models were used including Freundlich, Langmuir, Temkin, Jovanovich, and Harkins–Jura. Among these models, the Langmuir model provided a significant fit to the isotherm data with an R² of 0.9738. The kinetics data were fitted to the pseudo first order, pseudo second order, power function, Natarajan–Khalaf, and intraparticle diffusion models. The highest R² (0.9976) value was recorded for the pseudo second order model. Using the Langmuir isotherm, the highest uptake ability (84.74 mg/g) of Zn was recorded. The thermodynamic investigation, carried out at various temperatures, led to the conclusion that the biosorption process was exothermic and spontaneous in nature. The CMPVL, thus, has the potential to function well as an alternative to existing carbon-based adsorbents in the effective elimination of zinc from aquatic environments. Full article

Renewable energy resources have gained considerable attention in recent years due to their efficiency and economic benefits. Their proportion of total energy use continues to grow over time. Photovoltaic (PV) cell and wind energy generation are the least-expensive new energy sources in most countries. Renewable energy technologies significantly contribute to climate mitigation and provide economic benefits. Apart from these advantages, renewable energy sources, particularly solar energy, have drawbacks, for instance restricted energy supply, reliance on weather conditions, and being affected by several kinds of faults, which cause a high power loss. Usually, the local PV plants are small in size, and it is easy to trace any fault and defect; however, there are many PV cells in the grid-connected PV system where it is difficult to find a fault. Keeping in view the aforedescribed facts, this paper presents an intelligent model to detect faults in the PV panels. The proposed model utilizes the Convolutional Neural Network (CNN), which is trained on historic data. The dataset was preprocessed before being fed to the CNN. The dataset contained different parameters, such as current, voltage, temperature, and irradiance, for five different classes. The simulation results showed that the proposed CNN model achieved a training accuracy of 97.64% and a testing accuracy of 95.20%, which are much better than the previous research performed on this dataset. Full article

Objective: The objective was to study the association of Klotho gene G395A and C1818T single nucleotide polymorphisms with glycemia, serum, glycosylated hemoglobin (HbA1c) level and the risk of type 2 diabetes mellitus (T2DM) in the Pashtun population of Pakistan. Methods: In this study, 195 normal individuals and 217 T2DM patients were enrolled. All subjects were divided into three groups, namely overall subjects (control + T2DM patients), control individuals and T2DM patients, and their fasting glucose, HbA1c level, lipid profile and C1818T and G395A polymorphisms were determined. Results: The allele frequencies of G395A in overall subjects were 0.568 for A and 0.432 for G. Similarly, allele frequencies for G395A in overall subjects were 0.597 and 0.403 for C and T alleles, respectively. The AA genotype of G395A was observed to be a risk factor for T2DM. In normal individuals, no significant (p > 0.05) association was observed between klotho C1818T and G395A polymorphisms and hyperglycemia. In overall subjects, the C1818T polymorphism was associated (p < 0.05) with high fasting glucose and HbA1c levels in female subjects only. In T2DM patients, both C1818T and G395A polymorphisms were found to be significantly (p < 0.05) associated with high fasting glucose and HbA1c levels both in males and females. Conclusion: The G395A polymorphism was observed to increase the risk of T2DM. Both C1818T and G395 were associated with high fasting glucose and HbA1c levels in T2DM patients. Full article

Dargai District Malakand, Pakistan, is a tax-free zone that attracts many industrialists to install their plants in this area. Along with other industries, a number of steel mills are polluting the natural environment of this locality. This study aimed to evaluate heavy metals levels in steel mills effluents and fabricate an efficient adsorbent from the leaves of plants growing on the banks of the drainage lines of the industries and having high phytoremediation capabilities, through chemical modifications. Initially, the effluents were analyzed for heavy metal concentrations, then the leaves of a plant (Pteris vittata) with better phytoremediation capability were chemically modified. The leaves of Pteris vittata were crushed into a fine powder, followed by chemical modification with HNO₃, then washed with distilled water, neutralized with NaOH and finally activated through calcium chloride to enhance its biosorption ability, abbreviated as CMPVL. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), surface area analyzer, energy dispersive X-ray spectroscopy (EDX), and thermal gravimetric analysis (TGA) were used to characterize the CMPVL. The modified leaves in the powdered form were then used for the reclamation of Fe(II) present in the effluents of the mentioned industries. Batch biosorption tests were performed under varied physicochemical conditions of pH (2–9), contact time (10–140 min), temperature (293–333 K), biosorbent dose (0.01–0.13 g), and initial metal concentration (20–300 mg L⁻¹) to optimize the removal of the selected metal. Langmuir, Jovanovic, Freundlich, Temkin, and Harkins–Jura isotherm models were used to assess the equilibrium data. With a high R² value of 0.977, the Langmuir model offered an excellent match to the equilibrium data. The pseudo-first order, pseudo-second order, power function, intraparticle diffusion, and Natarajan–Khalaf models were applied to experimental kinetics data. With R² values of 0.999, the pseudo-second order model well fitted the obtained data. The Van’t Hoff equation was used to calculate ΔH°, ΔS° and ΔG° of Fe(II) sorption on CMPVL. The ∆H° and ∆G° were negative, whereas ΔS° was positive, suggesting that the biosorption process was exothermic, favorable, and spontaneous. The selected plant leaves were found to be efficient in the reclamation of iron from the industrial effluents (as the plant has a high natural capability for remediating the selected metal ion) after chemical modification and may be used as an alternative to activated carbon as being a low-cost material and a high phytoremediator of iron metal. Such natural phenomena of phytoremediation should be utilized in obtaining efficient adsorbents for other metals as well. Full article

During the time before the Millennium Development Goals (MDGs) are achieved, the international community has set goals to improve people’s lives worldwide. This is in line with the United Nations’ 2030 ambitions to strengthen and advance human society’s sustainable development. Goal number 7 (Affordable and Clean Energy), goal number 9 (Industry, Innovation, and Infrastructure), and goal number 13 (Climate Action) are highly correlated to each other. The current study investigates the role of human capital and technological innovation in achieving sustainable development goals (SDGs) through a carbon-free energy system. A 19-year dataset covering the years 2000−2018 for the G7 economies has been utilized by using the composite index, Multi-criteria decision analysis, and Quantile Autoregressive Distributed Lag (QARDL) methods. The study’s outcomes indicate that the human capital index and technological innovations contribute positively to SDGs in G7 economies. Both indicators also contribute positively to the carbon-free economy by contributing to carbon-free energy sources. The financial index and energy index results also indicate a positive association with the carbon-free economy in G7 nations. This study suggests policy guidelines for developed as well as for developing economies based on human capital and technological innovation to fulfill the SDGs. Full article

Nitrogen (N) is one of the indispensable factors in rice growth and development. China holds a premier position in the production of rice and at the same time also faces higher N fertilizer costs along with serious damage to the environment. A better solution is much needed to address these issues, without disrupting the production of rice as an important cereal, while minimizing all the deleterious effects on the environment. Two isogenic lines Kitaake (WT) and its genetically modified line CIPK2 (RC), overexpressing the gene for Calcineurin B-like interacting protein kinase 2 (OsCIPK2) with better nitrogen use efficiency (NUE), were compared for their growth and development under low versus normal levels of N. NUE is a complex trait mainly related to a plant’s efficiency in extraction, assimilation, and recycling of N from soil. The microbial population was analyzed using high-throughput Illumina Miseq 16S rRNA sequencing and found that RC with CIPK2, specifically expressed in rice root, not only performed better without nitrogen fertilizer (LN) but also increased the diversity of bacterial communities in rice rhizosphere compartments (rhizosphere, rhizoplane, and endosphere). The relative abundance of beneficial bacteria phyla increased, which are known to promote the circulation and transformation of N in rhizosphere soil. To further explore the potential of RC regarding better performance under LN, the ion fluxes in root apical were detected by non-invasive micro-test technique (NMT). We found that RC can absorb more Ca²⁺ and NO₃⁻ under LN as compared to WT. Finally, compared to WT, RC plants exhibited better growth of root and shoot, and increased yield and N uptake under LN, whereas there was no significant difference in the growth of two rice lines under normal nitrogen (NN) treatment. We are able to get preliminary results, dealing with the OsCIPK2 overexpressed rice line, by studying the rice molecular, physiological, and chemical parameters related to NUE. The results laid the foundation for further research on N absorption and utilization in rice from the soil and the interaction with microbial communities. Full article

Resources are limited, thus improving resource use efficiency is a key objective for cereal-based cropping systems. This field study was carried out to quantify resource use efficiencies in selected C₃ and C₄ cereals under split nitrogen (N) application regimes. The study included the following treatments: six cereals (three C₃: wheat, oat, and barley; and three C₄: maize, millet, and sorghum) and four split N application regimes (NS₁ = full amount of N at sowing; NS₂ = half N at sowing + half N at first irrigation; NS₃ = ⅓ N at sowing + ⅓ N at first irrigation + ⅓ N at second irrigation; NS₄ = ¼ N at sowing + ¼ N at first irrigation + ¼ N at second irrigation + ¼ N at third irrigation). Results revealed that C₄ cereals out-yielded C₃ cereals in terms of biomass production, grain yield, and resource use efficiencies (i.e., radiation use efficiency (RUE) and nitrogen use efficiency (NUE)), while splitting N into three applications proved to be a better strategy for all of the selected winter and summer cereals. The results suggest that C₄ cereals should be added into existing cereal-based cropping systems and N application done in three installments to boost productivity and higher resource use efficiency to ensure food security for the burgeoning population. Full article

Cotton leaf curl disease (CLCuD) in Pakistan and northwestern India is caused by monopartite begomoviruses in association with an essential, disease-specific satellite, Cotton leaf curl Multan betasatellite (CLCuMB). Following a recent upsurge in CLCuD problems in Sindh province (southern Pakistan), sequences of clones of CLCuMB were obtained from Sindh and Punjab province (central Pakistan), where CLCuD has been a problem since the mid-1980s. The sequences were compared to all sequences of CLCuMB available in the databases. Analysis of the sequences shows extensive sequence variation in CLCuMB, most likely resulting from recombination. The range of sequence variants differ between Sindh, the Punjab and northwestern India. The possible significance of the findings with respect to movement of the CLCuD between the three regions is discussed. Additionally, the lack of sequence variation within the only coding sequence of CLCuMB suggests that the betasatellite is not involved in resistance breaking which became a problem after 2001 in the Punjab and subsequently also in northwestern India. Full article