In the present review, we focused on the fundamental concepts of hydrogels—classification, the polymers involved, synthesis methods, types of hydrogels, properties, and applications of the hydrogel. Hydrogels can be synthesized from natural polymers, synthetic polymers, polymerizable synthetic monomers, and a combination of natural and synthetic polymers. Synthesis of hydrogels involves physical, chemical, and hybrid bonding. The bonding is formed via different routes, such as solution casting, solution mixing, bulk polymerization, free radical mechanism, radiation method, and interpenetrating network formation. The synthesized hydrogels have significant properties, such as mechanical strength, biocompatibility, biodegradability, swellability, and stimuli sensitivity. These properties are substantial for electrochemical and biomedical applications. Furthermore, this review emphasizes flexible and self-healable hydrogels as electrolytes for energy storage and energy conversion applications. Insufficient adhesiveness (less interfacial interaction) between electrodes and electrolytes and mechanical strength pose serious challenges, such as delamination of the supercapacitors, batteries, and solar cells. Owing to smart and aqueous hydrogels, robust mechanical strength, adhesiveness, stretchability, strain sensitivity, and self-healability are the critical factors that can identify the reliability and robustness of the energy storage and conversion devices. These devices are highly efficient and convenient for smart, light-weight, foldable electronics and modern pollution-free transportation in the current decade.

Leadership stains affect the follower’s performances regarding innovative work behavior, and a gap is found in leadership research in higher education, specifically in Pakistan. The basic purpose of this research is to point out the effect of leadership styles on innovative work behavior under the mediating and moderating roles of organizational culture and organizational citizenship behavior among the Head of the Departments (HODs) in higher education institutions (HEIs). A survey method has been carried out to collect data from 160 respondents to, further, verify how leadership styles of academic leaders affect employees’ performances in universities. The statistical study exposes a substantial positive effect of leadership styles on innovative work behaviors of employees highlighting mediating and moderating effects of organizational culture and OCB on such a relationship. This study carries various implications for prior research in both theoretical and practical fields, and its scope may also be enlarged, geographically or institutionally, to another context. This research uncovers the relationship of leadership styles and innovative work behavior in academic research, which has been ignored before in higher education of Pakistan.

In this study, ternary composites of polyaniline (PANI) with manganese dioxide (MnO₂) nanorods and carbon nanotubes (CNTs) were prepared by employing a hydrothermal methodology and in-situ oxidative polymerization of aniline. The morphological analysis by scanning electron microscopy showed that the MnO₂ possessed nanorod like structures in its pristine form, while in the ternary PANI@CNT/MnO₂ composite, coating of PANI over CNT/MnO₂, rods/tubes were evidently seen. The structural analysis by X-ray diffraction and X-ray photoelectron spectroscopy showed peaks corresponding to MnO₂, PANI and CNT, which suggested efficacy of the synthesis methodology. The electrochemical performance in contrast to individual components revealed the enhanced performance of PANI@CNT/MnO₂ composite due to the synergistic/additional effect of PANI, CNT and MnO₂ compared to pure MnO₂, PANI and PANI@CNT. The PANI@CNT/MnO₂ ternary composite exhibited an excellent specific capacity of 143.26 C g⁻¹ at a scan rate of 3 mV s⁻¹. The cyclic stability of the supercapattery (PANI@CNT/MnO₂/activated carbon)—consisting of a battery type electrode—demonstrated a gradual increase in specific capacity with continuous charge–discharge over ~1000 cycles and showed a cyclic stability of 119% compared to its initial value after 3500 cycles.

Fossil fuel-based energy systems are mostly used for supplying energy that creates negative impacts on the environment, so in this study, the development of a 100% renewable energy system is evaluated for Pakistan for sustainable climate change. This study modeled three scenarios, namely, ongoing (ONG), energy saving policy (ESP), and green energy policy (GEP) scenarios using low emission analysis platform (LEAP) software for the study period 2022 to 2050 for Pakistan. The results revealed that a 100% renewable energy supply could be achieved through the GEP scenario. Model results show that the share of renewable sources in the total energy mix is 1117.08 TWh and non-renewable sources contribute only 18.12 TWh to meet the energy demand of 966.05 TWh until 2050. Non-renewable production leads to the generation of 8.85 million metric tons of carbon emissions, which is too low compared with the 135.47 million metric tons under the ONG scenario. The USD 1482.46 billion investment cost required for adding renewable energy capacity until 2050 is too high as compared with the USD 46.80 billion under the ONG scenario. Energy demand and production requirements are reduced by 34.18% under the ESP scenario until 2050. This approach can also be applicable to the majority of nations worldwide.

Developments in the design of wind turbines with augmentation are advancing around the globe with the goal of generating electricity close to the user in built-up areas. This is certain to help lessen the power generation load as well as distribution and transmission network costs by reducing the distance between the user and the power source. The main objectives driving the development and advancement of vertical-axis wind turbines are increasing the power coefficient and the torque coefficient by optimizing the upstream wind striking on the rotor blades. Unlike horizontal-axis wind turbines, vertical axis turbines generate not only positive torque but also negative torque during operation. The negative torque generated by the returning blade is a key issue for vertical-axis wind turbines (VAWTs) that is counterproductive. Installation of wind deflectors for flow augmentation helps to reduce the negative torque generated by the returning blades as well as enhance the positive torque by creating a diversion in the upstream wind towards the forwarding blade during operation. This paper reviews various designs, experiments, and CFD simulations of wind deflectors reported to date. Optimization techniques for VAWTs incorporating wind deflectors are discussed in detail. The main focus of the review was on the installation position and orientation of the deflectors and their potential contribution to increasing the power coefficient. Topics for future study are suggested in the conclusion section of the paper.

In this manuscript, a series of dye-sensitized solar cells (DSSCs) were fabricated as a function of post-processing temperature based on mesoporous CuO@Zn(Al)O-mixed metal oxides (MMO) in conjunction with dye N719 as the main light absorber; the proposed CuO@Zn(Al)O geometry was, in turn, attained using Zn/Al-layered double hydroxide (LDH) as a precursor via combination of co-precipitation and hydrothermal techniques. In particular, the dye loading amount onto the deposited mesoporous materials was anticipated via regression equation-based UV-Vis technique analysis, which evidently demonstrated a robust correlation along with the fabricated DSSCs power conversion efficiency. In detail, of the DSSCs assembled, CuO@MMO-550 exhibited short-circuit current ($J_{SC}$) and open-circuit voltage ($V_{OC}$) of 3.42 (mA/cm²) and 0.67 (V) which result in significant fill factor and power conversion efficiency of 0.55% and 1.24%, respectively. This could mainly be due to the relatively high surface area of 51.27 (m²/g) which in turn validates considerable dye loading amount of 0.246 (mM/cm⁻²).