Search

The overconsumption of fossil fuels is leading to worsening environmental damage, making the generation of clean, renewable energy an absolute necessity. Two common components of electrochemical energy storage (EES) devices are batteries and supercapacitors (SCs), which are among the most promising answers to the worldwide energy issue. In this study, we introduce an exceptionally efficient electrode material for supercapacitors, composed of a hydrothermally synthesized composite known as MnNiS@MXene. We utilized XRD, SEM, and BET to analyze the material’s crystallinity, morphology, and surface area. The Qs of MnNiS@MXene was a remarkable 1189.98 C/g or 1983.3 F/g at 2 A/g under three electrode assemblies in 1 M KOH electrolyte solution. Activated carbon was used as the negative electrode, while MnNiS@MXene served as the positive electrode in the assembled supercapattery device (MnNiS@MXene//AC). This device showed exceptional performance, a specific capacity of 307.18 C/g, a power density of 1142.61 W/kg, and an energy density of 34.79 Wh/kg. Additionally, cyclic durability was evaluated through 7000 cycles of charging/discharging, demonstrating that it maintained approximately 87.57% of its original capacity. The successful integration of these materials can lead to electrodes with superior energy storage capabilities and efficient photoelectrochemical performance. The aforementioned findings suggest that MnNiS@MXene exhibits promising potential as an electrode material for forthcoming energy storage systems.

Two-dimensional (2D) sulfide-based transition metal dichalcogenides (TMDs) have shown their crucial importance in energy storage devices. In this study, the tungsten disulfide (WS2) nanosheets were combined with hydrothermally synthesized cobalt magnesium sulfide (CoMgS) nanocomposite for use as efficient electrodes in supercapattery energy storage devices. The characteristics of the WS2@CoMgS nanocomposite were better than those of the WS2 and CoMgS electrodes. XRD, SEM, and BET analyses were performed on the nanocomposite to examine its structure, morphology, and surface area in depth. In three-electrode assemblies, the composite (WS2@CoMgS) electrode showed a high specific capacity of 874.39 C g−1 or 1457.31 F g−1 at 1.5 A g−1. The supercapattery device (WS2@CoMgS//AC) electrode demonstrated a specific capacity of 325 C g−1 with an exceptional rate capability retention of 91% and columbic efficiency of 92% over 7000 cycles, according to electrochemical studies. Additionally, the high energy storage capacity of the WS2@CoMgS composite electrode was proved by structural and morphological investigations.

Based on the ab-initio calculations, we have investigated the electronic, optical, and thermal properties of pristine SnSe and doped with oxygen (O) and sulphur (S) at the Se-site at concentration of 3.125%. The calculated negative formation energy indicates the stability of the pristine SnSe and doped system. We find that pristine SnSe possesses a direct bandgap value of 0.90 eV having good comparable to experimental value. The doping of O and S tunes the bandgap of SnSe, which can be promising for photovoltaic devices. Further, for the technological applications of O-/S-doped SnSe, we have analyzed optical properties in terms of absorption of photon energy and polarization. Strong absorption peaks confirms the direct transition of electrons from valence band to conduction band. Moreover, the thermal properties are calculated in terms of electrical/thermal conductivities, Seebeck coefficient, and figure of merit (ZT). At room temperature the ZT values are calculated round about 0.41 for O- and S-doped SnSe, respectively. We expect that our calculated thermoelectric parameters of the O- and S-doped SnSe could pave a new route for the application in the thermoelectric devices.

Abstract The development of electrical and optoelectronic devices that are based on transition metal dichalcogenides require the fabrication of high‐quality homogeneous junctions. This paper demonstrates how to accomplish this using a lateral or vertical 2D material‐based p‐type/intrinsic/n‐type (p–i–n) homojunction. The capacitance across the junction is reduced, which is a result of the continuous band alignments, and there is less carrier entrapment at the homointerface. Various types of p–i–n diodes are examined in order to demonstrate the current modes of transportation and the optoelectronic effects. This review demonstrates how to make a high‐performance homointerface as well as describes the tunneling process in detail, which will be useful in the future development of new electrical and optoelectronic devices. A performance comparison of different parameters is also performed among various doping strategies in order to form homogenous junctions. It is assumed that this summary of the current research on nanomaterials will help 2D materials be used in order to make reliable p–i–n homojunction diodes for low‐power and high‐speed electronics. Finally, this paper concludes by summarizing the current challenges and the current prospects.

This review article attempts to provide a comprehensive review of the recent progress in cerium oxide (CeO2)-based resistive random-access memories (RRAMs). CeO2 is considered the most promising candidate because of its multiple oxidation states (Ce3+ and Ce4+), remarkable resistive-switching (RS) uniformity in DC mode, gradual resistance transition, cycling endurance, long data-retention period, and utilization of the RS mechanism as a dielectric layer, thereby exhibiting potential for neuromorphic computing. In this context, a detailed study of the filamentary mechanisms and their types is required. Accordingly, extensive studies on unipolar, bipolar, and threshold memristive behaviors are reviewed in this work. Furthermore, electrode-based (both symmetric and asymmetric) engineering is focused for the memristor’s structures such as single-layer, bilayer (as an oxygen barrier layer), and doped switching-layer-based memristors have been proved to be unique CeO2-based synaptic devices. Hence, neuromorphic applications comprising spike-based learning processes, potentiation and depression characteristics, potentiation motion and synaptic weight decay process, short-term plasticity, and long-term plasticity are intensively studied. More recently, because learning based on Pavlov’s dog experiment has been adopted as an advanced synoptic study, it is one of the primary topics of this review. Finally, CeO2-based memristors are considered promising compared to previously reported memristors for advanced synaptic study in the future, particularly by utilizing high-dielectric-constant oxide memristors.

Electrolytes are one of the most influential aspects determining the efficiency of electrochemical supercapacitors. Therefore, in this paper, we investigate the effect of introducing co-solvents of ester into ethylene carbonate (EC). The use of ester co-solvents in ethylene carbonate (EC) as an electrolyte for supercapacitors improves conductivity, electrochemical properties, and stability, allowing greater energy storage capacity and increased device durability. We synthesized extremely thin nanosheets of niobium silver sulfide using a hydrothermal process and mixed them with magnesium sulfate in different wt% ratios to produce Mg(NbAgS)x)(SO4)y. The synergistic effect of MgSO4 and NbS2 increased the storage capacity and energy density of the supercapattery. Multivalent ion storage in Mg(NbAgS)x(SO4)y enables the storage of a number of ions. The Mg(NbAgS)x)(SO4)y was directly deposited on a nickel foam substrate using a simple and innovative electrodeposition approach. The synthesized silver Mg(NbAgS)x)(SO4)y provided a maximum specific capacity of 2087 C/g at 2.0 A/g current density because of its substantial electrochemically active surface area and linked nanosheet channels which aid in ion transportation. The supercapattery was designed with Mg(NbAgS)x)(SO4)y and activated carbon (AC) achieved a high energy density of 79 Wh/kg in addition to its high power density of 420 W/kg. The supercapattery (Mg(NbAgS)x)(SO4)y//AC) was subjected to 15,000 consecutive cycles. The Coulombic efficiency of the device was 81% after 15,000 consecutive cycles while retaining a 78% capacity retention. This study reveals that the use of this novel electrode material (Mg(NbAgS)x(SO4)y) in ester-based electrolytes has great potential in supercapattery applications.

Objective: To determine the frequency of postoperative residual stone based on preprocedural Guy’s scoring system. Methodology: This cross-sectional descriptive study was conducted from1st June 2018 to 30th November 2019 at University Medical College Faisalabad. All patients with stones in the kidney undergoing PCNL, 20 to 60 years of age of both genders were included. Patients with secondary stones due to pelviureteric junction obstruction, CRF and recurrent stones were excluded. In all patients Guy’s scoring was measured. Then all patients underwent PCNL. After 24 hours of operation, CT scan was done in each patient and residual stone (present/absent) was noted. Results: This study was comprised of 91 patients of age ranged from 20- 60 years. Fifty-three patients (58.24%) were males and 38 (41.76%) females. Seven (7.69%) were of Guy’s grade I, 48(52.75%) grade II, 21(23.08%) grade III and 15 of grade IV. Number of patients with residual stone was 09 (9.89%), 0.0% of GS 1, 12.5% of GS 2, 4.76% of GS 3 and 13.33% of GS 4 patients had residual stone. Conclusion: Pre-PCNL Guy’s scoring is easy, rapid and useful for predicting the residual stone after percutaneous nephrolithotomy. Keywords: Percutaneous nephrolithotomy, Guy’s scoring system, residual stone.

BACKGROUND & OBJECTIVE: Urinary system stone disease is a common entity. Small renal stones are preferably treated using Extracarporeal Shock Wave Lithotripsy (ESWL) technique. Passage of stone fragments result in pain, hematuria and urinary tract obstruction. This can be avoided by the use selective α-1 receptor antagonists like Tamsulosin. However, their efficacy remains a matter of debate. In this study the role of selective α-1 blocker was evaluated in facilitating spontaneous expulsion of renal stone fragments after ESWL. The objective of our study was to find out the Efficacy of Tamsulosin (Selective α-1 blocker) in facilitating the transit of stone fragments (4-7mm) after ESWL. Follow up X-ray KUB was used to confirm the stone clearance. Efficacy was measured in terms of stone expulsion rate. METHODOLOGY: It was randomized controlled trial including 150 patients coming to outpatient department of Urology Lahore General Hospital, Lahore from January 25, 2010­ to July 25, 2010. Total 150 patients with renal stones broken down into fragments (4-7mm) after ESWL were enrolled using non-probability purposive sampling technique. Patients were categorized into group A and B. Patients of group A received cap. Tamsulosin 0.4mg along with Tab. Diclofenac sodium 50mg. Whereas, patients belonging to group B received only diclofenac sodium 50 mg twice daily. Patients underwent ESWL every three weeks, in case of non-fragmentation, to the maximum of 4 sessions. All the patients were followed with X Ray KUB for stone clearance. The data of all patients was incorporated into pre designed Performa. Statistical evaluation of clinical variables done in terms of efficacy i.e. stone clearance. RESULTS: Stone clearance rate of patients in group A was 86.6% as compared to only 76% in group B. Usage of selective α-1 blockers in group A enhanced the stone clearance rate as compared to group B. However this difference was statistically insignificant (p-value-0.094). CONCLUSION: There was increased stone clearance in alpha one blocker group but not statistically significant. Further studies with larger sample size are required to evaluate the role of Selective α-1 blockers (Tamsulosin) after ESWL.

Modern supply chains are vulnerable to high impact, low probability disruption risks. A supply chain usually operates in such a network of entities where the resilience of one supplier is critical to overall supply chain resilience. Therefore, resilient planning is a key strategic requirement in supplier selection decisions for a competitive supply chain. The aim of this research is to develop quantitative resilient criteria for supplier selection and order allocation in a fuzzy environment. To serve the purpose, a possibilistic fuzzy multi-objective approach was proposed and an interactive fuzzy optimization solution methodology was developed. Using the proposed approach, organizations can tradeoff between cost and resilience in supply networks. The approach is illustrated using a supply chain case from a garments manufacturing company.

With advanced manufacturing technology, organizations like to cut their operational cost and improve product quality, yet the importance of human labor is still alive in some manufacturing industries. The performance of human-based systems depends much on the skill of labor that varies person to person within available manpower. Much work has been done on human resource and management, however, allocation of manpower based on their skill yet not investigated. For this purpose, this study considered offline inspection system where inspection is performed by the human labor of varying skill levels. A multi-objective optimization model is proposed based on Time-Varying factors; inspection skill, operation time and learning behavior. Min-max goal programming technique was used to determine the efficient combination of inspectors of each skill level at different time intervals of a running order. The optimized results ensured the achievement of all objectives of inspection station: the cost associated with inspectors, outgoing quality and inspected quantity. The obtained results proved that inspection performance of inspectors improves significantly with learning and revision of allocation of inspectors with the proposed model ensure better utilization of available manpower, maintain good quality and reduce cost as well.

To form a smart production system, the effect of energy and machines’ failure rate plays an important role. The main issue is to make a smart production system for complex products that the system may produce several defective items during a long-run production process with an unusual amount of energy consumption. The aim of the model is to obtain the optimum amount of smart lot, the production rate, and the failure rate under the effect of energy. This study contains a multi-item economic imperfect production lot size energy model considering a failure rate as a system design variable under a budget and a space constraint. The model assumes an inspection cost to ensure product’s quality under perfect energy consumption. Failure rate and smart production rate dependent development cost under energy consumption are considered, i.e., lower values of failure rate give higher values of development cost and vice versa under the effect of proper utilization of energy. The manufacturing system moves from in-control state to out-of-control state at a random time. The theory of nonlinear optimization (Kuhn⁻Tucker method) is employed to solve the model. There is a lemma to obtain the global optimal solution for the model. Two numerical examples, graphical representations, and sensitivity analysis of key parameters are given to illustrate the model.