MAXIMIZING THE ELECTROCATALYTIC ACTIVITIES OF NON-NOBLE TRANSITION METAL???S COMPOUNDS FOR WATER ELECTROLYSIS

Department of Chemical EngineeringThe rapid growth in population and advancement in heavy industry, has badly influenced world economy due to sharp rise in cost of oil prices. Currently, about 80% of energy is produced from fossil fuels, which adds greenhouse gases (CO2, SOx & NOx) to the environment by increasing global temperature and environmental pollution. Therefore, development of sustainable, environmentally friendly and alternatives energy sources to fossil fuels attracts much attentions in recent decades. Among the various alternative advanced clean energy technologies, the fuel cells, CO and CO2 to liquid fuel conversions, water electrolysis, solar, wind, marine energy, electrochemical energy storage (EES) devices including various types of batteries and supercapacitors (SCs) have been attracted much attention in recent years. Although, many efforts have been exercised to improve these technologies but they are still facing many challenges like high cost, durability, reliability, efficiency and maintenance to commercialize at public sectors. The hydrogen (H2) is the only alternative clean fuel which can mitigate energy and environmental related issues. Among the various alternative energy technologies, for example fuel cells, CO2 conversions and water electrolysis uses hydrogen as the primary energy carrier. Currently, about 95% of total hydrogen is produced by using conventional technologies like steam methane reforming (SMR) and coal gasification (CG). Evidently, these methods are adding more greenhouse gases to the environment and the quality of hydrogen is also poor. The pure hydrogen is generated by water electrolysis which is usually conducted either photochemically and photoelectrochemically or electrochemically. Amongst all water electrolysis processes, the electrochemical water splitting is the only available greener, sustainable and rapid route of generating highly pure H2 at commercial scale. Transition metal compounds (TMCs) such as phosphides, carbides and chalcogenides have attracted massive attention as alternatives of noble metals (Pt, Ru or Ir) since last few years due to their superior electrical conductivity, mechanical strength, and chemical stability. In spite of the success, there are still many challenges like poor performance, stability in wide pH range, expensive and poisonous starting precursors, environmentally unsafe synthetic procedures, lack of in-depth mechanistic knowledge and so on which are creating hurdles for sustainable hydrogen production with both economic and environmental advantage. Here, simple, economical, ecofriendly and commercially adoptable synthesis procedures are developed to increase the number of active sites and intrinsic catalytic activity of transition metals carbides, phosphides and sulfides through heteroatom doping. Moreover, these nanostructures are grafted on conductive substrates (like doped-graphene, carbon cloth, nickel foam etc.) for electrochemical water splitting applications. The electrochemical properties of molybdenum carbides are tuned either by encapsulating or imbedding them in boron (B) and nitrogen (N) co-doped carbon network (BCN) via a unique organometallic complex-assisted approach. Due to the synergic effect of BCN network, the molybdenum carbides show a remarkable electrocatalytic hydrogen evolution (HER), oxygen evolution (OER) and oxygen reduction (ORR) performances and excellent durability in both acidic and basic aqueous defeating the most of earlier reported molybdenum carbides based electrocatalyst in the literature. The mechanistic study for water electrolysis and the synergic effect BCN network at electrochemical performance of molybdenum carbides is also discussed in detail. The intrinsic catalytic activity stability of molybdenum phosphides nanocrystallite (MoP) are modulated by dual-doping of S and N into its structure via a unique, inexpensive and environmental-friendly thiourea-phosphate-assisted rout. The number of active sites are also increased by controlling the shape of nanoparticles and loading them on S, N self-doped graphene. The obtained MoP/SNG catalysts displays extraordinary hydrogen evolution (HER) performance in both acidic and alkaline media. Similarly, the sulfur-doped CoP (S:CoP) and Co2P (S:Co2P) nanoparticles are also synthesized as a noble metal-free electrocatalyst via above indigenously developed thiourea-phosphate-assisted route. The S-doped Co-phosphide based electrode exhibits excellent activity and stability for overall water splitting defeating noble mental-based Pt/C, IrO2, and reported non-noble metal-based electrocatalysts. Density functional theory calculations reveal that the excellent activity is attributable to the modified electronic structures of Co-phosphides which favor the overall water splitting at both S:CoP and S:Co2P electrodes. The S-doping also increases the number of exposed active sites especially on the conductive substrates which works as the excellent alkaline electrolyzers for overall water splitting. The electroctalytic hydrogen evolution reaction (HER) activity of MoS2 increases when it possesses multifunctional active sites including structural defects, Mo-exposed edges, S-vacancies, 1T-phase and expanded interlayer distances. Previous reports on MoS2-based catalysts targeted only a single or few of these active sites, the all-in-one MoS2 electrocatalyst synthesized herein contains all of the above characteristics by using a supramolecular structure of melamine-phosphomolybdate (MA-PMo12) and a weakly reducing thiourea. During preparation, the in-situ produced NH3 gas acts as interculants between MoS2 sheets and makes expanded interlayers spacing ammoniated 1-T MoS2 (A-MoS2). After reduction of guest NH3 into interlayer-expanded MoS2 in hydrogen leads to form an MoS2 with multiple active sites described above (R-MoS2) which exhibits surprisingly high hydrogen evolution reaction (HER) activity in alkaline media outperforms to all earlier reported MoS2-based electrocatalysts.ope

Performance Evaluation of LoRaWAN for Green Internet of Things

LoRa is a long-range, low power and single-hop wireless technology that has been envisioned for Internet of Things (IoT) applications having battery driven nodes. Nevertheless, increase in number of end devices and varying throughput requirements impair the performance of pure Aloha in LoRaWAN. Considering these limitations, we evaluate the performance of slotted Aloha in LoRaWAN using extensive simulations. We employed packet error rate (PER), throughput, delay, and energy consumption of devices under different payload sizes and varying number of end devices as benchmarks. Moreover, an analytical analysis of backlogged and non-backlogged under slotted Aloha LoRaWAN environment is also performed. The simulation shows promising results in terms of PER and throughput compared to the pure Aloha. However, increase in delay has been observed during experimental evaluation.Finally, we endorse slotted aloha LoRaWAN for Green IoT Environment

Volumetric Properties of Furan and 2‑5-Dimethylfuran in Different Industrial Solvents at Temperatures from 278 to 343 K

Peer reviewedPostprin

Surface Tension of Aqueous Solutions of Small-Chain Amino and Organic Acids

Peer reviewedPostprin

Artificial Intelligence and Internet of Things Enabled Intelligent Framework for Active and Healthy Living

Obesity poses several challenges to healthcare and the well-being of individuals. It can be linked to several life-threatening diseases. Surgery is a viable option in some instances to reduce obesity-related risks and enable weight loss. State-of-the-art technologies have the potential for long-term benefits in post-surgery living. In this work, an Internet of Things (IoT) framework is proposed to effectively communicate the daily living data and exercise routine of surgery patients and patients with excessive weight. The proposed IoT framework aims to enable seamless communications from wearable sensors and body networks to the cloud to create an accurate profile of the patients. It also attempts to automate the data analysis and represent the facts about a patient. The IoT framework proposes a co-channel interference avoidance mechanism and the ability to communicate higher activity data with minimal impact on the bandwidth requirements of the system. The proposed IoT framework also benefits from machine learning based activity classification systems, with relatively high accuracy, which allow the communicated data to be translated into meaningful information

Ethambutol Induced Ocular Toxicity in Patients Receiving “Directly Observed Treatment Short-Course” Therapy

Background: To determine the frequency of Ocular toxicity due to Ethambutol in Category-1 patients after receiving DOTS therapy. Methods: Category-1 tuberculosis patients of 15-60 years (both gender) with normal ocular parameters on ophthalmological assessment at time of initiation of DOTS therapy were included in the study. A total of 242 eyes (121 patients) were studied for any change in the vision or occurrence of any other ocular symptom while on the Ethambutol treatment. Each patient was followed up for Ethambutol compliance status at the completion of one month and again at two months of treatment, all the ophthalmological assessments for ocular toxicity were repeated for every selected patient. Category-2 patients with sputum smear positive who have relapsed, who have treatment failure or who are receiving treatment after treatment interruption were excluded from the study. The patient’s information was gathered on a specifically designed proforma. The information on the proforma was filled by the researchers themselves. Results: Out of 121 patients (242 eyes), 64 (52.9%) were males and 57 (47.1%) were females. There was no sign of ocular toxicity after a month period. However, after second month ocular toxicity was developed in 02 (1.65%) of the patients. Besides, decrease in visual acuity, color vision abnormalities, decrease in contrast sensitivity, and optic disc abnormalities were also observed in these 02 patients. Conclusion: There is a possibility of the occurrence of ocular toxicity when the Ethambutol is taken by the tuberculosis patients. Thus, the early identification of ocular symptoms and signs is vital to avoid unnecessary delay in diagnosis and probable irreversible visual loss

Exploiting W. Ellison model for seawater communication at gigahertz frequencies based on world ocean atlas data

Electromagnetic (EM) waves used to send signals under seawater are normally restricted to low frequencies (f) because of sudden exponential increases of attenuation (α) at higher f. The mathematics of EM wave propagation in seawater demonstrate dependence on relative permeability (μr), relative permittivity (εr), conductivity (σ), and f of transmission. Estimation of εr and σ based on the W. Ellison interpolation model was performed for averaged real‐time data of temperature (T) and salinity (S) from 1955 to 2012 for all oceans with 41088 latitude/longitude points and 101 depth points up to 5500 m. Estimation of parameters such as real and imaginary parts of εr, εr′, εr″, σ, loss tangent (tan δ), propagation velocity (Vp), phase constant (β), and α contributes to absorption loss (La) for seawater channels carried out by using normal distribution fit in the 3 GHz–40 GHz f range. We also estimated total path loss (LPL) in seawater for given transmission power Pt and antenna (dipole) gain. MATLAB is the simulation tool used for analysis

Efficacy of Steroid Therapy in Management of Sydenham’s Chorea in Children: A Comparative Prospective Study

Objective: To determine the efficacy of steroid therapy in Sydenham’s chorea in children. Study Design: Comparative prospective study. Place and Duration of Study: Inpatient and Outpatient Department of Pediatric Neurology, Children Hospital and Institute of Child Health, Lahore Pakistan, from Dec 2019 to May 2020. Methodology: Sixty-eight children of Sydenham’s chorea were divided in Group A and B. Each Group was treated with Diazepam (0.3mg-1mg/kg/day) and an injection of Benzathine Penicillin. Group-B was given additional oral prednisolone (2mg/kg/day) for four weeks, with tapering in the next two weeks. Epidemiological data, clinical features and laboratory parameters were collected. The Universiade Federal de Minas Gerais Sydenham’s chorea Rating Scale (USCRS) was applied to both groups at the presentation after two weeks and four weeks. Results: Out of 68 patients, the mean Universidade Federal de Minas Gerais (UFMG) Sydenham's Chorea Rating Scale (USCRS) got progressively better in Group-B (mean score improvement was 25.73±5.56 at two weeks and 41.06±6.89 at four weeks) than in Group-A (mean score improvement was 9.12±3.75 at two weeks and 17.97±3.89 at four weeks) with p-value of <0.05. Conclusion: Steroid therapy significantly improved patients with Sydenham’s chorea compared to those who did not receive any steroid therapy. Keywords: Efficacy, Steroid therapy, Sydenham chorea